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1.
何利亚  王鹏飞 《科技信息》2007,(24):302-304
CASIO系列可编程计算器在道路与桥梁施工测量工作中,只需输入里程桩号,即可提供线路任意点坐标、高程,并解决了缓和曲线段以知线外任意点坐标,求对应线路里程的难点问题。  相似文献   

2.
宁瑜  王丽莉 《甘肃科技》2011,27(19):54-55
在工程测量及设计工作中,以往计算两条直线交点坐标的方法,需要列出两条直线的数学方程式,或者求出直线的斜率,才能应用相应公式计算出两条直线交点的坐标,计算比较复杂,某些情况下还会出现数学错误而得不出结果。本研究推导出了直接利用直线上点的坐标数据计算两条直线交点坐标的通用公式,可以用来计算任意两条相交直线交点的坐标。  相似文献   

3.
公路三维视距的检验方法   总被引:1,自引:0,他引:1  
为了精确计算公路在三维空间中的实际视距,在公路行车视距的基础上,结合道路平、纵、横的道路线形,提出了三维计算模型和三维视距计算模型;通过检验三维视线上任意一点与其对应道路上点的高程关系,判断路面或路侧是否对视线造成遮挡,最后提出了三维视距检验的流程.研究结果表明:该模型和算法简洁直观,易于实现;在设计中,能及时表现行车视距的不利因素,为改进线形设计提供帮助;为自动检验三维视距提供了实现手段,同时也为利用三维视距进行安全性评价提供了技术支撑.  相似文献   

4.
直线Bresenham生成改进算法研究   总被引:1,自引:0,他引:1  
为了在数字设备上高质量地快速绘制任意方向的直线,采用了Bresenham直线生成算法中的误差参数控制方法,对误差进行补偿控制;采用递归式计算不做浮点运算,提高了运算速度;采用对称分析方法,简化了任意方向直线Bresenham程序代码设计。通过Bresenham直线生成算法研究,提出了一个完整的任意方向直线生成算法和程序。  相似文献   

5.
本文利用可编程计算器的坐标计算程序、坐标转换公式,可方便快速的确定线路上任意点的桩号、坐标以及任意点至线路中线的距离。  相似文献   

6.
为解决各种道路条件下中央分隔带防眩植物高度设置统一而引发的一些路段防眩效果较差的问题,基于道路平纵横线形组合的不同特征,考虑超高、曲率和纵坡等不同因素单独或组合的影响,根据车型选择最不利位置作为特征点;利用空间几何和平面线形理论,研究不同路段任意桩号中央分隔带防眩植物高度的计算方法;利用计算机建立仿真模型,求解各桩号防眩植物的有效高度。研究结果表明:不同的平纵组合,最不利特征点的位置不同;不同桩号的中央分隔带防眩植物的高度也不同;可为改进道路绿化设计提供帮助,为交通安全评价提供技术支撑。  相似文献   

7.
公路空间视距计算方法与检测技术   总被引:3,自引:0,他引:3  
为了精确计算公路在三维空间中的实际视距,提出了空间视距的概念,通过延伸应用空间两点通视原理,建立了空间视距计算和分析的数学模型。基于计算机仿真技术开发出对空间视距的实时检测技术,通过将设计视距、运行视距和空间视距3种视距对比分析,给出了发现视距不足的方法。与早前的视距计算方法和研究相比,该方法对正常路面、行车道空间视距计算准确,能够计算和分析公路路侧附属设施对视距的影响,为公路几何设计和安全评价提供了依据。  相似文献   

8.
本文从n元酸溶液的质予传递体系出发,导出具下面形式的统一酸度方程式 并证明国内外现行分析化学教材及文献中对特定元数弱酸溶液建立的酸度方程式,不过是上面统一方程式在n取某确定值时的特例。本文主要是提出了统一酸度方程式系数的矩阵表现形式,并讨论了该方程的计算机求解.计算結果表明,本文建立的统一酸度方程式是正确的,且尤为适合用计算机处理任意元数酸溶液PH值的求解问题。  相似文献   

9.
本文讨论了采用直线形靠模机构磨削双曲线刃口刀片的若干问题,分析了所磨削的切料机刀片的刃口曲线方程,建立了直线靠模的磨削运动方程式,并进行了磨削误差的分析计算。  相似文献   

10.
通过对空间任意直线和平面定位问题的研究,推导出了一种用解析法计算和确定空间任意直线和平面定位角度的运算公式,并对其在机械工程中的应用进行了初步的探讨  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.
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.  相似文献   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
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.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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