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Research on Gravity and Apparent Density Changes in the Focal Area before and after the Wushi Ms7.1 Earthquake 认领 引用
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作者 Zhao Lei Abdutair Yassen +5 位作者 Liu Dai-Qin Ailixiati YuShan Chen Li Li Jie Han Kai Kong Xiang-Kui 《Applied Geophysics》 SCIE CSCD 2026年第2期649-668,869,共20页
On January 23,2024,an Ms 7.1 earthquake struck Wushi County,Aksu region,Xinjiang,with its seismogenic structure identified as the NE-striking sinistral compressional Maidan Fault.To gain deeper insights into the se... On January 23,2024,an Ms 7.1 earthquake struck Wushi County,Aksu region,Xinjiang,with its seismogenic structure identified as the NE-striking sinistral compressional Maidan Fault.To gain deeper insights into the seismogenic mechanism and precursory characteristics of this event,this study systematically investigates the spatiotemporal evolution of the gravity fi eld,crustal apparent density changes,and time-series responses at specifi c points in the epicentral area.The analysis is grounded in the"fi eld-source interaction"theoretical framework and utilizes high-precision mobile gravity observation data from Southern Xinjiang,covering the period from March 2020 to January 2024.The results reveal several key fi ndings.Firstly,the spatiotemporal evolution of the gravity fi eld shows a signifi cant correlation with the earthquake triggering mechanism.During the seismogenic phase,the regional gravity fi eld exhibited a characteristic four-quadrant distribution pattern,with the epicenter located near the center and the high-gradient zone.Immediately preceding the earthquake,the gravity fi eld in the source area underwent a reversal from negative to positive,refl ecting shear stress concentration caused by the migration of deep materials,which aligns with the Coulomb failure criterion.Secondly,multi-temporal apparent density inversion elucidates the deep response of tectonic activity.Equivalent source inversion results indicate that the apparent density changes in the epicentral crust ranged from-1.0 to+3.0 kg/m3,showing a signifi cant correlation with the surface gravity anomaly intensity(±80μGal).This confi rms the effi cacy of the equivalent source method in extracting weak tectonic signals from complex background fi elds and clarifi es that crustal mass migration and stress accumulation are crucial physical mechanisms driving the earthquake.Finally,time-series analysis of point values uncovers the evolutionary pattern of gravity precursors.Data from fi ve measurement points near the epicenter show a slow upward trend in gravity before the earthquake,which transitioned to an accelerated rise during the immediate foreshock period,with a maximum change of 103μGal.This indicates that the directional migration of materials,such as deep high-pressure fl uids,led to a sharp increase in density in the source area,ultimately triggering the instability of the fault.Through multi-dimensional gravity analysis,this study systematically reveals the coupled evolution characteristics of the gravity,density,and stress fi elds during the preparation of the Wushi earthquake.It enhances the understanding of the mechanisms behind strong earthquakes and validates the signifi cant value of time-varying gravity fi elds in identifying seismic precursors and delineating hazardous zones. 展开更多
关键词 Wushi Earthquake Time-Varying Gravitational Field Apparent Density Inversion Gravity Anomaly Earthquake Precursor
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Simultaneous estimation of Bouguer gravity anomaly and near-surface density using Bayesian approach:A Yunnan case study 认领 引用
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作者 Feng-gui Niu Shi Chen +3 位作者 Yong-bo Li Hong-lei Li Yuan-yuan Niu Yu-hang Pan 《Applied Geophysics》 SCIE CSCD 2025年第4期1109-1124,1495,共16页
Gravity anomalies reflect the geophysical response to subsurface density structures.Traditionally,the terrain density is assumed to be a constant when calculating Bouguer gravity anomaly.But deviations from this assum... Gravity anomalies reflect the geophysical response to subsurface density structures.Traditionally,the terrain density is assumed to be a constant when calculating Bouguer gravity anomaly.But deviations from this assumption may induce high-frequency signals in the Bouguer gravity anomaly.This study introduces a Bayesian method for computing Bouguer gravity anomaly.It incorporates a smoothness prior for the Bouguer gravity anomaly and estimates near-surface density parameters to minimize the Akaike's Bayesian Information Criterion(ABIC)value.The effectiveness of this method is validated through theoretical model tests and calculations on two observed gravity profiles in Yunnan.The results indicate that the Bouguer gravity anomaly profiles estimated using the Bayesian approach need no extra filtering,exhibit