检索结果-南通市图书馆

中国财政管理体制改革30年规律总结与取向展望

在线全文

学校读者我要写书评

暂无评论

云南财经大学学报 2009年第2期25卷 44-49页

作者：张海燕北京师范大学经济与工商管理学院北京100875

分析中国30年来的财政管理体制改革进程,总结出财政管理体制模式选择的关键因素:社会经济主体与政府间的关系决定了政府间财政关系选择的主要模式。以此为基础,认为中国目前横向地方政府间财政分配关系的处理模式还不适应社会经济主体... 详细信息

分析中国30年来的财政管理体制改革进程,总结出财政管理体制模式选择的关键因素:社会经济主体与政府间的关系决定了政府间财政关系选择的主要模式。以此为基础,认为中国目前横向地方政府间财政分配关系的处理模式还不适应社会经济主体与政府间关系的现实需要,从而一定程度上制约了经济社会的发展。基于这一现实基础上,进一步提出中国财政管理体制改革的取向,就是建立与完善横向的地方政府间财政分配关系。

关键词：财政管理体制政府间财政关系分税制

在线全文

学校读者我要写书评

暂无评论

H桥级联整流器的原理与控制技术研究

电力电子技术 2014年第9期48卷 65-67页

作者：张海燕张超上海电机学院电气学院上海200240 中国矿业大学(北京) 机电学院北京100083

在高压领域的应用中,由于开关耐压能力的影响,使得一般的电路拓扑不能满足要求。研究了一种多H桥级联多电平的整流技术,该拓扑随着级联H桥的增多,总电压被开关管分压,降低了每个开关上的耐压要求。同时该拓扑可实现能量的双向流动,对功... 详细信息

在高压领域的应用中,由于开关耐压能力的影响,使得一般的电路拓扑不能满足要求。研究了一种多H桥级联多电平的整流技术,该拓扑随着级联H桥的增多,总电压被开关管分压,降低了每个开关上的耐压要求。同时该拓扑可实现能量的双向流动,对功率因数进行校正。探究了级联整流器四象限运行的原理、抑制谐波的方法,采用d-q解耦分析控制原理,并对如何稳定输出功率,使输出电压在不同负载下保持恒定进行了探讨。使用Matlab/Simulink进行仿真,并研制了一台低压的实验样机,通过实验验证了控制理论的可行性。

关键词：整流器 H桥级联均压控制

基于COM的呼吸道纤毛摆动频率测量软件开发

在线全文

学校读者我要写书评

暂无评论

计算机工程与应用 2008年第29期44卷 96-98,104页

作者：张海燕张罗首都医科大学生物医学工程学院北京100069 北京市耳鼻咽喉科研究所北京100730

纤毛摆动频率是准确评估纤毛运动状况的一项重要参数,为实现纤毛摆动频率测量过程的全自动化,设计并开发了基于COM的呼吸道纤毛摆动频率的测量软件。将纤毛摆动频率的精确测量方法和Visual Basic友好的界面结合在一起;使用COM和ACTIVEX... 详细信息

纤毛摆动频率是准确评估纤毛运动状况的一项重要参数,为实现纤毛摆动频率测量过程的全自动化,设计并开发了基于COM的呼吸道纤毛摆动频率的测量软件。将纤毛摆动频率的精确测量方法和Visual Basic友好的界面结合在一起;使用COM和ACTIVEX客户端技术开发一个独立运行的应用程序获取用户的输入指令,经过和OLE服务器之间的通讯,获取服务器的数据处理结果并返回给用户;软件还提供曲线图表绘制及其它辅助功能以方便用户对测量结果进行分析。实现了对纤毛摆动频率的全自动化精确测量。

关键词：纤毛摆动频率组件对象模型(COM) 自动化技术

回炉料对K441合金熔化温度及铸造工艺性的影响

在线全文

学校读者我要写书评

暂无评论

铸造 2013年第8期62卷 789-792页

作者：张海燕于兴福中航金属材料理化检测科技有限公司贵州安顺561005 中国科学院金属研究所辽宁沈阳110016 沈阳工业大学材料科学与工程学院辽宁沈阳110870

