检索结果-南通市图书馆

Science China(Technological Sciences) 2022年第4期65卷 956-965页

作者： WANG Na XU LuYu XIE Fei shi Yan WANG YiXuan Engineering Training Center Beihang UniversityBeijing 100191China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Department of Pulmonary and Critical Care Medicine Chinese PLA General HospitalBeijing 100191China

Pneumatic proportional control servo regulator is the core component of a pneumatic-loading experimental system,which is very important in solving the overcharging ***,previous research on control of pneumatic proportional regulator in a pneumatic-loading experimental system led to failure in analysis of the influence of opening error of the switch regulator because it did not analyze the regulator basic working principle and *** traditional control method cannot fully solve the overcharging problem nor ensure adequate control performance of the *** seriously studying the working principle and key mechanical parameters of the valve,a fuzzy parameter-adaptive controller is designed by introducing a linear mixture of the pressure and opening errors of the switch regulator to reduce pressure overshoot and optimize its control *** to the fuzzy-control strategy based on the working characteristics and mechanical parameters of the valve,the overshoot phenomenon of the pneumatic-loading system is solved,and the pressure overshoot is *** error of the output air pressure of the regulator is 1.24%,which is *** adjustable pressure range of the regulator is 0.2–0.6 *** maximum deviation is 0.012 *** linearity of the case is 1.34%F.S.

关键词： pneumatic proportional servo regulator pneumatic-loading experimental system mathematical model fuzzy parameter-adaptive controller opening error of the switch regulator

同方期刊数据库

New branched benign compounds including double antibiotic scaffolds:synthesis,simulation and adsorption for anticorrosion effect on mild steel

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2023年第2期17卷 167-182页

作者： Yueting shi Lingli Chen Shengtao Zhang Hongru Li Fang Gao College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China

In this study,two novel environmental benign double antibiotic norfloxacin or ciprofloxacin scaffolds included branched molecules were prepared by multi-step routes and purified by simple performance,which were used as the target compounds(TCs).Meanwhile,a single norfloxacin or ciprofloxacin skeleton based molecules were synthesized as the reference compounds(RCs).The molecular geometry optimization and material simulation computation revealed that TCs presented smaller HOMOLUMO energy gaps and larger binding energy levels on mild steel surface than *** chemical adsorption of TCs on steel surface was confirmed by X-ray photoelectron spectroscopy,which could be processed by TCs chelation with iron *** was shown that TCs could be self-adsorbed on steel surface,which was demonstrated by atomic force microscopy and scanning electron *** anticorrosion of the studied compounds for mild steel in HCl solution was investigated by electrochemistry *** results suggested that the anticorrosion efficiency could reach 95.86%(TC1)and 97.05%(TC2)at 0.050 mmol·L^(−1) based on electrochemical impedance spectroscopy,which were much better than RCs(RC1,69.23%;RC2,74.16%).The adsorption isotherms of TCs on steel were further fitted,and a deep insight on adsorption was discussed.

关键词： branched compounds floxacin scaffold mild steel anticorrosion environmentally benign

Application of gas wettability alteration to improve methane drainage performance:A case study

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2021年第4期31卷 621-629页

作者： Lin Jia Kewen Li Xiaohong shi Lipeng Zhao Jianshe Linghu School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationBeijing 100083China Department of Energy Resources Engineering Stanford UniversityStanfordCA 94305USA Huayang New Material Technology Group Co. Ltd.Yangquan 045000China School of Resources and Environment Henan Polytechnic UniversityJiaozuo 454000China

Hydraulic fracturing technique is widely used for methane drainage and has achieved good effects in numerous coal mines,but negative effects may occur as the fracturing fluids are absorbed into the coal *** wettability alteration(GWA)technology can be used as it can enhance the gas and water mobility during dewatering process as a result of capillary pressure ***,there have been few reported field tests in coal mines using GWA *** paper describes a pilot-scale field test in Xinjing coal mine,Yangquan,*** fluorocarbon surfactants perfluorooctyl methacrylate monomer-containing polymethacrylate(PMP)was used to alter the wettability of coal seam to strong gas-wetness during the hydraulic fracturing *** study focuses on the comparison of two boreholes(Boreholes#9 and#10)and one other borehole(Borehole#8)with and without using GWA approach.A well-defined monitoring program was established by measuring the dewatering volume of the fracturing fluid and the drainage volume of methane as well as the *** field test results showed that the average methane drainage rates of Boreholes#9(39.28 m^(3)/d)and#10(51.04 m^(3)/d)with GWA treatment exceeded that of Borehole#8(21.09 m^(3)/d)without GWA treatment,with an increase of 86.3%and 142.1%,*** average methane concentrations of Boreholes#9(4.05%)and#10(6.18%)were 64.6%and 151.2%higher than that of Borehole#8(2.46%),*** the other hand,the dewatering ratio of Boreholes#9(4.36%)and#10(3.11%)was almost 19 times and 13 times greater than that of Borehole#8(0.22%).These field test results were in agreement with the experimental *** significant increase in both methane concentration and dewatering ratio demonstrated that GWA technology could be applied for enhanced methane drainage in coal *** lessons learned at Xinjing coal mine might be applied to other coal mines in China and elsewhere.

