变压器火灾及预防

本文通过详细分析变压器火灾原因，提出预防变压器火灾的技术措施，供生产厂家、使用单位和消防监督管理部门有关技术人员、生产者、监管人员参考。     

无铅焊料合金中重金属元素浸出行为的研究

选用Sn.3.5Ag-0.5Cu、Sn-3.5Ag、Sn-0.5Cu无铅焊料合金及它们与Cu的钎焊接头,研究了它们在典型的酸性、碱性和盐溶液中的重金属元素的浸出规律.结果表明,焊料合金中的主要浸出元素Sn在酸性或碱性溶液中的浸出量都不是太多,而在NaCl盐溶液中浸出量增大2个数量级.制备成钎焊接头后,在酸性环境中,Sn-3.5Ag和Sn.0.5Cu钎焊接头中Sn的浸出量增加1个数量级以上,而在NaOH碱性环境中.Sn-3.5Ag-0.5Cu钎焊接头中Sn的浸出量相对较高.该结果对电子垃圾填埋环境选择及相关决策提供了参考.     

模拟地下水中重碳酸盐浓度对零价铁还原硝基苯的影响

通过静态试验研究了重碳酸盐浓度在0,100,300,500,800mg/L时对零价铁还原硝基苯的影响,检测反应过程中硝基苯和苯胺的浓度变化,同时检测溶液中pH值、Eh、Fe2+、CO32-的变化,结果表明,重碳酸盐浓度较低(100~500mg/L)时对零价铁还原硝基苯有促进作用,且促进作用随着重碳酸盐浓度的升高而增强.重碳酸盐浓度为500mg/L的反应体系中硝基苯去除率及苯胺生成率最高分别为88%,173mg/L,且在该体系中重碳酸盐对pH值的缓冲能力最强、Eh下降幅度最大,Fe2+浓度最高.重碳酸盐浓度为800mg/L的体系不利于硝基苯的还原.     

Chromium accumulation by the hyperaccumulator plant Leersia hexandra Swartz

Leersia hexandra Swartz (Gramineae), which occurs in Southern China, has been found to be a new chromium hyperaccumulator by means of field survey and pot-culture experiment. The field survey showed that this species had an extraordinary accumulation capacity for chromium. The maximum Cr concentration in the dry leaf matter was 2978 mg kg(-1) on the side of a pond near an electroplating factory. The average concentration of chromium in the leaves was 18.86 times as that in the pond sediment, and 297.41 times as that in the pond water. Under conditions of the nutrient solution culture, it was found that L. hexandra had a high tolerance and accumulation capacity to Cr(III) and Cr(VI). Under 60 mg l(-1) Cr(III) and 10 mg l(-1) Cr(VI) treatment, there was no significant decrease of biomass in the leaves of L. hexandra (p>0.05). The highest bioaccumulation coefficients of the leaves for Cr(III) and Cr(VI) were 486.8 and 72.1, respectively. However, L. hexandra had a higher accumulation capacity for Cr(III) than for Cr(VI). At the Cr(III) concentration of 10 mg l(-1) in the culture solution, the concentration of chromium in leaves was 4868 mg kg(-1), while at the same Cr(VI) concentration, the concentration of chromium in leaves was only 597 mg kg(-1). These results confirmed that L. hexandra is a chromium hyperaccumulator which grows rapidly with a great tolerance to Cr and broad ecological amplitude. This species could provide a new plant resource that explores the mechanism of Cr hyperaccumulation, and has potential for usage in the phytoremediation of Cr-contaminated soil and water.     

甲苯在负载型铜催化剂上吸附和氧化的原位红外光谱分析

利用原位红外光谱(in situIR)技术研究甲苯在γ-Al2O3、Cu/γ-Al2O3催化剂上的吸附、氧化分解行为.综合考虑了载体和活性组分的作用,分析了甲苯在富氧和缺氧条件下催化剂上的吸附和氧化行为.结果表明,甲苯在催化剂上的吸附较弱,但其中间产物苯甲酸却可以在催化剂表面形成较强的化学吸附,苯甲酸的深度氧化是甲苯深度氧化过程中的速度控制步骤,氧化铜是催化剂中的主要活性组分.     

Improving the stability,lithium diffusion dynamics,and specific capacity of SrLi2Ti6O14 via ZrO2 coating

SrLi2Ti6O14 (SLTO) coated with different amount of ZrO2 was successfully prepared. The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity. Furthermore, ZrO2 coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film. As a result, the redox polarization was reduced, and the reversibility of the electrochemical reaction was enhanced. Particularly, SLTO-ZrO2-2 sample delivers a high initial lithiation capacity of 283.6 mA h g-1, and the values maintain at 251.7, 228.0, 207.4, 175.3, and 147.7 mA h g-1 at the current densities of 0.13, 0.26, 0.54, 1.31, and 2.62 A g-1, respectively. Our experiment also confirmed that SLTO materials coated with ZrO2 are suitable for high power density applications, and the lithiation specific energy efficiency of SLTO-ZrO2-2 is 200％as high as that of pure SLTO at a power density of 1257 W kg-1.     

分置式膜-生物反应器凝胶层膜污染模型研究

通过紊流条件下阻力模型和凝胶极化模型对膜生物反应器的阻力进行分析,结果表明,膜面流速在3～10 m/s,运行时间在5h之内时,阻力模型可以很好地符合凝胶模型.通过分置式膜-生物反应器对染料废水超滤膜阻力进行了分析,膜的总阻力随着运行时间增加而增加,在所有阻力中,凝胶阻力占比重最大.     

Preparation and Adsorption Performance of Nano-hydroxyapatite-Enhanced Acrylamide Hydrogel Adsorbent

Journal of Polymers and the Environment - In this study, a hydrogel adsorbent was successfully synthesized using hydroxyapatite/acrylamide/β-cyclodextrin to adsorb heavy metal ions and dyes in...