检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2018年第1期26卷 67-72页

作者： panliang Zhang pan jiang Weifeng Xu Yu Liu Biquan Xiong Yunren Qiu Kewen Tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China College of Chemical Engineering Xiangtan UniversityXiangtan 411105China

In this work,the kinetic study on reactive extraction ofα-cyclopentylmandelic acid(α-CPMA)enantiomers was performed in a Lewis cell using hydroxyethyl-β-cyclodextrin(HE-β-CD)as chiral *** enantioselective complexation equilibrium between HE-β-CD andα-CPMA enantiomers was studied by phase solubility *** important process parameters affecting the initial extraction rate were separately studied and the reaction rate equations were *** optimal conditions for kinetic study were as follows:stirring speed of 75 r·min^(-1),interfacial area of 12.56 cm^2,pH of 2.5,initial HE-β-CD concentration of 0.05 mol·L^(-1),initialα-CPMA concentration of 5 mmol·L^(-1),and temperature of 278 *** reaction has been found to be first order inα-CPMA and second order in HE-β-CD with the forward rate constants of 2.056×10^(-3)m^6·mol^(-2)·s^(-1)and 1.459×10^(-3)m^6·mol^(-2)·s^(-1)for(S)-α-CPMA and(R)-α-CPMA,*** complexation equilibrium constants were evaluated as 61 L·mol^(-1) and 117 L·mol^(-1)for(S)-α-CPMA and(R)-α-CPMA,and the intrinsic enantioselectivity is estimated as 1.92.

关键词： Kinetics Liquid-liquid extraction Chiral resolution α-Cyclopentylmandelic acid

Analysis of a reduced-ML algorithm in BLAST

在线全文

学校读者我要写书评

暂无评论

Science in China(Series F) 2008年第12期51卷 2094-2100页

作者： pan Wen jiang ZhanJun DU ZhengFeng WANG Yan YOU XiaoHu National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

The performance of ML algorithm is much better than other algorithms in the MIMO wireless communication system. However, it is based on the expense of an increase in the complexity. A reduced maximum likelihood （RML） algorithm is proposed in this paper, which derives from the combination of the ML and ZF algorithms. It is shown that the complexity of RML is far lower than that of ML, while in the same performance condition by both theoretic analyses and simulation.

关键词： MIMO BLAST ML

Analysis of active sites for N_2 and H^+ reduction on FeMo-cofactor of nitrogenase

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第15期52卷 2088-2094页

作者： GUAN Feng ZHAO DeHua pan Miao jiang Wei LI Jilun State Key Laboratory for Agrobiotechnology and Department of Microbiology & Immunology China Agricultural University Beijing100094 China

Dinitrogen (N2) and proton (H+),which act as physiological substrates of nitrogenase,are reduced on FeMo-co of the MoFe protein. However,researchers have different opinions about their exact reduction sites. Nitrogenases were purified from the wild type (WT) and five mutants of Azotobacter vinelandii (Av),including Qα191K,Hα195Q,nifV-,Qα191K/nifV- and Hα195Q/nifV-; and the activities of these en-zymes for N2 and H+ reduction were analyzed. Our results suggest that the Fe2 and Fe6,atoms closed to the central sulfur atom (S2B) within FeMo-co,are sites for N2 binding and reduction and the Mo atom of FeMo-co is the site for H+ reduction. Combining these data with further bioinformatical analysis,we propose that two parallel electron channels may exist between the 8Fe7S cluster and FeMo-co.

关键词：固氮酶固氮菌双氮质子还原电子转移路径

蜗壳断面形状对大型双吸泵性能影响的数值模拟

在线全文

学校读者我要写书评

暂无评论

中国农村水利水电 2024年第7期 262-269页

作者：赵万勇潘江龙胡炳彤张宇翔于帅兰州理工大学能源与动力工程学院甘肃兰州730050

为研究蜗壳不同断面形状对大型双吸离心泵性能的影响,在确保其他因素不变的条件下,设计3种不同的蜗壳方案进行瞬态数值模拟。结果表明:3种蜗壳断面方案在设计工况下,圆形蜗壳的效率最高为90.7%,其次是梨形蜗壳,效率为90.2%,矩形蜗壳的... 详细信息

为研究蜗壳不同断面形状对大型双吸离心泵性能的影响,在确保其他因素不变的条件下,设计3种不同的蜗壳方案进行瞬态数值模拟。结果表明:3种蜗壳断面方案在设计工况下,圆形蜗壳的效率最高为90.7%,其次是梨形蜗壳,效率为90.2%,矩形蜗壳的效率最低为88.9%,且圆形蜗壳的高效区有所扩大;在各流量工况下圆形蜗壳能量损失率均为最少,在设计工况时圆形蜗壳的能量损失率为0.3%,矩形蜗壳的能力损失率为1.1%;在大流量和设计流量下,圆形蜗壳的叶轮所受径向力均最小,梨形蜗壳次之,矩形蜗壳最大;在设计工况下,3种蜗壳方案对蜗壳上的压力脉动均呈现周期性变化,圆形蜗壳在各检测点处压力脉动的振幅幅度均为最小。

