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Acoustic impedance inversion of zero-offset VSP data

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Applied Geophysics 2009年第2期6卷 150-158页

作者： Wang Jing liu yang Sun Zhe Tian Hong Su Hua Zhao Qianhua liu Yingyu State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China CNPC Key Laboratory of Geophysical Exploration China University of Petroleum Beijing 102249 China Oilfield Technology Department China Oilfield Services Limited Beijing 101149 China

Highly precise acoustic impedance inversion is a key technology for pre-drilling prediction by VSP data. In this paper, based on the facts that VSP data has high resolution, high signal to noise ratio, and the downgoing and upgoing waves can be accurately separated, we propose a method of predicting the impedance below the borehole in front of the bit using VSP data. First, the method of nonlinear iterative inversion is adopted to invert for impedance using the VSP corridor stack. Then, by modifying the damping factor in the iteration and using the preconditioned conjugate gradient method to solve the equations, the stability and convergence of the inversion results can be enhanced. The results of theoretical models and actual data demonstrate that the method is effective for pre-drilling prediction using VSP data.

关键词： zero-offset VSP impedance inversion non-linear iterative inversion damping factor pre-conditioned conjugate gradient method

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离散介质中应变计算的非线性插值方法

岩土工程学报 2006年第9期28卷 1129-1133页

作者：刘洋周健北京科技大学土木与环境工程学院土木工程系北京100083 同济大学地下建筑与工程系上海200092

分析了离散介质中的应变计算特点,采用‘等效连续’的运动均一化技术,对空间三角化线性插值方法作了类似于更新Lagrange格式的修正。在此基础上,提出了离散介质应变计算的无网格非线性插值算法,并给出了二维验证。初步研究表明,采用的... 详细信息

分析了离散介质中的应变计算特点,采用‘等效连续’的运动均一化技术,对空间三角化线性插值方法作了类似于更新Lagrange格式的修正。在此基础上,提出了离散介质应变计算的无网格非线性插值算法,并给出了二维验证。初步研究表明,采用的应变计算方法与试样的宏观应变相吻合,比起三角化方法更能体现细观局部的应变特征,因此更适合于研究如剪切带等应变局部化问题。

关键词：运动均一化离散元法离散介质无网格法

PTEN-L promotes type I interferon responses and antiviral immunity

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Cellular & Molecular Immunology 2018年第1期15卷 48-57页

作者： Yuanyuan Cao Hongyun Wang liu yang Zhen Zhang Chenlin Li Xu Yuan Lang Bu Lang Chen Yu Chen Chun-Mei Li Deyin Guo Modern Virology Research Center College of Life SciencesWuhan UniversityWuhan430072China School of Basic Medical Sciences Wuhan UniversityWuhan430072China Laboratory for Medical Virology School of MedicineSun Yat-sen UniversityGuangzhou510080China

Phosphatase and tensin homolog deleted on chromosome ten(PTEN)is a well-known tumor suppressor that acts as a dual-specificity phosphatase and is frequently mutated in human *** previous work has demonstrated that PTEN also plays a vital role in type I interferon responses and antiviral innate ***,a translational variant of PTEN with a long N-terminal extension(PTEN-L)has been discovered that is secreted into the extracellular environment and enters recipient cells,where it exerts a phosphatase function antagonistic to PI3K/Akt signaling and *** this study,we demonstrate that PTEN-L promotes type I interferon responses and antiviral innate immunity during viral infection in a phosphatase activity-dependent *** with canonical PTEN,PTEN-L also exerts its antiviral function when it is applied exogenously in protein *** finding was confirmed in cell cultures and mouse infection ***,PTEN-L enhances the responses of both type I interferon and proinflammatory cytokines,thus suggesting that PTEN-L might possess additional functions compared with those of ***,the antiviral function of PTEN-L may open an avenue for the use of PTEN-L in antiviral therapy,particularly in patients with PTEN-deficient tumors.

关键词： antiviral responses innate immunity PTEN PTEN-L type I interferon

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多圆柱上的H^2 Corona问题

同济大学学报（自然科学版） 2008年第2期36卷 273-276页

作者：刘洋韩静同济大学数学系上海200092

考虑的是多圆柱上的H2 Corona问题.将多圆柱上的问题转化到单位圆盘上,利用单位圆盘上的H2Hardy空间,定义出一个算子.在证明此算子有界的情况下,利用Hahn-Banach定理及Reize表示找到了方程的解,并且给出了此解的范数估计.

