检索结果-南通市图书馆

Melt flow,heat transfer and solidification in a flexible thin slab continuous casting mold with vertical-combined electromagnetic braking

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 401-415页

作者： Lin Xu ze-feng Han Christian Karcher en-gang wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina Key Laboratory of Liaoning Province for Clean Combustion Power Generation and Heating Technology Shenyang Institute of EngineeringShenyang110136LiaoningChina Institute of Thermodynamics and Fluid Mechanics Technische Universität IlmenauIlmenau98684Germany

During continuous casting of steel slabs,the application of electromagnetic braking technology(EMBr)provides an effective tool to influence solidification by controlling the pattern of melt flow in the mold.Thus,the quality of the final product can be improved considerably.A new electromagnetic braking(EMBr)method,named vertical-combined electromagnetic braking(VC-EMBr),is proposed to be applied to a flexible thin slab casting(FTSC)mold.To evaluate the beneficial effects of the VC-EMBr,the melt flow,heat transfer,and solidification processes in the FTSC mold are studied by means of numerical simulations.In detail,a Reynolds-averaged Navier–Stokes turbulence model together with an enthalpy-porosity approach was used.The numerical findings are compared with respective simulations using the traditional Ruler-EMBr.The results demonstrate that the application of the VC-EMBr contributes significantly to preventing relative slab defects.In contrast to the Ruler-EMBr,the additional vertical magnetic poles of the VC-EMBr preferentially suppress the direct impact of jet flow on the narrow face of FSTC mold and considerably diminish the level fluctuation near the meniscus region.For instance,by applying a magnetic flux density of 0.3 T,the maximum amplitude of meniscus deflection reduces by about 80%.Moreover,the braking effect of the VC-EMBr effectively improves the homogeneity of temperature distribution in the upper recirculation region and increases the solidified shell thickness along the casting direction.On this basis,the newly proposed VC-EMBr shows a beneficial effect in preventing relative slab defects for FTSC thin slab continuous casting.

关键词： Electromagnetic braking Mold Melt flow Heat transfer Solidification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Gas storage in shale pore system:A review of the mechanism,control and assessment

引用

Petroleum Science 2023年第5期20卷 2605-2636页

作者： Yue Feng Xian-Ming Xiao en-ze wang Ping Gao Chen-Gang Lu Gang Li School of energy Resources China University of Geosciences(Beijing)Beijing100083China School of Earth and Space Sciences Peking UniversityBeijing100871China

In the past 15 years,the shale gas revolution and large-scale commercial developments in the United States have driven the exploration and development of shale plays worldwide.Among many factors affecting shale gas exploration potential,the gas-bearing properties of shale(quantity,storage state,composition)and their controlling factors are the essential research attracting wide attention in the academic community.This paper reviews the research progress on the retention mechanism,influencing factors,and evaluation methods for resource potential of the shale gas system,and proposes further research directions.Sorption is the main mechanism of gas retention in organic-rich shales;the gas is mainly stored in nanopores of shale in free and sorption states.The presence of water and nonhydrocarbon gases in pores can complicate the process and mechanism of methane(CH4)sorption,and the related theoretical models still need further development.The in-situ gas content and gasbearing properties of shale are governed by the geological properties(organic matter abundance,kerogen type,thermal maturity,mineral composition,diagenesis),the properties of fluids in pores(water,CH_(4),non-hydrocarbon gases),and geological conditions(temperature,pressure,preservation conditions)of the shale itself.For a particular basin or block,it is still challenging to define the main controlling factors,screen favorable exploration areas,and locate sweet spots.Compared to marine shales with extensive research and exploration data,lacustrine and marine-continental transitional shales are a further expanding area of investigation.Various methods have been developed to quantitatively characterize the in-situ gas content of shales,but all these methods have their own limitations,and more in-depth studies are needed to accurately evaluate and predict the in-situ gas content of shales,especially shales at deep depth.

