低温固相反应合成锡酸锌

以氯化锡、硝酸锌、氢氧化钠为原料,用低温固相反应法合成尖晶石型复合氧化物锡酸锌晶体.用红外光谱表征产物的晶体结构,结果表明:固相反应完全,合成的前躯体经600 ℃煅烧2 h后可以得到单相的锡酸锌粉体.该方法不仅降低了锡酸锌物相形成的温度,也符合材料合成化学绿色化的要求,而且有效避免了液相法团聚、操作过程烦琐的缺点.具有设备简单、计量比易于控制、所需反应温度低的优点.为此类材料的合成提出了一种廉价、简单的方法.     

云母钛珠光颜料前驱体煅烧工艺的研究

以硫酸沸腾水解法制备出的珠光颜料前驱体为研究对象,采用差热-热重分析仪对前驱体进行热分析,初步确定煅烧温度范围;借助X射线粉末衍射分析仪对煅烧后的产物进行晶相鉴定与分析,并利用扫描电镜观察煅烧后的产物的微观形貌,以此来反馈煅烧温度和煅烧时间对产物的影响.研究结果表明:在850 ℃下煅烧1 h样品的珠光效果强烈,其表面的TiO2多晶膜致密光滑无裂痕;且TiO2已完全转化为金红石型晶体,从而提高了珠光颜料的耐热性和耐候性.     

十二烷基苯磺酸钠辅助尿素共沉淀制备超细铜铬黑颜料

以十二烷基苯磺酸钠为表面活性剂,采用尿素共沉淀法合成超细尖晶石型铜铬黑颜料。以铬和铜硝酸盐为原料,系统研究了沉淀剂、煅烧温度和表面活性剂等条件对铜铬黑颜料晶型、形貌和粒度的影响;并探讨了合成条件对铜铬黑颜料着色力的影响。研究表明,尿素和十二烷基苯磺酸钠可有效地控制形貌、颗粒大小及均匀性;在尿素用量为理论量4倍、表面活性剂添加量为5%、煅烧温度800℃的条件下制备出了形貌为六面体、平均粒径为300 nm、粒径分布均匀、着色力优异的超细铜铬黑颜料。     

棕红色颜料的制备及呈色机理研究

本以ZnO、Cr2O3、Fe2O3、MnO2为原料合成了棕红色的尖晶石型颜料，并用XRD、DAT等手段对合成产物进行了表征。结果表明：该颜料在1129℃开始合成，其主晶相为锌铁尖晶石(ZnFe2O4)、铬铁尖晶石(FeCrO4)，且在l260～l300℃下，该颜料具有良好的稳定性；分析了颜料的发色机理及矿化剂在颜料制备中的作用。     

固相合成CuFe2O4及其气敏性能

以无机盐为原料,采用低热固相化学反应法合成了尖晶石型复合氧化物CuFe2O4的前驱体,通过不同温度煅烧,最后得到尖晶石复合氧化物CuFe2O4.用X射线衍射和透射电镜对合成产物进行了表征.结果表明:煅烧温度对尖晶石结构的形成有较明显的影响,当温度达到800℃时固相反应完全.合成材料的尺寸约为50 nm,但由于铁酸盐有磁性而存在轻微团聚.将样品制成旁热式气敏元件,气敏测试结果表明:元件在较低的工作温度时,对H2S气体具有较高的灵敏度和选择性,对体积分数为25×10-6的H2S气体的灵敏度接近9.     

不同盐类原料对水热合成CoAl_2O_4尖晶石纳米色料的影响

分别采用钴和铝的硝酸盐、硫酸盐和氯化物作为原料,在245℃温度下水热处理24 h,制备纳米尖晶石型CoAl_2O_4蓝色料。通过3 M NaOH溶液调节Co-Al前驱体溶液的pH值。采用X射线衍射分析(XRD)、透射电镜(TEM)、差示扫描量热法-热重分析(DSC-TG),傅里叶红外光谱(FTIR)以及色度计对所得合成产物进行了表征分析。结果表明,钴、铝的硝酸盐为原料所得水热产物在三类原料中呈色最差;以硫酸钴和硫酸铝为原料、pH=11时所得产物的蓝度值最佳(b*=-28.92),随着pH值的变化,对产物的色度产生显著影响;钴、铝的氯化物为原料合成的产物为蓝色或者蓝绿色,能在9~11的较宽pH值范围内得到呈色稳定的蓝色料。水热产物呈现出绿色调的主要原因是部分Co~(3+)取代了Al~(3+)填充的CoAl_2O_4晶体中的八面体空隙,为六配位结构。     

