不同气氛下自然冷却黄磷炉渣析晶动力学研究

以自然冷却黄磷炉渣为研究对象,采用熔融法制备CaO-Al2O3-SiO2 (CAS)系微晶玻璃.分别通过Owaza方程和修正后的Kissinger方程方程计算自然冷却黄磷炉渣基础玻璃的析晶活化能(E),利用Augis-Bennett方程计算了自然冷却黄磷炉渣基础玻璃的晶体生长指数(n),利用差热分析和X射线衍射分析技术分析了不同气氛下自然冷却渣微晶玻璃的析晶规律和晶相组成.结果表明:基础玻璃在空气气氛下较氮气气氛下更容易析晶;在一定的升温速率下,基础玻璃的析晶方式均为三维体积晶化;无论是在空气气氛下还是在氮气气氛下,自然冷却黄磷炉渣微晶玻璃的主晶相均为硅灰石(CaSiO3).     

ZnO对黄磷炉渣微晶玻璃析晶影响

以黄磷炉渣为主要原料,通过添加不同比例ZnO,采用熔融法制备了CaO-Al2O3-SiO2系微晶玻璃.借助Kissinger方程分析黄磷炉渣基础玻璃的析晶能力,借助化学热力学软件FactSage 6.4模拟计算黄磷炉渣微晶玻璃晶相类型,借助X射线衍射仪(XRD)和扫描电子显微镜(SEM)进行验证.结果表明:随着ZnO添加量的增加,黄磷炉渣基础玻璃的析晶峰温度Tp和析晶活化能E逐渐减小;当ZnO添加量为7wt％时,黄磷炉渣基础玻璃的析晶活化能E最小,析晶能力最强;随着ZnO的加入量的增大,黄磷炉渣微晶玻璃晶相类型并不发生改变,主晶相为硅灰石(CaSiO3),次晶相为铝透辉石(Ca(Mg,Al)(Si,Al)2O6),这与FactSage 6.4模拟计算结果一致.     

包钢高炉渣制备微晶玻璃的析晶方式研究

以包钢高炉渣为主要原料,采用熔融法制备CaO-MgO-Al2O3-SiO2系微晶玻璃,通过差热分析(DTA)、X射线衍射(XRD)、扫描电子显微镜(SEM)分析方法,并借助Ozawa方程研究了添加不同数量晶核剂时的析晶方式.研究结果表明:分别加入8％ CaF2、8％ TiO2和4％ P2 O5作晶核剂时,晶化指数n均小于3,析晶方式为表面析晶;当加入晶核剂为8％ P2O5时,晶化指数n大于3,析晶方式为整体析晶.     

MgO对黄磷炉渣微晶玻璃析晶影响

以黄磷炉渣为基础原料,通过加入辅料和MgO,以熔融法制备CaO-Al2 O3-SiO2(CAS)系微晶玻璃;通过差热分析(DTA)、X射线衍射(XRD)和扫描电子显微镜(SEM)等分析方法分析MgO对黄磷炉渣微晶玻璃晶化行为的影响.结果显示:随着加入MgO的量的增加,基础玻璃的核化温度和晶化温度下降,析晶活化能E减小;黄磷炉渣微晶玻璃的晶相类型并未因MgO添加量的增多而改变,其主晶相为硅灰石(CaSiO3),次晶相为铝透辉石(Ca(MgAl)(SiAl)2O6);但随着MgO添加量的增多,抑制了硅灰石(CaSiO3)晶相的生成,促进铝透辉石(Ca(MgAl)(SiAl)2O6)生成.     

含复合晶核剂CaO-MgO-A12O3-SiO2微晶玻璃析晶与性能

采用高温熔制法制备了含复合晶核剂的CaO-MgO-A12O3-SiO2(CMAS)微晶玻璃,并借助差热分析、X射线衍射、扫描电子显微镜分析了复合晶核剂组成对CMAS微晶玻璃的析晶和性能的影响规律.结果表明:复合晶核剂CaF2+TiO2能使CMAS玻璃的析晶活化能E降至329.2 kJ/mol,且促进晶体快速生长;CaF2+P2O5可促进大量晶核生成,使晶体生长指数n增至2.87,从而实现CMAS玻璃整体析晶;CMAS微晶玻璃的主晶相为钙长石和透辉石,形状为长条状,TiO2和ZrO2的加入对主晶相种类和形状没有影响,但P2O5加入后玻璃不能析出透辉石晶相,而是辉石晶相,并产生许多细小晶粒;含复合晶核剂的微晶玻璃均具有较高Vicker硬度(7.0 GPa以上),但引入CaF2+TiO2+P2O5时,微晶玻璃的Vicker硬度较低,这主要是晶粒排列不致密所致.     

