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Serum proteins differentially expressed in gestational diabetes mellitus assessed using isobaric tag for relative and absolute quantitation proteomics 被引量:3
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作者 Wei-Li Cao Cui-Ping Yu Ling-Li Zhang 《World Journal of Clinical Cases》 SCIE 2024年第8期1395-1405,共11页
BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients a... BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM. 展开更多
关键词 Gestational diabetes mellitus Liquid chromatography-tandem mass spectrometry Isobaric tag for relative and absolute quantitation PROTEOMICS BIOMARKER
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Controlled thermally-driven mass transport in carbon nanotubes using carbon hoops
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作者 李耀隆 李松远 +1 位作者 王美芬 张任良 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期66-69,共4页
Controlling mass transportation using intrinsic mechanisms is a challenging topic in nanotechnology.Herein,we employ molecular dynamics simulations to investigate the mass transport inside carbon nanotubes(CNT)with te... Controlling mass transportation using intrinsic mechanisms is a challenging topic in nanotechnology.Herein,we employ molecular dynamics simulations to investigate the mass transport inside carbon nanotubes(CNT)with temperature gradients,specifically the effects of adding a static carbon hoop to the outside of a CNT on the transport of a nanomotor inside the CNT.We reveal that the underlying mechanism is the uneven potential energy created by the hoops,i.e.,the hoop outside the CNT forms potential energy barriers or wells that affect mass transport inside the CNT.This fundamental control of directional mass transportation may lead to promising routes for nanoscale actuation and energy conversion. 展开更多
关键词 molecular dynamics thermal drive nanotube hoop mass transport
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Identification and the molecular mechanism of novel duck liver-derived anti-inflammatory peptides in lipopolysaccharide-induced RAW264.7 cell model
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作者 Xiankang Fan Laidi Zhang +5 位作者 Yangying Sun Changyu Zhou Qiang Xia Lihui Du Zhen Wu Daodong Pan 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第6期3595-3605,共11页
In this study,10 novel anti-inflammatory peptides were identified from duck liver,and their molecular mechanism was demonstrated based on machine learning and molecular docking.Using Sephadex G-15 gel chromatography s... In this study,10 novel anti-inflammatory peptides were identified from duck liver,and their molecular mechanism was demonstrated based on machine learning and molecular docking.Using Sephadex G-15 gel chromatography separation,reversed-phase high-performance liquid chromatography purification,liquid chromatography-tandem mass spectrometry identification,and BIOPEP database comparison,10 novel antiinflammatory peptides were initially found.Their splendid angiotensin-converting enzyme(ACE)inhibition and anti-inflammatory properties were confirmed by machine learning.With binding energies less than–20.93 kJ/mol,molecular docking revealed that they could efficiently bind to the active pockets of tumor necrosis factorα(TNF-α),interleukin 6(IL-6),cyclooxygenase 2(COX-2),and nuclear factorκB(NF-κB)proteins with efficiency,indicating that the compounds can spontaneously form complexes through hydrogen bonding and hydrophobic interactions with the protein binding pockets.In the lipopolysaccharide-induced RAW264.7 cell model,the release of NO,TNF-α,and IL-6 and the mRNA expression of inflammatory factors(TNF-α,IL-6,COX-2,and NF-κB)were significantly inhibited by these peptides.We concluded it might be due to their anti-inflammatory effects by inhibiting the protein phosphorylation of inhibitor of NF-κB(IκBα)in the cytoplasm and preventing the translocation of NF-κB p65 in the cytoplasm to the nucleus,thereby regulating the NF-κB signaling pathway.This study is essential for the screening of anti-inflammatory peptides and the investigation of the mechanism of action. 展开更多
关键词 PEPTIDES Machine learning molecular docking Infl ammation Liquid chromatography-tandem mass spectrometry
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Mass-spring model for elastic wave propagation in multilayered van der Waals metamaterials
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作者 Yabin JING Lifeng WANG Yuqiang GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第7期1107-1118,共12页
