共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
为了满足未来火箭、战略/战术导弹及空间飞行器对高能钝感含能材料的应用需求,利用声共振技术制备了3种CL-20基共晶材料-CL-20/2-巯基-1-甲基咪唑、CL-20/4-甲基-5-硝基咪唑及CL-20/己内酰胺共晶体,并采用XRD、SEM、TG-DSC、TG-MS与激光点火试验系统研究这些共晶材料的结构、形貌、热分解与激光点火特性。结果表明,在共振加速度70g、微量溶剂的条件下混合15min可得到前两种共晶材料,混合30min后可得到CL-20/己内酰胺共晶,声共振技术与溶液挥发法制备这些共晶材料所使用的溶剂一致,不需要重新更换/筛选溶剂,而且相对于溶液挥发法,声共振技术溶剂使用量大幅减少,反应时间也更短。SEM结果表明,利用声共振技术制备的共晶材料颗粒大小不一、形状不规则;热分解研究发现3种CL-20共晶的放热峰温相对于CL-20都有所降低,热解过程、热释放量、热解产物与CL-20结合的共晶分子熔融峰温、初始热解温度等特征参数有关,CL-20/4-甲基-5-硝基咪唑共晶材料相对于CL-20热解速率更快,热释放量更大,共晶后热解产物中CO2和H2 相似文献
3.
结晶分解法合成超细钴蓝颜料 总被引:4,自引:0,他引:4
研究了结晶分解法合成钴蓝颜料的工艺,采用铝和钴的硝酸盐或硫酸盐混合溶液为原料,蒸发结晶后获得硝酸盐或硫酸盐的混晶体。硝酸盐混晶体在1 000℃下煅烧2 h可获得尖晶石型产物,得到的粉体团聚严重;以硫酸盐为母盐则在1 200℃下煅烧2 h得到尖晶石型结构的产物,加入一定量助熔剂后合成温度下降约100℃,煅烧得到的产物团聚较少,形貌规则,粒度分布均匀;通过对颜料反射性能分析,探讨了母盐种类的选择对所得到产物的性能影响情况,硫酸盐结晶分解法可以获得具有优良反射性能的产物,适合作为彩色显象管中蓝色荧光粉的着色颜料。 相似文献
4.
含钒灰渣酸浸液结晶铵明矾的工艺条件 总被引:4,自引:1,他引:3
为获得含钒灰渣酸浸液结晶铵明矾的优化工艺条件,利用正交优选法研究了Al2(SO4)3浓度、铵/铝摩尔比、冷却速度和结晶温度对铵明矾结晶率的影响,分析了铵明矾晶体和滤液的成分,计算得到了铵明矾的结晶率. 结果表明,4种因素对铵明矾结晶率均有较大影响,Al2(SO4)3浓度、铵/铝摩尔比对铵明矾结晶率影响较为显著. 合理的铵明矾结晶工艺条件为:Al2(SO4)3浓度150~200g/L,铵/铝摩尔比1.2左右,冷却速度15℃/h左右,结晶温度5℃左右. 在此条件下,铵明矾结晶率为89.32%. 相似文献
5.
6.
7.
利用含甲醇携带剂的超临界CO2(ScCO2)对由双酚A(BPA)和碳酸二苯酯(DPC)合成的聚碳酸酯(PC)预聚物进行了诱导结晶,所得结晶预聚物经固相缩聚得到了高分子量PC。采用凝胶渗透色谱(GPC)测定了产物分子量,并通过差示扫描量热仪(DSC)和X射线衍射仪(XRD)对产物进行了测试表征;考察了压力、温度和诱导时间等因素对PC结晶度的影响,以及不同结晶度的预聚物对缩聚产物分子量的影响。结果表明:随着温度的升高,PC结晶度先升后降,理想结晶温度为90℃;另外,结晶度随着压力的增大而增大,较佳的结晶压力为30 MPa;此外,在较高温度下PC预聚物的诱导结晶速度加快,并且相同条件下预聚物结晶度越大缩聚产物的分子量越大。 相似文献
8.
9.
使用扫描电镜及扫描探针分析了锌铝镁镀层的表面形貌及成分,使用X射线光电子能谱仪及电化学技术分析了锌铝镁镀层腐蚀产物的化学组成、电化学性能,对锌铝镁镀层的耐蚀机制进行了探讨,结果表明:锌铝镁镀层主要由初生锌相、富铝相及共晶组织组成,Mg元素主要分布于共晶组织中。在3.5%NaCl介质腐蚀过程中,锌镀层腐蚀产物主要由Zn5(CO3)2(OH)6及ZnO组成,锌铝镁镀层腐蚀产物主要由Mg(OH)2、4MgCO3·Mg(OH)2及Zn5(CO3)2(OH)6组成。锌镀层腐蚀产物电荷传输电阻逐渐降低,而锌铝镁镀层腐蚀产物电荷传输电阻逐渐增大,且后者大于前者。即锌镀层腐蚀产物无法抑制镀层的腐蚀,而锌铝镁镀层腐蚀产物则可以对镀层电化学反应起到抑制作用,对镀层提供一定程度的保护。 相似文献
10.
11.
12.
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
13.
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
14.
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
15.
16.
17.
18.
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
19.
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
20.
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