通过差热扫描量热法(DSC)测定出K441回炉料合金的初熔温度、固相线温度和液相线温度;并采用回炉料合金制备导向叶片,统计出合格率,确定出回炉料合金对初熔温度、相变温度及合金铸造工艺性的影响。研究结果表明:随返回次数的增加,回炉料... 详细信息

通过差热扫描量热法(DSC)测定出K441回炉料合金的初熔温度、固相线温度和液相线温度;并采用回炉料合金制备导向叶片,统计出合格率,确定出回炉料合金对初熔温度、相变温度及合金铸造工艺性的影响。研究结果表明:随返回次数的增加,回炉料合金的初熔温度升高,合金的固相线温度及液相线温度变化不大。对叶片的铸造和加工表明,回炉料合金叶片的合格率高于新料合金。新料合金难以将碳含量控制在较低的水平,而回炉料熔炼合金可精确控制碳含量,使其低于0.025%,可控制铸件出现裂纹。回炉料合金铸造合格率和加工合格率均好于新料合金。

关键词： K441合金回炉料合金初熔温度夹渣

Maintaining moderate levels of hypochlorous acid promotes neural stem cell proliferation and differentiation in the recovery phase of stroke

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 845-857页

作者： Lin-yan Huang Yi-De zhang Jie Chen hai-Di Fan Wan Wang Bin Wang Ju-Yun Ma Peng-Peng Li hai-Wei Pu Xin-Yian Guo Jian-Gang Shen Su-Hua Qi School of Medical Technology Xuzhou Key Laboratory of Laboratory DiagnosticsXuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Pharmacy Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina Department of Laboratory Medicine Branch Hospital of Huai’an First People’s HospitalHuai’anJiangsu ProvinceChina Department of Laboratory Medicine the Affiliated Hospital of Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Chinese Medicine The University of Hong KongHong Kong Special Administrative RegionChina

It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late ***,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain *** previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently *** simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic *** found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous ***,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid *** results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/***,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and *** suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion *** levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-*** transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear ***,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.

关键词： cell differentiation cerebral ischemia/reperfusion injury chlorination hypochlorous acid microglia neural stem cell neurogenesis nuclear translocation stroke β-catenin

2005年美国肝病学会肝细胞癌诊断治疗推荐意见(摘要)

在线全文

学校读者我要写书评

暂无评论

中华肝脏病杂志 2006年第7期14卷 556-557页

作者：张海燕罗生强解放军第三○二医院感染11科北京100039

美国Hepatology杂志于2005年11月刊登了由Bruix和Sherman共同执笔的美国肝病学会肝细胞癌（HCC）诊治的临床实践指南。现摘译指南中推荐的建议及部分重要的图表。

关键词：癌,肝细胞诊断治疗

非连续阻抗粘接结构脱粘缺陷的稀布阵列超声成像

在线全文

学校读者我要写书评

暂无评论

物理学报 2023年第2期72卷 144-152页

作者：张辉朱文发范国鹏张海燕上海工程技术大学城市轨道交通学院上海201620 上海大学通信与信息工程学院上海200444

无砟轨道是典型的非连续阻抗粘接结构,在重载、环境恶化等因素的影响下,脱粘现象频发,严重危及列车运行安全.本文提出一种高精度阵列超声快速成像方法,建立考虑层间声速差异的非连续阻抗粘接结构声速理论模型,采用射线追踪方法获取声波... 详细信息

无砟轨道是典型的非连续阻抗粘接结构,在重载、环境恶化等因素的影响下,脱粘现象频发,严重危及列车运行安全.本文提出一种高精度阵列超声快速成像方法,建立考虑层间声速差异的非连续阻抗粘接结构声速理论模型,采用射线追踪方法获取声波在介质中的传播路径和时间.基于实数编码设计高自由度稀布阵列,构建稀布阵列合成孔径聚焦技术(synthetic aperture focusing technique,SAFT)成像,提高检测效率.在无砟轨道结构上的实验结果表明:射线追踪方法能够准确计算超声波的传播路径和传播时间,提高检测精度;优化设计的稀布阵列方向图主瓣宽度窄,旁瓣增益低,可提高检测效率和声场指向性;脱粘缺陷成像误差在±5%以内时,稀布阵列SAFT成像方法效率提高了30.9%,可为该类缺陷检测提供理论支撑.

