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16篇 您的检索式:作者名="Xiangfeng Guo"
    题名 作者 年代 出处 被引量
1Friction Characteristics of Impregnated and Non-Impregnated Graphite against Cemented Carbide under Water Lubrication显示文摘The friction behavior of resin-impregnated and non-impregnated graphite sliding against a cemented carbide in dry, oil, and water environments using a ring–ring configuration was investigated. Friction coefficients were recorded at various speeds. The results showed that the impregnated graphite exhibited much better friction properties under water or oil lubrication than non-impregnated graphite, and the impregnated graphite could remain in the stable friction regime under high pressure × velocity(pv).Based on scanning electron microscopy and Raman spectroscopy analyses, the different characteristics between impregnated and non-impregnated graphite were able to be attributed to the structure of the graphite and wettability of the lubricants.Gaolong Zhang Ying Liu Fei Guo Xiangfeng Liu Yuming Wang 2017Journal of Materials Science & Technology2017,33,10:8
2Wear behavior of WC-Ni sliding against graphite under water lubrication显示文摘Wear of hard materials in contact with softer materials is a neglected area of research. However, we observed considerable wear phenomenon at a hard WC-Ni surface sliding over soft graphite under water lubrication. The influences of applied load and the application history on the wear of surface were addressed in our experimental design. Wear of both graphite and WC-Ni surfaces increased with a greater applied load and repeated sliding. The topographies of the worn surfaces showed clear micro-scratches on the hard WC-Ni surface. Scanning electron microscopy and X-ray photoelectron spectroscopy analyses revealed that the abrasive wear of the WC-Ni surface could be attributed to hard WC particles embedded in the graphite surface. These hard particles were formed by shearing of sharp WC-Ni asperities under certain conditions and intrinsic defects of the WC-Ni surface could accelerate this wear process.Gaolong Zhang Ying Liu Yuechang Wang Fei Guo Xiangfeng Liu Yuming Wang 2017Journal of Materials Science & Technology2017,33,11:5
3Dietary proline supplementation alters colonic luminal microbiota and bacterial metabolite composition between days 45 and 70 of pregnancy in Huanjiang mini-pigs显示文摘Background: Pregnancy is associated with important changes in gut microbiota composition. Dietary factors may affect the diversity, composition, and metabolic activity of the intestinal microbiota. Among amino acids, proline is known to play important roles in protein metabolism and structure, cell differentiation, conceptus growth and development, and gut microbiota re-equilibration in case of dysbiosis.Results: Dietary supplementation with 1% proline decreased(P < 0.05) the amounts of Klebsiella pneumoniae,Peptostreptococcus productus, Pseudomonas, and Veillonella spp. in distal colonic contents than that in the control group. The colonic contents of Butyrivibrio fibrisolvens, Bifidobacterium sp., Clostridium coccoides, Clostridium coccoides-Eubacterium rectale, Clostridium leptum subgroup, Escherichia coli, Faecalibacterium prausnitzii,Fusobacterium prausnitzii, and Prevotella increased(P < 0.05) on d 70 of pregnancy as compared with those on d 45 of pregnancy. The colonic concentrations of acetate, total straight-chain fatty acid, and total short-chain fatty acids(SCFA) in the proline-supplemented group were lower(P < 0.05), and butyrate level(P = 0.06) decreased as compared with the control group. Almost all of the SCFA displayed higher(P < 0.05) concentrations in proximal colonic contents on d 70 of pregnancy than those on d 45 of pregnancy. The concentrations of 1,7-heptyl diamine(P = 0.09) and phenylethylamine(P < 0.05) in proximal colonic contents were higher, while those of spermidine(P = 0.05) and total bioamine(P = 0.06) tended to be lower in the proline-supplemented group than those in the control group. The concentrations of spermidine, spermine, and total bioamine in colonic contents were higher(P < 0.05) on d 70 of pregnancy than those measured on d 45 of pregnancy. In contrast, the concentration of phenylethylamine was lower(P < 0.05) on d 70 than on d 45 of pregnancy.(Continued on next page)(Continued from previous page)Conclusion: These findings indicate that L-proline supplementation modifies both the colonic microbiota composition and the luminal concentrations of several bacterial metabolites. Furthermore, our data show that both the microbiota composition and the concentrations of bacterial metabolites are evolving in the course of pregnancy. These results are discussed in terms of possible implication in terms of luminal environment and consequences for gut physiology and health.Yujiao Ji Qiuping Guo Yulong Yin Francois Blachier Xiangfeng Kong 2018Journal of Animal Science and Biotechnology2018,9,2:5
