甲基烯丙醇饱和蒸汽压的测定与关联

采用静态法测定了甲基烯丙醇在335.05~388.29 K温度区间的饱和蒸汽压数据,并用Antoine方程lnps=AB/(T+C)进行了关联,获得Antoine常数A、B、C分别为15.0499、3020.65和-98.10。Antoine方程计算得到的饱和蒸汽压值与实验数据吻合较好,平均相对误差为0.86%。通过Clausius-Clapeyron方程计算得到甲基烯丙醇在335.05~388.29 K范围内的平均摩尔蒸发热为46.47 kJ·mol-1。实验所得饱和蒸汽压方程对甲基烯丙醇的精馏分离过程设计具有重要意义。     

新铃兰醛饱和蒸汽压测定和关联

采用静态法,利用Rose釜测定了新铃兰醛在391.85~416.35K范围的饱和蒸汽压,并用Antoine方程lnP=A-B/(T+C)进行关联,确定了蒸汽压方程的三个参数A=10.701,B=558.048,C=-296.730。新铃兰醛饱和蒸汽压测定值与上述Antoine方程关联值吻合较好,相对误差均在1%以内。所得饱和蒸汽压方程对新铃兰醛精馏分离设计和操作具有重要意义。     

1,1,1-三氟-2,3-二氯丙烷饱和蒸汽压的测定与关联

采用静态法,测定了1,1,1-三氟-2,3-二氯丙烷(HCFC-243db)在293.59—400.80 K温度区间的饱和蒸汽压数据,并用Antoine方程ln p=A-B/(T+C)进行关联,确定了蒸汽压方程的3个参数A,B,C的值分别为17.205,5 485.902和90.276。Antoine方程计算得到的饱和蒸汽压与实验数据吻合较好,相对误差在-1.05%—2.88%之间。通过Clausius-Clapeyron方程计算得到HCFC-243db在293.59—400.80 K范围内的平均摩尔蒸发热为28 326.222 J/mol,通过Antoine方程计算得到的常压沸点为345.12 K。     

263~373K温度区间2-氯-3,3,3-三氟丙烯饱和蒸气压的实验研究

采用静态法,测定了2-氯-3,3,3-三氟丙烯(HCFO-1233xf)的饱和蒸气压97个数据点,温度263.15~372.90 K,温度不确定度小于±2 mK,压力不确定度小于±1.2 kPa,并用Antoine方程lnP=A-B/(T+C)进行关联,确定了蒸气压方程的三个参数A、B、C的值分别为15.119、3070.575和7.198。Antoine方程计算得到的饱和蒸气压与实验数据吻合较好,相对误差均在±1%以内。通过Clausius—Clapeyron方程计算得到HCFO-1233xf在263.15~372.90 K的平均摩尔蒸发热为24363.31 J?mol-1,通过Antoine方程计算得到的常压沸点为285.22 K。     

光学戊醇与其乙酸酯体系等压汽液相平衡研究

用静态法分别测定了在298.15—413.15 K,乙酸2-甲基-1-丁酯饱和蒸汽压,进一步用Antoine方程关联实验数据,得到Antoine方程3个参数A=22.823 7,B=4 490.6,C=-14.377 66。采用双循环汽液平衡釜,测定了100 kPa下2-甲基-1-丁醇/乙酸2-甲基-1-丁酯二元体系的x-y-t数据和活度系数,并通过热力学一致性检验。结果表明:2-甲基-1-丁醇与乙酸2-甲基-1-丁酯可形成二元最低共沸物,共沸点温度为128.19℃,共沸组成摩尔分率x1=0.754 5。分别采用Wilson和NRTL模型对汽液平衡数据进行了关联,计算出相应的汽相组成和温度,并与实验值比较,其平均偏差分别小于0.003 7和0.004 12,为建立2-甲基-1-丁醇和乙酸2-甲基-1-丁酯的精馏分离数学模型提供了基础数据。     

高精度全氟甲烷R14饱和蒸汽压测定及关联

在141.76—225.71 K温度条件下,运用高精度(温度精度为±0.01 K,压力精度为±0.01%)可视化汽液相平衡装置测量了30组全氟甲烷(R14)的饱和蒸汽压实验数据,并分别运用Wagner方程,朱明善提出的改进Wagner方程及项-谭提出的方程对实验数据进行拟合。对计算值和实验数据进行对比分析,前2个方程计算结果较为接近,朱明善改进型方程略优,项-谭提出的方程误差最大。通过拟合得到上述温度范围内的较高精度的饱和蒸汽压方程。     

甲基苯基二乙氧基硅烷饱和蒸汽压的测定与关联

静态法测定了甲基苯基二乙氧基硅烷在378.10—423.84 K之间的饱和蒸汽压数据。采用非线性回归的方法得到Antoine常数A,B,C的值分别为8.809 9,3 935.933,87.61,饱和蒸汽压的计算值与实验值之间的误差介于0—2.36%;在2.27—101.325 kPa之间,沸点计算值与文献值的绝对误差不超过3.80 K,以开尔文温度表示的最大相对误差不超过0.77%。通过Clausius-Clapeyron方程计算得到甲基苯基二乙氧基硅烷在378.10—423.84 K之间的平均摩尔蒸发热为50 653.79 J/mol,常压沸点为494.66 K。     

新型平衡釜测定高沸物的饱和蒸汽压

设计和安装了一套由新型平衡釜测定高沸物饱和蒸汽压的装置。用邻苯二甲酸二甲酯在396.75～522.26K的温度范围对其可靠性进行了校验,实验结果与文献值相符。用Antoine方程对实验数据进行了关联,结果表明这种关联方法对于高沸物是可靠的。在476.49～549.66K温度范围测定了MSⅡ的饱和蒸汽压。提出了适宜的Antoine方程。计算值和实验值相符,结果令人满意,为工业设计提供了有用的基础数据。     

二氢月桂烯和二氢月桂烯醇饱和蒸汽压测定与关联

为了给二氢月桂烯醇精制工艺设计提供基础热力学数据,采用静态法,利用 Rose 釜测定了二氢月桂烯在330.05~434.78 K和二氢月桂烯醇在373.55~468.65 K的饱和蒸汽压,并用Antoine方程和Riedel方程进行关联,得出相应方程的参数.结果表明Antoine方程和Riedel方程均能较好地描述二氢月桂烯和二氢月桂烯醇的饱和蒸汽压,但Riedel方程的精度更高,误差更小.所得饱和蒸汽压的参数对二氢月桂烯醇减压精馏分离的设计提供了基础数据.     

甲基二苯基乙氧基硅烷饱和蒸汽压测定与关联

通过减压精馏的方法得到高纯度的甲基二苯基乙氧基硅烷,使用精馏法测定了甲基二苯基乙氧基硅烷在0.04—23.03 kPa范围内的饱和温度数据。采用非线性回归方法,利用EVIEWS 5.0软件得到甲基二苯基乙氧基硅烷的Antoine常数A,B,C的值分别为7.026 9,2 372.59和181.47,安托尼方程计算出的饱和蒸汽压与实验数据的误差在0—5.56%之间,与文献值的误差不超过7.41。通过Clausius-Clapeyron方程计算得到甲基二苯基乙氧基硅烷在373.20—512.23 K范围内平均摩尔蒸发热为72 942.96 J/mol,常压沸点为556.20 K。     

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.     

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。     

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.     

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。