“绿云扰扰”为何意

人教版《阿房宫赋》中“绿云扰扰,梳晓鬟也”参考译文不明,教材没有详细注释。文章从词语解释的角度,明确该句的翻译。

基于AHDL扰码和解扰仿真设计

数字通信技术与EDA技术的结合是现代通信系统发展的一个必然趋势。介绍扰码和解扰的基本原理,基于AHDL语言实现了对扰码和解扰电路的设计,并在MAX+PLUSII环境下对电路进行了仿真,仿真结果表明了该设计的可行性。

伞翼无人机线性自抗扰高度控制

针对伞翼无人机参数不确定性和复杂环境干扰敏感的问题,提出一种伞翼无人机线性自抗扰(Linear Active Disturbance Rejection Control,LADRC)高度控制方法。建立伞翼无人机8自由度飞行动力学模型,并引入风场和降雨模型以更加准确地模拟真实飞行环境。基于LADRC确定总体控制架构,设计线性扩张状态观测器对所有扰动进行估计,并引入误差反馈率在控制中实时补偿。使用该控制方法在多种扰动工况下进行伞翼无人机高度控制仿真实验。仿真结果表明,基于LADRC的高度控制方法能够有效克服内扰和外扰的影响,实现高精度高度控制;与传统PID控制效果相比,LADRC控制器具有更好的抗扰能力和鲁棒性。

Progress and Research on Interconnects Crosstalk in Deep Submicron Technology

As develops in deep sub micron designs,the interconnect crosstalk becomes much more serious.Espe cially, the coupling inductance can not be ignored in gigahertz designs.So shield insertion is an efficient technique to reduce the inductive noise.In this paper,the characteristics of on chip mutual inductance (as well as self) for coplanar,micro stripline and stripline structures are introduced first.Then base on the coplanar interconnect structures,the effective coupling K eff model and the RLC explicit noise model are proposed respectively.The results of experiments show that these two models both have high fidelity.

Sinusoidal FM Fuze's Channel Leak and Its Jamming Mechanism

Aim To get the theory base of designing FM fuze's jamming signal, its jamming mechanism was studied. Methods A sinusoidal FM fuze was analyzed in time domain and frequency domain and the concept of channel leak was presented. Results It was proved that information channel leak exists in FM fuze because of the nonlinear property of the mixer. The jamming signal was designed based on the channel leak and the jamming mechanism was analyzed in detail. Conclusion This kind of jamming signal can jam the sinusoidal FM fuzes effectively just depending on the jamming signal's feature itself. It's different from the traditional jamming way of simulating echo. Though the sinusoidal FM fuze was just analyzed, the principle is applicable to all FM fuzes. At the same time, it may be used as the reference for FM radar and communication countermeasures.

Method of Jamming C/A Code GPS Receiver

The schemes and effects of electronically jamming GPS’s C/A code receivers are studied by using CW as the narrow band jamming signal and BPSK signal modulated by Gold code which is incoherent to that adopted by GPS as the wide band one. By simulating with Monte Carlo method and programming in Matlab language, the various jamming results in terms of bit error rate under several jamming scenarios are obtained. Through analyzing the simulation results and quantitative dependences of jamming effects on the distance from jammer to GPS receiver and the jammer’s height over ground, it is concluded that jamming with wide band jammer is much more effective than that with narrow band one.

数据通信模拟实验系统的设计与实现

差错控制和扰码是数据通信原理教学过程的难点,本文介绍了针对这些问题所设计的两个教学模拟实验原理和实现方法。

“通中扰、扰中通”技术研讨

本文针对一种全新的综合对抗技术——“通中扰、扰中通”，提出了其技术开发的总体方案、研究方法、技术路线和技术特点。

Attribute Disturbance of Knowledge and Attribute Disturbance Theorems

By using the dynamic characteristic of one direction S-rough sets（one direction singular rough sets） and dual of one direction S-rough sets（dual of one direction singular rough sets）, the concepts of attribute disturbance of knowledge, the attribute disturbance degree of knowledge, and the disturbance coefficient of knowledge are given. By employing these concepts, the cardinal order theorem of the attribute disturbance knowledge, the unit circle theorem of the attribute disturbance knowledge, and the discernible theorem of the attribute disturbance knowledge are presented.

