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971.
972.
973.
974.
为适应新的海域使用功能要求,科学管理、严格保护海洋环境,结合全市海洋功能区划和总体发展规划,对天津市近岸海域环境功能区划进行调整。展现了调整方法、过程及成果。调整后的天津近岸海域环境功能区共分为四大类21个环境功能区,相比之前的区划,调整后的区划中一类环境功能区范围有较大缩小,二、三、四类近岸海域环境功能区面积均有增加。对本次区划调整过程中发现的主要问题进行了分析,在此基础上提出若干建议,包括将近岸海域环境功能区提升至战略高度,将《近岸海域环境功能区划分技术规范》上升为国家标准,修订《近岸海域环境功能区划分技术规范》及《近岸海域环境功能区管理办法》等。 相似文献
975.
采用Daniel趋势检验法对哈尔滨市近年来SO2、NO2和PM10年均浓度变化趋势分析,并对城市总人口与经济、产业结构、民用汽车保有量和能源状况五个城市发展因素进行数据统计分析,用SPSS探究城市发展过程中影响大气污染的因素及相关性.结果表明:浓度变化趋势是SO2明显上升;NO2缓慢上升;PM10整体明显下降,但在2013年点突增至了0.119 mg/m3.SO2与NO2显著相关,相关系数为0.533.经统计,哈尔滨人口经济发展、产业结构调整较为缓慢,全市民用汽车保有量增加并未对NO2浓度影响显著,能源结构依然以煤为主,虽然能源强度提升,但也存在着煤质、散煤的问题.哈尔滨市各城市发展因素与污染物浓度关联度不显著. 相似文献
976.
977.
金属冶炼产生的废渣在无法采用资源化处置情况下需要安全填埋。安全填埋的前提是转移到具备优良地质条件并且采取了足够的工程防渗措施的场地,通常会遇到选址困难和二次污染等系列问题。以云南东北部某铅锌冶炼企业历史产生的废渣堆为研究对象,通过详细勘察研究渣堆下部基础地质和水文地质条件,并在渣堆下部及周边污染特征组分空间分布特征详细调查和分析的基础上,论证了该历史渣堆具有就地处置可行性的水文地质条件,可以通过系列地下水防污工程措施来控制地下水污染源。处置方案已经提交企业并处于工程实施阶段。该研究提出的解决问题的思路和技术方案对我国具有类似地质及水文地质条件的固废处置具有一定的参考价值。 相似文献
978.
We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials, which were formed by layered deposition of multiple anatase TiO2 nanosheets. The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet, including crystal steps and edges, thereby fixing the Au–TiO2 perimeter interface. Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au–TiO2 interface. The doped Au induced the formation of oxygen vacancies in the Au–TiO2 interface. Such vacancies are essential for generating active oxygen species (*O−) on the TiO2 surface and Ti3 + ions in bulk TiO2. These ions can then form Ti3 +–O−–Ti4 + species, which are known to enhance the catalytic activity of formaldehyde (HCHO) oxidation. These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials. 相似文献
979.
Mercury(Hg), mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines(CPMs) was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry(ICP-MS). The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar(2.5%–30.9%), the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower(0.037%). By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives(FAO/WHO) safety guideline, the average daily intake dose(ADD) of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs. 相似文献
980.
As an insufficiently utilized energy resource,oil shale is conducive to the formation of characteristic microbial communities due to its special geological origins.However,little is known about fungal diversity in oil shale.Polymerase chain reaction cloning was used to construct the fungal ribosomal deoxyribonucleic acid internal transcribed spacer(r DNA ITS)clone libraries of Huadian Mine in Jilin Province,Maoming Mine in Guangdong Province,and Fushun Mine in Liaoning Province.Pure culture and molecular identification were applied for the isolation of cultivable fungi in fresh oil shale of each mine.Results of clone libraries indicated that each mine had over 50% Ascomycota(58.4%–98.9%)and 1.1%–13.5%unidentified fungi.Fushun Mine and Huadian Mine had 5.9% and 28.1% Basidiomycota,respectively.Huadian Mine showed the highest fungal diversity,followed by Fushun Mine and Maoming Mine.Jaccard indexes showed that the similarities between any two of three fungal communities at the genus level were very low,indicating that fungi in each mine developed independently during the long geological adaptation and formed a community composition fitting the environment.In the fresh oil-shale samples of the three mines,cultivable fungal phyla were consistent with the results of clone libraries.Fifteen genera and several unidentified fungi were identified as Ascomycota and Basidiomycota using pure culture.Penicillium was the only genus found in all three mines.These findings contributed to gaining a clear understanding of current fungal resources in major oil-shale mines in China and provided useful information for relevant studies on isolation of indigenous fungi carrying functional genes from oil shale. 相似文献