GPRS在供水调度监控系统中的应用

针对当前城市供水调度监控点分布范围广、数量多、距离远的现状，提出了一种基于GPRS技术的城市供水调度监控系统的设计和实现方法。具体描述了监控现场的硬件连接；同时对该技术的应用前景进行了展望。     

Polarized Optoelectronics of CsPbX3 (X = Cl,Br, I) Perovskite Nanoplates with Tunable Size and Thickness

Low dimensional semiconductor nanomaterials have shown their tailorable properties for a variety of promising applications in decades. Here a general strategy to synthesize all‐inorganic CsPbX₃ (X = Cl, Br, I or their mixture) perovskite 2D nanoplates by introducing additional metal halides MX'₂ or MX'₃ (M = Cu, Zn, Al or Pb, etc.; X' = Cl, Br or I) is reported. These CsPbX₃ perovskite nanoplates have uniform thickness and tunable size, which can be feasibly controlled by the component and ratio of the metal halides, temperature, time, and ligands. The well‐defined morphology of the nanoplates makes them ideal building blocks for the self‐assembly in the face‐to‐face and column‐by‐column arrangement. Compared to the optically isotropic CsPbX₃ nanocubes, the 2D CsPbX₃ nanoplates exhibit remarkable polarized UV–vis absorption and photoluminescence not only in liquid solvent and solid resin matrix, but also in self‐assembled films. An optoelectronic photodetector sensitive for linear polarized light is fabricated to demonstrate the proof‐of‐concept.     

服务质量约束下的IP组播通信可靠性评估方法

In order to estimate the reliability performance of multicast communication under multiple constraint conditions, the weight of service rate and the reliability index are defined, accompanying the calculation method. Firstly, according to the Quality of Service requirements, the appropriate routings between the central node and target nodes that meet the requirements are calculated using the iterative method in the weighted internet. Then, the disjoint set of network state and the coefficients of weighted service rate are calculated by decomposition and merge methods. Lastly, the formula for calculating the service rate is obtained based on the disjoint set of network state and the calculation of the reliability index will be completed. The simulation result shows that the reliability of multicast communication can be appropriately reflected by the weight of service rate and the calculation method, which can provide the theoretical basis for the reliability evaluation of multicast communication.     

两性淀粉的制备及表征

以正磷酸盐为阴离子化剂,对高取代度的阳离子淀粉进行改性,制备阴阳离子比为0.5的两性淀粉,其最佳工艺为:磷酸盐与阳离子淀粉质量比为1.94～2.02.反应温度145～155℃,反应时间3～3.5 h。用红外光谱、X射线衍射、扫描电镜对其结构进行了表征,结果表明此种两性淀粉仅使淀粉结构中的非晶态区发生改变,并未改变整体结晶结构,因此其生物降解性会同天然高分子淀粉一样可完全降解。     

MOS器件中寄生双极型晶体管模型参数的提取

在晶体管GP模型基础上,采用Silvoca公司的UTMOST模型参数提取程序,得到一种双极型晶体管模型参数的提取方法.用此方法对PCM测试芯片的寄生三极管进行参数提取和模拟,模拟结果与测试结果符合得较好.     

基于图像智能识别的农作物防治系统设计与开发

农药播撒在农作生产环节中至关重要,针对我国存在农药漏用、乱用的现象,设计的农作物防治系统将信息技术与农业生产相结合,基于Spring MVC框架,构建移动端微信小程序与后端管理系统,集合了病虫害图像识别、疫区防治信息维护和代理防控等模块。系统覆盖"播种—查虫—识别—防治"的业务闭环,提高了农业生产效率,助力我国农业信息化发展。     

应变Sil-xGex/Si △i能谷附近色散关系的KP理论推导

基于对称性分析,应用KP微扰理论确定了应变Si1-xGex(0≤x<0.45)/(001),(111),(101)Si的△i能谷附近的色散关系.结果证明:应变Si1-xGx中的△i能级大小不同于弛豫Si-xGex的△1能级,而二者的横向、纵向有效质量(m*l,m*t)相同.△i和△1能级之差由形变势理论确定.最后,描述了双轴应变下外延层材料的导带带边特征.     

Na2高位振动态与CO_2分子间碰撞能量转移的研究

利用受激发射抽运将Na2分子激发到Na2X1Σ+g(33,11)高位振动态,研究了高激发Na2与CO2的态-态能量转移过程。窄线宽激光扫描Na2的X1Σ+g(33,11)→A1Σ+u(21,10)跃迁,测量它的透射光强,从吸收系数得到Na2X1Σ+g(33,11)原生态布居数密度。利用高分辨率瞬时吸收测量技术,得到CO2基振动态(0000)上转动态的布居数密度。通过速率方程分析,在一次碰撞的条件下,得到了与高振动激发Na2碰撞产生CO2(0000)高转动态的速率系数。对于J=46~64,速率系数在4.5×10-12~6.5×10-13cm3s-1之间,相对于J态的Na2(ν″=33)的猝灭速率系数在2.3×10-11~9.1×10-11cm3s-1之间。实验数据表明,在Na2高位振动态与CO2的碰撞能量转移中,Na2激发态倒空对CO2转动能量的增加更有效。观察到了Na2高位振动态的多量子弛豫,得到了弛豫速率系数。     

云计算技术简述

云计算(Cloud computing)是当今IT界的热门技术,借助云计算,网络服务提供者可以在瞬息之间,处理数以千万计甚至亿计的信息,实现和超级计算机同样强大的效能。同时,用户可以按需弹性地使用这些资源和服务,从而实现将计算作为一种公用设施来提供的梦想。本文首先介绍了云计算的基本概念、组成部分、技术要点和国内外发展情况,然后分别从服务器虚拟化、存储虚拟化、应用虚拟化、平台虚拟化和桌面虚拟化五个方面重点介绍虚拟化技术同云计算之间密不可分的关系。     

一种应用于无线局域网收发机的0.13 μm CMOS ΔΣ 分数型频率综合器

本文提出一种应用于IEEE 802.11b/g 无线局域网收发机的ΔΣ 分数型频率综合器。该设计采用了0.13 μm CMOS 工艺。LC型的压控振荡器采用了片上集成的差分电感。分数分频器由吞脉冲式分频器和带噪声整形技术的3阶MASH类型的ΔΣ调制器构成。测试结果表明,参考频率为20 MHz环路带宽为100 kHz的情况下,该设计所有信道的相位噪声性能均可达到带内-93 dBc/Hz,带外-118 dBc/Hz。积分均方相位误差小于0.8。整个设计在1.2V电源条件下消耗8.4 mW的功耗,占用0.86 mm2的面积。