关键词： Shale gas Retention mechanism Multi-component adsorption Influencing factors Evaluation method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

entanglement quantification via weak measurements assisted by deep learning

引用

Photonics Research 2024年第4期12卷 712-719页

作者： MU YANG YA XIAO ze-YAN HAO YU-WEI LIAO JIA-HE CAO KAI SUN en-HUI wang ZHenG-HAO LIU YUTAKA SHIKANO JIN-SHI XU CHUAN-FenG LI GUANG-CAN GUO CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China College of Physics and Optoelectronic engineering Ocean University of ChinaQingdao 266100China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Electric Power Research Institute State Grid Anhui Electric Power Co.Ltd.Hefei 230601China Institute of Systems and Information engineering University of TsukubaIbaraki 305-8573Japan Center for Artificial Intelligence Research University of TsukubaIbaraki 305-8577Japan Graduate School of Science and Technology Gunma UniversityGunma 371-8510Japan Institute for Quantum Studies Chapman UniversityOrangeCalifornia 92866USA JST PRESTO Saitama 332-0012Japan

entanglement has been recognized as being crucial when implementing various quantum information tasks.Nevertheless, quantifying entanglement for an unknown quantum state requires nonphysical operations or post-processing measurement data. For example, evaluation methods via quantum state tomography require vast amounts of measurement data and likely estimation.

关键词： estimation quantum angle

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution and resource evaluation of natural gas hydrate in South China sea by combing phase equilibrium mechanism and volumetric method

引用

Petroleum Science 2022年第1期19卷 26-36页

作者： Tong wang Tao Hu Xiong-Qi Pang Xing-Wen Zhang Xiao-Han Liu Zhi Xu en-ze wang Zhuo-Ya Wu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China School of Earth&Space Sciences Peking UniversityBeijing100871China Research Institute of Petroleum Exploration and Development PetroChina Company LimitedBeijing100083China

China Geological Survey conducted the second trial production of natural gas hydrate(NGH)in the Shenhu Area in South China Sea(SCS)from 2019 to 2020.Compared with the first trial production in 2017,the second trial showed significantly increased daily gas production and total gas production,and removed some technical obstacles for large-scale NGH resource developments in the SCS.However,current NGH resource evaluation in the SCS is still at the stage of prospective gas content assessment,which is unable to guide further NGH exploration and development.This study utilized the hydrate phase balance to delineate the NGH distribution range and effective thickness and volumetric method to evaluate NGH resource.Based on the latest exploration and production data from the Shenhu Area,Monte Carlo simulation was performed to calculate the NGH resource amount with different probabilities.By assuming a 50%cumulative probability,the in-situ NGH resources in the SCS was estimated to be11.7×10^(12)m^(3) and the recoverable NGH resources was 2.8×10^(12)m^(3).These results will provide a more reliable resource basis for China to formulate comprehensive development strategies for oil and gas exploration in the SCS.

关键词： South China Sea Oil and gas resource Natural gas hydrate In-situ resource Recoverable resources

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of natural gas hydrate resources in the South China Sea using a new genetic analogy method

引用

Petroleum Science 2022年第1期19卷 48-57页

作者： Xiao-Han Liu Tao Hu Xiong-Qi Pang Zhi Xu Tong wang Xing-Wen Zhang en-ze wang Zhuo-Ya Wu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing 102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China School of Earth&Space Sciences Peking UniversityBeijing100871China Research Institute of Petroleum Exploration&Development CNPCBeijing100083China

