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Fabrication and evaluation of high-performance 3D interpenetrated network structures SiC/Al composites with high-purity plate-like a-SiC framework

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Journal of Materiomics 2024年第2期10卷 499-510页

作者： Jiawei Xie Jinhui Zou liangcheng Tong Syiel.ing Wong Xin guo Hang Qin Pengzhao Gao Wenming guo Hanning Xiao College of Materials Science and Engineering Hunan UniversityChangsha410082China Department of Chemical Engineering and Chemistry Eindhoven University of TechnologyEindhoven5612 AZNetherlands College of Automation and information Engineering Xi'an University of TechnologyXi'an710048China

To reinforce compatibility with the thermophysical and mechanical properties of SiC/Al composites for electronic packaging to improve the stability and reduce fatigue failure of electronic integrated devices,a novel 3D SiC reinforced framework with interpenetrated plate-like a-SiC grains was synthesized.A small amount of doped a-SiC was seeded to induce the transformation of b-SiC to plate-like a-SiC at 2,300℃,forming a high-purity a-SiC strongly bonded ***/gas pressure infiltration of Al alloy was subsequently used to manufacture the 3D interpenetrated network structure SiC/Al(SiC3D/Al)*** results showed that 15%(in mass)seeds provided the composite with the optimal comprehensive performance,including a low coefficient of thermal expansion(CTE)of 5.54×10^(-6)K^(-1),a high thermal conductivity(l)of 239.08 W·m^(-1)·K^(-1),the highest flexural strength of 326.84 MPa,and a low thermal deformation parameter(TDP)of ***-purity plate-like grains enhanced the purity of the framework promoting a significant improvement in *** the seed content increased to 20%(in mass),both CTE and l reached optimal values of 5.22×10^(-6)K^(-1)and 243.14 W·m^(-1)·K^(-1),but the mechanical properties declined by 10.30%.The synergistic effect of the well-bonded interface and the high-purity 3D SiC framework balanced excellent mechanical properties and mul.iple thermal functions.

关键词： α-SiC seed Phase transformation Thermophysical properties SiC_(3D)/Al composites Electronic packaging

An active learning workflow for predicting hydrogen atom adsorption energies on binary oxides based on local electronic transfer features

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Green Energy & Environment 2024年第10期9卷 1489-1496页

作者： Wenhao Jing Zihao Jiao Mengmeng Song Ya liu liejin guo international Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Department of Energy and Power Engineering Shandong University of Technology

Machine learning combined with density functional theory（DFT） enables rapid exploration of catalyst descriptors space such as adsorption energy, facilitating rapid and effective catalyst screening. However, there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination environment. This work proposes an active learning workflow（le NN） founded on local electronic transfer features（e） and the principle of coordinate rotation invariance. By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures, le NN mitigates abrupt feature changes due to different element types and clarifies coordination environments. As a result, it enables the prediction of *H adsorption energy on binary oxide surfaces with a mean absolute error（MAE） below 0.18 e V. Moreover, we incorporate local coverage（θl） and leverage neutral network ensemble to establish an active learning workflow, attaining a prediction MAE below 0.2 e V for 5419 mul.i-*H adsorption structures. These findings validate the universality and capability of the proposed features in predicting *H adsorption energy on binary oxide surfaces.

关键词： Machine learning Adsorption energy Binary oxide Electron transfer Active learning

impacts of inter-satel.ite links on the ECOM model performance for BDS-3 MEO satel.ites

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Satel.ite Navigation 2024年第1期5卷 140-154页

作者： Chao Yang Jing guo Xiaolong Xu longyu Wang Qile Zhao GNSS Research Center Wuhan UniversityNo.129 Luoyu RoadWuhan430079China

inter-satel.ite link(iSl)plays an essential role in current and future Global Navigation Satel.ite System(GNSS).in this study,we investigate the impact of iSl observations on precise orbit determination for BeiDou-3 Navigation Satel.ite System(BDS-3)Medium Earth Orbit(MEO)satel.ites based on different Extended CODE Orbit Models(ECOM).Thanks to the better observation geometry of the Ka-band iSl data compared to the l-band data for BDS-3 MEO satel.ites,the iSl solution substantially reduces Orbit Boundary Discontinuity(OBD)errors,except for C30,which suffers from unstable Ka-band hardware *** the external quality analysis,iSl significantly enhances the reliability of the orbit of MEO satel.ites manufactured by the China Academy of Space Technology(CAST).The standard deviation(STD)of the satel.ite laser ranging(SlR)residuals is approximately 2.5 cm,and the root mean square(RMS)is reduced by 10–23%compared to l-band ***,the Sun-elongation angle dependent systematic error in SlR residuals nearly vanishes based on the reduced 5-parameter ECOM(ECOM1)or extended 7-parameter ECOM(ECOM2)with iSl *** is because the iSl reduces the correlation between state parameters and solar radiation pressure(SRP)parameters as well as those among SRP parameters,leading to a more accurate estimation of both orbit and SRP perturbations,particularly those along B *** confirms that the deficiency of the SRP models for BDS-3 CAST satel.ites can be compensated by using better observation geometry from iSl *** the other hand,for the satel.ite manufactured by Shanghai Engineering Center for Microsatel.ites(SECM),the iSl allows for a more accurate estimation of the Bc_(1)parameter in the ECOM1 *** only reduces linear systematic error,possibly because the impact generated by the satel.ite bus cannot be entirely absorbed by the B-direction parameters.

