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Fast least-squares prestack time migration via accelerating the explicit calculation of Hessian matrix with dip-angle Fresnel zone

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Petroleum Science 2022年第3期19卷 1031-1047页

作者： Bo-Wu Jiang Jiang-Jie Zhang hao Zhang wen-Kai Lu College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing100029China The Institute for Artificial Intelligence(THUAI) Beijing100084China State Key Laboratory of Intelligent Technology and Systems Beijing100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing100084China The Department of Automation Tsinghua UniversityBeijing100084China Key Laboratory of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China

Amplitude versus offset analysis is a fundamental tool for determining the physical properties of reservoirs but generally hampered by the blurred common image gathers(CIGs).The blurring can be optimally corrected using the blockwise least-squares prestack time migration(BLS-PSTM),where common-offset migrated sections are divided into a series of blocks related to the explicit offsetdependent Hessian matrix and the following inverse filtering is iteratively applied to invert the corresponding ***,calculating the Hessian matrix is *** present a fast BLS-PSTM via accelerating Hessian calculation with dip-angle Fresnel zone(DFZ).DFZ is closely related to optimal migration aperture,which significantly attenuates migration swings and reduces the computational cost of ***,our fast BLS-PSTM is implemented as a two-stage ***,we limit the aperture for any imaging point with an approximated the projected Fresnel zone before calculating the Hessian ***,we determine whether a seismic trace contributes to the imaging point via DFZ during calculating the Hessian *** tests on synthetic and field data validate the distinct speedup with higher-quality CIGs compared to BLS-PSTM.

关键词： Prestack time migration Fresnel zone Hessian Least squares migration Migrated gather

硫醇吸附挥发性有机气体(VOCs)的气敏机理

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原子与分子物理学报 2025年第3期42卷 35-44页

作者：张海燕李琦王梓臻文豪刘丹凤中国环境科学研究院北京100012 中国汽车工程研究院股份有限公司重庆401122 中国科学院微电子研究所北京100029

化学电阻气体传感器对于空气质量、食品检测和人体呼吸有着重要作用.传感器上修饰物硫醇与待测的VOCs之间吸附的气敏机理分析是选择硫醇、预测吸附能力与特异性的重要手段.本文选取了11-巯基-1-十一醇(MUD)和4-甲氧基苄硫醇(MTT)两种常... 详细信息

化学电阻气体传感器对于空气质量、食品检测和人体呼吸有着重要作用.传感器上修饰物硫醇与待测的VOCs之间吸附的气敏机理分析是选择硫醇、预测吸附能力与特异性的重要手段.本文选取了11-巯基-1-十一醇(MUD)和4-甲氧基苄硫醇(MTT)两种常见的硫醇与六种典型的VOCs(乙醇ETN、异丙醇IPA、丙酮ACN、正己烷HXN、甲苯TLN、苯甲醛BND),基于密度泛函理论(DFT),计算其表面静电势(ESP)并建立气体吸附模型.在气体吸附模型的基础上计算其吸附能,并分析其弱相互作用,从微观角度解释气体吸附的作用机理.实验结果表明,具有羟基的MUD分子对同样有羟基的气体(如ETN、IPA)能够以氢键的方式吸附,具有较强的选择效果;具有苯环的MTT分子与具有苯环结构的气体分子(如TLN、BND)吸附时会在苯环之间形成π-π堆积,基于色散作用进行吸附,这表明MTT分子对具有苯环结构的气体有着较强的吸附作用.研究发现其色散作用吸附的强弱与分子的表面ESP绝对值有关.本文对于传感器表面修饰物吸附气体的气敏机理进行了探究,并对表面修饰物的选择和实验结果预测提供了理论指导.

关键词：硫醇 VOCs DFT 表面静电势气体吸附模型弱相互作用分析

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Energy-Based Current Control for Stabilizing a Flexible Electrodynamic Tether System

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Journal of Beijing Institute of Technology 2017年第1期26卷 1-4页

作者： hao wen Bensong Yu Dongping Jin State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

An energy-based controller of electric current is synthesized for the libration stabilization of an electrodynamic tether system,which consists of a relatively large main-satellite and a sub-satellite of much smaller *** dynamic models with different levels of accuracy are considered in this ***,a dumbbell model of the system is used for the controller design,which aims at damping injection on the libration motions via the real-time regulation of the electric ***,the efficacy and performance of the proposed scheme are numerically verified by using a more complex multi-body model which accounts for not only the tether flexibility but also the attitude of the main-satellite.

