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Frontiers of Materials Science 2024年第2期18卷 61-74页

作者： Jie Meng Hongmei Liu Sainan Zhang Baogui Ye Min Feng Daoai Wang School of Chemistry and Chemical Engineering Lanzhou Jiaotong UniversityLanzhou 730000China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Qingdao Centerof Resource Chemistry and New Materials Qingdao 266100China Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 265503China

The solar-to-hydrogen conversion using the photoelectrochemical(PEC)method is a practical approach to producing clean ***,it relies on the availability of photocatalyst *** this work,a novel photocatalyst comprising molybdenum telluride quantum dots(MoTe_(2) QDs)-modified titanium dioxide nanorods(TiO_(2) NRs)was prepared for the enhancement of the PEC water splitting performance after combination with a Al_(2)O_(3) layer using the atomic layer deposition(ALD)***_(2) QDs were initially prepared,and then they were loaded onto TiO_(2) NRs using a warm water bath-based heating *** a layer of Al_(2)O_(3) was deposited onto resulted TiO_(2) NRs/MoTe_(2) QDs,the composite TiO_(2) NRs/MoTe_(2) QDs/Al_(2)O_(3) was finally *** simulated sunlight(100 mW·cm^(-2)),such a composite exhibited a maximum photocurrent density of 2.25 mA·cm^(-2) at 1.23 V(versus RHE)and an incident photon-to-electron conversion efficiency of 69.88%at 380 nm,which are 4.33 and 6.66 times those of pure TiO_(2) NRs,***,the composite photocatalyst fabricated in this work may have promising application in the field of PEC water splitting,solarcells andotherphotocatalyticdevices.

关键词： MoTe_(2)quantum dot TiO_(2)nanorod Al_(2)O_(3) atomic layer deposition photoelectrochemistry

Invisible and semi-invisible decays of bottom baryons

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Chinese Physics C 2024年第8期48卷 127-139页

作者： Yong Zheng Jian-Nan Ding Dong-Hao Li Lei-Yi Li Cai-Dian Lü Fu-Sheng Yu MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Center for High Energy Physics Peking UniversityBeijing 100871China Institute of High Energy Physics CASBeijing 100049China School of Physical Sciences University of Chinese Academy of SciencesBeijing 101408China

The similar densities of dark matter and baryons in the universe imply that they may arise from the same ultraviolet model.B-Mesogenesis,which assumes dark matter is charged under the baryon number,attempts to simultaneously explain the origin of baryon asymmetry and dark matter in the *** particular,B-Mesogenesis may induce bottom-baryon decays into invisible or semi-invisible final states,which provide a distinctive signal for probing this *** this work,we systematically study the invisible decays of bottom baryons into dark matter and the semi-invisible decays of bottom baryons into a meson or a photon together with a dark matter *** particular,the fully invisible decay can reveal the stable particles in *** QCD-based frameworks are used to calculate the hadronic matrix elements under the B-Mesogenesis *** estimate the constraints on the Wilson coefficients or the product of some new physics couplings with the Wilson coefficients according to the semi-invisible and invisible decays of bottom baryons detectable at future colliders.

关键词： baryon asymmetry dark matter B-Mesogenesis invisible and semi-invisible decay bottom baryons

Phylotranscriptomic discordance is best explained by incomplete lineage sorting within Allium subgenus Cyathophora and thus hemiplasy accounts for interspecific trait transition

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Plant Diversity 2024年第1期46卷 28-38页

作者： Zengzhu Zhang Gang Liu Minjie Li State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems College of EcologyLanzhou UniversityLanzhou 730000GansuPR China

The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and *** can be learned about this process from phylogeny-based trait ***,such inference is often plagued by genome-wide gene-tree discordance(GTD),mostly due to incomplete lineage sorting(ILS)and/or introgressive hybridization,especially when the genes underlying the traits appear ***,by collecting transcriptomes,whole chloroplast genomes(cpDNA),and population genetic datasets,we used the coalescent model to turn GTD into a source of information for ILS and employed hemiplasy to explain specific cases of apparent“phylogenetic discordance”between different morphological traits and probable species phylogeny in the Allium *** concatenation and coalescence methods consistently showed the same phylogenetic topology for species tree inference based on single-copy genes(SCGs),as supported by the KS ***,GTD was high across the genomes of ***:~27%e38.9%of the SCG trees were in conflict with the species *** and nuclear incongruence was also *** coalescent simulations indicated that such GTD was mainly a product of *** hemiplasy risk factor calculations supported that random fixation of ancient polymorphisms in different populations during successive speciation events along the *** phylogeny may have caused the character transition,as well as the anomalous cpDNA *** study exemplifies how phylogenetic noise can be transformed into evolutionary information for understanding character state transitions along species phylogenies.

