2007年国外有机硅进展

根据2007年公开发表的相关资料,综述了2007年国外有机硅行业的市场动向、行业动向及有机硅产品的研发进展.     

狭小场地条件下大跨度预应力混凝土拱板的运输及吊装

介绍了大跨度预应力混凝土拱板在狭小场地条件下的起模、运输及空间滑移吊装的方法，经在众多中直粮库中的应用，证明该方法简单、适用、经济。     

Specific interactions in blends containing Chitosan and functionalized polymers. Molecular dynamics simulations

Chitosan (CS)/poly(vinyl alcohol) (PVA) and Chitosan/poly(2-hydroxyethyl methacrylate) (P2HEM) blends have been studied through molecular dynamic simulations. In a previous work it was found miscibility between these polymers and it was attributed to hydrogen bonding formation. However, the experimental information obtained was not enough to know which of the interacting groups of Chitosan, i.e. -CH₂OH or -NH₂, are responsible of the interaction. Therefore, we have performed molecular dynamics simulation runs of 1 ns in order to calculate radial distribution functions (RDF) for the groups tentatively involved in the interaction. The results are correlated with our previous experimental data. This way, we have obtained a more precise conclusive information about the interactions involved as function of the blends composition. For low compositions of PVA and P2HEM the interaction is predominantly with the hydroxymethyl groups of CS while as the composition of PVA and P2HEM increases, the interaction with the amine groups increases.     

Elimination of organic matter present in wastewaters from the cork industry by membrane filtration

BACKGROUND: The first stage of the cork industrial process generates great volumes of wastewater with moderate to high organic pollutant content that must be purified using different procedures, such as filtration by membranes. RESULTS: The tangential filtration of these wastewaters was studied using two different laboratory equipments. In the first one, three ultrafiltration (UF) membranes were tested, with molecular weight cut‐off (MWCO) 100 kDa and 30 kDa, and two operating modes were used: total recycling of permeate and retentate streams, and in continuous mode, without recycling both streams. In the total recycling UF experiments, the influence of the operating variables on the permeate flux was first established. The effectiveness of the different membranes was determined by evaluating the rejection coefficients for several parameters that measure the global pollutant content of the effluent. The values found for these rejection coefficients were in the following order: ellagic acid and color > absorbance at 254 nm > tannic content > COD (chemical oxygen demand). In the continuous mode experiments, the fouling mechanism for each membrane was established by fitting the experimental data to various filtration fouling models given in the literature. The operating mode in the second equipment was batch concentration, and additional experiments were carried out with an UF membrane (2 kDa), and with a NF membrane (with MWCO in the range 150–300 Da). CONCLUSIONS: The three operating modes tested provided different rejection levels of organic matter; among them, the most effective procedure tested was batch concentration mode using a NF membrane. Copyright © 2007 Society of Chemical Industry     

Molecular weight effect on the obtainment of parallel and perpendicular orientation in thermotropic poly(diethylene glycol <Emphasis Type="Italic">p,p′</Emphasis>-bibenzoate)

Summary The effect of molecular weight on the uniaxial orientation process has been analyzed in two samples of thermotropic poly(diethylene glycol p,p′-bibenzoate), evaluating the influence of that parameter on the type of orientation obtained. Several strain rates and deformation temperatures have been tested in order to map out the conditions for obtaining the two different kinds of orientation. The results show that in the lower molecular weight PDEB sample (M_w=31200) it is rather easy to get exclusively perpendicular “anomalous” orientation, with the molecular axes aligned transversely to the stretching direction. However, it is extremely difficult to obtain 100% parallel “normal” orientation. On the contrary, either type of orientation or a mixture of them can be easily developed for the higher molecular weight PDEB sample (M_w=102900).     

基于XML的基金会现场总线设备描述技术

本文简单介绍了基金会现场总线FF的设备描述和新一代稳定、可靠、通用的网络标记语言XML的特点，提出了一种用XML语言实现设备描述的方法。     

火焰图像特征在火灾数字图像识别中的运用

火焰尖角数目和圆形度是早期火灾火焰的主要特征,本文主要论述了如何在数学形态学基础上,利用火灾火焰的两个特点判断和识别早期火情。实验中,对火焰的二值图像进行开运算,即先腐蚀,再膨胀,目的是为了对火焰图像进行形态学滤波,去噪。从实验结果可以看出,该算法可以很好的识别火焰和干扰源。     

稀土改善09CuPTiRE耐候钢耐蚀性的作用机理

应用扫描电镜(SEM)、离子探针(IMA)、X射线光电子能谱(XPS)和交流阻抗法研究含不同稀土耐候钢稀土提高耐大气腐蚀作用机理。结果表明,合适的稀土含量可显著提高钢的耐腐蚀性,稀土能促进Si、Cu和P在内锈层中以Si~(4+)、Cu~+和P~(5+)形态富集,并观察到锈层中的稀土。钢中加入稀土形成了致密连续厚而粘附性好的含硅铜稀土的复合铁锈层,从而提高了抗大气腐蚀性能。     

AMBE-1000声码器接口电路设计方法

DVSI公司的AMBE-1000声码器芯片是一款高性能的全双工、实时语音压缩编解码芯片,可以应用于卫星通信、保密通信、视频会议等领域.文中简要介绍AMBE-1000声码器的A/D-D/A接口以及信道接口的工作原理;结合实例分别给出了AMBE-1000声码器与PCM编解码器MC14LC5480的A/D-D/A接口电路、与单片机AT89C51的信道接口电路的设计方法;最后指出了电路设计中应该注意的问题.     

Effect of Heat Treatment on Luminescent Properties of White Organic Light Emitting Device

The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated. Heat treatment is used to control the ratio between the intensities of main electroluminescent spectral peaks. The electroluminescent spectrum of our device is quite similar to that of white inorganic LED produced by Nichia Corporation after being annealed, and its turn-on voltage can be decreased by 1V.