结晶型塑料注塑平板冷却模型的研究

从注塑的实际出发，针对注塑结晶型塑料平板的冷却本质，利用有限厚度区域内注塑平板的冷却模型，运用数值分析的常用算法和多项式拟合的方法进行计算机精确分析求解。进行了详细的理论推导，求得了固液两相内的温度分布，凝固系数的函数以及平板中心层温度冷却至熔点所需的时间。     

基于SA-ELM的声学层析成像温度分布重建算法

在化工领域中,获取准确的温度分布信息具有极其重要的意义。声学层析成像(AT)具有非侵入传感、廉价等优点,因而被认为是一种具有广阔发展前景的可视化温度分布测量方法。将AT用于温度分布测量,提出一种SA-ELM算法改进重建质量。首先,利用稳健估计建立了基于L1范数的目标泛函,采用模拟退火算法(SA)对目标泛函进行求解,得到粗网格下的温度分布;最后,采用极限学习机(ELM)来预测经细化网格后的温度分布。数值仿真和实验研究途径评估该方法的可行性与有效性,结果表明SA-ELM算法能够有效提高温度分布重建质量和鲁棒性,从而为AT反问题的求解提供了一种新的有效方法。     

基于SA-ELM的声学层析成像温度分布重建算法

在化工领域中,获取准确的温度分布信息具有极其重要的意义。声学层析成像（AT）具有非侵入传感、廉价等优点,因而被认为是一种具有广阔发展前景的可视化温度分布测量方法。将AT用于温度分布测量,提出一种SA-ELM算法改进重建质量。首先,利用稳健估计建立了基于L1范数的目标泛函,采用模拟退火算法（SA）对目标泛函进行求解,得到粗网格下的温度分布;最后,采用极限学习机（ELM）来预测经细化网格后的温度分布。数值仿真和实验研究途径评估该方法的可行性与有效性,结果表明SA-ELM算法能够有效提高温度分布重建质量和鲁棒性,从而为AT反问题的求解提供了一种新的有效方法。     

SIMPLE算法方腔流动数值仿真

二维方腔流动是不可压缩黏性的典型流动,可以用来检验各种数值算法计算精度和可靠性,目前尚不能求得它的解析解。基于Matlab编程,采用SIMPLE算法求解二维方腔流动,得到流动达到稳定状态时各物理量的分布。结果表明:随着雷诺数增大,流函数最大值减小,最大流函数的位置也更趋于方腔的中心。SIMPLE算法可以有效求解方腔流动,具有较高的求解精度。     

数值模拟方法在橡胶冷流道设计中的应用研究

将数值模拟方法与正交试验方法相结合,对橡胶注射模具冷流道浇注系统的温度场进行数值分析和研究。数值计算采用隐式定常求解,用k-ε湍流模型封闭运动方程,近壁区的流动采用标准的壁面函数法,固体壁面用无滑移边界条件,压力-速度耦合用SIMPLE算法。试验设计采用三水平三因子的正交试验法,得出不同水平组合下的温度场分布,导热油油路直径为10 mm、导热油入口温度为95℃、导热油入口流速为3.5 m·s-1时,胶料温度最佳,温度分布均匀。     

聚合物熔体全三维非等温数值模拟

采用基于交错网格的有限体积法(FVM)离散了4大方程,给出了能量方程的全三维离散格式。运用SIMPLE算法求解了矩形截面流道内熔体的速度场和压力场,通过耦合动量方程和能量方程,进而得到整个机头流道内温度的分布。计算中采用了Carreau流变模型,并给出了作为温度函数的流动指数n的解析表达式。模拟结果表明:在入口区,熔体从近壁面区域向流道的中心区域汇集,进入全展流区后,熔体的流场不再变化;熔体内温度分布较为复杂,影响因素众多。     

采用化学反应示踪剂数值模拟测定流动系统的温度分布

R.M.Chemburkar.L.F.Broun 等报导了采用化学反应示踪剂测定流动系统内部温度分布的数学基础。对平推流体系,描述反应物转化率的微分方程组可以合并成一个积分方程.包含一个温度关于体积的未知函数,在某些情况下,此方程可存在多个解。本文讨论了三种求解方法:前两种是用一个修正的温度分布函数把系统方程     

小波配置算法

Y Liu等人将小波分析的思想引入突跃分布沿轴向移动的问题的求解中 ,采用小波基函数对描述过程的偏微分方程进行配置求解 ,与传统的有限元上正交配置法相比 ,小波分析的多尺度特性使得求解过程无须对移动的突跃前沿进行跟踪。小波配置算法@曹彬     

数值模拟技术在橡胶冷流道设计中的应用研究

将数值模拟技术与正交试验方法相结合,对橡胶注射模具冷流道浇注系统的温度场进行了数值分析及研究。数值计算采用隐式定常求解,用k-ε湍流模型封闭运动方程,近壁区的流动采用标准的壁面函数法,固体壁面用无滑移边界条件,压力—速度耦合用SIMPLE算法。试验设计采用三水平三因素的正交试验法,得出三个不同水平的导热油油路直径、导热油的入口温度以及入口速度温度场分布,经过统计计算获得最佳结果：导热油油路直径为10mm、导热油的入口温度为95℃、流动速率为3.5m/s。     

绝势吸收的理论模型和求解方法

本文对伴有溶剂挥发的绝热吸收过程进行分析，建立了描述填料塔内气液浓度分布和温度分布的微分方程组，采用二元三次样条插值拟合平衡数据，运用Ｒｕｎｇｅ Ｋｕｔｔａ法试差求解气液浓度分布、温度分布以及所需填料层高度。     

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。