Path planning for recovery is studied on the engineering background of double unmanned surface vehicles(USVs)towing oil booms for oil spill recovery.Given the influence of obstacles on the sea,the improved artificial ...Path planning for recovery is studied on the engineering background of double unmanned surface vehicles(USVs)towing oil booms for oil spill recovery.Given the influence of obstacles on the sea,the improved artificial potential field(APF)method is used for path planning.For addressing the two problems of unreachable target and local minimum in the APF,three improved algorithms are proposed by combining the motion performance constraints of the double USV system.These algorithms are then combined as the final APF-123 algorithm for oil spill recovery.Multiple sets of simulation tests are designed according to the flaws of the APF and the process of oil spill recovery.Results show that the proposed algorithms can ensure the system’s safety in tracking oil spills in a complex environment,and the speed is increased by more than 40%compared with the APF method.展开更多
Autism spectrum disorder(ASD)is a neurodevelopmental disorder where de novo mutations play a significant role.Although coding mutations in ASD have been extensively characterized,the impact of non-coding de novo mutat...Autism spectrum disorder(ASD)is a neurodevelopmental disorder where de novo mutations play a significant role.Although coding mutations in ASD have been extensively characterized,the impact of non-coding de novo mutations(ncDNMs)remains less understood.Here,we integrate cortex cell-specific cis-regulatory element annotations,a deep learning-based variant prediction model,and massively parallel reporter assays to systematically evaluate the functional impact of 227,878 ncDNMs from Simons Simplex Collection(SSC)and Autism Speaks MSSNG resource(MSSNG)cohorts.Our analysis identifies 238 ncDNMs with confirmed functional regulatory effects,including 137 down-regulated regulatory mutations(DrMuts)and 101 up-regulated regulatory mutations(UrMuts).Subsequent association analyses reveal that only DrMuts regulating loss-of-function(LoF)intolerant genes rather than other ncDNMs are significantly associated with the risk of ASD(Odds ratio=4.34;P=0.001).A total of 42 potential ASD-risk DrMuts across 41 candidate ASD-susceptibility genes are identified,including 12 recognized and 29 unreported genes.Interestingly,these noncoding disruptive mutations tend to be observed in genes extremely intolerant to LoF mutations.Our study introduces an optimized approach for elucidating the functional roles of ncDNMs,thereby expanding the spectrum of pathogenic variants and deepening our understanding of the complex molecular mechanisms underlying ASD.展开更多
Radix Bupleuri(RB)is commonly used to treat depression,but it can also lead to hepatotoxicity after longterm use.In many anti-depression prescriptions,RB is often used in combination with Radix Paeoniae Alba(RPA)as an...Radix Bupleuri(RB)is commonly used to treat depression,but it can also lead to hepatotoxicity after longterm use.In many anti-depression prescriptions,RB is often used in combination with Radix Paeoniae Alba(RPA)as an herb pair.However,whether RPA can alleviate RB-induced hepatotoxicity remain unclear.In this work,the results confirmed that RB had a dose-dependent antidepressant effect,but the optimal antidepressant dose caused hepatotoxicity.Notably,RPA effectively reversed RB-induced hepatotoxicity.Afterward,the mechanism of RB-induced hepatotoxicity was confirmed.The results showed that saikosaponin A and saikosaponin D could inhibit GSH synthase(GSS)activity in the liver,and further cause liver injury through oxidative stress and nuclear factor kappa B(NF-kB)/NOD-like receptor thermal protein domain associated protein 3(NLRP3)pathway.Furthermore,the mechanisms by which RPA attenuates RBinduced hepatotoxicity were investigated.The results demonstrated that RPA increased the abundance of intestinal bacteria with glycosidase activity,thereby promoting the conversion of saikosaponins to saikogenins in vivo.Different from saikosaponin A and saikosaponin D,which are directly combined with GSS as an inhibitor,their deglycosylation conversion products saikogenin F and saikogenin G exhibited no GSS binding activity.Based on this,RPA can alleviate the inhibitory effect of saikosaponins on GSS activity to reshape the liver redox balance and further reverse the RB-induced liver inflammatory response by the NFkB/NLRP3 pathway.In conclusion,the present study suggests that promoting the conversion of saikosaponins by modulating gut microbiota to attenuate the inhibition of GSS is the potential mechanism by which RPA prevents RB-induced hepatotoxicity.展开更多
Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and stator.This study presents an Immersed Boundary Method(IBM)for hig...Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and stator.This study presents an Immersed Boundary Method(IBM)for high-Reynolds turbomachinery internal flows,and shows the advantage of the automatic grid generation techniques and flexible moving boundary treatments.The wall functions are used in the present method to alleviate the wall resolution restriction of turbulence simulation.The Two-Dimensional(2-D)IBM solver,which was previously developed and tested for a low-speed compressor,is further validated for a well-documented Low-Pressure Turbine(LPT)cascade.Both the blade loading and the total pressure losses in the wake are well captured by the present 2-D solver.The complex Three-Dimensional(3-D)effects in turbomachines motivate the further development of an extended 3-D IBM solver by using a curvilinear-coordinate system that facilitates the hub and casing boundary treatment.The good performance of the 3-D solver is demonstrated through comparison with CFX solver solutions for the rotor configuration of Advanced Noise Control Fan(ANCF).Further effects of the grid resolution on capturing the blade wake are discussed.The results indicate that the present 3-D solver is capable of reproducing the evolution of the blade wake with suitable computational grid.展开更多
Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain...Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain model is extended to predict CROR noise.It builds explicitly the relationship between harmonic loadings and corresponding tonal noise,by which the influential parameters to noise generation can be clearly understood.The real distribu-tions of steady and unsteady blade loadings are calculated by the Nonlinear Harmonic(NLH)method.In the present hybrid approach,both the CFD and acoustic modules are solved in the fre-quency domain.To assess the accuracy of the developed method,the loading noise of a CROR is calculated and compared against results by using the time-domain FW-H module of NUMECA.The predicted sound directivities by the two methods are in good agreements.The present acoustic model in the frequency domain is proven to be accurate and have high efficiency in far-field noise prediction and data processing.Furthermore,the characteristics of the CROR interaction tonal noise are analyzed and discussed.展开更多
In this paper,we describe the structure of Verma modules over the two kinds of Lie algebras g(λ)of W-type.We determine the reducibility and the singular vectors of their Verma modules under some conditions.
The photoluminescence of four polyoxoniobates [Nb6O19]8-, [Nb10O28]6-, [Ti2Nb8O28]8- and [H2Si4Nb16O56]14- was observed, and its origin was revealed in the view of molecular orbital by means of the computational metho...The photoluminescence of four polyoxoniobates [Nb6O19]8-, [Nb10O28]6-, [Ti2Nb8O28]8- and [H2Si4Nb16O56]14- was observed, and its origin was revealed in the view of molecular orbital by means of the computational method. The photoluminescence is originated from singlet transitions, and the calculated values agree well with the experimental data. The results indicate that the size of clusters and the foreigner atoms can affect the fluorescent properties of PONbs. The absorption and emission of these PONbs are originated molecular orbitals contributed mainly by μ2-O and Nb atoms according to NBO analysis. These PONbs were also found as electrochemical catalysts with high performance for water oxidation, which can effectively split water into oxygen under basic condition with a high catalytic current, and pH values have remarkable influence on the electrocatalytic activities of these PONbs for water oxidation.展开更多
Chiral zero-dimensional(0D)hybrid metal halides,merging chirality with exceptional emission properties,are highly promising for circularly polarized luminescence(CPL).For CPL applications,it is difficult to simultaneo...Chiral zero-dimensional(0D)hybrid metal halides,merging chirality with exceptional emission properties,are highly promising for circularly polarized luminescence(CPL).For CPL applications,it is difficult to simultaneously achieve large dissymmetry factor(glum)and photoluminescence quantum yield(PLQY).Herein,we propose a chemical design strategy to systematically control the glum and PLQY.We take achiral or chiral organic cations,to partially substitute the original A-site in A3SbCl6(A=(R/S)-morpholin-2-ylmethanol,R/S-MOR),to form ordered chiral-achiral halides(A)2(B)SbCl6(B=ethylammonium,isopropylammonium,2-chloroethylammonium,n-propylammonium,n-butylammonium),and ordered mixed chiral-chiral halides(A)2(C)SbCl6(C=(R/S)-1-amino-2-propanol),respectively.The introduction of different natures of cations not only systematically alters the PLQY(up to 86.0%)by increasing the Sb···Sb distances and[SbCl6]3-octahedral distortion,but also significantly amplifies the chirality with enhanced glum.Among them,the mixed chiral-chiral material achieves the largest glum value(~9×10-3)with a high PLQY of 71.6%.The added dimension of a different chiral source reinforces the chirality and suppresses the inorganic octahedra vibration via hydrogen bonding interactions between the hydroxyl group and[SbCl6]3-octahedra.This work showcases an effective strategy to enhance the chiroptic properties and unlocks a large variety of new functional hybrid halides with ordered chiral/achiral cation combinations.展开更多
