检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

云南煤炭资源与活性炭生产

昆明理工大学学报（理工版） 2003年第4期28卷 27-30页

作者：李新柱范艳青陈雯昆明理工大学材料与冶金工程学院云南昆明650093

介绍了活性炭的应用及市场前景 ,指出了活性炭生产应用的良好前景 ,同时在收集大量云南省煤炭资源资料的基础上 ,介绍了云南煤炭资源分布及利用现状 ,指出了褐煤在云南煤炭资源中的重要地位 ,论述了云南煤基活性炭生产现状 ,及利用褐煤... 详细信息

介绍了活性炭的应用及市场前景 ,指出了活性炭生产应用的良好前景 ,同时在收集大量云南省煤炭资源资料的基础上 ,介绍了云南煤炭资源分布及利用现状 ,指出了褐煤在云南煤炭资源中的重要地位 ,论述了云南煤基活性炭生产现状 ,及利用褐煤生产活性炭的可行性。

关键词：云南煤炭资源活性炭褐煤生产现状发展

控制方向未知的受限多智能体系统的预设时间模糊控制

在线全文

学校读者我要写书评

暂无评论

工程科学学报 2025年第1期47卷 121-129页

作者：李菲周超范利蓉王芳燕山大学理学院秦皇岛066004 河北农业大学海洋学院秦皇岛066003

综合考虑受控制方向未知、输入受限和状态时延影响的有领导者多智能体系统的编队控制问题,设计基于模糊逻辑系统的预设时间一致性控制策略.为了保证编队输出误差在预设时间内满足预定的约束范围要求,引入预设时间性能函数,构造Lyapunov-... 详细信息

综合考虑受控制方向未知、输入受限和状态时延影响的有领导者多智能体系统的编队控制问题,设计基于模糊逻辑系统的预设时间一致性控制策略.为了保证编队输出误差在预设时间内满足预定的约束范围要求,引入预设时间性能函数,构造Lyapunov-Krasovskii(L-K)泛函解决状态时延问题,将外界干扰和L-K泛函的导数中的部分项定义为未知非线性函数,并利用模糊逻辑系统对其进行估计,利用Nussbaum函数和均值定理分别处理控制方向未知和输入受限问题,基于以上设计,提出预设时间模糊控制策略,并通过Lyapunov稳定性理论,分析闭环系统的有界稳定性,数值对比仿真和两级化学反应器应用仿真说明控制方法的有效性.

关键词：多智能体系统状态时延输出误差约束输入受限控制方向未知

Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第11期13卷 2508-2517页

作者： GAO Kun CHEN fan-jun YUAN li-xing MI Guo-hua Key Laboratory of Plant-Soil Interaction Ministry of Agriculture/Center for Resources Environment and Food Security College of Resources and Environmental Sciences China Agricultural University

Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize （Zea mays L., cv. Zhengdan 958） were grown in hydroponics with the control （4 mmol L-1） or low-nitrogen （40 μmol L-1） for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate （by 2.5-fold）, the length of elongation zone （by 1.5-fold）, and ifnal cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred speciifcally in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

关键词： cell length elemental expansion kinematic analysis root diameter root elongation Zea mays L

Credit Risk Transfer in SME Loan Guarantee Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2017年第5期30卷 1084-1096页

作者： LENG Aolin xing Guangyuan fan Weiguo School of Management Xi'an Jiaotong UniversityXi'an 710049China School of Economics and Finance Xi'an Jiaotong UniversityXi'an 710061China Pamplin College of Business Virginia Tech24060USA

Joint loan guarantee contracts and mutual guarantee contracts among SMEs form the basis of SME guarantee networks. The expansion of these networks increases the fragility of a financial system as a result of the regional and industrial risk contagion embedded within them. By providing a theoretical framework of a loan guarantee network, a method is proposed for calculating the amount of risk spillover caused by loan guarantees taking the perspective of the entire network. In addition,the route of risk contagion in guarantee networks is analyzed, revealing that when default risk shocks occur, risk contagion travels along the nodes not once but for several rounds and that the risk control of one firm cannot prevent these systemic risks. Therefore, a risk control scheme is designed based on the location and importance of firms in the network. Using data from a real guarantee network,we demonstrate that identifying the node locations of firms' in the guarantee network(including the coritivity and closeness of the firm) can help in understanding risk contagion mechanisms and preventing systemic credit risk before a crisis occurs.

关键词： Closeness coritivity guarantee network risk contagion.

Ionic liquid mediated CO_2 activation for DMC synthesis

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2012年第4期21卷 476-479页

作者： Jun Du Jing Shi Zhengfei li Zuohua liu xing fan Changyuan Tao College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400030China

Promoted catalytic reaction between methanol and CO2 for dimethyl carbonate （DMC） synthesis is conducted over K2CO3/CH3I catalyst in the presence of ionic liquid under microwave irradiation. The effect of ionic liquids incorporated with microwave irradiation on the yield of DMC is investigated. DMC was found to form at lower temperature in a relative short time, which indicated an enhanced catalytic process by ionic liquid. Among the ionic liquids used, 1-butyl-3-methylimidazolium chloride is the most effective promoter. Density functional theory calculations indicate that CO2 bond lengths and angles changed due to the molecular interaction of ionic liquid and CO2, resulting in the activation of CO2 molecules and consequently the acceleration of reaction rate.

