喷水推进系统在两栖战斗车辆上的研究与应用

经对美国先进两栖突击车（AAAV）水上航速的分析，提出了两栖车辆喷水推进理论的研究，主要目的是使新型两栖战斗车辆能在水上航速有大的提高。     

Computational Analysis of Structure-Based Interactions for Novel H1-Antihistamines

As a chronic disorder, insomnia affects approximately 10% of the population at some time during their lives, and its treatment is often challenging. Since the antagonists of the H₁ receptor, a protein prevalent in human central nervous system, have been proven as effective therapeutic agents for treating insomnia, the H₁ receptor is quite possibly a promising target for developing potent anti-insomnia drugs. For the purpose of understanding the structural actors affecting the antagonism potency, presently a theoretical research of molecular interactions between 129 molecules and the H₁ receptor is performed through three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. The ligand-based comparative molecular similarity indices analysis (CoMSIA) model (Q² = 0.525, R²_ncv = 0.891, R²_pred = 0.807) has good quality for predicting the bioactivities of new chemicals. The cross-validated result suggests that the developed models have excellent internal and external predictability and consistency. The obtained contour maps were appraised for affinity trends for the investigated compounds, which provides significantly useful information in the rational drug design of novel anti-insomnia agents. Molecular docking was also performed to investigate the mode of interaction between the ligand and the active site of the receptor. Furthermore, as a supplementary tool to study the docking conformation of the antagonists in the H₁ receptor binding pocket, molecular dynamics simulation was also applied, providing insights into the changes in the structure. All of the models and the derived information would, we hope, be of help for developing novel potent histamine H₁ receptor antagonists, as well as exploring the H₁-antihistamines interaction mechanism.     

SCD1000熟料输送链斗机头轮齿块结构改进

正1存在的问题我公司SCD1000熟料输送链斗机自投产以来,一直存在头轮齿块松动的问题。齿块松动会造成齿块与链条啮合不到位,加剧齿块和链条磨损,如不及时处理,可能会导致齿块断裂,链条跑偏甚至脱落等严重设备事故。故每次停机检修,均需安排人员对     

Accurate rotor flux orientation technique for indirect rotor flux oriented control of induction motor drives

Abstract

In this paper, a novel detuning index is first proposed for indicating the proper timing required to correct the rotor time constant of indirect rotor flux oriented controlled single‐cage induction motor drives. This index can faithfully reflect the influence of rotor resistance changes as well as rotor flux changes. It also reduces greatly the number of rotor time constant estimations in practical applications. The theoretical basis of the index and the physical meaning are described in the paper in detail. Based on the proposed index, an on‐line rotor time constant estimator is also proposed to make corrections. Only existing available quantities of the closed loop controller are used for calculating the estimated rotor time constant accurately. Both simulation and experimental results verify the effectiveness of the proposed rotor flux orientation technique. It is seen that the proposed rotor flux orientation technique is suitable for practical applications.     

特高压直流换流站消防系统分析

特高压换流站作为国家电力系统重点单位,消防系统对保证电力设备的安全运行极为重要。本文以金华换流站消防系统为例,介绍了换流站消防系统的组成、功能以及与其他相关系统的联动关系,重点分析了阀厅火灾报警跳闸系统,具有十分重要的现实意义。     

A Method to Reduce Sampling Rate of the ADC in Feedback Channel for Wideband Digital Predistortion

This paper presents a new digital predistortion (DPD) solution for wideband signals with low feedback sampling rate. To reduce the minimum sampling rate of the analog-to-digital converter (ADC) for wideband digital predistortion, the proposed method uses a bandpass filter to form a narrowband signal before the ADC. Then, a deconvolution operation is performed to recover the original wideband signal from the ADC samples. The proposed method is evaluated with an international mobile telecommunication-advanced signal with 100 MHz bandwidth. The simulation results show that the recovered signal of the proposed method closely approximates to the original signal in the passband of the filter, and the mean square error of the deconvolution decreases as the signal-to-noise ratio increases. The proposed algorithm can reduce the sampling rate of the ADC from 1105.92 million samples per second (MSPS) to 368.64 MSPS, and improve the adjacent channel power ratio more than 20 dB, which is merely 5.6 dB less than the conventional DPD with 1105.92 MSPS sampling rate.     

永磁同步电机在低速大转矩设备上的直驱应用及节能分析

永磁同步电动机具有节能高效、低速直接驱动效果良好的特点,在某大型建材企业对大功率主电机进行了"更新-直驱"改造试验,即采用新型节能高效永磁同步电动机替代原来的鼠笼异步电动机,去掉减速机及其稀油站系统,直接驱动球磨机运行。试验结果表明,永磁直驱电机除能满足正常生产外,还同时满足了带负荷平稳起动、检修定位停机等要求,不需岗位人员进行切换操作。该项目节能效果明显,平均节电率20%左右,且能显著降低设备维护成本和操作人员劳动强度。     

电化学膜生物反应器应用于难生化降解有机废水深度处理的试验研究

文章考察电化学膜生物反应器(EMBR)对难生化降解废水的污染物去除效果和MBR的膜污染控制情况。在相同的微电场工作条件和MBR操作条件下,通过对照试验研究EMBR系统的对废水污染物去除情况和膜抗污染性能。实验结果表明,电化学膜生物反应器可提高难生化降解废水的可生化性,COD_(Cr)、氮元素的去除率分别达到92.7%、84.4%。外加微电场的作用下,MBR的膜污染情况得到有效减缓,使得EMBR具有更好的运行效能。