检索结果-南通市图书馆

A seismic elastic moduli module for the measurements of low-frequency wave dispersion and attenuation of fluid-saturated rocks under different pressures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 162-181页

作者： Yan-Xiao He Shang-Xu Wang Gen-Yang Tang Chao Sun hong-bing li San-Yi Yuan Xian Wei li-Deng Gan Xiao-Feng Dai Qiang Ge Peng-Peng Wei Hui-Qing Zhang National Key Laboratory of Petroleum Resources and Engineering CNPC Key Lab of Geophysical ExplorationCollege of GeophysicsChina University of Petroleum(Beijing)Beijing102249China School of Resources and Geosciences China University of Mining and TechnologyXuzhou221116JiangsuChina Research Institute of Petroleum Exploration and Development CNPCBeijing100083China Beijing Vocational College of Labour and Social Security Beijing100029China PetroChina Dagang Oilfield Exploration and Development Research Institute CNPCTianjin300280China

Knowledge about the seismic elastic modulus dispersion,and associated attenuation,in fluid-saturated rocks is essential for better interpretation of seismic observations taken as part of hydrocarbon identification and time-lapse seismic surveillance of both conventional and unconventional reservoir and overburden performances.A Seismic Elastic Moduli Module has been developed,based on the forced-oscillations method,to experimentally investigate the frequency dependence of Young's modulus and Poisson's ratio,as well as the inferred attenuation,of cylindrical samples under different confining pressure *** with three standard samples showed that the measured elastic moduli were consistent with the published data,indicating that the new apparatus can operate reliably over a wide frequency range of f∈[1-2000,10^(6)]*** Young's modulus and Poisson's ratio of the shale and the tight sandstone samples were measured under axial stress oscillations to assess the frequency-and pressure-dependent *** dry condition,both samples appear to be nearly frequency independent,with weak pressure dependence for the shale and significant pressure dependence for the *** particular,it was found that the tight sandstone with complex pore microstructure exhibited apparent dispersion and attenuation under brine or glycerin saturation conditions,the levels of which were strongly influenced by the increased effective *** addition,the measured Young's moduli results were compared with the theoretical predictions from a scaled poroelastic model with a reasonably good agreement,revealing that the combined fluid flow mechanisms at both mesoscopic and microscopic scales possibly responsible for the measured dispersion.

关键词： Low-frequency measurements Dispersion and attenuation Rock physics Fluid flow

A two-step method to apply Xu–Payne multi-porosity model to estimate pore type from seismic data for carbonate reservoirs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2020年第3期17卷 615-627页

作者： hong-bing li Jia-Jia Zhang Sheng-Juan Cai Hao-Jie Pan Research Institute of Petroleum Exploration and Development Petrochina Company LimitedBeijing 100083China School of Geosciences China University of Petroleum(East China)Qingdao 266580China

Carbonate reservoirs exhibit strong heterogeneity in the distribution of pore types that can be quantitatively characterized by applying Xu–Payne multi-porosity ***,there are some prerequisites to this model the porosity and saturation need to be *** general,these application conditions are difficult to satisfy for seismic *** order to overcome this problem,we present a two-step method to estimate the porosity and saturation and pore type of carbonate reservoirs from seismic *** step one,the pore space of the carbonate reservoir is equivalent to a single-porosity system with an effective pore aspect ratio;then,a 3D rock-physics template(RPT)is established through the Gassmann’s equations and effective medium models;and then,the effective aspect ratio of pore,porosity and fluid saturation are simultaneously estimated from the seismic data based on 3D *** step two,the pore space of the carbonate reservoir is equivalent to a triple-porosity *** with the inverted porosity and saturation in the first step,the porosities of three pore types can be inverted from the seismic elastic *** application results indicate that our method can obtain accurate physical properties consistent with logging data and ensure the reliability of characterization of pore type.

关键词： Carbonate reservoirs Pore type Physical properties Rock-physics modeling Rock-physics inversion

Experimental quantum secure network with digital signatures and encryption

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第4期10卷 86-96页

作者： Hua-Lei Yin Yao Fu Chen-Long li Chen-Xun Weng bing-hong li Jie Gu Yu-Shuo Lu Shan Huang Zeng-bing Chen National Laboratory of Solid State Microstructures School of Physics Collaborative Innovation Center of Advanced Microstructures Nanjing University MatricTime Digital Technology Co.Ltd.

Cryptography promises four information security objectives, namely, confidentiality, integrity, authenticity and non-repudiation, to support trillions of transactions annually in the digital economy. Efficient digital signatures, ensuring integrity, authenticity and non-repudiation of data with information-theoretical security are highly urgent and intractable open problems in cryptography. Here, we propose a high-efficiency quantum digital signature(QDS) protocol using asymmetric quantum keys acquired via secret sharing, one-time universal2hashing and a one-time pad. We just need to use a 384-bit key to sign documents of lengths up to 264with a security bound of 10-19. If a one-megabit document is signed, the signature efficiency is improved by more than 108times compared with previous QDS ***, we build the first all-in-one quantum secure network integrating information-theoretically secure communication, digital signatures, secret sharing and conference key agreement and experimentally demonstrate this signature efficiency advantage. Our work completes the cryptography toolbox of the four information security objectives.

