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既有铁路客车服役性能研究

中国铁路 2024年第1期 106-115页

作者：魏庆王兴华沈金鑫孙利苹杨智朋徐宁吴潇肖齐丁瑞志中国铁道科学研究院研究生部北京100081 中国国家铁路集团有限公司机辆部北京100844 中国铁道科学研究院集团有限公司机车车辆研究所北京100081 中车唐山机车车辆有限公司河北唐山063099 中车南京浦镇车辆有限公司江苏南京210012 北京交通大学机械与电子控制工程学院北京100044 西南交通大学轨道交通运载系统全国重点实验室四川成都610031 北京纵横机电科技有限公司北京100089

我国既有铁路客车保有量大、运用时空环境复杂,其服役性能的演变对运行安全和运维保障带来极大挑战。为系统掌握铁路客车服役状态,调研我国普速客车运营现状,并以车体钢结构为例,开展影响客车服役性能的因素分析。调研发现,大部分普速... 详细信息

我国既有铁路客车保有量大、运用时空环境复杂,其服役性能的演变对运行安全和运维保障带来极大挑战。为系统掌握铁路客车服役状态,调研我国普速客车运营现状,并以车体钢结构为例,开展影响客车服役性能的因素分析。调研发现,大部分普速客车已逐步进入服役中后期,5T等信息化手段实现了对客车的全面监控。不同运用环境下,钢结构腐蚀情况不同,随着运行时间/运行里程的增加,钢结构腐蚀有明显加剧趋势。针对服役期间RW2.G车体和2.9P型转向架疲劳强度开展研究,各关键部位均满足服役寿命30年设计要求;针对服役期间YZ2.T车体和CW-2.0K型转向架开展跟踪测试,发现转向架个别关键承载位置产生损伤值较大。针对服役期间2.T型客车动力学性能开展研究,采用TPDS、TCDS和添乘等手段开展跟踪测试,并结合实测车轮磨耗数据和减振器劣化数据开展仿真分析,结果表明,在1个旋修周期内,车辆运行安全性存在一定冗余;随服役时间增加,转向架关键部件的性能劣化或失效会对车辆蛇行稳定性和运行平稳性产生不利影响;开展随机参数的动力学仿真,发现极端工况下轮重减载率上升明显,应予以充分关注。

关键词：铁路客车服役性能疲劳强度钢结构转向架车辆动力学

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Efficient Chebyshev Spectral Method for Solving Linear Elliptic PDEs Using Quasi-Inverse Technique

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Numerical mathematics(Theory,Methods and Applications) 2011年第2期4卷 197-215页

作者： Fei Liu Xingde Ye xinghua wang department of mathematics Zhejiang UniversityHangzhouZhejiang 310027China

We present a systematic and efficient Chebyshev spectral method using quasiinverse technique to directly solve the second order equation with the homogeneous Robin boundary conditions and the fourth order equation with the first and second boundary *** key to the efficiency of the method is to multiply quasiinverse matrix on both sides of discrete systems,which leads to band structure *** can obtain high order accuracy with less computational *** multi-dimensional and more complicated linear elliptic PDEs,the advantage of this methodology is *** results indicate that the spectral accuracy is achieved and the proposed method is very efficient for 2.D high order problems.

关键词： Chebyshev spectral method quasi-inverse Helmholtz equation Robin boundary conditions general biharmonic equation

Mass transport in nanofluidic devices

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Science china Chemistry 2012年第4期55卷 453-468页

作者： wang Chen XU JingJuan CHEN HongYuan XIA xinghua State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China department of Physical Chemistry China Pharmaceutical UniversityNanjing 210009China

Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Debye length, and the size of biomolecules such as DNA and proteins gives the unique features of nanofluidic devices. Of various unique properties of the nanofluidics, mass transport in nanochannel plays determining roles in fundamental reaches and practical applications of nanofluidic device. Thus, much work including numerical and experimental researches has been performed to investigate the mass transport behaviors in nanofluidic devices. This review summarizes the fabrication technologies for nanofluidic devices, the mass transport behaviors in nanochannel, and their applications in bioanalysis. The main focus will be laid on the effects of nanochannel size and surface charge on mass transport including electrokinetic transport of charged analytes, diffusion of electric neutral molecules, ionic current rectification, concentration polarization, nonlinear electrokinetic flow at the micro-nanofluidic interfaces.

