压电式传感器的特性分析

通过压电式传感器与电感式传感器的特性对比，得出压电式传感器的电压衰减所引起的误差是压电式粗糙度测量仪一般只能提供被测表面单参数值的模式，而不能提供被测表面的轮廓曲线的主要原因。要完善压电式粗糙测量仪的特性并扩大其使用范围，应选择电压衰减小的压电式传感器，并合理设计压电式粗糙度测量仪系统和配置方案。     

磁座对压电式加速度传感器安装传递系数的影响研究

在井眼碰撞预警地面监测中,安装于邻井套管头的压电式加速度传感器采用磁座安装方式,针对磁座安装对信号传递效果的影响,从理论分析和检测实验两方面进行了研究。首先分析了压电式加速度传感器结构原理,推导出其在磁座安装测量条件下的力学模型,基于模型计算得到不同信号频率下的理论安装传递系数,然后通过传感器磁座安装振动台检测实验,获得安装传递系数实验值。对比分析实验结果与理论计算结果之间的误差及误差存在的原因,在此基础上引入安装传递系数的修正系数,最后提出由传感器测量值计算套管头振动输入量的方法,能够克服磁座安装对信号传递的影响,进而提高井眼碰撞的监测精度。     

磁座对压电式加速度传感器安装传递系数的影响

在井眼碰撞预警地面监测中,安装于邻井套管头的压电式加速度传感器采用磁座安装方式,针对磁座安装对信号传递效果的影响,从理论分析和检测实验两方面进行了研究。首先分析了压电式加速度传感器结构原理,推导出其在磁座安装测量条件下的力学模型,基于模型计算得到不同信号频率下的理论安装传递系数,然后通过传感器磁座安装振动台检测实验,获得安装传递系数实验值。对比分析实验结果与理论计算结果之间的误差及误差存在的原因,在此基础上引入安装传递系数的修正系数,最后提出由传感器测量值计算套管头振动输入量的方法,能够克服磁座安装对信号传递的影响,进而提高井眼碰撞的监测精度。     

连铸中间包测温传感器热惯性响应函数的研究

中间包钢水黑体空腔连续测温传感器的保护套管由耐高温、耐冲刷材质构成,导致传感器在测量中存在热传导惯性,测温输出信号滞后于被测温度的变化,产生动态测量误差。针对于黑体空腔连续测温传感器的热响应惯性,根据传感器实际物理参数,运用有限元分析方法构建传感器的模型,建立传感器的热响应函数,进而根据传感器初始温度测量值对其钢水温度进行预估。最终为降低传感器温度测量动态误差、提高测量实时性提供了一种有效的补偿方法。     

压电式谷物质量流量传感器设计及试验

设计了一种新型压电式谷物质量流量传感器,以实现实时动态测量田间谷物产量.应用LS-DYNA显式动力学软件仿真研究了谷粒冲击力敏元件的过程,对力敏元件的材料进行筛选,根据计算结果确定传感器力敏元件的材料为铝合金;建立了压电式谷物质量流量传感器的三维有限元模型,应用ANSYS软件对压电式谷物质量流量传感器进行模态分析,使传...     

压电传感器动态特性数字化补偿方法研究

从压电式传感器物理原理出发,导出了压电式传感器动态特性的物理数学方程;提出了压电式传感器动态特性补偿原理,并给出了具体的数字化动态补偿实现方法．该方法成功应用于一种新型钵状差动式压电加速度传感器,获得了很好的动态特性补偿效果．     

基于无线传感器网络的室内输电线路热老化预测研究

通过对传统的电缆热老化预测方法比较分析,提出了基于无线传感器网络的输电线路热老化研究方法.利用部署在输电线路周围的传感器节点连续地采集温度数据,并结合绝缘材料的热老化方程进行了实验.实验表明,该方法在误差允许范围内结果精确,解决了传统预测方法无法连续测量温度的问题.     

基于最大误差的热传感器数量分配方法

为了更好地监控微处理器的运行温度，提出了一种考虑奇异点的改进聚类求解策略和新颖的热传感器数量分配方案.该方案分析了在给定最大热点监控误差下所需要的热传感器数量，并且在满足工程上所需要求的情况下，使热传感器数量尽可能地少.实验结果表明，所提出的方法能够在广泛应用的微处理器架构上计算出给定误差要求下所需的热传感器数量，并且与现有的k-means聚类算法相比，所使用的传感器数量明显减少.     

压电式传感器工作的力学过程及测量误差分析

本文结合压电式传感器在振动测试中的使用,提出了简化的力学模型;利用机械阻抗方法分析这类传感器工作的力学过程,给出压电式传感器的测量误差表达式。     

引线分布电容对压电式传感器性能的影响

利用实验的方法,分析了引线分布电容对压电式传感器的性能影响。合理利用现有的实验装置,巧妙设置实验线路,讨论了引线分布电容对压电式传感器的不同测量线路的性能影响。实验结论正确、实验方法先进,理论与实践紧密结合。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-