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排序方式: 共有2975条查询结果,搜索用时 15 毫秒
31.
随着国家对环境保护力度的提高,为了满足火电厂大气污染物排放标准的新要求,湿式静电除尘器(WESP)作为一项新型高效除尘技术被广泛关注.论述了WESP的工作原理、分类、技术特点,探讨了WESP的研究和应用现状,表明湿式电除尘器技术是成熟可靠的,具有很好的发展前景. 相似文献
32.
In this paper,a fifth-order fully differential interface circuit( IC) is presented to improve the noise performance for micromechanical sigma-delta( Σ-Δ) accelerometer. A lead compensator is adopted to ensure the stability of the closed-loop high-order system. A low noise capacitance detection circuit is described with a correlated-double-sampling( CDS) technique to decrease 1 /f noise and offset of the operational amplifier. This paper also proposes a self-test technique for the interface circuit to test the harmonic distortion. An electrostatic force feedback linearization circuit is presented to reduce the harmonic distortion resulting in larger dynamic range( DR). The layout of the IC is implemented in a standard 0. 6 μm CMOS technology and operates at a sampling frequency of 250 kHz. The interface consumes 20 mW from a 5 V supply. The post-simulation results indicate that the noise floor of the digital accelerometer is about- 140 dBV /Hz1 /2at low frequency. The sensitivity is 2. 5 V /g and the nonlinearity is 0. 11%. The self-test function is achieved with 98. 2 dB thirdorder harmonic distortion detection based on the electrostatic force feedback linearization. 相似文献
33.
H型静电聚结分离器油水分离技术研究 总被引:1,自引:0,他引:1
介绍了国外新一代高效紧凑型静电聚结设备———H型静电聚结分离器CES的结构和工作原理。通过对其油水分离的工作机理进行理论分析,探讨了运行中临界流量产生的原因和影响因素,提出了进行工程化设计时应注意的问题和改进思路,对于自主开发新型静电聚结技术,满足石油行业对高效紧凑型原油脱水设备的需求具有积极意义。 相似文献
34.
利用静电纺丝和原子层沉积(ALD)方法制备了ZnFe2O4/ZnO纳米复合纤维并对其进行退火处理。利用扫描电子显微镜、X射线衍射仪、光致发光、紫外-可见分光光度计对其进行了性质的研究。结果表明,制备样品为一维核壳结构的纳米复合纤维,ZnO壳层由于高温退火的原因结晶度提高,ZnFe2O4纳米纤维与ZnO薄膜间的表面化学键连结起来并成功复合,降低了ZnO自由载流子的重结合几率,实现了光生载流子的大程度分离。并且直观的比较了不同催化剂的降解性能。 相似文献
35.
36.
电除尘器气流分布技术研究进展 总被引:4,自引:0,他引:4
气流分布状态是影响电除尘器收尘效率的关键因素之一.本文介绍了电除尘器气流分布技术的研究和应用现状,并指出了其发展方向. 相似文献
37.
38.
Jae?H.?KimEmail author Jung?M.?Lee Ho?C.?Shin Young?H.?Paik 《Metals and Materials International》2003,9(6):593-597
It is known that oxide inclusions in liquid metal carry mostly positive charges on their surfaces. In an electrostatic field,
therefore, such charged particles suspended in a liquid metal experience forces and accumulate in the region of the negatively
charged surface, resulting in the separation of oxide inclusions from the liquid metal. In this study, this principle was
experimentally demonstrated for the case of a capacitor cell by the imposition of a d.c. potential on electrodes. The capacitor
cell consisted of a dielectric container of Pyrex tube, a high voltage d.c. source, and two electrodes, which were symmetrically
attached onto the outer surface of the Pyrex. tube. Experiments were carried out for suspensions of liquid tin/metal oxides,
such as SnO2, WO3, and PbO under an applied potential of up to 12 kV. All experimental results were in good agreement with the theoretical
prediction and showed that the degree of separation was significantly increased with the applied potential. 相似文献
39.
Clausen CH Dimaki M Panagos SP Kasotakis E Mitraki A Svendsen WE Castillo-León J 《Scanning》2011,33(4):201-207
In this report electrostatic force microscopy (EFM) is used to study different peptide self-assembled structures such as tubes and particles. It is shown that not only geometrical information can be obtained using EFM, but also information about the composition of different structures. In particular we use EFM to investigate the structures of diphenylalanine peptide tubes, particles, and CSGAITIG peptide particles placed on pre-fabricated SiO(2) surfaces with a backgate. We show that the cavity in the peptide tubes could be due to the presence of water residues. Additionally we show that self-assembled amyloid peptides form spherical solid structures containing the same self-assembled peptide in its interior. In both cases transmission electron microscopy is used to verify these structures. Further, the limitations of the EFM technique are discussed, especially when the observed structures become small compared with the radius of the AFM tip used. Finally, an agreement between the detected signal and the structure of the hollow peptide tubes is demonstrated. 相似文献
40.
Jiu‐Gang Dong 《国际强度与非线性控制杂志
》2013,23(16):1891-1898
》2013,23(16):1891-1898
Recently, a model for flocking was introduced by Cucker and Smale together with a proof of convergence. This proof established unconditional convergence to flocking (i.e., to a common velocity), provided the interaction between agents was strong enough and conditional convergence otherwise. The strength of the interaction is measured by a parameter β, and the critical value at which unconditional convergence stops holding is β = 1 ∕ 2. This model was extended by Shen to allow for a hierarchical leadership structure among the agents, and similar convergence results were proved. But, for discrete time, convergence result was only for the flock with an overall leader moving with a constant velocity. In this note, we establish convergence result for the flock with a free‐will leader. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献