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通过对大庆石油管理局2000年度在水环境、大气环境、固体废物排放等方面的现状分析,总结了大庆石油管理局2000年环境保护工作,并针对石油化工废水处理、脱硫、废钻井液处理、垃圾处理和资源化等技术提出重点注意的问题。最后介绍了管理局“十五”期间环境保护技术发展的总体思路和环保科技主攻方向。     

深厚覆盖层中弱透水层特性对渗流场的影响

中国西部地区的深厚覆盖层坝基中常存在弱透水层,对坝基渗流场有一定影响。基于非饱和土渗流理论,借助有限元软件Seep/w建立数值模型,得出渗流量和出逸坡降,并结合2个实际工程分析弱透水层深度、厚度、连续性对渗流场的影响。结果表明,采用悬挂式防渗墙或无防渗墙时,深度越小的弱透水层控渗效果越佳;深度越大的弱透水层与防渗墙形成的半封闭式联合防渗体系,越能有效控制渗流量和抑制出逸坡降。渗流量和出逸坡降都随着弱透水层厚度的增大而降低;弱透水层厚度及连续性对采用半封闭式防渗墙控渗时的渗流场影响最大,悬挂式防渗墙次之,全封闭式防渗墙最小。渗流量和出逸坡降随上游、底端开口长度的增加而增大;渗流量随下游开口长度的增加而增大,但出逸坡降随下游开口长度的增加呈先增大后减小的趋势。弱透水层的连续性对渗流场影响较小。采用半封闭式防渗墙时,渗流量和出逸坡降从高到低排序为底端开口、上游开口、下游开口。采用全封闭式防渗墙时,防渗墙承担主要的控渗任务,弱透水层的深度、厚度、连续性对渗流场的影响极小。     

超固结比对黏土热固结特性的影响研究

通过开展固结压缩试验,研究了超固结比(OCR)对海相沉积软黏土热固结特性的影响。试验结果表明:加温可能使软土发生沉降或回弹。在OCR较小的情况下,加温将使软黏土产生沉降;OCR越小,温度效应导致的沉降量越大,降温后回弹较少。在OCR较大的情况下,加温将使软土产生膨胀;降温后膨胀可部分恢复,且OCR越大恢复量越大。在此基础上,根据测试结果拟合了考虑OCR影响的热固结经验关系式。该式可用来预测不同应力状态条件下软土应变随温度变化的关系。     

内质网应激在PFOS致大鼠肝损伤中的作用

通过全氟辛烷磺酸(PFOS)28 d大鼠经口染毒评价PFOS肝损伤效应,探讨内质网应激在PFOS毒效应中的作用。Wistar大鼠随机分组,分别以0 mg·kg~(-1)、5 mg·kg~(-1)和10 mg·kg~(-1)PFOS灌胃染毒28 d。HE染色观察大鼠肝脏形态改变。ELISA法测定各组丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)、碱性磷酸酶(ALP)和淀粉酶(AMY)含量变化。紫外分光光度法测定肝组织匀浆中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性变化。RT-PCR检测肝脏内质网应激标志蛋白表达水平。结果表明,PFOS造成大鼠体重降低、肝重增高(P0.05),组织切片显示肝细胞出现脂质沉积。PFOS不同剂量组大鼠ALT随暴露浓度增加,分别为(50.96±10.02)U·L~(-1)、(71.73±11.55)U·L~(-1),显著高于对照组(P0.05),AST、ALP含量与对照组相比显著上升(P0.05),高剂量组AMY水平为(833.46±63.05)U·L~(-1),与对照组相比显著降低(P0.05)。GSH-Px和SOD水平随PFOS浓度增加出现了显著降低(P0.05),而MDA水平显著升高(P0.05)。内质网应激标志蛋白表达均较对照组显著上升(P0.05)。以上结果说明PFOS可导致大鼠肝细胞损伤,其机制可能与内质网应激调控有关。     

An assessment of China-Japan-Korea Free Trade Agreement’s economic and environmental impacts on China

Recently, China, Japan, and the Republic of Korea (Korea) are conducting a government-commissioned feasibility study on the Free Trade Agreement among the three countries (CJKFTA) to form a regional free trade zone in East Asia. Considering that freer trade can cause unexpected impact on domestic environment, there is a need to evaluate the environmental impact of such a trade policy. This move should be made to help negotiators understand and pay more attention to environmental issues during CJKFTA negotiations, and to help lobby with the government to carry out appropriate policy instruments for adaptation or mitigation. Following the Chain Reaction Assessment Method that integrates and links the elements of trade, production, and environment, the present research aims to quantitatively assess CJKFTA’s possible impact on China’s environment. This is done by estimating the variations of China’s major conventional pollutants and greenhouse gases (GHGs) emission in two policy scenarios to represent CJKFTA’s scale and composition effects on China’s environment. Estimating the variations is based on a static Computable General Equilibrium model, working with Global Trade Analysis Project (GTAP) 7 database and China’s energy-environment statistics. Based on these assessments, CJKFTA is predicted to lead to notable environmental impact, including increased emissions of agricultural total nitrogen, agricultural total phosphorus, chemical oxygen demand, and GHGs. On the other hand, decreased emissions of industrial SO₂ and dust are also expected to happen. Suitable policies need to be made to combat negative effects and amplify positive ones, while aiming at a more sustainable regional freer trade system.     

Testing homogeneity of capture probabilities of animals in a removal experiment

Consider the removal experiment used to estimate population sizes. Statistical methods towards testing the homogeneity of capture probabilities of animals, including a graphical diagnostic and a formal test, are presented and illustrated by real biological examples. Simulation is used to assess the test and compare it with the χ² test.

用系统生成技术提高会计电算化系统的安全性

会计电算化是管理现代化的重要组成部分 ,会计电算化系统的安全性一直是管理信息系统的难点之一。根据多年实践的经验 ,提出采用系统生成技术改进提高会计电算系统的安全性 ,有助于广大中小企业会计电算化的推广应用。     

Effects of La3+, Ce3+ on nitrogen removal in sequencing batch reactor

Batch experiments were conducted to study the short-term biological effects of rare earth ions (La³⁺, Ce³⁺) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH₄ ⁺-N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1 mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH₄ ⁺-N removal efficiency by 15.7% and 10%–15%, respectively. When the concentrations of REEs were higher than 1 mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0 mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.     

湿法脱硫系统设计无旁路相关问题的探讨

介绍国内电厂首次投运的无旁路脱硫系统,其具有无GGH、引风机和增压风机合并、"烟塔合一"的特点。通过与其他脱硫系统的比较,讨论了无旁路脱硫系统吸收塔、烟道、公用系统以及除尘器的设计和选型特点,总结了其易出现的问题及运行中的控制方法。根据调试经验,给出了无脱硫旁路系统的运行步序原则。     

西安市灰霾天气时间和区域分布特征及影响因素

依据1961—2005年共45年,西安、户县、长安、蓝田、临潼、高陵和周至7个气象台站灰霾观测资料,分析了灰霾天气时间和区域分布特征,并根据1996—2005年近10年西安逐月平均灰霾日数与近10年逐月主要气象要素相关性分析,得出:西安市20世纪70年代是灰霾日出现的高峰时期,并呈逐年减少趋势,灰霾发生的中心区域也在向郊区东南部转移;从影响灰霾天气形成的气象条件来看,气温越低,降水量和风速越小,日照越少,气压越高,越有利于灰霾天气的形成。