检索结果-南通市图书馆

基于WebGL的汽轮机拆装三维可视化方法研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

热力透平 2024年第3期53卷 199-203页

作者：刘云雷乔梁倪云泽上海电气电站设备有限公司汽轮机厂上海200240

为提升汽轮机安装和检修的工作效率和质量,提出了基于WebGL的汽轮机拆装三维可视化方法。基于汽轮机安装和拆卸工艺,对汽轮机模型进行数据处理和显示优化,然后在网页端渲染,由此建立了汽轮机可视化拆装平台,实现了汽轮机产品安装和拆卸... 详细信息

为提升汽轮机安装和检修的工作效率和质量,提出了基于WebGL的汽轮机拆装三维可视化方法。基于汽轮机安装和拆卸工艺,对汽轮机模型进行数据处理和显示优化,然后在网页端渲染,由此建立了汽轮机可视化拆装平台,实现了汽轮机产品安装和拆卸的三维交互式说明和指导。研究成果可为推进汽轮机产品生命周期数字化工作提供重要参考。

关键词：汽轮机 3维可视化模型处理显示优化

Ground experimental investigations into an ejected spray cooling system for space closed-loop application

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2016年第3期29卷 630-638页

作者： Zhang Hongsheng Li yunze Wang Shengnan liu Yang Zhong Mingliang School of Aeronautic Science and Engineering Beihang University School of Automation Science and Electrical Engineering Beihang University

Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space enviromnents. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper- imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ℃ and 78.2 ℃ under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11,22 L：h to 15.76 L·h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

关键词： Ejected spray cooling systemEvaluation models Ground experiment Heat transfer performance High heat flux Space closed-loop

高架火炬附塔蒸汽管道可拆卸式支架研究与应用

在线全文

学校读者我要写书评

暂无评论

化工设备与管道 2024年第3期61卷 111-117页

作者：于浩潘博陈擎宇刘金龙李昀泽薛茂梅中国船舶集团有限公司第七一一研究所上海201108

针对现有的高架火炬附塔蒸汽管线支架采用大量焊接作业的施工方法,产生的安装偏差较大,高空焊接量多,高空作业难度大,用工成本高,检修时难以拆卸等问题,从设计、机加工、安装等方面对支架的要点和难点进行解析,研究并应用新型的高架火... 详细信息

针对现有的高架火炬附塔蒸汽管线支架采用大量焊接作业的施工方法,产生的安装偏差较大,高空焊接量多,高空作业难度大,用工成本高,检修时难以拆卸等问题,从设计、机加工、安装等方面对支架的要点和难点进行解析,研究并应用新型的高架火炬附塔蒸汽管线可拆卸式支架。新型式的支架可增加支架的可靠性,减少高空作业难度,降低项目实施成本,同时具备可拆卸功能。

关键词：火炬附塔支架可拆卸

Thinning intensity aff ects carbon sequestration and release in seasonal freeze–thaw areas

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2023年第4期34卷 993-1006页

作者： Tong Gao Xinyu Song yunze Ren Hui liu Hangfeng Qu Xibin Dong Key Laboratory of Sustainable Forest Management and Environmental Microorganism Engineering of Heilongjiang Province Northeast Forestry UniversityHarbin 150040People’s Republic of China

To explore how to respond to seasonal freeze–thaw cycles on forest ecosystems in the context of climate change through thinning,we assessed the potential impact of thinning intensity on carbon cycle *** varying the number of temperature cycles,the eff ects of various thinning intensities in four *** rate of mass,litter organic carbon,and soil organic carbon(SOC)loss in response to temperature variations was examined in two degrees of *** unfrozen season had the highest decomposition rate of litter,followed by the frozen ***-decomposed litter had a higher decomposition rate than undecomposed *** decomposition rate of litter was the highest when the thinning intensity was 10%,while the litter and SOC were *** litter had a good carbon sequestration impact in the unfrozen and freeze–thaw seasons,while the converse was confi rmed in the frozen and thaw *** best carbon sequestration impact was identifi ed in litter,and soil layers under a 20–25%thinning intensity,and the infl uence of undecomposed litter on SOC was more noticeable than that of semi-decomposed *** litter and soil can store carbon:however,carbon is transported from undecomposed litter to semi-decomposed litter and to the soil over *** summary,the best thinning intensity being 20–25%.

关键词： Forest carbon cycle Seasonal freeze–thaw Thinning Climate change

Recent active thermal management technologies for the development of energy-optimized aerospace vehicles in China

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第2期34卷 1-27页

作者： Jixiang WANG yunze LI Xiangdong liu Chaoqun SHEN Hongsheng ZHANG Kai XIONG College of Electrical Energyand Power EngineeringYangzhou UniversityYangzhou 225009China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China Institute of Engineering Thermophysics North China University of Water Conservancy and Electrical PowerZhengzhou 450045China HiWING General Aviation Equipment Corporation Limited Beijing 100074China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen Graduate SchoolShenzhen 518117China

Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste heat and heat flux to be dissipated to maintain the devices within a safe temperature range. However, both the total heat sinks aboard and the cooling capacity of currently utilized thermal control strategy are severely limited, which threatens the lifetime of the on-board equipment and even the entire flight system and shrink the vehicle’s flight time and range. Facing these thermal challenges, the USA proposed the program of "INVENT" to maximize utilities of the available heat sinks and enhance the cooling ability of thermal control strategies. Following the efforts done by the USA researchers, scientists in China fought their ways to develop thermal management technologies for Chinese advanced energy-optimized airplanes and spacecraft. This paper elaborates the available on-board heat sinks and aerospace thermal management systems using both active and passive technologies not confined to the technology in China. Subsequently, active thermal management technologies in China including fuel thermal management system, environment control system, non-fuel liquid cooling strategy are reviewed. At last, space thermal control technologies used in Chinese Space Station and Chang’e-3 and to be used in Chang’e-5 are *** issues to be solved are also identified, which could facilitate the development of aerospace thermal control techniques across the world.

