期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到5,830篇文章
< 1 2 … 250 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
Investigation and application of diffusive gradients in thin films for in situ monitoring of pharmaceuticals in surface water during rainfall events 认领 引用
1
作者 Hongmei Cao Qingshan Li +2 位作者 Qingwei Bu Lei Yang Jianfeng Tang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第6期382-393,共12页
Pharmaceutically active compounds have garnered increased attention as emerging contaminants due to their widespread presence and potential ecological impacts.This study conducted a field evaluation under varied rainf... Pharmaceutically active compounds have garnered increased attention as emerging contaminants due to their widespread presence and potential ecological impacts.This study conducted a field evaluation under varied rainfall conditions,assessing the effects of rainfall intensity and duration on pharmaceutical concentrations.Grab sampling was complemented by the deployment of diffusive gradients in thin films(DGT)passive samplers along two urban rivers in Beijing,China.Twenty-four target pharmaceuticals were detected,with concentrations ranging from 370 to 686 ng/L in the Beixiao River and 376 to 610 ng/L in the Qing River.Rainfall influenced pharmaceutical concentrations through either dilution or enhancement,depending on local factors.Rainfall had a minimal impact on DGT performance,while biofouling showed compound-specific effects.For about 70%of the pharmaceuticals,hydrophilic poly tetrafluoroethylene(PTFE)membranes used over 9–15 days effectively minimized biofouling influence(Mbiofouled/Mclean>0.8).The effectiveness of DGT for long-term monitoring depended on the biofilm formation time.Overall,DGT proved to be a reliable tool for accurately characterizing pharmaceutical concentrations in dynamic water systems.This study represents the first attempt to evaluate DGT performance for pharmaceuticals under fluctuating concentration scenarios in the field,providing valuable insights into the occurrence and environmental behavior of these contaminants. 展开更多
关键词 Pharmaceuticals Diffusive gradients in thin films(DGT) Rainfall event Passive sampling Biofouling
暂未订购 下载PDF
Effects of soil aging on distribution and desorption kinetics of per-and polyfluoroalkyl substances by diffusive gradients in thin films 认领 引用
2
作者 Xinting Zhao Qinghua Zhou +3 位作者 Jiaxing Xie Xin He Yan Wang Feng Tan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第5期262-271,共10页
Soil aging is recognized to influence the soil-water partitioning behavior of organic pollutants,altering their mobility and bioavailability.However,the specific impacts of soil aging on the desorption behavior of per... Soil aging is recognized to influence the soil-water partitioning behavior of organic pollutants,altering their mobility and bioavailability.However,the specific impacts of soil aging on the desorption behavior of per-and polyfluoroalkyl substances(PFAS)from the solid phase require further investigation.This study investigated the impact of soil aging on the distribution and desorption kinetics of eleven legacy and emerging PFAS in agricultural soils,using the diffusive gradients in thin films(DGT)technique.The results demonstrate that soil aging strengthened interactions between PFAS and soil particles,simultaneously reducing concentrations in both the soil solution and solid phase compartments.Additionally,high organic matter content facilitated PFAS sequestration.The nonlinear increase in PFAS mass accumulated by DGT device suggested that the consumption of PFAS at the DGT surface was partially offset by the resupply of labile PFAS from the solid phase.Modeling with the DGT-induced fluxes in soil model indicated that the labile pool size decreased following soil aging,with values ranging from 0.11 to 168 mL/g after 14 days and from 0.34 to 83 mL/g after 120 days.Overall,this study demonstrates that soil aging reduced PFAS concentration in the soil solution while also decreasing the labile pool size.These findings are significant for assessing PFAS transfer,fate,bioavailability,and potential risks to ecosystems and human health. 展开更多
关键词 Soil aging Per-and polyfluoroalkyl substances Desorption kinetics Diffusive gradients in thin films DGT-induced fluxes in soil
暂未订购 下载PDF
Mathematical and Computer Modeling of Electroosmotic Peristaltic Transport of a Biofluid with Double-Diffusive Convection and Thermal Radiation 认领 引用
3
作者 Yasir Khan Arshad Riaz +3 位作者 Iqra Batool Safia Akram A.Alameer Ghaliah Alhamzi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第3期692-717,共26页
