Energy Control for Microwave Amplifier Arrays

In large systems using microwave amplifier arrays, the size, weight, and cost of individual energy sources require consideration of the use of a common power supply and energy storage bank. Complex energy control techniques may be necessary to protect the RF amplifier and to provide isolation of the faulted amplifier from the common energy source. Four approaches are discussed. Three of these are dependent on either the development of reliable arc-free microwave amplifiers or special isolator tubes, gas or vacuum types. A practical circuit using available components is suggested. Its advantages and limitations are discussed. Calculations are presented showing this approach can result in increased system efficiency, improved regulation, and large decreases in the size of the secondary capacitance bank for each microwave amplifier.     

我国商业银行拆入资金业务内部控制体系研究

资金拆入是指商业银行因资金周转需要而在金融机构之间借入资金的行为，是商业银行的一项常规性业务，拆入资金业务内部控制是我国商业银行内部控制体系中的一个重要组成部分。拆入资金业务内部控制体系可以为我国商业银行加强拆入资金业务管理、提高拆入资金业务的运作效率提供可靠的理论借鉴。我国商业银行拆入资金业务内部控制体系的设计必须密切联系我国商业银行拆入资金业务的运作实践。因子分析可以为理论模型提供现实性检验，从而展现我国商业银行拆入资金业务内部控制的现实性微观机理。     

基于噪声匹配的有源接收天线设计

为了提高接收天线的增益和灵敏度,采用将天线与低噪声放大器集成到一起设计的方案,将天线的输出阻抗作为放大器的源阻抗,省略了天线与放大器之间的阻抗匹配网络。通过调节天线馈电系统的尺寸调节天线阻抗,使其等于放大器的最佳源阻抗。利用HFSS仿真软件计算天线的辐射特性及阻抗,用ADS Designer软件对低噪声放大器进行优化设计。利用2SC5507晶体管设计了一个工作于2．0GHz的与低噪声放大器集成在一起的缝隙耦合微带天线,所设计的噪声系数为1．664dB,放大器增益为16．75dB。     

用于磁悬浮轴承的三电平PWM开关功放设计

三电平PWM开关功放是适用于磁悬浮轴承的新型放大器。本文简述了该放大器的工作原理,在此基础上设计了以FPGA为核心的功放电路。分别介绍了电路各部分组成,工作原理及设计中的注意事项。试验结果证明了此种功放在系统所需频率范围内具有良好的动态特性。     

我国网络银行风险及其管理措施

网络银行具有超越时空、创新发展快、运作工具有别于传统银行等特点。网络银行能否顺畅发展,一个关键问题是如何防范和控制风险。网络银行的风险主要包括金融风险和业务风险等方面。金融风险所包含的信用风险是网络银行最大的风险,而市场风险对网络银行的冲击也越来越显著。加强我国网络银行的风险管理,主要通过以下措施来实现：（1）强化网络银行的信誉管理,完善社会信用体系;（2）营造良好的市场发展环境,控制市场交易风险;（3）加强银行业务监管,减少银行操作风险。     

Interrelationship of single-filter and multiple-model adaptivealgorithms

An equivalent filter bank structure for multiple model adaptive estimation (MMAE) is developed that uses the residual and state estimates from a single Kalman filter and linear transforms to produce equivalent residuals of a complete Kalman filter bank. The linear transforms, which are a function of the differences between the system models used by the various Kalman filters, are developed for modeling differences in the system input matrix, the output matrix, and the state transition matrix. The computational cost of this new structure is compared with the cost of the standard Kalman filter bank (SKFB) for each of these modeling differences. This structure is quite similar to the generalized likelihood ratio (GLR) structure, where the linear transforms can be used to compute the matched filters used in the GLR approach. This approach produces the best matched filters in the sense that they truly represent the time history of the residuals caused by a physically motivated failure model     

燃气源开槽导管出口烧蚀特性分析

针对某火箭弹控制系统燃气源在点火试验过程中出现的导管出口烧蚀现象,利用数值计算模拟气流流动参数分布, 考虑到导管管壁的非稳态传热过程, 计算出不同时刻在导管开槽出口附近管壁的温度分布, 得出与试验一致的结论     

