计算机控制与检测气动换向阀试验台

介绍一种采用计算机控制与检测气动换向阀试验台的特点和测试系统设计。     

渤海Q油田层间干扰定量表征技术及应用

针对渤海Q油田北区块油井多层合采导致的含水上升快、采油速度低、采出程度差异大等问题,对不同含水阶段的层间干扰现象进行分析,建立了层间干扰定量表征技术,并结合Q油田油藏类型和储层纵向非均质性,研究了底水关闭前后不同含水阶段的层间干扰规律,提出了高含水期细分层系开发的技术对策:对北区块进行调整,将原来的一套开发层系细分为三套开发层系,采用水平井开发,同时对老井进行关层。调整后全区含水率下降了10%,采油速度提高了0.5%,采收率提高了10.6%。     

Accuracy of the zero crossings of the second directional derivative as an edge detector

In this paper the accuracy of the second directional derivative edge detector is analyzed, based on a number of idealized edge models. The results are compared with those for the Laplacian edge detector. Errors are shown to be small under a number of conditions. These conditions are less severe for the second directional derivative than for the Laplacian edge detector. Spurious or phantom edges can be removed by checking the sign of the third directional derivative, though this is not enough to remove all large errors. Indeed, it is also shown that large errors will be obtained if no threshold is set on the magnitude of a third order derivative.This work was supported by the Belgian National Fund for Scientific Research (NFWO).     

双向主动式高精度晶体控温仪

利用半导体致冷器可以加热又可以致冷的双向性，研制成双向主动式高精度控温仪。在１５～３２℃范围内，控温精度高达±０．００４℃。用于控制ＫＴＰ晶体温度，在ＯＰＯ实验中获得稳定的参量下转换输出。     

SAGD双水平井随钻磁导向系统的研制及应用

针对实测信号微弱、频变、窄带的特点,设计出低噪声、窄通频带、高精度的数据采集滤波电路,有效地滤除了干扰和噪声,使系统探测精度达到±0.3m左右;根据磁感应强度数据的采集要求,制定了单组数据校验的通信协议,减少了干扰导致的个别数据传输错误对整体数据的影响。     

Hydrodynamic constraints on evolution of chemically mediated interactions between aquatic organisms in unidirectional flows

Two hydrodynamic habitats can be defined in unidirectional flow: (1) A boundary where molecular diffusion dominates is found within roughly 1 mm of solid substrates. The actual thickness of this diffusion boundary is a function of current velocity and topography of the substrates. (2) A zone of turbulent flow is present outside the diffusion boundary where chemicals are rapidly diluted and transported downstream. The mode of chemically mediated interaction between organisms in streams is constrained differently depending on which of these two habitats they occupy. Within a diffusion boundary, reciprocal interaction between small organisms is possible because mixing is low, diffusion flux high, and organisms share the same water. Outside a diffusion boundary, in unidirectional flow, organisms unable to move effectively against flow are only chemically influenced by upstream organisms and can only influence downstream organisms. Organisms that are able to move upstream can interact reciprocally with other organisms, even if one or both organisms are found primarily in areas of turbulent mixing.     

一种短波宽带定向耦合器的设计

根据变压器串并联同时耦合的原理，提出了一种利用三线变压器魔T和传输线变压器构成定向耦合器的方法，给出了设计原理，设计制作了一种短波宽频带、大功率定向耦合器。并对其参数进行了理论计算和实际测量，测试结果与理论分析吻合，满足设计要求。经过实际应用，验证了设计方法的可行性。     

航空多角度偏振成像仪及其光学系统设计

航空多角度偏振成像仪采用面阵CCD探测器进行画幅式成像,分时获取三个偏振方向图像的工作方式,并最终解析出偏振信息.光学系统设计充分考虑了该系统的特点,设计出了全视场80°的像方远心超低畸变的镜头,满足了航空多角度偏振成像仪的系统要求.     

三分支可变阻抗任意分贝集总元件定向耦合器

通过奇偶模分析方法,得到了可变阻抗任意分贝二分支集总元件定向耦合器的设计公式,并给出了8种拓扑结构,然后通过级联得到了三分支可变阻抗任意分贝集总元件定向耦合器的设计公式及拓扑结构.经ADS仿真验证,设计所得结果与仿真结果完全一致,隔离度和反射都在20 dB以上,(3±0.5)dB带宽达到了20 MHz.     

基于方向性小波变换的图像稀疏修复

图像修复有着重要的应用价值,稀疏表示作为前沿的信号处理方法,也已经使用在图像修复中。但是,传统方法在稀疏图像的时候利用的是预先给定的图像基,不能自适应图像,因此稀疏表示能力有限。文中提出从参考图中估计出图像的最佳几何方向使得稀疏变换能自适应图像几何信息,提供更稀疏的图像表示方法。稀疏修复通过最小化1范数模型进行求解。实验结果表明,所提方法较传统的二维小波变换可以更好地保留图像中边缘和纹理,获得更高的峰值信噪比。