检索结果-南通市图书馆

Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

Chinese Journal of Polymer Science 2024年第9期42卷 1360-1367,I0008页

作者： You-cai xue Yi-Ming Yang Di Jia Beijing National Laboratory for Molecular Sciences Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Polyampholyte gels,which have hierarchical structures,exhibit excellent self-healing properties and have great promise for biomaterials and *** investigated the relationship between microscopic structures and macroscopic viscoelastic properties of polyampholyte gels and found three factors influencing their viscoelastic properties,including the chemical crosslinking bonds,topological entanglements controlled by monomer concentration,and the ionic *** strength plays a major role on the strength of ionic bonds.A crossover point of elastic modulus and loss modulus was observed in the dynamic frequency sweeps at low monomer concentration or low chemical crosslinking density for gels with intermediate strength of ionic *** solid-liquid transition signaled by the crossover point is a typical feature of dynamic associated gels,representing the dynamical association-dissociation of the ionic bonds and full relaxation of the topological entanglements in the gel *** the crossover point disappears when the ionic bonds are too weak or too strong to form“permanent”***,in the non-linear yielding measurement,gels with intermediate strength of the ionic bonds are ductile and yield at very large shear strain due to the self-healing properties and the dynamic association-dissociation of the ionic *** the self-healing properties disappear when the ionic bond strength is too weak or too *** work reveals the mechanism of how the dynamic association-dissociation of ionic bonds influences both the linear and non-linear viscoelastic properties of the polyampholyte gels.

关键词： Polyampholyte gel Ionic bond Topological entanglement Self-healing Hierarchical structure

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

PREPARATION AND CHARACTERIZATION OF HUMIDITY SENSOR BASED ON POLY(3-ALKYL)PYRROLE CONTAINING PHOSPHONIC ACID GROUPS

引用

Chinese Journal of Polymer Science 2013年第10期31卷 1443-1450页

作者： xue-diao cai Ru Huang Ya-nan Guo Key Laboratory of Macromolecular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal University

Poly（3-alkyl）pyrroles containing phosphonic acid groups with different alkyl segment lengths were chemical synthesized and the properties were measured by FTIR and UV-Vis spectroscopy. FTIR and UV-Vis results showed that the synthesized polymers were in a low doping level through chemical polymerization. By spin-coating on the surface of substrates, the polymer can be used as a humidity sensor. The change of DC electric current of the polypyrroles varies with the chain length of the alkyl substituents. The capacitance increases with the increase of the humidity and resistance decreases with the increase of humidity. This result is different from that ofpolypyrrole without alkyl substituents due to the influence of the phosphonic acid group. The sensor showed the resistive-type at high relative humidity, and the capacitive- type at the low relative humidity. The sensor exhibited very fast response to the change of environment humidity.

关键词： Poly(3-alkyl)pyrrole Humidity sensor Phosphonic acid group Capacitive-type Resistive-type.

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

PAHs in aquatic sediment in Hangzhou, China: Analytical methods, pollution pattern, risk assessment and sources

引用

Journal of Environmental Sciences 2005年第5期17卷 748-755页

作者： ZHU Li-zhong cai xue-fen WANG Jing Department of Environmental Science Zhejiang University Hangzhou 310028 China Women＇s Hospital School of Medicine Zhejiang University Hangzhou 310006 China Zhejiang Provincial Environmental Monitoring Centre Hangzhou 310012 China

Eleven surface sediment samples, from Hangzhou section of Qiantang River and Jinghang Canal, west Lake the inland river were collected to investigate 17 polycycUc aromatic hydrocarbons（PAHs） pollution in aquatic sediments of Hangzhou. Accelerated solvent extraction（ASE） was used to extract PAHs from sediments with satisfactory recoveries. It was found that the total PAHs in the sediments ranged from 308.4 to 3037 ng/g dw, and PAHs pollution in sediments from Jinghang Canal were the heaviest. Lowest effect level（LEL） and severe effect level （SEL） sediment quality guidelines were introduced to perform risk assessment for PAHs pollution in aquatic sediments. Only one sample in Jinghang Canal had adverse impact on benthic organism. 2-3 ring PAHs had a noticeable contribution to total PAHs, especially NA, PHEN. A quantity method was used to determine the major source, the results showed petroleum origin was the chief source to PAHs pollution in all sediments with the exception of sediments from Jinghang Canal where combustion sources had a larger contribution.