WARLOC: A High-Power Coherent 94 GHz Radar

This paper describes the development of a high-power, coherent radar system at W-band and discusses potential applications of radars with this new capability. Previous radars in this frequency band were limited by available power-amplifier technology to about 500 W of average power; WARLOC radar represents an increase in power, by 20 times, over previous coherent radars at 94 GHz. This performance improvement is possible due to the development of a gyroklystron amplifier specifically for this and future radars in this frequency band. The gyroklystron amplifier tubes deliver 100 kW peak power and 10 kW of average power at a center frequency of approximately 94 GHz. Other novel features of this radar include the use of highly overmoded waveguides and rotary joints for the transmission of power from the final power amplifier (FPA) to the antenna, and a high-power quasi-optical duplexer. The system uses a relatively large 1.8 m diameter (580-wavelength) Cassegrain antenna, which required the development of an antenna with an rms surface accuracy of 0.0025 in, to obtain long-range detection and identification of small objects. Test data show an antenna gain of 62.5 dB, confirming that the needed surface accuracy was achieved. Two mobile shelters house the radar system, permitting relocation to various test sites. WARLOC is presently operational at the Naval Research Laboratory's Chesapeake Bay Detachment facility, Maryland. It is being employed in radar imaging of airborne and surface objects, and in the scientific study of propagation effects and atmospheric physics phenomena.     

基于混合卡尔曼滤波器组故障传感器定位方法

为了在发动机性能蜕化与传感器故障并存的情况下实现故障传感器的定位与部件蜕化情况的估计,并实现故障诊断基准数据的修正,构建了1种包含了机载模型与线性卡尔曼滤波器的组合结构混合卡尔曼滤波器组。该卡尔曼滤波器组能够在之前所描述的故障/蜕化耦合情况下定位故障传感器,并得到较为准确的部件蜕化估计结果。为了验证了混合卡尔曼滤波器组的有效性,进行了相关仿真。仿真结果表明:混合卡尔曼滤波器组能够在发动机动态过程中遭遇传感器故障与部件蜕化并存的情况下完成故障定位与蜕化估计。     

隔振系统限位器的非线性动力学设计

根据经典线性理论设计隔振系统弹性限位器的约束空间往往太小,在小阻尼情况下会诱发非线性共振,使隔振系统变为放大系统。从非线性动力学角度讨论了弹性限位器的设计问题,给出了若干设计原则及参数选择范围     

一种新型压电陶瓷驱动器电源设计

设计并研制了一种新型压电陶瓷驱动电源。该电源采用高压直流放大器加功率放大器原理,具有良好的动态响应性能,能很好地满足微细电火花加工的伺服要求。     

“小信号谐振放大器”的教学策略

小信号谐振放大器是高频电子线路课程的基本单元电路之一,主要应用在通信系统的接收机电路中,高频放大和中频放大是信号传输电路中的核心部分。掌握小信号谐振放大器的分析方法,对电子信息类、通信工程类专业学生的学习及工作是非常关键的。     

Bandwidth maximization for satellite laser communication

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. The basic free space optical communication network includes at least two satellites. In order to communicate between them, the transmitter satellite must track the beacon of the receiver satellite and point the information optical beam in its direction. The pointing systems for laser satellite communication suffer during tracking from vibration due to electronic noise, background radiation from interstellar objects such as Sun, Moon, Earth, and Stars in the tracking field of view, and mechanical impact from satellite internal and external sources. Due to vibrations the receiver receives less power. This effect limits the system bandwidth for given bit error rate (BER). In this research we derive an algorithm to maximize the communication system bandwidth using the transmitter telescope gain as a free variable based on the vibration statistics model and the system parameters. Our model makes it possible to adapt the bandwidth and transmitter gain to change of vibration amplitude. We also present an example of a practical satellite network which includes a direct detection receiver with an optical amplifier. A bandwidth improvement of three orders of magnitude is achieved in this example for certain conditions, as compared with an unoptimized system     

一种低相位噪声频标分配放大器的设计实现

随着测控试验系统对低相位噪声频标指标要求的不断提高,国内市场上的绝大部分相关产品已无法满足要求。本文给出一种低相位噪声频标分配放大器的设计实例,实例采用基于MAX4104增益放大和LMH6609分配放大的2级放大电路结构,充分利用MAX4104的低相位噪声放大特性和LMH6609的大电流驱动分配特性,同时采用先进的PCB（印制电路板）设计技术和有效的电路噪声抑制手段,实现了频标的低相位噪声分配放大输出。最后对实例设计进行了验证分析。本设计相关产品已广泛应用于卫星地面测控系统的时频分系统中,实践证明设计指标满足航天测控和武器试验用户的要求。     

