Water and heat transport in hilly red soil of southern China: Ⅱ. Modeling and simulation

Simulation models of heat and water transport have not been rigorously tested for the red soils of southern China.Based on the theory of nonisothermal water-heat coupled transfer, a simulation model, programmed in Visual Basic 6.0, was developed to predict the coupled transfer of water and heat in hilly red soil. A series of soil column experiments for soil water and heat transfer, including soil columns with closed and evaporating top ends, were used to test the simulation model. Results showed that in the closed columns, the temporal and spatial distribution of moisture and heat could be very well predicted by the model,while in the evaporating columns, the simulated soil water contents were somewhat different from the observed ones. In the heat flow equation by Taylor and Lary (1964), the effect of soil water evaporation on the heat flow is not involved, which may be the main reason for the differences between simulated and observed results. The predicted temperatures were not in agreement with the observed one with thermal conductivities calculated by de Vries and Wierenga equations, so that it is suggested that Kh, soil heat conductivity, be multiplied by 8.0 for the first 6.5 h and by 1.2 later on. Sensitivity analysis of soil water and heat coefficients showed that the saturated hydraulic conductivity, Ks, and the water diffusivity, D(θ), had great effects on soil water transport; the variation of soil porosity led to the difference of soil thermal properties, and accordingly changed temperature redistribution,which would affect water redistribution.     

Study of cellulolytic soil fungi and two nova species and new medium

This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under sterilized conditions and incubated at 30 ℃ for 4 to 7 d. The identified fungal species were incubated in self-designed cellulose medium for testing their cellulolytic ability. Forty-two species, including2 nova species, representing sixteen genera showed growth and sporulation in the cellulose medium. Most of the isolated species were from genus Aspergillus and Penicillium. Aspergillus niger and Mucor hiemalis showed highest occurrence frequency （45% and 36% respectively）, as these species were collected from about 80% of soil samples. Being agar free and cheaper, the new fungal medium designed showed results equivalent to Sabouraud medium.     

三明市区水土流失与环境整治

随着城市化进程的不断加快,城市水土流失问题日趋严重,城市更需要水土保持。福建是南方水土流失较严重的地区,该文对南方山区城市水土流失的环境特征、成因、特点及对城市环境的危害进行了探讨,并在此基础上提出了防治对策与建议。     

甲醇装置主精馏塔侧壁腐蚀的修复及防腐措施

本文主要讲述甲醇装置主精馏塔侧壁腐蚀的修复方法和防腐措施.     

重建土壤水库是黄土高原治本之道

基于黄土高原严重的生态环境问题,在分析黄土高原成因机理及结构特点基础上,探讨了黄土高原“土壤水库”的功能,研究了地表水库、土壤水库、地下水库三库协防在治理黄土高原环境方面的重要作用。结果表明,应将重建土壤水库,实现三库协防,作为构建和谐黄土高原,再现秀美山川的理论依据和指导方针,而地表径流调控与水土资源持续利用技术研究,可为黄土高原国土整治“28字方略”理论实现提供重要的技术支撑。     

水土保持经济效益计算方法研究─-以铁瓦河小流域为例

遵循《水利建设项目经济评价规范》（ＳＬ７２-９４）及《水土保持综合治理效益计算方法》（ＧＢ／Ｔ１５７７４─１９９５）,以铁瓦河小流域水土保持工程为例,研究水土保持直接经济效益计算方法,得出的结果符合铁瓦河小流域实际情况,与一般规律是相吻合的,表明铁瓦河小流域的直接经济效益是显著的。     

特殊类型土的固化研究

根据膨胀土和砂质粘上的结构特点与理化性质,调整粉状固化剂的组成与配比,采用新型固化剂,使固化土稳定强度大幅度提高膨胀土24h快速养护浸水后强度为2.45～2.95MPa,而砂质粘土为4．24～4.45MPa．     

三种禾亚科植物在南方水蚀荒漠地区的适应性比较

研究类芦、斑茅、芭芒三种禾亚科植物在福建省长汀县河田镇朱溪河流域水蚀荒漠区生长情况,结果表明：类芦生长最好,全年均有一定的生长,进入冬季,其生长量还占全年生长量的25．3%．与斑茅和芭芒相比,类芦地上部分叶鲜重分别高20．97和70．51％,且根系分布最深,深度可达180cm以上,各层根系分布均匀,但物候期与其他两种植物相比无明显差异．因此,类芦在该区域有很好的适应性,可应用于该区域的水蚀荒漠化治理．     

应力历史和含水率对滑带土抗剪强度特性的影响分析

滑带土是滑坡土体的重要组成部分,滑带土的强度特性是分析滑坡稳定性重要前提。边坡滑带土的强度特性受多种因素的影响,正确分析各种影响因素对选择合理的强度特性指标具有重要意义。本文通过某潜在土层滑移带的现场取样,首先采用室内试验得到滑带土的物理力学性质,然后分析应力历史和含水率对滑带土抗剪强度的影响。经过分析得到滑带土的应力-应变关系具有应变硬化特征;土样的抗剪强度指标值随着先期固结压力增大而增大;含水率增大会导致土样的抗剪强度降低。     

土壤固化剂研究进展

综述了土壤固化剂研究进展;介绍了四类土壤固化剂的特点;详述了土壤固化剂的机理;展望了高性能土壤固化剂的发展方向和应用前景;指出了高分子化合物辅以无机化合物类土壤固化剂是其研究的方向。