关键词： PAHs ASE sediment source risk assessment

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

Density functional theory study on organic semiconductor for field effect transistors: Symmetrical and unsymmetrical porphyrazine derivatives with annulated 1,2,5-thiadiazole and 1,4-diamyloxybenzene moieties

引用

Science China Chemistry 2009年第6期52卷 840-848页

作者： cai xue ZHANG YueXing QI DongDong JIANG JianZhuang Department of Chemistry University of Science and Technology BeijingBeijing 100083China Department of Chemistry Mudanjiang Normal CollegeMudanjiang 157012China Department of Chemistry Shandong UniversityJinan 250100China

Density functional theory (DFT) calculations were carried out to investigate the organic field effect transistor (OFET) performance of the symmetrical metal-free tetrakis (1,2,5-thiadiazole) porphyrazine (S4)PzH2 and tetrakis (1,4-diamyloxybenzene) (A4)PzH2 as well as the low-symmetry metal-free porphy- razine with annulated 1,2,5-thiadiazole and 1,4-diamyloxybenzene groups in the ratio 2:2 (cis) and 1:3, that is, (cis-S2A2)PzH2 and (SA3)PzH2, (S = 1,2,5-thiadiazole ring, A = annulated 1,4-diamyloxy-benzene ring, Pz = porphyrazine) in terms of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy, ionization energy (IE), electron affinity (EA), and their reorganization energy (λ) during the charge-transport process. On the basis of Marcus electron transfer theory, electronic couplings (V) and field effect transistor (FET) properties for the four compounds with known crystal structure have been calculated. The electron transfer mobility (μ -) is revealed to be 0.056 cm2·V-1·s-1 for (S4)PzH2. The hole transfer mobility (μ+) is 0.075, 0.098, and 8.20 cm2·V-1·s-1 for (cis-S2A2)PzH2, (SA3)PzH2, and (A4)PzH2, respectively. The present work represents the theoretical effort towards understanding the OFET properties of symmetrical and unsymmetrical porphyrazine derivatives with annulated 1,2,5-thiadiazole and 1,4-diamyloxybenzene.

关键词： porphyrazine organic field effect transistor reorganization energy density functional 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

Backstepping Control of Speed Sensorless Permanent Magnet Synchronous Motor Based on Slide Model Observer

引用

International Journal of Automation and computing 2015年第2期12卷 149-155页

作者： cai-xue Chen Yun-Xiang Xie Yong-Hong Lan School of Electric Power South China University of Technology School of Information Engineering Xiangtan University

This paper presents a backstepping control method for speed sensorless permanent magnet synchronous motor based on slide model observer. First, a comprehensive dynamical model of the permanent magnet synchronous motor(PMSM) in d-q frame and its space-state equation are established. The slide model control method is used to estimate the electromotive force of PMSM under static frame, while the position of rotor and its actual speed are estimated by using phase loop lock(PLL) method. Next,using Lyapunov stability theorem, the asymptotical stability condition of the slide model observer is presented. Furthermore, based on the backstepping control theory, the PMSM rotor speed and current tracking backstepping controllers are designed, because such controllers display excellent speed tracking and anti-disturbance performance. Finally, Matlab simulation results show that the slide model observer can not only estimate the rotor position and speed of the PMSM accurately, but also ensure the asymptotical stability of the system and effective adjustment of rotor speed and current.

关键词： Permanent magnet synchronous motor(PMSM) slide model observer backstepping control speed sensorless alternating current(AC).

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

Stability of Two-Component Bose-Einstein Condensates in Bessel Optical Lattices

引用

Communications in Theoretical Physics 2008年第6期49卷 1519-1526页

作者： CHEN Hai-Jun LI Hao-cai xue Ju-Kui College of Physics and Electronics Engineering Northwest Normal University Lanzhou 730070 China

The stability of the ground state of two-component Bose-Einstein condensates （BEGs） loaded into the central well of an axially symmetric Bessel lattices （BLs） potential with attractive or repulsive atoms interactions is studied using the time-dependent Gross-Pitaevskii equation （GPE）. By using the variational method, we find that stable ground state of two-component BEGs can exist in BLs. The BLs＇s depth and the intra-species atom interaction play an important role in the stability of ground state. The collapse of two-component BEGs in BLs is also studied and a collapse condition for trapped two-component BEGs is obtained. It is shown that the two-component BEGs exhibit rich collapse dynamics. That is, the two-component BEGs can collapse in the system with both intra- and inter-attractive, or with intra-attractive and inter-repulsive, or with intra-repulsive and inter-attractive atom interactions. Furthermore, the control of the collapse of the two-component BEGs in BLs is discussed in detail. The stability diagram of the ground state in parameter space is obtained. The results show that the collapse of two-component BEGs can be controlled by temporal modulation of the atom interaction.

关键词： two-component Bose-Einstein condensates Gross-Pitaevskii equation Bessel optical lattice ground state

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

Suppression of the Drift Field in the p-Type Quasineutral Region of a Semiconductor p-n Junction

引用

Chinese Physics Letters 2012年第9期29卷 151-154页

作者： cai xue-Yuan YANG Jian-Hong WEI Ying Institute of Microelectronics School of Physical Science and TechnologyLanzhou UniversityLanzhou 730000

An improved analytical model of the drift field suppressed by the Dember field due to ambipolar diffusion in the p-type quasineutral region(p-QNR)of a forward silicon p–n junction at low injection levels is presented with a good fit to the numerical simulation *** ambipolar transport of both carriers,the diode current in the p-QNR is found to consist of a minority-electron diffusion-current component and majority-hole drift-and diffusion-current components,and the Dember field plays a dominant role in balancing all the components mentioned above to keep the current *** analytical model is beneficial to completely understand ambipolar current transport mechanisms in semiconductor p–n junction devices.

