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However, in many practical situations, a manager may control processing time by reallocating resources.


Biorefinery based on biomass resources is an important approach for the oil refining and petrochemical industry to achieve sustainable development.


Two types of biorefinery suitable for China's biomass resources are presented in this paper.


It is recognized throughout history that understanding the properties of resources and transforming these resources into products are regarded as the nucleus of science and technology.


A novel bandwidth allocation strategy along with a connection admission control technique was proposed to improve the utilization of network resources.

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 Water regulation or control by storage capacities is often one of the main water resource problems. The hydrologic magnitude has a significant stochastic component, the theory of probability and statistics may be applied to determine the probability of water supply, and mean water deficit, surplus in a reservoir of the annual flow regulation, that is, the increase of low flows from water stored partly during flood seasons. In the first part, this paper discusses the probability of the annual flow... Water regulation or control by storage capacities is often one of the main water resource problems. The hydrologic magnitude has a significant stochastic component, the theory of probability and statistics may be applied to determine the probability of water supply, and mean water deficit, surplus in a reservoir of the annual flow regulation, that is, the increase of low flows from water stored partly during flood seasons. In the first part, this paper discusses the probability of the annual flow regulation. In the second part, this paper develops a method of calculation of the mean water deficit, and surplus of the annual flow regulation. It starts with the following formula where Kεp may be determined by the probability distribution function F (Kε), For detailed discussion of these formulas see references[ 1] ,[2] . Then equations of the mean water surplus and deficit are given as  水库的水量调节，是开发水利资源的重要问题之一。水文量具有明显的随机成分，可以应用概率论与数理统计来确定年调节水库供水概率、不足水量与多用水量的多年平均值。 本文的第一部分论述了年调节水库供水的概率或保证率。 本文第二部分建议确定年调节水库不足与多用水量多年平均值的计算方法。按著者在文献［１］中所推导的公式（１）出发式中 Ｋεｐ。可由Ｆ（Ｋε）的概率分布函数确定（对上述公式的导出与讨论可参阅参考文献（１）、（２））。 得到计算年调节水库多年平均多用水量与不足水量的公式：（４）  This paper deals with the reasonably planning of irrigation and water power systems. In both the general arrangement and the determination of the size of drop fall, it should be considered to generate electric energy as much as possible in order to make full use of water resources, on the premise of meeting needs of irrigation. If pump stations are installed in such systems, great effect on saving energy will be produced. In this paper, the problem of dividing a river into stages is also discussed.  本文讨论灌溉发电系统的合理规划问题.无论在总体布置中,还是在决定跌水高差时,均在满足灌溉要求的同时,做到尽可能多发电能,充分利用水资源.灌溉发电系统中加入抽水站,有明显的节能效果.文中还讨论了灌溉发电系统的划分梯级问题.  This paper deals with the preliminary experimental study of drag reduction by adding minute quantity of polyacrylamide, a watersoluble longchain high molecular polymer, into tube flow of clear water and muddy water. Tests were performed in two tubes of inside diameters of 0.682 and 0.798 cm respectively. The mean grain diameters d_(50) of suspended sediment are 0.0052 and 0.0185 mm respectively. The consistency of polymer in the flow is 5100 ppm. Data measured from tests in clear water agrees with von Karman's... This paper deals with the preliminary experimental study of drag reduction by adding minute quantity of polyacrylamide, a watersoluble longchain high molecular polymer, into tube flow of clear water and muddy water. Tests were performed in two tubes of inside diameters of 0.682 and 0.798 cm respectively. The mean grain diameters d_(50) of suspended sediment are 0.0052 and 0.0185 mm respectively. The consistency of polymer in the flow is 5100 ppm. Data measured from tests in clear water agrees with von Karman's drag equation for turbulent flow in smooth tube. The rule of drag variation, conditions of drag reduction and the relation between drag reduction effect and the related parameters for flow of clear water and muddy water with polymer additives are presented in the paper. The effect of drag reduction increases with the consistency of polymer and the flow velocity. The maximum drag reduction is up to 71% for clear water and 39％ for muddy water which is less than that for clear water under the same test condition. The effect of drag reduction decreases as the concentration of sediment in muddy water increases, and the effect of sediment grain size on drag reduction is not obvious. The drag equation (4)for clear water flow with polymer addi tives (1/f~(1/2))_p=4log(Re_1f(1/2)_p0.4+A (4) is presented in the paper, This equation conforms with the experimental results on the whole. For muddy water flow with polymer additives, not only the drag force decreases, the critical velocity also decreases. When the concentration of muddy water S_v=20％, the critical velocity V_D decreases about 30％, thus the flow characteristics and the economic index of muddy water flow will be improved. This is of great importance for the long distance transportation of sediment and the full use of water and sediment resources.  本文简述了在特制装置内,对清水及浑水管流中添加微量水溶性长链型高分子聚合物聚丙烯酰胺的方法来降低摩阻损失进行了初步试验研究。关于聚合物减阻的理论及试验研究是一个相当广泛而又重要的课题。文中首先介绍了清水聚合物流减阻条件、阻力变化规律及减阻效果与流速及聚合物浓度的关系,并提出清水聚合物流阻力表达式(4),该式与试验结果大体相符;继而着重介绍了浑水聚合物流减阻效应,并讨论了减阻效果与流速、聚合物浓度、悬沙粒径及浑水浓度等基本参数之间的关系。浑水聚合物流不但使阻力大幅度下降,同时临界流速也显著减小,从而改善了浑水流动特性和经济指标。对泥沙长距离输送、充分利用水沙资源有很大意义。   << 更多相关文摘 
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