Multilayered van der Waals(vdW)materials have attracted increasing interest because of the manipulability of their superior optical,electrical,thermal,and mechanical properties.A mass-spring model(MSM)for elastic wave... Multilayered van der Waals(vdW)materials have attracted increasing interest because of the manipulability of their superior optical,electrical,thermal,and mechanical properties.A mass-spring model(MSM)for elastic wave propagation in multilayered vdW metamaterials is reported in this paper.Molecular dynamics(MD)simulations are adopted to simulate the propagation of elastic waves in multilayered vdW metamaterials.The results show that the graphene/MoS_(2)metamaterials have an elastic wave bandgap in the terahertz range.The MSM for the multilayered vdW metamaterials is proposed,and the numerical simulation results show that this model can well describe the dispersion and transmission characteristics of the multilayered vdW metamaterials.The MSM can predict elastic wave transmission characteristics in multilayered vdW metamaterials stacked with different two-dimensional(2D)materials.The results presented in this paper offer theoretical help for the vibration reduction of multilayered vdW semiconductors. 展开更多
关键词 multilayered van der Waals(vd W)metamaterial molecular dynamics(MD) mass-spring model(MSM) dispersion relation transmission characteristic
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Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion 被引量:5
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作者 张美玲 孙现亭 +2 位作者 王肖肖 解银丽 贾利群 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期19-22,共4页
Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion are studied. The determining equation of Lie symmetry of Nielsen equations for a ... Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion are studied. The determining equation of Lie symmetry of Nielsen equations for a variable mass holonomic system of relative motion under the infinitesimal transformations of groups is given. The expression of generalized Hojman conserved quantity deduced directly from Lie symmetry for a variable mass holonomic system of relative motion is obtained. An example is given to illustrate the application of the results. 展开更多
关键词 variable mass relative motion Lie symmetry generalized Hojman conserved quantity
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Mei symmetry and Mei conserved quantity of Appell equations for a variable mass holonomic system of relative motion 被引量:3
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作者 张美玲 王肖肖 +1 位作者 韩月林 贾利群 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期17-21,共5页
Mei symmetry and Mei conserved quantity of Appell equations for a variable mass holonomic system of relative motion are studied.The definition and criterion of the Mei symmetry of Appell equations for a variable mass ... Mei symmetry and Mei conserved quantity of Appell equations for a variable mass holonomic system of relative motion are studied.The definition and criterion of the Mei symmetry of Appell equations for a variable mass holonomic system of relative motion under the infinitesimal transformations of groups are given.The structural equation of Mei symmetry of Appell equations and the expression of Mei conserved quantity deduced directly from Mei symmetry for a variable mass holonomic system of relative motion are gained.Finally,an example is given to illustrate the application of the results. 展开更多
关键词 variable mass relative motion Appell equations Mei conserved quantity
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CHARACTERIZATION OF MOLECULAR MASS OF SIX WATER-SOLUBLE POLYSACCHARIDE -PROTEIN COMPLEXES FROM GANODERMA TSUGAE MYCELIUM 被引量:1
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作者 张俐娜 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2003年第3期309-316,共8页
Six water-soluble polysaccharide-protein complexes coded as GM1, GM2, GM3, GM4, GM5 and GM6 wereisolated from the mycelium of Ganoderma tsugae by extracting with 0.2 mol/L phosphate buffer solution at 25, 40 and80℃, ... Six water-soluble polysaccharide-protein complexes coded as GM1, GM2, GM3, GM4, GM5 and GM6 wereisolated from the mycelium of Ganoderma tsugae by extracting with 0.2 mol/L phosphate buffer solution at 25, 40 and80℃, water at 120℃, 0.5 mol/L aqueous NaOH solution at 25 and 65℃, consecutively. Their chemical components wereanalyzed by using IR, GC, HPLC and ^(13)C-NMR, and some new results were obtained. The four samples GM1, GM2, GM3and GM4 are heteropolysaccharide-prote in complexes, in which, α- (1→3) linked D-glucose is the major monosaccharidewhile galactose, mannose and ribose are the secondary ones. GM5 and GM6 are β-(1→3)-D-glucan-protein complexes. Theprotein content increased from 32% to 69% with the progress of isolation. Weight-average molecu1ar mass M_w and theintrinsic viscosity [η] of the GM samples in 0.5 mol/L aqueous NaCl solution at 25℃ were measured systematically by laserlight scartering (LLS), size exclusion chromatography (SEC) combined with LLS, and viscometry. The M_w of GM1 to GM6are 35.5, 46.8, 58.9, 41.6, 3.3 and 22.0×10~4, respectively. The conformation and molecular mass of the two fractions of sample GM5 were characterized satisfactorily by SEC-LLS without further fractionation. 展开更多
