Free-release static coating of glass capillary columns: Coating with medium polar and polar stationary phases

Summary Principles are proposed to select solvents for the coating of glass capillary columns with medium-polar and polar stationary phases applying the free-release static-coating technique, practical examples are given, demonstrating that this technique is suitable to coat stationary phases like OV-1701 and Carbowaxes.     

Polar structure of N,N′-dimethylurea crystals

In the crystal structure of N,N′-dimethylurea, there is one molecule in the asymmetric unit, but with two halves related by an axis of pseudosymmetry. All nonhydrogen atoms of each molecule lie on a plane. In the crystal the molecules are held together by hydrogen bonds in the direction of the “a” axis. They form parallel rows with the same sense orientation, so that the crystal has a polar structure.     

Solution of Hadwiger-Levi's Covering Problem for Duals of Cyclic 2k-Polytopes

For a collection C of convex bodies let h(C) be the minimum number m with the property that every element K of C can be covered by m or fewer smaller homothetic copies of K. Denote by C _d ^* the collection of all duals of cyclic d-polytopes, d 2. We show that h(C _2k ^* )=(k +1)2 for any k 2. We also prove the inequalities (d+1) (d+3)/4 h(C _d ^* ) (d+1) 2/2$ for any d 2.     

A Bose-Burton Theorem for Elliptic Polar Spaces

In bose&burton, Bose and Burton determined the smallest point sets of PG(d, q) that meet every subspace of PG(d, q) of a given dimension c. In this paper an equivalent result for quadrics of elliptic type is obtained. It states the folloing. For 0 c n - 1 the smallest point set of the elliptic quadric Q ^-(2n + 1, q) that meets every singular subspace of dimension c of Q ^-(2n + 1, q) has cardinality (q ⁿ⁺¹ + q ^c )(q ^n-c - 1)/(q - 1). Furthermore, the point sets of the smallest cardinality are classified.     

基于FPGA的高速Fast-SSC译码器测试系统

为了满足Polar码高性能测试时大数据量的要求,设计了一种针对Fast-SSC译码器的FPGA硬件测试平台,包含信源、信道编码器、调制器、信道、解调器、译码器和统计模块,采用Verilog在Altera Stratix V 5SGXEA7N2F45C2上实现,并采用PCIe接口与上位机进行通信。该平台对码长1024、码率1/2的Polar码进行测试,结果表明测试频率为300MHz、测试数据为1.4*1010 位时,译码耗时仅为19.18s。     

Optimizing low complexity encoding method for systematic polar code

In order to solve the delay caused by step-by-step calculation and the computational complexity caused by iterative “exclusive-or” computation during the encoding process,a dimensionality reduction strategy was proposed and defined.Based on this,system polarization code parallel coding algorithm for cracking strategy was proposed.Simulation and computational complexity analysis were carried out on AWGN channel.The results show that the coding gain of the above algorithm is slightly better than the traditional one or almost the same,but the computational complexity is up to 80.92%,which is more suitable for hardware implementation and engineering application.It is more suitable for hardware implementation and has a certain practical value.     

基于极坐标Lagrange插值的航拍图像畸变校正算法

由于航拍图像的拍摄高度远低于卫星图像拍摄高度,因此每个拍摄地点的建筑投影差大小和方向都不相同,图片畸变严重。此外,考虑到图像边缘区域的畸变程度远大于图像中心区域的畸变程度,本文提出了一种基于极坐标的Lagrange插值的逐点畸变校正方法。利用该方法在极坐标系内对单个像素点进行插值,然后根据插值结果对像素点进行校正,再将其坐标从极坐标系变换回直角坐标系,最后采用此方法在整个航拍图像内逐点进行畸变校正。实验结果表明,校正后的航拍图像畸变程度不超过3%,证明该方法不但能有效地校正畸变图像,且与传统的利用DLT线性求解畸变校正矩阵等校正方法相比具有更为广泛的适用性。     

Transflective blue-phase liquid crystal display with polar opposite electrodes

A submillisecond response, wide view and single-cell-gap transflective (TR) display employing a blue-phase liquid crystal is proposed. The device employs polar opposite in-plane switching (IPS) electrodes. To balance the optical phase retardation between transmissive (T) and reflective (R) regions, the IPS electrodes are formed with unequal gaps in the two regions. This display exhibits reasonably high optical efficiency and well-matched voltage-dependent transmittance and reflectance curves.     

High energy Au+ ion implantation of polar and nonpolar ZnO—Structure modification and optical properties

The paper presents a study of 5-MeV energy Au⁺ ion implantation in polar c-plane (0001), nonpolar a-plane (11-20) and m-plane (10–10) ZnO crystallographic cuts using fluences of 5 × 10¹⁴ and 1 × 10¹⁵ cm⁻². The implanted samples were subsequently annealed in O₂ atmosphere at 600°C. It was shown that a-plane ZnO exhibited a lowest level of Zn sublattice disorder evidenced by Rutherford backscattering spectroscopy in channelling mode (RBS-C); in contrast, m-plane ZnO showed the highest disorder. The disorder in the Zn sublattice grew progressively in the subsurface as well as in the implanted layer in c-plane and m-plane ZnO, while a-plane has shown slight increase of disorder just in the implanted layer. Angular scans provided using RBS-C have shown the preservation of channelling effect in the subsurface layer in a-plane ZnO. On the contrary, the narrowed and shallow angular scan dips were seen in m-plane ZnO. Raman spectroscopy has shown significant O-sublattice disorder and O rearrangement mainly in a-plane and m-plane ZnO compared to c-plane. After ion implantation, the exciton-related luminescence band at 375 nm vanished almost completely, and the defect-related band ‘shifted’ to shorter wavelengths. Annealing has beneficial influence on near-band-edge (NBE) luminescence recovery, whereas deep-level-emission (DLE) luminesce has been shifted to lower wavelengths than appeared after implantation.     

神光-Ⅲ原型装置两极驱动的均匀照明研究

梳理了两极驱动的研究思路和神光-Ⅲ原型装置两极驱动的研究内容;提出了针对靶丸表面均匀照明设计的光束近似原则,基于该原则建立了"逐次递进"的方法,优化设计了不同条件下靶丸表面均匀照明的激光条件,并对设计方法进行了数值模拟分析,设计内容在神光一III原型装置上进行了初步的实验验证,结果进一步支持了靶丸表面均匀照明设计的合理性,研究结果为后续的实验设计和理论研究提供了指导方向。