A Relation in the Stable Homotopy Groups of Spheres

Let p≥7 be an odd prime. Based on the Toda bracket α1βp-11, α1 β1, p, γs,the authors show that the relation α1βp-11h2,0 γs= βp/p-1γs holds. As a result, they can obtain α1βp1h2,0 γs = 0 ∈π*(S0) for 2≤s≤p- 2, even though α1h2,0γs and β1α1h2,0 γs are not trivial. They also prove that βp-11α1 h2,0 γ3 is nontrivial in π*(S0) and conjecture that βp-11α1 h2,0 γs is nontrivial in π*(S0) for 3≤s≤p- 2. Moreover, it is known thatβp/p-1γ3 = 0 ∈ Ext5,*BP*BP(BP*, BP*), but βp/p-1γ3 is nontrivial in π*(S0) and represents the element βp-11α1 h2,0 γ3.     

Synthesis and Structure of a New Coordination Polymer Based on Indium and 1,4-Benzenedicarboxylate

A new coordination polymer {[In(bdc)(OH)]·4H2O}n(H2bdc=1,4-benzenedi-carboxylic acid) has been synthesized through hydrothermal conditions,and was characterized by X-ray single-crystal diffraction and other measurements.The complex crystallizes in the orthorhombic system,space group Imma with a=18.3621(13),b=7.1932(5),c=11.8278(8),V=1562.24(19)3,Z=4.Dc=1.565g/cm3,Mr=368.00,F(000)=728,μ(MoKα)=1.542 mm-1,S=1.019,R=0.0468 and wR=0.1326 for 884 observed reflections(2σ(Ⅰ)).The title compound represents a 3-D framework containing four kinds of tunnels in different shapes and sizes.     

茂县大骨节病病区水化学特征

茂县大骨节病区分布具有明显的地域特点,考察了当地地质环境概况,同时对该区地表水、地下水取样,对常量组分、腐殖酸、微量组分进行了分析,阐述了该区的水化学特征。     

Preparation of High-Density Nanocrystalline Bulk Selenium by Rapid Compressing of Melt

The melt＇s solidification behavior of elemental selenium is investigated by a series of experiments including rapid compressing to 2.8 and 3.5 GPa within 20ms respectively, slow compressing to 2.8 GPa for 20 min and natural cooling at ambient pressure. Based on the x-ray diffraction, scanning electron microscope and transmission electron microscope results of the recovered samples, it is clearly shown that homogenous nanostructures are formed only by the rapid compression processes, and that the average crystal sizes are about 18.7 and 19.0 nm in the samples recovered from 2.8 and 3.5 GPa, respectively. The relative density of the nanocrystalline bulk reaches 98.17% of the theoretical value. It is suggested that rapid compression could induce pervasive nucleation and restrain grain growth during the solidification, which is related to fast supercooling, higher viscosity of the melt and lower diffusivity of atoms under high pressure.     

虚拟化环境下的功耗管理

虚拟化的服务整合为降低功耗带来新的机遇,它可以将多个平台的服务,整合到一个平台上,以提高资源利用率,并关掉空闲平台节省功耗;同时,它的层次模型也为功耗控制带来了新的挑战,使得虚拟机各自独立的功耗管理缺少全局状态。就虚拟化环境下的功耗降低和功耗控制这两方面,对国内外的研究现状进行调研和分析,并对未来研究方向进行展望。     

片上网络GALS接口设计

本文提出了一种基于握手协议的GALS接口设计方法。该接口采用异步FIFO作为输入缓冲区,有效降低了数据传输延迟;采用环形缓冲的概念来管理缓冲区,使接口具有了可扩展性。FPGA验证结果表明,该接口保证了适配单元与网络路由之间完成准确的异步传输,4通道的接口共占用了405个ALUT（Adaptive Look-Up Table）和支持211 MHz的时钟频率。     

一种用于大气温度梯度测量的光斑图像质心算法

光斑质心的计算是折射法大气温度梯度测量的关键.提出了一种用于折射法大气温度梯度测量的光斑图像质心算法.该算法使用了自适应阚值选取,适应性强.实验表明,该光斑图像质心算法实时性强、实现简单,适用于大气温度梯度测量.     

一种带宽自适应的滤波器

设计了一种全新的带宽自适应滤波器。主要特点是:在输入信号频率不确定或时变的情况下,能够通过对输入信号频率的探测而自适应的调节滤波器带宽。该结构被成功地应用在了模拟处理器内,有效地实现了对频率不确定或时变的输入信号进行低通或带通滤波处理。滤波器由四阶的全差分开关电容电路实现,带宽可在直流到40kHz内自适应调节。整个电路基于0.18μmCMOS工艺实现,电源电压3.3V,功耗为560μW。芯片测试结果表明,电路具有良好的自适应滤波性能。     

LOS环境下散射体对MIMO信道特性的影响

针对室外视距(LOS)传输情况下的MIMO信道,结合电磁散射分析研究了典型散射体对MIMO信道性能的影响.该模型考虑了实践中常用的微带天线,并推导出在传输路径外存在圆柱电磁散射体条件下MIMO信道矩阵的解析公式,应用该公式分析了MIMO信道容量和矩阵条件数等特征参量.仿真结果表明,该模型能够描述出不同参数下信道特性的变化,对实际MIMO系统的设计有一定的参考意义.     

基于模糊推理的网络可生存性的建模与分析

首先用对象Peui网对网络系统进行了形式化的描述与建模,接着构建了系统的攻击失效模型,并用模糊推理方法对系统在攻击发生时状态的变化进行了描述,最后在此基础上对攻击行为的严重程度和服务等级进行了有效量化,提出了分布式系统可生存的评价参数.这种在复杂攻击发生的早期推理分布式系统的生存能力的建模与分析方法可有效地度量贯穿攻击各阶段的系统的可生存能力,并为系统进行持续服务和进行应急响应提供可靠依据.