检索结果-南通市图书馆

Numerical Study of Two Opposing Weak Polyelectrolyte Brushes by the Self-consistent Field Theory

Chinese Journal of Polymer Science 2024年第11期42卷 1668-1678,I0007页

作者： Bei-Ning Wang huan-da ding Zhi-Kuan Chen Chao-Hui Tong Department of Physics Ningbo UniversityNingbo315211China Ningbo Institute of Northwestern Polytechnical University Ningbo315103China

The self-consistent field theory(SCFT)was employed to numerically study the interaction and interpenetration between two opposing weak polyelectrolyte(PE)brushes formed by grafting weak PE chains onto the surfaces of two long and parallel columns with rectangularshaped cross-section immersed in a salty aqueous *** dependences of the brush heights and the average degree of ionization on various system parameters were also *** the brush separation is relatively large compared with the unperturbed brush height,the degree of interpenetration between the two opposing PE brushes was found to increase with increasing grafting density and bulk degree of *** degree of interpenetration also increases with the bulk salt concentration in the osmotic brush *** results further revealed that,at a brush separation comparable to the unperturbed brush height,the degree of interpenetration does not increase further with increasing bulk degree of ionization,bulk salt concentration in the osmotic regime and grafting *** saturation of the degree of interpenetration with these system parameters indicates that the grafted PE chains in the gap between the two columns retract and tilt in order to reduce the unfavorable electrostatic and steric repulsions between the two opposing PE *** on salt ion concentrations at the midpoint between the two opposing brushes,a quantitative criterion in terms of the unperturbed brush height and Debye screening length was established to determine the threshold value of the brush separation beyond which they are truly independent from each other.

关键词： Polyelectrolyte Polymer brush Self-consistent field theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Calculations of Energy-Loss Function for 26 Materials

引用

Chinese Journal of Chemical Physics 2016年第6期29卷 663-670,I0001页

作者： Yang Sun huan Xu Bo da Shi-feng Mao Ze-jun ding HefeiNationalLaboratoryforPhysicalSciencesattheMicroscaleandDepartmentofPhysics UniversityofScienceandTechnologyofChinaHefei230025China

We present a fitting calculation of energy-loss function for 26 bulk materials, including 18 pure elements （Ag, A1, Au, C, Co, Cs, Cu, Er, Fe, Ge, Mg, Mo, Nb, Ni, Pd, Pt, Si, Te） and 8 compounds （AgCl, Al2O3, AlAs, CdS, SiO2, ZnS, ZnSe, ZnTe） for application to surface electron spectroscopy analysis. The experimental energy-loss function, which is derived from measured optical data, is fitted into a finite sum of formula based on the Drude-Lindhard dielectric model. By checking the oscillator strength-sum and perfect- screening-sum rules, we have validated the high accuracy of the fitting results. Further-more, based on the fitted parameters, the simulated reflection electron energy-loss spec- troscopy （REELS） spectrum shows a good agreement with experiment. The calculated fitting parameters of energy loss function are stored in an open and online database at http：//***/ELF/***.

关键词： Energy loss function Dielectric function Optical data

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Weakened carbon and nitrogen metabolisms under post-silking heat stress reduce the yield and dry matter accumulation in waxy maize

引用

Journal of Integrative Agriculture 2020年第1期19卷 78-88页

作者： YANG huan GU Xiao-tian ding Meng-qiu LU Wei-ping LU da-lei Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology/Agricultural College Yangzhou UniversityYangzhou 225009P.R.China Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009P.R.China Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education Yangzhou UniversityYangzhou 225009P.R.China

Post-silking high temperature is one of the abiotic factors that affects waxy maize(Zea mays L. sinensis Kulesh) growth in southern China. We conducted a pot trial in 2016–2017 to study the effects of post-silking daytime heat stress(35°C) on the activities of enzymes involved in leaf carbon and nitrogen metabolisms and leaf reactive oxygen species(ROS) and water contents. This study could improve our understanding on dry matter accumulation and translocation and grain yield production. Results indicated that decreased grain number and weight under heat stress led to yield loss, which decreased by 20.8 and 20.0% in 2016 and 2017, respectively. High temperature reduced post-silking dry matter accumulation(16.1 and 29.5% in 2016 and 2017, respectively) and promoted translocation of pre-silking photoassimilates stored in vegetative organs, especially in leaf. The lower leaf water content and chlorophyll SPAD value, and higher ROS(H2O2 and O2^-·) content under heat stress conditions indicated accelerated senescent rate. The weak activities of phosphoenolpyruvate carboxylase(PEPCase), Ribulose-1,5-bisphosphate carboxylase(Ru BPCase), nitrate reductase(NR), and glutamine synthase(GS) indicated that leaf carbon and nitrogen metabolisms were suppressed when the plants suffered from a high temperature during grain filling. Correlation analysis results indicated that the reduced grain yield was mainly caused by the decreased leaf water content, weakened NR activity, and increased H2O2 content. The increased accumulation of grain weight and post-silking dry matter and the reduced translocation amount in leaf was mainly due to the increased chlorophyll SPAD value and NR activity. Reduced PEPCase and Ru BPCase activities did not affect dry matter accumulation and translocation and grain yield. In conclusion, post-silking heat stress down-regulated the leaf NR and GS activities, increased the leafwater loss rate, increased ROS generation, and induced pre-silking carbohydrate tran

