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Extreme value theory applied to the auroral electrojet indices

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Earth and Planetary Physics 2024年第2期8卷 375-381页

作者： Si Chen Hong Yuan yong wei Guang Yang FengZheng Yu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The study of extreme weather and space events has gained paramount importance in modern society owing to rapid advances in high *** and describing exceptional occurrences plays a crucial role in making decisive assessments of their potential impact on technical,economic,and social aspects in various *** research focuses on analyzing the hourly values of the auroral electrojet(AE)geomagnetic index from 1957 to 2019 by using the peak over threshold method in extreme value *** fitting the generalized Pareto distribution to extreme AE values,shape parameter indices were derived,revealing negative values that establish an upper bound for this time ***,it became evident that the AE values had reached a plateau,suggesting that extreme events exceeding the established upper limit are *** a result,although the need for diligent precautions to mitigate the consequences of such extreme events persists,surpassing the upper limit of AE values becomes increasingly *** is also possible to observe an aurora in the middle-and low-latitude regions during the maximum period of the AE index.

关键词： auroral electrojet indices extreme value theory extreme events

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum Science 2024年第3期21卷 1969-1979页

作者： Yang Zhang yong-An Li Xiang-wei Kong Hao Liu Teng-Fei Sun College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100027China School of Petroleum Engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

In-situ measurement via the flow-through method and numerical simulations for radon exhalation during measurements of the radon exhalation rate

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Nuclear Science and Techniques 2024年第7期35卷 192-207页

作者： Ming Xia yong-Jun Ye Shan-wei Shang Ting Yu Dai-Jia Chen School of Resources Environment and Safety Engineering University of South ChinaHengyang421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang421001China

Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two *** abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was *** on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and *** in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the *** consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air *** synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1×10^(−11) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.

关键词： Radon exhalation Flow-through Numerical simulation Accumulation chamber Multivariate regression

Pathological mechanisms of amyotrophic lateral sclerosis

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Neural Regeneration Research 2024年第5期19卷 1036-1044页

作者： Yushu Hu Wenzhi Chen Caihui wei Shishi Jiang shu Li Xinxin Wang Renshi Xu Department of Clinical Medicine Nanchang UniversityNanchangJiangxi ProvinceChina Department of Neurology Jiangxi Provincial People’s HospitalNanchangJiangxi ProvinceChina Department of Neurology The First Affiliated Hospital of Nanchang Medical CollegeThe Clinical College of Nanchang Medical CollegeNanchangJiangxi ProvinceChina

Amyotrophic lateral sclerosis refers to a neurodegenerative disease involving the motor system,the cause of which remains unexplained despite several years of ***,the journey to understanding or treating amyotrophic lateral sclerosis is still a long *** to current research,amyotrophic lateral sclerosis is likely not due to a single factor but rather to a combination of mechanisms mediated by complex interactions between molecular and genetic *** progression of the disease involves multiple cellular processes and the interaction between different complex mechanisms makes it difficult to identify the causative factors of amyotrophic lateral ***,we review the most common amyotrophic lateral sclerosis-associated pathogenic genes and the pathways involved in amyotrophic lateral sclerosis,as well as summarize currently proposed potential mechanisms responsible for amyotrophic lateral sclerosis disease and their evidence for involvement in amyotrophic lateral *** addition,we discuss current emerging strategies for the treatment of amyotrophic lateral *** the emergence of these new therapies may help to further our understanding of the pathogenic mechanisms of the disease.

关键词： amyotrophic lateral sclerosis cellular pathways disease mechanisms motor neuron neurodegenerative disease

Effect of cooling method on TiN precipitation behavior of high-titanium high-strength steel during solidification

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Journal of Iron and Steel Research International 2024年第7期31卷 1692-1703页

作者： Xue-jian Zhang Guang-wei Yang yong Wan yong-hong Wen Chuan-sheng Tang Ming-qi Liu Li-jie Tian Key Laboratory of Metallurgical Emission Reduction and Resources Recycling Anhui University of TechnologyMa'anshan 243002AnhuiChina School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina Baosteel Central Research Institute Baoshan Iron and Steel Co.Ltd.Shanghai 201999China

