现代效度理论指导下的建筑空间效验研究

以现代效度理论为指导,将建筑空间中的各个体验作为分析因子,从多重角度对建筑空间进行效验,寻求应用于空间效验的方法,得到一个评价建筑空间的方法和最佳设计准则。以便指导学生对建筑空间的认识和理解,设计出适合的建筑。     

A comparison of methods used for determination of cation exchange capacity

Abstract

Cation exchange capacity of ten non‐calcareous and non‐saline soils from Queensland, Australia, has been determined by the ammonium acetate method using different procedures, by an ammonium chloride method at pH8.5, and by three methods which attempt to approximate field conditions. Procedural differences in the ammonium acetate method produced variation in results, and methods using approximate field conditions gave much lower values for those soils considered to have variable charge properties.     

传统民俗声在当代城市声景观设计中的运用

针对当前声景设计在我国景观设计中被逐渐认知与推广,通过声景研究范筹之一的历史人文声,解析了传统民俗声在当代城市景观中声景设计的具体运用手法。本文主要探讨传统民俗声的研究范畴、在当代城市景观设计的具体营造手段、原则以及目前的实例运用。     

畜牧专业核心技能饲养及饲料配方设计的相关问题探讨

对我国畜禽饲养标准制订的背景以及饲养标准与饲养实践的关系和配方设计的方法进行详细剖析,并对配方设计人员应岗或从业应具备的能力进行了评述,可为学院的教学实训和技术培训提供理论和应用支持,也为今后建设精品课程奠定基础。     

浅谈求数列通项公式的方法

数列是高中数学教学的重点,而求数列通项公式又是数列问题的难点.文章系统的总结了高中数学中求数列通项公式的方法     

Response of corn seedlings to high concentrations of ammonium phosphates

Abstract

When in‐row subsoilers are used to plant crops in no‐tillage systems, starter fertilizers are often applied in the in‐row subsoil track. Although rates applied are small, the actual concentration within the rooting zone can be excessive, and injury to germinating seed and young plants can be severe. The purpose of this greenhouse study was to determine the effect of starter fertilizer placement, rate, and source on germination, growth, and nutrient uptake ef corn (Zea mays L.) seedlings. Fertilizers were surface applied, mixed with the upper 7.5‐cm, 7.5‐ to 15‐cm and the 0‐ to 15‐cm soil depths. Fertilizer rates were equivalent to 15 and 30 kg/ha of field applied P. Sources were diammonium phosphate (DAP, 18–46–0) and ammonium polyphosphate (APP, 10–34–0). Treatments did not affect germination, but the surface application resulted in severe crust formation which had to be mechanically broken. Plant heights and weights and root weights were increased by fertilizer. Nitrogen was primarily responsible for increased plant growth 2 weeks after emergence, but P appeared to have the greatest effect at 4 and 6 weeks. Although seedling death or severe damage to plants did not result from any source, rate, or application zone, some damage did occur. Optimum treatments varied with sampling dates, but after 6 weeks, optimum treatments in terms of greatest root and shoot weights and plant heights were the low rate of APP mixed with the 0‐ to 7.5‐ or the 0‐ to 15‐cm soil depths.     

新筑长江堤防地下管道保护方法与控制(英文)

介绍了新筑长江堤防地下管新筑堤防的基本概况,管道加固方案的设计及实施。管道加固方案包括对每根管道独立设置管涵结构进行保护;采用高压喷射注浆法进行地基处理;在迎水坡护坡增设复合土工膜,延长护脚长度提高堤防防渗能力。优化施工方案,加强施工期沉降观测,确保了管道安全运行。     

无性系林业--工业原料林培育的新途径

介绍了无性系林业的概念、发展状况、发展历史以及当前存在的主要问题，并就解决方法进行了简单探讨。     

Attempts to determine available carbon in soils

Summary The size of the C pool that is readily available to microorganisms affects important N transformations that occur in soils, e.g., denitrification and N immobilization. In the present work, the C content of soil extracts, the C in water displaced from soil and biomass C were compared as indicators of available C. A comparison of C measured by the anthrone method and a total organic-C analysis of extracts indicated that only a small portion of C was in carbohydrates. The substrate-induced respiration method of measuring biomass in conjunction with the Wright-Hobbie model was used as an additional determination of available C. Total organic-C analysis of a 1 N H₂SO₄ extract gave the highest C values (500–1700 mg C kg^-1 soil) and the substrate-induced respiration method gave the lowest (1–5 mg glucose equivalents kg^-1 soil). The C values closest to the C turnover measured in long-term incubation studies were obtained by the substrate-induced respiration method using the Wright-Hobbie model.Contribution from the Soil-Microbial Systems Laboratory, NRI, USDA-ARS, Beltsville, MD 20705, USA     

The measurement of chronic disturbance and its effects on the threatened cactus Mammillaria pectinifera

Measuring how anthropogenic disturbance affects biological systems is crucial for conservation and management. However, it is often difficult to quantify disturbance when it occurs in a slow, long-lasting - or chronic - fashion. Because various human activities influence gradually an area, chronic disturbance must be measured on a continuous scale that accounts for different sources of disturbance. Here we propose a method to develop multimetric indices for chronic disturbance. The approach is exemplified by considering the effects of disturbance on the threatened cactus Mammillaria pectinifera. Fourteen indicators of three agents of disturbance (human activities, livestock raising and land degradation) were measured in 10 populations of M. pectinifera, and summarised through principal components analysis (PCA). An index for each agent was also developed. M. pectinifera achieved maximum density at intermediate values of the first PCA axis, which was related to disturbance intensity. Assessing only both extremes of the disturbance gradient, where density is low, would erroneously suggest that disturbance has no effect on this plant. The different disturbance agents act synergistically on M. pectinifera, and their combined effects are detrimental. Land degradation reduces plant density, while livestock enhances it. However, overgrazing promotes degradation, so maintaining appropriate livestock levels is critical for management. Our method allowed us to identify which agents have more impact on threatened species, and sets the basis to manage disturbance agents in a way compatible with conservation. The method proposed here can be easily modified for its use in other environments and to account for different forms of anthropogenic disturbance.