关键词： electrodynamic tether flexible energy-based control current control

Numerical Study on Aerodynamic Performance of Floating Dual-Rotor Wind Turbines in Heave and Surge Motions

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China Ocean Engineering 2023年第6期37卷 1011-1021页

作者： WU Xiao-di LU wen-hao WANG Kai HU Wei-fei FANG Jian-hao ZHA Ruo-si School of Ocean Engineering and Technology Sun Yat-sen University&Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China School of Mechanical Engineering Zhejiang UniversityHangzhou 310058China

Compared with the traditional wind turbine of a single rotor,dual-rotor wind turbines(DRWTs)have higher wind energy capture efficiency and a more complex ***,the aerodynamic performance of the DRWT installed on the floating platform will be greatly affected by the motion caused by wind and wave *** this paper,5 MW and 750 kW single rotor wind turbines(SRWTs)are combined into a 5 MW-5 MW DRWT and a 5 MW-750 kW DRWT,and their power output and wake field characteristics in different motions are *** flow field is obtained by solving the Reynolds-averaged Navier–Stokes equation(RANS).The overset grid technique is employed to achieve the large-amplitude multiple-degree-of-freedom motion of the *** overall performance of the 5 MW single rotor wind turbine is determined by a numerical *** the DRWTs,numerical results show that the surge motion and heave motion both have a negative effect on the power output of the *** surge motion is a critical factor that causes the power output of the DRWT to periodically change with *** average power output of the DRWT influenced by motion is lower than that of a DRWT with a fixed *** surge motion significantly disturbs the wake of the DRWT due to the mutual interference between the upstream and downstream *** the influence of heave motion,low-velocity regions downstream of the blade tip are *** study indicates that attenuating the surge and heave motion of offshore DRWT is very significant for improving its efficiency and should be taken into consideration during the design procedure.

关键词： DRWT surge motion heave motion wake field power output

Pancreatic triglyceride lipase is involved in the virulence of the brown planthopper to rice plants

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Journal of Integrative Agriculture 2020年第11期19卷 2758-2766页

作者： YUAN Long-yu hao Yuan-hao CHEN Qiao-kui PANG Rui ZHANG wen-qing State Key Laboratory of Biocontrol/School of Life Sciences SunYat-sen UniversityGuangzhou 510275P.R.China

The brown planthopper(BPH),Nilaparvata lugens,an important rice insect pest,can enhance its virulence to BPH-resistant rice within as short a span as several ***,we cloned a pancreatic triglyceride lipase(PTL)gene(NlPTL)in ***,and found that its mRNA level was higher in the high virulence population(fed on variety Rathu Heenati,P-RH)than in the low virulence population(fed on variety Taichung Native 1,P-TN1).Knocking down NlPTL caused BPH individuals to spend more time in non-penetration and the pathway phases and less time feeding on the phloem of rice plants;these changes consequently decreased food intake,lipid content,survival rate,and fecundity in the *** findings reveal for the first time that PTL in BPH is involved in its virulence to rice plants.

关键词： pancreatic triglyceride lipase Nilaparvata lugens virulence rice lipid

Inherent relationship between process parameters,crystallization and mechanical properties of continuous carbon fiber reinforced PEEK composites

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Defence Technology（防务技术） 2023年第6期24卷 269-284页

作者： Xiao-long Ma Li-hua wen Shi-yu Wang Jin-you Xiao wen-hao Li Xiao Hou School of Astronautics Northwestern Polytechnical UniversityXi'an710072China China Aerospace Science and Technology Corporation Beijing100048China

High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence ***,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious *** purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)*** composite laminates are fabricated according to orthogonal experiments via the thermoforming *** mechanical performance is investigated in terms of crystallization properties and fracture morphology *** results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing *** increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the *** is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural *** well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.

