检索结果-南通市图书馆

A design method and numerical study for a new type parabolic trough solar collector with uniform solar flux distribution

引用

Science China(Technological Sciences) 2014年第3期57卷 531-540页

作者： wang Kun he YaLing cheng ZeDong Key Laboratory of Thermo-Fluid Science and Engineering of MOE School of Energy and Power Engineering Xi'an Jiaotong University

The non-uniform concentrated solar flux distribution on the outer surface of the absorber tube can lead to large circumferential temperature difference and high local temperature of the absorber tube wall,which is one of the primary causes of parabolic trough solar receiver(PTR)*** this paper,a secondary reflector used as a homogenizing reflector(HR)in a conventional parabolic trough solar collector(PTSC)was recommended to homogenize the solar flux distribution and thus increase the reliability of the *** design method of this new type PTSC with a HR was also ***,the concentrated solar flux distribution was calculated by adopting the Monte Carlo ray-trace(MCRT)***,the coupled heat transfer process within the PTR was simulated by treating the solar flux calculated by the MCRT method as the heat flux boundary condition for the finite volume method *** solar flux distribution on the outer surface of the absorber tube,the temperature field of the absorber tube wall,and the collector efficiency were analyzed in *** was revealed that the absorber tube could almost be heated uniformly in the PTSC with a *** a result,the circumferential temperature difference and the maximum temperature could be reduced significantly,while the efficiency tended to decrease slightly due to the inevitably increased optical *** the conditions studied in this paper,although the collector efficiency decreased by about 4%,the circumferential temperature difference was reduced from about 25 to 3 K and the maximum temperature was reduced from667 to 661 K.

关键词： parabolic trough solar collector evacuated tubular receiver secondary reflector solar flux distribution temperature distribution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

大直径圆形混凝土结构滑模沉井施工技术

引用

施工技术 2005年第S1期34卷 349-353页

作者：牛昆山王和气成淑贞冯永庆山西省长治市建筑工程总公司山西长治046000

介绍了运用的液压滑模沉井综合施工法施工的大直径圆形混凝土地下结构物,无论是在缩短施工工期、提高工程质量、确保安全文明施工,还是在节能增效方面均取得了良好的效果。

关键词：滑模沉井大直径混凝土

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

引用

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie wang Wei wang Xuheng Chen Junfang Bao Qiuyue Hao heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

教学的文化实践属性及三个基本认识向度

引用

新疆师范大学学报（哲学社会科学版） 2025年第2期46卷 137-143页

作者：程良宏王芸新疆师范大学教育科学学院新疆高等教育发展研究中心新疆乌鲁木齐830017

教学不仅是知识传递行为,而且是具有文化交往和文化生产属性的实践活动。文本认为,从教学目的、教学主体和教学内容入手探析教学在知识传递传承背后的文化实践特质,是理解教学具有文化交往和文化生产属性的三个基本认识向度。因此,要深... 详细信息

教学不仅是知识传递行为,而且是具有文化交往和文化生产属性的实践活动。文本认为,从教学目的、教学主体和教学内容入手探析教学在知识传递传承背后的文化实践特质,是理解教学具有文化交往和文化生产属性的三个基本认识向度。因此,要深入体认教学作为一种特殊的文化交往和生产实践形态,明晰以文化人、以文育人的导引和践行为目的指引,以教师与学生为文化交往和文化生产的实践主体,以教学过程中对教材与师生文化的理解再造为文化实践的基本内容。

关键词：教学实践教学的文化属性文化生产

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

高凝原油降凝剂的制备

引用

大连轻工业学院学报 2006年第1期25卷 9-11页

作者：戴洪义赵君于长顺王成和王岩大连轻工业学院化工与材料学院辽宁大连116034

分别采用碳十八直链醇、碳十六支链醇与丙烯酸合成烷基酯,将烷基酯再与顺丁烯二酸酐、苯乙烯聚合制备的三元共聚物,对辽河油田的高凝原油的降凝效果进行了评价,实验发现这两种聚合物对凝固点为30℃原油都具有较好的效果,降幅可达10℃左... 详细信息

分别采用碳十八直链醇、碳十六支链醇与丙烯酸合成烷基酯,将烷基酯再与顺丁烯二酸酐、苯乙烯聚合制备的三元共聚物,对辽河油田的高凝原油的降凝效果进行了评价,实验发现这两种聚合物对凝固点为30℃原油都具有较好的效果,降幅可达10℃左右,但对凝固点为41℃的原油较差分别为3℃和6℃。具有支链烷基结构的聚合物对原油的感受性较好,最佳降凝浓度小,降幅大。实验还发现,溶剂对石蜡的凝固点降低作用明显,但对高凝原油的凝固点降低作用甚微。

