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Rhodium-catalyzed addition reactions of benzylic C–H bonds to cyclic N-sulfonyl ketimines viaπ-coordination

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Chinese Chemical Letters 2024年第3期35卷 287-291页

作者： Yuntong Li Hang Shi Department of Chemistry Zhejiang UniversityHangzhou 310027China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

Mannich-type reactions are a widely used method for the synthesis of amines due to the readily availability of nucleophiles and ***,the inclusion of alkylarenes instead of active carbon pronucleophiles such as aldehydes and ketones in these addition reactions has been a challenge due to the inherent difficulty of benzylic *** this study,we present a novel approach for the construction of N-sulfonyl amines via rhodium-catalyzed addition of unbiased benzylic C–H bonds to cyclic N-sulfonyl ketamines throughπ-*** strategy enables the synthesis of a diverse range of N-sulfonyl amines,and subsequent diversification of the addition products showcases the synthetic potential of this protocol.

关键词： Benzylic deprotonation Cyclic N–sulfonyl ketimines π-Coordination Mannich-type addition Rhodium catalysis

Contact engineering for temperature stability improvement of Bi-contacted MoS2 field effect transistors

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Science China(Information Sciences) 2024年第6期67卷 172-179页

作者： Zizheng LIU Qing ZHANG Xiaohe HUANG Chunsen LIU Peng ZHOU State Key Laboratory of Integrated Chip and Systems School of MicroelectronicsZhangjiang Fudan International Innovation CenterFudan University Frontier Institute of Chip and System Shanghai Key Lab for Future Computing Hardware and SystemFudan University Shaoxin Laboratory

Semimetallic bismuth（Bi） is one of the most effective strategies for reducing the contact resistance of two-dimensional transition metal dichalcogenide field effect transistors（FETs）. However, the low melting point of Bi contact（271.5℃） limits its reliable applications. In this study, we demonstrated that the temperature stability of Bi-contacted electrodes could be improved by inserting a high-melting point semimetallic antimony（Sb） between the Bi contacting layer and the gold（Au） capping layer. The proposed Bi/Sb/Au contact electrodes tended to form a metal mixture with a continuous surface during the heating process（Voids appeared on the surface of the Bi/Au contact electrodes after heating at 120℃）. Because of the improved contacting layer formed by the semimetal Bi/Sb alloy, the fabricated Bi/Sb/Au-contacted molybdenum sulfide（MoS2） FETs with different gate lengths demonstrated higher on-state current stability after heating treatment than the Bi/Au contact. Because of the Bi/Sb/Au contact and poly（methyl methacrylate） package, the MoS2FETs demonstrated time stability of at least two months from the almost unchanged transfer characteristics. The electrical stability indicates that the insertion of semimetallic Sb is a promising technology for reliable Bi-based contact.

关键词： temperature stability semimetallic bismuth contact semimetallic antimony contact MoS$_{2}$ FETs time stability

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Boring holes in Au nanoplates by active surface etching

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Nano Research 2024年第9期17卷 8610-8617页

作者： Haiyang Hu Yuntao Wang Qian Wang Xudong Peng An Su Hong Wang Hongyu Chen Institute of Advanced Synthesis(IAS)and School of Chemistry and Molecular Engineering Jiangsu National Synergetic Innovation Centre for Advanced MaterialsNanjing Tech UniversityNanjing 211816China Department of Environmental Science and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry School of Science and Key Laboratory for Quantum Materials of Zhejiang ProvinceResearch Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make *** critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the ***,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly *** choice of ligand MBIA is also of importance,as it carries negative charge and repels each *** inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less *** etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are *** believe that the ability of boring holes is an important tool for future synthetic designs.

