加快淮北地区杂交粳稻发展的几个问题

回顾了淮北地区十多年来杂交粳稻示范推广的发展过程，分析了影响杂交粳稻发展的主要原因，并论述了加快该地区杂交粳稻发展的几个主要问题。     

计算机计算含未知量元素行列式的“保值回跳”法

本文探讨了用计算机计算含未知量元素行列式的方法与途径,提出了“保值回跳”的思想。并提供了以该思想为基础而编制的空间桁架结构位移响应关于截面设计变量显式表达式程序计算的若干算例。     

Prospects for improving potato crop protection against aphid vectors

Conventional ways to control aphid vectors on potato crops rely essentially on cultural and chemical methods. The extensive use of insecticides, too often applied regardless of real needs and consequences, has resulted in more and more failures in both controlling aphids and virus spread. This paper stresses the need to introduce more rationale in the operation of existing methods by improving the efficiency of some of them like forecasting systems, to assess the potential of others like fertilization and semiochemicals and to put most efforts on resistant cultivars so that integrated pest management can be operated in the near future.     

烫漂及冻结对青头菌营养价值的影响

研究了在不同的烫漂温度和烫漂时间下青头菌过氧化物酶(Peroxidase，POD)活性的变化．烫漂及冻藏对青头菌过氧化物酶活性、氨基酸、矿质元素、维生素及氨基酸态氨等成分的影响结果表明：采用95～96℃烫漂温度效果最好，在4min内过氧化物酶活性降低了95．5％；烫漂及冻藏都使青头菌营养成分受到不同程度的损失建议采用一70℃以下温度不经烫漂而冻结，冻品在-26℃冰箱中贮藏12个月，其营养价值保持很好。     

不同生长年限王草的营养价值研究

本文对生长第1、2、3年的王草在100cm高度时刈割的营养成分及其体外干物质、有机物降解率进行分析研究。结果表明:不同生长年限王草第1年的粗蛋白质显著高于第2、3年(P<0.05),而中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)显著低于第3年(P<0.05)。干物质、有机物的降解率第1年最高,第3年的最低,但差异不大。     

双低菜籽粕在饲料中的应用

双低菜籽粕具有高产优质的特点,其饲用品质优于普通菜籽粕,营养价值与豆粕相当,被广泛应用于饲料。为了更有效开发其对饲料业和养殖业的应用潜力,本文就双低菜籽粕的营养价值和在动物饲用方面进行的一系列的基础性研究作一简要介绍。     

Designating a greenbelt around the city of Riga, Latvia

Latvian legislation demands that forest protection belts are established around all cities and towns. The main goal of a protection belt is to provide suitable opportunities for recreation to urban dwellers and to minimise any negative impacts caused by urban areas on the surrounding environment. Legislation states the main principles to be adopted, which include the maximum area of protection belts, their integration in territorial development plans and restrictions placed on forest management activities. The largest part of the forest area around Riga is owned by the municipality of Riga, which, as a result, has two competing interests: to satisfy the recreational needs of the inhabitants of Riga, and to maximise the income from its property. In order to compile sufficient background information to solve this problem, the Board of Forests of Riga Municipality initiated the preparation of a proposal for the designation of a new protection belt.The proposal was based on the development and application of a theoretical framework developed during the 1980s. The analysis of the recreational value of the forest (5 classes of attractiveness) was carried out based on categories of forest type, dominant tree species, dominant age, stand density, distance from urban areas and the presence of attractive objects. Information was derived from forest inventory databases, digital forest maps and topographic maps. Additional information was digitised and processed using ArcView GIS 3.2. Local foresters were asked about the recreation factors unique to different locations, such as the number of visitors and the main recreation activities. From a recreational point of view and taking into account legal restrictions and development plans for the Riga region, it was proposed to create three types of zones in the forest: a protection belt, visually sensitive areas and non-restricted areas.     

Pest Management in Traditional Tropical Agroecosystems: Lessons for Pest Prevention Research and Extension

Based on current agroecological theory and IPM practices, this review explores the role of traditional practices, involving site selection, soil management, timing of planting and harvesting, crop resistance, intercropping, weed management, harvest residue management, post-harvest management, natural enemies management, mechanical control, repellents and traps in the natural regulation of potential pests. In synthesis, the literature suggests that although pest management professionals focus their efforts on pest control, the preventative approach taken by traditional farmers is more effective. Potential constraints to the implementation of this preventive pest management approach include:(1) lack of integration of ecological theory and pest management, (2) lack of cooperation among social and biological scientists, and (3) lack of real efforts to work with farmers as equals and support mechanisms that protect their knowledge. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同碳源对虎奶菇菌核蛋白质营养价值的影响

测定了四种碳源对虎奶菇菌核蛋白质营养价值的影响。结果表明，以玉米淀粉为碳源，虎奶薅菌蛋白质的化学评分，必需氨基酸指数，生物价和营养指数分别为11．63、69．80、64．40和9．98，均居四种参试碳源的第一位；氨基酸评分和氨基酸比值系数分分别为14．55和12．45，均居四种参试碳源的第二位，这些结果证实，以玉米淀粉为碳源，虎奶菇菌核蛋白质营养价值高，值得推广应用。     

黄花苜蓿的优良特性与开发利用

本文简要介绍了苜蓿属植物黄花苜蓿的分布、生境以及饲用价值高、抗寒、抗旱、耐盐碱等优良特性，并对其与紫花苜蓿相比所占的优势、对苜蓿育种的贡献及在草地改良中的生态价值进行了评述。在简述目前我国黄花苜蓿国研究现状的同时，提出要大力开发利用这一牧草资源，它必将对我国畜牧业生产、退化草地改良及水土保持等发挥重要作用。