关键词： nanofluidics mass transport fabrication ionic current rectification microfluidics concentration polarization nonlinear electrokinetic flow bioanalysis

NOVEL METHOD FOR ERROR ANALYSIS AND SELF-CALIBRATION OF LASER TRACKING MIRROR MECHANISM

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 1-6页

作者： OUyang Jianfei LIU Wanli QU xinghua YAN Yonggang {2. Zhankui Precision Engineenng Institute Henan Polytechnic University Jiaozuo 454003 China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University Tianjin 300072 China department of Mechanical and Electric Engineering Henan Institute of Science and Technology Xinxiang 453003 China

Laser tracking system （LTS） is an advanced device for large size 3D coordinates measuring with the advantages of broad range, high speed and high accuracy. However, its measuring accuracy is highly dominated by the geometric errors of the tracking mirror mechanism. Proper calibration of LTS is essential prior to the use of it for metrology. A kinematics model that describes not only the motion but also the geometric variations of LTS is developed. Through error analysis of the proposed model, it is claimed that gimbals axis misalignments and tracking mirror center off-set are the key contributors to measuring errors of LTS. A self-calibration method is presented of calibrating LTS with planar constraints. Various calibration strategies utilizing single-plane and multiple-plane constraints are proposed for different situations. For each calibration strategy, issues about the error parameter estimation of LTS are exploded to find out in which conditions these parameters can be uniquely estimated. Moreover, these conditions reveal the applicability of the planar constraints to LTS self-calibration. Intensive studies have been made to check validity of the theoretical results. The results show that the measuring accuracy of LTS has increased by 5 times since this technique for calibration is used.

关键词： Laser tracking Error analysis Self-calibration Planar constraints Tracking mirror

慢性自发性荨麻疹伴与不伴血管性水肿患者131例临床特征回顾分析

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中华皮肤科杂志 2024年第6期57卷 510-515页

作者：王林霞张立明史美慧高兴华陈洪铎肖汀中国医科大学附属第一医院皮肤科、卫健委免疫皮肤病学重点实验室、教育部免疫皮肤病学重点实验室、免疫性皮肤病诊治技术国家地方联合工程研究中心沈阳110001

目的探讨伴血管性水肿(AE)的慢性自发性荨麻疹(CSU)患者的临床特点。方法回顾性分析2.19年1月至2.2.年12.于中国医科大学附属第一医院诊治的活动期成人CSU门诊患者的临床资料,包括性别、年龄、病程、血管性水肿伴发情况、日荨麻疹活动... 详细信息

目的探讨伴血管性水肿(AE)的慢性自发性荨麻疹(CSU)患者的临床特点。方法回顾性分析2.19年1月至2.2.年12.于中国医科大学附属第一医院诊治的活动期成人CSU门诊患者的临床资料,包括性别、年龄、病程、血管性水肿伴发情况、日荨麻疹活动度评分、既往治疗史、既往史、家族史、实验室检查结果、疗效和不良反应。治疗方案参照2.18版中国荨麻疹诊疗指南和2.14版美国荨麻疹诊疗指南。统计分析采用Mann-Whitney U检验、两独立样本t检验、χ2.验、校正χ2.验及Fisher精确检验。结果纳入CSU患者131例,男53例,女78例;初诊年龄(44.6±13.3)岁,病程[M(Q1,Q3)]4.0(2.0,10.0)个月;伴AE组58例,无AE组73例。伴AE组病程[6.0(3.0,2..0)个月]显著长于无AE组[3.5(2.0,6.0)个月,Z=-2.78,P=0.005],日荨麻疹活动度评分[5.0(3.0,5.3)分]亦显著高于无AE组[4.0(3.0,5.0)分,Z=-2.63,P=0.008]。伴AE组用标准剂量第二代H1抗组胺药(sgAH)达到完全控制的CSU患者比例(8.6%,5/58)低于无AE组(2..7%,18/73),未控制比例(91.4%,53/58)高于无AE组(74.0%,54/73),差异有统计学意义(Z=-2.53,P=0.011);用sgAH单药加量或多种sgAH 2.4倍相当剂量达完全控制及未控制的患者比例、用4倍相当剂量sgAH联合非H1抗组胺药达完全控制及未控制的患者比例,两组间差异均无统计学意义(P>0.05)。结论与无AE的CSU患者相比,伴AE的CSU患者病程更长,疾病活动度更高,标准剂量sgAH治疗达到完全控制的患者比例更低,而未控制的患者比例更高。

关键词：荨麻疹血管性水肿慢性自发性荨麻疹临床特点治疗结果

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三伏灸对变应性鼻炎血清总IgE水平的影响

中国中医药现代远程教育 2024年第11期22卷 104-106页

作者：朱金矿王施君龚智程石狮市医院检验科福建石狮362700 福建中医药大学附属晋江中医院脾胃病科福建晋江362200 石狮市医院康复医学科福建石狮362700

目的探讨三伏灸治疗变应性鼻炎(AR)的效果及其对血清总IgE的影响,以期为此病的临床效果评价提供客观依据。方法选取50例AR患者作治疗组,行三伏灸治疗,观察6个月后的近期效果,于治疗前后检测血清总IgE水平;并选取2.例健康体检者作对照组... 详细信息