Metallographic microscopy,scanning electron microscopy and TiN growth thermodynamic and kinetic equations were used to investigate the morphology,quantity,and size of TiN in the center of high-titanium high-strength steels under different solidification cooling *** results showed that TiN in the center of the experimental steels mainly existed in three forms:single,composite(Al2O3-TiN),and multi-particle *** began precipitating at around 1497℃(solidification fraction of 0.74).From the end of melting to solidification for 180 s,the cooling rates in the center of the experimental steels for furnace cooling,air cooling,refractory mold cooling,and cast iron mold cooling tended to stabilize at 0.17,0.93,1.65,and 2.15℃/s,*** size of TiN in the center of the experimental steel cooled using furnace cooling was mainly concentrated in the 5-15 pm *** contrast,the size of TiN in the center of the experimental steels cooled using air cooling,refractory mold cooling,and cast iron mold cooling were mainly concentrated in the 1-5 pm *** addition,their density of TiN in the center of the experimental steels is signif-icantly higher than that of the furnace-cooled experimental *** and kinetic precipitation models of TiN established predicted the growth size of TiN in a high-titanium high-strength steel when the solidification cooling rates are not below 0.93℃/s.

关键词： High-titanium steel Cooling method TiN Thermodynamics Kinetics

Attributes of Specialized Households'Resilience and Its Impact on Rural Industrial Advancement:A Case Study of National Musical Instrument Production Specialized Households in Lankao County,Henan,China

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Chinese Geographical Science 2024年第3期34卷 383-400页

作者： WU Nalin wei Yike FAN Sizhe LI Li SUN Yufan ZHANG Yan shu Yan Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(Henan University) Ministry of Educa-tion/The College of Geography and Environmental ScienceHenan UniversityKaifeng 475001China College of Urban and Envir-onmental Science Central China Normal UniversityWuhan 430079China Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Specialized households serve as the primary units within specialized villages in China,and their capacity to withstand risks and external influences significantly shapes the future trajectory of specialized villages and the overall vitality of the rural *** this study,we established a measurement indicator system based on the definition of specialized households’resilience,elucidating the logical connection between specialized households’resilience and rural industrial development in *** musical instrument industry in Lankao County,Henan Province of China,was employed as a case;survey data,the entropy method,and an obstacle diagnosis model were used to examine how instrument production specialized households responded to the challenges posed by Corona Virus Disease 2019(COVID-19)and the tightening of national environmental protection policies,yielding the following key findings:1)there exists substantial variation in the comprehensive resilience levels among different specialized households;2)the ability to learn and adapt is the most significant contributor to the overall resilience level of specialized households;3)technological proficiency and access to skilled talent emerge as pivotal factors influencing specialized households’resilience;4)the positioning of specialized households within the industrial supply chain and the stability of their income have a direct bearing on their resilience *** influence of specialized households’resilience on industrial development primarily manifests in the following ways:stronger resilience correlates with increased stability in production and sales,fostering a more proactive approach to future ***,heightened exposure to the external macroeconomic environment can lead to a higher rate of export *** enhance the development resilience of entities like specialized households and family farms,and to invigorate rural economic development,escalating investments in rural science and technology

关键词： resilience specialized households rural industry Lankao County,China

Hydrocarbon gas huff-n-puff optimization of multiple horizontal wells with complex fracture networks in the M unconventional reservoir

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Petroleum Science 2024年第2期21卷 1018-1031页

作者： Hao-Chuan Zhang yong Tang You-wei He yong Qin Jian-Hong Luo Yu Sun Ning Wang De-Qiang Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina CNPC Research Institute of Petroleum Exploration&Development Beijing100083China Southwest Oil&Gas Field Company PetroChinaChengdu610051SichuanChina State Key Laboratory of Offshore Oil Exploitation CNOOC Research Institute Co.LtdBeijing100027China

The oil production of the multi-fractured horizontal wells(MFHWs) declines quickly in unconventional oil reservoirs due to the fast depletion of natural energy. Gas injection has been acknowledged as an effective method to improve oil recovery factor from unconventional oil reservoirs. Hydrocarbon gas huff-n-puff becomes preferable when the CO_(2) source is limited. However, the impact of complex fracture networks and well interference on the EOR performance of multiple MFHWs is still unclear. The optimal gas huff-n-puff parameters are significant for enhancing oil recovery. This work aims to optimize the hydrocarbon gas injection and production parameters for multiple MFHWs with complex fracture networks in unconventional oil reservoirs. Firstly, the numerical model based on unstructured grids is developed to characterize the complex fracture networks and capture the dynamic fracture ***, the PVT phase behavior simulation was carried out to provide the fluid model for numerical simulation. Thirdly, the optimal parameters for hydrocarbon gas huff-n-puff were obtained. Finally, the dominant factors of hydrocarbon gas huff-n-puff under complex fracture networks are obtained by fuzzy mathematical method. Results reveal that the current pressure of hydrocarbon gas injection can achieve miscible displacement. The optimal injection and production parameters are obtained by single-factor analysis to analyze the effect of individual parameter. Gas injection time is the dominant factor of hydrocarbon gas huff-n-puff in unconventional oil reservoirs with complex fracture networks. This work can offer engineers guidance for hydrocarbon gas huff-n-puff of multiple MFHWs considering the complex fracture networks.