关键词： BDS-3 MEO inter-satel.ite link Solar radiation pressure ECOM

Glacial.interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

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Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan ZHANG Chunxia ZHANG Yan ZHAO Bin HU Zhengtang guo Key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key laboratory of land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the ***,high-al.itude clay mineral.indications and long-term and orbital variations have not been fully ***,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core *** results revealed that the clay minerals in core ZB13-C2 are mainly il.ite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of il.ite-smectite(i/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate *** watershed was limited to the southeastern region with al.itudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial.interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka *** expanded to higher al.itudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial.interglacial variations under a cooling and drying climate during 621-100 ka ***,it expanded to its highest al.itudes of~4700 to~5200 m *** of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MiS 3 on the *** watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka *** results reveal that long-term temperature changes and the wet/dry alternation at high al.itudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especi

关键词： Quaternary Zoige Basin lacustrine sediments Paleoenvironment Weathering

A highly sensitive fluorescent HClO probe for discrimination between cancerous and normal cells/tissues

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Chinese Chemical letters 2024年第6期35卷 417-420页

作者： linfang Wang Jing liu Minghao Ren Wei guo Department of Chemistry Changzhi UniversityChangzhi 046011China School of Chemistry and Chemical Engineering Shanxi UniversityTaiyuan 030006China

Elevated level of hypochlorous acid(HClO)is closely associated with cancer *** HClO level.in cancer cells would provide important evidence in either early-stage cancer diagnostics or monitoring of its treatment *** this work,a new pyronine-based fluorescent probe for rapid and sensitive detection of HClO was developed by condensing meso-formyl pyronine(PyCHO)with 2-hydrazinopyridine to form meso-pyridylhydrazone-functionalized pyronine PyHP,PyHP is nonfluorescent due to the excited-state C=N isomerization nonradiative decay,whereas the HClO-triggered formation of meso-triazolopyridyl pyronine PyTP abolishes the C=N isomerization and thus greatly enhances the *** the probe,the cancer cells/tumor were distinguished with high-contrast from normal ones by laser confocal fluorescence imaging,and the tumor-to-normal(T/N)ratios obtained exceed the clinically acceptable threshold of ***,its capability of in vivo imaging tumor was also *** results indicate the potential of PyHP as an effective tool.in the early clinical diagnosis of cancers.

关键词： Meso-pyridylhydrazone-functionalized pyronine Meso-substituents Tumor-to-normal(T/N)ratios Fluorescent probes Hypochlorous acid

Crystal.ine-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang Xiao-Chuan Duan Shao-Hui guo Xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystal.ine-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal.ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystal.ine M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystal.ine *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·l^(-1)H_(2)SO_4 and1.0 mol·l^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystal.ine-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts iron group metals Heterojunction Crystal.ine-amorphous structure

Microbiomics and metabolomics insights into the microbial regulation on the formation of flavor components in the traditional fermentation process of Chinese Hongqu aged vinegar

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Food Science and Human Wellness 2024年第5期13卷 2765-2778页

作者： Shangong Tong Wenlong li Yuandong Rao Yanqin Xiao Yingyin Yan Weiling guo Xucong lü Jinyuan Sun lianzhong Ai li Ni institute of Food Science and Technology College of Biological Science and EngineeringFuzhou UniversityFuzhou 350108China Food Nutrition and Health Research Center School of Advanced ManufacturingFuzhou UniversityJinjiang 362200China School of Food Science and Technology Jiangnan UniversityWuxi 214122China Beijing laboratory for Food Quality and Safety Beijing Technology and Business UniversityBeijing 100048China School of Health Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China