4Damage characteristics and catastrophic failure mechanism of coal rock induced by gas adsorption under compression显示文摘To reveal the damage characteristics and catastrophic failure mechanism of coal rock caused by gas adsorption,physical tests and theoretical methods are employed.The results show that adsorption swelling can damage coal rock,which can be distinguished by fractal dimension.A fitting relationship between the adsorption damage and fractal dimension is proposed by experimental testing and theoretical analysis.High gas adsorption pressure proves to be the dominant factor that leads to coal failure softening and gas outburst disasters.Three main parameters concerning adsorption damage include the change rate of released energy density,the transition difference in the post-peak acoustic emission(AE)b value and the change rate of cumulative AE energy.Results show that all the three parameters present a step-type decreasing change with the increase in fractal dimension,and the fractal dimension shows a linear relationship within the same failure mode.Finally,a method is proposed to evaluate coal rock disaster transformation,based on the aforementioned three main parameters of adsorption damage.Xiaochun Xiao Lei Wang Jun Xu Xiangfeng Lv Pengfei Guo Yishan Pan 2020Journal of Rock Mechanics and Geotechnical Engineering2020,12,3:3
5A field-effect approach to directly profiling the localized states in monolayer MoS2显示文摘A fundamental understanding of the charge transport mechanism in two-dimensional semiconductors(e.g., MoS2) is crucial for fully exploring their potential in electronic and optoelectronic devices. By using monolayer graphene as the barrier-free contact to MoS2, we show that the field-modulated conductivity can be used to probe the electronic structure of the localized states. A series of regularly distributed plateaus were observed in the gate-dependent transfer curves. Calculations based on the variable-range hopping theory indicate that such plateaus can be attributed to the discrete localized states near mobility edge. This method provides an effective approach to directly profiling the localized states in conduction channel with an ultrahigh resolution up to 1 meV.Hao Wu Yuan Liu Zeyu Deng Hung-Chieh Cheng Dehui Li Jian Guo Qiyuan He Sen Yang Mengning Ding Yun-Chiao Huang Chen Wang Yu Huang Xiangfeng Duan 2019Science Bulletin2019,64,15:2
6Effect of bovine serum albumin on the micellization of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers in aqueous solutions by fluorescence spectroscopy显示文摘Effect of bovine serum albumin (BSA) on the temperature-dependent association behavior of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers was investigated using pyrene fluorescence spectroscopy. The critical micellization temperature (CMT) of pluronics in aqueous solution was increased by the addition of BSA. A closed association model was used to obtain the standard free energies (△G0), enthalpies (△H 0), and entropies (△S 0) of micellization. The standard enthalpy and entropy of micellization for pluronic polymers in water were decreased with an increase of the BSA content. The more PPO component in the pluronic polymer, the higher the changed values of micellization enthalpy and entropy. The hydrophobic part of the pluronics, PPO, was responsible for the interaction between pluronics and BSA. Hydrophobic interaction between PPO and BSA was correlated to the alternation of the PPO-PPO interaction by the addition of BSA, which would shift the CMT toward higher temperature and alter the thermodynamic parameters of micellization for pluronics in aqueous solutions.GUO Chen WANG Jing LIANG Xiangfeng ZHENG Lili LIU Huizhou 2006Science China Chemistry2006,49,6:2