Tangent hyperbolic fluids characterized by shear-thinning behavior,are widely utilized in diverse industrial and scientific fields such as polymer engineering,inkjet printing,biofluids modeling,thermal insulation mate... Tangent hyperbolic fluids characterized by shear-thinning behavior,are widely utilized in diverse industrial and scientific fields such as polymer engineering,inkjet printing,biofluids modeling,thermal insulation materials,and chemical manufacturing.Additionally,double-diffusive convection involving simultaneous heat and mass transfer driven by temperature and concentration gradients plays a critical role in many natural and industrial systems,including oceanic circulation,geothermal energy extraction,crystal solidification,alloy formation,and enhanced oil recovery.The current work examines the peristaltic transport of a tangent hyperbolic nanofluid under the concurrent effects of thermal radiation,electroosmotic forces,slip boundary conditions,and double diffusion.The governing nonlinear equations are numerically solved using Mathematica’s NDSolve command after being simplified under the presumptions of a long wavelength,a low Reynolds number,and Debye-Huckel linearization.The analysis reveals that a rise in the velocity slip parameter decreases the core fluid velocity but increases it closer to channel walls,while increased solutal Grashof number and electroosmotic parameter result in non-uniform velocity distributions,reducing the flow towards the left wall and increasing it towards the right.The pressure gradient increases with higher electroosmotic effects and Helmholtz-Smoluchowski velocity,but decreases under more intense thermal radiation and increased Prandtl number.The magnetic field increases pressure in the retrograde area and moves the enhanced zone towards the right wall,emphasizing increased flow resistance.Also,the trapping effects intensify with increasing solutal Grashof number and Helmholtz-Smoluchowski velocity,providing better particle transport and mixing in microfluidic devices. 展开更多
关键词 Tangent hyperbolic fluid double diffusion convection thermal radiation electro-osmotic flow slip effect peristaltic flow viscous dissipation asymmetric channel
暂未订购 下载PDF
Pattern Optimization of Fractional Diffusive Schnakenberg System by PD Control Strategy 认领 引用
4
作者 Shunke Dong Min Xiao +3 位作者 Zhengxin Wang Wenwu Yu Weixing Zheng Leszek Rutkowski 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第2期451-462,共12页
Reaction-diffusion systems are widely used to describe pattern formation,and various control strategies have been applied to reaction-diffusion systems to achieve control objectives such as boundary control,output fee... Reaction-diffusion systems are widely used to describe pattern formation,and various control strategies have been applied to reaction-diffusion systems to achieve control objectives such as boundary control,output feedback stabilization,and synchronization.However,controlling pattern dynamics in reaction-diffusion systems with fractional-order diffusion remains an unresolved problem.This paper presents a proportional-derivative(PD)control strategy for the Schnakenberg system with fractional-order diffusion and cross-diffusion.Theoretical analysis explores the amplitude equation near the Turing bifurcation threshold,determining the selection and stability of pattern formations.Numerical simulations demonstrate that the PD controller accomplishes the modification of pattern structures and suppression of Turing instability by adjusting only two control parameters.Additionally,it is found that for smaller fractional diffusion order,the region can accommodate more hexagonal and stripe patterns in space.This work contributes to the control of complex pattern dynamics and offers a new approach to enhancing stability in fractional reaction-diffusion systems. 展开更多
关键词 Cross-diffusion fractional-order diffusion PD control strategy schnakenberg system turing instability
暂未订购 下载PDF
Emulation of short-term and long-term synaptic plasticity with high uniformity in chalcogenide-based diffusive memristor device for neuromorphic applications 认领 引用
5
作者 Haider Abbas Jiayi Li +3 位作者 Asif Ali Sajjad Hussain Jongwan Jung Diing Shenp Ang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2025年第13期99-107,共9页
