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Quantitative structure-activity relationship study on the biodegradation of acid dyestuffs

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Journal of Environmental Sciences 2007年第7期19卷 800-804页

作者： li yin XI Dan-li College of Environmental Science and Engineering Dong Hua University Shanghai 201620 China.

Quantitative structure-biodegradability relationships （QSBRs） were established to develop predictive models and mechanistic explanations for acid dyestuffs as well as biological activities. With a total of four descriptors, molecular weight （MW）, energies of the highest occupied molecular orbital （EHOMO）, the lowest unoccupied molecular orbital （ELUMO）, and the excited state （EES）, calculated using quantum chemical semi-empirical methodology, a series of models were analyzed between the dye biodegradability and each descriptor. Results showed that EHOMO and Mw were the dominant parameters controlling the biodegradability of acid dyes. A statistically robust QSBR model was developed for all studied dyes, with the combined application of EHOMO and Mw. The calculated biodegradations fitted well with the experimental data monitored in a facultative-aerobic process, indicative of the reliable prediction and mechanistic character of the developed model.

关键词： quantitative structure-activity relationship (QSAR) acid dyestuff biodegradability decolorization

Influence of Cl substitution on the electronic structure and catalytic activity of ceria

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Science China Chemistry 2015年第4期58卷 601-606页

作者： li-li yin Xue-Qing Gong Key Laboratory for Advanced Materials Centre for Computational Chemistry and Research Institute of Industrial Catalysis East China University of Science and Technology

Cl-containing cerium dioxide(Ce O2) catalysts have been found to exhibit unique catalytic activities. In the present work, using density functional theory calculations with the inclusion of on-site Coulomb correction, we systematically studied the effect of Cl on the physicochemical properties of Ce O2 surfaces by substituting one subsurface O with Cl. The calculated results show that substituting an O atom with a Cl atom results in structural distortion and the reduction of one surface Ce4+ cation to Ce3+. The protruding Ce3+ cation greatly improves the adsorption energy of O2 to produce an active O2- species, and maintains the catalytic oxidation cycle of CO on Ce O2(110). These results may help us obtain a better understanding of Cl-ceria interacting systems and provide some guidance for the design of effective Ce O2-based catalysts.

关键词： cerium dioxide Cl substitution DFT+U O2 adsorption CO oxidation

Effects of Phase Composition on Microstructure and Mechanical Properties of Lu_2O_3-doped Porous Silicon Nitride Ceramics

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Journal of Materials Science & Technology 2011年第6期27卷 529-533页

作者： Quan li Xiaowei yin National Key Laboratory of Thermostructure Composite Materials Northwestern Polytechnical University Xi'an 710072 China

Porous silicon nitride ceramics（Si3N4） were fabricated by pressureless sintering using different particle size of silicon nitride ***2O3 was used as sintering *** to phase relationships in the ternary system Si3N4-SiO2-Lu2O3,porous Si3N4 ceramics with different phase composition were designed through the change of the content of SiO2 which was formed by the oxidation at 800℃ in *** Si3N4 with different phase compositions was obtained after sintering at 1800℃ in N2atmosphere.A small content of SiO2 favored the formation of secondary phase Lu4Si2O7N2,while large content of SiO2 favored the formation of secondary phase Lu2Si2O7 and *** Si3N4 ceramics with secondary phase Lu4Si2O7N2 had a flexural strength of 207 MPa,while that with secondary phase Si2N2O and Lu2Si2O7 had lower flexural strength.

关键词： Porous silicon nitride ceramics Secondary phase SiO2

Searching Activity Tra jectories with Semantics

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Journal of Computer Science & Technology 2019年第4期34卷 775-794页

作者： li-Hua yin Huiwen liu Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou 510006China School of Information System Singapore Management UniversitySingapore 188065Singapore

With the widespread use of smart phones and mobile Internet,social network users have generated massive geo-tagged tweets,photos and videos to form lots of informative trajectories which reveal not only their spatio-temporal dynamics,but also their activities in the physical *** spatial trajectory query studies mainly focus on analyzing the spatio-temporal properties of the users'trajectories,while leaving the understanding of their activities largely *** this paper,we incorporate the semantics of the activity information embedded in trajectories into query modelling and processing,with the aim of providing end users more informative and meaningful *** this end,we propose a novel trajectory query that not only considers the spatio-temporal closeness but also,more importantly,leverages a proven technique in text mining field,probabilistic topic modelling,to capture the semantic relatedness of the activities between the data and *** support efficient query processing,we design a hierarchical grid-based index by integrating the probabilistic topic distribution on the substructures of trajectories and their spatio-temporal extent at the corresponding level of the index *** specialized structure enables a top-down search algorithm to traverse the index while pruning unqualified trajectories in spatial and topical dimensions *** experimental results on real-world datasets demonstrate the good efficiency and scalability performance of the proposed indices and trajectory search methods.

