20世纪90年代以来美国地方政府行政改革与企业管理理念

19世纪末20世纪初的美国市政改革借鉴成功的企业管理体制,用专业管理人员取代职业政客及其党派机器,确立了现行的市政体制。20世纪90年代初,美国州、市两级政府再次掀起改革高潮,试图将绩效体制和以顾客为导向等成功的企业经营管理理念引入公共管理领域,以革除官僚机构积弊。历史证明,建立真正负责、高效低耗的政府,不但要借鉴成功的企业管理体制,还须借鉴成功的管理理念,进而塑造“企业型”的政府管理文化

The Dynamics of the City-Manager Plan

正式确立于19世纪末20世纪初进步运动时期的美国三大市政体制在20世纪经历了多次调整与改革。在此过程中，委员会制逐步衰落；市长暨议会制虽无较大起落，但其主要形式已过渡为“强市长型”；城市经理制显示出强大的生命力，它有效地改善了市政管理，适应了城市发展的需要，被越来越多的城市相继采用，成为美国城市中采用面最广的市政体制。在城市经理制得到较普遍认可的同时，其所倡导和实践的专业化、科学化的城市管理理念也逐渐成为政府管理领域的共识，对其他的地方政府体制产生了重要而广泛的影响。本文拟在对城市经理制的确立与发展进行整体探讨的基础上，对城市经理制的内部机制及其演化进行深入分析，力图揭示城市经理制长足发展、经...Three major American municipal government forms---city-manager plan, mayor-council plan and commission plan were officially established in the progressive movement at the turn of last century which underwent numerous adjustments and changes in the 20th century. Compared with commission plan and mayor-council, the city-manager plan has proved very successful by improving performance of municipal a...学位：历史学博士院系专业：人文学院历史学系_专门史学号：B19990200

THE EVOLUTION OF AMERICAN MUNICIPAL GOVERNMENT SYSTEM

美国国内采用的市政体制有三种 ,即 :市长暨议会制、城市经理制和委员会制。这三种体制确立于 1 9世纪末市政改革时期 ,在其后的发展过程中 ,委员会制逐步衰落 ;城市经理制则长足发展 ;“强市长型”取代“弱市长型”成为市长暨议会制的主要形式 ,并在其基础上演化出了另一亚型———行政官制。目前 ,不同城市依其规模或各自特点采纳不同的市政体制。美国市政体制确立及发展反映出市政府行政部门权力不断扩大和市政管理专业化等值得注意的趋向Three basic forms of American municipal government are identified as the mayor council, commission and council manager, which were founded in the municipal reform at the late 19th century. The commission system was emerged but then developed slowly or even declined; the city manager system proved very successful and became very popular in many medium and small sized cities. Chief Administrative Officers was added to the strong-mayor-council system. Nowadays, American cities adopted different municipal systems according to their size and character. Some noticeable trends have been found from the evolution of municipal forms: the growth of the administrative power and the professionalism of the management

Structural and functional investigation of allophycocyanin trimer

Nature has been developing and optimizing photosynthesis billions years, including green plants, algae, photosynthetic bacteria and cyanobacteria. Phycobiliproteins system, as the phycobilisomes, in cyanobacteria and red algae is the one of two major light-harvesting systems, after evolution in billions years. Allophycocyanin (APC) trimer is a primary composition of phycobilisomes core for efficient lower-energy photons funneling pathway. In 2009, Liu et al. have firstly assembled the highly soluble self-assembled recombinant APC trimer with N-terminus polyhistidine, which the entire biosynthesis pathway of APC trimer was reconstituted in Escherichia coli strain with the full-length genes of apoprotein a subunit and b subunit from Synechocystis sp. PCC 6803. The recombinant APC trimer was used to be the subject in this research. An optimum protocol with immobilized metal-ion affinity chromatography with chelating transition metal ion (Ni~(2+)) was used to purify the recombinant protein. Then, the second purification was performed to obtain APC trimer with a higher purity (A650/A620=1.346), using density gradient centrifugation. Single molecules of recombinant APC trimers were investigated with atomic force microscopy. Three-dimensional images with resolution at nanoscale indicated that the recombinant allophycocyanin trimers were approximately 1.5 nm in short axis, and 15 nm in long axis, which were in accordance with the sizes of natural allophycocyanin trimer measured by transmission electron microscopy or X-ray crystallography. Moreover, the correct conformation of recombinant allophycocyanin trimer was confirmed by fluorescence spectra (studied energy transfer ability), absorption spectra (studied the light-harvesting ability), and circular dichroism (CD) spectra (studied changes of secondary structure and aggregation state). The CD spectra of recombinant allophycocyanin induced by a wide range of pH were analyzed both at wavelengths in ultraviolet range (190-250 nm) and visible range (450-750 nm). The a-helices were the dominant secondary structure in recombinant allophycocyanin trimer by analysis of CD spectra in ultraviolet range, while the analysis of CD spectra in visible range suggested the existence of exciton-coupled pairs of phycocyanobilins, in which the energy transfer was mainly in the form of exciton splitting. By studying its spectra property variations in response to pH changes, we found that recombinant APC trimer showed good absorbance and fluorescence stability at varying pH. The conformation of chromophores in recombinant APC trimer was relatively stable, between the range of pH 4-9, which was revealed by the stable absorption and fluorescence spectra properties of recombinant APC trimer. The trimeric structure of recombinant APC was maintained while local variations of protein peptides were also shown in response to the environmental disturbance. Beyond this pH range, secondary structure as well as overall conformation of recombinant APC dramatically changed, and the energy absorption and transfer ability were also disrupted. This work demonstrated that correct function in energy transfer was retained in the recombinant allophycocyanin trimer compared with nature allophycocyanin trimer

高超声速吸气发动机燃气模拟装置

本文阐述了用于提高冲压发动机在高马赫数飞行条件下的推力,而发展的简单可靠的催化复合效应实验研究所需要高温燃气的产生方法;进行了理论分析与数值计算:成功研制了一座能产生高温空气与气态燃料燃烧产物的高温燃气激波风洞实验装置,并得到了压力为20大气压,温度为3200K,定常实验时间约为17ms且状态参数稳定的实验结果

面向地质灾害监测预警的智能多媒体传感器网络

文章针对地质灾害防御采用先进的智能多媒体传感器技术,在地质灾害区应用位移、水压、倾斜角、降雨量计等传感器组建无线传感网,并针对地灾监测传感网的特点设计了多协议支持的网络结构,实现了对山体滑坡等自然灾害监测的可靠性和预报预警的实时性,以及对环境的远程监测和控制