21世纪初黑龙江省粮食生产的区域差异及成因分析

以县域为基本空间单元,运用塞尔指数和GIS方法分析了黑龙江省粮食生产的空间格局及其区域差异,并基于2000～2007年42个典型县域粮食生产的面板数据建立多元回归评估模型,探讨该省粮食生产区域差异的成因.研究结果表明:(1) 黑龙江省粮食生产主要集中于省域东部、南部和西部,三大片区行政面积约占全省的46%,粮食总产量约占全省的80%.(2) 2000年以来,全省及三大片区内部各县域粮食生产的区域差异逐渐由波动趋于相对稳定.(3) 化肥使用量、农村用电量、耕地面积比重、农村居民人均纯收入、除涝面积是黑龙江省粮食生产区域差异扩大的主要原因,而耕地面积、水库容量则在一定程度上缩小了区域差异.     

Sulfur in pesticide action and metabolism: Edited by J. D. Rosen,P. S. Magee,and J. E. Casida,American Chemical Society,Washington, D.C., 1981. 172 pp., $33.00

The distribution of ¹⁴C-acid-, ¹⁴C-alcohol-, and ¹⁴C-cyano-labeled deltamethrin and selected metabolites were followed in the liver, blood, cerebrum, cerebellum, and spinal cord after iv administration of a toxic, but nonlethal dose (1.75 mg/kg) to rats. Approximately 50% of the dose was cleared from the blood within 0.7–0.8 min, after which the rate of clearance decreased. 3-Phenoxybenzoic acid (PBacid) was isolated from the blood in vivo, and was also the major metabolite when ¹⁴C-alcohol-labeled deltamethrin was incubated with blood in vitro. Deltamethrin levels in the liver peaked at 7–10 nmol/g at 5 min and then decreased to 1 nmol/g by 30 min. In contrast, peak central nervous system levels of deltamethrin were achieved within 1 min (0.5 nmol/g), decreasing to 0.2 nmol/g at 15 min, and remaining stable until 60 min. peak levels of deltamethrin did not correspond to the severity of toxicity, although the levels of non-pentane-soluble radiolabel did appear to correlate with motor signs of toxicity. Experiments with brain homogenates, using in vivo concentrations of deltamethrin, failed to reproduce the pentane-unextractable radioactivity in vitro nor was any metabolism demonstrated.     

绿洲发展面临的挑战、目标及21世纪发展研究展望

:本文认为 ,当前中国绿洲发展上的主要问题是荒漠化的威胁、资源利用过度、科技含量低下和产业结构失调。未来建设方向是建立知识密集绿洲体系。这一体系由农业科技、工业科技和高新技术组成 ,并从干旱区优势资源出发 ,探讨了如何通过知识产业化设计实现绿洲高效、持续发展的途径。文章指出 ,2 1世纪绿洲发展研究的热点问题有绿洲合理发展规模及其发展空间研究、绿洲知识经济产业化演进过程研究、知识经济下绿洲资源产业结构研究、绿洲发展保障体系调控研究 ,以及知识经济与 PRED协调发展体系建设等。     

EPPO Council Colloquium on 'Plant health and the environment', Dublin, 2000-09-21

The National Plant Protection Organizations of EPPO countries have a basic responsibility to prevent the introduction and spread of pests of plants and plant products. This has been for many years defined by the IPPC (International Plant Protection Convention) and now by its new revised text. The Agreement on Sanitary and Phytosanitary Measures of the World Trade Organization has in the past 10 years aimed to prevent the use of phytosanitary measures as unjustified barriers to trade. In the past 2 years, new constraints have appeared, particularly on account of the Convention on Biological Diversity (CBD). International co-operation is now developing on biosafety (restricting the movement of potentially dangerous organisms, whether GMOs, alien species or invasive species) and on the protection of the environment and biodiversity as such. The new obligations of countries under the CBD, and the measures which they can take to implement them, overlap to a significant extent with their obligations under the IPPC. The responsibilities and tasks of NPPOs (under Ministries of Agriculture) can at a technical level be extended to cover the concerns of the CBD, but in so doing may conflict with those of the equivalent authorities under the Ministries of the Environment. The aim of the EPPO Council Colloquium in Dublin was to examine these areas of potential overlap and conflict and consider the consequences for the international organizations concerned with plant health (like EPPO) and for the NPPOs.