Effect of Temperature on Sensing Performance of Optical Fiber Relative Humidity Sensor Based on Nafion-crystal Violet Film

The optical fiber relative humidity sensor based on Nafion-crystal violet film was developed. The effect of samples temperature in the range from 299.15 K to 324.15 K on the sensing performance of the sensor was investigated. The mathematical function between temperature and the sensitivity of the sensor was established according to the reactive theory of sensor to the relative humidity, which was validated with the experiment. With the research, the application range of the sensor was extended, which made the sensor keep a good veracity when it was used in situ.国家“八六三”计划海洋监测技术主题项目(批准号:818-09-07)资助

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今日、一部を除いて、多くの大学に勤務する教員は、研究活動と教育やその他の学務との両立の面で、大きな困難に直面している。本研究は、大学教員の研究意欲に影響を与える要因を明らかにするため、大学の組織における研究促進のための方策や資源（物理的・制度的な支援、組織構成の柔軟性）、教育活動と研究活動とのニーズの一致、研究時間の不足といった要因が、教員の研究意欲にどのような影響を及ぼしているかを、質問紙調査により検討した。大学教員1250名に回答を依頼し、314名から有効回答を得た。その結果、先行研究と同様、大学からの物理的・制度的な支援が研究意欲を促進するとともに、大学組織構成の柔軟性が研究意欲を向上させる面と低下させる面の両方を持つこと、教育活動と研究活動とのニーズの一致が研究意欲を促進することなどが明らかとなった。また、研究時間が不足すると教員は教育が研究に結びつくような工夫をする傾向があることが示された

Effect of temperature on sensing performance of optical fiber relative humidity sensor based on nafion-crystal violet film

The optical fiber relative humidity sensor based on Nafion-crystal violet film was developed. The effect of sample's temperature in the range from 299.15 K to 324.15 K on the sensing performance of the sensor was investigated. The mathematical function between temperature and the sensitivity of the sensor was established according to the reactive theory of sensor to the relative humidity, which was validated with the experiment. With the research, the application range of the sensor was extended, which made the sensor keep a good veracity when it was used in situ

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

Surface Tension-Driven Flow and Its Correlation with Mass Transfer during L-DED of Co-Based Powders

Laser direct energy deposition (L-DED) is one of the most promising additive manufacturing methods, which has been paid more and more attention in recent years. An improved heat and mass transfer model was developed here to analyze thermal behavior, driving force, surface tension-driven flow and its correlation with dilution during L-DED of Co-based powders to a 38MnVS substrate. Thermal behavior was firstly studied for its fundamental influence on fluid flow and mass transfer. Next, the roles of capillary force and thermal capillary force were characterized using both the dimensional analysis and simulation methods, and the mechanism of surface tension-driven flow was also qualitatively investigated. Finally, flow characteristics inside the melt pool were studied in detail and their correlation with the dilution phenomenon was analyzed based on the multi-component mass transfer model. The temperature gradient was found to be much larger at the front of the melt pool, and it took about 200 ms for the melt pool to reach a quasi-steady condition. Moreover, sharp changes in the curvature of the solid/liquid boundary were observed. Surface tension was demonstrated as the main driver for fluid flow and resulted in centrally outward Marangoni flow. Capillary force contributes to the reduction of the curvature of the free surface, and thermal capillary force (Marangoni force) dominated the Marangoni convection. Alloy elements from the powders, such as Co and Ni, were added to the front part of the melt pool and mainly diluted at the upper side of the rear region near the symmetric plane of the melt pool. Fundamental results in this work provide a valuable understanding of the surface tension-driven flow and its correlation with concentration dilution during the additive manufacturing process