期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Ti6Al4V合金表面激光熔覆NiCoCrAlY-B_(4)C复合涂层的结构特征及高温摩擦学性能 被引量:5
1
作者 王文昌 李嘉兴 +1 位作者 葛源 孔德军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第9期2729-2739,共11页
为提高Ti6Al4V合金的硬度和摩擦学性能,采用激光熔覆技术在其表面制备NiCoCrAlY-B_(4)C复合涂层(B_(4)C的质量分数分别为5%、10%和15%)。利用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对所制备涂层的形貌、化学成分和物相进... 为提高Ti6Al4V合金的硬度和摩擦学性能,采用激光熔覆技术在其表面制备NiCoCrAlY-B_(4)C复合涂层(B_(4)C的质量分数分别为5%、10%和15%)。利用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对所制备涂层的形貌、化学成分和物相进行分析,并采用球-盘磨损试验机研究B_(4)C质量分数对NiCoCrAlY-B_(4)C涂层在600℃时摩擦因数和磨损率的影响。结果表明,不同B_(4)C质量分数的NiCoCrAlY-B_(4)C涂层主要由NiTi、NiTi_(2)、α-Ti、CoO、AlB_(2)、TiC、TiB和TiB_(2)物相组成。NiCoCrAlY-B_(4)C涂层的平均摩擦因数和磨损率随着B_(4)C质量分数的增加而有所降低,主要归因于B_(4)C的添加提高了涂层硬度。随着B_(4)C质量分数的增加,NiCoCrAlY-B_(4)C涂层的磨损机制由粘着磨损、氧化磨损转变为疲劳磨损。 展开更多
关键词 TI6AL4V合金 激光熔覆 NICOCRALY涂层 B4C 摩擦行为 磨损
下载PDF
Vocal repertoire of the critically endangered whiteheaded langur(Trachypithecus leucocephalus): Call types, acoustic structures, and related social-ecological contexts 被引量:2
2
作者 Peng-Lai Fan jia-xing li +6 位作者 li-Ting Yang Tao Sun Shi-Jun Wu Cyril CGrueter Cheng-Ming Huang Qi-Hai Zhou Ming li 《Zoological Research》 SCIE CAS CSCD 2022年第5期875-879,共5页
DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in China.We identified 17 call types across all age/sex cla... DEAR EDITOR,We examined the vocal repertoire of the critically endangered white-headed langur(Trachypithecus leucocephalus)inhabiting karst limestone forests in China.We identified 17 call types across all age/sex classes based on human auditory perception,spectrogram assessment,and quantitative analysis of 25 acoustic parameters extracted from 409 high-quality calls.In total,11 types of calls produced by adults corresponded to the simple one-male multi-female social groups of white-headed langurs. 展开更多
关键词 WHITE critically KARST
下载PDF
Nuclear alternating parity bands and transition rates in a model of coherent quadrupole–octupole motion in neutron-rich barium isotopes
3
作者 Xing Zhang Yong Peng +1 位作者 Chao-Biao Zhou jia-xing li 《Nuclear Science and Techniques》 SCIE CAS CSCD 2016年第6期150-154,共5页
Deformed even–even nuclei Barium isotopes with quadrupole–octupole deformations are investigated on the basis of a collective model.The model describes energy levels of the yrast band with alternating parity in the ... Deformed even–even nuclei Barium isotopes with quadrupole–octupole deformations are investigated on the basis of a collective model.The model describes energy levels of the yrast band with alternating parity in the neutron-rich^(140;142;144;146;148)Ba.The structure of the alternating parity bands is examined by odd–even (△I=1) staggering diagrams.An analytical method of the collective model is proposed for the calculation of E2 transition probabilities in alternating spectra of the nuclei^(140;142;144;146)Ba. 展开更多
关键词 运动模型 钡同位素 丰中子同位素 四极 奇偶 校验带 相干 E2跃迁几率
下载PDF
Cradle for the newborn Monochamus saltuarius:Microbial associates to ward off entomopathogens and disarm plant defense
4
作者 Si-Xun Ge jia-xing li +2 位作者 Zhuo-Heng Jiang Shi-Xiang Zong li-li Ren 《Insect Science》 SCIE CAS CSCD 2023年第4期1165-1182,共18页
The Japanese pine sawyer,Monochamus saltuarius,as a beetle vector of Bur-saphelenchus xylophilus(pine wood nematode),is an economically important forest pest in Eurasia.To feed on the phloem and xylem of conifers,M.sa... The Japanese pine sawyer,Monochamus saltuarius,as a beetle vector of Bur-saphelenchus xylophilus(pine wood nematode),is an economically important forest pest in Eurasia.To feed on the phloem and xylem of conifers,M.saltuarius needs to overcome various stress factors,including coping with entomopathogenic bacteria and also various plant secondary compounds(PSCs).As an important adaptation strategy to colonize host trees,M.saltuarius deposit eggs in oviposition pits to shield their progeny.These pits har-bor bacterial communities that are involved in the host adaptation of M.saltuarius to the conifers.However,the composition,origin,and functions of these oviposition pit bacteria are rarely understood.In this study,we investigated the bacterial community associated with M.saltuarius oviposition pits and their ability to degrade PSCs.Results showed that the bacterial community structure of M.saltuarius oviposition pits significantly differed from that of uninfected phloem.Also,the