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Synthesis of Organofluorine Compounds with Acylsilanes

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Chinese Journal of Chemistry 2024年第8期42卷 887-902页

作者： Youyuan Guo gang zhou Xiao Shen The Institute for Advanced Studies Engineering Research Center of Organosilicon Compounds&MaterialsMinistry of EducationWuhan University299 Bayi RoadWuhanHubei430072 China

Comprehensive Summary,Organofluorine compounds are central in synthetic chemistry,medicinal chemistry and material *** this review,we summarize the investigations on the synthesis of organofluorine compounds with *** the non-fluorinated acylsilanes,the in situ generation of difluoroenoxysilanes from the reactions of the acylsilanes with trifluoromethylation reagents is the major pathway,leading to the facile preparation of variousα,α-*** the fluoroalkylacylsilanes,apart from the in situ generation of difluoroenoxysilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acylsilanes and the selective control of reactivities of the biradicals pave the way for the synthesis of a variety of organofluorine *** general,most of these reactions gave racemic products,and the asymmetric synthesis of organofluorine compounds with acylsilanes is still rare,which would be a future.

关键词： Acylsilanes Organofluorine compounds Brook rearrangement Radical rearrangement β-Fluoride elimination Asymmetric catalysis Photocatalysis Defluoroalkylation

Progress in the generation of spinal cord organoids over the past decade and future perspectives

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Neural Regeneration Research 2024年第5期19卷 1013-1019页

作者： gang zhou Siyuan Pang Yongning Li Jun Gao Department of Neurosurgery Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina Department of International Medical Service Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijingChina

Spinal cord organoids are three-dimensional tissues derived from stem cells that recapitulate the primary morphological and functional characteristics of the spinal cord in *** emerging bioengineering methods have led to the optimization of cell culture protocols,spinal cord organoids technology has made remarkable advancements in the past *** literature search found that current spinal cord organoids do not only dynamically simulate neural tube formation but also exhibit diverse cytoarchitecture along the dorsal-ventral and rostral-caudal ***,fused organoids that integrate motor neurons and other regionally specific organoids exhibit intricate neural circuits that allows for functional *** qualities make spinal cord organoids valuable tools for disease modeling,drug screening,and tissue *** utilizing this emergent technology,researchers have made significant progress in investigating the pathogenesis and potential therapeutic targets of spinal cord ***,at present,spinal cord organoid technology remains in its infancy and has not been widely applied in translational *** of the next generation of spinal cord organoids will depend on good manufacturing practice standards and needs to focus on diverse cell phenotypes and electrophysiological functionality evaluation.

关键词： development organoid-on-a-chip pluripotent stem cells progress spinal cord diseases spinal cord organoids vascularization

An interesting synergistic effect of heteronuclear dual-atom catalysts for hydrogen production:Offsetting or promoting

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Nano Research 2024年第6期17卷 5742-5752页

作者： Zhonghao Wang Wei Tang Jialin Liu gang zhou School of Science Hubei University of TechnologyWuhan 430068China

To elucidate the synergistic effect of dual-atom catalysts(DACs)at the microscopic level,we propose and construct a prototype heteronuclear system,CuNi/TiO_(2),in which the two elements of a pair have significantly different d electron-donating abilities,as a piece in the *** density functional theory calculations,we investigate charge-dependent configurations of Cu-Ni dimers anchored on TiO_(2)by the mixing of individual constituent *** d electron-donating ability determines deposition sequence and position of transition metal atoms on oxides,establishing dimer pattern and metal-support *** interaction between Cu and Ni,beyond the coordination environment,predominately contributes to the synergistic effect.A complex adsorption-reduction behavior of H species on CuNi/TiO_(2)is *** reaction mechanism and catalytic activity of CuNi/TiO_(2)for hydrogen production are *** room temperature and high H coverages,CuNi/TiO_(2)shows better performance and efficiency than Ni1/TiO_(2).Our findings provide a new understanding of the synergistic effect on structure-activity relationships of supported dimers,which would be beneficial in the future design of various DACs or even atomically dispersed metal catalysts.

关键词： dual-atom catalysts heteronuclear/homonuclear dimers synergistic effect density functional theory hydrogen production

A Facile Synthesis of the C-11 isomer of 5-epi-Kudtriol

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Chinese Chemical Letters 2000年第2期11卷 111-112页

作者： gang zhou1 Xiao Lei GAO1 Zhe ZHANG1 Yu Lin LI1 Zhi Zhen SHANG2 Ren An LIAO2 (1National Laboratory of Applied Organic Chemistry and Institute of Organic Chemistry, Lanzhou University, Lanzhou 730000 2State Key Laboratory of of Elemento-Organic Chemis Natl. Lab. of Appl. Organ. Chemistry Institute of Organic Chemistry Lanzhou University Lanzhou 730000 China State Key Lab. Elemento-Organ. Chem. Nankai University Tianjin 300071 China

The C-ll isomer of natural trihydroxyl sesquiterpene 5-epi-kudtriol has been synthesized starting from (+)-dihydrocarvone via asymmetric dihydroxylation as a key step.

