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1.
数字水准仪的一体化检测   总被引:1,自引:0,他引:1  
梁菲  曹智翔 《科技信息》2009,(33):T0149-T0149,T0148
数字水准仪的出现代表了精密水准测量的一个巨大进步。结合本次工程,论述了数字水准仪的发展历程,详细介绍了数字水准仪的应用原理,在工程中通过利用数字水准仪进行路面厚度测量工程的实践,验证了数字水准仪的具有精度高、测量速度快等一系列优点,并提住了在使用数字水准仪应注意的事项。  相似文献   

2.
采用了一种基于数字信号处理器(DSP)的开关磁阻电机控制器,利用DSP的运算能力强、速度快的特点,简化了系统硬件,实现了双闭环控制。并用实验的方法进一步验证了所提方案的正确性。  相似文献   

3.
本文论述了单片机在高精度微型电机高速系统中的应用,通过稳态数字修正的方式提高了模拟调速系统的精度,该系统工作可靠,适用于仪器仪表的高精度化,智能化和产品化的场合。  相似文献   

4.
本文论述了单片机在高精度微型电机调速系统中的应用,通过稳态数字修正的方式提高了模拟调速系统的精度.该系统工作可靠,适用于仪器仪表的高精度化,智能化和产品化的场合  相似文献   

5.
研究了用位总线微机构成的液压阀控马达速度闭环数字控制系统.该系统采用转速数字检测取代了测速发电机加A/D的方案,实现了数字反馈.IBM—PC微机与位总线的互连,实现了系统的在线监控.系统具有操作方便、工作可靠和良好的性能价格比等特点.与测速发电机相比,数字测速方法检测精度高.通过实验研究,对数字PI控制器参数进行了合理匹配,使系统获得了良好的控制效果。  相似文献   

6.
提出了将混沌编码器取代传统Turbo码中递归系统卷积编码器的方案,实现了新型的基于非线性滤波器的混沌数字编译码系统,该方案通过MAP算法的多次循环迭代,使得系统的误码率大大降低,从而解决了传统直接混沌译码抗噪声干扰性能较差的问题,计算机的仿真结果证实了该方案是可行的。  相似文献   

7.
分析了图书馆数字资源在远程教育中的重要性,探讨了保障图书馆数字资源在远程教育中得到充分应用的策略,提出了图书馆数字资源的保护方案,  相似文献   

8.
着重分析了在电子数字计数器安装中计数脉冲信呈源的脉冲抖动问题,给出了正确获得不失夫计数脉冲信号的方法。  相似文献   

9.
分析了当前高校图书馆数字资源整合研究的现状,结合重庆大学图书馆的实践,提出了数字资源整合方案。  相似文献   

10.
本文在实验的基础上,探讨了实现一种价廉的MCS-51单片机控制的数字式闭环直流调速系统。重点对数字系统的硬件和软件进行了设计。文中还给出了试验特性曲线及数字仿真结果。  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 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   

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 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   

15.
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   

16.
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   

17.
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.  相似文献   

18.
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   

19.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

20.
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   

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