雷州无瓣海桑群落7种元素的生物累积和循环

在雷州市附城镇岚北人工生态恢复的 7a生无瓣海桑群落生物量调查的基础上 ,对所采集的无瓣海桑进行了植物体各组分样品的灰分和元素含量测定与循环分析 ,结果表明 :无瓣海桑植物体不同组分的灰分含量范围为 2 .2 7%～ 2 6 .4 1% ,以细根的含量最高 ,枯枝的含量最低 .植物体各组分中 7种元素质量分数范围分别为K 0 .11%～ 1.5 6 % ,Na0 .11%～ 1.6 6 % ,Ca 0 .2 0 %～ 2 .6 6 % ,Mg 0 .15 %～ 1.5 9% ,Fe 0 .0 4× 10 -3 ～ 9.6 4× 10 -3 ,Zn 0 .0 5× 10 -4～ 1.0 3× 10 -4,Cu0 .16× 10 -5～ 1.5 0× 10 -5.其加权平均的富集系数为 0 .0 5～ 9.70 ,其中Ca >K >Cu >Na >Mg>Zn >Fe .群落现存生物量中的累积储量分别为K 10 9.76gm-2 ,Ca 138.89gm-2 ,Na 86 .5 7gm-2 ,Mg 81.0 7gm-2 ,Fe 13.139gm-2 ,Zn 0 .4 83gm-2 ,Cu 0 .10 8gm-2 .群落 2 0 0 1年的元素存留累积储量分别为Ca4 1.6 8gm-2 ,K 37.2 4gm-2 ,Mg 2 7.33gm-2 ,Na2 5 .5 6gm-2 ,Fe 4 .2 75gm-2 ,Zn 0 .188gm-2 ,Cu 0 .0 39gm-2 .2 0 0 1年归还量分别为Ca 2 8.5 9gm-2 ,K 16 .83gm-2 ,Mg 12 .0 7gm-2 ,Na 11.5 8gm-2 ,Fe 0 .916gm-2 ,Zn 0 .14 1gm-2 ,Cu 0 .0 2 6gm-2 .年吸收量分别为Ca 70 .2 7gm-2 ,K 5 4 .0 7gm-2 ,Mg 39.4 0gm-2 ,Na 37.1     

炼油企业合理用水评价方法研究

炼油企业是用水大户,也是水污染大户,如何降低该类企业的用水量和排污量是当前节水研究的焦点之一,也是环境管理的重要内容.以提高企业节水减排的积极性为目标,本文依据层次分析法原理建立了炼油企业合理用水评价指标体系,分别采用相关系数法、相似系数法来确定指标体系中各层指标的权重,这样即保留了层次分析法分类清楚、解释性强的特点,又发挥了客观赋权法人为因素少的优点.     

深圳市局地PM2.5污染事件的时空特征及典型背景环流分析

利用深圳及周边地区22个环保监测站的PM_(2.5)小时数据、深圳市152个高密度(2.5 km×2.5 km)自动气象站及3部边界层风廓线仪的探测数据,分析了深圳市局地PM_(2.5)污染事件的时空变化特征及其背景环流特征.结果表明:深圳市西北角和东北角是局地PM_(2.5)污染最频繁的2个区域,局地污染事件发生次数约占总污染事件次数的40%,每日夜间至次日凌晨是局地污染高发期.各个季节局地PM_(2.5)污染发生的大尺度环流形势不同,春季为变性高压脊配合西南低槽发展型,夏季为热带气旋外围环流影响型,秋季为副高控制下的弱高压脊型,冬季主要为冷锋前、弱高压脊或均压场控制型.局地海-陆、丘陵-平原热力差异造成的局地环流易导致地面弱风和局地辐合的出现,成为诱发局地PM_(2.5)污染的直接原因.     

综放工作面覆岩破坏特征及裂隙演化相似模拟试验研究

针对煤层开采后常出现矿压显现剧烈、煤岩透气性增大和地表下沉等问题,利用二维相似模拟试验研究综放工作面覆岩破坏特征并通过分形理论表征裂隙演化规律.试验结果表明:煤层基本顶初次来压步距为78 m,周期来压步距为24 m;煤层采动裂隙发育,距煤层顶板超过35 m;煤层开采后形成的覆岩裂隙具有分形特征,其分形维数随工作面的推进...     