关键词： Field test Hydraulic fracturing Wettability alteration to gas-wetness Drainage of methane

Fast electrothermal coupling calculation method for supporting digital twin construction of electrical equipment

在线全文

学校读者我要写书评

暂无评论

High Voltage 2023年第2期8卷 390-400页

作者： Xiaosong Zhu Youyuan Wang Ruixiao Meng shi Long Shaowen Wu State Key Laboratory of Power Transmission Equipment and System Security and New Technology(Chongqing University) ChongqingChina

The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment *** real-time condition monitoring method of electrical equipment based on digital twin(DT)has received extensive attention and is considered as a technology with great engineering values and excellent application ***,the current calculation of DT mostly relies on the traditional finite element method(CFEM).This method becomes less computationally efficient as the size of the DT increases,especially for electrical equipment with high *** is difficult to meet the requirements real-time calculation in ***,starting from the algorithm optimization and parallel architecture,based on the weighted residual method and stabilised conforming nodal integration,a novel discrete method of electrothermal coupling equation is proposed and the data storage structure of the algorithm from the bottom layer is redesigned,and the corresponding GPU and multi-core CPU parallel framework are ***,taking the high voltage bushing as an example,the correctness of the method in this paper is verified by the CFEM code and commercial software *** the same grid and accuracy requirement,the calculation time is shortened by at least five times than *** the method is easy to extend to other types of multi-physics calculations.

关键词： electrical coupling method

Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles

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

Defence Technology（防务技术） 2024年第4期34卷 282-294页

作者： Wei Wang Yuchen Wang shiwei Chen Yongcang Guo Zhongjiao shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China Northwest Industries Group CO. Ltd.Xi'an 710043China

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external *** on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial *** introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated ***,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired *** the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov *** of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

关键词： Spinning glide-guided projectile Attitude control Sliding mode disturbance observer Fixed-time stable theory High-order fully actuated approach

Analytical transient phase change heat transfer model of wearable electronics with a thermal protection substrate

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第11期41卷 1599-1610页

作者： Yingli shi Junyun JI Yafei YIN Yuhang LI Yufeng XING Institute of Solid Mechanics Beihang UniversityBeijing 100191China BOE Technology Group Company Limited Beijing 100176China University Electronic Science and Technology China State Key Laboratory of Electronic Thin Films and Integrated DeviceChengdu 610054China Institute of Structure and Environment Engineering Beijing 100076China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024Liaoning ProvinceChina

As thermal protection substrates for wearable electronics,functional soft composites made of polymer materials embedded with phase change materials and metal layers demonstrate unique capabilities for the thermal protection of human ***,we develop an analytical transient phase change heat transfer model to investigate the thermal performance of a wearable electronic device with a thermal protection *** model is validated by experiments and the finite element analysis(FEA).The effects of the substrate structure size and heat source power input on the temperature management efficiency are investigated systematically and *** results show that the objective of thermal management for wearable electronics is achieved by the following thermal protection *** metal thin film helps to dissipate heat along the in-plane direction by reconfiguring the direction of heat flow,while the phase change material assimilates excessive *** results will not only promote the fundamental understanding of the thermal properties of wearable electronics incorporating thermal protection substrates,but also facilitate the rational design of thermal protection substrates for wearable electronics.

关键词： wearable electronics functional composite theoretical heat transfer analysis thermal management

Exploring the relationship between the cloud-top and tropopause height in boreal summer over the Tibetan Plateau and its adjacent region

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2018年第2期11卷 173-179页

作者： shi Chun-Hua CHANG shu-Jie GUO Dong XU Jian-Jun ZHANG Chen-Xin Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology South China Sea Institute of Marine Meteorology Guangdong Ocean University

The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period *** maximum values of cloud-top vertical cumulative frequency above the tropopause （CTAT） are concentrated in three tropical regions：the Asian summer monsoon region,Central America,and western *** contributions to the area-weighted CTAT frequency in the three regions from the Northern Hemisphere are 49.0%,13.5%,and 12.4%,***,the contribution of troposphere-to-stratosphere transport （TST） in the Asian monsoon region to global TST can be far greater than 50%,according to analysis of the continuous equation,velocity potential,and divergent wind from ERA-Interim ***,the Asian summer monsoon circulation system controls the distribution of the cloud *** the south side of the Tibetan Plateau,the maximum frequency of the cloud top,more than 10% per 500 m vertically,is most likely to appear in the core of the high-level easterlyjet near the tropopause height （16.5 km）.Over the Tibetan Plateau,the maximum frequency of the cloud top,greater than 3% per 500 m vertically,is suppressed below 11 km,far away from the thermodynamic tropopause height but close to the dynamic tropopause height of 2 PVU （potential vorticity units）.

