检索结果-南通市图书馆

High Voltage 2017年第1期2卷 32-38页

作者： longhui zheng Li Yuan Qingbao Guan Aijuan Gu Guozheng Liang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu 215123People’s Republic of China

High dielectric loss has been the biggest sticky problem for high-k conductor/polymer ***,a new asymmetric material consisting of one layer ofβ-phase poly(vinylidene fluoride)(PVDF)and another layer of carboxylated carbon nanotube(eCNT)/cyanate ester(CE)composite was fabricated,coded as PVDFx–eCNTq/CE,where x is the thickness of PVDF layer ranging from 3 to 70μm,q is the loading of eCNTs(f),taking values of 1.2 and 1.7 wt%.The influences of f and x values on dielectric properties and breakdown strengths of PVDF–eCNT/CE materials were systematically *** f is smaller than the percolation threshold(fc)of eCNT/CE(fc=1.6 wt%),the corresponding PVDF–eCNT1.2/CE materials have similar conductive and dielectric properties as eCNT1.2/CE *** f>fc,all PVDF–eCNT1.7/CE materials have much lower dielectric loss than eCNT1.7/CE,while with suitable thickness of PVDF layer(<70μm),PVDF–eCNT/CE materials have significantly improved dielectric constants and breakdown *** the PVDF–eCNT1.7/CE material of which the thickness of PVDF layer is 5μm,its dielectric constant at 1 Hz is 1699,about ten times of that of eCNT1.7/CE,while the dielectric loss is only 2.31×10−2 times of that of the *** origin behind was intensively studied in terms of space charge distribution.

关键词： dielectric origin asymmetric

Engineering vacancies for solar photocatalytic applications

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

Chinese Journal of Catalysis 2017年第4期38卷 617-624页

作者： Mingce Long longhui zheng School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Key Laboratory for Thin Film and Microfabrication of the Ministry of Education Shanghai Jiao Tong University Shanghai 200240 China

In contrast to the exploration of novel photocatalytic materials,vacancy engineering of traditionalphotocatalysts comprising earth‐abundant elements represents an effective method for enhancingphotocatalytic performance without introducing alien *** minireview analyzes the latestprogress in engineering vacancies in photocatalysts,remarks on state‐of‐the‐art characterizationtechniques for vacancies,and reviews the formation chemistry and fundamental benefits of anionand cation vacancies in typical *** knowledge of these vacancies is increasing,challenges remain in this field,and possible further research is therefore also discussed.

关键词： Oxygen vacancy Hydrogenated treatment Photocatalysis Chemisorption Titanium vacancy

Humic acid-mediated visible-light degradation of phenol on phosphate-modified and Nafion-modified TiO_2 surfaces

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2017年第12期38卷 2076-2084页

作者： longhui zheng Xiaojuan Yu Mingce Long Qilin Li School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Key Laboratory for Thin Film and Microfabrication of the Ministry of Education Shanghai Jiao Tong University Shanghai 200240 China Department of Civil and Environmental Engineering Rice University Houston Texas 77005 United States

Although humic acid(HA)can inhibit TiO2photocatalysis,it can sensitize TiO2and induce significant visible‐light(VL)activity in phenol *** favorable effect of HA was negligible on phosphate‐modified TiO2(P‐TiO2),but significantly stronger on Nafion‐modified TiO2(Nf‐TiO2).The reaction rate constants for phenol degradation on Nf‐TiO2increased from(0.003±0.001)to(0.025±0.003)min?1when the reaction was performed in the presence of20mg/L *** different effects of HA on P‐TiO2and Nf‐TiO2photocatalysis cannot be attributed to adsorption changes,because the adsorption capacities of P‐TiO2and Nf‐TiO2were only slightly lower than that of TiO2at an initial HA concentration of20mg/*** tests,electron paramagnetic resonance spectroscopy,and H2O2detection were taken to understand the low VL activity of the P‐TiO2/HA *** main active species for phenol degradation in the TiO2and Nf‐TiO2suspensions were superoxide *** were negligible amounts of superoxide radicals in the P‐TiO2/HA suspension,possibly because a direct four‐electron oxygen reduction reaction *** better VL activity of Nf‐TiO2was rationalized on the basis of Mott–Schottky and electrochemical impedance *** modification resulted in cathodic shifts of the energy band positions,increased electron density,and less resistance to electron transfer across the interface between TiO2and *** these factors facilitated electron transfer and improved the production of active *** modification therefore did not improve the VL response of HA sensitized TiO2,and low concentrations of HA can facilitate VL photocatalytic degradation of organic pollutants on Nafion surface‐modified TiO2.

