A simplified tensile damage analysis method for composite laminates using a quasi-three-dimensional model

Measurement of the strength of laminated composites is very difficult because their failure processes imply various failure modes, which are, for example, an interlaminar delamination, a destruction of matrix and an interfacial fracture between fiber and matrix. However, that strength is one of the most important characteristics in structural design using laminated composites. Hence we try a fractural progress analysis of laminated composites using a quasi-three-dimensional analysis method under a tensile load. The quasi-three-dimensional model is constructed of shell elements and beam elements which represent fiber and matrix respectively. The fractural progress analyses of the laminated composites are carried out to evaluate this proposed model. The precision is very good. Therefore we confirm that this proposed model can simulate a transverse crack and an interlaminar delamination.     

Yeast sequencing reports. Molecular cloning and sequencing of the hcs gene,which encodes 3-hydroxy-3-methylglutaryl coenzyme a synthase of Schizosaccharomyces pombe

We have cloned and sequenced the hcs gene, which is thought to encode a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase consisting of 447 amino acids, from the fission yeast Schizosaccharomyces pombe. The predicted amino acid sequence of the hcs product of S. pombe has homology with the HMG-CoA synthase of rat (47·8%), chicken (49·2%), hamster (47·1%) and human cells (46·9%). One of the hcs genes was replaced with a marker gene in the diploid cell. No viable hcs-disrupted haploid was isolated after tetrad dissection, suggesting that the hcs gene is essential for growth. However the hcs-defective mutant could be grown on a medium containing 5 mg/ml mevalonate. These results strongly support that the hcs gene encodes HMG-CoA synthase and S. pombe contains a single copy of the hcs gene. The sequence of the hcs gene has been entered into the public data libraries under Accession Number U32187.     

Impact ionisation ratio in In0.73Ga0.27As0.57P0.43

A window structure InGaAsP avalanche photodiode (a.p.d.) has been fabricated by using liquid-phase epitaxy on (111B) InP. Multiplication characteristics show that the impact ionisation rate for electrons is larger than that for holes (?>?). The ionisation ratio ?/? was estimated to be 3?4. A low-noise a.p.d. will be realised by a structure with electron-initiated multiplication.     

Effects of boron addition on some properties of hard-type carbons

The boron-containing hard-type (HT) carbons were prepared by heating the raw coke compacts with 1.6 wt% boron at temperatures ranging from 1000 to 2800° C. Some physical and mechanical properties of boron-doped HT carbons have been measured and compared with those for boron-free materials. It was confirmed that the boron enters the HT carbon at a relatively low temperature of 1400° C and enhances the densification process of compacts during heat-treatment above 1800° C. The addition of boron caused increases in Young's modulus and thermal conductivity, and decreases in hardness and electrical conductivity of HT carbons. The effects are discussed, and compared with those for graphitizable carbons.     

A fast rendering method for clouds illuminated by lightning taking into account multiple scattering

Methods for rendering natural scenes are used in many applications such as virtual reality, computer games, and flight simulators. In this paper, we focus on the rendering of outdoor scenes that include clouds and lightning. In such scenes, the intensity at a point in the clouds has to be calculated by taking into account the illumination due to lightning. The multiple scattering of light inside clouds is an important factor when creating realistic images. However, the computation of multiple scattering is very time-consuming. To address this problem, this paper proposes a fast method for rendering clouds that are illuminated by lightning. The proposed method consists of two processes. First, basis intensities are prepared in a preprocess step. The basis intensities are the intensities at points in the clouds that are illuminated by a set of point light sources. In this precomputation, both the direct light and also indirect light (i.e., multiple scattering) are taken into account. In the rendering process, the intensities of clouds are calculated in real-time by using the weighted sum of the basis intensities. A further increase in speed is achieved by using a wavelet transformation. Our method achieves the real-time rendering of realistic clouds illuminated by lightning.     

Oxidation of isobutane over Mo–V–Sb mixed oxide catalyst

The catalytic performances of Mo–V–Sb mixed oxide catalysts have been studied in the selective oxidation of isobutane into methacrolein. V–Sb mixed oxide showed the activity for oxidative dehydrogenation of isobutane to isobutene. The selectivity to methacrolein increased by the addition of molybdenum species to the V–Sb mixed oxide catalyst. In a series of Mo–V–Sb oxide catalysts, Mo₁V₁Sb₁₀O_x exhibited the highest selectivity to methacrolein at 440°C. The structure analyses by XRD, laser Raman spectroscopy and XPS showed the coexistence of highly dispersed molybdenum suboxide, VSbO₄ and -Sb₂O₄ phases in the Mo₁V₁Sb₁₀O_x. The high catalytic activity of Mo₁V₁Sb₁₀O_x can be explained by the bifunctional mechanism of highly dispersed molybdenum suboxide and VSbO₄ phases. It is likely that the oxidative dehydrogenation of isobutane proceeds on the VSbO₄ phase followed by the oxidation of isobutene into methacrolein on the molybdenum suboxide phase.     

Direct Spectroscopic Determination of Europium（ Ⅱ ） Concentration During Europium（ Ⅲ ） Electro-Reduction in Hydrochloric Acid Medium

Europiumis one of the most important rare earth(RE) element .It is widely used as a component ofcathode ray tubes , with screen coated with red phos-phor ,as phosphorescent pigments ,andinlaser optics .It can also be used as neutron-absorbing material .In…     

Discovery of User Communities Based on Terms of Web Log Data

The Web is a huge network composed of Web pages and hyperlinks. It is often reported that related Web pages are densely linked with each other. Finding groups of such related pages, which are called Web communities, is important for information retrieval from the Web. Several attempts have been made for the discovery of Web communities such as Kumar’s trawling and Flake’s method. In addition to the communities of related Web pages, there are communities of users sharing common interests. Finding the latter communities, which we called user communities in this paper, is also important for clarifying the behaviors of Web users. It is expected that the characteristics of user communities in the Web correspond to those in real human communities. A method for discovering user communities is described in this paper. Client-level log data (Web audience measurement data) is used as the data of users’ Web watching behaviors. Maximal complete bipartite graphs are searched from term-user graph obtained from the log data without analyzing the contents of Web pages. Experimental results show that our method succeeds in discovering many interesting user communities with labels that characterize the communities.