烟煤层燃炉颗粒物的生成特征与管理控制

以95台中小型燃烟煤层燃炉(≤70MW)的燃料特性分析数据和颗粒物(PM)排放实测数据为基础,利用统计分析方法,研究了锅炉出力、过量空气系数、燃煤灰分含量对燃烧过程中PM初始排放浓度的影响,分析了燃煤锅炉PM排放现状,讨论了我国中小型燃煤锅炉PM排放管理控制的潜力和可行性。结果表明,在锅炉运行负荷≥80%的条件下,PM初始排放浓度随过量空气系数和燃煤灰分含量的增加略有增大,而与锅炉出力无关;在用烟煤层燃炉PM排放浓度基本上能够满足国家现行污染物排放标准规定的排放限值要求;有96%的锅炉所采用的除尘装置的除尘效率大于80%;与其他国家相比,目前我国对于中小型燃煤锅炉PM的排放控制还处于中等水平,建议在国家层面上适时提高燃煤锅炉颗粒物的排放限制。     

DEHP经sirt1/pgc-1a通路诱导的HepG2细胞线粒体损伤效应

为研究邻苯二甲酸二（2-乙基己基）酯（DEHP）是否通过sirt1/pgc-1a通路对细胞产生损伤效应， 通过体外培养HepG2细胞，在1.6， 8， 40， 200， 1000mmol/L DEHP处理24或48h后，采用CCK-8测定细胞活力，ATP试剂盒检测细胞内ATP含量，NO试剂盒检测细胞上清NO含量，ELISA试剂盒检测细胞上清炎症因子TNF-a、IL-6的含量；同时在DEHP作用于HepG2细胞24或48h后，用Western blot检测线粒体调控基因sirt1、pgc-1a，nrf1、tfam的蛋白表达.结果表明：不同浓度的DEHP处理24， 48h后，细胞活力在高剂量都呈显著下降趋势.DEHP能引起ATP含量的显著下降、炎症因子含量的显著提高，但NO含量无显著变化.4种线粒体调控基因的蛋白表达水平sirt1、pgc-1a，nrf1、tfam在24h时无显著变化.而在48h时，随着剂量增加蛋白含量呈上升后下降趋势，并且sirt1在8mmol/L呈显著上升趋势，随后每个蛋白都在1000mmol/L显著下降（P < 0.05）.DEHP能引起HepG2细胞氧化应激，并通过影响sirt1/pgc-1a信号通路表达来影响线粒体生物合成从而造成细胞损伤.     

Environmental regulatory and policy framework in China: an overview

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Evaluation of design alternatives for sewing scissors with respect to hand performance,discomfort and usability

The effects of three re-designed models of sewing scissors on hand performance measures, discomfort and usability were investigated, and the results were compared with those of conventional scissors. Adjustments were made to the scissors handle with emphasis on more neutral wrist postures (bent handle - model A), correction of the thumb's position and movements (model B) and reducing hand/finger discomfort (model C) while working with the tool. The results showed some improvements in hand performance, muscular effort, usability and discomfort with model B compared to the conventional model. Better hand performance and usability and lower discomfort were recorded with model C compared to the conventional model. The results suggest that the correction of the thumb's position and movement (model B) or even reduced hand/finger discomfort (model C) are perhaps more important considerations in scissors design than improved wrist posture (model A) for improving users' performance and usability of the tool.     

某大型机加车间数控机床减噪工程测试与分析研究

为研究大型机加车间噪声减噪工程现状效果和特点,选取某大型机加车间数控机床为研究对象,对其进行减噪工程治理,现场实测了治理前和治理后的噪声数据,并对噪声测量结果进行分析。研究结果表明:数控机床操作人员8 h连续等效A声级从治理前的89.2 dB(A),降到治理后的74.3 dB(A),降低了16.7%.;数控机床操作岗位位置测点,在加工1个机件的测量时间段里,噪声值从治理前的85.9 dB(A),降到治理后的55.1 dB(A),降低了33.85%;对机加车间现场布置了67个测点,在加工1个机件的测量时间段里进行测量,得到该车间噪声治理前和治理后噪声分布图;对数控机床减噪工程治理前和治理后的频谱进行了分析,得出治理前和治理后各自的最大声级所在频段不随距离的改变而改变,高频减噪效果显著。     

ESTIMATING NONPOINT SOURCE POLLUTION LOADS WITH A GIS SCREENING MODEL1

ABSTRACT: The St. Johns River Water Management District (SJR-WMD) is using a Geographic Information System (GIS) screening model to estimate annual nonpoint source pollution loads to surface waters and determine nonpoint source pollution problem areas within the SJRWMD. The model is a significant improvement over current practice because it is contained entirely within the district's GIS software, resulting in greater flexibility and efficiency, and useful visualization capabilities. Model inputs consist of five spatial data layers, runoff coefficients, mean runoff concentrations, and stormwater treatment efficiencies. The spatial data layers are: existing land use, future land use, soils, rainfall, and hydrologic boundaries. These data layers are processed using the analytical capabilities of a cell-based GIS. Model output consists of seven spatial data layers: runoff, total nitrogen, total phosphorous, suspended solids, biochemical oxygen demand, lead, and zinc. Model output can be examined visually or summarized numerically by drainage basin. Results are reported for only one of the SJRWMD's ten major drainage basins, the lower St. Johns River basin. The model was created to serve a major planning effort at the SJRWMD; results are being actively used to address nonpoint source pollution problems.     