Emerging bio-inspired computing systems simulate the cognitive functions of the brain for the realiza-tion of future computing systems.For the development of such efficient neuromorphic electronics,the emulation of sh... Emerging bio-inspired computing systems simulate the cognitive functions of the brain for the realiza-tion of future computing systems.For the development of such efficient neuromorphic electronics,the emulation of short-term and long-term synaptic plasticity behaviors of the biological synapses is an es-sential step.However,the electronic synaptic devices suffer from higher variability issues which hinder the application of such devices to build neuromorphic systems.For practical applications,it is essen-tial to minimize the cycle-to-cycle and device-to-device variations in the synaptic functions of artifi-cial electronic synapses.This study involves the fabrication of diffusive memristor devices using WTe2 chalcogenide as the main switching material.The choice of the switching material provides a facile so-lution to the variability problem.The greater uniformity in the switching characteristics of the WTe2-based memristor offers higher uniformity for the synaptic emulation.These devices exhibit both volatile and nonvolatile switching properties,allowing them to emulate both short-term and long-term synaptic functions.The WTe2-based electronic synaptic devices present a high degree of uniformity for the emula-tion of various essential biological synaptic functions including short-term potentiation(STP),long-term potentiation(LTP),long-term depression(LTD),spike-rate-dependent plasticity(SRDP),and spike-timing-dependent plasticity(STDP).A higher recognition accuracy of∼92%is attained for pattern recognition using the modified National Institute of Standards and Technology(MNIST)handwritten digits,which is attributed to the enhanced linearity and higher uniformity of LTP/LTD characteristics. 展开更多
关键词 Diffusive memristor Chalcogenide switching layer WTe2 Uniformity Neuromorphic computing
暂未订购 下载PDF
Quantification of the Kinetics of Soil Selenium Diffusive Gradients in Thin-Films Process under Long-Term Moisture Changes 认领 引用
6
作者 Yu Zhang Xinghan Wang +4 位作者 Yanan Liu Yankui Chen Luxuan Zhang Yuxin Zhang Yu Zhang 《Journal of Environmental & Earth Sciences》 CAS 2025年第4期266-279,共14页
The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is... The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is still unclear.Based on the DGT(Diffusive Gradients in Thin-films)technology,this study sets up three moisture control scenarios:continuous wet,wet-dry alternating,and continuous dry,and carries out a 6-month soil moisture control experiment.In the experiment,the DGT device collected the diffusion gradient data of soil selenium under different scenarios,and analyzed the migration characteristics of selenium in combination with the adsorption isotherm.Meanwhile,the release rate,migration coefficient,and bioavailability parameters of selenium are calculated by fitting the first-order kinetic model,further verifying the reliability and applicability of the DGT data.The experimental results demonstrate that under continuous wet conditions,the release rate of soil selenium reaches 1.85µg·cm-2·h-1,with a migration coefficient of 0.012 cm2·h-1and a bioavailability parameter of 0.74;under wet-dry alternating conditions,they are 1.42µg·cm-2·h-1,0.01 cm2·h-1,and 0.68,respectively;under continuous dry conditions,the release rate of soil selenium is the smallest,at 0.88µg·cm-2·h-1,with a migration coefficient of 0.004 cm-2·h-1and a bioavailability parameter of 0.5.The results of this experiment reveal the dynamic behavior of soil selenium under different moisture conditions and reflect the high efficiency of DGT technology in dynamic monitoring and quantitative analysis of soil selenium behavior,providing a scientific basis for the optimal management of rhizosphere soil selenium. 展开更多
关键词 Soil Selenium Dynamics Moisture Regulation Effects Diffusive Gradients in Thin-Films Selenium Bioavail-ability Analysis Kinetic Analysis
暂未订购 下载PDF
Diffusive Transfer between a Droplet and an Immiscible Oscillating Liquid in a Radial Hele-Shaw Cell 认领 引用
7
作者 Ivan Karpunin Denis Polezhaev 《Fluid Dynamics & Materials Processing》 EI 2025年第3期543-553,共11页
An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetricHele-Shaw cell is carried out.Theliquid oscillates radially in the cell.Thetransv... An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetricHele-Shaw cell is carried out.Theliquid oscillates radially in the cell.Thetransverse size of the droplet exceeds the cell thickness.The viscosities of the droplet and the surrounding liquid are comparable.Relevant effort is provided to design and test an experimental setup and validate a protocol for determining the mass transfer rate of a solute in a two-liquid system.In particular,fluorescent dye Rhodamine B is considered as the solute.A critical comparison of the situations with and without oscillation is implemented.A procedure is introduced and validated to determine the molecular and effective diffusion coefficients through evaluation of the growth of the diffusion zone width over time.It is shown that,in the presence of the liquid oscillations,there is a significant increase in the width of the zone in which Rhodamine B is present compared to the reference case with no oscillations.The oscillatory flow leads to an intensification of the solute diffusion due to intense time-averaged flows inside the droplet and the surrounding liquid and oscillations of the drop itself.Thestudy is of significant practical interest with particular relevance to typical processes for liquid-liquid extraction. 展开更多