关键词： Cloud top tropopause troposphere-to-stratospheretransport Asian summermonsoon circulation TibetanPlateau

Why does nitrogen-doped graphene oxide lose the antibacterial activity?

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第3期62卷 44-51页

作者： Jiajun Qiu Lu Liu shi Qian Wenhao Qian Xuanyong Liu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Shanghai Xuhui District Dental Center Shanghai 200032China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Graphene and its derivatives attract extensive research interests in the biomedicine field due to their outstanding physiochemical *** of studies have reported that graphene materials exhibit antibacterial ***,antibacterial mechanisms of graphene materials still remain controversial and need further ***,graphene oxide(GO)with and without nitrogen-doping were fabricated on the titanium surface by cathodic electro phoretic deposition and antibacterial activities were systematically *** showed that GO on the titanium surface presented antibacterial activity,while nitrogen-doped GO lost the antibacterial *** reason is that antibacterial mechanisms for the GO-metal system contain two ***,electron transfer occurs from bacterium's cell membrane to GO surface which destroys the bacterial respiratory chain;subsequently,electrons on GO surface induce the production of reactive oxygen species(ROS)that damage the membrane structure and eventually lead to bacterial *** nitrogen-doped GO,nitrogen atoms denote electrons into GO leading to n-type ***-doped GO as an electron donor cuts off the electron transfer from the cell membrane to GO and subsequently inhibits the production of *** is why nitrogen-doped GO exhibits no antibacterial *** work confirms the antibacterial mecha nisms for the GO-metal system with a synergistic effect of non-oxidative electron transfer and ROS mediated oxidative stress.

关键词： Graphene oxide Nitrogen-doping Antibacterial activity Electron transfer Reactive oxygen species

One-step crosslinking preparation of tannic acid particles for the adsorption and separation of cationic dyes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第5期57卷 309-318页

作者： Yujia Cui Zhiqiang Tan Yanan Wang shuxian shi Xiaonong Chen Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029China

In this study,a new tannic acid adsorbent(ethylene glycol diglycidyl ether crosslinked tannic acid,TAEGDE)for adsorptive removal of dyes from water was prepared using EGDE as a cross-linking *** resultant TA-EGDE was in particulate form with rough surface morphology and a diameter ranging from 10 to 30μ*** adsorption performance of the TA-EGDE was evaluated in a flow-through mode using water samples contaminated with methylene blue(MB)and two-component mixed dyes,*** TA-EGDE provided adsorption capacity up to 721.8 mg·g^(-1)at 65°C for *** showed a high removal efficiency(99%)of MB(50 mg·L^(-1))from the water sample and could recovery 90%of the adsorbed MB by eluting with acidic ethanol aqueous *** excellent adsorption of MB and neutral red on the TA-EGDE may be the result of the synergy of electrostatic interaction andπ-π***,the TA-EGDE could separate dyes from water samples contaminated with twocomponent mixed dyes with a separation coefficient ranging from 1.8 to *** anionic TA-EGDE would be an effective adsorbent to remove and recycle dyes from the contaminated water.

关键词： Tannic acid Water treatment Cationic dyes Adsorption Recovery Dyes separation

Review on the design of high-strength and hydrogen-embrittlement-resistant steels

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1572-1589页

作者： Zhiyu Du Rongjian shi Xingyu Peng Kewei Gao Xiaolu Pang Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Institute for Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110010China

Given the carbon peak and carbon neutrality era,there is an urgent need to develop high-strength steel with remarkable hydrogen embrittlement *** is crucial in enhancing toughness and ensuring the utilization of hydrogen in emerging iron and steel ***,the pursuit of enhanced metallic materials presents a cross-disciplinary scientific and engineering *** high-strength,toughened steel with both enhanced strength and hydrogen embrittlement(HE)resistance holds significant theoretical and practical *** ensures secure hydrogen utilization and further carbon neutrality objectives within the iron and steel *** on the design principles of high-strength steel HE resistance,this review provides a comprehensive overview of research on designing surface HE resistance and employing nanosized precipitates as intragranular hydrogen *** also proposes feasible recommendations and prospects for designing high-strength steel with enhanced HE resistance.

关键词： hydrogen embrittlement surface design hydrogen traps nanosized precipitates