碳酸氢钠共沉淀法制备超细铜铬黑颜料

以Cu(NO_3)_2·3H_2O、Cr(NO_3)_3·9H_2O为原料,NaHCO_3为沉淀剂,采用共沉淀法合成超细尖晶石型铜铬黑颜料。研究了沉淀剂浓度、煅烧温度对CuCr_2O_4结晶度、晶相纯度、粒径大小以及色度值的影响。通过X-射线衍射分析、扫描电镜图、粒度分析、色度值以及紫外-可见光吸收光谱分析得出,当碳酸氢钠浓度为0.3 mol/L,煅烧温度为800℃时可获得结晶完整、粒径细小、呈色性能好的CuCr_2O_4黑色颜料。     

一步烧结法合成镁铝尖晶石的研究与工业应用

以特级铝矾土生料、轻烧氧化镁粉等为原料,纸浆废液为结合剂,在1600℃煅烧3h,研究了活性Al2O3微粉、镁铝尖晶石粉、硼酸(H3BO3)、MgCl2.6H2O等对合成镁铝尖晶石体积密度的影响。结果表明,添加硼酸能有效提高合成尖晶石的体积密度,而且对工业生产成本增加有限,本试验的最佳加入量(质量分数)为1.5%。在不改变基本原料和工艺参数的情况下进行了工业试验,即将质量分数为1.5%的硼酸与矾土生料和轻烧镁粉共磨,然后加入适量纸浆废液混练并压球成型,干燥后在回转窑中于1700℃煅烧。结果表明,在矾土基合成镁铝尖晶石的生产工艺中,添加少量硼酸能促进合成尖晶石的烧结,提高合成尖晶石的体积密度和产品回收率,具有一定的应用价值。     

添加TiO_2对铁铝尖晶石合成和烧结的影响

以氧化铁粉、α-Al2O3粉、石墨为主要原料,分别外加质量分数为0、2%、5%和8%的钛白粉,以亚硫酸纸浆废液为结合剂混练均匀后,压制成型为50 mm×50 mm的试样,于100℃干燥24 h,在氮气气氛中分别于1400、1450、1500和1550℃保温4 h煅烧,然后检测烧后试样的体积密度,并分析其物相组成和显微结构。结果表明:在氮气气氛下,TiO2的引入能降低铁铝尖晶石的合成温度,1450℃煅烧后铁源几乎完全转化为铁铝尖晶石;TiO2的引入能明显促进铁铝尖晶石的烧结,引入2%质量分数的钛白粉的试样体积密度最高,物相组成最好;引入多于2%质量分数的钛白粉的试样中有一定量的Fe2TiO5-Al2TiO5固溶相生成,试样体积密度下降,而且随着温度升高,Ti4+更容易被还原而抑制Fe3+还原,从而阻碍铁铝尖晶石的合成。     

喷雾热解法合成高性能球形钴蓝的研究

研究了喷雾热解法合成高性能球形钻蓝。试验对比了两种不同喷雾热解前驱体溶液对钻蓝形貌及反射性能的影响，一种是硝酸盐溶液体系；另一种是聚合物溶液体系，聚合物溶液是由硝酸铝溶液加入氨水水解合成的。由X射线荧光光谱分析可知，喷雾热解合成的钻蓝较商品钻蓝的纯度高。喷雾热解产物再经1000℃煅烧2h，由硝酸盐溶液体系合成的钻蓝的形貌是不规则的，而由聚合物体系合成出的是实心球形的钻蓝，且比不规则外形的及商品的钻蓝有较高的反射性能。     

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。