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1.
以工业原料采用水热法在不同硅铝比(投料比)下合成了方钠石,利用XRD对产物进行了表征,讨论了碱度(H_2O/Na_2O、Na_2O/SiO_2)、晶化温度、晶化时间对沸石结晶的影响,通过实验研究得到了在不同硅铝比(投料比)下方钠石的结晶变化规律,并优化出最佳合成工艺条件;另外,对合成的方钠石进行了Li~+、K~+离子交换,研究了其吸水性能。  相似文献   

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.
将卡马西平和薄桃酸在110℃条件下加热熔融得到卡马西平-薄桃酸共晶。以异丙醇为溶剂,溶液结晶得到白色细针状晶体,抽滤干燥,即获得卡马西平-薄桃酸共晶单晶。应用单晶X射线衍射(SCXRD)、X射线粉末衍射(PXRD)、傅里叶红外光谱分析(FTIR)对卡马西平-薄桃酸进行了结构表征。结果表明:通过研磨的方法不能得到共晶,熔融法可以制备两分子卡马西平和一分子薄桃酸组成的卡马西平-薄桃酸共晶。  相似文献   

6.
胺基取代单茂钛/MAO催化降冰片烯聚合   总被引:1,自引:0,他引:1  
采用胺基取代单茂钛{Cp~*TiCl_2N[Si(CH_3)_3]_2}与甲基铝氧烷(MAO)组成催化体系催化降冰片烯聚合,得到有一定结晶结构的、可溶的聚降冰片烯。聚合物为乙烯型加成聚合物,热分解温度在450℃以上。该催化体系在60℃时催化活性最高,产物相对分子质量随聚合温度的下降明显增大,在20~80℃,聚合物重均分子量为(2~5)×10~4。使用不同三甲基铝残余量的MAO作为助催化剂,对催化活性有一定的影响。  相似文献   

7.
肖杨  宁皇飞 《塑料科技》2013,41(1):57-60
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.
在较高温度条件下,碘与铝在封闭的真空玻璃管中直接反应,产生碘化铝蒸气。采用淬冷方法可以得到纯净的无水碘化铝白色结晶。考察了反应物配比、反应温度及反应时间对反应的影响。结果表明:n(I)∶n(A l)=2.13∶1,反应温度为500℃,反应4.0 h,A lI3收率可达91%。产物用化学分析法、X射线衍射光谱和红外波谱法进行了检测。  相似文献   

9.
郝玉林  生海  赵一 《涂料工业》2018,48(12):7-15
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.
以元素粉钛、铝、碳为原料 ,采用放电等离子烧结工艺在 1 1 0 0℃的温度下成功地制备了高纯、致密Ti2 AlC材料。合成材料的X -射线衍射 (XRD)和扫描电镜 (SEM)分析的结果表明 :多晶体Ti2 AlC形貌为板状结晶 ,晶粒大小平均约为 2 0 μm ,厚度在 3~ 5 μm。  相似文献   

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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.
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.
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   

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.
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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