Metal-organic framework(MOF)/polymer composites have attracted extensive attention in the recent years.However,it still remains challenging to efficiently and effectively fabricate these composite materials.In this st...Metal-organic framework(MOF)/polymer composites have attracted extensive attention in the recent years.However,it still remains challenging to efficiently and effectively fabricate these composite materials.In this study,we propose a facile one-pot electrospinning strategy for preparation of HKUST-1/polyacrylonitrile(PAN)nanofibrous membranes from a homogeneous stock solution containing HKUST-1 precursors and PAN.MOF crystallization and polymer solidification occur simultaneously during the electrospinning process,thus avoiding the issues of aggregation and troublesome multistep fabrication of the conventional approach.The obtained HKUST-1/PAN electrospun membranes show uniform MOF distribution throughout the nanofibers and yield good mechanical properties.The membranes are used as separators in Li-metal full batteries under harsh testing conditions,using an ultrathin Li-metal anode,a high mass loading cathode,and the HKUST-1/PAN nanofibrous separator.The results demonstrate significantly improved cycling performance(capacity retention of 83.1%after 200 cycles)under a low negative to positive capacity ratio(N/P ratio of 1.86).The improvement can be attributed to an enhanced wettability of the separator towards electrolyte stemmed from the nanofibrous structure,and a uniform lithium ion flux stabilized by the open metal sites of uniformly distributed HKUST-1 particles in the membrane during cycling.展开更多
To overcome the shortcomings of traditional dairy cow feed intake assessment model andBP neural network, this paper proposes a method of optimizing BP neural network usingpolynomial decay learning rate, taking the cow...To overcome the shortcomings of traditional dairy cow feed intake assessment model andBP neural network, this paper proposes a method of optimizing BP neural network usingpolynomial decay learning rate, taking the cow’s body weight, lying duration, lying times,walking steps, foraging duration and concentrate-roughage ratio as input variables andtaking the actual feed intake is the output variable to establish a dairy cow feed intakeassessment model, and the model is trained and verified by experimental data collectedon site. For the sake of comparative study, feed intake is simultaneously assessed by SVRmodel, KNN logistic regression model, traditional BP neural network model, and multilayerBP neural network model. The results show that the established BP model using the polynomial decay learning rate has the highest assessment accuracy, the MSPE, RMSE, MAE,MAPE and R2 are 0.043 kg2/d and 0.208 kg/d, 0.173 kg/d, 1.37% and 0.94 respectively. Compared with SVR model and KNN mode, the RMSE value reduced by 43.9% and 26.5%, it isalso found that the model designed in this paper has many advantages in comparison withthe BP model and multilayer BP model in terms of precision and generalization. Therefore,this method is ready to be applied for accurately evaluating the dairy cow feed intake, andit can provide theoretical guidance and technical support for the precise-feeding and canalso be of high significance in the improvement of dairy precise-breeding.展开更多
Due to the complicated three-dimensional behaviors and testing limitations of reinforced concrete(RC)members in torsion,torsional mechanism exploration and torsional performance prediction have always been difficult.I...Due to the complicated three-dimensional behaviors and testing limitations of reinforced concrete(RC)members in torsion,torsional mechanism exploration and torsional performance prediction have always been difficult.In the present paper,several machine learning models were applied to predict the torsional capacity of RC members.Experimental results of a total of 287 torsional specimens were collected through an overall literature review.Algorithms of extreme gradient boosting machine(XGBM),random forest regression,back propagation artificial neural network and support vector machine,were trained and tested by 10-fold cross-validation method.Predictive performances of proposed machine learning models were evaluated and compared,both with each other and with the calculated results of existing design codes,i.e.,GB 50010,ACI 318-19,and Eurocode 2.The results demonstrated that better predictive performance was achieved by machine learning models,whereas GB 50010 slightly overestimated the torsional capacity,and ACI 318-19 and Eurocode 2 underestimated it,especially in the case of ACI 318-19.The XGBM model gave the most favorable predictions with R2=0.999,RMSE=1.386,MAE=0.86,andλ=0.976.Moreover,strength of concrete was the most sensitive input parameters affecting the reliability of the predictive model,followed by transverse-to-longitudinal reinforcement ratio and total reinforcement ratio.展开更多
Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs2P...Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs2Pb(SCN)2Br2 has been reported that opens up new potential for the development of 2D RP perovskites.However,recent reports of unusual dual emissions and two-edge absorption in Cs2Pb(SCN)2Br2 have generated intense debate about its origin and remains controversial.Here,by combining continuous pressure tuning with in situ diagnostics,we have unambiguously revealed the underlying mechanisms that the 2D Cs2Pb(SCN)2Br2 exhibits an intrinsic blue emission at 2.66 eV and an absorption edge close to the emission peak.While the gradually formed CsPbBr3 is responsible for the green emission at 2.33 eV with the absorption shoulder at 2.41 eV.Furthermore,by fitting the temperature-dependent intensity of the intrinsic blue emission,we have determined the corrected value of exciton binding energy for 2D Cs2Pb(SCN)2Br2 to be 90 meV.Intriguingly,an emission enhancement of 2.5 times is achieved in Cs2Pb(SCN)2Br2 under a mild pressure within 0.8 GPa,caused by the pressuresuppressed exciton-phonon interaction.This work not only elucidates the origin of the dual emissions and two-edge absorption in Cs2Pb(SCN)2Br2,but it also provides a potential means to regulate and optimize the optoelectronic properties of 2D perovskites.展开更多
