Nanodisc体系在膜蛋白结构与功能研究中的应用

膜蛋白是生物膜功能的主要执行者,在生物体内参与许多重要的生理过程. 但是,由于很难获得稳定均匀并且维持膜蛋白正确构象的膜模拟环境, 膜蛋白研究远远滞后于水溶型蛋白. 磷脂纳米盘（Nanodisc）是由高密度脂蛋白发展而来的用于膜蛋白研究的新型类膜结构. VDAC-1, GPCRs和细胞色素P450s等膜蛋白已成功的与Nanodisc组装起来,并且被人们利用液体核磁共振(NMR)和表面等离子体共振(SPR)等方法对其进行了相关的结构和生化研究. 随着高密度脂蛋白自身的设计修饰和Nanodisc相关技术的发展,Nanodisc将为膜蛋白的研究提供更多重要的信息.     

340GHz太赫兹室内信道测量及仿真研究

太赫兹波的衰减性及高可用带宽使其在局域网环境中拥有广阔的应用前景.而太赫兹波的窄波束问题需要借助波束成形技术来解决.作为波束成形技术的关键内容,非直视情况下太赫兹频段的室内信道建模成为了当前亟待开展的工作.本文在340 GHz频段对多种常见室内装饰材料的太赫兹波反射特性和室内多径反射信道特性进行了实验研究,并基于射线追踪法对太赫兹室内信道进行仿真,仿真结果与测量结果符合较好,为进一步太赫兹室内信道建模提供了基础.     

准二维电荷密度波导体钾紫青铜KxMo6O17单晶样品的制备

采用碳酸盐替代高钼酸盐电解还原的方法成功制备出了准二维电荷密度波导体钾紫青铜单晶.通过x射线衍射、透射电子显微术等方法对单晶进行结构分析表明：晶胞参数a=b=0.5540nm，c=1.3508nm，单晶为三角晶系，对称群为P3.电阻温度关系曲线的测量显示：钾紫青铜K_xMo₆O₁₇单晶在112K附近发生金属到金属的Peierls相变. 关键词： 钾紫青铜 电荷密度波 Peierls相变     

二（胍基）锆配合物的合成和表征

Addition of one equivalent of LiN（i-Pr）2 or LiN（CH2）5 to carbodiimides, RN=C=NR [R=cyclohexyl （Cy）, isopropyl （i-Pr）], generated the corresponding lithium of tetrasubstituted guanidinates {Li[RNC（N R^′2）NR]（THF）}2 [R=i-Pr, N R^′2=N（i-Pr）2 （1）, N（CH2）5 （2）; R=Cy, N R^′2=N（i-Pr）2 （3）, N（CH2）5 （4）]. Treatment of ZrCl4 with freshly prepared solutions of their lithium guanidinates provided a series of bis（guanidinate） complexes of Zr with the general formula Zr[RNC（N R^′2）NR]2Cl2 [R=i-Pr, N R^′2=N（i-Pr）2 （5）, N（CH2）5 （6）; R=Cy, N R^′2=N（i-Pr）2 （7）, N（CH2）5 （8）]. Complexes 1, 2, 5-8 were characterized by elemental analysis, IR and ^1H NMR spectra. The molecular structures of complexes 1, 7 and 8 were further determined by X-ray diffraction studies.     

Steady state speed distribution analysis for a combined cellular automaton traffic model

Cellular Automaton （CA） based traffic flow models have been extensively studied due to their effectiveness and simplicity in recent years. This paper develops a discrete time Markov chain （DTMC） analytical framework for a Nagel-Schreckenberg and Fukui Ishibashi combined CA model （W^2H traffic flow model） from microscopic point of view to capture the macroscopic steady state speed distributions. The inter-vehicle spacing Maxkov chain and the steady state speed Markov chain are proved to be irreducible and ergodic. The theoretical speed probability distributions depending on the traffic density and stochastic delay probability are in good accordance with numerical simulations. The derived fundamental diagram of the average speed from theoretical speed distributions is equivalent to the results in the previous work.     

