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Strain-promoted S-arylation and alkenylation of sulfinamides using arynes and cyclic alkynes

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Science China Chemistry 2024年第3期67卷 928-935页

作者： Xi zou Boming Shen Gao-lin Li Qian Liang Yanhua Ouyang binghe Yang Peiyuan Yu bing Gao State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringInstitute of Chemical Biology and NanomedicineHunan UniversityChangsha 410082China Department of Chemistry and Shenzhen Grubbs Institute Guangdong Provincial Key Laboratory of CatalysisSouthern University of Science and TechnologyShenzhen 518055China

The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center(N-R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.

关键词： arylation alkenylation sulfoximines sulfinamides arynes

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Method of fabricating artificial rock specimens based on extrusion free forming(EFF)3D printing

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1455-1466页

作者： Xiaomeng Shi Tingbang Deng Sen lin Chunjiang zou Baoguo Liu Key Laboratory for Urban Underground Engineering of the Ministry of Education Beijing Jiaotong UniversityBeijing100044China School of Civil Engineering Beijing Jiaotong UniversityBeijing100044China Department of Civil Engineering Monash UniversityMelbourne3800Australia

Three-dimensional(3D)printing technology has been widely used to create artificial rock samples in rock *** 3D printing can create complex fractures,the material still lacks sufficient similarity to natural *** free forming(EFF)is a 3D printing technique that uses clay as the printing material and cures the specimens through high-temperature *** this study,we attempted to use the EFF technology to fabricate artificial rock *** results show the physico-mechanical properties of the specimens are significantly affected by the sintering temperature,while the nozzle diameter and layer thickness also have a certain *** specimens are primarily composed of SiO_(2),with mineral compositions similar to that of natural *** density,uniaxial compressive strength(UCS),elastic modulus,and tensile strength of the printed specimens fall in the range of 1.65–2.54 g/cm3,16.46–50.49 MPa,2.17–13.35 GPa,and 0.82–17.18 MPa,*** is capable of simulating different types of rocks,especially mudstone,sandstone,limestone,and ***,the simulation of hard rocks with UCS exceeding 50 MPa still requires validation.

关键词： Artificial rock 3D printing Extrusion free forming(EFF) Similarity analysis Mechanical properties

Boosting Hydrogen Storage Performance of MgH_(2) by Oxygen Vacancy-Rich H-V_(2)O_(5) Nanosheet as an Excited H-Pump

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Nano-Micro Letters 2024年第8期16卷 398-416页

作者： Li Ren Yinghui Li Zi Li Xi lin Chong Lu Wenjiang Ding Jianxin zou National Engineering Research Center of Light Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Shanghai Engineering Research Center of Mg Materials and Applications&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Instrumental Analysis Center of SJTU Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

MgH_(2) is a promising high-capacity solid-state hydrogen storage material,while its application is greatly hindered by the high desorption temperature and sluggish ***,intertwined 2D oxygen vacancy-rich V_(2)O_(5) nanosheets(H-V_(2)O_(5))are specifically designed and used as catalysts to improve the hydrogen storage properties of MgH_(2).The as-prepared MgH_(2)-H-V_(2)O_(5) composites exhibit low desorption temperatures(Tonset=185℃)with a hydrogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) H_(2) for desorption),and long cycling ***,hydrogen absorption can be achieved at a temperature as low as 30℃ with a capacity of 2.38 wt%within 60 ***,the composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and theoretical calculations demonstrate that the in-situ formed VH_(2)/V catalysts,unique 2D structure of H-V_(2)O_(5) nanosheets,and abundant oxygen vacancies positively contribute to the improved hydrogen sorption ***,the existence of oxygen vacancies plays a double role,which could not only directly accelerate the hydrogen ab/de-sorption rate of MgH_(2),but also indirectly affect the activity of the catalytic phase VH_(2)/V,thereby further boosting the hydrogen storage performance of MgH_(2).This work highlights an oxygen vacancy excited“hydrogen pump”effect of VH_(2)/V on the hydrogen sorption of Mg/MgH_(2).The strategy developed here may pave a new way toward the development of oxygen vacancy-rich transition metal oxides catalyzed hydride systems.

