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951.
燃煤飞灰制备脱硫剂的试验研究   总被引:1,自引:0,他引:1  
以飞灰和石灰为原料,经消化制得不同消化时间、消化温度和原料配比的脱硫剂,对实验样品进行比表面积、孔径分布等表面特性测定,并在固定床上进行脱硫试验研究。研究表明,合理的孔径分布利于脱硫反应,实验制得最佳脱硫剂的比表面积是54.953m2/g。  相似文献   
952.
Researchers have noted that current water quality protection strategies, like nutrient management plans, lack a sound hydrological underpinning for pollutant transport processes. This is especially true for areas like the northeastern U.S. where copious research has shown that variable source area hydrology largely governs runoff generation. The goal of this study was to develop a scientifically justified method to identify the locations that generate overland flow. Furthermore, this methodology must be computationally simple enough that it can be utilized or incorporated into nutrient management plans and other established water quality tools. We specifically tested the reliability of the 'distance from a stream,'D(s), and the 'topographic index,'lambda, to predict areas with a high propensity for generating overland flow, i.e. hydrologically sensitive areas (HSA). HSAs were defined by their probability of generating runoff, P(sat), based on 30 year simulations using a physically based hydrological model. Using GIS, each location's P(sat) was correlated with D(s) and lambda. We used three Delaware Co., NY watersheds in the New York City watershed system with areas varying in size from 1.6 to 37 km2 and with forested and agricultural land uses. The topographic index gave stronger, more regionally consistent correlations with P(sat) than did D(s). Equations correlating lambda and P(sat) for each month are presented and can be used to estimate hydrological sensitivity in the region surrounding our study watersheds, i.e. in Delaware Co. This work is currently being incorporated into an Internet Mapping System to facilitate user-friendly, on-line identification of HSAs.  相似文献   
953.
AbstractIn the current Anthropocene Era, with numerous escalating challenges for biodiversity conservation, the inclusion of the social dimension into management decisions regarding wildlife and protected areas is critical to their success. By conducting 354 questionnaires in a Mediterranean protected area (the Biosphere Reserve of Bardenas Reales, Northern Spain), we aim to determine sociodemographic factors influencing knowledge levels and perceptions of species and functional groups as, emblematic and threatened. We found that hunters and animal husbandry workers knew more species than other social actors. Additionally, the perception of functional groups as threatened or emblematic differed between social actor groups, with statistically significant associations between perceptions and the characteristics of respondents. Interestingly, we found that although elusive steppe species are globally considered as endangered, these species were the least known by all social actor groups and rarely perceived as emblematic. This research is a novel approach and provides a better understanding of how perceptions can facilitate conservation decisions, particularly regarding endangered speciesGraphic abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01546-6.  相似文献   
954.
Introduction Landfill is still the m ost com m on w ay to treat m ore and m ore m unicipal solid w aste (M SW ) in all over the w orld, especially in C hina (Feng and C hen, 2000). H ow ever, the leachate produced from landfill is very com plicated and va…  相似文献   
955.
划分地下水水源地保护区的研究   总被引:10,自引:1,他引:9       下载免费PDF全文
从环境水文地质学的角度探讨地下水水源地保护区的划分,并提出局地服从区域、地面服从地下,以区定性,不以点定区等项划分原则及包气带防护能力评价,包气带粘性厚度等值线分区方法,并在唐山市城市地下水水源地保护区的划分中得到实际应用。  相似文献   
956.
本文采用全国统一方法,检测了广西柳州地区常用建材中~(226)Ra、~(232)Th、~(40)K的比活度.以煤灰砖最高,石灰石最低。比活度依次为煤灰砖>粘土砖≈土壤>水泥>灰砂砖>混凝土制品>石灰石.经估算,煤灰砖致居民的有效剂量当量较大,为3.98mSv·a~(-1);其它各种建材致居民的有效剂量当量在0.23—1.01mSv·a~(-1)之间,低于、等于或略高于本底.  相似文献   
957.
以黄河中游多沙粗沙区子洲径流站和离石王家沟试验站的径流场观测资料为基础,对黄土高原丘陵沟壑区坡沟系统中高含沙水流特征与地貌因素及重力侵蚀的关系进行了研究.研究结果表明,黄土坡面的地貌垂直结构和由此所决定的侵蚀作用垂直分异,对坡面高含沙水流的形成有很大的影响,高含沙水流形成于峁坡下部和沟坡,并在各级沟道中进一步发展.坡度对高含沙水流的形成有较大影响,如果侵蚀过程以溅蚀、面蚀、细沟侵蚀为主,不发生切沟及显著的重力侵蚀,则存在着一个坡度临界值,大于此值后,含沙量反而减小.重力侵蚀对坡沟系统高含沙水流的形成起着十分重要的作用,由于强烈的重力侵蚀的参与,高含沙水流的沙峰滞后于洪峰,落水阶段的含沙量常常大于同流量下涨水阶段的含沙量.  相似文献   
958.
解毒铬渣安全性研究   总被引:13,自引:1,他引:12  
用扫描电镜、比表面测定仪、X-射线衍射仪测定了铬渣及解毒铬渣的表面形貌、比表面及物相组成。在模拟环境条件下对解毒铬渣进行了浸出毒性试验,结果表明,解毒铬渣在环境条件下是安全的。   相似文献   
959.
崔平  姚亨  齐立文 《环境科学》1996,17(2):26-28
通过对北京地区稻田种植上空甲烷浓度持续2a的观测发现,该地区大气中1992和1993年甲烷的年平均浓度1.16,1.17μg/L,且季节性变化规律以及年际变化规律有比较的趋势,一年中当地上空甲烷的浓度呈明显的冬春低夏秋高的趋势,且夏季甲烷浓度的变化幅度比较大。该地区甲烷浓度的日变化趋势不明显。在水稻期内的7、8月莘,稻上空甲烷浓度和水稻甲烷排放速率有密切的关系,动态分析表明,该地区大气中甲烷浓度年  相似文献   
960.
Two-week average NO2 concentrations were measured in Amsterdam (NL), Huddersfield (UK) and Prague (CZ) at 80 sites in each study area, to assess small area spatial variation, using a tube type and a badge type passive sampler. The badges appeared to be less robust than the tubes. The lower detection limit for tubes and badges was 3.7 and 0.91 µg/m3, respectively for fortnightly measurements. Accuracy of the samplers was determined with reference methods (chemiluminescence). The mean ratio of the concentration measured by diffusion tube over that by the reference method was 1.16, 1.03 and 0.77 in Amsterdam, Huddersfield and Prague, respectively. Standardizing the badges for the results obtained in Amsterdam, the relative mean ratio of the concentration measured by the badges over that by the reference method was 0.95 and 0.58 in Huddersfield and Prague, respectively. NO2 concentrations measured by the two designs did not differ significantly. Mean NO2 concentrations were 36, 26 and 22 µg/m3 in Amsterdam, Huddersfield and Prague, respectively. The precision of duplicate tubes and badges was 8% and 11%, respectively. Both samplers are suitable for determining real variation in small area NO2 concentrations in the ranges which occurred. It is concluded that low-cost, simple NO2 passive samplers can provide reliable information about variation in NO2 concentrations within urban or rural areas on a small spatial scale. Based on its robustness and its precision, tubes were preferred over badges.  相似文献   
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