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From ice superlubricity to quantum friction: Electronic repulsivity and phononic elasticity

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Friction 2015年第4期3卷 294-319页

作者： Xi ZHANG Yongli HUANG Zengsheng MA Lengyuan niu Chang qing SUN Institute of Nanosurface Science and Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Low-dimensional Materials and Application Technology(MOE)and School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Institute of Coordination Bond Metrology and Engineering College of Materials Science and EngineeringChina Jiliang UniversityHangzhou 310018China NOVITAS School of EEENanyang Technological University639798Singapore

Superlubricity means non-sticky and frictionless when two bodies are set contacting *** this occurrence has been extensively investigated since 1859 when Faraday firstly proposed a quasiliquid skin on ice,the mechanism behind the superlubricity remains *** report features a consistent understanding of the superlubricity pertaining to the slipperiness of ice,self-lubrication of dry solids,and aqueous lubricancy from the perspective of skin bond-electron-phonon adaptive *** presence of nonbonding electron polarization,atomic or molecular undercoordination,and solute ionic electrification of the hydrogen bond as an addition,ensures the *** vibration creates soft phonons of high magnitude and low frequency with extraordinary adaptivity and recoverability of *** undercoordination shortens the covalent bond with local charge densification,which in turn polarizes the nonbonding electrons making them localized *** locally pinned dipoles provide force opposing contact,mimicking magnetic levitation and hovercraft.O:H−O bond electrification by aqueous ions has the same effect of molecular undercoordination but it is throughout the entire body of the *** a Coulomb repulsivity due to the negatively charged skins and elastic adaptivity due to soft nonbonding phonons of one of the contacting objects not only lowers the effective contacting force but also prevents charge from being transited between the counterparts of the *** between theory predictions and observations evidences the validity of the proposal of interface elastic Coulomb repulsion that serves as the rule for the superlubricity of ice,wet and dry frictions,which also reconciles the superhydrophobicity,superlubricity,and supersolidity at contacts.

关键词： friction slipperiness bond electron phonon ice acid fluid

On lowest-lying 1/2^(-) octet baryons

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Chinese Physics C 2022年第8期46卷 1-6页

作者： Chang Chen Wen-Qi niu Han-qing Zheng Department of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China College of Physics Sichuan UniversityChengdu 610065China Collaborative Innovation Center of Quantum Matter Beijing 100871China

The recently proposed N^(*)(890)1/2^(-)baryon is studied in a flavor SU(3) scheme with K-matrix unitarization,by fitting to low-energy cross section and phase shift *** is found that N^(*)(890) co-exists with low-lying poles in other channels,which have been extensively discussed in the literature,though they belong to different octets in the SU(3) ***,the existence of N^(*)(890) is further verified.

关键词： πN scatterings baryon resonance SU(3)octet

Identification of integrin β6 gene promoter and analysis of its transcription regulation in colon cancer cells

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World Journal of Gastrointestinal Oncology 2020年第5期12卷 526-534页

作者： Wei niu Qi-Yu Bo Jun niu Zheng-Chuan niu Cheng Peng Xue-qing Zou Zhao-Yang Zhang Department of Hepatobiliary Surgery Qilu HospitalShandong UniversityJinan 250012Shandong ProvinceChina Department of Nursing Qilu HospitalShandong UniversityJinan 250012Shandong ProvinceChina Department of Emergency Surgery Qilu HospitalShandong UniversityJinan 250012Shandong ProvinceChina

BACKGROUND The integrinβ6 gene,which is expressed in epithelial cancer,plays a pivotal role in various aspects of cancer *** present research for integrinβ6 regulation mainly focuses on the post-transcription and translation related regulation mechanism and its role in *** mechanisms of how the integrinβ6 gene is regulated transcriptionally,and the promoter and transcription factors responsible for basic transcription of integrinβ6 gene remain *** To clone and characterize the integrinβ6 *** Software analysis was used to predict the region of integrinβ6 *** reporter plasmids,which contained the integrinβ6 promoter,were *** deletion analysis was performed to identify the location of core promoter and binding sites for transcription *** The regulatory elements for the transcription of the integrinβ6 gene were located between-286 and-85 and contained binding sites for transcription factors such as STAT3 and *** For the first time,we found the region ofβ6 core promoter and demonstrated the binding sites for transcription factors such as Ets-1 and STAT3,which are important for integrinβ6 promoter transcription *** findings are important for investigating the mechanism of integrinβ6 activation in cancer progression.

