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991.
徐学耘 《制冷空调与电力机械》1997,(4)
机械采制煤制样是目前唯一能够采到具有代表性煤样的手段,但国产的机械采制煤样装置存在着全断面采样难和水分适性差两大难题。DJY刮斗式自动采制煤样装置比较好地解决了这两个问题,主要技术性能已接近进口设备的水平。文中介绍了构成机械采制煤样装置的五大件──—采样机、给料机、破碎机、缩分机和余煤运料机的各种型式及要求,提出了应修改我国原有的采制煤样装置技术标准的意见。 相似文献
992.
以长兴地区基于电力线载波通信的远程抄表系统为研究对象,分析了影响数据采集完整率的因素,指出了电能计量装置的安装和使用情况、台区的管理水平、配电网络环境,以及采集终端的安装和运行状况是影响数据采集完整率的主要因素. 相似文献
993.
In this study, removal of the cationic dye acridine orange (AO) from aqueous solution using 4A zeolite was studied. The adsorption experiments were performed using batch system, and full factorial design was employed for investigating the condition of removal efficiency of dye. The four most important operating variables were the initial pH of the solution, the concentration of dye, the contact time, and the temperature. The 18 experiments were required to investigate the effect of variables on removal of the dye. The results were statistically analyzed to define important experimental variables and their levels using the analysis of variance (ANOVA). A regression model that considers the significant main and interaction effects was suggested and fitted the experimental data very well. Model predictions were found to be in good agreement (R2 = 99.99%, adjusted R2 = 99.86%) with experimental data. The optimized conditions for dye removal were at initial pH 3.0, 20.0 mg L?1 dye, temperature 298.0 K and 80.0 min adsorption time. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Sips adsorption models. The maximum predicted adsorption capacities for AO was obtained as 29.851 mg g?1. The adsorption thermodynamic parameters, namely ΔH°ads, ΔG°ads and ΔS°ads, were determined. Furthermore, the kinetic of AO adsorption on the 4A zeolite was analyzed using pseudo-first- and second-order kinetic models and the results showed that the removal was mainly a pseudo-second-order process. 相似文献
994.
Multicast beamforming with LOS self‐interference cancellation in full‐duplex wireless communications
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In this paper, we consider a full‐duplex system where the access point installed with multiple transmitting antennas and a single receiving antenna serves several single‐antenna remote users. In this case, there are 2 kinds of interferences. One is the near‐field self‐interference (SI) induced by the simultaneous transmitting and receiving over the same band, and the other is the cochannel interference caused by the multicast broadcasting in the same band. A problem of near‐field SI cancellation and the cochannel interference suppression using transmit beamforming is formulated at the access point. This problem of ensuring the near‐field line‐of‐sight SI suppression benchmark and maximizing the minimum received signal‐to‐interference‐plus‐noise ratio of remote receivers leads to a nonconvex NP‐hard optimization. Furthermore, we introduce a semidefinite relaxation technique coupled with linear program power adjustment and an outer bisection search loop to transform the problem into a convex optimization. This can be solved by the modern interior point methods. Simulations show that the proposed method is feasible even when the local receive antenna in near‐field and the remote receivers in far field are in the same direction. 相似文献
995.
A full‐condition monitoring method for nonstationary dynamic chemical processes with cointegration and slow feature analysis
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Chemical processes are in general subject to time variant conditions because of load changes, product grade transitions, or other causes, resulting in typical nonstationary dynamic characteristic. It is of a considerable challenge for process monitoring to consider all possible operation conditions simultaneously including multifarious steady states and dynamic switchings. In this work, a novel full‐condition monitoring strategy is proposed based on both cointegration analysis (CA) and slow feature analysis (SFA) with the following considerations: (1) Despite that the operation conditions may vary over time, they may follow certain equilibrium relations that extend beyond the current time, and (2) there may exist certain dynamic relations that stay invariant under normal process operation despite process may operate at different operating conditions. To monitor both equilibrium and dynamic relations, in the proposed method, nonstationary variables are separated from stationary variables first. Then by CA and SFA, the long‐term equilibrium relation is distinguished from the specific relation held by the current conditions from both static and dynamic aspects. Various monitoring statistics are designed with clear physical interpretation. It can distinguish between the changes of operation conditions and real faults by checking deviations from equilibrium relation and deviations from the specific relation. Case study on a chemical industrial scale multiphase flow experimental rig shows the validity of the proposed full‐condition monitoring method. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1662–1681, 2018 相似文献
996.
997.
998.
P. Vijaya Lakshmi Sarada Musala Avireni Srinivasulu 《International Journal of Electronics》2018,105(8):1416-1432
In this paper, three novel designs for single-stage, 3-input XOR logic cells are proposed. The design uses either Transmission Gate (TG) or Pass Transistor (PT) on similar topologies. The proposed circuits are area and power efficient because minimum-sized transistors are used in ratioless realisations. At the output, the designs give strong logic-levels. The topologies have minimised delay because the critical path consists of only three minimum-sized transistors. The delay estimation is presented. The circuits are simple and layouts are easy to build. Further, rail-to-rail voltage-swing at the output ensures good driving capability even at low voltages and at high frequencies ranging up to 10 GHz with minimum transistor count. The proposed designs and other existing candidate designs are simulated in a pragmatic condition on Cadence 90 nm CMOS technology at various supply voltages ranging from +0.8 V to +1.2 V. The simulation results illustrate that the proposed designs have comparable delay time to most candidate designs while it outperform all of them on total power consumption and PDP. As expected, the TG-based design reports best performance while the PT-based design follow as closed second with better component economy and control input overload. An application of the proposed XORs in ripple carry adders confirms the functionality of the cells in circuit implementation. 相似文献
999.
Mojtaba Maleknejad Somayyeh Mohammadi Hamid Reza Naji Mehdi Hosseinzadeh 《International Journal of Electronics》2018,105(10):1753-1768
In this article, a low-power and energy-efficient hybrid full adder circuit is proposed, which is implemented based on multi-threshold NAND and NOR gates and transmission gate multiplexers. In order to implement this circuit, carbon nano tube field effect transistors are utilised. For evaluating the proposed design, comprehensive simulations are performed with regard to the most important aspects power, delay and power-delay product. The results are presented and displayed the superiority of the proposed cell in different voltage levels, load conditions, temperatures and robustness against process variations. 相似文献
1000.
相对辐射校正是实现多角度偏振探测仪全视场高精度辐射定标的关键技术之一。提出了一种高精度自动化的相对辐射校正方法,采用15×15个分视场扫描测量的方式,通过高精度大型二维转台和大口径积分球参考光源实现全视场的辐射响应测量;模拟在轨工作模式,规范了数据采集流程,编写数据采集软件实现了辐射响应图像数据获取;设计数据图像拼接算法和相关的数据处理方法,完成了相对辐射校正的数据处理和精度分析。数据比对分析和精度分析结果表明相对辐射校正精度在0.5%~0.8%之内。 相似文献