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Design study of charge-stripping scheme of heavy ion beams for HIAF-BRing

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Nuclear Science and Techniques 2024年第5期35卷 30-41页

作者： Jun-Jie Zhang Zhi-You Xu Jin-Quan Zhang wen-wen ge Liang-Ting Sun Huan-Yu Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Charge strippers play an essential role in heavy-ion accelerators by stripping the projectile ions to higher charge states to enhance the acceleration efficiency downstream of the *** the high-energy mode of the booster ring(BRing)of the high-intensity heavy-ion accelerator facility,the pre-accelerated ions from the iLinac will be stripped by a carbon foil to higher charge states and then injected into the *** key parameters of the stripper and stripped ions were calculated,and the influence of stripping on the beam quality was *** get high stripping efficiencies,the foil thicknesses and resultant charge state distributions for the typical ions were determined by the code *** equilibrium thickness was obtained for the U beam,while the stripper thicknesses for the Xe and Kr beams were determined based on a compromise between the stripped charge states and the stripping *** energy loss,energy straggling,and emittance growth due to stripping have a non-negligible impact on the transport of the stripped beams and the injection of the ***,these parameters were simulated by *** addition,the foil’s temperature evolution,which greatly affects the foil lifetime,was simulated by *** maximum temperature of the foil bombarded by the U and Xe beams with the nominal parameters will exceed the safe value in terms of the impact of evaporation on the foil’s *** the foil temperature constraint,the highest tolerable beam intensity and the injected ion number into the ring were derived for different beam *** results of this paper will present important reference data for the optimization design and commissioning of the beamline and injection to the BRing for the stripped ions.

关键词： High-intensity heavy-ion accelerator facility Charge stripper Energy spread Thermal analysis Emittance growth Injection turns

Disentangling distinct Cu surface sites for electrocatalytic CO_(2)-to-CO and CO-to-C_(2+)conversion

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Science China Chemistry 2024年第4期67卷 1047-1048页

作者： Kun Jiang wen-Bin Cai Interdisciplinary Science Research Centre School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Electrochemical CO_(2)reduction reaction(CO_(2)RR)is a promising strategy to curb anthropogenic carbon emissions,for which intermittent renewable electricity could be stored as chemical energy within carbon-based fuel... 详细信息

关键词： carbon Electrochemical surface

A highly selective electrochemical impedimetric sensor for imidacloprid determination based on WO_(3)/MoS_(2)nanosheets/molecularly imprinted polymer composite

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Rare Metals 2024年第3期43卷 1309-1315页

作者： Long-Hua Ding Ya-wen wa.g Qiu-wen Li Li-Li Zhang Ai-Zhu wa.g Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China HCA Florida Healthcare Westside/Northwest Hospital Internal Medicine PlantationFL33324USA

In this study,an electrochemical impedimetric sensor was established for imidacloprid(IMI)detection based on WO_(3)/MoS_(2)and molecular imprinted polymer(MIP)*** layer was prepared on electrode surface by electropolymerization of o-phenylenediamine(o-PD)in the presence of IMI template,which ensured the specific rec-ognization toward IMI.

关键词： electrochemical polymer polymerization

Object use in insects

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Insect Science 2024年第4期31卷 1001-1014页

作者： Chao wen Cai wa.g Xiaoli guo Hongyu Li Haijun Xiao Junbao wen Shikui Dong School of grassland Science Beijing Forestry UniversityBeijingChina College of Forestry and Landscape Architecture South China Agricultural UniversityGuangzhouChina Beijing Key Laboratory for Forest Pest Control Beijing Forestry UniversityBeijingChina

Insects are the most diverse group of organisms in the animal kingdom,and some species exhibit complex social *** research on insect object use is still in its early stages,insects have already been shown to display rich object-use *** review focuses on patterns and behavioral flexibility in insect object-use behavior,and the role of cultural evolution in the development of object-use *** use in insects is not widespread but has been documented in a diverse set of *** insects can use objects flexibly and display various object-use *** mammals and birds,insects use objects in diverse activities,including foraging,predator defense,courtship,and ***,pre-existing manipulative behaviors,and anatomical structure affect innovations in object *** addition,learning and imitation are the main mechanisms underlying the spread of object-use behaviors within *** that insects are one of the major animal groups engaging in object use,studies of insect object use could provide general insights into object use in the animal kingdom.

关键词： cognition evolution insects learning object use

All types of base conversions allowed by base editors

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Science China(Life Sciences) 2024年第2期67卷 431-433页

作者： Shun-Qing Liang wen Xue RNA Therapeutics Institute UMass Chan Medical SchoolWorcester 01655USA Department of Molecular Cell and Cancer BiologyUMass Chan Medical SchoolWorcester 01655USA Department of Molecular Medicine UMass Chan Medical SchoolWorcester 01655USA Li Weibo Institute for Rare Diseases Research UMass Chan Medical SchoolWorcester 01655USA

Base editors(BEs) hold great promise as tools for introducing single-base-pair changes in both basic research and therapeutic applications(Rees and Liu,2018).Base editors are composed of a Cas9 nickase fused to a DNA-modifying enzyme,which chemically modifies nucleobases within a specific targeting window near the Cas9-binding site.

