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Oxidation resistant low-alloyed Ti alloys with good ductility

Rare Metals 2024年第8期43卷 3921-3936页

作者： Meng li Zhang-Zhi Shi jun-Yi Xu Fu-Zhi Dai xiang-Min li Zi-lin li Lu-Ning Wang Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advance Metals and MaterialsSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Oxidation resistance enhancement of pure Ti often comes at the cost of reduced ductility,which is frequently the problem through alloying with sole Al,Si,W,Mo and *** overcome the short coming of single element alloying,this paper proposes a multi-element low-alloying strategy to take advantage of synergistic effects and resolve the conflict between oxidation resistance and *** demonstrates that the addition of a small quantity of Ta(0.51wt%)can boost both oxidation resistance and ductility in comparison to pure ***,the combined addition of a small amount(0.54 wt%)of Ta,Nb and Si not only preserves good ductility of pure Ti,but also reduces mass gains to 14%-67%of pure Ti during 100 h oxidation at 650-850℃in *** indicates even better oxidation resistance than that obtained through the use of Ta,Nb,or Nb+Ta *** Ta+Nb+Si alloying creates an oxide layer that is less porous and more resistant to stratification and ***,a 3-μm N-rich layer can form in the Ti substrate beneath the oxide scale,in which phase transformation generates coherent Ti_(2)N with(0001)_(Ti)as the habit plane,with N atoms prefers to diffuse along■than along[0001]_(Ti).The completely transformed Ti_(2)N region or partially transformed Ti+Ti_(2)N region can effectively impede oxygen ***,the multielement low-alloying strategy is promising for enhancing both oxidation resistance and mechanical properties of metallic materials in the future.

关键词： Ti alloys Multi-element Co-alloying Oxidation resistance Mechanical properties

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MR diffusion-weighed imaging of rabbit liver

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World Journal of Gastroenterology 2005年第35期11卷 5506-5511页

作者： You-Hong Yuan En-Hua Xiao Zhong He jun xiang Ke-li Tang Rong-Hua Yan Ke Jin Zi-Wen Peng Departmentof Radiology the Second Xiangya Hospital Central South University Changsha410011 Hunan Province China

AIM： To study the techniques of MR diffusion-weighed imaging （DWI） for normal rabbit liver. METHODS： After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesthetized with 30 soluble pentobarbitone, DWI was performed respectively for different b values, repetition times （TR） or thicknesses, when other parameters were the same and magnetic resonance imaging （MRI） was performed respectively, or with different field of views （FOV） or coil when other parameters were the same. The distinction between groups was analyzed by SPSS10.0 with apparent diffusion coefficient （ADC）, quality index （QI） or signal-noise ratio （SNR）. RESULTS： As b value increased, liver ADC, QI and SNR of DWI became smaller and simultaneously （F= 292.87, 156.1, 88.23, P〈0.01）. QI of DWI was high, when bvalue was 10, 50 or 100 respectively, but the distinction between them was insignificant; when b value was 800, QI and SNR of DWI were low. QI and SNR of DWI had no significant difference between TR = 4 000, 6 000 and 8 000. QI of DWI with 2 mm thickness was bigger than that with 5 mm thickness （t = 3.04, P〈0.01）, but SNR of DWI with 2 mm thickness was significantly smaller （t = -17.86, P〈0.01）. SNR of MRI with knee joint coil was obviously bigger than that with cranium coil It = -5.77 （TlWI） or -4.02 （T2WI）, P〈0.01], but QI of MRI was smaller on the contrary It = 7.10 （TlWI） or 3.97 （T2WI）, P〈0.01]. When FOV was enlarged gradually, SNR of MRI increased IF= 85.81 （T1WI） or 221.96 （T2WI）, P〈0.01], but QI firstly increased, then decreased IF= 68.67 （TlWI） or 69.46 （T2WI）, P〈0.01] and QI of MRI was the biggest when FOV was 20 crux15 cm. CONCLUSION： The scanning technique is very important in DWl of rabbit liver and the overall quality of DWl with b （100 s/mm2）, thickness （2 mm）, cranium coils and FOV（20 cm×15 cm） was best in our study, when other parameters were the same.

