直接氯化法合成对硝基氯化苄

介绍了以对硝基甲苯和氯气为原料 ,在催化剂存在下合成对硝基氯化苄的方法 ,考察了催化剂种类、反应温度、溶剂配比等因素对反应的影响 ,优化的反应条件为 :对硝基甲苯用量 1 3 7g,对硝基甲苯 /邻二氯苯 (摩尔比 ) =1∶ 0 .6,w (偶氮二异丁腈 ) =0 .6% ,反应时间 3 h,反应温度 1 60℃ ,产物单程收率大于 65 % ;将反应混合物中未反应的原料分离后 ,以无水乙醇为溶剂结晶纯化 ,物料 /溶剂 (摩尔比 ) =1∶ 1 .5时晶体含量在 99.0 %以上 ,结晶收率达 67     

Pruning Redundant Alarm Correlation Patterns

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｔｉｃｋｉｎｇｐｏｉｎｔｏｆａｓｓｏｃｉａｔｉｏｎｒｕｌｅａｌｇｏｒｉｔｈｍｓｄｅｐｅｎｄｓｏｎｅｆｆｅｃｔｉｖｅｌｙｆｉｎｄｉｎｇａｌｌｃｏｒｒｅｌａｔｉｏｎｐａｔｔｅｒｎｓｔｈａｔｓａｔｉｓｆｙｖａｌｕｅｒｅｑｕｉｒｅｍｅｎｔｉｎｔｈｅｍａｇｎａｎｉｍｉｔｙｏｆｄａｔａ.Ｂｕｔｔｈｅａｌｇｏｒｉｔｈｍｓａｌｓｏｂｒｉｎｇａｎｅｇａｔｉｖｅｅｆ ｆｅｃｔ:ｔｈｅｎｕｍｂｅｒｏｆａｓｓｏｃｉａｔｉｏｎｒｕｌｅｓｉｓｖｅｒｙｌａｒｇｅ.Ａｌｓｏｉｎｆｏｒｍａｔｉｏｎ…     

Parameters evaluation of SOLA algorithm for time scale modification

Successful operation of the Synchronous Overlap and Add (SOLA) algorithm for Time Scale Modification (TSM) of speech is closely tied to the proper choice of parameters. This paper investigates the quality of time scale modified speech under different values of primary parameters. Based on Mean Opinion Score (MOS) tests and Bark Spectral Distortion (BSD) measure, the proper choices of synthesis shift (Ss) and the duration of the shift search interval (K _max?) are given experimentally. The conclusions can be helpful for operating the SOLA algorithm for time scale modification of speech.     

The Effect of the Estimation on Goodness‐of‐Fit Tests in Time Series Models

Abstract. We analyze, by simulation, the finite‐sample properties of goodness‐of‐fit tests based on residual autocorrelation coefficients (simple and partial) obtained using different estimators frequently used in the analysis of autoregressive moving‐average time‐series models. The estimators considered are unconditional least squares, maximum likelihood and conditional least squares. The results suggest that although the tests based on these estimators are asymptotically equivalent for particular models and parameter values, their sampling properties for samples of the size commonly found in economic applications can differ substantially, because of differences in both finite‐sample estimation efficiencies and residual regeneration methods.     

Structural transformation of FePt nanocomposite films during annealing and its effects on magnetic properties

Fe100-xPtx(x=30at.%-60at.% ) nanocomposite films were deposited on natural-oxidized Si(100) substrates by magnetron sputtering. The as-deposited films were annealed between 373 and 1073 K. In situ X-ray diffraction shows that the FePt nanocomposite films undergo a phase transformation from a disordered FCC phase to an ordered L10 phase between 673 and 773 K. The coercivity is 306 kA·m-1 whiles the average grain sizes is about 10 nm in the optimized FePt alloy film sample annealed at 673K. The adjustable coercivity and fine grain size suggest that this FePt nanocomposites system is suitable as recording media at extremely high areal density.     

航空自导深弹攻潜效能模型与仿真

文中依据航空自导深弹的战术技术性能,给出了反潜直升机使用航空自导深弹攻潜模型,采用蒙特卡洛法通过计算机仿真,得出了反潜直升机空投航空自导深弹的攻潜效能,并通过仿真结果分析提出了直升机最优的攻潜方法.     

Space–Time Power Schedule for Distributed MIMO Links Without Instantaneous Channel State Information at the Transmitting Nodes

A space-time optimal power schedule for multiple distributed multiple-input multiple-output (MIMO) links without the knowledge of the instantaneous channel state information (CSI) at the transmitting nodes is proposed. A readily computable expression for the ergodic sum capacity of the MIMO links is derived. Based on this expression, which is a non-convex function of power allocation vectors, a projected gradient algorithm is developed to optimize the power allocation. For a symmetric set of MIMO links with independent identically distributed channels, it is observed that the space-time optimal power schedule reduces to a uniform isotropic power schedule when nominal interference is low, or to an orthogonal isotropic power schedule when nominal interference is high. Furthermore, the transition region between the latter two schedules is seen to be very sharp in terms of nominal interference-to-noise ratio (INR). For MIMO links with correlated channels, the corresponding space-time optimal power schedule is developed based on the knowledge of the channel correlation matrices. It is shown that the channel correlation has a great impact on the ergodic capacity and the optimality of different power scheduling approaches.     

提高自来水水质的策略

一、前言 供水公司分为四类。第三、四类公司供水50×104 m~3/d以下,要求其供水水质符合国家标准GB/5749-85“生活饮用水卫生标准”;供水100×104 m~3/d以下的第二类水司供水水质要达到80年代国际水平;供水100×104m~3/d以上的直辖市、对外开放城市、重点旅游城市要达到     

宏蜂窝模型的传播模型校正研究

详细介绍了 宏蜂窝传播模 型校正的基本操作流程 结果分析及注意事项 对工程 ,人员了解和开展模型校正工作有一定的指导作用 。     

Analysis and synthesis of on-chip spiral inductors

This paper presents a physically based compact model for estimating high-frequency performance of spiral inductors. The model accurately accounts for skin and proximity effects in the metal conductors as well as eddy current losses in the substrate. The model shows excellent agreement with measured data mostly within 10% across a variety of inductor geometries and substrate dopings up to 20 GHz. A web-based spiral inductor synthesis and analysis tool COILS, which makes use of the compact models, is presented. An optimization algorithm using binary searches speeds up the synthesis of inductor designs.