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Vortex identification based on the Liutex method and its effect on fish passage upstream

Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo Yang Xiao-tao shi Ming-ming Wang shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

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A highly sensitive multiple-mode optical thermometer designed in Eu^(2+/3+)and Li^(+)co-doped polymorphism compound LaSc_(3)(BO_(3))_(4)

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Journal of Advanced Ceramics 2024年第6期13卷 821-833页

作者： Nan Yang Zhuo Li Tingxia Zhou Ziwang Zhang Wen shi Yexiang Tong Jianxin shi School of Chemistry IGCMESun Yat-sen UniversityGuangzhou 510006China MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry IGCMEThe Key Lab of Low-Carbon Chemistry&Energy Conservation of Guangdong ProvinceSun Yat-sen UniversityGuangzhou 510006China

Noncontact optical thermometers have attracted widespread attention,but existing problems such as single-mode and low-sensitivity thermometers still urgently need to be ***,a novel multiple-mode thermometer was designed for the polymorphism LaSc_(3)(BO_(3))_(4):Eu^(2+/3+),Li^(+).X-ray diffraction(XRD)patterns revealed a slight transition betweenα-andβ-phases with the concentrations of the dopants,which is further proved by structure refinements and first-principles *** coexistence of Eu^(2+)and Eu^(3+)in the phosphors and their relative percentages were confirmed by X-ray absorption near-edge structure(XANES)*** from appropriate emissions from Eu^(2+)and Eu^(3+)without obvious energy transfer and their opposite changing trends with temperatures under 307 nm excitation,a triple-mode optical thermometer is obtained for this material within the temperature range of 150–450 *** highest sensitivities of 27.65,14.05,and 7.68%·K^(−1)are achieved based on two fluorescence intensity ratio(FIR)modes of Eu^(2+)and Eu^(3+)(5d–4f/^(5)D_(0)–^(7)F_(2,4))and the fluorescence lifetime(FL)mode of Eu^(2+),*** the best of our knowledge,the former is almost the highest in Eu^(2+)and Eu^(3+)co-doped *** results indicate that this material may be used as an excellent multiple-mode optical thermometer.

关键词： phase transition europium(Eu)ions multiple-mode optical thermometer thermal quenching properties fluorescence intensity ratio(FIR) fluorescence lifetime(FL)

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Enantioselective Alkylation of Aldehydes with Organoborons Enabled by Nickel/N-Heterocyclic Carbene Catalysis

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Chinese Journal of Chemistry 2024年第18期42卷 2161-2165页

作者： Song-Yang Liu Zi-Chao Wang shi-Liang shi College of Chemistry and Material Science Shanghai Normal University100 Guilin RoadShanghai 200234China State Key Laboratory of Organometallic Chemistry Shanghai Institute of rganic ChemitryUniversity of Chinee Academy of Scienc Chinese Academy of Sciences345 Lingling RoadShanghai 200032China

Transition-metal-catalyzed asymmetric alkylation of aldehydes represents a straightforward strategy for the synthesis of chiral secondary ***,efficient methods using organoborons as coupling reagents are ***,we report a highly enantioselective nickel-catalyzed alkylation reaction of aldehydes,using readily available alkylborons as nucleophiles.A wide variety of chiral secondary alcohols were prepared from commercially available aldehydes with high *** key to the excellent enantioselectivity and chemoselectivity was the employment of a bulky C2-symmetric chiral NHC *** protocol features excellent enantiocontrol,mild conditions,and good functional group compatibility.

关键词： Enantioselective alkylation Nickel catalysis N-Heterocyclic carbene Organoborons Chiral alcohols Asymmetric catalysis C-C coupling Synthetic methods

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Theory and test of underground explosions:Coupling rule between cratering and ground shock

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Underground Space 2024年第4期17卷 146-160页

作者： Wei Guo Jie Li Benjun shi Tianhan Xu Xiaohui Xu Gan Li Jie shi State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact Army Engineering University of PLANanjing 210007China

