通过某样品中硫酸根的多种测定方法探讨硫、硫酸以及硫酸根测定

本文对矿样、产品中的硫单质、硫化物以及硫酸盐的测定原理进行了分析研究,通过实验对其测定方法进行了总结,使我们在遇到含有硫化物或硫单质或硫酸盐的矿物、产品,特别是硫的多种状态混合的产品时,可以根据归纳,快速找到最合适的测定方法,减少实验中摸索的人力物力的浪费。本文是在分享自己的经验,同时也是交流思想的一种方式。     

煤的电化学脱硫机理研究

本文在研究煤的电化学脱硫基础上 ,利用 X-射线衍射和红外光谱等现代测试手段研究了煤中无机硫和煤系黄铁矿硫的电化学脱硫机理。研究表明煤中无机硫和煤系黄铁矿硫的脱硫机理有相似之处。首先在电极表面产生活性氧或高价离子 ,活性氧氧化煤或煤系黄铁矿中无机硫为单质硫或硫酸盐硫。其中煤中硫氧化为硫酸盐硫 ,煤系黄铁矿硫氧化为硫或硫酸盐硫。     

含硫重钙中总硫含量的测定

开发了两步法测定含硫重钙中总硫的方法。用盐酸溶解样品中的硫酸盐,玻璃砂芯坩埚过滤后,滤液用硫酸钡重量法测定硫酸盐含量。滤渣用硫饱和丙酮溶出干扰物质,再以二硫化碳溶出单质硫,通过减量法测定单质硫。结果显示,运用此方法对实验样品多次平行测定的相对标准偏差分别在2.30%～2.81%和1.09%～1.23%,回收率分别在96.8%～102.5%和98.7%～103.0%。     

无副盐脱硫新技术在煤气净化系统中的应用

介绍了在煤气净化技术领域,能使煤气中的H_2S、HCN快速吸收,在催化剂作用下S~(2-)快速、全部氧化为单质硫,合适的催化氧化电位,又使S不过度氧化产生硫代硫酸盐、硫氢酸盐和硫酸盐等副盐的一种新技术。     

氟法硫磷铵复合肥工艺的开发

硫元素的肥效,已越来越引起人们的重视,现在已有人提出,在肥料中,氮与硫之比,应保持5:1的比例为好。我国福建等沿海省份,土壤严重缺硫,早已开始施用元素硫作肥料。目前,含硫肥料主要是普钙、硫酸铵、重钙以及少量的硫磷铵复合肥。硫磷铵的生产,现在主要是由硫酸铵与磷酸铵混合制成的,其产量严重受到硫酸和磷酸的限制。开发化学法制硫磷铵新工艺,早有人在探求。近两年来,我做了“氟法”硫磷铵工艺试验,在实验室制出了产品。实验证明     

炼焦过程中硫元素迁移规律研究

以华北地区的峰峰低硫肥煤和山西中硫焦煤为原料,利用1 kg热解试验装置进行模拟炼焦试验,并对所得焦炭、煤焦油和煤气产品中硫元素形态和质量进行测定,揭示了炼焦煤中硫元素的迁移规律。结果表明:两种炼焦煤挥发分差别不大,硫元素迁移规律基本相同;炼焦过程中,不但原料煤中硫酸盐硫得以保留,还有其它形态硫经过复杂的热解化合反应生成新的硫酸盐硫;无机硫中的黄铁矿硫和有机硫中的脂肪硫、硫醚、硫醇等在炼焦过程中以H2S形式转移到煤气中,转移效率一般低于50%;原料煤中黄铁矿硫含量越高,H2S的转移率也越高;其他噻吩硫等在炼焦过程中不分解,留在焦炭中。     

微生物燃料电池处理模拟含硫废水的初步研究

采用微生物燃料电池(Microbial fuel cell,MFC)处理模拟含硫废水,硫化物能全部被氧化戍单质硫或硫酸盐.MFC的最大功率密度达到(20±1)W·m~(-3),库仑效率为(20±2)%.阳极中有机质的氧化与硫化物的氧化存在一定竞争关系,进水碳硫比是影响单质硫生成率的关键因素.试验中,进水碳硫质量比大于1250:1,S~(2-)质量浓度为50mg·L~(-1)时,硫化物氧化成单质硫的转化率可达61%～77%.此外,阳极表面单质硫的积累很可能是造成MFC电极失效或运行不稳定的原因之一.     

硫酸催化法糠醛生产工艺中的硫平衡研究

对玉米芯、糠醛渣及其燃烧后炉渣进行了全硫和形态硫分析,并根据水解反应原理得出结论:催化剂硫酸在水解反应后仍以硫酸形态存在于糠醛渣中,糠醛渣在锅炉中燃烧后,质量分数为97.4%的硫酸以SO3形态析出,并在高温环境下很快裂解为SO2,剩余的硫酸主要以硫酸盐形态存在于炉渣中。     

土壤中硫形态分析方法

关于土壤中各种形态的硫的分析方法较少。本文整理了一系列土壤中硫形态:水溶性硫、吸附性硫、酸可溶性硫、黄钾铁矾硫、有机硫、单质硫的提取方法及测试方法,希望为环境监测人员提供参考。     

含氨和硫酸盐废水的处理技术展望

目前许多废水不仅含有高浓度的氨氮,而且含有高浓度的硫酸盐,给废水治理带来难度。对同步脱硫反硝化工艺和硫酸盐型厌氧氨氧化工艺的研究进展进行了综述。同步脱硫反硝化工艺和硫酸盐型厌氧氨氧化工艺能同时脱氮和除硫,不仅无H2S排放,而且还具有节约碳源、污泥产量小和实现单质硫回收的优点。其中硫酸盐型厌氧氨氧化工艺无需曝气和有机物,具有更高的技术和经济优势,将是未来生物脱氮除硫技术的新方向。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.