基于多核LS-SVM的河涌水质预测模型

研究了多变量非线性河涌水质预测问题,提出了多核最小二乘支持向量机河涌水质预测模型。模型采用协同结构的非线性函数将水质时序样本映射到高维特征空间,进行多元线性回归。然后将该回归问题转化成半无限线性规划问题,运用交换集法求解。文章利用东江流域河涌水质数据进行了拟合预测实验,结果表明,与单核最小二乘支持向量机河涌水质预测模型相比,多核模型的预测误差减小了23%以上,它较单核模型具有更高的预测精度和更好的泛化推广性能。     

楚雄德胜钢铁公司烧结机尾除尘改造实践

介绍楚雄德胜钢铁公司19·6m2烧结机尾除尘系统改造工程中使用三电极电除尘器的工艺及有关设计技术问题,并根据使用效果进行分析总结。结果表明,在设计参数选择恰当的情况下,三电极电除尘器对烧结烟气有较好的除尘效果,这些经验和操作中存在的问题供烧结机尾除尘工程设计参考。     

城市固定噪声源之一风机噪声的综合治理

本文对风机噪声的治理 ,提出了系统的解决办法 ,通过风机连管 ,风机隔声罩、消音器、机座的柔性安装等多种措施 ,解决了风机的空气动力噪声 ,机壳的机械噪声、风机振动等噪声源问题并充分考虑了风机密闭后防过热及能源回用等技术难点     

Urbanization, environmental consequences and management in China

Ｕｒｂａｎｉｚａｔｉｏｎ，ｅｎｖｉｒｏｎｍｅｎｔａｌｃｏｎｓｅｑｕｅｎｃｅｓａｎｄｍａｎａｇｅｍｅｎｔｉｎＣｈｉｎａＬｕＹｏｎｇｌｏｎｇ（ＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏ－ＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ），ＣｈｉｎｅｓｅＡｃａｄｅ...     

支持向量机在环境空气质量评价中的应用

环境质量评价是环境科学的重要组成部分。建立环境空气质量评价的支持向量机模型,并用实例进行验证,评价结果与实际情况及其它方法相吻合,表明支持向量机在环境空气质量评价中的可行性和有效性。     

The impact of the gulf war on the Arabian environment—I. Particulate pollution and reduction of solar irradiance

This paper investigates some of the air pollution problems which have been created as a result of the Gulf war in early 1991. Temporary periods of increased dust storm activity have been observed in Saudi Arabia. This is presumably due to disturbance of the desert surface by the extremely large number of tanks and other war machines before and during the war. The concentrations of inhalable dust particles (<15 μm) increased during the months just after the war by a factor of about 1.5 of their values during the same months of the previous year, 1990.The total horizontal solar energy flux in Riyadh has been significantly reduced during dry days with no clouds. This is attributed to the presence of soot particles, which have been generated at an extremely high rate from the fired oil fields in Kuwait.The direct normal solar insolation were also measured at the photovoltaic solar power plant in Riyadh during these days and significant reductions were observed due to the effective absorption of solar radiation by soot particles. The generated power from the plant has been reduced during days with a polluted atmosphere by about 50–80% of the expected value for such days, if the atmosphere were dry and clear.     

Environmental problems in a coal mining area affected by coal fires --A case study in Ruqigou Coalfield, Ningxia, China

Ruqigou Coalfield, being one of the most important coal mining areas in China, has suffered coal fire problems for more than one hundred years. Due to coal fires, about 4.513 million tons coal resources has been lost each year, and apart from a large volume of CO2 delivered into air, environmental problems such as land degradation, land pollution and air pollution are also produced. Air pollution, as one related to coal fires, is the most dangerous problems for local people and has already led to vegetation pollution in this area. Land degradation is mainly induced with occurrence of land subsidence, fissures with due to coal mining/coal fires, and debris slide/flow. With development of opencast coal mining, a large volume of waste was produced, which is the major source of land pollution. All these environmental problems are associated with coal mining or coal fires and their comprehensive effects are deterioration of environment.     

