Cu-SBA-15催化湿式过氧化氢氧化水溶液中罗丹明B

采用水热晶化法合成了不同含铜量的Cu—SBA-15介孔分子筛,并且用XRD、N2吸附、TEM以及uV—vis对所合成的样品进行表征。以Cu—SBA-15为催化剂,H2O2为氧化剂,催化湿式过氧化水溶液中的罗丹明B,主要考察H2O2浓度、催化剂用量、处理温度、初始pH等因素对罗丹明B氧化效果的影响。结果表明,在同样的处理条件下罗丹明的脱色率明显高于TOC去除率,处理温度、初始pH对罗丹明B的脱色与氧化有重要影响。在罗丹明B初始浓度100mg／L,H2O2初始浓度1．8g／L,催化剂量0．3g／L,温度60℃,pH为7．0,处理时间100min时,罗丹明B的脱色率为98．6％,TOC去除率为62．8％。     

重庆主城区建设用地扩展的时空特征及驱动因子分析

以多时相的遥感影像为基础,选用归一化裸露指数（NDBI）、重归一植被指数（RDVI）和改进的归一化水体指数（修改后的NDWI）,通过阈值分割、掩膜处理提取建设用地信息,结合重庆主城区的社会经济数据,利用扩展速度指数、扩展强度指数、扩展弹性指数、紧凑度指数、建设用地扩展系数及扩展方向分析研究了不同阶段建设用地扩展的时空动态特征,并运用灰色关联分析,对建设用地扩展的驱动因子进行探讨。结果表明：1988～2011年重庆主城区建设用地扩展了39332 km2,扩展速度和扩展强度呈现增大的趋势;扩展弹性系数、建设用地扩展系数波动变化,反映了重庆主城区建设用地逐渐由粗放型向集约型转变;建设用地扩展的空间分析表明重庆主城区的城市形态由非紧凑型向紧凑型发展,同时扩展方向具有明显的分异性,主要向正北和西北方向扩展;人口增长,尤其是城市人口的增长是重庆主城区建设用地扩展最主要的驱动因子;经济发展、产业结构变化与建设用地的扩展也有明显的相关性     

近51年川滇地区气候暖干化与旱涝灾害趋势判断

为揭示川滇地区气候特征与旱涝灾害趋势,以川滇地区70个气象站点1961～2011年的逐月气温、降水资料为基础,采用线性回归、五年滑动平均、M K突变检验、反距离加权空间插值、Z指数法、Morlet小波变换等方法,对川滇地区气候变化特征与旱涝灾害进行了分析。结果表明：近51 a川滇地区气温以021℃/10 a的速率增加;降水量以1076 mm/10 a的速率减少;尤其是20世纪90年代末期以来正经历着以增温和变干为趋势的气候变化特征,气候暖干化趋势明显。近51 a川滇地区年旱涝灾害总的趋势是向干旱发展,以2000年为转折点,2000年以前该区多涝灾,2000年后多旱灾,这与该区的气温与降水变化一致,气候暖干化的结果直接导致了旱灾加剧。川滇地区春、冬两季旱涝年际周期变化规律强,Z指数呈上升趋势,降水量增加;夏季旱涝周期变化十分显著,旱涝灾害程度加剧,干旱化趋势明显;秋季旱涝变化周期性不强,呈弱干旱化趋势发展     

Analysis of reduction stage of chemical looping packed bed reactor based on the reaction front distribution

Traditional combustion of syngas derived from biomass has incurred numerous environmental problems, and syngas chemical looping combustion is environmentally friendly for syngas energy conversion. As a key part of chemical looping combustion, reactor configuration is noticeable. The dynamically operated packed bed reactor is an emerging conception applied to chemical looping combustion. Our attention is paid to the conversion of the oxygen carrier in the packed bed as the limited maximum conversion of the oxygen carrier in a packed bed is unclear. In this paper, the reaction front distribution during iron oxide reduced by CO is firstly proposed on the basis of chemical equilibrium and then validated by the effluent gas profile. Based on the reaction front distribution, the detail of the reduction stage in iron-based chemical looping combustion is analyzed to obtain the characteristics of reaction fronts. The reaction rates of reduction from Fe₂O₃ to Fe₃O₄, Fe₃O₄ to Fe_0.947O and Fe_0.947O to Fe are 5.280, 3.329 and 4.379 mol m^?3 s^?1, respectively. And the velocities of reaction front I, II, III are 0.605, 0.326, 0.044 cm min^?1, respectively, which demonstrate the reaction front distribution. The methodology established in this paper can be used to study multiple reaction front system in the packed bed reactor.     

