C~#语言计算绘制Pb-Sn二元金属相图

针对物理化学实验教学中的Pb-Sn二元金属体系的相图,采用C~#高级计算机语言编制了程序,结合文献中该体系的热力学参数,快捷方便地获得了该二元相图的液-固相平衡线的组成和温度数据,并绘制了该二元体系的相图。将计算的该体系的最低熔点的组成和温度数据与文献报道的数据进行了比较,发现两者吻合很好,说明该二元体系的相图计算是准确可靠的,将其用于学生相图实验数据的比较,可以促进物理化学相图的实验教学。     

杠杆定律在典型二元合金相图中的应用与实践

使用杠杆定律对典型二元合金相图,即匀晶相图,共晶相图和包晶相图的两相区展开分析和说明,确定在不同温度区间内平衡组织的组成相和及其相对含量的计算方法。在此基础上,归纳总结杠杆定律在二元合金相图的使用方法,帮助材料专业的学生能更好理解二元合金,特别是铁碳相图,分析其冷却结晶过程及对其进行定量计算。     

SigmaPlot软件在相图绘制中的应用

为了能快速、精确地绘制满意的二元、三元系的平衡相图,本文应用SigmaPlot软件处理二元、三元相图实验数据及绘制图相图。结果表明,用SigmaPlot对实验数据作处理,解决了实验中数据多、处理麻烦、手工作图误差大等问题,使处理过程简单、快捷,提高了效率和准确性。     

杠杆法在相图分析中的应用

对于二元相图的合金结晶过程分析,采用了一种新的分析方法——杠杆法,在相图的两相区内运用杠杆定律进行判断相的组成。将合金结晶过程中的杠杆作出后,当杠杆支点和杠杆上两相成分端点不重合时,合金由两相组成,当杠杆支点和杠杆上某相成分端点重合时,合金仅由一相(即杠杆支点与之重合的相)组成。运用这种方法,学生能迅速掌握二元共晶合金相图、铁碳合金相图及其它相图。     

相图与耐火材料(Ⅰ)

相图是耐火材料研究的基础。为了让广大耐火材料工作者更好地了解相图及其在耐火材料中的应用,本刊将在2013年第1—6期中连载陈肇友教授的专题报告"相图与耐火材料"。该报告中重点介绍了单元系耐火材料、二元系相图与耐火材料、三元系相图与耐火材料、四元系相图与耐火材料、含碳耐火材料,同时还介绍了三元交互体系相图、耐火材料中常见的凝聚相稳定存在区域图以及水盐体系材料。     

ZrO2—Y2O3ZrO2—MgO赝二元系相平衡的研究

用双亚点阵模型处理了ZrO_2-Y_2O_3、ZrO_2-MgO系统中的体心立方ZrO_2基固溶体相。用正态分布函数和样条函数相结合的方法,由部分相图数据优化了上述赝二元系中各相的相互作用参数,并用优化的相互作用参数及本工作估计的各氧化物的点阵稳定性参数计算了上述赝二元系相图。此外,还用DTA和X射线衍射方法测定了赝二元系在1300℃以下的固态相关系。计算结果与实验结果符合。     

2,3-2,5-2,6-二甲基苯酚常压固液相平衡的测定及关联

为了探索采用熔融结晶分离二甲基苯酚系列同分异构体的可行性,并为后续的熔融结晶机理、动力学研究及工艺开发提供数据支撑,采用差示扫描量热法测定了2,3-2,5-2,6-二甲基苯酚(DMP)3个二元体系的固液相平衡数据,结果表明:2,3-2,5-DMP,2,3-2,6-DMP,2,5-2,6-DMP 3个二元体系的相图均属于带有最低共熔点的简单二元体系相图。采用理想溶液模型、Wilson与NRTL活度系数模型对相平衡数据进行拟合,结果表明2种活度系数模型均可较好地关联二元体系的固液相平衡。     

二元体系N,N—二甲基肼—N,N—二甲基腙气液相平衡图的测定

本文利用沸点仪测定了二元体系N,N-二甲基肼-N,N-二甲基腙的气液相平衡数据,绘制了气液平衡相图,并根据相图用图解法及A·Rose公式计算了精馏法分离二者的理论塔板数。     

二元液系气液平衡相图实验的改进

二元液系气液平衡相图实验是物理化学基础实验之一。在该实验中最困扰大家的是溶液的配制问题,因为只有合理地配制溶液才能使数据点在相图里分布合理。文章采用依次添加法配制溶液,优化了试剂的添加次序和添加量,使学生在有限的实验时间内得到更加完善的相图。     

用拟二元方法研究iPP-DBP-DOP三元体系的热致相分离热力学

采用拟二元方法研究等规聚丙烯（iPP）‐邻苯二甲酸二丁酯（DBP）‐邻苯二甲酸二辛酯（DOP）三元聚合物溶液的热致相分离热力学,得出了拟二元相图的数学关联方法.采用光学显微镜法测定浊点温度, 采用差式扫描量热法（DSC）测定熔点、动态结晶温度.利用浊点测定数据回归聚合物-共溶剂的交互作用参数 χ的表达式,χ是共溶剂配比和温度的函数,以此为基础计算的拟二元相图与实验数据吻合较好.发现共溶剂中DBP份数增加,相分离类型由单纯固液分相形式转变为液液分相、固液分相依次发生形式,共溶剂配比能调控拟二元相图结构.研究表明,只需测定一个较低冷却速率下几种共溶剂配比的拟二元溶液的浊点温度、分别测定几个冷却速率下iPP–DOP二元溶液的动态结晶温度即可掌握该三元溶液热致相分离热力学的全部信息.其可用来指导制膜过程,并能准确预测形成的膜结构形貌.     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

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。