Parallel Kinematic Machine Positioning Accuracy Assessment and Improvement

Although parallel kinematic machines potentially offer high force/torque capacity, structural rigidity, speeds, and dexterity, characterization of the first generation of hexapods has proven the need for improving the positioning accuracy before these new machines will be accepted for manufacturing applications. This paper proposes a systematic approach to assess the accuracy of a parallel kinematic machine subject to structural errors and then to effectively compensate for them. Analytical models were constructed for both the nominal and actual structures. Sensitivity analysis was performed, and it was determined-that of the 33 sources of error, only the six due to strut length deviations are significant. Simulations indicate that the accuracy of strut length calculations shows a discrepancy of at most ±4 micrometers. In summary, the simulation and preliminary experimental results show that the performance of parallel kinematic machines can be enhanced through error modeling and compensation.     

A tutorial on learning human welder's behavior: Sensing,modeling, and control

Human welder's experiences and skills are critical for producing quality welds in manual GTAW process. Learning human welder's behavior can help develop next generation intelligent welding machines and train welders faster. In this tutorial paper, various aspects of mechanizing the welder's intelligence are surveyed, including sensing of the weld pool, modeling of the welder's adjustments and this model-based control approach. Specifically, different sensing methods of the weld pool are reviewed and a novel 3D vision-based sensing system developed at University of Kentucky is introduced. Characterization of the weld pool is performed and human intelligent model is constructed, including an extensive survey on modeling human dynamics and neuro-fuzzy techniques. Closed-loop control experiment results are presented to illustrate the robustness of the model-based intelligent controller despite welding speed disturbance. A foundation is thus established to explore the mechanism and transformation of human welder's intelligence into robotic welding system. Finally future research directions in this field are presented.     

国产旋压设备的发展和应用

概述了国内旋压设备 30余年来的发展历程 ,指出了国产设备与发达国家的产品存在的差距 ,以及近年来国内旋压机床制造业取得的成绩。并结合国内外市场的需求 ,提出了旋压设备今后发展的方向     

机器学习方法在污水处理系统中的应用

由于污水处理系统一般较为复杂且受外界因素影响较多,对其进行精准调控一直是环境领域的难题之一。传统方法无法满足日益复杂的工程项目需求。近年来发展起来的机器学习方法为此类问题提供了一系列有效的解决方案。介绍了人工神经网络、支持向量机、随机森林等机器学习方法的特点,并从水质预测预警、污水处理系统故障诊断和智能控制3个方面阐述了机器学习方法在污水处理领域的应用,分析了机器学习方法相较于传统方法的优势及其应用于污水处理系统中存在的问题,展望了机器学习方法未来在污水处理领域应用的前景和趋势。     

我国海洋环境保护的法律原则和政策措施

通过对近年来我国海洋环境保护法律法规和一些政策措施的分析,论述了基本的法律原则和当前所采取的污染防治和生态保护措施,结果表明,国家通过加强立法、增加投入,实施重点污染物总量控制、加强海洋生态保护和实施重点流域污染防治计划、重点海域碧海行动计划等措施,在一定程度上减缓了沿海经济建设和海洋产业开发给海洋环境带来的压力,近岸海域环境污染加剧的趋势得到初步控制,局部海域的环境质量有所改善。指出了当前存在的主要问题是城市环境基础没施建设滞后、工业污染防治水平不高、海上污染事故应急能力不足等,并提出了相应的建议。     

宁夏人口、粮食与水土资源利用

人口、粮食与水土资源利用是宁夏回族自治区国民经济发展中的重要问题。文中分析了宁夏人口、粮食与水土资源利用现状,应用灰色系统理论及回归分析,建立人口、粮食预测模型,对2000年宁夏的人口、粮食进行了预测。分析2000年水土资源不同开发利用条件下粮食供需平衡情况后指出,充分合理利用黄河水资源,扩大灌溉面积,配合先进的农业技术,宁夏粮食不仅能自给,而且还能提供一定数量的商品粮。最后提出了解决粮食问题,防止生态环境恶化的主要途径。     

工程机械不同工况下PM_(2.5)排放及其碳质组分特征

我国工程机械排放控制起步较晚.为研究实际工况下工程机械的PM2.5排放特性及其碳质组分构成,采用便携式颗粒物稀释采样系统,对3台工程机械(2台挖掘机和1台装载机)在不同典型工况(行驶、作业和怠速)下的PM2.5及其碳质组分〔OC(有机碳)和EC(元素碳)〕的现场排放特征进行了测试.结果表明:沃尔沃挖掘机、山河智能挖掘机的PM2.5排放因子(基于燃油)分别为1.85~3.26和1.56~2.62 g/kg,厦工装载机的PM2.5排放因子为0.98~1.48 g/kg.不同工况对PM2.5排放因子影响较大,怠速工况下PM2.5排放因子是行驶工况下的1.49~1.76倍.工程机械排放的PM2.5中,碳质组分是最主要的成分,其质量分数高达71.0%~84.5%.其中,w(OC)为44.6%~72.0%,在怠速工况下最高;w(EC)则为8.6%~30.9%,在行驶工况下较高.测试工程机械的PM2.5排放水平较高,因此应尽快加强工程机械排放的污染防治.     

Fisheries management: integrating societal preference, decision analysis, and ecological risk assessment

Fisheries management is the practice of analyzing and selecting options to maintain or alter the structure, dynamics, and interaction of habitat, aquatic biota, and man to achieve human goals and objectives. The theory of fisheries management is: managers or decision makers attempt to maximize renewable `output' from an aquatic resource by choosing from among a set of decision options and applying a set of actions that generate an array of outputs. Outputs may be defined as a tangible catch, a fishing experience, an existence value, or anything else produced or supported by renewable aquatic resources. Overall output is always a mix of tangible and intangible elements. However defined, management goals and objectives are essential components of fisheries management or any other field of renewable natural resource management. Reaching consensus on management goals and objectives has never been a simple task. Beyond the broad and often conflicting goals of an agency, managers must decide who should set specific management objectives — agency personnel, the public, or a combination of the two. Historically, rhetoric aside, fisheries managers in North America nearly always have consulted with professionals in governmental roles to set management objectives. In a strongly pluralistic society, this often resulted in protracted political and legal conflict. Increasingly, there are calls for use of risk assessment to help solve such ecological policy and management problems commonly encountered in fisheries management. The basic concepts of ecological risk assessment may be simple, but the jargon and details are not. Risk assessment (and similar analytical tools) is a concept that has evoked strong reactions whenever it has been used. In spite of the difficulties of defining problems and setting management objectives for complex ecological policy questions, use of risk assessment to help solve ecological problems is widely supported. Ecological risk assessment will be most useful (and objective) in political deliberations when the policy debate revolves around largely technical concerns. To the extent that risk assessment forces policy debate and disagreement toward fundamental differences rather than superficial ones, it will be useful in decision making.     

The application of automated metaphase scanning to direct preparations of chorionic villi

In order to increase the speed of analysis of metaphases from chorionic villi direct preparations, we have investigated the use of two automatic scanning devices, the Magiscan II and a version of Metafip (the research laboratory precursor of Cytoscan). The speed, efficiency, and ranking system have been compared to manual scanning. Results show that both machines detect approximately 80 per cent of the total analysable metaphases detected by a trained cytogeneticist. There appears to be reasonable agreement in ranking between methods.     

贵州六盘水红粘土的工程特性

针对贵州六盘水地区红粘土地基大量工程实践中出现的不良工程地质问题,对该区红粘土的化学成分、物理力学性质、胀缩性、沉降量等进行了研究,发现该区红粘土与国内其它地区相比,具有强度低、均匀性差、裂隙性强、土洞与塌陷发育等特征,因此该区红粘土地基的处理应根据这些特征采取一些针对性的措施。     

Corporate environmental management and regulation of mining operations in the Cyclades,Greece

The mining industry plays an important role in the local economy in many islands of the Cyclades, contributing significantly to overall growth. However, it has simultaneously caused many environmental problems and has had adverse impacts upon other important economic activities, such as tourism. As a result, questions have been raised as to whether mining should be allowed to continue. This paper assesses the mining operations of the Cyclades, examining the corporate environmental management of mining companies and the process of granting permission for mining operations. Specifically, the regulatory and environmental problems of mining operations are assessed, and the process of obtaining a ‘social licence to operate’ is explored. A number of recommendations are made in order to overcome regulatory inefficiencies and promote corporate environmental management in the mining sector of the Cyclades.