太阳能利用技术的广泛前途

在太阳能热利用方面，太阳能热水器是当今世界利用各种再生能源中技术最成熟、最具经济性的产品，在上期已作介绍。太阳能利用技术之广泛应用笔者再予介绍。 1、被动式太阳系统，在世界各地区已被广泛应用于建筑物的采暖(被动太阳房)。目前，在美国这种系统已普及25万套左右，日

室温和350℃下注Mn的GaAs/AlGaAs超晶格的磁学性质

通过室温和350℃注Mn后热退火,在GaAs/AlGaAs超晶格中引入了不同的亚微米磁性颗粒.利用原子力显微镜、能量散射X射线谱、X射线衍射和交变梯度磁强计研究了该颗粒膜材料的结构和磁学性质.通过比较这些颗粒的饱和磁化强度、剩余磁化强度、矫顽力和剩磁比,发现350℃注Mn的样品含有MnGa和MnAs两种磁性颗粒,而室温注Mn的样品主要含有MnAs颗粒.

“三北”防护林工程的生态环境评估

“三北”防护林工程的生态环境评估ＥｃｏｌｏｇｉｃＥｎｖｉｒｏｎｍｅｎｔｏｆＥｎｇｉｎｅｅｒｉｎｇｏｆＳｈｅｌｔｅｒｂｅｌｔＮｅｔｗｏｒｋｉｎＮｏｒｔｈ，ＮｏｒｔｈｗｅｓｔａｎｄＮｏｒｔｈｅａｓｔＣｈｉｎａ￥肖笃宁（中国科学院沈阳应用生态研究所，沈阳１...

对我国林业政策绩效评价体系的思考

结合林业政策绩效评价的特点,详细阐述了其原则、方法和内容,并针对当前林业政策绩效评价存在的问题提出了相应的建议。

Adsorption of arsenite and arsenate on amorphous iron hydroxide

Adsorption isotherms in solutions with ionic strengths of 0.01 at 25°C were measured over the arsenite and arsenate concentration range 10−7−10−3 M and the pH range 4–10. At low concentrations, these isotherms obeyed equations of the Langmuir type. At higher concentrations the adsorption isotherms were linear, indicating the existence of more than one type of surface site on the amorphous iron hydroxide adsorbent. Removal of arsenite and arsenate by amorphous iron hydroxide throughout the concentration range were determined as a function of pH. By careful selection of the relative concentration of arsenic and amorphous iron hydroxide and pH, removals on the order of 92% can be achieved.

中国水土流失的基本概况及其综合治理对策

水土流失是一个全球性的环境问题。给人类的生命与物质财产造成极大的危害与破坏。在现代社会，由于人口的持续增长，社会经济生产规模的不断扩大，植被破坏的急剧发展，对国家经济的发展均构成威胁。在上述背景下，本文在对以往研究结果进行综合分析的基础上，根据“再造一个山川秀美的西北地区”之要求，因地制宜地提出了我国水土流失的防治途径。

Glucose biosensor based on gold nanoparticle-catalyzed luminol electrochemiluminescence on a three-dimensional sol-gel network

An electrochemiluminescent glucose biosensor was proposed based on gold nanoparticle-catalyzed luminol electrochemiluminescence (ECL). Gold nanoparticles were self-assembled onto silica sol-gel network, and then glucose oxidase was adsorbed on the surface of gold nanoparticles. The surface assembly process and the electrochemistry and ECL behaviors of the biosensor were investigated. The assembled gold nanoparticles could efficiently electrocatalyze luminol ECL ECL intensity of the biosensor depended on scan rate, luminol concentration, and size of gold nanoparticles.