拜耳法赤泥强化沉降研究

本文以拜耳法赤泥固化堆存为背景,研究了拜耳法赤泥的物理特性和自然沉降特性,比较了不同促沉剂在不同掺量条件下对赤泥浆体沉降性能的影响;通过正交试验优选出赤泥促沉剂的合理配比:腐植酸钠/萘系减水剂/六偏磷酸钠/十二烷基苯磺酸钠=1/11/2/3,在浓度为40％的赤泥浆体中掺用3.4‰的促沉剂,沉降8h后沉降层浆体浓度可以达到52.6％,24h后沉降层浓度可以达到59.8％;与自然沉降24h相比,沉降层浓度提高了27％;对强化浓缩赤泥进行固化,并与自然沉降赤泥固化体相比,内聚力提高了50％,提高了固化堆存的稳定性和安全性.     

铝土矿浮选尾矿中铁的溶解行为

研究了复杂铝土矿浮选尾矿在酸介质中铁的溶解行为. 结果表明,在一定的温度下,铝土矿中的赤褐铁矿能较好地溶于硫酸溶液中,而铝土矿中矿物等的性质不发生变化,这为铝土矿尾矿的进一步加工利用提供了条件. 实验详细讨论了反应温度、反应时间、硫酸浓度等因素对铁溶解行为的影响,得出在反应温度80℃、反应时间3 h、硫酸浓度2.70 mol/L、草酸浓度0.25 mol/L、液固比1:6时除铁率可达90%左右.     

助凝助沉剂在含镍废水化学处理中的应用

研究了助凝助沉剂在化学中和-混凝沉淀处理含镍废水过程中的助凝助沉作用.结果表明,采用化学中和-混凝沉淀处理含镍废水,可以使出水Ni2 质量浓度＜1 mg/L.助凝助沉剂粉煤灰、焦炭、硅藻土和碳酸钙均有很好的助凝助沉作用,可以大大地改善污泥的特性,可使含镍污泥7 min和15 min的沉降比降低70%以上.采用粉煤灰作为助凝助沉剂,适宜投加质量浓度为2 g/L;污泥的沉降时间由30 min缩短到5 min,污泥体积减少58%;过滤后,滤饼的含水量降低6.8%.工业实验的结果与小试实验结果基本一致.     

大红山微细粒铁尾矿沉降特性研究

本文以大红山铁尾矿的充填为研究对象,研究了尾矿的粒度分布和自然沉降特性,比较了PAM和CBC-T对矿浆的沉降效果.研究结果表明:大红山铁尾矿属于微细粒尾矿的范畴,由于颗粒细、沉降速度慢、含水率高,很难满足充填要求;采用PAM进行絮凝处理,可以提高沉降速度,但絮体结构疏松,对胶结体强度有不良影响;采用CBC-T处理矿浆,能够显著地提高沉降速度和改善水质,在1 h内使沉降体浓度提高到60％以上,能够满足充填工程对尾矿的技术要求.     

铝土矿尾矿多孔陶瓷的制备研究

以铝土矿尾矿为主要原料,分别选用碳粉、石墨粉、碳酸氢钠和淀粉作为造孔剂制备出铝土矿尾矿多孔陶瓷试样,采用抗弯测试、XED、SEM等对其主要力学性能和热物理性能进行测试与表征,结果表明:不同的造孔剂制备的铝土矿尾矿多孔陶瓷试样的抗弯强度、显气孔率、晶相组成和显微组织不同;以碳粉作为造孔剂制备的铝土矿尾矿多孔陶瓷试样的综合性能较好,因此最终选用碳粉作为制备铝土矿尾矿多孔陶瓷试样的造孔剂。     

丁黄药用作高硫铝土矿浮选除硫的捕收剂

采用浮选方法对我国含硫一水硬铝石型铝土矿进行脱硫,采用单因素实验研究了高硫铝土矿在浮选剂丁基钠黄药作用下反浮选除硫的工艺条件,考察了浮选剂用量、浮选时间、浮选矿浆浓度(液固质量比)、pH值及矿石粒度对浮选的影响. 结果表明,反浮选除硫的合适工艺条件为,矿浆pH 10、浮选剂用量0.16 kg/t、起泡剂20 g/t、浮选刮泡时间15 min、液固质量比10、矿石粒度0.15 mm. 在此工艺条件下,铝土矿中硫含量由2.08%降低到0.41%,符合我国氧化铝工业对矿石中硫含量的要求,Al2O3回收率达90.83%. 浮选过程基本符合一级动力学反应方程.     

纯碱行业卤水中硫酸根的脱除

在纯碱生产过程中,原料卤水中一般硫酸根浓度较高,必须脱除才能生产。采用蒸氨废液（主要成分为氯化钙）去除卤水中的硫酸根,产生副产品硫酸钙,在保证硫酸根去除效果的前提下,向反应体系中加入聚丙烯酰胺作为助沉剂,有效地提高了硫酸钙的沉降速度。实验考察了聚丙烯酰胺的种类、相对分子质量、用量及体系温度、pH、搅拌时间等因素对沉降效果的影响,并比较了几种常见絮凝剂的助沉效果。结果表明,采用相对分子质量为1.2×107的阴离子型聚丙烯酰胺,用量为20 mg/L,在体系温度为50~60 ℃和pH=4~8的条件下搅拌反应30 min,得到良好的助沉效果,极大降低了硫酸钙沉淀颗粒的沉降时间,提高了生产效率。     

盐水精制过程中絮凝剂助沉效果的分析

在纯碱生产过程中,为提高盐水精制过程中硫酸钙、碳酸钙、氢氧化镁等沉淀泥的沉降速度,确保去除钙、镁反应过程的精制效果,需要向粗盐水中加入聚丙烯酰胺絮凝剂做为助沉剂。通过对不同厂家的聚丙烯酰胺助沉剂、粗盐水浓度、溶液温度等的比较试验,得到适合本公司助沉剂使用数据,降低了钙、镁等沉淀泥颗粒的沉降时间,使澄清桶的澄清能力得到提高。     

铝土矿选尾矿制备低温陶瓷泡沫材料工艺研究

本文研究出了用铝土矿选尾矿制备低温陶瓷泡沫材料工艺条件.探讨了尾矿活化条件、矿物组成、激发剂用量、水胶比、胶骨比的影响机理.分析了材料的矿物组成和微观结构.制备出了以尾矿为胶凝材料主原料、煤渣为骨料、铝粉为发泡剂的新型高强轻质泡沫复合材料.其抗压强度10.78 MPa、密度0.94 g/cm3、平均孔径2～5 mm.     

氢氧化镁制备过程中沉降速率的初步研究

以氯化镁、碱液和表面活性剂等为试验材料,对沉镁反应中颗粒沉降过程进行初步研究,从而得出结论:当氢氧化钠浓度为1.5mol/L,采用正向加料方式的沉镁反应速率高于反向加料方式;沉淀剂采用氨水使得沉降速率有所提高;沉镁反应速率随着葡萄糖浓度的增加呈锯齿状波动,并确定了最优值;并且随着Mg²⁺浓度的增加,氢氧化镁的沉降速率有降低的趋势;最佳操作温度为60℃;最佳pH为9.87。     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。