人工影响天气用碘化银催化剂对区域环境影响的研究进展

中国自1958年以来开展人工影响天气作业。碘化银作为主要的催化剂,是否会对环境造成影响备受关注。分析了国内外使用碘化银开展人工增雨雪和人工防雹外场试验作业后降水、土壤和湖泊等的Ag+含量,尽管催化后Ag+含量会有不同程度的增加,尤其是地面燃烧炉催化和人工防雹作业,但降水和水库中的Ag+含量远低于饮用水标准。统计了我国外场人工影响天气作业的碘化银用量,结合降水和水库中Ag+浓度观测,认为我国人工影响天气使用的碘化银不会对水资源和环境造成影响。     

移动Agent 在集群系统中的应用研究

从任务级的角度，在基于主／从模式的集群系统中引入了移动Agent技术，建立了基于移动Agent的并行计算模型。基于该模型，对移动Agent之间的通信接口、容错机制和负载平衡策略等问题进行了研究。     

REVIEWS OF GEOGRAPHIC SOFTWARE

Geographic Software Reviewed in this article: THE DIFFUSION GAME . Christopher J. Lovelock and Charles B. Weinberg . MAPIT . Raymond J. Kalush , Jr . SIMODEL . Peter A. Williams and A. Stewart Fotheringham . WEATHER FRONTS . P. C. Moyer . WORLD DYNAMICS . Mark Lewis Baldwin     

水流注入方式和填料层高度对人工湿地流态的影响

流态模拟实验作为评价人工净化湿地系统运行状况、物质在其中停留时间的有效工具,在污水处理领域具有重要作用。罗丹明B背景浓度低、重现性好,被选为评价升流式、降流式和填料层高度对水力流态影响的示踪剂。实验使用罗丹明B和NaCl作为示踪剂,在湿地系统中进行流态实验,探究升流式、降流式和填料层高度对人工净化湿地流态的影响。实验结果表明,升流式人工湿地比降流式人工湿地处理效果好,示踪剂水力停留时间(hydraulic retention time,HRT)的体积利用率分别为82.0%和76.8%,升流式人工湿地无效体积中死区占更大比例,而降流式人工湿地滞留区占无效体积的比例更大;人工湿地填料层高度对示踪剂停留时间分布影响不大,体积利用率都在80%以上,但是,其死区和滞留区随着填料层高度的变化在无效体积中所占的比例有所差异,死区所占的比例随着填料层高度的增加先增加后减少,滞留区所占的比例则先减少后增加。     

Effect of structure-directing agent on AlPO4-n synthesis from aluminum dross

The hydrothermal synthesis of AlPO₄-n which is a functional material of aluminophosphate, was conducted from two kinds of aluminum dross discharged in an aluminum regeneration factory. The effect of structure-directing agent (SDA) on the formation behavior of AlPO₄-n from aluminum dross, the suitable condition to obtain AlPO₄-n efficiently, and the pore structure and gas adsorption property were investigated in this study.AlPO₄-5 and AlPO₄-34 are mainly formed from aluminum dross as a raw material, and it is possible to make AlPO₄-5 successfully as a main product by adjusting the amount of triethylamine (TEA) as SDA. The gas adsorption amount with AlPO₄-5 is the following order; ammonia > dipropylamine > benzene, and it is found that this order mainly corresponds with the polarity of molecule among them.     

土壤保水剂的吸水保水性能研究动态

土壤保水剂是一种新型化学农业抗旱材料, 在干旱地区农林业生产中具有广泛的应用前景。从保水剂的吸水和保水性能方面介绍了国内外学者的研究成果。     

Genesis of the Kamioka Skarn Deposits: An Important Role of Clinopyroxene Skarn and Graphite-bearing Limestone in Precipitating Sulfide Ore

Abstract: A genetical relationship between skarn formation and mineralization is investigated for the Kamioka skarn deposits which are the largest Zn-Pb producer in Japan. In the Mozumi deposit, one of main deposits in the Kamioka mining area as well as Tochibora and Maruyama, clinopyroxene skarn was generally subjected to later replacement by garnet or magnetite–calcite–quartz during the Zn-Pb mineralization. The replacement of hedenbergitic clinopyroxene by andraditic garnet resulted in the formation of diopsidic clinopyroxene relicts. With the progress of replacement, the S/So value (So: an estimated area occupied by an original clinopyroxene grain in a thin section, S: a total area of relict clinopyroxene fragments) which is an index of the degree of replacement decreases from 0. 7 to 0. 1, and the hedenbergite mole percent of relict clinopyroxene decreases drastically from about 65 to less than 40. A close association of andraditic garnet and sphalerite suggests that heden-bergitic clinopyroxene skarn played an important role to reduce the relatively oxic ore-forming fluid enriched in Zn²⁺ and SO4^2– and to precipitate sphalerite from the fluid. Ferrous iron in the hedenbergitic clinopyroxene skarn was oxidized to form andraditic garnet. Besides this garnet formation, the mineral assemblage of magnetite–calcite–quartz replaced the clinopyroxene skarn at the time of mineralization. In both cases, the reduction of relatively oxic ore-forming fluid by hedenbergitic clinopy-roxene skarn at the later stage brought about the precipitation of sulfide minerals. In contrast, these types of later replacement are not found in the Tochibora deposit. Instead, graphite-bearing crystalline limestone and relatively fresh clinopyroxene skarn are common. Mineralized clinopyroxene skarn has high graphite carbon contents relative to barren one, suggesting that the amount of graphite in the skarn was an important controlling factor for mineralization. It is very likely that the graphite played a role of reducing agent during the mineralization in the Tochibora deposit.     

