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Increase of chiral sensing ability in host-guest chemistry by magnetic anisotropy

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Science China Chemistry 2024年第8期67卷 2775-2782页

作者： jia-Liang Chen Bin Li feng Yang Tiesheng Shi Xun-cheng Su State Key Laboratory of Elemento-organic Chemistry Tianjin Key Laboratory of Biosensing and Molecular RecognitionCollege of ChemistryNankai UniversityTianjin 300071China College of Chemistry Chemical Engineering and Materials ScienceZaozhuang UniversityZaozhuang 277160China

Enantiomeric molecules generally play distinct functions in chemistry,biology,and *** physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the *** report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition *** installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD *** addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide *** reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host *** transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral *** strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.

关键词： chiral recognition nuclear magnetic resonance host-guest chemistry magnetic anisotropy lanthanide ions

Flexible,self-powered,and polarization-sensitive photodetector based on perovskite lateral heterojunction microwire arrays

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Photonics Research 2023年第12期11卷 2231-2241页

作者： SHUN-XIN LI jia-cheng feng YANG AN HONG XIA State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China College of Physics Jilin UniversityChangchun 130012China

The fabrication of different perovskite materials with superior properties into lateral heterostructures can greatly improve device performance and polarization ***,the sensitivity of perovskites to solvents and environmental factors makes the fabrication of lateral heterojunctions ***,we realize high-quality perovskite microwire crystal heterojunction arrays using regioselective ion *** with responsivity and detectivity up to 748 A W^(-1)and 8.2×10^(12)Jones are *** photodetector exhibits responsivity as high as13.5 A W^(-1)at 0 V *** addition,the device exhibits ultra-high polarization sensitivity with a dichroic ratio of 5.6,and 81% of its performance was maintained after 144 days of exposure to air.

关键词： polarization heterojunction arrays

Inimitable 3D pyrolytic branched hollow architecture with multi-scale conductive network for microwave absorption

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Journal of Materials Science & Technology 2024年第6期173卷 170-180页

作者： jiajun Li Qianqian Zhu jiahui Zhu Yuhang cheng Zirui jia feng Lu Chao Wang Guanglei Wu Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao266071China College of Chemistry and Chemical Engineering Qingdao UniversityQingdao266071China Technical Center of Qingdao Customs Qingdao266002China

To solve the electromagnetic pollution problem,the reasonable structure design and component control of the electromagnetic absorber is *** this work,three-dimensional(3D)pyrolytic branched hollow architecture carbon PBHAC/MoS_(2)composites were prepared via a hydrothermal and calcination two-step *** narrow-gap nano-size MoS_(2)acquired after vulcanization and micro-size 3D branched carbon skeleton PBHAC possess intensified conduction ***,the presence of potential differences between different phases creates a space charge region at the heterogeneous interface,resulting in strong interfacial *** resulting 3D branched hollow PBHAC/MoS_(2)composites exhibit optimized impedance matching and multiple loss ***,the 3D branched hollow carbon PBHAC/MoS_(2)composites have the best electromagnetic wave(EMW)absorption *** minimum reflection loss(RLmin)is-57.8 dB at 1.93 mm and the maximum effective absorption bandwidth(EAB_(max))is 6.08 GHz at 2 mm,which indicates the excellent EMW absorption performance of the ***,this composite is expected to be a microwave absorber with the characteristics of“thin,light,wide,and strong”.

关键词： Dielectric loss MoS_(2) Impedance matching Schottky barrier Microwave absorption

Development and application of a GIS database for the Miyun Reservoir water quality protection

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Journal of Environmental Sciences 1999年第4期11卷 485-491页

作者： jia Hai\|feng, cheng Sheng\|tong, XIAO Yang (Department of Environmental Sciences and Engineering, Tsinghua University, Beijing 100084,China) 清华大学环境科学与工程系北京

A high quality database is the starting point for any GIS application. For the Miyun Reservoir, a large amount of spatial data has been accumulated by numerous studies. This paper introduces a GIS database development in support of these studies. And some applications of the GIS database, include integration with GPS, view and management of data, and integration with WASP5 model, are also introduced.

关键词： GIS database ARC/INFO Arcview Miyun Reservoir water quality

Quantum phase transition of the Jaynes-Cummings model

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： cheng Liu Jin-feng Huang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong *** tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be ***,a deep-strong JC model is *** ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi *** scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad *** nonzero average cavity photons of the ground state indicate the emergence of a quantum phase ***,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation *** the parameters used in our scheme are within the reach of current experimental *** scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation

Numerical analysis of the correlation between fluid dynamic modes and hydrodynamic noise in flows around a three-dimensional circular cylinder

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Journal of Hydrodynamics 2024年第1期36卷 119-129页

作者： jia-jia Qin Ming-xin Zou Yuan Zhuang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Wuhan Second Ship Design and Research Institute Wuhan430205China

The flow around a circular cylinder for Re=1000 is characterized by flow separation and Karman vortex *** typical flow features can be captured to study the correlation between fluid fields and sound *** this paper,the three-dimensional circular cylinder is taken as the research object,and the probes of surface fluctuating pressure and far field sound pressure are arranged every 10°.The directional diagram and the coherence of fluctuating pressure and sound pressure are *** relationship between the flow mode and hydrodynamic noise is studied by using dynamic mode decomposition(DMD).The characteristics of the dipole and quadrupole sound source term of a long span cylinder are *** results show that at the angles between 30°–120°and 190°–350°,the fluctuating pressure contributes more to the generation of dipole *** quadrupole sound source shows three-dimensional effects,which is more obvious in a cylinder with large spanwise length.

