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921.
This paper extends previous works on total factor productivity decomposition when firms receive both operating and capital subsidies. It shows that previous works considered either the lump-sum or substitution effects of these subsidies but not together. Using constrained cost minimization as the framework it offers formal proofs to show that cost increases are inevitable if the total effects of the subsidies are considered, and that total factor productivity growth results from increasing amounts of subsidies under economies of scale and in the absence of technical change. Applications of the decomposition equations derived to a sample of transit systems finds near constant returns to scale and negative contributions of these subsidies to total factor productivity growth. Technical change reverses this decline and results in total factor productivity growth. Further, it finds that the lump-sum effects of the subsidies reduce total factor productivity more than does the substitution effect.  相似文献   
922.
终端短路法进行数据处理时会涉及到解超越方程的问题,如果采用手工计算费时且会降低测量结果的精确度.采用数学软件matlab处理,可以克服上述的缺点.为进一步提高整个操作流程的易用性,采用labview 做人机界面,将matlab作为脚本程序嵌入其中进行算法处理是一个不错的方法.  相似文献   
923.
Silicon dynamics in the Oder estuary, Baltic Sea   总被引:1,自引:0,他引:1  
Studies on dissolved silicate (DSi) and biogenic silica (BSi) dynamics were carried out in the Oder estuary, Baltic Sea in 2000–2005. The Oder estuary proved to be an important component of the Oder River–Baltic Sea continuum where very intensive seasonal DSi uptake during spring and autumn, but also BSi regeneration during summer take place. Owing to the regeneration process annual DSi patterns in the river and the estuary distinctly differed; the annual patterns of DSi in the estuary showed two maxima and two minima in contrast to one maximum- and one minimum-pattern in the Oder River. DSi concentrations in the river and in the estuary were highest in winter (200–250 μmol dm− 3) and lowest (often less than 1 μmol dm− 3) in spring, concomitant with diatom growth; such low values are known to be limiting for new diatom growth. Secondary DSi summer peaks at the estuary exit exceeded 100 μmol dm− 3, and these maxima were followed by autumn minima coinciding with the autumn diatom bloom. Seasonal peaks in BSi concentrations (ca. 100 μmol dm− 3) occurred during the spring diatom bloom in the Oder River. Mass balance calculations of DSi and BSi showed that DSi + BSi import to the estuary over a two year period was 103.2 kt and that can be compared with the DSi export of 98.5 kt. The difference between these numbers gives room for ca. 2.5 kt BSi to be annually exported to the Baltic Sea. Sediment cores studies point to BSi annual accumulation on the level of 2.5 kt BSi. BSi import to the estuary is on the level of ca. 10.5 kt, thus ca. 5 kt of BSi is annually converted into the DSi, increasing the pool of DSi that leaves the system. BSi concentrations being ca. 2 times higher at the estuary entrance than at its exit remain in a good agreement with the DSi and BSi budgeting presented in the paper.  相似文献   
924.
介绍了在公路工程试验室管理中,运用Visual VC++实现公路工程试验室数据处理系统的方法,其中包括数据存储、窗口界面、报表打印等主要功能的构成。叙述了系统总体设计、数据存储、菜单设计、工具栏设计、用户窗口设计及报表打印的步骤和方法。  相似文献   
925.
Objective To investigate the electrochemiluminescence (ECL) behavior of cloperustine hydrochloride.Methods ECL intensity of tris (2,2'-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of dupernstine hydrochloride was established using capillary electrophoresis (CE) coupled with electrochemilumolinescence (ECL) detection. Results Under the optimum conditions, ECL intensity varied linearly with cloperastine hydrochloride concentration from 7.0×10-6 g/mL to 1.0×10-4 g/mL. The detection limit (S/N=3) was 8.05×10-7g/mL. he relative standard deviation of the ECL intensity and the migration time for 11 consecutive injections of 1.0 ×10-5g/mL cloperastine hydrochloride was 2.9% and 1.5%, respectively. This method was successfully applied to eloperastine hydrochloride tablet determination. Conclusion The method has been established, validated and applied for determination of cloperastine hydrochloride.  相似文献   
926.
燃料电池汽车因具有零排放、续驶里程长、燃料加注快和噪声低等优势,引起了国内外汽车产商的广泛关注,将燃料电池新能源汽车作为研发的重点,并推出了一些量产的燃料电池汽车。基于丰田Mirai燃料电池汽车,对其技术原理和核心总成部件进行了综述分析,并对燃料电池汽车的发展方向和关键技术问题进行了思考和建议,为读者提供了有益的参考和借鉴。  相似文献   
927.
928.
张强 《中国铁路》2011,(1):91-94
产业园创新体系的建立和完善可以有效提高入园企业的竞争力,推动整体产业的良性快速发展。分析国内产业园普遍创新能力弱、缺乏核心竞争力的原因,阐述在中铁轨道交通高科技产业园的建设中,如何充分利用中国中铁的资源优势,聚集企业,为入园企业构建一个优良的产业生态环境,有效培育企业核心竞争力。  相似文献   
929.
This paper presents an approach to optimize planar mechanisms for function generation synthesis. It is applied to the design of different steering linkages used in road vehicles where the Ackermann condition is formulated as the objective function. Four different mechanisms are kinematically defined and synthesized in terms of the proposed method. Limitations of the size of the elements are also considered by means of inequality constraints. Solutions are presented as the difference between desired behaviour, established by Ackermann, and actual generated performance. The results show that the accuracy achieved by the proposed procedure is satisfactory for working conditions in this type of linkages.  相似文献   
930.
张发才  陈行  安萌 《交通科技》2011,(4):110-112
以重庆北站北场交通规划为例,分析和判断了铁路客流对象、车站客流组织、旅客立体换乘、车站功能布局和车站管理模式5个方面的发展趋势;提出了现代铁路客运站在综合交通枢纽、站前集散广场、机动车进出通道、交通设施布局、客流组织方面的规划设计理念.  相似文献   
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