关键词： spatio-temporal database activity trajectory semantic understanding trajectory indexing trajectory query processing

基于密度泛函理论研究Ag-Co团簇的结构、电子和光学性能

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原子与分子物理学报 2025年第2期42卷 63-69页

作者：李维银尚瑞咏王春勇张永莉北方民族大学电气信息工程学院物理与光电信息功能材料重点实验室微电子与固体电子器件研究中心银川750021

基于密度泛函理论研究了7个原子Ag-Co团簇结构的稳定性、电子和光学性能.研究结果表明,7个原子Ag-Co团簇的最稳定结构都是十面体结构,Co原子数量较少时,Co原子主要占据十面体的轴向位,Ag原子主要占据赤道位,随着Co原子数的增加,Co原子... 详细信息

基于密度泛函理论研究了7个原子Ag-Co团簇结构的稳定性、电子和光学性能.研究结果表明,7个原子Ag-Co团簇的最稳定结构都是十面体结构,Co原子数量较少时,Co原子主要占据十面体的轴向位,Ag原子主要占据赤道位,随着Co原子数的增加,Co原子逐渐替换了赤道位上的Ag原子.当Co原子数增加时,Ag-Co团簇的垂直电离势、垂直电子亲能和最高占据轨道与最低未占据轨道之间的能隙整体上都呈现出下降趋势,表明电子稳定性降低;Ag-Co团簇的吸收光谱整体出现了红移,吸收峰的强度逐渐减弱,吸收谱的宽度变窄.

关键词：银钴团簇几何结构电子性能光学性能

Decay rates of higher-order norms of solutions to the Navier-Stokes-Landau-lifshitz system

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Applied Mathematics and Mechanics(English Edition) 2018年第10期39卷 1499-1528页

作者： Ruiying WEI yin li Zheng'an YAO School of Mathematics and Statistics Shaoguan University Department of Mathematics Sun Yat-sen University

In this paper, we investigate a system of the incompressible Navier-Stokes equations coupled with Landau-lifshitz equations in three spatial dimensions. Under the assumption of small initial data, we establish the global solutions with the help of an energy method. Furthermore, we obtain the time decay rates of the higher-order spatial derivatives of the solutions by applying a Fourier splitting method introduced by Schonbek(SCHONBEK, M. E. L2decay for weak solutions of the Navier-Stokes equations. Archive for Rational Mechanics and Analysis, 88, 209–222(1985)) under an additional assumption that the initial perturbation is bounded in L1(R3).

关键词： Navier-Stokes-Landau-lifshitz system Fourier-splitting method decay rate

Size effect on the static behavior of electrostatically actuated microbeams

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Acta Mechanica Sinica 2011年第3期27卷 445-451页

作者： li yin Qin Qian lin Wang Department of Mechanics Huazhong University of Science and Technology 430074 Wuhan China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment 430074 Wuhan China

We present a new analytical model for electrostatically actuated microbeams to explore the size effect by using the modified couple stress theory and the minimum total potential energy principle. A material length scale parameter is introduced to represent the size-dependent characteristics of microbeams. This model also accounts for the nonlinearities associated with the mid-plane stretching force and the electrostatical force. Numerical analysis for microbeams with clamped-clamped and cantilevered conditions has been performed. It is found that the intensity of size effect is closely associated with the thickness of the microbeam,and smaller beam thickness displays stronger size effect and hence yields smaller deffection and larger pull-in voltage. When the beam thickness is comparable to the material length scale parameter,the size effect is significant and the present theoretical model including the material length scale parameter is adequate for predicting the static behavior of microbeam-based MEMS.

关键词： Electrostatically actuated microbeam - Size ef-fect.Deflection. Pull-in voltage . MEMS

Joint study on VMs deployment, assignment and migration in geographically distributed data centers

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Frontiers of Computer Science 2016年第3期10卷 559-573页

作者： Chuang liN Min YAO yin li Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Enterprises build private clouds to provide IT re- sources for geographically distributed subsidiaries or prod- uct divisions. Public cloud providers like Amazon lease their platforms to enterprise users, thus, enterprises can also rent a number of virtual machines （VMs） from their data centers in the service provider networks. Unfortunately, the network cannot always guarantee stable connectivity for their clients to access the VMs or low-latency transfer among data centers. Usually, both latency and bandwidth are in unstable network environment. Being affected by background traffics, the net- work status can be volatile. To reduce the latency uncertainty of client accesses, enterprises should consider the network status when they deploy data centers or rent virtual data cen- ters from cloud providers. In this paper, we first develop a data center deployment and assignment scheme for an enter- prise to meet its users＇ requirements under uncertain network status. To accommodate to the changes of the network status and users＇ demands, a VMs migration-based redeployment scheme is adopted. These two schemes work in a joint way, and lay out a framework to help enterprises make better use of private or public clouds.

关键词： data center deployment VMs migration Min-Max stochastic optimization

Engineering cyanobacteria for fuels and chemicals production

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Protein & Cell 2010年第3期1卷 207-210页

作者： Jie Zhou yin li Institute of Microbiology Chinese Academy of SciencesBeijing 100101China

The world’s energy and global warming crises call for sustainable,renewable,carbon-neutral alternatives to replace fossil fuel ***,most biofuels are produced from agricultural crops and residues,which lead to concerns about food security and land *** to the current biofuel production system,cyanobacteria,as autotrophic prokaryotes,do not require arable land and can grow to high densities by efficiently using solar energy,CO2,water,and inorganic ***,powerful genetic techniques of cyanobacteria have been *** these reasons,cyanobacteria,which carry out oxygenic photosynthesis,are attractive hosts for production of fuels and ***,several chemicals including ethanol,isobutanol and isoprene have been produced by engineered cyanobacteria directly using solar energy,CO2,and *** is therefore a potential novel cell factory for fuels and chemicals production to address global energy security and climate change issues.

关键词： chemicals attractive crops