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区域互联网深化、信息摩擦与进口增长——基于进口二元边际视角

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山西财经大学学报 2025年第1期47卷 72-85页

作者：庄金凤马野青王冠宇南京大学商学院

信息技术发展是驱动城市数字经济发展和高水平对外开放的基础。基于此，创新性地提出考虑信息摩擦作用的垄断竞争分析框架，并从进口二元边际视角实证检验区域互联网深化对进口增长的作用。研究发现，区域互联网深化能显著促进进口规模... 详细信息

信息技术发展是驱动城市数字经济发展和高水平对外开放的基础。基于此，创新性地提出考虑信息摩擦作用的垄断竞争分析框架，并从进口二元边际视角实证检验区域互联网深化对进口增长的作用。研究发现，区域互联网深化能显著促进进口规模扩张，增长来源于进口价格、进口数量与进口种类，主要影响机制为降低信息摩擦。异质性分析表明，低对外贸易开放城市互联网深化显著降低了进口产品数量。进一步讨论发现，区域互联网深化对进口“数量”增长及“质量”增长均有促进作用。

关键词：互联网深化进口广延边际进口集约边际信息摩擦进口产品质量可变加价垄断竞争市场进口贸易

NUMERICAL SIMULATION OF 3-D AERATED JET BEHIND FLIP BUCKET OF OVERFLOW DAM

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Journal of Hydrodynamics 2000年第1期12卷 49-56页

作者： Liu, Shihi ye, qing Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

Aerated jets, such as the jet flow behind the flip bucket of an overflow dam, widely exists in hydraulic engineering. Up to now the model test and prototype observation have been two main methods of studying the aerated jet for a special hydraulic project. A three-dimensional mathematical model for the aerated jet was established. It seems that the suggested model has high predictive power in comparison with the original two methods of model test and prototype observation which is very useful in the study of energy dissipation and jet flow atomization.

关键词： Computer simulation Dams Flow of water Mathematical models Three dimensional

Numerical simulation of cook-off characteristics for AP/HTPB

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Defence Technology（防务技术） 2018年第5期14卷 451-456页

作者： qing ye Yong-gang Yu School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094China

The present study is devoted to researching the thermal security problems of large-scale solid rocket motor with Ammonium perchlorate/Hydroxyl-terminated polybutadiene(AP/HTPB). A two-dimensional axisymmetric model for the cook-off of solid rocket motor is established. The reaction kinetics for the cook-off process of AP/HTPB is described by the two-step global chemical mechanism. Numerical predictions of the cook-off behavior for the propellant are conducted at fast heating rate of 1.45-2.45 K/s,and slow heating rate of 0.001-0.003 K/s, respectively. The results show that in the fast cook-off condition. the initial ignition position of AP/HTPB occurs in the annular region of the outer wall of propellant without exception, and the center point in the region is(889.1,149.5). For the region, the axial width is1.8 mm and radial thickness is 0.8 mm. However, in the slow cook-off condition, the ignition center position is shifted along the axial direction toward the right end face of the propellant with the increase of heating rate. Therefore, the influence of heating rate on ignition temperature and ignition delay time is nonnegligible within a certain range.

关键词： Cook-off Numerical simulation AP/HTPB

arcPycor:an open-source automated GIS tool to co-register elevation datasets

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Journal of Mountain Science 2021年第4期18卷 923-931页

作者： WANG Yu-zhe ye qing-hua College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Geography and Environment Shandong Normal UniversityJinan 250358China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Subtraction of elevation datasets(*** elevation models(DEMs)and non-continuous elevation points)acquired at different times is a useful method to monitor landform surface *** to heavy post-processing of these elevation datasets,multi-source errors are introduced into the resulting elevation data *** improve the estimation of elevation change,co-registration of elevation datasets is a *** paper presents an open-source automated GIS tool(arc Pycor)for co-registering elevation *** Pycor is coded in Python 2.7 and is run via Arc GIS for *** performances of arc Pycor have been evaluated using a series of *** benchmark tests,the resolved co-registration vectors of arc Pycor are compared to the predefined shift vectors obtained by artificially misaligning the slave DEMs from the master elevation *** show that arc Pycor is able to co-register DEMs with relative high accuracy and can well align slave DEMs to non-continuous elevation points,which indicates its robustness in co-registering of elevation *** Pycor is also able to co-register multi-sourced DEMs of different resolutions in mountain areas.