关键词： Hydrogen storage MgH_(2) V_(2)O_(5)nanosheets Oxygen vacancies VH_(2)

Investigation on occupant presence and appliance operation schedules for university campus in south China sub-tropical area

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Building Simulation 2024年第2期17卷 301-318页

作者： Siwei Lou Zhongyuan lin Yukai zou Dawei Xia Yu Huang Zhuohong Li Zhaowen Gu School of Civil Engineering Guangzhou UniversityGuangzhou Higher Edu.Mega CenterGuangzhouChina School of Architecture and Urban Planning Guangzhou UniversityGuangzhou Higher Edu.Mega CenterGuangzhouChina

Building occupant presence during varying periods is crucial to the performance studies of buildings and city ***,the understanding of the building occupancies on the university campus remains *** address this gap,our study employs field measurements,payment records,course arrangements,and building access systems to depict the occupancy patterns of the canteen,dormitory,library,and teaching and lab buildings during weekdays and *** found that the occupancy rates across different buildings are somehow interrelated,given that the total number of occupants on campus is generally ***,dormitory occupancy rates tend to be low during the morning and afternoon course hours,which inversely correlates with the high occupancy rates in the teaching and lab buildings during these ***,canteens experience surges in occupancy during meal times,which coincide with a decrease in library ***,we established appliance operation schedules for dormitories through surveys and on-site *** dispensers and electronic devices were identified as the primary energy consumers for both male and female occupants,with desk-top fans and hairdryers being significant energy users for male and female occupants,*** findings are essential for energy studies within a campus setting,underlining the importance of considering occupant behaviors on a regional scale.

关键词： building occupant behavior university campus occupancy schedule appliance operation schedule

Lanthanum promoting bone formation by regulating osteogenesis,osteoclastogenesis and angiogenesis

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Journal of Rare Earths 2024年第3期42卷 621-628,I0007页

作者： Dandan zou Runlian lin Yu Han Juan Jia Guoqiang Zhou Haisong Zhang Kun Ge Hebei Key Laboratory of Chronic Kidney Diseases and Bone Metabolism Affiliated Hospital of Hebei UniversityBaoding071000China Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education Key Laboratory of Chemical Biology of Hebei ProvinceCollege of Chemistry and Environmental ScienceHebei UniversityBaoding071002China

With lanthanum(La) in agriculture, medicine, and the chemical industry, La shows accumulation in the body, especially in the bone, because of its similar structure to calcium. Moreover, La has a direct role in bone formation regulating osteoblasts and osteoclasts. Nevertheless, bone formation is complex under the regulation of osteogenesis, osteoclastogenesis, and angiogenesis in the bone microenvironment. It is difficult to comprehensively understand the regulation of bone homeostasis from a single kind of ***, some bone microenvironment-related cells and mouse calvaria culture models were used to study the regulatory effect of La-based compound-lanthanum nitrate(La(NO_(3))_(3)) on bone ***(NO_(3))_(3) has good biological safety, and the osteogenic differentiation is significantly increased under La(NO_(3))_(3) treatment for bone marrow mesenchymal stem cells(BMMSC). In contrast, the differentiation,maturation, and bone erosion ability of osteoclasts are significantly decreased. Meanwhile, the angiogenesis ability of human umbilical vein endothelial cells(HUVEC) is significantly promoted when treated with La(NO_(3))_(3). Furthermore, bone metabolism and angiogenesis are improved under La(NO_(3))_(3) treatment in the calvaria ex vivo culture model and BMMSC-HUVEC co-culture system. These results suggest that La has the beneficial effect of promoting bone metabolism and improving bone formation in the bone microenvironment.

关键词： Lanthanum Bone microenvironment Osteogenic differentiation Angiogenesis Rare earths

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： lin zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

Meibomian glands segmentation in infrared images with limited annotation

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International Journal of Ophthalmology(English edition) 2024年第3期17卷 401-407页

作者： Jia-Wen lin ling-Jie lin Feng Lu Tai-Chen Lai Jing zou lin-ling Guo Zhi-Ming lin Li Li College of Computer and Data Science Fuzhou UniversityFuzhou 350108Fujian ProvinceChina Fujian Provincial Key Laboratory of Networking Computing and Intelligent Information Processing Fuzhou UniversityFuzhou 350108Fujian ProvinceChina Shengli Clinical Medical College of Fujian Medical University Fuzhou 350001Fujian ProvinceChina Department of Ophthalmology Fujian Provincial Hospital South BranchFujian Provincial HospitalFuzhou 350001Fujian ProvinceChina

