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171.
William E. Sopper L. A. V. Hiemstra 《Journal of the American Water Resources Association》1970,6(5):754-766
A mathematical model was developed to simulate the hydrologic behavior of five small watersheds in central Pennsylvania. Continuous hydrographs for the 6-month period, April to September 1964, were simulated. Synthesized rainfall cycles consisting of increasing rainfall by 10, 20, and 30 percent to simulate the effects of cloud seeding were processed through the watershed model to determine the effects on low flow augmentation. Other rainfall cycles used consisted of increasing every third storm by 30 percent and of developing a rainfall cycle by processing daily radiosonde data through a mathematical cumulus cloud model to obtain a prediction of rainfall following seeding. A comparison of actual and predicted hydrographs indicated that simulated cloud seeding resulted in significant monthly and seasonal water yields. In general, the results of the study appear to indicate that on a theoretical basis cloud seeding would be a feasible method of augmenting low stream-flow during the summer months on watersheds in the northern Appalachian region. 相似文献
172.
Edward H. Seely Donn G. DeCoursey 《Journal of the American Water Resources Association》1975,11(2):365-369
ABSTRACT: Weather modification is being proposed as a routine method of augmenting agricultural water supplies in the Southern Great Plains. This paper discusses some of the potential hydrologic impacts of weather modification. Previous work in assessing hydrologic impact is covered; the conclusion is drawn that the work is insufficient. An approach based on hydrologic models is suggested that can consider uncertainties about the effect of weather modification on rainfall and some uncertainties about the effect of model error on impact conclusions. 相似文献
173.
David R. De Walle Albert Rango 《Journal of the American Water Resources Association》1972,8(4):697-703
ABSTRACT. Stream channel characteristics were found to be useful indices to the hydrology of 27 small forested basins in the Northeast United States. Channel width alone explained 37 percent of the variation in mean annual runoff, whereas channel width combined with basin area explained 78 percent of the variation in mean annual runoff. This approached the percentage of variation in mean annual runoff explained by mean annual precipitation (83 percent). A simulated 15% increase in precipitation, such as might occur in a weather modification project, produced increases in channel width, depth, and channel area of 3, 4, and 8 percent, respectively. 相似文献
174.
针对聚合硫酸铁碱化度的国标测定方法提出了一点改进,扩大了碱化度的测定范围,使其适合于某些碱化度较高或铁含量较高的聚铁样品的测定。改进之处在于先加入较多量的盐酸分解试样,用氟化钾掩蔽Fe3+后,再加入定量的NaOH溶液中和部分多余的酸,最后用较稀(01mol/L)的NaOH溶液滴定至终点。 相似文献
175.
Sean?A.?WeaverEmail author Michael?C.?Morris 《Journal of Agricultural and Environmental Ethics》2005,18(2):157-189
We present an annotated bibliography of peer reviewed scientific research highlighting the human health, animal welfare, and environmental risks associated with genetic modification. Risks associated with the expression of the transgenic material include concerns over resistance and non-target effects of crops expressing Bt toxins, consequences of herbicide use associated with genetically modified herbicide-tolerant plants, and transfer of gene expression from genetically modified crops through vertical and horizontal gene transfer. These risks are not connected to the technique of genetic modification as such, but would be present for any conventionally produced crops with the same heritable traits. In contrast, other risks are a direct consequence of the method used in gene manipulation. These come about because of the unstable nature of the transgene and vectors used to insert it, and because of unpredictable interactions between the transgene and the host genome. The debate over the release of genetically modified organisms is not merely a scientific one; it encompasses economics, law, ethics, and policy. Any discussion on these levels does, however, need to be informed by sound science. We hope that the scientific references provided here will provide a useful starting point for further debate. 相似文献
176.
Soybean protein has been considered as a potential biodegradable polymer in the manufacture of plastics. The purpose of this investigation was to characterize the effect of storage time on thermal and mechanical properties of soybean protein isolate (SPI) plastics. SPI was separated from defatted soy flour, modified with 1M or 2M urea, or plasticized with glycerol, and compression molded into plastics. Plastic made from SPI alone was used as a control. For all SPI plastics, glass transition temperatures and dynamic storage modulus increased and loss tangent decreased during storage. Excess enthalpy of relaxation of all SPI plastics had an exponential relationship with storage time, indicating a fast aging rate at the beginning of storage. All SPI plastics tended to be stiff and brittle during storage. The plastics with glycerol had the slowest aging rate and were fairly stable after 60 days, with about 8.8 MPa tensile strength and 168% strain at break. Plastics with the 2M urea-modification SPI also had a slow aging rate and became relative stable after 60 days, with about 10 MPa tensile strength and 72% elongation. 相似文献
177.
寒冷地区化粪池具有水温低,处理效果差的特点,针对哈尔滨市幸福家园化粪池的水质情况进行了研究,为化粪池的改造和优化提供依据,并对化粪池问题和技术进行探讨。在化粪池前后的检查井处进行取样,每隔1个小时取一个样,总共取24小时,然后对CODtot、CODss、CODcol、CODdis、NH3-N、总氮、总磷、SS、VSS、pH、水温进行测定。水温在14~17度下,平均去除率分别是16.9%、47.2%、26.4%、-49.1%、-39.3%、7.5%、12.4%、59.3%和59.5%,可见,污水的可生化性有明显提高,但是对污染物的去除作用不大。研究结果对于全面评价寒冷地区化粪池的功能特征,进而为化粪池的取舍和改造提供技术的参考依据。 相似文献
178.
179.
铁-镍交联改性膨润土的制备及应用 总被引:1,自引:1,他引:0
以钠基膨润土为原料,制备了铁-镍无机交联、铁-镍有机交联系列改性膨润土,比较了二者对废水的COD、色度、浊度和废水中Cr^6+的去除效果;考察了改性嘭润土加入量、pH、搅拌时间等因素对实验结果的影响。结果表明,铁-镍有机交联改性嘭润土对Cr^6+的去除效果明显好于铁-镍无机交联改性膨润土,对COD的去除效果略好于铁-镍无机交联改性膨润土;铁-镍无机交联改性膨润土对废水浊度的去除效果略好于铁-镍有机交联改性膨润土;二者对色度的去除效果相当。吸附行为符合Langmuir方程。 相似文献
180.