Adenosine-to-inosine(A-to-I)RNA editing is a widespread posttranscriptional modification that has been shown to play an important role in tumorigenesis.Here,we evaluated a total of 19,316 RNA editing sites in the tiss...Adenosine-to-inosine(A-to-I)RNA editing is a widespread posttranscriptional modification that has been shown to play an important role in tumorigenesis.Here,we evaluated a total of 19,316 RNA editing sites in the tissues of 80 lung adenocarcinoma(LUAD)patients from our Nanjing Lung Cancer Cohort(NJLCC)and 486 LUAD patients from the TCGA database.The global RNA editing level was significantly increased in tumor tissues and was highly heterogeneous across patients.The high RNA editing level in tumors was attributed to both RNA(ADAR1 expression)and DNA alterations(mutation load).Consensus clustering on RNA editing sites revealed a new molecular subtype(EC3)that was associated with the poorest prognosis of LUAD patients.Importantly,the new classification was independent of classic molecular subtypes based on gene expression or DNA methylation.We further proposed a simplified model including eight RNA editing sites to accurately distinguish the EC3 subtype in our patients.The model was further validated in the TCGA dataset and had an area under the curve(AUC)of the receiver operating characteristic curve of 0.93(95%CI:0.91-0.95).In addition,we found that LUAD cell lines with the EC3 subtype were sensitive to four chemotherapy drugs.These findings highlighted the importance of RNA editing events in the tumorigenesis of LUAD and provided insight into the application of RNA editing in the molecular subtyping and clinical treatment of cancer.展开更多
For the closure of the subgrid-scale(SGS)stress tensor,an artificial neural network(ANN)-based SGS model that takes account of the inverse energy cascade in isotropic turbulence is developed.The data required for trai...For the closure of the subgrid-scale(SGS)stress tensor,an artificial neural network(ANN)-based SGS model that takes account of the inverse energy cascade in isotropic turbulence is developed.The data required for training this ANN-based SGS model are provided by direct numerical simulation of isotropic turbulence with an inverse energy cascade.Two input features,the root mean square of the rate-of-strain tensor and the product of the eigenvalues of the rate-of-strain tensor,are employed to characterize the inverse energy cascade.An a priori test reveals that the ANN-based model adequately predicts the SGS stress tensor in the backward energy transfer process,and the predictive capability of the gradient model is found to be slightly poorer than that of the ANN-based model,while that of the Smagorinsky model is not satisfactory.In comparison with the gradient model,the ANN-based model even predicts a few backward energy transfer events in the stage of excessive energy dissipation.In addition,the off-diagonal component of the SGS stress tensor,rather than the diagonal component,may be intimately associated with the inverse energy cascade.The ANN-based SGS model presented here is expected to provide inspiration for future investigations of the construction of SGS models that take account of the inverse energy cascade.展开更多
Low-dimensional hybrid inorganic-organic perovskites are excellent candidates for stable optoelectronic devices.The dimensionality of these perovskites depends largely on the organic and inorganic compositions,as well...Low-dimensional hybrid inorganic-organic perovskites are excellent candidates for stable optoelectronic devices.The dimensionality of these perovskites depends largely on the organic and inorganic compositions,as well as the synthetic conditions.Here,we report five new hybrid iodides,(ETU)4Ge5I18,(ETU)GeI4,(ETU)SnI4,(ETU)PbI4,and(ETU)3Pb2I10using only one type of organic cation,namely,S-(2-aminoethyl)isothiouronium(ETU).展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 52071097)Hainan Provincial Natural Science Foundation of China (Grant No. 522MS162)Research Fund from Science and Technology on Underwater Vehicle Technology Laboratory (Grant No. 2021JCJQ-SYSJJ-LB06910)。
摘要Path planning for recovery is studied on the engineering background of double unmanned surface vehicles(USVs)towing oil booms for oil spill recovery.Given the influence of obstacles on the sea,the improved artificial potential field(APF)method is used for path planning.For addressing the two problems of unreachable target and local minimum in the APF,three improved algorithms are proposed by combining the motion performance constraints of the double USV system.These algorithms are then combined as the final APF-123 algorithm for oil spill recovery.Multiple sets of simulation tests are designed according to the flaws of the APF and the process of oil spill recovery.Results show that the proposed algorithms can ensure the system’s safety in tracking oil spills in a complex environment,and the speed is increased by more than 40%compared with the APF method.