oviposition pit bacteria were predicted to be enriched in PSC degradation pathways.The microbial community also harbored a lethal strain of Serratia,which was significantly inhibited.Meanwhile,metatranscriptome anal-ysis indicated that genes involved in PSCs degradation were expressed complementarily among the microbial communities of oviposition pits and secretions.In vitro degrada-tion showed that bacteria cultured from oviposition pits degraded more monoterpenes and flavonoids than bacteria cultured from uninfected phloem isolates.Disinfection of ovipo-sition pits increased the mortality of newly hatched larvae and resulted in a significant decrease in body weight in the early stages.Overall,our results reveal that M.saltuarius construct oviposition pits that harbor a diverse microbial community,with stronger PSCs degradation abilities and a low abundance of entomopathogenic bacteria,resulting in the increased fitness of newly hatched larvae. 展开更多
关键词 community structure entomopathogenic bacteria host plant adaptation plant secondary metabolites symbiotic bacteria
原文传递
Evaporation residue cross sections of superheavy nuclei based on optimized nuclear data
5
作者 李佳星 张鸿飞 《Chinese Physics C》 SCIE CAS CSCD 2023年第12期124-130,共7页
This study proposes an optimized method for estimating atomic nucleus masses by combining the finiterangedroplet model (FRDM) with the support vector machine algorithm. The optimization process significantly improvest... This study proposes an optimized method for estimating atomic nucleus masses by combining the finiterangedroplet model (FRDM) with the support vector machine algorithm. The optimization process significantly improvesthe accuracy of the FRDM by reducing the root mean square error from 0.606 to 0.253 MeV. The optimizedmass data obtained from this method are then used to calculate the evaporation residue cross-sections (ERCSs) forfusion-evaporation reactions, employing the di-nuclear system model. The experimental results for the 48Ca+238U reactionare relatively well reproduced using these optimized mass data. Additionally, the study investigates the impactof mass uncertainties on fusion and survival probabilities. By considering the mass uncertainties, the ERCSs fornew elements 119 and 120 are predicted based on the obtained optimized mass data. 展开更多
关键词 superheavy nuclei SVM algorithm DNS model evaporation residue cross-sections
原文传递
A general two-phase mixture model for sediment-laden flow in open channel 被引量:1
6
作者 jia-xing li Xin Chen 《Journal of Hydrodynamics》 SCIE EI CSCD 2022年第2期286-298,共13页
This work extends the sediment-laden mixture model with consideration of the turbulence damping and particle wake effects under the framework of improved efficiency and accuracy.The mixture model consists of the conti... This work extends the sediment-laden mixture model with consideration of the turbulence damping and particle wake effects under the framework of improved efficiency and accuracy.The mixture model consists of the continuity and momentum equations for the sediment-laden mixture,and the continuity equation for the sediment.A theoretical formula is derived for the relative velocity between the water and sediment phases,with consideration of the effects of the pressure gradient,the shear stress and the lift force.A modified expression of the particle wake effect,inducing the local turbulence enhancement around the sediment particle,is employed to improve the turbulent diffusion of the coarse sediment.The k_(m)-ε_(m) model is proposed to close the mixture turbulence,with the turbulence damping effect due to the high sediment concentration expressed by the density-stratification term without an empirical parameter.The k_(m)-ε_(m) turbulence model requires smaller computational work and offers better results than an empirical density-stratification turbulence model in high sediment concentration cases.Consequently,with the proposed mixture model,the sediment transport in the open channel under a wide range of sediment sizes and concentrations can be revealed with the results in good agreement with experimental data for the velocity,the sediment concentration and the turbulent kinetic energy. 展开更多
关键词 Sediment-laden flow two-phase mixture model particle wake effect turbulence damping effect density stratification
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部