Edge and Size Effects in Micro Composite Structure

Because of the load transfer effect of interface layer, the stress distribution inside the composite structure of film/substrate can be very different from the Timoshenko's model. In this paper, we give the derivation and analysis of such load transfer effect of shear-lag (S-L) model. The micro-structure size (boundary conditions) effect together with interface load transfer effect becomes more and more important as the microstructure size including the three dimensions of thickness, width and length shrinks. The microstructure size is also responsible for the so-called edge-induced stress. The edge effect and difference of S-L model and Timoshenko model are also demonstrated.

Characterization of stress induced in SOS and Si/gamma-Al2O3/Si heteroepitaxial thin films by Raman spectroscopy

Raman spectroscopy technique has been performed to investigate the stress induced in as-grown silicon-on-sapphire (SOS), solid-phase-epitaxy (SPE) re-grown SOS, and Si/gamma-Al2O3/Si double-heteroepitaxial thin films. It was demonstrated that the residual stress in SOS film, arising from mismatch and difference of thermal expansion coefficient between silicon and sapphire, was reduced efficiently by SPE process, and that the stress in Si/gamma-Al2O3/Si thin film is much smaller than that of as-grown SOS and SPE upgraded SOS films. The stress decrease for double heteroepitaxial film Si/gamma-Al2O3/Si mainly arises from the smaller lattice mismatching of 2.4% between silicon top layer and the gamma-Al2O3/Si epitaxiial composite substrate, comparing with the large lattice mismatch of 13% for SOS films. It indicated that gamma-Al2O3/Si as a silicon-based epitaxial substrate benefits for reducing the residual stress for further growth of silicon layer, compared with on bulk sapphire substrate. (c) 2005 Elsevier B.V. All rights reserved.

Investigation on Fe, Mn, Zn, Cu, Pb and Cd fractions in the natural surface coatings sampled and surficial sediments collected in the Songhua River, China

Natural surface coatings sampled (NSCSs) from the surface of shingles and surficial sediments (SSs) in the Songhua River, China were employed to investigate the similarities and difference in fractions of heavy metals (Fe, Mn, Zn, Cu, Pb, and Cd) between NSCSs and SSs using the modified sequential extraction procedure (MSEP). The results show that the differences between NSCSs and SSs in Fe fractions were insignificant and Fe was dominantly present as residual phase (76.22% for NSCSs and 80.88% for SSs) and Fe-oxides phase (20.33% for NSCSs and 16.15% for SSs). Significant variation of Mn distribution patterns between NSCSs and SSs was observed with Mn in NSCSs mainly present in Mn-oxides phase (48.27%) and that in SSs present as residual phase (45.44%). Zn, Cu, Pb and Cd were found dominantly in residual fractions (>48%), and next in solid oxides/hydroxides for Zn, Pb and Cd and in easily oxidizable solids/compounds form for Cu, respectively. The heavy metal distribution pattern implied that Fe/Mn oxides both in NSCSs and SSs were more important sinks for binding and adsorption of Zn, Pb and Cd than organic matter (OM), and inversely, higher affinity of Cu to OM than Fe/Mn oxides in NSCSs and SSs was obtained. Meanwhile, it was found that the distributions of heavy metals in NSCSs and SSs were similar to each other and the pseudo-total concentrations of Zn, Cu, Pb and Cd in NSCSs were greater than those in SSs, highlighting the more importance for NSCSs than SSs in controlling behaviours of heavy metals in aquatic environments.

Outer wave number spectrum and statistical distribution of apparent wave number vector

Based on the ray theory and Longuet-Higgins's linear,model of sea waves, the joint distribution of wave envelope and apparent wave number vector is established. From the joint distribution, we define a new concept, namely the outer wave number spectrum, to describe the outer characteristics of ocean waves. The analytical form of the outer wave number spectrum, the probability distributions of the apparent wave number vector and its components are then derived. The outer wave number spectrum is compared with the inner wave number spectrum for the average status of wind-wave development corresponding to a peakness factor P = 3. Discussions on the similarity and difference between the outer wave number spectrum and inner one are also presented in the paper. (C) 2002 Elsevier Science Ltd. All rights reserved.

