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1.
《国外塑料》1996,14(3):54-59
新设备新材料新技术(新工艺)新产品新设备近红外线树脂种类分辨装置日本东亚电波工业公司和塑料处理促进协会共同开发出用近红外线塑料材料的树脂种类分辨装置。该操作简单,将探测器压着对象物上1~2秒钟就可辨别出是什么材料。其原理是将近红外光照射到塑料上获得的...  相似文献   

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综述了塑料辨别的必要性、塑料种类及辨别技术的进展。  相似文献   

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《应用化工》2019,(1):238-241
采集15种塑料样本的X射线吸收光谱(XAS),对光谱数据进行预处理和主成分分析,建立误差反向传播(BP)神经网络和遗传算法优化的误差反向传播(GA-BP)神经网络模型,利用训练集进行网络训练,并通过测试集进行验证。结果表明,GA-BP神经网络相比于BP神经网络可以更好更稳定的对塑料样本的XAS进行识别,这对塑料的回收具有重要的指导意义。  相似文献   

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《应用化工》2022,(1):238-241
采集15种塑料样本的X射线吸收光谱(XAS),对光谱数据进行预处理和主成分分析,建立误差反向传播(BP)神经网络和遗传算法优化的误差反向传播(GA-BP)神经网络模型,利用训练集进行网络训练,并通过测试集进行验证。结果表明,GA-BP神经网络相比于BP神经网络可以更好更稳定的对塑料样本的XAS进行识别,这对塑料的回收具有重要的指导意义。  相似文献   

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为了实现塑料的分类回收,需要对塑料进行快速准确的鉴别。收集了丙烯腈-丁二烯-苯乙烯(ABS)、聚丙烯(PP)、聚乙烯(PE)、聚对苯二甲酸乙二醇酯(PET)、聚苯乙烯(PS)、聚氯乙烯(PVC)、聚碳酸酯(PC)等7种常用的塑料,利用近红外光谱仪分别测得其反射光谱,应用主成分分析和反向传播(BP)神经网络建立模型进行鉴别。首先利用主成分分析提取光谱的特征信息,前8个主成分的累计贡献率达到94.367%,包含了原始光谱的主要信息,将这8个主成分作为BP神经网络的输入,7种塑料的种类作为输出,建立三层BP神经网络模型。每种塑料各30个样本共210个用来训练神经网络模型,各10个共70个用来预测,预测结果准确率达98.571%,能够有效鉴别常用塑料。  相似文献   

6.
基于RBF神经网络的生产线控制方案,采用Matlab搭建实验仿真平台对温度控制系统进行实验设计,并对控制系统进行验证分析。仿真结果表明:基于RBF神经网络塑料成型生产线温度控制系统具有较好的抗干扰性、稳定性,控制系统能够有效满足于控制需求,在塑料成型生产线温度控制中,恒定性和鲁棒性控制效果良好。基于RBF神经网络塑料成型生产线温度控制系统能更大程度上提高系统智能化水平与温度控制精度,提升产品质量。  相似文献   

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在简述了国内外双螺杆塑料挤出机控制技术发展现状的基础上,提出了现阶段国内塑料挤出机智能控制研究难点,分析了提高塑料挤出机控制系统的精度和工作效率的重要意义。文中以常用的电容传感器测量塑料薄膜厚度为例,介绍了薄膜厚度测量的工作原理,建立了模糊神经网络算法模型,并对模糊神经网络PID控制器的工作流程进行了设计,利用Matlab仿真软件对比了模糊神经网络算法和传统PID算法的输出曲线,并结合实验验证了仿真的可行性与模糊神经网络PID算法的优越性。  相似文献   

8.
《聚氯乙烯》2001,(1):64
日本仓坊公司最近开发出了一种高速辨别传感器,能够在1‰ s的时间内辨认出5种废塑料瓶的材料种类。 这种传感器能够辨别用聚对苯二甲酸乙二酯、氯乙烯、聚乙烯、聚丙烯和聚苯乙烯制造的各种瓶子。 研究人员发现,将远红外线照射到塑料瓶子上,不同的材料就会吸收特定的波长。他们利用这一原理开发了这种传感器。由于采用独自的信号处理技术,辨别速度得到了很大提高。 这项成果已在日立造船公司的废料工厂进行了测试,取得了良好的效果。  相似文献   

9.
基于混沌理论与Elman神经网络的气固流化床流型识别   总被引:1,自引:0,他引:1  
采用混沌理论对气固流化床压力脉动信号进行混沌特性分析,包括求延迟时间τ、Hurst指数、关联维数、Kolmogorov熵、Lyapunov等混沌参数,并结合统计参数作为流型辨别的特征输入量,利用Elman神经网络对其训练.试验结果表明,气固流化床压力脉动信号具有混沌特性,Elman神经网络能够有效地快速地识别流化床的五种流型,识别率达95%,为在线识别气固流化床流型提供了一种新的有效方法.  相似文献   

10.
长短时记忆(LSTM)循环神经网络的塑料编织机故障诊断法通过提取振动信号的能量矩,突出信号在时间轴上的分布特征,降低输入模型的向量维度。从多个特征向量构成的样本集中选择80%作为训练样本,训练LSTM循环神经网络模型,并利用剩余样本验证模型的检测精度;以准确率、查准率和查全率作为评价指标,利用多组不同的振动数据样本,对BP神经网络模型、卷积神经网络(CNN)模型和LSTM循环神经网络模型进行比较分析。结果表明:LSTM循环神经网络模型在不同样本中能够同时达到较高的准确率、查准率和查全率,其平均值分别可达95.69%、86.96%、96.89%,证明LSTM循环神经网络能充分学习具有时序特性的故障信息,对塑料编织机的故障诊断具有可行性和有效性。  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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