Measuring and modeling atmospheric particles and particle bound mercury Hg(p) at five characteristic-sampling sites

The main purpose of this study was to monitor ambient air particles and particulate-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic-sampling sites. In addition, the calculated/measured dry deposition flux ratios of ambient air particles and particulate-bound mercury Hg(p) using three dry deposition models during the years of 2009–2010 were also studied. The results showed that the order of seasonal variations for mean particulate-bound mercury Hg(p) concentrations in TSP at Bei-shi (suburban/coastal), Chang-hua (downtown) and He-mei (residential) were all shown as spring > fall, winter > summer, respectively. However, the order of seasonal variations mean particulate-bound mercury Hg(p) concentrations in TSP that occurred at Gao-mei (wetland) were shown as spring > fall > winter > summer, respectively. Finally, the results of this study also indicated that using the Noll and Fang model exhibited batten prediction results for ambient air particles and particulate-bound mercury Hg(p) dry deposition when compared with the other depositions models at any of the characteristic-sampling sites for this study.     

Financial factors affecting oil price change and oil-stock interactions: a review and future perspectives

Natural Hazards - Traditionally, fundamental factors of supply and demand were important in understanding oil price dynamics before the financial crisis. These factors, however, are no longer...     

Urban flood susceptibility analysis using a GIS-based multi-criteria analysis framework

Natural Hazards - Pluvial flooding is a common type of natural hazard caused by rainfall events with high intensity and short duration, which may lead to substantial property damages,...     

Socioeconomic development and the impact of natural disasters: some empirical evidences from China

Significant advancements have been made in examining the relationship between economic development and disaster losses at the global and national scales, but very little research has been done at the sub-national level, especially in China. Based on socioeconomic and disaster impact data from 31 provinces (municipalities, and autonomous regions) in China from 1990 to 2010, ordinary least squares regression was used to determine the relationship between socioeconomic development and effects of natural disasters. Results showed that economic development played a distinct role in mitigating disaster damages in the whole China and its eastern, central and western regions. There existed a U-shaped relationship between economic growth and disaster losses in the whole China and its eastern region, and an inverted-U nonlinearity linkage in its central and western areas. These findings further confirmed the existence of a nonlinear relationship between economic development and disaster losses. Economic growth had played a more important role in mitigating disaster losses in the central region of China than that in the western one. Further investigations demonstrated that as economic develops, there were fewer deaths caused by natural hazards in whole China and all its three regions. The combination of the lower level of education, higher unemployment rate and greater gross dependence ratio has contributed to the increase in death toll caused by natural disasters, but this trend could be partly offset by wealth growth.     

埋藏条件下碳酸盐岩实验室溶蚀作用模拟的热力学模型与地质勘探方向——以陕甘宁盆地下奥陶统马家沟组第五段为例

陕甘宁盆地下奥陶统马家沟组五段为潮坪相碳酸盐岩夹蒸发盐沉积。马五段经历了多期复杂的成岩作用，其中溶蚀作用对马五段影响深刻。首次引用热力学理论对埋藏条件下碳酸盐岩溶蚀作用进行了理论分析和计算。其结果表明碳酸盐岩在埋藏成岩的不同温度压力条件下，酸性介质中溶解反应的吉布斯自由能均为负值，说明反应可自动向方解石、白云石溶解的方向进行，并随着温压的升高溶解的趋势增大，而且白云石溶解的趋势比方解石更大。碳酸盐岩溶蚀作用是受热力学规律支配的自然地质作用。碳酸盐岩溶蚀实验模拟的热力学数学模型对陕甘宁盆地油气田勘探具有重大的理论意义和实际应用价值。     

New Prediction Models for Mean Particle Size in Rock Blast Fragmentation

The paper refers the reader to a blast data base developed in a previous study. The data base consists of blast design parameters, explosive parameters, modulus of elasticity and in situ block size. A hierarchical cluster analysis was used to separate the blast data into two different groups of similarity based on the intact rock stiffness. The group memberships were confirmed by the discriminant analysis. A part of this blast data was used to train a single-hidden layer back propagation neural network model to predict mean particle size resulting from blast fragmentation for each of the obtained similarity groups. The mean particle size was considered to be a function of seven independent parameters. An extensive analysis was performed to estimate the optimum value for the number of units for the hidden layer for each of the obtained similarity groups. The blast data that were not used for training were used to validate the trained neural network models. For the same two similarity groups, multivariate regression models were also developed to predict mean particle size. Capability of the developed neural network models as well as multivariate regression models was determined by comparing predictions with measured mean particle size values and predictions based on one of the most applied fragmentation prediction models appearing in the blasting literature. Prediction capability of the trained neural network models as well as multivariate regression models was found to be strong and better than the existing most applied fragmentation prediction model. Diversity of the blasts data used is one of the most important aspects of the developed models.     

Phosphorus speciation in surface sediments of a hypertrophic lake,Southwestern China: insights from fractionation and 31P NMR

Acta Geochimica - Phosphorus (P) species in surface sediments from a shallow, hypertrophic lake, Lake Dianchi, China, were investigated by P fractionation and 31P nuclear magnetic resonance (NMR)...     

强烈气洗作用导致原油成分变化的定量计算:以库车坳陷天然气藏为例

库车坳陷以产天然气为主,同时产出少量原油和凝析油,油气充注不同步,普遍具有"油早气晚"的特点,晚期大量天然气的侵入,必然对早期聚集的油藏发生改造作用。对气藏中原油成分变化的定量计算和讨论,可为天然气的注入强度定量评价提供直接证据。未遭受气洗的原油,正构烷烃摩尔浓度的对数与相应的碳数呈线性关系,而气洗作用可使轻组分的正构烷烃最先溶解于干气中,并随着天然气继续向前运移,原始油藏中的轻组分正构烷烃大大减少。以此为理论基础,建立了正构烷烃损失的定量计算模型。结果表明克拉2构造原油正构烷烃损失程度最高,平均可达70%左右,大北构造带原油正构烷烃损失程度差异较大,与该地区断块发育有关。气洗作用导致原油正构烷烃减少,而金刚烷、多环芳烃等在天然气中溶解度较低的化合物得以浓缩富集,相对含量大大增加。轻芳烃含量也会随之而增加,原油芳香度增加,石蜡度降低。在模拟实验基础上对气洗程度进行了定量评价,初步估算表明,克拉2构造原油遭受的气洗作用最强,是其他构造带的2～5倍。     

Arching effect and displacement on theoretical estimation for lateral force acting on retaining wall

Natural Hazards - A new approach is proposed to evaluate the non-limit active earth pressure in c–φ soil based on the horizontal slices method and limit equilibrium method, which takes...