A theoretical study of hydrogen-bonded molecular clusters of sulfuric acid and organic acids with amides

Amides, a series of significant atmospheric nitrogen-containing volatile organic compounds (VOCs), can participate in new particle formation (NPF) throught interacting with sulfuric acid (SA) and organic acids. In this study, we investigated the molecular interactions of formamide (FA), acetamide (AA), N-methylformamide (MF), propanamide (PA), N-methylacetamide (MA), and N,N-dimethylformamide (DMF) with SA, acetic acid (HAC), propanoic acid (PAC), oxalic acid (OA), and malonic acid (MOA). Global minimum of clusters were obtained through the association of the artificial bee colony (ABC) algorithm and density functional theory (DFT) calculations. The conformational analysis, thermochemical analysis, frequency analysis, and topological analysis were conducted to determine the interactions of hydrogen-bonded molecular clusters. The heterodimers formed a hepta or octa membered ring through four different types of hydrogen bonds, and the strength of the bonds are ranked in the following order: SOH???O > COH???O > NH???O > CH???O. We also evaluated the stability of the clusters and found that the stabilization effect of amides with SA is weaker than that of amines with SA but stronger than that of ammonia (NH₃) with SA in the dimer formation of nucleation process. Additionally, the nucleation capacity of SA with amides is greater than that of organic acids with amides.     

青藏高原东南部自然带垂直分布的数学模型及生态学研究

采用三维数学模型研究了青藏高原东南部自然带垂直分布规律，影响垂直带分布的主要因子是热量条件。常绿阔叶林带、针阔叶混交林带、山地暗针叶林带和高山灌丛草甸带上限的温暖指数、寒冷指数分别为６５℃·月、４３℃·月、１６℃·月和１０℃·月及－１０℃·月、－２４℃·月、－５５℃·月和－７５℃·月；其可能蒸散值分别为６２０ｍｍ、５００ｍｍ、４１０ｍｍ和３００ｍｍ。     

Urban garbage disposal and management in China

This paper, probing into the present situation of urban domestic garbage by analyzing its growing trend, compositional change and regional difference, reveals the problems existing in its disposul and management in China. Meanwhile, a questionnaire was conducted in five big cities around China for surveying urban residents‘ attitudes towards garbage disposal and management policies and measures. Results showed the outlmt of urban domestic garbage in Chinese cities is ever increasing, and the recoverable materials and energy in garbage composition are also increasing. The population growth, economic development, and increase of residents‘ expenditure level are the main factors influencing the growing output and changing composition of the garbage. Information acquired from the questionnaire showed that majority of the urban residentsare in favor d the garbage reduction policies and managerial measures and are willing to collaborate with municipal government in battling against gadbage. Based on the analysis and questionnaire, some policymaking-oriented suggestions such as operating the garbage disposal from a social welfare service to a sector of profit-gaining enterprises, transferring the garbage management from passive end control to active source control,promoting the classified garbage collection in cities around China, and charging garbage fees for its cleanup and disposal, have also been put forward in the paper.     

环境友好型城市环境指标体系研究

在提出环境友好性城市的基础上,阐述了环境友好型城市的基本内涵,提出了建设环境友好型城市环境指标体系的原则,并从环境保护与污染控制、环境经济社会协调度、环境生态建设与管理、环境伦理和意识方面选取了具体指标,构成了环境友好型城市完整的环境指标体系;同时对各评价指标因子的量化标准值的确定进行了分析研究,并提出了指标体系的计算方法和今后环境指标的研究方向.     

中文Windows环境下的海上溢油预报系统

本文以辽东湾为示范海区，建立了中文Ｗｉｎｄｏｗｓ环境下的海上溢油预报系统。采用已经验证的环境动力和溢油行为模型，可提供海面油膜的位置和覆盖面积，水体中油的浓度分布以及溢油的比重、粘度、蒸发量、残留量、平均厚度等物化参数的实时预报信息，或用于溢油的环境风险评价。系统界面友好，输入方便，操作简单，反应快捷、后处理功能完备，并具有可扩充性。     

三氯乙烯和四氯乙烯与羟基自由基加成反应的理论研究

用从头计算法在ＵＨＦ／６－３１Ｇ水平上研究了三氯乙烯和四氯乙烯与羟基自由基的加成反应，通过振动分析确认了过渡态，计算了内禀反应坐标（ＩＲＣ）。研究表明，该反应能生成较稳定的加成中间体，活化势垒分别为５０．８７ｋＪ·ｍｏｌ＾－１和６３．８３ｋＪ·ｍｏｌ＾－１，且二者反应在常温下均为熵减、放热、吉布斯自由能变化小于零，能自发进行的过程。     

大学校园环境噪声的影响分析与防治对策

通过监测广西大学校园功能区环境噪声及周边市政道路交通噪声,并进行对比分析.监测结果表明,广西大学校园环境已受噪声污染,校园外部环境噪声大于内部,周边市政道路交通噪声及校内交通噪声是校园的主要噪声源.提出了校园环境噪声污染的防治对策.树木、花草、建筑物等具有减噪作用应充分利用.     

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days lal)oratory incubations. The herbicides were applied to soil alone, soiI-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soilSDBS mixtures and soil-HA mixtures were 4.6d, 6, ld and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2-melhvl-6-ethvlaniline for acetochlor, and hvdroxvbutachlor and 2,6-diethvlaniline for butachlor.     

Influence of nonionic surfactant on the solubilization and biodegradation of phenanthrene

Phenanthrene was solubilized in two different nonionic surfactants, Tween80 and Triton X-100. The bioavailability of phenanthrane to the bacteria isolated from the petroleum contaminated soils was studied based on the rotary flasks experiments. The results showed that the concentration of nonionic surfactants above the critical micelle concentration (CMC) can increase the solubility of phenanthrene in water andwere innoxious to the phenanthrene-degrading bacteria; phenanthrene solubilized in the micelles of Tween80 was bioavailable and biodegradable. The research demonstrated the potential of surfactant-enhanced bioremediation of soils contaminated by hydrophobic organic comoounds( HOCs).     

掺杂ZrO2、TiO2、γ－Al2O3对Pt、Pd／Al2O3燃烧

运用ＸＲＤ、ＢＥＴ、ＤＴＡ等测试技术，研究并考察了掺杂ＺｒＯ２，ＴｉＯ２，ｒ－Ａｌ２Ｏ３对Ｐｔ－Ｐｄ．Ａｌ２Ｏ３燃烧催化剂性能的影响，结果表明，ＺｒＯ２对Ａｌ２Ｏ３晶相的γ型转为α型有明显的抑制作用，而ＴｉＯ２的添入则起促进作用。