INTERACTIVE COMPUTER-AIDED HYDRAULIC DESIGN: CULVERTS1

ABSTRACT: Regular use of interactive computer programs in hydraulic design can materially increase the productivity of designers without sacrificing accuracy. This article considers the hydraulic design of culverts by interactive use of a computer program; this approach most profitably combines the speed and accuracy of the computer with the experience of the designer.     

A SELF-VERIFYING HYBRID COMPUTER MODEL OF RIVER-BASIN HYDROLOGY1

ABSTRACT. As demands upon available water supplies increase, there is an accompanying increase in the need to assess the downstream consequences resulting from changes at specific locations within a hydrologic system. The problem is approached in this study by hybrid computer simulation of the hydrologic system. Modeling concepts are based upon the development of basic relationships which describe the various hydrologic processes. Within a system these relationships are linked by the continuity-of-mass principle. Spatial resolution is achieved by considering the modeled areas as a series of subbasins. The time increment adopted for the model is one month, so that time varying quantities are expressed in terms of mean monthly values. The model is general in nature and is applied to a particular hydrologic system through a programmed verification procedure whereby model coefficients are evaluated for the particular system. In this study the model is applied to the Bear River basin of western Wyoming, southern Idaho, and northern Utah. Comparisons between observed and computed outflow hydrographs show good agreement. The utility of the model is demonstrated by predicting the effects of various possible water resource management alternatives. The verified hybrid computer program can be digitized for application to the digital computer.     

A HYBRID COMPUTER PROGRAM FOR PREDICTING THE CHEMICAL QUALITY OF IRRIGATION RETURN FLOWS1

ABSTRACT. A hybrid computer program was developed to predict the water and salt outflow from a river basin in which irrigation is the major user of water. The model combines a chemical model which predicts the quality of water percolated through a soil profile with a general hydrologic model. The chemical model considers the reactions that occur in the soil, including the exchange of calcium, magnesium, and sodium cations on the soil complex, and the dissolution and precipitation of gypsum and lime. The chemical composition of the outflow is a function of these chemical processes within the soil, plus the blending of undiverted inflows, evaporation, transpiration, and the mixing of sub surface return flows with groundwater. The six common ions of western waters, namely calcium (Ca⁺⁺), magnesium (Mg⁺⁺), sodium (Na⁺), sulfate (SO₄⁼), chloride (Cl^?), and bicarbonate (HCO₃^?) were considered in the study. Total dissolved solids (TDS) outflow was obtained by adding the individual ions. The overall model operates on a monthly time unit. The model was tested on a portion of the Little Bear River basin in northern Utah. The model successfully simulated measured outflows of water and each of the six ions for a 24-month period. The usefulness of the model was demonstrated by a management study of the prototype system. For example, preliminary results indicated that the available water supply could be used to irrigate additional land without unduly increasing the salt outflow from the basin. With minor adjustments the model can be applied to other hydrologic areas.     

计算机网络安全的防范措施

随着传播媒体和信息技术高速发展，Internet广泛应用，共享信息与网上业务在不断增加。伴随而来的网络攻击和犯罪日益猖橛。本文概要地介绍了网络信息安全面临的主要威胁，阐述了计算机网络安全的基本防范措施。     

洛铜集团除尘系统的改造

洛铜集团有5台低频炉，均设有滤袋式除尘系统。但除尘效果不理想，厂房内烟尘四溢，污染严重。尤其在加料和转炉时，排烟量剧增，岗位工作环境恶劣。对系统进行改造后，效果较好。     

Information presentation compatibility in a simple digital control panel design: eye-tracking study

Various designs of typical digital control panels were analyzed experimentally from both the effectiveness and efficiency points of view. Subjects performed information comparison tasks aimed at keeping vehicle velocity at the same level. The experiment involved two versions of speedometers for displaying current and target velocities (clock-face and digital). The stimuli were also differentiated by the target velocity value (20, 50 and 80?km/h) and the correct response type (increase or decrease). Subjects’ performance results along with the eye-tracking data were qualitatively and quantitatively analyzed for all 24 experimental conditions.     

E‐waste in the world today: An overview of problems and a proposal for improvement in Brazil

Environmental issues have been at the center of society's concerns for a long time. Recently, this kind of concern is growing even more due to the damage caused to the environment by electrical and electronic product waste. Based on this same concern, this work aimed to analyze, through a literature review, the production and treatment of electronic waste in today's world, with an emphasis on Brazil and China. The articles reviewed point to an increase in the production of this type of waste, in both Brazil and China, and reveal that the current processes of treatment of electronic waste mostly aim to obtain profit through the recovery of precious metals such as copper. This paper concluded that although Brazil is one of the major producers of e‐waste, more than 90% of its e‐waste has not had a proper final destination. This deficiency in e‐waste treatment in Brazil is mainly due to financial factors and the lack of a robust educational policy focused on the environment. Thus, this work suggests the implementation of an effective educational policy aimed at environmental conservation, as well as investments in research on recycling methods in Brazil, especially on the use of e‐waste as an aggregate in the manufacture of concrete.     

嵌入式技术在重大危险源监控预警中的应用

通过对重大危险源监控预警系统的功能需求分析,并结合嵌入式技术的特点,提出基于嵌入式系统的监控预警主机的设计方案。所设计的集过程监控预警与视频监控为一体的的监控预警主机,具有实际应用价值。     

Numerical technique for estimating equilibrium concentrations from initial concentrations when using the freundlich adsorption equation

Abstract

The Freundlich equation, X/m = K C_e ^N, is frequently used to express the partitioning of pesticides between solid (soil, sediment) and aqueous phases. When designing adsorption‐desorption experiments, it would be useful to be able to estimate the equilibrium concentration, C_e, in terms of the initial concentration, C_o, if reasonable estimates of K and N can be made. Because of the usual non‐integer nature of N, only a numerical solution of the Freundlich equation is possible for C_e in terms of C_o. A simple computer program is presented which produces almost an exact solution for the value of C_e.     

基于高职计算机应用专业的动态教学模型研究

结合高职教育的特点和计算机应用专业的教学,提出了"一线、二体、三层、五框架、多考核"的动态教学模型,并从多角度分析了实际教学中应该采取的改革措施,阐明了各个环节的具体做法。