Natural gas hydrate(NGH)has attracted much attention as a new alternative energy globally.However,evaluations of global NGH resources in the past few decades have casted a decreasing trend,where the estimate as of today is less than one ten-thousandth of the estimate forty years ago.The NGH researches in China started relatively late,but achievements have been made in the South China Sea(SCS)in the past two decades.Thirty-five studies had been carried out to evaluate NGH resource,and results showed a flat trend,ranging from 60 to 90 billion tons of oil equivalent,which was 2-3 times of the evaluation results of technical recoverable oil and gas resources in the SCS.The big difference is that the previous 35 group of NGH resource evaluations for the SCS only refers to the prospective gas resource with low grade level and high uncertainty,which cannot be used to guide exploration or researches on development strategies.Based on the analogy with the genetic mechanism of conventional oil and gas resources,this study adopts the newly proposed genetic method and geological analogy method to evaluate the NGH resource.Results show that the conventional oil and gas resources are 346.29×10^(8)t,the volume of NGH and free dynamic field are 25.19×10^(4)km^(3) and(2.05-2.48)×10^(6)km^(3),and the total amount of in-situ NGH resources in the SCS is about(4.47-6.02)×10^(12)m^(3).It is considered that the resource of hydrate should not exceed that of conventional oil and gas,so it is 30 times lower than the previous estimate.This study provides a more reliable geological basis for further NGH exploration and development.

关键词： South China Sea Natural gas hydrate Natural gas hydrate resources Conventional oil and gas resources Genetic method Analogy method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of natural gas hydrate resources in the South China Sea by combining volumetric and trend-analysis methods

引用

Petroleum Science 2022年第1期19卷 37-47页

作者： Xing-Wen Zhang Tao Hu Xiong-Qi Pang Yao Hu Tong wang en-ze wang Zhi Xu Xiao-Han Liu Zhuo-Ya Wu Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing 102249China College of Geosciences China University of Petroleum(Beijing)Beijing 102249China CNOOC International Limited Beijing 100029China School of Earth&Space Sciences Peking UniversityBeijing 100871China Research Institute of Petroleum Exploration and Development PetroChina Company LimitedBeijing 100083China

Natural gas hydrate(NGH),considered as a type of premium energy alternative to conventional hydrocarbons,has been broadly studied.The estimate of the total NGH resources in the world has decreased by more than 90%since the first evaluation in 1973.Geographic and geophysical conditions of the South China Sea(SCS)are favorable for the formation of NGH,which has been proved by drilling results up to date.The recoverability of the NGH in the SCS has been confirmed by the production tests using both vertical and horizontal wells.Since 2001,35 estimates of NGH resources in the SCS have been made,with relatively stable results varying between 600 and 900×109 ton oil equivalent.In these estimations,the volumetric method was commonly adopted,but the geological conditions,the migration-accumulation mechanisms of NGH,and the practical recoverability were not considered.These estimates cannot be regarded as evaluated resources according to the international resource evaluation standards,but are at most about prospective gas content of NGH,thus inefficient for guiding explorations and developments.To solve these problems,this study divides the past NGH surveys in the SCS into seven stages,acquires key geological parameters of every stage based on previous studies and analogy with other areas,evaluates the NGH resources of these seven stages by using the volumetric method,then adopts a new trend-analysis method to simulate the downward trend of these estimates,and finally predicts the NGH resources in the SCS at 2025 and 2030.The downward trend is because of the continuous improvement of NGH understanding over time,which is consistent with the trend of global NGH estimates.At the present stage(from 2019 to 2021),the average technically recoverable resource(ATRR)is 7.0×10^(12)m^(3),and the estimates of 2025 and 2030 ATRR are 6.46×10^(12)m^(3) and 4.01×10^(12)m^(3)respectively,with a difference of less than 40%.Therefore,it can be inferred that the ATRR of NGH in the SCS is between 4.0 and 6.5×10^(12)m^(3),with an average of 5.2

关键词： Resource evaluation Natural gas hydrates The South China Sea Volumetric method Trend-analysis method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research progress and challenges of natural gas hydrate resource evaluation in the South China Sea

