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Transition Dipole, Charge Transfer, and Electron-hole Coherence in Two-photon Absorption： Visualizations with Two Dimensional Site and Three Dimensional Cube Representations

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Chinese Journal of Chemical Physics 2009年第5期22卷 529-534,I0002页

作者： Yuan-zuo Li wen-qin zhang Xiao-hong Zhao Feng-cai Ma Mao-du Chen School of Physics and Optoelectronic Technology and College of Advanced Science and Technology Dalian University of Technology Dalian 116024 China Department of Physics Liaoning University Shenyang 110036 China

The developed visualization methods of two dimensional （2D） site and three dimensional （3D） cube representations have been performed to show the orientation of transition dipole, charge transfer, and electron-hole coherence in two-photon absorption （TPA）. The 3D cube representations of transition density can reveal visually the orientation and strength of transition dipole moment, and charge different density show the orientation of charge transfer in TPA. The 2D site representation can reveal visually the electron-hole coherence in TPA. The combination of 2D site and 3D cube representations provide clearly inspect into the charge transfer process and the contribution of excited molecular segments for TPA.

关键词： 2D site and 3D cube representations Charge transfer Transition dipole,Two-photon absorption

Large eddy simulation of boundary layer combustion of hydrogen and hydrocarbon fuel films in a modeled scramjet combustor

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Chinese Journal of Aeronautics 2024年第7期37卷 109-133页

作者： Jianfei WEI Silong zhang Jingying ZUO Xin LI Jiang qin wen BAO School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Supersonic fuel film cooling is a promising way to simultaneously reduce the severe wall heat and friction load of the internal passage in a scramjet engine when operating at hypersonic *** eddy simulations were performed to investigate the cooling and wall friction characteristics of hydrogen and hydrocarbon films under inert and reactive *** results show that the essential difference of the turbulent state in the mixing layer contributes to the totally different behaviors of the cooling and wall friction reduction performances of the two fuel *** turbulent transport processes between the hydrogen film and the mainstream are much weaker as compared to the case of hydrocarbon film,making inert hydrogen rather superior in cooling and friction reduction ***,the increase of wall temperature for hydrogen film under the inert case is mainly driven by the loss of hydrogen with high heat capacity instead of by direct heat ***,the film cooling performance severely deteriorates when the hydrogen film burns due to presence of severe heat release sources near the *** the other hand,combustion of hydrocarbon film in the boundary layer can remarkably improve its originally barely-satisfactory cooling and friction reduction performance to the level comparable to that of hydrogen film,due to the suppression of turbulent transport processes in the mixing layer and presence of heat absorption sources near the ***,the hydrogen film is more advantageous in friction reduction,while the hydrocarbon film is more suitable for cooling.

关键词： Supersonic film cooling Hydrogen Hydrocarbon Boundary layer combustion Large eddy simulation

New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

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Science China Chemistry 2024年第3期67卷 945-952页

作者： Jia-Lu zhang wen-Bo He Xiu-qin Hu Peng-Fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China State Key Laboratory of Veterinary Etiological Biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

关键词： enantioselective photocatalysis asymmetric organocatalytic/photocatalysis relay catalysis five consecutive chiral centers chirality-induced strategy chirality vicinal amino alcohols

Sensing-Assisted Accurate and Fast Beam Management for Cellular-Connected mmWave UAV Network

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China Communications 2024年第6期21卷 271-289页

作者： Cui Yanpeng zhang Qixun Feng Zhiyong qin wen Zhou Ying Wei Zhiqing zhang Ping School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science Northwestern Polytechnical UniversityXi’an 710072China

Beam management,including initial access(IA)and beam tracking,is essential to the millimeter-wave Unmanned Aerial Vehicle(UAV)***,the conventional communicationonly and feedback-based schemes suffer a high delay and low accuracy of beam alignment,since they only enable the receiver to passively“hear”the information of the transmitter from the radio *** paper presents a novel sensing-assisted beam management approach,the first solution that fully utilizes the information from the visual domain to improve communication *** employ both integrated sensing and communication and computer vision techniques and design an extended Kalman filtering method for beam tracking and ***,we also propose a novel dual identity association solution to distinguish multiple UAVs in dynamic ***-world experiments and numerical results show that the proposed solution outperforms the conventional methods in IA delay,association accuracy,tracking error,and communication performance.

