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To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.

A series Co-(18.5–20.7) at.% B melts encompassing the eutectic composition (Co 81.5 B 18.5 ) were solidified at different degrees of undercooling. It is found that the metastable Co 23 B 6 phase solidifies as a substitute for the stable Co 3 B phase in the alloy melts undercooled above a critical undercooling value of ~60 K. The Co 23 B 6 and α-Co phases make up a metastable eutectic. The corresponding eutectic composition and temperature are Co 80.4 B 19.6 and 1343 K, respectively. On exposure of the metastable Co 23 B 6 phase at a given temperature above 1208 K, it does not decompose even after several hours. But it transforms by a eutectoid reaction to α-Co + Co 3 B at lower temperature. [ABSTRACT FROM AUTHOR]

There are three freshwaters, namely Majiagou river, Hejiagou river and Xinyigou river in Harbin city, the Hejiagou river has been seriously polluted due to no renovation conducted, which causes great impact on water quality after discharging into the Songhua River and results in water functional decline.The article focuses on the study on water environmental bearing capacity of Hejiagou river so as to provide references for comprehensive treatment of Hejiagou river.

In this paper, the research and development of the distribution of air-holes in the groove of air-cushion belt conveyor were introduced. The expressions of air-cushion pressure were given and the graph of it was shown as well. The air flow model nearby groove-holes and air outflow model on cross section were given too. In the same time, the distributing mode of equidistant air-holes with unequal diameter was studied and analyzed. In order to make up the shortage of the study on air-hole distributing mode of equidistant air-holes with unequal diameter on the air-cushion belt conveyor, an instance of the air-cushion flow field was numerically simulated based on the CFD software ,Fluent software. Several groups of data of different air-hole distributions, (for example, the center distances of air-holes in the groove of air-cushion belt conveyor are the same as each other and their diameters are different), were selected to compare with each other , and then, the results were compared with existing theory. According to the different results of the numerical simulation on the distributing mode of equidistant air-holes with unequal diameter, the optimal parameters of air-hole distributing mode were obtained, and the effect of prevent offset that comes the balance groove-hole on air-cushion belt conveyor. Moreover, the verification to prove the agreement between the results of numerically simulated and basic theory was carried out by the comparison analyses. The theoretical feasibility of air-hole distributing mode of equidistant air-holes with unequal diameter was analyzed.

The unitary thermal insulation fiber materials can not satisfy rigorous high temperature environment usually. New inorganic coatings were prepared by adding SiO2 aerogels super-insulation powder into high temperature adhesive. Aerogels are high dispersive solid materials which consist of colloid particles or high polymer molecule and have continuous random network structure filling with gaseous dispersive medium. The coatings with super insulation function were made by means of adding thermal-proof materials to the coatings. The microstructure of light porous power and the states of coatings on the surface of fiber paper under different state were observed by scanning electron microscope (SEM). The insulated effect of the composite materials was tested by considering thermal conductivity. On the basis of this, the coatings on the surface of fiber paper were optimized according to the material thermal-insulation performance and the materials that could be satisfactory to the service conditions were made in the end. The results show that silica aerogels powder is dispersed equably in high temperature adhesive. The new inorganic coatings possess themselves of good thermal-insulation effect and can be used as insulated space-layers. The insulation ability of fiber paper is improved obviously.

SiO2 core/TiO2 shell composite particles were synthesized by four different heterogeneous coagulation techniques. The configurations of the composite particles and the microstructure of assembly were characterized by SEM and TEM. The colloidal stability of nano-particles was also computer-simulated by a discrete element method (DEM) in consideration of Brownian motion occurring on the nano-particles. The results indicated that uniform adsorption of the fine particle absolutely needed fine tuning of surface charging conditions and processing steps.

The near-tip asymptotic mechanical field in plane Neo–Hookean hyperelastic media is characterized by the appearance of two singular terms and, as a consequence, needs to be described by four stress parameters. Direct computation of the asymptotic stress field therefore appears to be difficult. In this paper, we propose two pairs of contour integrals. The integrals are shown to be path-independent in a modified sense and so they can be evaluated by using finite element approximations with sufficient accuracy. Also, the relationship between these integrals and the stress parameters is analytically derived. Once the integrals are accurately computed, the stress parameters and, consequently, the asymptotic stress field can then be properly determined. The formulation is considered to be suited for problems under large deformation and subjected to general far-field mixed-mode loads. No particular singular elements are used in the calculations. [Copyright &y& Elsevier]

This paper deals with the nonlinear controller design for attitude control system of spacecraft. The dynamics equations of spacecraft, which has both the nonlinear coupling characteristics and the disturbance, are discussed. A new controller based on the Lyapunov theory has been proposed to deal with this complex model. In addition, it is must be noted that we do not use the assumption of the small angles to ignore the product items. Since neither the linearization nor the decoupling has been used to simplify the model, the control result could be more precise. A simulation result illustrates the validity of this controller

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The friction and wear performances of three kinds of self-mated silicon carbide (SiC), reaction sintered SiC, pressureless sintered SiC and toughened SiC, were investigated with a block-on-ring arrangement under water-lubricated sliding. Furthermore, the morphologies, phases and element valences of the worn surface were observed, examined and analysed employing scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometer and Fourier transform infrared spectroscopy respectively. In addition, the effects of microstructure and mechanical properties of the ceramics on their tribological properties were also discussed. It was found that the three kinds of SiC obviously showed different tribological properties. Higher friction coefficient and wear coefficient occurred for reaction sintered SiC and pressureless sintered SiC. The wear mechanisms of them were explained in term of pull-outs of grains and grain fracture. However, excellent tribological property, friction coefficient of 0.01, which suggested the characterization of hydrodynamic lubrication and wear coefficient of 4.2 × 10−7mm3N−1m−1, was obtained for toughened SiC. This resulted from that tribochemical oxidation took place and a ultraflat surface was formed on the worn track as a result that the toughened SiC possessed higher fracture toughness.

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A phase controller for coherent beam combining (CBC) of fibre lasers has been designed and manufactured based on a stochastic parallel gradient descent (SPGD) algorithm and a field programmable gate array (FPGA). The theoretical analysis shows that the iteration rate is higher than , and the average compensation bandwidth of CBC for 5 or 20 channels is or , respectively. The tests show that the phase controller ensures reliable phase locking of lasers: When the phases of five lasers are locked by the improved control strategy with a variable gain, the energy encircled in the target is increased by than that in the single output, the phase control accuracy is better than , and the combining efficiency is 92 %.