关键词： Au nanoplates active surface etching boring etching mode cetyltrimethylammonium bromide(CTAB)passivation holes

Reversibly sensitizing-storing-releasing ^(1)O_(2) within a single platinum(Ⅱ)-acetylide-based metallacycle molecule via laser power modulation

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Science China Chemistry 2024年第2期67卷 604-611页

作者： Ruyi Zhou Wen Lv Bo Li Bo Yu Sudi Zhang Yucheng Zhou Shujuan Liu Qiang Zhao State Key Laboratory of Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)&Institute of Flexible Electronics(Future Technology)Nanjing University of Posts and Telecommunications(NUPT)Nanjing210023China College of Electronic and Optical Engineering&College of Flexible Electronics(future Technology) Jiangsu Province Engineering Research Center for Fabrication and Application of Special Optical Fiber Materials and DevicesNanjing University of Posts and Telecommunications(NUPT)Nanjing210023China

Tumor hypoxia severely limits the therapeutic efficacy of photodynamic therapy(PDT) for solid tumors,which is highly dependent on tissue oxygen *** this study,we developed a platinum(Ⅱ)-acetylide-based metallacycle compound bearing six 1,4-dimethylnaphthalenes(DMN) groups,and controlled the photodynamic and photothermal effects of the compound by adjusting the power of 730 nm laser to achieve reversible sensitization,storage and release of 1~O_(2) within a single *** compound formed nanoparticles by self-assembly and exhibited good water solubility and *** laser irradiation,the strong spin-orbit coupling of platinum atoms in the metallacycle facilitated 1~O_(2) *** produced 1~O_(2) was captured by the DMN carriers and transported into the hypoxic tumor,where 1~O_(2) release was triggered owing to the good photothermal effect of the extended conjugation of the *** therapy,the metallacycle serving as a photosensitizer,1~O_(2) carrier,and photothermal reagent,achieved the synergistic therapy of PDT/PTT,demonstrating the versatility of the *** study proposes a new strategy to develop phototherapy agents that are suitable for hypoxic tumors.

关键词： metallacycles singlet oxygen endoperoxides near-infrared absorption synergistic treatment

A Comprehensive Systematic Review: Advancements in Skin Cancer Classification and Segmentation Using the ISIC Dataset

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2131-2164页

作者： Madiha Hameed Aneela Zameer Muhammad Asif Zahoor Raja Department of Computer Sciences Pakistan Institute of Engineering and Applied SciencesNilore50700Islamabad future Technology Research center National Yunlin University of Science and TechnologyDouliou64002Taiwan Directorate of IT Services University of GujratGujrat50700Pakistan

The International Skin Imaging Collaboration(ISIC)datasets are pivotal resources for researchers in machine learning for medical image analysis,especially in skin cancer *** datasets contain tens of thousands of dermoscopic photographs,each accompanied by gold-standard lesion diagnosis *** challenges associated with ISIC datasets have spurred significant advancements,with research papers reporting metrics surpassing those of human *** cancers are categorized into melanoma and non-melanoma types,with melanoma posing a greater threat due to its rapid potential for metastasis if left *** paper aims to address challenges in skin cancer detection via visual inspection and manual examination of skin lesion images,processes historically known for their *** notable advancements in machine learning and deep learning models,persistent challenges remain,largely due to the intricate nature of skin lesion *** review research on convolutional neural networks(CNNs)in skin cancer classification and segmentation,identifying issues like data duplication and augmentation *** explore the efficacy of Vision Transformers(ViTs)in overcoming these challenges within ISIC dataset *** leverage their capabilities to capture both global and local relationships within images,reducing data duplication and enhancing model ***,ViTs alleviate augmentation issues by effectively leveraging original *** a thorough examination of ViT-based methodologies,we illustrate their pivotal role in enhancing ISIC image classification and *** study offers valuable insights for researchers and practitioners looking to utilize ViTs for improved analysis of dermatological ***,this paper emphasizes the crucial role of mathematical and computational modeling processes in advancing skin cancer detection methodologies,highlighting their significance in improving algorithmic

关键词： Medical image skin cancer classification skin cancer segmentation international skin imaging collaboration convolutional neural network deep learning

