碟式分级机分选微细粉的研究

通过对碟式分级机的模型实验。系统地研究了碟分级机分级微细颗粒的特性。结果表明，碟式分级机可用来分级微颗粒。分级性能受到分级机结构参数和操作参数的影响，产品的颗粒中位径ｄ５０为０．５μｍ左右。     

UHMWPE锂电池隔膜树脂微粉气流分级的试验研究

超高分子量聚乙烯(UHMWPE)锂电池隔膜专用树脂微粉受生产工艺的限制,因静电原因其产品中含有大量团聚粗颗粒,降低了总体的粒度指标,得到的微粉颗粒较粗且分布范围较宽。利用自制WTPC-300型高速气流分级机对UHMWPE微粉进行分级试验,分别考察分级轮转速、分级风速、二次风流量等操作参数对分级细粉平均粒径d50和150μm粒径以下细粉收率的影响。研究结果表明:分级轮转速、分级风速、二次风流量变化对分级细粉平均粒径d50和150μm粒径以下细粉收率的影响都存在中间最优值,即分级轮转速为3300r/s,二次风流量为30m3/h,分级风速为11.5m/s时分级得到的UHMWPE微粉最细,相关粒径指标优于进口产品。     

硬质磨料高精度分级研究

对自行设计的射流式短程多流态分级器操作的影响进行了实验研究，探讨了分级实验的最佳条件，该设备具有高精度分级的能力，可以同时获得四个粒段的产品，其中两段产品的分级精度达到１００％；分级产品最小粒度〈２．５μｍ。     

新型超微细粉末干法分级设备的研究与应用

本文基于旋风分级收尘器设计研究了新超细粉末干法分级设备,主要用于无机粉体材料微细粉的分级,该分级器可同时获得粗,细,微三种不同粒度的产品。该设备在旋风分级器下部引入一定量的二次风,淘洗夹带在粗颗粒中的微粉,从而提高微粉的提取率。     

超细活性重晶石生产工艺研究

将含ＢａＳＯ２９４．５％的重晶石矿经雷蒙磨初级粉碎，酸洗，五级湿法剥片超细粉碎等处理可获得超细产品，其粒度组成：ｄ１０＝０．１μｍ，ｄ５０－０．４５μｍ，ｄ９０＝１．４５μｍ。粉料经稀硫酸处理，可提高其白度及耐候等性能，在剥片中加入活化剂可在超细粉碎的同时进行活化处理。     

超细活性重晶石生产工艺研究

将含ＢａＳＯ４ ９２－５ ％ 的重晶石矿经雷蒙磨初级粉碎、酸洗、五级湿法剥片超细粉碎等处理可获得超细产品, 其粒度组成： ｄ１０ ＝ ０ ．１μｍ , ｄ５０ ＝ ０ ．４５μｍ , ｄ９０ ＝ １ ．４５μｍ 。粉料经稀硫酸处理, 可提高其白度及耐候等性能。在剥片中加入活化剂可在超细粉碎的同时进行活化处理。通过加入到几种油漆中使用和检测, 说明本工艺生产的产品具有分散性好、稳定性好等优点, 是沉淀硫酸钡的一种理想替代品。     

新型旋风式超细机的开发研究

研制开发了以改进结构的旋风分离器为主体的组合式新型旋风式微细分级机，并通过对高岭土和碳化硅磨料的正交分级试验，测试研究了其分级性能有关因素对分级效果的因素。试验结果表明，５μｍ颗粒和２μｍ颗粒的分级效率分别大于９０％和８８％，分级所得细粉的平均粒度为２μｍ左右，其中小于５μｍ的颗粒含量可达９４％以上。导向对片角度和分级器入口风速对分级效率的影响较大，而给料速度对其影响不大。     

锆英石、莫来石、碳化硅、尖晶石微粉的性能

对国产的锆英石、莫来石、碳化硅和尖品名微粉作了水化增重率、粒度分布、烧结性能的研究。结果表明：制品中加入一定量的微粉有促进烧结的作用。对锆英石微粉而言．粒度为３μｍ的微粉加入量５％时能明显地促进烧结。     

碟式分级机分级超细粉效率的模型

通过转速、料浆浓度及喂料速度等操作参数对碟式分级机分级超细粉性能的影响试验，分析了蝶式分级机部分分级效率曲线的特性，通过特征分级径ｄ１０ｃ及分级精度ｍ，建立了分级机分级超细粉分级效率模型，由多元线性回归得到了模型参数与各操作参数的关联式。并用此模型分析了分级机操作条件对模型参数的影响。     

对二甲氨基苯甲醛比色法测定尿素水解系统中的微量尿素

通过正确选择波长和显色条件,用二对甲氨基甲醛比色法准确测定尿素水解系统中的微量尿素,方法检出限为０．７μｇ／ｍｌ,线性范围为０～５０μｇ／ｍｌ,测定２μｇ／ｍｌ尿素样品的变异系数为４．５％。此法检出限较低,线性范围宽,精密度好,操作简便。     

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。