引用

Petroleum Science 2022年第1期19卷 13-25页

作者： Zhi Xu Tao Hu Xiong-Qi Pang en-ze wang Xiao-Han Liu Zhuo-Ya Wu Di Chen Chang-Rong Li Xing-Wen Zhang Tong wang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China School of Earth&Space Sciences Peking UniversityBeijing100871China Research Institute of Petroleum Exploration&Development CNPCBeijing100083China

As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including determination of the favorable distribution areas and favorable strata thickness,identification of the dual source for accumulation,evaluation of the prospective gas contents,verification of the widespread existence,and confirmation of the technical recoverability of NGH resources.However,there are three major challenges in the NGH studies.First,all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years,while 8 of the 10 international NGH research projects focused on resource potential.Second,resource evaluation methods are outdated and some parameter selection are subjective.Third,the existing resource evaluation results are low-level with a great uncertainty,and cannot be used to guide NGH exploration and production or strategic research.To improve the evaluation of NGH resources in the SCS,future researches should focus on four aspects:(1)improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation;(2)apply new theories and methods from the global NGH research;(3)boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins;(4)innovate the theory and method of NGH resource potential evaluation.

关键词： South China Sea Natural gas hydrate Oil and gas resource evaluation Comprehensive exploration of oil and gas Oil and gas development strategy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characterization of a pangolin SARS-CoV-2-related virus isolate that uses the human ACE2 receptor

引用

Science China(Life Sciences) 2024年第7期67卷 1502-1513页

作者： Luo-Yuan Xia Xue-Feng wang Xiao-Ming Cui Yi-Ming Zhang Zhen-Fei wang en-Tao Li Chang-Fa Fan Ke Song Yuan-Guo Li Run-ze Ye Fang-Xu Li Dai-Yun Zhu Jie Zhang Zhuang-Zhuang Shi Ming-Zhu Zhang Liang-Jing Li Shi-Jing Shen Song Jin Ya-Wei Zhang Wei-Guang Fu Lin Zhao Wen-Hao wang Tie-Cheng wang You-Chun wang Jia-Fu Jiang Yan-Ling Hu Na Jia Yu-Wei Gao Wu-Chun Cao Institute of EcoHealth School of Public HealthCheeloo College of MedicineShandong UniversityJinan 250012China Changchun Veterinary Research Institute Changchun 130122China State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and EpidemiologyBeijing 100071China Division of Animal Model Research Institute for Laboratory Animal ResourcesNational Institutes for Food and Drug ControlBeijing 102629China National Institutes for Food and Drug Control Beijing 102629China Life Sciences Institute Guangxi Medical UniversityNanning 530020China College of Life Sciences Shandong Normal UniversityJinan 250014China Research Unit of Discovery and Tracing of Natural Focus Diseases Chinese Academy of Medical SciencesBeijing 100071China

Various SARS-CoV-2-related coronaviruses have been increasingly identified in pangolins,showing a potential threat to humans.Here we report the infectivity and pathogenicity of the SARS-CoV-2-related virus,PCoV-GX/P2V,which was isolated from a Malayan pangolin(Manis javanica).PCoV-GX/P2V could grow in human hepatoma,colorectal adenocarcinoma cells,and human primary nasal epithelial cells.It replicated more efficiently in cells expressing human angiotensin-converting enzyme 2(hACE2)as SARS-CoV-2 did.After intranasal inoculation to the hACE2-transgenic mice,PCoV-GX/P2V not only replicated in nasal turbinate and lungs,but also caused interstitial pneumonia,characterized by infiltration of mixed inflammatory cells and multifocal alveolar hemorrhage.Existing population immunity established by SARS-CoV-2 infection and vaccination may not protect people from PCoV-GX/P2V infection.These findings further verify the hACE2 utility of PCoV-GX/P2V by in vivo experiments using authentic viruses and highlight the importance for intensive surveillance to prevent possible cross-species transmission.