Coral records of Mid-Holocene sea-level highstands and climate responses in the northern South China Sea

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Acta Oceanologica Sinica 2024年第2期43卷 43-57页

作者： Yuanfu Yue Lichao Tang Kefu Yu Rongyong Huang School of Marine Sciences Coral Reef Research Center of ChinaGuangxi UniversityNanning 530004China Guangxi Laboratory on the study of Coral Reefs in the South China Sea Nanning 530004China

High-resolution sea-level data and high-precision dating of corals in the northern South China Sea(SCS)during the Holocene provide a reference and historical background for current and future sea-level changes and a basis for scientific assessment of the evolutionary trend of coral reefs in the *** sporadic studies have been performed around Hainan Island in the northern SCS,the reconstructed sea level presents different values or is controversial because the indicative meaning of the sea-level indicators were neither quantified nor uniform ***,we determined the quantitative relationship between modern living coral and sea level by measuring the top surfaces of 27 live Porites corals from the inner reef flat along the east coast of Hainan Island and assessed the accuracy of results obtained using coral as sea-level ***,three in situ fossil Porites corals were analyzed based on elevation measurements,digital X-ray radiography,and U-Th *** survey results showed that the indicative meanings for the modern live Porites corals is(146.09±8.35)cm below the mean tide level(MTL).It suggested that their upward growth limit is constrained by the sea level,and the lowest low water is the highest level of survival for the modern live Porites *** on the newly defined indicative meanings,6 new sea-level index points(SLIPs)were obtained and 19 published SLIPs were *** SLIPs indicated a relative sea level fluctuation between(227.7±9.8)cm to(154.88±9.8)cm MTL between(5393±25)cal a BP and(3390±12)cal a BP,providing evidences of the Mid-Holocene sea-level highstand in the northern *** that,our analysis demonstrated that different sea-level histories may be produced based on different indicative meanings or *** dataset of 276 coral U-Th ages indicates that coral reef development in the northern SCS comprised the initial development,boom growth,decline,and flourishing development again.A comparison wit

关键词： northern South China Sea Middle Holocene sea-level highstand Porites corals climate response

Proteomic mechanism of Bacillus cereus endospore against plasma-activated water(PAW)

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Food Science and Human Wellness 2024年

作者： Xiao Hu Jinsong Feng Xinyu Liao Tian Ding Ruiling Lü School of Biosystems Engineering and Food Science Zhejiang University future Food Laboratory Innovation center of Yangtze River Delta Zhejiang University Ningbo Innovation center Zhejiang University

Plasma-activated water (PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus， which eliminated its evolutionary endospore that improves its survival ability. However， the spore inactivation mechanism by PAW at molecular level was not well understood. The mechanism of the Bacillus cereus endospore against PAW at proteomic levels was demonstrated. The Tandem Mass Tag (TMT) labeling was performed. By comparing the treatment groups with control (including PAW and PAW added superoxide dismutase (SOD)) ， the expression of 251 proteins (with the number of 207 up- and 44 down-regulated) and 379 proteins (with the corresponding number of 238 and 141) were drastically affected， separately. The six categories based on the protein-protein interaction (PPI) networks included oxidation-reduction， transport， sporulation and DNA topological change， gene expression， metabolism， and others. The three dehydrogenases (Gene hisD， BC＿2176， and asd) in PAW while oxidoreductase (Gene BC＿0399 and BC＿2529) in SOD were activated to maintain the antioxidation of spores. The proteins (BC＿4271 and BC＿2655) in SOD were dramatically activated， which were involved in the carbohydrate， amino acid， and energy-coupling transport. All the small， acid-soluble spore proteins were activated in both groups to protect the spores’ DNA. In SOD， genes metG2 and rpmC also were considered important factors in translation while this role was played in gene groES but not rpmF in PAW. The PAW activated the biogenesis of cell wall/membrane/envelope and phosphorelay signal transduction system to contribute to the survival of spores whereas the SOD damaged these two processes as well as cell division， chromosome separation， organic acid phosphorylation， base- and nucleotide-excision repair to lead to the death of spores. This would promise to lay the foundation for advancing the study of the intrinsic mechanism of spore killing against PAW and can also provide a reference f