基金supported by the National Natural Science of China(82322032 and 82221005)the Outstanding Youth Foundation of Jiangsu Province(BK20220050)+4 种基金the National Key Research&Development(R&D)Program of China(2024YFC2706800 and 2021YFC2700600)the Major Project of Changzhou Medical Center(CZKY1040101)the Major Project of Taizhou Clinical Medical College(TZKY20240003)the Major Program of Gusu School(GSKY20210102)the China Postdoctoral Science Foundation(2024M760296).
摘要Autism spectrum disorder(ASD)is a neurodevelopmental disorder where de novo mutations play a significant role.Although coding mutations in ASD have been extensively characterized,the impact of non-coding de novo mutations(ncDNMs)remains less understood.Here,we integrate cortex cell-specific cis-regulatory element annotations,a deep learning-based variant prediction model,and massively parallel reporter assays to systematically evaluate the functional impact of 227,878 ncDNMs from Simons Simplex Collection(SSC)and Autism Speaks MSSNG resource(MSSNG)cohorts.Our analysis identifies 238 ncDNMs with confirmed functional regulatory effects,including 137 down-regulated regulatory mutations(DrMuts)and 101 up-regulated regulatory mutations(UrMuts).Subsequent association analyses reveal that only DrMuts regulating loss-of-function(LoF)intolerant genes rather than other ncDNMs are significantly associated with the risk of ASD(Odds ratio=4.34;P=0.001).A total of 42 potential ASD-risk DrMuts across 41 candidate ASD-susceptibility genes are identified,including 12 recognized and 29 unreported genes.Interestingly,these noncoding disruptive mutations tend to be observed in genes extremely intolerant to LoF mutations.Our study introduces an optimized approach for elucidating the functional roles of ncDNMs,thereby expanding the spectrum of pathogenic variants and deepening our understanding of the complex molecular mechanisms underlying ASD.
基金This study is funded by the National Nature Science Foundation of China(Grant Nos.:82074323,and 81673572)Key Research and Development Program of Shanxi Province(Program No.:202102130501010)+2 种基金The major science and technology project for“Significant New Drugs Creation”(Project No.:2017ZX09301047)Research Project Supported by Shanxi Scholarship Council of China(Project No.:2020019)The special fund for Science and Technology Innovation Teams of Shanxi Province(Grant No.:202204051002011).
摘要Radix Bupleuri(RB)is commonly used to treat depression,but it can also lead to hepatotoxicity after longterm use.In many anti-depression prescriptions,RB is often used in combination with Radix Paeoniae Alba(RPA)as an herb pair.However,whether RPA can alleviate RB-induced hepatotoxicity remain unclear.In this work,the results confirmed that RB had a dose-dependent antidepressant effect,but the optimal antidepressant dose caused hepatotoxicity.Notably,RPA effectively reversed RB-induced hepatotoxicity.Afterward,the mechanism of RB-induced hepatotoxicity was confirmed.The results showed that saikosaponin A and saikosaponin D could inhibit GSH synthase(GSS)activity in the liver,and further cause liver injury through oxidative stress and nuclear factor kappa B(NF-kB)/NOD-like receptor thermal protein domain associated protein 3(NLRP3)pathway.Furthermore,the mechanisms by which RPA attenuates RBinduced hepatotoxicity were investigated.The results demonstrated that RPA increased the abundance of intestinal bacteria with glycosidase activity,thereby promoting the conversion of saikosaponins to saikogenins in vivo.Different from saikosaponin A and saikosaponin D,which are directly combined with GSS as an inhibitor,their deglycosylation conversion products saikogenin F and saikogenin G exhibited no GSS binding activity.Based on this,RPA can alleviate the inhibitory effect of saikosaponins on GSS activity to reshape the liver redox balance and further reverse the RB-induced liver inflammatory response by the NFkB/NLRP3 pathway.In conclusion,the present study suggests that promoting the conversion of saikosaponins by modulating gut microbiota to attenuate the inhibition of GSS is the potential mechanism by which RPA prevents RB-induced hepatotoxicity.
基金co-supported by the National Natural Science Foundation of China(No.52022009)the Science Center for Gas Turbine Project of China(No.P2022-A-II-003-001)the Key Laboratory Foundation,China(No.2021-JCJQ-LB-062-0102).
摘要Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and stator.This study presents an Immersed Boundary Method(IBM)for high-Reynolds turbomachinery internal flows,and shows the advantage of the automatic grid generation techniques and flexible moving boundary treatments.The wall functions are used in the present method to alleviate the wall resolution restriction of turbulence simulation.The Two-Dimensional(2-D)IBM solver,which was previously developed and tested for a low-speed compressor,is further validated for a well-documented Low-Pressure Turbine(LPT)cascade.Both the blade loading and the total pressure losses in the wake are well captured by the present 2-D solver.The complex Three-Dimensional(3-D)effects in turbomachines motivate the further development of an extended 3-D IBM solver by using a curvilinear-coordinate system that facilitates the hub and casing boundary treatment.The good performance of the 3-D solver is demonstrated through comparison with CFX solver solutions for the rotor configuration of Advanced Noise Control Fan(ANCF).Further effects of the grid resolution on capturing the blade wake are discussed.The results indicate that the present 3-D solver is capable of reproducing the evolution of the blade wake with suitable computational grid.
