Advance in in-beam PET

Tumor radiotherapy was a promising modality and over 100 years. Beams of heavy-charged particles show high RBE advantages and become the optimum tool for tumors therapy. Newly, along with the development of accelerators, scintillators, micro-electronics and computers, the heavy ion tumor therapy has been recognized more and developed.

颅颌运动仿真系统(牙合)接触精度初探

目的 探讨颅颌运动仿真系统的骀接触模拟精度,为该仿真系统的应用提供依据.方法 制作10副石膏模型并上(牙合)架.用(牙合)架模拟侧方运动,三维扫描侧方运动终点(牙合)架上的上下颌模型,重建数字化上下颌模型作为对照组.运用仿真系统模拟耠架的侧方运动,以仿真系统输出的侧方运动终点的数字化上下颌模型为试验组.通过比较试验组与对照组下颌牙列之间的位置差异评价仿真系统的(牙合)接触模拟精度.结果 仿真系统模拟的下颌牙列与对照组下颌牙列之间的绝对平均距离为(0.18±0.05)mm;在前后左右四个分区中,两组右后牙区之间的绝对平均距离最大,为(0.19±0.07)mm.结论 该仿真系统的体外胎接触模拟精度为0.19mm.

在线双向适应的笔手势界面框架研究

提出一个在线双向适应的笔手势界面框架,该框架针对传统笔手势界面中静态手势识别器不能支持用户的个性化输入以及用户在笔手势界面中面临的手势记忆问题,提出了在线双向适应的策略:一方面系统能够适应用户(系统可以在线支持用户的个性化输入);另一方面用户可以学习系统(用户可以学习系统提供的某些笔手势).该框架包括5个部分:(1)双向适应笔手势输入解释模型;(2)双向适应笔手势输入解释流程;(3)上下文优先级定义;(4)纠错和模糊消解界面;(5)在线笔手势查询帮助系统.在该框架的指导下作者开发了一个原型系统并进行了对比实验评估.结果表明该框架在可用性上具有较大的优势.

The study on automorphism group of ESESOC

It is necessary to generate the automorphism group of a chemical graph in computer-aided structure elucidation. In this paper, an algorithm was developed by the all-paths topological symmetry algorithm to build the automorphism group of a chemical graph. A comparison of several topological symmetry algorithms reveals that the all-paths algorithm (APA) could yield the correct class of a chemical graph. It lays a foundation for the ESESOC system in computer-aided structure elucidation.

Phase transition temperature of HPT(2,3,6,7,10,11-hexa-n-pentyloxytriphenylene) from molecule dynamic simulation

Molecule dynamics simulation was used on HPT(2,3,6,7,10,11-hexa-n-pentyloxytriphenylene), which is a discotic Liquid crystal. From analyzing the energy and displacement varying with the temperature, the phase transition temperature of PM6MPP can be predicted. The deviations of T-g, T-m and T-i due to the MD time scale are small enough that it should be possibly used to predict the material properties especially when more powerful computers are available.

Chemical environment code and measure of molecular similarity

A new scheme for the code of chemical environments of compounds is described in this paper, and three molecular similarity methods have been used to select nearest neighbors from four different types of probe compounds. One of the methods is based on the C-13 NMR spectra. The second method is based on the code of chemical environments and molecular topological index A(x). The third approach, i.e. the Tanimoto coefficient, is also based on the code of chemical environments, but not to use the topological index. Five nearest neighbors for each probe compound using these three molecular similarity methods were determined and taken from the database of 7309 structures. The results indicate that the scheme of the chemical environment code and the method for similarity measure of intermolecules suggested in this study are reasonable. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

A NEWLY PROPOSED MOLECULAR TOPOLOGICAL INDEX FOR THE DISCRIMINATION OF CIS/TRANS ISOMERS AND FOR THE STUDIES OF QSAR/QSPR

A new topological index, the general a(N)-index (GAI), on quantum chemistry, is described in this paper. The GAI can be applied to molecules that contain heteroatoms and multiple bonds, and performs well in distinguishing cis/trans isomers. The relationships between the GAIs and physicochemical properties of olefins and neutral phosphorus compounds were observed with satisfactory results.

CORRELATION-ANALYSIS IN STRUCTURE AND CHROMATOGRAPHIC DATA OF ORGANOPHOSPHORUS COMPOUNDS BY GAI

This approach is undertaken to examine the correlation ability of the general a(N)-index (GAI) to predict chromatographic behavior. The test is performed on various types of organophosphorus compounds. The results demonstrate that the GAI possesses a good correlation with chromatographic properties.

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

A total of 10446 expressed sequence tags (ESTs) are obtained by a large-scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis. An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

基于web的远程控制机器人研究

Internet连接了全球的计算机 ,它为人们提供了分享数据、图片、影像甚至实时影像的机会 ,但与远程地点的真实交互还是离不开象机器人这样的智能设备 .Web技术与机器人控制技术的结合 ,促成了基于 web的远程控制机器人概念的诞生 .本文将就基于 web的远程控制机器人的发展历程、研究现状、主要技术与实现、发展趋势及应用前景等做综合的介绍 .