检索结果-南通市图书馆

Fundamental Research 2024年第3期4卷 690-692页

作者： mu mu bo Qin Guokun Dai Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Key Laboratoryof PolarAmospherecean-iceSystemfor Weatherand Climate Ministryof EducationFudan Universityhanghai200438China

Skillful weather forecasts have the potential to save lives,support emergency management,and mitigate economic and social losses,which capture the public's attention.The present framework of numerical weather prediction(NWP)can trace its origins back to the 1950s,by solving partial differential equations(PDEs)that describe atmospheric motion,to infer future atmospheric states.Such forecasts typically require several hours on a supercomputer with hundreds of nodes for the upcoming days.Among the various numerical models used by operational centers,the Integrated Forecasting System(IFS)from the European Centre for Medium-Range Weather Forecasts(ECMWF)stands out for its superior skills in medium-range weather forecasts.The quiet revolution of NwP has also been evaluated by the World Meteorological Organization as one of the most significant scientific,technological and social advances in the twentieth century[1].

关键词： weather forecasting breakthrough

Observer-based dynamic event-triggered control for distributed parameter systems over mobile sensor-plus-actuator networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 237-243页

作者：穆文英庄波邱芳 Shandong Engineering Research Center of Aeronautical Materials and Devices Shangdong University of AeronauticsBinzhou 256600China School of Information Engineering Shangdong University of AeronauticsBinzhou 256600China School of Science Shangdong University of AeronauticsBinzhou 256600China

We develop a policy of observer-based dynamic event-triggered state feedback control for distributed parameter systems over a mobile sensor-plus-actuator network.It is assumed that the mobile sensing devices that provide spatially averaged state measurements can be used to improve state estimation in the network.For the purpose of decreasing the update frequency of controller and unnecessary sampled data transmission, an efficient dynamic event-triggered control policy is constructed.In an event-triggered system, when an error signal exceeds a specified time-varying threshold, it indicates the occurrence of a typical event.The global asymptotic stability of the event-triggered closed-loop system and the boundedness of the minimum inter-event time can be guaranteed.Based on the linear quadratic optimal regulator, the actuator selects the optimal displacement only when an event occurs.A simulation example is finally used to verify that the effectiveness of such a control strategy can enhance the system performance.

关键词： distributed parameter systems event-triggered control mobile sensors mobile actuators

维普期刊数据库

Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第1期98卷 150-167页

作者： FANG Chaogang ZHANG Chengcheng MENG Guixi XU Jinlong XU Naicen LI Hualing LIU mu LIU bo Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650500China Nanjing Center China Geological SurveyNanjing 210016China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefei 230088China China United Coalbed Methane Corporation Ltd. Beijing 100015China Geological Survey of Anhui Province Hefei 230001China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.

关键词： geochemistry redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region

维普期刊数据库

Dynamical Dark Energy in Light of Cosmic Distance Measurements. Ⅱ. A Study Using Current Observations

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期 17-22页

作者： Xiaoma Wang Gan Gu Xiaoyong mu Shuo Yuan Gong-bo Zhao National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University

We extract key information on dark energy from current observations of BAO, OHD and H0, and find hints of dynamical behavior of dark energy. In particular, a dynamical dark energy model whose equation of state crosses-1 is favored by observations. We also find that the Universe has started accelerating at a lower redshift than expected.

关键词：

Perioperative remedial antiviral therapy in hepatitis B virus-related hepatocellular carcinoma resection:How to achieve a better outcome

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1833-1848页

作者： Fan mu Liang-Shuo Hu Kun Xu Zhen Zhao Bai-Cai Yang Yi-Meng Wang Kun Guo Jian-Hua Shi Yi Lv bo Wang Department of Hepatobiliary Surgery First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Department of Anaesthesiology First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina Department of Gynaecology Wenzhou Medical University Affiliated Jiaxing Women and Children HospitalJiaxing 314000Zhejiang ProvinceChina

BACKGROUND Although the benefits of antiviral therapy for hepatitis B virus(HBV)-related hepatocellular carcinoma(HCC)have been proven,researchers have not con-firmed the differences in patient outcomes between patients who received preoperative antiviral therapy for a period of time(at least 24 wk)and patients who received remedial antiviral therapy just before radical resection for HBV-related HCC.AIM To investigate the efficacy of perioperative remedial antiviral therapy in patients with HBV-related HCC.METHODS A retrospective study of patients who underwent radical resection for HBV-related HCC at the First Affiliated Hospital of Xi’an Jiaotong University from January 2016 to June 2019 was conducted.Considering the history of antiviral therapy,patients were assigned to remedial antiviral therapy and preoperative antiviral therapy groups.RESULTS Kaplan–Meier analysis revealed significant differences in overall survival(Pmultivariate analysis demonstrated that a history of preoperative antiviral treatment was independently related to improved survival(hazard ratio=0.27;95%confidence interval:0.08-0.88;P=0.030).CONCLUSION In patients with HBV-related HCC,it is ideal to receive preoperative long-term antiviral therapy,which helps patients tolerate more extensive hepatectomy;however,remedial antiviral therapy,which reduces preoperative HBV-DNA levels to less than 4 Log10 copies DNA/mL,can also result in improved outcomes.

