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Using Copula functions to predict climatic change impacts on floods in river source regions

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Advances in Climate Change Research 2024年第3期15卷 406-418页

作者： Ting-Xing CHEN Hai-Shen LYU Robert HORTON Yong-Hua ZHU Ren-Sheng CHEN Ming-Yue SUN Ming-Wen LIU Yu LIN The National Key Laboratory of Water Disaster Prevention College of Hydrology and Water ResourcesHohai UniversityNanjing 2098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Departmentof Agronomy lowa State UniversityAmes IA5oollUSA qilian Alpine Eology and Hydrology Research station Northwest Instiuteof Eco-Environmentand ReourcesChinese Academy of SciencesLanzhou0000 China

Flood frequency in river source regions is significantly affected by rainfall and snowmelt as part of climatic changes.A traditional univariate flood frequency analysis cannot reflect the complexity of floods,and when used in isolation,it can only underestimate flood *** effective flood prevention and mitigation,it is essential to consider the combined effects of precipitation and *** functions can effectively quantify the joint distribution relationship between floods and their associated variables without restrictions on their distribution *** study uses copula functions to consider a multivariate probability distribution model of flood peak flow(q)with cumulative snowmelt(CSm)and cumulative precipitation(CPr)for the Hutubi River basin located in northern Xinjiang,*** joint frequencies of rainfall and snowmelt floods are predicted using copula models based on the Coupled Model Intercomparison Project Phase 6 *** results show that q has a significant positive correlation with 24-d CSm(r=0.559,p=0.002)and 23-d CPr(r=0.965,pquency will increase in the future,and mid-(2050e2074)and long-term(2075e2099)floods will be more severe than those in the near-term(2025e2049).The probability of flood occurrence is higher under the SSP2-4.5 and SSP1-2.6 scenarios than under *** during the historical period(1990e2014)led to extreme floods,and increasing future precipitation trends are found to be *** increases with rising temperatures and occurs earlier than estimated,leading to an earlier flood period in the basin and more frequent snowmelt *** q under the joint return period is larger than that during the same univariate return *** difference indicates that neglecting the interaction between precipitation and snowmelt for floods leads to an underestimation of the flood risk(with underestimations ranging from 0.3%to 22%).The underestimations decrease with an increase

关键词： Climate change Flood frequency Copula CMIP6 River source regions

The 2‑Width of Embedded 3‑Manifolds

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Peking Mathematical Journal 2022年第1期5卷 21-35页

作者： Michael Freedman microsoft Research Station Qand Department of MathematicsUniversity of California Santa BarbaraSanta BarbaraCA 93106USA

We discuss a possible definition for“k-width”of a closed d-manifold Md,and on embedding Md e↪ℝn,n>d≥k,generalizing the classical notion of width of a *** show that for every 3-manifold 2-width(M3)≤2 but that there are embeddings ei∶T3↪ℝ4 with 2-width(ei)→∞.We explain how the divergence of 2-width of embeddings offers a tool to which might prove the Goeritz groups Gg infinitely generated for g≥*** we construct a homomorphismg∶Gg→MCG(#g S2×S2),suggesting a potential application of 2-width to 4D mapping class groups.

关键词： Morse theory Minimax Width

Effects of weaning on intestinal longitudinal muscle-myenteric plexus function in piglets

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Science China(Life Sciences) 2024年第2期67卷 379-390页

作者： Jing Li Fenfen Liu Kaibin Mo Hengjia Ni Yulong Yin Key Laboratory of Agro-Ecological Processes in Subtropical Region Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic ProcessHunan Research Center of Livestock and Poultry SciencesSouth Central Experimental Station of Animal Nutrition and Feed Science in the Ministry of AgricultureInstitute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China University of Chinese Academy of Sciences Beijing 100008China Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation College of Veterinary MedicineSouth China Agricultural UniversityGuangzhou 510642China

