用复杂可编程逻辑器件（CPLD）实现的数字钟控系统

以Lattice半导体公司的ispLSI1032E-70PLCC84为典型器件,ISP Synario System 3.0为编程软件,介绍了利用在系统高密度可编程逻辑器件构成数字钟控系统的基本方法。     

基于ISP器件可扩量程的数字频率计的设计

采用Lattice公司的可编程逻辑器件ispLSI 1016的设计出可扩量程的数字频率计,给出了设计过程及部分模块的电路结构。     

基于ISP器件的可编程倍频鉴相逻辑电路的设计

用一片ispLSI1032设计了一种任意倍频系数的可编程倍频鉴相逻辑电路．该倍频鉴相电路抗干扰能力强，稳定可靠，特别适应于实现高精度位置和速度反馈的数控系统。     

用ispPAC20和isp1032实现可编程计数式ADC

ispPAC20可编程模拟器件内含运算放大器、比较器、8位D／A转换器，通过编程可实现放大器、有源滤波器、方波发生器等模拟电路单元的设计。本文利用isppac20的有效资源，将其与CPLDisp1032结合实现了可编程计数式ADC的设计。实验结果表明可编程计数式ADC可方便的嵌入到电子系统中。可编程计数式ADC是可编程模拟器件和可编程逻辑器件典型应用之一。文中给出的设计方案合理，测试指标符合要求，有很好的应用价值。     

可编程逻辑器件的发展概述

数字集成电路经历了从小规模集成电路(SSI)，中规模集成电路(MSI)，大规模集成电路(LSI)，和超大规模集成电路(VLSI)的发展过程。PLD器件由早期的可编程只读存储器、可编程逻辑阵列、可编程阵列逻辑、通用阵列逻辑发展到复杂可编程逻辑器件和现场可编程门阵列。PLD器件使数字系统的设计更加便利和高效，FPGA／CPLD和ASIC融合的趋势也越来越明显。     

可编程逻辑器件及在教学实验中的应用前景

本文简明介绍可编程逻辑器件的结构、特点，阐明了可编程逻辑器件与定制器件相比较所具有的优点，以及在教学实验中的应用前景。     

可编程逻辑器件在教学实践中的应用

本文分析了可编程逻辑器件的特点及在教学实践中的应用优势，并介绍了可编程逻辑器件在教学实践中的应用，并给出了一个基于可编程逻辑器件的课程设计实例．     

用CPLD实现的FIR滤波器

介绍一种在系统可编程逻辑器件（CPLD）设计FIR滤波器的方案,该方案采用Lattice公司ispLSI CPLD芯片,并利用窗函数法实现线性FIR数字滤波器硬件电路的方法,从而提高了FIR数字滤波器的实时性,设计一个十阶低FIR滤波器,并通过软件程序进行仿真验证和硬件实测,结果表明,此电路工作正确可靠,实时性好,灵活性强,能满足设计要求。     

用可编程逻辑器件设计语言“ABEL”开发GAL器件

可编程逻辑器件ＰＬＤ是七十年代发展起来的新型逻辑器件，近几年发展十分迅速。而ＰＬＤ中的一种－ＣＡＬ器件由于其性能及价格优良，在我国应用发展更是日益广泛。本文通过几个实例简要叙述怎样用可编程逻辑器件语言－“ＡＢＥＬ”开发可编程逻辑器件ＧＡＬ。     

定时控制电器的可编程逻辑器件的实现

本文介绍利用可编程逻辑器件FPGA,设计一种器件少、可靠性高、实用性强的电器定时控制电器,详细阐述了其硬件原理、逻辑实现及可编程逻辑器件的设计思路.     

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-