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91.
This paper presents a new zero-voltage-switching (ZVS) bidirectional dc-dc converter. Compared to the traditional full and half bridge bidirectional dc-dc converters for the similar applications, the new topology has the advantages of simple circuit topology with no total device rating (TDR) penalty, soft-switching implementation without additional devices, high efficiency and simple control. These advantages make the new converter promising for medium and high power applications especially for auxiliary power supply in fuel cell vehicles and power generation where the high power density, low cost, lightweight and high reliability power converters are required. The operating principle, theoretical analysis, and design guidelines are provided in this paper. The simulation and the experimental verifications are also presented. 相似文献
92.
Dear editor,
Many complicated real-world systems can be considered as complex networks to analyze their macroscopic properties,e.g.,the Internet,power grids,and... 相似文献
93.
Xu Li Bingyang Dai Jiaxin Guo Lizhen Zheng Quanyi Guo Jiang Peng Jiankun Xu Ling Qin 《纳微快报(英文)》2021,(10):29-76
Osteoarthritis is the most prevalent chronic and debilitating joint disease, resulting in huge medical and socioeconomic burdens. Intra-articular administration... 相似文献
94.
Sentiment ambiguous adjectives, which have been neglected by most previous researches, pose a challenging task in sentiment analysis. We present an evaluation task at SemEval-2010, designed to provide a framework for comparing different approaches on this problem. The task focuses on 14 Chinese sentiment ambiguous adjectives, and provides manually labeled test data. There are 8 teams submitting 16 systems in this task. In this paper, we define the task, describe the data creation, list the participating systems, and discuss different approaches. 相似文献
96.
A GIS Framework for Changing Cropping Pattern Under Different Climate Conditions and Irrigation Availability Scenarios 总被引:1,自引:1,他引:0
Irrigation water availability is a main driver which determines cropping patterns for an irrigation area. Irrigation water availability will potentially reduce due to changes in climate and irrigation extraction limits. Cropping patterns should be adjusted to meet this challenge. This study presents a new approach for assessing future cropping patterns using GIS in combination with an Irrigation Water Availability Simulation model (IWAS) at irrigation area scale. The IWAS-GIS framework was developed for analysis of cropping pattern options based on the forecast of irrigation water availability in 2030 for the Murrumbidgee Irrigation Area (MIA) which is one of the most important irrigation areas in Australia. Six scenarios considering climatic conditions and the irrigation availabilities were input into the IWAS-GIS framework to simulate cropping pattern changes corresponding to predicted monthly irrigation water availability. Cropping patterns were designed by integration of soil type and irrigation water availability to improve irrigation sustainability. Simulations results indicate that the total irrigated areas will likely decrease with drier climate and less irrigation availability. Rice and pasture areas change significantly when climate and irrigation availability varies. Under the same climate condition, horticulture area increases when irrigation availability decrease. The percentage of lands which are unsuitable for cropping has reduced with the drying climate and shrinking irrigation availability. The IWAS-GIS is simple to implement and provides an easy way for assessing spatial cropping pattern changes based on irrigation water availability. This framework was developed to help irrigators plan cropping patterns corresponding to irrigation water availability. It is flexible to be adopted for similar applications in other irrigation areas. 相似文献
97.
随着知识经济的到来,职工培训在组织发展中扮演着越来越重要的角色。本文针对盐业钻井大队职工培训的现状,进行了问题分析,提出了建立学习型组织、完善的培训体系和畅通的运行机制的建议,最后强调了制定培训计划应从加强培训需求性的调查研究、加强组织培训的协调性等五个方面把握。 相似文献
98.
99.
Superalloy Inconel 825 has been extensively used in chemical industry and transportation industry due to its excellent creep rupture strength and prominent corrosion resistant properties under various circumstances.However,the mass production of this alloy by continuous casting method is restricted because of the serious macrosegregation and coarse grains in the billet.In current,a linear travelling magnetic field was introduced in the solidification process of Inconel 825 with the aim of changing the fmal microstructure by electromagnetic stirring(EMS)force.The results have indicated that the dendrite structure of Incoloy 825 is refined obviously with applying EMS,and the mechanism of dendrite refinement is presumed to the introduction of a forced convection within the solidifying melt.Moreover,The number and the size of precipitated phases including carbide and nitride were found to be significantly reduced with EMS,a phenomenon on the reduction of interdendritic segregation of titanium and molybdenum was simultaneously observed,which demonstrated that he release of interdendritic segregation by EMS inhibits the growth dynamic of carbide and nitride from the melt. 相似文献
100.
Peng Wang 《Corrosion Science》2010,52(3):943-123
Uniform, crack-free vanadium-based corrosion inhibitor films were grown on aluminum alloy 2024. Neutron and X-ray reflectivity were utilized to investigate the structure, water-barrier properties and speciation of the inhibitor film. The top part of the alloy participates in the formation of vanadate film. The similarity of films prepared from H2O and D2O implies the vanadate film is not hydrated. The film has a layered structure with vanadium enriched at the alloy interface. The film behaves as an effective water barrier when the thickness is greater than 800 Å. Films grown without K3Fe[CN]6 accelerator are found to be extremely thin. 相似文献