首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
为了提高软件开发的有效性和正确性,提出了一种基于公理设计的构件设计与优化新方法,详细给出了该方法的设计和实现过程.在此基础上,以调度构件的开发作为研究实例,分别对按照公理设计和传统方法得到的两种设计方案进行了设计、分析、比较和优化,验证了该方法在软件开发方面的有效性和正确性.  相似文献   

2.
戴军 《科技信息》2009,(27):I0090-I0090
介绍了大功率柴油机连杆设计的方法和原则。通过对连杆静力和动力的综合分析,解释了连杆设计中的关键问题,为大功率柴油机的连杆设计提供了一种实用的设计方法。  相似文献   

3.
内燃机的活塞设计   总被引:1,自引:0,他引:1  
戴军 《科技信息》2009,(33):114-114,133
介绍了内燃机活塞设计的方法和原则。通过对温度场计算和温度应力、机械应力的计算以及二者叠加的综合应力的分析,解释了活塞设计中的关键问题,为内燃机的活塞设计提供了一种实用的设计方法。  相似文献   

4.
戴军 《科技信息》2009,(31):105-105,130
介绍了大功率柴油机曲轴设计的方法和原则。通过对静力和动力的综合分析,解释了曲轴设计中的关键问题,为大功率柴油机的曲轴设计提供了一种实用的设计方法。  相似文献   

5.
提出一个支持工程图档设计过程的设计事务管理模型,并详细介绍了设计过程管理组件的安全管理方法和日志管理方法的设计与实现。  相似文献   

6.
通过对工业设计专业基础课程的设计素描与传统素描进行的比较,分析了对于工业设计专业设计素描的重要性,并从设计素描的教学实践中归纳和总结了关于设计素描教学的一些心得和方法,包括:结构素描、设计素描中的光影、关于质感和细部表现等内容。  相似文献   

7.
本文利用软件模块化结构设计的优点,对波纹管元件强度和性能计算、各类型膨胀节的结构设计,典型管线的膨胀节补偿设计等提出了计算机设计软件的模块化设计方法,并对软件系统的结构、组成和功能进行了论述。  相似文献   

8.
齿轮机构两种设计方法的对比设计研究   总被引:1,自引:0,他引:1  
通过对齿轮机构类零件的一次性机械的设计方法的研究,并按常规方法和一次性机械的设计方法对齿轮机构的样件分别进行了设计.通过对比结果可知,一次性机械的设计方法能够有效地减小机械零件的体积.在满足传动要求的前提下,用一次性机械的设计方法,可以得到传动机构体积的最小极限.  相似文献   

9.
非线性系统的递推设计   总被引:1,自引:0,他引:1  
对非线性系统的递推设计方法进行综述,包括反演设计、前推设计和交替设计,对该类方法的某些重要的概念和思想进行了阐述,指出了未来的主要研究方向,期望对这一领域的理论和应用研究有一定的辅助作用。  相似文献   

10.
从推导与分布类型无关的可靠度下限引出概率设计方程 ,通过概率设计方程可实现用传统设计方法解决可靠性设计问题。为建立概率设计方程绘制了可靠度下限和安全系数间的关系曲线Rmin -n 。通过实例说明了用概率设计方程解决可靠性设计问题的方法  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.
何延凌 《科技信息》2008,(4):258-258
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.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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   

16.
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   

17.
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.  相似文献   

18.
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   

19.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号