关键词： dimethyl carbonate direct synthesis microwave ionic liquids K2CO3/CH3I CO2

Optimization of vinegar-steaming process for Wuweizi (Fructus Schisandrae Chinensis) with response surface method

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2013年第5期33卷 682-685页

作者： Yan Zhang Kangwei li Kuan Yang xing fan Mengxin Zhang Teaching and Research Section of Pharmacognosy of Pharmacy Department Xi'an Medical University

OBJECTIVE:To optimize the vinegar-steaming process of Wuweizi(Fructus Schisandrae Chinensis)using the response surface method(RSM)based on the Box-Behnken ***:A regression model was constructed with the response variables,the content of Deoxyschizandrin,and the three explanatory factors:length of steaming time,the quantity of vinegar and length of moistening time to evaluate the effects on the processing of Wuweizi(Fructus SchisandraeChinensis).RESULTS:There was a linear relationship between the content of Deoxyschizandrin and the three explanatory *** the steaming time was5.49 h,with 2.365 g of vinegar added and a moistening time of 4.13 h,the content of Deoxyschizandrin reached the maximum predicted value of0.1076%,and under the conditions the average content of Deoxyschizandrin was 0.1058%.CONCLUSION:The correlation coefficient of thenonlinear mathematical model was relatively high and the model matched the data well,potentially providing a method for the study of the steaming process.

关键词： Processing Wuweizi(Fructus SchisandraeChinensis) Vinegar-steaming Regression analysis Response surface method Correlation coefficient

Effects of Ce on catalytic combustion of methane over Pd-Pt/Al_2O_3 catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第3期24卷 507-511页

作者： xing fan fan Wang Tianle Zhu Hong He School of Chemistry and Environment Beihang UniversityBeijing 100191China College of Environmental and Energy Engineering Beijing University of TechnologyBeifing 100124China

Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated. The catalysts before and after reaction were characterized by BET, CO chemisorption, XRD and XPS techniques. Results showed that the presence of Ce significantly increased the activity and thermal stability of the Pd-Pt/Al2O3 catalyst towards methane combustion, which could be attributed to more highly-dispersed active PdO particles over the Pd-Pt/Ce/Al2O3 catalyst surface as well as the retarded sintering of PdO and the maintained oxidized state of surface Pd during the combustion process in the presence of Ce.

关键词： catalytic combustion methane Pd-Pt/Ce/Al2O3 catalyst stability metal dispersion

Safety-enhanced Polymer Electrolytes with High Ambient-temperature lithium-ion Conductivity Based on ABA Triblock Copolymers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第1期40卷 21-28页

作者： Dong liu fan Wu Zhi-Hao Shen xing-He fan Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Matter Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

liquid electrolytes used in lithium-ion batteries suffer from leakage,flammability,and lithium dendrites,making polymer electrolyte a potential ***,a series of ABA triblock copolymers(ABA-x)containing a mesogen-jacketed liquid crystalline polymer(MJLCP)with a polynorbornene backbone as segment A and a second polynorbornene-based polymer having poly(ethylene oxide)(PEO)side chains as segment B were synthesized through tandem ring-opening metathesis *** block copolymers can self-assemble into ordered morphologies at 200℃.After doping of lithium salts and ionic liquid(IL),ABA-x self-assembles into cylindrical *** MJLCP segments with a high glass transition temperature and a stable liquid crystalline phase serve as physical crosslinking points,which significantly improve the mechanical performance of the polymer *** ionic conductivity of ABA-x/lithium salt/IL is as high as 10-3 S·cm-1 at ambient temperature owing to the high IL uptake and the continuous phase of conducting PEO *** relationship between ionic conductivity and temperature fits the Vogel-Tamman-Fulcher(VTF)*** addition,the electrolyte films are flame retardant owing to the addition of *** polymer electrolytes with good safety and high ambient-temperature ionic conductivity developed in this work are potentially useful in solid lithium-ion batteries.

关键词： ABA triblock copolymer Polymer electrolyte Ionic conductivity Inflammability Cylindrical structure

Review of Real-time Simulation of Power Electronics

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第4期8卷 796-808页

作者： Fei li Yichao Wang fan Wu Yao Huang Yang liu xing Zhang Mingyao Ma School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology HefeiChina

Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and *** there is no energy transfer during the course of the usage,real-time simulation has a lot of advantages in the process of development and *** the perspective of real-time simulation,this paper focuses on the main problems in modeling accuracy,system bandwidth and stability,limitations on communication interface and energy interface,and the cost of platform ***,we provide further research directions.

关键词： Hardware-in-the-loop simulation modeling and simulation of power electronics correction method power interface algorithm numerical method