钠钙双碱法烟气脱硫主要影响因素的实验研究

采用纤维栅洗涤器在实验室对钠钙双碱法烟气脱硫效率的主要影响因素 :洗涤器的风速、烟气SO2 初始浓度、吸收液 p H值及 [Na+ ]浓度、液气比等进行了模拟实验 ,得出了它们与烟气脱硫效率的关系。     

The accumulation of geophysical data in digitized format may give glimpses into the evolution of the Earth

The increasing use of computers since the 1960s, has implied the digitization of observations in meteorology, oceanography and other observational sciences. Enough data has been accumulated to suggest that some patterns of evolution in the world may be discernable. The present article deals with what appears as changing tides around Canada.     

西部开发与生态经济

论述了西部大开发必须走生态型经济发展的路子，并依托西部地区资源的开发与保护，提出了西部经济开发类型的选择和有关政策支持。     

西部生态旅游模式的市场研究

西部地区具有丰富的生态旅游资源，中国名山资源的23％都集中在西部地区，西部少数民族文化旅游资源也极为丰富。我国正在西部实施可持续战略，发展生态旅游模式正顺应了这一战略。作者对在西部建立生态旅游的要素市场、国内外游客市场、资金市场进行了考察研究，并结合西部大开发战赂，论证了生态旅游在西部的市场可行性。     

The source and fate of sediment and mercury in the Tapajós River, Pará, Brazilian Amazon: Ground- and space-based evidence

We present results of mercury (Hg) in surface waters and soils and an analysis of satellite imagery from the Tapajós River basin, Brazilian Amazon, and the Reserva Garimpeira do Tapajós, the legal gold mining district of the basin. Hg bound to suspended sediment was roughly 600 and 200 times the concentration of dissolved Hg per litre of water, in impacted and pristine areas, respectively. Suspended sediments thus represent the major pathway of river-borne Hg. Median concentrations of Hg in suspended load from both impacted and pristine waters were 134 ppb, and 80% of samples were below 300ppb-in the range of naturally occurring surficial materials in the tropics. Regionally, riverine Hg fluxes were proportional to the concentration of total suspended solids. This shows that the dominant source of Hg is the sediment itself rather than anthropogenic mercury discharge from the small-scale mines. To independently test this conclusion, a mass balance was performed. A conservative calculation of the annual export of mercury (Hg) from the Creporí River (a minimum) was 1.6 tonnes for the year 1998-it could be significantly larger. This amount of Hg is difficult to account for by anthropogenic discharge alone, confirming that enhanced physical erosion caused by sluicing and dredging operations is the dominant source of Hg. We therefore conclude that gold mining operations are primarily responsible for elevated Hg concentrations. The dominant source of contamination is not, however, the loss of Hg in the gold amalgamation process. Rather, the disturbance and mobilization of large quantities of Hg-rich sediment and floodplain soil into the water column during mining operations is the source of contamination. These findings shift the focus of remediation and prevention efforts away from Hg control toward soil and sediment erosion control. The minimization or elimination of Hg losses in the mining process remains important for the health of local peoples and environments, but keeping basin soils and sediments in place would be a much more effective means of minimizing Hg fluxes to the region's rivers. To gain a spatial and historical perspective on the source and extent of emissions, satellite imagery was used. We were able to reconstruct historical mining activity, locate impacted areas, and estimate historical Hg fluxes with the imagery. To do so, the spectral characteristics of satellite images were calibrated to the concentration of suspended sediment in the rivers, which, in turn, is proportional to the Hg concentration. This analysis shows that mining-induced sediment plumes have been a dominant source of sediment to the Tapajós River system for decades. As well, the intensity and location of these emissions has varied through time. For example, sediment discharge from the Creporí River was greater in 1985 than in 1998; and the tributaries on the west bank of the Tapajós were actively being mined in 1985 but had been abandoned in 1998. This type of information should greatly assist in understanding original and ongoing sources of emissions, and in managing prevention and remediation efforts.     