关键词： waxy maize heat stress nitrogen metabolism photosynthetic enzymes senescence dry matter

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cross-coupled controller design for triaxial motion systems based on second-order contour error estimation

引用

Science China(Technological Sciences) 2015年第7期58卷 1209-1217页

作者： ZHAO huan ZHU LiMin ding Han State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

The cross-coupled control(CCC)is widely applied to reduce contour errors in contour-following *** such situation,the contour error estimation plays an important ***,the linear or second-order estimation approach is adopted for biaxial motion systems,whereas only linear approach is available for triaxial *** this paper,the second-order contour error estimation,which was presented in our previous work,is utilized to determine the variable CCC gains for motion control systems with three *** integrated stable motion control strategy,which combines the feedforward,feedback and CCC controllers,is developed for multiaxis CNC *** results on a triaxial platform indicate that the CCC scheme based on the second-order estimation,compared with that based on the linear one,significantly reduces the contour error even in the conditions of high tracking feedrate and small radius of curvature.

关键词： cross-coupled controller contour error cross-coupled gains triaxial motion system computer numerical control (CNC)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulation of Metal Transfer in GMAW Based on FLUENT

引用

Acta Metallurgica Sinica(English Letters) 2013年第3期26卷 265-270页

作者： Xueping ding huan LI Lijun YANG Ying GAO Tianjin Key Laboratory of Advanced Joining Technology Tianjin University Tianjin Key Laboratory of High Speed Cutting and Precision Machining Tianjin University of Technology and Education

A new numerical approach is presented, which is used to simulate the dynamic process of metal transfer. The process of metal transfer in gas metal arc welding is simulated based on FLUENT. A two-dimensional axisymmetric numerical model is developed using volume of fluid method and the distributions of physical quantities including pressure, current density, electric potential in the droplet are investigated. For improving the veracity of the simulated results and decreasing the effect of the uncertain surface tension coefficient on the simulated results, the relationship between the welding current and surface tension coefficient is modified by analysis of regression. Meanwhile for testing the accuracy of simulated results, the welding experiments are performed and the high-speed photography system is used to record the real process of metal transfer. The results show that the simulated results are in reasonably good agreement with the experimental ones.

关键词： Metal transfer FLUENT Dynamic simulation High-speed photography

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development of FPGA Based NURBS Interpolator and Motion Controller with Multiprocessor Technique

引用

Chinese Journal of Mechanical Engineering 2013年第5期26卷 940-947页

作者： ZHAO huan ZHU Limin XIONG Zhenhua ding Han State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University

The high-speed computational performance is gained at the cost of huge hardware resource,which restricts the application of high-accuracy algorithms because of the limited hardware cost in practical *** solve the problem,a novel method for designing the field programmable gate array(FPGA)-based non-uniform rational B-spline(NURBS) interpolator and motion controller,which adopts the embedded multiprocessor technique,is proposed in this *** hardware and software design for the multiprocessor,one of which is for NURBS interpolation and the other for position servo control,is *** analysis and experiments on an X-Y table are carried out,hardware cost as well as consuming time for interpolation and motion control is compared with the existing *** experimental and comparing results indicate that,compared with the existing methods,the proposed method can reduce the hardware cost by 97.5% using higher-accuracy interpolation algorithm within the period of 0.5 ms.A method which ensures the real-time performance and interpolation accuracy,and reduces the hardware cost significantly is proposed,and it’s practical in the use of industrial application.

