关于幂级数收敛半径的一点注记

本文对幂级数的乘积级数与商级数的收敛半径的有关问题进行了讨论,更正了参考文献中的一些错误,并得到了一些有用的结论。

油田专用双速电机研制与应用

为满足油田生产的需要,通过电机变极调速原理,对原抽油机电机进行改造为油田专用双速可调电机,经过近2年的生产运行,改造后的油田专用双速可调电机成功应用于陆梁油田生产,达到了控制抽油机运转速率进行控液稳产、合理开发、科学管理油田的目的,实现了大功率高极数(双速)电动机和低速状态下温升的有效控制等技术的突破,并产生了可观的经济效益和社会效益,60口抽油井1年仅减少换泵作业量一项,就可节约操作费用210×104元。

High-order generalized screen propagator migration based on particle swarm optimization

Various migration methods have been proposed to image high-angle geological structures and media with strong lateral velocity variations; however, the problems of low precision and high computational cost remain unresolved. To describe the seismic wave propagation in media with lateral velocity variations and to image high-angle structures, we propose the generalized screen propagator based on particle swarm optimization （PSO-GSP）, for the precise fitting of the single-square-root operator. We use the 2D SEG/EAGE salt model to test the proposed PSO-GSP migration method to image the faults beneath the salt dome and compare the results to those of the conventional high-order generalized screen propagator （GSP） migration and split-step Fourier （SSF） migration. Moreover, we use 2D marine data from the South China Sea to show that the PSO-GSP migration can better image strong reflectors than conventional imaging methods.

Video Valley的虚拟漫游

在50年代彩色电视最初成形的同一个实验室里,工程师们正致力于几种数据可视化和显示技术的研究,未来某天这些技术将让PC具备看见并解释事物的能力。 David Sarnoff Research Center座落在Video Valley(新译西州南部Princeton-Rutgers技术走廊,这里还分布着Hitachi、Panasonic和Samsung等公司),它是高级数字化高清晰度电视(HDTV,high-defintion television)开发的策源地。

Exact Solutions to Nonlinear Schr(?)dinger Equation and Higher-Order Nonlinear Schr(?)dinger Equation

We study solutions of the nonlinear Schroedinger equation （NLSE） and higher-order nonlinear Sehroedinger equation （HONLSE） with variable coefficients. By considering all the higher-order effect of HONLSE as a new dependent variable, the NLSE and HONLSE can be changed into one equation. Using the generalized Lie group reduction method （CLGRM）, the abundant solutions of NLSE and HONLSE are obtained.

Atomic force microscopy study on microstructure of various ranks of coals

As a new technology, Atomil Force Microscopy （AFM） is being used in the research of microscopic structure on coal surface in recent years. By this technology, we can observe the nanoscale pore and crack shape of coal surface, and measure some structural parameters. Different metamorphic grades produce different feature of surface microscopic structure of coal. This paper analyzes the surface microscopic structure of different metamorphic grade coal by AFM. The results show that the coal surface microstructure has a trend from rough to smooth with the increasing of metamorphic grade. The low rank coals contain large or medium pores and the high rank coals contain micro pores. The values of surface morphology characteristic parameters （Sq and Sa） nonlinearly decrease with the increasing coal rank. That is, the coal surface becomes smoother during coalification.

High-Order Radial Derivatives of Harmonic Function and Gravity Anomaly

The first through ninth radial derivatives of a harmonic function and gravity anomaly are derived in this paper. These derivatives can be used in the analytical continuation application. For the downward continuation of gravity anomaly, the Taylor series approach developed in the paper is equivalent theoretically to but more efficient and storage-saving computationally than the well-known gradient operator approach. Numerical simulation shows that Taylor series expansion constructed by the derived formulas for the radial derivatives of gravity disturbance is still convergent for height up to 4 km.

Studies on TOP executive performance evaluation system of Chinese listed companies

According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices to evaluate a top executive’s performance and award performance-based stock options to them scientifically and reasonably. This thesis sets indices from the perspective of the top executive’s behaviour and results, which differs from the traditional methods performance evaluation.

Secure encryption embedded processor design for wireless sensor network application

This paper presents a new encryption embedded processor aimed at the application requirement of wireless sensor network （WSN）. The new encryption embedded processor not only offers Rivest Shamir Adlemen （RSA）, Advanced Encryption Standard （AES）, 3 Data Encryption Standard （3 DES） and Secure Hash Algorithm 1 （SHA - 1 ） security engines, but also involves a new memory encryption scheme. The new memory encryption scheme is implemented by a memory encryption cache （MEC）, which protects the confidentiality of the memory by AES encryption. The experi- ments show that the new secure design only causes 1.9% additional delay on the critical path and cuts 25.7% power consumption when the processor writes data back. The new processor balances the performance overhead, the power consumption and the security and fully meets the wireless sensor environment requirement. After physical design, the new encryption embedded processor has been successfully tape-out.

Study on coupled vibration characteristics of a cylindrical container with multiple elastic annular baffles

The coupled vibration characteristics of multiple elastic annular baffles of the same inner radius in a partially liquid-filled rigid cylindrical container were studied. The liquid domain was divided into several simple sub-domains so that the liquid velocity potential in each liquid sub-domain was of class C 1 with continuous boundary conditions. Based on the superposition principle, the general solution of the liquid velocity potential corresponding to each liquid sub-domain was obtained by means of the method of separation of variables. The coupled modes of the multiple elastic annular baffles were expressed in terms of dry-modal functions. The free surface condition, the interface conditions and coupled vibration conditions were expressed in terms of Fourier series along the liquid height and Bessel series in the radial direction, respectively. Stable and fast numerical computations were investigated by the convergence study. Excellent agreements have been achieved in the comparison of re- suits obtained by the proposed approach with those given by the finite element software ADINA. The natural frequencies and mode shapes versus the position, the inner radius and the number of the annular baffles were thoroughly discussed.

Globally generated vector bundles on a smooth quadric surface

We give the classification of globally generated vector bundles of rank 2 on a smooth quadric surface with c1(2,2)in terms of the indices of the bundles,and extend the result to arbitrary higher rank case.We also investigate their indecomposability and give the sufficient and necessary condition on numeric data of vector bundles for indecomposability.

High performance computing of DGDFT for tens of thousands of atoms using millions of cores on Sunway TaihuLight

High performance computing(HPC)is a powerful tool to accelerate the Kohn–Sham density functional theory(KS-DFT)calculations on modern heterogeneous supercomputers.Here,we describe a massively parallel implementation of discontinuous Galerkin density functional theory(DGDFT)method on the Sunway Taihu Light supercomputer.The DGDFT method uses the adaptive local basis(ALB)functions generated on-the-fly during the self-consistent field(SCF)iteration to solve the KS equations with high precision comparable to plane-wave basis set.In particular,the DGDFT method adopts a two-level parallelization strategy that deals with various types of data distribution,task scheduling,and data communication schemes,and combines with the master–slave multi-thread heterogeneous parallelism of SW26010 processor,resulting in large-scale HPC KS-DFT calculations on the Sunway Taihu Light supercomputer.We show that the DGDFT method can scale up to 8,519,680 processing cores(131,072 core groups)on the Sunway Taihu Light supercomputer for studying the electronic structures of twodimensional(2 D)metallic graphene systems that contain tens of thousands of carbon atoms.