后处理对离子交换磷酸盐玻璃平面光波导的影响

研究了退火和二次离子交换对Er^3＋／Yb^3＋共掺的磷酸盐玻璃平面光波导传输特性的影响。在退火过程中，由于热效应和波导层Ag^＋离子的浓度差使得Ag^＋离子重新分布；随着退火时间的延长和温度的升高，光波导模式数目逐渐增加，波导层深度加深，且波导表面折射率与玻璃基质折射率差减小，退火扩散深度与退火时间的平方根成正比。电子探针结果显示在二次离子交换后形成了掩埋式的光波导，Ag^＋离子浓度接近二次方分布，而掩埋式的光波导有助于降低光波导的传输损耗。

无压灌溉土壤湿润体特征值变化规律与经验解

无压灌溉土壤湿润体形状为球冠,径向和垂向最大湿润距离相等且与时间存在显著的幂函数关系,随着时间的延长,径向和垂向最大湿润距离趋于一定值。湿润体大小与供水压力之间呈抛物线关系,在零压力附近湿润体体积最大。湿润体半径与累计入渗量呈幂函数关系,拟合方程中的系数和指数为一定值,与入渗时间和供水压力无关,在试验条件下,分别为18.467和0.5037。综合以上结果,提出了预测无压灌溉土壤湿润体特征值的经验解模型。

Flexural fatigue behavior of injection-molded composites based on poly(phenylene ether ketone)

Flexural fatigue tests were conducted on injection-molded short fiber composites, carbon fiber/poly(phenylene ether ketone) (PEK-C) and glass fiber/PEK-C (with addition of polyphenylene sulfide for improving adhesion between matrix and fibers), using four-point bending at stress ratio of 0.1. The fatigue behavior of these materials was presented. By comparing the S-N curves and analyzing the fracture surfaces of the two materials, the similarity and difference of the failure mechanisms in the two materials were discussed. It is shown that the flexural fatigue failure of the studied materials is governed by their respective tensile properties. The matrix yielding is main failure mechanism at high stress, while at lower stress the fatigue properties appear fiber and interface dominated. (C) 1997 John Wiley & Sons, Inc.

Evaluation of induced triploid shrimp Penaeus (Fenneropenaeus) chinensis cultured under laboratory conditions

Triploid Penaeus (Fenneropenaeus) chinensis was successfully produced by heat shock. Their metamorphosis, the relationship between body weight and length and difference in appearance between triploids and their diploid siblings under laboratory culture were studied. Hematological studies showed a smaller number of haemocytes, but larger cell volume, in triploids than in diploids. Triploid shrimp did not show higher growth during the immature stage, but exhibited superior growth during the maturation stage. Characteristics of reproductive organs indicated that triploid shrimp may be sterile and sex ratio can be changed through triploidization of shrimp. This paper summarizes the progress made in triploid shrimp research which would be helpful in understanding more about triploids of crustaceans. (c) 2006 Elsevier B.V. All rights reserved.

Application of effective medium approximation theory to ocean remote sensing under wave breaking

Based on the effective medium approximation theory of composites, the empirical model proposed by Pandey and Kakar is remedied to investigate the microwave emissivity of sea surface under wave breaking driven by strong wind. In the improved model, the effects of seawater bubbles, droplets and difference in temperature of air and sea interface (DTAS) on the emissivity of sea surface covered by whitecaps are discussed. The model results indicate that the effective emissivity of sea surface increases with DTAS increasing, and the impacts of bubble structures and thickness of whitecaps layer on the emissivity are included in the model by introducing the effective dielectric constant of whitecaps layer. Moreover, a good agreement is obtained by comparing the model results with the Rose's experimental data.

天津滨海新区软土不同含砂量的强度特征研究

Based on the features of soft soil in Tianjing Coastal New Developing Area, this kind of soil with different content of sand was researched systematically, according to the indoor experiment, about its characteristics of strength and deformation. The main results are summarized in the following: Firstly, on the basis of geological engineering investigation, the systemic experiments about the physical characteristics were conducted. The test soil samples were taken from the gray and gray-yellow silty soft soil which was formatted by near-shore marine sediment and marine-continental interactive sediment. The original condition of the sample soil was in saturation and the basic indexes are: liquid limit36.1%, plastic limit 18.8%, plasticity index. Then, the condensation characteristics of the soft soil were analyzed through high-pressure consolidation tests. The results show that，in various loading serials, the coefficient of compressibility under P=100kPa and 200kPa are all larger than 0.5MPa-1. So the sample soil is a kind of high-compressibility soil. Secondly, triaxial strength of undisturbed soil and remoulded soil was researched by using triaxial test. The types of stress-strain curve of both undisturbed and remoulded soil are the stress stabilization and softening type, which show the specific plastic character. Furthermore, the cohesion and friction angle of undisturbed soil changes, when the ambient pressure is different, instead of a stable value for all time; the cohesion and friction angle of remoulded soil changes with the compactness and sand-carrying capacity which is wholly higher than undisturbed soil. At last, the stress-strain results of both undisturbed and remoulded soil were normalized by using the ambient pressure as the normalization factor. The results show that, there are all some normalization characters in both undisturbed and remoulded soil, however, the feature of normalization of undisturbed soil is worse than the remoulded ones. The main reason is that the undisturbed samples are worse in equality and the unavoidable disturb through the process of sampling and experiments will also make them can not put up good normalization. Therefore, it is feasible to normalize the soil in Tianjing Coastal New Developing Area with the ambient pressure as normalization factor.

