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1.
闫小雨  王义安  刘昭君  林毅 《广州化工》2020,48(15):16-17,50
对羟基苯甲酸酯对人体及动物的内分泌系统具有一定的负面影响作用。对羟基苯甲酸酯对内分泌系统的影响研究有助于了解其危害,为有效控制其生物毒性提供强有力的依据。本文主要介绍了关于对羟基苯甲酸酯对生物体内分泌系统包括内分泌器官、肾上腺活性、甲状腺活性、脂肪组织活性和神经发育的影响研究进展,以及对其进行相关展望。并对以后进一步研究对羟基苯甲酸酯对生物体的毒性作用具有重要意义。  相似文献   

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旋转机械对中误差的分析与调整   总被引:1,自引:0,他引:1  
范忠先 《化工机械》2010,37(5):631-634
以旋转机械的对中误差为研究对象,分析旋转机械回转轴线的对中空间状态和对中误差对机器产生的不良影响,指出对中精度要求不同应采用不同的对中找正方法,同时介绍百分表测量找正法对设备对中误差的检测、计算、调整方法及其注意事项。  相似文献   

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高丰琴  王珊  范广  高奕红 《应用化工》2014,(10):1874-1878
概述了顺式对叔丁基环己醇的3种不同的合成方法:方法一是以对叔丁基苯酚为起始原料经加氢来合成顺式对叔丁基环己醇;方法二是以对叔丁基环己酮为起始原料经加氢或者强还原剂还原来合成顺式对叔丁基环己醇;方法三主要是目前顺式对叔丁基环己醇合成的新方法。同时总结了顺式对叔丁基环己醇的分离现状,分析了影响顺式对叔丁基环己醇工业化的多种因素,并对其合成及分离的发展趋势作了展望。  相似文献   

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我捧着和冰心老人的合影照片,重读着她在照片背面给我的题词:“有了爱便有了一切冰心”冰心走了,她哼着《平安歌》叩开兔年大门后,平静而去,安祥而归,只把对祖国、对人民、对世界、对人类、对自然、对亲人、对故乡、对师生、对朋友、对少年儿童……精深的爱永留在了人间……  相似文献   

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碱性介质中对硝基芳香醚的醚键稳定性研究   总被引:1,自引:0,他引:1  
设计合成了对硝基苯乙醇、对硝基苯氧乙酸、对硝基苯氧丙酸、对硝基苯氧丁酸、对硝基苯丁醚等一系列的对硝基芳香醚,并以它们作为研究对象,对碱性介质中芳醚键的稳定性进行了研究。发现了对硝基苯氧丙酸亲核取代的异常情况,推测是分子内邻基参与的亲核取代反应。  相似文献   

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介绍了煤制甲醇的生产工艺,其次研究氮气工况对煤制甲醇的影响,其中包括对变换效率的影响、对低温甲醇洗的影响、对合成质量的影响。最后,研究二氧化碳工况对煤制甲醇的影响,其中主要包括二氧化碳工况的切换、对变换装置的影响、对低温甲醇洗装置的影响以及对煤制甲醇合成装置的影响四方面内容。  相似文献   

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根据挪威食品安全委员会对米尔贝霉素的风险评估报告,在果树上喷洒米尔贝霉素对操作人员有一定的风险,需要防护装备,而对草莓及观赏作物喷洒时对操作人员和农业操作者无风险。米尔贝霉素对哺乳动物、鸟类无影响,对蜜蜂存在风险。当作物喷洒2次米尔贝霉素时,在土壤中的残留对节肢动物中野生食肉动物和拟寄生物有较高风险,对蚯蚓存在中等的风险。在果树喷洒推荐剂量的米尔贝霉素对30m范围内地表水的水生生物存在中等的毒性风险,而对草莓及观赏作物喷洒米尔贝霉素不会对水生生物产生风险。  相似文献   

8.
介绍了对苯基苯酚的主要用途,国内外对苯基苯酚主要的工艺路线及技术现状,通过对主要生产工艺路线的比较,对今后我国的对苯基苯酚的生产发展提出了建议。  相似文献   

9.
采用酶动力学方法研究了对羟基肉桂酸对酪氨酸酶单酚酶和二酚酶活力的抑制效应。结果表明,对羟基肉桂酸对酪氨酸酶单酚酶和二酚酶活性均有抑制作用,导致单酚酶活力和二酚酶活力下降50%的对羟基肉桂酸浓度约分别为0.12 mmol/L和0.50 mmol/L。对羟基肉桂酸能明显延长单酚酶的迟滞时间,0.2 mmol/L对羟基肉桂酸能使迟滞时间由1.1 min延长至6.2 min。对羟基肉桂酸对二酚酶的抑制作用为混合型抑制,对游离酶的抑制常数和对酶-底物络合物的抑制常数分别为0.29 mmol/L和0.60 mmol/L。  相似文献   

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对羟基苯甲酸或对羟基苯甲酸酯粒状物及其制备方法;在绿色植物中高水平地生产对羟基苯甲酸;从对羟基苯甲酸生产排水中回收对羟基苯甲酸的方法;一种处理印染废水用混凝剂及其生产方法;合成对羟基苯甲酸丁酯的固体超强酸催化剂的制备方法;  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   

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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   

16.
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   

17.
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   

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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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Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.  相似文献   

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