日光温室山墙对室内太阳直接辐射得热量的影响

该文计算了日光温室室内各个面的太阳直接辐射，结果表明：山墙内侧的太阳直接辐射日变化规律不同于室内其它各个面。对于长度较短的温室，如果忽略山墙的作用，将会忽略山墙内外侧太阳辐射对室内得热的影响，同时忽略山墙在室内各个面产生的阴影，从而高估了室内其它面的太阳辐射得热，高估值随着温室长度的递减而递增，给日光温室热环境的分析带来误差。该文还测量了日光温室各个面的热流量，分析了山墙的蓄热放热过程及其随温室长度变化对室内得热的影响。因此，对长度较短的温室，必须考虑山墙对室内得热的影响。同时也为日光温室长度的确定和室内作物布局提供理论依据。     

土壤溶质运移参数估计图解方法

基于土壤中溶质运移的对流 弥散方程 (CDE)提出了溶质运移参数估计的图解方法。根据土柱溶质运移“穿透曲线”(BTC)数据计算通量浓度随时间变化 (dc/dt)。应用绘图软件 ,例如MicrosoftExcel,绘制出t1 5dc/dt和dc/dt相对于时间的变化曲线。这两条曲线都是单峰曲线 ,并被用于估计CDE中延迟因子(R)和弥散系数 (D0 )。设计算例和穿透实验数据被用于校正图解法估计参数的精度和稳定性。参数估计的稳定性由估计参数对它们平均值的标准差评价 ;参数的估计精度与CXTFIT法和等斜率法比较。结果表明图解法具有较高的精度和较好的稳定性 ,特别是对于运移参数R的估值。图解法是一个确定性方法 ,它具备确定性方法中估计参数唯一性特点 ,克服了统计方法中需要给定参数初值的缺点。因此 ,这个方法是土壤溶质运移参数估计的可选方法之一。     

重庆市畜禽粪便年排放量的估算研究

畜禽养殖产生的粪便已成为我国农村面源污染的主要来源，因而畜禽粪便的排放量也越来越引起人们的重视。通过对重庆市畜禽养殖业进行调查，结合国内外有关研究，确定重庆市畜禽粪便年排放量估算方法和各种估算参数。以2001年为基准，估算出重庆市主要畜禽(猪、牛、羊、马、兔、家禽等)年粪尿排放量和粪尿中对环境产生污染的主要物质量(有机质、氮、磷、钾)，以便对重庆市畜禽粪便污染作一个定量的认识。估算结果为重庆市2001年畜禽粪尿排放7421万t，其中有机质为806万t，氮42.5万t、磷21.48万t、钾44.98万t。该研究结果可为重庆市工农业生产布局和环境污染治理提供决策依据。     

三川河二期重点治理成效与经验

三川河二期重点治理成效与经验宋志学（黄河水利委员会水土保持局，郑州４５０００３）黄河流域四片水土流失重点治理区第二期工程治理任务重、时间短，治理难度大、要求高，投资水平低。如何保质保量按期完成二期重点治理任务，山西省三川河片的做法，提供了好经验。１９...     

一类带跳的线性回归模型

针对普通的常系数线性回归模型存在预测误差较大的缺陷，对Hildreth-Houck模型进行修正，得到带跳的线性回归模型(LRMJ)，对该模型中各参数进行估计，并对模型中被解释变量的数学期望与方差等统计性质进行讨论．最后将该模型运用于一个实际问题，证明该模型不仅可行而且能够得到比普通常系数线性回归模型更为精确的预测值。     

Discrimination and abundance estimation of wild and released abalone Haliotis diversicolor using stable carbon and oxygen isotope analysis in north-eastern Taiwan

The discrimination between wild and released Taiwan abalone Haliotis diversicolor was performed by stable carbon isotope analysis. Abalone samples were collected from Mao Aw Gulf in north-eastern Taiwan. Live abalone and dead shells were collected by divers with an 80 × 80 cm frame. The densities and amounts of wild and released abalone, as well as the survival rates of released abalone, in 1997 and 1998 were estimated. The age of the specimens was also determined from the specific temperature of each month and the inverse relationship between oxygen isotope values and temperatures. Results show that examining stable isotopic profiles proves to be a practical and feasible method for stock discrimination as well as density and abundance estimation. These data would be helpful in assessing the success of abalone culture and release programs, which aim to enhance this valuable marine resource.     

炼山对杉木人工林生态系统影响的计量与评价

在炼山、不炼山径流场定位观测基础上，根据炼山对杉木人工林生态系统的影响程度，首次采用定量方法对不同林地清理方式杉木林的生产效益、涵养水源效益及保持水土效益进行研究的结果表明：不炼山杉木人工体综合效益比炼山杉木人工林高１３６５．７６元／ｈｍ２，炼山清理迹地弊大于利。     

Phänotyp und Futterqualitat einschliefilich Konservierungseigenschaften bei Grasern

Phenotype and forage value, including conservation properties, of grasses The phenotype of grasses can be influenced by the date of harvest as well as by breeding programs. In contrast to dicotyledons, the stems of grasses are younger than the leaves, although the grass leaves are usually considered to have a higher nutritional value than the stems. In a field experiment, Lolium multiflorum Lam. ssp. gaudini (Parl.) Schinz et Kell. was grown as a model-plant in order to study effects of ploidy-level, N-fertilization, stage of development, and growth time on the main aspects of nutritional value and conservation properties in relation to the phenotype. As regards the nutritional value, the interactions of ploidy × plant organ (=stem or leaf) and of ploidy × N-input were not significant. Hence, the results for leaf and stem can be generahzed. Until the emergence of the inflorescence, EC 49, the stem showed a significant higher net energy content than the leaf; at later stages of development this relationship changed. The evaluation of the net energy content of leaf and stem was significantly influenced by the method of estimation. In vitro methods with rumen liquor may show the best approximation to the real value. The crude protein/energy ratio of the stem as compared to the leaf better meets the nutritional requirements of ruminants; on the other hand the leaf was more valuable than the stem in relation to the nitrate content, especially when the whole plant showed an increased nitrate level. The general relationship between the mineral content and the phenotype was not evident. The investigation indicated significant differences between stem and leaf in relation to their conservation properties. The leaf showed more favourable drying properties than the stem but ensilability was better for the stem than for the leaf. As a result of this investigation it is assumed that, in the past, the nutritional value of young stem has been underestimated whereas the value of the leaf has been overemphasized. This may also be due to the criteria and determination methods of the nutritional value.     

NOAA资料在草地资源监测中的应用研究

本文阐述了如何利用ＮＯＡＡ资料进行草地监测和产草量估计，在对不同时象的植被指数景象进行纠正的配准后，可叠加得到平均植被指数影象ＡＶＩ。使用聚类分析和数字地面高程模型，可将纠正的平均植被指数影象ＡＲＶＩ制成草地产量等级图。依据草地产量等级图，可对阜康县的１０个不同的草地产量级及其总产量给出准确的估计。