Weaning piglets usually suffer from severe diarrhea(commonly known as postweaning diarrhea,PWD)along with intestinal motility *** peristalsis is mainly regulated by the longitudinal muscle-myenteric plexus(LM-MP).To understand the relationship between intestinal LM-MP function and the development of PWD,we compared the intestinal electrical activity,and the transcriptional profile of the LM-MP between 21-day-old piglets(just weaned,n=7)and 24-day-old piglets(suffered the most severe weaning stress,n=7).The results showed that 24-day-old piglets exhibited different degrees of diarrhea.A significant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old piglets,while c-kit expression in the intestinal LM-MPs was significantly decreased,indicating that PWD caused by elevated slow-wave frequency may be associated with loss of *** real-time quantitative PCR(RT-q PCR)and enzyme-linked immunosorbent assay(ELISA)showed that intestinal LM-MPs in 24-day-old piglets may undergo inflammation and oxidative *** increases in 8-hydroxy-2′-deoxyguanosine and decreases in thioredoxin suggest that weaning may lead to DNA damage in the LM-MP of 24-day-old *** addition,activating transcription factor 3 was significantly upregulated,indicating nerve damage in the LM-MP of 24-day-old *** transcriptomic results showed that most of the differentially expressed genes in the ileal LM-MP after weaning were downregulated and closely related to the cell cycle *** RT-q PCR analysis showed that the relative expression of p21 was upregulated,while the expression of cyclin A2,cyclin B1,and proliferating cell nuclear antigen was downregulated in the ileal and colonic LM-MP of 24-day-old piglets,suggesting that weaning may inhibit cell proliferation and cause G1/S cell cycle arrest in ileal and colonic *** conclusion,weaning may lead to cell cycle arrest by causing DNA damage in the LM-MP,impairing i

关键词： weaning piglets diarrhea longitudinal muscle-myenteric plexus

On generalized symmetries and structure of modular categories

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Science China Mathematics 2019年第3期62卷 417-446页

作者： Shawn Xingshan Cui Modjtaba Shokrian Zini Zhenghan Wang Stanford Institute for Theoretical Physics Stanford University Department of Mathematics Virginia Polytechnic Institute and State University Department of Mathematics University of California at Santa Barbara microsoft station q

Pursuing a generalization of group symmetries of modular categories to category symmetries in topological phases of matter, we study linear Hopf monads. The main goal is a generalization of extension and gauging group symmetries to category symmetries of modular categories, which include also categorical Hopf algebras as special cases. As an application, we propose an analogue of the classification of finite simple groups to modular categories, where we define simple modular categories as the prime ones without any nontrivial normal algebras.

关键词： modular category category symmetry Hopf monad tensor functor

Spatiotemporal Variability and Environmental Controls of Temperature Sensitivity of Ecosystem Respiration across the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第9期41卷 1821-1842页

作者： Danrui SHENG Xianhong MENG Shaoying WANG Zhaoguo LI Lunyu SHANG Hao CHEN Lin ZHAO Mingshan DENG Hanlin NIU Pengfei XU Xiaohu WEN Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Zoige Plateau Wetlands Ecosystem Research station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Warming-induced carbon loss via ecosystem respiration(R_(e))is probably intensifying in the alpine grassland ecosystem of the Tibetan Plateau owing to more accelerated warming and the higher temperature sensitivity of R_(e)(q_(10)).However,little is known about the patterns and controlling factors of q_(10)on the plateau,impeding the comprehension of the intensity of terrestrial carbon-climate feedbacks for these sensitive and vulnerable ***,we synthesized and analyzed multiyear observations from 14 sites to systematically compare the spatiotemporal variations of q_(10)values in diverse climate zones and ecosystems,and further explore the relationships between q_(10)and environmental ***,structural equation modeling was utilized to identify the direct and indirect factors predicting q_(10)values during the annual,growing,and non-growing *** results indicated that the estimated q_(10)values were strongly dependent on temperature,generally,with the average q_(10)during different time periods increasing with air temperature and soil temperature at different measurement depths(5 cm,10 cm,20 cm).The q_(10)values differentiated among ecosystems and climatic zones,with warming-induced q_(10)declines being stronger in colder regions than elsewhere based on spatial *** was the most cardinal factor in predicting annual q_(10)values,significantly and positively correlated with q_(10).Soil temperature(Ts)was identified as the other powerful predictor for q_(10),and the negative q_(10)-Ts relationship demonstrates a larger terrestrial carbon loss potentiality in colder than in warmer regions in response to global *** that the interpretations of the effect of soil moisture on q_(10)were complicated,reflected in a significant positive relationship between q_(10)and soil moisture during the growing season and a strong quadratic correlation between the two during the annual and non-growing *** findings are conducive to imp

关键词： carbon cycle eddy covariance measurements ecosystem respiration q_(10)value Tibetan Plateau climate change

Automatic Generation Control in a Distributed Power Grid Based on Multi-step Reinforcement Learning

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Protection and Control of Modern Power Systems 2024年第4期9卷 39-50页

