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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

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Frontiers of Information Technology & Electronic Engineering 2017年第6期18卷 796-807页

作者： Zhen-hua YUAN Chen CHEN Xiang CHENG Guo-cheng LV Liu-qing YANG ye JIN State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University Department of Electrical & Computer Engineering Colorado State University

This article is focused on secure relay beamformer design with a correlated channel model in the relay-eavesdropper network. In this network, a single-antenna source-destination pair transmits secure information with the help of an amplify-and-forward (AF) relay equipped with multiple antennas, and the legitimate and eavesdropping channels are correlated. The relay cannot obtain the instantaneous channel state information (CSI) of the eavesdropper, and has only the knowledge of correlation information between the legitimate and eavesdropping channels. Depending on this information, we derive the conditional distribution of the eavesdropping channel. Two beamformers at the relay are studied for the approximate ergodic secrecy rate:(1) the generalized match-andforward (GMF) beamformer to maximize the legitimate channel rate, and (2) the general-rank beamformer (GRBF).In addition, one lower-bound-maximizing (LBM) beamformer at the relay is discussed for maximizing the lower bound of the ergodic secrecy rate. We find that the GMF beamformer is the optimal rank-one beamformer, that the GRBF is the iteratively optimal beamformer, and that the performance of the LBM beamformer for the ergodic secrecy rate gets close to that of the GRBF for the approximate secrecy rate. It can also be observed that when the relay has lower power or the channel gain of the second hop is low, the performance of the GMF beamformer surpasses that of the GRBF. Numerical results are presented to illustrate the beamformers' performance.

关键词： Physical layer security Relay beamforming Correlated channels Ergodic secrecy rate

Quantification and timing of porosity evolution in tight sand gas reservoirs:an example from the Middle Jurassic Shaximiao Formation,western Sichuan,China

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Petroleum Science 2015年第2期12卷 207-217页

作者： Zheng-Xiang Lü Su-Juan ye Xiang Yang Rong Li Yuan-hua qing State Key Laboratory of Oil and Gas Reservoir Geology &Exploitation Chengdu University of Technology Exploration and Production Research Institute Sinopec Southwest Chengdu Institute of Geology and Mineral Resources PetroChina Tarim Oilfield Company

The diagenesis and porosity evolution of the Middle Jurassic Shaximiao sandstones were analyzed based on petrographic observations, X-ray diffractometry, scanning electron microscopy observations, carbon and oxygen stable isotope geochemistry, fluid inclusion mi- crothermometry, and thermal and burial history modeling results. The point count data show that secondary pores （av. 5.5 %） are more abundant than primary pores （av. 3.7 %） and are thus the dominant pore type in the Shaximiao sandstones. Analysis of porosity evolution indicates that alteration of sandstones mainly occurred during two paragenetic stages. Mechanical compaction and cementa- tion by early chlorite, calcite, and quartz typically decrease the depositional porosity （40.9 %） by an average of 37.2 %, leaving porosity of 3.7 % after stage I （〈85 ℃, 175-145 Ma）. The original intergranular porosity loss due to compaction is calculated to be 29.3 %, suggesting that mechanical compaction is the most significant diagenetic process in primary porosity destruction. Stage II can be further divided into two sub-stages （Stage IIa and Stage IIb）. Stage IIa （85-120 ℃, 145-125 Ma） is characterized by late dissolution, which enhanced porosity by 8.8 %, and the porosity increased from 3.7 % to 12.5 %. During stage IIb （〉120 ℃, 125-0 Ma）, the precipitation of late chlorite, calcite, quartz, and kaolinite destroyed 3.3 % porosity, leaving porosity of 9.2 % in the rock today.

关键词： Diagenesis Porosity evolution -Tight gas sandstones Jurassic Western Sichuan

Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method

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Nuclear Science and Techniques 2023年第2期34卷 13-27页

作者： Jian‑hua ye Tao Yu State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices East China University of TechnologyNanchang 330013China School of Nuclear Science and Engineering East China University of TechnologyNanchang 330013China

The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from *** this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic *** length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,*** most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater *** separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was *** experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage *** the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage ***,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from *** novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities

关键词： Pulsed liquid chromatography Nuclide separation Seawater uranium extraction Uranium enrichment

Design and characterization of metallic glass/graphene multilayer with excellent nanowear properties

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Friction 2022年第11期10卷 1913-1926页

作者： qing ZHOU Dawei LUO Dongpeng hua Wenting ye Shuo LI Qiguang ZOU Ziqiang CHEN Haifeng WANG State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

The excellent properties of metallic glass(MG)films make them perfect candidates for the use in miniature systems and ***,their high coefficients of friction(COFs)and poor wear resistance considerably limit their long-term performance in nanoscale *** report the fabrication of a MG/graphene multilayer by the repeated deposition of Cu_(50)Zr_(50) MG with alternating layers of *** microstructure of the multilayer was characterized by the transmission electron microscopy(TEM).Its mechanical and nanotribological properties were studied by nanoindentation and nanoscratch tests,respectively.A molecular dynamics(MD)simulation revealed that the addition of graphene endowed the MG with superelastic recovery,which reduced friction during *** comparison with the monolithic MG film,the multilayer exhibited improved wear resistance and a low COF in repeated nanowear tests owing to the enhanced mechanical properties and lubricating effect caused by the graphene *** work is expected to motivate the design of other novel MG films with excellent nanowear properties for engineering applications.