三峡库区堆积层斜坡稳定性分级与应用研究

Considering the lacking of standard for the classification of Accumulative slopes so far, research working was conducted based on the results of geological investigation, data analysis and experiment carried out in Wanzhou. By mean of statistical method and grey system, the author studied in detail inflationary factors to Accumulative slopes. In order to study the mechanism of Rock-Soil Aggregate (RSA), numerical testing method was used. Coordinates in the two and three dimensional space and its corresponding rock fragments in the sample were generated randomly by VB and Particle flow code. After being built the models of RSA with different rock content, uniaxial and triaxial numerical simulation tests were carried out respectively. In order to study the effect of rainfall in Accumulative slopes, in situ infiltration testing had been conducted on site in Wanzhou, Three Gorges Area. Relationship between the infiltration rate and amount of precipitation has been obtained. Eleven factors are considered in the classification of Accumulative slopes in this paper.(1)On the basis of four basic factors and four inducing factors, sum-and-difference method for the classification system has been built. (2)After weight of factors being determined by analytic hierarchy process and membership function of Accumulative slopes stability being built in virtue of fuzzy mathematics, AHP-FM model of Accumulative slopes stability has been completed. In the end of this paper, having been applied on stability of Accumulative slopes in Three Gorge area and compared with result by limit equilibrium, classification system has good effect.

大港油田孔南地区孔一段储层流动单元研究

The main reservoir type in the south of Dagang Oilfield is alluvial reservoir. In this paper, the reservoir structure model and the distribution of connected body and flow barrier were built on base of the study of high-resolution sequential stratigraphic skeleton and fine sedimentary microfacies on level of single sandbody. Utilizing the static and dynamic data synthetically and carrying out the comparision of the classification method for reservoir flow unit in different reservoir, the criterion, which can be used to classify the flow unit in first section of Kongdian formation of Kongnan area, was defined. The qualitative method of well-to-well correlation and the quantitative method of conditional simulation using multiple data are adopted to disclose the oil and water moving regulation in different flow unit and the distribution rule of remaining oil by physical simulation measure. A set of flow unit study method was formed that is suit for the Dagang Oilfield on account of the remaining oil production according to the flow unit. Several outstanding progresses was obtained in the following aspects:It is considered that the reservoir structure of Zao V iow oil group- Zao Vup4 layerand are jigsaw-puzzled reservoir, while ZaoVup3-ZaoVupi layers are labyrinth reservoir,which are studied on base of high-resolution sequential stratigraphic skeleton on the levelof single sandbody in first section of Kongdian formation of Kongnan area and accordingto the study of fine sedimentary microfacies and fault sealeing.When classifying the flow unit, only permeability is the basic parameter using thestatic and dynamic data and, and also different parameters should be chose or deleted, suchas porosity, effective thickness, fluid viscosity and so on, because of the weak or stronginterlayer heterogeneous and the difference of interlayer crude oil character.The method of building predicting-model of flow unit was proposed. This methodis according to the theories of reservoir sedimentology and high-resolution sequencestratigraphic and adopts the quantitative method of well-to well correlation and the quantitative method of stochastic simulation using integrateddense well data. Finally the 3-D predicting-model of flow unit and the interlay er distribution model in flow unit were built which are for alluvial fan and fan delta fades in first section of Kongdian formation of Kongnan area, and nine genetic model of flow unit of alluvial environment that spread in the space were proposed.(4) Difference of reservoir microscopic pore configuration in various flow units and difference of flow capability and oil displacement effect were demonstrated through the physical experiments such as nuclear magnetic resonance (NMR), constant rate mercury penetration, flow simulation and so on. The distribution of remaining oil in this area was predicted combining the dynamic data and numerical modeling based on the flow unit. Remaining oil production measure was brought up by the clue of flow unit during the medium and late course of the oilfield development.