关键词 Ganoderma tsugae mycelium Polysaccharide-protein complex Chemica1 component molecular mass Light scattering Size exclusion chromatography
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Preparation of high viscosity average molecular mass poly-L-lactide 被引量:2
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作者 周智华 阮建明 +2 位作者 邹俭鹏 周忠诚 申雄军 《Journal of Central South University of Technology》 EI 2006年第6期608-612,共5页
Poly-L-lactide(PLLA) was synthesized by ring-opening polymerization fi'om high purity L-lactide with tin octoate as initiator, and characterized by means of infi'ared, and ^1H-nuclear magnetic resonance. The influ... Poly-L-lactide(PLLA) was synthesized by ring-opening polymerization fi'om high purity L-lactide with tin octoate as initiator, and characterized by means of infi'ared, and ^1H-nuclear magnetic resonance. The influences of initiator concentration, polymerization temperature and polymerization time on the viscosity average molecular mass of PLLA were investigated. The effects of different purification methods on the concentration of initiator and viscosity average molecular mass were also studied. PLLA with a viscosity average molecular mass of about 50.5×1^04 was obtained when polymerization was conducted for 24 h at 140℃ with the molar ratio of monomer to purification initator being 12 000. After purification, the concentration of tin octoate decreases; however, the effect of different purification methods on the viscosity average molecular mass of PLLA is different, and the obtained PLLA is a typical amorphous polymeric material. The crystallinity of PLLA decreases with the increase of viscosity average molecular mass. 展开更多
关键词 POLY-L-LACTIDE POLYMERIZATION PURIFICATION high viscosity average molecular mass
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Viscous-flow properties and viscosity-average molecular mass of orange peel pectin
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作者 周尽花 吴宇雄 沈志强 《Journal of Central South University》 SCIE EI CAS 2008年第S1期520-524,共5页
The viscous-flow properties of pectin from the residue of orange peel after extraction of essential oil and flavonoid were studied and the viscosity-average molecular mass(Mv,ave) of this kind of pectin was determined... The viscous-flow properties of pectin from the residue of orange peel after extraction of essential oil and flavonoid were studied and the viscosity-average molecular mass(Mv,ave) of this kind of pectin was determined.Experimental results show that Arrhenius viscous-flow equation can be applied to describing the effect of temperature on viscosity of this kind of orange peel pectin solutions with the average viscous-flow activation energy being 17.91 kJ/mol(depending on the concentration).Neither power equation,η =K1 cA1,nor exponential equation,η=K2exp(A2c) can describe the effect of concentration on viscosity of this kind of orange peel pectin solutions well.However,it seems that exponential equation model is more suitable to describe their relation due to its higher linear correlation coefficient.Schulz-Blaschke equation can be used to calculate the intrinsic viscosity of this kind of orange peel pectin.The Mv,ave of the orange peel pectin is 1.65×105 g/mol. 展开更多
关键词 PECTIN VISCOUS-FLOW properties viscosity-average molecular mass ORANGE PEEL
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Strength and deformation characteristics of irregular columnar jointed rock mass: A combined experimental and theoretical study 被引量:2
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作者 Xiangcheng Que Zhende Zhu +2 位作者 Yanxin He Zihao Niu Haonan Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第2期429-441,共13页
