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Effects of Bifidobacterium lactis BLa80 on fecal and mucosal flora and stem cell factor/c-kit signaling pathway in simulated microgravity rats

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World Journal of Gastroenterology 2025年第1期31卷 93-109页

作者： Ping Zhang Ying Zhu Pu Chen Tong Zhou Zhe-Yi Han Jun Xiao jian-feng Ma Wen Ma Peng Zang Ying Chen Graduate School Hebei North UniversityZhangjiakou 075000Hebei ProvinceChina Key Laboratory of Aerospace Nutrition and Food Engineering China Astronaut Research and Training CenterBeijing 100094China Department of Gastroenterology The Air Force Medical CenterBeijing 100142China Department of Blood Transfusion Air Force Medical CenterBeijing 100142China

BACKGROUND Simulated microgravity environment can lead to gastrointestinal motility *** pathogenesis of gastrointestinal motility disorders is closely related to the stem cell factor(SCF)/c-kit signaling pathway associated with intestinal flora and Cajal stromal ***,intestinal flora can also affect the regulation of SCF/c-kit signaling pathway,thus affecting the expression of Cajal stromal *** cells are the pacemakers of gastrointestinal *** To investigate the effects of Bifidobacterium lactis(***)BLa80 on the intestinal flora of rats in simulated microgravity and on the gastrointestinal motility-related SCF/c-kit *** The internationally recognized tail suspension animal model was used to simulate the microgravity environment,and 30 rats were randomly divided into control group,tail suspension group and drug administration tail suspension group with 10 rats in each group for a total of 28 *** tail group was given *** BLa80 by intragastric administration,and the other two groups were given water intragastric administration,the concentration of intragastric administration was 0.1 g/mL,and each rat was 1 mL/***&eosin staining was used to observe the histopathological changes in each segment of the intestine of each group,and the expression levels of SCF,c-kit,extracellular signal-regulated kinase(ERK)and p-ERK in the gastric antrum of each group were detected by Western blotting and *** fecal flora and mucosal flora of rats in each group were detected by 16S *** Simulated microgravity resulted in severe exfoliation of villi of duodenum,jejunum and ileum in rats,marked damage,increased space between villi,loose arrangement,shortened columnar epithelium of colon,less folds,narrower mucosal thickness,reduced goblet cell number and crypts,and significant improvement after probiotic *** microgravity reduced the expressions of SCF and c-kit,and increased the express

关键词： Simulated microgravity Rat Intestinal flora Gastrointestinal motility Stem cell factor/c-kit signaling pathway

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Bulk viscosity of interacting magnetized strange quark matter

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Nuclear Science and Techniques 2021年第10期32卷 101-109页

作者： jian-feng Xu School of Physics and Electrical Engineering AnYang Normal UniversityAnyang 455000China

The bulk viscosity of interacting strange quark matter in a strong external magnetic field B m with a real equation of state is *** is found that interquark interactions can significantly increase the bulk viscosity,and the magnetic field B_(m) can cause irregular oscillations in both components of the bulk viscosity,ξ||(parallel to B_(m))and ξ⊥(perpendicular to B_(m)).A comparison with non-interacting strange quark matter reveals that when B_(m) is sufficiently large,ξ⊥is more affected by interactions than ξ||.Additionally,the quasi-oscillation of the bulk viscosity with changes in density may facilitate the for-mation of magnetic ***,the resulting r-mode instability windows are in good agreement with observational data for compact stars in low-mass X-ray ***,the r-mode instability window for interacting strange quark matter in high magnetic fields has a minimum rotation frequency exceeding 1050 Hz,which may explain the observed very high spin frequency of a pulsar with V=1122 Hz.

关键词： Strange quark matter Bulk viscosity Strong magnetic field Strange star R-mode instability window

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Solute-solute interactions and their impacts on solute co-segregation and interfacial cohesion of{1012}twin boundary in zinc

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Journal of Materials Science & Technology 2023年第7期138卷 117-128页

作者： Zhifeng Huang jian-feng Nie Department of Materials Science and Engineering Monash UniversityMelbourneVIC 3800Australia

Interactions of solute atoms in biodegradable zinc alloys and their effect on alloy mechanical properties have been less *** this work,the interactions between the common solutes(Li,Mg,Mn,Cu,and Ag)used in the biodegradable Zn alloys,including a solute-solute pair with the same element or with two different elements,are investigated based on first-principles *** is found that the energetically favorable configuration is the third nearest-neighboring for most solute-solute pairs in the bulk lattice because of the relatively strong electronic interaction between solute and Zn atoms or the relatively small local elastic deformation associated with the *** that interfacial cleavage is a key fracture mode of zinc,the segregation ability of these solutes and their effect on the{1012}twin boundary cohesion are also *** result shows that Li tends to fully occupy its preferred site in the twin boundary,while Mg,Mn,Cu,or Ag has a concentration limitation in the twin *** twin boundary cohesion can be significantly enhanced by the segregation of Mn,followed by Cu and Ag,because of the contribution of their d states close to the Fermi ***,the co-segregation ability of two solute atoms in the twin boundary increases with increasing the binding tendency of these two solute atoms in the *** and Li or Mg show a relatively strong co-segregation ability in the twin *** Mn to Zn-Li or Zn-Mg alloys can significantly enhance the resistance to fracture of twin boundaries.