correlations with the crustal structure along the profiles,and effectively reveal subsurface crustal density variations.Moreover,the obtained density variations offer insights into the near-surface rock density in different geological periods.Specifically,Cenozoic formations have a density of roughly 2.65–2.90 g·cm-3,Mesozoic formations 2.61-2.91 g·cm-3,and Paleozoic formations 2.61–2.92 g·cm-3.Magmatic rock regions generally show higher density values.Additionally,these estimated densities show a positive correlation with the global VS30 seismic velocity estimates,suggesting a new geophysical approach for seismic site classification.The findings of this study are significantly valuable for near-surface density estimation and Bouguer gravity anomaly calculations. 展开更多
关键词 Near-surface density Bouguer gravity anomaly ABIC Bayesian inversion Seismic site classification
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Trends in Low Bone Density-Related Fall Burden and Mendelian Randomization Evidence on Waist Circumference and Bone Density—China,1990–2023 认领 引用
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作者 Ying Li Yuhan Wang Zhuo Zhang 《China CDC weekly》 SCIE CSCD 2026年第31期977-982,I0001,共6页
Introduction:Low bone density(LBD)-related falls impose a growing public health burden in China;however,the age-specific impact of abdominal obesity on bone density remains unclear.Methods:Using data from the Global B... Introduction:Low bone density(LBD)-related falls impose a growing public health burden in China;however,the age-specific impact of abdominal obesity on bone density remains unclear.Methods:Using data from the Global Burden of Disease 2023,we analyzed trends in mortality and disability-adjusted life-years(DALYs)due to LBDrelated falls in China(1990–2023).Joinpoint regression assessed temporal trends and age-stratified two-sample Mendelian randomization(MR)examined the association between genetically predicted waist circumference and bone density.Results:From 1990 to 2023,deaths increased 3.66-fold,and DALYs increased 3.01-fold.When age standardized,mortality increased slightly and DALY rates increased.In 2023,the burden was concentrated in adults≥60 years old.MR showed that genetically predicted waist circumference was inversely associated with bone density in the 30–44-year[β=−0.24,95%confidence interval(CI):−0.39,−0.07,P=0.004]and≥60-year groups(β=−0.24,95%CI:−0.37,−0.12,P<0.001).Conclusion:LBD-related falls impose an increasing burden on older adults in China.This growing burden highlights the need for age-and sex-specific preventive measures.MR findings based on European genomewide association study data suggested an inverse association between genetically predicted waist circumference and total-body bone density,which requires validation in Chinese populations. 展开更多
关键词 bone density public health burden age specific impact genetically predicted waist circumference low bone density abdominal obesity mortality disability adjusted life years
3D density inversion of gravity gradiometry data with a multilevel hybrid parallel algorithm 认领 引用 被引量：7
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作者 Hou Zhen-Long Huang Da-Nian +1 位作者 Wang En-De Cheng Hao 《Applied Geophysics》 SCIE CSCD 2019年第2期141-152,252,共12页
The density inversion of gravity gradiometry data has attracted considerable attention;however,in large datasets,the multiplicity and low depth resolution as well as efficiency are constrained by time and computer mem... The density inversion of gravity gradiometry data has attracted considerable attention;however,in large datasets,the multiplicity and low depth resolution as well as efficiency are constrained by time and computer memory requirements.To solve these problems,we improve the reweighting focusing inversion and probability tomography inversion with joint multiple tensors and prior information constraints,and assess the inversion results,computing efficiency,and dataset size.A Message Passing Interface(MPI)-Open Multi-Processing(OpenMP)-Computed Unified Device Architecture(CUDA)multilevel hybrid parallel inversion,named Hybrinv for short,is proposed.Using model and real data from the Vinton Dome,we confirm that Hybrinv can be used to compute the density distribution.For data size of 100×100×20,the hybrid parallel algorithm is fast and based on the run time and scalability we infer that it can be used to process the large-scale data. 展开更多
关键词 gravity gradiometry data density inversion GPU MPI hybrid parallel inversion
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Gravity inversion using the frequency characteristics of the density distribution 认领 引用 被引量：10
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作者 陈石 张健 石耀霖 《Applied Geophysics》 SCIE 2008年第2期99-106,共8页
