人工神经网络-遗传算法优化化学镀四元合金工艺

利用BP神经网络-遗传算法对化学镀Ni-Fe-Co-P工艺进行寻优。首先利用正交试验表安排一定数量的实验,以构成人工神经网络的训练集。对训练集训练并利用实验数据检验,得到化学镀工艺的人工神经网络模型。最终再利用遗传算法对其进行寻优,以确定最佳的工艺参数。结果表明该方法结果可靠,可以用于实际各种工艺参数的寻优。     

碳纤维表面化学镀Ni-Co-Fe-P工艺研究

介绍了碳纤维表面化学镀Ni-Fe-Co-P的工艺流程,探讨了碳纤维的去胶方法.通过正交实验法优化了化学镀Ni-Fe-Co-P的配方和工艺条件,观察了碳纤维的表面形貌,测试了镀层的结合力,研究了碳纤维增重率与时间和温度的关系.结果表明,在400℃灼烧30min,可去胶完全.本工艺得到的镀层均匀致密,结合力好.     

基于人工神经网络的充填浮选柱捕集区气含率特性研究

论述了用人工神经网络的方法对影响充填浮选柱捕集区气含率工艺参数(捕集区高径比、气体加入量和起泡剂用量)进行模拟、训练和预测的过程.结合实验结果讨论了各个影响因素对气含率的作用规律,并用基于实验数据建立的人工神经网络对气含率进行预测分析.所建立的神经网络模型的输出值与实验测量值误差在±5％以内,显示神经网络方法预测分析气含率具有较高的适用性,为充填浮选柱的放大研究提供可行的方法.     

用MATLAB神经网络预测气力输送过程物料破碎率

物料在气力输送过程中的破碎率大小,是评判气力输送系统及输送工艺优劣的重要参数之一.利用MATLAB语言,将炭黑气力输送系统各位置的压力数据输入BP神经网络,用训练好的网络模型进行仿真,对炭黑的破碎率进行了预测.与实验结果对比,采用BP神经网络对炭黑破碎率的预测具有比较高的精确度,可对气力输送系统的优化设计以及输送工艺参数的优化选取提供指导.     

应用BP神经网络预测加氢裂化尾油蒸汽裂解产物收率

研究了BP神经网络对加氢裂化尾油蒸汽裂解产物收率的预测,并介绍了该BP神经网络的结构、基础数据以及研究结果。从预测数据和实验数据对比结果来看,应用神经网络对加氢裂化尾油裂解产物收率进行预测是可行的。结论是：在保证基础训练数据的准确性和合理选取的情况下,BP神经网络将是一种有效的预测加氢裂化尾油裂解产物收率的方法。     

基于人工神经网络的大型浇注型聚氨酯弹性体收缩规律的模拟

收缩率的选取是决定大型浇注型聚氨酯弹性体（CPUE）模具设计是否成功的关键因素之一.以大量的实验为基础,系统地研究了各种工艺参数对大型聚氨酯弹性体制品收缩率的影响,并建立了制品的结构模型以及基于BP网的神经网络模型.通过对实验数据的学习,利用该神经网络模型可以实现以工艺参数为输入,制品收缩率为输出的大型聚氨酯弹性体收缩率的预测.预测结果和实验数据的对比表明此方法可以较为准确地对不同工艺条件下的弹性体收缩率进行预测,从而减少修模次数,降低生产成本.     

基于BP神经网络的注塑成型收缩率预测

首先通过正交优化与数值模拟相结合的方法,分析了影响电连接器孔盖板体积收缩率的因素,通过极差分析,确定了主要工艺参数对体积收缩率影响的敏感性。其次基于设计和训练的BP神经网络模型,预测了体积收缩率,并与数值模拟结果进行了比较。最后利用BP神经网络的可预测性,结合正交试验方法对注塑成型工艺参数进行优化分析,对优化后的数据进行极差分析,得到了最佳成型工艺参数值。     

橡胶开炼机塑炼工艺优化的神经网络研究方法

运用神经网络方法,建立了预测橡胶开炼机塑炼工艺参数的计算模型。运用该模型计算橡胶开炼机塑炼的工艺参数,并与实验结果进行了比较。结果表明,该模型精度较高,在橡胶开炼机塑炼工艺参数研究方面具有较好的工程应用价值。     

基于改进神经网络的注塑工艺参数优化

以鼠标壳为实例,利用正交试验数据得到训练样本。以减小翘曲变形量为目标,运用竞争型神经网络的预测功能,实现注塑成型工艺参数控制。为进一步提高注塑成型质量,采用遗传算法完成工艺参数的优化,并得到最优解。最后,进行相关实验验证。结果表明:优化后,塑件翘曲变形量降低了23.67%,实验结果和预测结果基本吻合,在一定程度上提高了塑件的成型质量。     

基于神经网络集的注射成型工艺参数多目标优化

以计算机辅助工程（CAE）数值仿真正交试验所得工艺参数与质量指标的数据作为训练样本,对经过优化的BP神经网络进行训练,得到工艺参数与制品质量指标之间的神经网络集近似计算代理模型,该模型快速准确,有明确的数学公式,可以利用遗传算法进行全局寻优,得到使多个质量指标综合最优的工艺参数组合。通过对比验证,这种多目标优化方法可以在正交试验结果数据较少的情况下较大程度地提高制品的多个质量指标。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。