基于负温度系数的多晶硅电阻电热激励/压阻检测微桥谐振器的新型红外探测器

报道了一种基于负电阻温度系数的多晶硅电阻电热激励/压阻检测SiO 2/Si3N4/SixNy微桥谐振器的新型红外探测器.微桥谐振器吸收的红外辐射引起微桥温度升高,激励电阻和检测电桥的阻值减小,使得恒定激励电压作用下激励电阻的静态功率和惠斯登电桥的焦耳热增加,等效于增加了辐射在微桥谐振器上的红外辐射.初步的实验证实了该方案的可行性.     

微型薄膜电阻的制备及研究

将具有优异特性的碳纳米管（CNTS）与负性感光胶（SU-8 2002）混合得到复合材料,将不同比例的碳纳米管通过超声工艺分散到SU-8 2002感光胶中,通过UV-LIGA加工工艺,热压处理后实现了微型电阻的快速制备。对复合薄膜电阻的性能进行测试,测试结果表明复合薄膜电阻率随着碳纳米管比例的增加而减小,当碳纳米管的比例为12%时,电阻率减小到0.06 ,复合材料达到逾渗阈值,频率小于1.2GHz时,电阻值的变化范围小于5%,为快速制备微型电阻提供了新的方法。     

TBD-Catalyzed Trifluoromethylation of Carbonyl Compounds with (Trifluoromethyl)trimethylsilane

Trifluoromethylation of carbonyl compounds using (trifluoromethyl) trimethylsilane catalyzed by 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) afforded the corresponding α-trifluoromethyl alcohols in good to excellent yields under mild reaction conditions.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Metal‐Ion‐Binding Analogs of Ribonucleosides: Preparation and Formation of Ternary Pd2+ and Hg2+ Complexes with Natural Pyrimidine Nucleosides

Four metal‐ion‐binding nucleosides, viz. 2,6‐bis(1‐methylhydrazinyl)‐9‐(β‐D ‐ribofuranosyl)‐9H‐purine ( 2a ) and its N‐acetylated derivative, 2b , 2,4‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐5‐(β‐D ‐ribofuranosyl)pyrimidine ( 3 ), and 2,4‐bis(1‐methylhydrazinyl)‐5‐(β‐D ‐ribofuranosyl)pyrimidine ( 4 ) have been synthesized. The ability of these nucleosides and the previously prepared 2,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐9‐(β‐D ‐ribofuranosyl)‐9H‐purine to form Pd²⁺‐ and Hg²⁺‐mediated complexes with uridine has been studied by ¹H‐NMR spectroscopy. To obtain additional support for the interpretation of the NMR data, comparative measurements on the ternary‐complex formation between pyridine‐2,6‐dicarboxamide ( 5 ), pyrimidine nucleosides, and K₂PdCl₄ were carried out.     

Supramolecular organogelators based on Janus type AT nucleosides

J-AT nucleoside-based organogelators 1a and 1b were designed and synthesized. They were endowed with unparalleled superiority to natural nucleobase analogues 2–6 to gelate aromatic solvents due to their excellent self-assembly properties. The J-AT nucleoside-based organogelators showed a specific self-complementary base pair recognition characteristic. The gel stabilities of 1a and 1b were drastically influenced by adenine analogue 2, hardly affected by thymine analogue 3, uracil analogue 4, cytosine analogue 5, and mildly interrupted by guanine analogue 6.     

A hybrid nanofluid analysis near a parabolic stretched surface

Two dimensional incompressible steady viscous nano-fluid flow with the impacts of heat generation and porous medium is examined numerically. For this objective Ti₆Al₄v are taken as nano-particles dispersed in different base fluids such as methanol, engine oil and water. Basically in this study we will compare three different nano-fluids to assess their flow behaviour and thermal performance. The flow model is developed under certain assumptions. The two dimensional non-linear PDEs are converted into non-linear ODEs with suitable transformation. The numerical procedure is adopted to find the results by using Bvp4c technique in MATLAB. Moreover, graphs are generated for various parameters against the temperature and velocity profiles. The fluid behaviour for different parameter is examined on velocity and temperature profile. It is depicted that for high values of volume fraction and curvature parameter nano-particles leads to high velocity and temperature profile. Moreover, velocity profile decreases for permeability parameter, while temperature profile enhances for heat generation parameter. The influence of Nusselt number and skin friction also assessed. The model of entropy generation is also presented.     

水环境对GC和AT碱基对质子转移的影响

采用B3LYP/DZP++的方法研究了第一水化层作用和连续化处理的水溶剂作用对鸟嘌呤-胞嘧啶(GC)碱基对和腺嘌呤-胸腺嘧啶(AT)碱基对质子转移反应的影响. GC和AT碱基对在连续化水溶剂作用下,均发生单质子转移(SPT1)和分步的双质子转移(DPT),而在第一水化层5 个水分子的作用下(GC·5H₂O,AT·5H₂O)或同时考虑第一水化层作用和连续化水溶剂作用(GC·5H₂O+PCM,AT·5H₂O+PCM)时,GC和AT碱基对的质子转移均只得到单质子转移反应(SPT1). 单质子转移过程中的活化能变化情况表明：第一水化层对GC和AT碱基对结构和质子转移影响较大,水环境对碱基对的作用主要发生在第一水化层.     

CMOS集成温度传感器中的器件模型分析

根据CMOS集成温度传感器对器件的要求,对MOS器件的亚阈值模型和MOS工艺下的双极型器件进行了分析对比,选用后者更适合作为CMOS集成温度传感器的器件,并对衬底PNP管压电结型效应对温度传感器的影响进行了分析,最后对不同类型电阻进行了分析对比,为CMOS集成温度传感器设计打下了理论基础。     

SMDP-based sleep policy for base stations in heterogeneous cellular networks

A dense heterogeneous cellular network can effectively increase the system capacity and enhance the network coverage. It is a key technology for the new generation of the mobile communication system. The dense deployment of small base stations not only improves the quality of network service, but also brings about a significant increase in network energy consumption. This paper mainly studies the energy efficiency optimization of the Macro-Femto heterogeneous cellular network. Considering the dynamic random changes of the access users in the network, the sleep process of the Femto Base Stations (FBSs) is modeled as a Semi-Markov Decision Process (SMDP) model in order to save the network energy consumption. And further, this paper gives the dynamic sleep algorithm of the FBS based on the value iteration. The simulation results show that the proposed SMDP-based adaptive sleep strategy of the FBS can effectively reduce the network energy consumption.     

透反液晶显示器在头盔显示器中的应用

在强光条件下头盔显示器高亮度显示带来的视觉模糊问题较为突出,透反液晶显示器能够较好地解决这个问题,设计了光敏电阻控制电路感知外界光线强度,控制透视模式和反射模式的切换,并给出了电路安装的方案,仿真试验取得了较好的效果,具有良好的应用前景.