Three-dimensional gravity inversion based on the mass property model is very popular in recent years. The time and efficiency of inversion algorithms is relative to the magnitude of the target mesh. One approach is to... Three-dimensional gravity inversion based on the mass property model is very popular in recent years. The time and efficiency of inversion algorithms is relative to the magnitude of the target mesh. One approach is to search over the entire solution space for a more refined result. However, the inversion will be difficult with the increased parameters in the large search space and the number of computations increases exponentially. ｜n this paper, we propose a novel approach based on the frequency characteristics of the density distribution over the mesh. The purposes of our study are to reduce the parameters of three- dimensional gravity inversion and to lighten the image quality of the inversion result. The results show that the new method can expedite the inversion processing and get a better geological interpretation than tradition methods. 展开更多
关键词 Gravity inversion frequency decomposition 3D density distribution potential field
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Influence of light availability on the specific density,size and sinking loss of Anabaena flos-aquae and Scenedesmus obliquus 认领 引用 被引量：2
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作者 HUANG Yingylng ZHANG Haichun +3 位作者 GAO Rufeng HUANG Xiaochen YU Xiaojuan CHEN Xuechu 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第4期1053-1062,共10页
Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and... Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and reservoirs. To develop a better understanding of the effects of light on algal growth, specific density, colony size and sinking loss, Anabaena flos-aquae(cyanobacteria) and Scenedesmus obliquus(green algae) were evaluated in varying light scenarios. The results showed that the specific density and colony size of these two species varied during growth, and there were obvious differences among the light scenarios. At the end of exponential phase, S. obliquus incubated under light-limited condition maintained a higher specific density and formed larger aggregates, whereas A. flos-aquae formed a longer filament length. Both species exhibited higher sinking loss rates with lower light availability. These results implied that the sinking loss rate was not always constant but should be considered as a variable response to the change of light availability, and in-situ light availability control might result in a significant increase of the sinking loss of algae due to the change of size and specific density, thereby further affecting the algal biomass in the water column. 展开更多
关键词 specific density size light availability control sinking loss
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Construction of a high-density genetic map based on specific-locus amplified fragment sequencing and identification of loci controlling anthocyanin pigmentation in Yunnan red radish 认领 引用 被引量：2
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作者 Jing Tao Shikai Li +7 位作者 Qian Wang Yi Yuan Jiqiong Ma Minghui Xu Yi Yang Cui Zhang Lijuan Chen Yiding Sun 《Horticulture Research》 SCIE CSCD 2022年第1期947-961,共15页
Radish(Raphanus sativus L.)belongs to the family Brassicaceae.The Yunnan red radish variety contains relatively large amounts of anthocyanins,making them important raw materials for producing edible red pigment.Howeve... Radish(Raphanus sativus L.)belongs to the family Brassicaceae.The Yunnan red radish variety contains relatively large amounts of anthocyanins,making them important raw materials for producing edible red pigment.However,the genetic mechanism underlying this pigmentation has not been fully characterized.Here,the radish inbred line YAAS-WR1(white root skin and white root flesh)was crossed with the inbred line YAAS-RR1(red root skin and red root flesh)to produce F1,F2,BC1P1,and BC1P2 populations.Genetic analyses revealed that the pigmentedon-pigmented and purpleed traits were controlled by two genetic loci.The F2 population and the specific-locus amplified fragment sequencing(SLAF-seq)technique were used to construct a high-density genetic map(1230.16 cM),which contained 4032 markers distributed in nine linkage groups,with a mean distance between markers of 0.31 cM.Additionally,two quantitative trait loci(QAC1 and QAC2)considerably affecting radish pigmentation were detected.A bioinformatics analysis of the QAC1 region identified 58 predicted protein-coding genes.Of these,RsF3'H,which is related to anthocyanin biosynthesis,was revealed as a likely candidate gene responsible for the purpleed trait.The results were further verified by analyzing gene structure and expression.Regarding QAC2,RsMYB1.3 was determined to be a likely candidate gene important for the pigmentedon-pigmented trait,with a 4-bp insertion in the first exon that introduced a premature termination codon in the YAAS-WR1 sequence.Assays demonstrated that RsMYB1.3 interacted with RsTT8 and activated RsTT8 and RsUFGT expression.These findings may help clarify the complex regulatory mechanism underlying radish anthocyanin synthesis.Furthermore,this study’s results may be relevant for the molecular breeding of radish to improve the anthocyanin content and appearance of the taproots. 展开更多