机载SAR异源图像匹配与定位方法

SAR匹配导航作为一种自主导航方式，具备全天候、全天时的工作能力，具有很高的应用价值。针对机载SAR景象匹配导航需要异源图匹配的难题，提出一种基于深度学习与附加尺度旋转因子的模板标准化相关匹配的异源匹配算法。所提算法通过语义分割网络模型提取图像中的道路河流特征，再对特征添加一定程度的尺度与旋转变化，实现特征的扩充。最后，对扩充后的特征图进行模板滑窗匹配，找到最大得分位置，从而实现图像匹配。根据真实数据的测试试验结果表明：匹配精度优于1.41像素（1σ），匹配成功率优于86.6%（匹配误差小于5像素）。另外，还提出一种面向SAR匹配导航系统的多点高精度定位方法，仿真结果表明：五匹配点定位精度可达15米。     

基于ANSYS的弹载记录仪优化设计分析

针对记录仪在高强度、高速撞击挤压等恶劣环境下出现损坏的现象,为了防止弹载记录仪的外壳被挤压变形,对记录仪的机械结构设计进行了优化改进。将记录仪外壳材料由优化前的45#钢更换为高强度钢35Cr Mn Si A,并将靠近内层保护壳的外壳壁厚由8mm增加到17mm,内层核心电路保护壳也采用高强度钢35Cr Mn Si A,壳体内部采用环氧树脂灌封。通过ANSYS/LS-DYNA软件仿真计算,结合高冲击下能量吸收理论分析得出:优化改进前和改进后外壳所能承受的极限强度分别为1.490GPa和4.973GPa;外壳吸收能量与整体吸收能量的比值由58.63%提高到75.52%。由此证明该方案是可行的,能够防止记录仪在配重模块质量为20kg、初速度为200m/s的高强度撞击下出现外壳破损,能够很好地保护记录仪核心模块。本文结果对弹上产品的机械结构设计以及核心电路保护具有一定的参考价值。     

一种基于碳纳米管场发射的发光二极管

制作了一个基于碳纳米管场发射的发光二极管,实验结果表明,这种发光二极管驱动场强低,亮度高,能够满足常用显示器和发光管的亮度要求,同时也用边界元法讨论了碳纳米管之间的场屏蔽效应.     

Direct Observation of High-Temperature Superconductivity in One-Unit-Cell FeSe Films

We prepared one-unit-ceil （1-UC） thick FeSe films on insulating SrTiOa substrates with non-superconducting FeTe protection layers by molecular beam epitaxy for ex situ studies. By direct transport and magnetic measurements, we provide definitive evidence for high temperature superconductivity in the 1-UC FeSe films with an onset Tc above 40 K and an extremely large critical current density fie Jc-1.7× 106 A/cm2 at 2K, which are much higher than Tc-8K and Jc-104 A/cm^2 for bulk FeSe, respectively. Our work may pave the way to enhancing and tailoring superconductivity by interface engineering.     

A quantum efficiency analytical model for complementary metal–oxide–semiconductor image pixels with a pinned photodiode structure

A quantum efficiency analytical model for complementary metal–oxide–semiconductor（CMOS） image pixels with a pinned photodiode structure is developed. The proposed model takes account of the non-uniform doping distribution in the N-type region due to the impurity compensation formed by the actual fabricating process. The characteristics of two boundary PN junctions located in the N-type region for the particular spectral response of a pinned photodiode, are quantitatively analyzed. By solving the minority carrier steady-state diffusion equations and the barrier region photocurrent density equations successively, the analytical relationship between the quantum efficiency and the corresponding parameters such as incident wavelength, N-type width, peak doping concentration, and impurity density gradient of the N-type region is established. The validity of the model is verified by the measurement results with a test chip of 160×160 pixels array,which provides the accurate process with a theoretical guidance for quantum efficiency design in pinned photodiode pixels.