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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

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Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-Bo Li Qi Zhang Jun-Zhao Xiao Yi-fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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Robust facial expression recognition via lightweight reinforcement learning for rehabilitation robotics

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Optoelectronics Letters 2025年第2期21卷 97-104页

作者： CHEN Yifan fan Weiming GAO Hongwei YU Jiahui JU Zhaojie School of Computing University of Portsmouth School of Automation and Electrical Engineering Shenyang Ligong University Department of Biomedical Engineering Zhejiang University

This paper proposes a lightweight reinforcement network (LRN) and auxiliary label distribution learning (ALDL)based robust facial expression recognition (FER) *** designed representation reinforcement (RR) network mainly comprises two modules,i.e.,the RR module and the auxiliary label space construction (ALSC) *** RR module highlights key feature messaging nodes in feature maps,and ALSC allows multiple labels with different intensities to be linked to one ***,LRN has a more robust feature extraction capability when model parameters are greatly reduced,and ALDL is proposed to contribute to the training effect of LRN in the condition of ambiguous training *** tested our method on FER-Plus and RAF-DB datasets,and the experiment demonstrates the feasibility of our method in practice during rehabilitation robots.

关键词： Reinforcement learning

Detection using mask adaptive transformers in unmanned aerial vehicle imagery

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Optoelectronics Letters 2025年第2期21卷 113-120页

作者： YE Huibiao fan Weiming GUO Yuping WANG Xuna ZHOU Dalin China Telecommunication Corporation Zhejiang Branch Innovation Center for Smart Medical Technologies & Devices Binjiang Institute of Zhejiang University School of Computing University of Portsmouth

Drone photography is an essential building block of intelligent transportation,enabling wide-ranging monitoring,precise positioning,and rapid ***,the high computational cost of transformer-based methods in object detection tasks hinders real-time result transmission in drone target detection ***,we propose mask adaptive transformer (MAT) tailored for such ***,we introduce a structure that supports collaborative token sparsification in support windows,enhancing fault tolerance and reducing computational *** structure comprises two modules:a binary mask strategy and adaptive window self-attention (A-WSA).The binary mask strategy focuses on significant objects in various complex *** A-WSA mechanism is employed to self-attend for balance perfomance and computational cost to select objects and isolate all contextual *** experiments on the challenging CarPK and VisDrone datasets demonstrate the effectiveness and superiority of the proposed ***,it achieves a mean average precision (mAP@0.5) improvement of 1.25%over car detector based on you only look once version 5 (CD-YOLOv5) on the CarPK dataset and a 3.75%average precision(AP@0.5) improvement over cascaded zoom-in detector (CZ Det) on the VisDrone dataset.

关键词： Drones

Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： fan YANG Zhaoyang MA Xingming GUO Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai Institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

关键词： Vibration analysis

Marine dispersion of Fukushima-derived radiocesium in the North Pacific and its implications

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Science China Earth Sciences 2025年

作者： Tong ZHANG Xiaolin HOU Yukun fan State Key Laboratory of Loess and Quaternary Geology Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application Xi'an AMS Center Institute of Earth Environment Chinese Academy of Sciences University of Chinese Academy of Sciences Xi'an Institute for Innovative Earth Environment Research

A key scientific approach to addressing the environmental radiation risks from Fukushima nuclear contaminated water （FNCW） discharge into the ocean is understanding and predicting the marine dispersion of *** dispersion of radiocesium (CsF:134Cs,137Cs) from the Fukushima nuclear accident in the North Pacific and its marginal seas post-2011 was systematically summarized,focusing on pathways,vertical distribution changes,and transit *** research examined CsFdispersion through the Kuroshio Extension and denser central mode water （D-CMW） to the eastern North Pacific,as well as through subtropical mode water （STMW）,lighter central mode water （L-CMW）,and D-CMW to the subtropical western North Pacific,China Seas,and Sea of *** considered broader implications of CsFdispersion in light of ongoing FNCW *** this prolonged liquid discharge and Kuroshio Extension’s barrier effect,it is crucial to emphasize the role of CMW besides STMW in transporting FNCW to the subtropical western North Pacific and its marginal *** research should focus on the key mechanism and longitude range of CMW crossing the Kuroshio *** short-lived134Cs decays rapidly during the storage and dispersion of FNCW,long-lived135Cs and135Cs/137Cs ratios can serve as valuable tracers for detecting and quantifying ***,there is an urgent need for high-precision analysis of these key radionuclides and their characteristic *** promptly detect,assess,and respond to FNCW intrusion,continuous monitoring and identification of nuclear pollution sources in key ocean currents and straits are ***,interdisciplinary research integrating monitoring with marginal sea circulation dynamics and high-resolution numerical simulations should be a priority

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GFRF R-CNN:Object Detection Algorithm for Transmission Lines

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Computers, Materials & Continua 2025年第1期82卷 1439-1458页

作者： Xunguang Yan Wenrui Wang fanglin Lu Hongyong fan Bo Wu Jianfeng Yu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of Sciences Beijing100049China Jingwei Textile Machinery Co. Ltd.Beijing100176China