关键词 molecular breeding anthocyanin pigmentation Yunnan red radish bioinformatics analysis high density genetic map quantitative trait loci genetic mechanism specific locus amplified fragment sequencing
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Density structure of the crust in the Emeishan large igneous province revealed by the Lijiang-Guiyang gravity profile 认领 引用 被引量：1
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作者 Xi Zhang Peng Wang +3 位作者 Tao Xu Yun Chen José Badal JiWen Teng 《Earth and Planetary Physics》 CAS 2018年第1期74-81,共8页
The Emeishan large igneous province(hereafter named by its acronym ELIP) is the first accepted large igneous region in China.The current study tries to reconstruct the density structure of the crust in this region. Fo... The Emeishan large igneous province(hereafter named by its acronym ELIP) is the first accepted large igneous region in China.The current study tries to reconstruct the density structure of the crust in this region. For this purpose, we conducted the gravity survey along an 800-km-long profile, which stretched laterally along the latitude 27°N from Lijiang(Yunnan province) to Guiyang(Guizhou province). The fieldwork included 338 gravity measurements distributed from the inner zone to the outer zone of the mantle plume head.After a series of gravity reductions, we calculated the Bouguer gravity anomaly and then constructed the density model for ELIP by iterative forward modeling from an initial density model tightly constrained by wide-angle seismic reflection data. The topography of the Moho, here physically interpreted as a density discontinuity of ~0.4 g·cm–3, gradually rises from the inner zone(~50 km deep) to the outer zone(~40 km), describes a thicker crust in the inner zone than in any other segment of the profile and largely reproduces the shape of the Bouguer gravity anomaly curve. Both the Bouguer gravity and the density structure show significant differences with respect to the inner zone and the other two zones of ELIP according to the commonly accepted partition of the Emeishan area. A thicker and denser middle-lower crust seems to be the main feature of the western section of the profile, which is likely related to its mafic magmatic composition due to magmatic underplating of the Permian mantle plume. 展开更多
关键词 Bouguer gravity seismic reflection data forward modeling crustal density structure Emeishan large igneous province South China
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Prostate-specific antigen density predicts favorable pathology and biochemical recurrence in patients with intermediate-risk prostate cancer 认领 引用 被引量：4
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作者 Ho Won Kang Hae Do Jung +5 位作者 Joo Yong Lee Jong Kyou Kwon Seong Uk Jeh Kang Su Cho Won Sik Ham Young Deuk Choi 《Asian Journal of Andrology》 SCIE CAS CSCD 2016年第3期480-484,I0012,共5页
This study was designed to identify clinical predictors of favorable pathology and biochemical recurrence （BCR） in patients with intermediate-risk prostate cancer （IRPCa）. Between 2006 and 2012, clinicopathologica... This study was designed to identify clinical predictors of favorable pathology and biochemical recurrence （BCR） in patients with intermediate-risk prostate cancer （IRPCa）. Between 2006 and 2012, clinicopathological and oncological data from 203 consecutive men undergoing robot-assisted radical prostatectomy （RARP） for IRPCa were reviewed in a single-institutional retrospective study. Favorable pathology was defined as Gleason score 〈6 and organ-confined cancer as detected by surgical pathology. Logistic regression analysis was used to determine predictive variables of favorable pathology, and the Kaplan-Meier and multivariate Cox regression model were used to estimate BCR-free survival after RARP. Overall, 38 patients （18.7%） had favorable pathology after RARP. Lower quartile prostate-specific antigen density （PSAD） was associated with favorable pathology compared to the highest quartile PSAD after adjusting for preoperative PSA, clinical stage and biopsy Gleason score （odds ratio, 5.42; 95% confidence interval, 1.01-28.97; P = 0.048）. During a median 37.8 （interquartile range, 24.6-60.2） months of follow-up, 66 patients experienced BCR. There were significant differences with regard to BCR free survival by PSAD quartiles （log rank, P = 0.003）. Using a multivariable Cox proportion hazard model, PSAD was found to be an independent predictor of BCR in patients with IRPCa after RARP （hazard ratio, 4.641; 95% confidence interval, 1.109-19.417; P = 0.036）. The incorporation of the PSAD into risk assessments might provide additional prognostic information and identify some patients in whom active surveillance would be appropriate in patients with IRPCa. 展开更多