关键词： asymmetric synthesis asymmetric dihydroxylation 5-epi-kudtriol

Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

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Food Science and Human Wellness 2024年第3期13卷 1135-1151页

作者： Enning zhou Qiangqiang Li Dan Zhu gang Chen Liming Wu Institute of Apicultural Research Chinese Academy of Agricultural SciencesBeijing 100093China Department of Food Science University of OtagoDunedin 9016New Zealand School of Food and Health Beijing Technology and Business UniversityBeijing 100048China

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding *** the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce *** here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic *** techniques for characterizing changes in these properties of food allergens are *** processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new ***,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food *** provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

关键词： Food allergens Protein structural characterization Immunogenicity evaluation Food processing modification

Alignment error modeling and control of a double-sided microlens array during precision glass molding

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Microsystems & Nanoengineering 2024年第2期10卷 311-322页

作者： Zihao Zeng Tianfeng zhou Qian Yu Jia zhou gang Wang Qiuchen Xie Zifan Wang Xiaoqiang Yao Yubing Guo School of Medical Technology Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China School of Mechanical Engineering Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China

Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of *** glass molding(PGM)is used to fabricate DSMLAs,but controlling alignment errors during this process is *** this paper,a mold assembly was manufactured with a novel combination of materials to improve the alignment accuracy of mold cores during PGM by using the nonlinear thermal expansion characteristics of the various materials to improve the DSMLA alignment *** establishing a mathematical model of the DSMLA alignment error and a thermal expansion model of the mold-sleeve pair,the relationship between the maximum alignment error of the DSMLA and the mold-sleeve gap was *** research provides a method to optimize the mold-sleeve gap and minimize the alignment error of the *** measured DSMLA alignment error was 10.56μm,which is similar to the predicted maximum alignment *** measurements showed that the uniformity of the homogenized beam spot was 97.81%,and the effective homogeneous area accounted for 91.66%of the total *** proposed method provides a novel strategy to improve the performance of DSMLAs.

关键词： sided alignment error

Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application

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Nuclear Science and Techniques 2024年第4期35卷 165-175页

作者： Hong-Shuang Wang Xing Yang Yong-Bin Leng Yi-Mei zhou Ji-gang Wang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage *** technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous *** bunch signal is obtained using a button electrode with a bandwidth of several *** data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of *** bunch-length and synchronous phase information were extracted via offline calculations using Python *** calibration coefficient of the system was determined using a commercial streak ***,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 *** dynamic range exceeded 10 *** technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings.

关键词： Bunch-by-bunch diagnostic Bunch-length measurement Synchronous phase measurement Joint time–frequency-domain analysis Longitudinal instability

Asymmetric configuration activating lattice oxygen via weakening d-p orbital hybridization for efficient C/N separation in urea overall electrolysis

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Journal of Energy Chemistry 2024年第5期92卷 233-239页

作者： Chongchong Liu Peifang Wang Bin Hu Xiaoli Liu Rong Huang gang zhou Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education College of EnvironmentHohai UniversityNanjing 210098JiangsuChina

Urea oxidation reaction(UOR)is proposed as an exemplary half-reaction in renewable energy applications because of its low thermodynamical ***,challenges persist due to sluggish reaction kinetics and complex by-products *** this end,we introduce the lattice oxygen oxidation mechanism(LOM),propelling a novel UOR route using a modified CoFe layered double hydroxide(LDH)catalyst termed *** calculations and in-situ characterizations highlight the activated lattice oxygen(O_(L))within CFRO-7 as pivotal sites for UOR,optimizing the reaction pathway and accelerating the *** the urea overall electrolysis application,the LOM route only requires a low voltage of 1.54 V to offer a high current of 100 mA cm^(-2) for long-term utilization(>48 h).Importantly,the by-product NCO^(-)−is significantly suppressed,while the CO_(2)2/N_(2) separation is efficiently *** work proposed a pioneering paradigm,invoking the LOM pathway in urea electrolysis to expedite reaction dynamics and enhance product selectivity.

关键词： Lattice oxygen Urea oxidation reaction Overall electrolysis Products selectivity

Improved damage tolerance and oxidation resistance of (Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–SiC by introducing chopped carbon fibers

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Journal of Advanced Ceramics 2024年第1期13卷 101-112页

作者： Feilong Huang Hailong Wang Cheng Fang Mingliang Li gang Shao Jinpeng Zhu Yanchun zhou School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

High-entropy diborides(HEBs)are considered as promising high-temperature structure materials owing to their high melting point and excellent thermal ***,the intrinsic brittleness is the main obstacle that seriously limits their practical *** overcome with this obstacle,carbon fibers(Cf)with outstanding mechanical properties are used in the present work as a first attempt to improve the damage tolerance of *** as-prepared C_(f)/(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–SiC composite(C_(f)/HEB–SiC)shows high relative density(97.9%)and good mechanical properties with flexural strength of 411±3 MPa and fracture toughness of 6.15±0.11 MPa·m^(1/2).More importantly,the damage tolerance parameter(Dt)has increased from 0.10 m^(1/2) for HEB–SiC to 0.29 m^(1/2) for C_(f)/HEB–*** microstructural analysis and Vickers indentation of the composite,the toughening mechanisms are *** carbon fibers coated with carbon coatings demonstrate unique capacity for prolonging the crack propagation path,which promotes the reliability of the composite ***,the C_(f)/(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)–SiC composite also exhibits good static oxidation resistance in the temperature range of 1100–1500℃in air due to the formation of the protective oxide layer constituting of multicomponent oxides(Zr)HfTiO4 and(Zr)Hf_(6)Ta_(2)O_(17) embedded in a continuous SiO_(2) *** results are promising,and this primary work can be used as a reference to the synthesis of C_(f)/HEBs for thermal protection materials under hightemperature serving conditions.

关键词： high-entropy ceramics carbon fibers(Cf) toughening mechanisms oxidation resistance