新手性氨基醇在酮的对映选择还原中的应用

用一个新的氨基醇（１Ｒ,２Ｓ）－２－氨基－３－甲基－１－（２,５－二甲基苯基）－１－丁醇为手性配体,硼烷为还原剂,研究了２,２′,４′－三氯苯乙酮和２－咪唑基－２′,４′－二氯苯乙酮的对映选择还原。并讨论了催化剂用量、温度对还原效果的影响。     

NANOTECHNOLOGY: Beyond Gedanken Experiments

For future nanomechanical devices to be realized, sophisticated ways of manipulating small structures must be developed, and fundamental elements of macroscopic machines, such as switches and bearings, must be reproduced in the nanoscale. Forró highlights the nanotube nanobearings and nanoswitches reported by Cumings and Zettl and concludes that multiwall nanotubes are ideal starting materials for future nanodevices.     

Catalysis: new perspectives from surface science

One-sixth of the value of all goods manufactured in the United States involves catalytic processes. However, in spite of this dramatic economic impact, little is known about this broad subject at the molecular level. In the last two decades a variety of techniques have been developed for studying at the atomic level the structure, composition, and chemical bonding at surfaces. These techniques have been used to study adsorption and reaction on metal single crystals in an ultrahigh vacuum environment or to analyze catalysts before and after reaction. An important new development has been the coupling of an apparatus for the measurement of reaction kinetics at elevated pressures with an ultrahigh vacuum system for surface analysis. This approach has demonstrated that metal single crystals can be used to successfully model many important catalytic reactions and has established a direct link between the results of ultrahigh vacuum surface measurements and the chemistry that occurs under typical catalytic-processing conditions.     

Landcare in Australia: Beyond the expert farmer

The landcare program has been embraced by governments, farmer organizations and conservation groups throughout Australia as offering a model for effective community action to assist the move to more sustainable resource use. Over 2,500 landcare-type groups now operate across Australia with 65,000 members including almost 30% of the farming community. This research used surveys of landcare group activity in most Australian states, a study of the regional landcare action plan (RLAP) process in the state of Victoria, and a survey of landholders in north east Victoria to assess landcare program effectiveness, and particularly, the assumptions underlying the program logic. Information provided revealed the vast scale of community participation in landcare and the considerable amount of onground work undertaken by groups and landholders. Analysis of north east landholder surveys indicated landcare participation had a significant impact upon landholder awareness of issues, level of knowledge, and adoption of best bet practices. However, research findings also highlighted a number of concerns about the program logic and implementation, and the authors suggest it is time to adopt a revised landcare program model.     

树池在园林中的应用

介绍了树池形式、规格及其功能,提出树池的建池原则,分析了树池存在的问题,并提出了解决措施。     

Beyond predictions: biodiversity conservation in a changing climate

Climate change is predicted to become a major threat to biodiversity in the 21st century, but accurate predictions and effective solutions have proved difficult to formulate. Alarming predictions have come from a rather narrow methodological base, but a new, integrated science of climate-change biodiversity assessment is emerging, based on multiple sources and approaches. Drawing on evidence from paleoecological observations, recent phenological and microevolutionary responses, experiments, and computational models, we review the insights that different approaches bring to anticipating and managing the biodiversity consequences of climate change, including the extent of species' natural resilience. We introduce a framework that uses information from different sources to identify vulnerability and to support the design of conservation responses. Although much of the information reviewed is on species, our framework and conclusions are also applicable to ecosystems, habitats, ecological communities, and genetic diversity, whether terrestrial, marine, or fresh water.     

毛细管区带电泳在药物分析中的研究进展

近年来,有关毛细管区带电泳在药物领域中的相关研究骤增。综述了手性拆分中常用的环糊精类化合物手性选择剂的发展及其应用;同时对毛细管电泳在手性药物分析中的应用进行了展望。     

手性农药研究进展

从手性农药的合成技术、选择性环境行为和选择性毒性效应等方面进行了论述,总结了近些年来手性农药的研究进展,并对手性农药的研究进行了展望,这将为合理安全使用手性农药提供指导。     

手性农药研究进展

从手性农药的合成技术、选择性环境行为和选择性毒性效应等方面进行了论述,总结了近些年来手性农药的研究进展,并对手性农药的研究进行了展望,这将为合理安全使用手性农药提供指导.     

达氏鲟亲鱼池塘人工培育试验

在室外水泥池塘养殖条件下,研究了4+龄达氏鲟(均重:2.38±0.11kg)在3～9月的生长特点.结果表明,在人工饲料投喂条件下,达氏鲟生长较好,增重率和特定生长率分别为165.18 %、163.03 %、149.40 %和0.46、0.45、0.43,但饵料系数偏高.达氏鲟在水温处于16～32 ℃时均可摄食生长,水温在18～25 ℃时,生长情况较好,水温高于28 ℃以上时,达氏鲟的生长缓慢,并容易出现死亡.试验表明,在达氏鲟最适的生长条件下,用饲料投喂能获得较好的生长效果.     

沼气池日常管理技术

沼气池的日常管理直接关系到沼气使用的好坏。只有掌握了沼气池的正确管理技术，才能实现沼气的效益。合理选料，定期补料，控制浓度，调节PH值，定期搅拌和防止结壳等都是沼气池日常管理的关键。     

80:20池塘主养德黄鲤试验

试验利用80：20池塘养鱼模式，以德黄鲤为主养鱼，鲢鳙鱼为配养鱼。投喂鲤鱼配合颗粒饲料。试验于2001年4月30日至9月14日在土默特左旗2814项目区进行，经过130d的饲养，德黄杂交鲤平均体重达到940g／尾，单产迭433kg／667m^2；花鲢、白鲢平均体重达到1120g／尾，单产迭108kg／667m^2。