关键词： Hepatectomy Hepatitis B virus Antiviral therapy Hepatocellular carcinoma Hepatitis B virus-DNA

Dynamical Dark Energy in Light of Cosmic Distance Measurements. Ⅰ.A Demonstration Using Simulated Datasets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期 9-16页

作者： Gan Gu Xiaoma Wang Xiaoyong mu Shuo Yuan Gong-bo Zhao National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University

We develop methods to extract key dark energy information from cosmic distance measurements including the BAO scales and supernova(SN) luminosity distances. Demonstrated using simulated data sets of the complete DESI, LSST and Roman surveys designed for BAO and SN distance measurements, we show that using our method, the dynamical behavior of the energy, pressure, equation of state(with its time derivative) of dark energy and the cosmic deceleration function can all be accurately recovered from high-quality data, which allows for robust diagnostic tests for dark energy models.

关键词：

Two-dimensional bifunctional electrocatalyst(Mo-NiFe-LDH)with multilevel structure for highly efficient overall water splitting

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2613-2622页

作者： Bao-Jie Zhang Bin Chang Shi-Peng Qiu Gang Zhao Xiao Wang Xi-Jin Xu Lan mu Wen-bo Liao Xiao-Jing Dong School of Physics and Technology University of Jinan KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) School of Chemical Engineering and Technology Tianjin University School of Physics and Physical Engineering Qufu Normal University

To effectively address energy challenges,it is crucial to explore efficient and stable bifunctional nonprecious metal catalysts.In this study,a Mo-doped nickeliron layered double hydroxide with flower-cluster architecture was successfully prepared by a one-step hydrothermal method,which demonstrated a good water splitting performance.After an appropriate amount of Mo doping,some lattice distortions in the material provided reactive sites for the adsorption and conversion of intermediates,thus optimising the charge distribution of the material.Moreover,the multidimensional void structures formed after doping had a larger specific surface area and accelerated the penetration of the electrolyte,which significantly improved the activity of the catalyst in alkaline media.At 10 mA·cm-2,the hydrogen and oxygen evolution overpotentials of Mo-doped nickel-iron double hydroxides（Mo-NiFe LDH/NF-0.2） were 167 and 220 mV,respectively,with an excellent durability up to 24 h.When the Mo-NiFe LDH/NF-0,2 catalyst was used as the cathode and anode of an electrolytic cell,the catalyst achieved a current density of 10 mA·cm-2at an applied voltage of 1.643 V.This study provides a novel approach for designing excellent bifunctional electrocatalysts containing nonprecious metals.

关键词： Bifunctional electrocatalysts 2D multilevel structure Overall water splitting Mo-doped Ni–Fe LDH

Disentangling the relative contributions of variables determining the divergence of hoarding strategies of rodents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2024年第2期70卷 270-272页

作者： bo Wang School of Resources and Environmental Engineering Anhui UniversityHefei 230601China Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration Anhui UniversityHefei 230601China Anhui Shengjin Lake Wetland Ecology National Long-Term Scientific Research Base DongzhiAnhui 247230China

Understanding the driving mechanism of the divergence of hoarding strategies of animals(i.e.,scatter-hoarding vs.larder-hoarding)is crucial to understand the ecological and evolutionary implications of plant-animal interactions.Zhang et al.(2022)compiled a global-scale dataset from the published literature including 183 species of seed-hoarding rodents,and concluded that phylogenetic conservatism,functional traits,and environmental factors counted for the hoarding behavior divergence of rodents.A more thought-provoking question may be asked:Do these variables contribute equally or not to explain the divergence of hoarding strategies?Here,we re-analyzed Zhang et al's(2022)dataset using partial Ralk calculation(Ives 2019)to parse out the relative contri-lik butions of these variables.

关键词： hoarding strategies rodents

Perenniality:From model plants to applications in agriculture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2024年第1期17卷 141-157页

作者： bo Zhao Jia-Wei Wang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences(CEMPS)Institute of Plant Physiology and Ecology(SIPPE)Chinese Academy of Sciences(CAS)Shanghai 200032China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Plant Carbon Capture CASShanghai 200032China New Cornerstone Science Laboratory Shanghai 200032China

To compensate for their sessile nature,plants have evolved sophisticated mechanisms enabling them to adapt to ever-changing environments.One such prominent feature is the evolution of diverse life history strategies,particularly such that annuals reproduce once followed by seasonal death,while perennials live longer by cycling growth seasonally.This intrinsic phenology is primarily genetic and can be altered by environmental factors.Although evolutionary transitions between annual and perennial life history strategies are common,perennials account for most species in nature because they survive well under year-round stresses.This proportion,however,is reversed in agriculture.Hence,perennial crops promise to likewise protect and enhance the resilience of agricultural ecosystems in response to climate change.Despite significant endeavors that have been made to generate perennial crops,progress is slow because of barriers in studying perennials,and many developed species await further improvement.Recent findings in model species have illustrated that simply rewiring existing genetic networks can lead to lifestyle variation.This implies that engineering plant life history strategy can be achieved by manipulating only a few key genes.In this review,we summarize our current understanding of genetic basis of perenniality and discuss major questions and challenges that remain to be addressed.

关键词： perenniality developmental plasticity flowering time poplar Arabis alpina perennial crops life history strategy

Catalysis by subsurface metal atoms in Al(001) through electron transfer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 12-13页

作者： bo Sun Ding Ma Beijing National Laboratory for Molecular Science New Cornerstone Science Laboratory College of Chemistry and Molecular Engineering Peking University

Heterogeneous catalysis plays a crucial role in the chemical industry, which has evolved from the investigation of chemisorption to an electronic structure[1]. Diverse strategies, such as alloying,doping, and confining, have been applied to enhance the catalytic properties of active sites through electronic modulation. The electron transfer between active sites and substrates profoundly influences catalytic activity [2].

关键词：