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采用热重分析(TG)技术和差示扫描量热(DSC)技术研究了含二缩三乙二醇二硝酸酯(TEGDN)的混合酯发射药动态气氛下的热分解性能.结果表明,该类混合酯发射药的热分解主要分两步进行:第一步为发射药中NG和TEGDN的挥发分解,第二步为发射药中NC和二号中定剂(C2)的分解;两步分解过程的失重量和最快失重温度点随配方中TEGDN和NG质量比的不同而有差异;混合酯发射药在不同压强下的DSC曲线上均只呈现一个明显的分解放热峰,且放热峰的峰温随压强增大而降低. 相似文献
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为了研制一种具有高能高燃速特性的新型发射药,在含有CL-20的高能发射药配方基础上,添加适量高燃速功能材料乙二胺-三乙烯二胺高氯酸盐(SY);利用热重分析法(TG)、差示扫描量热法(DSC)和绝热加速量热仪(ARC)研究了高燃速功能材料SY对高能发射药热分解反应的影响,并计算对比了热分解过程的相关动力学参数。结果表明,高燃速功能材料SY可以明显加快发射药的质量损失速率,使最大质量损失速率提高了43%,主要促进了NC组分的热分解;添加质量分数3%的SY可使高能发射药的绝热分解终止温度由790.4提高到1305.7℃,提高了515.3℃,且最终放热量由1294.72增至2335.22J/g,增加了1040.50J/g,热分解反应更完全;SY的加入降低了高能发射药热分解反应的表观活化能,利用Kissinger法和Ozawa法求得的活化能分别降低40.5和38.5kJ/mol。 相似文献
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采用差示扫描量热法(DSC)、热重法(TG-DTG)和密闭爆发器试验研究了RDX/POLY(BAMO-AMMO)基发射药在常压下的热分解与燃烧性能。结果表明,POLY(BAMO-AMMO)热分解反应过程可分为具有不同热效应的前后两个阶段:第一阶段为热效应突出的叠氮基团分解;第二阶段为热效应微弱的残余碳分子骨架热分解。RDX/POLY(BAMO-AMMO)基发射药的热分解过程表现为明显的RDX热分解属性,具有吸热和放热两个主要过程。RDX/POLY(BAMO-AMMO)基发射药的燃速压力指数大于1,且随RDX含量的增加而减小,燃速由RDX决定,并随其含量的增加而提高。 相似文献
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为了解溴酸钾(KBrO3)的热性能,利用差热分析(DTA)研究了KBrO3的非等温热分解过程.采用Kissinger法和Ozawa法计算了KBrO3的热力学参数,并与硝酸铵(NH4NO3)的热稳定性进行了对比.结果发现:KBrO3在400℃附近开始熔化,随后发生放热分解,其热分解是分两个阶段进行的,在升温速率为5℃?min-1时,第一阶段的放热峰温为432.28℃,第二阶段的放热峰温为439.86℃;第一阶段热分解活化能E、焓变???、熵变???及吉布斯自由能???分别为175.17 kJ?mol-1、169.15 kJ?mol-1、-25.32 kJ?K-1?mol-1和187.51 kJ?mol-1;对比KBrO3两阶段热分解的熵变???,发现第二阶段热分解比第一阶段热分解更易发生;KBrO3的热稳定性优于硝酸铵(NH4NO3). 相似文献
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含RDX高能硝胺发射药的热分解动力学补偿效应 总被引:1,自引:0,他引:1
为了解高能硝胺发射药的热分解特性和动力学补偿效应,用高压DSC测试了含5组16种发射药的热分解行为,通过Kissinger方程获得了双基药和含RDX高能硝胺发射药的热活化能(Ea)和指前因子(A),讨论了其动力学参数的补偿效应。结果表明,含RDX高能硝胺发射药配方中的NC/NG和RDX的热分解反应动力学参数间存在动力学补偿效应,说明NC/NG和RDX的热分解反应分别有各自不同的反应过程或者由各自不同的速度决定步骤,不受配方中其他组分的影响。 相似文献
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为探索金属氢化物(MgH2和Mg(BH4)2)对硝酸铵(AN)热稳定性的影响,在升温速率分别为2、5、10和20℃/min条件下,用DSC测试了纯AN及其与MgH2或Mg(BH4)2混合物的热分解特性,根据DSC数据计算了热分解反应的表观活化能和指前因子等动力学参数,分析了加入金属氢化物引起AN热稳定性的变化机理。结果表明,加入MgH2后,AN分解反应的表观活化能变化较大,初始分解温度大大降低,AN的分解机理发生了改变;而加入Mg(BH4)2对AN的热分解过程影响不大,且表观活化能没有明显变化。 相似文献
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为了改善改性单基发射药的安定性和力学性能,制备了含3种不同粒径(50、80和110μm)球形硝基胍(NQ)的改性单基发射药,通过差示扫描量热法、真空安定性试验和甲基紫试验研究了其热分解过程和热安定性,并测试了其抗冲击和抗压缩强度,分析了NQ粒径变化对改性单基发射药热行为和力学性能的影响。结果表明,3种含球形NQ的改性单基发射药试样有两个热分解过程,第一个分解过程对应的是混合硝化棉的分解,第二个分解过程是RDX和NQ的分解,但是第二个分解过程不明显;随着NQ粒径从50μm增至110μm,发射药试样的热分解峰温从176.84℃提高至179.71℃;真空安定性试验中试样48h放气量从0.7558mL/g降至0.5964mL/g,甲基紫试纸变为橙色的时间从44min延长至54min,且加热5h后未发生爆炸;发射药试样的抗冲击强度从4.23kJ/m~2降至3.81kJ/m~2,抗压缩强度从56.93MPa降至53.85MPa。表明球形NQ粒径的增加有利于提高发射药的热安定性,但会降低其力学性能。 相似文献
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TGA-FTIR联用技术研究ABS树脂热降解行为 总被引:1,自引:0,他引:1
采用热失重-傅里叶变换红外光谱(TGA-FTIR)联用技术研究了在N2气氛下ABS(丙烯腈-丁二烯-苯乙烯三元共聚物)的热稳定性及其分解失重情况.结果表明.ABS的TGA曲线只有1个失重区间.随着升温速率的增加.起始和峰值失重温度增加,热分解温度为380~480℃;ABS热分解活化能(Ea)在59.39~74.70 kJ/mil,通过Ea变化发现.分解可分为多个阶段;经FTIR测试发现.ABS的热分解过程首先是橡胶相PB(聚丁二烯)主链上接枝的SAN(苯乙烯-丙烯腈共聚物)侧链降解,随着温度升高PB主链开始分解,失重质量分数大于50%时,以连续相的高相对分子质量SAN分解为主. 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