辊涂花纹厚铝板浅谈

在1.0mm～3.0mm厚的铝板上辊涂花纹,是涂装领域的新课题,是亟待研发的新产品.对此,本文以行业扫描的眼光,蜻蜓点水,略谈几点个人浅见.     

Pattern search algorithms for nonlinear inversion of high-frequency Rayleigh-wave dispersion curves

Inversion of Rayleigh wave dispersion curves is challenging for most local-search methods due to its high nonlinearity and to its multimodality. In this paper, we implemented and tested a Rayleigh wave dispersion curve inversion scheme based on GPS Positive Basis 2N, a commonly used pattern search algorithm. Incorporating complete poll and complete search strategies based on GPS Positive Basis 2N into the inverse procedure greatly enhances the performance of pattern search algorithms because the two steps can effectively locate the promising areas in the solution space containing the global minima and significantly reduce the computation cost, respectively.The proposed inverse procedure was applied to nonlinear inversion of fundamental-mode Rayleigh wave dispersion curves for a near-surface shear (S)-wave velocity profile. The calculation efficiency and stability of the inversion scheme are tested on three synthetic models and a real example from a roadbed survey in Henan, China. Effects of the number of data points, the reduction of the frequency range of the considered dispersion curve, errors in P-wave velocities and density, the initial S-wave velocity profile as well as the number of layers and their thicknesses on inversion results are also investigated in the present study to further evaluate the performance of the proposed approach.Results demonstrate that pattern search algorithms applied to nonlinear inversion of high-frequency surface wave data should be considered good not only in terms of accuracy but also in terms of the computation effort due to their global and deterministic search process.     

An accurate and practical buffer allocation model for the buffer cache based on marginal gains

A new dynamic buffer allocation strategy based on the notion of marginal gains is presented for the buffer cache that is used by the operating system to store frequently accessed disk blocks in main memory, and the performance of the proposed strategy is compared with those of previous allocation strategies. In the proposed strategy, marginal gain values are predicted by exploiting functions that approximate the expected number of buffer hits per unit time. Experimental results from both trace-driven simulation and an actual implementation in the FreeBSD operating system show that the proposed strategy accurately predicts the marginal gain values for various workloads resulting in significantly improved buffer hit ratios.     

Preparation of Compound Ultrafine CeO2 by Wet-Solid-Phase Mechanochemical Modification

To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was proposed.The effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was investigated.The phase evolutions of preparation process were characterized by XRD.SEM micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized particles.The method is readily available in raw material, low in cost, simple in process, and has great potential for industrialization.The compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.     

Measured equation of invariance with linear tensor relation for three-dimensional scattering problems

The postulate of a linear tensor relation in the measured equation of invariance (MEI) is proposed for three-dimensional (3D) problems. As a result, all three components of the field vector to be solved are coupled in the MEI. Combined with the finite difference method, the present method is applied to the analysis of scattering by 3D conducting objects and results in a significant improvement in the accuracy of numerical results as compared to those obtained with an uncoupled linear relation.     

多粒度全光网中的多层联合路由

多粒度交换技术利用波带级路由以及光纤级路由,可有效降低光交叉连接器的复杂度.但多粒度交换增加了光网络的逻辑层次结构,使得网络中的路由与资源分配问题更为复杂,因此,在多粒度全光网中实现多层联合路由是提高网络性能的关键.本文对多粒度交叉连接结构进行了分析,并对多粒度全光网中的多层联合路由问题进行了研究.     

Effect of thermal treatment on ZnO substrate for epitaxial growth

ZnO is a highly efficient photon emitter, and has optical and piezoelectric properties that are attractive for a variety of applications in sensors and potentially optoelectronic devices such as emitters. Due to its identical stacking order and close lattice match to GaN, it is also being developed as a substrate material for GaN epitaxy. However, the surface finish of the ZnO is such that much of the damage induced by sawing and follow up mechanical polishing remains. We developed a thermal treatment method to eliminate surface damage on the 0 face of ZnO (0 0 0 1) to prepare it for epitaxial growth. Atomic force microscopy images of ZnO (0 0 0 1) annealed at 1050 °C for 3 h etc. show that residual scratches from mechanical polishing are removed and atomically flat, terrace-like surfaces are attained. In addition, low-temperature photoluminescence and high-resolution X-ray diffraction measurements have been employed to investigate the effect of annealing on ZnO substrates.     

高阻值Cd1-xZnxTe晶体的生长及其性能测试

通过适当的工艺措施，采用Bridgman法生长了直径为30mm的X射线及γ射线探测器级的Cd.9Zn0．1Te晶锭．测试结果表明：该晶锭结晶质量良好，位错密度低，成分均匀，杂质含量低，红外透过率和电阻率都十分接近本征Cd.9Zn0．1Te的值．并从晶体的生长特性、缺陷和杂质的角度，分析了生长高性能晶体的条件，研究了生长Cdl-xZnxTe晶体的x值与缺陷和杂质浓度之间的关系．     

Synthesis of minerals using alternative energy sources

A technology for the synthesis of synthetic minerals (using the example of spinels) using a low-temperature plasma flame is developed. The diagnostic properties of spinels are identified.     

杭-宁输气管道工程定向钻穿越设计浅析

杭州-宁波天然气输气管道工程（简称杭-宁输气管道工程）是浙江省天然气长输管网主干线之一，根据工程河流穿越众多、渠塘穿越频繁的特点，对杭-宁输气管道工程水域穿越的特点和穿越方式作了总结；重点分析了水域定向钻穿越设计及需要注意的问题，为今后浙江省天然气管网建设的水域穿越设计作了探讨。