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1.
船舶在浅水中航行下沉量的计算方法   总被引:3,自引:1,他引:3  
针对大型船舶在浅水域航行时的安全问题,讨论了影响富余水深的因素之一,即船体下沉量的计算问题.收集了多年来国际上应用比较广泛的多种计算方法,用不同的代表船型对各种船速下的浅水航行下沉量进行了计算,并对各种计算方法的适用范围及其误差进行了分析.计算可知:在船速相同时,同一种船型,用不同的公式进行计算的差别是很大的,特别是在船速大于8kn时,其差别随着船速的提高而越来越大.在分析的基础上,对于开敞的浅水水域,建议采用既安全又合理的Huuska(1976)计算公式.  相似文献   

2.
给出了两个数值积分中的对偶公式,通过数值例子说明了它的应用。  相似文献   

3.
两个新的数论函数的均值   总被引:2,自引:0,他引:2  
引入了两个新的数论函数,用Perron公式和解析方法研究了这两个函数的均值性质,并给出了两个渐近公式。  相似文献   

4.
网络系统中的公式表达方法研究   总被引:2,自引:0,他引:2  
为了探讨网络系统中的公式表达,提出了一种基于XML(eXtensible Markup Language)的公式标记语言FML(Formula Markup Language).首先分析了FML与网络系统的关系以及FML与MathML的联系和区别,阐述了、ML和MathML并不适合于网络上的传输应用,而且不能作为成熟的规范指导实际应用;然后描述了FML语法,阐述了用FML来表达公式的实现技术,提出了在网络系统中解析和再现FML的工具FML Viewer.探讨FML及其应用,对于XML的研究,具有一定的理论和应用价值.  相似文献   

5.
运用文献[1]的结果建立了如下的渐进展开式:n∫π/20sinnxdx~π2∞i=0aini其中,al由下面的递推公式所决定:li=0aibl-i=(-1)l1/2(1/2-1)…(1/2-l+1)l!,a0=1,l=1,2,3式中:b0=1,b1=a1,bi+1=a1+i1!a2+i(i-1)2!a3+…+i(i-1)…(i-i+2)(i-1)!ai+i!i!ai+1,i>1这个新递推公式的作用是简化了系数计算的复杂性。此外,还给出了有关的Walis公式渐进性的应用。  相似文献   

6.
公式输入技术是指将公式或方程组作为一个输入量,以类似于输入数值一样的方式输入计算机,然后由计算机对其求解的技术,这一技术在计算机软件开发方面具有广阔的应用前景,可大幅度提高软件通用性和易用性,本文阐述了公式输入技术的原理,并利用公式输入技术开发出“:数据处理与数值计算”软件1.0,使大量科学与工程的计算问题在利用计算机进行求解时避免编程,从而缓解大量非计算机类科技工作者面临的编程难的问题。  相似文献   

7.
运用Gauss型求积公式解决奇性积分时,需求解含τi(i=0,1,2,…)通项的奇性积分。给出了一类含奇性核  ,  ,  的积分公式,可具体应用于计算含源空间的电场、磁场、引力场等的场强以及求解活动边界的杂质扩散等问题。  相似文献   

8.
本文证明了一对反演公式,并利用此公式结合Heine变换给出了著名的Rogers公式的一个新证明。  相似文献   

9.
谈Joshi水平井产量公式   总被引:2,自引:0,他引:2  
认为Joshi在推导水平井的产量公式时,把水平井的流动视做向一个点汇的垂直流动与向一与水平井等长的垂直裂缝的水平流动的代数相加,这种简化处理是不对的,物理解释是牵强的,所给的水平井产量公式是错误的,文中在保证地层内具有稳定流动的基础上,利用保角变换对顶底不渗透油藏中心有一口水平井的产量公式进行了重新推导,给出了水平井产量公式的修正公式,并且利用等值渗流阻力法进行了解释。  相似文献   

10.
本文研究了广义Dedekind和S(h,p,x)均值的算术性质,给出了一个有趣的重要的均值公式从而推广了当k=p时Dedekind和的均值公式。  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   

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