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71.
乌鲁木齐河流域地下水水质监测网设计 总被引:1,自引:0,他引:1
文章运用地下水易污性编图及污染源分布图法进行了乌鲁木齐河流域地下水水质监测网设计。共设计了130监测孔,现有46个监测孔,另需要84个新的监测孔。按监测类型分为面源监测点22个,点源监测点87个,重点水源地与泉水监测点21个。按监测运行分长期监测点55个,流域普查监测点75个。普查监测点监测频率为1次/5年,长期监测点监测频率为1次/年。首期有针对性地在污染严重的柴窝堡新化厂排污区、乌鲁木齐河谷老排污区、米泉污灌区、米泉工业污染区、老龙河污染区取了25个污染水样测试分析,结果显示地下水已经受到严重污染。 相似文献
72.
旋转轴套在超深井工作时,其井下流动是三维湍流流动,旋转轴套的旋转和表面曲率效应以及随之而来的哥氏力和离心力,使流场在超深井的流动中极其复杂,同时,由于流体介质泥浆属于液固两相流,更致使内部流场测试困难,而且超深井中的工况在使用常规方法已很难得到较准确的数据。为此,将计算流体力学软件Fluent应用于超深井下流场的模拟,基于Navier-Stokes方程和Reynolds应力方程模型,建立多种仿真模型,在相同条件下,使用CFD仿真软件Fluent模拟仿真的不同结果,优化与旋转轴套叶片设计相关的几何参数,提高 相似文献
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76.
鲁中南隆起区第四纪晚期断裂活动特征 总被引:6,自引:1,他引:6
根据野外调查,并综合前人的研究资料,对鲁中南地区第四纪晚期断裂活动进行了分析,研究表明,鲁中南隆起区第四纪断裂活动具有时空不均匀性,主要表现为第四纪时期断层活动强度变化和断裂活动的群集性以及第四纪晚期断裂活动段分布的局限性上。对于鲁中南地区而言,活动断层可以分为中更新世中期(500kaBP)至晚更新世初期(90kaBP)活断层和晚更新世中、晚期至全新世早期活断层两类;其中前一类(主要是中更新世断裂)断裂数量较多,分布较为广泛,而晚更新世晚期以来的活动断裂段的数量较少,分布较局限。它们对地震的控制能力不同,前者可控制5.5级左右的地震,而后一类可控制6-7级地震的发生。 相似文献
77.
R.F. Lee B. Dornseif F. Gonsoulin K. Tenore R. Hanson 《Marine environmental research》1981,5(2):125-143
Addition of a heavy oil to a Spartina salt marsh in the autumn resulted in high concentrations of polycyclic aromatic hydrocarbons in sediment and benthic animals. The highest concentrations of phenanthrene, chrysene and fluoranthene in the sediment were 112, 105 and 75 ng/g sediment, respectively. These concentrations rapidly decreased during the 20 week period following the spill. The times for these hydrocarbons to decrease to 50% of their highest values, i.e. half-life, were approximately 100, 70 and 30 days in sediment, mussels and oysters, respectively. Benthic macrofauna species showed three responses to oil addition which included no change, an increase, or a decrease in the population. No changes were noted in populations of fiddler crabs (Uca pugnax), oysters (Crassostrea virginica), and mussels (Modiolus demissus). Mud snails (Nassarius obsoleta) increased in density after the spill due to immigration of adult snails from untreated areas to scavenge on animals killed by the oil. Many of the adult periwinkles (Littorina irrorata) were killed by the oil. In the spring, juvenile periwinkles recolonised to oiled areas as a result of larvae settling. 相似文献
78.
Lee Shugart 《Marine environmental research》1988,24(1-4)
This paper reports a rapid and facile procedure for obtaining of DNA from small, whole aquatic organisms (fathead minnow, Pimephales promelas) as well as from the liver of another species (bluegill sunfish, Lepomis macrochirus) and the subsequent estimation of its double strandedness. DNA was isolated from various tissues by homogenization in a basic pH solution containing detergent followed by differential extraction using organic solvents. Additional purification was accomplished by molecular sieve chromatography. Under defined alkaline unwinding conditions, the amount of double-stranded and single-stranded DNA was determined using the bisbenzimidazole dye Hoechst 33258. The technique was used to detect the occurrence of strand breaks in DNA of fathead minnows chemically exposed to benzo[a]pyrene. 相似文献
79.
By analysing the scatter diagrams of characteristic the wave height H and the period T on the basis of instrumental data from various ocean wave stations, we found that the conditional expectation and standard deviation of wave period for a given wave height can be better predicted by using the equations of normal linear regression rather than by those based on the log- normal law. The latter was implied in Ochi' s bivariate log-normal model(Ochi. 1978) for the long-term joint distribution of H and T. With the expectation and standard deviation predicted by the normal linear regression equations and applying proper types of distribution, we have obtained the conditional distribution of T for given H. Then combining this conditional P(T / H) with long-term marginal distribution of the wave height P(H) we establish a new parameterized model for the long-term joint distribution P(H,T). As an example of the application of the new model we give a method for estimating wave period associated with an extreme w 相似文献
80.
In this study, we investigate two internal wave generation methods in numerical modeling of time-dependent equations for water wave propagation, i.e., delta source function method and source term addition method, the latter of which has been called the line source method in literatures. We derive delta source functions for the Boussinesq-type equations and extended mild-slope equations. By applying the fractional step splitting method, we show that the delta source function method is equivalent to the source term addition method employing the energy velocity. This suggests that the energy velocity should be used rather than the phase velocity for the transport of incident wave energy in the source term addition method. Finally, the performance of the delta source function method is verified by accurately generating nonlinear cnoidal waves as well as linear waves for horizontally one-dimensional cases. 相似文献