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苑鹏 《国际沙棘研究与开发》2016,(6)
本文根据水源地水文地质条件,结合抽水试验数据资料,确定该区域含水层平均厚度、单井涌水量、渗透系数、影响半径及水力坡度等水文地质参数,采用水均衡法计算地下水资源量,分析补给量与排泄量平衡情况,采用开采系数法确定地下水可开采量,并分析区域地下水位动态变化趋势. 相似文献
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水文地质参数是地下水数值模拟中重要的参数,通过抽水试验进行水文地质参数的反演,用一个复杂的非线性优化问题来描述,由于传统方法如图解法等因人为因素造成计算结果精度低。利用鱼群算法良好的全局搜索能力和模拟退火较强的局部寻优能力相结合的混合算法反演含水层参数。实例证实,混合算法计算结果比传统方法计算结果更可靠、精度更高,反演的参数代入泰斯公式后计算降深值符合实际降深值,与人工鱼群算法相比,运行更短,计算效率更高,是一种求解出含水层参数的简单、有效的方法。 相似文献
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以泰斯公式为基础,提出了一种分析非稳定流抽水试验数据,确定含水层导水系数和弹性释水系数的新方法。不同于Jacob-Cooper直线图解法的简化方式,而是取泰斯井函数级数展开式的前三项作为井函数的近似表达式。以这样的简化方式而提出的改进直线解析法,在满足与Jacob-Cooper直线图解法相同计算精度的条件下,要求无量纲变量的值 u<0.2 或u<1.0。显然,这样的条件较Jacob-Cooper直线图解法要求的u<0.01 或u<0.05更易得到满足。最后,通过实例说明了方法的具体步骤,并对方法的适用性进行了初步讨论。 相似文献
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以泰斯公式为基础,提出了一种分析非稳定流抽水试验数据,确定含水层导水系数和弹性释水系数的新方法.不同于Jacob-Cooper直线图解法的简化方式,而是取泰斯井函数级数展开式的前三项作为井函数的近似表达式.以这样的简化方式而提出的改进直线解析法.在满足与Jacob-Cooper直线图解法相同计算精度的条件下,要求无量纲变量的值u<0.2或u<1.0.显然.这样的条件较Jacob-Cooper直线图解法要求的u<0.01或u<0.05更易得到满足.最后,通过实例说明了方法的具体步骤,并对方法的适用性进行了初步讨论. 相似文献
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刘伟才 《国际沙棘研究与开发》2017,(2)
在沧州市规划区西北部将要开发的龙岸清华小区开凿了一组共9眼浅层地下水井,用抽水试验的方法确定抽水井和建筑物的安全距离.通过实验发现在试验区特定的水文地质条件下,单井抽水的最大影响半径为55.1m;结合以往资料确定抽水井距离建筑物的安全距离为大于18m. 相似文献
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应用有限差分法,对承压地下水非稳定流进行计算,并对承压地下水中的各主要水文地质参数进行专门的敏感性分析研究,得出各种参数对地下水水头变化的影响的非一致性的结论. 相似文献
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应用有限差分法,对承压地下水非稳定流进行计算,并对承压地下水中的各主要水文地质参数进行专门的敏感性分析研究,得出各种参数对地下水水头变化的影响的非一致性的结论。 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献