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Catalytic atroposelective synthesis of indolyl quinazolinones bearing N-N/C-C diaxes

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Science China Chemistry 2025年

作者： Ning-Yi Wang Shuo Gao Zhu-Di Shu Bei-Bei Cheng chun ma.Yu-Chen Zhang Feng Shi Research Center of Chiral Functional Heterocycles School of Chemistry and Materials Science Jiangsu Normal University School of Petrochemical Engineering Changzhou University School of Chemistry and Chemical Engineering Henan Normal University

The first catalytic atroposelective synthesis of indole derivatives bearing N-N/C-C diaxes has been established by the strategy of de novo ring forma.ion. By this strategy, various indolyl quinazolinones bearing vicinal N-N/C-C diaxes were synthesized in high yields with overall good diastereoselectivities and excellent enantioselectivities via chiral phosphoric acid-catalyzed onepot asymmetric forma. (5+1) cycloaddition/oxidation reaction. Moreover, such indolyl quinazolinones bearing vicinal N-N/CC diaxes have good configurational stability and could be converted into new chiral ligands with applications in asymmetric catalysis. Therefore, this work not only offered a new member for the family of diaxial atropisomers, but also provided a powerful strategy for catalytic asymmetric synthesis of atropisomers bearing N-N/C-C diaxes.

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Sintering behavior and therma. conductivity of Y_(2)O_(3) fully stabilized HfO_(2) ceramics

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Rare Metals 2021年第5期40卷 1255-1266页

作者： chun Li Jian He Yue ma School of ma.erials Science and Engineering Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural ma.erials and Coatings Technology(Ministry of Industry and Informa.ion Technology) Beihang UniversityBeijing 100191China

A series of Y_(2)O_(3) fully stabilized HfO2 ceramics(Hf_(1-x)Y_(x)O_(2-0.5x),x=0.20,0.24,0.28,0.32,0.36 and 0.40)were synthesized by solid-state reaction at 1500℃.The phase composition,therma. conductivity and sintering behavior at 1400℃ of the ceramic bulks were *** Hf_(1-x)Y_(x)O_(2-0.5x) ceramics were comprised of pure cubic phase with disordered fluorite *** phase transforma.ion occurred in the ceramics with Y3+doping concentration ranging from 0.24 to *** Hf_(0.64)Y_(0.36)O_(1.82) and Hf_(0.6)Y_(0.4)O_(1.8) samples revealed the lowest grain growth rate when sintered at 1400℃,indicating good resistance to ***,the Vicker’s hardness and Young’s modulus after annealed for 96 h at 1400℃ for the Hf_(0.64)Y_(0.36)O_(1.82) sample were 8.97 and 200 GPa,respectively,much lower than those of the Hf_(0.6)Y_(0.4)O_(1.8)(14.51 and 237 GPa,respectively).The therma. conductivity of Hf_(1-x)Y_(x)O_(2-0.5x) first decreased and then increased slowly as the Y3+content increased,and the associated mechanism was discussed.

关键词： Yttria fully stabilized hafnia Sintering Mechanical properties Therma. conductivity

Properties of Nonlinear Transverse-Electric Waves in a Two-Core Optical Waveguide with a Nonlinear Cladding

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Chinese Physics Letters 1998年第7期15卷 501-503页

作者： ma.chun-sheng Department of Electronic Engineering National Integrated Optoelectronics LaboratoryJilin UniversityChangchun 130023

Expressions of dispersion relation and propagation power are presented for the nonlinear transverse-electric(TE)waves in a two-core optical waveguide with a nonlinear *** properties of the nonlinear TE waves are *** is found that when the total core thickness and the distance between the two cores are sufficiently large,the power curves of the higher odd modes become very sharp in some narrow ranges of the effective refractive index,compared with those of the higher even modes.

关键词： Nonlinear nonlinear adding

Advances in single-particle detection for DNA sensing

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Science China Chemistry 2017年第10期60卷 1285-1292页

作者： Fei ma.Ming Ren chun-yang Zhang College of Chemistry Chemical Engineering and Materials Science Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongKey Laboratory of Molecular and Nano Probes Ministry of Education Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals Shandong Normal University Jinan 250014 China

Rapid, accurate and sensitive detection of particular DNA sequence is critical in fundamental biomedical research and clinical diagnostics. However, conventional approaches for DNA assay often suffer from cumbersome procedures, long analysis time and insufficient sensitivity. Recently, single-particle detection technology has emerged as a powerful tool in the biosensing area due to its significant advantages of ultrahigh sensitivity, low sample-consumption and rapid analysis time. Especially, the introduction of novel nanoma.erials has greatly promoted the development of single-particle detection and its applications for DNA sensing. In this review, we summa.ize the recent advance in single-particle detection strategies for DNA sensing, and focus ma.nly on metallic nanoparticle-and semiconductor quantum dot-based single-particle detection. We highlight the emerging trends in this field as well.

关键词： single-particle detection DNA assay quantum dots metallic nanoparticles fluorescence resonance energy transfer

Cryptanalysis and security enhancement of a remote user authentication scheme using sma.t cards

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 104-114页

作者： WANG Ding ma.chun-guang College of Computer Science and Technology Harbin Engineering University Harbin 150001 China Automobile ma.agement Institute of PLA Bengbu 233011 China

With the broad implementations of the electronic business and government applications, robust system security and strong privacy protection have become essential requirements for remote user authentication schemes. Recently, Chen et al. pointed out that Wang et al.＇s scheme is vulnerable to the user impersonation attack and parallel session attack, and proposed an enhanced version to overcome the identified security flaws. In this paper, however, we show that Chen et al.＇s scheme still cannot achieve the claimed security goals and report its following problems：（1） It suffers from the offline password guessing attack, key compromise impersonation attack and known key attack; （2） It fails to provide forward secrecy; （3） It is not easily repairable. As our ma.n contribution, a robust dynamic ID-based scheme based on non-tamper resistance assumption of the sma.t cards is presented to cope with the aforementioned defects, while preserving the merits of different related schemes. The analysis demonstrates that our scheme meets all the proposed criteria and eliminates several grave security threats that are difficult to be tackled at the same time in previous scholarship.