村镇银行可持续发展的制约因素及对策研究——以河南省为例

村镇银行是我国新型农村金融机构的一种基本形式和新生银行形态,对农村社会经济发展具有不可或缺的重要作用.文章以农业大省河南为例,通过描述性研究和个案分析,深入系统地剖析了影响和制约河南村镇银行可持续发展的制度、功能、社会、定位、风险、结算和人力等诸多因素,并从村镇银行的外部保障环境营造、内部经营机制完善和国外经验借鉴等方面,提出了河南村镇银行可持续发展的基本路径和一系列对策建议.     

一种叠加独立颤振的阀用电机双向驱动器

为了实现阀用动圈式直线电机双向驱动及驱动过程中的颤振要求,研发了一种运用脉宽调制信号驱动新型动圈式直线电机的比例放大器,提出将脉宽调制信号与颤振信号相互叠加的驱动方案,能够实现对动圈式直线电机的颤振调节。理论分析与仿真研究表明,所研发的比例放大器性能可靠,能满足动圈式直线电机驱动要求。     

A Closely Regulated TWT Converter

The design concept for the traveling wave tube amplifier converter for possible use in the Thermoelectric Outer Planet Spacecraft (TOPS) is presented. An unusual combination of semiconductors and magnetics were utilized to achieve very stable voltage regulation on a number of separate outputs to satisfy the requirements of a high-power traveling wave tube (TWT), and at the same time operate at an efficiency of better than 90 percent from a 30-volt source. The circuitry consists of an output filter, an auxiliary Jensen oscillator driving a high-reactance transformer to provide current limiting to the heater, a variable time delay, a main Jensen oscillator driving the power transformer with a maximum step-up ratio of 120 to 1, and series transistorized post regulators to provide precise voltage adjustment and low output impedance. This paper discusses the design of the high-reactance transformer and the high step-up ratio transformer, as well as the high-voltage series regulators that are limited in range and operate at the top of the unregulated output voltage. Test data is presented, and details of current transients caused by charging the filter circuits, input current ripple, and output voltage ripples are considered. The circuit provides better than 0.5 percent regulation against load change, input voltage change, and over-operating temperature range of from -20 to + 80°C, with output ripple voltage of less than 2 volts peak-to-peak on top of the 3600-Vdc output. The measured efficiency was typically 87 percent. and recommendations are included to improve this to in excess of 90 percent.     

Characterization of Kalman filter residuals in the presence ofmismodeling

The mean and covariance of a Kalman filter residual are computed for specific cases in which the Kalman filter model differs from a linear model that accurately represents the true system (the truth model). Multiple model adaptive estimation (MMAE) uses a bank of Kalman filters, each with a different internal model, and a hypothesis testing algorithm that uses the residuals from this bank of Kalman filters to estimate the true system model. At most, only one Kalman filter model will exactly match the truth model and will produce a residual whose mean and standard deviation have already been analyzed. All of the other filters use internal models that mismodel the true system. We compute the effects of a mismodeled input matrix, output matrix, and state transition matrix on these residuals. The computed mean and covariance are compared with simulation results of flight control failures that correspond to mismodeled input matrices and output matrices     

通用型题库系统（TH1.0）的设计

介绍了一个集题库管理、试卷管理及ＷＰＳ排版打印于一体的题库系统的设计与实现，给出了系统的结构与主要功能，提供了一个可支持要求各异的不同学科进行题库生成的实用性和通用性较强的计算机辅助教学的工具。     

Small-size rocket impulse-reaction launch dynamics

The method of analyzing the small-size rocket liftoff is presented. Under consideration is a system that consists of a rocket with an operating rocket engine, a launch tube, and an operating gas generator mounted in the tube under the rocket. The liftoff parameters including the rocket motion velocity inside the tube and the loads applied are calculated. The calculated and experimental data were compared and their adequate agreement is presented with respect both dynamics of rocket impulse-reaction liftoff from the launch tube and the launch velocity.