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排序方式: 共有10000条查询结果,搜索用时 218 毫秒
31.
32.
钻井参数仪的模块化设计方法研究 总被引:1,自引:0,他引:1
文章以模块化设计原理为基础,讨论了钻井参数仪的模块划分,模块化设计准则和主要设计内容。采用模块化设计方法、现场设备网络的开放网络和现场总线解决方案设计的钻井参数仪,具有传输信号稳定、可靠性高、抑制噪声能力强、组建现场网络成本低等特点。 相似文献
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34.
U. KEICH 《时间序列分析杂志》2003,24(2):173-192
Abstract. In Keich (2000 ),we define a stationary tangent process, or a locally optimal stationary approximation, to a real non-stationary smooth Gaussian process. This paper extends the idea by constructing a discrete tangent – a `locally' optimal stationary approximation – for a discrete time, real Gaussian process. Analogously to the smooth case, our construction relies on a generalization of the recursion formula for the orthogonal polynomials of the spectral distribution function. More precisely, we use a generalization of the Schur parameters to identify the stationary tangent. By way of discretizing, we later demonstrate how this tangent can be used to obtain `good' local stationary approximations to non-smooth continuous time, real Gaussian processes. Further, we demonstrate how, analogously to the curvatures in the smooth case, the Schur parameters can be used to determine the order of stationarity of a non-smooth process. 相似文献
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36.
Investigation into polishing process of CVD diamond films 总被引:1,自引:0,他引:1
A new technique used for polishing chemical vapor deposition (CVD) diamond films has been investigated, by which rough polishing of the CVD diamond films can be achieved efficiently. A CVD diamond film is coated with a thin layer of electrically conductive material in advance, and then electro-discharge machining (EDM) is used to machine the coated surface. As a result, peaks on the surface of the diamond film are removed rapidly. During machining, graphitization of diamond enables the EDM process to continue. The single pulse discharge shows that the material of the coated layer evidently affects removal behavior of the CVD diamond films. Compared with the machining of ordinary metal materials, the process of EDM CVD diamond films possesses a quite different characteristic. The removal mechanism of the CVD diamond films is discussed. 相似文献
37.
A study of the effects of collector and environment parameters on the performance of a solar powered solid adsorption refrigerator 总被引:1,自引:0,他引:1
Based on the heat and mass transfer model validated by experiment, the performance of the plate solar ice-maker is analyzed systemically with the opinion of two-type characteristic parameters, which includes parametric effects of adsorbent bed of solar ice-maker and outer parameters referring to circumstance. A large number of simulations were undertaken to test the performance of the refrigerator for various collector design parameters and environmental parameters. These works are beneficial to further study the optimization design of a solar cooling system. 相似文献
38.
Didier Lemoine 《Computer Physics Communications》1996,97(3):331-344
A quantum wave packet code for studying nonreactive scattering of closed-shell atoms or diatomic molecules from a rigid surface is described. The time evolution relies on the Chebychev propagator. Up to 5 collider degrees of freedom, 3 in translation and 2 in rotation, are treated in a pseudospectral way with the momentum or finite basis representation as the primary space. Potential matrix elements are efficiently evaluated by means of sequential 1D transformations between momentum and coordinate spaces. Fast Fourier transforms are performed for the translational and azimuthal coordinates whereas a Gauss-Legendre transform is used for the polar coordinate. This pseudospectral strategy minimizes memory requirements because no off-diagonal Hamiltonian matrix elements need to be stored. In addition, a wide variety of physical systems can be studied since no particular functional form is imposed for the interaction potential. 相似文献
39.
ABSTRACT: Texture changes during ripening of Port Salut Argentino cheese for different sampling zones were studied. Compression relaxation tests were performed and results were analyzed using both Maxwellian and Peleg's models. Elastic equilibrium modulus obtained from the Maxwellian model decreased from 1.22 to 0.11 104 Pa during ripening. The constants derived from Peleg's model, k1 and k2 , diminished with ripening time from 1.18 to 0.71 min and from 1.27 to 1.12, respectively. Asymptotic equilibrium modulus from Peleg's model decreased from 0.95 to 0.07 104 Pa during ripening. Rate parameters derived from a 1st order kinetics applied to both equilibrium moduli showed that the decrease was faster in the external zone (0.0846 d−1 ) than in the central zone (0.0368 d−1 ). The correlation between equilibrium moduli, salt concentration, moisture content, and maturation indexes was obtained with a determination coefficient of 0.76. 相似文献
40.
莱钢中小型连轧生产线技术装备状况及改进 总被引:1,自引:1,他引:0
介绍了莱钢引进的具有 90年代国际先进水平的中小型型钢连轧生产线的工艺、设备特点及主要技术参数 ,以及对原机械设备、电气及工艺备件的改进和新产品开发情况 ,均取得良好效果。 相似文献