检索结果-南通市图书馆

Science China Earth Sciences 2011年第9期54卷 1441-1452页

作者： tang xiaoming College of Geosciences and Technology China University of Petroleum (East) Qingdao 266555 China

Rocks in earth＇s crust usually contain both pores and cracks. This phenomenon significantly affects the propagation of elastic waves in earth. This study describes a unified elastic wave theory for porous rock media containing cracks. The new theory extends the classic Biot＇s poroelastic wave theory to include the effects of cracks. The effect of cracks on rock＇s elastic prop- erty is introduced using a crack-dependent dry bulk modulus. Another important frequency-dependent effect is the ＂squirt flow＂ phenomenon in the cracked porous rock. The analytical results of the new theory demonstrate not only reduction of elas- tic moduli due to cracks but also significant elastic wave attenuation and dispersion due to squirt flow. The theory shows that the effects of cracks are controlled by two most important parameters of a cracked solid： crack density and aspect ratio. An appealing feature of the new theory is its maintenance of the main characteristics of Biot＇s theory, predicting the characteristics of Blot＇s slow wave and the effects of permeability on elastic wave propagation. As an application example, the theory cor- rectly simulates the change of elastic wave velocity with gas saturation in a field data set. Compared to Biot theory, the new theory has a broader application scope in the measurement of rock properties of earth＇s shallow crust using seismic/acoustic waves.

关键词： poroelasticity wave propagation cracked medium rockphysics

基于岩石力学的井周裂缝流体疏导性分析与产能评价

在线全文

学校读者我要写书评

暂无评论

石油物探 2024年第1期63卷 207-216页

作者：张翰林苏远大王淼唐晓明中国石油大学(华东)地球科学与技术学院山东青岛266580 中海石油(中国)有限公司天津分公司天津300459

电成像测井技术与偶极横波远探测技术可以有效识别井周裂缝。对于裂缝性油气藏,由于裂缝作为油气主要的储集空间与渗流通道,因此对识别的井周裂缝进行流体疏导性能评价对于油田实际生产具有重要意义。利用岩石力学中的三维应力莫尔圆对... 详细信息

电成像测井技术与偶极横波远探测技术可以有效识别井周裂缝。对于裂缝性油气藏,由于裂缝作为油气主要的储集空间与渗流通道,因此对识别的井周裂缝进行流体疏导性能评价对于油田实际生产具有重要意义。利用岩石力学中的三维应力莫尔圆对地应力作用下从井壁延伸至储层的裂缝进行应力状态分析,并结合莫尔库仑破裂准则进行裂缝临界应力状态判别,进而评价整体的流体疏导性能。数值模拟结果表明,除地应力大小外,不同断层类型的地应力状态和孔隙压力大小也决定着裂缝的临界应力状态。根据裂缝面应力状态求取裂缝的摩擦系数并进行校正可以定量反映裂缝的流体疏导性能,将裂缝发育层段内校正后的裂缝摩擦系数加权于裂缝密度,可实现目标井段流体疏导性能定量评价并为产能评价提供可靠依据。在渤中19-6裂缝性潜山凝析气田的应用实例表明,该方法可以有效地分析井周裂缝的流体疏导性能,实现不同裂缝对于产能贡献的定量评价,评价结果与地层实际测试产能结果有较好的相关性,为现场试油与开采方案的制定提供有效指导。

关键词：裂缝流体疏导性莫尔圆莫尔库仑准则声波远探测摩擦系数产能评价潜山

维普期刊数据库博看期刊

井中方位纵波远探测: 理论、实验与现场应用

在线全文

学校读者我要写书评

暂无评论

地球物理学报 2024年第2期67卷 630-640页

作者：苏远大饶博孔令文李盛清谭宝海庄春喜唐晓明中国石油大学(华东)地球科学与技术学院青岛266580 深层油气全国重点实验室(中国石油大学(华东)) 青岛266580 崂山实验室海洋矿产资源评价与探测技术功能实验室青岛266071 中国石化石油勘探开发研究院无锡石油地质研究所无锡214126

能够测量井外数十米地质构造距离和方位的远探测声波测井正成为一种重要的地球物理应用技术.1:1地层条件下井外含反射界面的远探测测量和分析为此技术提供了物理验证.本文首先利用虚源和柱面波展开理论推导了充液井孔中单极反射纵波方... 详细信息