Expression of interferon-alpha/beta receptor protein in liver of patients with hepatitis C virus-related chronic liver disease

ABM: To study the expression of interferon-alpha/beta (IFN-α/β) receptor protein in liver of patients with hepatitis C virus (HCV)-related chronic liver disease and its clinical significance. METHODS: A total of 181 patients with HCV-related chronic liver disease included 56 with HCV-related liver cirrhosis (LC) and 125 with chronic hepatitis C (CHC). CHC patients were treated with five megaunits of interferon-α1b six times weekly for the first 2 weeks and then every other day for 22 wk. The patients were divided into interferon (IFN) treatment-responsive and non-responsive groups, but 36 patients lost follow-up shortly after receiving the treatment. The expression of IFN-α/β receptor (IFN-α/βR) protein in liver of all patients was determined with immunofluorescence. RESULTS: In liver of patients with HCV-related chronic liver disease, the expression of IFN-α/βR protein in liver cell membrane was stronger than that in cytoplasm and more obvious in the surroundings of portal vein than in the surroundings of central vein. Moreover, it was poorly distributed in hepatic lobules. The weak positive, positive and strong positive expression of IFN-α/βR were 40% (50/125), 28% (35/125), 32% (40/125), respectively in CHC group, and 91.1% (51/56), 5.35% (3/56), and 3.56% (2/56), respectively in LC group. The positive and strong positive rates were higher in CHC group than in LC group (P<0.01). In IFN treatment responsive group, 27.8% (10/36) showed weak positive expression; 72.2% (26/36) showed positive or strong positive expression. In the non-responsive group, 71.7% (38/53) showed weak positive expression; 28.3% (15/53) showed positive or strong positive expression. The expression of IFN-α/βR protein in liver was more obvious in IFN treatment responsive group than in non-responsive group. CONCLUSION: Expression of IFN-α/βR protein in liver of patients with HCV-related chronic liver disease is likely involved in the response to IFN treatment.

Application of pseudo-random frequency domain electromagnetic method in mining areas with strong interferences

Due to the strong electromagnetic interferences and human interference,traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines.The wide field electromagnetic method(WFEM),in which the pseudo-random signal is taken as the transmitter source,can extract high quality resistivity data in areas with sever interference by only measuring the electric field component.We use the WFEM to extract the resistivity information of the Dongguashan mine in southeast China.Compared with the audio magnetotelluric(AMT)method,and the controlled source audio-frequency magnetotelluric(CSAMT) method,the WFEM can obtain data with higher quality and simpler operations.The inversion results indicate that the WFEM can accurately identify the location of the main ore-body,which can be used for deep mine exploration in areas with strong interference.

线性自抗扰控制理论及工程应用的若干进展

自抗扰控制(ADRC)是我国著名控制论学者韩京清教授创立的一种不依赖于被控过程模型的原创性控制思想和方法,实践表明这是一种具有很好工程应用潜力的新型先进控制技术.在此基础上,高志强学者等将ADRC的主要环节进行了线性化处理,提出线性自抗扰控制(LADRC).LADRC具有结构简单、易于进行性能分析和参数整定等特点,因此它极大地促进了自抗扰控制理论的深入发展及在工程中的推广应用.本文在简要概述线性自抗扰控制原理及其设计方法的基础上,总结了近年来LADRC在理论及应用方面的最新研究进展,包括稳定性分析、针对典型控制问题的设计与综合方案以及在实际工程应用中所取得的一些显著成果.最后对该方向的后续研究给出了进一步的展望.

Pegylated IFN-α2b added to ongoing lamivudine therapy in patients with lamivudine-resistant chronic hepatitis B

AIM： To investigate the role of pegylated-interferon （IFN）α-2b in the management of patients with lamivudineresistant chronic hepatitis B. METHODS： Twenty consecutive anti-HBe positive patients were treated with pegylated IFN α-2b （100 IJg sc once weekly） for 12 mo. There was no interruption in lamivudine therapy. Hematology, liver biochemistry, serum HBV DNA levels were detected by PCR, and vital signs were also assessed. Liver histology was assessed in some patients at entry and at wk 52 for comparison. RESULTS： Nine patients （45%） had a partial virological end-treatment response; seven patients （35%） showed complete virological end-treatment response. Eight patients （40%） showed biochemical end-treatment response. There was a trend for higher virological response rates in patients who had previously responded to IFN and relapsed compared to IFN non-responders （four out of seven patients vs none out of six patients, respectively; P=0.1）. Patients without virological endtreatment response showed significant worsening of fibrosis [median score 2 （range, 1 to 3） vs median score 3 （range, 1 to 4）], in the first and second biopsy respectively （P=0.014）, whereas necroinflammatory activity was not significantly affected. Patients with complete or partial virological end-treatment response did not show any significant changes in histological findings, possibly due to the small number of patients with paired biopsies （n = 5）. Nevertheless, after 12 mo of follow-up, only onepatient （5%） showed sustained virological response and only 2 patients （10%） showed sustained biochemical response. Two patients （10%） discontinued pegylated ]FN both after 6 mo of treatment due to flu-like symptoms. CONCLUSION： Pegylated IFNα-2b, when added to ongoing lamivudine therapy in patients with lamivudineresistant chronic hepatitis B, induces sustained responses only in a small minority of cases.

Indoor measurement method of smoke screen disturbance efficiency based on Gaussian diffusion model

Because of ground clutter wave interf e rence,it is difficult to measure smoke screen disturbance in the field.In this pape r,a kind of indoor measurement method of smoke screen disturbance efficiency ba sed on Gaussian diffusion model is put forward.As a characteristic,the measur ement result of smoke screen area density proves that the indoor measurement met hod of smoke screen disturbance efficiency based on Gaussian diffusion model is fea sible.

