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71.
工业用水优化配置模型研究   总被引:2,自引:0,他引:2  
探讨了工业部门内部水资源优化配置理论与方法,建立了水资源优化配置经济效益模型。在此基础上,深入研究了经济效益、社会效益、环境效益、水资源的可持续利用及其与国民经济、社会的协调发展等因素对水资源优化配置的影响。通过对上述影响因素的分析,给出了工业内部各行业综合影响系数的计算公式,建立了水资源优化配置综合效益数学模型。以山东省高密市为例,在收集分析了各行业的用水量、产值、利税等基本资料的基础上,以每个行业的历史用水量为样本,采用数理统计的方法推求出行业需水量上、下限,并利用综合效益模型,以1989年7月这一最枯月份为例,对工业内部各行业进行水资源重分配,结果比较符合实际情况。  相似文献   
72.
Eddy fluxes of CO2, water vapor,and sensible heat over a deciduous forest   总被引:12,自引:0,他引:12  
Fluxes of CO2, latent heat and sensible heat were measured above a fully-leafed deciduous forest in eastern Tennessee with the eddy correlation technique. These are among the first reported observations over such a surface. The influences of solar radiation, vapor pressure deficit and the aerodynamic and canopy resistances on these mass and energy exchanges are examined. Following a concept introduced by McNaughton and Jarvis (1983), examination of our data suggest that the water vapor exchange of a deciduous forest is not as strongly coupled with net radiation as is that of agricultural crops. The degree of decoupling is smaller than in the case of a coniferous forest. This difference may be attributable in part to the greater aerodynamic resistance to water vapor transfer in a deciduous forest. It appears that the concept of decoupling may be extended to the CO2 exchange of a deciduous forest as well.Published as Paper No. 7832, Journal Series, Nebraska Agricultural Research Division. ATDD Contribution No. 85-17.  相似文献   
73.
SPOT5卫星影像在土地变更调查中的应用   总被引:1,自引:0,他引:1  
SPOT5因为具有很高的分辨率,在土地变更调查中有着广泛的应用。对于不同的用地类型,SPOT5的分辨能力也不同,本文利用SPOT5影像室内判读发现的变化图斑与实际变化情况进行对比,介绍了SPOT5卫星影像在北京大兴区土地变更调查实际应用中的具体方法。  相似文献   
74.
Experimental Investigations on Laminated Rubber Bearings   总被引:1,自引:0,他引:1  
Increasing application of base isolation as a seismic protection method has subsequently increased its analytical and experimental studies. Being the most critical part of the base isolated buildings, accurate evaluation of structural properties and precise modeling of isolation devices is of utmost importance in predicting the response of the buildings during the earthquakes. This technical note is concerned with experimental study on laminated rubber bearings. Free vibration and harmonic base excitation tests are performed on a three-storey building model to evaluate the properties of the structure, efficiency of the system, and effect of base excitations. It is found that these experimental methods can effectively be used for this purpose.  相似文献   
75.
The Hydrobios in Dongping Lake, Shandong Province, mainly includes phytoplankton, zooplankton, benthic animals, fishes and hydrophytic vascular plants. Nitrogen and phosphorus are the restrictive factors for the growth and propagation of hydrophyta, therefore the key to the prevention and control of eutrophication in lakes lies in the control of the contents of the two elements in the water. Artificial fishing of algae can reduce the concentrations of trophic substances such as nitrogen and phosphorus in the water bodies, and biological measures may decrease the contents of these trophic substances in the bottom sediments and the water bodies, thereby playing an active role in modifying the eutrophication of the lake.  相似文献   
76.