Groundwater as a geologic agent: An overview of the causes, processes, and manifestations

 The objective of the present paper is to show that groundwater is a general geologic agent. This perception could not, and did not, evolve until the system nature of basinal groundwater flow and its properties, geometries, and controlling factors became recognized and understood through the 1960s and 1970s. The two fundamental causes for groundwater's active role in nature are its ability to interact with the ambient environment and the systematized spatial distribution of its flow. Interaction and flow occur simultaneously at all scales of space and time, although at correspondingly varying rates and intensities. Thus, effects of groundwater flow are created from the land surface to the greatest depths of the porous parts of the Earth's crust, and from a day's length through geologic times. Three main types of interaction between groundwater and environment are identified in this paper, with several special processes for each one, namely: (1) Chemical interaction, with processes of dissolution, hydration, hydrolysis, oxidation-reduction, attack by acids, chemical precipitation, base exchange, sulfate reduction, concentration, and ultrafiltration or osmosis; (2) Physical interaction, with processes of lubrication and pore-pressure modification; and (3) Kinetic interaction, with the transport processes of water, aqueous and nonaqueous matter, and heat. Owing to the transporting ability and spatial patterns of basinal flow, the effects of interaction are cumulative and distributed according to the geometries of the flow systems. The number and diversity of natural phenomena that are generated by groundwater flow are almost unlimited, due to the fact that the relatively few basic types are modified by some or all of the three components of the hydrogeologic environment: topography, geology, and climate. The six basic groups into which manifestations of groundwater flow have been divided are: (1) Hydrology and hydraulics; (2) Chemistry and mineralogy; (3) Vegetation; (4) Soil and rock mechanics; (5) Geomorphology; and (6) Transport and accumulation. Based on such a diversity of effects and manifestations, it is concluded that groundwater is a general geologic agent. Received, December 1998 · Revised, January 1999 · Accepted, January 1999     

Contributions of groundwater conditions to soil and water salinization

 Salinization is the process whereby the concentration of dissolved salts in water and soil is increased due to natural or human-induced processes. Water is lost through one or any combination of four main mechanisms: evaporation, evapotranspiration, hydrolysis, and leakage between aquifers. Salinity increases from catchment divides to the valley floors and in the direction of groundwater flow. Salinization is explained by two main chemical models developed by the authors: weathering and deposition. These models are in agreement with the weathering and depositional geological processes that have formed soils and overburden in the catchments. Five soil-change processes in arid and semi-arid climates are associated with waterlogging and water. In all represented cases, groundwater is the main geological agent for transmitting, accumulating, and discharging salt. At a small catchment scale in South and Western Australia, water is lost through evapotranspiration and hydrolysis. Saline groundwater flows along the beds of the streams and is accumulated in paleochannels, which act as a salt repository, and finally discharges in lakes, where most of the saline groundwater is concentrated. In the hummocky terrains of the Northern Great Plains Region, Canada and USA, the localized recharge and discharge scenarios cause salinization to occur mainly in depressions, in conjunction with the formation of saline soils and seepages. On a regional scale within closed basins, this process can create playas or saline lakes. In the continental aquifers of the rift basins of Sudan, salinity increases along the groundwater flow path and forms a saline zone at the distal end. The saline zone in each rift forms a closed ridge, which coincides with the closed trough of the groundwater-level map. The saline body or bodies were formed by evaporation coupled with alkaline-earth carbonate precipitation and dissolution of capillary salts. Received, May 1998 · Revised, July 1998 · Accepted, September 1998     

水性多彩涂料的制备工艺研究

阐述了改性聚乙烯醇胶水的制备工艺,并以此作彩粒成型剂,应用羟乙基纤维素———膨润土复合增稠剂作抗沉剂和稳定剂,与苯丙乳液等成膜剂、无机颜料等制成无毒、阻燃的水性多彩涂料。