关键词： Unconventional oil reservoir Complex fracture network Hydrocarbon gas huff-n-puff Parameter optimization Numerical simulation

The prognostic value of collateral circulation in coronary chronic total occlusion underwent percutaneous coronary intervention

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Journal of Geriatric Cardiology 2024年第2期21卷 232-241页

作者： Xiao-Ying HU wei-Xian YANG Chang-Dong GUAN Li-Hua XIE Ke-Fei DOU yong-Jian WU Jin-Qing YUAN Jie QIAN Yue-Jin YANG shu-Bin QIAO Lei SONG Department of Cardiology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina National Clinical Research Center for Cardiovascular Diseases BeijingChina Catheterization Laboratories Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

BACKGROUND The prognostic value of coronary collateral circulation(CC)in patients undergoing chronic total occlusion(CTO)percutaneous coronary intervention(PCI)is *** purpose of the study was to assess the prognostic value of current two CC grading systems and their association with long-term outcomes in patients with CTO underwent *** We consecutively enrolled patients with single-vessel CTO underwent PCI between January 2010 and *** patients were categorized into well-developed or poor-developed collaterals group according to angiographic Werner's CC(grade 2 *** 0–1)or Rentrop(grade 3 *** 0–2)grading *** primary endpoint was 5-year cardiac *** Of 2452 enrolled patients,the overall technical success rate was 74.1%.Well-developed collaterals were present in686 patients(28.0%)defined by Werner's CC grade 2,and in 1145 patients(46.7%)by Rentrop grade *** to Werner's CC grading system,patients with well-developed collaterals had a lower rate of 5-year cardiac death compared with those with poordeveloped collaterals(1.6%vs.3.3%,P=0.02),those with suboptimal recanalization was associated with higher rate of 5-year cardiac death compared with optimal recanalization(4.7%vs.0.8%,P=0.01)and failure patients(4.7%vs.1.6%,P=0.12).However,the similar effect was not shown in Rentrop grading *** In patients with the single-vessel CTO underwent PCI,well-developed collaterals by Werner's CC definition were associated with lower rate of 5-year cardiac ***'s CC grading system had a greater prognostic value than Rentrop grading system in patients with CTO underwent PCI.

关键词： coronary collateral occlusion

Enhancing cellular behavior in repaired tissue via silk fibroin-integrated triboelectric nanogenerators

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Microsystems & Nanoengineering 2024年第3期10卷 137-147页

作者： Zhelin Li shuxing Xu Zijie Xu Sheng shu Guanlin Liu Jianda Zhou Ding Lin wei Tang Changsha Aier Eye Hospital Aier School of OphthalmologyCentral South UniversityChangshaHunanChina The Xiangya Hospital Central South UniversityChangshaHunanChina Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China Center on Nanoenergy Research School of Physical Science&TechnologyGuangxi UniversityNanning 530004China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Department of Plastic Surgery the Third Xiangya HospitalChangshaHunanChina

Triboelectric nanogenerators(TENGs)have emerged as a promising approach for generating electricity and providing electrical stimuli in medical electronic *** their potential benefits,the clinical implementation of TENGs faces challenges such as skin compliance and a lack of comprehensive assessment regarding their biosafety and ***,further research is imperative to overcome these limitations and unlock the full potential of TENGs in various biomedical *** this study,we present a flexible silk fibroin-based triboelectric nanogenerator(SFB-TENG)that features an on-skin substrate and is characterized by excellent skin compliance and air/water *** range of electrical output generated by the SFB-TENG was shown to facilitate the migration and proliferation of Hy926,NIH-3T3 and RSC96 ***,apoptosis of fibroblast NIH-3T3 cells was observed when the output voltage increased to more than 20 V at a frequency of 2 *** addition,the moderate electrical stimulation provided by the SFB-TENG promoted the cell proliferation cycle in Hy926 *** research highlights the efficacy of a TENG system featuring a flexible and skin-friendly design,as well as its safe operating conditions for use in biomedical *** findings position TENGs as highly promising candidates for practical applications in the field of tissue regeneration.

关键词： overcome spite generating