镁铝和锌铝水滑石作为润滑油添加剂的摩擦性能和机理（英文）

利用共沉淀法,合成了镁铝水滑石和锌铝水滑石。采用X射线粉末衍射、扫描电子显微镜和X射线荧光光谱对粉末进行了表征。利用四球摩擦磨损试验机对水滑石粉体作为润滑油固体添加剂的摩擦特性进行了测试。采用扫描电子显微镜和X射线光电子能谱对磨损表面进行了分析。结果表明:2种水滑石均具有典型的六方片层结构,晶粒尺寸在100～200nm之间。四球摩擦磨损试验中,2种水滑石润滑的磨损表面的主要元素化学态接近。锌铝水滑石与润滑油自身极压抗磨剂二烷基二硫代磷酸锌协同增效,提高了磨损表面Zn元素含量,其抗磨损特性明显优于镁铝水滑石。此外,锌铝水滑石也促进了摩擦副表面的氧化,减少了C元素的沉积。     

钛改性水滑石深度脱砷性能研究

选择了层状水滑石类化合物,通过添加钛柱撑剂进行了水滑石改性研究,考察了制备条件以及柱撑剂改性对水滑石晶体结构和吸附性能的影响,通过X射线光电子能谱(XPS)、原红外光谱(FT-IR)、X射线衍射分析(XRD)及透射电子显微镜分析(TEM)钛改性前后水滑石进行了表征。结果表明,光催化条件下钛柱撑水滑石脱砷效果优秀,20 min内脱砷率达95%;水浴振荡法制备的水滑石晶体结构规整性较为理想,晶粒尺寸均匀,XRD图谱表明吸附脱砷性能与晶型之间并无明显联系。     

LDHs的制备与改性及其在软聚氯乙烯阻燃中的应用

采用快速成核晶化法合成锌镁铝类水滑石(Zn Mg Al-LDHs),以油酸钠为改性剂对LDHs进行湿法表面改性;通过FT-IR、XRD、FESEM、TG等对改性前后LDHs进行表征;考察改性前后LDHs的添加量对LDHs/软PVC复合材料阻燃及力学性能的影响。结果表明,油酸钠质量浓度为1.75 g/L,改性温度为65℃,改性时间为30 min,改性后LDHs的平均活化指数为99.65%。LDHs/软PVC复合材料的极限氧指数(LOI)值随LDHs添加量的增加而增大,改性后LDHs的阻燃效果明显改善;当LDHs添加量在0~10份(PVC为100份)左右,添加改性后LDHs的复合材料的拉伸强度和断裂伸长率均优于空白样;添加量在10~50份时,复合材料的断裂伸长率和拉伸强度均随着添加量的增加而下降,改性后LDHs的下降趋势明显弱于未改性LDHs。     

低温等离子体对纳米材料表面引发

简单介绍了传统的对纳米粉体表面改性的方法,同时在实验的基础上自行发展的一种新的利用低温等离子体对纳米材料表面引发接枝聚合改性的方法,通过红外(FT-IR)、X射线光电子能谱(XPS)以及热失重分析(TGA)测试表明该聚合膜是通过化学键连接在纳米粉体表面的,X射线衍射光谱(XRD)表明经等离子体处理改性的纳米粉体只是其表面性质发生了改变,其晶体结构并没有发生任何变化.     

Zn/Fe/Al-LDHs制备及其光催化还原CO_2性能研究

采用共沉淀法制备不同摩尔比的Zn/Fe/Al-LDHs光催化剂,利用X射线衍射(XRD)、热重(TG)、扫描电镜(SEM)及傅里叶变换红外光谱(FTIR)研究不同Zn/Fe/Al摩尔比和煅烧温度对类水滑石结晶度、形貌结构的影响。常温常压下,研究了Zn/Fe/Al-LDHs光催化剂对CO2(g)+H2O(g)光催化还原制CH4的催化反应活性。结果表明,Zn/Fe/Al比例为5∶1∶5时,Zn/Fe/Al-LDHs呈现片状结构,形貌规整、结晶度较高。紫外灯照射下,Zn/Fe/AlLDHs表现出较强的光催化活性,随焙烧温度的升高,其光催化活性进一步提高,焙烧温度为500℃时光催化活性最好,CH4产率可达2.23 mmol/gcat。     