The present investigation evaluates the adsorption effectiveness of Cd(II) ions on Ficus religiosa leaf powder (FRL). The experimental parameters chosen included time, pH, particle size, temperature, adsorbate, anion, and Pb(II) concentrations. The time data followed pseudo‐second‐order kinetics. Cd(II) adsorption increased from 1.38 to 75.17% with the increase in pH from 2 to 4 and further increase in pH to 5.5 resulted in its marginal increase to 77.52%. Based on regression coefficient values, the isothermic data fitted the various models in the order Langmuir > Redlich–Peterson > Temkin > Freundlich model. The maximum loading capacity of FRL was estimated to be 27.14 mg g?1. The presence of Cl?, , or Pb2+ exhibited adverse effect on Cd(II) uptake. The thermodynamic parameters of enthalpy (ΔH0) and entropy (ΔS0) were estimated to be 8.31 kJ mol?1 and 38.22 J mol?1 K?1, respectively. SEM‐EPMA of the loaded FRL showed Cd(II) distribution at specific sites. The XRD patterns of Cd(II) loaded FRL sample showed disappearance of some peaks corresponding to β‐Ca(PO3)2; shifting of peaks and decrease in %RI corresponding to γ‐CaSO4 phase. Positive shift of IR bands for the Cd(II) loaded sample was observed.  相似文献   
77.
基于改进的地表温度-植被覆盖特征空间估算地表蒸散   总被引:1,自引:0,他引:1  
地表温度-植被指数特征空间被广泛应用与地表蒸散估算和土壤湿度监测,而利用散点图直接拟合干边会造成很大的不确定性。本研究采用改进的地表温度-植被覆盖特征空间进行地表通量的计算。该方法是基于能量平衡公式进行干边定位,从而减少干边确定过程中的不确定性。我们选取的17天的MODIS数据以及相应气象数据进行地表蒸散计算,并采用郑州的LAS观测站验证显热通量计算值,估算结果均方根误差(RMSE)、偏差(Bias)和相关系数平方(R^2)分别为44.06Wm^-2、36.99Wm^-2和0.71。总体来讲,通过能量平衡公式确定的理论干边相比通过散点图拟合的实测干边更合理。  相似文献   
78.
The resolution of self-potential anomalies due to closely spaced multiple sheet-like bodies by the potential difference and potential gradient is studied in this paper. Self-potential anomalies due to several synthetic models were inverted through a very fast simulated annealing (VFSA) global optimization. Increase in depth to the top, polarization constant and depth extent of the body decreases resolution at a particular target separation. It has been observed that depth to the top and separation between two targets play an important role in the resolution. Vertical sheets at equal depth can be resolved in the potential difference measurement only if they are separated by at least four times their depth, while they can be resolved in the gradient method, if they are separated by twice the depth. Resolution using potential difference becomes more difficult for dipping sheets, although the potential gradient method can resolve them efficiently. Efficacy of potential gradient data in the inversion is demonstrated in the study using synthetic data as well as field measurement from South Purulia Shear Zone related with uranium investigation.  相似文献   
79.
Recent studies, using OGLE data for LMC Cepheids in the optical, strongly suggest that the period–luminosity (PL) relation for the Large Magellanic Cloud (LMC) Cepheids shows a break or non-linearity at a period of 10 d. In this paper we apply statistical tests, the chi-squared test and the F -test, to the Cepheid data from the MACHO project to test for a non-linearity of the V - and R -band PL relations at 10 d, and extend these tests to the near-infrared ( JHK -band) PL relations with 2MASS data. We correct the extinction for these data by applying an extinction map towards the LMC. The statistical test we use, the F -test, is able to take account of small numbers of data points and the nature of that data on either side of the period cut at 10 d. With our data, the results we obtained imply that the VRJH -band PL relations are non-linear around a period of 10 d, while the K -band PL relation is (marginally) consistent with a single-line regression. The choice of a period of 10 d, around which this non-linearity occurs, is consistent with the results obtained when this 'break' period is estimated from the data. We show that robust parametric (including least-squares, least absolute deviation, robust regression) and non-parametric regression methods, which restrict the influence of outliers, produce similar results. Long-period Cepheids are supplemented from the literature to increase our sample size. The photometry of these long-period Cepheids is compared with our data and no trend with period is found. Our main results remain unchanged when we supplement our data set with these long-period Cepheids. By examining our data at maximum light, we also suggest arguments as to why errors in reddening are unlikely to be responsible for our results. The non-linearity of the mean V -band PL relation as seen in both of the OGLE and the MACHO data, using different extinction maps, suggests that this non-linearity is real.  相似文献   
80.
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