关键词： NURBS interpolator FPGA-based interpolation multiprocessor system on a programmable chip (SOPC) motion controller

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electrodeposition Process for the Fabrication of Copper Dendrites Film with Stable Superhydrophobicity

引用

Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 641-646页

作者： huan SHEN Fengping WANG Yanwei ding Jun YANG Faculty of Chemistry and Chemical Engineering Liaoning Normal University School of Materials Science and Engineering Dalian Jiaotong University

Copper dendrites on the copper surface were successfully prepared by electrodeposition in acidic copper sulfate aqueous solution containing ethanol. The XRD （X-ray diffraction） patterns indicate that the Cu dendrites possess fcc （face-centered cubic） crystal structure. The contact angle of the as-prepared Cu dendrites surface without palmitic acid modification is almost 0~ and the surface is completely wetted by water. After modified with palmitic acid, the Cu dendrite surface shows superhydrophobicity with a contact angle of 160~. The polarization curves reveal that the superhydrophobic Cu dendrites surface exhibits a distinct passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solution. The weight loss measurements show that the corrosion values of superhydrophobic surface is much lower than that of the bare copper, further meaning that the as-prepared surface has the anticorrosion performance.

关键词： Copper Electrodeposition Superhydrophobic surface Ethanol

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interpolation-based contour error estimation and componentbased contouring control for five-axis CNC machine tools

引用

Science China(Technological Sciences) 2018年第11期61卷 1666-1678页

作者： LI XiangFei ZHAO huan ZHAO Xin ding Han State key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology

High accuracy contour error estimation and direct contour error control are two major approaches to reduce the contour ***, two key factors make them complex for five-axis machine tools: the nonlinear kinematics and the coupling between the tool position and orientation. In this study, by finding the reference point nearest to the current actual position, and interpolating the point with two neighboring reference points and using the distance ratio, a new contour error estimation method for five-axis machine tools is proposed, which guarantees high accuracy while depending on only the reference points. By adding a weighted contour error on the tracking error in the workpiece coordinate system, and specifying a desired second-order error dynamics based on the error variable, an effective contouring control method is proposed, which can alleviate the problem: when the contour error components are introduced into the controller, the contour errors increase instead in some regions of the tracking trajectory. A series of experiments are performed on a tilting-rotary-table(TRT) type five-axis machine tool. The results reveal that the proposed estimation method has high accuracy, and compared with the case without contour error control, the proposed control approach can reduce the contour error along the whole trajectory.

关键词： five-axis contour error contouring control interpolation component-based

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on anti-attack performance of a private cloud safety computer based on the Markov-Percopy dynamic heterogeneous redundancy structure

引用

Transportation Safety and Environment 2023年第4期5卷 107-116页

作者： Jiakun Wen Zhen Liu huan ding CRSC Research&Design Institute Group Co.Ltd Beijing 100070China

With the increasing computing demand of train operation control systems,the application of cloud computing technology on safety computer platforms of train control system has become a research hotspot in recent *** to improve the safety and availability of private cloud safety computers is the key problem when applying cloud computing to train operation control *** the cloud computing platform is in an open network environment,it can face many security loopholes and malicious network ***,it is necessary to change the existing safety computer platform structure to improve the attack resistance of the private cloud safety computer platform,thereby enhancing its safety and ***,a private cloud safety computer platform architecture based on dynamic heterogeneous redundant(DHR)structure is proposed,and a dynamic migration mechanism for heterogeneous executives is ***,a generalized stochastic Petri net(GSPN)model of a private cloud safety computer platform based on DHR is established,and its steady-state probability is solved by using its isomorphism with the continuous-time Markov model(CTMC)to analyse the impact of different system structures and executive migration mechanisms on the system's anti-attack ***,through experimental verifcation,the system structure proposed in this paper can improve the anti-attack capability of the private cloud safety computer platform,thereby improving its safety and reliability.

关键词： Safety computer logical monitoring method continuous time Markov modelling,cloud computing anti-attack analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of Duty Cycle on the Characteristics of Pulse-Modulhted Radio-Frequency Atmospheric Pressure Dielectric Barrier Discharge

引用

Plasma Science and Technology 2012年第12期14卷 1069-1072页

作者： LI Xuechun WANG huan ding Zhenfeng WANG Younian School of Physics and Optoelectronic Technology Dalian University of TechnologyDalian 116024 China

Using a one-dimensional fluid model, the pulse-modulated radio-frequency dielectric barrier discharge in atmospheric helium is described. The influences of the pulse duty cycle on the discharge characteristics are studied. The numerical results show that the dependence of discharge characteristics on the duty cycle is sensitive in the region of around 40% duty cycle under the given simulation parameters. In the case of a larger duty cycle, the plasma density is higher, the discharge becomes more intense, but the power consumption is higher. When the duty cycle is lower, one can get a weaker discharge, lower plasma density and higher electron temperature in the bulk plasma. In practical applications, in order to get a higher plasma density and a lower power consumption, it is more important to choose a suitable duty cycle to modulate the RF power supply.

关键词： pulse-modulation simulation radio-frequency atmospheric pressure dielectric barrier discharge

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：