山东省土壤有机碳密度的空间分布特征及其影响因素

利用2010年完成的山东省多目标区域地球化学调查获得的双层网格化大密度、高精度土壤碳数据,估算了全省土壤表层(0～20 cm)、中上层(0～100 cm)和全层(0～160 cm)的土壤有机碳(SOC)密度及其储量,并分析不同土壤类型、地貌类型、土地利用类型下土壤有机碳密度及其储量的空间分布特征及影响因素. 结果表明:①山东省不同深度土壤碳库组成存在一定差异,其中表层土壤碳库以有机碳为主,而全层土壤碳库则以无机碳为主. ②全省表层土壤有机碳储量为350.65×106 t,平均土壤有机碳密度为2.22 kg/m2,但在不同土壤类型、地貌类型和土地利用类型之间差异显著. ③土壤中较高的w(黏粒)、w(Se)、w(TN)和稳定的C/N等土壤条件均可促使w(SOC)增加,而土壤盐渍化、高硅、富盐基离子的沙性土壤环境则不利于有机碳的积累;此外,人类活动对林地、草地的破坏,以及灌溉水田、园地、林地等土地利用方式的改变也会导致土壤有机碳流失;土壤有机碳积累受降水量影响明显,随多年平均降水量的增加而增大,但受气温影响不明显. 在各因素综合影响下,山东省表层土壤有机碳密度分布呈沿海低、鲁西北平原和胶莱盆地中等、鲁中南山地丘陵和中低山区偏高的分布特征.      

美国粮仓农工的安全风险识别与防护

本文通过谷物装卸设备存在危险的实例,强调了储粮仓内农工存在淹埋及窒息风险,重点介绍了美国职业安全和健康署（OSHA）提出的标准和相关法规,以及粮仓农工的安全风险识别与防护经验,以对我国粮仓农工的安全与防护提供帮助。     

固定式消防水炮在火电厂封闭圆形煤场中的应用

以某2×300MW级火电厂封闭圆形煤场消防系统的设计为例,对该建筑采用的消防炮灭火系统的选择进行了阐述,详细介绍了该工程采用的固定式消防炮灭火系统,指出固定式消防水炮灭火系统是大型封闭圆形煤场灭火的理想设施,总结了固定式消防水炮在该工程应用中的优缺点。     

液化石油气贮配站安全评价的实践

针对液化石油气贮配站火灾爆炸危险性大的特点，采用规范评价和危险度分级相结合的方法，对其进行安全评价，为液化石油气贮配企业进行整改、保障自身安全和社会公共安全，以及政府有关部门对液化石油气贮配企业实施宏观管理，提供科学的依据。     

我国磷石膏处置现状及绿色发展对策

磷石膏的大量堆存不仅占用土地、浪费资源,存在巨大的环境和安全风险,更与我国无废城市发展理念相违背.本文系统梳理了近年来我国磷石膏产排现状、资源化利用现状和资源化利用途径.分析了磷石膏资源化所面临的问题和挑战,主要包括政策支持不配套、标准体系不完善、技术支撑不足和产品市场竞争力弱等.提出磷石膏绿色发展应从政策扶持、技术突...     

Effects of a carbon monoxide-dominant gas mixture on the explosion and flame propagation behaviors of methane in air

This work aimed to experimentally evaluate the effects of a carbon monoxide-dominant gas mixture on the explosion characteristics of methane in air and report the results of an experimental study on explosion pressure measurement in closed vessel deflagration for a carbon monoxide-dominant gas mixture over its entire flammable range. Experiments were performed in a 20-L spherical explosion tank with a quartz glass window 110 mm in diameter using an electric spark (1 J) as the ignition source. All experiments were conducted at room temperature and at ambient pressure, with a relative humidity ranging from 52 to 73%. The peak explosion pressure (P_max), maximum pressure rise rate ((dp/dt)_max), and gas deflagration index (K_G) were observed and analyzed. The flame propagation behavior in the initial stage was recorded using a high-speed camera. The spherical outward flame front was determined on the basis of a canny method, from which the maximum flame propagation speed (S_n) was calculated. The results indicated that the existence of the mixture had a significant effect on the flame propagation of CH₄-air and increased its explosion risk. As the volume fraction of the mixed gas increases, the P_max, (dp/dt)_max, K_G and S_n of the fuel-lean CH₄-air mixture (7% CH₄-air mixture) increase nonlinearly. In contrast, addition of the mixed gas negatively affected the fuel-rich mixture (11% CH₄-air mixture), exhibiting a decreasing trend. Under stoichiometric conditions (9.5% CH₄-air mixture), the mixed gas slightly lowered P_max, (dp/dt)_max, K_G, and S_n. The P_max of CH₄-air mixtures at volume fractions of 7%, 9.5%, and 11% were 5.4, 6.9, and 6.8 bar, respectively. The S_n of CH₄-air mixtures at volume fractions of 7%, 9.5%, and 11% were 1.2 m/s, 2.0 m/s, and 1.8 m/s, respectively. The outcome of the study is comprehensive data that quantify the dependency of explosion severity parameters on the gas concentration. In the storage and transportation of flammable gases, the information is required to quantify the potential severity of an explosion, design vessels able to withstand an explosion and design explosion safety measures for installations handling this gas.     

储罐两环段喷淋圈管对供给强度的影响

国内储罐火灾爆炸事故时有发生,储罐消防冷却系统实施有效的冷却是控制火势和扑救初期火灾的主要因素之一。为了研究油罐消防喷淋系统在灭后冷却中的影响,本文选取4座5×10~3内浮顶罐组,开展消防冷却水系统喷洒实验,通过测试分析发现:实际的冷却水供给强度不满足规范的要求,并探讨了储罐固定冷却水系统供给强度不足的原因,结合分析的原因建议对规范中着火罐和临近罐供水强度要求统一均为2.5 L/(min·m^2),其冷却水喷淋圈管设置应为四段以上。     

Exploring the linkages between river water chemistry and watershed characteristics using GIS-based catchment and locality analyses

A typology of land characteristics for the Humber catchment in central/eastern England is identified in relation to land use, hydrology and demographic, topographic and geological characteristics, using GIS and statistical analyses. Empirical relationships between land characteristics and water quality were examined in relation to the spatial variability in water quality across the Humber catchment. Analyses of relationships between land characteristics and water quality were undertaken at two hierarchical scales: (1) individual catchments and (2) localities of 10 km radius draining to each sampling site. The importance of urban and agricultural sources was identified, together with a hydrological component linked to dilution of point source inputs and mobilisation of specific sediment-associated contaminants in higher-energy (higher-flow) environments. High-solubility (dissolved) chemical determinands (such as B, Cl and SO₄), which undergo conservative transport through the river network, show the strongest linkages with land characteristics at the catchment scale. Cr, Zn and Ca show stronger correlations with land characteristics at the locality rather than the catchment scale, indicating that the concentrations of these determinands are more closely linked to the availability of localised sources. This work provides a starting point for investigating how changes in land use and management of drainage basins might impact river water quality at the regional scale and fluxes to the coastal zone, by providing a mechanism for examining linkages between regional-scale land characteristics and river water quality. The next step requires development of the approach within a more rigorous statistical framework and the extension of the regional analysis within a wider national and international context. Electronic Publication