能够测量井外数十米地质构造距离和方位的远探测声波测井正成为一种重要的地球物理应用技术.1:1地层条件下井外含反射界面的远探测测量和分析为此技术提供了物理验证.本文首先利用虚源和柱面波展开理论推导了充液井孔中单极反射纵波方位接收声场的解析形式,通过模拟证明了单井的声波辐射和接收与双井之间的辐射和接收的等效性,在此基础上提出利用两口模型井来实现方位纵波远探测实验,即在测量井中放置多方位反射纵波接收声系,在另一口副井中放置单极子声源向测量井定向辐射纵波以等效来自井外地质体的反射波,依托实验室的模型井群进行井中方位纵波远探测实验研究.实验测量结果表明井中接收反射纵波的幅度和到时对井外反射体(定向辐射波)具有较好的方位灵敏度,可由此来实现井外地质异常体的精准定位.在理论与实验指导下自主设计研制了方位纵波远探测仪器样机并开展了现场井测试成功获得高信噪比的方位反射信号,充分验证了方位纵波远探测技术的准确性和有效性.

关键词：单极纵波远探测平行双井模型实验测量测井仪器方位接收响应

Scalable Clock Synchronization Analysis:A Symmetric Noncooperative Output Feedback Tubes-MPC Approach

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1604-1626页

作者： Ting Wang Xiaoquan Xu xiaoming tang Key Laboratory of Industrial Internet of Things&Networked Control Ministry of Education and the School of Advanced Manufacturing EngineeringChongqing University of Posts and TelecommunicationsChongqing 400065China College of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065China

In the cyber-physical environment,the clock synchronization algorithm is required to have better expansion for network *** this paper,a new measurement model of observability under the equivalent transformation of minimum mean square error(MMSE)is constructed based on basic measurement unit(BMU),which can realize the scaled expansion of MMSE *** on the state updating equation of absolute clock and the decoupled measurement model of MMSElike equivalence,which is proposed to calculate the positive definite invariant set by using the theoretical-practical Luenberger observer as the synthetical observer,the local noncooperative optimal control problem is built,and the clock synchronization system driven by the ideal state of local clock can reach the exponential convergence for synchronization *** from the problem of general linear system regulators,the state estimation error and state control error are analyzed in the established affine system based on the set-theoryin-control to achieve the quantification of state deviation caused by noise *** on the BMU for isomorphic state map,the synchronization performance of clock states between multiple sets of representative nodes is evaluated,and the scale of evaluated system can be still *** the synchronization is completed,the state of perturbation system remains in the maximum range of measurement accuracy,and the state of nominal system can be stabilized at the ideal state for local clock and realizes the exponential convergence of the clock synchronization system.

关键词： Affine system clock synchronization model predictive control output feedback

A joint maximum likelihood algorithm for simultaneous track correlation and sensorbias estimation

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第10期56卷 44-54页

作者： HE You ZHU HongWei tang xiaoming Institute of Electronic and Information Engineering Naval Aeronautical and Astronautical University

In this study a joint maximum likelihood(JML)algorithm was developed to solve problems regarding interdependent and contradictory relationships between track correlation and sensor bias estimation in multi-sensor information fusion ***,the relationships between track correlation and sensor bias estimation of a multi-sensor system were ***,based on these relationships,a JML function of the track correlation and sensor bias estimation was developed,while an iterative two-step optimization procedure was adopted to solve the JML *** addition,transformation of sensor bias from Cartesian coordinates to polar coordinates and a complete design of track quality and ambiguity processing were ***,several Monte Carlo simulations were built to test the efect of target density and diferent sensor bias in the JML *** results showed that the JML algorithm presented in this paper had a higher correct correlation rate and more accurate sensor bias estimation than traditional methods,demonstrating that the JML algorithm had good performance.

关键词： joint maximum likelihood algorithm track correlation sensor bias estimation design of track quality ambiguity processing

An acoustic-wave theory for casing bond evaluation using viscoelastic slip boundary modeling

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2018年第8期61卷 1057-1064页

作者： xiaoming tang Can JIANG YuANDa SU Xuelian CHEN School of Geosciences China University of Petroleum

Slip boundary condition is commonly utilized to model elastic wave propagation through layered earth media. The same approach is used here to characterize acoustic wave propagation along a cased borehole with various cement bond conditions. By modeling the cement layer between casing and formation as a viscoelastic slip interface with complex coupling rigidity parameters, one can not only reduce the complexity in the classical elastic wave modeling of the problem, but also efficiently model various complicated wave phenomena that are difficult for the existing modeling. More specifically, the new theory can well describe the effect of the cement bond condition change and the location of the change(i.e., whether it is in the first interface between casing and cement, or the second interface between cement and formation) on the acoustic waves,demonstrating the good modeling capability and predicting power. Application of the theory to field data shows that the theory can correctly model the acoustic wave characteristics and interpret the cement bond condition, thus providing a useful fundament theory for casing bond evaluation using acoustic logging.

