Static and dynamic photoinduced magnetic effects in yttrium-iron garnet lightly doped with barium ions

In yttrium-iron garnet lightly doped with barium, direct measurements of the photoinduced changes in magnetostrictive strains disagree with those in magnetostriction constants at 78–100 K. This is attributed to a considerable photoinduced modification of the initial state in this sample due to a redistribution of the charge (during illumination) between cations of the ferromagnetic octahedral sublattice. In the same sample, the temperature dependence of the photoinduced disaccomodation of magnetic permeability characterizing the initial demagnetized state is measured and calculated. A change in the electron mechanism of the phenomenon during the transition to room temperature is shown. The conclusion about the promising prospects for using such samples for remagnetization by light is advanced.     

Cooperative Communications in Future Home Networks

The basic idea behind cooperative communications is that mobile terminals collaborate to send data to each other. This effectively adds diversity in the system and improves the overall performance. In this paper, we investigate the potential gains of cooperative communication in future home networks. We derive analytical expressions for the error probability of binary phase shift keying (BPSK) signals over Nakagami-m fading channels in a multi relay communication network. Following to the analytical study, we analyze the contribution of cooperative relaying to the 60GHz network connectivity through simulations using a realistic indoor environment model. We compare the performance of different relay configurations under variable obstacle densities. We show that a typical 60GHz indoor network should employ either a multi-relay configuration or a single-relay configuration with a smart relay selection mechanism to achieve acceptable outage rates. In the use of multiple-relay configuration, both analytical and simulation studies indicate that increasing the number of cooperative relays does not improve the system performance significantly after a certain threshold.     

The self-formation graded diffusion barrier of Zr/ZrN

In this paper, the 5 nm ZrN diffusion barrier was deposited by high vacuum magnetron sputtering method on Si substrate and the 300 nm Cu(Zr) alloy film or Cu film was sputtered on ZrN barrier without break vacuum. The self-formation graded Zr/ZrN diffusion barrier was obtained by annealing Cu(Zr)/ZrN bilayer system in N₂/H₂ (10% H₂) atmosphere. The X-ray diffraction (XRD) and four-point probe method were used to study graded Zr/ZrN diffusion barrier. The results revealed that the self-formation Zr barrier and ZrN barrier all obviously improved the thermal stability of Cu/Si system.     

关注TD-LTE的发展

介绍了全球电信运营商高度重视LTE的发展以及从3G向LTE平滑演进的现状,阐述了具有我国自主知识产权的3G标准TD—LTE的研究取得的重大进展,指出面对LTE商用进程的加快发展的新形势,全球所有重量级食业都在加快研发,抢占这一新兴领域。     

污水集中排放监控终端的设计和实现

设计了一套针对污水处理厂的排污企业污水排放监控系统。主要监测其排放污水的实时流量、流速等现场数据。采用485通信、无线DTU传输、因特网接入等多种通信方式,解决了远程现场环境下的数据传输问题,实现了污水排放现场数据实时上传和排污现场控制功能。     

Terahertz Sub-harmonic Mixer Using Discrete Schottky Diode for Planetary Science and Remote Sensing

Sub-harmonic mixers are the core element of terahertz room temperature, high spectral resolution heterodyne receivers for planetary science, and remote sensing. Here, terahertz sub-harmonic mixer up to 400 GHz using discrete Schottky diode is presented. Measured performance is in agreement with results from the linear and nonlinear co-simulations, and this methodology shows its practicability for the discrete planar GaAs Schottky diode-based terahertz core circuit design.     

纳伏级微弱信号放大电路的设计

针对工程测量领域的实际需求,设计了纳伏级微弱信号的放大电路,在信号输入端,通过仿真软件仿真设计,最终选用AD公司的超低噪声差分信号放大芯片AD620,放大倍数为10倍,降低了等效输入噪声。设计了相应的信号调理电路,采用多级放大电路组态方式,运用超低噪声四运放（OP470A）来组建多级带通滤波器,经过多级滤波、多级放大,逐步提高信噪比。通过实验,采用不同频段的噪声,验证SNR的改善情况。利用Multisim仿真软件对系统噪声进行了分析,分析结果显示,在低频段有效地抑制对电路造成影响的各种噪声,信噪比得到了较大的提升。     

用于高重复率激光测距系统的环状传递延时式时间数码转换器

本文报导一种创新的“环状传递延时式”单芯片时间数码转换器,由于线性度优异,测量“预时段”极短,故适用于高重复率光学飞时测距应用,例如扫瞄式三维测量激光雷达。使用一种简单的电路让循环脉冲第一周均回复其脉宽,使可转换的时间长度不会如以往装置因脉冲之前沿与后沿前进速度不同而受到限制。使用讥售可编程逻辑片所制造之原型样机。实验测得「之微分误差小于１１５ｐｓｅｃ,非线笥度小于０．３１％,而最长可测时间只受限