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介绍了基于USB接口芯片SL811HS和ARM微处理器LPC2214的嵌入式USB主机的设计,并给出了USB主机系统的软件设计结构. 相似文献
74.
This paper studies a yard storage allocation problem in a transshipment hub where there is a great number of loading and unloading activities. The primary challenge is to efficiently shift containers between the vessels and the storage area so that reshuffling and traffic congestion is minimized. In particular, to reduce reshuffling, a consignment strategy is used. This strategy groups unloaded containers according to their destination vessel. To reduce traffic congestion, a new workload balancing protocol is proposed. A mixed integer-programming model is then formulated to determine the minimum number of yard cranes to deploy and the location where unloaded containers should be stored. The model is solved using CPLEX. Due to the size and complexity of this model two heuristics are also developed. The first is a sequential method while the second is a column generation method. A bound is developed that allows the quality of the solution to be judged. Lastly, a numerical investigation is provided and demonstrates that the algorithms perform adequately on most cases considered. 相似文献
75.
Study on the reduction behavior of CoOOH during the storage of nickel/metal-hydride battery 总被引:1,自引:0,他引:1
Xiaofeng Li Tongchi Xia Huichao Dong Yanwei Wei 《Materials Chemistry and Physics》2006,100(2-3):486-489
The storage of nickel/metal-hydride (Ni-MH) battery with co-precipitated cobalt hydroxide and post-added cobalt compound as the additives for pasted Ni(OH)2 electrode is studied in this paper by using galvanostatic charge–discharge, cyclic voltammetry and X-ray diffraction (XRD). It is shown that (I) capacity loss occurs only on the battery with post-added cobalt compound during the storage; (II) CoOOH derived from co-precipitated cobalt hydroxide has a better stability than the one from post-added cobalt compound and an irreversible reduction of the latter is observed; and (III) an inactive Co + 3O(OH) is obtained from Ni(OH)2 electrode with post-added cobalt compound after the storage and should be responsible for the property deterioration of Ni-MH battery. Thus, it is important to increase the stability of CoOOH derived from post-added cobalt compound when Ni-MH battery suffers a long-term storage. 相似文献
76.
A.S. Popov E.V. Popova T.V. Nikishina O.N. Vysotskaya 《International Journal of Refrigeration》2006,29(3):403
Cryopreservation is the most reliable method for long-term storage of plant genetic resources. A review of cell injury by ice crystals and dehydration during a freeze–thaw cycle is given. For successful regeneration of plants and cultures after cryopreservation of their cells, the development of reliable cryopreservation procedure is required including preliminary cultivation, treatment by cryoprotectors, freezing by different methods, thawing and recultivation. Up to now 27 cell lines successfully resumed their growth after storage in liquid nitrogen and preserved their specific features and biosynthetic potential. Besides, shoot tips of 40 cultivars of potato, rose, strawberry and raspberry regenerated plants both in vitro and in vivo after cryopreservation. The longest storage duration was 25 years. Now in liquid nitrogen we continuously store 24 cell strains of rare medicinal plants, shoot tips of seven cultivars of strawberry and raspberry and seeds of 250 endangered plant species collected over all Russian territory. 相似文献
77.
A. Hofmann 《低温学》2006,46(11):825-830
It is a normal operating condition for a lot of cryogenic storage vessels that no boil-off gas is vented over long periods, which leads to a simultaneous pressure increase of the stored fluid. One main reason therefore is to avoid product losses during transport or between withdrawals. At transport conditions the mixing of the fluid can be assumed to be ideally, which results in a maximum reachable pressurising period. At stationary conditions the pressurising period is expected to be shorter, because a stratification is rising up, so that the heat capacity of the stored fluid cannot be used completely.In a thermodynamic view, an isochore change of state takes place and the heat flux into the vessel rises the internal energy of the fluid. For the representation of the isochore change of state a new developed Δu/v-v-diagram with the 1 × 105 Pa reference as a basis line is introduced. The basis line is linear for the filling rate and functionally connected with the specific volume.For the fluids He and H2 e.g., Δu/v-v-diagrams are pointed out, using the u- and v-values on the saturation lines for the two phase region and those of some isobar lines for the region above the critical pressure. 相似文献
78.
针对蓄电池组充放电系统中单体电池数量较多,充放电时间较长,全部采集数据难于保存在微控制器中的实际情况,提出了一种EPP-CAN的智能接口解决方案,给出了硬件电路组成以及基于Delphi的软件实现方法。 相似文献
79.
针对广域网上多媒体资源访问服务质量问题,设计一种面向媒体资源的高性能分布媒体存储系统(DMSS)。系统以按多媒体文件特征设计的高效媒体文件系统(MFS)为基础,通过自适应创建资源副本服务器来保证服务质量,降低网络带宽消耗。给出了系统构架和原型描述,通过性能分析验证了其高效性。 相似文献
80.