基金co-supported by the National Natural Science Foundation of China(Nos.52022009,51790514)the National Science and Technology Major Project,China(No.2017-II-003-0015)the Key Laboratory Foundation,China(No.2021-JCJQ-LB-062-0102).
摘要Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain model is extended to predict CROR noise.It builds explicitly the relationship between harmonic loadings and corresponding tonal noise,by which the influential parameters to noise generation can be clearly understood.The real distribu-tions of steady and unsteady blade loadings are calculated by the Nonlinear Harmonic(NLH)method.In the present hybrid approach,both the CFD and acoustic modules are solved in the fre-quency domain.To assess the accuracy of the developed method,the loading noise of a CROR is calculated and compared against results by using the time-domain FW-H module of NUMECA.The predicted sound directivities by the two methods are in good agreements.The present acoustic model in the frequency domain is proven to be accurate and have high efficiency in far-field noise prediction and data processing.Furthermore,the characteristics of the CROR interaction tonal noise are analyzed and discussed.
基金Supported by the National Natural Science Foundation of China(Grant No.11771122).
摘要In this paper,we describe the structure of Verma modules over the two kinds of Lie algebras g(λ)of W-type.We determine the reducibility and the singular vectors of their Verma modules under some conditions.
摘要The photoluminescence of four polyoxoniobates [Nb6O19]8-, [Nb10O28]6-, [Ti2Nb8O28]8- and [H2Si4Nb16O56]14- was observed, and its origin was revealed in the view of molecular orbital by means of the computational method. The photoluminescence is originated from singlet transitions, and the calculated values agree well with the experimental data. The results indicate that the size of clusters and the foreigner atoms can affect the fluorescent properties of PONbs. The absorption and emission of these PONbs are originated molecular orbitals contributed mainly by μ2-O and Nb atoms according to NBO analysis. These PONbs were also found as electrochemical catalysts with high performance for water oxidation, which can effectively split water into oxygen under basic condition with a high catalytic current, and pH values have remarkable influence on the electrocatalytic activities of these PONbs for water oxidation.
基金supported by the Research and Development Fund of Inner Mongolia University(21300-5187174)the Program of Higher-Level Talents of Inner Mongolia University(10000-23112101/105)the National Natural Science Foundation of China(22275077,22461160285 and 22401161).
摘要Chiral zero-dimensional(0D)hybrid metal halides,merging chirality with exceptional emission properties,are highly promising for circularly polarized luminescence(CPL).For CPL applications,it is difficult to simultaneously achieve large dissymmetry factor(glum)and photoluminescence quantum yield(PLQY).Herein,we propose a chemical design strategy to systematically control the glum and PLQY.We take achiral or chiral organic cations,to partially substitute the original A-site in A3SbCl6(A=(R/S)-morpholin-2-ylmethanol,R/S-MOR),to form ordered chiral-achiral halides(A)2(B)SbCl6(B=ethylammonium,isopropylammonium,2-chloroethylammonium,n-propylammonium,n-butylammonium),and ordered mixed chiral-chiral halides(A)2(C)SbCl6(C=(R/S)-1-amino-2-propanol),respectively.The introduction of different natures of cations not only systematically alters the PLQY(up to 86.0%)by increasing the Sb···Sb distances and[SbCl6]3-octahedral distortion,but also significantly amplifies the chirality with enhanced glum.Among them,the mixed chiral-chiral material achieves the largest glum value(~9×10-3)with a high PLQY of 71.6%.The added dimension of a different chiral source reinforces the chirality and suppresses the inorganic octahedra vibration via hydrogen bonding interactions between the hydroxyl group and[SbCl6]3-octahedra.This work showcases an effective strategy to enhance the chiroptic properties and unlocks a large variety of new functional hybrid halides with ordered chiral/achiral cation combinations.