Photocatalytic degradation kinetics and mechanism of phenobarbital in TiO2 aqueous solution

5-Ethyl-5-phenylpyrimidine-2,4,6(1H, 3H, 5H)-trione is an anti-convulsant used to treat disorders of movement, e.g. tremors. This work deals with the transformation of phenobarbital by UV/TiO₂ heterogeneous photocatalysis, to assess the decomposition of the pharmaceutical compound, to identify intermediates, as well as to elucidate some mechanistic details of the degradation. The photocatalytic removal efficiency of 100 μm phenobarbital is about 80% within 60 min, while the degradation efficiency of phenobarbital was better in alkaline solution. The study on contribution of reactive oxidative species (ROSs) has shown that OH is responsible for the major degradation of phenobarbital, while the photohole, photoelectrons and the other ROSs have the minor contribution to the degradation. Finally, based on the identification of degradation intermediates, two main photocatalytic degradation pathways have been tentatively proposed, including the hydroxylation and cleavage of pyrimidine ring in the phenobarbital molecule respectively. Certainly, the phenobarbital can be mineralized when the photocatalytic reaction time prolongs.     

杭州市主城区浅层地下水水质现状

调查了杭州市主城区浅层地下水水质现状。结果表明,杭州市主城区浅层地下水污染较重,"三氮"超标现象普遍,而主要污染项目为NH3-N、NO2--N、IMn和总大肠菌群及细菌总数。指出,农业面源污染和生活污水,是造成杭州市主城区浅层地下水氮污染的主要原因。提出分析了地下水水质污染的成因。指出应加强地下水保护以及地下水资源的质量管理。进行科学、合理地开发利用,实现地下水水资源的可持续利用,支持杭州市国民经济的可持续发展。     

ASE萃取-SPE净化-气相色谱法测定土壤中有机氯农药

建立了加速溶剂萃取-固相萃取净化-气相色谱测定土壤中α-六六六、β-六六六、γ-六六六、δ-六六六、P,P′-DDE、P,P′-DDD、O,P′-DDT、P,P′-DDT等8种有机氯农药的方法。在0μg／L～500μg／L范围内方法线性良好,8种有机氯农药的检出限在0．06μg／kg～0．21μg／kg之间,基质加标试验的相对标准偏差为2．2％～5．8％,回收率为81．5％～113％。     

An examination of the effect of landscape pattern, land surface temperature, and socioeconomic conditions on WNV dissemination in Chicago

This paper developed an approach by the synthesis of remote sensing, landscape metrics, and statistical methods to examine the effects of landscape pattern, land surface temperature, and socioeconomic conditions on the spread of West Nile virus (WNV) caused by mosquitoes and animal hosts in Chicago, USA. Land use/land cover and land surface temperature images were derived from Terra’s Advanced Spaceborne Thermal Emission and Reflection Radiometer imagery. An analytical procedure using landscape metrics was developed, applying configuration analysis of landscape patterns in the study area. The positive reports of mosquitoes and animal hosts for WNV in fall, 2001–2006, were collected from the Cook County Public Health Department. Forty-nine municipalities were found to have WNV-positive records in mosquitoes and animal hosts in fall 2004. Socioeconomic data were obtained from the 2000 US Census. Statistical analysis was applied to WNV data in fall 2004 to identify the relationship between potential predictors and WNV spread. As a result, landscape factors, such as landscape aggregation index and the urban areas and areas of grass and water, showed strong correlations with the WNV-positive records. Socioeconomic conditions, such as the population over 65 years old, also showed a strong correlation with WNV-positive records. Thermal conditions of water showed a less but still considerable correlation to WNV-positive records. This research offers an opportunity to explore the effects of landscape pattern, land surface temperature, and socioeconomic conditions on the spread of WNV caused by mosquitoes and animal hosts. Results can contribute to public health and environmental management in the study area.     

江苏省种粮补贴区域差异化理论与实证研究

粮食种植补贴是农业补贴的核心内容。从现行种粮补贴政策出发,构建了差异化情景下种粮补贴效率的理论命题,并认为差异化补贴更体现 “效率优先,兼顾公平”原则;在此基础上,构建了种粮补贴区域差异化指标体系及计算方法并对江苏省进行实证研究。结果发现：江苏省种粮补贴应呈现苏北>苏中>苏南的态势,最高值为总额的182%,分布在苏北地区,最低值为总额的117%,分布在苏南地区;各评价指标空间分布差异显著,补贴政策地区间指向应有所不同;最后提出差异控制系数θ,通过对θ的选择,可以较为有效的控制种粮补贴差异波动范围,为政策的制定提供简便的手段