天水旱作区自然降水生产潜力的适度开发对策

通过10年的定点资料统计,分析了天水旱作地区自然降水生产潜力开发程度、适宜开发程度及可开发程度;并就资源和环境条件对水分生产潜力开发的制约问题进行了讨论,分阶段分层次提出了生产潜力适度开发对策措施。     

中国出境旅游市场潜力的空间分布及深入发展对策分析

在回顾中国出境旅游发展历程和市场规模变动的基础上,通过相关分析,我们发现中国出境旅游规模与人均GDP的相关度极高,这意味着中国的出境旅游市场主要分布在经济发达地区,文章进一步分析了中国出境旅游市场潜力的分布情况,并对中国出境旅游客源市场的深入发展提出了具体建议。     

伊犁河流域地表水资源优势及开发利用潜力研究

伊犁河流域是新疆地表水系最发达、径流最发育、水资源最丰富的内陆河流域,具有流域降水丰沛,径流补给充分,径流量大;水系发达,河川密布;水量变化较小、泥沙含量较少、水质较好的资源优势。但受经济发展水平及产业结构层次的限制,伊犁河流域水资源总体上仍处于利用效率低下、生产经营方式落后、综合利用潜力巨大的初级开发阶段。依据部颁SL201-9《江河流域规划编制规范》和流域整体规划目标,经过水资源多目标开发平衡分析与评价,给出了伊犁河流域水资源综合开发和合理配置远景规划方案。     

新疆塔里木盆地蒸发力的研究

本文首先对国内外蒸发力的计算方法进行了较全面的评述，然后利用Ｐｅｎｍａｎ法的修正式计算了塔里木。盆地的蒸发力，最后分析了该地区蒸发力的分布特征。     

小麦品种在低温下膜功能变化的生物物理学分析

本文以冬性及春小麦品种为试材，用示踪，液闪计数及测定电解质泄漏的方法，测定低温胁迫下膜脂的代谢和电解质渗透的变化，并根据热力学的原理，分析其生物膜上的化学反应和扩散过程及膜上物质通量Ｊｊ与跨膜电势Ｅｍ的函数关系。     

沈阳地区玉米光热水生产潜力研究

在玉米光热生产潜力的基础上，进一步讨论沈阳地区水分对玉米生产潜力发挥的限制作用，结果表明：水分的限制率为１８．５％，使玉米经济产量降低３９５．０１ｋｇ／ｍｕ。     

不同处理方法对美国截叶胡枝子种子发芽的影响

美国截叶胡枝子的硬实率很高,发芽率只有17.3%。经过种子预处理,如采用不同温度下浸种、98%浓硫酸浸泡、机械破皮和机械破皮结合热水浸种等处理,结果表明,机械破皮后用60℃热水浸种处理的效果最好,发芽势和发芽率分别达到64.0%和74.3%;其次是机械破皮,平均发芽率达到50%;浓硫酸浸种可以显著提高种子发芽势,浓硫酸浸种5min效果最好,发芽率达到44.7%;热水浸种的处理效果不佳,最好的90℃热水浸种处理发芽率也仅有26.7%。     

外来有害生物适生性研究方法及需要注意的若干问题

在分析利用生态位技术结合气候统计学方法及利用试验数据建立预测模型评估开展有害生物适生性研究的大量文献的基础上,本文详细讨论了在有害生物适生性研究中涉及的有关有害生物生物学资料的评估与分析、有害生物分布点的选择及预测结果的准确性等问题。认为有害生物的生物学特性及地理学的资料在研究有害生物适生性方面具有十分重要的作用。从统计学角度探讨了提高适生性预测结果正确性的途径。     

The separate effects of the nature of diet and grazing mobility on metabolic potential of muscles from Charolais steers

The objectives of the two experiments presented were to determine the separate effects of diet and mobility associated with grazing on the metabolic potential of muscles of Charolais steers reared at similar growth rates and slaughtered at the same age (31 months on average).Glycolytic [lactate dehydrogenase (LDH), phosphofructokinase (PFK)] and oxidative [β-hydroxyacyl-CoA dehydrogenase (HAD), citrate synthase (CS), isocitrate dehydrogenase (ICDH), cytochrome c oxidase (COX)] enzyme activities were measured spectrophotometrically in semitendinosus (ST), a glycolytic muscle, and rectus abdominis (RA), an oxidative muscle.In Experiment 1, 24 weaned steers were assigned to two groups: grazing grass (GG) and maize silage (MS). In Experiment 2, 30 weaned steers were assigned to five groups: grazing grass (GG), cut grass without walking (CG), cut grass with walking (CGW), maize silage without walking (MS) and maize silage with walking (MSW). Both experiments lasted for 2 years. All grass fed animals were fed grass silage during the two winter seasons. During the two summer seasons, GG steers were grazing and did not receive any supplementation while CG and CGW steers were fed indoor freshly cut grass alone. MS and MSW steers were fed maize silage indoor during the entire experiment. For the second summer before slaughter, half of the indoor fed steers on each type of diet (CGW and MSW groups) was submitted 7 days a week to a 5.2 km walk daily.At slaughter, carcass weight and composition did not differ between groups. Oxidative HAD, CS and ICDH enzyme activities were higher for GG, as compared with MS group, in RA muscle in both experiments (P < 0.05 to 0.01) and in ST muscle (P < 0.05) in Experiment 2. Muscles from the GG group were thus more oxidative than those of the MS group. It was further tested whether these effects could be specifically attributed to the nature of the diet or to differences in mobility. A cut grass diet (vs. maize silage) increased HAD and ICDH activities (P < 0.05) and mobility induced by walking increased HAD and CS (P < 0.01) activities. In conclusion, the more oxidative metabolic orientation of muscles of grazing steers originates from a combination of two effects: an increase mobility at pasture and a grass (vs. maize silage)-based diet.     

应用可拓学原理评价黄瓜根分泌物的化感潜势

 对黄瓜组培根分泌物的化感潜势进行可拓评价, 得出黄瓜组培根分泌物对菜豆幼苗生长有显著促进作用, 而对其它3种作物有明显的毒害作用, 毒害程度为黄瓜>甜瓜>番茄。同时, 建立了黄瓜组培根分泌液的化感效应的数学模型R_E = [ k₁R_p0 / ( k₂ - k₁ ) ] ( e^{- k1t} - e^{- k2t} ) ( e- ^k1a - e^{- k2a} ) , 说明了黄瓜组培根分泌液的化感效应与组培根培养时间( t) 以及根分泌液浓度( a) 显著相关。黄瓜根分泌物对4种受体作物显示出显著的化学干扰差异, 论证了植物种内(间) 发生的干扰作用与植物的品种(系) 有关, 从理论上得出菜豆可以作为黄瓜的间套作物或下茬作物。