关键词： Integrinβ6 Integrinβ6 promoter Regulatory elements Transcription factors Colon cancer cell

Nuclear dynamics in multinucleon transfer reactions near Coulomb barrier energies

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Nuclear Science and Techniques 2018年第12期29卷 128-133页

作者： Peng-Hui Chen Fei niu Ya-Fei Guo Zhao-qing Feng Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000 China University of Chinese Academy of Sciences Beijing 100190China South China University of Technology Guangzhou 510641China

The mechanism of multinucleon transfer reactions has been investigated within the dinuclear system model, in which the sequential nucleon transfer is described by solving a set of microscopically derived master equations. The transfer dynamics in the reaction of^(136)Xe+^(208)Pb near Coulomb barrier energies is thoroughly analyzed. It is found that the total kinetic energies of primary fragments are dissipated from the relative motion energy of two touching nuclei and exhibit a symmetric distribution along the fragment mass. The angular distribution of the projectile-like fragments moves forward with increasing beam energy. However, the target-like fragments exhibit an opposite trend. The shell effect is pronounced due to the fragment yields in multinucleon transfer reactions.

关键词：原子动力学转移反应精力库仑相对运动显微镜子转移原子核

Microstructural Evolutions and Mechanical Properties of Energetic Al_(1) (TiZrNbTaMoCr)_(15) High-Entropy Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 620-632页

作者： Xuan-Hong Cai Zhen-Hua Wang Ben niu Jin-Feng Li qing Wang Show authors Key Laboratory of Materials Modification By Laser Ion and Electron Beams(Ministry of Education)Engineering Research Center of High Entropy Alloy Materials(Liaoning Province)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Institute of Materials China Academy of Engineering PhysicsMianyang621908China

The present study focuses on investigating the microstructural evolutions and mechanical properties of energetic Al_(1)(TiZrNbTaMoCr)_(15) refractory high-entropy alloys with the different heat treatments at low Al content state. It is found that even with a reduction in the Al content, the strength of these alloys remains unaffected at room temperature and high temperature, while the plasticity improves significantly. In particular, the coherent BCC/B_(2) microstructure with needle-like B_(2) nanoprecipitates dispersed into the BCC matrix is formed in 873 K-aged Al_(1)Ti_(6)Zr_(2)Nb_(3)Ta_(3)Mo_(0.5)Cr_(0.5) alloy. Therefore, this alloy exhibits the highest compression yield strength (σ_(YS) = 1333 and 717 MPa) at room temperature and 1073 K, respectively. After 973 K-aged, the coherent BCC/B_(2) microstructure underwent destabilization, and the B_(2) phase transforms into the brittle Zr5Al3 phase which then coarsens and dominates the microstructure of S3-AlTa_(3) alloy after 1073 K-aged. Moreover, these current alloys exhibit exceptionally high theoretical exothermic enthalpy (ΔH), surpassing 11606 J·g^(−1), which highlights their significant potential as innovative high-performance energetic structural materials.

关键词： Refractory high-entropy alloy Coherent microstructure Mechanical property Exothermic enthalpy

A heteropolysaccharide from Rhodiola rosea L.:preparation,purification and anti-tumor activities in H22-bearing mice

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Food Science and Human Wellness 2023年第2期12卷 536-545页

作者： Yaru Wu qing Wang Huiping Liu Lulu niu Mengyu Li Qi Jia State Key Laboratory of Food Nutrition and Safety Key Laboratory of Food Nutrition and SafetyMinistry of Education of ChinaCollege of Food Science and EngineeringTianjin University of Science and TechnologyTianjin 300457China

Numerous polysaccharides isolated from plants have been used to augment traditional drugs in the treatment of *** order to explore the influence to hepatocellular carcinoma,a novel cold water-soluble polysaccharide was separated from Rhodiola rosea ***(RLP)and then its structure and anti-cancer activities were *** chemical compositions and high performance gel permeation chromatography(HPGPC)results indicated that RLP was an acid heteropolysaccharide with the molecular weight of about1.15×10~6 ***,ion chromatography(IC),Fourier transform infrared(FT-IR)and nuclear magnetic resoance(NMR)further indicated that RLP was main composed of→2,4)-α-Rha(1→,→5)-α-L-Araf-(1→,α-D-Glu,→6)-β-D-Galp-(1→,β-D-Man and→4)-α-GalpA-(1→.In vivo antitumor activities of RLP were carried out by using H22 tumor-bearing mice *** results shown that RLP(100 and 300 mg/kg)could inhibit tumor growth of H22 cells from 23.59%to 45.52%and protect thymuses and spleen without *** addition,according to cell cycle,AV-FITC/PI and JC-1,RLP could induce dose-dependent apopto sis of H22 cells via S phase arrested which was through a mitochondrial related *** data indicated that RLP has a broader application prospect in anti-tumor preparations.

关键词： Polysaccharide Antitumor activity Rhodiola rosea L. Structure analysis

Surface Patterns of a Tetrahedral Polyelectrolyte Brush Induced by Grafting Density and Charge Fraction

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Chinese Journal of Polymer Science 2020年第4期38卷 394-402,I0007页

作者： Hong-Ge Tan Gang Xia Li-Xiang Liu Xiao-Hui niu qing-Hai Hao College of Science Civil Aviation University of ChinaTianjin 300300China

A tetrahedral polyelectrolyte brush in the presence of trivalent counterions is researched under the condition of good solution by mea ns of molecular dynamics simulati *** density and charge fraction are varied to gen erate a series of surface patter *** microphase separation happens and various interesting pinned patches appear at appropriate charge fraction and grafting *** a careful analysis on the brush thickness,the pair correlation functions,the distributions of net charge,and the four states of trivalent counterions in the brush,we find that the ordered surface patterns and special properties are induced by the pure electrostatic correlation effect of trivalent ions even in the good ***,the dependences of electrostatic correlation on the charge fraction of tethered chains are evaluated for fixed grafting den ***,our results can serve as a guide for precise control over the stimuli-responsive materials rational and self-assembly of nanoparticles.

关键词： Surface patterns Tetrahedral polyelectrolyte brush Molecular dyn amics simulation Electrostatic cor relation

On the Structure of the Arginine-carboxylate Salt Bridge:A Density Functional Theory Study

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Chinese Chemical Letters 2001年第3期12卷 219-222页

作者： Ting Wei mu Yong FENG Lei LIU qing Xiang GUO Department of Chemistry University of Science and Technology of ChinaHefei 230026

High level density functional theory (DFT) calculations are performed for the first time to answer the question whether the arginine-carboxylate salt bridge stays in a zwitterionic state or a neutral one. The results indicate that in the gas phase, the neutral form is more stable and hence proton transfer occurs from guanidinium to carboxylate. However, in an aqueous solution the zwitterionic form should be favored. The difference might he caused by the electrostatic interaction between the salt bridge and its molecular environment. Therefore, the solvation effect has to be considered in the modeling of proteins, whose stabilization depends heavily on the salt-bridges.

关键词： Arginine-carboxylate interaction salt bridge DFT proton transfer solvation effect

Current Sheet Formation in Weakly Ionized Plasmas

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Chinese Physics Letters 2001年第6期18卷 788-789页

作者： JI Hai-Sheng LI Xiao-qing SONG mu-Tao Purple Mountain Observatory Chinese Academy of ScienceNanjing 210008 Department of Physics Nanjing Normal UniversityNanjing 210087 National Astronomical Observatories Chinese Academy of SciencesBeijing 100080

Using the two fluid model,the problem of two-dimensional steady-state magnetic reconnection in incompressible resistive weakly ionized plasmas is *** the strong-coupling condition such as in the Sun's photosphere,it allows us to express the current sheet *** this case the current sheet scales as η^(1/2).Then this model is used to understand magnetic flux cancellation which is observed in the Sun's *** account for a canceling flux of 1 × 10^(18)Max in a time interval of 77 min,the width of the current sheet is about ten kilometers.

关键词： weakly Weakly coupling