用照度计测定固体推进剂燃烧的火焰温度分布

本文介绍了用照度计测定固体推进剂燃烧火焰温度分布的原理、方法和装置。用标准温度灯验证了该测试系统。在常压、室温下测定了两种双基推进剂和一种复合推进剂的燃烧火焰温度分布。实验指出:双基推进剂的燃烧火焰温度分布符合稳态的燃烧模型,而复合推进剂燃烧的多次实验证明:在火焰相对长度20％和80％附近分别存在两个高温燃烧区;在火焰相对长度40％附近,存在着低温燃烧区。     

推进剂火焰烟尘对CARS测温精确度的影响

采用透过率(激光透过率、可见光透过率)表征推进剂火焰烟尘的量,以理论计算温度作为CARS(Coherent Anti-Stokes Raman Spectrometry)测温的相对标准温度,并将测得的CARS温度与热电偶温度进行了对比。通过研究CARS温度和理论计算温度的差值与透过率的相关性得到烟尘对CARS测温的影响规律：CARS测温的偏差随着推进剂火焰中烟尘量的增加而增大;推进剂火焰烟尘对CARS测温精度的影响规律基本呈线性关系。     

宽带CARS在诊断固体推进剂燃烧场中的应用

为了测量固体推进剂燃烧场温度和氮气组分的浓度,建立了10 Hz重复频率运转的宽带CARS实验系统.结果表明,氮气CARS谱测量温度的相对不确定度优于4%;在较低浓度范围内,测量组分浓度的相对不确定度优于5%.采用宽带CARS技术测量了常压和2 MPa背景压力下固体推进剂燃烧场,获得了较高信噪比的单次脉冲氮气CARS实验谱,用CARS理论计算软件拟合CARS实验谱给出了固体推进剂瞬态燃烧场温度和氮气浓度随高度的分布.     

推进剂燃烧火焰温度CARS测试技术问题的探讨

论述了推进剂燃烧CARS(Coherent Anti-Srokes Raman Scattering)测温中烟尘及其产生的碎片C2基和激光强度对测温的影响,探讨了时间分辨率和空间分辨率对推进剂燃烧测温的重要性,表明研究推进剂火焰烟尘对CARS测温精确度影响的必要性,实现高时空分辨率的重要性。     

无烟交联改性双基推进剂的高、低压燃烧特性

分析了无烟交联改性双基推进剂样品的火焰结构、燃烧波温度分布和熄火表面成分，初步研究了无烟交联改性双基推进剂在高、低压力下的燃烧特性。结果表明，压力升高，无烟交联改性双基推进剂的燃烧模式由双基推进剂的燃烧模式转变为与复合推进剂类似的燃烧模式。     

NEPE推进剂燃烧机理研究

应用微热电偶测温和燃烧火焰单幅照相技术测得 NEPE推进剂在稳态燃烧条件下的燃烧波温度分布及火焰结构 ,研究了该推进剂中主要组分对燃烧性能的影响 ,同时利用扫描电镜 -能谱仪观测了熄火表面形貌和元素分布规律。经过综合分析 ,提出了 NEPE推进剂的燃烧过程 ,为该类推进剂燃烧物理模型的建立奠定了基础     

红外辐射吸收法测量火焰温度

简述了几种温度测量的方法，介绍了红外辐射吸收法测温原理及实验装置，并对稳定的煤气火焰进行温度测量，试图在此基础上测量固体推进剂火焰的温度。     

加压、升温对正十二烷/空气火焰层流燃烧特性的影响

化石燃料的燃烧是当今社会主要的能源供给形式，但随着化石能源的消耗殆尽，发展新型替代燃料已刻不容缓。正十二烷(n-C₁₂H₂₆)是航空煤油的重要组成成分之一，也是多种航空煤油替代燃料的重要组成。本工作采用CHEMKIN/PREMIX数值模拟研究了正十二烷/空气火焰的层流燃烧特性，为发展航空煤油替代燃料提供一定的理论参考。实验的初始温度设置为400,403,423和470 K，初始压力设置为0.1,0.2,0.3,0.5,1.0 MPa，当量比设置为0.6～1.6。本研究主要聚焦火焰的传播燃烧特性、温度敏感性分析和中间自由基的分布情况，探究了正十二烷/空气火焰的层流燃烧速度、绝热火焰温度、净热释放率和中间自由基生成速率随初始温度和压力的变化规律。结果表明，层流燃烧速度的模拟值对其他研究者的实验值预测良好，与其他模型的预测趋势保持一致。绝热火焰温度在化学计量比附近达到峰值。温度敏感性分析表明，与其他碳氢燃料相似，在正十二烷氧化过程中引起火焰温度升高促进放热的最敏感反应为R1 ■。通过对中间自由基的生成速率及摩尔分数分布规律的研究，验证了正十二烷燃烧...     

DNTF-CMDB推进剂的燃烧机理（英文）

采用燃烧火焰单幅照相技术、微热电偶测温和扫描电镜-能谱仪研究了DNTF-CMDB推进剂的火焰结构、燃烧波温度分布、熄火表面形貌及元素分布。结果表明,含10%DNTF改性双基推进剂的火焰结构为预混火焰,其燃烧波结构与双基推进剂类似。含50%DNTF改性双基推进剂的火焰结构为扩散火焰,其燃烧波结构与AP-HTPB复合推进剂类似。燃烧表面炭物质的减少是推进剂压强指数升高的主要原因。     

无烟推进剂的临界压强

叙述了固体推进剂的临界压强概念，从推进剂燃烧火焰模型的分析中，阐述了维持RDX－CMDB无烟推进剂稳定燃烧的条件，以及降低该推进剂临界压强的实验研究。     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

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.     

2007～2008年世界塑料工业进展

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.     

2005～2006年国外塑料工业进展

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。