基金We sincerely thank the State Key Laboratory of Chemical Engineering at Zhejiang University(No.SKL-ChE-20D01)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2017ZT07C291)+1 种基金Shenzhen Science and Technology Program(No.KQTD20170810141424366)2019 Special Program for Central Government Guiding Local Science and Technology Development:Environmental Purification Functional Materials Research Platform,and Shenzhen Key Laboratory of Advanced Materials Product Engineering(No.ZDSYS20190911164401990)for supporting this research work。
摘要Metal-organic framework(MOF)/polymer composites have attracted extensive attention in the recent years.However,it still remains challenging to efficiently and effectively fabricate these composite materials.In this study,we propose a facile one-pot electrospinning strategy for preparation of HKUST-1/polyacrylonitrile(PAN)nanofibrous membranes from a homogeneous stock solution containing HKUST-1 precursors and PAN.MOF crystallization and polymer solidification occur simultaneously during the electrospinning process,thus avoiding the issues of aggregation and troublesome multistep fabrication of the conventional approach.The obtained HKUST-1/PAN electrospun membranes show uniform MOF distribution throughout the nanofibers and yield good mechanical properties.The membranes are used as separators in Li-metal full batteries under harsh testing conditions,using an ultrathin Li-metal anode,a high mass loading cathode,and the HKUST-1/PAN nanofibrous separator.The results demonstrate significantly improved cycling performance(capacity retention of 83.1%after 200 cycles)under a low negative to positive capacity ratio(N/P ratio of 1.86).The improvement can be attributed to an enhanced wettability of the separator towards electrolyte stemmed from the nanofibrous structure,and a uniform lithium ion flux stabilized by the open metal sites of uniformly distributed HKUST-1 particles in the membrane during cycling.
基金This research is financially supported by National Thirteenth Five-Year National Key R&D Plan(2016YFD0700204)China Postdoctoral Science Foundation(2017M611346)+3 种基金the China Agriculture Research System(CARS-36)the Natural Science Foundation of Heilongjiang Province of China(C2018018)Postdoctoral Science Foundation of Heilongjiang(LBHZ12040)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province under Grant(UNPYSCT-2018143).
摘要To overcome the shortcomings of traditional dairy cow feed intake assessment model andBP neural network, this paper proposes a method of optimizing BP neural network usingpolynomial decay learning rate, taking the cow’s body weight, lying duration, lying times,walking steps, foraging duration and concentrate-roughage ratio as input variables andtaking the actual feed intake is the output variable to establish a dairy cow feed intakeassessment model, and the model is trained and verified by experimental data collectedon site. For the sake of comparative study, feed intake is simultaneously assessed by SVRmodel, KNN logistic regression model, traditional BP neural network model, and multilayerBP neural network model. The results show that the established BP model using the polynomial decay learning rate has the highest assessment accuracy, the MSPE, RMSE, MAE,MAPE and R2 are 0.043 kg2/d and 0.208 kg/d, 0.173 kg/d, 1.37% and 0.94 respectively. Compared with SVR model and KNN mode, the RMSE value reduced by 43.9% and 26.5%, it isalso found that the model designed in this paper has many advantages in comparison withthe BP model and multilayer BP model in terms of precision and generalization. Therefore,this method is ready to be applied for accurately evaluating the dairy cow feed intake, andit can provide theoretical guidance and technical support for the precise-feeding and canalso be of high significance in the improvement of dairy precise-breeding.
基金The authors are extremely grateful to the funds including the National Natural Science Foundation of China(Grant No.51808258)the Fundamental Research Funds for the Central Universities(No.2022QN1031).
摘要Due to the complicated three-dimensional behaviors and testing limitations of reinforced concrete(RC)members in torsion,torsional mechanism exploration and torsional performance prediction have always been difficult.In the present paper,several machine learning models were applied to predict the torsional capacity of RC members.Experimental results of a total of 287 torsional specimens were collected through an overall literature review.Algorithms of extreme gradient boosting machine(XGBM),random forest regression,back propagation artificial neural network and support vector machine,were trained and tested by 10-fold cross-validation method.Predictive performances of proposed machine learning models were evaluated and compared,both with each other and with the calculated results of existing design codes,i.e.,GB 50010,ACI 318-19,and Eurocode 2.The results demonstrated that better predictive performance was achieved by machine learning models,whereas GB 50010 slightly overestimated the torsional capacity,and ACI 318-19 and Eurocode 2 underestimated it,especially in the case of ACI 318-19.The XGBM model gave the most favorable predictions with R2=0.999,RMSE=1.386,MAE=0.86,andλ=0.976.Moreover,strength of concrete was the most sensitive input parameters affecting the reliability of the predictive model,followed by transverse-to-longitudinal reinforcement ratio and total reinforcement ratio.
基金supported by the National Natural Science Foundation of China(NSFC)(grant nos.22275004,U1930401,and 52325309)the Shanghai Science and Technology Committee(grant no.22JC1410300)+2 种基金the Shanghai Key Laboratory of Novel Extreme Condition Materials(grant no.22dz2260800)supported by the NSFC(grant no.22275077).Q.H.is supported by the CAEP Research(grant no.CX20210048)the Tencent Xplorer Prize(grant no.XPLORER-2020-1013).