关键词： Zinc alloys Twin boundary Solute-solute interaction Co-segregation Interfacial fracture

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Twin-solute, twin-dislocation and twin-twin interactions in magnesium

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Journal of Magnesium and Alloys 2023年第10期11卷 3427-3462页

作者： Yuan Yue jian Wang jian-feng Nie Department of Materials Science and Engineering Monash UniversityVictoria 3800Australia Department of Mechanical&Materials Engineering University of Nebraska-LincolnLincolnNE 68583USA

Magnesium alloys have received considerable research interest due to their lightweight,high specific strength and excellent ***,their plastic deformation is more complicated compared to cubic materials,primarily because their low-symmetry hexagonal closepacked(hcp) crystal *** twinning is a crucial plastic deformation mechanism in magnesium,and twins can affect the evolution of microstructure by interacting with other lattice defects,thereby affecting the mechanical *** paper provides a review of the interactions between deformation twins and lattice defects,such as solute atoms,dislocations and twins,in magnesium and its *** review starts with interactions between twin boundaries and substitutional solutes like yttrium,zinc,silver,as well as interstitial solutes like hydrogen and *** is followed by twin-dislocation interactions,which mainly involve those between {10■2} tension or {10■1} compression twins and , or type *** following section examines twin-twin interactions,which occur either among the six variants of the same {10■2} or {10■1} twin,or between different types of *** resulting structures,including twin-twin junctions or boundaries,tension-tension double twin,and compression-tension double twin,are discussed in ***,this review highlights the remaining research issues concerning the interactions between twins and lattice defects in magnesium,and provides suggestions for future work in this area.

关键词： Magnesium alloys Twin-solute interactions Twin-dislocation interactions Twin-twin interactions Microstructure Mechanical properties

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Stability of Fullerene Cages:C_(30) to C_(70) and Their Dependence on Shared Pentagon Bonds

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Chinese Journal of Structural Chemistry 2006年第9期25卷 1051-1056页

作者： WU Hai-Shun TIAN Xin-Xin jian jian-feng feng Rui-Juan Chemistry and Material Science Institute Shanxi Normal University Linfen 041004 China

The topological characters of all fullerene isomers from C30 to C70 with respect to their number of shared pentagon bonds have been investigated. Systematic calculations were also carried out at the B3LYP/6-31G^＊ level. It is found that the most stable structure has the smallest number of shared pentagon bonds, and the relative energies of a given size show an increasing tendency to rise with Nss number which denotes the number of C-C bonds shared by pentagon. The topological criterion that has extremely low computational cost can be used as filtering principle to prescreen the thermodynamically viable fullerenes and predict the relative stability of isomers.

关键词： fullerene density functional theory most stable isomer topology Nss

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Tool wear criterion,tool life,and surface roughness during high-speed end milling Ti-6Al-4V alloy

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第8期11卷 587-595页

作者： Song ZHANG jian-feng LI MOE Key Laboratory of High Efficiency and Clean Mechanical Manufacture School of Mechanical Engineering Shandong University Jinan 250061 China

The objective of the present research is to investigate the relationship among tool wear, surface topography, and surface roughness when high-speed end milling Ti-6Al-4V alloy, and also to define an optimal flank wear criterion for the cutting tool to integrate tool life and the surface roughness requirements of the finish milling process. An annealed Ti-6Al-4V alloy was selected as the workpiece material, undergoing end milling with uncoated carbide inserts. The flank wear of the insert was observed and measured with the toolmaker's microscope. To examine machined surfaces, 3D surface topography was provided by the white light interferometer, and the arithmetical mean roughness (Ra) was calculated with the WYKO Vision32 software. The flank wear increases with cutting time, and the maximal flank wear is set as the flank wear criterion. As the cutting process progresses, tool wear is the predominant factor affecting the variation of surface roughness. According to the plots for the tool wear propagation and surface roughness variation, an optimal flank wear criterion can be defined which integrates the tool life and the surface roughness requirements for the finish milling process.

