Distribution of Al-, Fe- and Mn-pools and their correlation in soils from two acid deposition small catchments in Hunan, China

Distribution of Al-, Fe- and Mn-pools was investigated in five forest soil profiles (consisting of four horizons) in each of two Hunan catchments (BLT and LKS) where acid deposition has been considered critical. Al- and Fe-pools were higher in BLT than those in LKS, but Mn-pools much lower in BLT. Mn-pools vary from topsoils to bottom soils, but there are different trends for different Mn speciation. Al- and Fe-pools, except amorphous Fe_ox, were positively correlated to contents of soil organic matter (OM) showed by the loss on ignition in the two catchments. Accumulation of Al- and Fe-pools may occur in the area where soil organic matter was enriched (e.g. in top soil and rhizosphere soil). However, no direct correlation is observed between Mn and OM. Acidic atmospheric deposition may affect transforming among speciations of Al-, Fe- and Mn-pools and leaching of soil Al, Fe and Mn through formation of soluble organo-metal dissolved Al which was potentially toxic, increased. There were significant correlations between Al-pools complexes or change of oxidation–reduction conditions. Mn_ex (exchangeable Mn) and Mn_ox (amorphous and organic Mn) were highly linearly correlation with soil pH values at LKS but at BLT. Under acid deposition, the availability of the nutrient Fe increased with the amount of dissolved Al, which was potentially toxic, in the two catchments. There are no significant correlations between Al_ex (exchangeable Al) and Mn_ex, Fe_ex (exchangeable Fe) and Mn_ex in this work, indicating potentially toxic Mn increase seldom accompanying with Al increase in the two catchments.     

A TiO2/crosslinked carboxymethyl starch composite for high-efficiency adsorption and photodegradation of cationic golden yellow X-GL dye

In this paper, a crosslinked carboxymethyl starch (CCMS) was prepared with corn starch as the raw material, epichlorohydrin as the crosslinking agent, and chloroacetic acid as the etherifying agent through a series of crosslinking, alkalization, and etherification reactions, respectively. Nano-TiO₂ was loaded onto the surface of the CCMS by the sol-gel method to obtain a TiO₂/CCMS composite. The TiO₂/CCMS composite was characterized by XPS, XRD, SEM, and BET. XPS showed that the surface chemical composition of the TiO₂/CCMS composite material contained titanium; XRD diffraction patterns indicated that the crystal form of the TiO₂/CCMS composite was a combination of the CCMS and anatase TiO₂. The surface morphology obtained by SEM showed that there were nano-TiO₂ particles on the surface of the CCMS. The specific surface area of the TiO₂/CCMS composite was larger than that of CCMS. The adsorption-photodegradation performance of the TiO₂/CCMS composite was also studied under UV irradiation, and the results showed that significant adsorption-photodegradation synergies occurred.

     

关于硝酸铵爆炸事前评价的探讨

硝酸铵主要用作肥料大量使用 ,或作为制造工业炸药的重要原料 ,是一种强氧化剂 ,同时又是自反应性物质 ,国内外因对其控制或管理不当 ,曾发生多起重大爆炸事故。为防止在生产、贮存、运输以及使用过程中的爆炸事故 ,笔者探讨并提出了硝酸铵爆炸事前评价模式。这种评价方法 ,对控制和预防硝酸铵发生事故 ,有借鉴、推广和现实意义。     

生物工程对提高路基安全稳定的研究

详细阐述了路基边坡遭受侵蚀破坏的机理及边坡破坏的表现方式 ;着重分析了植被措施对路基的重要防护作用 ;提出了综合生物工程技术应在路基工程中广泛应用。     

LNG accident dynamic simulation: Application for hazardous consequence reduction

The evaluation of exclusion (hazard) zones around the LNG stations is essential for risk assessment in LNG industry. In this study, computational fluid dynamics (CFD) simulations have been conducted for the two potential hazards, LNG flammable vapor dispersion and LNG pool fire radiation, respectively, to evaluate the exclusion zones. The spatial and temporal distribution of hazard in complex spill scenario has been taken into account in the CFD model. Experimental data from Falcon and Montoir field tests have been used to validate the simulation results. With the valid CFD model, the mitigation of the vapor dispersion with spray water curtains and the pool fire with high expansion foam were investigated. The spray water curtains were studied as a shield to prevent LNG vapor dispersing, and two types of water spray curtain, flat and cone, were analyzed to show their performance for reduction and minimization of the hazard influencing distance and area. The high expansion foam firefighting process was studied with dynamic simulation of the foam action, and the characteristics of the foam action on the reduction of LNG vaporization rate, vapor cloud and flame size as well as the thermal radiation hazard were analyzed and discussed.     

试用期可以依法延长

在上一期的文章中,笔者表达了试用期不能由单方强行延长的观点,这一立论的依据是,试用期乃是劳动合同的一部分,而劳动合同则是劳动关系当事人双方合意的产物,不能由任何一方通过单方的行为来加以改变.基于这一前提,或许有人会问,既然单方改变不合法,那么双方协商一致变更试用期总可以吧？     

添加剂对烟气脱硫的强化作用

采用鼓泡式烟气脱硫反应装置,研究了己二酸、硫酸镁、无机盐A和无机盐B等4种添加剂的脱硫强化作用。实验结果表明:4种添加剂均能较明显地提高脱硫浆液的脱硫率,且添加无机盐A和无机盐B的脱硫效果更好;随着添加剂加入量的增加,脱硫率逐渐提高,综合考虑,本实验适宜的添加剂加入量为1.0 g/L。现场实际应用中加入质量比为1∶1的无机盐A和无机盐B作为复合添加剂,在使用2台循环泵、烟气流量约1 020 km3/h、初始SO2质量浓度由2 981 mg/Nm3增加至约3 843 mg/Nm3的条件下,脱硫率仍由81.79%提高到89.92%。     

故障树分析法在高炉炉前灼伤事故中的应用

应用故障树分析法能系统地分析高炉炉前灼伤的原因,在故障村图上,因果关系明确,并能找出事故发生的主要原因,从而制定措施,以有效地预防事故的发生。     

选钼中间矿浓缩溢流水回收及钼精矿干燥粉尘治理

介绍了德兴铜矿对选钼中间矿浓缩溢流水循环利用所采取的措施和所取得的成果。对原钼精矿干燥除尘系统存在问题进行了整治,达到了预期效果。     

浅谈事故隐患消减的三个关键环节

长庆油田目前已成立30多年,地处鄂尔多斯盆地,是典型的低渗透油田,生产环境条件苛刻,过程连续性强,原料及产品多为易燃易爆、有毒有害有腐蚀的物质,生产技术复杂,设备种类繁多,生产过程中的风险非常大。加之,企业发展的头20多年,由于投资限制,安全管理水平层次低,生产建设坚持“三从一新”（从简、从快、从省,适用新技术）的原则,安全投入欠帐较多、