博斯腾湖水质矿化度模型及预测研究

根据博斯腾湖１９８５～１９９５年水质监测数据和出入湖水量等水文数据观测值，采用水质扩散模型和盐量平衡关系推导出博斯腾湖大湖区（简称博湖）水质矿化度模型，并预测了几种情况下博湖水质矿化度及近几年变化趋势，分析了影响博湖水质矿化度的主要因素，为博湖的近期和远期环境保护规划、环境管理等提供科学依据．     

Pesticide dissipation curves in peach,pear and tomato crops in Uruguay*

Dissipation curves of azoxystrobin and of the neonicotinoids acetamiprid and thiacloprid in peach; azinphos-methyl and carbaryl in pear and azoxystrobin, chlorfenapyr and chlorpyrifos in high-tunnel tomato crops were studied in the Southern region of Uruguay. An analytical methodology based on solid phase extraction (SPE) and detection by High Performance Liquid Chromatography with Diode Array Detector (HPLC/DAD) was used for acetamiprid and thiacloprid. Coupled SPE and detection by Gas Chromatography with Mass Selective Detector (GC/MSD) was used for the detection of azinphos-methyl, azoxystrobin, carbaryl, chlorfenapyr and chlorpyrifos residues. Curves were modeled mathematically with Solver program of Microsoft Excel®. The best fit for acetamiprid and thiacloprid in peach was achieved with the exponential model (r²=0.961 and 0.944, respectively). In the case of peach fruits there is not a Maximum Residue Limit (MRL) for acetamiprid in the Codex Alimentarius, while 0.5 mg/kg is the value rated for thiacloprid. The MRLs accepted by the European Union (EU) are 0.1 mg/kg for acetamiprid and 0.3 mg/kg for thiacloprid. According to the curves determined in these experiments, thiacloprid residues 10 to 12 days after application (daa) were below the MRLs established by both sources. In the case of acetamiprid, 25 daa would be required, according to the exponential mathematical model, to get residues levels below the MRL values established by the EU. For azinphos methyl in pear, the residues detected were mathematically fitted to an exponential model (r²=0.999). According to it, residue levels under the MRL established by the EU (0.05 mg/kg) are gotten in our conditions in 20 daa. In plastic tunnel tomato chlorfenapyr residues were not detected from 16 daa, having the dissipation curve an exponential trend. In the same condition, there was not a decay of the azoxystrobin concentration during a 24-day trial, being it around 0.40 ± 0.05 mg/kg.     

除尘系统加接新支管的理论和实践

对于一个现有的除尘系统,若其除尘器、通风机的工作能力有足够的富余量,则可以在该系统管网上加接新的支管,来治理新的扬尘点。     

垃圾问题的思考

垃圾在告急：垃圾的恶性累积,已成为世界性的环境灾难。对垃圾问题的哲学思考：垃圾是与人类社会同时产生,同步发展的。根据事物发展否定之否定规律,垃圾危机的产生正是对已往社会发展的一种否定。解决垃圾问题,必需树立社会全面发展观和科技全面进步观,运用法律的、经济的、行政的和道德的手段,大力发展处理垃圾的科学技术,减少垃圾的产生,并将产生的垃圾“变废为宝”,才能使社会在否定之否定的过程中持续发展。     

A CODED ALGORITHM FOR CAPACITY EXPANSION OF A WATER QUALITY MANAGEMENT SYSTEM1

ABSTRACT: This paper describes a mathematical model, an algorithm and a computer program that were specially developed to study the problem of a water quality management system undergoing a rapidly increasing environmental stress. The model output will determine the locations, sizes and the timing of construction of new treatment plants plus an overall treatment plant operating policy so that environmental standards are maintained at a minimum cost. The model, as formulated, is a 0-1 mixed integer programming problem which is solved by decomposing it into a capital budgeting problem (solved by Little's branch and bound algorithm) and an operational policy problem (solved by linear programming). The coded algorithm (in FORTRAN 10) has been tested with a semi-realistic example.     