关键词： liver Rabbits Magnetic resonance imaging Diffusion-weighted imaging Technology

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A general synthetic strategy for N, P co-doped graphene supported metal-rich noble metal phosphides for hydrogen generation

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Green Energy & Environment 2024年第1期9卷 152-162页

作者： Jingwen Ma xiang li Guangyu Lei jun Wang Juan Wang Jian liu Ming Ke Yang li Chunwen Sun School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Lab of Advanced Nano-structures&Transfer Processes Department of Chemical EngineeringTianjin UniversityTianjin300354China PetroChina Planning and Engineering Institute Beijing100083China

The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a *** have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction ***,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked *** obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/*** addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,*** superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the ***,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for *** work provides an effective strategy for designing NMP-based electrocatalysts.

关键词： Noble metal phosphides Electrocatalyst Deoxyribonucleic acid Hydrogen evolution pH universal

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Construction of daily precipitation series and the observational characteristics of extreme precipitation in Tianjin,China during 1888-2022

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Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： Peng SI Qing-xiang li Xiao-Yang CHEN Min WANG Chuan-jun LUO Tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for Tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the Tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in Tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

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Perfect digital holographic imaging with high resolutionusing a submillimeter-dimension CCD sensor

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Frontiers of physics 2016年第6期11卷 149-158页

作者： Hua-Ying Wang Nan-Yah Xiong jun-xiang li Zhao Dong Xia-Nan Jiang Feng Fan Ya-Guang Geng Qiao-Fen Zhu College of Science Hebei University of Engineering Handan 056038 China College of Medicine Hebei University of Engineering Handan 056038 China College of Clinical Medicine Hebei University of Engineering Handan 056038 China Hebei Hanguang Industry Company limited Handan 056028 China

In order to improve the resolution of digital holography with a common-dimension charge-coupled device (CCD) sensor, the point spread functions are briefly derived for the commonly used and practical post-magnification, pre-magnification, and image-plane digital holographic microscopic systems. The ultimate resolutions of these systems are analyzed and compared. The results show that the ultimate lateral resolution of pre-magnification digital holography is superior to that of post-magnification digital holography in the same conditions. We also demonstrate that the ultimate lateral resolution of image-plane digital holography has no correlation with the photosensitive dimension of the CCD sensor, and it is not significantly related to the pixel size of the sensor. Moreover, both the ultimate resolution and the imaging quality of image-plane digital holography are superior to that of pre- and post-magnification digital holographic microscopy. High-resolution imaging, whose resolution is close to the ultimate resolution of the microscope objective, can be achieved by image-plane digital holography even with a submillimeter-dimension sensor. This system, by which perfect imaging can be achieved, is optimal for commonly used digital holographic microscopy. Experimental results demonstrate the correctness of the theoretical analysis.

关键词： digital holography digital holographic microscopy image-plane digital holography ultimate lateral resolution small-dimension CCD

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Demonstration of safety characteristics and effects on gut microbiota of Lactobacillus gasseri HMV18

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Food Science and Human Wellness 2024年第2期13卷 611-620页

作者： Xianxian Jia Miaomiao Jia xiang Gao xiang li Mengyuan Wang Shengqiang Du Rui Huang Xiaotong li jun Zhang Shujin li Chunling Ma Yan Zhang Bin Cong Department of Pathogen Biology Institute of basic MedicineHebei Medical UniversityShijiazhuang 050017China Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology Chinese Academy of Medical SciencesShijiazhuang 050017China Institute of Basic Medicine Hebei Medical UniversityShijiazhuang 050017China College of Forensic Medicine Hebei Key Laboratory of Forensic MedicineCollaborative Innovation Center of Forensic Medical Molecular IdentificationHebei Medical UniversityShijiazhuang 050017China Hebei Food Safety Key Laboratory Hebei Food Inspection and Research InstituteShijiazhuang 050227China