关键词： Pressure coherence dynamic mode decomposition flow-sound correlation circular cylinder

Weak Merging Scenario of CLASH Cluster A209

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Research in Astronomy and Astrophysics 2024年第4期24卷 174-182页

作者： Wen-cheng feng Heng Yu Hai-Hui Zhao Xiao-Lan Hou Shu-Mei jia cheng-Kui Li Yu-Lin cheng Paolo Tozzi Ming Sun Yong Chen Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Astronomy Yunnan UniversityKunming 650091China INAF—Osservatorio Astrofisico di Arcetri Largo E.Fermi50122 FirenzeItaly Department of Astronomy University of VirginiaP.O.Box 400325CharlottesvilleVA 22904-4325USA

We study the structural and dynamical properties of A209 based on Chandra and XMM-Newton *** obtain detailed temperature,pressure,and entropy maps with the contour binning method,and find a hot region in the NW *** X-ray brightness residual map and corresponding temperature profiles reveal a possible shock front in the NW direction and a cold front feature in the SE *** with the galaxy luminosity density map we propose a weak merger scenario.A young sub-cluster passing from the SE to NW direction could explain the optical subpeak,the intracluster medium temperature map,the X-ray surface brightness excess,and the X-ray peak offset together.

关键词： X rays:galaxies:clusters galaxies:clusters:intracluster medium galaxies:clusters:Abell 209

AP-1 and SP1 trans-activate the expression of hepatic CYP1A1 and CYP2A6 in the bioactivation of AFB1 in chicken

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Science China(Life Sciences) 2024年第7期67卷 1468-1478页

作者： jiang Deng jia-cheng Yang Yue feng Ze-Jing Xu Kamil Kuča Meng Liu Lv-Hui Sun State Key Laboratory of Agricultural Microbiology Hubei Hongshan LaboratoryFrontiers Science Center for Animal Breeding and Sustainable ProductionCollege of Animal Sciences and TechnologyHuazhong Agricultural UniversityWuhan 430070China Department of Chemistry Faculty of ScienceUniversity of Hradec KraloveHradec Kralove 50003Czech Republic

Dietary exposure to aflatoxin B1(AFB1)is harmful to the health and performance of domestic *** hepatic cytochrome P450s(CYPs),CYP1A1 and CYP2A6,are the primary enzymes responsible for the bioactivation of AFB1to the highly toxic exo-AFB1-8,9-epoxide(AFBO)in ***,the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1metabolism remains ***-luciferase reporter assay,bioinformatics and site-directed mutation results indicated that specificity protein 1(SP1)and activator protein-1(AP-1)motifs were located in the core region-1,063/-948,-606/-541 of the CYP1A1 promoter as well as-636/-595,-503/-462,-147/-1 of the CYP2A6 ***,overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and ***,bioactivation of AFB1to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression,which was trans-activated owing to the upregulation of AP-1,rather than SP1,stimulated by AFB1-induced reactive oxygen ***,nano-selenium could reduce ROS,downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6,thus alleviating the toxicity of *** conclusion,AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1to AFBO in chicken liver,which could provide novel targets for the remediation of aflatoxicosis in chicks.

关键词： aflatoxin B1 CYP1A1 CYP2A6 SP1 AP-1 transcriptional activation

Deep insight of unique phase transition behaviors and mechanism in Zr_(2)Co-H isotope system with ultra-low equilibrium pressure

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Rare Metals 2024年第1期43卷 212-224页

作者： Yang Liu Pan-Pan Zhou Xue-Zhang Xiao jia-cheng Qi jia-Peng Bi Tiao Ying Xing-Wen feng Yan Shi Wen-Hua Luo Li-Xin Chen State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China Institute of Materials China Academy of Engineering PhysicsMianyang 621907China Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province Hangzhou 310013China

Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter material with ultra-low hydrogenation equilibrium pressure is considered as a reliable *** this work,Zr_(2)Co alloy was selected as a tritium-getter material and prepared through induction levitation *** performance test results show that Zr_(2)Co exhibits an ultra-low hydrogenation equilibrium pressure of 3.22 × 10^(-6) Pa at 25℃ and excellent hydriding kinetics under a low hydrogen pressure of 0.005 ***,unique phase transition behaviors were presented in Zr_(2)Co-H ***,Zr_(2)CoH_(5) formed by Zr_(2)Co hydrogenated at room temperature is initially decomposed into ZrH_(2) and ZrCoH_(3) at200 ℃.With the temperature increasing to 350 ℃,ZrCoH_(3)is dehydrogenated to ZrCo,and then ZrCo further reacts with ZrH_(2) at 650 ℃ to reform Zr_(2)Co and *** the staged phase transition pathways during dehydrogenation,the decomposition of Zr_(2)CoH_(5) occurs preferentially,which is well accordance with both the smallest reaction energy barrier and the maximum reaction spontaneity that are determined respectively from kinetics activation energy and thermodynamics Gibbs free ***,first principles calculation results indicate that the stronger binding of hydrogen in interstitial environments of ZrCoH_(3)and ZrH_(2) triggers the hydrogen-stabilized phase transformation of Zr_(2)CoH_(5).The unique phase transition mechanisms in Zr_(2)Co-H system can shed light on the further exploration and regulation of analogous staged phase transition of hydrogen storage materials.

关键词： Zr_(2)Co alloy Tritium-getter materials Ultralow equilibrium hydrogen pressure Phase transition mechanism