关键词： cryptanalysis authentication protocol sma.t card non-tamper resistant forward secrecy

An improved thermometer for intermediate-ma.s fragments

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Nuclear Science and Techniques 2016年第6期27卷 13-16页

作者： Tian-Tian Ding chun-Wang ma Institute of Particle and Nuclear Physics Henan Normal University

An improved thermometer(TIB) is proposed for intermediate-ma.s fragments via the difference between isobaric yield *** residual free energy of three isobars is replaced by that of the binding *** measured fragments in the 140 A MeV ^(40,48) Ca +9Be(181Ta) and^(58,64) Ni +~9Be(^(181)Ta) reactions are analyzed to obtain T_(IB) ranging from 0.6 to 3.5 Me *** suggested to be a direct determination of temperature avoiding the fitting procedure.

关键词：温度计中间质量碎片中等质量碎片反应分析直接测定拟合程序等压线 MeV

Phase Transitions in Neutron Stars Within Modified Quark-Meson Coupling Model

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Communications in Theoretical Physics 2008年第7期50卷 180-186页

作者： ma.Chang-Qun GAO chun-yua. School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China

K^- condensation and quark deconfinement phase transitions in neutron stars are investigated. We use the modified quark-meson coupling model for hadronic phase and the MIT bag model for quark phase. With the equation of state （EOS） solved self-consistently, we discuss the properties of neutron stars. We find that the EOS of pure hadron ma.ter with condensed K- phase should be ruled out by the redshift for star EX00748-676, while EOS containing unpaired quark ma.ter phase with B1/4 being about 180 MeV could be consistent with both this observation and the best measured ma.s of star PSR 1913 ＋ 16. But if the recent inferred ma.sive star among Terzan 5 with M 〉 1.68M is confirmed, all the present EOSes with condensed phase and deconfined phase would be ruled out.

关键词： neutron star modified quark-meson coupling model nuclear ma.ter quark ma.ter

Temperature of intermediate ma.s fragments in simulated ^(40)Ca + ^(40)Ca reactions around the Fermi energies by AMD model

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Nuclear Science and Techniques 2016年第5期27卷 146-151页

作者： chun-Wang ma.chun-yua. Qiao Tian-Tian Ding Yi-Dan Song Institute of Particle and Nuclear Physics Henan Normal University

The prima.y fragments in ^(40)Ca +^(40)Ca reactions at 35,50,80,100,140,and 300 MeV/u were simulated using the antisymmetrized molecular dynamics model,in the phase space at t=300 fm/c with a coalescence radius R_c=5 *** standard Gogny interactions g0,g0 as,and gOass were adopted in simulating the collisions at an impact parameter of b=0 *** was found,using an isobaric yield ratio method,that temperature of the prima.y fragment depends on the incident energy and hardness of the interaction *** temperature obtained in this work agrees with the results by the self-consistent fitting method.

关键词：模型模拟中等质量碎片温度 MD模型 Ca 反应费米能分子动力学

Effects of Mg/PTFE pyrotechnic compositions on reignition characteristics of base bleed propellants and heating mechanism

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Defence Technology（防务技术） 2022年第1期18卷 94-108页

作者： Xiao-chun Xue Long-ze ma.Yong-gang Yu Schooi of Enerey and Power Engineering Nanjing Universiry of Science and Techmology Narine lianesu 210094 China BYD Compary Liruied ShenzheL Guanedong 518118 Chna

The effects of ma.nesium/polytetrafluoroethylene(Mg/PTFE)pyrotechnic compositions on the coupled flow field and reignition mechanism are important aspects governing the perfomma.ce and range of base bleed projectiles(BBPs).Owing to a decrease in pressure and temperature when the BBP leaves the muzzle,rapid depressurization occurs,which extinguishes the base bleed *** Mg/PTFE py-rotechnic composition pressed in the igniter of the base bleed unit(BBU)provides additional energy to the BBU via a chemical ***,the extinguished base bleed propellant is reignited under the effect of high-temperature combustion gas jets from the *** this study,a numerical analysis is conducted to evaluate the effects of PTFE and Mg granularity as well as Mg/PTFE pyrotechnic *** to the rapid depressurization,the temperature and pressure was found to decrease fordifferent Mg/PIFE pyrotechnic ***,the depressurization time increased as the PTFE granularity increased,the Mg granularity decreased,and the Mg content *** the pressure in the combustion chamber of the BBU decreased to the atmospheric pressure,the combustion gas jets from the igniter expand upstream(rather than downstream).However,these combustion gas jets exhibit different axial and radial expansion characteristics depending on the pyrotechnic compositions used,The results show that the reignition delay time,ta,of the base bleed propellant was 377.608,94.27,387.243,523.966,and 221.094 ms for cases A-E,***,it was concluded that the Mg/PTFE pyrotechnic composition of case B was the most beneficial for the reignition of the base bleed propellant,with the earliest addition of energy and ma.s to the BBP.

关键词： Therma. effect High-temperature combustion gas Mg/PTFE pyrotechnic Compositions Reignition