林木绿化工程改善工业污染区生态环境的研究

通过对广州市员村工业区２０个监测点的大气监测资料及天河区环境监测站１９８９年～１９９４年连续６ａ大气监测资料，运用模糊数学进行环境现状及回顾评价，采用统计方法进行方差分析，并用灰色系统理论建立污染物时空分布模型，找出污染物分布规律，获得员村地区环境现状及发展趋势的基本资料．同时在对员村植被与绿化现状调查研究基础上，依据环境生态及生态园林理论和国家一级大气环境质量标准，组建高效的自然净化系统．     

浙江诸暨城市林业建设思路探讨

城市林业是林业现代化建设的重要组成部分。结合诸暨实际,分析了林业建设的现状,阐述了诸暨城市林业建设的基本思路,提出要以构建生态安全体系和森林景观体系为重点的观点及其措施。     

汽车零部件再制造工艺研究

再制造一直是人们研究的热点之一。根据当前汽车再制造的研究现状,阐述了汽车零部件再制造的工艺问题。以逆向工程的角度,从旧件检测、旧件加工(配备相关设备)、工艺性能评价和质检等过程分析了典型的汽车零部件再制造的研究方法、工艺要求和工艺流程,提出了汽车零部件再制造工艺需要解决的法律、技术和政策等关键问题。     

曲靖市麒麟区生态林业建设的成就和展望

曲靖市麒辟区为国家级可持续发展综合实验区，1998年以来工程造林7239．3hm^2，累计实施森林管护面积167480hm^2，全区森林覆盖率由27．4％提高到29．4％，在总结经验的基础上，提出了今后建设目标。     

Plant biotechnology: A case study ofBacillus thuringiensis (Bt) and its application to the future of genetic engineered trees

Agricultural productivity may be raised in a sustainable way by many different technologies such as biological fertilizers, soil and water conservation, biodiversity conservation, improved pest control, and changes in land ownership and distribution. Of these measures, biotechnology applications probably hold the most promise in augmenting conventional agricultural productivity, because biotechnology applications give not only the need to increase production, but also protect the environment and conserving natural resources for future generations. Biotechnology applications will have the possibilities to increase productivity and food availability through better agronomic performance of new varieties, including resistance to pests; rapid multiplication of disease-free plants; ability to obtain natural plant products using tissue culture; diagnosis of diseases of plants and livestock; manipulation of reproduction methods increasing the efficiency of breeding; and the provision of incentives for greater participation by the private sector through investments. Insect resistance through the transfer of a gene for resistance fromBacillus thuringiensis (Bt) is one of the most advanced biotechnology applications already being commercialized in many parts of the world. This paper reviews the development and the status ofBt technology and application ofBt transgenic plants in current agriculture, and discusses specific issues related to the transfer of the technology to the future of genetic engineered trees with emphasis on conifers. Biography: Tang Wei (1964-), male, Ph. Doctor, Research associate, Department of Biology, Howell Science Complex, East Carelina University, Greenville, NC 27858-4353, USA. Responsible editor: Chal Ruihai     

林木遗传工程及木质素的生物合成调节(英文)

林木遗传工程有利于保存林木遗传资源，改善全球气候，减轻自然林的过度采伐和满足人类日益增长的林木产品需求。控制林木真菌、病毒病、虫害和杂草的遗传工程方法正被广泛地研究和应用。尽管转基因林木的历史不长，种类不多，但它有广泛的应用前景。目前，抗除草剂基因、抗虫基因以及和木材质量相关的基因已被分离并应用于林木遗传工程。植物分子生物学和基因组学中的新技术使得高效林木遗传改良成为可能并将促进这些技术的商业化应用。木质素的应用已有一百年的历史，但木质素生物合成的全过程并不完全清楚。有关松树自然突变体和转基因林木的最新研究结果表明，木质素的生物合成是一个可以调节的过程。这些发现对完善木质素的生物合成途径、加深对木质素前体生物合成途径的理解和通过遗传工程改善木材质量有促进作用。本文综述了林木遗传工程在这些领域中取得的一些进展。     

乌兰布和沙漠抗逆植物选择试验及利用

乌兰布和地区光，热，水，土资源丰富，在国家开发西北地区的大政策下，适合进行农，林，牧业开发，但是限于本地区干旱，少雨，风沙大的现状，开发要在以改善生态环境为目的的防护林建设的基础上进行，为本地区增选抗性强，生长快，见效快的灌木品种是当务之急，也是长远需要，本试验选取了干旱地区常见的8种沙旱生灌木进行造林实验，选择出最适于该地区生长的灌木品种主造林方式。     

Surveying farmers' agroforestry plots: experiences in evaluating alley-cropping and tree border technologies in Western Kenya

Evaluation of existing on-farm agroforestry plots should provide useful supplementary information for the design of improved agroforestry systems, in both research and development projects. Such evaluation has been little used, however, largely due to the methodological difficulties of surveying highly variable on-farm plots, and difficulties in identifying key variables for measurement. This paper describes a set of methods and tools used in evaluating plots of alley-cropping and tree borders around crop fields established by farmers working with the CARE Agroforestry Extension Project in western Kenya. Details of survey design, sampling, and implementation are discussed, and suggestions made for carrying out agroforestry surveys in other projects. A condensed version of the questionnaire is appended.     

Modeling spatial variability in the life-cycle costs of low-volume forest roads

Cost estimation is probably the most decisive factor in the process of computer-aided, preliminary planning for low-volume road networks. However, the cost of construction is normally assumed to be route-independent for a specific project area, resulting in sub-optimal layouts. This is especially true for mountainous terrain and in areas with unstable subsoil. Here, we present a model for more accurately estimating spatial variability in road life-cycle costs, based on terrain surface properties as well as geological properties of the subsoil. This parametric model incorporates four structural components: embankment, retaining structures, pavement, and drainage and stream-crossing structures. It is linked to a geo-database that allows users to derive location-specific parameter values as input. In applying this model, we have demonstrated that variability in costs ranges widely for mountainous areas, with the most expensive construction being approximately five times greater there than on more favorable sites. This variability strongly affects the optimal layout of a road network. First, when location-specific slope gradients are considered, costs are reduced by about 17% from those calculated via currently available engineering practices; when both slope gradient and geotechnical formations are included, those costs are decreased by about 20%. Second, the length of the road network is increased by about 4% and 10% respectively, compared with current practices.     

加快转产项目建设积极进行产业、产品结构调整

本文结合大兴安岭地区的实际情况,以实施“天保工程”为出发点,分析了转产项目建设面临的诸多问题,并提出了改革建议和转产项目开发建设应遵循的原则及发展方向。