液压系统原理图的自动布局和布线

本文研究液压系统原理图自动绘制问题,把原理图自动绘制分为布局和布线两部分.阐述了用专家系统自动布局的方法,讨论了布局规则的提取原理,并提出一种适合绘制液压系统原理图的面向目标的优化布线算法.     

液压气动元件符号图形输入系统

建立了一套计算机液压气动元件符号图形输入系统，从而解决了液压及气动系统原理图中大量元件符号的绘制问题。     

无线LED电子公告条屏的系统硬件的设计

首先叙述了基于无线传输的LED显示屏显示系统的总体方案,根据功能将系统划分为主控制模块、无线收发模块和LED显示模块3个部分,然后叙述各个模块的硬件电路设计。硬件电路重点研究了模块的技术参数和主控制、显示模块的电路,利用Protel软件进行电路原理图的绘制,实现了系统的基本功能。     

计算机绘制液压系统图

本文介绍了计算机绘制液压系统的程序,本程序是在AVTOCAD软件支持下,以GB786—76液压气动图形为基础,并根据工厂的需要增添一些图形符号构成第二次开发软件,主要用于液压和气动系统原理图计算机辅助绘图.该软件功能齐全,使用方便,便于修改、存贮和复制.有明显的经济效益.     

YK7232A磨床液压伺服控制片上系统的研究与设计

对于YK7232A磨床液压伺服控制系统由较多的分立元件构成,可靠性较低,响应速度较慢,而且故障率较高,不便于系统维护等问题.采用了EDA设计技术,将系统中大部分的分立元件以及PID控制模块,采用逻辑重构的方式集成到体积较小的FPGA芯片中,形成具有低功耗、高集成度的液压伺服片上系统.采用Verilog-HDL语言对伺服控制系统的大部分模块进行逻辑重构.着重介绍了滤波整形模块以及增量式浮点数PID控制模块的设计,经Modelsim仿真校验达到了设计的要求.并最终设计出液压伺服控制片上系统顶层原理图.     

基于模板的智能型启闭机液压系统

在分析了启闭机液压系统特点的基础上，提出了一种便于计算机处理，能概括启闭机液压系统原理图的原始拓扑模型（模板），并介绍了基于该模板的液压才机智能型辅助设计系统ＨＧＨＳＣＡＤ的体系结构和工作流程。     

液压系统动态仿真模型可视化建模技术研究

从计算机与仿真技术的发展和应用需求出发,对液压系统动态仿真模型的可视化建模技术进行了较为深入的研究,建立了一个基于图形和面向对象技术的仿真模型可视化输入环境,介绍了该环境的体系结构及设计思想,着重对液压原理图和功率键合图输入子模块的功能实现机理作了详尽的论述。     

基于Vlisp的液压布管CAD的二次开发

运用Visual Lisp语言,以AutoCAD2004为平台,开发了液压自动布管系统.通过调用参数化图库,实现了管接头的快速绘制;指定管道的起点终点后,系统自动完成液压管路的绘制,提高了设计效率,有较好的使用价值.     

带式输送机液压自动拉紧装置动态仿真

为了保障带式输送机安全稳定运行,根据带式输送机运行的非线性特征,设计一种新的带式输送机液压自动拉紧系统,给出了液压伺服系统原理图,建立了系统的动力学模型和自动控制模型,给出了系统的模糊PID控制原理图,应用matlab/smulink对液压自动拉紧系统的张力控制性能进行了分析,仿真结果表明带式输送机液压自动拉紧系统对于控制带式输送机系统的动态特性具有较好的效果.     

电梯式立体车库升降系统设计与安全研究

以电梯式立体车库为主要研究对象,介绍了电梯式立体车库的主体结构及其运行原理。通过对市面上各类立体车库升降系统的研究分析,对比各类升降系统的优缺点,确定了以液压升降为主的升降方案,设计了适用于电梯式立体车库的新型液压式升降系统,并绘制了结构示意图和液压控制系统原理图。同时对升降系统的安全性进行了研究,提出了相应的安全措施。此设计以较短的液压缸行程实现了较大的升降高度,为电梯式立体车库的升降方式提供了一种全新的解决方案。     

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.     

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.     

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.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.