Behaviour of mesogenic side group polyacrylates in dilute and semidilute regime

The solution behaviour of a new mesogenic side group polyacrylate in tetrahydrofuran and toluene has been investigated by static and dynamic light scattering. In the dilute regime the polymer behaves as typical polydisperse linear chains in good solvent and the dynamics is dominated by a single fast mode. Cluster formation was detected starting at a concentration around 50 g l⁻¹. It seems to be independent of the solvent as well as of polymer molecular weight. In the semidilute regime, the behaviour of the reduced osmotic modulus leads to the conclusion that repulsion between the chains is stronger than in linear macromolecules. The appearance of larger clusters was revealed above a characteristic concentration and is slightly dependent on the polyacrylate molecular weight. The dynamics was generally characterised by a fast mode related to the cooperative diffusion and by a slow mode associated with large clusters. The existence of a network of multiconnected clusters is envisaged with increasing solution concentration.     

Accumulation and Mixing of Oils in Jinghu Sag of Subei Basin： Constraints from Thermal Maturity Parameters

Oils in Jinghu sag are abundant with high content of polar compounds and have a low ratio of saturate to aromatic hydrocarbons and a high ratio of resin to asphaltene. The gross composition of oils in the Jinghu sag suggests typical immature to low mature characteristics. Some compounds with low thermal stability were identified. Light hydrocarbons, a carbon preference index, an odd even index, n-alkane and hopane maturity parameters show mature features and little differences in the maturity level among oils. Sterane isomerization parameters indicate an immature to low mature status of oil. Transfer of the sedimentary center during sedimentation has led to different thermal histories among subsags and thus generated oils with different maturities. On the basis of source analyses, four migration and accumulation patterns with different maturity can be classified. Combined with available information on mergers of source, reservoir and long distance oil lateral migration, mixing conditions were present in the Jinghu sag. Experimental results indicate that maturity variations are caused by mixtures of hydrocarbons with different maturity.     

Optical pattern recognition using two-channel joint transform correlation

A new joint transform correlation (JTC) technique, named two-channel JTC (TJTC), is proposed in this paper for optical pattern recognition applications. The TJTC technique independently evaluates the autocorrelation and crosscorrelation values of the reference and the target images and employs a modified decision algorithm. In addition, optical threshold operation and fringe-adjusted filter are incorporated in the proposed technique to enhance the correlation output and to improve the discrimination performance. The proposed technique shows better recognition performance compared to existing JTC techniques. Computer simulation are presented to investigate the salient features of the proposed TJTC technique with noise-free as well as noisy input scenes. The text was submitted by the authors in English.     

用远红外HCN激光干涉仪测量等离子体电子密度

在大多数托克马克上，远红外激光干涉仪是等离子体诊断中的一种重要的装置。本文介绍了用远红外ＨＣＮ激光干涉仪测量等离子体电子密度的原理和激光干涉仪结构，并给了了首次在我国第一以大型超导托克马克ＨＴ－７装置上测到的中心弦等离子体电子平均密度。     

万安水利枢纽底孔坝段中隔墙流激振动响应分析

 研究了万安水利枢纽底孔坝段中隔墙在水流脉动壁压作用下的结构随机振动问题，进行了一种泄流工况下的隔墙结构流激振动响应统计量的理论计算，模拟计算了隔墙－水流－基础耦合系统固有频率对流激振动响应的影响，并对水流脉动壁压随机荷载作用下的结构动力可靠度进行了理论分析。     

费索激光波长计的温度补偿

论文概述了费索干涉仪型激光波长计的原理和标定。详细分析了环境温度变化使仪器参数发生微小变化；论述了ＳＩＯＭ－０１激光波长计以一种新颖的将标准激光引入测量光路的方法，随时对仪器参数实行单点标定，克服了由环境温度变化引进的测量误差。     

高灵敏度的多波长多光束干涉仪

作者用多纵模He-Ne激光照明多光束Fabry-Perot或Fizeau干涉仪,在一个自由光谱范围内,形成与不同波长对应的子条纹,相邻条纹间的间隔代表的波长数依赖于He-Ne激光腔的光学长度npL与F-P腔长nd之比r=nd/npL.当r是整数时,不同波长对应的相邻干涉级次相互重叠,条纹间隔为λ/2且强度最大;当r是分数时,r=N/M,N,M为互质的整数,相邻条纹之间间隔为λ/2M.不难做到M=10,条纹间隔为K/20.由于多光束干涉条纹细而锐,有利于读数精度提高,可以测量λ/500的程差变化,不需内插就可以给出空间分布的足够信息.这对光学元件的高精度面形检验及低密度流场显示有实际的应用前景.给出了应用的若干例子.     

Spread Spectrum PN Code Acquisition Using Hybrid Correlator Architectures

A hybrid correlator architecture is described which combines the serial structure of an active correlator with the parallel structure of a matched filter correlator. The mean PN code acquisition time performance of this hybrid serial-parallel correlator structure is analysed. Results are shown which compare the acquisition performance of the serial, parallel, and serial-parallel structures. The results are for a PN code length of 64 code chips and assumes a Gaussian channel with the receiver detection threshold set to obtain a constant false alarm rate. An enhancement to the serial-parallel acquisition algorithm is also described which can increase the acquisition time performance by about 15% for typical operating conditions. Overall the results demonstrate that the hybrid correlator can provide rapid code acquisition with a limited receiver complexity.     

三维目标旋转畸变不变光学相关滤波器组的设计

研究了三维目标旋转畸变不变光学相关滤波器组的设计原理，完成了滤波器组参数的计算和编码，以及光学相关识别的计算机模拟。     

巡航导弹机动地形相关系统

研究了一种适用于巡航导弹辅助导航的机动地形相关系统(MTCS)。介绍了 MTCS的工作原理、相关定位算法以及提高定位概率的技术途径,指出了系统设计中的关键技术。另外还讨论了 MTCS 的计算机运算,研究结论对地形辅助系统的设计有参考价值。