关键词：双吸离心泵蜗壳断面形状径向力能量损失压力脉动

维普期刊数据库博看期刊

Real-Time Intelligent Diagnosis of Co-frequency Vibration Faults in Rotating Machinery Based on Lightweight-Convolutional Neural Networks

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 264-282页

作者： Xin pan Xiancheng Zhang Zhinong jiang Guangfu Bin Beijing Key Laboratory of Health Monitoring and Self-recovery for High-End Mechanical Equipment College of Mechanical and Electrical EngineeringBeijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Engine Health Monitoring-Control and Networking(Ministry of Education) College of Mechanical and Electrical EngineeringBeijing University of Chemical TechnologyBeijing 100029China College of Mechanical Engineering Hunan University of Science and TechnologyXiangtan 411201China

The co-frequency vibration fault is one of the common faults in the operation of rotating equipment,and realizing the real-time diagnosis of the co-frequency vibration fault is of great significance for monitoring the health state and carrying out vibration suppression of the *** engineering scenarios,co-frequency vibration faults are highlighted by rotational frequency and are difficult to identify,and existing intelligent methods require more hardware conditions and are exclusively ***,Lightweight-convolutional neural networks(LW-CNN)algorithm is proposed in this paper to achieve real-time fault *** critical parameters are discussed and verified by simulated and experimental signals for the sliding window data augmentation *** on LW-CNN and data augmentation,the real-time intelligent diagnosis of co-frequency is ***,a real-time detection method of fault diagnosis algorithm is proposed for data acquisition to fault *** is verified by experiments that the LW-CNN and sliding window methods are used with high accuracy and real-time performance.

关键词： Co-frequency vibration Real-time diagnosis LW-CNN Data augmentation

双吸离心泵吸水室隔舌位置对空化性能影响分析

在线全文

学校读者我要写书评

暂无评论

中国农村水利水电 2024年第5期 70-77页

作者：赵万勇于帅胡炳彤张宇翔潘江龙兰州理工大学能源与动力工程学院甘肃兰州730050

双吸离心泵吸水室隔舌位置的不同,影响了叶轮进口的速度及压力分布,对泵空化性能具有重要影响。以一台单级双吸离心泵为研究对象,采用数值模拟的方法研究分析隔舌位置分别位于与水平方向呈45°(原模型),90°,135°及-45°四种吸水室内... 详细信息

双吸离心泵吸水室隔舌位置的不同,影响了叶轮进口的速度及压力分布,对泵空化性能具有重要影响。以一台单级双吸离心泵为研究对象,采用数值模拟的方法研究分析隔舌位置分别位于与水平方向呈45°(原模型),90°,135°及-45°四种吸水室内部流动变化对空化性能的影响。结果表明:采用隔舌位于90°和135°的吸水室,吸水室出口附近低压区明显增大,出口与转速方向相反的圆周分速度范围逐渐增大,在叶轮进口水力损失逐渐增大,临界空化数逐渐上升,泵空化性能降低。采用隔舌位于-45°的吸水室,吸水室出口附近低压区明显减少,出口不再存在与转速方向相反的圆周分速度,在叶轮进口水力损失减小,小流量及额定工况下虽然临界空化数变化不大,但在空化各个阶段叶轮内空泡率及空化区域均有所降低,在大流量工况下临界空化数下降较为明显。综合比较之下隔舌-45°吸水室,具有较好的空化性能。为吸水室的设计提供一定参考。

关键词：双吸泵吸水室隔舌空化性能

维普期刊数据库博看期刊

提高中医住院医师针灸技能的临床带教模式探索

在线全文

学校读者我要写书评

暂无评论

中国毕业后医学教育 2024年第4期8卷 311-315页

作者：娄必丹石文英余兆安潘江湖南中医药大学第一附属医院针灸推拿康复科湖南长沙410007

目的在中医住院医师规范化培训(简称住培)大纲中要求所有住院医师均要到针灸科进行轮转学习,如何提高住院医师尤其是非针灸科住院医师在针灸科的培养质量,提高他们对针灸基本技术的兴趣和掌握程度,湖南中医药大学第一附属医院进行了积... 详细信息

