A mathematical model for solid liquid and mass transfer coupling and numerical simulation for hydraulic fracture in rock salt

Thehydraulicfracturingtechniqueiswidelyused intheoilengineering,naturalgasexploiting,under groundheatextractingandothermineralresources mining,etc.withwelldevelopedhydraulicfracture modelsforordinaryrocks[1—3].Inthefieldofsolu tionminingofsaltdeposit,thistechniqueisusedto producefracturealongtheplanelayerofthedeposit,thustoconnecttheinjectionandtargetwells[4,5].However,duetothespecialphysicalandmechanical characteristicsofrocksalt,executinghydraulicfrac tureinrocksaltdepositisdifferentfromtha…     

ME4ET:一个基于EDOC ER模型的模型转换工具

模型驱动体系结构（MDA）是一个以模型和元数据为中心的软件体系结构．在MDA体系中，抽象模型是软件开发的主要产品．与传统的软件开发过程相比，模型转换，特别是平台无关模型和平台相关模型之间的转换，在MDA体系中具有重要作用．模型转换需要自动化的模型转换工具的支持以减少软件开发的成本．介绍一个MDA模型转换工具——ME4ET．陔上具支持EDOC ER模型的建模，并支持将EDOC ER模型自动转换为数据库平台和EJB平台上具体的实现，主要介绍ME4ET工具的模型转换规则和算法．     

一种基于Agent的服务质量管理框架

为了更好地满足应用的服务质量需求，应建立一种结构良好的服务质量管理框架，以便进行服务质量协商和资源管理．根据服务质量的结构、目标以及Agent的特性，提出了一种基于Agent的服务质量管理框架．首先，介绍了框架的构成，给出了服务质量的定义和各层参数的映射机制．其次，介绍了框架的核心部分“基于Agent的服务质量管理站”，说明了站中各种静态、移动Agent的作用和相互关系．最后，给出了基于Agent端到端的服务质量协商过程。     

Rs测试方法的研究与进展

介绍了国内采用蓝宝石介质谐振器法测试Rs的几种不同的结构,该方法由低损耗高介电常数的蓝宝石构成,工作在TE011 δ谐振模式的介质谐振器,在温度为77K时,利用它对高温超导薄膜的微波表面电阻Rs进行测试。并且对目前国际和国内正在制定的Rs测试标准进行了讨论。     

A Novel Digital Audio Watermarking Scheme in the Wavelet Domain

We present a novel quantization-based digital audio watermarking scheme in wavelet domain. By quantizing a host audio‘s wavelet coefficients (Integer Lifting Wavelet Transform ) and utilizing the characteristics of human auditory system ( HAS), the gray image is embedded using our watermarking method. Experimental results show that the proposed watermarking scheme is inaudible and robust against various signal processing such as noising adding, lossy compression, low pass filtering, re-sampling, and re-quantifying.     

Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

Since the 1990s, the papers and data involved withthe South China Sea (SCS) have been emerging in largenumbers in the world as people pay more attention to thepaleoceanography of the SCS. There have been more than100 cores mentioned in papers containing p…     

Modulation of low-frequency oscillations in GaAs MESFETs’ channel current by sidegating bias

Low-frequency oscillations in channel current are usually observed when measuring the GaAs MESFET‘s output characteristics. This paper studies the oscillations by testing the MESFET‘s output characteristics under different sidegate bias conditions. It is shown that the low-frequency oscillations of channel current are directly related to the sidegate bias. In other words, the sidegate bias can modulate the oscillations. Whether the sidegate bias varies positively or negatively, there will inevitably be a threshold voltage after which the low-frequency oscillations disappear. The observation is strongly dependent upon the peculiarities of channel-substrate (C-S) junction and impact ionization of traps-EL2 under high field. This conclusion is of particular pertinence to the design of low-noise GaAs IC‘s.     

垂直主振系冲击消振运动过程分析及仿真研究

提出一种垂直主振系冲击消振力学模型，在此基础上对该模型的典型运动过程进行了定性分析，并使用MATLAB的Simulink组件建立了仿真模型，对系统的运动性状进行的初步研究，为以后的相关理论研究打下了一定基础。     

二维非线性Schr(o)dinger方程平衡解的稳定性分析

讨论了非线性Schrdinger方程:i(eu)/(et)=-Δu-λ|u|2u-(1 iα)u,α≠0,λ∈R.平衡解的稳定性,并应用行波解的方法证明了:当α＞0时相应的平衡解是不稳定的; 当α＜0时,相应的平衡解是渐近稳定的.     

Behavior of MC3T3-E1 Osteoblast Cultured on Chitosan Modified with Polyvinylpyrrolidone

The physical and chemical properties of four kinds of modified chitosan materials made by blending chitosan with polyvinylpyrrolidone （PVP） were investigated. All four of these modified chitosan materials were hydrophilic with water contact angles ranging from 59°to 69°. Fourier transform-infrared spectra of the modified materials showed a new band at 1288 cm^-1, implying formation of a surface physical interpenetrating network structure. Enzyme linked immunosorbent assay results indicated that much less fibronectin was adsorbed on the modified materials than on only chitosan. The viability of MC3T3-E1 osteoblasts cultured on the materials was assessed by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl- 2H-tetrazolium bromide assay. The results show that adding PVP10000 into the chitosan promotes adhesion of MC3T3-E1 osteoblasts on the modified materials, but has no effect on cell growth and proliferation; while adding PVP40000 reduces cell adhesion, growth, and proliferation. The results suggest that the increased hydrophilicity of the material surface does not always improve its biocompatibility, which will influence the selection and design of biomaterials.