Calculating the parameters of the ground shock induced by an underground explosion is a complex energy coupling *** is difficult to establish a unified ground shock coupling law from limited test *** paper summarizes the research results obtained at home and abroad and systematically analyzes the coupling mechanism of craters formed by an underground explosion and the ground *** differences between the concepts of"closed-explosion critical depth"and"equivalent closed-explosion critical depth"are clearly *** spreading of the ground shock energy is attributed to the explosive expansion of the air cavity,revealing a linear relationship between the volume of the cavity region(or the volume of the crack region)and the ground shock energy associated with the underground *** proportionality factor is related to the mechanical properties of the medium and is independent of the magnitude of the explosion *** on this,a theoretical calculation formula and conversion method for the ground shock coupling coefficient were *** tests were conducted in clay and Plexiglass under varying burial *** test results were consistent with the theoretically calculated *** study provides a theoretical basis for the design of explosion-resistant structures in underground engineering.

关键词： Underground explosion Ground shock coupling Coupling coefficient Equivalent closed explosion Experimental study

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Design strategies and recent advancements of solid-state supercapacitor operating in wide temperature range

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Carbon Energy 2024年第6期6卷 248-281页

作者： Jie Zhou Zhengfeng Zhu Wenhui shi Xiangyu shi Zhuoyuan Zheng Ye Xiong Yusong Zhu School of Energy Science and Engineering Nanjing Tech UniversityNanjingJiangsuChina Kucap Smart Technology(Nanjing)Co. Ltd.NanjingJiangsuChina

Solid-state supercapacitors(SSCs)are emerging as one of the promising energy storage devices due to their high safety,superior power density,and excellent cycling ***,performance degradation and safety issues under extreme conditions are the main challenges for the practical *** the expansion of human activities,such as space missions,polar exploration,and so on,the investigation of SSC with wide temperature tolerance,high energy density,power density,and sustainability is highly *** this review,the effects of temperature on SSC are systematically illustrated and clarified,including the properties of the electrolyte,ion diffusion,and reaction dynamics of the ***,we summarize the recent advances in wide-temperature-range SSCs from the aspect of electrolyte modification,electrode design,and interface adjustment between electrode and electrolyte,especially with critical concerns on ionic conductivity and cycling *** the end,a perspective is presented,expecting to promote the practical application of the SSC in harsh conditions.

关键词： electrode interface solid-state electrolyte solid-state supercapacitor wide temperature

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Projections of summer light rain frequency in typical terrain over eastern China under wind speed constraint

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Science China Earth Sciences 2024年第6期67卷 1885-1894页

作者： Xuechen DONG Daoyi GONG Cuicui shi Institute of Disaster Risk Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster MOEFaculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China School of Systems Science Beijing Normal UniversityBeijing 100875China

The variation in near-surface wind speed is a key dynamic parameter in the orographic effect of precipitation over eastern *** this study,we used the latest high-resolution outputs from six GCMs in CMIP6-HighResMIP to evaluate the performance of high-resolution models in simulating the orographic precipitation characteristics of typical mountainous areas in summer over eastern *** orographic precipitation under warming scenarios was projected and constrained according to observational *** results indicated that during the contemporary climate reference period(1979-2009),although the relationship between model-simulated near-surface wind speed and orographic light rain frequency was consistently stable,the sensitivity of the orographic light rain frequency to surface wind variability was generally underestimated,with a deviation approximately 24.1% lower than the observational *** estimated orographic light rain frequency corrected based on the observed near-surface wind speed under a 1.5℃ warming scenario,was 36.1% lower than that of the contemporary period;this reduction was 8.6 times that without the wind speed constraint(4.2%).The MRI-AGCM3-2-S model,with a longer dataset,demonstrated relatively stable reductions in orographic light rain frequency under different warming scenarios(1.5℃,2℃,3℃,and 4℃)after the application of wind speed *** all cases,the reductions exceeded those for the predictions made without the wind speed constraint.

