Flow Depletion of Semipervious Streams Due to Pumping

Expressions for the rate and volume of flow depletion of semipervious streams due to pumping are presented in computationally simple forms. Analytical expressions have been proposed to take into account both partial penetration and semipervious bed and banks of the stream. Graphs suitable for engineering applications are presented for siting wells, and the effect of an intermittent pumping cycle on the rate and volume of stream flow depletion has also been discussed. The exclusive volume of flow depletion during a cycle is shown to vary with the selection of the end of the cycle.     

Flow Depletion of Semipervious Streams Due to Unsteady Pumping Discharge

Analytical expressions for rate and volume of flow depletion of semipervious streams due to sinusoidal variation in pumping rate are obtained. An analytical but approximate method is developed for obtaining the rate and volume of stream flow depletion due to arbitrary unsteady pumping discharge. The method uses the ramp kernel and convolution. The use of ramp kernels permits linear interpolation between two consecutive discretized discharge values. The analytical equations for the ramp kernels for the rate and volume of stream flow depletion are derived. The proposed method is applicable for homogeneous and isotropic aquifers that are hydraulically connected to streams.     

新时期企业档案馆馆员的素质要求

信息技术时代,社会信息需求的激增和丰富的信息资源,有助于档案馆发展的积极因素.馆员是促进这两个因素有效结合,发挥档案馆信息中心的作用的关键因素.科学提升馆员素质,促进档案馆的发展至关重要.文章针对信息时代档案馆发展形势,分析新时代馆员素质的基本责任、素质要求,并结合馆员素质现状,力求得出提高馆员素质的有效途径.     

Rapid Calculation of Oxygen in Streams: Approximate Delta Method

The “approximate delta method” is a simple procedure for simultaneous calculation of the stream reaeration coefficient, primary production rate, and respiration rate from a single-station stream diurnal profile of dissolved oxygen (DO). It approximates the exact graphs of results for the “delta method” reported in 1991 by Chapra and Di Toro by means of simple logistic curve-fitting approximations. The necessity of reading graphs or of obtaining numerical solutions is thereby avoided, so making it suitable for inclusion in a decision support system, particularly for streams reaeration coefficients less than 10?day?1 and for moderate photoperiods (10–14?h). Worked examples are given for streams in the USA and in New Zealand. Results are used to show that the constellation of parameters for the three fundamental processes is much more important than their individual values in calculating diurnal DO profiles. Independent measurement of the reaeration coefficient enhances the utility of the method, by enabling separate calculation of production and respiration rates.     

Pipe Index Vector: A Method to Improve Genetic-Algorithm-Based Pipe Optimization

This paper proposes a methodology for the optimal design of water distribution systems based on genetic algorithms. The objective of the optimization is to minimize the capital cost, subject to ensuring adequate pressures at all nodes during peak demands. The proposed method is novel in that it involves the use of a pipe index vector to control the genetic algorithm search. The pipe index vector is a measure of the relative importance of pipes in a network in terms of their impact on the hydraulic performance of the network. By using the pipe index vector it is possible to exclude regions of the search space where impractical and infeasible solutions exist. By reducing the search space it is possible to generate feasible solutions more quickly and hence process much healthier populations than would be the case in a standard genetic algorithm. This results in optimal solutions being found in a fewer number of generations resulting in a substantial saving in terms of computational time. The method has been tested on several networks, including networks used for benchmark testing least cost design algorithms, and has been shown to be efficient and robust.     

适应现代优质钢材要求的铁资源及新工艺技术

概述了现代优质钢材对铁资源的要求以及为适应优质钢材和纯净钢要求而发展的钢铁生产新工艺、新技术。     

原矿石质量波动对选矿指标的影响及对策

原矿石质量波动对选矿工艺的影响是多方面的,原矿石质量波动是选矿生产指标持续异常的主要原因。通过配矿,使入选原矿石的品位、矿物组成、硬度、粒度及其它物理性质得到稳定的质量指标,是减小入选原矿石质量波动对选矿生产指标不良影响最有效的做法。     

Allocation of Flow to Plots in Pressurized Irrigation Distribution Networks: Analysis of the Clément and Galand Method and a New Proposal

This article reviews the method for allocating flow to irrigation plots proposed by Clément and Galand in (1979). Mention is made of its shortcomings, such as the lack of consideration given to the specific technical and economic factors governing current pressurized (drip or sprinkler) irrigation systems and how they provide water to plots. We propose a method for fixed irrigation systems, which takes into account the irrigation method on the plot and the existence of an optimum block area. The result is to allocate a constant flow of water to plots up to an established value of maximum surface area. From there on, we propose applying linear increases related to the total plot area. We also present a formula for calculating the maximum number of blocks based on variables that are easily obtainable during the project phase.     