关键词： Hemiplasy Multispecies coalescence Lineage sorting Gene tree discordance Phylotranscriptomics Allium subg.Cyathophora

Response of vegetation variation to climate change and human activities in the Shiyang River Basin of china during 2001-2022

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Journal of Arid Land 2024年第8期16卷 1044-1061页

作者： SUN Chao BAI Xuelian WANG Xinping ZHAO Wenzhi WEI Lemin Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Gansu Provincial Academy of Water Sciences Lanzhou 730000China

Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem ***,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of china during *** climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during *** regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation *** increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation ***-significant decreasing trends were detected in the SVT and SVP of the SYRB during *** were spatial differences in vegetation variation,SVT,and *** NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream *** and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the d

关键词： vegetation variation climate change land use change normalized difference vegetation index(NDVI) enhanced vegetation index(EVI) Shiyang River Basin

Modeling and prediction of tribological properties of copper/aluminum-graphite self-lubricating composites using machine learning algorithms

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Friction 2024年第6期12卷 1322-1340页

作者： Huifeng NING Faqiang CHEN Yunfeng SU Hongbin LI Hengzhong FAN Junjie SONG Yongsheng ZHANG Litian HU School of Electrical and Mechanical Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The tribological properties of self-lubricating composites are influenced by many variables and complex ***-driven methods,including machine learning(ML)algorithms,can yield a better comprehensive understanding of complex problems under the influence of multiple parameters,typically for how tribological performances and material properties *** of friction coefficients and wear rates of copper/aluminum-graphite(Cu/Al-graphite)self-lubricating composites with their inherent material properties(composition,lubricant content,particle size,processing process,and interfacial bonding strength)and the variables related to the testing method(normal load,sliding speed,and sliding distance)were analyzed using traditional approaches,followed by modeling and prediction of tribological properties through five different ML algorithms,namely support vector machine(SVM),K-Nearest neighbor(KNN),random forest(RF),eXtreme gradient boosting(XGBoost),and least-squares boosting(LSBoost),based on the tribology experimental *** demonstrated that ML models could satisfactorily predict friction coefficient and wear rate from the material properties and testing method variables ***,the LSBoost model based on the integrated learning algorithm presented the best prediction performance for friction coefficients and wear rates,with R^(2) of 0.9219 and 0.9243,*** importance analysis also revealed that the content of graphite and the hardness of the matrix have the greatest influence on the friction coefficients,and the normal load,the content of graphite,and the hardness of the matrix influence the wear rates the most.

关键词： self-lubricating composites machine learning(ML) tribological properties prediction

Influence of exchange bias on spin torque ferromagnetic resonance for quantification of spin–orbit torque efficiency

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Chinese Physics B 2024年第5期33卷 688-694页

作者：赵乾张腾飞何斌李子木张森富于国强王建波刘青芳魏晋武 Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou 730000China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Special Functional Materials and Structural Design Ministry of EducationLanzhou UniversityLanzhou 730000China

Antiferromagnet(AFM)/ferromagnet(FM)heterostructure is a popular system for studying the spin–orbit torque(SOT)of ***,the interfacial exchange bias field induces that the magnetization in FM layer is noncollinear to the external magnetic field,namely the magnetic moment drag effect,which further influences the characteristic of SOT *** this work,we study the SOT efficiencies of IrMn/NiFe bilayers with strong interfacial exchange bias by using spin-torque ferromagnetic resonance(ST-FMR)method.A full analysis on the AFM/FM systems with exchange bias is performed,and the angular dependence of magnetization on external magnetic field is determined through the minimum rule of free *** ST-FMR results can be well fitted by this *** obtained the relative accurate SOT efficiencyξ_(DL)=0.058 for the IrMn *** work provides a useful method to analyze the angular dependence of ST-FMR results and facilitates the accurate measurement of SOT efficiency for the AFM/FM heterostructures with strong exchange bias.

关键词： antiferromagnets spin-orbit torque exchange bias spin torque ferromagnetic resonance

Catalytic behavior of Mo-Bi-Fe-Co-K-M-O(M=Ce,Gd,CeGd)catalysts for selective oxidation of isobutene

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Journal of Rare Earths 2024年第1期42卷 84-93,I0003页

作者： Qinghui Li Huahua Zhao Jian Yang Jun Zhao Liang Yan Huanling Song Lingjun Chou State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China

The further improvement of methacrolein(MAL)selectivity from isobutene(IB)oxidation is crucial and *** this study,based on the typical Mo-Bi-Fe-Co-K-O mixed metal oxide,the rare earth element Gd-doped,Ce-doped and CeGd co-doped catalysts were prepared by co-precipitation strategy to increase the selectivity of MAL from 47.9%to 49.8%,64.2% and 68.6%,*** order to elucidate in-depth the promoting effect of Ce and/or Gd,various characterizations were utilized including X-ray diffraction patterns(XRD),Raman,X-ray fluorescence spectrometry(XRF),X-ray photoelectron spectroscopy(XPS),O_(2)-temperature programmed desorption(O_(2)-TPD),H2-temperature programmed reduction(H2-TPR),CO_(2)-temperature programmed desorption(CO_(2)-TPD),IB-temperature programmed desorption(i-C4-TPD)and in-situ IB-Fourier transform infrared spectroscopy(IB-FTIR).Both Ce and Gd finely regulate the bulk and surface structure of the catalyst,thus altering the redox ability,oxygen mobility and storage ability and *** with Ce,Gd addition slightly regulates the variation of Co^(2+)/Co^(3+)redox couples,greatly enhances the interaction among the components on the catalyst,thus only increases the content of surface oxygen species and has little effect on their *** Cecontaining catalyst performs stronger oxygen storage and migration ability,thus leading to the overproduction of surface Odefectspecies,which are proposed to be the active sites for the production of MAL and *** CeGd co-doped catalyst possesses the proper content of surface Odefectspecies,thus exhibits much higher MAL ***,the promoting mechanism of Ce and/or Gd over IB oxidation is ***,this work is helpful for understanding the influence of rare earth elements on the structure of mixed metal oxides and the olefin selective oxidation reaction.

