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Journal of Thermal Science 2024年第3期33卷 888-898页

作者： ZHANG lei YANG Zhenyu SUN Enhui ZHANG Qian AN Guangyao YUAN wei Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology North China Electric Power UniversityBaoding071003China School of Energy Power&Mechanical EngineeringNorth China Electric Power UniversityBaoding071028China

The low power consumption of the near-critical compressor is the key factor for the high efficiency of supercritical CO_(2)Brayton *** the numerical simulation of the compressor,the rapid changes in the thermophysical properties of the CO_(2)near the critical point make it difficult to capture the condensation *** paper investigates the influence of fluid physical properties on the condensation ***,the differences in the physical properties of CO_(2)in the SRK EOS(equation of state),PR EOS,and SW EOS are ***,the simulation of nozzles and compressors were carried out and *** show that the condensation positions predicted by the three EOSs are basically the *** with SW EOS,the disparities between the maximum condensation mass fraction predicted by the PR and SRK EOSs is5.7%and 11.5%,and that of total pressure ratio is 0.3%and 3.8%,*** results show that PR EOS can be considered for numerical simulation in engineering *** its physical property calculation results are closer to the actual physical properties while the physical properties change more gently,it has considerable accuracy and numerical stability.

关键词： supercritical carbon dioxide equation of state centrifugal compressor numerical simulation condensation

Human influence on the duration of extreme temperature events in Asia's hotspot regions

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Advances in Climate Change Research 2024年第2期15卷 312-326页

作者： Zi-Meng WANG Hong-Yun MA wei LI hai-Shan CHEN Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)Nanjing University of Information Science and TechnologyNanjing 210044China

Observations and models indicate that human activities exert a considerable impact on the frequency and intensity of extreme temperature events,which are associated with global ***,changes in the duration of extreme temperature events and their association with human influence have not been considered in most ***,the possible relationship between the observed changes in the warm and cold spell duration(WSDI and CSDI)in hotspot regions during 1960-2014 and human influence was investigated based on the NCEP/NCAR reanalysis version 1 and Coupled Model Inter-comparison Project Phase 6(CMIP6)*** projection based on these attribution results was also *** optimal fingerprinting technique was used to compare observed changes in WSDI and CSDI to simulated changes averaged across eight CMIP6 *** show that anthropogenic(ANT)forcing contributed to the observed increase in WSDI in the three hotspot regions(West Asia,South Asia and Southeast Asia),with the majority of the changes being attributed to greenhouse gas ***,a generally weak ANT signal can be observed in the decreasing trend of CSDI and can be detected in South and Southeast *** influence of aerosol forcing remains undetected in either WSDI or CSDI,which differs from the results for frequency and intensity of extreme *** attribution results revealed that the constrained projection of WSDI is lower than the raw projection for 2015-2100 in West Asia and Southeast ***,no differences in future CSDI changes are found in Southeast Asia between the constrained and raw projections.

关键词： Extreme temperature events Duration Detection attribution Constraint projection Hotspot regions

Supermassive black holes triggered by QCD axion bubbles

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Communications in Theoretical Physics 2024年第5期76卷 134-139页

作者： hai-Jun Li Ying-Quan Peng wei Chao Yu-Feng Zhou Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still *** this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion *** this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after *** QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase *** consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))*** PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

Controlled fluorescent switch based on a cation grease/brake rotor system of pillar[5]arene

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Chinese Chemical Letters 2024年第3期35卷 5-7页

作者： wei-lei Zhou Siwei Wang Yong Chen College of Chemistry and Material Science Inner Mongolia Key Laboratory of Chemistry for Nature Products and Synthesis for Functional MoleculesInnovation Team of Optical Functional Molecular DevicesInner Mongolia Minzu UniversityTongliao 028000China College of Chemistry Nankai UniversityTianjin 300071China

In recent years,molecular shuttles,motors,pumps,and elevators,*** specifically respond external physical or chemical stimuli including light,temperature,pH,redox,solvent and chemical additive to change the structure a... 详细信息

关键词： additive system showing

Irrational-Behavior-Proof Conditions for Stochastic Games over Event Trees

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Journal of the Operations Research Society of China 2024年第1期12卷 243-263页

作者： lei Wang Cui Liu Hong-wei Gao Chong Lin School of Automation Institute of Complexity ScienceQingdao UniversityQingdao 266071ShandongChina School of Mathematics and Statistics Institute of Applied Mathematics of ShandongQingdao UniversityQingdao 266071ShandongChina

In this paper,the irrational-behavior-proof conditions in a class of stochastic dynamic games over event trees are *** kinds of irrational-behavior-proof conditions are proposed by the imputation distribution procedure,and their relationships are *** specific properties for the general transformation of characteristic functions are developed,based on which,the irrational-behavior-proof conditions are proved to be true in a transformed cooperative game.

