Chiral gels derived from secondary ammonium salts of (1R, 3S)-(+)-camphoric acid

In order to have access to chiral gels, a series of salts derived from (1R, 3S)-(+)-camphoric acid and various secondary amines were prepared based on supramolecular synthon rationale. Out of seven salts prepared, two showed moderate gelation abilities. The gels were characterized by differential scanning calorimetry, table top rheology, scanning electron microscopy, single crystal and powder X-ray diffraction. Structure property correlation based on X-ray diffraction techniques remain inconclusive indicating that some of the integrated part associated with the gelation phenomena requires a better understanding.

Chiral Synthons from Carvone. Part 10. Synthesis of (+)-(1S,3S,4S,7S, 8R)-5,7-Dimethyl-10-oxatetracyclo-(5.3.0.03,5,04,8)decan-9-one.

Degradation of the tolyl group in the tricyclic ketone 1b followed by stereospecific reduction of the resultant ketoester (6) furnishes the title compound (4) containing a new tetracyclic framework, establishing the stereochemistry of the aryl group in 1.

(1S*,3S*,8S*,10S*)-10-Fluoro-15-oxatetracyclo[6.6.1.0(1,10).0( 3,8)]pentadeca-5,12-dien-3-ol

The title compound, C(14)H(17)FO(2), was obtained from anti-4a, 9a:8a,10a-diepoxy-1,4,4a,5,8,8a, 9,9a, 10,10a-decahydroanthracene via tandem hydrogen-fluoride-mediated epoxide ring-opening and transannular oxacyclization. With the two cyclohexene rings folded towards the oxygen bridge, the title tetracyclic fluoroalcohol molecule displays a conformation reminiscent of a pagoda. The crystal packing is effected via intermolecular O-H center dot center dot center dot O hydrogen bonds, which link the molecules into a zigzag chain along the b axis.

基于3S技术的深圳市水土保持管理信息系统研究

深圳市水土保持管理信息系统采用B/W/D三层体系结构,实现GIS和MIS的紧密结合,克服了C/S结构的客户端维护量大的弱点,发挥B/W/D结构良好的数据交互能力和便于集中控制、维护简单的优点,充分利用了GIS优越的空间分析、直观的信息表达功能和MIS强大的数据存储、处理功能。系统通过对水土保持工作必需的信息进行分析和检索,利用地图、文字、表格、影像等多种手段进行信息表达。通过开发的水土流失估算模型,可对将要进行开发的建设项目的水土流失量进行估算,同时可以载入遥感影像图,为水土流失状况的对比、分析提供更为直观、清晰的效果,也可利用GPS接口转入GPS设备采集的数据,进行地块数据自动、批量录入、更新,实现系统专题图等数据的动态更新。

基于3S技术的中国东北地区林地时空动态特征及驱动力分析

利用3S技术和中国资源环境数据库中用LandSatTM(ETM)解译获取的东北地区1985,1995,2000年林地空间分布数据,建立林地时空演变模型,定量分析东北地区林地变化时空特征。结果表明:1985～2000年东北地区林地发生较大幅度变化,时空差异明显;1995～2000林地急剧减少趋势得到有效遏止,有林地面积出现一定程度增长,但林地变化的广度和强度仍然超过1985～1995年,突出表现在大兴安岭地区林地动态度增加。从空间格局上看,大小兴安岭、长白山山麓地带林地动态变化最强烈,主要表现为林地与耕地和草地相互转换。

基于3S的自然植被光能利用率的时空分布特征的模拟

光能利用率(LUE)直接影响植被各层中的能量分布和光合速率,在确定环境对光合和地上部生长分配的综合限制上十分有价值,是衡量系统功能的一个重要指标。本研究以遥感图像(TM)作为数据源,获取了影响植被LUE的重要变量———叶面积指数(LAI);用程序语言编写了描述系统碳循环和水循环的景观尺度生态系统生产力过程模型(EPPML),对长白山自然保护区的太阳总辐射、净初级生产力(NPP)和LUE等的季节动态和空间分布进行了模拟;并用地理信息系统(GIS)手段对空间数据进行处理、分析和显示,从而实现了将植物生理生态研

“3S”技术系统集成研究及其在县级土地利用动态监测中的应用

用遥感（Remote Sensing, RS）进行小比例尺的土地动态监测已是比较成熟的技术，随着“3S”技术的发展，如何用“3S”技术进行县级1：10000大比例尺土地利用动态监测是一个新课题，本文以国家“九五”重点科技攻关课题为基础，提出用“3S”技术进行县级土地利用动态监测的技术路线：用RS发现靶区；GPS实测变化地块数据，保证精度；GIS做为集成平台，进行土地数据的日常管理。在包头示范区，用“3S”技术进行县级1：1万大比例尺土地利用动态监测取得了圆满成功：RS“靶区”发现率在92%以上；GPS实测精度在2M以内；选国产GIS软件MAPGIS，进行二次开发而成的县级土地利用动态监测系统界面友好，功能强大。实现证明用“3S”技术进行县级土地利用动态监测方法具有明显的优势。本文对用“3S”技术进行县级土地利用动态监测的技术路线，和实施过程作了较详细的说明。

Effective collision strengths for transitions among the 3s(2), 3s3p and 3p(2) configurations of Fe xv

Effective collision strengths for transitions among the ten energetically lowest fine-structure levels belonging to the (1s(2)2s(2)2p(6))3s(2), 3s3p and 3p(2) configurations of Fe xv have been calculated in the electron temperature range of 10(5)-10(7) K, using the recent Dirac atomic R-matrix code of Norrington and Grant. The results are compared with the other recently available independent Breit-Pauli R-matrix calculations of Eissner et al (Eissner W, Galavis M E, Mendoza C and Zeippen C J 1999 Astron. Astrophys. Suppl. 137 165) and Griffin et al (Griffin DC, Badnell N R, Pindzola M S and Shaw J A 1999 J. Phys. B: At. Mol. Opt. Phys. 32 2139, 4129). Large differences are observed for many transitions over almost the entire temperature range. These differences are analysed and discussed, and the accuracy of the calculations is assessed.

Angular distributions of electrons in photoionization of 3s subshell of atomic chlorine

R-matrix calculated photoelectron angular distribution asymmetry parameters, beta for Cl+ 3s3p(5) P-3(o) and 3s(2)3p(3) (D-2(o))3d P-1(o) final ionic states in photoionization of the ground state of atomic Cl are presented in the photon energy range from threshold to 80 eV. The results, characterized by prominent autoionization structures which are sensitive to multielectron correlations, are compared with those recently measured by Whitfield et al (Whitfield S B, Kehoe K, Krause M 0 and Caldwell C D 2000 Phys. Rev. Lett. 84 4818). Contrary to experiment and previous theoretical calculations, our detailed CIV3 structure calculation (Deb N C, Crothers D S F, Felfli Z and Msezane A Z 2002 J. Phys. B: At. Mol. Opt. Phys. submitted) has identified the lowest P-1(o) level of Cl+ as 3S(2)3p(3)(D-2(o))3d P-1(o) rather than 3s3p(5) P-1(o). The implications and consequences of the measured data for the 3s P-1(o) level are also discussed in the context of our calculated energies for Cl+ and beta for 3d P-1(o).