目的探讨三伏灸治疗变应性鼻炎(AR)的效果及其对血清总IgE的影响,以期为此病的临床效果评价提供客观依据。方法选取50例AR患者作治疗组,行三伏灸治疗,观察6个月后的近期效果,于治疗前后检测血清总IgE水平;并选取2.例健康体检者作对照组,检测血清总IgE水平。结果治疗组的总有效率为86.0%(43/50)。治疗前,治疗组患者血清总IgE阳性有39例(占78.0%),且血清总IgE水平明显高于对照组(P<0.01);经过三伏灸治疗后,治疗组血清总IgE水平明显降低,但仍明显高于对照组(P<0.01)。结论AR患者经三伏灸治疗后,血清总IgE水平明显降低,可为AR的疗效评价提供客观依据。三伏灸可通过降低IgE水平达到治疗AR的效果。

关键词：鼻鼽变应性鼻炎三伏灸中医外治法

Enantioselective Organocatalytic Aza-Michael Additions of Phthalimide Derivatives to α,β-Unsaturated Aldehydes

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Chinese Journal of Chemistry 2013年第6期31卷 726-730页

作者： shijun Ma Ming Liu Yaodong Huang Yongmei wang department of Chemistry The Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China department of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

Phthalimide derivatives as nitrogen nucleophiles with α,β-unsaturated aldehydes for asymmetric aza-Michael additions have been reported. The reactions proceed smoothly to afford corresponding Michael adducts in goo... 详细信息

关键词： phthalimide derivatives α,β-unsaturated aldehydes aza-Michael addition enantioselectivity

Flexible path planning-based reconfiguration strategy for maximum capacity utilization of battery pack

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Journal of Energy Chemistry 2023年第11期86卷 362-372,I0008页

作者： xinghua Liu Guoyi Chang Jiaqiang Tian Zhongbao Wei Xu Zhang Peng wang School of Electrical Engineering Xi’an University of TechnologyXi’an 710061ShaanxiChina School of Electrical Engineering and Automation Anhui UniversityHefei 230039AnhuiChina National Engineering Research Centre for Electric Vehicles School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Institute for Advanced Research Anhui University of Science and TechnologyHefei 230000AnhuiChina School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

Maximizing the utilization of lithium-ion battery capacity is an important means to alleviate the range anxiety of electric *** pack inconsistency is the main limiting factor for improving battery pack capacity utilization,and poses major safety hazards to energy storage *** solve this problem,a maximum capacity utilization scheme based on a path planning algorithm is ***,the reconfigurable topology proposed is highly flexible and fault-tolerant,enabling battery pack consistency through alternating cell discharge and reducing the increased risk of short circuits due to relay *** Dijkstra algorithm is used to find the optimal energy path,which can effectively remove faulty cells and find the current path with the best consistency of the battery pack and the lowest relay ***,the effectiveness of the scheme is verified by hardware-in-the-loop experiments,and the experimental results show that the state-of-charge SOC consistency of the battery pack at the end of discharge is increased by 34.18%,the relay energy loss is reduced by 0.16%,and the fault unit is effectively isolated.

关键词： Lithium-ion battery Capacity maximum utilization Reconfigurable topology Digraph

Theoretical Studies on the Hydrogen-bonding and π-Stacking Interactions in the m-Nisoldipine Polymorphism Dimers

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Chinese Journal of Chemistry 2012年第2期30卷 233-240页

作者： Zhu,Min Meng,Lingpeng Zheng,shijun wang,Jing Zeng,Yanli Institute of Computational Quantum Chemistry College of Chemistry and Material ScienceHebei Normal UniversityShijiazhuangHebei 050016China School of Pharmaceutical Sciences Hebei Medical UniversityShijiazhuangHebei 050017China

The intermolecular interactions in the dimers of m-nisoldipine polymorphism were studied by B3LYP calculations and quantum theory of ＂atoms in molecules＂（QTAIM） studies. Four geometries of dimers were obtained： dimer I （a：dimer, O…H--N）, dimer II （b-dimer, O…H--N）, dimer III （b-dimer, n-stacking-c）, and dimer IV （b-dimer, n-stacking-p）. The interaction energies of the four dimers are along the sequence of II〉I〉III〉IV. The intermolecular distance of the interactions follows the order： I （O…H--N）〈II （O…H--N）, and III （n-stacking）〈 IV （n-stacking）. Both the O…H--N hydrogen-bonding and n-stacking interactions belong to weak non-covalent interactions. The O…H--N hydrogen-bonding interactions with more electrostatic characters are stronger than the n-stacking interactions. The strength of the weak interactions decreases in the order： I〉II〉III〉IV, and the electrostatic character decreases along the sequence： I〉II〉III〉IV.

关键词： intermolecular interaction QTAIM study density functional calculations hydrogen bonds n-stacking interaction