Plasma modification of aromatic polyamide reverse osmosis composite membrane surface

The surface of aromatic polyamide reverse osmosis composite membrane was modified by oxygen and argon plasma. The water permeability of oxygen-plasma-modified membrane increases, and the chlorine resistance of argon-plasma-modified membrane increases. The spectra of the attenuated total reflection-Fourier transform infrared and X-ray photoelectron spectroscopy and the contact angle of the water were analyzed to explain the improvement of the two performances of the composite membrane. The carboxyl groups were introduced when modified by oxygen plasma, and cross-linking occurred when modified by argon plasma. (C) 1997 John Wiley & Sons, Inc.

甲基膦酸二甲庚酯与伯胺N1923对Cd(Ⅱ)的协同萃取

本文研究了甲基膦酸二甲庚酯(P_(350),以 B 表示)与伯胺 N_(1923)(以RNH_2表示)的正庚烷溶液,在(Na,H)C1介质中对 Cd(Ⅱ)的协同萃取。用等摩尔系列法和斜率法确定二元协萃配合物组成为(RNH_3C1)_2·CdC1_2·B;求得协萃反应平衡常数1gK_(Bc)=2.08,协萃配合物的生成常数1gβ=0.70;计算了协萃反应的热力学函数△H=-14.56kJ/mol,△G=-12.07kJ/mol 和△S=-8.22J/mol·K;还讨论了协萃配合物的 IR 和NMR 谱。

仲碳伯胺萃取铈(Ⅳ)机理的~1H,~(15)N核磁共振谱研究

仲碳伯胺N_(1923)萃取铈(Ⅳ)的~1H,~(15)N-NMR研究表明,在萃取铈(Ⅳ)时也同时萃取H_2O和H_2SO_4进入有机相,当铈(Ⅳ)浓度较高时,铈(Ⅳ)与N_(1923)生成配合物。

Effects of temperature, hypoxia, ammonia and nitrate on the bleaching among three coral species

Coral bleaching, which is defined as the loss of colour in corals due to the loss of their symbiotic algae (commonly called zooxanthellae) or pigments or both, is occurring globally at increasing rates, and its harm becomes more and more serious during these two decades. The significance of these bleaching events to the health of coral reef ecosystems is extreme, as bleached corals exhibited high mortality, reduced fecundity and productivity and increased susceptibility to diseases. This decreased coral fitness is easily to lead to reef degradation and ultimately to the breakdown of the coral reef ecosystems. Recently, the reasons leading to coral bleaching are thought to be as follows: too high or too low temperature, excess ultraviolet exposure, heavy metal pollution, cyanide poison and seasonal cycle. To date there has been little knowledge of whether mariculture can result in coral bleaching and which substance has the worst effect on corals. And no research was conducted on the effect of hypoxia on corals. To address these questions, effects of temperature, hypoxia, ammonia and nitrate on bleaching of three coral species were studied through examination of morphology and the measurement of the number of symbiotic algae of three coral species Acropora nobilis, Palythoa sp. and Alveopora verrilliana. Results showed that increase in temperature and decrease in dissolved oxygen could lead to increasing number of symbiotic algae and more serious bleaching. In addition, the concentration of 0.001 mmol/L ammonia or nitrate could increase significantly the expulsion of the symbiotic algae of the three coral species. Except for Acropora nobilis, the numbers of symbiotic algae of other two corals did not significantly increase with the increasing concentration of ammonia and nitrate. Furthermore, different hosts have different stress susceptibilities on coral bleaching.

A new genus of grasshopper (orthoptera : acridoidea : Catantopidae : Cyrtacanthacridinae) from China

This paper reports a new genus i.e. Parapachyacris gen. nov and a new species Parapachyacris taiwanensis sp. nov in Cyrtacathacridinae. The new genus is similar to Pachyacris Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) hind tibiae with 10 spines on inner side and 8 spines on outer side; 3) basal part of prostemal process thickened; 4) cross veins right angled with longitudinal veins in apical part of tegmina and 5) the back of body with yellow longitudinal stripe in middle. The new genus is also similar to Patanga Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) basal part of prostemal process thickened; 3) upper side of hind femora with three dark bands and 4) black spots of tegmina lacking. Type specimen is deposited in the National Museum of Natural Science (NMNH), Taichung, Taiwan, China.

用光学阵列传感器的机器人物体分类系统

本文介绍用光学阵列传感器的机器人物体分类系统。传感器直接安装在机器人的两个手指上。被抓物体的阴影通过光导纤维传到安放在“安全区”的光敏元件上。计算机识别物体的轮廓后命令机器人抓握物体,并把它运送到指定的地点从而达到物体分类的目的。

几种萃取剂对土壤中重金属生物有效部分的萃取效果

采用6种萃取剂：pH=7的0.01mol/L CaCl2、pH＝7.3的0.005mol/L DTPA+0.1mol/L TEA(三乙醇胺）＋0.01mol/L CaCl2、0.1mol/L NaNO3、0.43mol/L HOAc、pH=7的0.05mol/L EDTA和pH=4.65的0.5mol/L NH4OAc+0.01mol/L EDTA浸取液，对污染土壤中的重金属Cu、Zn、Cd、Pb的进行了萃取，并比较了萃取剂的萃取能力。实验结果表明，HOAc、EDTA以及NH4OAc－EDTA萃取各种重金属的能力远远大于其它几种萃取剂的萃取能力，是比较理想的萃取剂。