大开孔安全性有限元分析及建议

石化行业压力容器大开孔结构应用普遍,开孔区域应力情况复杂,利用分析设计技术对大开孔结构进行强度有限元分析,准确地得出了最大应力的位置及数值,保证了结构的安全性,为大开孔结构局部优化提供了计算依据。     

Carbon dioxide adsorption behaviors of aluminum-pillared montmorillonite-supported alkaline earth metals

The Al-pillared montmorillonite-supported alkaline earth metal 5M/Al-PILC (PILC = pillared clay, M = Mg, Ca, Sr, and Ba) and xMg/Al-PILC (x = 1, 3, 5, and 7 wt.%) samples were prepared using an impregnation method. Physical properties of the materials were determined by means of X-ray diffraction (XRD) and N₂ adsorption-desorption, and their CO₂ adsorption behaviors were investigated using the thermogravimetric analyzer (TG), CO₂ temperature-programmed desorption (CO₂-TPD), and in situ diffuse reflectance infrared transform spectroscopy (in situ-DRIFTS) techniques. It is shown that 5Mg/Al-PILC possessed the highest CO₂ adsorption capacity (2.559 mmol/g). The characterization results indicate that Al-pillaring increased the specific surface area of montmorillonite, which was beneficial for the adsorption of CO₂. The CO₂ adsorption process on the sample was mainly chemical adsorption, and alkalinity was the main factor influencing its adsorption capacity. The alkalinity of the sample was enhanced by loading an appropriate amount of alkaline earth metal, and the adsorbed CO₂ was present in the form of bicarbonate and carbonate. In addition, the 5Mg/Al-PILC sample exhibited an excellent regeneration efficiency. We believe that the outcome of this research would provide a good option for developing highly effective CO₂ adsorption materials.     

Effect of water chemistry on the aggregation and photoluminescence behavior of carbon dots

Carbon dots are rapidly emerging carbon-based nanomaterials that, due to their growing applications, will inevitable find their way to natural waters; however, their environmental fate is mostly unknown. Carbon dots with different surface functionality were fabricated and characterized by TEM and FT-IR. Their surface charge, given by the zeta potential, and their hydrodynamic diameter in suspension were investigated under a variety of environmentally relevant conditions. The effect of ionic strength was studied in the presence of monovalent (NaCl) and divalent (CaCl₂) cations, for pH levels from 3 to 11; humic acid was used as a model for dissolved natural organic matter. Total potential energies of interactions were modeled by classical DLVO theory. The experimental results showed that water chemistry altered the surface charge of the nanomaterials, but their hydrodynamic size could not be correlated to those changes. Evidence of specific interactions was found for the amino functionalized particles in most cases, as well as the plain carbon dots in the presence of Ca^2 + and humic acid. Nanoparticles remained largely stable in suspension, with some exception at the highest ionic strength considered. DLVO theory did not adequately capture the aggregation behavior of the system. Moreover, cation and/or humic acid adsorption negatively affected the emission intensity of the particles, suggesting limitations to their use in natural water sensing applications. The particular stability shown by the carbon dots results in exposure to organisms in the water column and the possibility of contamination transported to significant distances from their source.     

Analysis of the origin of peak aerosol optical depth in springtime over the Gulf of Tonkin

By aggregating MODIS(moderate-resolution imaging spectroradiometer) AOD(aerosol optical depth) and OMI(ozone monitoring instrument) UVAI(ultra violet aerosol index)datasets over 2010–2014, it was found that peak aerosol loading in seasonal variation occurred annually in spring over the Gulf of Tonkin(17–23°N, 105–110°E). The vertical structure of the aerosol extinction coefficient retrieved from the spaceborne lidar CALIOP(cloud-aerosol lidar with orthogonal polarization) showed that the springtime peak AOD could be attributed to an abrupt increase in aerosol loading between altitudes of 2 and 5 km.In contrast, aerosol loading in the low atmosphere(below 1 km) was only half of that in winter. Wind fields in the low and high atmosphere exhibited opposite transportation patterns in spring over the Gulf of Tonkin, implying different sources for each level. By comparing the emission inventory of anthropogenic sources with biomass burning, and analyzing the seasonal variation of the vertical structure of aerosols over the Northern Indo-China Peninsula(NIC), it was concluded that biomass burning emissions contributed to high aerosol loading in spring. The relatively high topography and the high surface temperature in spring made planetary boundary layer height greater than 3 km over NIC. In addition, small-scale cumulus convection frequently occurred, facilitating pollutant rising to over 3 km, which was a height favoring long-range transport. Thus, pollutants emitted from biomass burning over NIC in spring were raised to the high atmosphere, then experienced long-range transport, leading to the increase in aerosol loading at high altitudes over the Gulf of Tonkin during spring.     