关键词： beam management integrated sensing and communication UAV communication

Tmem39b promotes tumor progression and sorafenib resistance by inhibiting ferroptosis in hepatocellular carcinoma

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Oncology Research 2024年第8期32卷 1347-1357页

作者： MING ZHUANG XUE zhang LU LI LIMING wen JIAMIN qin Department of Gastroenterology Sichuan Mianyang 404 HospitalMianyang621000China

Hepatocellular carcinoma(HCC)poses a signiﬁcant threat to human *** to sorafenib in the chemotherapy of HCC is a common and signiﬁcant issue that profoundly impacts clinical *** several members of the transmembrane(TMEM)protein family have been implicated in the occurrence and progression of HCC,the association between TMEM39b and HCC remains *** study revealed a signiﬁcant overexpression of TMEM39b in HCC,which correlated with a poor *** investigation revealed that RAS-selective lethal 3(RSL3)induced pronounced ferroptosis in HCC,and knocking down the expression of TMEM39b signiﬁcantly decreased its ***,following the induction of ferroptosis in HCC by sorafenib,knocking down the expression of TMEM39b also decreased the severity of ferroptosis,enhancing HCC tolerance to *** conclusion,we propose that TMEM39b promotes tumor progression and resistance to sorafenib by inhibiting ferroptosis in HCC.

关键词： TMEM39b Sorafenib Ferroptosis Hepatocellular carcinoma

High-Pressure Behavior of Ferromagnesite(Mg_(0.81)Fe_(0.19))CO_(3)by Synchrotron X-Ray Diffraction and Raman Spectroscopy up to 53 GPa

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Journal of Earth Science 2024年第2期35卷 525-535页

作者： Lin Liang Guibin zhang Shengxuan Huang Jingjing Niu Dongzhou zhang Jingui Xu wen Liang Shan qin Key Laboratory of Orogenic Belts and Crustal Evolution MOEand School of Earth and Space SciencesPeking UniversityBeijing100871China CAS Center of Excellence in Tibetan Plateau Earth Sciences and Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China Hawai’i Institute of Geophysics and Planetology School of Ocean and Earth Science and TechnologyUniversity of Hawai’i at ManoaHawai’i96822USA Key Laboratory of High Temperature and High Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang550081China

Ferromagnesite(Mg,Fe)CO_(3)with 20 mol%iron is a potential host mineral for carbon transport and storage in the Earth *** high-pressure behavior of synthetic ferromagnesite(Mg_(0.81)Fe_(0.19))CO_(3)up to 53 GPa was investigated by synchrotron X-ray diffraction(XRD)and Raman *** iron bearing carbonate underwent spin transition at around 44–46 GPa accompanied by a volume collapse of 1.8%,which also demonstrated a variation in the dνi/dP slope of the Raman *** pressure-volume data was fitted by a third-order Birch-Murnaghan equation of state(BM-EoS)for the high spin *** best-fit K_(0)=108(1)GPa and K_(0)'=4.2(1).Combining the dνi/dP and the K_(0),the mode Grüneisen parameters of each vibrational mode(T,L,ν4 andν1)were *** effects of iron concentration on the Mg_(1−x)Fe_(x)CO_(3)system related to high-pressure compressibility and vibrational properties are *** results expand the knowledge of the physical properties of carbonates and provide insights to the potential deep carbon host.

关键词： ferromagnesite synchrotron XRD Raman spectroscopy high pressure geochemistry mineral

Global and regional soil organic carbon estimates:Magnitudes and uncertainties

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Pedosphere 2024年第4期34卷 685-698页

作者： Ziqi LIN Yongjiu DAI Umakant MISHRA Guocheng WANG Wei SHANGGUAN wen zhang zhangcai qin School of Atmospheric Sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Computational Biology&Biophysics Sandia National LaboratoriesLivermore CA 94550USA Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Globally,soil is the largest terrestrial carbon(C)*** quantification of soil organic C(SOC)stocks in existing global observation-based estimates avails accurate predictions in carbon-climate feedbacks and future climate *** investigated the magnitudes and distributions of global and regional SOC estimates(i.e.,density and stocks)based on five widely used global gridded SOC datasets,a regional permafrost dataset developed in 2021(UM2021),and a global-scale soil profile database(World Soil Information Service)reporting measurements of a series of physical and chemical edaphic *** five global gridded SOC datasets were the Harmonized World Soil Database(HWSD),World Inventory of Soil Emission Potentials at 30 arc-second resolution(WISE30sec),Global Soil Dataset for Earth System Models(GSDE),Global Gridded Soil Information at 250-m resolution(SoilGrids250m),and Global Soil Organic Carbon Map(GSOCmap).Our analyses showed that the magnitude and distribution of SOC varied widely among datasets,with certain datasets showing region-specific *** the global scale,SOC stocks at the top 30 and 100 cm were estimated to be 828(range:577–1171)and 1873(range:1086–2678)Pg C,*** estimates from GSDE,GSOCmap,and WISE30sec were comparable,and those of SoilGrids250m and HWSD were at the upper and lower *** spatial SOC distribution varied greatly among datasets,especially in the northern circumpolar and Tibetan Plateau permafrost ***,UM2021 and WISE30sec performed well in the northern circumpolar permafrost regions,and GSDE performed well in *** estimates of SOC by different datasets also showed large variabilities across different soil layers and *** discrepancies were generally smaller for the 0–30 cm soil than the 0–100 cm *** datasets demonstrated relatively higher agreement in grasslands,croplands,and shrublands/savannas than in other biomes(e.g.,wetlands).The users should be mindful of the gaps b

