盐和铬对单细胞藻生理生化的影响

以3种单细胞海洋藻类:新月菱形藻、亚心形扁藻、湛江叉鞭金藻为实验材料,研究了几种外界因子6-苄氨基腺嘌呤(6-BA)和二脘基氨基乙醇羧酸酯(DA-6)、盐度、铬等对其生长、光合作用、呼吸作用、叶绿素合成及SOD酶谱的影响.结果表明,在一定的浓度范围内DA-6和6-BA对藻类的生长有促进作用,超过一定浓度,则有抑制作用.在一定的盐度范围内,藻类的增长随着盐度的加大而加快,而超过一定范围,则盐度越大,生长越慢,盐度对藻类光合作用、呼吸作用及叶绿素合成的影响也大致如此.而铬则明显地抑制藻类叶绿素的合成,降低酶活,对藻类有很大的毒害作用.     

Growth ofNostoc muscorum mutants in the presence of diuron (DCMU) and L-methionine-DL-sulfoximine

Summary Diuron (DCMU) is inhibitory to the photoautotrophic and photoheterotrophic growth of the N₂-fixing blue-green algaNostoc muscorum at concentrations of 1.0×10^–5 M and 2.0×10^–5 M, respectively. A mutant of this organism resistant to 5.0×10^–5 M DCMU under its photoheterotrophic growth conditions, with the ability to utilize DCMU as a carbon and nitrogen source for growth, and complete inability to grow photoautotrophically has been isolated. With the apparent defect in its photosynthetic ability, it is suggested that theDCMU ^r mutant lacks the step inhibited by 1.0×10^–5 M DCMU, and metabolizes DCMU by an existing enzyme system in the absence of such inhibition. That this enzyme may be glutamine synthetase (GS) is explained with the help of a L-methionine-DL-sulfoximine (MSO)-resistant mutant ofN. muscorum which is able to grow faster with 2.0×10^–5 DCMU and is known to contain an altered GS.Thanks are due to the Council of Scientific and Industrial Research, CSIR Complex, Govt. of India, New Delhi-110012, for appointing the author to the Scientists' Pool for undertaking researches on the physiological and genetic controls of nitrogen metabolism in blue-green algae, a part of which is presented in this literature.     

Experimental study of gold distribution in the algae-organic matter-fluid system

Conclusion Gold distribution and transformation in algae-organic matter-fluid system is very complicated. Gold is first concentrated in kerogen after algae died. With the increase of dissolved organic matter owing to the increase of temperature and pressure, part of gold simultaneously emigrates from kerogen to DOM. When DOM forms organic fluid and emigrates from the strata, gold is simultaneously carried away by organic fluid in acidic condition, but by water in alkali condition. When the auriferous fluid flows through carbonaceous strata, gold in fluid is unloaded by kerogen. Gold migration in the system, accompanied by the evolution of algae-organic matter-fluid, provides the basic information of biometallogenetic evolution of gold.     

随机过程性质的应用

应用二维 Ｂｒｏｗ ｎ 运动的常返性质、 Ｍａｒｋｏｖ 过程及二维连续局部鞅的一些性质，通过随机分析的方法，对著名的古典问题给出了一个新的证明，证明过程体现了随机分析方法的优越特点．     

基于迭代的中点位移法对山脉地形的模拟

本文以分数布朗运动原理为基础，提出了基于迭代的中点位移法进行地形模拟，此方法可有效地对地形的局部进行控制，算法简单，运算速度快，是解决“折痕问题”的一种方法。     

添加2．5％桔皮粉对罗曼蛋鸡产蛋量的影响

在45周龄的罗曼蛋鸡饲料中添加2．5％的桔皮粉，进行42d的饲养试验，结果表明，试验组比对照组的产蛋量提高5．23％（P＜00．1），说明桔皮粉作为鸡饲料添加剂，能促进饲料营养物质在鸡体内的沉积，刺激鸡卵泡成熟，增加排卵数，从而提高养鸡效益。     

黄河兰州段藻类群落结构演替特征研究

2014年对黄河兰州段水体的浮游藻类调查结果表明,该段藻类的数量不同,随月份与水温变化差异明显,丰水期是藻类的爆发期,藻类数量最多达到63 700个/L;枯水期藻类数量最少10 800个/L.硅藻在藻类群落中占有优势地位,与黄河水体富含泥沙的特性息息相关,而绿藻类和蓝藻类在各断面的优势种属中也占据了一定的比例.兰州段各采样点氮磷比介于56~282之间,磷成为藻类生长的主要营养制约因子.藻类数量与水温呈明显的正相关.     

饮用水中藻类及藻毒素去除技术进展

水体富营养化日趋严重,藻类及藻毒素给饮用水处理带来很多不利影响,对饮用水中藻类与藻毒素去除技术从物理、化学、生物及其他方法进行具体论述,系统分析了各种技术的去除效果和局限性,并对饮用水中藻类及藻毒素去除技术进行了展望。     

分数布朗运动下带红利的欧式期权定价

基于股票价格遵循有分数布朗运动驱动的分数阶随机微分方程.运用Black-Scholes方程理论建立带红利的欧式看涨期权定价模型,根据分数阶随机微分方程理论将方程的求解问题转化为偏微分方程的求解问题,给出期权定价的解析解.