关键词： Digital elevation models DEM coregistration ArcGIS Elevation change Terrain analysis

Low-temperature(NO + O_(2)) adsorption performance of alkaline earth metal-doped C-FDU-15

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Journal of Environmental Sciences 2021年第5期33卷 172-184页

作者： Runping Wu qing ye Kai Wu Hongxing Dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Chemistry and Chemical EngineeringCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China

To improve the removal capacity of NO + O_(2) effectively, the alkaline earth metal-doped order mesoporous carbon(A-C-FDU-15(0.001)(A = Mg, Ca, Sr and Ba)) and Mg-C-FDU-15( x)( x = 0.001-0.003) samples were prepared, and their physicochemical and NO + O_(2) adsorption properties were determined by means of various techniques. The results show that the sequence in(NO + O_(2)) adsorption performance was as follows: Mg-C-FDU-15(0.001)(93.2 mg/g) > Ca-C-FDU-15(0.001)(82.2 mg/g) > Sr-C-FDU-15(0.001)(76.1 mg/g) > Ba-C-FDU-15(0.001)(72.9 mg/g) > C-FDU-15(67.1 mg/g). Among all of the A-C-FDU-15(0.001) samples, Mg-C-FDU-15(0.001) possessed the highest(NO + O_(2)) adsorption capacity(106.2 mg/g). The species of alkaline earth metals and basic sites were important factors determining the adsorption of NO + O_(2) on the A-C-FDU-15( x) samples, and(NO + O_(2)) adsorption on the samples was mainly chemical adsorption. Combined with the results of(NO + O_(2))-temperatureprogrammed desorption((NO + O_(2))-TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS) characterization, we deduced that there were two main pathways of(NO + O_(2)) adsorption: one was first the conversion of NO and O_(2) to NO_(2) and then part of NO_(2) was converted to NO_(2)^(-) and NO_(3)^(-);and the other was the direct oxidation of NO to NO-2 and NO_(3)^(-).

关键词： C-FDU-15 Alkaline earth metal NO+O_(2)adsorption Adsorption mechanism Adsorption kinetics

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Contribution of diffusion,perfusion and functional MRI to the disconnection hypothesis in subcortical vascular cognitive impairment

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Stroke & Vascular Neurology 2018年第3期3卷 131-139页

作者： qing ye Feng Bai Department of Neurology Affiliated Drum Tower HospitalNanjing University Medical SchoolNanjingJiangsuChina Jiangsu Province Stroke Center for Diagnosis and Therapy NanjingChina Nanjing Neuropsychiatry Clinic Medical Center NanjingChina Jiangsu Key Laboratory for Molecular Medicine Nanjing University Medical SchoolNanjingChina

Vascular cognitive impairment(VCI)describes all forms of cognitive impairment caused by any type of cerebrovascular *** identification of VCI is quite difficult due to the lack of both sensitive and specific *** damage to the white matter tracts,which connect the cortical and subcortical regions,has been shown in subcortical VCI(SVCI),the most common subtype of VCI that is caused by small vessel *** specific MRI sequences,including diffusion tensor imaging(DTI)and functional MRI(fMRI),have emerged as useful tools for identifying subtle white matter changes and the intrinsic connectivity between distinct cortical *** review describes the advantages of these two modalities in SVCI research and the current DTI and fMRI findings on *** DTI technique,a variety of studies found that white matter microstructural damages in the anterior and superior areas are more specific to ***,functional brain abnormalities detected by fMRI have also been mainly shown in anterior brain areas in *** characteristic distribution of brain abnormalities in SVCI interrupts the prefrontal-subcortical loop that results in cognitive impairments in particular domains,which further confirms the‘disconnection syndrome’*** addition,another MRI technique,arterial spin labelling(ASL),has been used to describe the disconnection patterns in a variety of conditions by measuring cerebral blood *** role of the ASL technique in SVCI research is also ***,the review proposes the application of multimodality fusion in the investigation of SVCI pathogenesis.