关键词： biome carbon cycle Earth System Models permafrost region soil dataset soil map

Corrugated Graphene Paper Reinforced Silicone Resin Composite for Efficient Interface Thermal Management

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Chinese Journal of Polymer Science 2024年第7期42卷 1002-1014,I0010页

作者： Bo-wen Wang Heng zhang qing-Xia He Hui-Tao Yu Meng-Meng qin Wei Feng Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin300350China International Engineering Institute Tianjin UniversityTianjin300350China

With the rapid development of high-power-density electronic devices,interface thermal resistance has become a critical barrier for effective heat management in high-performance electronic ***,there is an urgent demand for advanced thermal interface materials(TIMs)with high cross-plane thermal conductivity and excellent compressibility to withstand increasingly complex operating *** achieve this aim,a promising strategy involves vertically arranging highly thermoconductive graphene on ***,with the currently available methods,achieving a balance between low interfacial thermal resistance,bidirectional high thermal conductivity,and large-scale production is ***,we prepared a graphene framework with continuous filler structures in in-plane and cross-plane directions by bonding corrugated graphene to planar graphene *** interface interaction between the graphene paper framework and polymer matrix was enhanced via surface functionalization to reduce the interface thermal *** resulting three-dimensional thermal framework endows the polymer composite material with a cross-plane thermal conductivity of 14.4 W·m^(-1)·K^(-1)and in-plane thermal conductivity of 130W·m^(-1)·K^(-1)when the thermal filler loading is 10.1 wt%,with a thermal conductivity enhancement per 1 wt%filler loading of 831%,outperforming various graphene structures as *** its high thermal conductivity,low contact thermal resistance,and low compressive modulus,the developed highly thermoconductive composite material demonstrates superior performance in TIM testing compared with TFLEX-700,an advanced commercial TIM,effectively solving the interfacial heat transfer issues in electronic *** novel filler structure framework also provides a solution for achieving a balance between efficient thermal management and ease of processing.

关键词： Graphene paper Vertically aligned structure Cross-plane thermal conductivity Low compressive modulus Thermal interface material

Numerical study on the blocking effect of skin on Flash-Ball Impact and damage assessment

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Defence Technology（防务技术） 2024年第3期33卷 532-545页

作者： Dihua Ouyang Chunwei qin Xiaowen qin Qiantao zhang Xingyu Liu Xi'an University of Architecture and Technology Xi'an 710055China Analysis and Testing Center Xi'an University of Architecture and TechnologyXi'an 710055China Engineering University of PAP Xi'an 710086China

To explore the response law of non-lethal large-size kinetic energy projectiles to blunt attack on skin tissue,and to evaluate the skin injury characteristics of the attacked personnel and the use safety of kinetic energy *** on the LS-DYNA simulation software,a three-layer skin simulation model and a Flash-Ball rubber bullet model are established,and the force-time and deformation-time biomechanical corridors of the Flash-Ball rubber bullet impacting human skin tissue are *** corridor curve and the energy transfer and diffusion are analyzed and *** safety evaluation of the damage caused by the rubber bullet shooting a human body at different distances is carried out using the empirical formula of the penetration ***,the safe shooting distance is *** results show that the model used in the simulation has a good correlation with the experimental data,its biomechanical corridor characteristics are different from those of conventional vehicle impact and smallsize projectile response *** energy transfer and action time of medium and low-speed impact may cause greater *** fat layer is the largest energy absorption *** minimum safe shooting distance to ensure skin tissue from penetrating damage is 15.8 m,and the limit specific kinetic energy of skin damage is 7.88 J/cm^(2).This study can be extended to the study of biomechanical response law and safety evaluation under the impact of the same type of large kinetic energy projectile,which provides an important theoretical reference for the police to use large kinetic energy projectiles to conduct safe shooting in peacekeeping operations.

关键词： KIPs Blunt strike Biomechanical response Damage analysis