关键词： quantum digital signature information-theoretical security secret sharing one-time universal2 hashing cryptography toolbox

Rare massive hepatic hemangioblastoma:A case report

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2022年第12期14卷 2415-2421页

作者： De-Fu li Xue-Jun Guo Shi-Peng Song hong-bing li Department of Radiology Fuyong People’s Hospital of Shenzhen BaoanShenzhen 518103Guangdong ProvinceChina Department of Radiology Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Hepatobiliary Surgery Fuyong People’s Hospital of Shenzhen BaoanShenzhen 518103Guangdong ProvinceChina

BACKGROUND Hepatic hemangioblastoma is an extremely rare disease;only three cases have been reported in the literature,and its magnetic resonance imaging(MRI)findings are *** SUMMARY We report a case of incidental hepatic *** patient had no history of von Hippel-lindau disease or associated clinical *** tomography and MRI showed a large tumor occupying almost half of the right side of the liver with expansive growth,well-defined borders,heterogeneous mildly progressive enhancement,and visibly enlarged blood supply *** voids were observed on T2-weighted *** diffusion-weighted imaging(DWI)and apparent diffusion coefficient(ADC)map findings of the mass were predominantly *** pathology indicated a diagnosis of *** Enlarged peripheral blood-supplying vessels and progressive enhancement seem to be typical imaging features of hepatic ***,a solid significantly enhanced mass with a low signal on DWI and a high signal on ADC may also be helpful for the diagnosis of hepatic hemangioblastoma.

关键词： Computed tomography Hemangioblastoma Magnetic resonance imaging liver von Hippel lindau disease Case report

Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1746-1762页

作者： Wei liu hong-li Zhao bing-xing Wang Yong Tian State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control *** investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the *** results revealed that the increase in Ni content from 1 to 2 wt.%reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed,which promoted grain *** optimized combination of grain size,high-angle grain boundaries(HAGBs),and martensite-austenite(M-A)islands parameter contributed to the excellent impact toughness of S1 steel at-100℃(impact absorbed energy of 218.2 J at-100℃).As the Mo increases from 0 to 2 wt.%,the matrix structure changes from multiphase structure to granular bainite,which increases the average effective grain size to~4.62 pm and reduces HAGBs proportion to~36.22%.With these changes,the low-temperature impact toughness of S3 steel is *** addition,based on the analysis of the characteristics of crack propagation path,it was found that M-A islands with low content(~2.21%)and small size(~1.76 pm)significantly retarded crack propagation,and the fracture model of M-A islands with different morphologies was further ***,correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters.

关键词： High-strength low-alloy steel Microstructural regulation Ni addition Mo addition Crack propagation Low-temperature toughness

A Granularity-Aware Parallel Aggregation Method for Data Streams

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2006年第1期11卷 133-137页

作者： WANG Yong-li XU hong-bing XU li-zhen QIAN Jiang-bo liU Xue-jun Department of Computer Science and Engineering Southeast University Nanjing 210096 Jiangsu China

This paper focuses on the parallel aggregation processing of data streams based on the shared-nothing architecture. A novel granularity-aware parallel aggregating model is proposed. It employs parallel sampling and linear regression to describe the characteristics of the data quantity in the query window in order to determine the partition granularity of tuples, and utilizes equal depth histogram to implement partitio ning. This method can avoid data skew and reduce communi cation cost. The experiment results on both synthetic data and actual data prove that the proposed method is efficient, practical and suitable for time-varying data streams processing.

关键词： data streams parallel processing linear regression aggregation data skew

Vinyltrimethylsilane as a novel electrolyte additive for improving interfacial stability of li-rich cathode working in high voltage

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 534-538页

作者： bing Jiang Hao li Bi Luo Lehao liu lihua Chu Qiaobao Zhang Meicheng li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of New EnergyNorth China Electric Power UniversityBeijing 102206China State Key Laboratory of Physical Chemistry of Solid Surfaces College of MaterialsXiamen UniversityXiamen 361005China

Boosting the interfacial stability between electrolyte and li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of li-rich cathode materials for high-performance li-ion *** this work,vinyltrimethylsilane as a new type of organic silicon electrolyte additive is studied to address the interfacial instability of li-rich cathode material at high operating *** cells using vinyltrimethylsilane additive shows the high capacity retention of 73.9%after 300 cycles at 1 C,whereas the cells without this kind of additive only have the capacity retention of 58.9%.The improvement of stability is mainly attributed to the additive helping to form a more stable surface film for li-rich cathode material,thus avoiding direct contact between the electrolyte and the cathode material,slowing down the dissolution of metal ions and the decomposition of the electrolyte under high operating *** findings in this work shed some light on the design of stable cycling performance of li-rich cathode toward advanced li-ion batteries.

关键词： Vinyltrimethylsilane Electrolyte additive li-rich cathode Interfacial stability Capacity retention

Optimization of Regulation Valve Location for Heating System

在线全文

学校读者我要写书评

暂无评论

湖南大学学报（自然科学版） 2009年第S1期36卷 88-90页

作者： liU ling-ling,CHEN hong-bing,li De-ying(School of Environment and Energy Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China) School of Environment and Energy Engineering Beijing University of Civil Engineering and Architecture Beijing 100044 China

This paper mainly studied how to determine the best location of the self-operated flow control valve at the heating system *** the location of regulating valve directly affects the pipe network performance,the simulation and analysis of pressure change in heating system was carried out with Computational Fluid Dynamics(CFD)*** study shows the best location of regulating valve varies with the change of the supply and return pipe length when the heating area of each user is small,and when the heating area of each user is large(2 000 000～3 000 000 m2),the best location is on the supply pipe.

关键词： regulating valve optimization CFD simulation

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第2期31卷 377-388页

作者： Tao Pan hong-chun Zhu Zhou-hua Jiang Hua-bing li Rui Zhang Hao Feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh *** results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width ***,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium *** melt rate increases,both the molten pool depth and the mushy width *** is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the *** nonlinear increment in sensible heat leads to a nonlinear increase in the mushy *** addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then *** melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time