Synthesis and electrochemical behavior of poly N, N′-dithiobis (1,3-phenylenediamine)

A novel organic disulfide, N, N′-dithiobis(3-nitroaniline)(1) was prepared by the reaction of 3-nitroaniline with sulfur monochloride in chloroform. Compound 1 was reduced by zinc powder to give N, N′-dithiobis(1,3-phenylenediamine) (2). Poly N, N′-dithiobis (1,3-phenylenediamine) (3) was prepared by electrochemical polymerization of compound 2 and its basic electrochemical behavior is discussed. Foundation item: Supported by the National Natural Science Foundation of China (29833090) Biography: Li Zao-ying (1949-), female, Professor, research direction: synthesis and properties of organic cathode materials of rechargeable lithium batteries.     

Change of water use efficiency and its relation with root system growth in wheat evolution

Raising crop water use efficiency (WUE) is the physiological basis to implement crop high efficiently using water. The present soil column and field experiments are designed to investigate the change of wheat WUE (Triticum aestivum L.) at whole plant level and root system growth in evolution and the relationship between WUE and its root system growth using 10 wheat evolution genotypes with different ploidy chromosomes sets. Results show that in wheat evolution from 2n→6n, WUE at whole plant level increases with the increase of ploidy chromosomes, and root system growth (root weight, root length) and root/shoot ratio of wheat decrease with the increase of ploidy chromosomes under dry and irrigated conditions. WUE is negatively correlated with root weight and root/shoot ratio of wheat in evolution, significantly. Root system growth has an adverse redundancy for WUE in wheat evolution, and the root redundancy reduces with the increase of ploidy chromosomes, which result in the increase of wheat WUE at whole plant level.     

Occupant evacuation model based on cellular automata in fire

By applying the rules set in traffic flow and pedestrian flow models, a basic cellular automata model is presented to simulate occupant evacuation in fire. Some extended models are introduced to study the special phenomena of evacuation from the fire room. The key of the models is the introduction of the danger grade which makes the route choice convenient and reasonable. Fire not only influences the emotional and behavioral characteristics of an individual but also affects his physical constitution, which reduces his maximal possible velocity. The models consider these influence factors by applying a set of simple but effective rules. It is needed to emphasize that all rules are established according to the essential phenomenon in fire evacuation, that is, all the occupants would try to move to the safest place as fast as possible. Some simulation examples are also presented to validate the applicability of the models.     

Adsorption of Xe in zeolite MCM-22

Adsorption of xenon in zeolite MCM-22, a zeolite containing two separate pore systems，has been investigated in detail by variable temperature (VT) ¹²⁹Xe NMR spectroscopy. NMR results suggest that Xe atoms are preferentially adsorbed in the supercages of the zeolite at low Xe pressure (less than a few atmosphere), while Xe atoms can penetrate into the two-dimensional sinusoidal channels at high Xe pressure. Exchange of xenon at the different adsorption sites in the same supercage, i.e. xenon atoms in the two pockets and those in the central part of the supercage, was confirmed at 145 K by two-dimensional (2D) ¹²⁹Xe NMR exchange spectroscopy. The time scale for the exchange is about several milliseconds.     

Effect of alkyl substitutions on self-assembly

The self-assemblies of 4-hexadecyloxybenzoic acid and 3,4,5-trihexadecyloxybenzoic acid have been studied by using scanning tunneling microscopy (STM). The well-ordered assemblies with different arrangement have been investigated. The structural change is attributed to the different number of substituted alkyl chains on periphery.     

Genetic Diversity of Three Aristichthys nobilis Populations and One Inbreeding Stock

Genetic diversity of three Aristichthys nobilis populations and one inbreeding stock was studied using random amplified polymorphic DNA(RAPD)method. Materials of natural populations were collected from two counties of Guangxi Province, Hengxian (NH) and Shanglin (NS) and one city of Hubei Province, Wuhan city.(NW). Shanglin and Hengxian's river system respectively belongs to Qianjiang and Yujiang River, two tributaries confluencing to Xunjiang River, main tributary of Xijiang River, which is the biggest tributary of the Zhujiang River system, and Wuhan's water system belongs to the Yangtse River system. The inbreeding stock (RS) was the more than 10 generation descendant by brother-sister mating system whose parents were collected from Shanglin. The results showed that the genetic variety of individuals of RS was very low (0.105 4), whereas that of natural populations was relatively high,which from high to low was 0.158 1 (NW), 0.132 0 (NH) and 0.110 5 (NS). As an index for genetic distance pair-wise populations, the genetic variety between populations was studied, which characterized the genetic distance between populations. The genetic distance of NW and NH, NW and NS, NW and RS were respectively high, whereas that of NH and NS, NS and RS, NH and RS was low. Chi-test(χ2) and the analysis of the genetic variety pair-wise populations was taken as efficient approach for studying population difference.     

基于神经网络的公路边坡冲刷量模拟计算

神经网络模拟采用三层前馈网络模型，输入层有3个结点，分别代表30min降雨强度、降雨历时和降雨量，表示冲刷外因。输出层只有一个结点，代表坡面冲刷量；隐层结点数采用7个，即土压实度、坡度坡长、径流流速、径流流量、土颗粒粘聚力、植被指数和人为干扰等，为影响冲刷量的主要因素。为了验证模型，在连徐高速公路路堤边坡用SR型人工降雨设施进行冲刷试验，得到冲刷量实测资料，将通过模型计算的冲刷量值与之比较，显示了模型具有较好的模拟预测效果。     

清江隔河岩水利枢纽坝体内部监测研究

根据清江隔河岩水电站近几年的大坝内部监测资料，对大坝接缝与裂缝、坝内钢筋应力、拱座基岩与拱端坝体应力进行了监测研究，并应用物理推断法和统计相关法分析了压应力计的相关因子及变化规律，通过逐步回归分析得出了压应力计统计模型，应用所设的统计模型分析实测资料，其分析结果与实测值拟合较好。     

一种新型电磁搅拌器计算机控制系统

介绍一种电磁搅拌器分布式计算机控制系统，下位机以内含式PLC为核心控制多台电磁搅拌器；上位机可进行工况设置，存储和远程现场监控，上位机和下位机采用串行联接，为保证实时性，本系统采用双字节通信编码技术。     

高层住区外环境的可持续发展研究

本文在剖析当代高层住区外环境面临问题的基础上，通过对弹性规划、生态系统和各要素和谐共生等三方面的深入探讨，努力寻找出高层住区外环境建设的发展之路，使现代高层住区外环境在发展中能融入城市的整体环境，走上良性循环的可持续发展道路。