关键词： Dynamic cooperative game Event tree Irrational-behavior-proof condition Imputation distribution procedure Transformation of characteristic function

A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

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Petroleum Science 2024年第1期21卷 327-342页

作者： Qian Zhang Wen-Dong Wang Yu-Liang Su wei Chen Zheng-Dong lei lei Li Yong-Mao Hao Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Oil Development Branch Changqing Oilfield CompanyPetroChinaQingyang745708GansuChina PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China

A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.

关键词： Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory

Global trend of nondrug and nonsedativehypnotic treatment forinsomnia: a bibliometric study

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Journal of Traditional Chinese Medicine 2024年第3期44卷 595-608页

作者： lei Hanzhou XU Guixing wei Zepeng ZHAO Ling LIANG Fanrong Acupuncture and Tuina School Chengdu University of Traditional Chinese MedicineChengdu 610075China Department of Haematology Royal North Shore HospitalSydney2065Australia

OBJECTIVE: To present a bibliometric analysis of global scientific publications on the nondrug and nonsedative hypnotic treatment of insomnia with regard to influential institutions, publications, countries, research hotspots,trends, and frontiers. METHODS: A literature review was conducted by searching the Web of Science Core Collection(Wo SCC) and China National Knowledge Infrastructure(CNKI) databases to identify all publications related to the nondrug and nonsedative hypnotic treatment of insomnia from 2000 to 2021. Eligible publications were reviewed, including annual publication increments, citation analyses, international collaborations, and keyword analyses. The data were analysed using Cite Space(vers5.8.R3, 6.1.R2 and 6.1.6, College of Computing and Informatics, Philadelphia, PA, USA) and virtualized by knowledge maps. RESULTS:In total, 9832 publications were included in this analysis. The results from the WoSCC showed that the United States of America(Count = 2268, 40.33%), Stanford University(Count = 141, 2.51%), and the United States Department of Health and Human Services were the leading country, institute, and funding agency regarding the number of publications, respectively. “Cognitive-behavioural therapy” was the most popular research topic generated from the cocited reference. The most frequently co-occurring keywords were insomnia, cognitive behavioural therapy, disorder, depression, quality of life, Meta-analysis, older adult, sleep, prevalence and efficacy, while keywords including clinical practice guideline, guideline, and Tai Chi remained popular after 2021. Circadian rhythm was the strongest research frontier for 2000-2021. In China, Chengdu University of Traditional Chinese Medicine(Count = 69, 4.79%) was the most productive institute in this field. The most frequently co-occurring keywords from Chinese literature were sleep disorder, sleep quality, acupuncture and moxibustion, Parkinson's disease, transcranial magnetic stimulation, health

关键词： hypnotics and sedatives cognitive behavioral therapy complementary therapies bibliometrics CiteSpace visualization analysis scientometrics

Detour for the inexperienced? Migration count data suggest mostly juvenile Greater Spotted Eagles appear in coastal peninsulas in China

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Avian Research 2024年第2期15卷 249-254页

作者： Xu Shi Xiaoping Wang Qian wei Qiwei Lin lei Zhu School of the Environment The University of QueenslandSt LuciaQLD4072AustraliaAustralia Centre for Ecology and Conservation and Environment and Sustainability InstituteUniversity of ExeterPenrynCornwallTR109FEUK Guangxi Biodiversity Research and Conservation Association Nanning530022China Snake Island Laotieshan National Nature Reserve Dalian116041China Chongqing Birdwatching Society Chongqing400054China Huqiu Rd Gusu DistrictSuzhou215008China Raptor Research Group of Chengdu Chengdu610000China Guangxi Academy of Marine Science Nanning530007China

Soaring bird migration often relies on suitable terrain and airflow;therefore,route selection is vital for successful *** age and experience have been identified as key factor influencing migration route selection among soaring raptors in the African-Eurasian Flyway,how they shape the migration route of soaring raptors in East Asia is still largely *** this study,we investigated potential variations in the routes and timing in autumn migration of juvenile and older soaring birds,using count data of Greater Spotted Eagles(Clanga clanga)from two coastal sites and two inland sites in *** 2020 to 2023,we recorded a total of 340 individuals,with the highest site averaging over 90 individuals per autumn,making it one of the world’s top single-season counts and thus a globally important site for this *** found that 82% and 61% records from coastal sites were juveniles,significantly higher than inland sites(15% and 24%).Juveniles at all four sites exhibited markedly earlier median passage time than non-juveniles,with brief overlapping in their main migration *** coastal sites are located on the tip of peninsulas stretching southwest,requiring long overwater flights if crossing the Bohai Bay or Beibu Gulf,which would be energetically demanding and increase mortality *** individuals may have learned to avoid such terrain and subsequent detour,while juveniles are more prone to enter these peninsulas due to lack of experience and opportunities for social learning,or following other raptor species that are more capable of powered *** findings highlight the importance of age and experience in migration route selection of large soaring birds.

