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橡胆虽有良好的伸缩弹性,却无理想的强度,故早已使用补强性填料和各种骨架材料加以增强,以帘线,帘布和布等形式使用的上述骨架材料大部分由连续长纤维组成,虽有强能力高,制品形状保持性好等特点,但因伸长小,在使用上受到限制,此外,加工比较复杂,而且短纤维补强的胶料,虽无大如长纤维的补强效果,但去有充分的制品形状保持性,能控制纤维的取向和胶料的定伸强度,以及加工简便等优点,故自用添加石棉的胶料制作密封胶件始,今已广泛应用来制作胶管,三角带,轮胎,胶鞋,汽车橡胶配件,圈垫,保护面罩,防弹背心,火箭件垫,查胶海绵,电磁波屏蔽材料,防静电材料和导电橡胶等产品。 相似文献
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报道了用盐酸,氢氟酸,高氯酸溶样,以稀盐酸为介质,空气-乙烯火焰原子吸收法连续测定地质样品中的Cu,Pb,Zn,Fe,Co,Ni,Cr,Li,Mn,Rb,K,Na,方法简单快速,并讨论了仪器工作条件和主要干扰因素的消除,对于地质标样,测定结果的相对标准偏差不超过5%。 相似文献
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陶瓷美术作品的艺术魅力,在于巧用艺术手法,艺术手法大致可分引用,映衬,象征,双关,拟人,夸张,借代,对比,比喻,渲染等类,巧用这些手法,能大大地增强作品的艺术感染力。 相似文献
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本评述及介绍氯乙酸母液回收,处理,利用技术以及得到的有价值的化学产品,这些产品包括氯乙酸,二氯乙酸,乙酸,氯乙酸甲酯,二氯乙酸甲酯,草酸钠,乙醇酸,羧甲基纤维素钠,三氯乙酸,氯仿,巯基乙酸,氮川三乙酸及乙醛酸等十多种。 相似文献
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当前,市场经济越发展,企业就越要依靠市场,企业要在市场中开展经济活动,参与竞争,不但不能放松,而且更应重视。一方面市场经济要求企业必须重视内部管理。例如,则模相似的企业生产同样的产品,有的企业欣欣向荣,有的企业却岌岌可危。追本溯源,其主要差别就在管理上,事实表明,暂时效益好的企业若陷入盲目性,放弃内部管理,则可能运转着的市场抛出来,亏损或倒闭。暂时效益差的企业,只要艰苦奋斗,自强不息,深挖内部潜力,加强内部管理,保质,高产,低消耗,亦有机会跃出低谷,在市场竞争中取胜。诚然,企业在市场经济体制下有更多的自主权,但也得冒更锪风险。企业要在复杂多变的市场中取胜,就要发挥优势在同等条件下与对手抗衡,这就要求扎扎实实抓内部管理。不但要在生产技术领域内挖潜;而且要在管理领域内挖潜,使产品品种新,质量好,成本低,物美价兼,从而占领市场,在竞争中击败对手,立于不败之地。另一方面,企业的生存和发展也依靠企业重视内部. 加强管理是企业自立自强的有效途径。同时,企业发展的经历也告诉我们,那种持短期行为的企业领导者,不重视管理,既违背了市场规律,又损害了企业的前途,只有善于预测未来,把目前的经济效益和企业未来的发展有机地结合在一起,认真地为企业准备后劲,强化内部管理,按市场规律办事才是远见的企业家,才能使企业繁荣和发展。 相似文献
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走进唐自强的画室,主人不在,却见架上摆满了他的作品,那大小不一、造型迥异的瓷雕,有鹰,有马,有虎,有武将,有美女,也有鲜花瑞鸟,桌上有画好的彩瓷,有青花山水,也有新彩风景,令人目不暇接,流连忘返。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 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
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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