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1.
井下大功率多极子声波换能器激励源的设计   总被引:1,自引:0,他引:1  
介绍了一种用于石油仪器的大功率多极子阵列声波换能器激励源的设计方案.该方案中,大规模复杂可编程器件执行DSP通过专用串行线路发送的命令,精确地控制多个激励源的激励时刻和激励宽度,实现了对声波辐射能量的最佳控制.对该方案进行了实验测试.测试结果表明,所设计的激励源能够保证控制电路系统在150℃环境温度下稳定工作,适于井下高温高压恶劣环境应用.  相似文献   

2.
在微机电系统(micro-electro-mechanical system,MEMS)热电堆器件的测试中,如何给热电堆器件施加合理的周期性红外辐射激励是能否得到正确器件参数的关键。在开发适用于MEMS热电堆器件的晶圆级测试系统的过程中,提出了一种光学能量传输方案,该方案采用MEMS红外光源JSIR450替代了传统黑体炉作为红外辐射激励源,采用快门替代了光学斩波器对红外信号进行周期性调制。通过实验证明了该方案的有效性,且通过积分的方法证明了MEMS红外光源能量发射端的黑体发射率满足项目要求。  相似文献   

3.
针对某商用车怠速时前照灯抖动的问题,研究了前照灯产生怠速抖动的机理。对激励源和传递路径进行了测试分析;并利用CAE仿真技术对前照灯总成模块进行固有频率及振型分析。仿真分析表明,前照灯总成模块与激励频率重叠而发生了共振。通过CAE仿真分析,提出了在前照灯与下防护之间增加支撑的优化方案。仿真结果表明,优化后的固有频率与激励频率之间的间隔在6 Hz以上,避开了激励频率,有效地解决了前照灯怠速工况下的抖动问题。实车测试验证了该方案的有效性。  相似文献   

4.
介绍了一种利用声波大小以测量水平磨煤机内煤量的系统。该系统采用单片机处理非线性声波数据,准确控制水平磨煤机内煤量的动态平衡,使磨煤机工作处于最佳状态,提高生产效率.现场测试证明,该系统结构简单,成本低廉,性能可靠,易于维护。  相似文献   

5.
声波换能器是声波测井仪器的关键部件,其温度特性直接影响仪器的性能.为满足声波换能器在高温环境下的性能测试要求,针对控制系统的特点采用了Fuzzy-PID参数自整定控温方案,提出了分段控温及小温差逐次逼近控制方法,并实现了根据飞升曲线测定控温对象数学模型的算法.理论分析和仿真结果表明,该方法在各种指标上都能达到较满意的控制效果.  相似文献   

6.
有效地给出了一种新的基于软件自测试的串扰故障渐进式激励检测模型实现,这种基于软件自测试的检测方案是利用SOC中的处理器核的计算和处理能力来产生激励矢量,对串扰故障进行激励并对测试响应进行分析。为了提高测试速度,还提出了一种对IP核透明化处理的测试结构,该测试结构在增加较少额外硬件开销的前提下,极大地减少了测试时间。同时,这种改进的测试结构也满足串扰故障激励检测的实时、并行的要求。  相似文献   

7.
从动力学观点分析了水中球形微气泡无外部激励时平衡态的稳定性及受到声波激励时受迫振荡的复杂动力学行为;分析了无声波激励时平衡态的稳定性和奇点类型,并对其相应的物理现象进行了解释;对于受到声波激励的微气泡受迫振荡,结合Poincaré映射法确定了Poincaré映射的不动点,并根据Floquet理论分析了周期解的稳定性及分岔.分析表明:无声波激励时水中球形微气泡的平衡态是一稳定焦点,而受到声波激励时,随着激励频率的升高,微气泡的周期振荡从失稳转变为倍周期运动,进而转变成准周期运动,最终进入混沌状态;随着压力脉动幅值的增加,微气泡的振荡经过一系列倍周期分岔通向混沌.研究结果揭示了水中球形微气泡的复杂动力学特性,为进一步控制奠定了基础.  相似文献   

8.
钻杆中声波传输特性测试   总被引:6,自引:1,他引:5  
在实验室进行钻杆声波传输特性测试试验.使用激振器和自制激励装置作为激发源、特制的钻杆短节为传输信道,研究声波在钻杆充气、充水、压沙袋3种状态下的传输特性;利用扫频信号激励钻杆,确定钻杆中声波的最佳传输频率点,得出钻杆中声波衰减的经验公式.结果表明:钻杆接箍和声波频率是造成声波衰减的主要因素;纵波是相对较好的信息传输载体;钻杆信道通带为非平滑的梳状滤波器结构.  相似文献   

9.
以往的地面风洞实验研究表明等离子体流动控制具有极大的实用价值。为探索等离子体流动控制应用的关键技术,开展了低速无人机等离子体流动控制飞行验证研究。首先,设计了无人机试飞实验系统和试飞方案,据此进行激励特性测试和地面风洞实验,测试了毫秒脉冲等离子体激励的放电特性,在风洞中验证了毫秒脉冲等离子体流动控制对Viper Jet无人机失速分离的控制效果。然后,进行了Viper Jet无人机等离子体流动控制飞行验证,结果表明AC-DBD激励能有效减小飞机起飞与降落滑跑距离。  相似文献   

10.
提出一种用于微处理器系统故障诊断的测试系统,该系统基于特征分析,采用软件切换技术,使测系统与被测系统在一CPU控制下工作,由测试系统从外部向被测系统施加激励,能对内部不含特征激励的微处理器系统进行故障诊断,确定测量窗口宽度的启、停信号直接由测试系统的内部产生,该测试系统可通过RS-232接口与微机联机,以8031单片机为被测对象,对本测试系统的功能进行了验证。  相似文献   

11.
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   

12.
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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
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   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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