关键词： Cased borehole Acoustic logging Cement evaluation Viscoelastic slip boundary Cement bond quality

脊柱矢状位失衡对骨质疏松性椎体压缩性骨折行椎体后凸成形术后新发骨折的影响

在线全文

学校读者我要写书评

暂无评论

中国临床研究 2024年第5期37卷 699-702,708页

作者：李瑶戴健马健杨钊琦孙宇唐晓明南京医科大学附属淮安第一医院骨科江苏淮安223300 南京医科大学江苏南京211100

目的探讨脊柱矢状位失衡与骨质疏松性椎体压缩性骨折(OVCF)患者接受经皮椎体后凸成形术(PKP)后新发椎体骨折的相关性,为临床预防新发骨折提供新的思路。方法回顾性选择南京医科大学附属淮安第一医院2020年2月至2023年6月因OVCF入院行PK... 详细信息

目的探讨脊柱矢状位失衡与骨质疏松性椎体压缩性骨折(OVCF)患者接受经皮椎体后凸成形术(PKP)后新发椎体骨折的相关性,为临床预防新发骨折提供新的思路。方法回顾性选择南京医科大学附属淮安第一医院2020年2月至2023年6月因OVCF入院行PKP手术的患者,以术后有新发骨折的64例患者作为研究组,无新发骨折的64例作为对照组。分析比较两组患者术后1年随访时各脊柱矢状位参数之间的差异,同时比较两组患者术后VAS评分、日本骨科协会(JOA)评分、Oswestry功能障碍指数(ODI)。结果研究组的年龄、术后VAS评分、术后ODI评分显著高于对照组,而术后JOA评分显著低于对照组,差异有统计学意义(P<0.05)。研究组的骨盆倾斜角(PT)(22.66°±2.41°vs 20.36°±3.68°,t=4.18,P<0.01)和胸椎后凸角(TK)(45.95°±4.87°vs 40.22°±4.22°,t=7.12,P<0.01)大于对照组,而骶骨倾斜角(SS)(23.44°±6.35°vs 28.47°±5.46°,t=4.81,P<0.01)、骨盆入射角(PI)(46.09°±5.57°vs 48.83°±5.46°,t=2.80,P<0.01)和腰椎前凸角(LL)(39.06°±6.08°vs 44.30°±6.20°,t=4.83,P<0.01)小于对照组。结论脊柱矢状位失衡和OVCF患者行PKP术后新发椎体骨折具有密切的相关性。

关键词：骨质疏松性椎体压缩性骨折脊柱矢状位失衡新发骨折经皮穿刺椎体后凸成形术

Dynamic fluid transport property of hydraulic fractures and its evaluation using acoustic logging

在线全文

学校读者我要写书评

暂无评论

Petroleum Exploration and Development 2022年第1期49卷 223-232页

作者： LI Huanran tang xiaoming LI Shengqing SU Yuanda China University of Petroleum(East China) Qingdao 266580China Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China

The existing acoustic logging methods for evaluating the hydraulic fracturing effectiveness usually use the fracture density to evaluate the fracture volume, and the results often cannot accurately reflect the actual productivity. This paper studies the dynamic fluid flow through hydraulic fractures and its effect on borehole acoustic waves. Firstly, based on the fractal characteristics of fractures observed in hydraulic fracturing experiments, a permeability model of complex fracture network is established. Combining the dynamic fluid flow response of the model with the Biot-Rosenbaum theory that describes the acoustic wave propagation in permeable formations, the influence of hydraulic fractures on the velocity dispersion of borehole Stoneley-wave is then calculated and analyzed, whereby a novel hydraulic fracture fluid transport property evaluation method is proposed. The results show that the Stoneley-wave velocity dispersion characteristics caused by complex fractures can be equivalent to those of the plane fracture model, provided that the average permeability of the complex fracture model is equal to the permeability of the plane fracture. In addition, for fractures under high-permeability(fracture width 10~100 μm, permeability ~100 μm^(2)) and reduced permeability(1~10 μm, ~10 μm^(2), as in fracture closure) conditions, the Stoneley-wave velocity dispersion characteristics are significantly different. The field application shows that this fluid transport property evaluation method is practical to assess the permeability and the connectivity of hydraulic fractures.

