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Pericyclases for cycloaddition

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National Science Review 2022年第11期9卷 13-16页

作者： Bo Zhang hui ming ge State Key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life Sciences Chemistry and Biomedicine Innovation Center (ChemBIC) Nanjing University

The Diels–Alder (DA) reaction is a simple yet very powerful pericyclic transformation involving the cycloaddition of a 1,3-diene and a dienophile to synthesize a cyclohexene ring via a cyclic transition state. Its importance was recognized by Nobel Prizes in Chemistry. Since the first application of the DA reaction in the total synthesis of the steroids cortisone and cholesterol in 1952, significant progress has been made in the understanding and utility of DA reactions [1].

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Enhancing Isolated Ti(Ⅳ) Framework Sites in HMS

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Chemical Research in Chinese Universities 2007年第2期23卷 127-130页

作者： YU Wei-hua ZHOU Chun-hui NI Zhe-ming ge Zhong-hua College of Chemical Engineering and Materials Science Zhejiang University of Technology Hangzhou 310024 P. R. China

Ti-HMS materials were prepared by grafting titanocene onto the inner wails of hexagonal mesoporous silica （HMS）. The materials were characterized via powder X-ray diffraction, N2 adsorption-desorption isotherms, diffuse reflectance UV-Vis spectroscopy, and thermo-gravimetric analysis. The template of HMS was removed by calcination, ethanol-extraction, and ethanol-extraction followed by hydrolysis. The available grafting sites of OH groups depend on the different template removal methods of HMS. Ethanol-extraction followed by hydrolysis favors site-isolated Ti atoms in HMS. The catalytic performances of Ti-HMS materials were tested in the oxidation of 4-tert-butyholuene with aqueous hydrogen peroxide. Ti-HMS prepared from HMS via the processing of ethanol-extraction followed by hydrolysis as support gave a maximum conversion of 7. 5% and a complete selectivity to 4-tert-butyl-benzaldehyde, and showed a higher activity compared with those prepared by calcination and ethanol-extraction.

关键词： Ti-HMS Grafting Oxidation 4-tert-Butyltoluene

Discovery of daspyromycins A and B,2-aminovinyl-cysteine containing lanthipeptides,through a genomics-based approach

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Chinese Chemical Letters 2022年第1期33卷 511-515页

作者： Jing Shi Jia-Qi Ma Yong-Chao Wang Zi-Fei Xu Bo Zhang Rui-Hua Jiao Ren-Xiang Tan hui-ming ge State Key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life SciencesNanjing UniversityNanjing 210023China Chemistry and Biomedicine Innovation Center(ChemBIC) Nanjing UniversityNanjing 210023China

Lanthipeptides are one of the largest groups of ribosomally synthesized and post-translationally modified peptides(RiPPs)and are characterized by the presence of lanthionine(Lan)or methyllanthionine residues(MeLan).Only very few lanthipeptides contain a C-terminal 2-aminovinyl-cysteine(AviCys)motif,but all of them show potent antibacterial *** advances of genome sequencing led to the rapid accumulation of new biosynthetic gene clusters(BGCs)for *** this study,through our genome mining strategy,we found the AviCys containing lanthipeptides are widespread in the bacterial kingdom.A lanthipeptide-type biosynthetic gene cluster was identified from public bacterial genome *** new lanthipeptides,daspyromycins A and B(1 and 2)containing AviCys motif,along with two degraded products,daspyromycins C and D(3 and 4),were obtained after heterologous expression of the gene cluster in Streptomyces albus *** A and B showed potent antimicrobial activity against a spectrum of Gram-positive and-negative bacteria including methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE).

关键词： Lanthipeptides genomics-based approach Daspyromycin RiPPs 2-Aminovinyl-cysteine motif

Isochromophilones from an endophytic fungus Diaporthe sp.

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Natural Products and Bioprospecting 2012年第3期2卷 117-120页

作者： Le-Yun ZANG Wei WEI Ting WANG Ye GUO Ren-Xiang TAN hui-ming ge Institute of Functional Biomolecules State Key Laboratory of Pharmaceutical BiotechnologySchool of Life ScienceNanjing UniversityNanjing 210093China

Three new azaphilone compounds,isochromophilones X-XII(1-3),together with two known ones sclerotioramine(4)and isochromophilone VI(5)were isolated from the cultures of an endophytic fungus Diaporthe *** structures were elucidated by extensive HRESIMS and NMR spectroscopic *** compounds were tested for their cytotoxicities against five human cancer cell lines by MTT method,among which compound 1 showed moderate inhibitory effects on these cell *** was the first report of azaphilones isolated from Diaporthe sp.

关键词： azaphilone endophyte Diaporthe sp. cytotoxicity

Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction

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Chinese Journal of Chemical Engineering 2024年第6期70卷 1-8页

作者： Lixin Chen hui Zhang Linxi Hou Xin ge Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Department of Materials-Oriented Chemical Engineering School of Chemical EngineeringFuzhou UniversityFuzhou 350116China Qingyuan Innovation Laboratory Quanzhou 362801China

Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and ***,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling *** this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of ***,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

关键词： Design Copper-based metal-organic frameworks (Cu-MOFs) Adsorption C-S coupling reaction Multiphase reaction

Lightweight,Strong and High Heat-Resistant Poly(lactide acid)Foams via Microcellular Injection Molding with Self-Assembly Nucleating Agent

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Chinese Journal of Polymer Science 2024年第6期42卷 739-750页

作者： Xiao-Hu Bing Wen-Yu Ma ming-hui Wu Peng Gao Xiao Zhou Hai-Bin Luo Long Wang Wen-ge Zheng School of materials Science and Engineering Shanghai UniversityShanghai200444China Ningbo Key Lab of Polymer Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China

