合理调整山西人民食物结构的策略与途径

合理调整我国人民的食物结构是提高全民族身体素质,推进社会文明进步,具有深远的战略意义的一项国策。调整国民食物结构是一个科学性,政策性很强,社会涉及面广,地区人群民食习惯差别大的极为复杂的动态系统工程。作者针对山西省情实际,从追朔我国饮食传统,膳食民习,食物资源及演变趋向探求,提出合理调整山西人民食物结构的策略与途径。     

七星瓢虫幼虫空间分布型及抽样技术研究

采用颍次分布X~2检验、Iwao平均拥挤度m~*=a+βx和Taylor幂法则S~2=am~b等8种方法,分析了七块麦田中七星瓢虫幼虫的空间分布型,认为其分布型为负二项分布,且聚集的原因是由于个体之间存在着相互吸引,并确定了代表性较强的棋盘式抽样技术,最佳抽样数量为:Q=28.7088/+0.7552。     

甘肃省水资源时间序列模型及其变化规律研究

水文水资源序列是一个具有周期变化、随机变化和递增或递减趋势变化的复杂时间序列。作为一种近似,可以把水文序列{Qt}分为趋势序列{Nt}、周期序列{Pt}和随机性的平稳时间序列{St},即式:Qt=Nt+Pt+St。采用时间序列分析的方法,建立了甘肃省水资源的时间序列模型,分析了其变化规律,结果表明,甘肃省水资源呈明显下降趋势,并存在一定的周期变化规律。     

试论灰色系统关联度分析法在生物科学研究中应用的合适性

灰色系统关联度分析法的主要研究对象是社会经济等非技术的抽象系统。近年来，在生物科学领域如畜牧、兽医、草原等技术性强和具体系统的科学研究中，发现有应用该法分析其试验数据的论文。经研究核实，应用该法分析生物科学研究的数据，似欠合适。这可能是由于该方法本身有不足处，或由于论文作者误用该法。特提出供读者与学者讨论与研究。     

浅谈农村环保型养鸡

针对农村养鸡现状与存在的问题，提出在选种、饲料的科学配合、饲养管理制度、合理用药以降低药物残留、加强养鸡场内外环境保护等方面，建立具有农村特色的环保型养鸡模式。     

茄子早熟育种研究Ⅱ选择指数与早熟性选择

研究结果表明,由性状果实最大周长,果实体积,门茄显蕾期,单株产量等性状构成的选择指数较好;进一步进行遗传相关分析结果认为,应用选择指数时应注意果实体积这个性状,单株产量是一个重要的辅助性状,门茄显蕾期是一个限制性因子。应用选择指数对品种评价结果认为,早熟性较好的品种有:天津早茄、西安绿茄、二民、七叶茄、白线茄和汉中荷包。     

新疆森工技术进步贡献份额的测算

新疆森工企业是新疆林业的重要组成部分。森工技术进步率是全面考核林业综合水平的重要指标之一。本文根据新疆森工统计资料，首次采用增长速度方程、综合要素生产率指数、总因子生产率指数三种模型测算了新疆森工技术进步贡献份额（１９８１年到１９８６年）。结果表明，新疆森工年均技术进步率在０．５％～０．５２２％之间，技术进步对森工总产值增长的贡献份额在３４％～３６％之间。     

夏大豆亩产262.1kg生理指标研究

研究了夏大豆中油－８９Ｄ亩产２６２．１ｋｇ各项生理指标：叶面积系数，开花期、结荚期、鼓粒期分别为３．９８、５．８０、４．９１；总光合势１８．２万ｍ＾２·日，平均净光合生产率４．８１ｇ／ｍ＾２·日，氮磷总积累量分别为２２．２８ｋｇ和３．１３ｋｇ，每生产１００ｋｇ籽粒需吸收氮８．５０ｋｇ，磷１．１９ｋｇ，总干物质积累８７６．４７ｋｇ，粒茎比０．５１，经济系数０．３０。     

Wetland effects on lake water quality in the Minneapolis/St. Paul metropolitan area

A method developed to evaluate the cumulative effect of wetland mosaics on water quality was applied to 33 lake watersheds in the seven-county region surrounding Minneapolis-St. Paul, Minnesota. A geographic information system (GIS) was used to record and measure landscape variables derived from aerial photos. Twenty-seven watershed land-use and land-cover variables were reduced to eight principal components which described 85% of the variance among watersheds. Relationships between lake water quality variables and the first six principal components plus an index of lake mixis were analyzed through stepwise multiple regression analysis. A combination of three landscape components (wetland/watershed area, agriculture/wetlands, and forest/soils components) explained 49% of the variance in a trophic state index, even though most of the lakes examined were already highly eutrophic, and thus were influenced by internal loading. The regression equations explained a range of 14 to 76% of the variation in individual water quality variables. Forested land-use was associated with lower lake trophic state, chloride, and lead. High lake trophic state was associated with agricultural land-use and with wetland distance from the lake of interest. The extent of wetlands was associated with low total lead and high color in lakes downstream. Wet meadows or herbaceous, seasonally-flooded wetlands contributed more to lake water color than did cattail marshes.     

Analysis of Growth and Productivity of Indian Mustard (Brassica juncea) in Relation to FYM, Nitrogen and Source of Fertilizer

A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha⁻¹ significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha⁻¹), N (75 kg ha⁻¹) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages.