夹扣的弯曲成形连续模

此文介绍一种在合理大间隙冲裁和延时回程的条件下,使落料件回位嵌入条料中,从而实现连续弯曲成形的一种工艺方法。     

大伙房水库放流对浑河沈阳段环境容量影响及调控对策

结合沈阳市近年来关于浑河污染综合整治的实际情况，运用河流的稀释与净化理论，科学的分析了大伙房水库放流对浑河沈阳段水环境容量的影响，在此基础上提出了如何增加浑河水环境容量的对策。     

云龙水库水环境污染成因分析与控制对策建议

云龙水库径流区污染物负荷的调查结果显示,云龙水库水污染特征以面源污染为主,入库水量TN占91.8%,TP占98.4%.根据云龙水库水环境污染成因提出了防治面源污染的控制对策建议.     

Spatial analysis of plant detritus processing in a Mediterranean river type: the case of the River Tirso Basin,Sardinia, Italy

The river continuum concept represents the most general framework addressing the spatial variation of both structure and function in river ecosystems.In the Mediterranean ecoregion,summer drought events and dams constitute the main sources of local disturbance to the structure and functioning of river ecosystems occurring in the river basin.In this study,we analysed patterns of spatial variation of detritus processing in a 7th order river of the Mediterranean ecoregion(River Tirso,Sardinia0Italy)and in three 4th order sub-basins which were exposed to different summer drought pressures.The study was carried out on phragmites australis and Alnus glutionsa leaf detritus at 31 field sites in seasonal field experiment Detritus processing rates were higher for Alnus glutionsa than for Phragmites australis plant detritus.Processing rates of Alnus glutionsa leaves varied among seasons and study sites from 0.006d^-1 to 0.189d^-1 and those of Phragmites australis leaves ranged from 0.0008d^-1 to 0.102d^-1,with the lowest values occurring at sites exposed to summer drought.Seasons and sites accounted for a significant proportion of such variability.Alder detritus decay rates generally decreased with increasing stream order,while reed detritus decay rates generallyincreased on the same spatial gradient.Summer drought events affected these spatial patterns of variation by influencing significantly the decay rates of both plant detritus.The comparisons among and within sub-basins showed strong negative influence of summer drought on detritus processing rates.Similarly,in the entire River Tirso basin decay rates were always lower at disturbed than at undisturbed sites for each stream order;decay rates of reed detritus remained lower at those sites even after the end of the disturbance events,while alder decay rates recovered rapidly from the summer drought perturbations.The different recovery of the processing rates of the two leaves could also explain the different patterns of spatial variation observed between the two leaves.     

大伙房水库水环境现状及变化趋势

于1992-2002年对大伙房水库水质进行了监测分析。结果表明：大伙房水库水体受到轻度污染，主要污染物质为氮、磷。水库上游流域的种、养殖、生活污水是水库氮磷污染的主要因子。     

石油测井作业HSE管理刍议

测井作业是石油勘探开发工程作业的重要一环,它包括电法测井、声波测井和放射性测井等.由于是野外作业,作业条件恶劣,作业人员饮食睡眠无规律,易疲劳,主要职业危害是放射性测井作业--如果放射源发生泄漏、丢失,在无防护措施状态下会造成人员伤害、环境污染;同时,测井作业容易发生各种工程事故.各种事故的发生都会造成巨大经济财产损失,影响测井公司的声誉和形象.     

内蒙古大针茅草原的N2O和CH4通量变化特征

 利用透光密闭箱对内蒙古半干旱典型草原大针茅草原土壤-植被系统温室气体N₂O和CH₄通量在不同年份进行了较长期的原位观测研究.结果表明,大针茅草地作为大气N₂O的源和CH₄的汇而起作用,N₂O与CH₄的排放强度分别为(1.37～16.33μg/(m2·h)和-227～-1μg/(m2·h), N₂O和CH₄的通量具有明显的日变化和季节变化特征,并且主要的环境因子(温度、水分)对其有重要影响.N₂O通量的季节变化特征表现为:夏>秋>春>冬;CH₄通量的季节变化特征表现为:春>夏>秋>冬.     

柴石滩水库水质污染成因分析

通过对柴石滩水库及上游河道的水质评价及其污染源分析，得出水库上游河段污染物的不断累积是柴石滩水库水质污染主要成因，其中又以生活污染的贡献率最大的结论，并提出了相应的改善水质的建议和措施。     

河口沉积物反硝化反应影响因子综述

本文在分析国内外河口沉积物反硝化主要研究内容、研究结果的基础上 ,综述了影响反硝化作用的主要因子 :氧气浓度 ,有机质含量 ,NO-3 浓度 ,盐度和PH值 ,生物作用等。并指出了反硝化过程中存在的若干负效应 ,以期为河口沉积物 -水界面反硝化研究提供一定的理论依据