●AIM:To investigate a pioneering framework for the segmentation of meibomian glands(MGs),using limited annotations to reduce the workload on ophthalmologists and enhance the efficiency of clinical diagnosis.●METHODS:Totally 203 infrared meibomian images from 138 patients with dry eye disease,accompanied by corresponding annotations,were gathered for the study.A rectified scribble-supervised gland segmentation(RSSGS)model,incorporating temporal ensemble prediction,uncertainty estimation,and a transformation equivariance constraint,was introduced to address constraints imposed by limited supervision information inherent in scribble *** viability and efficacy of the proposed model were assessed based on accuracy,intersection over union(IoU),and dice coefficient.●RESULTS:Using manual labels as the gold standard,RSSGS demonstrated outcomes with an accuracy of 93.54%,a dice coefficient of 78.02%,and an IoU of 64.18%.Notably,these performance metrics exceed the current weakly supervised state-of-the-art methods by 0.76%,2.06%,and 2.69%,***,despite achieving a substantial 80%reduction in annotation costs,it only lags behind fully annotated methods by 0.72%,1.51%,and 2.04%.●CONCLUSION:An innovative automatic segmentation model is developed for MGs in infrared eyelid images,using scribble annotation for *** model maintains an exceptionally high level of segmentation accuracy while substantially reducing training *** holds substantial utility for calculating clinical parameters,thereby greatly enhancing the diagnostic efficiency of ophthalmologists in evaluating meibomian gland dysfunction.

关键词： infrared meibomian glands images meibomian gland dysfunction meibomian glands segmentation weak supervision scribbled annotation

A NONLOCAL KRONECKER-BASIS-REPRESENTATION METHOD FOR LOW-DOSE CT SINOGRAM RECOVERY

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Journal of Computational Mathematics 2024年第4期42卷 1080-1108页

作者： Jian Lu Huaxuan Hu Yuru zou Zhaosong Lu Xiaoxia Liu Keke Zu lin Li Shenzhen Key Laboratory of Advanced Machine Learning and Applications College of Mathematics and StatisticsShenzhen UniversityShenzhen 518060China National Center for Applied Mathematics Shenzhen(NCAMS) Shenzhen 518055China Department of Industrial and Systems Engineering University of Minnesota Twin CitiesMinneapolisMN55455USA Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong Kong SARChina School of Electronic Engineering Xidian UniversityXi'an 710071China

Low-dose computed tomography(LDCT)contains the mixed noise of Poisson and Gaus-sian,which makes the image reconstruction a challenging *** order to describe the statistical characteristics of the mixed noise,we adopt the sinogram preprocessing as a stan-dard maximum a posteriori(MAP).Based on the fact that the sinogram of LDCT has non-local self-similarity property,it exhibits low-rank *** conventional way of solving the low-rank problem is implemented in matrix forms,and ignores the correlations among similar patch *** avoid this issue,we make use of a nonlocal Kronecker-Basis-Representation(KBR)method to depict the low-rank problem.A new denoising model,which consists of the sinogram preprocessing for data fidelity and the nonlocal KBR term,is developed in this *** proposed denoising model can better illustrate the generative mechanism of the mixed noise and the prior knowledge of the ***-merical results show that the proposed denoising model outperforms the state-of-the-art algorithms in terms of peak-signal-to-noise ratio(PSNR),feature similarity(FSIM),and normalized mean square error(NMSE).

关键词： Low-dose computed tomography Kronecker-basis-representation Low-rank imation.Noise-generating-mechanism

Extrusion-base d 3D-printe d“rolle d-up”composite scaffolds with hierarchical pore structure for bone growth and repair

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Journal of Materials Science & Technology 2024年第4期171卷 222-234页

作者： Yufan Li Li Chen Yijing Stehle Mingyue lin Chenxin Wang Rui Zhang Min Huang Yubao Li Qin zou Research Center for Nano Biomaterials Analytical&Testing CenterSichuan UniversityChengdu 610064China Analytical&Testing Center Sichuan UniversityChengdu 610064China Department of mechanical engineering Union College807 Union St.SchenectadyNY 12308USA Sichuan Institute of Atomic Energy Chengdu 610101China

Three-dimensional(3D)bioprinting,specifically direct ink writing(DIW)capable of printing biologically active substances such as growth factors or drugs under low-temperature conditions,is an emerging di-rection in bone tissue ***,limited by the bio-ink mobility and the poor resolution of this printing technology,the lateral pores of current crisscross-stacked scaffolds printed through DIW tend to clog and are inimical to bone ***,it is critical to develop DIW printed biologi-cal scaffold structure with high mechanical strength,porosity,and biocompatibility ***,patterned polylactic acid(PLA)/polycaprolactone(PCL)/nano-hydroxyapatite(n-HA)based scaffold was printed through DIW technological and rolled-up for properties characterization,cytocompatibility test,and bone repair *** result not only shows that the hexagonal patterned scaffolds are me-chanically strong with porosity,but also demonstrated that the hierarchical pore structure formed during rolled-up has the potential to address the clogging problem and stimulates bone growth and repair.

关键词： Direct ink writing(DIW) Bone repair scaffold,Micro-CT Bio composites