大气中CO2与O3浓度升高对植物光合作用影响研究

随着工业化进程的加快,两种温室气体CO2和O3在大气中浓度不断升高,对植物光合作用产生重要影响.通过从气体交换参数、光合色素含量、叶绿素荧光特性、光合酶、生物量及产量等多方面分析国内外CO2O3单独作用及复合作用对植物光合过程和机理、光合作用物质基础及光合产物的影响,深入了解两种污染气体作用下植物光合响应机制,以期为植物光合作用分子水平的研究以及有效应对未来全球大气变化提供理论依据.     

CTAC改性膨润土吸附去除水体中高氯酸盐的离子交换性能研究

选用阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)改性膨润土以提高膨润土对ClO4-的吸附能力.试验结果表明,CTAC改性能显著提高膨润土对ClO4-的吸附能力,在0.1～l mmol·L-1的C1O4-溶液中,6h内能迅速达到吸附平衡.有机膨润土对ClO4-的吸附最符合Langmuir等温吸附模型,其吸附容量可达0.48 mmol·g-1.pH值在4～10范围内变化对ClO-的吸附几乎没有影响.高的分配系数(Kd＞1.5×103cm3·g-1)表明有机膨润土对ClO4-有很高的选择性,各阴离子的分配系数从小到大的顺序为HPO42-＜ SO42-＜ NO3-＜ ClO4-,这与阴离子的自由水合能大小相一致.1 mol·L-1 HCl溶液对吸附剂的再生效率在96％左右,可直接使用,不用再改性.     

浅谈环境监管人员如何解读渎职司法解释研究

文章结合两高关于渎职司法解释,探讨环境监管人员的依法履职。首先简明扼要地阐述了《解释》关于滥用职权罪、玩忽职守罪的定罪量刑标准等9个方面的内容,并就失误、失职、渎职和徇私舞敝的概念进行了分析与鉴别,最后重点论述了环境监管人员在环境监管与应急管理工作中环境监管失职罪、滥用职权罪、玩忽职守罪以及企业涉嫌污染环境罪的定义、主体、时效等适用《解释》的情况,并对环境污染经济损失认定和涉嫌犯罪案件的移送进行了探讨。     

矩形独立承台受柱冲切模型在岩溶塌陷计算中的应用

结合"湘中岩溶塌陷调查项目"成果及认识,将岩溶塌陷划分为土洞发育、地面塌陷、坑壁趋稳三个阶段;通过引入基础工程学领域的矩形独立承台受柱冲切计算模型,经一定推导得出岩溶地面塌陷阶段的计算公式,并对该公式的力学意义进行了简要分析;最后以湘中典型地区岩溶塌陷为实例,对该岩溶地面塌陷计算公式进行了验证。结果表明:公式计算结果与实际情况基本相符,表明该公式可以应用于岩溶地面塌陷的预测,但需进一步验证公式的适用性和正确性,以期为岩溶塌陷灾害的防治提供依据。     

装饰不锈钢管抛光粉尘的治理

通过装饰不锈钢管抛光粉尘治理实例，介绍除尘系统密闭罩设计、除尘以及装置的降噪、防腐、防磨。     

浅议环境与经济可持续发展

介绍了可持续发展的概念、特征，论述了环境与经济发展的关系以及我国可持续发展的战略选择。     

Long-term evaluation of activated carbon as an adsorbent for biogas desulfurization

ABSTRACT

In this study, granular activated carbon (GAC) was used as an adsorbent for biogas desulfurization. Biogas containing 932–2,350 ppm of H₂S was collected from an anaerobic digester to treat the wastewater from a dairy farm with about 200 cows. An adsorption test was performed by introducing the biogas to a column that was packed with approximately 50 L of commercial GAC. The operation ceased if the effluent gas had an H₂S concentration of over 100 ppm. The GAC was replaced by a given weight of new GAC in a subsequent test. According to the results, for H₂S concentrations in the range of 932–1,560 ppm (average±SD = 1,260 ± 256 ppm), 1 kg of the GAC yielded biogas treatment capacities of 568 ± 112 m³ and H₂S adsorption capacities of 979 ± 235 g. For the higher influent H₂S concentrations of 2,110 ± 219 ppm, the biogas treatment and H₂S-adsorption capacities decreased to 229 ± 18 m³ and 668 ± 47 g, respectively. An estimation indicated a requisite cost of US$16.5 for the purification of 1,000 m³ of biogas containing 2,110 ppm of H₂S. This cost is approximately 5% of US$330, the value of 1,000 m³ of biogas.     

Acute toxicity of benzene derivatives to the tadpoles (Rana japonica) and QSAR analyses

Acute lethal toxicity (the negative logarithm of molar concentrations of 12 h acute median lethal, expressed as 12 h-log1/LC50) of 46 benzene derivatives to Rana japonica tadpoles was determined. 1-octanol/water partition coefficient (logKow)-dependent models were developed to study the toxicity of different categories chemicals. In an effort to model all chemicals, response surface analyses and stepwise multiple regression analyses were performed and successful models were obtained. A general and robust QSAR model was achieved with the combined application of variables reflecting hydrophobicity, electric property, and molecular size respectively (12h-log1/LC50 = 0.393logKow - 0.428Elumo + 0.0110Vol. + 1.362 n = 51, r2 = 0.834) using stepwise multiple regression analyses. Because of strong dissociation of carboxyl group greatly decreasing their observed toxicity, using logDow in instead of logKow the quality of the models is greatly improved. The conventional r2 and cross-validation r2(CV) were 0.914 and 0.785, respectively, indicating that QSAR was both internally consistent and highly predictive.     

Atmospheric volatilization and distribution of (Z)- and (E)-1,3-dichloropropene in field beds with and without plastic covers

The fumigant 1,3-dichloropropene (1,3-D) is considered to be a potential replacement for methyl bromide when methyl bromide is phased out in 2005. This study on surface emissions and subsurface diffusion of 1,3-D in a Florida sandy soil was conducted in field beds with or without plastic covers. After injection of the commercial fumigant Telone II by conventional chisels to field beds at 30cm depth which were covered with polyethylene film (PE), virtually impermeable film, or no cover (bare), (Z)- and (E)-1,3-D rapidly diffused upward. Twenty hours after injection, majority of (Z)- and (E)-1,3-D had moved upward from 30 cm depth to the layer of 5-20 cm depth. Downward movement of the two isomers in the beds with or without a plastic cover was not significant. (Z)-1,3-D diffused more rapidly than (E)-1,3-D. Virtually impermeable films (VIF) had a good capacity to retain (Z)- and (E)-1,3-D in soil pore air space. Vapor concentrations of the two isomers in the shallow subsurface of the field bed covered with VIF were greater than that in the two beds covered with polyethylene film (PE) or no cover (bare). In addition, VIF cover provided more uniform distribution of (Z)- and (E)-1,3-D in shallow subsurface than PE cover or no cover. Virtually impermeable film also had a better capability to retard surface emissions of the two isomers from soil in field beds than PE cover or no cover.     

基于可靠度约束的高层建筑结构优化设计

本文以文献中提出的结构体系可靠度分析的最弱失效模式法为基础,充分考虑结构体系的造价和结构的损失期望与结构体系可靠度的关系,以及结构构件的可靠度约束,提出了结构体系目标可靠度的优化决策方法;基于优化决策的结果,提出了结构体系的最优设计准则;最后,依所提出的最优设计准则,实现了高层建筑基于构件和结构可靠度约束的结构优化设计。