关键词： impairment subcortical diffusion

LoS sensing-based superimposed CSI feedback for UAV-assisted mmWave systems

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Chinese Journal of Aeronautics 2023年第12期36卷 349-360页

作者： Chaojin qing qing ye Wenhui LIU Zilong WANG Jiafan WANG Jinliang CHEN School of Electrical Engineering and Electronic Information Xihua UniversityChengdu 610039China School of Aeronautics and Astronautics Xihua UniversityChengdu 610039China

In Unmanned Aerial Vehicle(UAV)-assisted millimeter Wave(mmWave)systems,Channel State Information(CSI)feedback is critical for the selection of modulation schemes,resource management,beamforming,***,traditional CSI feedback methods lead to significant feedback overhead and energy consumption of the UAV transmitter,therefore shortening the system operation *** tackle these issues,inspired by superimposed feedback and Integrated Sensing and Communications(ISAC),a Line of Sight(LoS)sensing-based superimposed CSI feedback scheme is ***,on the UAV transmitter side,the Ground-to-UAV(G2U)CSI is superimposed on the UAV-to-Ground(U2G)data to feed back to the ground Base Station(gBS).At the gBS,the dedicated LoS Sensing Network(LoS-SenNet)is designed to sense the U2G CSI in LoS and NLoS *** the sensed result of LoS-SenNet,the determined G2U CSI from the initial feature extraction will work as the priori information to guide the subsequent ***,for the G2U CSI in NLoS,a CSI Recovery Network(CSI-RecNet)and superimposed interference cancellation are developed to recover the G2U CSI and U2G *** for the LoS scenario,a dedicated LoS Aid Network(LoS-Aid Net)is embedded before the CSI-RecNet and the block of superimposed interference cancellation to highlight the feature of the G2U *** with other methods of superimposed CSI feedback,simulation results demonstrate that the proposed feedback scheme effectively improves the recovery accuracy of the G2U CSI and U2G ***,against parameter variations,the proposed feedback scheme presents its robustness.

关键词： Channel State Information(CSI) Integrated Sensing and Communications(ISAC) Line of Sight(LoS)sensing Superimposed CSI feedback Unmanned Aerial Vehicle(UAV)-assisted millimeter Wave(mmWave)systems

The damage to model concrete gravity dams subjected to water explosions

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Defence Technology（防务技术） 2023年第9期27卷 119-137页

作者： Shang Ma ye-qing Chen Zhen-qing Wang Shu-tao Li qing Zhu Long-ming Chen College of Aerospace and Civil Engineering Harbin Engineering UniversityHarbin150001China Institute of Defense Engineering AMSPLABeijing100036China

Over the past century,the safety of dams has gradually attracted attention from all *** on the dynamic response and damage evolution of dams under extreme loads is the basis of dam safety *** recent decades,scholars have studied the responses of dams under earthquake loads,but there is still much room for improvement in experimental and theoretical research on small probability loads such as *** this paper,a 50-m-high concrete gravity dam is used as a prototype dam,and a water explosion model test of a 2.5-m-high concrete gravity dam is *** water pressure and the acceleration response of the dam body in the test are *** pressure characteristics and dynamic response of the dam body are *** the dam damage test as an example,a numerical model of concrete gravity dam damage is established,and the damage evolution of the dam body is *** combining experiments and numerical simulations,the damage characteristics of the dam body under the action of different charge water explosions are *** integrity of the dam body is well maintained under the action of a small-quantity water explosion,and the dynamic response of the dam body is mainly caused by the shock *** the shock wave and the bubble pulsation cause the dam body to accelerate,and the peak acceleration of the dam body under the action of the bubble pulsation is only one percent of the peak acceleration of the dam body under the action of the shock *** subjected to explosions in large quantities of water,the dam body is seriously *** the action of a shock wave,the dam body produces a secondary acceleration response,which is generated by an internal interaction after the dam body is *** damage evolution process of the dam body under the action of a large-scale water explosion is analysed,and it is found that the shock wave pressure of the water explosion causes local damage to the dam body facing the ***

关键词： Underwater explosion Concrete gravity dam Model test Damage evolution

An Examination of Some Factory Physics Principles

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Journal of the Operations Research Society of China 2016年第2期4卷 131-145页

作者： Hong Chen Heng-qing ye Shanghai Advanced Institute of Finance Shanghai Jiaotong UniversityShanghai 200240China Faculty of Business Hong Kong Polytechnic UniversityHong KongChina

In this paper,we examine some principles in managing manufacturing sys*** principles are concerned with the variability,the utilization,the rework,the lead time,and the constant work-in-process *** these principles are developed through analyzing some simpler disconnected flow line manufacturing systems,we examine whether they can have broad *** some of these principles,we provide sufficient conditions,while for others,we provide counterex*** analysis suggests that we should be very cautious about these laws when applied to non-Markov and non-tandem systems.

关键词： Factory physics Manufacturing system Variability Utilization Rework Constant work-in-process Lead time