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Microwave-accelerated direct regeneration of LiCoO_(2)cathodes for Li-ion batteries

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Science China Chemistry 2024年第7期67卷 2181-2189页

作者： Xueshan Hu Yun-Chao Yin Chao Li Lihui Zhou Lin Yang Yitian Feng Daxian Zuo Chenhui Ning Das Soham Sheng Dai Longbin Qiu Lin Zeng Haw Jiunn Woo Jiayu Wan future Battery Research center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Centre for Ionics University of Malaya Department of PhysicsFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research center School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Department of Natural and Applied Sciences Duke Kunshan UniversityKunshan 215316China

Recycling spent lithium-ion batteries is integral to today's low-carbon environmental protection *** concept of direct regeneration,acknowledged for its environmental sustainability,economic viability,and consistent performance of recycled materials,is gaining *** study presents an efficient and nondestructive approach by utilizing an ultrafast microwave technology to directly regenerate spent lithium cobaltate(LCO)cathode *** contrast to conventional furnacebased processes,this method significantly reduces the regeneration *** subjecting the spent LCO mixed with lithium sources to three microwave heating cycles(at approximately 1,350 K),LCO regeneration is achieved,yielding a specific capacity of 140.8 mAh g^(-1)(0.2 C)with a robust cycle *** further environmental and economic benefits,the ultrafast microwave technology holds scientific promise for directly regenerating cathode materials,while establishing competitiveness for industrial applications.

关键词： battery recycling spent lithium cobaltate microwave directly regeneration cathode materials

Achieving superior performance in powder-metallurgy near-βtitanium alloy by combining hot rolling and rapid heat treatment followed by aging

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Journal of Materials Science & Technology 2024年第4期171卷 24-36页

作者： Fucheng Qiu Tuo Cheng Yuchao Song Orest M.Ivasishin Dmytro G.Savvakin Guangyu Ma Huiyan Xu College of Materials Science and Engineering Jilin UniversityChangchun 130025China International center of future Science Jilin UniversityChangchun 130025China G.V.Kurdyumov Institute for Metal Physics KyivUkraine College of Biological and Agricultural Jilin UniversityChangchun 130025China

Heat treatment plays an important role in tailoring the mechanical properties of powder-metallurgy(PM)titanium ***,only limited work about the rapid heat treatment(RHT)of PM titanium alloys has been *** this work,RHT was applied to PM Ti-5Al-5Mo-5V-1Cr-1Fe alloy after hot rolling to study the evolution of its mechanical properties and the influence of residual pores on its *** hot rolling and annealing,a fine and uniformα+βstructure with few residual pores is *** RHT,the primaryαdissolves gradually and completes in theβregion,and theβgrains then grow,resulting in the continuous decrease in elongation after ***,the tensile strength first increases and then decreases with increasing RHT temperature,owing to the increase in volume fraction of secondaryαinα+βregion and theβgrain growth inβ*** contrast to the RHT of cast-and-wrought titanium,the negative influence of residual pores lowers the RHT temperature for obtaining the highest tensile strength to a temperature below theβ-transus *** the negative influence of the residual pores,retained primaryαand fineβgrains with fine secondaryαinside contribute to achieving a good strength/ductility balance(1570 MPa and 6.1%,respectively).Addi-tionally,although at higher cycles to failure,the negative influence of residual pores increases as it affects the crack initiation zone at the subsurface,the good resistance of secondaryαto fatigue crack propaga-tion still enhances the fatigue strength considerably(about 300 MPa).This work suggests a cost-effective strategy to produce titanium alloys with high performance.

关键词： Rapid heat treatment Powder metallurgy Mechanical properties Near-βtitanium Residual pores