The irregularity of jointed network poses a challenge to the determination of field mechanical param-eters of columnar jointed rock mass(CJRM),and a reasonable prediction of deformation and strength characteristics of... The irregularity of jointed network poses a challenge to the determination of field mechanical param-eters of columnar jointed rock mass(CJRM),and a reasonable prediction of deformation and strength characteristics of CJRM is important for engineering construction.The Voronoi diagram and three-dimensional printing technology were used to make an irregular columnar jointed mold,and the irregular CJRM(ICJRM)specimens with different dip directions and dip angles were prepared.Uniaxial compression tests were performed,and the anisotropic strength and deformation characteristics of ICJRM were described.The failure modes and mechanisms were revealed in accordance with the final appearances of the ICJRM specimens.Based on the model test results,the empirical correlations for determining the field deformation and strength parameters of CJRM were derived using the dip angle and modified joint factor.The proposed empirical equations were used in the Baihetan Project,and the calculated mechanical parameters were compared with the field test results and those obtained from the tunneling quality index method.Results showed that the deformation parameters determined by the two proposed methods are all consistent with the field test results,and these two methods can also estimate the strength parameters effectively. 展开更多
关键词 Irregular columnar jointed rock mass (ICJRM) Physical model test Anisotropic characteristic Empirical relations Dip angle Modified joint factor
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Determination of Molecular Mass of Strong Acids by Differential Temperature Model (DTM) Using H<sub>3</sub>PO<sub>4</sub>and HBF<sub>4</sub>for Classical Demonstration
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作者 I. A. Akpan 《Journal of Materials Science and Chemical Engineering》 2015年第6期41-47,共7页
A new chemical hypothesis based on the differential temperature model (DTM) for estimation of molecular masses of some strong acids (H2SO4, HNO3 and HCl) in solutions have previously been propounded and tested theoret... A new chemical hypothesis based on the differential temperature model (DTM) for estimation of molecular masses of some strong acids (H2SO4, HNO3 and HCl) in solutions have previously been propounded and tested theoretically and analytically by the author. The results were published in the Bulletin of Pure and Applied Sciences–Chemistry in 2012. The changes in temperature following various dilutions of the acids were found to be proportional to their molecular properties. The new chemical hypothesis and model is hereby tested on H3PO4 and HBF4 and their exact molecular masses have been evaluated analytically and theoretically. The validity of the hypothesis and the model is hereby presented for chemical proof and adoption to theory by chemists. 展开更多
关键词 DIFFERENTIAL Temperature molecular mass Strong ACIDS
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Relative Molecular Orientations in Organic Optoelectronic Films Probed via Polarization-Selected UV/IR Mixed Frequency Ultrafast Spectroscopy
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作者 Chengzhen Shen Jie Peng +4 位作者 Jianxin Guan Chuangqing Hao Zhihao Yu Hong Jiang Junrong Zheng 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第1期95-103,I0013,I0014,I0063,共12页
Molecular packing patterns are crucial factors determining electron/energy transfer processes that are critical for the optoelectronic properties of organic thin film devices.Herein,the polarization-selective ultravio... Molecular packing patterns are crucial factors determining electron/energy transfer processes that are critical for the optoelectronic properties of organic thin film devices.Herein,the polarization-selective ultraviolet/infrared(UV/IR)mixed frequency ultrafast spectroscopy is applied to investigate the relative molecular orientations in two organic thin films of 7-(diethylamino)coumarin-3-carboxylic acid(DEAC)and perylene.The signal anisotropy changes caused by intermolecular energy/electron transfers are utilized to calculate the cross angles between the electronic transition dipole moment of the donor and the vibrational transition dipole moments of the acceptor,yielding the relative orientation between two adjacent molecules.Using this method,the relative orientation angle in DEAC film is determined to be 53.4°,close to 60°of its single crystalline structure,and that of the perylene film is determined to be 6.2°,also close to-0.2°of its single crystalline structure.Besides experimental uncertainties,the small difference between the angles determined by this method and those of single crystals also results from the fact that the thin film samples are polycrystalline where some of the molecules are amorphous. 展开更多
关键词 OPTOELECTRONICS relative molecular orientations Organic films
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Entanglement of the Common Eigenvector of Two Particles‘ Center—of—Mass Coordinate and Mass—Weighted Relative Momentum