秦皇岛市气候变化对河流径流的影响及对策

50年来秦皇岛市气候明显变暖，多年平均气温上升约2℃；同时变干，降水减少18．3％，进而使河流径流也明显减少，其幅度超过30％。河流径流减少给生态系统带来广泛复杂的影响，也给农业、工业、城乡建设带来威胁，因此必须尽快采取发展节水技术、污水治理循环利用、海水淡化等措施。     

昌黎黄金海岸自然保护区现状

昌黎黄金海岸自然保护区的建立给当地及相邻地区带来多种效益，其中有保护生物多样性、维护海岸稳定、完善防护林等作用的生态效益；促进当地经济发展的社会效益及以生态旅游和水产养殖为主的经济效益。与此同时，也带来一些问题，如海洋执法问题。对此，保护区要建立海监机构,并与科学管理处合作，加强执法以保护生态环境。     

Slow Growth and Lack of Recovery in Overfished Holothurians on the Great Barrier Reef: Evidence from DNA Fingerprints and Repeated Large-Scale Surveys

Abstract:  Commercially fished holothurians have important functions in nutrient recycling, which increases the benthic productivity of coral reef ecosystems. Thus, removal of these animals through fishing may reduce the overall productivity of affected coral reefs. To investigate the potential for recovery of overfished holothurian (  Holothuria nobilis ) stocks on the Great Barrier Reef (GBR), we (1) conducted field surveys on 23 reefs after fishery closure, (2) modeled total virgin biomass and compared it with the total amount fished, and (3) estimated individual growth rates with a DNA fingerprinting technique. Two years after fishery closure, no recovery of H. nobilis stocks on reefs previously open to fishing was observed. Densities on reefs protected from fishing since the onset of the fishery in the mid 1980s remained about four times higher than on fished reefs. Based on density estimates and geographic information system data on the habitat area of each reef, we calculated that the virgin biomass (in the main fished area between 12° and 19°S) was about 5500 t and is now about 2500 t. The reduction is on the same order of magnitude as the total amount fished until 1999 (approximately 2500 t). The DNA analysis of repeated samples on three locations indicated high recapture rates of fingerprinted and released individuals of H. nobilis . Fitting growth curves with Francis's growth function indicated that medium-sized individuals (1 kg) grew 35–533 g /year, whereas large animals (2.5 kg) consistently shrank. Small animals (<500 g) were rarely observed. In combination, these data indicate that production of H. nobilis stocks is very low, presumably with low mortality, low recruitment, and slow individual growth rates. Consistent with anecdotal evidence, recovery of H. nobilis stocks on the GBR may take several decades, and we suggest a highly conservative management plan to protect both the stocks and the ecosystem.     

Impact of Climate Change on Urban Agglomerations in China＇s Coastal Region

Climate change and urbanization issues are the two key factors that make humans liable to be affected by disasters, which are overlapped in urban agglomeration. The five big urban agglom- erations of C...     

基于总过氧自由基观测研究合肥市西郊夏季O3生成特征

2020年8月利用化学放大法对合肥市西郊大气总过氧自由基RO^*₂·(RO₂·+HO₂·)体积分数进行监测,并结合O₃和其前体物,分析了过氧自由基体积分数、O₃生成速率和O₃生成对前体物的敏感性.结果表明,观测期间总过氧自由基体积分数的日均值呈典型的单峰型变化,12:00左右出现最高值,日间峰值体积分数为43.8×10^-12,日间RO^*₂·与太阳辐射强度、温度和O₃呈明显的相关性.利用实测RO^*₂·和NO,获得合肥市西郊夏季O₃生成速率,日间峰值为10.6×10^-9h^-1,O₃生成速率对NO变化更为敏感.基于大气自由基和NO_x(NO+NO₂)反应去除速率占比(Ln/Q),对合肥...