共查询到20条相似文献,搜索用时 140 毫秒
1.
本文给出了由有限循环群出发构造的Burnside环的增广理想的基底,并讨论了它们的n次幂与n 1次幂之商,完整地给出了这类商群的结构. 相似文献
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本文较系统介绍了Glauber基本理论。分析了它的优越性,较详细地讨论了所做的各种近似,并且对某些约束条件进行了适当的修正。 相似文献
3.
断层的大地电磁响应的研究 总被引:4,自引:0,他引:4
朱仁学 《长春科技大学学报》1999,29(3):290-294
对TE极化和TM极化情况下高阻和低阻基底垂直断层进行了研究,首先从理论上对断层的TE极化的MT电磁响应进行了数学数学推导,得到了解析表达式。对四种情况进行了编程计算,得到了大量图件,然后对图件进行了详细分析,总结出了断层的MT响应的诸多特征,最后指出了如何应用于MT资料的解释中。 相似文献
4.
简要介绍了数字图书馆的发展 ,对数字图书馆的定义进行了概括 ,指出了信息资源数据库群建设的重要性和方法 ,肯定了数字图书馆的发展趋势 ,指出了数字图书馆建设是涵盖广泛学科及技术领域的漫长过程 ,提出了数字图书馆资源建设的必要性、重要作用及规范标准 ,设想了数字图书馆应当建设的一些数据库 ,拟出了国家支持建立无偿数据库的思路和行业自行建立有偿数据库的思路 相似文献
5.
王宾 《安徽理工大学学报(自然科学版)》2013,(3):34-38
在屏弃了传统的通讯单一化,或者无网络单点刷卡门禁系统结构的同时,将射频网络、GSM网络及以太网引入到了门禁系统中,形成了2级网络结构,极大的增强了系统的适应性,提高了性价比。初级网络采用资源丰富的ATMEGA128L作为主控器,次级网络由ATMEGA16L负责控制,并采用了自动请求重传机制,保证通讯的可靠性。 相似文献
6.
基于窗函数的FIR滤波器的设计 总被引:3,自引:1,他引:2
何小河 《四川理工学院学报(自然科学版)》2008,21(3)
文章主要阐述了FIR算法的基本原理,推导了其中所有的重要公式,并且对几种窗函数做了比较,阐明了加窗函数对结果的影响。在这里还给出了实现FIR算法的结构图.介绍了几种常用滤波窗函数的特点,给出了包络图和幅度响应图。在分析了各种滤波之后,我们决定选用海明窗,并且给出了滤波效果图形. 相似文献
7.
介绍了段式液晶的工作原理,并探讨了几种常用的驱动方式,同时给出了通过51单片机驱动段式液晶显示的硬件原理和驱动程序.由于实现了以软件为主的驱动方式,为51单片机在仪器仪表等需要段式液晶显示领域的应用提供了一种简单实用的解决方案. 相似文献
8.
软件测试决定了软件产品的质量及市场占有率,直接关系到软件企业的经济效益。文章从软件结构和软件功能这两个方面对软件的测试了整个过程进行了研究,同时论述了软件开发过程中的相关问题。 相似文献
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10.
张庆政 《西南民族学院学报(自然科学版)》1995,21(2):132-133,137
给出了具有半序结构的Hausdorff空间X上集值增算子的不动点定理,推广了文献〔1〕中定理1,减弱了其对空间X的要求,如果X仅为半序集,给出了X上单值增算子的不动点定理,改进了文献〔1,2,3〕中的相应结果。 相似文献
11.
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. 相似文献
12.
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. 相似文献
13.
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。 相似文献
14.
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. 相似文献
15.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
16.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
17.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献
18.
Michael Springborg 《华南师范大学学报(自然科学版)》2014,(6):136
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the 相似文献
19.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献