实验室无线数据采集系统的设计

文章以射频芯片CC2540为核心,构建一个低功耗、低时延的无线数据通信网络,将实验室负载工作电流、温度、湿度等物理量实时传送到上位机。文中给出了系统硬件电路及上、下位机软件设计。测试表明系统数据传输稳定、准确,设计方案有效、可行。     

NGB-W系统综述

NGB-W作为新一代的智能融合媒体网络及全新的双向开放技术平台,可承载多种三网融合业务,为用户提供精细化的服务,从而实现对现有无线广播电视网络体系的全面升级换代。在分析NGB-W系统架构及重要组成部分的基础上,详细介绍了NGB-W系统的9大特点,三大业务覆盖范围及基础广播电视、交互广播电视、移动互联网接入、物联网业务、紧急广播、跨行业应用等主要应用场景,对中国地面电视行业的发展具有重要的指导意义。     

带相依终止事件的复发事件数据的可加可乘比率模型

本文对带相依终止事件的复发事件数据提出了一个联合建模分析方法,用一个带脆弱变量的可加可乘比率模型来刻画复发事件过程,还用带脆弱变量的Cox风险率模型来刻画终止事件过程,而且这两个过程的相依性由脆弱变量来刻画.我们利用估计方程的方法,对模型参数进行了估计,给出了所得估计的渐近性质.同时,通过数值模拟分析验证了估计的渐近性质.最后,利用该方法分析了弗吉尼亚大学慢性心脏病病人医疗诊费数据.     

应用于六旋翼飞行器航迹规划的改进Voronoi算法

六旋翼飞行器是一种新型的旋翼飞行器,文中主要针对该飞行器在航迹规划时的Voronoi算法进行了改进,优化了飞行器的航迹规划路线.通过对电院大草坪的树林作为障碍物的情况下,飞行器穿过树林到达空旷地方的航迹规划的数学建模发现,使用传统的Voronoi算法的航迹规划的距离为169.113m,使用改进的Voronoi算法的航迹规划的距离为152.8753m,比起传统的Voronoi算法规划出来的航迹的距离缩短了10.6％.     

基于GaN HEMT新型负反馈结构固态宽带功率放大器的研究

The design and fabrication of an ultra-broadband power amplifier based on a Ga N HEMT, which operates in the frequency range from 3 to 8 GHz, is presented in this paper. A TGF2023-02 Ga N HEMT chip from Tri Quint is adopted and modeled. A novel negative feedback structure is applied in the circuit. The measured results show that the amplifier module has a wide range frequency response that is almost consistent with those of simulation at frequencies from 3 to 6.5 GHz. The measured power gain is greater than 7 d B between 3 and 6.5 GHz.The saturated output power is 38.5 d Bm under DC bias of Vds D28 V, Vgs D 3:5 V at the frequency of 5.5 GHz.     

IR,PMR and Mössbauer studies on the complexes of triphenyltin chloride and triphenyltin isothiocyanate with a series of N-alkylsalicylideneimines

Eleven new complexes of the type Ph₃SnX: o-HOC₆H₄CHNR (X = Cl, NCS; R = CH₃, t-Bu, PhCH₂, n-C₆H₁₃, c-C₆H₁₁, HOCH₂CH₂) have been synthesized by the reactions of triphenyltin chloride or isothiocyanate with the N-alkylsalicylideneimines. The complexes are non-electrolytes in nitrobenzene. IR, PMR and Mössbauer spectroscopic studies indicate that the ligands are behaving as monodentates via the phenolic oxygen atoms, and that the complexes all have trigonal bipyramidal geometry with the phenyl groups occupying the equatorial positions.     

Synthesis and Characterization of SiCOF/a-C∶F Double-Layer Films with Low Dielectric Constant for Copper Interconnects

用等离子体化学气相淀积系统制备了一种新颖的SiCOF/a-C:F双层低介电常数介质薄膜,并用红外光谱表征了该薄膜的化学结构.通过测量介质的折射率发现该薄膜长时间暴露在空气中,其光频介电常数几乎不变.然而,随退火温度的增加,其光频介电常数则会减小.基于实验结果讨论了几种可能的机理.二次离子质谱分析表明在Al/a-C:F/Si结构中F和C很容易扩散到Al中,但在Al/SiCOF/a-C:F/Si结构中,则没有发现C的扩散,说明SiCOF充当了C扩散的阻挡层.分析还发现在SiCOF和a-C:F之间没有明显的界面层.     

Performance of coding-spreading tradeoff in DS-CDMA systems using RCPT and RCPC codes

The use of rate-compatible punctured turbo and rate-compatible punctured convolutional (RCPT/RCPC) codes as channel codes in a direct-sequence code-division multiple-access system where the system bandwidth expansion is fixed is investigated. The best RCPC and RCPT code rate in terms of maximizing the system spectral efficiency and minimizing the optimal power allocation where the receiver is either a matched filter (MF) or a minimum mean-square error (MMSE) device is assessed. It is shown that for the MF receiver, the coding-spreading tradeoff favors a code-rate reduction. In the case of the MMSE receiver, when the E/sub b//N/sub 0/ value and the system load are increased, the best code rate also increases. By examining the slope of the performance curves, it is deduced that, under similar operating conditions, the best code rate of the RCPT codes is lower than that of the RCPC codes. Also, the best code rate for a Rayleigh fading channel is lower than that for an additive white Gaussian noise channel.     

Definition of Measure-theoretic Pressure Using Spanning Sets

We introduce a new definition of measure-theoretic pressure for ergodic measures of con-tinuous maps on a compact metric space.This definition is similar to those of topological pressureinvolving spanning sets.As an application,for C~(1 α)(α>0) diffeomorphisms of a compact manifold,we study the relationship between the measure-theoretic pressure and the periodic points.     

非线性时滞系统的K-稳定性

本文研究非线性时滞系统的K-稳定性理论,在较一般的情况下建立了两个非线性时滞微分不等式,从而为研究K-稳定性提供了强有力的手段,文中利用了上述不等式分析了一些非线性时滞系统的K-稳定性条件,文末举例说明本文结果的优越性。