关键词 biochemical recurrence prostatectomy prostate-specific antigen prostate-specific antigen density prostatic neoplasms
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Specific Heat and Charge Density of Quasi-One-Dimensional Interchain Coupling Organic Ferromagnets 认领 引用 被引量：2
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作者 WANG Zhong-Long YAO Kai-Lun 《Communications in Theoretical Physics》 SCIE CAS 2008年第12期1435-1438,共4页
On the basis of a generalized SSH model, an organic polymer ferromagnet theory is proposed at the finite temperature in the self-consistent mean field approximation, and the specific heat and charge density of the qua... On the basis of a generalized SSH model, an organic polymer ferromagnet theory is proposed at the finite temperature in the self-consistent mean field approximation, and the specific heat and charge density of the quasione-dimensional interehain coupling organic ferromagnets are presented. We find that an obvious feature is to present itself the round peak for the specific heat with the temperature. This indicates unambiguously the presence of the phase transition in the system. The transition temperature plays down with increasing of the interchain coupling t2 or decreasing of the electron repulsion u. The curves of charge density with the temperature debase monotonously. This result illustrates that the higher the temperature is, the more electrons are excited. 展开更多
关键词 specific heat charge density organic ferromagnets
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Wood specific gravity of some tree species in the Garhwal Himalayas, India 认领 引用 被引量：2
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作者 Mehraj A.SHEIKH Munesh KUMAR Jahangeer A.BHAT 《Forestry Studies in China》 2011年第3期225-230,共6页
Estimation of terrestrial biomass depends critically on reliable information about wood specific gravity of forest trees. In recent years, wood specific gravity has become more important when exploring the universalit... Estimation of terrestrial biomass depends critically on reliable information about wood specific gravity of forest trees. In recent years, wood specific gravity has become more important when exploring the universality of functional traits of plants and estimating their global carbon stocks. To estimate their specific gravity, wood samples were collected from a total of 34 tree species, 30 from lower elevations and 4 from upper elevations in the Garhwal Himalayas, India. The results show that the average wood specific gravity was 0.631 （ranging between 0.275 ± 0.01 and 0.845 ± 0.03） for the species at lower elevations and 0.727 （ranging between 0.628 ± 0.02 and 0.865 ± 0.02） for the upper elevations. The average wood specific gravity for the upper elevation species was 9.6% greater than that for the species at lower elevations. Aegle marmelos among the lower elevation species and Quercus leucotrichophora among the upper elevation species had the highest wood specific gravity, which were 0.845 ± 0.03 and 0.865 ± 0.02, respectively. 展开更多
关键词 specific gravity biomass elevation
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Effi cient modeling of the gravity anomaly caused by a sedimentary basin with lateral variable density contrast and its application in basement relief estimation 认领 引用 被引量：1
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作者 Feng Xu-Liang Liu Sheng-Rong Shen Hong-Yan 《Applied Geophysics》 SCIE CSCD 2021年第2期145-158,272,共14页
The forward calculation of gravity anomalies is a non-negligible aspect contributing to the time consumption of the entire process of basement relief estimation.In this study,we develop a fast hybrid computing scheme ... The forward calculation of gravity anomalies is a non-negligible aspect contributing to the time consumption of the entire process of basement relief estimation.In this study,we develop a fast hybrid computing scheme to compute the gravity anomaly of a basement.We use the vertical prism source equation in a given region R centered at a certain gravity observation point and the vertical line source equation outside R to derive the gravity anomaly.We observe that the computation with the vertical line source equation is much faster than that of the vertical prism source equation,but the former is slightly inaccurate.Therefore,our method is highly effi cient and able to avoid the errors caused by the low accuracy of the vertical line source equation near the observation point.We then derive the general principle of choosing the size of R via a series of prism model tests.Our tests on the gravity anomaly over the Los Angeles Basin confirm the correctness of our proposed forward strategy.We modify Bott’s method with an accelerating factor to expedite the inversion procedure and presume that the density contrast between the sediments and the basement in a sedimentary basin varies laterally and can be obtained using the equivalent equation.Synthetic data and real data applications in the Weihe Basin illustrate that our proposed method can accurately and effi ciently estimate the basement relief of sedimentary basins. 展开更多
