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971.
T. V. Kotova I. M. Miklyaeva G. N. Ogureeva E. G. Suslova L. V. Shvergunova 《Russian Journal of Ecology》2000,31(5):318-323
Objectives and methods of mapping the ecological state of the plant cover at different spatial levels—federal, regional, and local—are analyzed. The maps used as examples are as follows: at the federal level, “Ecological State of Rangelands in Russia” (1:10 000 000); at the regional level, “Vegetation of Moscow Oblast” (1:200 000); and at the local level, “Vegetation of Narofominskii Raion” and “Current State of the Plant Cover in Narofominskii Raion” (1:50 000). 相似文献
972.
Methodological approaches to the construction of phytoecological maps are described regarding specially protected nature areas and their specific features. Such maps offer new possibilities for the assessment and analysis of current and predicted states of vegetation. 相似文献
973.
This study gives a brief demonstration of impurity removal efficiency upon salt solution treatment of phosphogypsum (PG). The experimental set up has been designed according to a multi-variable Box–Behnken Design (BBD) with stirring time, solid: liquid (PG:salt solution) ratio and temperature as the conducted in various salt solutions. PG sample has been treated with sea water, 5% NaCl and 10% NaCl solutions according to the BBD matrix. Fluoride (F), copper (Cu), manganese (Mn), and nickel (Ni) amounts in the PG sample have been measured upon pre- and post-treatment with salt solutions. Among other operating conditions, temperature has been the dominant factor on fluoride removal efficiency, and responses for the factors determined in the experiment runs indicated that a significant correlation could be established between temperature and fluoride removal, sea water being the most efficient salt solution. Higher copper, manganese, and nickel removal efficiencies have been observed in single salt NaCl solution systems however no significant correlation could be established between factors. Results indicate that pre-treatment of PG located near coastal regions with sea water can be a cost-effective approach and applicable on industrial scale when fluoride removal is of importance. 相似文献
974.
采用固相萃取-气相色谱质谱联用仪测定京津潮白河中的多环芳烃(PAHs)及其衍生物(SPAHs)的污染水平,并采用絮凝法分析水样中自由态PAHs/SPAHs和结合态PAHs/SPAHs的分布。结果表明,京津潮白河中PAHs和SPAHs总质量浓度分别为55.06~215.02 ng·L~(-1)和92.37~227.33 ng·L~(-1),上游河段PAHs和SPAHs质量浓度均低于下游河段。7种致癌PAHs占比为22%~41%,需引起重视。本研究中的SPAHs包括三类物质:氧化PAHs(OPAHs)、甲基PAHs(MPAHs)和氯代PAHs(Cl PAHs)。其中,OPAHs对SPAHs贡献最大(59%~71%),其次是Cl PAHs(22%~32%)和MPAHs(7%~14%)。京津潮白河中PAHs和SPAHs主要以自由态形式存在,总浓度可以准确估计污染物的环境风险。 相似文献
975.
为研究海水环境中共存的溶解性物质的复合效应对抗生素光解的影响,以磺胺吡啶为模型化合物,采用响应面法(RSM)研究了海水环境中代表性溶解性物质(溶解性有机质(DOM)、HCO3-、NO3-和Cl-)的复合效应对磺胺吡啶光解动力学的影响.结果表明在P <0.05显著性水平,DOM和HCO3--NO3-是影响磺胺吡啶光解的显著因素.HCO3-淬灭NO3-光诱导形成的·OH致使HCO3--NO3-相互作用抑制磺胺吡啶光解.自由基淬灭实验证实DOM促进磺胺吡啶光解主要是由其激发三重态DOM(3DOM*)诱导.DOM小分子类似物(芳香酮类)稳态光化学实验发现磺胺吡啶的光解速率常数(k)的对数与3DOM*的氧化电势呈现正相关,同时研究也发现SAs的最低未占据轨道和最高占据轨道能级差影响SAs与3DOM*的反应活性. 相似文献
976.
Titania nanomaterial with an anatase structure and 5.6 nm crystallite size and 280.7 m2 g−1 specific surface areas had been successfully prepared by sol–gel/hydrothermal route. The effect of pH as a type of autoclave and calcination was studied. Crystallite size and phase composition of the prepared samples were identified. X-ray diffraction analyses showed the presence of anatase with little or no rutile phases. The crystallite size of the prepared TiO2 with acidic catalyst was both smaller than that prepared with basic catalyst, and was increasing after acidic calcinations by a factor 4–5. Basic calcinations produced a specific increase of 1.5. Rutile ratio and the particle size were increased after calcination at 500 °C. However, TiO2 powder synthesized using a basic catalyst persisted the anatase phase and a loosely aggregation of particles. Anatase TiO2 as prepared with acidic catalyst in Teflon lined stainless steel autoclave demonstrated the highest photocatalytic activity for degradation of 2,6-dichlorophenol-indophenol under ultraviolet irradiation with t½ 0.8 min. 相似文献
977.
矿柱是地下矿山支撑顶板围岩、维持采场稳定的关键结构要素。为迅速准确地判别矿柱稳定性,选取矿柱宽度、矿柱高度、矿柱宽高比、矿岩单轴抗压强度和矿柱承受载荷作为影响指标,利用高斯过程机器学习算法建立矿柱状态与其主要影响因素之间的非线性映射关系,进而提出一种基于高斯过程二元分类(GPC)的矿柱状态识别模型。结合工程实例,以40组样本数据进行训练,以10组样本数据对该模型进行检验,并与ANN和SVM进行对比。结果表明,矿柱状态识别的高斯过程模型是科学可行的,该模型具有参数自适应化获取、分类精度高、计算复杂度低等优点,还可对矿柱状态判别结果的不确定性或可信度进行定量化评价。 相似文献
978.
Xiaofeng Liao Shuangyan Zhu Delai Zhong Jingping Zhu Li Liao 《Waste management (New York, N.Y.)》2014,34(11):2278-2284
In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH4–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded.We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production. 相似文献
979.
980.