Poly(lactide acid)(PLA)foams have shown considerable promise as eco-friendly alternatives to nondegradable plastic foams,such as polystyrene(PS)***,PLA foam typically suffers from low heat-resistance and poor cellular structure stemming from its inherent slow crystallization rate and low melt *** this study,a high-performance PLA foam with well-defined cell morphology,exceptional strength and enhanced heat-resistance was successfully fabricated via a core-back microcellular injection molding(MIM)*** scanning calorimetry(DSC)results revealed that the added hydrazine-based nucleating agent(HNA)significantly increased the crystallization temperature and accelerated the crystallization process of ***,the addition of a 1.5 wt%of HNA led to a significant reduction in PLA’s cell size,from 43.5µm to 2.87µm,and a remarkable increase in cell density,from 1.08×10^(7)cells/cm^(3)to 2.15×10^(10)cells/cm^(3).This enhancement resulted in a final crystallinity of approximately 55.7%for the PLA blend foam,a marked improvement compared to the pure PLA ***,at 1.5 wt%HNA concentration,the tensile strength and tensile toughness of PLA blend foams demonstrated remarkable improvements of 136%and 463%,***,the Vicat softening temperature of PLA blend foam increased significantly to 134.8°C,whereas the pure PLA foam exhibited only about 59.7℃.These findings underscore the potential for the preparation of lightweight injection-molded PLA foam with enhanced toughness and heat-resistance,which offers a viable approach for the production of high-performance PLA foams suitable for large-scale applications.

关键词： Poly(lactide acid) Nucleating agent Microcellular injection molding Heat-resistance Toughness

Communication Resource-Efficient Vehicle Platooning Control With Various Spacing Policies

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 362-376页

作者： Xiaohua ge Qing-Long Han Xian-ming Zhang Derui Ding IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Platooning represents one of the key features that connected automated vehicles may possess as it allows multiple automated vehicles to be maneuvered cooperatively with small headways on roads. However, a critical challenge in accomplishing automated vehicle platoons is to deal with the effects of intermittent and sporadic vehicle-to-vehicle data transmissions caused by limited wireless communication resources. This paper addresses the co-design problem of dynamic event-triggered communication scheduling and cooperative adaptive cruise control for a convoy of automated vehicles with diverse spacing policies. The central aim is to achieve automated vehicle platooning under various gap references with desired platoon stability and spacing performance requirements, while simultaneously improving communication efficiency. Toward this aim, a dynamic event-triggered scheduling mechanism is developed such that the intervehicle data transmissions are scheduled dynamically and efficiently over time. Then, a tractable co-design criterion on the existence of both the admissible event-driven cooperative adaptive cruise control law and the desired scheduling mechanism is derived. Finally, comparative simulation results are presented to substantiate the effectiveness and merits of the obtained results.

关键词： Automated vehicles constant time headway spacing constant spacing cooperative adaptive cruise control event-triggered communication vehicle platooning

Anomalous response to creep deformation from dislocation density during electrically assisted creep aging

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Rare Metals 2024年第10期43卷 5268-5283页

作者： Chang Zhou Li-Hua Zhan Chun-hui Liu ming-hui Huang College of Mechanical and Electrical Engineering Central South University Light Alloys Research Institute State Key Laboratory of Precision Manufacturing for Extreme Service PerformanceCentral South University

Adding numerous dislocations into metallic materials before the forming stage significantly enhances their deformability. However, this beneficial effect of dislocation defects may not have a simple monotonic relationship with increased dislocation density during electroplastic deformation. This is due to the complex interactions among the drifting electrons, dislocations and solute atoms. This study explores the effect of diverse initial dislocation densities on creep deformation during electrically aided creep aging of an aluminum–lithium alloy. Surprisingly, we discovered a threshold value for the dislocation density that affects electroplastic creep, i.e., an enhanced effect from dislocations weakens when exceeding this density threshold(an anomalous response to creep). Microstructural data also reveal that such an anomalous response originates mainly from differences in various dislocation density-tailored configurations, which can influence the dislocation motions and precipitation kinetics of the strengthening T1precipitates under the same action of pulsed currents. This study provides important insights into the dislocation density-mediated electroplastic creep of an aluminum–lithium alloy.

关键词： Al–Cu–Li alloy Creep aging Dislocation density Pulsed currents

Uniqueness on Difference Operators of Meromorphic Functions of Infinite Order

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Acta Mathematica Sinica,English Series 2024年第2期40卷 511-527页

作者： hui LI ming Liang FANG Xiao YAO School of Science China University of Mining and TechnologyBeijing 100083P.R.China Institute of Mathematics Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing 100190P.R.China School of Sciences Hangzhou Dianzi UniversityHangzhou 310012P.R.China School of Mathematical sciences and LPMC Nankai UniversityTianjin 300071P.R.China

We investigate the uniqueness problems of meromorphic functions and their difference operators by using a new *** is proved that if a non-constant meromorphic function f shares a non-zero constant and ∞ counting multiplicities with its difference operators Δcf(z) and Δ_(c)^(2)f(z), thenΔcf(z)≡Δ_(c)^(2)f(z).In particular,we give a difference analogue of a result of *** method has two distinct features:(ⅰ) It converts the relations between functions into the corresponding *** makes it possible to deal with the uniqueness problem by linear algebra and combinatorics.(ⅱ) It circumvents the obstacle of the difference logarithmic derivative lemma for meromorphic functions of infinite order,since this method does not depend on the growth of the ***,the idea in this paper can also be applied to the case for several variables.

关键词： Uniqueness meromorphic functions difference operators infinite order