钽铌冶炼厂酸性含氟废水处理试验研究

用单纯的石灰中和沉淀法处理高浓度酸性含氟废水很难达到排放标准(≤10mg·L-1)。试验采用两步中和沉淀法处理稀土冶炼产生的酸性高氟废水,即分两次投加石灰乳,并用PAM作为混凝剂。结果表明,采用该工艺处理后的出水含氟量低于5mg·L-1,重金属离子含量也可达到排放标准,同时可提高石灰的利用率和改善处理效果。     

二苯基硫脲的合成与分析

探讨了一种合成二苯基硫脲(DPTU)的新方法，以酸性树脂作为催化剂、苯胺和二硫化碳作为反应物在温和条件下选择性地合成了DPTU，考察了催化剂用量和反应时间对产物收率的影响．结果表明：酸性树脂对本反应有显著促进作用；反应4h内DPTU收率随反应时间迅速增加，4h后则增加缓慢；用4g催化剂、9．1ml。苯胺和12mL CS2(摩尔比为1：2)在回流温度下反应6h，DPTU的收率达82．7％，选择性为100％，用GC／MS，HPLC／MS，FTIR，UV和^1H NMR分析了合成的DPTU。     

Influence of surfactant addition for the texture etching process on multi-crystalline silicon wafer

This study investigates the effects of different recipes and concentrations of surfactant on the texture and reflectance of a multi-crystalline silicon wafer surface. The morphology of the surface was examined and photographed using a field emission scanning electronic microscope. The reflectance of the surface was measured and analyzed using a self-designed optical system. The results of this study show that a higher hydrocarbon-surfactant (CH-surfactant) concentration in the etchant resulted in a slower reaction time. The optimum concentration of CH-surfactant was 1%. However, there were many white bubbles in the etching process. The optimum recipe for surfactant included fluoride 2% to diminish these bubbles. The reflectance was less than 22% in visible light. This cost effective acid chemical etching method is suitable for texturing silicon surfaces on 50?nm nanostructures. This is a critical criterion for determining the optimum recipe for surface texturing of acidic etching in solar cells.     

紫金山含铜酸性水资源化及无害化处理试验研究

采用硫化法和螯合法对紫金山含铜酸性水进行了资源化、无害化处理对比试验研究,结果表明:硫化法和螯合法均可有效处理紫金山含铜酸性水,铜回收率均在99%以上,处理后铜质量浓度均小于0.5 mg/L,可达到排放标准。两种处理方法的经济技术指标盈亏平衡点主要受到铜质量浓度和铁质量浓度变化的影响,硫化法的经济性优于螯合法。     

Synergistic effects of high pressure processing and slightly acidic electrolysed water on the inactivation of Bacillus cereus spores

Bacillus spores are concerns for their resistance to heat, high pressure processing (HPP), and disinfectants. We examined the effects of HPP and slightly acidic electrolysed water (SAEW) on inactivation of B. cereus spores. Spores' suspensions were prepared with 2‐(N‐morpholino) ethanesulfonic acid (MES) buffer or SAEW with available chlorine content (ACC) of 24, 35, 44 or 55 mg L^?1, and then subjected to HPP. The individual effects of HPP or SAEW on spores were negligible (<1.0 log CFU mL^?1). With factorial design and anova analysis, HPP + SAEW treatment was shown to have significantly positive effects on spores’ inactivation. The optimal conditions were 300 MPa HPP + SAEW with 44 mg L^?1 ACC or 200 MPa HPP + SAEW with 44 mg L^?1 ACC + 500 MPa HPP, producing reductions of 3.27 and 3.99 log CFU mL^?1, respectively. HPP + SAEW have potentials to serve as two effective hurdle techniques for inactivating B. cereus spores.     

In-Situ Investigation on Nanoscopic Biomechanics of Streptococcus mutans at Low pH Citric Acid Environments Using an AFM Fluid Cell

Streptococcus mutans (S. mutans) is widely regarded as the main cause of human dental caries via three main virulence factors: adhesion, acidogenicity, and aciduricity. Citric acid is one of the antibiotic agents that can inhibit the virulence capabilities of S. mutans. A full understanding of the acidic resistance mechanisms (ARMs) causing bacteria to thrive in citrate transport is still elusive. We propose atomic force microscopy (AFM) equipped with a fluid cell to study the S. mutans ARMs via surface nanomechanical properties at citric acid pH 3.3, 2.3, and 1.8. Among these treatments, at pH 1.8, the effect of the citric acid shock in cells is demonstrated through a significantly low number of high adhesion zones, and a noticeable reduction in adhesion forces. Consequently, this study paves the way to understand that S. mutans ARMs are associated with the variation of the number of adhesion zones on the cell surface, which is influenced by citrate and proton transport. The results are expected to be useful in developing antibiotics or drugs involving citric acid for dental plaque treatment.     

橄榄油与椰子油混油基对类蛋黄酱乳液流变及冻融稳定性的影响

以类蛋黄酱体系为研究对象，运用Turbiscan、流变仪、粒度仪、显微镜研究在pH 3条件下橄榄油与椰子油不同比例复配（10∶ 0、9∶ 1、8∶ 2、7∶ 3）的混油基对于乳清分离蛋白-蛋黄卵磷脂稳定的乳液体系流变性质及冻融稳定性的影响。结果表明：随着椰子油比例增加，乳液黏度增加，弹性模量增加，橄榄油与椰子油质量比7∶ 3复配混油基制得的乳液具有最大的黏度和最高的弹性模量；所有乳液在4~40 ℃弹性模量下降，说明乳液在贮存、冷藏运输过程中内部结构完整，乳液具有良好的稳定性;蛋黄卵磷脂能够提高含椰子油（饱和脂肪酸含量高）乳液的冻融稳定性，并且椰子油比例越大（饱和程度越高），冻融稳定性提高效果越好;乳液冻融稳定性从高到低依次为橄榄油与椰子油质量比为7∶ 3>8∶ 2>9∶ 1>10∶ 0。     

酸性离子液体催化合成聚内烯烃的研究

以氯化卜丁基-3-甲基咪唑[Bmim]Cl为阳离子、氯化铁为阴离子合成酸性离子液体作为催化剂，用于内烯烃的齐聚反应，考察了不同反应温度、反应时间、催化剂用量等工艺条件对内烯烃齐聚反应的影响。通过气相色谱分析可知，合成的聚内烯烃主要是二聚、三聚、四聚和较少的五聚物，没有裂解产品。并在温度为120℃，反应时间为3h，催化剂质量分数为5％的条件下，内烯烃的转化率最高达到82％，这为进一步工业化合成高质量的聚内烯烃类润滑油提供了有效数据。     

Mill scale as a potential additive to improve the quality of hematite ore pellet

Hematite pellet is required to be indurated at very high temperature to achieve its good strength as there is no exothermic heat of oxidation unlike magnetite. As mill scale contains mainly FeO and Fe₃O₄, any minor amount of its addition in pellet can provide in situ heat and enhance diffusion bonding and sintering. In this study, the mill scale generated in steel plant is added as magnetite input in hematite pellet both in acidic and in basic condition. It has been found that in fluxed pellet, mill scale can improve the properties of pellet. In acidic pellet, the induration temperature has been reduced to a great extent (1250–1275°C) and all properties have been found to be improved due to the addition of 15% mill scale. Mill scale shows enough potential to eliminate the flux addition in producing blast furnace quality pellet from hematite ore. Thus, the flux free acidic pellet has been developed even at very low temperature (1275°C) of induration.