TiO2对CaO-MgO-Al2O3-SiO2微晶玻璃析晶的影响

本文运用差示扫描量热分析(DSC)、X射线衍射(XRD)和场发射扫描电镜(FESEM)研究了TiO2含量对CaO-MgO-Al2O3-SiO2系微晶玻璃析晶过程和析晶动力学的影响.结果表明:随着TiO2含量的增加,玻璃转变温Ts和析晶峰温度Tp逐渐降低.当不加TiO2或者添加5wt％的TiO2时,玻璃发生表面析晶,析出的晶相为斜长石.当添加10wt％的TiO2时,玻璃样品在800℃热处理后发生剧烈分相,910℃晶化后出现整体析晶,晶相为普通辉石.随着TiO2含量的增加,析晶动力学常数k值增大.当添加10wt％的TiO2时,k值达到最大,为0.545,此时玻璃最容易析晶,相应的析晶活化能E和析晶指数n分别为643.329 kJ/mol和3.25.     

含复合晶核剂CaO–MgO–Al2O3–SiO2微晶玻璃析晶与性能

采用高温熔制法制备了含复合晶核剂的CaO–MgO–Al2O3–SiO2(CMAS)微晶玻璃,并借助差热分析、X射线衍射、扫描电子显微镜分析了复合晶核剂组成对CMAS微晶玻璃的析晶和性能的影响规律。结果表明:复合晶核剂CaF2+TiO2能使CMAS玻璃的析晶活化能E降至329.2kJ/mol,且促进晶体快速生长;CaF2+P2O5可促进大量晶核生成,使晶体生长指数n增至2.87,从而实现CMAS玻璃整体析晶;CMAS微晶玻璃的主晶相为钙长石和透辉石,形状为长条状,TiO2和ZrO2的加入对主晶相种类和形状没有影响,但P2O5加入后玻璃不能析出透辉石晶相,而是辉石晶相,并产生许多细小晶粒;含复合晶核剂的微晶玻璃均具有较高Vicker硬度(7.0GPa以上),但引入CaF2+TiO2+P2O5时,微晶玻璃的Vicker硬度较低,这主要是晶粒排列不致密所致。     

CaF2含量对熔融态高炉渣微晶玻璃析晶及性能的影响

利用液态高炉渣为主要原料,采用熔融法制备了微晶玻璃.借助DSC、XRD、SEM等分析测试方法研究了CaF2含量对高炉渣微晶玻璃析晶及性能的影响.试验结果表明,CaF2能够有效降低微晶玻璃的形核析晶温度,促进微晶玻璃析晶.微晶玻璃中晶体含量随着CaF2含量的增加而增加.当CaF2含量小于4％时,微晶玻璃的晶相为透辉石、普通辉石和钙镁黄长石;当CaF2含量大于4％时,析出了新晶相枪晶石.最终确定CaF2的最佳添加量为6％,此时微晶玻璃结晶度高,平均晶粒粒度100 nm,体积密度2.81 g/cm3,吸水率0.04％,耐酸腐蚀性98.92％,耐碱腐蚀性99.98％,抗弯强度173.41MPa.     

TiO2对R2O-MgO-Al2O3-SiO2-ZrO2系微晶玻璃析晶及性能的影响

以花岗岩废渣为主要原料,用熔融法制备了添加TiO2的R2O-MgO-Al2 O3-SiO2-ZrO2(RMASZ)系微晶玻璃.采用X-射线衍射(XRD)、扫描电子显微镜(SEM)、电子万能材料试验机和显微硬度测试仪研究了TiO2对RMASZ系微晶玻璃的晶相组成、显微结构以及力学性能的影响.结果表明:当TiO2含量为0wt％、0.5wt％、1wt％时析出的主晶相为t-ZrO2和顽火辉石;当TiO2含量为2wt％和3wt％时析出假蓝宝石相,顽火辉石相减少.当TiO2为0.5wt％时晶粒细致均匀,其四点抗弯强度达到122.41 MPa,显微硬度为9.35 GPa.     

TiO2含量对高炉渣微晶玻璃结构和性能的影响

利用高炉渣并添加辅料制备了基础玻璃,对基础玻璃进行热处理制备出以钙长石为主晶相的微晶玻璃.运用DSC、XRD、SEM等测试方法,综合分析TiO2含量对高炉渣微晶玻璃结构和性能的影响.结果表明:随着TiO2含量从1.29wt％增加至5.29wt％,微晶玻璃析晶温度逐渐降低,微晶玻璃主晶相均为钙长石、次晶相均为透辉石,微晶玻璃的体积密度、显微硬度及抗折强度呈现上升趋势.当TiO2含量为5.29wt％时,样品机械性能最好,体积密度为2.738 g·cm-3,抗折强度为79.8 MPa,显微硬度为930.2 HV.     

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。