关键词： metallic glass(MG) multilayer nanowear properties molecular dynamics(MD)simulation

Synchronization mechanism of clapping rhythms in mutual interacting individuals

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Chinese Physics B 2021年第1期30卷 197-206页

作者： Shi-Lan Su Jing-hua Xiao Wei-qing Liu ye Wu School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China School of Science Jiangxi University of Science and TechnologyGanzhou 341000China Computational Communication Research Center Beijing Normal UniversityZhuhai 519087China School of Journalism and Communication Beijing Normal UniversityBeijing 100875China

In recent years, clapping synchronization between individuals has been widely studied as one of the typical synchronization phenomena. In this paper, we aim to reveal the synchronization mechanism of clapping interactions by observing two individuals’ clapping rhythms in a series of experiments. We find that the two synchronizing clapping rhythm series exhibit long-range cross-correlations(LRCCs);that is, the interaction of clapping rhythms can be seen as a strong-anticipation process. Previous studies have demonstrated that the interactions in local timescales or global matching in statistical structures of fluctuation in long timescales can be sources of the strong-anticipation process. However, the origin of the strong anticipation process often appears elusive in many complex systems. Here, we find that the clapping synchronization process may result from the local interaction between two clapping individuals and may result from the more global coordination between two clapping individuals. We introduce two stochastic models for mutually interacting clapping individuals that generate the LRCCs and prove theoretically that the generation of clapping synchronization process needs to consider both local interaction and global matching. This study provides a statistical framework for studying the internal synchronization mechanism of other complex systems. Our theoretical model can also be applied to study the dynamics of other complex systems with the LRCCs, including finance, transportation, and climate.

关键词： synchronization mechanism clapping rhythm numerical simulation

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

A hyaluronic acid granular hydrogel nerve guidance conduit promotes regeneration and functional recovery of injured sciatic nerves in rats

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Neural Regeneration Research 2023年第3期18卷 657-663页

作者： Jie Yang Chia-Chen Hsu Ting-Ting Cao hua ye Jing Chen Yun-qing Li Institute of Medical Research Northwestern Polytechnical UniversityXi’anShaanxi ProvinceChina Institute of Biomedical Engineering Department of Engineering ScienceUniversity of OxfordOxfordUK The Oxford Suzhou Centre for Advanced Research(OSCAR) SuzhouJiangsu ProvinceChina Department of Anatomy Histology and Embryology&K.K.Leung Brain Research CentreThe Fourth Military Medical UniversityXi’anShaanxi ProvinceChina Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province Hainan Medical UniversityHaikouHainan ProvinceChina Department of Anatomy College of Basic Medical SciencesDali UniversityDaliYunnan ProvinceChina

A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural ***,in vivo experiments have not been *** this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve *** Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve *** conduit results were superior to those of a bulk hydrogel or silicone tube *** findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic *** nerve conduits have the potential as a material for repairing peripheral nerve defects.

关键词： functional recovery granular hydrogel hyaluronic acid myelin sheath nerve conduit nerve regeneration peripheral nerve regeneration sciatic nerve injury tissue engineering transection injury

SPME-Arrow/GC-MS结合多元统计分析研究不同批次爆珠香精组分差异

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分析测试学报 2025年第1期44卷 135-144页

作者：刘琪张华叶远青刘昌泽袁益来廖惠云吴君章江苏中烟工业有限责任公司江苏南京210019 广东中烟工业有限责任公司广东广州510385

以箭型固相微萃取(SPME-Arrow)为样品萃取手段,通过优化萃取头种类、氯化钠添加量、萃取温度、平衡时间及萃取时间等条件,构建了高效鉴定爆珠香精中挥发性及半挥发性化合物的箭型固相微萃取结合气相色谱-质谱联用(SPME-Arrow/GC-MS)法... 详细信息

以箭型固相微萃取(SPME-Arrow)为样品萃取手段,通过优化萃取头种类、氯化钠添加量、萃取温度、平衡时间及萃取时间等条件,构建了高效鉴定爆珠香精中挥发性及半挥发性化合物的箭型固相微萃取结合气相色谱-质谱联用(SPME-Arrow/GC-MS)法。采用该方法对不同批次爆珠香精进行分析,结合主成分分析(PCA)、正交偏最小二乘-判别分析(OPLS-DA)及显著性F检验等多元统计分析手段,筛选显著性差异成分。结果表明:最佳萃取条件为优选DVB/CAR/PDMS萃取头,添加2.0 g氯化钠,在60℃下平衡50 min,萃取时间为40 min;经谱库检索结合保留指数辅助定性,共鉴定出96种挥发性、半挥发性组分,目标物峰面积的日间相对标准偏差(RSD)小于10%的色谱峰数量占总峰数量的92.7%,表明方法的重复性较好;从不同批次爆珠香精中共筛选出17个潜在差异化合物,通过显著性检验,确定10种显著性差异化合物,分别为α-蒎烯、柠檬烯、桉叶油醇、异胡薄荷醇、薄荷酮(含异构体)、新异薄荷醇、乙酸新薄荷酯、三辛酸甘油酯和二辛酸单癸酸甘油酯。该法可有效区分不同批次爆珠样品的组分差异,具有客观真实、准确可靠、可视化强等特点,能够为爆珠产品质量检验提供技术支持。

关键词：箭型固相微萃取气相色谱-质谱联用多元统计分析爆珠香精差异化合物