检索结果-南通市图书馆

Research on Test and Trusted Defense of Railway Communication Network based on Zigbee and GPRS

在线全文

学校读者我要写书评

暂无评论

Research on Test and Trusted Defense of Railway Communicatio...

Research on Railway Real-time Online Power Supply Automation Network Communication System

作者： Li Liu Wei Liu kaiqin peng Wuhan Railway Vocational College of Technology Hubei Provincial Water Resources and Hydropower Planning Survey and Design Institute

Using the respective characteristics of ZigBee and GPRS technology,it shows its reliability and security in data *** the same time,the combination of the two communication modes brings complementary *** paper studies the railway communication network test and credible defense based on ZigBee and *** system adopts the communication mode of waking up module when star topology and requirement are adopted,which effectively reduces the power consumption of each sensor node and the probability of collision between sensor nodes when reporting data to sink *** GPRS network to transmit data of sink node has changed the limitation of traditional wireless sensor networks that need to rely on wired public network for data *** system scheme of low cost and low power wireless sensor network based on ZigBee technology and GPRS network proposed in this paper has broad application prospects in environmental monitoring,military,medical health,home intelligent monitoring and wireless meter reading system.

关键词： ZigBee GPRS communication network monitoring system

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Research on Railway Real-time Online Power Supply Automation...

作者： Li Liu Wei Liu kaiqin peng Wuhan Railway Vocational College of Technology Hubei Provincial Water Resources and Hydropower Planning Survey and Design Institute

Railway construction has entered a stage of rapid *** design and construction of high-speed railways are further *** the face of competition from advanced technologies,it is very urgent to study the real-time online power supply automation system for *** the same time,network communication problems have become a core issue in the research and development of traction power supply automation *** this paper,the communication system is *** high-speed railway runs at high speed,the train time interval is short,and the maintenance time is *** the premise of considering the safe and reliable operation of the system,the whole data of TPSAS is re-planned according to the principle of management and control diversion *** solution for industrial Ethernet of traction substation is proposed,which is distributed switching double-loop fiber self-healing *** shows that TSAS adopts distributed-switched double-loop fiber self-healing Ethernet,which is a better choice for railway network communication systems.

关键词： Railway Power supply automation Industrial ethernet Communication real-time

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

县域农村劳动力转移过程中存在的问题及原因

科技创业月刊 2007年第10期20卷 7-9页

作者：彭开勤武汉铁路职业技术学院湖北武汉430205

针对当前农村劳动力转移过程中存在的问题,研究分析了当前我国县域经济中农村劳动力转移受阻的原因,分别从农村劳动力隐性失业问题、农业劳动力非农化与农村城镇化进程之间滞后的问题入手,结合农村劳动力转移受阻的外部因素和自身因素,... 详细信息

针对当前农村劳动力转移过程中存在的问题,研究分析了当前我国县域经济中农村劳动力转移受阻的原因,分别从农村劳动力隐性失业问题、农业劳动力非农化与农村城镇化进程之间滞后的问题入手,结合农村劳动力转移受阻的外部因素和自身因素,分析了县域农村劳动力转移存在的问题及原因,以期为制定合理性转移的政策提供参考。

关键词：农村劳动力劳动力转移陷性失业农村城镇比

Time-Periodic Solutions to Quasilinear Hyperbolic Systems on General Networks

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第1期45卷 41-72页

作者： peng QU School of Mathematical Sciences Fudan UniversityShanghai 200433China

For quasilinear hyperbolic systems on general networks with time-periodic boundary-interface conditions with a dissipative structure,the existence and stability of the time-periodic classical solutions are discussed.

关键词： Time-periodic solution Quasilinear hyperbolic system General net-work Classical solution Asymptotic stability

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 82-90页

作者： Kun Gao Yan peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

医护一体化模式在胸腰椎骨折患者护理中的应用

在线全文

学校读者我要写书评

暂无评论

临床医学工程 2020年第5期27卷 665-666页

作者：彭凯琴彭惠欣广州市红十字会医院骨科二区广东广州510220

目的探讨医护一体化模式在胸腰椎骨折患者护理中的应用效果。方法将46例胸腰椎骨折患者随机分为对照组(n=23)和观察组(n=23)。对照组采用常规护理,观察组在对照组基础上采用医护一体化模式,两组均连续护理14 d。对比两组患者的相关手术... 详细信息

目的探讨医护一体化模式在胸腰椎骨折患者护理中的应用效果。方法将46例胸腰椎骨折患者随机分为对照组(n=23)和观察组(n=23)。对照组采用常规护理,观察组在对照组基础上采用医护一体化模式,两组均连续护理14 d。对比两组患者的相关手术指标、护理前后VAS评分及并发症发生率。结果观察组的术中出血量少于对照组,手术时间、住院时间短于对照组(P均0.05);护理后,两组的VAS评分低于护理前,且观察组的VAS评分低于对照组(P均<0.05)。观察组的并发症发生率为8.70%,明显低于对照组的34.78%(P <0.05)。结论医护一体化模式在胸腰椎骨折患者护理中的应用效果显著,可有效减轻患者的疼痛情况,减少术中出血量,缩短手术时间和住院时间,降低并发症发生率,值得临床推广应用。

关键词：胸腰椎骨折医护一体化模式并发症

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Two-Stage Online Debiased Lasso Estimation and Inference for High-Dimensional Quantile Regression with Streaming Data

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

Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： peng Yanjin WANG Lei School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

In this paper,the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(QR)models in the presence of streaming *** the first stage,the authors modify the QR score function based on kernel smoothing and obtain the online lasso smoothed QR estimator through iterative *** estimation process only involves the current data batch and specific historical summary statistics,which perfectly accommodates to the special structure of streaming *** the second stage,an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be *** authors conduct extensive numerical experiments to evaluate the performance of the proposed *** experiments demonstrate the effectiveness of the proposed method and support the theoretical *** application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regres-sion

Electronic origin of structural degradation in Li-rich transition metal oxides:The case of Li_(2)MnO_(3)and Li_(2)RuO_(3)

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2024年第4期45卷 82-86页

作者： peng Zhang Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics andOp toelec-tronic EngineeringShenzhen UniversityShenzhen 518060China

Li_(2)MnO_(3)and Li_(2)RuO_(3)represent two prototype Li-rich transition metal(TM)oxides as high-capacity cathodes for Li-ion batteries,which have similar crystal structures but show quite different cycling ***,based on the first-princi-ples calculations,we systematically studied the electronic structures and defect properties of these two Li-rich cathodes,in order to get more understanding on the structural degradation mechanism in Li-rich TM *** calculations indicated that the structural and cycling stability of Li_(2)MnO_(3)and Li_(2)RuO_(3)depend closely on their electronic structures,especially the energy of their highest occupied electronic states(HOS),as it largely determines the defect properties of these *** Li_(2)MnO_(3)with low-energy HOS,we found that,due to the defect charge transfer mechanism,various defects can form spontaneously in its host structure as Li ions are extracted upon delithiation,which seriously deteriorates its structural and cycling *** for Li_(2)RuO_(3),on the other hand,we identified that the high-energy HOS prevents it from the defect formation upon delithi-ation and thus preserve its cycling *** studies thus illustrated an electronic origin of the structural degradation in Li-rich TM oxides and implied that it is possible to improve their cycling performances by carefully adjusting their TM compo-nents.

关键词： defects Li-ion batteries first-principles calculations