关键词： hydraulic fracture dynamic fluid transport property acoustic logging Stoneley-wave velocity dispersion fracture characterization

在线全文

学校读者我要写书评

暂无评论

甘薯块根物理机械特性试验研究

沈阳农业大学学报 2024年第5期55卷 545-551页

作者：赵萍张红印李本帅徐庆炳唐晓明沈阳农业大学工程学院沈阳110161 辽宁省农业发展服务中心沈阳110034

甘薯机械化生产机具大多数参考马铃薯生产机具研制,缺乏理论设计和分析依据。为了给甘薯收获、运输、分选机械的设计和优化提供相关理论参数及分析依据,探究成熟期甘薯块根不同方向、不同部位的压缩物理机械特性,为高性能机具研制奠定... 详细信息

甘薯机械化生产机具大多数参考马铃薯生产机具研制,缺乏理论设计和分析依据。为了给甘薯收获、运输、分选机械的设计和优化提供相关理论参数及分析依据,探究成熟期甘薯块根不同方向、不同部位的压缩物理机械特性,为高性能机具研制奠定基础。以辽宁地区广泛种植的烟薯25品种为研究对象,测定成熟期块根含水率及密度,确定试验块根的基本物理参数;利用INSTORN5944型电子万能试验机进行块根轴向、径向以及不同部位压缩力学特性试验,得出破裂力随加载速度变化趋势,分析不同压缩方向和不同部位薯块的弹性模量、泊松比以及剪切模量,确定甘薯材料特性。结果表明:成熟期烟薯25含水率为79.64%,密度为1 028 kg·m^(-3);不同压缩方向上薯块的弹性模量、泊松比及剪切模量差异不显著,甘薯为各向同性材料;不同部位薯块弹性模量、泊松比及剪切模量差异不显著,甘薯为均质材料;甘薯弹性模量为3.22~4.19 MPa,泊松比为0.28~0.40,剪切模量为1.26~1.50 MPa。研究结果对甘薯生产机械化机具设计及后续仿真分析模型的建立具有重要意义。

关键词：甘薯物理机械特性压缩力学特性

Optically Controlled Coercive Field of MAPbl_(3)/P(VDF-TrFE)Ferroelectric Composite Films

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2023年第2期39卷 228-233页

作者： SU Yangfan SUN Yiran ZHOU Dikui tang xiaoming HAN Gaorong REN Zhaohui State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou310027P.R.China Center of Electron Microscope School of Materials Science and EngineeringZhejiang UniversityHangzhou310027P.R.China Research Center for Humanoid Sensing Zhejiang LabHangzhou311100P.R.China

Ferroelectric polymers,such as poly(vinylidene fluoride-trifluoroethylene)[P(VDF-TrFE)or PVTF]have attracted growing interest in developing flexible devices because of their excellent ferroelectricity and *** coercive field(E c)inherent to PVTF for switching its polarization,however,is not beneficial for practical memory or sensor device *** strategies,including irradiation and interface control,have been thus developed to reduce E *** many efforts,a facile approach to tailoring intrinsic E_(c) of PVTF has not been *** this work,an optically controlled E_(c) was reported,which is achieved for the first time by introducing photosensitive MAPbI3 nanocrystals into PVTF *** exposed to the irradiation of 532 nm laser light,a decreased E_(c) of the composites can be achieved reversibly by increasing the light *** decreased level of E_(c) increases as the MAPbI3 content enhanced,and a 10.7%reduction of E_(c) can be achieved in 15%(mass fraction)MAPbI3/PVTF *** results could be attributed to loading an internal stress on PVTF,which was generated by the photostriction of MAPbI3 *** explanation was further supported by in-situ XRD results under irradiation of 532 nm laser *** findings may offer the opportunity to optically modulate the ferroelectric properties of PVTF composites for optimized device performances.

关键词： Poly(vinylidene fluoride-trifluoroethylene)[P(VDF-TrFE)] MAPbI_(3) Photostriction Optically controlled coercive field