7A highly selective and sensitive fluorescent chemosensor for Hg^2+in neutral buffer aqueous solution 显示文摘Guo Xiangfeng Qian Xuhong Jia Lihua 2004Journal of American Chemical Society2004,126,8:1
8Hydrothermal synthesis and thermodynamic analysis of dawsonite-type compounds 显示文摘Xiangfeng Zhang Zhaoyin Wen Guo Zhonghua 2004Journal of Solid State Chemistry2004,177,:1
9Rapid synthesis of LiFePOJC composite by microwave method 显示文摘Guo Xiangfeng Zhan Hui Zhou Yunhong 2009Solid State Ionics2009,180,45:1
10Reliability-based settlement analysis of embankments over soft soils reinforced with T-shaped deep cement mixing piles显示文摘This paper presents a reliability-based settlement analysis of T-shaped deep cement mixing(TDM)pile-supported embankments over soft soils.The uncertainties of the mechanical properties of the in-situ soil,pile,and embankment,and the effect of the pile shape are considered simultaneously.The analyses are performed using Monte Carlo Simulations in combination with an adaptive Kriging(using adaptive sampling algorithm).Individual and system failure probabilities,in terms of the differential and maximum settlements(serviceability limit state(SLS)requirements),are considered.The reliability results for the embankments supported by TDM piles,with various shapes,are compared and discussed together with the results for conventional deep cement mixing pile-supported embankments with equivalent pile volumes.The influences of the inherent variabilities in the material properties(mean and coefficient of variation values)on the reliability of the piled embankments,are also investigated.This study shows that large TDM piles,particularly those with a shape factor of greater than 3,can enhance the reliability of the embankment in terms of SLS requirements,and even avoid unacceptable reliability levels caused by variability in the material properties.Chana PHUTTHANANON Pornkasem JONGPRADIST Daniel DIAS Xiangfeng GUO Pitthaya JAMSAWANG Julien BAROTH 2022Frontiers of Structural and Civil Engineering2022,16,5:1
11Ethanol gas sensor based on CoFe 2 O 4 nano-crystallines prepared by hydrothermal method显示文摘Chu Xiangfeng Jiang Dongli Guo Yu Zheng Chenmou 2006Sensors & Actuators: B. Chemical2006,,1:1
12Cu-doped mesoporous VOx-TiO2in catalytic hydroxylation of benzene to phenol显示文摘Xu Dan Jia Lihua Guo Xiangfeng 2013Chinese Journal of Catalysis2013,34,:1
13Safety and immunogenicity of a mosaic vaccine booster against Omicron and other SARS-CoV-2 variants:a randomized phase 2 trial显示文摘An ongoing randomized,double-blind,controlled phase 2 trial was conducted to evaluate the safety and immunogenicity of a mosaic-type recombinant vaccine candidate,named NVSI-06-09,as a booster dose in subjects aged 18 years and older from the United Arab Emirates(UAE),who had administered two or three doses of inactivated vaccine BBIBP-CorV at least 6 months prior to enrollment.The participants were randomly assigned with 1:1 to receive a booster dose of NVSI-06-09 or BBIBP-CorV.The primary outcomes were immunogenicity and safety against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant,and the exploratory outcome was cross-immunogenicity against other circulating strains.Between May 25 and 30,2022,516 adults received booster vaccination with 260 in NVSI-06-09 group and 256 in BBIBP-CorV group.Interim results showed a similar safety profile between two booster groups,with low incidence of adverse reactions of grade 1 or 2.For immunogenicity,by day 14 post-booster,the fold rises in neutralizing antibody geometric mean titers(GMTs)from baseline elicited by NVSI-06-09 were remarkably higher than those by BBIBP-CorV against the prototype strain(19.67 vs 4.47-fold),Omicron BA.1.1(42.35 vs 3.78-fold),BA.2(25.09 vs 2.91-fold),BA.4(22.42 vs 2.69-fold),and BA.5 variants(27.06 vs 4.73-fold).Similarly,the neutralizing GMTs boosted by NVSI-06-09 against Beta and Delta variants were also 6.60-fold and 7.17-fold higher than those by BBIBP-CorV.Our findings indicated that a booster dose of NVSI-06-09 was well-tolerated and elicited broad-spectrum neutralizing responses against divergent SARS-CoV-2 variants,including Omicron and its sub-lineages.Nawal Al Kaabi Yun Kai Yang Yu Liang Ke Xu Xue Feng Zhang Yun Kang Yu Qin Jin Jun Wei Hou Jing Zhang Tian Yang Salah Hussein Mohamed Saif ElDein Ze Hua Lei Hao Zhang Shuai Shao Zhao Ming Liu Ning Liu Xiang Zheng Ji Guo Su Sen Sen Yang Xiangfeng Cong Yao Tan Wenwen Lei Xue Jun Gao Zhiwei Jiang Hui Wang Meng Li Hanadi Mekki Mekki Walid Zaher Sally Mahmoud Xue Zhang Chang Qu Dan Ying Liu Jing Zhang Mengjie Yang Islam Eltantawy Peng Xiao Fu Jie Shen Jin Juan Wu Zi Bo Han Li Fang Du Fang Tang Shi Chen Zhi Jing Ma Fan Zheng Ya Nan Hou Xin Yu Li Xin Li Zhao Nian Wang Jin Liang Yin Xiao Yan Mao Jin Zhang Liang Qu Yun Tao Zhang Xiao Ming Yang Guizhen Wu Qi Ming Li 2023Signal Transduction and Targeted Therapy2023,8,2:0