关键词： neutral diffusion transport

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

Characterization and quantification of multi-field coupling in lithium-ion batteries under mechanical constraints

引用

Journal of Energy Chemistry 2024年第8期95卷 364-379,I0009页

作者： xue cai caiping Zhang Zeping Chen Linjing Zhang Dirk Uwe Sauer Weihan Li National Active Distribution Network Technology Research Center Beijing Jiaotong UniversityBeijing 100044China Chair for Electrochemical Energy Conversion and Storage Systems Institute for Power Electronics and Electrical Drives(ISEA)RWTH Aachen UniversityCampus Boulevard 8952074 AachenGermany Center for Ageing Reliability and Lifetime Prediction of Electrochemical and Power Electronic Systems(CARL)Campus-Boulevard 8952074 AachenGermany Juelich Aachen Research Alliance JARA-EnergyAachenGermany Helmholtz Institute Münster(HI MS) IEK-12Forschungszentrum JülichGermany

The safety and durability of lithium-ion batteries under mechanical constraints depend significantly on electrochemical,thermal,and mechanical fields in *** and quantifying the multi-field coupling behaviors requires interdisciplinary ***,we design experiments under mechanical constraints and introduce an in-situ analytical framework to clarify the complex interaction mechanisms and coupling degrees among multi-physics *** proposed analytical framework integrates the parameterization of equivalent models,in-situ mechanical analysis,and quantitative assessment of coupling *** results indicate that the significant impact of pressure on impedance at low temperatures results from the diffusion-controlled step,enhancing kinetics when external pressure,like 180 to 240 k Pa at 10℃,is *** diversity in control steps for the electrochemical reaction accounts for the varying impact of pressure on battery performance across different *** thermal expansion rate suggests that the swelling force varies by less than 1.60%per unit of elevated temperature during the lithiation *** introducing a composite metric,we quantify the coupling correlation and intensity between characteristic parameters and physical fields,uncovering the highest coupling degree in electrochemical-thermal *** results underscore the potential of analytical approaches in revealing the mechanisms of interaction among multi-fields,with the goal of enhancing battery performance and advancing battery management.

关键词： Lithium-ion battery Muti-field coupling Mechanical constraints Interaction mechanisms Quantitative analysis

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

Optimal Energy Efficiency Resource Allocation Strategy for Cognitive Clustering Network under PUEA Attack

引用

China Communications 2020年第10期17卷 249-263页

作者： Linna Hu Ning Cao Rui Shi xue cai Minghe Mao Zhiyu Chen Computer&Information College Hohai UniversityNanjing 210098China Nanjing University of Science&Technology Zijin College Nanjing 210023China State Grid Information&Telecommunication Branch State Grid Corporation of ChinaBeijing 100761China School of Electronic and Information Engineering Suzhou universitySuzhou 215006China

5G has pushed the use of radio spectrum to a new level,and cognitive clustering network can effectively improve the utilization of radio spectrum,which is a feasible way to solve the growing demand for wireless ***,cognitive clustering network is vulnerable to PUEA attack,which will lead to the degradation of system detection performance,thereby reducing the energy *** at these problems,this paper investigates the optimal energy efficiency resource allocation scheme for cognitive clustering network under PUEA attack.A cooperative user selection algorithm based on selection factor is proposed to effectively resist PUEA user attack and improve detection *** construct the energy efficiency optimization problem under multi-constraint conditions and transform the nonlinear programming problem into parametric programming problem,which is solved by Lagrangian function and Karush-Kuhn-Tucker *** the sub-gradient iterative algorithm based on optimal energy efficiency under PUEA attack is proposed and its complexity is *** results indicate that proposed method is effective when subjected to PUEA attacks,and the impact of different parameters on energy efficiency is analyzed.

关键词： cognitive clustering network energy efficiency resource allocation PUEA cooperative user selection

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

Discrimination of industrial products by on-line near infrared spectroscopy with an improved dendrogram

引用

Chinese Chemical Letters 2011年第10期22卷 1241-1244页

作者： Jing Jing Liu Heng Xu Wen Sheng cai xue Guang Shao Research Center for Analytical Sciences College of Chemistry Nankai University Tianjin 300071 China

Near infrared（NIR） spectroscopy technique has shown great power and gained wide acceptance for analyzing complicated *** present work is to distinguish different brands of tobacco products by using on-line NIR spectroscopy and pattern recognition ***,since each brand contains a large number of samples,an improved dendrogram was proposed to show the classification of different *** results suggest that NIR spectroscopy combined with principal component analysis （PCA） and hierarchical cluster analysis（HCA） performs well in discrimination of the different brands,and the improved dendrogram could provide more information about the difference of the brands.

关键词： Near infrared spectroscopy Principal component analysis Hierarchical cluster analysis Tobacco products

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：