关键词： Tool wear Surface topography Surface roughness Optimal flank wear criterion

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Photocatalysts of Cr Doped TiO2 Film Prepared by Micro Arc Oxidation

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Chinese Journal of Chemical Physics 2008年第5期21卷 487-492页

作者： Li Wan jian-feng Li Jia-you feng Wei Sun Department of Material Science and Engineering of Education Tsinghua University Beijing 100084China Institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China

A series of Cr doped TiO2 films were prepared by micro arc oxidation （MAO） using an electrolyte of Na3PO4＋K2Cr2O7. X-ray diffraction and scanning electron microscopy revealed that the films mainly consisted of anatase phase with a porous surface morphology. The films have an excellent photocatalytic effect for degradation of methylene blue and decomposition of water under visible light illumination. This arises from the formation of Cr3＋/Cr4＋ and oxygen vacancy energy levels owing to Cr doping. The former reduces the electron-hole recombination chance, while the latter generates a new gap between the conduction band （CB） and valence band （VB） of TiO2, which lowers the photo energy of the excited electron in the VB to the oxygen vacancy states. The mechanisms for film synthesis during the MAO process are also presented.

关键词： TiO2 Cr doping Photocatalysis Micro arc oxidation

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Green Chemical Engineering

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Engineering 2017年第3期3卷 283-284页

作者： jian-feng Chen State Key Laboratory of Organic-lnorganic Composites College of Chemical Engineering Beifing University of Chemical Technology Beijing 100029 China

1. Introduction Green chemical engineering is regarded as one of the most effi- cient means of achieving sustainable development in chemical in- dustrial processes. It can be divided into two main categories： Green product engineering. Examples include the develop- ment of new catalysts and the development and use of renewa- ble resources （e.g., solar energy and biomass）.

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THREE-DIMENSIONAL FLOW AROUND TWO TANDEM CIRCULAR CYLINDERS WITH VARIOUS SPACING AT Re=220

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Journal of Hydrodynamics 2006年第1期18卷 48-54页

作者： DENG jian REN An-lu ZOU jian-feng Department of Mechanics Zhejiang University Hangzhou 310027 China

The flow around two tandem circular cylinders was studied by a three-dimensional numerical simulation of the Navier-Stokes equations at Re=220 . The improved virtual boundary method was applied to model the no-slip boundary condition of the cylinders. The results show that as the spac ing ratio L/D≥4 , the three dimensionality occurs in the wake. When L/D≤3.5 the wake keeps a two-dimensional state at the Reynolds number Re=220 . The critical spacing for the appearance of three-dimensional instability obtained is at the range 3.5〈 L/D 〈 4, similar to the critical spacing found in two-dimensional case. Two sources of instability from upstream and downstream cylinder generate a complicat ed vortex structures in the wake, investigated by streamlines topology analysis in the streamwise plane. Many other interesting problems were also addressed in this paper.

关键词： three-dimensional Navier-Stokes equations,virtual boundary method flow around two tandem circular cylinders three-dimensional vortex structure

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Application of low-temperature thermochronology on ore deposits preservation framework in South China:a review

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Acta Geochimica 2022年第2期41卷 165-184页

作者： Kang Min jian-feng Gao State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China

South China can be divided into four metallogenic belts:The Middle-Lower Yangtze Metallogenic Belt(MLYB),Qinzhou-Hangzhou Metallogenic Belt(QHMB),Nanling Metallogenic Belt(NLMB),and Wuyi Metallogenic Belt(WYMB).The major mineralization in the four metallogenic belts is granite-related Cu–Au–Mo and porphyrite Fe-apatite,porphyry Cu(Au),and epithermal Pb–Zn–Ag,hydrothermal Cu–Au–Pb–Zn–Ag,and granite-related skarn-type and quartz-veins W–Sn,***-temperature thermochronology,including fissiontrack and U-Th/He dating,has been widely used to constrain tectonic thermal evolution and ore deposits *** fission-track annealing and He diffusion kinetics in accessory minerals,such as zircon and apatite,is essential for dating and *** this study,previous zircon fission-track(ZFT)and apatite fission-track(AFT)ages in South China were *** result shows that the ZFT ages are mainly concentrated at140–90 Ma,and the AFT ages are mainly distributed at70–40 *** age distribution and inversion temperature–time paths reveal heterogeneous exhumation histories in South *** MLYB experienced Late CretaceousCenozoic extremely slow exhumation after rapid cooling in the Early *** northern QHMB(*** southern Anhui province to the Hangzhou Bay)had a relatively faster rate of uplifting and denudation than the southern QHMB in the ***,the northern QHMB rapidly exhumed,while the continuously slow exhumation operated the southern QHMB in the *** southern NLMB had a more rapid cooling rate than the northern NLMB during the Cretaceous time,and the whole NLMB experienced rapid cooling in the Cenozoic,except that the southern Hunan province had the most rapid cooling *** WYMB possibly had experienced slow exhumation since the Late *** exhumation thickness of the four metallogenic belts since90 Ma is approximately calculated as follows:the MLYB≤3.5 km,the northern QHMB concentrated at

关键词： Low-temperature thermochronology Fissiontrack annealing and He diffusion kinetics South China Exhumation history Deposits preservation

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