Assessment of conservative load transfer for fluid–solid interface with non‐matching meshes

We present a detailed comparative study of three conservative schemes used to transfer interface loads in fluid–solid interaction simulations involving non‐matching meshes. The three load transfer schemes investigated are the node‐projection scheme, the quadrature‐projection scheme and the common‐refinement based scheme. The accuracy associated with these schemes is assessed with the aid of 2‐D fluid–solid interaction problems of increasing complexity. This includes a static load transfer and three transient problems, namely, elastic piston, superseismic shock and flexible inhibitor involving large deformations. We show how the load transfer schemes may affect the accuracy of the solutions along the fluid–solid interface and in the fluid and solid domains. We introduce a grid mismatching function which correlates well with the errors of the traditional load transfer schemes. We also compare the computational costs of these load transfer schemes. Copyright © 2005 John Wiley & Sons, Ltd.     

Evaluations and Modifications on Reynolds Stress Model in Cyclone Simulations

The prediction performance of the Reynolds stress model (RSM) on the flow field in a cyclone has been validated by using particle imaging velocimetry (PIV) experimental results. The validations mainly focus on two features of the flow information with averaged and fluctuating flow fields, which can mostly reflect the turbulent flow properties in the cyclone. The comparisons between predictions and measurements show that the RSM has good performance on the averaged flow field prediction, especially on the prediction of the mean tangential velocity. However, for the fluctuating flow field, the prediction performance of RSM is rather poor. The predicted root mean square (RMS) velocities are greatly underestimated. The standard model coefficients used in RSM have to be modified to enhance its accuracy when used to predict the fluctuating structure of the strong swirling flow in the cyclone. The recommended model coefficients give much better predictions on the fluctuating flow field than the standard coefficients, without decreasing the prediction accuracy on the mean flow field.     

半导体厂含氟废水处理工程改造

半导体生产废水中氟化物浓度较高，原有除氟工艺为二级加药[石灰、A1（SO）3]、二级沉淀，但出水氟化物不能达标。现将工艺调整为原水与石灰反应后即直接与A1（SO）3反应，再沉淀，同时改善反应条件。在基本不增加总投药量的情况下，出水氟化物浓度可稳定控制在8．0mg／L左右，达到了广东省《水污染物排放限值》（DB44／26--2001）的一级标准。     

Relationships between oil price shocks and stock market: An empirical analysis from China

This paper investigates the interactive relationships between oil price shocks and Chinese stock market using multivariate vector auto-regression. Oil price shocks do not show statistically significant impact on the real stock returns of most Chinese stock market indices, except for manufacturing index and some oil companies. Some “important” oil price shocks depress oil company stock prices. Increase in oil volatility may increase the speculations in mining index and petrochemicals index, which raise their stock returns. Both the world oil price shocks and China oil price shocks can explain much more than interest rates for manufacturing index.     

A New Ceramic Substrate Glaze with High Resistance to Molten Aluminum

Corrosion resistance of ceramic substrate glazes to molten aluminum was studied in this paper. The glazes can spread slightly in aluminum alloy according to SEM examination of solidified interface between the glazes and aluminum alloy. The components of B2O3-P2O5 glazes were not detected with electron probe at the side of aluminum alloy near the interface, but the components of boron-free glaze were detected. It is shown that borophosphate glazes can resist the corrosion of molten aluminum.     

采用半球形柱塞阀的新型斜井抽油泵

目前,一些造斜点浅、斜度大的定向井仍采用普通有杆泵生产,因井斜和受力状态改变,使泵阀启闭动作滞后,阀球偏击旁落,泵效明显降低甚至不出油。为此,设计了一种适用于大斜度井和水平井的新型斜井抽油泵。这种泵的泵筒采用特殊的固体渗硼工艺,柱塞采用热喷焊镍基合金工艺,防腐且耐磨性优越;泵阀件采用带导向杆的半球形柱塞结构,弹簧制动,精确控制阀球与阀座对中,启闭动作及时。实践证明,该泵用于大斜度油井具有泵效高、寿命长等优点。     

聚羟基脂肪酸酯的合成和应用

介绍了聚羟基脂肪酸酯(PHA)的合成方法,重点讨论了微生物合成法的菌种、碳源、分离提取及降低PHA生产成本的方法,叙述了作为PHA中的一种-PHB的性能及其改性研究,并论述了PHA在生物医学、农业、电子、食品包装等领域的应用。     

RIGOROUS FULL-WAVE ANALYSIS OF THE BASE-STATION ANTENNAS

Rigorous analysis of the Base-Station (BS) antennas with reflector is made in this letter. The wire-grid modeling of BS antenna is established. In order to improve the solution accuracy and efficiency, some efficient techniques such as three-term sinusoidal interpolation basis function and discrete wavelet transform are used. Numerical examples considered here are the typical vertically polarized and the dual-polarized BS antennas. The calculated results for the vertically polarized BS antenna are in good agreement with the measured data, which show that the analysis modeling used is accurate and reliable.     

14MnNbq钢焊接性试验

对芜湖长江大桥钢梁用14MnNbq钢焊接性进行了试验研究，并与国内外常用桥梁用钢16Mnq、SM490C进行了相关对比分析，通过试验为14MnNbq钢梁焊接工艺的制定提供依据。     

低渗地层动态泥饼形成的研究

用淡水泥浆、分散性泥浆和絮凝泥浆在动滤失装置上研究了不同流速下动态泥饼形成的条件。通过分析作用在粘土颗粒上的流体动力学作用力,建立了与泥浆性能和渗透率有关的数学模型,可预测动态泥饼形成的最低压力和岩心的最小渗透率。文中指出,低于临界渗透率时,动态泥饼就不能形成。而临界渗透率又与泥浆液柱压力有关,液柱压力越高,临界渗透率就越小。文中室内试验的结果可以直接用到现场中。