关键词 Oscillations droplet viscosity diffusion Rhodamine B fluorescence radial Hele-Shaw cell
暂未订购 下载PDF
Patterns and drivers of CH4 concentration and diffusive flux from a temperate river–reservoir system in North China 认领 引用 被引量：8
8
作者 Fanyan Yang Jicheng Zhong +6 位作者 Shaoming Wang Xiaokang Hu Hongwei Wang Mengyao Tang Min Zhang Chuanzhe Sun Lei Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第6期184-197,共14页
Freshwater reservoirs are regarded as an important anthropogenic source of methane(CH4)emissions. The temporal and spatial variability of CH4 emissions from different reservoirs results in uncertainty in the est... Freshwater reservoirs are regarded as an important anthropogenic source of methane(CH4)emissions. The temporal and spatial variability of CH4 emissions from different reservoirs results in uncertainty in the estimation of the global CH4 budget. In this study, surface water CH4 concentrations were measured and diffusive CH4 fluxes were estimated via a thin boundary layer model in a temperate river–reservoir system in North China, using spatial(33 sites) and temporal(four seasons) monitoring;the system has experienced intensive aquaculture disturbance. Our results indicated that the dissolved CH4 concentration in the reservoir ranged from 0.07 to 0.58 μmol/L, with an annual average of 0.13 ± 0.10 μmol/L, and the diffusive CH4 flux across the water–air interface ranged from 0.66 to 3.61 μmol/(m2·hr),with an annual average of 1.67 ± 0.75 μmol/(m2·hr). During the study period, the dissolved CH4 concentration was supersaturated and was a net source of atmospheric CH4 . Notably,CH4 concentration and diffusive flux portrayed large temporal and spatial heterogeneity.The river inflow zone was determined to be a hotspot for CH4 emissions, and its flux was significantly higher than that of the tributary and main basin;the CH4 flux in autumn was greater than that in other seasons. We also deduced that the CH4 concentration/diffusive flux was co-regulated mainly by water temperature, water depth, and water productivity(Chla, trophic status). Our results highlight the importance of considering the spatiotemporal variability of diffusive CH4 flux from temperate reservoirs to estimate the CH4 budget at regional and global scales. 展开更多
关键词 River–reservoir system Greenhouse gas Methane(CH4) Temperate zone Diffusive flux
暂未订购 下载PDF
New approach for deriving the exact time evolution of the density operator for a diffusive anharmonic oscillator and its Wigner distribution function 认领 引用 被引量：4
9
作者 孟祥国 王继锁 梁宝龙 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期146-151,共6页
Using thermal entangled state representation,we solve the master equation of a diffusive anharmonic oscillator（AHO） to obtain the exact time evolution formula for the density operator in the infinitive operator-sum ... Using thermal entangled state representation,we solve the master equation of a diffusive anharmonic oscillator（AHO） to obtain the exact time evolution formula for the density operator in the infinitive operator-sum representation.We present a new evolution formula of the Wigner function（WF） for any initial state of the diffusive AHO by converting the WF calculation into an overlap between two pure states in an enlarged Fock space.It is found that this formula is very convenient in investigating the WF＇s evolution of any known initial state.As applications,this formula is used to obtain the evolution of the WF for a coherent state and the evolution of the photon-number distribution of diffusive AHOs. 展开更多
关键词 diffusive anharmonic oscillator thermal entangled state representation infinitive operator-sum representation Wigner function
暂未订购 下载PDF
Structure and properties of diffusive titanium nitride layers produced by hybrid method on AZ91D magnesium alloy 认领 引用 被引量：2
10
作者 Michal TACIKOWSKI Jerzy MORGIEL +2 位作者 Monika BANASZEK Konrad CYMERMAN Tadeusz WIERZCHON 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第9期2767-2775,共9页
A diffusive titanium nitride layers were produced on AZ91 D magnesium alloy by a hybrid method which combines the titanium coating physical vapor deposition（PVD） with subsequent nitriding. The layers are composed of... A diffusive titanium nitride layers were produced on AZ91 D magnesium alloy by a hybrid method which combines the titanium coating physical vapor deposition（PVD） with subsequent nitriding. The layers are composed of a thin surface zone of titanium nitrides and oxides, an intermediate titanium zone and Ti-Al-Mg type diffusive zone. Since the layers improve the corrosion resistance, the best corrosion resistance is obtained when the layers are produced on aluminum base sub-layer by oxynitriding. 展开更多