关键词： pangolin SARS-CoV-2-related virus infectivity pathogenicity human cell lines human ACE2 receptor hACE2-transgenic mice

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

多特征融合和孪生注意力网络的高分辨率遥感图像目标检测

引用

吉林大学学报（工学版） 2024年第1期54卷 240-250页

作者：王春华李恩泽肖敏黄淮学院动画学院河南驻马店463000 武汉理工大学计算机与人工智能学院武汉430063

为提高高分辨率遥感图像目标检测效果,本文将多特征融合方法和孪生注意力网络相结合,提出一种新的目标检测方法。构建遥感图像目标检测的整体框架,基于锚框模型对遥感图像目标进行多层特征的提取及融合;运用孪生注意力网络对遥感图像目... 详细信息

为提高高分辨率遥感图像目标检测效果,本文将多特征融合方法和孪生注意力网络相结合,提出一种新的目标检测方法。构建遥感图像目标检测的整体框架,基于锚框模型对遥感图像目标进行多层特征的提取及融合;运用孪生注意力网络对遥感图像目标实时视觉跟踪检测,引入通道和空间的双重自注意力机制,提高目标图像的特征表达能力,由此得到更加精准的检测结果。实验分析结果表明,本文方法的平均总体精度为93.8,F1指数平均值为0.88,Kappa系数平均值为0.93,均明显高于对比方法,说明本文方法具有较好的检测效果。

关键词：多特征融合高分辨率遥感图像孪生注意力目标检测语义特征

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reduction of global natural gas hydrate(NGH)resource estimation and implications for the NGH development in the South China Sea

引用

Petroleum Science 2022年第1期19卷 3-12页

作者： Xiong-Qi Pang Cheng-Zao Jia Zhang-Xing Chen He-Sheng Shi Zhuo-Heng Chen Tao Hu Tong wang Zhi Xu Xiao-Han Liu Xing-Wen Zhang en-ze wang Zhuo-Ya Wu Bo Pang State Key Laboratory of Petroleum Resources and Prospecting Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China China National Petroleum Corporation Beijing100007China Chemical and Petroleum engineering Schulich School of EngineeringUniversity of CalgaryCalgaryT2N 1N4Canada Shenzhen Branch of China National Offshore Oil Corporation Ltd. GuangzhouGuangdong 510240China Geological Survey of Canada Natural Resources CanadaCalgaryT2L 2A7Canada School of Earth&Space Sciences Peking UniversityBeijing100871China

There have been at least 29 groups of estimates on the global natural gas hydrate(NGH)resource since1973,varying greatly with up to 10,000 times and showing a decreasing trend with time.For the South China Sea(SCS),35 groups of estimations were conducted on NGH resource potential since 2000,while these estimates kept almost the same with time,varying between 60 and 90 billion tons of oil equivalent(toe).What are the key factors controlling the variation trend?What are the implications of these variations for the NGH development in the world and the SCS?By analyzing the investigation characteristics of NGH resources in the world,this study divided the evaluation process into six stages and confirmed four essential factors for controlling the variations of estimates.Results indicated that the reduction trend reflects an improved understanding of the NGH formation mechanism and advancement in the resource evaluation methods,and promoted more objective evaluation results.Furthermore,the analysis process and improved evaluation method was applied to evaluate the NGH resources in the SCS,showing the similar decreasing trend of NGH resources with time.By utilizing the decreasing trend model,the predicted recoverable resources in the world and the SCS are(205-500)×10^(12)m^(3)and(0.8-6.5)×10^(12)m^(3),respectively,accounting for 20%of the total conventional oil and gas resources.Recoverable NGH resource in the SCS is only about 4%-6%of the previous estimates of 60-90 billion toe.If extracted completely,it only can support the sustainable development of China for 7 years at the current annual consumption level of oil and gas.NGH cannot be the main energy resource in future due to its low resource potential and lack of advantages in recovery.

关键词： Natural gas hydrate Resource evaluation South China Sea Global NGH resource Reduction trend in NGH resource

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：