关键词： Aerospace engineering Efficiency promotion Fluid dynamics Heat and mass transfer Thermal management

Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2017年第3期12卷 281-302页

作者： Shoudao HUANG Xuan WU Xiao liu Jian GAO yunze HE College of Electrical and Information Engineering Hunan University Changsha 410082 China

Electric power conversion system （EPCS）, which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine （DD-WT）. However, this component accounts for the most failures （approximately 60% of the total number） in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring （CM） and fault diagnostics （FD）. Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

关键词： direct-drive wind turbine electric power conversion system condition monitoring fault diagnosis,operation control under faults fault tolerance

Study of amplification coefficient in a water-cooling Gardon-type heat power measuring apparatus

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 Aeronautics 2015年第2期28卷 410-417页

作者： Li Miao Li yunze Zhang Hongsheng Wang Shengnan Li Yunhua liu Jia School of Automation Science and Electrical Engineering Beihang University School of Aeronautic Science and Engineering Beihang University China Dfh Satellite Co. Ltd.

A new water-cooling Gardon-type heat power measuring apparatus is designed to meet the need of heat power source management and distribution. The steady state measurement mathe- matic model of the apparatus is built up in theory and the system amplification coefficient is defined as the ratio of the heat power to the temperature difference of the device, with which the value of the measured source power can be calculated easily with the corresponding temperature difference. In order to obtain an optimal heat power measuring system, the coefficients that can influence the relationship between the amplification coefficient, the temperature difference, and the heat power are analyzed. On the basis of these analyses, a set of experimental device is constructed and a num- ber of experiments are carried on. Compared with the input heat power sample data, the error of the experimental measuring results is less than 4-2%, and the experimental measuring values are in good agreement with the calculated theoretical ones. The heat power measuring apparatus can be applied in heat flux or heat power measurement in other fields due to its simple structure and high accuracy.

关键词： Amplification coefficient Gardon-type Heat flux Heat power Measuring apparatus Water-cooling

Reliable sensors based on graphene textile with negative resistance variation in three dimensions

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第8期14卷 2810-2818页

作者： Wenpeng Han Yijun Wu He Gong Linxin liu Junxiang Yan Mengfei Li yunze Long Guozhen Shen College of Physics Qingdao UniversityQingdao 266071China State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Beijing National Laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

The weft-knitted reduced graphene oxide(r-GO)textile that is made up of many conductive r-GO coated fibers was successfully prepared dependent on the electrospray deposition ***,the r-GO textile presents negative resistance variation not only in axial direction as the pressure increases but also in transverse direction as the lateral stretch increases which makes it has the advantage to fabricate the reliable sensors based on strain-resistance *** transverse-strain and pressure sensors based on the r-GO textiles all show the excellent sensing characteristics such as high sensitivity,reliability,and good durability,*** maximum gauge factors(GF)of the transverse-sensor are 27.1 and 153.5 in the x-and/-direction,*** the practical detection range can up to 40%in the x-direction and 35%in the y-direction,*** r-GO textile pressure sensor also shows high sensitivity for a broad pressure range that with a GF up to 716.8 kPa-1 for less than 4.5 kPa region and still has more sensitive pressure sensing characteristics even the pressure goes up to 14 *** on those good performances of r-GO textile sensors,its potential applications in human body states monitoring have been studied.

关键词： reduced graphene oxide textile transverse-strain sensor pressure sensor negative resistance variation human body states

小青龙汤类方治疗小儿咳嗽变异性哮喘Meta分析

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

中医学报 2018年第10期33卷 1895-1899页

作者：刘运泽蓝皓月杨建秀王东强李志军天津中医药大学天津300193 天津市第一中心医院天津300192

目的:系统评价小青龙汤类方治疗小儿咳嗽变异性哮喘的临床疗效。方法:计算机检索Embase、Cochrane Library、Pubmed、中国知网、维普中文科技期刊数据库、万方数据库,检索时间为自建库至2016年6月,检索内容为关于小青龙汤、小青龙加石... 详细信息

目的:系统评价小青龙汤类方治疗小儿咳嗽变异性哮喘的临床疗效。方法:计算机检索Embase、Cochrane Library、Pubmed、中国知网、维普中文科技期刊数据库、万方数据库,检索时间为自建库至2016年6月,检索内容为关于小青龙汤、小青龙加石膏汤、射干麻黄汤、厚朴麻黄汤与西药对比治疗小儿咳嗽变异性哮喘的随机对照试验,由两名评价者独立筛选、评价、提取,采用Revman 5. 3软件进行Meta分析。结果:共纳入13个随机对照试验,合计1 150例患儿。Meta分析结果显示:与对照组比较,小青龙汤类方可显著提高治疗的有效率[OR=3. 24,95%CI(2. 30,4. 57),P <0. 000 01],其差异均有统计学意义。结论:小青龙汤类方治疗小儿咳嗽变异性哮喘临床疗效显著。

关键词：小青龙汤类方厚朴麻黄汤小儿咳嗽变异性哮喘 Meta分析随机对照试验