A comprehensive evaluation of re-circulated bio-filter as a pretreatment process for petroleum refinery wastewater

Conventional biological treatment process is not very efficient for the treatment of petroleum refinery wastewater (PRW) that contains high-concentration of organic contaminants. Prior to biological treatment, an additional pretreatment process for PRW is required for the effluent to meet the discharge standards. While re-circulated bio-filter (RBF) has been applied as a pretreatment process in several PRW treatment plants, its effects have not been comprehensively evaluated. In this study, the parameters of operation, the changes in pollution indexes and contaminant composition in an engineered RBF have been investigated. We found that mainly highly active de-carbonization bacteria were present in the RBF, while no nitrification bacteria were found in the RBF. This indicated the absence of nitrification in this process. The biodegradable organic contaminants were susceptible to degradation by RBF, which decreased the Biological Oxygen Demand (BOD₅) by 83.64% and the Chemical Oxygen Demand (COD_Cr) by 54.63%. Consequently, the alkalinity and pH value of RBF effluent significantly increased, which was unfavorable for the control of operating parameters in subsequent biological treatment. Along with the decrease of COD_Cr, the RBF effluent exhibited a reduction in biodegradability. 834 kinds of recalcitrant polar organic contaminants remained in the effluent; most of the contaminant molecules having complex structures of aromatic, polycyclic and heterocyclic rings. The results of this study showed that RBF could efficiently treat PRW for biodegradable organic contaminants removal; however, it is difficult to treat bio-refractory organic contaminants, which was unfavorable for the subsequent biological treatment process operation. An improved process might provide overall guarantees for the PRW treatment.     

复杂工业系统中人因失误根本原因分析

在现代大规模复杂人 -机 -环境系统中 ,人因失误诱发的故障或事件呈上升趋势。人因事件的根本原因分析 ,对于防范复杂系统中事故的发生是非常必要的。人因事件根本原因的分析包括 :需要分析的人因事件的确定 ;对事实进行调查 ,分析调查结果 ;确定根本原因 ;制定纠正措施 ;完成最终报告。人因事件的分析最终需要找出失效屏障并提出修补的方法 ,笔者采用事件与原因因子分析技术来进行分析。在分析过程中 ,需要绘出事件和原因因子图 (E&CF图 ) ,而E&CF图可以显示出从开始到结束全过程中事件发生的正确次序 ,通常包括失效屏障 ,预先存在的条件、次级事件、不恰当的动作和形成事件的原因因子。形成人因事件的原因因子在复杂工业系统中 ,可以分成 12个部分。笔者给出了核电厂蒸汽发生器 (SG)主给水阀门泄漏的人因事件的分析实例 ,确认了该实例中失效的屏障和事件的根本原因并提出了纠正措施。     

中国兵器工业事故的分布特点

兵器工业事故容易受噪声影响。在时序上发生爆炸事故和机械伤害事故的事件明显地受社会状态的影响，社会混乱则事件数上升。各类爆炸物的事故与季节存在明显依赖关系，但是机械伤害事故与季节的关系不明显。本文提供了１６种事故的季节分布图。     

Diffusion of ISO 14001 environmental management systems in China: rethinking on stakeholders’ roles

Since the release of ISO 14001 in 1996, China has witnessed a surge in the number of ISO 14001 certification. As an international environmental standard, ISO 14001 has two basic functions: one is playing as an environmental management instrument, while the other as a signal of firms’ better environmental performance to stakeholders. Based on the stakeholder theory, we have examined the effects of community, regulatory and some organizational stakeholders on the diffusion of ISO 14001 certification at Chinese provincial levels. Using a panel data of ISO 14001 certification from each province for the period of 2004-2008 in China, empirical evidence of such relations is found. The finding reveals that signaling to foreign customers and community stakeholders plays a dominant role in encouraging diffusion of ISO 14001 certification. However, as an important organizational stakeholder, foreign investors have shown no significant effect on the diffusion of ISO 14001 in China.     

中国资源枯竭城市的转型效果评价

论文通过对资源枯竭城市转型发展中各方面变化的分析总结,提出以基础、经济、社会、生态4个要素为框架建立资源枯竭城市转型发展指标体系的思路,并根据2005-2009年《中国城市统计年鉴》数据,测量各个资源枯竭城市在自身转型和区域发展地位提升两方面的发展状态。之后对城市的转型效果进行分类分析,发现资源枯竭城市转型总体态势较好,但城市转型效果在空间上以及不同类别城市间存在明显差异,部分城市没有实现经济、社会、环境协调转型发展。     

我国垃圾渗滤液处理存在问题及对策分析

分析了垃圾渗滤液的特点以及在垃圾渗滤液管理方面存在的问题。指出了我国垃圾渗滤液处理面临的技术难点。从环境技术管理以及工程技术开发方面进行了分析,以期为我国垃圾渗滤液的管理与控制提供支持。