14A Retrospective Modeling Study of the Targeted Non-Pharmaceutical Interventions During the Xinfadi Outbreak in the Early Stage of the COVID-19 Pandemic — Beijing, China, 2020显示文摘Summary What is already known about this topic?China has repeatedly contained multiple severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)outbreaks through a comprehensive set of targeted nonpharmaceutical interventions(NPIs).However,the effectiveness of such NPIs has not been systematically assessed.Yan Wang Kaiyuan Sun Yang Pan Lan Yi Da Huo Yanpeng Wu Shuaibing Dong Jinxin Guo Xiangfeng Dou Wei Wang Shuangsheng Wu Xufang Bai Hongjie Yu Quanyi Wang 2023China CDC weekly2023,5,5:0
15Tuning the Oxygen Anionic Redox Reversibility in Na_(0.67)Mn_(0.8)Fe_(0.1)Co_(0.1)O_(2)Through Sn Doping显示文摘Oxygen anion redox chemistry in layered oxide cathodes for sodium-ion batteries has attracted great interest.However,the release of lattice oxygen caused by the irreversible anionic redox and Jahn–Teller effect accelerates the structural distortion and electrochemical degradation.Herein,we rationally construct a stable crystal lattice to enhance the reactivity and reversibility of oxygen redox and inhibit the Jahn–Teller effect by Sn doping.The stronger binding energy of Sn–O enhances the structural stability of the cathode,which is favorable to suppress the oxygen release and Jahn–Teller effect.Thus,the reversibility of oxygen redox and the stability of the layered structure are enhanced.The expansion of the interlayer spacing decreases the energy barriers for Na+ion intercalation,improving the rate performance of the electrode.Benefitting from the rational design,the electrode delivers an enhanced rate performance and cycling stability.This work offers some insights into tuning the oxygen anion redox chemistry as well as suppressing the Jahn–Teller effect by lattice modulation.Huibo Wang Ling Li Wenze Han Hao Guo Ivan ABobrikov Yujun Chai Xiangfeng Liu 2023Renewables2023,1,2:0
16Reliability assessment for serviceability limit states of stiffened deep cement mixing column-supported embankments显示文摘The reliability and deterministic analyses of wood-cored stiffened deep cement mixing and deep cement mixing column-supported embankments(referred to as WSCSE and DCSE,respectively)considering serviceability limit state requirements are presented in this paper.Random field theory was used to simulate the spatial variability of soilcement mixing(SCM)material in which the adaptive Kriging Monte Carlo simulation was adopted to estimate the failure probability of a columnsupported embankment(CSE)system.A new method for stochastically generating random values of unconfined compressive strength(qu)and the ratio(Ru)between the undrained elastic modulus and qu of SCM material based on statistical correlation data is proposed.Reliability performance of CSEs concerning changes in the mean(μ),coefficient of variation(CoV),and vertical spatial correlation length(θv)of qu and Ru are presented and discussed.The obtained results indicate that WSCSE can provide a significantly higher reliability level and can tolerate more SCM material spatial variability than DCSE.Some performance of DCSE and WSCSE,which can be considered satisfactory in a deterministic framework,cannot guarantee an acceptable reliability level from a probabilistic viewpoint.This highlights the importance and necessity of employing reliability analyses for the design of CSEs.Moreover,consideration of only μ and CoV of qu seems to be sufficient for reliability analysis of WSCSE while for DCSE,uncertainties regarding the Ru(i.e.both μ and CoV)and θv of qu cannot be ignored.Chana Phutthananon Pornkasem Jongpradist Kangwan Kandavorawong Daniel Dias Xiangfeng Guo Pitthaya Jamsawang 2023Journal of Rock Mechanics and Geotechnical Engineering2023,15,9:0
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