关键词 magnesium alloys titanium nitride diffusive layers hybrid method
暂未订购 下载PDF
Determination of Ni2+ in Waters with Sodium Polyacrylate as a Binding Phase in Diffusive Gradients in Thin-films 认领 引用 被引量：2
11
作者 CHEN Hong DONG Jia +1 位作者 NIU Yong-xin SUN Ting 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2011年第4期703-707,共5页
An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four ty... An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated. 展开更多
关键词 Diffusive gradient in thin-film Sodium polyacrylate Binding agent Ni2＋
暂未订购 下载PDF
Partially Diffusive Helium-Silica Compound under High Pressure 认领 引用 被引量：2
12
作者 Cong Liu Junjie Wang +7 位作者 Xin Deng Xiaomeng Wang Chris J.Pickard Ravit Helled Zhongqing Wu Hui-Tian Wang Dingyu Xing Jian Sun 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第7期52-57,共6页
Helium is the second most abundant element in the universe, and together with silica, they are important components of giant planets. Exploring the reactivity and state of helium and silica under high pressure is cruc... Helium is the second most abundant element in the universe, and together with silica, they are important components of giant planets. Exploring the reactivity and state of helium and silica under high pressure is crucial for understanding of the evolution and internal structure of giant planets. Here, using first-principles calculations and crystal structure predictions, we identify four stable phases of a helium-silica compound with seven/eight-coordinated silicon atoms at pressure of 600–4000 GPa, corresponding to the interior condition of the outer planets in the solar system. The density of He Si O2 agrees with current structure models of the planets.This helium-silica compound exhibits a superionic-like helium diffusive state under the high-pressure and hightemperature conditions along the isentropes of Saturn, a metallic fluid state in Jupiter, and a solid state in the deep interiors of Uranus and Neptune. These results show that helium may affect the erosion of the rocky core in giant planets and may help to form a diluted core region, which not only highlight the reactivity of helium under high pressure but also provide evidence helpful for building more sophisticated interior models of giant planets. 展开更多
关键词 red Partially Diffusive Helium-Silica Compound under High Pressure
暂未订购 下载PDF
Double diffusive convection in the finger regime for different Prandtl and Schmidt numbers 认领 引用 被引量：5
13
作者 Yantao Yang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2020年第4期797-804,共8页
In this work fingering double diffusive convection,i.e.the buoyancy-driven flow with fluid density being affected by two different scalar components,is investigated numerically with special efforts on the influences o... In this work fingering double diffusive convection,i.e.the buoyancy-driven flow with fluid density being affected by two different scalar components,is investigated numerically with special efforts on the influences of the physical properties of two scalar components.We show that different scalar properties can affect the global transport behaviors.The concentration flux exhibits different exponents in their power-law scalings for different combinations of scalar components.The scaling exponents of heat flux,however,depend mainly on the ratio of the diffusivities of two scalars.If one uses the local parameters of the finger layer in the bulk,the behaviors are very similar to those found in the fully periodic simulations.The horizontal width of the fingers is consistent with the wavelength of the fast growing mode.For one case we observe evidences of the thermohaline staircase,namely,the typical width of the flow structures changes significantly in different layers within the flow domain. 展开更多
关键词 Double diffusive convection Convection turbulence Hirbulent mixing
暂未订购 下载PDF
Optical solitons supported by finite waveguide lattices with diffusive nonlocal nonlinearity 认领 引用
14
作者 Changming Huang Hanying Deng +4 位作者 Liangwei Dong Ce Shang Bo Zhao Qiangbo Suo Xiaofang Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第12期424-429,共6页