作者： Wenmeng Zhao Tuo Zeng Zhihong Liu Lihui Xie Lei Xi Hui Ma the Electric Power Research Institute Southern Power GridGuangzhou 510663China the Heyuan Power Supply Bureau Guang-dong Power Grid Co.Ltd.Heyuan 517000China the College of Electrical Engineering&New Energy China Three Gorges UniversityYichang 443002China the College of Electrical Engineering&New Energy and Hubei Provincial Key Laboratory for Operation and Control of Cascaded Hydropower station China Three Gorges UniversityYichang 443002China IEEE

The increasing use of renewable energy in the power system results in strong stochastic disturbances and degrades the control performance of the distributed power *** this paper,a novel multi-agent collaborative reinforcement learning algorithm is proposed with automatic optimization,namely,Dyna-DqL,to quickly achieve an optimal coordination solution for the multi-area distributed power *** proposed Dyna framework is combined with double q-learning to collect and store the environmental *** can iteratively update the agents through buffer replay and real-time *** the environmental data can be fully used to enhance the learning speed of the *** mitigates the negative impact of heavy stochastic disturbances caused by the integration of renewable energy on the control *** are conducted on two different models to validate the effectiveness of the proposed *** results demonstrate that the proposed Dyna-DqL algorithm exhibits superior stability and robustness compared to other reinforcement learning algorithms.

关键词： Automatic generation control Dyna framework distributed power grid multi-agent mod-el-based reinforcement learning

Lactonization of dyes promoted by a coordination cage facilitates cavity-induced chromism as ion mobile detector

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Science China Chemistry 2024年第5期67卷 1554-1560页

作者： Liangliang Zhang Yu Liang Zhifeng Xiao Yuxuan Meng Jinyi Huang Xi Lin Ji Li Hong-Cai Zhou Yu Fang Strait Institute of Flexible Electronics(SIFE Future Technologies)Fujian Normal University and Strait Laboratory of Flexible Electronics(SLoFE)Fuzhou 350017China State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Department of Chemistry Texas A&M UniversityCollege StationTexas 77842-3012USA State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Frontiers Science Center for Flexible Electronics(FSCFE) MIIT Key Laboratory of Flexible Electronics(KLoFE)Northwestern Polytechnical UniversityXi’an 710072China

Dye molecules often change colors(so-called “chromism”) according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coordination cage(PCC-2), Rhodamine B(1) is transformed from red quinonoid form(1q) into colorless lactone form(1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncommon zwitterion intermediate(1z), followed by converting to 1l, thus accelerating the equilibrium. The chromism is catalyzed by 0.25 mol% of PCC-2, and the reaction rate is improved by 80,400times. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional intermediate by a catalytic amount of the coordination cage provides fundamental insights into molecular isomerization and has potential use in chemical sensing.

关键词： porous coordination cage Zwitterion intermediate cavity Rhodamine B chromism

Seismic and geological evidence of hidden faults in the Yinpan Reservoir area based on a dense seismic array

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Science China Earth Sciences 2024年第7期67卷 2401-2407页

作者： Guangyao YIN Huai ZHANG Liwen GONG q ipeng BAI Yicun GUO Bing ZHANG Yaolin SHI Key Laboratoryof Earth System Numerical Modeling and Application(Chinese Academyof Sciences) College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Computational Geodynamics Chinese Academy of SciencesBeijing 100049China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Beijing Yanshan Critical Zone National Field Scientific Observation and Research station Beijing 101408China Chongqing Earthquake Agency Chongqing 401147 China Institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China Hangzhou Applied Acoustics Research Institute Hangzhou 311100China State Key Laboratory of Geodesy and Earths Dynamics Innovation Academy for Precision Measurement Science and TechnologyCASWuhan 430077China

*** November 23,2017,an M_(S)5.0 earthquake occurred in Wulong,Chongqing,China,resulting in tens of casualties and considerable economic ***,the epicenter of this earthquake was located in the transition zone from the... 详细信息

关键词： earthquake southeast seismic

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（3＋ 1）-TqFTs and topological insulators

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Frontiers of physics 2012年第2期7卷 150-159页

作者： Kevin Walker (1) Zhenghan Wang (1) 1. microsoft station q CNSI Bldg. Rm. 2243 University of California Santa Barbara CA 93106-6105 USA

Levin-Wen models are microscopic spin models for topological phases of matter in （2＋ 1）-dimension. We introduce a generalization of such models to （3 ＋ 1）-dimension based on unitary braided fusion categories, also known as unitary premodular categories. We discuss the ground state degeneracy on 3-manifolds and statistics of excitations which include both points and defect loops. Potential con- nections with recently proposed fractional topological insulators and projective ribbon permutation statistics are described.

关键词： topological quantum field theory (TqFT) topological insulator premodular category