Human normal flora is a source of *** safety characteristics of a specific isolate determine its application in foods or *** food-borne-pathogen antagonist strain Lactobacillus gasseri HMV18 is one of the isolates from normal human *** this work,we assessed the in vitro pH tolerance,bile tolerance,biogenic amine production,mucin utilization,and safety of in vivo administration to mice to evaluate general health,organ-body weight index,organ histopathological change,whether *** HMV18 can colonize in the gut or modulate the gut microbiota after oral *** results suggest that *** HMV18 can tolerate pH 3 for 2 h,3%bile for 3 h,biogenic amine negative,mucin usage negative,does not encode verified toxins,and cause no visible change in mice's *** HMV18 might not colonize in mice's gut,but can significantly affect the structure of gut microbiota.A bibliographical survey suggested that there were as few as 8 opportunistic infection cases from 1984 to 2022 and that the possibility for *** to cause infection is relatively ***,this work provides a basis for the foods or drugs application of *** HMV18 and gives a map of experiments for the safety assessment of probiotics.

关键词： Probiotics Lactobacillus gasseri Safety assessment Gut microbiota

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Continuous Orbit Equivalence of Semigroup Actions

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1581-1598页

作者： xiang Qi QIANG Cheng jun HOU School of Mathematical Science Yangzhou UniversityYangzhou 225002P.R.China

We introduce notions of continuous orbit equivalence and its one-sided version for countable left Ore semigroup actions on compact spaces by surjective local homeomorphisms,and characterize them in terms of the corresponding transformation groupoids and their operator *** particular,we show that two essentially free semigroup actions on totally disconnected compact spaces are continuously orbit equivalent if and only if there is a canonical abelian subalgebra preserving C^(∗)-isomorphism between the associated transformation groupoid C^(∗)-*** also give some examples of orbit equivalence,consider the special case of semigroup actions by homeomorphisms and relate continuous orbit equivalence of semigroup actions to that of the associated group actions.

关键词： Semigroup action continuous one-sided orbit equivalence continuous orbit equivalence groupoid C^(∗)-algebras

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In situ modification of heavy oil catalyzed by nanosized metal-organic framework at mild temperature and its mechanism

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Chinese Journal of Chemical Engineering 2024年第3期67卷 166-173页

作者： li Wang Ji-xiang Guo Rui-Ying Xiong Chen-Hao Gao Xiao-jun Zhang Dan Luo The Unconventional Oil and Gas Institute China University of Petroleum-BeijingBeijing 102200China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Two catalysts, nano-sized cobalt-metal-organic framework(Co-MOF) and nickel(Ni)-MOF, were successfully prepared by the modification method. Tetralin(C10H12) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures(<300°C), leading to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was 0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280°C, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50°C from 15761.9 m Pa.s to 1266.2 m Pa.s,with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 m Pa.s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon-carbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

关键词： Nano-sized MOF Petroleum Viscosity reduction Catalyst Nanomaterials

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A nano-sheet graphene-based enhanced thermal radiation composite for passive heat dissipation from vehicle batteries

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Nano Materials Science 2024年第4期6卷 443-455页

作者： Ji-xiang Wang Christopher Salmean Jiaxin li Chaojie Lei jun li Mingliang Zhong Bo Qi Yufeng Mao Hebei Key Laboratory of Man-machine Environmental Thermal Control Technology and Equipment Hebei Vocational University of Technology and Engineering College of Electrical Energy and Power EngineeringYangzhou University Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and Technology Taizhou Wavexploration Energy Ltd. Department of Electrical and Computer Engineering University of Toronto China Academy of Launch Vehicle Technology Beijing Sino-Spark Technology Co. Ltd. School of Environmental Science and Engineering Suzhou University of Science and Technology Institute of Optics and Electronics Chinese Academy of Sciences National Key Laboratory of Optical Field Manipulation Science and Technology Chinese Academy of Sciences

