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1.
微机电系统将对引信的发展提供其它技术不可比拟的技术支撑。该文论述了基于MEMS引信固态安全系统的概念及作用原理;针对可应用引于信安全系统的硅微压阻式加速度传感器,用有限元法计算了不同厚度悬壁梁结构在10000g加速度作用下的应力分布、固有频率,设计了力敏电阻电桥结构,并计算了传感器的灵敏度。最后介绍了压阻式悬壁梁结构的加传感器制作工艺。  相似文献   

2.
轮辐式三维加速度传感器弹性元件优化设计   总被引:1,自引:2,他引:1  
介绍了一种新型非径向三梁轮辐式三维加速度传感器的弹性元件及其结构优化设计方法。三梁结构可提高传感器的灵敏度、标定精度,改善了径向效应。运用多变量多目标优化方法及复合形法,在保证灵敏度和固有频率这两项主要性能指标的前提下对弹性元件进行结构优化,得到应变梁截面的最佳尺寸。  相似文献   

3.
高gn值悬臂梁式硅微加速度传感器的结构设计   总被引:1,自引:0,他引:1  
针对高冲击加速度测量,分别就硅微加速度传感器等载面和变载面悬臂枯不同结构尺寸下的应力状及固有频率进行了有限元数值模拟;对等截面和变截面悬臂梁结构的灵敏度进行了分析比较和数值计算,结果都说明了采用变截面悬臂梁结构,灵敏度可提高近30%;对选择的变截面悬臂梁结构的加速度传感器其量程为10000gn,有足够的抗过载能力,且横向灵敏度足够小。  相似文献   

4.
四梁式扭矩传感器的设计与优化   总被引:1,自引:0,他引:1  
为了解决复合振动攻丝研究中的扭矩和轴向力测量问题,设计了一种基于电阻应变的四梁式扭矩传感器。四梁为两端固支结构,均匀分布在半径为R的圆周上,可以测量扭矩和轴向力。为了提高传感器性能,对弹性元件进行了受力分析,以灵敏度为优化目标函数,建立了数学模型,采用Matlab优化工具箱,对传感器的结构进行优化。该传感器工作在振动条件下,为了使传感器的固有频率避开振动攻丝机的工作频率,防止产生共振现象,采用有限元分析软件Ansys对传感器的模态进行了分析,得出传感器的各阶振型及固有频率。  相似文献   

5.
提出了一种跑道型谐振腔与固支梁相结合的新型加速度传感器结构.采用FDTD法分析了环形微环谐振腔和跑道型微环谐振腔的光谱特性,得出具有高值的跑道型微环谐振器更适用于作传感器件,利用输出光谱在加速度作用下产生漂移的特性测得了系统的加速度值.仿真结果表明:加速度值在0~50 范围内,系统的灵敏度可达到47.7 pm/ ,并且固支梁的厚度是影响系统灵敏度的重要因素.该结构为制备高灵敏度、低成本的微型加速度传感器提供了理论基础.  相似文献   

6.
介绍了一种新型的基于陶瓷基片加工工艺的π形梁15 000 m/s2厚膜压阻式加速度传感器.在加工过程中采用厚膜工艺与梁加工成型工艺,从而保证了梁结构的完整性.分析了该传感器的结构参数和灵敏度,同时介绍了其工艺流程及封装后的测试结果.基片尺寸为15 mm×6 mm×1 mm,其中敏感质量块尺寸为6 m×6 mm×1 mm,梁尺寸为3 mm×6 mm×0.3 mm.经初步测试,在采用12 V电源供电时灵敏度为0.002 4mVs2/m左右,响应频率为1.29 kHz.  相似文献   

7.
通过冲击试验得到了纵向安装压力传感器的冲击响应规律,在激波管中同时加载冲击波压力与瞬态高冲击研究了压力传感器在冲击作用下冲击寄生响应峰值与冲击加速度的关系以及冲击寄生响应脉宽与结构固有频率的关系,最后在实际爆炸场中进行了验证试验。结果表明,压力传感器的加速度灵敏度近似为定值,且不同传感器加速度灵敏度相差很大;瞬态高冲击作用下压力传感器冲击寄生响应峰值与传感器的加速度灵敏度有关,脉宽与测点的固有频率有关;应合理选择压力传感器降低冲击寄生输出,控制测点结构固有频率使加速度峰值远离压力峰值。  相似文献   

8.
通过冲击试验得到了纵向安装压力传感器的冲击响应规律。在激波管中同时加载冲击波压力与瞬态高冲击,研究了压力传感器在冲击作用下冲击寄生响应峰值与冲击加速度的关系;以及冲击寄生响应脉宽与结构固有频率的关系。最后在实际爆炸场中进行了验证试验。结果表明,压力传感器的加速度灵敏度近似为定值;且不同传感器加速度灵敏度相差很大。瞬态高冲击作用下压力传感器冲击寄生响应峰值与传感器的加速度灵敏度有关。脉宽与测点的固有频率有关;应合理选择压力传感器降低冲击寄生输出,控制测点结构固有频率使加速度峰值远离压力峰值。  相似文献   

9.
研究了在远场条件下 ,用PVDF传感器测量梁结构的振动功率流 用传统的加速度传感器测量振动功率流时 ,不可避免地产生有限差分误差 ,而PVDF薄膜是一种新型压电高分子材料 ,根据其积分特性 ,在理论上设计出两种形状的PVDF传感器 ,用它们测量功率流 ,结果中不会出现有限差分误差 通过试验验证了PVDF传感器测量梁结构振动功率流是可行的 试验结果表明 :PVDF传感器不仅可以精确地测量功率流 ,而且还能够直接得到测量点的位移 (速度或加速度 )、弯矩和剪力  相似文献   

10.
硅压阻式加速度传感器的结构研究   总被引:2,自引:0,他引:2  
结合实际器件设计,对三种压阻式加速度传感器结构即双悬臂梁,四梁和双岛五梁结构进行了详细的力学分析和特性比较,得到了理论计算的灵敏度,固有频率和阻尼等特性,器件的测试结果与理论计算基本相符,目前三种结构的器件都已实用化,封装后的小于1g。该项工作为实际应用中根据不同量程要求选取不同的器件结构与参数提供了依据。  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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