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作者 FANHong-Yi SUNMing-Zhai 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第5期535-538,共4页
We reveal that the common eigenvector of two particles' center-of-mass coordinate and mass-weightedrelative momentum is an entangled state. Its Schmidt decomposition exhibits that the entanglement involves squeezi... We reveal that the common eigenvector of two particles' center-of-mass coordinate and mass-weightedrelative momentum is an entangled state. Its Schmidt decomposition exhibits that the entanglement involves squeezingwhich depends on the ratio of two particles' masses. The corresponding entangling operators are derived. 展开更多
关键词 center-of mass coordinate mass-weighted relative momentum entangled state
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Molecular Probes in Tandem Electrospray Ionization Mass Spectrometry: Application to Tracing Chemical Changes of Specific Phospholipid Molecular Species
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作者 Hiroko Tominaga Tomoe Ishihara +8 位作者 A. K. M. Azad Shah Rumiko Shimizu Arnold N. Onyango Hideyuki Ito Toshinori Suzuki Yasuhiro Kondo Hiroshi Koaze Koretaro Takahashi Naomichi Baba 《American Journal of Analytical Chemistry》 2013年第10期16-26,共11页
New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specif... New ionization and detection techniques in mass spectrometry have been successfully applied for efficient analyses of complex biological systems. It is, however, still difficult to trace structural changes of a specific molecular species in such systems. In the present study, a molecular probe strategy in combination with tandem electrospray ionization mass spectrometry has been examined using synthetic deuterium-labeled phosphatidylcholine hydroperoxide (PC-OOH/D3) and ethyl-labeled phosphatidylcholine having docosahexaenoic acid side chain (DHA-PC/Et). Administration of a mixture of PC-OOH/D3 and DHA-PC/Et to human blood and human skin surface, followed by extraction and analysis with collision-induced tandem electrospray ionization mass spectrometry demonstrated that metabolites of both molecular probes can be detected simultaneously with strict selectivity. The present method is also found to be useful in tracing chemical changes of the unstable docosahexaenoyl group on the surface of processed fish. The activity of phospholipase A2 can also be assessed using a phospholipid molecular probe with a linoleoyl and a deuteriomethyl group via selective detection of the lyso-phospholipid product by mass spectrometry. The advantage of the present method is that no chromatographic separation is required and analysis can be performed under strictly the same condition for different molecular probes, affording multiple data by one experiment. The present strategy may be useful for tracing time-dependent phenomena in dynamic phospholipid biochemistry, and can be widely used for any biological and food systems. 展开更多
关键词 molecular Probe Stable ISOTOPE mass Spectrometry ELECTROSPRAY Ionization LIPID PEROXIDATION LIPID Oxidation Skin Surface
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Friction and wear properties of ultra-high molecular mass polyethylene reinforced with Al2O3 nano-particle
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作者 FAN Dong-li XIONG Dang-sheng 《中国有色金属学会会刊:英文版》 CSCD 2004年第z1期354-358,共5页
The ultra-high molecular mass polyethylene (UHMMPE) as an artificial joint acetabular material was filled with nano-powder of Al2O3 of various mass fractions. The effect of Al2O3 mass fraction on the hardness, wetting... The ultra-high molecular mass polyethylene (UHMMPE) as an artificial joint acetabular material was filled with nano-powder of Al2O3 of various mass fractions. The effect of Al2O3 mass fraction on the hardness, wetting property and tribological properties of the Al2O3-UHMMPE composites under dry friction sliding against both stainless steel and Ti-6Al-4V alloy was investigated. The morphologies of the worn surfaces of composites were observed with optical microscope. The results show that, wetting property and wear resistance of the composites are improved by filling Al2O3, while the friction coefficient is decreased largely under dry friction as compared with that of the unfilled UHMMPE. This is attributed to the reinforcing function of the nano-powder of Al2O3 in the composites. The wear of UHMMPE is dominated by plowing, plastic deformation and fatigue wear; while the Al2O3-UHMMPE composites are characterized by the mild fatigue wear. 展开更多
关键词 ultra-high molecular mass POLYETHYLENE AL2O3 NANO-POWDER FILLING modification friction and WEAR properties artificial joint