关键词： Clanga clanga East Asia Greater Spotted Eagle Juvenile Migration route Social learning

Manipulating the Phase Transition Behavior of Dual Temperature-Responsive Block Copolymers by Adjusting Composition and Sequence

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Chinese Journal of Polymer Science 2024年第2期42卷 176-187,I0006页

作者： Zhi Zou Xiang Xu hai-Tao Zhao Jian-Nan Cheng wei-wei He Li-Fen Zhang Zhen-Ping Cheng Suzhou key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationState and Local Joint Engineering Laboratory for Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of JiangsuSoochow UniversitySuzhou215123China

Temperature-responsive polymers have garnered significant attention due to their ability to respond to external *** this work,dual temperature-responsive block copolymers are synthesized via reversible addition-fragmentation chain transfer polymerization(RAFT)polymerization utilizing zwitterionic monomer methacryloyl ethyl sulfobetaine(SBMA) and N-isopropyl acrylamide(NIPAAm) as *** thermal responsive behaviors can be easily modulated by incorporating additional hydrophobic monomer benzyl acrylate(BN) or hydrophilic monomer acrylic acid(AA),adjusting concentration or pH,or varying the degree of polymerization of the block chain *** cloud points of the copolymers are determined by UV-Vis spectrophotometry,and these copolymers exhibit both controlled upper and lower critical solu bility temperatures(LCST and UCST) in aqueous *** study analyzes and summarizes the influencing factors of dual temperature responsive block copolymers by exploring the effects of various conditions on the phase transition temperature of temperature-sensitive polymers to explore the relationship between their properties and environment and structure to make them more selective in terms of temperature application range and regulation *** is very interesting that the introduction of poly-acrylic acid(PAA) segments in the middle of di-block copolymer PSBMA_(55)-b-PNIPAAm_(80) to form PSBMA_(55)-b-PAA_(x)-b-PNIPAAm_(80) results in a reversal of temperature-responsive behaviors from 'U'(LCST UCST) type,while the copolymer PSBMA_(55)-b-P(NIPAAm_(80)-co-AA_(x)) *** work provides a clue for tuning the phase transition behavior of polymers for manufacture of extreme smart materials.

关键词： Temperature responsive polymers High critical solubility temperature(UCST) Low critical solubility temperature(LCST) Block copolymers

Empowering smart city situational awareness via big mobile data

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 286-307页

作者： Zhiguang SHAN lei SHI Bo LI Yanqiang ZHANG Xiatian ZHANG wei CHEN State Information Center Beijing100045China School of Computer Science and Engineering Beihang UniversityBeijing100191China Zhongguancun Laboratory Beijing100094China Beijing Tendcloud Tianxia Technology Co. Ltd.Beijing100027China The State Key Lab of CAD&CG Zhejiang UniversityHangzhou310027China

Smart city situational awareness has recently emerged as a hot topic in research societies,industries,and governments because of its potential to integrate cutting-edge information technology and solve urgent challenges that modern cities *** example,in the latest five-year plan,the Chinese government has highlighted the demand to empower smart city management with new technologies such as big data and Internet of Things,for which situational awareness is normally the crucial first *** traditional static surveillance data on cities have been available for decades,this review reports a type of relatively new yet highly important urban data source,i.e.,the big mobile data collected by devices with various levels of mobility representing the movement and distribution of public and private agents in the *** especially focus on smart city situational awareness enabled by synthesizing the localization of hundreds of thousands of mobile software Apps using the Global Positioning System(GPS).This technique enjoys advantages such as a large penetration rate(∼50%urban population covered),uniform spatiotemporal coverage,and high localization *** first discuss the pragmatic requirements for smart city situational awareness and the challenges *** we introduce two suites of empowering technologies that help fulfill the requirements of(1)cybersecurity insurance for smart cities and(2)spatiotemporal modeling and visualization for situational awareness,both via big mobile *** main contributions of this review lie in the description of a comprehensive technological framework for smart city situational awareness and the demonstration of its feasibility via real-world applications.

关键词： Smart city Mobile data Situational awareness