关键词： Titanium dioxide Humic acid Nafion Phosphate Surface modification

Modeling and Analysis of Production Logistics Spatio-Temporal Graph Network Driven by Digital Twin

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2022年第5期39卷 461-474页

作者： zheng longhui SUN Yicheng ZHANG Huihui BAO Jinsong CHEN Xiaochuan ZHAO Zhenhong CHEN Zhonghao GUAN Ruifeng College of Mechanical Engineering Donghua UniversityShanghai 201620China Shanghai Frontier Science Research Center for Modern Textiles Donghua UniversityShanghai 201620China Guangzhou Zhijing Information Technology Co. Ltd.Guangzhou 510220China

In the process of logistics distribution of manufacturing enterprises, the automatic scheduling method based on the algorithm model has the advantages of accurate calculation and stable operation, but it excessively relies on the results of data calculation, ignores historical information and empirical data in the solving process, and has the bottleneck of low processing dimension and small processing scale. Therefore, in the digital twin(DT) system based on virtual and real fusion, a modeling and analysis method of production logistics spatio-temporal graph network model is proposed, considering the characteristics of road network topology and time-varying data. In the DT system, the temporal graph network model of the production logistics task is established and combined with the network topology, and the historical scheduling information about logistics elements is stored in the nodes. When the dynamic task arrives, a multi-stage links probability prediction method is adopted to predict the possibility of loading, driving, and other link relationships between task-related entity nodes at each stage. Several experiments are carried out, and the prediction accuracy of the digital twin-based temporal graph network(DTGN) model trained by historical scheduling information reaches 99.2% when the appropriate batch size is selected. Through logistics simulation experiments, the feasibility and the effectiveness of production logistics spatio-temporal graph network analysis methods based on historical scheduling information are verified.

关键词： digital twin(DT) production logistics job scheduling spatio-temporal analysis

Gender May Affect the Dose-Dependent Action of Capsaicinoids on Plasma and Hepatic Cholesterol Levels of Rats

在线全文

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2013年第8期4卷 791-798页

作者： Guoshan Fang longhui zheng Lei Zhang Min Zhou Duanli Zhang Xiong Liu College of Food Science Southwest University Chongqing China.

Sex differences on the effect of dose-dependent capsaicinoids on lipid metabolism were studied in rats. 24 rats of each sex were administered orally 0 mg/kg, 2.5 mg/kg, 5 mg/kg or 7.5 mg/kg capsaicinoids daily for 28 days. In male rats, body weight gained, and the levels of total lipids, total cholesterol and triglycerides in the liver were significantly decreased as the dose of capsaicinoids increased. On the other hand, plasma total cholesterol (TC), triglycerides (TG), HDL- and LDL-cholesterol concentration and liver weight were not affected by capsaicinoids. While in female rats, plasma TC, TG, HDL-C and LDL-C concentration, liver total lipids, TC and TG concentration were significantly decreased as the dose of capsaicinoids increased. The mRNA level of hepatic TRPV1, ileac ASBT and IBABP were increased as the dose of capsaicinoids increased in all rats groups. The mRNA level of hepatic HMG-CoA reductase, CYP7A1 and FXR were significantly decreased in female rats groups. These results show that the hypocholesterolemic effect of capsaicinoids in dose-dependent manner in rats was mediated by inhibited synthesis of endogenous cholesterol, female rats were more sensitive than male rats on hypolipidemic effect of capsaicinoids.

关键词： Capsaicinoids Cholesterol Bile Acids Dose-Dependent Sex Difference

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

基于数字孪生的行车多因素隐性级联故障诊断

计算机集成制造系统 2023年第6期29卷 2086-2101页

作者：张辉辉郑龙辉孙奕程杨芸李婕黄德林鲍劲松张丹东华大学机械工程学院上海201620 约克大学机械工程系加拿大安大略多伦多M4Y1M7

针对行车传统运维方式中存在的可管可控状态不明、故障时定位分析耗时久、设备宕机时间长等问题,为实现行车状态运维的智能化转型升级,基于数字孪生技术和数据驱动方法,提出一种用于行车多机构联动、多因素耦合的隐性级联故障诊断分析... 详细信息

针对行车传统运维方式中存在的可管可控状态不明、故障时定位分析耗时久、设备宕机时间长等问题,为实现行车状态运维的智能化转型升级,基于数字孪生技术和数据驱动方法,提出一种用于行车多机构联动、多因素耦合的隐性级联故障诊断分析方法。以数据驱动为核心,构建了数据驱动的行车数字孪生模型,详细阐述了行车数字孪生系统的组成和交互行为;对显性故障和隐性故障进行分类和定义,设计了SDAE—MCSVM—FBN方法解决多因素隐性级联故障;构建了数据驱动的行车数字孪生模型的原型系统,以某大型国企钢厂某车间内的行车作业过程为例,与传统运维方式中的人工点检对比,在所提方法应用前后,故障维修时长和设备宕机时长分别减少的时间比例区间为24.5%~32.8%,20.5%~32.4%,证实了所提方法对隐性级联故障诊断分析的有效性和可行性。

关键词：数字孪生数据驱动堆栈降噪自编码器多类支持向量机模糊贝叶斯网络

在线全文

学校读者我要写书评

暂无评论

超高压技术在肉品加工中的应用

肉类研究 2010年第11期24卷 24-28页

作者：陆红佳郑龙辉西南大学食品科学学院重庆400715

超高压技术是近年来食品领域热点研究的高新技术之一,具有广泛的应用前景。本文综述了超高压技术的概念和特点,着重介绍了超高压处理在肉品加工中的应用,并对超高压技术在肉品加工中的发展前景进行了展望。