关键词 gravity anomaly basement relief fast forward inversion lateral variable density contrast
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Gravity effect calculation of threedimensional linear density distribution andits application 认领 引用 被引量：1
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作者 楼海 王椿镛 《Acta Seismologica Sinica(English Edition)》 1999年第3期327-334,共8页
An algorithm for calculating gravity effect of three-dimensional (3D) linear density distribution is presented in this paper. The linear continuous density distribution is represented with 3D grid model, which has a r... An algorithm for calculating gravity effect of three-dimensional (3D) linear density distribution is presented in this paper. The linear continuous density distribution is represented with 3D grid model, which has a resemblance to the velocity model used in some seismic tomography codes. The consensus in representation method of density model and velocity model facilitates the seismic-gravity-integrated interpretation or simultaneous inversion. The numerical test of synthetic data shows that although the analytical gravity formula for linear density distribution is more complex than that for piecewise constant density distribution, it takes less time to calculate the gravity effect with linear density model than that with piecewise constant density model. In addition, this method is used in the integrated interpretation of 3D seismological tomography and gravity data in Dabie Mountain area. 展开更多
关键词 three-dimensional linear density distribution analytical gravity formula seismic-gravityintegrated interpretation
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Theoretical study on separation density of gravity beneficiation 认领 引用
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作者 JIAO Hong-guang ZHAO Xiao-nan ZHAO Yue-min 《Journal of Coal Science & Engineering(China)》 2010年第2期193-197,共5页
Separation density is one of the most concerned operating parameters in gravity beneficiation.Although equal-errors cut point or distribution density is usually used as practical separation density in gravity benefici... Separation density is one of the most concerned operating parameters in gravity beneficiation.Although equal-errors cut point or distribution density is usually used as practical separation density in gravity beneficiation, the gravity separating process complexly affected by many kinds of factors is actually carried out at a fluctuant density; namely, the practical separation density is essentially a random variable.The studied results show that the equal-errors cut point is the mathematical expectation of this random variable, and the distribution density corresponds to the highest separation efficiency in the gravity separation process.This shows that the distribution density is the best working point of the gravity separation equipment under a particular operating condition.Therefore,in order to fully develop the function of the gravity separation equipment, the distribution density should be close to the theoretical separation density unlimitedly in the range of minimum fluctuation. 展开更多
关键词 separation density gravity beneficiation equal-errors cut point distribution density random variable
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Three-Dimensional Density Structure of the Pamir Plateau and Adjacent Regions:Implications for Deep Tectonics,Dynamics,and Metallogeny 认领 引用
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作者 YAN Jiayong LUO Fan +5 位作者 LIANG Feng XIAO Hong CHEN Changxin LI Wuyang YOU Yuexin WANG Xiaojuan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2025年第6期1544-1555,共12页
The Pamir Plateau,located in the western syntaxis of the Tibetan Plateau,is a critical region for understanding continental collision dynamics and associated metallogenic processes.First,on the basis of the spherical ... The Pamir Plateau,located in the western syntaxis of the Tibetan Plateau,is a critical region for understanding continental collision dynamics and associated metallogenic processes.First,on the basis of the spherical coordinate system,Bouguer gravity anomalies were derived from satellite gravity data covering the Pamir Plateau and adjacent regions.A three-dimensional density structure model spanning crustal to upper mantle depths(0-200 km)was subsequently inverted through an advanced three-dimensional physical property inversion methodology.Finally,the depth of the Moho surface in the study area was calculated using an interface inversion method with variable density,which was improved on the