关键词： base bases allowed

Decadal Changes in Dry and Wet Heatwaves in Eastern China:Spatial Patterns and Risk Assessment

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Advances in Atmospheric Sciences 2024年第10期41卷 2011-2026页

作者： Yue ZHANg wen ZHOU Ruhua ZHANg Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan University CMA-FDU Joint Laboratory of Marine Meteorology Fudan University Key Laboratory of Polar Atmosphere-ocean-ice System for Weather and Climate Ministry of Education Fudan University

Under global warming, understanding the long-term variation in different types of heatwaves is vital for China's preparedness against escalating heat stress. This study investigates dry and wet heatwave shifts in eastern China over recent decades. Spatial trend analysis displays pronounced warming in inland midlatitudes and the Yangtze River Valley, with increased humidity in coastal regions. EOF results indicate intensifying dry heatwaves in northern China, while the Yangtze River Valley sees more frequent dry heatwaves. On the other hand, Indochina and regions north of 25°N also experience intensified wet heatwaves, corresponding to regional humidity increases. Composite analysis is conducted based on different situations: strong, frequent dry or wet heatwaves. Strong dry heatwaves are influenced by anticyclonic circulations over northern China, accompanied by warming SST anomalies around the coastal midlatitudes of the western North Pacific(WNP). Frequent dry heatwaves are related to strong subsidence along with a strengthened subtropical high over the *** and frequent wet heatwaves show an intensified Okhotsk high at higher latitudes in the lower troposphere, and a negative circumglobal teleconnection wave train pattern in the upper troposphere. Decaying El Ni?o SST patterns are observed in two kinds of wet heatwave and frequent dry heatwave years. Risk analysis indicates that El Ni?o events heighten the likelihood of these heatwaves in regions most at risk. As global warming continues, adapting and implementing mitigation strategies toward extreme heatwaves becomes crucial, especially for the aforementioned regions under significant heat stress.

关键词： decadal changes dry heatwave eastern China wet heatwave

Rhodium-Catalyzed N-Arylation Addition of Arylboronic Acids to Ketimines

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Chinese Journal of Chemistry 2024年第18期42卷 2243-2248页

作者： Xue-Wei Qian Xing-wen Sun Department of Chemistry Fudan University220 Handan RoadShanghai 200433China

Herein,we report rhodium catalyzed N-arylation via addition of arylboronic acids to electron-deficientα-iminoesters which can be prepared in high efficiency by using easily accessible B-carbonyl *** reaction is highly regiospecific to achieve the N-aryl addition efficiently with up to 99%yield under mild *** corresponding product can be further efficiently converted into indoles andaseries of other important building blocks.

关键词： Rhodium catalyzed N-Arylation addition Amines Umpolung Indole C-C coupling

The centrosymmetric to non-centrosymmetric transformation induced by alkaline-earth cations producing infrared nonlinear optical AeMn_(6)ga_(6)S_(16)(Ae=Ca,Sr)

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Science China Chemistry 2024年第9期67卷 2941-2948页

作者： Yang-Ping Zhang Shao-Min Pei wen-Fa Chen Bin-wen Liu Xiao-Ming Jiang guo-Cong guo State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China

Non-centrosymmetric(NCS)structure is an indispensable prerequisite for second-order nonlinear optical(NLO)***,the mainstream approach for designing new NCS structures still relies on chemical substitution,necessitating an urgent infusion of fresh *** this work,two isomorphic sulfides AeMn_(6)ga_(6)S_(16)(Ae=Ca,1;Sr,2)are afforded by modifying the skeleton of centrosymmetric(CS)Mn_(2)ga_(2)S_(5) via introducing strong electropositive alkaline-earth ***,the incorporation of Ca^(2+)/Sr^(2+)cations allows the elementary[MngaS_(9)]_(∞)chains to reconfigure into bumpy[MnS_(6)]-[gaS_(4)]layers in a new engagement manner,thus enabling the conversion from CS to NCS *** modifications cause not only strong second-harmonic generation(SHg)responses(~1.5×benchmark AggaS_(2)@1,700 nm),but also significantly feasible bandgaps(2.60-2.64 e V)compared to the sulfide Mn_(2)ga_(2)S_(5)(1.36 e V),which ultimately facilitate ultrahigh laser-induced damage thresholds(4.4-6.6×AggaS_(2)@1,064 nm for compounds 1 and 2).The present study offers an ingenious approach for the transformation of CS to NCS structure.

关键词： second-harmonic generation non-centrosymmetrical structure NLO functional motif solid-state method

Divergent defluorocarboxylation of α-CF_(3) alkenes with formate via photocatalyzed selective mono-or triple C-F bond cleavage

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Science China Chemistry 2024年第1期67卷 368-373页

作者： Xing-Yu wa.g Pei Xu wen-wen Liu Hao-Qiang Jiang Song-Lei Zhu Dong guo Xu Zhu Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy School of PharmacyXuzhou Medical UniversityXuzhou 22100China

Unprecedented divergent synthesis of gem-difluorovinylacetic acid and glutaric acid derivatives fromα-CF_(3)alkenes with formate as the carbonyl source was *** reaction can undergo selective mono-or triple C-F bond cleavage by simply switching the photocatalyst and hydrogen atom transfer(HAT)catalyst under visible-light-induced conditions at room *** acts as both the C1 source and the reductant through the generation of CO_(2)^(·-)species,which underwent giese radical addition to electron-deficient alkenes to trigger the consecutive C-F bond cleavage and carboxylation process.

关键词： C-F bond activation defluorocarboxylation carbon dioxide radical anion visible light