触发器的典型应用

为了提高触发器的使用效率,对触发器的原理、运行机制和作用进行了剖析、分解,并对其作用进行归纳,结合大量的实践与应用,由此得出数据触发类型主要有：不同数据库系统之间的数据转换、数据的合并和数据间的相关完整性的实现。最后把触发器的应用归纳为三类,并给出了它们的模型和使用中的注意事项。     

基于异步计数器的实验探究

计数器是数字系统中必不可少的组成部分,和同步计数器不同,组成异步计数器的触发器不是共用同一个时钟源,所以触发器的翻转是异步的。该文对异步计数器的逻辑功能以及异步计数器的级联扩展进行探讨,旨在使学生掌握应用异步计数器进行电路设计。     

触发器在实验管理系统中的设计与应用

在设计开发实验管理系统过程中,我们设计并应用了数据库管理系统提供的触发器机制,使用DML类触发器实现了级联更新以及保证数据完整性的功能,最后总结了目前触发器机制的几个潜在应用。     

触发器在sybase数据库中的应用

讨论了在大型数据库中，利用触发器来实现在不同数据结构的表与表之间的数据一致性和实时性。为了说明触发器的用法和作用，本文给出了触发器在SYBASE数据库中的应用示例。     

基于网络演算的确定性以太网性能评估

采用网络演算理论研究复杂拓扑下确定性以太网的性能,提出级联拓扑和双通道级联拓扑,应用反卷积理论建立两种复杂拓扑下的网络演算模型,并建立相应仿真模型.最后将仿真结果和理论结果进行比较,并且根据不同大小的时间触发数据、速率受限数据和尽力而为数据分别在端到端时延、吞吐量以及丢包率三方面进行性能分析.分析结果表明:理论结果与仿真结果相符合,说明确定性以太网具有良好的确定性和实时性,且在双通道级联拓扑下具有很好的容错能力.     

图像相似性计算的级联小波变换

研究图像不同幅度局部(子图像)小波变换之间的关系,分析这种关系下的图像相似性.首先用小波矩阵表示推导子图像小波变换之间的级联关系,在此基础上研究基于级联小波变换的线性相似性.最后以特定类型的医学图像为对象,研究子图像之间和k 规格小波相似性测度,并讨论相应的相似性测度算法.数值实验结果表明,CT、MRI图像中相邻子图像之间具有很高的线性相似性.     

离心级联全分离因子的实验数据分析

在离心级联分离多组分稳定同位素过程中,找出组分间的全分离因子同它们的相对分子质量差之间存在的确定性关系,有利于级联的分离计算和实验研究。建立了实验数据可靠性分析原则,确定了符合实验条件的数据;得到在定常态下短离心级联中,任意组分间的全分离因子与其组分间的相对分子质量之差存在指数关系。应用所建立的级联全分离因子关系式,对文献中发表的离心级联分离稳定同位素的实验数据进行了分析研究和补全工作。     

一种基于级联滤波的手眼在线标定方法

在机器人末端关节处安装线结构光传感器可实现物体表面的非接触测量,针对该结构光测量机器人系统中的手眼标定问题,提出了一种基于级联滤波的在线标定方法.与以往先采集数据然后标定的离线方式不同,该方法在采集数据的同时可对手眼关系进行递归估计.首先对齐次标定方程AX=XB解耦展开,将展开后的子方程改写成状态空间模型,完成手眼关系级联滤波模型的建立.然后根据级联模型中子模型属性的不同,选择最适合的滤波方法,应用粒子滤波迭代估计手眼关系的旋转部分,用卡尔曼滤波实现平移向量的递推估计.实验表明了该方法的有效性,满足实际工程应用要求.     

电能计量系统中数据库触发器的设计

以电能计量系统为应用背景,分析了采用功能强弱不同的数据库管理系统之间应用软件的设计差别,给出了一种以减少应用软件开发工作量及提高其运行效率为目的的数据库设计思路.设计触发器时,重点考虑存放实时与历史的电能数据及故障信息,并反映计量点的状态转移情况.     

数据同步中差异数据捕获的设计与实现

综合触发器和影子表法进行数据库变化的捕捉跟踪过程是由使用触发器来定位变化的记录、使用影子表跟踪相应记录的变化、在关系映射索引下进行差异记录的异构运算等步骤实现。综合法在传输数据变化时完成异构数据结构的转化,实现异构数据的应用级同步,为日益增多的数据库应用同步提供一个的解决实现。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that