锌镁铝类水滑石对次甲基蓝的吸附研究

以Al(NO3)3、Zn(NO3)2、Mg(NO3)2为起始原料,用NH3·H2O做沉淀剂,采用非稳态共沉淀法制备锌镁铝类水滑石Zn Mg Al-LDHs。并探讨了该材料对偶氮类污染物次甲基蓝的吸附性质。结果表明,温度为40℃,摩尔比为Zn2+/Mg2+=1∶2,浓度6×10-6~8×10-6mol·L-1,用量为0.03g时,该Zn Mg Al-LDHs对次甲基蓝具有较好的吸附性能。     

油酸钠改性锌镁铝水滑石的制备及对聚丙烯的增强作用

为改善水滑石(LDHs)的颗粒分散性和表面活性,提高LDHs填料与聚合物的界面相容性,采用快速成核/晶化法合成了锌镁铝水滑石(ZnMgAl-LDHs),并以油酸钠为表面改性剂,对ZnMgAl-LDHs进行了表面改性,通过粒度分析、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、热重分析(TG)及扫描电镜(SEM)/透射电镜(TEM)对改性前后的ZnMgAl-LDHs进行了表征。将改性前后的ZnMgAl-LDHs分别添加到聚丙烯(PP)中,制得ZnMgAl-LDHs/PP复合材料,通过拉伸强度和弯曲强度测试考察改性前后ZnMgAl-LDHs的添加量对复合材料力学性能的影响。结果表明:所制备的ZnMgAl-LDHs的平均粒径为838.9 nm,当油酸钠的质量浓度为0.6 g/L时,平均粒径减小至647.2 nm。当ZnMgAl-LDHs添加量的质量分数为2%~8%时,改性前后的ZnMgAl-LDHs均对PP的力学性能有增强作用。改性ZnMgAl-LDHs具有更好的颗粒分散性,改性ZnMgAl-LDHs与PP相容性更好,对PP力学性能的增强作用优于未改性的ZnMgAl-LDHs。     

焙烧态Ca-Mg-Al类水滑石的制备及其吸附As(V)的研究

实验合成了一种焙烧态Ca-Mg-Al类水滑石,通过吸附动力学、吸附热力学及pH值的影响实验研究其对As (V)的吸附性能;并通过X射线衍射(XRD)、比表面积及孔径(BET)、场发射扫面电子显微镜(FESEM)、傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)等测试对合成材料进行表征并分析其吸附机理.实验结果表明,焙烧态Ca-Mg-Al 类水滑石对As(V)具有较强的吸附能力,其最大吸附量为71.86 mg/g,其吸附行为较符合Freundlich吸附等温方程和准一级动力学方程,且在不同的pH值下均能保持较好的吸附能力.焙烧态Ca-Mg-Al 类水滑石吸附As(V)的吸附机理主要包括类水滑石晶体结构的重建以及其表面羟基官能团的络合作用.     

焙烧态Ca-Mg-Al类水滑石的制备及其吸附As(Ⅴ)的研究

实验合成了一种焙烧态Ca-Mg-Al类水滑石,通过吸附动力学、吸附热力学及pH值的影响实验研究其对As(Ⅴ)的吸附性能;并通过X射线衍射(XRD)、比表面积及孔径(BET)、场发射扫面电子显微镜(FESEM)、傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)等测试对合成材料进行表征并分析其吸附机理。实验结果表明,焙烧态Ca-Mg-Al类水滑石对As(Ⅴ)具有较强的吸附能力,其最大吸附量为71.86 mg/g,其吸附行为较符合Freundlich吸附等温方程和准一级动力学方程,且在不同的pH值下均能保持较好的吸附能力。焙烧态Ca-Mg-Al类水滑石吸附As(Ⅴ)的吸附机理主要包括类水滑石晶体结构的重建以及其表面羟基官能团的络合作用。     

镁铝水滑石阻燃剂表面改性及其机理

采用三聚磷酸钠(STPP)对镁铝水滑石(MAH)进行表面改性。X射线衍射、扫描电子显微镜、能谱、热重–差热、红外光谱比表积测试和粒度分析对改性前后的镁铝水滑石进行表征,考察了改性前后镁铝水滑石的吸油性能和润湿性能。结果表明:三聚磷酸根(53 10P O)包覆于镁铝水滑石粒子表面,改性后的镁铝水滑石粒子表面疏水性增强,分散性明显提高。将改性前后镁铝水滑石样品(SMAH)与聚丙烯(PP)混合固化,测试其复合材料(MAH/PP、SMAH/PP)阻燃性和力学性能,发现相对于MAH/PP,SMAH/PP复合材料力学性能有所提高,阻燃性能也得以改善。     

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。     

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.     

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.     

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。