关键词： Frequency of orographic light rain HighResMIP High-resolution projection Observational constraint Eastern China

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mRNA medicine:Recent progresses in chemical modification,design,and engineering

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Nano Research 2024年第10期17卷 9015-9030页

作者： Xiaowen Hou Jinjun shi Yuling Xiao Department of Cardiology Zhongnan Hospital of Wuhan UniversitySchool of Pharmaceutical SciencesWuhan UniversityWuhan 430071China Center for Nanomedicine and Department of Anesthesiology Perioperative and Pain MedicineBrigham and Women’s HospitalHarvard Medical SchoolBostonMA 02115USA

Messenger RNA(mRNA)is a type of RNA that carries genetic information from DNA to the ribosome,where it is translated into *** has emerged as a powerful platform for development of new types of medicine,especially after the clinical approval of COVID-19 mRNA *** modification and nanoparticle delivery have contributed to this success significantly by improving mRNA stability,reducing its immunogenicity,protecting it from enzymatic degradation,and enhancing cellular uptake and endosomal ***,substantial progresses have been made in new modification chemistries,sequence design,and structural engineering to generate more stable and efficient next-generation *** innovations could further facilitate the clinical translation of mRNA therapies and *** that numerous review articles have been published on mRNA nanoparticle delivery and biomedical applications over the last few years,we herein focus on overviewing recent advances in mRNA chemical modification,mRNA sequence optimization,and mRNA engineering(e.g.,circular RNA and multitailed mRNA),with the aim of providing new perspectives on the development of more effective and safer mRNA medicines.

关键词： mRNA self-amplifying RNA circular RNA multitailed mRNA chemical modification machine learning

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Large magnetostriction of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites in a wide temperature range

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Journal of Rare Earths 2024年第4期42卷 705-709页

作者： Hehe Ding Yangguang shi Shaolong Tang MIIT Key Laboratory of Aerospace Information Materials and Physics Department of Applied PhysicsNanjing University of Aeronautics and AstronauticsNanjing210016China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

We report the magnetostrictive performance of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy *** of M?ssbauer spectra and the XRD results indicate that the easy magnetic direction of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)compound is alongdirection with spontaneous magnetostrictionλ111 of1900 ***-oriented Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites with particle volume fractions of20 vol%-55 vol%were *** measurements demonstrate that the composite is highly *** raw material cost of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)is about 85%of that of the Terfenol-D(Tb_(0.3)Dy_(0.7)Fe_(2))***_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites possess comparable magnetostriction with those composites made of Tb_(0.3)Dy_(0.7)Fe_(2)*** room temperature,the magnetostrictionλ_Ⅱof the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composite reaches 420 ppm at a low field of 80 kA/m and about1000 ppm at 239 kA/*** addition,the composite exhibits a large saturation magnetostrictionλ_Ⅱover1200 ppm from 300 to 100 K,suggesting its potential applications as a low-cost magnetostrictive material in a wide temperature ***,the current study offers an opportunity to widen the operating temperature range of the magnetostrictive composite.

关键词： Magnetostrictive composite Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93) Wide temperaturerange Laves phase Rare earths

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Robust AUC maximization for classification with pairwise confidence comparisons

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Frontiers of Computer Science 2024年第4期18卷 73-83页

作者： Haochen shi Mingkun XIE Shengjun HUANG College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China MIIT Key Laboratory of Pattern Analysis and Machine Intelligence Nanjing 211106China

Supervised learning often requires a large number of labeled examples,which has become a critical bottleneck in the case that manual annotating the class labels is *** mitigate this issue,a new framework called pairwise comparison(Pcomp)classification is proposed to allow training examples only weakly annotated with pairwise comparison,i.e.,which one of two examples is more likely to be *** previous study solves Pcomp problems by minimizing the classification error,which may lead to less robust model due to its sensitivity to class *** this paper,we propose a robust learning framework for Pcomp data along with a pairwise surrogate loss called *** provides an unbiased estimator to equivalently maximize AUC without accessing the precise class ***,we prove the consistency with respect to AUC and further provide the estimation error bound for the proposed *** studies on multiple datasets validate the effectiveness of the proposed method.

关键词： method pairwise weakly

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Cooperative control for heterogeneous multi-agent systems: progress, applications, and challenges

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Science China(Information Sciences) 2024年第5期67卷 318-320页

作者： Bing YAN Peng shi Jonathon CHAMBERS School of Electrical and Mechanical Engineering Faculty of Science Engineering and TechnologyThe University of Adelaide School of Engineering College of Science and Engineering University of Leicester

Cooperative control for heterogeneous multi-agent systems(MASs) is a critical and rapidly evolving field in modern automation and robotics. Characterized by the integration of agents with diverse capabilities and func... 详细信息

关键词： Multi agent systems

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