关键词：高凝原油降凝剂碳十六支链醇三元共聚物

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

除盐水站自控系统的适应性改造

引用

机械工程与自动化 2014年第3期 144-145页

作者：范彩霞李晋王成和韩学敏莱芜钢铁集团有限公司山东莱芜271104

介绍了除盐水站自控系统的改造方案,改造后提高了自动化程度,保证了设备的安全稳定生产。

关键词：除盐水站自控系统反渗透

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

舌系带短缩畸形手术整复体会

引用

中国美容医学 2012年第1期21卷 14-16页

作者：汪城河苏振民林文雄泉州市儿童医院整形外科福建泉州362000

目的:探索舌系带短缩畸形手术整复的最佳方法和最佳时机。方法:回顾2007年04月～2011年01月接受舌系带短缩治疗的516例患儿,通过分析治疗效果、治疗过程等各项目,以探讨其治疗方法、治疗时机的合理性。结果:绝大多数患儿(94.4%)术后随访... 详细信息

目的:探索舌系带短缩畸形手术整复的最佳方法和最佳时机。方法:回顾2007年04月～2011年01月接受舌系带短缩治疗的516例患儿,通过分析治疗效果、治疗过程等各项目,以探讨其治疗方法、治疗时机的合理性。结果:绝大多数患儿(94.4%)术后随访6个月～4年,舌活动良好,发音清晰。结论:舌系带短缩畸形应早期及时治疗,早期门诊行系带延长术是安全有效的治疗方法。

关键词：舌系带短缩治疗

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic Positioning Control of Surge−Pitch Coupled Motion for Small-Waterplane-Area Marine Structures

引用

China Ocean Engineering 2021年第4期35卷 598-608页

作者： he Hua-cheng XU Sheng-wen wang Lei wang Xue-feng State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

For general dynamic positioning systems,controllers are mainly based on the feedback of motions only in the horizontal ***,for marine structures with a small water plane area and low metacentric height,undesirable surge and pitch oscillations may be induced by the thruster *** this paper,three control laws are investigated to suppress the induced pitch motion by adding pitch rate,pitch angle or pitch acceleration into the feedback control *** numerical simulations are conducted with a semi-submersible platform for each control *** influences of additional terms on surge−pitch coupled motions are analyzed in both frequency and time *** mechanical constraints of the thrust allocation and the frequency characters of external forces are simultaneously *** is concluded that adding pitch angle or pitch acceleration into the feedback loop changes the natural frequency in pitch,and its performance is highly dependent on the frequency distribution of external forces,while adding pitch rate into the feedback loop is always effective in mitigating surge−pitch coupled motions.

关键词： surge−pitch coupled motion control small-waterplane-area marine structures actuation constraints frequency and time domain analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Fuzzy-based Sliding Mode Control Approach for Acceleration Slip Regulation of Battery Electric Vehicle

引用

Chinese Journal of Mechanical Engineering 2022年第4期35卷 287-297页

作者： Qin Shi Mingwei wang Zejia he cheng Yao Yujiang Wei Lin he School of Automotive and Transportation Engineering Hefei University of TechnologyHefei 230009China Laboratory of Automotive Intelligence and Electrifcation Hefei University of TechnologyHefei 230009China

Due to quick response and large quantity of electric motor torque,the traction wheels of battery electric vehicle are easy to slip during the initial phase of *** this paper,a sliding mode control approach of acceleration slip regulation is designed to prevent the slip of the traction *** wheel slip ratio is used as the state variable for the formulation of system dynamics *** fuzzy algorithm is utilized to adjust the switch function of sliding mode *** stability and robustness analysis,the sliding mode control law is transferred into C code and downloaded into vehicle control unit,which is validated under wet and dry road *** experimental results with a small overshoot and a quick response during starting indicate that the sliding mode controller has good control efect on the slip ratio *** article proposes an acceleration slip regulation method that improves the safety during acceleration for battery electric vehicle.

关键词： Electric motor torque Wheel slip ratio Stability Fuzzy algorithm Robustness analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Risk factors of recurrent choledocholithiasis following therapeutic endoscopic retrograde cholangiopancreatography

引用

hepatobiliary & Pancreatic Diseases International 2023年第3期22卷 282-287页

作者： Lin Li Jing wang cheng-cheng Tong Chi-Yi he Department of Gastroenterology The First Affiliated Hospital of Wannan Medical CollegeWuhu 241001China

Background:The risk factors for the recurrent choledocholithiasis after endoscopic retrograde cholangiopancreatography(ERCP)have not been well *** aim of this study was to explore the risk factors of recurrent ***:We carried out a retrospective analysis of data collected between January 1,2010 and January 1,*** analysis and multivariate analysis were used to explore the independent risk factors of recurrent choledocholithiasis following therapeutic ***:In total,598 patients were eventually selected for analysis,299 patients in the recurrent choledocholithiasis group and 299 patients in the control *** overall rate of recurrent choledocholithiasis was 6.91%.Multivariate analysis showed that diabetes[odds ratio(OR)=3.677,95%confidence interval(CI):1.875-7.209;Phepatic bile duct stone(OR=4.208,95%CI:2.220-7.976;Phe abovementioned risk factors are more likely to have recurrent CBD *** who eat light food frequently and have a history of drinking are less likely to present with recurrent CBD calculi.

关键词： Recurrence Choledocholithiasis Endoscopic retrograde cholangiopancreatography

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：