THE EFFECTS OF ARTIFICIAL CIRCULATION ON A SMALL NORTHEASTERN IMPOUNDMENT1

ABSTRACT: Artificial circulation was applied at East Sidney Lake, a small, eutrophic impoundment in New York, to improve the water quality of the reservoir and tailwater. Treatment was successful at both reducing the stability of the reservoir and maintaining higher mean oxygen concentrations in the bottom waters. Discharge waters had lower metals and phosphorus concentrations during treatment years. However, vertical temperature differences, although minimal, were still sufficient to permit chemical stratification and some phosphorus release from the sediments. Frequent mixing events during periods of low stability, and runoff from storm events, also appeared to increase transport of phosphorus into the epilimnion. Overall, treatment did not result in decreases in algal populations or improvements in water clarity.     

全球能源消费与CO2排放量

在收集全球能源储量和流通状况的基础上，综述了世界各地区能源消费量和各国人均能源水平，汇总了全球ＣＯ２排放总量及各大洲对全球ＣＯ２排放量的贡献率，到２１００年，全球Ｃ矿量预计将从目前６０亿ｔ／ａ增加到３６０亿ｔ／ａ，同时，旨出１９９６年中世界人口１８．８％的北美、欧洲、日本、ＣＯ２排放３１．６亿ｔ（碳），占全球当年ＣＯ２排放总量的５２．４％。     

The Influence of Synoptic-scale Air Flow and Local Circulation on the Dust Layer Height in the North of the Taklimakan Desert

The present study investigates the influences of synoptic-scale air flows and local wind circulations on the dust layer height (DLH) in the Taklimakan Desert, based on lidar observations performed in the north of the desert in March 2003. The DLH fluctuates approximately every three days between 2500 m (above sea level) and 5000 m, including diurnal variations. Meteorological analyses and numerical simulations show that the three-day fluctuation of DLH corresponds with variations in synoptic-scale air flows over the Taklimakan Desert, and the diurnal variations are linked to downdrafts and updrafts that are formed over the north of the desert as part of local circulations. When strong northerly winds prevail in the upper troposphere and a developed valley wind blows toward the Tienshan Mountains in the lower troposphere, the downdrafts strengthen in the middle troposphere over the north of the desert, lowering the DLH to about 2500 m. In contrast, the DLH rises to about 5000 m when the updrafts develop between strong southerly winds in the upper troposphere and a developed mountain wind blowing from the Tienshan Mountains. Simulations for the local circulation behavior without the presence of the Tienshan Mountains demonstrate that the valley and mountain winds on the southern slope of the Tienshan Mountains control the intensity of the downdrafts and updrafts, thereby influencing the DLH over the north of the Taklimakan Desert.     

A HYDRODYNAMIC MODELING STUDY TO DETERMINE THE OPTIMUM WATER INTAKE LOCATION IN LAKE PALDANG,KOREA1

A three‐dimensional hydrodynamic model was applied to Lake Paldang, South Korea. The lake has three inflows, of which Kyoungan Stream has the smallest flow rate and poorest water quality. Since all drinking water intake stations are located near the confluence of Kyoungan Stream within the lake, this contaminated tributary may have a significant impact on the quality of drinking water sources. The optimum drinking water intake location was determined from the applied model. The model was calibrated and verified using the data measured under different hydrological conditions. The model results were in reasonable agreement with the field measurements in both calibration and verification. The circulation and spreading patterns of the incoming flows in the lake, as well as their composition ratios to the drinking water intakes were determined from the model, and three alternative intake locations were proposed. The simulation results suggested that the horizontal and vertical relocations of the intake aqueduct could significantly decrease the composition ratio of the contaminated water. From this study, it was concluded that the three‐dimensional hydrodynamic model could successfully simulate the temporal and spatial mixing patterns of incoming flows and become a useful tool in determining the optimum water intake location in Lake Paldang.     

武钢循环冷却水钢管腐蚀的原因及其对策

针对武钢循环冷却水系统部分钢管腐蚀,造成管管漏水,严重影响正常生产的问题.探讨了钢管产生腐蚀的原因及其对策.近2年,通过实施减缓循环冷却水钢管腐蚀的对策,取得了明显的效果.     

旋风水膜除尘器的捕尘性能和结构设计

借助于Leith和Licht的边界层分离理论 ,对轴向出风旋风水膜除尘器的捕尘性能进行了分析 ,得出了捕尘效率的理论公式、径高比等无量纲准数