basis of the Parker-Oldenburg formula.Our results reveal significant lateral density variations:Moho depths exhibit a mirror-image relationship with surface topography,and steep Moho gradients align with major tectonic boundaries,indicating deep structural controls on crustal thickening and plateau uplift.The Pamir uplift was driven by crustal thickening,mantle upwelling following slab break-off,and erosion-isostatic feedback.Lateral extrusion of Pamir material,constrained by the rigid Tarim Basin,further shapes the plateau's asymmetric topography.High-density anomalies at mid-crustal depths correlate with magmatic intrusions and fault systems,providing pathways for ore-forming fluids.The spatial associations of porphyry Cu-Au and skarn Fe deposits with Moho depth underscore the importance of crust-mantle interactions in mineralization. 展开更多
关键词 3D density structure gravity inversion continental collision Moho Pamir Plateau
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The performance characteristics of prostate-specific antigen and prostate-specific antigen density in Chinese men 认领 引用 被引量：18
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作者 Jeremv YC Teoh Steffi KK Yuen +6 位作者 James HL Tsu Charles KW Wong Brian SH Ho Ada TL Ng Wai-Kit Ma Kwan-Lun Ho Ming-Kwong Yiu 《Asian Journal of Andrology》 SCIE CAS CSCD 2017年第1期113-116,共4页
We investigated the performance characteristics of prostate-specific antigen （PSA） and PSA density （PSAD） in Chinese men. All Chinese men who underwent transrectal ultrasound-guided prostate biopsy （TRUS-PB） fro... We investigated the performance characteristics of prostate-specific antigen （PSA） and PSA density （PSAD） in Chinese men. All Chinese men who underwent transrectal ultrasound-guided prostate biopsy （TRUS-PB） from year 2000 to 2013 were included. The receiver operating characteristic （ROC） curves for both PSA and PSAD were analyzed. The sensitivity, specificity, positive predictive value （PPV） and negative predictive value （NPV） at different cut-off levels were calculated. A total of 2606 Chinese men were included. For the ROC, the area under curve was 0.770 for PSA （P〈 0.001） and 0.823 for PSAD （P〈 0.001）. PSA of 4.5 ng ml^-1 had sensitivity of 94.4%, specificity of 14.1%, PPV of 29.5%, and NPV of 86.9%; PSAD of 0.12 ng ml^-1cc^-1 had sensitivity of 94.5%, specificity of 26.6%, PPV of 32.8%, and NPV of 92.7%. On multivariate logistic regression analyses, PSA cut-off at 4.5 ng ml^-1 （OR 1.61, 95% CI 1.05-2.45, P = 0.029） and PSAD cut-off at 0.12 ng ml^-1 cc^-1 （OR 6.22, 95% CI 4.20-9.22, P 〈 0.001） were significant predictors for prostate cancer detection on TRUS-PB. In conclusion, the performances of PSA and PSAD at different cut-off levels in Chinese men were very different from those in Caucasians. PSA of 4.5 ng ml^-1 and PSAD of O. 12 ng ml^-1 cc^-1 had near 95% sensitivity and were significant predictors of prostate cancer detection in Chinese men. 展开更多
关键词 Chinese prostate cancer transrectal ultrasound-guided prostate biopsy prostate-specific antigen prostate-specific antigen density
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Forest aboveground biomass estimates in a tropical rainforest in Madagascar:new insights from the use of wood specific gravity data 认领 引用 被引量：2
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作者 Tahiana Ramananantoandro Herimanitra P.Rafidimanantsoa Miora F.Ramanakoto 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第1期47-55,共9页
To generate carbon credits under the Reducing Emissions from Deforestation and forest Degradation program(REDD+),accurate estimates of forest carbon stocks are needed.Carbon accounting efforts have focused on carbon s... To generate carbon credits under the Reducing Emissions from Deforestation and forest Degradation program(REDD+),accurate estimates of forest carbon stocks are needed.Carbon accounting efforts have focused on carbon stocks in aboveground biomass(AGB).Although wood specific gravity(WSG)is known to be an important variable in AGB estimates,there is currently a lack of data on WSG for Malagasy tree species.This study aimed to determine whether estimates of carbon stocks calculated from literature-based WSG values differed from those based on WSG values measured on wood core samples.Carbon stocks in forest biomass were assessed using two WSG data sets:(i)values measured from 303 wood core samples extracted in the study area,(ii)values derived from international databases.Results suggested that there is difference between the field and literaturebased WSG at the 0.05 level.The latter data set was on average 16%higher than the former.However,carbon stocks calculated from the two data sets did not differ significantly at the 0.05 level.Such findings could be attributed to the form of the allometric equation used which gives more weight to tree diameter and tree height than to WSG.The choice of dataset should depend on the level of accuracy(Tier II or III)desired by REDD+.As higher levels of accuracy are rewarded by higher prices,speciesspecific WSG data would be highly desirable. 展开更多