关键词： H^2 Corona问题格林公式多圆柱

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基于供需比和蓄水系数的云南农业干旱分析

水利学报 2014年第8期45卷 991-996,1003页

作者：傅豪杨小柳北京大学城市与环境学院北京100871

定义区域农业用水供需比RA和区域水库农业蓄水系数C,分析2006—2010年云南农业用水供需与干旱情况。4月云南各地农业用水普遍供不应求,其他月份供水充足;除临沧外,合理调度可保障旱季主要农作物需水;全年降水不足情况下全省整体供水不足... 详细信息

定义区域农业用水供需比RA和区域水库农业蓄水系数C,分析2006—2010年云南农业用水供需与干旱情况。4月云南各地农业用水普遍供不应求,其他月份供水充足;除临沧外,合理调度可保障旱季主要农作物需水;全年降水不足情况下全省整体供水不足,全省16州市中,有10州市缺水情况比较严重,受灾风险较大;2006年与2010年旱情看似相近,但2010年多数地区的干旱威胁程度比2006年严重。区域农业用水供需比和区域水库农业蓄水系数可用于指导区域水利和农业规划。

关键词：干旱区域农业用水供需比区域水库农业蓄水系数云南

DFT方法对LaNi_5及LaNi_5H_(0.5)晶体结构的预测

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功能材料 2005年第3期36卷 394-398页

作者：刘杨吴锋北京理工大学国家高技术绿色材料发展中心北京100081

根据密度泛函理论,以扩展平面波函数为基集,采用超软赝势技术,对LaNi5 储氢合金及其吸氢后的晶胞模型进行了优化,从理论上给出了其结构参数及性质。计算结果表明该方法能较好地符合 LaNi5 及其氢化物结构的实验值,为该类合金的结构预测... 详细信息

根据密度泛函理论,以扩展平面波函数为基集,采用超软赝势技术,对LaNi5 储氢合金及其吸氢后的晶胞模型进行了优化,从理论上给出了其结构参数及性质。计算结果表明该方法能较好地符合 LaNi5 及其氢化物结构的实验值,为该类合金的结构预测提供了一个理论估算途径。此外,根据模型的结构参数分析了LaNi5 中不同间隙位的吸氢稳定性,解释了影响间隙位稳定性的因素。

关键词： LaNi5 LaNi5H 密度泛函理论晶体结构

HRTF空间插值与多通路声重放的稳定性分析

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华南理工大学学报（自然科学版） 2013年第8期41卷 131-138页

作者：刘阳谢菠荪华南理工大学物理系∥声学研究所广东广州510640 华南理工大学亚热带建筑科学国家重点实验室广东广州510640

通常实验测量只能得到有限个离散空间位置的头相关传输函数(HRTF),并需要通过空间插值得到未测位置的HRTF.常用的插值方法包括相邻线性插值、全局插值、双线性插值和三角插值.在HRTF的实际测量过程中,受试者的轻微头动会引入测量误差,... 详细信息

通常实验测量只能得到有限个离散空间位置的头相关传输函数(HRTF),并需要通过空间插值得到未测位置的HRTF.常用的插值方法包括相邻线性插值、全局插值、双线性插值和三角插值.在HRTF的实际测量过程中,受试者的轻微头动会引入测量误差,从而影响到空间插值的准确性和稳定性.文中从头部偏移和头部转动带来的测量误差入手,以计算信号失真比(SDR)作为插值误差的量度,分析和对比头动对以上4种空间插值效果的影响.结果显示,头动前后,全局插值优于其余3种插值方法,且在一定的HRTF频带范围和头动程度内保持了较好的插值效果.由于HRTF空间插值方法和多通路声重放中信号的馈给方式相似,因此文中还利用所得方法和结果,在低于1.5 kHz的频率范围,分析了水平面均匀布置的6或8扬声器重放合成声像的稳定性.

关键词：头相关传输函数空间插值多通路声重放稳定性

Three novel dendritic chitosan derivatives for inhibiting acid corrosion of petroleum pipelines

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Petroleum Science 2023年第6期20卷 3918-3930页

作者： Guo-Dong Cui Yan-Ming Chen Qi-Ming Zhang Zheng Wang Tian Tang Qing Zhao Yu Zhang Li-Feng Zhang Yuan-Qi Gu yang-Sheng liu College of Environmental Sciences and Engineering Peking UniversityBeijing Key Laboratory for Solid Waste Utilization and ManagementBeijing100871China University of Houston HoustonTX77204United States State Key Laboratory of Heavy Oil Processing College of ScienceChina University of PetroleumBeijing102249China CenerTech Tianjin Chemical Research and Design Institute Co. LtdChina National Offshore Oil Corp(CNOOC)Tianjin300131China Faculty of Environment and Life Beijing University of TechnologyBeijing100124China Shanxi International Energy Group Co. LtdTaiyuan030002ShanxiChina

In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.

关键词： Chitosan derivatives Corrosion inhibitors Carbon steel Acid inhibition Efficient and environmental

非线性控制系统的能控性及在刚体动力学中的应用

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控制理论与应用 2000年第2期17卷 204-208页

作者：贺昌政杨柳四川联合大学(成都科技大学)应用数学系成都610065

在 [4 ]的基础上运用不变流形研究非线性系统的能控性问题 .由于不变流形的构造较为容易 ,通过实例表明 ,文中得到的仿射非线性系统能控性定理在刚体动力学中的应用是有效的 .

关键词：非线性控制系统能控性不变流形刚体动力学