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Star Formation in Magnetized, Turbulent and Rotating Molecular Cloud: The Critical Mass
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作者 Gemechu Muleta Kumssa Solomon Belay Tessema 《International Journal of Astronomy and Astrophysics》 2018年第4期347-367,共21页
In this paper, we present the critical mass of magnetized, turbulent and rotating star-forming molecular cloud core (MCc) in the presence of magnetic tension. The critical mass of star-forming magnetized cloud is infl... In this paper, we present the critical mass of magnetized, turbulent and rotating star-forming molecular cloud core (MCc) in the presence of magnetic tension. The critical mass of star-forming magnetized cloud is influenced by the magnetic tension, magnetic pressure and other pressures. Applying the method of theoretical modelling by taking into account the basic equations and assumptions, we formulate the critical mass of magnetized MCc in different cases. Accordingly, the minimum critical masses we find in both cases are different. Energy due to magnetic tension significantly triggers the collapse at relatively larger radius of the core. The model shows that when the initial radius of the parent cloud (Ro) is larger than that of collapsing core radius (Rcore) the magnetic tension also has the larger radius of curvature, so it plays a significant role in supporting gravity to collapse the core. The results indicate gravity without magnetic tension may not overcome magnetic pressure, turbulence pressure and pressure due to rotation. This shows the critical mass of MCc for the collapse depends on the tension force that magnetic field lines apply on the envelope. We conclude that if there is magnetic pressure in star-forming MCc, there is also unavoidable magnetic tension, which triggers the collapse of the core. If there is no magnetic tension, the magnetized MCc needs relatively larger mass and higher density within the small size to collapse. 展开更多
关键词 STAR Formation molecular Cloud Critical mass MAGNETIC Field TURBULENCE MAGNETIC Tension
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Star Formation in Self-Gravitating Molecular Cloud: The Critical Mass and the Core Accretion Rate
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作者 Gemechu M. Kumssa S. B. Tessema 《World Journal of Mechanics》 2020年第5期53-67,共15页
Understanding how stars form in molecular clouds is one of the ongoing research areas in astrophysics. Star formation is the fundamental process to which our current understanding remains incomplete due to the complex... Understanding how stars form in molecular clouds is one of the ongoing research areas in astrophysics. Star formation is the fundamental process to which our current understanding remains incomplete due to the complexity of the physics that drives their formation within molecular clouds. In this article theoretical modelling of the lowest possible mass of the cloud needed for collapse and the core accretion rate has been presented for the molecular cloud collapsing under its gravity. In many of previous studies the critical mass of star forming cloud under its gravity has been modelled using kinetic energy and gravitational potential energy. However, we test the effect of thermodynamic efficiency factor together with other physical processes in describing the critical mass, and controlling or triggering the rate of mass falling onto the central core. Assuming that, the ratio of radiation luminosity to gravitational energy released per unit time of the collapsing MC is less than unity. Following this conceptual framework we have formulated the critical mass and the core accretion rate of the self-gravitating molecular cloud. 展开更多
关键词 Star Formation molecular Cloud Critical mass Core Accretion
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Mechanism investigation of steam flooding heavy oil by comprehensive molecular characterization
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作者 Bo Zhang Chun-Ming Xu +4 位作者 Zhe-Yu Liu Qing-Hui Zhao Hai-Qing Cheng Yi-Qiang Li Quan Shi 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2554-2563,共10页