袋装控释铁肥压根法矫治桃树黄叶病的效果

本文介绍了袋装控释铁肥压根法矫治桃树缺铁黄叶病的效果。该法具有大幅度增加叶绿素含量．提高果实产量,改善果实品质,降低矫治成本,安全可靠,效果好的特点。     

An automatic approach for the control of the airflow volume and concentrations of hazardous gases in coal mine galleries

Intelligently controlling ventilation networks after an abnormal air branch is difficult. The key variable-frequency mine ventilator control factors that are used to correct this phenomenon were discussed. To improve the fitting accuracy of the mine ventilator characteristic curves, a database of characteristic curves for mine ventilators operating at different frequencies was established using the interpolation method for optimizing uniform approximations by Chebyshev. The concept of frequency sensitivity analysis by analyzing the sensitive branch in the ventilation network was proposed. The linear function between the mine ventilator working frequency and branch wind quantity was fitted out by experiments. A model based on Tikhonov regularization measured the branch wind quantity to calculate the wind resistance in the ventilation network, which yielded a unique branch resistance model solution. The mine air was monitored by calculating the variable wind resistance from the branch wind quantity. The sensitive branch coupling in the mine ventilator variable-frequency controlled ventilation was analyzed and combined with the control theory for ventilation networks. Two types of variable frequency were controlled to adjust the branch wind quantity, the frequency-concentration (f-w) servo control method and the curve search method. The experimental model was established for the Da Liu-ta coal mine ventilation system using the mine ventilator variable-frequency system controller to adjust the branch wind quantity. Because gas is explosive, CO₂ was used instead of gas for this experiment. The results indicate that the mine ventilator variable-frequency control automatically adjusted the branch wind quantity, which strictly followed the frequency-concentration servo control method and curve search method. Increasing the CO₂ concentration caused the mine ventilator variable-frequency controller to increase the branch wind quantity automatically to maintain the CO₂ concentration under the threshold value. The experimental results also demonstrated both the practicability of variable-frequency regulation for air branch systems and the feasibility of the branch quantity adjusted theory. Theoretical guidance for adjusting the ventilation branch quantity for a variable-frequency mine ventilator was provided.     

矿井通风网络复杂度与风机控制力量化计算

为了探究矿井通风网络复杂度与风机控制力的关系,提出分支关联度、最小距离、通风网络复杂度和风机控制力的概念。利用vCad2.0进行数字实验,对网络复杂度与风机控制力的关系进行定量研究。结果表明:随着网络复杂度的增加,矿井通风系统的有效风量率减小,且认为该值减小到60%时,视为风机控制力的极限,此时网络拓扑结构为风机所能控制的最大网络复杂度。地面集中供风时,同时工作的中段数量存在上限,最大值为7。将结论用于某有色金属矿进行实证研究,找出该矿深部中段通风困难的原因,为矿井进一步整改提供理论依据。     

长江入海口北支沿海滩涂养殖区底泥重金属污染特征及趋势评价

对长江入海口北支沿海滩涂养殖区底泥重金属污染的总体水平进行调查,结果表明,滩涂养殖区底泥重金属含量满足海洋沉积物质量一类标准要求,污染程度属于安全Ⅰ级水平,重金属潜在生态危害属轻微级别,6种重金属潜在生态危害由大到小排序依次为Cd﹥Hg﹥Cu﹥Cr﹥Pb﹥As,2005年～2011年,底泥重金属污染程度均处于安全的Ⅰ级水平。     

两种木材生物炭对铜离子的吸附特性及其机制

为探索高效利用废弃生物质资源制备生物炭去除水体和土壤中Cu~(2+)污染的可行性,本文以常见的农林废弃物苹果树枝和梧桐木锯末为原料,采用450℃限氧热裂解法制备生物炭,通过两种生物炭对Cu~(2+)的批量吸附试验,利用4种等温吸附模型(Langmuir、Freundlich模型、Temkim、D-R模型)和4种吸附动力学模型(准一级动力学、准二级动力学、Elovich模型、颗粒内扩散模型)研究了苹果枝和锯末生物炭对Cu~(2+)的吸附行为.同时,使用FTIR红外、SEM和BET比表面积及孔径分析等技术表征了生物炭的理化性质,研究了两种生物炭对Cu~(2+)吸附机制,分析了两种生物炭之间的吸附特性差异及其影响因素.结果表明:(1)苹果枝生物炭在3 h达到吸附平衡,理论最大吸附量为15.85 mg·g~(-1),锯末生物炭在6h达到吸附平衡,理论最大吸附量为17.44 mg·g~(-1),与其他研究相比,这两种生物炭体现了较高的Cu~(2+)吸附性能;(2)两种生物炭对Cu~(2+)的热力学吸附均较好地符合Langmuir模型,表明吸附过程主要是近似单分子层的有益吸附;动力学吸附均符合准二级吸附动力学模型,表明其对Cu~(2+)的吸附包括表面吸附、颗粒内扩散和液膜扩散等多种过程;(3)吸附机制主要包括静电吸附,配体(酚羟基)/离子(H+)交换和阳离子—π键作用.