关键词 Biomass estimates Carbon stocks Data quality Madagascar REDD+ Wood specific gravity
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Quasiparticle density of states of 2H-NbSe_2 single crystals revealed by low-temperature specific heat measurements according to a two-component model 认领 引用 被引量：1
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作者 闫静 单磊 +2 位作者 王越 肖志力 闻海虎 《Chinese Physics B》 SCIE EI CAS 2008年第6期2229-2235,共7页
Low-temperature specific heat in a dichalcogenide superconductor 2H-NbSe2 is measured in various magnetic fields. It is found that the specific heat can be described very well by a simple model concerning two componen... Low-temperature specific heat in a dichalcogenide superconductor 2H-NbSe2 is measured in various magnetic fields. It is found that the specific heat can be described very well by a simple model concerning two components corresponding to vortex normal core and ambient superconducting region, separately. For calculating the specific heat outside the vortex core region, we use the Bardeen-Cooper Schrieffer （BCS） formalism under the assumption of a narrow distribution of the superconducting gaps. The field-dependent vortex core size in the mixed state of 2H-NbSe2, determined by using this model, can explain the nonlinear field dependence of specific heat coefficient γ（H）, which is in good agreement with the previous experimental results and more formal calculations. With the high-temperature specific heat data, we can find that, in the multi-band superconductor 2H-NbSe2, the recovered density of states （or Fermi surface） below Tc under a magnetic field seems not to be gapped again by the charge density wave （CDW） gap, which suggests that the superconducting gap and the CDW gap may open on different Fermi surface sheets. 展开更多
关键词 2H-NbSe2 charge density wave superconductivity specific heat
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Variations in wood anatomical properties and specific gravity of half sib progenies of Populus deltoides 认领 引用
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作者 P.K.Pande R.C.Dhiman 《Journal of Forestry Research》 CAS CSCD 2012年第3期491-496,共6页
We studied radial and inter-progeny variations in the dimen- sions of the wood elements and specific gravity of 21 half sib progenies of Populus deltoides Bartr. ex Marsh. The female parents of half sib progenies were... We studied radial and inter-progeny variations in the dimen- sions of the wood elements and specific gravity of 21 half sib progenies of Populus deltoides Bartr. ex Marsh. The female parents of half sib progenies were G48 and $7C13 clones. Variance ratio （F） test indicated that inter-progeny variations in the dimensions of wood elements and specific gravity were significant for all wood traits while variations were significant for radial location for specific gravity only. Hierarchical clus- ter analysis was done by Squared Euclidean Distance for all of 21 proge- nies considering six wood traits. 21 progenies were grouped into 4 clus- ters. Cluster 1 was the largest cluster with 11 progenies, whereas cluster 3 had only one progeny. Selected progenies in clusters 3 （progeny 155, male） and 4 （progeny 108, 196, both female） were highly divergent from the other progenies so they were used in combinations as parents of hybrids to develop new clones with desired characters. Progeny 155 showed higher growth, fiber dimensions, and specific gravity, thus, should be used for the development of new clones. 展开更多
关键词 Fiber length specific gravity vessel element length wall thickness wood variations
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Theoretical simulation of the effect of deformation on local gravity in a density gradient zone 认领 引用 被引量：1
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作者 Zhu Liangyu Wang Qingliang Zhu Yiqing 《Geodesy and Geodynamics》 2013年第4期9-16,共8页
We modeled the effect of the deformation of a Density Gradient Zone （DGZ） on a local gravity field using a cubical model and introduced a new method to simulate a complex DGZ （CDGZ）. Then, we analyzed the features... We modeled the effect of the deformation of a Density Gradient Zone （DGZ） on a local gravity field using a cubical model and introduced a new method to simulate a complex DGZ （CDGZ）. Then, we analyzed the features of the model for the influence of the deformation of the DGZ on the local gravity field. We concluded that land-based gravity is not sensitive to the thickness of the DGZ and that the magnitude of the contribution of the DGZ is one order less than that of the volume strain with the same displacement. 展开更多
关键词 Density Gradient Zone （DGZ） density interface cubical model vertical deformation gravity anomaly
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