SELECTION OF WASTE DISPOSAL SITES USING GIS1

ABSTRACT: Geographic Information Systems (GIS) technology is used to identify candidate sites for a solid waste disposal facility in the Gölbasi region of Turkey that has suffered from the negative impact of a current but poorly-located open-dump site on the environment. The municipality of Gölbasi has noticed its deleterious effect on the environment, and has thus decided to dismiss this open-dump site and search for new landfill sites. In this study, the procedure followed under a GIS framework rejects the unacceptable sites considering environmental factors exclusively, other than economic and political issues, contained in the form of multiple layers of attribute information to select the candidate sites for landfilling wastes through an overlay analysis performed by GIS software, ARC/INFO V 7.1. For the spatial data requirements of GIS, a number of thematic map layers (ground water, wetlands and swamp areas, surface water, roads, topographic contours, ecological features, settlements, erosion susceptibility zones, and soil type) are prepared in digital form. In this application, GIS is considered as a screening tool in a site selection process to narrow the number of candidate sites, subsequently leading to one or more sites for detailed investigation. Preliminary ranking for a group of potential sites is done on the basis of simple calculations coupled with on-site field studies.     

减少木材加工企业粉尘污染的切削技术

木粉尘是我国木材加工企业环境污染及产生职业病的主要原因,为控制木粉尘产生量和散发量,笔者从切削及刀具技术角度探讨了降低空气中粉尘浓度的途径;指出粉尘是木材切削加工的产物,其产生量与散发量直接与木材切削方式、切削条件和刀具的结构密切相关;提出研究无屑、少屑和顺畅排屑等方面木材切削和刀具技术的重要性。综述了激光、高压水喷射等特种木材切削技术的研究及应用现状;介绍了金刚石木工铣刀及超薄硬质合金圆锯片等先进刀具技术;探讨并分析了影响木粉尘产生量的切削因素。指出我国大多数木材加工企业工作车间或作业场所的空气中,粉尘浓度严重超标,因此,研究和开发具有环保特点的绿色切削技术和木工刀具制造技术具有重要意义。     

Evaluating response surface designs for uncertainty analysis and prescriptive applications of a large-scale water quality model

Environmental models are often too large and cumbersome for effective use in regulatory decision making or in the characterization of uncertainty. This paper describes and compares four response surfaces that could complement a large-scale water quality model, the U.S. National Water Pollution Control Assessment Model (NWPCAM), in simulation and regulatory decision support applications. Results show that a physically based reduced-form model that exploits the mathematical structure of the underlying water quality model is a better predictor of policy-relevant outputs than the polynomial expansions that are frequently used in response surface studies.     

Long-term variation in surface ozone and its precursors in Athens,Greece

INTENTION, GOAL, SCOPE, BACKGROUND: Photochemical pollution is a very complex process involving meteorological, topographic, emission and chemical parameters. The most important chemical mechanisms involved in the atmospheric process have already been identified and studied. However, many unknown parameters still exist because of the large number of participating chemical reactions. OBJECTIVE: The present study investigates the processes involved in the photochemical pollution effect of an urban station located in the greater area of the Athens basin and gives a plausible explanation for the different seasonal ozone development between that station and another rural one. Furthermore, the distribution of the mean monthly surface ozone observed at the urban station during 1987-2001 is examined in order to create a relevant forecasting tool. METHODS: Averaged hourly data of O3 and NOx observations monitored at the above mentioned stations, during 1987-2001, have been used in order to derive the daytime (7:00-15:00) values. Trajectories calculated by using a 2D-trajectory code and meteorological data, during the period 1988-1996, have also been used. RESULTS AND DISCUSSION: At the urban station, the percentage negative trend of NO and NOx data in winter and summer is higher than that in spring and autumn, while the percentage ozone trend is maximum in the summer. On the contrary, the negative surface ozone trend at the rural station exhibits a minimum in summer and a maximum in autumn and winter. The mean seasonal wind-rose for the selected months shows that the northward wind flow dominates during June, the month of the lowest negative ozone trend in the rural station. Finally, the development of the forecasting tool shows that the mean monthly surface ozone data during the period (1987-2001) demonstrates a semi-log distribution. CONCLUSIONS: Air transport effect on the air pollution of the rural station (not blocked by mountains) is deduced as a possible reason for the different seasonal ozone development observed between the rural and the urban station. Finally, the discrepancies between the theoretical probabilities deduced by the model and the empirical ones appear to be very small, and the corresponding correlation coefficient is 0.99. RECOMMENDATION AND OUTLOOK: However, to interpret the aforementioned statistical results about the negative trends in ozone and its precursors, additional parameters can be taken into account. Changes in NOx concentrations, for instance, can result not only from changes in emissions or meteorological conditions. There might also be a contribution through changes in the atmospheric composition. A study of the contribution of changes in atmospheric composition to trends of observed NOx concentrations requires that a series of steps be taken (removal of meteorological influence in the time series, calculation of trends in OH concentrations, etc.).