This study aimed to investigate microbial succession and metabolic dynamics during the traditional fermentation of Hongqu aged vinegar,and explore the core functional microbes closely related to the formation of flavor *** analysis demonstrated that lactobacillus,Acetobacter,Bacillus,Enterobacter,lactococcus,leuconostoc and Weissella were the predominant bacterial genera,while Aspergillus piperis,Aspergillus oryzae,Monascus purpureus,Candida athensensis,***,Penicil.ium ochrosalmoneum and Simplicil.ium aogashimaense were the predominant fungal *** analysis revealed that Acetobacter was positively correlated with the production of tetramethylpyrazine,acetoin and acetic acid,lactococcus showed positive correlation with the production of 2-nonanone,2-heptanone,ethyl caprylate,ethyl caprate,1-hexanol,1-octanol and 1-octen-3-ol,*** and *** were positively associated with the production of diethyl malonate,2,3-butanediyl diacetate,acetoin,benzaldehyde and ***,non-volatile metabolites were also detected through ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.A variety of amino acids and functional dipeptides were identified during the traditional brewing of Hongqu aged *** analysis revealed that lactobacillus was significantly associated with Dl-lactate,indolelactic acid,D-(+)-3-phenyllactic acid,pimelic acid,pregabalin and 3-aminobutanoic *** study is useful for understanding flavor formation mechanism and developing effective strategies for the suitable strains selection to improve the flavor quality of Hongqu aged vinegar.

关键词： Hongqu aged vinegar Traditional fermentation Microbial dynamics Flavor components Bidirectional orthogonal partial least squares

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Fight or flee,a vital choice for Clostridioides difficile

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mlife 2024年第1期3卷 14-20页

作者： Ji Zeng Sshuying Fang Jinquan guo Min Dong guo-Bao Tian liang Tao School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhouChina Department of Brest Surgery Panyu Central Hospital.GuangzhouChina Department of Microbiology Harvard Medical SchoolBostonMassachusettsUSA Department of Urology Boston Children's HospitalHarvard Medical SchoolBostonMassachusettsUSA Department of Microbiology Zhongshan School of MedicineSun Yat-sen UniversityGuangzhouChina Advanced Medical Technology Center The First Affiliated HospitalZhongshan School of MedicineSun Yat-sen UniversityGuangzhouChina Key laboratory of Tropical Diseases Control(Sun Yat-sen University) Ministry of EducationGuangzhouChina School of Medicine Xizang Minzu UniversityXianyangChina Center for infectious Disease Research Westlake Laboratory of Life Sciences and BiomedicineWestlake UniversityHangzhouChina Research Center for industries of the Future School of Life SciencesWestlake UniversityHangzhouChina

Clostridioides difficile is a leading cause of healthcare-associated infections,causing bil.ions of economic losses every *** symptoms range from mild diarrhea to life-threatening damage to the *** and recurrence of *** infection(CDl)are mediated by the metabolically dormant spores,while the virulence of *** is mainly due to the two large clostridial toxins,TcdA and *** toxins or forming spores are two different strategies for *** to cope with harsh environmental *** is of great significance to understand the molecular mechanisms for *** to skew to either of the cellular ***,we summarize the current understanding of the regulation and connections between toxin production and sporulation in *** and further discuss the potential solutions for yet-to-be-answered questions.

关键词： C.difficile sporulation TcdA TcdB toxin production

透射式GaAs光电阴极性能提高以及结构优化

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物理学报 2024年第3期73卷 266-272页

作者：吕行富容国常本康郭欣王芝南京理工大学电子工程与光电技术学院南京210094 昆明物理研究所昆明650221 西安应用光学研究所西安710065

为了提高透射式GaAs光电阴极性能,将国内与美国iTT公司的透射式GaAs光电阴极量子效率曲线进行对比,可知我国透射式光电阴极积分灵敏度已经达到2130μA/lm,美国iTT达到了2330μA/lm.利用修正后的量子效率、光学性能以及积分灵敏度的理论... 详细信息

为了提高透射式GaAs光电阴极性能,将国内与美国iTT公司的透射式GaAs光电阴极量子效率曲线进行对比,可知我国透射式光电阴极积分灵敏度已经达到2130μA/lm,美国iTT达到了2330μA/lm.利用修正后的量子效率、光学性能以及积分灵敏度的理论模型,分别对两者进行光学结构拟合.结果表明,国内光电阴极在窗口层和发射层的厚度、电子扩散长度以及后界面复合速率等方面均与iTT有一定差距.为了缩短两者的差距,优化阴极结构参数,具体研究了电子扩散长度和发射层厚度对量子效率的影响,结果表明如果均匀掺杂透射式GaAs光电阴极发射层厚度为1.3μm、电子扩散长度为7μm,则积分灵敏度可以达到2800μA/lm以上.

关键词： Ga As光电阴极透射式结构优化光学性能光电发射性能

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