关键词： Polymer matrix composites Thermoplastic Processing parameters Mechanical properties Crystallization

An Improved Transosseous Pullout Suture Technique for Arthroscopic Repair of a Meniscus Root Tear

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Current Medical Science 2023年第4期43卷 779-783页

作者： wen-bin Zhao Feng TU hao WANG Department of Orthopedic Surgery Wuhan No.1 HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China

Objective:This study aimed to explore the clinical efficiency of an improved transosseous pullout suture technique for arthroscopic repair of a meniscus root ***:From January 2017 to January 2021,53 patients with posterior meniscus root tears combined with anterior cruciate ligament(ACL)and/or posterior cruciate ligament(PCL)tears were ***,in 29 patients(group A),the 2.0 mm modified pullout tunnel method was used to suture the posterior meniscus root,while 24 patients(group B)were treated with the traditional 4.5 mm pullout tunnel *** group A,20 patients had lateral meniscus posterior root(LMPR)combined with ACL tears,5 patients had LMPR combined with ACL and PCL tears,and 4 patients had medial meniscus posterior root(MMPR)combined with ACL *** group B,19 patients had LMPR combined with ACL tears,3 patients had LMPR combined with ACL and PCL tears,and 2 patients had MMPR combined with ACL *** improvement of the Lysholm and VAS scores and the incidence of complications in group A and group B before the operation,1 month and 3 months after the operation,and after the final follow-up were ***:Preoperative Lysholm score was 26.0±5.6 in group A and 26.7±5.8 in group B(P>0.05).One-month postoperative Lysholm score was 66.5±5.7 in group A and 54.3±2.4 in group B(P0.05).Preoperative VAS score was 6.3±1.4 in group A and 6.3±1.2 in group B(P>0.05).One-month postoperative VAS score was 1.8±0.7 in group A and 2.4±0.9 in group B(P0.05).VAS score after the final follow-up was 0.2±0.4 in group A and 0.3±0.5 in group B(P>0.05).Conclusion:The improved transosseous pullout suture technique using a smaller 2.0 mm bone tunnel can virtually eliminate the

关键词： meniscus root tear bone tunnel multiple ligament injury tunnel management windshield wiper effect

Modeling and scenario prediction of a natural gas demand system based on a system dynamics method

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Petroleum Science 2018年第4期15卷 912-924页

作者： Xian-Zhong Mu Guo-hao Li Guang-wen Hu Institute of Recycling Economy Beijing University of Technology

Based on the study of the relationship between structure and feedback of China’s natural gas demand system, this paper establishes a system dynamics model. In order to simulate the total demand and consumption structure of natural gas in China, we set up seven scenarios by changing some of the parameters of the model. The results showed that the total demand of natural gas would increase steadily year by year and reach in the range from 3600 to 4500 billion cubic meters in 2035. Furthermore, in terms of consumption structure, urban gas consumption would still be the largest term, followed by the gas consumption as industrial fuel, gas power generation and natural gas chemical industry. In addition, compared with the population growth, economic development still plays a dominant role in the natural gas demand growth, the impact of urbanization on urban gas consumption is significant, and the promotion of natural gas utilization technology can effectively reduce the total consumption of natural gas.

关键词： Natural gas demand system System dynamics Scenario prediction Consumption structure

An efficient way to coupling amine with derivatives of steric N-Boc-pyrrolidine-2-carboxylic acid

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Chinese Chemical Letters 2007年第4期18卷 393-396页

作者： Feng Zhi Liu hao Fang wen Fang Xu School of Pharmacy Shandong University Jinan 250012 China

An efficient way to coupling amine with the derivatives of steric N-Boc-pyrrolidine-2-carboxylic acid was reported in this paper. We have found that the synthesis of derivatives is problematic with the commonly used DCC/HOBT method. As a substitute, the mixed anhydride method was adopted. A series of 6-（3-nitroguanidino）hexanamidopyrrolidine derivatives were prepared with this method.

关键词： Synthesis 6-(3-Nitroguanidino)hexanamidopyrrolidine derivatives The mixed anhydride method