进一步提高冶金机械零件加工质量和生产率的新方法

在机械加工最后一道工序时，按中间公差加工，按中间公差验收，可以令零件达到百分之百的互换，装配顺利，不返修，产品质量和生产率均可得到进一步的提高。     

螺旋煤气流适应炼铁原料质量的工艺探索

西钢4#高炉因为原料质量原因，炉况不顺，强化冶炼受阻，为改变不利局面，利用现有无料钟炉顶设备进行扇形布料实验，改善了散料带透气性，形成了螺旋煤气流，保证了高炉冶炼强度的提高。     

创新铜电解配液方式保障第一批阴极铜质量

介绍江西铜业集团公司贵冶30万t规模铜电解车间2007年投产时,为稳定电铜质量在电解液准备方面采取的有效措施。在分析2003年铜电解生产线在开车之初电铜质量波动情况的基础上,采取尽量采用老电解液的配液方法,改进添加剂加入方式,在开车之初获得高质量电铜的同时,还节省了多项费用。     

3D扫描的产品质量检测方法

提出了一种基于逆向工程技术的光学3D扫描测量来检测产品质量的方法。介绍了该方法的硬件平台、软件平台、应用实例等。该方法可以解决曲面质量检测效率低、精度低的问题。     

Experimental Steep, Braided Flow: Application to Flooding Risk on Fans

Flooding processes occurring on alluvial fans are considerably different from those occurring along single thread rivers with well defined floodplains. Active erosion, rapid sedimentation, and the uncertainty in flow path make the prediction of flood evolution and extent difficult. Based on a large scale experiment, this study investigates the long term evolution of the flow on a steep, noncohesive sediment surface resembling a complex of merged alluvial fans. The results are pertinent to the assessment of flooding hazard on alluvial fans. At any given time, the average flow occupancy was 21% of the surface. However, the flow was characterized by active channel switching and overflow processes. The percentage of the surface remaining dry was found to decay harmonically with time. A reworking time was defined as the time at which half of the surface that was initially dry remained dry, whereas the other half was inundated at least once. An empirical expression was developed in which reworking time is proportional to the average cross sectional area of flow and inversely proportional to the sediment supply.     

New scales to assess change in the Addiction Severity Index for the opioid, cocaine, and alcohol dependent.

Analyses were performed to construct and confirm the validity of new conjoint intake and 6-month follow-up scales for the Addiction Severity Index (A. T. McLellan, L. Luborsky, G. E. Woody, & C. P. O'Brien, 1980) applied to a diverse sample of substance dependence patients (N?=?1,008). A multistage scaling strategy identified 5 psychometrically integral addiction problem scales. Exploratory item and factor analyses, confirmatory oblique item clustering, and variance partitioning verified that the scales comprised relatively little common variance and that each retained a substantial amount of unique and reliable variance. Resulting scales (Psychiatric, Drug, Alcohol, Family, and Legal Problems, respectively) were highly internally consistent and structurally stable overall, at intake and follow-up and across gender, age, ethnicity, and substance abuse categories. Concurrent and predictive validity over 2 years were supported for clinical subsamples based on comorbid psychopathology and mood, HIV risk behaviors, personality indices, urine toxicology, and criminal records. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New Approach to Determine Three-Dimensional Contacts in Blocks System: Penetration Edges Method

Detection of contacts between three-dimensional (3D) blocks is a key problem in three-dimensional distinct element analysis. In this paper, the limitations of the c–p method are discussed. The writers have also put forward the “penetration edges method” for the detection of contacts in 3D blocks system. The contact relations between two 3D blocks are classified into seven types and 3D contact detection is determined by the contact type. The principle of this new approach is simple to implement and can overcome the limitation of the c–p method as discovered in this study. Limited case studies have indicated that the present algorithm is as efficient as the c–p method but is free from the limitation of this method.