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671.
人文社科领域开展高等数学教学的研究与实践   总被引:4,自引:0,他引:4  
本文根据高等数学教学大纲的要求 ,紧密结合作者自身多年的教学实践经验 ,从教育目标、教材内容、教学原则与教学质量考评等方面深刻全面地阐述了人文社科领域开展高等数学教学值得研究与探讨的一些带根本性的问题 .它不论是在实践方面 ,还是在理论上皆有一定的意义  相似文献   
672.
Summary: In the last two decades, simulation technology had a large influence on process industries. Today, modern numerical methods, powerful personal computers and convenient software packages facilitate the solution of complex chemical engineering problems on the basis of rigorous process models at every office workplace. However, although in many cases process models are available from the process design step, model based operation of production plants can only be found rarely. Changing this situation would significantly contribute to the cost effectiveness of many production plants. This contribution focuses on the model based operation of polymer processes which are for some reasons not perfectly suited for model application: Polymer process models tend to be complex, meaningful online measurements are expensive and not always reliable, many polymer processes are performed in batch instead of steady-state and for most polymer plants, due to the smaller throughput, the economic impact of model application is much smaller than compared to for instance a steam cracker. When model based operation is considered, it has to be recognized that there is not one single approach but many different alternatives of which maybe only a single one will lead to a sustainable economical improvement of the process. From many successfully applied concepts for model based plant operation it can be clearly identified that always trying to implement the most complex solution (e.g. nonlinear closed-loop online optimization) is neither possible nor reasonable but that plant specific tailor-made solutions are necessary.  相似文献   
673.
Photo-Fenton氧化法是一种近几年来引起极大关注的新的有效的高级氧化技术,并逐渐应用于环境污染物的处理领域.本文简要介绍了这方面的研究进展情况,包括其机理研究和应用研究以及一些新的改进的Photo-Fenton氧化方法.  相似文献   
674.
互联网汽车发展及关键技术分析   总被引:1,自引:0,他引:1       下载免费PDF全文
李洁 《电信科学》2016,32(8):34-38
主要介绍了互联网汽车与智能汽车的定义及区别,并对国内外互联网汽车的发展现状进行了简要介绍,然后对互联网汽车发展过程中牵涉的问题及关键技术进行了分析,最后结合国内现状,对未来互联网汽车的发展提出展望。  相似文献   
675.
针对高功率固体激光发展的需求,总结了先进光学制造技术方面的研究进展。采用超精密制造技术提高了非球面等元件的加工精度和制造效率,并为解决低缺陷加工提供了技术途径。围绕面形误差控制,特别是中频波前误差控制,发展了多种确定性抛光技术。针对熔石英元件建立了去除-抑制模型及新的抛光技术,有效抑制了亚表面缺陷的产生。  相似文献   
676.
Abstract

Raman-based techniques have developed into excellent analytical tools in various research fields, primarily due to their noninvasive sampling capability, minimal sample preparation, and short analysis time. Major improvements in lasers, spectrometers, detectors, and holographic optical components have made Raman spectroscopy an effective tool for analyzing natural and synthetic materials. This article presents a short introduction to Raman spectroscopy and several recently related advances, including, Fourier transform (FT) Raman spectroscopy, micro-Raman spectroscopy, Raman sensing, and stand-off Raman spectroscopy techniques. Other topics discussed in this article are the importance of its combination with laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF).  相似文献   
677.
This paper presents a theoretical calculation of the effects of relativistic broadening and frequency down-shift on the electron cyclotron emission measurements for a wide range of plasma parameters in the Experimental Advanced Superconducting Tokamak (EAST). The calculation is based on the radiation transfer equation, with the reabsorption and reemission processes taken into account. The broadening effect contributes to the radial resolution of the measure- ment, and the calculation results indicate that it is ~ 2 cm in the case of the central electron temperature 10 keV. A pseudo radial displacement of the obtained electron temperature profile occurs if the relativistic frequency down-shift effect is not taken into account in the determination of the emission layer position. The shift could be a few centimeters as the electron temperature increases, and this effect should be taken into account.  相似文献   
678.
仇聪颖  管显涛  刘振  朱安娜  闫克平 《强激光与粒子束》2020,32(2):025010-1-025010-7
随着印染行业的快速发展,印染废水的排放与日俱增。由于废水中的有机物具有成分复杂、难以降解的特点,若未经有效处理直接排放,会对生态环境造成严重的污染和危害。试验设计了一种多针-网式反应器循环处理有机组分为酸性红73(AR73)的模拟废水,其采用自行设计的基于TLT(Transmission Line Transformer)的高压重频纳秒脉冲电源驱动。电源可以产生峰值电压为50 kV,脉宽40 ns,上升沿20 ns的纳秒脉冲信号,工作频率可达500 Hz。试验考察了峰值电压、放电频率、染料初始质量浓度及作用时间等因素对AR73降解效果的影响。为评价处理效果,采用紫外分光光度法分别测量了废水中剩余染料浓度、过氧化氢浓度等指标。结果表明,在初始浓度30 mg/L,循环流量3.4 L/min,放电间距30 mm,峰值电压44.26 kV,放电频率200 Hz条件下处理30 min,AR73降解率可以达到83.20%,单次脉冲注入能量为11.73 mJ,过氧化氢浓度为47.36 μmol/L,反应器脱色能效(G50)可以达到31.07 g·kW−1·h−1。增大放电电压可以进一步提高AR73降解率,溶液中活性物质浓度提高,但是能量效率有所下降。  相似文献   
679.
The paper considers a system of advanced‐type functional differential equations where F is a given functional, , r > 0 and xt(θ) = x(t + θ), θ∈[0,r]. Two different results on the existence of solutions, with coordinates bounded above and below by the coordinates of the given vector functions if t, are proved using two different fixed‐point principles. It is illustrated by examples that, applying both results simultaneously to the same equation yields two positive solutions asymptotically different for t. The equation where a,τ∈(0,), a < 1/(τe), are constants can serve as a linear example. The existence of a pair of positive solutions asymptotically different for t is proved and their asymptotic behavior is investigated. The results are also illustrated by a nonlinear equation. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
680.
In this paper, we investigate how an embedded pure network structure arising in many linear programming (LP) problems can be exploited to create improved sparse simplex solution algorithms. The original coefficient matrix is partitioned into network and non-network parts. For this partitioning, a decomposition technique can be applied. The embedded network flow problem can be solved to optimality using a fast network flow algorithm. We investigate two alternative decompositions namely, Lagrangean and Benders. In the Lagrangean approach, the optimal solution of a network flow problem and in Benders the combined solution of the master and the subproblem are used to compute good (near optimal and near feasible) solutions for a given LP problem. In both cases, we terminate the decomposition algorithms after a preset number of passes and active variables identified by this procedure are then used to create an advanced basis for the original LP problem. We present comparisons with unit basis and a well established crash procedure. We find that the computational results of applying these techniques to a selection of Netlib models are promising enough to encourage further research in this area.  相似文献   
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