低荧光阳离子防塌剂WFT─666的合成与性能

ＷＦＴ－６６６是由磺甲基腐殖酸钾、有机硅聚合物、低分子阳离子有机化合物、苯酚、甲醛缩聚而成的一种新型阳离子低荧光防塌剂。本文介绍了ＷＦＴ－６６６的合成及室内性能评定结果。ＷＦＴ－６６６可抗盐至饱和盐水，抗钙和镁，耐２００℃高温，荧光显示低。用该剂处理的钻井液性能稳定，流变参数合理，页岩回收率高，页岩相对膨胀率低，页岩稳定指数高，与其它处理剂的配伍性好。     

0412-1961

TAN Yanchang; HE Bin; ZHAO Yuhua (Northeast Institute of Technology, Shenyang)     

Analysis and Quantitation of Minor Di- and Trisaccharides in Honey, Using Capillary Gas Chromatography

Methodology is introduced to separate and quantitate most of the di- and trisaccharides composed of glucose and fructose moieties, found in honey. At least twelve closely related disaccharides and seven trisaccharides were successfully identified and quantitated employing a combination of reduction and trimethylsilylation followed by either temperature programmed (disaccharides) or isothermal (trisaccharides) gas chromatography. The oligosaccharides in honey, representing approximately 3% of the total sugars, could be isolated using preparative HPLC and analyzed using the aforementioned gas chromatographic methodology. In addition, these oligosaccharides could also be analyzed without employing a preparative HPLC separation by using a concomitantly larger sample volume. Palatinose, not previously reported in honey, was found in many honey samples.     

ZnSe纳米材料及界面的制备与表征

利用热蒸发法对ZnSe纳米材料的相控合成进行了研究,制备了多种具有稳定闪锌矿和亚稳纤锌矿结构的ZnSe纳米材料,如ZnSe纳米线、纳米圈、纳米轮及三晶纳米带。同时,在相控合成基础上,通过改变管式炉内反应压强获得了几种同质与异质界面。利用多种透射电子显微学手段对合成的ZnSe纳米材料及相关同质与异质界面进行了深入表征,并对ZnSe纳米材料的生长机理进行了探讨。     

Banana Shrimp, Penaeus merguiensis, Quality Changes During Iced and Frozen Storage

Shelf life of banana shrimps, Penaeus merguiensis, were studied along with formaldehyde changes in their muscles during iced and frozen storage. K-value, timethylamine oxide nitrogen (TMAO-N), trimethylamine nitrogen (TMA-N), volatile basic nitrogen (VB-N) and sensory quality were determined. Shelf life was 4 days in ice, 6 days at -3°C and 9 wk at ??10°C. They remained acceptable after 6 mo at ?20°C. Formaldehyde was a good indicator in shrimp shelf life assessment.     

Identification of Single and Multiple Teeth Damage in a Gear Transmission System

Abstract

The main objective of this article is to identify single and multiple gear teeth damage based on vibration signatures analysis of experimental results and their comparison with those by numerical simulations. In this study, vibration signals are experimentally acquired for the case with no tooth damage to cases with multiple teeth damage using the controllable wear/damage gear sets in the 75-HP gear test rig. Vibration signatures for cases similar to the experimental studies are numerically simulated based on a two-spool rotor-bearing model connected by a set of meshing gears. The effects of the wear on the gear tooth surface are numerically represented by the phase change in the gear teeth mesh stiffness during both gear mesh engagement and disengagement. Results from both experimental studies and numerical simulations are examined and compared in the time domain, the frequency domain, and the joint time-frequency domain using the Wigner-Ville distribution (WVD). Based on results of this comparative study, general conclusions are drawn concerning the identification of single and multiple gear teeth damage and their effects in affecting the global dynamics of the gear transmission system.     

Simulation and Control of an Active Tilting-Pad Journal Bearing

This study developed an active tilting-pad journal bearing with a feedback control system to regulate the orbit of a rotating shaft. The control is implemented by means of linear actuators installed behind the pivot of each pad, which allow the radial motion of the pads in real time. The control design uses the linear feedback of the state variables of the bearing-rotor system, with the feedback gains determined by the optimization of a quadratic performance index. The optimization is based on a linear spring-mass model that incorporates the direct stiffness and damping elements associated with each of the bearing pads. This linear model is found by the simulation of the system under small perturbations using a nonlinear Reynolds equation model. The nonlinear model is capable of simulating the radial motions of the pads by the actuators and is used to verify the effectiveness of the feedback control. It is shown that certain design parameters in the quadratic performance index may be used to determine both the stiffness and the damping of the closed-loop bearing system and that the shaft orbit can be thereby suitably regulated.     

陶瓷型铁电复合物厚片介电系数的电场依赖性

建立起高压介电测试装置和相应的数据处理方法。研究了PZT/P (VDF-T rFE) 和PT/P (VDF- rFE) 0-3型铁电复合物厚片介电系数的电场依赖性。对于陶瓷体积分数U> 0.3 的复合物, 介电系数随测试场强的升高明显增大。在U< 0.1 时, 可用M axw ell-Garnet t 方程拟合试验结果。B ruggeman 方程适合于低电场(< 1MV/m ) 下复合物介电系数的预测。通过L z 的变化, 用Yamada 模型可拟合复合物介电系数随电场变化的关系, 说明L z 是由复合物的组分维数、粒子形状以及粒子间静电相互作用所决定的参数。      

Fabrication of double-sided YBa2Cu3O7_x thin films by the off-axis pulsed-laser deposition

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.