关键词：超高压技术肉制品品质应用

伊洛河(巩义段)排污口表层水体微塑料的赋存特征、分布与风险评价

在线全文

学校读者我要写书评

暂无评论

环境科学研究 2024年第9期37卷 1948-1957页

作者：和兵赵长民马振芳李银月马丽张发文郑龙辉桂新河南省郑州生态环境监测中心河南郑州450007 河南农业大学林学院河南郑州450046

作为一种新污染物,微塑料可通过排污口进入河流。通过采集伊洛河(巩义段)13个入河排污口表层水体的样品,采用显微镜观察、激光红外等方法,对其赋存特征、分布进行分析及定性,并进行风险评价。结果表明:①伊洛河(巩义段)排污口表层水体... 详细信息

作为一种新污染物,微塑料可通过排污口进入河流。通过采集伊洛河(巩义段)13个入河排污口表层水体的样品,采用显微镜观察、激光红外等方法,对其赋存特征、分布进行分析及定性,并进行风险评价。结果表明:①伊洛河(巩义段)排污口表层水体中微塑料平均丰度为(96.5±35.5)n/L,检出形态纤维状和透明色占比较高,粒径以<0.5 mm为主。②检出塑料种类分别为聚酰胺(PA)、聚乙烯(PE)、聚丙烯(PP)、聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)和聚氯乙烯(PVC),其中,PET占比为16%~50%,PE占比为22%~48%,每个样点二者占比之和均超过50%。③污染负荷指数法评估该研究区段为低风险,而微塑料聚合物组成危害指数法和潜在生态风险指数法表明,有PVC检出的样点排污口表层水体风险会升高。研究显示,伊洛河(巩义段)排污口水体中微塑料引起的环境风险不仅与其丰度有关,还依赖于微塑料的种类,微塑料的潜在风险应引起重视。

关键词：微塑料排污口伊洛河污染特征风险评价

Unhatched and Hatched Eggshells of the Chinese Cobra Naja atra

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2014年第4期5卷 276-280页

作者： zheng WANG longhui LIN Xiang JI College of Biological and Environmental Sciences Nanjing Forestry University Jiangsu Key Laboratory for Biodiversity and Biotechnology College of Life Sciences Nanjing Normal University Hangzhou Key Laboratory for Animal Adaptation and Evolution School of Life Sciences Hangzhou Normal University

Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unhatched and hatched eggshells of the Chinese cobra Naja atra to determine the percentage of ash and the phase composition of calcium carbonate. The mean percentage of ash was significantly higher in unhatched eggshells （24.6%） than in hatched eggshells （22.3%）. The dominant phase in unhatched eggshells was the calcite form of calcium carbonate. In addition to the peaks of calcite, a few small peaks were found to be caused by the aragonite and vaterite phases of calcium carbonate, implying that there are small amounts of aragonite and vaterite in the eggshell. The concentration of the various phases calculated from the intensity of the X-ray diffraction spectra allowed the estimation that percentages of calcite, aragonite and vaterite were about 92%, 4% and 4%, respectively. Hatched eggshells produced similar spectral characteristics as unhatched eggshells, with one exception. The dominant phase composition in the hatched eggshell was also calcite, but the amount of the aragonite phase had a marked increase. Our study adds evidence that embryonic mobilization of minerals from the eggshell may result in changes in structure of the eggshell.

关键词： Elapidae Naja atra eggshell structure egg incubation X-ray diffraction spectra minerals

在线全文

学校读者我要写书评

暂无评论

有遮阳翻板的两栋多层建筑自然通风数值模拟

集美大学学报(自然科学版) 2025年第1期30卷 68-75页

作者：邱龙辉陶求华郑健雯集美大学海洋装备与机械工程学院福建厦门361021 福建省能源清洁利用与发展重点实验室福建厦门361021

文中基于计算流体力学(CFD)数值模拟,建立了一种室内外气流耦合模型,研究了翻板遮阳对多层建筑室内外风环境的影响。通过对比3种遮阳工况下的流线分布、风速云图和室内通风量大小,分析遮阳翻板的安装位置和前排建筑遮挡对室内风速分布... 详细信息

文中基于计算流体力学(CFD)数值模拟,建立了一种室内外气流耦合模型,研究了翻板遮阳对多层建筑室内外风环境的影响。通过对比3种遮阳工况下的流线分布、风速云图和室内通风量大小,分析遮阳翻板的安装位置和前排建筑遮挡对室内风速分布和通风量的影响。结果表明:在迎风遮阳工况下,由于前排建筑的遮蔽,后排建筑的室内通风量会显著下降;在背风遮阳工况下,后排建筑的室内通风量下降得最为明显;相比无遮阳,迎风遮阳会降低前排建筑的室内通风量,而背风遮阳则影响较小。

关键词：遮阳翻板自然通风数值模拟耦合模型