In response to thermal runaway(TR) of electric vehicles, recent attention has been focused on mitigation strategies such as efficient heat dredging in battery thermal management. Thermal management with particular focus on battery cooling has been becoming increasingly significant. TR usually happened when an electric vehicle is unpowered and charged. In this state, traditional active battery cooling schemes are disabled, which can easily lead to dangerous incidents due to loss of cooling ability, and advanced passive cooling strategies are therefore gaining importance. Herein, we developed an enhanced thermal radiation material, consisting of ～1 μm thick multilayered nano-sheet graphene film coated upon the heat dissipation surface, thereby enhancing thermal radiation in the nanoscale. The surface was characterized on the nanoscale, and tested in a battery-cooling *** found that the graphene-based coating's spectral emissivity is between 91 % and 95 % in the mid-infrared region, and thermal experiments consequently illustrated that graphene-based radiative cooling yielded up to15.1 % temperature reduction when compared to the uncoated analogue. Using the novel graphene surface to augment a heat pipe, the temperature reduction can be further enlarged to 25.6 %. The new material may contribute to transportation safety, global warming mitigation and carbon neutralization.

关键词： Battery thermal management Nano-sheet graphene Functional material Passive cooling Thermal radiation

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Serum metabolic profiling of traditional Chinese medicine syndromes in patients with diarrhea-predominant irritable bowel syndrome

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Journal of Integrative Medicine 2021年第3期19卷 274-281页

作者： Si-qi Tang Yun-liang Wang Zi-ye Xie Yang Zhang Yi Guo Kang-li Gao Tang-you Mao Chun-e Xie jun-xiang li Xiao-yan Gao School of Chinese Material Medica Beijing University of Chinese MedicineBeijing 102488China Gastroenterology Department Dongfang HospitalBeijing University of Chinese MedicineBeijing 100078China Gastroenterology Department Dongzhimen HospitalBeijing University of Chinese MedicineBeijing 100700China Gastroenterology Department First Affiliated HospitalAnhui University of Chinese MedicineHefei 230031Anhui ProvinceChina

Objective:The clinical symptoms of diarrhea-predominant irritable bowel syndrome(IBS-D)can be effectively improved by traditional Chinese medicine(TCM)treatment,based on the usage of specific therapies for different TCM ***,in the stage of diagnosis,the standard criteria for the classification of TCM syndrome were still *** serum metabolic profiling,this study aimed to explore potential biomarkers in IBS-D patients with different TCM syndromes,which can assist in diagnosis of the ***:Serum samples were collected from healthy controls(30 cases),IBS-D patients with liverStagnation and Spleen-Deficiency syndrome(LSSD,30 cases),Yang Deficiency of Spleen and Kidney syndrome(YDSK,11 cases)and Damp Abundance due to Spleen-Deficiency syndrome(DASD,22 cases).Serum metabolic profiling was conducted by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass *** potential biomarkers were screened by orthogonal partial least square-discriminate analysis,while metabolic pathways undergoing alterations were identified by pathway enrichment analysis in Metabo Analyst ***:Overall,34 potential biomarkers were identified in LSSD group,36 in YDSK group and 31 in DASD *** the 13 metabolites shared by three groups were determined as the potential biomarkers of *** metabolism was disturbed significantly in IBS-D patients,which may play a role in IBS-D through ***’s more,three TCM syndromes have the specific potential biomarkers in glycerophospholipid ***:The serum metabolomics revealed that different TCM syndrome types in IBS-D may have different metabolic patterns during disease progression and glycerophospholipid metabolism was one of the pathways,whose metabolism was disturbed differently among three TCM syndromes in ***,the specific potential biomarkers in glycerophospholipid metabolism of three TCM syndromes in IBS-D can serv

关键词： Diarrhe Irritable bowel syndrome Metabolomics Traditional Chinese medicine syndromes

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