We investigate the properties of fundamental,multi-peak,and multi-peaked twisted solitons in three types of finite waveguide lattices imprinted in photorefractive media with asymmetrical diffusion nonlinearity.Two opp... We investigate the properties of fundamental,multi-peak,and multi-peaked twisted solitons in three types of finite waveguide lattices imprinted in photorefractive media with asymmetrical diffusion nonlinearity.Two opposite soliton selfbending signals are considered for different families of solitons.Power thresholdless fundamental and multi-peaked solitons are stable in the low power region.The existence domain of two-peaked twisted solitons can be changed by the soliton self-bending signals.When solitons tend to self-bend toward the waveguide lattice,stable two-peaked twisted solitons can be found in a larger region in the middle of their existence region.Three-peaked twisted solitons are stable in the lower(upper)cutoff region for a shallow(deep)lattice depth.Our results provide an effective guidance for revealing the soliton characteristics supported by a finite waveguide lattice with diffusive nonlocal nonlinearity. 展开更多
关键词 optical solitons diffusive nonlocal nonlinearity linear stability analysis
暂未订购 下载PDF
Diffusive healing of internal fatigue micro-cracks in pure titanium 认领 引用 被引量：1
15
作者 杨君刚 孙军 张海龙 《中国有色金属学会会刊：英文版》 2001年第5期675-680,共6页
The internal micro cracks with the critical length about 30?μm and thickness less than 1?μm were introduced into the pure titanium samples by uniaxial tension compression low cycle fatigue method. The experimental r... The internal micro cracks with the critical length about 30?μm and thickness less than 1?μm were introduced into the pure titanium samples by uniaxial tension compression low cycle fatigue method. The experimental results indicate that the internal fatigue micro crack clearly evolves from the original penny shaped crack into a string of spherical voids in the longitudinal section plane of the fatigue sample after the vacuum diffusive healing at the high temperature. The quantitative relationship between the radius and the spacing of spherical voids depends on the crack position (within grains, on grain boundaries or transgranular sites) and its orientations within the grain. The diffusive healing, the related thermodynamics and mechanism, and the effect of the surface tension anisotropy on the relationship between void diameter and void spacing are also discussed. 展开更多
关键词 pure titanium internal fatigue micro crack diffusive healing
暂未订购 下载PDF
Evaluation of Cadmium Bioavailability in Soils Using Diffusive Gradients in Thin Film Technique and Traditional Methods 认领 引用
16
作者 姚羽 孙琴 +4 位作者 陈静 丁士明 刘慧 王超 王沛芳 《Journal of Donghua University(English Edition)》 EI CAS 2015年第3期426-433,共8页
The developed technique of diffusive gradients in thin film( DGT) has been suggested as a promising tool for evaluation of cadmium( Cd) availability in soils,but there exists considerable debate on its suitability. In... The developed technique of diffusive gradients in thin film( DGT) has been suggested as a promising tool for evaluation of cadmium( Cd) availability in soils,but there exists considerable debate on its suitability. In this study,Cd bioavailability in soils was systemically investigated by comparing this technique with seven traditional methods, including soil solution concentration and six commonly used extraction methods( HAc,EDTA,Na c,NH4Ac,CaCl2 and MgCl2). Two typical plants( wheat and maize) were examined for Cd uptake. Maize was more sensitive to increasing exposure to Cd in soils than wheat when the added amounts of Cd ranged from 3. 5 to 5. 0 mg · kg-1,accompanied by the significant decreases of shoot and root biomasses. Cd concentrations in shoots and roots of two plants increased continuously with increasing levels of Cd in soils. Cd uptake was higher in wheat than that in maize. The bioavailable concentrations of Cd measured by all methods increased nearly linearly with increasing addition of Cd in soils. Positive correlations were observed between various bioavailable indicators of Cd in soils and Cd concentrations in two plants. The extractable Cd by six chemical extractants was considerably higher for maize than for wheat,while the DGT-measured and soil solution concentrations of Cd were lower for maize than for wheat,following the same trend as plant Cd uptake. The results imply that DGT measurement can effectively predict the bioavailable levels of Cd in soil solutions and that it is an ideal tool for prediction of Cd bioavailability in soils. 展开更多
关键词 diffusive gradients in thin film(DGT) extraction method soil solution concentration cadmium bioavailability soil plant
暂未订购 下载PDF
Resistance of the diffusive boundary layer to salt release from saline sediments to freshwater 认领 引用
17
作者 GAO Zengwen ZHENG Xilai XU Qinxuan 《Acta Oceanologica Sinica》 SCIE CAS 2008年第1期23-28,共6页