目的在中医住院医师规范化培训(简称住培)大纲中要求所有住院医师均要到针灸科进行轮转学习,如何提高住院医师尤其是非针灸科住院医师在针灸科的培养质量,提高他们对针灸基本技术的兴趣和掌握程度,湖南中医药大学第一附属医院进行了积极的实践与探索。方法根据国家、省内文件精神,结合该院实际,从加强层级管理、强化师资建设、重视入科宣教、完善教学计划和注重全程考核等方面进行施教与管理。结果该院针灸推拿康复科住培通过构建管理-师资-培训-考核综合模式,全面提升住培质量,效果显著。结论积极探索有效的临床带教模式,有利于提升住培质量,对于提高中医住院医师针灸技能具有重要意义。

关键词：中医住院医师规范化培训针灸技能带教模式

Warm/cold rolling processes for producing Fe-6.5wt% Si electrical steel with columnar grains

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2013年第6期20卷 535-540页

作者： Hua-dong Fu Zhi-hao Zhang Hong-jiang pan Yuan-ke Mo Jian-xin Xie Institute for Advanced Materials and Technology University of Science and Technology Beijing School of Materials Science and Engineering Tsinghua University

A new technical prototype for producing Fe-6.5wt% Si electrical steel sheets by directional solidification, heat treatment before rolling, warm rolling, and cold rolling was proposed in the present study. The formability of Fe-6.5wt% Si electrical steel before rolling and the reasonable process parameters of this technical prototype were obtained. Experimental results reveal that the formability of Fe-6.5wt% Si electrical steel is improved significantly under the combination of directional solidification and heat treatment before rolling. Fe-6.5wt% Si electrical steel sheets with the thickness of 0.15 ram, bright surface, few edge cracks, and high rolling yield can be successfully fabricated using this technology without any intermediate annealing during the whole rolling. The combination of directional solidification, heat treatment before rolling, warm rolling, and cold rolling can work as a new process for highly efficient and compact fabrication of Fe-6.5wt% Si electrical steel sheets.

关键词： silicon steel deformation rolling mechanical properties plasticity

Improved cold rolling workability of warm rolled Fe?6.5wt%Si electrical steel with columnar grains by annealing

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第11期22卷 1171-1182页

作者： Yuan-ke Mo Zhi-hao Zhang Jian-xin Xie Hua-dong Fu Hong-jiang pan Institute for Advanced Materials and Technology University of Science and Technology Beijing

The effects of annealing temperature（with the annealing time being constant at 1 h） on the microstructure, ordering, residual stress, mechanical properties, and subsequent cold rolling workability of Fe-6.5wt%Si electrical steel with columnar grains were investigated, where the steel was warm rolled at 500℃ with a reduction of 95%. The results show that recrystallization began to occur in the sample annealed at 575℃ and that full recrystallization occurred in the sample annealed at 625℃. When the annealing temperature was 500℃ or greater, the extent of reordering in the sample was high, which reduced the room-temperature plasticity. However, annealing at temperatures below 300℃ did not significantly reduce the residual tensile stress on the edge of the warm rolled samples. Considering the comprehensive effects of annealing temperature on the recrystallization, reordering, residual stress, and mechanical properties of the warm rolled Fe-6.5wt%Si electrical steel with columnar grains, the appropriate annealing temperature range is 300℃-400℃. Unlike the serious edge cracks that appeared in the sample after direct cold rolling, the annealed samples could be cold rolled to a total reduction of more than 71.4% without the formation of obvious edge cracks, and bright-surface Fe-6.5wt%Si electrical steel strips with a thickness less than 0.1 mm could be fabricated by cold rolling.

关键词： electrical steel cold rolling annealing mechanical properties workability

Radical treatment strategies improve the long-term outcome of recurrent atypical meningiomas

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2011年第15期124卷 2387-2391页

作者： LI Fei LAI Zhao-pan LIN jiang-kai ZHU Gang FENG Hua Department of Neurosurgery Southwest Hospital Third Military Medical University Chongqing 400038 China

Background Atypical meningioma is one of the rare subtypes of meningioma, which is lacking of optimal consensus on treatment strategies. This study aimed to investigate the radical treatment strategies to improve the long-term outcome of recurrent atypical meningiomas. Methods The prognostic factors including the age and gender of patients; the location, histology, recurrence pattern and mitotic cell rate of the tumors; and the resection extents, surgical strategies and adjuvant therapies of 15 cases of recurrent atypical meningiomas were analyzed retrospectively. Results The age and gender of patients were not associated with tumor recurrence. However, high recurrence rates and poor prognosis for atypical meningiomas were associated with the high mitotic cell rate, failure to achieve Simpson grade Ⅰ-Ⅱ resection, and without the dura and bone flap replacement intraoperatively. Post-operative radiotherapy improved the outcomes of tumors in patients after the second surgery. Conclusion Radical treatment strategies such as dura and bone flap replacements and radiotherapy should be considered in patients diagnosed with atypical meningiomas.

关键词： recurrent atypical meningiomas neurosurgery long-term outcome management