A new PMSM speed modulation system with sliding mode based on active-disturbance-rejection control

A sliding mode and active disturbance rejection control(SM-ADRC)was employed to regulate the speed of a permanent magnet synchronous motor(PMSM).The major advantages of the proposed control scheme are that it can maintain the original features of ADRC and make the parameters of ADRC transition smoothly.The proposed control scheme also ensures speed control accuracy and improves the robustness and anti-load disturbance ability of the system.Moreover,through the analysis of a d-axis current output equation,a novel current-loop SM-ADRC is presented to improve the system’s dynamic performance and inner ability of anti-load disturbance.Results of a simulation and experiments show that the improved sliding-mode ADRC system has the advantages of fast response,small overshoot,small steady-state error,wide speed range and high control accuracy.It shows that the system has strong anti-interference ability to reduce the influence of variations in rotational inertia,load and internal parameters.

An Anti-multipath Frequency Hopped Communication Technique in Shallow-water Acoustic Channels

This paper introduces a frequency-hopped (FH) communication system to anti-intersymbol interferences (ISI) caused by the multipath propagation in shallow-water acoustic channels, and uses high-speed digital signal processor (DSP) and serial ADC (MAX121) chip to demodulate received signal efficiently based Fast Fourier Transform (FFT) algorithm. The field experimental results show: a data rate of 1Kbit/s with the bit error rates on the order of 10 -4 is demonstrated at 2000 m in the shallow-water acoustic channel of Xiamen harbor, and the key techniques of the system is analyzed in the paper.

Co-channel interference rejection for MIMO-OFDM systems

A method based on the maximum a posteriori probability （MAP） criterion is proposed to estimate the channel frequency response （CFR） matrix and interference- plus-noise spatial covariance matrix （SCM） for multiple input and multiple output orthogonal frequency division multiplexing （MIMO-OFDM） systems. An iterative solution is proposed to solve the MAP-based problem and an interference rejection combining （IRC） receiver is derived to suppress co-channel interference （CCI） based on the estimated CFR and SCM. Furthermore, considering the property of SCM, i. e., Hermitian and semi-definite, two schemes are proposed to improve the accuracy of SCM estimation. The first scheme is proposed to parameterize the SCM via a sum of a series of matrices in the time domain. The second scheme measures the SCM on each subcarrier as a low-rank model while the model order can be chosen through the penalized-likelihood approach. Simulation results are provided to demonstrate the effectiveness of the proposed method.

INTERFERENCE MITIGATING BASED ON FRACTIONAL FOURIER TRANSFORM IN TRANSFORM DOMAIN COMMUNICATION SYSTEM

The method of FRactional Fourier Transform (FRFT) is introduced to Transform Domain Communication System (TDCS) for signal transforming in the paper after theoretical analysis. The method yields optimal Basis Function (BF) by FRFT with optimal transform angle. The TDCS using the proposed method has wider usable spectrum, stronger robustness and better ability of anti non-stationary jamming than using usual methods, such as Fourier Transform (FT), Auto Regressive (AR), Wavelet Transform (WT), etc. The main simulation results are as follows. First, the Bit Error Rate (BER) Pb is close to theoretical bound of no jamming no matter in single tone or in linear chirp interference. Second, the interference-to-signal ratio J /E is at least 12dB more than that of Direct Spread Spectrum System (DSSS) under the same BER if the spectrum hopping-to-signal ratio is 1:20 in chirp plus hopping interfering. Third, the Eb /N 0(when estimation difference is 90% between trans- mitter and receiver) is about 3.5dB or about 0.5dB (when estimation difference is 10% between transmitter and receiver) more than that of theoretical result when no estimation difference un-der Pb=10-2.

串扰问题分析及对PCB设计的指导

文章介绍了引起串扰的原因,串扰的分类及估计,用Mentor Graphics的HyperLynx对不同的PCB叠层结构和线间距、耦合长度等情况下的串扰进行仿真,并总结串扰的特点,最后给出在PCB设计中减少串扰的一些方法。

Interference Robust Channel Hopping Strategies for Wireless Sensor Networks

Due to the shared nature of the wireless medium, the performance of wireless sensor network is often limited by both internal interference and external interference. The internal interference is that simultaneous traffic activity by neighboring nodes in the same network, while the external interference is from wireless transmissions by other types of devices, such as Wi-Fi and Bluetooth nodes. In this paper, we present two channel hopping algorithms for multichannel, single-radio wireless sensor networks. The first algorithm achieves collision-free transmission environment while do not introduce extra control overhead. The second algorithm, in addition to reducing internal interference effects, reduces the external interference effects from Wi-Fi devices. Simulation results show that both of them significantly improve performance in wireless sensor network.