The diffusive boundary layer(DBL)is the zone for matter exchange between surface water and aquatic sediments.To elucidate the influence of DBL on salt release from saline sediments to freshwater,two experiments with o... The diffusive boundary layer(DBL)is the zone for matter exchange between surface water and aquatic sediments.To elucidate the influence of DBL on salt release from saline sediments to freshwater,two experiments with or without wind blowing were conducted.According to the experiments,a 3.5 cm DBL is formed above the smoothed sediments at a steady wind field and this thickness is greater than other studies.The observed flux of salt through the DBL is 6%larger than the calculated value from Fick's first law.The results indicate that molecular diffusion is the dominant mechanism for salt transport through the DBL.The presence of DBL suppresses the hydrodynamic enhancement for matter exchange between sediments and overlying water.Therefore,salts in the sediments of a polder reservoir may influence the water quality chronically. 展开更多
关键词 sediment-water interface diffusive boundary layer molecular diffusion salt transport resistance effect
暂未订购 下载PDF
Wavefront solutions in diffusive Nicholson’s blowflies equation with nonlocal delay 认领 引用
18
作者 张存华 颜向平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第3期385-392,共8页
This paper is concerned with the diffusive Nicholson＇s blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R... This paper is concerned with the diffusive Nicholson＇s blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R. Assume that the delay kernel is a strong generic kernel. By the linear chain techniques and the geometric singular perturbation theory, the existence of travelling front solutions is shown for small delay. 展开更多
关键词 diffusive Nicholson＇s blowflies equation nonlocal delay strong generic kernel travelling wavefront solution
暂未订购 下载PDF
Biased Diffusive Search Triggered by ATP Binding During Kinesin's Stepping 认领 引用
19
作者 王海燕 《Communications in Theoretical Physics》 SCIE CAS 2010年第3期525-528,共4页
In this paper, we present an asymmetry conformational potential with a reflecting boundary and an absorbing boundary, in which the diffusive search of the free head of kinesin motor can be biased toward its forward bi... In this paper, we present an asymmetry conformational potential with a reflecting boundary and an absorbing boundary, in which the diffusive search of the free head of kinesin motor can be biased toward its forward binding site. Under a wide range of condition, using first-passage time analysis we perform numerical simulation to the Langevin equation, and obtain the dependence of the dwell time for forward steps on the load force. And we calculate the expression for the dwell time by the Laplace transform method. Both numerical and analytical results show that the dwell times exponentially depend on the load force, which provide a simple physical explanation for experimental data. Our results suggest that ATP binding-conformation change in the neck linker plays an important role in unidirectional steps during kinesin＇s mechanochemical cycle. 展开更多
关键词 biased diffusive search dwell time mean first passage time
暂未订购 下载PDF
Numerical Simulation of Double Diffusive Mixed Convection in a Horizontal Annulus with Finned Inner Cylinder 认领 引用 被引量：7
20
作者 Cherfi Ryad Sadaoui Djamel +1 位作者 Sahi Adel Mouloud Smail 《Fluid Dynamics & Materials Processing》 EI 2019年第2期153-169,共17页
The present work relates to a numerical investigation of double diffusive mixed convection around a horizontal annulus with a finned inner cylinder.The solutal and thermal buoyancy forces are sustained by maintaining ... The present work relates to a numerical investigation of double diffusive mixed convection around a horizontal annulus with a finned inner cylinder.The solutal and thermal buoyancy forces are sustained by maintaining the inner and outer cylinders at uniform temperatures and concentrations.Buoyancy effects are also considered,with the Boussinesq approximation.The forced convection effect is induced by the outer cylinder rotating with an angular velocity(ω)in an anti-clockwise direction.The studies are made for various combinations of dimensionless numbers;buoyancy ratio number(N),Lewis number(Le),Richardson number(Ri)and Grashof number(Gr).The isotherms,isoconcentrations and streamlines as well as both average and local Nusselt and Sherwood numbers were studied.A finite volume scheme is adopted to solve the transport equations for continuity,momentum,energy and mass transfer.The results indicate that the use of fins on the inner cylinder with outer cylinder rotation,significantly improves the heat and mass transfer in the annulus. 展开更多
关键词 Finned inner cylinder double diffusive flow heat and mass transfer rotating annulus mixed convection numerical simulation
暂未订购 下载PDF
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 250 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