关键词：超声成像稀布阵列非连续阻抗脱粘

Microalbuminuria associated with systolic blood pressure and arterial compliance in Chinese metabolic syndrome patients

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2007年第16期120卷 1395-1399页

作者： LI Xin-li XU Qiong LU Xin-zheng zhang hai-feng ZHOU yan-li CAO Ke-jiang HUANG Jun Department of Cardiology First Aftiliated Hospital of Nanjing Medical University Nanjing 210029 China

Background There is significant evidence showing that microalbuminuria and arterial compliance are sensitive markers for early cardiovascular diseases. However, whether microalbuminuria is associated with reduced arterial compliance in Chinese metabolic syndrome （MS） patients remains unknown. Methods According to the definition of MS proposed by ATPⅢ in 2001, USA, subjects （n=362） were divided into three groups according to the number of risk factors： group 1 （control）, group 2 （medium, 〈 3 risk factors） and group 3 （MS, ≥ 3 risk factors）. Both large artery compliance （C1） and small artery compliance （C2） were measured with the CVProfilor DO-2020 Cardiovascular Profiling System, and microalbuminuria was evaluated with the ratio of albumin to urine creatinine. Results （1） As C1 and C2 levels elasticity decreased, albumin creatinine ratio （ACR） and the prevalence of microalbuminuria increased within those groups with MS risk factors. C1 and C2 were negatively correlated with the ranking of MS risk factors, ACR was positively correlated with the ranking of MS risk factors （all P〈0.05）. （2） Subjects were also categorized into a microalbuminuria group and a normal group, C1 and C2 in the microalbuminuria group were lower than in the normal group. （3） Multivariate regression analysis showed that increased systolic blood pressure （SBP） and reduced arterial compliance were the main risk factors for microalbuminuria in the MS group. Conclusions The risk of developing microalbuminuria was higher in the subjects with multiple metabolic abnormalities. Increased systolic blood pressure and reduced arterial compliance may be the main predictors for microalbuminuria in MS.

关键词： metabolic syndrome microalbuminuria arterial elasticity

Effects of chronic multiple stress on learning and memory and the expression of Fyn,BDNF,TrkB in the hippocampus of rats

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2007年第8期120卷 669-674页

作者： LI Xiao-heng LIU Neng-bao zhang Min-hai ZHOU yan-ling LIAO Jia-wan LIU Xiang-qian CHEN Hong-wei Department of Histology and Embryology Tongji Medical School of Huazhong University of Science and Technology Wuhan 430030 China

Background The effect of chronic stress on cognitive functions has been one of the hot topics in neuroscience. But there has been much controversy over its mechanism. The aim of this study was to investigate the effects of chronic multiple stress on spatial learning and memory as well as the expression of Fyn, BDNF and TrkB in the hippocampus of rats. Methods Adult rats were randomly divided into control and chronic multiple stressed groups. Rats in the multiple stressed group were irregularly and alternatively exposed to situations of vertical revolution, sleep expropriation and restraint lasting for 6 weeks, 6 hours per day with night illumination for 6 weeks. Before and after the period of chronic multiple stresses, the performance of spatial learning and memory of all rats was measured using the Morris Water Maze （MWM）. The expression of Fyn, BDNF and TrkB proteins in the hippocampus was assayed by Western blotting and immunohistochemical methods. The levels of Fyn and TrkB mRNAs in the hippocampus of rats were detected by RT-PCR technique. Results The escape latency in the control group and the stressed group were 15.63 and 8.27 seconds respectively. The performance of spatial learning and memory of rats was increased in chronic multiple stressed group （P〈0.05）. The levels of Fyn, BDNF and TrkB proteins in the stressed group were higher than those of the control group （P〈0.05）. The results of immunoreactivity showed that Fyn was present in the CA3 region of the hippocampus and BDNF positive particles were distributed in the nuclei of CA1 and CA3 pyramidal cells as well as DG granular cells. Quantitative analysis indicated that level of Fyn mRNA was also upregulated in the hippocampus of the stressed group （P〈0.05）. Conclusions Chronic multiple stress can enhance spatial learning and memory function of rats. The expression of Fyn, BDNF and TrkB proteins and the level of Fyn mRNA are increased in the stessed rat hippocampus. These suggest that Fyn and BDNF/

关键词： chronic multiple stress learning and memory Fyn BDNF TrkB hippocampus