泾阳、临猗地震的地下流体异常特征

总结了１９９８ 年泾阳Ｍｓ４．８ 及临猗Ｍｓ ４．６ 级地震的地下流体异常特征, 结果表明： 异常点数量有随震中距的增大而减少的趋势, 同时又受构造条件的制约; 异常时间以短临为主, 短期异常主要集中在震前３ 个月左右, 临震异常出现在震前１０ ｄ 左右; 异常幅度与地震三要素关系不明显。     

气候变化和人类活动对天津海岸带影响综述

21世纪全球海平面上升和区域地面沉降叠加所致的相对海平面上升速率存在加快趋势,将加剧天津沿海地区风暴潮、洪涝灾害和土地淹没的危害,影响沿海地区的城市抗灾功能、建筑物安全及生态资源。为此,本文综合讨论了气候变化导致的海平面上升和地面沉降对天津沿海风暴潮、海岸侵蚀以及港口码头的影响。建议滨海新区建设要高度重视海洋灾害的监测预警,提高沿海地区防潮和防汛工程的设计标准和城市抗灾能力,以有效实现滨海新区经济和社会可持续发展。     

巢湖水华暴发期水-沉积物界面溶解性氮形态的变化

2008年4~10月,连续对巢湖8个样点进行采样,分析了上覆水和表层沉积物间隙水中溶解性氮形态在水华暴发过程中的变化,估算了水-沉积物界面无机氮的扩散通量.结果表明,上覆水中NH4+-N含量随水华暴发强度的增加而减小,溶解性总氮(DTN)含量在水华暴发后明显升高,而NO3--N含量只在水华暴发严重时才明显减少.在大规模水华暴发前(4~5月)上覆水中DTN的主要组成部分是NO3--N和NH4+-N,在水华暴发后则是溶解性有机氮(DON).间隙水中PDTN以NH4+-N为主,其浓度随温度的增加而升高; DON在水华暴发过程中呈先下降后上升的趋势.通量计算结果表明,沉积物作为NH4+-N的“源”一直由间隙水向上覆水释放,西半湖扩散通量在13.06~32.94mg/(m2·d)之间,东半湖扩散通量在4.54~17.41mg/(m2·d)之间.沉积物-水界面交换是湖泊营养盐重要的补充途径,为水华持续暴发提供营养来源.     

Preparation of metal-doped Cu–Mn/HTS-1 catalysts and their mechanisms in efficient degradation of toluene

In order to study their synergistic catalytic effects in toluene degradation, CuMn_2O_4/HTS-1(HTS-1 was a titanium silicon molecular sieve), Cu_(0.7)Mn_2Y_(0.3)O_x/HTS-1 and Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1 catalysts were prepared by the impregnation method.The textural properties, redox properties and acidity of the catalysts were characterized by X-ray diffractometer(XRD),transmission electron microscopy(TEM), scanning electron microscopy(SEM), H_2 temperature-programmed reduction(H_2-TPR), X-ray photoelectron spectroscopy(XPS),frustrated total internal reflection(FT-IR), ammonium temperature-programmed desorption(NH_3-TPD) and pyridine adsorption internal reflection(Py-IR) measurements.The potential roles of Lewis acid sites(activating dioxygen) were discussed, and the experimental results indicated that the most efficient route for toluene degradation over Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1(toluene conversion rate of 90%(T99) = 295℃) was ascribed to regulation of the synergistic effects of redox properties(activating molecular toluene) and Lewis acid sites(activating dioxygen).The Mars–Van–Krevelen(MVK) model was adopted to describe the reaction process of toluene oxidation, which gave an in-depth view into the toluene degradation over CuMn_2O_4/HTS-1, Cu_(0.7)Mn_2Y_(0.3)O_x/HTS-1 and Cu_(0.7)Mn_2Ce_(0.3)O_x/HTS-1.In addition, the synergistic effects between redox properties and Lewis acid sites were studied in detail.     

New models for calculating the electrical resistivity of loess affected by moisture content and NaCl concentration

Environmental Science and Pollution Research - Saline loess is an important cause of environmental geo-issues in northwest China. In this research, electrical resistivity of loess with different...     

Improving immobilization efficiency and mechanism analysis of sodium hexametaphosphate on MgO-based cementitious material solidified MSWI FA

Journal of Material Cycles and Waste Management - MgO-based cementitious material (MCM) is a potential green substitute for solidifying municipal solid waste incineration fly ash (MSWI FA). Sodium...     

Investigation of microplastic pollution on paddy fields in Xiangtan City,Southern China

Microplastics (MPs) have become a hot issue of environmental pollution. However, insufficient evidence exists regarding the distributions and fates of MPs in terrestrial environment, especially in farmlands. The distributions of MPs in paddy fields were investigated in Xiangtan City, a typical rice production area in China. The abundance of MPs in paddy seedling raising fields was 3805?±?511 n·kg^?1, which increased by approximately 9 times than that in common paddy fields. Transparent films became the dominant forms due to the huge usage of mulching films, corresponding to that the proportion of polyvinyl chloride (PVC) increased to 17% there. Moreover, an industrial plant nearby also contributed considerably to the MP pollution; the proportion of PVC (33%) in the paddy fields nearby increased to approximately 4 times of common paddy fields, while polyvinyl alcohol (PVA; 13%) used as an important chemical raw material to synthesis in various applications was uniquely detected there. These results highlight the input of MPs from agricultural and industrial activities in farmlands. Their contributions to the MP pollution in farmlands should be continuously investigated.

     

From waste tire to high value-added chemicals: an analytical Py-GC/TOF–MS study

Environmental Science and Pollution Research - A Pyroprobe 5000 pyrolyzer connected to a gas chromatography-time-of-flight mass spectrometry (Py-GC-TOF–MS) was used to analyze the...