品牌表现评价反应时与关注特性的关系

The decision making of customers has been a great concern in the field of customer research. Although China has entered the era of brand consumption and development, due to the different understanding of the regarded attributes between companies and customers, the phenomenon of “The awarded products don’t sell well, but the products which sell well can’t get the award.” appears. At the same time there is little research on the relationship between the brand and the customers has been conducted in China now. Traditional research on customer psychology employ questionnaires, depth interview and group discussions as the major methods. In cognitive psychology, the limitation of explicit memory has been revealed by implicit memory; moreover, unconscious cognition and implicit memory can also influence customers' remark of the brand. Therefore, the traditional methods are not accurate enough. Reaction time is an effective way to reveal testing equality, and it can also reveal implicit cognition. Based on the researches intends to investigate the validity of attention attributes in the method of reaction time by questionnaires and time reaction testing of 360 customers in 3 cities, which may, probably, overcomes the limitation of the traditional research methods. The 352 valid samples were analyzed by SPSS. The results showed there was no distinct corresponding relationship between the product attributes and reaction time. The different key attributes from questionnaire importance rating and the shortest reaction time standards were used to regressively analyze the results of customers’ overall rating (such as overall satisfaction,objective quality, recommend intention).The results indicated that the coefficiency of regression of the special attributes chosen from reaction time to overall rating was distinct, while the coefficiency of the special attributes chosen from importance rating to overall rating was not. The main conclusions are: 1. Regarded attributes can be obtained by the reaction time of brand performance rating. 2. Regarded attributes obtained by the reaction time of brand performance rating are more accurate than those by importance rating questionnaires. 3. The brand’s core attributes should includes regarded attributes during the decision making process.

汉语句子和语篇韵律层级边界的认知加工及其ERP效应

The aim of the present study was to explore whether the CPS (Closure Positive Shift) which reflected prosodic processing will be elicited when listeners perceived different hierarchical prosodic boundaries in Chinese sentence and discourse (Quatrain). In addiction, the similarity and difference in amplitude, onset latency and scalp distribution between these CPS were investigated. The nature of the CPS and its relationship to acoustic parameters was also explored systematically. The main results and conclusions of the present study were: (1) Phonological phrase boundaries and intonational phrase boundaries in Chinese sentences both elicited the CPS; however, phonological word boundaries can't evoke it. The CPS induced by phonological phrase boundaries was earlier than the one related to intonational phrase boundaries in onset latency, and the amplitude was also somewhat lower. When the pauses in the vicinity of these two boundaries were removed, the onset latency difference disappeared while amplitude in the new conditions was also lower. This indicates that whenever listeners segment sentence into phrases, the CPS will be elicited. Besides, pause was not the decisive factor to elicit the CPS, but can modify its onset latency and amplitude effectively. (2) The different hierarchical prosodic boundaries in seven character quatrain including phonological phrase boundaries, intonational phrase boundaries and sentence pair boundaries elicited the CPS respectively. Furthermore, just like in the sentence level, onset latency of the CPS induced by the prosodic boundaries in the discourse was also influenced by the length of pause: the shorter the pause was, the earlier the onset latency. For the comparison between the CPS evoked by the same and different hierarchical prosodic boundaries, its amplitude was influenced by the extent to which prosodic representations were activated. Thus, the condition of the CPS elicitation was extended to the prosodic bounaries in discourse, and further indicated that it was influenced by acoustic parameters. (3) No matter what task the participants completed, just like word detection or rythem matching task, the CPS will be evoked. However, its amplitude was larger in the anterior region, when listeners completed the word detection task which needed more attention and higher load of working memory. The present result indicated that the elicitation of the CPS was not influenced by the task the participants completed, but different task influence its scalp distribution. (4) The final syllable of the sentence and quatrain can't elicit the CPS, but a P300-like positive component. Although the scalp distribution was similar to the CPS, it was much higher in amplitude. The present result suggested that only the prosodic boundaries reflecting not only the closure of the former prosodic unit but also integrating the later one will elicit the CPS.

Analysis of super compact finite difference method and application to simulation of vortex-shock interaction

Turbulence and aeroacoustic noise high-order accurate schemes are required, and preferred, for solving complex flow fields with multi-scale structures. In this paper a super compact finite difference method (SCFDM) is presented, the accuracy is analysed and the method is compared with a sixth-order traditional and compact finite difference approximation. The comparison shows that the sixth-order accurate super compact method has higher resolving efficiency. The sixth-order super compact method, with a three-stage Runge-Kutta method for approximation of the compressible Navier-Stokes equations, is used to solve the complex flow structures induced by vortex-shock interactions. The basic nature of the near-field sound generated by interaction is studied.