Steam flooding is a widely used technique to enhance oil recovery of heavy oil.Thermal viscosity reduction and distillation effect are considered as two main displacement mechanisms in steam flooding process.However,t... Steam flooding is a widely used technique to enhance oil recovery of heavy oil.Thermal viscosity reduction and distillation effect are considered as two main displacement mechanisms in steam flooding process.However,the molecular composition understanding and contribution for oil production are still unclear.In this study,the composition analysis of the heavy oil was investigated in the core scale steam flooding process with the temperature from 120 to 280℃.The crude oil,produced oils and residual oils were characterized comprehensively by gas chromatography and high-resolution mass spectrometry.It is found that steam flooding preferentially extracts aromatics and remains more resins in the residual oil.Viscosity reduction is the dominant mechanism when steam is injected at a low temperature.Large molecular heteroatoms with high carbon number and high double bond equivalent(DBE)are eluted into the produced oil,while compounds with low carbon number and low DBE are remained in the residual oil.As the steam temperature rises,the increased distillation effect results in the extraction of light hydrocarbons from the residual oil to the produced oil.More small heteroatoms with low carbon number and low DBE enter into the produced oil,especially in the none water cut stage.The compositional difference of produced oils is characterized in DBE versus carbon number distribution of the N and O containing compound classes.This work uses a variety of composition analysis methods to clarify the steam flooding mechanism and provides a novel understanding of steam flooding mechanisms with various temperatures and production stages from the molecular perspective. 展开更多
关键词 Steam flooding mechanism molecular composition High-resolution mass spectrometry Heavy oil Enhance oil recovery
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A Theoretical Study on Energy of a Gaseous System Vis-a-Vis Mass and Temperature
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作者 Santosh K. Karn Necati Demiroglu 《Journal of Electronics Cooling and Thermal Control》 CAS 2023年第1期1-8,共8页
To study various properties of a gas has been a subject of rational curiosity in pneumatic sciences. A gaseous system, in general, is studied by using four measurable parameters namely, the pressure, volume, number of... To study various properties of a gas has been a subject of rational curiosity in pneumatic sciences. A gaseous system, in general, is studied by using four measurable parameters namely, the pressure, volume, number of moles and temperature. In the present work, an attempt is made to study the variation of energy of an ideal gas with the two measurable parameters, the mass and temperature of the gas. Using the well known ideal gas equation, PV = nRT where symbols have their usual meanings and some simple mathematical operations widely used in physics, chemistry and mathematics in a transparent manner, an equation of state relating the three variables, the energy, mass and temperature of an ideal gas is obtained. It is found that energy of an ideal gas is equal to the product of mass and temperature of the gas. This gives a direct relationship between the energy, mass and temperature of the gas. Out of the three variables, the energy, mass and temperature of an ideal gas, if one of the parameters is held constant, the other two variables can be measured. At a constant temperature, when the power or energy is stabilized, the increase in the mass of the gas may affect the new works and an engine can therefore be prevented from overheating. 展开更多
关键词 HYDRODYNAMICS Low Temperature Fluid Flow Ideal Gas Equation of State ENERGY mass Temperature and Their Relation
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Generation of Lepton Masses Complementary to Higgs
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作者 Peter I Porshnev 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期142-167,共26页
A generation of bare lepton masses alternative to Higgs-like mechanisms is proposed. It can be used in a combination with the latter ones in attempt to explain why the coupling strengths to Higgs field span a wide ran... A generation of bare lepton masses alternative to Higgs-like mechanisms is proposed. It can be used in a combination with the latter ones in attempt to explain why the coupling strengths to Higgs field span a wide range. The proposed mechanism also allows defining neutrino masses alternatively to the Dirac or Majorana types, since the effective bare masses of leptons are possible to generate without scalar terms in electroweak Lagrangians and motion equations. The proposed extension is fully compatible with standard methods of calculating radiative corrections and scattering amplitudes, since the left- and right-handed parts of EW Lagrangian do not change. 展开更多
关键词 Electroweak Left-Handed Lagrangian Dirac And Majorana masses Seesaw Relation
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