关键词： Mixed metal oxide catalyst Rare earth element Isobutene Selective oxidation Methacrolein

Spatiotemporal Variability and Environmental Controls of Temperature Sensitivity of Ecosystem Respiration across the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第9期41卷 1821-1842页

作者： Danrui SHENG Xianhong MENG Shaoying WANG Zhaoguo LI Lunyu SHANG Hao CHEN Lin ZHAO Mingshan DENG Hanlin NIU Pengfei XU Xiaohu WEN Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Zoige Plateau Wetlands Ecosystem Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Warming-induced carbon loss via ecosystem respiration(R_(e))is probably intensifying in the alpine grassland ecosystem of the Tibetan Plateau owing to more accelerated warming and the higher temperature sensitivity of R_(e)(Q_(10)).However,little is known about the patterns and controlling factors of Q_(10)on the plateau,impeding the comprehension of the intensity of terrestrial carbon-climate feedbacks for these sensitive and vulnerable ***,we synthesized and analyzed multiyear observations from 14 sites to systematically compare the spatiotemporal variations of Q_(10)values in diverse climate zones and ecosystems,and further explore the relationships between Q_(10)and environmental ***,structural equation modeling was utilized to identify the direct and indirect factors predicting Q_(10)values during the annual,growing,and non-growing *** results indicated that the estimated Q_(10)values were strongly dependent on temperature,generally,with the average Q_(10)during different time periods increasing with air temperature and soil temperature at different measurement depths(5 cm,10 cm,20 cm).The Q_(10)values differentiated among ecosystems and climatic zones,with warming-induced Q_(10)declines being stronger in colder regions than elsewhere based on spatial *** was the most cardinal factor in predicting annual Q_(10)values,significantly and positively correlated with Q_(10).Soil temperature(Ts)was identified as the other powerful predictor for Q_(10),and the negative Q_(10)-Ts relationship demonstrates a larger terrestrial carbon loss potentiality in colder than in warmer regions in response to global *** that the interpretations of the effect of soil moisture on Q_(10)were complicated,reflected in a significant positive relationship between Q_(10)and soil moisture during the growing season and a strong quadratic correlation between the two during the annual and non-growing *** findings are conducive to imp

关键词： carbon cycle eddy covariance measurements ecosystem respiration Q_(10)value Tibetan Plateau climate change

Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

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Nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo Nie Yue Zhang Zhi-Jie Hu Qi Zhao Huan-Yu Zhang Kuo-Zhi Xu Shi-Yu Zhang Xin-Yi Pan Chang-Lin Lan Jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the china Institute of Atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data

Modification of POSS and their tribological properties and resistant to space atomic oxygen irradiation as lubricant additive of multialkylated cyclopentanes

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Friction 2024年第5期12卷 884-896页

作者： Xingwei WANG Chaoyang ZHANG Chen ZHAO Yijing LIANG Ming ZHANG Wufang YANG Bo YU Qiangliang YU Meirong CAI Feng ZHOU Weimin LIU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai264000China

Developing functional additive resistant to space atomic oxygen(AO)irradiation through simple molecular design and chemical synthesis to enhance the lubricating performance of multialkylated cyclopentanes(MACs)oil is a significant ***,sulfur-containing polyhedral oligomere silsesquioxane(POSS)were synthesize via a click-chemistry reaction of octavinyl polyhedral oligomeric with alkyl *** reduce-friction(RF),anti-wear(AW)properties and anti-AO irradiation of POSS-S-R as MACs base oil additives in atmospheric and simulated space environments were systematically investigated for the first *** demonstrate that POSS-S-R not only possesses outstanding anti-AO irradiation capacity but also effectively improves the RF and AW of MACs in atmospheric or simulated space *** improvement is due to the excellent anti-AO irradiation properties of the POSS structure itself and the high load-carrying ability of silicon-containing and sulfur-containing compounds generated by tribo-chemical reactions,which effectively separates the direct contact of the friction *** believe that this synthesized POSS-S-R is a promising additive for space lubricants.

关键词： POSS additive reduce-friction anti-wear multialkylated cyclopentanes(MACs) resistant atomic irradiation