四台矿住宅区花园设计构想

通过对四台矿住宅中心花园的设计分析，探讨新世纪人居绿化环境的目标、原则和应采取的措施。     

Environmental effects on cv Cabernet Sauvignon (Vitis vinifera L.) grown in Hawke's Bay, New Zealand.: 2. Development of a site index

Based on observations of Cabernet Sauvignon phenology, cropping and fruit characteristics at six vineyard sites in Hawke's Bay (New Zealand) studied over three seasons, a numerical model is proposed to characterise environmental conditions of a vineyard site. The proposed model is based on air temperature in October and January, seasonal rainfall, rooting depth, gravel percentage and clay-to-silt ratio in topsoil. The 'Site Index' (SI) calculated from these variables was significantly correlated with soil temperature and volumetric soil moisture content, themselves closely linked with clay-to-silt ratio, air temperature and rainfall. Vegetative growth, canopy characteristics, precocity of veraison, total anthocyanins, TSS and malic acid concentration in grapes, as well as wine sensory score, were all significantly correlated with the SI values at six sites and over two seasons. Over the same period, correlation of SI with several viticultural variables was generally stronger than five existing climatic indices for viticulture calculated for these sites. The proposed SI index appears to have potential use for vineyard zoning and site selection and evaluation.     

Age-dependent changes in the nervous and endocrine control of the thymus

The immune system, especially the thymus, undergoes age-related modifications leading to structural and functional changes in the lymphoid organs and immunocompetent cells. Nevertheless, the consequences of thymic involution in the peripheral pool of T-cells are still a matter of controversy. The control of the thymic function is very complex and involves intrathymic signals, the autonomic nervous system, and the endocrine system. Both thymocytes and thymic stromal cells express receptors for a wide range of hormones, as well as for neurotransmitters and neuropeptides, thus affecting thymocytes maturation. This review summarizes the age-dependent variations in the extrathymic components of the thymic microenvironment, i.e., vegetative nerves and hormones, and the possible effects of those changes in the immune function.     

Use of elemental sulphur to enhance a cadmium solubilization and its vegetative removal from contaminated soil

To a soil artificially contaminated with cadmium, orthorhombic sulphur flower and a hydrophillic microbially produced elemental sulphur were added to induce the soil acidification. The soil was incubated in pots under opensky conditions. pH, sulphate, and cadmium solubility were recorded in time. Soil acidification with microbially produced sulphur proceeded without any delay and at considerably higher rates, compared to the sulphur flower. Cadmium solubilization was solely controlled by the soil pH during the experiments. Similar experiments with cultivation of common mustard (Sinapis alba, cultivar JARA) were performed, evaluating both changes of cadmium solubilization and uptake by biomass. Cadmium concentration in shoots increased with decreasing pH. However, biomass was negatively affected by the decreasing pH. Combining these two effects, a pH-optimum for maximum cadmium removal from the soil by plants was found at pH=5–5.5.     

当前植物造景中的几个问题分析及对策研究

文章就当前植物造景中存在的几个主要问题作了原因分析并提出了相应对策。     

植被过滤带的污染物去除效率研究进展

探讨植被过滤带(vegetative filter strips,VFS)污染物去除效率与VFS特征参数(长度、坡度、植被类型)、污染物特性之间的关系,归纳了计算VFS污染物去除效率的经验模型和物理模型。结果表明,VFS长度与污染物去除效率呈一定的相关关系,坡度改变对污染物去除效率无明显影响,农药的有机碳吸附系数对污染物去除效率有较大的影响;VFS去除效率经验模型可以依据VFS的长度来估算污染物质的去除效率,同时可以计算不同粒径泥沙的去除效率,针对氮、磷、农药也能估算不同去除方式(如下渗、吸附等过程)的贡献率;耦合了水文模型与污染物去除机制的物理模型也在逐步完善中,VFSMOD就是代表。未来需要加强VFS对其他面源污染物如胶体、纳米颗粒物去除效率的研究,关注VFS在流域尺度上的污染物去除效率。     

含植物河道等效床面阻力试验研究

植物广泛存在于滩地和河槽中,可有效改善水环境,但同时也增加了水流阻力。通常采用不同材料的棍状物或仿生植物模拟实际植物进行试验研究,将植物阻力附加于床面上与原床面阻力一起构成等效床面阻力,因模拟实际植物的不相似导致含植物河道等效床面阻力的研究不够完善。本文提出了对实际植物分区施加实际流速条件进行试验的思路,即按河道现场调研的植物密度布置,沿横向和垂向对河道横断面分区,对实际植物区域施加实际流速条件,试验研究分区水体中的植物阻力,最后换算得到表征等效床面阻力的等效床面糙率。以独流减河上游河道为对象,选用乔木、灌木和芦苇三种典型植物,考虑河道横断面不同分区的流速条件进行了试验,结果表明,当遭遇100年一遇洪水时,乔木种植区域的等效床面糙率为0.060～0.066,灌木种植区域的等效床面糙率为0.083～0.099,芦苇种植区域的等效床面糙率为0.698～0.989。研究成果可为防洪计算和水环境治理提供理论支持。     

Grass filter strip residence time‐trap efficiency relationship

This paper investigates the relationship between trap efficiency and residence time in vegetative filter strips under unsteady flow conditions. A mathematical model, based on a kinematic‐wave formulation of overland flow and a mass balance equation for suspended sediments, is employed. An empirical equation is used to estimate sediment removal. The governing equations are written and solved numerically in terms of a set of dimensionless variables. The results indicate that the relationships between the trap efficiency and residence time depend on the shape of the inflow hydrograph. Further analysis of results identified another non‐dimensional parameter that can predict the trap efficiency if only the volume and the peak rate of inflow are known. While the mathematical model employed includes many elements of the sophisticated vegetative filter strip models previously reported, the resulting charts are as easy to use as the oversimplified design methods currently in use