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991.
天津铁厂4号高炉热风炉改造前存在的总蓄热面积、炉容蓄热面积小、风温低设备隐患多等现象,通过技术改造后,增加了总蓄热面积和炉容面积,增强了严密性,减少了漏风、提高了风温及高炉利用系数,创造了历史最好生产水平。 相似文献
992.
Abstract. In this article, under a semi‐parametric partly linear autoregression model, a family of robust estimators for the autoregression parameter and the autoregression function is studied. The proposed estimators are based on a three‐step procedure, in which robust regression estimators and robust smoothing techniques are combined. Asymptotic results on the autoregression estimators are derived. Besides combining robust procedures with M‐smoothers, predicted values for the series and detection residuals, which allow to detect anomalous data, are introduced. Robust cross‐validation methods to select the smoothing parameter are presented as an alternative to the classical ones, which are sensitive to outlying observations. A Monte Carlo study is conducted to compare the performance of the proposed criteria. Finally, the asymptotic distribution of the autoregression parameter estimator is stated uniformly over the smoothing parameter. 相似文献
993.
设计一种适用于多种门禁场合下的防盗遥控器,具有活体指纹识别、射频无线遥控、无线加密数据传输、无线加密指令控制等功能。本文设计的防盗遥控发射器采用了刮擦式活体指纹识别芯片MBF310,属于第二代指纹识别技术,有效克服了第一代指纹识别技术识别率低、识别橡胶模塑指纹等缺点和不足,提高了安全等级和正确识别率。 相似文献
994.
本文叙述了一种基于DSP的恒压频比控制,空间电压脉冲宽度调制(SVPWM)的异步电动机变频调速系统。重点介绍了恒压频比控制的原理和利用TMS320LF240实现SVPWM的方法,并最终给了出了实验结果。 相似文献
995.
结合射弹发射药温度测量的实际需求,设计了超低功耗射弹药温计,给出了系统结构框图和软件流程,介绍了数字温度传感器TMP100和8引脚微控器PIC12F629,给出PIC12F629对TMP100的控制和数据读取过程,并介绍了系统的硬软件超低功耗设计. 相似文献
996.
A.W. Vreman B.A. Albrecht J.A. van Oijen L.P.H. de Goey R.J.M. Bastiaans 《Combustion and Flame》2008,153(3):394-416
Premixed and nonpremixed flamelet-generated manifolds have been constructed and applied to large-eddy simulation of the piloted partially premixed turbulent flames Sandia Flame D and F. In both manifolds the chemistry is parameterized as a function of the mixture fraction and a progress variable. Compared to standard nonpremixed flamelets, premixed flamelets cover a much larger part of the reaction domain. Comparison of the results for the two manifolds with experimental data of flame D show that both manifolds yield predictions of comparable accuracy for the mean temperature, mixture fraction, and a number of chemical species, such as CO2. However, the nonpremixed manifold outperforms the premixed manifold for other chemical species, the most notable being CO and H2. If the mixture is rich, CO and H2 in a premixed flamelet are larger than in a nonpremixed flamelet, for a given value of the progress variable. Simulations have been performed for two different grids to address the effect of the large-eddy filter width. The inclusion of modeled subgrid variances of mixture fraction and progress variable as additional entries to the manifold have only small effects on the simulation of either flame. An exception is the prediction of NO, which (through an extra transport equation) was found to be much closer to experimental results when modeled subgrid variances were included. The results obtained for flame D are satisfactory, but despite the unsteadiness of the LES, the extinction measured in flame F is not properly captured. The latter finding suggests that the extinction in flame F mainly occurs on scales smaller than those resolved by the simulation. With the presumed β-pdf approach, significant extinction does not occur, unless the scalar subgrid variances are overestimated. A thickened flame model, which maps unresolved small-scale dynamics upon resolved scales, is able to predict the experimentally observed extinction to some extent. 相似文献
997.
This article presents confidence interval methods for improving on the standard F tests in the balanced, completely between-subjects, fixed-effects analysis of variance. Exact confidence intervals for omnibus effect size measures, such as or and the root-mean-square standardized effect, provide all the information in the traditional hypothesis test and more. They allow one to test simultaneously whether overall effects are (a) zero (the traditional test), (b) trivial (do not exceed some small value), or (c) nontrivial (definitely exceed some minimal level). For situations in which single-degree-of-freedom contrasts are of primary interest, exact confidence interval methods for contrast effect size measures such as the contrast correlation are also provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
Zr-2.5wt%Nb pressure tubes, as used in the Indian pressurized heavy water reactors (PHWR), are fabricated through a combination of hot extrusion followed by two stages of cold pilgering and annealing. The present study makes an effort to systematically characterize the textural changes during the fabrication stages. The starting single-phase hcp martensitic structure was textured to start with and it also went through strong texture developments during hot extrusion. First and especially the second pilgering modified the texture. Such modifications were related to local discontinuity of the softer second phase, as an apparent continuity restricted lattice rotation in the primary hcp phase. Annealing caused discontinuity or spherodization of the bcc phase, but did not create recrystallization in the hcp matrix. The combination of two pilgering plus annealing operations, though the latter did not cause noticeable texture changes, however, reverted the final texture close to the parent hot-extruded texture. 相似文献
999.
C8051F320在USB设计中的应用 总被引:6,自引:0,他引:6
C8051F320是Cygnal公司推出的一款新型USB微控制器芯片。该器件具有较快的处理速度和较大的存储容量,并且具有在系统可编程的功能,是USB接口设计的理想选择。文中介绍了C8051F320的特点和引脚功能,并以一个USB-CAN接口转换模块为例介绍了USB接口的软硬件设计。 相似文献
1000.