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1.
人工神经网络法计算非芳香族多硝基化合物的生成焓   总被引:2,自引:0,他引:2  
用误差反向传播(BP)的人工神经网络模型及分子结构描述码作为输入特征参数预测非芳香族多硝基化合物的生成焓,研究了网络参数及分子结构描述码的影响,同时按分子结构描述码进行了多元线性回归,取得了满意的结果,其回归方程相关系数达到了0.9977,精度高于文献值。绝大多数相对误差在10%以内。  相似文献   

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采用Boosting算法对多硝基芳香族化合物(PNACs)的密度进行预估。选用分子结构描述码作为输入特征参数。结果表明,PNACs的密度与其分子结构存在良好的相关性,与人工神经网络相比,Boosting算法对预测的准确性有显著提高,预测结果的相对误差都在8%以内。  相似文献   

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傅若农 《火炸药》1993,(4):44-47
介绍胶束电动毛细管色谱分离非离子型的八种毒性很大的芳香族硝基化合物,探讨了这些化合物的迁移特性和电泳溶液PH值对分离的影响。  相似文献   

4.
研究了以硝酸铋和活性炭催化水合肼还原芳香族硝基化合物制备芳胺的反应.以硝基苯为底物,考察了硝酸铋和活性炭用量对反应的影响.结果表明,还原1 mmol硝基苯,Bi(NO3)3·5H2O和活性炭的适宜用量分别为0.06和0.1 g.在适宜的条件下,9种芳香族硝基化合物被还原为芳胺的收率为78%~99%.芳香族硝基化合物中取代基对反应结果有较大影响.催化剂的活性随使用次数的增加而下降,其活性下降的原因是硝酸铋的流失.  相似文献   

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综述了近年来国内外芳香族硝基化合物检测方法的应用实例与研究进展,并对各方法适用条件、检测限、检测范围、优势与不足等方面进行了介绍。旨在为各种芳香族硝基化合物的检测与定量分析提供参考,并对分析方法发展趋势做出展望。  相似文献   

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获得了一种温和的将芳香族硝基化合物选择性还原为相应的芳胺的方法,产率高,反应温度仅80℃。这一方法特别适用于分子中存在如Cl,Br和COCH_3等还原性基团的芳香族硝基化合物的还原,反应清洁高效,Cu(Ⅰ)-BCA催化剂可重复使用。  相似文献   

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从物理、化学和生化3个方面综述了芳香族硝基化合物废水处理技术的现状,介绍了最新的废水处理技术——纳米技术,并展望了含芳香族硝基化合物废水处理技术的应用前景。  相似文献   

8.
采用Boosting算法对多硝基芳香族化合物(PNACs)的密度进行预估.选用分子结构描述码作为输入特征参数.结果表明,PNACs的密度与其分子结构存在良好的相关性,与人工神经网络相比,Boosting算法对预测的准确性有显著提高,预测结果的相对误差都在8%以内.  相似文献   

9.
芳香族硝基化合物合成的最新研究进展   总被引:1,自引:0,他引:1  
胡玲芳  吴阳恒  严国兵 《广州化工》2012,40(20):8-11,34
综述了近年来芳香族硝基化合物合成的研究进展,主要包括芳香硼酸、芳香卤化物及拟卤化物、芳香羧酸及芳烃碳-氢键的硝化反应、芳香胺及叠氮化合物的氧化及其反应机理的探讨。  相似文献   

10.
芳香族硝基化合物改性煤沥青研究   总被引:1,自引:0,他引:1  
以煤沥青为原料,通过添加不同含量的芳香族硝基化合物对煤沥青进行改性处理,采用TG、CO2反应性、XRD和SEM对改性沥青焦进行表征。结果表明,芳香族硝基化合物有效地促进了煤沥青在炭化过程中的焦化缩聚,使产物沥青焦结构更加致密,并在一定程度上改变了沥青焦的氧化行为,从而显著提高了沥青黏结焦的抗氧化性能。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

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Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

18.
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008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、不饱和聚酯树脂、环氧树脂)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.  相似文献   

19.
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

20.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

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