镉胁迫对水车前叶片抗氧化酶系统和亚显微结构的影响

报道了模拟镉污染对水车前叶片抗氧化酶系统的影响及对叶细胞超微结构 ,主要是叶绿体、线粒体和细胞核的损伤情况。随胁迫程度的增大 ,超氧化物歧化酶活性和可溶性蛋白含量下降明显 ,丙二醛含量则上升 ,过氧化物酶和过氧化氢酶活性在 0 1mg/L浓度处达到最高后呈下降趋势。电镜观察结果表明 :毒害初期 ,叶绿体和线粒体膨胀 ,类囊体明显空泡化 ;高浓度镉处理使破坏程度加重 ,叶绿体被膜消失和叶绿体解体 ;线粒体间质溶解 ,濒临解体 ;细胞核染色质凝集并散入细胞质中。由于镉胁迫破坏了植物的抗氧化酶系统 ,并对超微结构造成不可逆损伤 ,最终使细胞死亡     

高效液相色谱法检测与化感现象相关的5种酚酸

建立了香草酸、对羟基苯甲酸、丁香酸、香豆酸和阿魏酸等5种酚酸的高效液相色谱测定方法,利用本方法在土壤溶液和残茬腐解产物中进行5种酚酸的检测,结果表明,大豆生长一段时间后,在灭菌土壤中、未灭菌土壤中和不同茬口的土壤中,均检测到丁香酸,在残茬腐解产物中检测到香草酸、丁香酸、香豆酸和阿魏酸。     

Mineral economics: Overview of a discipline

Mineral economics is the academic discipline that investigates and promotes understanding of economic and policy issues associated with the production and use of mineral commodities. While its origins can be traced back at least 200 years to the writings of David Ricardo and other early Classical economists, it emerged as a separate academic field only after World War II and then primarily in the United States. As a separate academic discipline, its roots are found in mining schools that needed to consider the milieu in which minerals are sold. While geologists, mining engineers, and others with technical backgrounds were largely responsible for creating the first stand-alone mineral-economics programs, ultimately trained economists became participants as well. Moreover, even after the rise of mineral-economics departments, most of the research in the field continued and continues to be carried out in other academic units, including traditional economic departments and engineering schools, as well as in government agencies, nonprofit research organizations, consulting firms, and international organizations.     

The supply behaviour of state mining enterprises: A case study of the Jordanian phosphate industry

An important feature of export-oriented production in mineral-rich developing countries for almost three decades after 1960 was the growth of state-owned enterprises. For the phosphate industry, this was reflected in the expansion of companies such as Office Cherifienne des Phosphate (OCP) in Morocco and the Jordan Phosphate Mines Company (JPMC). There was a strategic importance of the industry for these nations and the large capital outlays necessary for phosphate and fertilizer production expansion often required considerable government assistance because of the perceived high risks of private investment in the industry.     

重庆三峡库区重楼属药用植物资源调查

经调查鉴定,重庆三峡库区有重楼属药用植物6种9变种,其中以巫溪分布的种类最多,华重楼、七叶一枝花分布最广。重点介绍了它们的地理分布、资源状况及其开发前景,为更好地开发利用三峡库区重楼属药用植物资源提供科学依据。