公斤工作基准稳定性误差的统计与分析

本文对力学室一等质量实验室的26、27、32三个公斤工作基准砝码的稳定性误差分别作了分析。经过对历年的检定记录和中间核查的分析汇总，得出各个公斤工作基准的稳定性误差，采用多个砝码多次全组合测量，利用最小二乘法计算出这三个公斤工作基准砝码之间的质量差值，找出它们的稳定性误差的变化趋势。     

Effects of contact shape on biological wet adhesion

Wet adhesion is widely adopted in biological adhesion systems in nature. Wet adhesion is studied in this paper with the focus on the effect of different contact shapes (flat, concave, convex, and ring-like) on the adhesion force. The evolution of the liquid bridge between a fiber tip and substrate during the detaching process shows two transition points. The first transition from the radius-controlled to the contact-angle controlled process is critical to influence the strength and robustness of adhesion. We show that a concave shape is more effective than a flat one, while a convex shape has no advantage. A ring-like contact shape has advantages in a hydrophobic environment and on a rough surface.     

无线技术的新领域--WUSB

无线USB(WUSB)技术是一个全新的无线传输标准.实现USB(通用串行总线)无线化以后,既可以保持有线USB的高速传输等优点,又可以去掉电缆的羁绊,给各种设备带来更大的便捷和移动性.文中首先介绍了WUSB技术的由来--UWB技术规范的标准化难以确定,然后对WUSB技术的规范标准进行了阐述,最后概述了WUSB技术的发展现状及目前和今后的技术研发重点,并对WUSB的发展前景进行了展望.     

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.     

分频解释技术在川西砂岩储层预测中的应用

分频解释技术是沿着储层或固定时窗对地震反射波各频率成分对应的调谐能量进行识别和成像,它避免了常规属性分析方法中的调谐陷阱,提高了识别薄储层的能力,能更客观地刻画地质体.在川西地区陆相隐蔽岩性气藏勘探中,存在调谐陷阱、波阻抗特征不明显、复杂地层结构中的有效薄储层不易识别等问题.为此,利用分频解释技术对川西地区侏罗系千佛崖组冲积扇相砾岩储层、上三叠统须四段河流三角洲相砂岩储层进行了描述.在多频率振幅叠加图上,冲积扇、三角洲水下分流河道等地质体形态和边界反映清晰;在单频振幅图上,清楚地显示出冲积扇内的辫状河道相薄层砾岩储层,与钻井结果相吻合,提高了储层预测精度.     

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     

面向企业信息化实现管理现代化

为适应社会信息化技术的发展，必须积极推行企业信息化，企业信息化引发管理革命，从而丰富了企业管理现代化的内容。本文论述了上述三方面的内部及演化关系，指出只有面向企业信息化，才能充分实现企业管理现代化。     

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。     

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.