摘要Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs2Pb(SCN)2Br2 has been reported that opens up new potential for the development of 2D RP perovskites.However,recent reports of unusual dual emissions and two-edge absorption in Cs2Pb(SCN)2Br2 have generated intense debate about its origin and remains controversial.Here,by combining continuous pressure tuning with in situ diagnostics,we have unambiguously revealed the underlying mechanisms that the 2D Cs2Pb(SCN)2Br2 exhibits an intrinsic blue emission at 2.66 eV and an absorption edge close to the emission peak.While the gradually formed CsPbBr3 is responsible for the green emission at 2.33 eV with the absorption shoulder at 2.41 eV.Furthermore,by fitting the temperature-dependent intensity of the intrinsic blue emission,we have determined the corrected value of exciton binding energy for 2D Cs2Pb(SCN)2Br2 to be 90 meV.Intriguingly,an emission enhancement of 2.5 times is achieved in Cs2Pb(SCN)2Br2 under a mild pressure within 0.8 GPa,caused by the pressuresuppressed exciton-phonon interaction.This work not only elucidates the origin of the dual emissions and two-edge absorption in Cs2Pb(SCN)2Br2,but it also provides a potential means to regulate and optimize the optoelectronic properties of 2D perovskites.
基金supported by the National Natural Science Foundation of China(81922061,82072579,81521004,81973123and 81871885)the National Key Research and Development Project(2017YFC0907905)Research Unit of Prospective Cohort of Cardiovascular Diseases and Cancer,Chinese Academy of Medical Sciences(2019RU038)。
摘要Adenosine-to-inosine(A-to-I)RNA editing is a widespread posttranscriptional modification that has been shown to play an important role in tumorigenesis.Here,we evaluated a total of 19,316 RNA editing sites in the tissues of 80 lung adenocarcinoma(LUAD)patients from our Nanjing Lung Cancer Cohort(NJLCC)and 486 LUAD patients from the TCGA database.The global RNA editing level was significantly increased in tumor tissues and was highly heterogeneous across patients.The high RNA editing level in tumors was attributed to both RNA(ADAR1 expression)and DNA alterations(mutation load).Consensus clustering on RNA editing sites revealed a new molecular subtype(EC3)that was associated with the poorest prognosis of LUAD patients.Importantly,the new classification was independent of classic molecular subtypes based on gene expression or DNA methylation.We further proposed a simplified model including eight RNA editing sites to accurately distinguish the EC3 subtype in our patients.The model was further validated in the TCGA dataset and had an area under the curve(AUC)of the receiver operating characteristic curve of 0.93(95%CI:0.91-0.95).In addition,we found that LUAD cell lines with the EC3 subtype were sensitive to four chemotherapy drugs.These findings highlighted the importance of RNA editing events in the tumorigenesis of LUAD and provided insight into the application of RNA editing in the molecular subtyping and clinical treatment of cancer.
基金supported by the National Natural Science Foundation of China(Grant No.12002318)the Fundamental Research Program of Shanxi Province(Grant No.202303021221118)the China Postdoctoral Science Foundation(Grant No.2022M721630)
摘要For the closure of the subgrid-scale(SGS)stress tensor,an artificial neural network(ANN)-based SGS model that takes account of the inverse energy cascade in isotropic turbulence is developed.The data required for training this ANN-based SGS model are provided by direct numerical simulation of isotropic turbulence with an inverse energy cascade.Two input features,the root mean square of the rate-of-strain tensor and the product of the eigenvalues of the rate-of-strain tensor,are employed to characterize the inverse energy cascade.An a priori test reveals that the ANN-based model adequately predicts the SGS stress tensor in the backward energy transfer process,and the predictive capability of the gradient model is found to be slightly poorer than that of the ANN-based model,while that of the Smagorinsky model is not satisfactory.In comparison with the gradient model,the ANN-based model even predicts a few backward energy transfer events in the stage of excessive energy dissipation.In addition,the off-diagonal component of the SGS stress tensor,rather than the diagonal component,may be intimately associated with the inverse energy cascade.The ANN-based SGS model presented here is expected to provide inspiration for future investigations of the construction of SGS models that take account of the inverse energy cascade.
基金supported by the Department of Energy,Office of Science,Basic Energy Sciences,under grant SC0012541The work at SUSTech was supported by SUSTech startup grant(Y01216150).
摘要Low-dimensional hybrid inorganic-organic perovskites are excellent candidates for stable optoelectronic devices.The dimensionality of these perovskites depends largely on the organic and inorganic compositions,as well as the synthetic conditions.Here,we report five new hybrid iodides,(ETU)4Ge5I18,(ETU)GeI4,(ETU)SnI4,(ETU)PbI4,and(ETU)3Pb2I10using only one type of organic cation,namely,S-(2-aminoethyl)isothiouronium(ETU).