近距离红外无线数据通信技术研究

近年来无线数据通信技术不断发展,红外无线技术也得到了较大的进步,该技术具有低耗、电磁干扰较小、价格低廉、保密性强等优点,在我国属于应用非常广泛的无线通讯技术.近年来近距离无线通信得到了社会各界的广泛重视,在编码调制技术逐渐成熟的环境中,红外通信技术的应用频率逐渐增高,成为移动设备、办公设备、手持设备进行通信的重要方法.该文根据红外通信技术原理进行分析,重点研究了室内红外传输方式的性能,并且对应用限制进行了介绍,探讨了红外无线局域网架设的方法,希望为我国无线通信技术的发展做出贡献.     

关于无线网络及发展前景探讨

近年来，随着个人数据通信的发展，功能强大的便携式数据终端以及多媒体终端得到了广泛的应用。为了实现使用户能够在任何时间、任何地点均能实现数据通信的目标，要求传统的计算机网络由有线向无线、由固定向移动、由单一业务向多媒体业务演进，由此无线网络技术得到了快速的发展。在互联网应用快速普及的今天，无线网络技术已成为通信发展的重要新兴领域。无线技术使得人们使用品种广泛的设备在世界任何位置访问数据的愿望成为可能。     

浅谈无线网络

近年来,随着个人数据通信的发展,功能强大的便携式数据终端以及多媒体终端得到了广泛的应用。为了实现使用户能够在任何时间、任何地点均能实现数据通信的目标,要求传统的计算机网络由有线向无线、由固定向移动、由单一业务向多媒体业务演进,由此无线网络技术得到了快速的发展。在互联网应用快速普及的今天,无线网络技术已成为通信发展的重要新兴领域。无线技术使得人们使用品种广泛的设备在世界任何位置访问数据的愿望成为可能。     

在Novell网络中实现对等数据通信

在Ｎｏｖｅｌｌ网络中，利用Ｎｅｔｗａｒｅ的ＩＰＸ协议实现对等数据通信，这种数据通信具有实时性好、可靠性高、效率高等优点．在数据通信设计中。设计了若干重要的数据结构和Ｃ语言程序．     

感应无线数据通信技术研究

感应无线数据通信是利用电磁感应原理,实现数据通信的新型通信方式.感应无线数据通信既有别于有线数据通信,又不同于无线数据通信,在工业生产中有着广泛的应用前景.本文探讨了感应无线数据通信的原理和特点,阐述了利用相关技术抑制同频干扰噪声的方法,给出了感应无线数据通信的硬件电路.     

数据通信网络维护与网络安全问题的探讨

在全球信息技术不断发展的环境中,通信与网络的基本内容也得到了不断的丰富与拓展,特别是在近十几年的时间内,随着互联网技术的广泛普及与渗透,通信与网络的内涵更是获得了加大程度的填充。不管是从基本的理论感念上,还是从实际的应用来看,数据通信与网络都得到了长足的发展,而通信无处不在、信息无处不在以及网络无处不在的理想化目标正在逐步的实现。但与此同时,在数据通信与网络不断发展的条件下,要保证数据通信的安全性与准确性也成为数据通信与网络技术发展的重要研究课题,通过网络的安全来加强对数据通信网络的维护已经成为必然之举。因而,本文主要围绕数据网络通信维护与网络安全的问题进行相应的探讨。     

简单介绍数据通信系统的设计

随着计算机的广泛应用,特别是Internet的出现与发展,人们对信息技术的需求和依赖越来越大,人们对数据业务的需求日益增加,也就促进了数据通信的快速发展。数据通信是通信技术和计算机技术相结合而产生的一种新的通信方式。本设计主要设计一个完整的数据通信系统,包括各个通信模块构成的总体完整数据通信系统框图、各模块的设备参数、网络结构、通信协议、软件技术的基本原理和硬件相应的设备参数。     

浅析红外通信技术在数据通讯中的作用

所谓红外通讯技术即利用红外线来传递数据，是无线通讯技术的一种。红外通讯技术具有简单易用并且成本较低，因而被广泛应用于小型移动设备互换数据和电器设备的控制中。同样，在基于单片机应用豕统中，红外通信技术也在其中起到了非常重要的作用。本文中笔者将对红外通信技术在数据通讯中的重要作用展开论述。     

浅谈计算机网络与数据通信的发展

数据通信是通信技术和计算机技术相结合而产生的一种新的通信方式,未来通信行业发展必将以数据通信为主要方式,推动了整个产业结构的优化发展,它实现了计算机与计算机之间,计算机与终端之间的传递。由于不同业务需求的变化及通信技术的发展使得数据通信经过了不同的发展历程。本文主要探讨了计算机网络与数据通信的发展,分析了数据通信的应用,阐述了计算机网络以及数据通信的发展前景。     

数控系统的数据通信

数据通信是数控设备程序和参数输入输出的主要方式之一，随着制造业信息化的发展，其应用越来越广泛，并直接关系到数控设备的使用效能，明确数据通信的相关概念和实际操作，有利于提高数控设备的应用水平。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-