To maintain the reliability of power systems,routine inspections using drones equipped with advanced object detection algorithms are essential for preempting power-related *** increasing resolution of drone-captured images has posed a challenge for traditional target detection methods,especially in identifying small objects in high-resolution *** study presents an enhanced object detection algorithm based on the Faster Regionbased Convolutional Neural Network(Faster R-CNN)framework,specifically tailored for detecting small-scale electrical components like insulators,shock hammers,and screws in transmission *** algorithm features an improved backbone network for Faster R-CNN,which significantly boosts the feature extraction network’s ability to detect fine *** Region Proposal Network is optimized using a method of guided feature refinement(GFR),which achieves a balance between accuracy and *** incorporation of Generalized Intersection over Union(GIOU)and Region of Interest(ROI)Align further refines themodel’s *** results demonstrate a notable improvement in mean Average Precision,reaching 89.3%,an 11.1%increase compared to the standard Faster *** highlights the effectiveness of the proposed algorithm in identifying electrical components in high-resolution aerial images.

关键词： Faster R-CNN transmission line object detection GIOU GFR

Evidence and Expert Opinions:Drying Needling versus Acupuncture(Ⅰ)--The American Alliance for Professional Acupuncture Safety(AAPAS)White Paper 2016

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Chinese Journal of Integrative Medicine 2017年第2期23卷 3-9页

作者： fan arthur yin XU Jun LI Yong-ming American Alliance for Professional Acupuncture Safety GreenwichConnecticut 06878U.S.A American Traditional Chinese Medicine Association ViennaVirginia 22182U.S.A American Acupuncture Association of Greater New York New York 10016U.S.A

In the last twenty years, in the United States and other Western countries, dry needling （DN） became a hot and debatable topic, not only in academic but also in legal fields. This White Paper is to provide the authoritative information of DN versus acupuncture to academic scholars, healthcare professional administrators, lawmakers, and the general public through providing the authoritative evidence and experts＇ opinions regarding critical issues of DN versus acupuncture, and then reach consensus. DN is the use of dry needles alone, either solid filiform acupuncture needles or hollow-core hypodermic needles, to insert into the body for the treatment of muscle pain and related myofascial pain syndrome. DN is sometimes also known as intramuscular stimulation, trigger points （TrP） acupuncture, TrP DN, myofascial TrP DN, or biomedical acupuncture. InWestern countries, DN is a form of simplified acupuncture using biomedical language in treating myofascial pain, a contemporary development of a portion of Ashi point acupuncture from Chinese acupuncture. It seeks to redefine acupuncture by reframing its theoretical principles in a Western manner. DN-like needling with filiform needles have been widely used in Chinese acupuncture practice over the past 2,000 years, and with hypodermic needles has been used in China in acupuncture practice for at least 72 years. In Eastern countries, such as China, since late of 1800s or earlier, DN is a common name of acupuncture among acupuncturists and the general public, which has a broader scope of indications, not limited to treating the myofascial pain.

关键词： dry needling acupuncture biomedical acupuncture authoritative evidence experts' opinions,consensus

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Evidence and Expert Opinions：Dry Needling versus Acupuncture(Ⅲ)--The American Alliance for Professional Acupuncture Safety(AAPAS) White Paper 2016

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Chinese Journal of Integrative Medicine 2017年第3期23卷 163-165页

作者： fan arthur yin XU Jun LI Yong-ming American Alliance for Professional Acupuncture Safety GreenwichConnecticut(06878)U.S.A American Traditional Chinese Medicine Association ViennaVirginia(22182)U.S.A American Acupuncture Association of Greater New York NewYork(10016)U.S.A

Summary of Dry Needling Issues Academic Perspective In regards to terminology,dry needling（DN） is a synonym to acupuncture,just a different English translation from the original Chinese term ＂针刺＂（Zhen Ci）.In C... 详细信息

关键词： acupuncture Acupuncture AAPAS synonym terminology versus profession Alliance replace simplified

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Industrial solid wastes to environmental protection materials for removal of gaseous pollutants:A review

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Green Energy & Environment 2025年第1期10卷 34-83页

作者： Jiacheng Bao Xin Sun Ping Ning Kai Li Jie Yang Fei Wang Lei Shi Maohong fan Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming650500China College of Engineering and Physical Sciences and School of Energy ResourcesUniversity of WyomingLaramieWY82071USA College of Engineering Georgia Institute of TechnologyAtlantaGA30332USA

The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective *** this review,we investigate the development of industrialwaste-based functional materials for various gas pollutant removal and consider the relevant reaction mechanism according to different types of industrial solid *** see a recent effort towards achieving high-performance environmental functional materials via chemical or physical modification,in which the active components,pore size,and phase structure can be *** review will discuss the potential of using industrial solid wastes,these modified materials,or synthesized materials from raw waste precursors for the removal of air pollutants,including SO_(2),NO_(x),Hg^(0),H_(2)S,VOCs,and CO_(2).The challenges still need to be addressed to realize this potential and the prospects for future research *** suggestions for future directions include determining the optimal composition of these materials,calculating the real reaction rate and turnover frequency,developing effective treatment methods,and establishing chemical component databases of raw industrial solid waste for catalysts/adsorbent preparation.

关键词： Industrial solid waste Reaction mechanism Modification method Air pollutants