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61.
62.
分时蓄冷时负荷变化大,但可充分利用低谷电来制冰蓄冷,而在高峰时,制冷机不开以融冰供冷,满足空调负荷要求,真正起到在电网中削峰填谷作用。分时蓄冷时,负荷变化大,在融冰循环运行时,流量变化幅度随之变大,情况特殊,因此需要系统要有应对策略。 相似文献
63.
We consider trapezoidal load-time pulses with linearly increasing and affinely decreasing durations equal to integer multiples of the time period of the first bending mode of vibration of a linearly elastic structure. For arbitrary spatial distributions of loads applied to monolithic and laminated orthotropic plates, it is shown through numerical solutions that plates’ vibrations become miniscule after the load is removed. This phenomenon is independent of the dwell time (i.e., the time duration between the rising and the falling portions) during which the load is kept constant. The primary reason for this response is that for such time-dependent loads, nearly all of plate’s strain energy is concentrated in deformations corresponding to the fundamental bending mode of vibration. Thus plate’s deformations can be studied by taking the mode shape of the 1st bending mode as the basis function and reducing the problem to that of solving a single second-order ordinary differential equation. We have verified this postulate by comparing strain energies computed from the 3-dimensional deformations of different plate geometries and boundary conditions with those determined by using the single degree of freedom (DoF) model. Thus for trapezoidal time-dependent loads applied on plates, the 1 DoF model provides reasonably accurate results and saves considerable computational effort. 相似文献
64.
The ac conductivity of three fluorides of A2MII+ MIII + F9 type, Sr2NiAlF9, Sr2ZnGaF9 and Ba2MnCrF9, between 293 and 773K, has been analyzed within a combined complex impedance and modulus formalism. The antiferroelectric-paraelectric phase transition of Sr2ZnGaF9 has been characterized. A hopping mechanism for charge carriers is suggested for the three materials; their electrical performance are relatively weak. Sr2NiAlF9 and Sr2ZnGaF9 can be considered as ionic conductors of the F- ion. On the contrary, the conductivity in Ba2MnCrF9 is rather of an electronic nature. 相似文献
65.
本文分析了节能问题的几个方面。主要有:负载需求与节能的关系,调速方法与节能的关系,以及大马拉小车的节能问题等。 相似文献
66.
铅锑电极上PbO_2生长过程的阻抗跟踪法研究韦国林,杨鸿兴,王家荣(上海大学嘉定校区化学系,上海,201800)利用交流阻抗技术研究Pb/H2SO4体系中电化学过程,通常采用某一等效电路,并对所得的多频率阻抗频谱进行拟合处理,由此获得相关电化学信息。?.. 相似文献
67.
Solid-supported thin liquid films of lipids, contacting an electrolyte phase, turned out to be a dependable system in the field of bosensors. The investigations of these objects during the past decade reveal some of their intriguing features enabling the application in constructions of receptor part with 'two-dimensional' arrangement. As a model system, complementary to the other artificial analogs of biomembranes, the wetting films of lipids offer certain advantages concerning the compromise between the stability and flexibility of the molecular structures involved in sensing. The basic principles underlaying the techniques of formation, as well as the conditions of the films stability are emphasized in the present consized review. While no limitations are imposed by the way of preparation, the films seem especially profitable in conjunction with methods for electrochemical signal transduction. In this regard some prominent examples are discussed. 相似文献
68.
S.?Pi?olEmail author M.?Najib D.?M.?Bastidas A.?Calleja X.?G.?Capdevila M.?Segarra F.?Espiell J.?C.?Ruiz-Morales D.?Marrero-López P.?Nu?ez 《Journal of Solid State Electrochemistry》2004,8(9):650-654
We have prepared pure electrolytes of Ce0.8Gd0.2O1.9 (CGO) and Ce0.8Sm0.2O1.9 (CSO), useful for SOFCs, by a sol–gel-related technique like the acrylamide method. This method consists of preparing a solution from the single oxides followed by gelation. Then, the combustion or decomposition of the organic molecules is initiated, producing nanometric calcined powders of the above-mentioned compounds. Thermal treatments were optimized in order to obtain good electrochemical properties of the electrolytes. We have observed that the synthesis temperature to obtain the pure phase is lower for the sol–gel samples than for the pellets prepared by solid-state reaction, and the final density is higher. The microstructure and composition of the powders were characterized by TEM, SEM, and EDX analysis. The electrical properties of the electrolytes were measured by impedance spectroscopy at different temperatures and oxygen partial pressures.Presented at the OSSEP Workshop Ionic and Mixed Conductors: Methods and Processes, Aveiro, Portugal, 10–12 April 2003 相似文献
69.
E.?Gourba P.?Briois A.?RinguedéEmail author M.?Cassir A.?Billard 《Journal of Solid State Electrochemistry》2004,8(9):633-637
Gadolinia-doped ceria (GDC) remains, up to now, the most promising candidate for replacing yttria-stabilised zirconia (YSZ) as electrolyte for solid oxide fuel cells (SOFC) operating at intermediate temperature. Literature data point out that GDC could be used as electrolyte, anode material, or interlayers for avoiding the chemical interactions occurring at the interfaces. In the present work, GDC thin layers were produced by d.c. reactive magnetron sputtering and deposited over a thickness domain between 450 nm and 5.5 µm. According to our knowledge, the deposition of GDC sputtered layers has never been reported. The physicochemical features of these thin films have been characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Impedance measurements have been carried out in order to determine the electrical properties of electrolyte thin films and in particular their ionic conductivity.Presented at the OSSEP Workshop Ionic and Mixed Conductors: Methods and Processes, Aveiro, Portugal, 10–12 April 2003 相似文献
70.
济钢第三炼钢厂1#连铸机引进的是VAI(奥钢联)的板坯连铸机,为了实现对多达20台拉矫电机的控制,它用了负载分配控制技术。为实现负载分配技术,拉矫系统采用了基于PROFIBUS的西门予6SE70变频器构成的现场总线控制系统。本文介绍了该系统PROFIBUS硬件配置、软件编程和116SE70变频器通讯参数的设置. 相似文献