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spectral principal component analysis of the Hβ region of low-redshift sDss quasars

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Research in Astronomy and Astrophysics 2019年第12期19卷 169-178页

作者： Bin ma Zhaohui shang Michael s.Brotherton National Astronomical Observatories Chinese Academy of Sciences.Beijing 100101China school of Astronomy and space science University of Chinese Academy of SciencesBeijing 100049China Tianjin Astrophysics Center Tianjin Normal UniversityTianjin 300387China Department of Physics and Astronomy University of WyomingLaramieWY 82071.USA

studying the relationships among quasar spectral features is essential to unveil the origins of the emission lines and the quasars’ physical processes. Principal component analysis(PCA) is a powerful tool to investigate correlations between variables. Here, we present the results of PCA on the spectra of low-redshift sDss quasars. The rest-frame wavelength range studied is 4000 – 5500 ?, involving some typical features of quasar spectra, such as Hβ, [O Ⅲ] and Fe Ⅱ emission lines. The first principal component is the anti-correlation between [O Ⅲ] and Fe Ⅱ, the well-known eigenvector one(EV1). The next six principal components also show clear(anti-)correlations between line strengths and/or velocity widths of various features, which agree well with measured spectral properties. By comparing the weights of these principal components with other quasar properties, we can identify their underlying drivers. We find that the second principal component represents spectral slope, and can quantify quasar host fraction, intrinsic slope and reddening well. The third component exhibits the velocity width variation of Hβ, and may be a proxy for orientation. In addition, we calculate the fractional-contribution spectra to investigate which components dominate the variance at individual wavelength ranges. Our results also indicate that the optical Fe Ⅱ emission may have distinct origins.

关键词： quasars:emission lines quasars:general

Nonlinear free vibrations of porous composite microplates incorporating various microstructural-dependent strain gradient tensors

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Applied mathematics and Mechanics(English Edition) 2022年第6期43卷 825-844页

作者： Duquan ZUO B.sAFAEI s.sAHmaNI Guoling ma Aviation Engineering College Civil Aviation Flight University of ChinaGuanghan 618307Sichuan ProvinceChina Chongqing Engineering Research Center for Advanced Intelligent manufacturing Technology Chongqing Three Gorges UniversityChongqing 404100China Department of Mechanical Engineering Eastern Mediterranean UniversityFamagusta 99628North Cyprus via Mersin 10Turkey school of science and Technology The University of GeorgiaTbilisi 0171Georgia

The main objective of the present numerical analysis is to predict the nonlinear frequency ratios associated with the nonlinear free vibration response of porous composite plates at microscale in the presence of different microstructural gradient *** achieve this end,by taking cubic-type elements into account,isogeometric models of porous composite microplates are obtained with and without a central cutout and relevant to various porosity patterns of distribution along the plate *** established unconventional models have the capability to capture the effects of various unconventional gradient tensors continuity on the basis of a refined shear deformable plate *** the simply supported microsized uniform porous functionally graded material(UPFGM)plate having the oscillation amplitude equal to the plate thickness,it is revealed that the rotation gradient tensor causes to reduce the frequency ratio about 0.73%,the dilatation gradient tensor causes to reduce it about 1.93%,and the deviatoric stretch gradient tensor leads to a decrease of it about 5.19%.On the other hand,for the clamped microsized U-PFGM plate having the oscillation amplitude equal to the plate thickness,these percentages are equal to 0.62%,1.64%,and 4.40%,***,it is found that by changing the boundary conditions from clamped to simply supported,the effect of microsize on the reduction of frequency ratio decreases a bit.

关键词： size dependency isogeometric approach nonlinear dynamics geometric approximation micromechanics

A hybrid multi-degree-of-freedom vibration isolation platform for spacecrafts by the linear active disturbance rejection control

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Applied mathematics and Mechanics(English Edition) 2020年第5期41卷 805-818页

作者： Weichao CHI s.J.ma J.Q.sUN College of science Northeastern UniversityShenyang 100819China Key laboratory of Ministry of Education on safe Mining of Deep Metal Mines Northeastern UniversityShenyang 100819China Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

The hybrid vibration isolation, which takes advantages of both the passive and active approaches, has been an important solution for space missions. The objective of this paper is to design a vibration isolation platform for payloads on spacecrafts with the robust, wide bandwidth, and multi-degree-of-freedom(MDOF). The proposed solution is based on a parallel mechanism with six voice-coil motors(VCMs) as the actuators. The linear active disturbance resistance control(lADRC) algorithm is used for the active control. Numerical simulation results show that the vibration isolation platform performs effectively over a wide bandwidth, and the resonance introduced by the passive isolation is eliminated. The system robustness to the uncertainties of the structure is also verified by simulation.

关键词： hybrid vibration isolation stewart platform linear active disturbance rejection control(lADRC) stability robustness

不同运动模式影响心肌梗死致心力衰竭大鼠骨骼肌重塑的机制

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中国组织工程研究 2025年第2期29卷 221-230页

作者：付常喜何瑞波马刚朱政马文超徐州工程学院体育学院江苏省徐州市221008 中国人民武装警察部队后勤学院卫生勤务系天津市300309

背景:急性心肌梗死可引起心脏重塑和心力衰竭,同时导致骨骼肌病变,影响患者生活质量。运动疗法是心力衰竭患者的重要康复手段,然而最佳运动处方尚未明确。目的:对比不同运动模式(有氧运动、抗阻运动)对急性心肌梗死诱导心力衰竭模型大... 详细信息

背景:急性心肌梗死可引起心脏重塑和心力衰竭,同时导致骨骼肌病变,影响患者生活质量。运动疗法是心力衰竭患者的重要康复手段,然而最佳运动处方尚未明确。目的:对比不同运动模式(有氧运动、抗阻运动)对急性心肌梗死诱导心力衰竭模型大鼠骨骼肌重塑的影响,探讨其可能的作用机制,为优化运动康复方案提供依据。方法:48只sD大鼠随机分为假手术组、心肌梗死组、有氧运动组和抗阻运动组。利用冠状动脉结扎术进行心力衰竭模型制作,3个月后有氧运动组和抗阻运动组进行12周相应运动模式干预,假手术组和心肌梗死组于鼠笼内安静饲养。实验后,利用递增负荷跑台运动实验和爬梯实验分别测定大鼠最高跑速和最大负重,超声心动图评估心脏结构与功能;分离出心脏,分别行苏木精-伊红染色和天狼星红染色观察心脏重塑情况;分离出腓肠肌,行ATP酶染色观察肌纤维类型和细胞横截面积改变,二氢乙锭法评估活性氧水平,酶联免疫吸附法测定丙二醛含量以及抗氧化酶活性,免疫印迹法测定泛素-蛋白酶体系统蛋白表达量,双重免疫荧光染色检测活化的卫星细胞数(Pax7^(+)/MyoD^(+))。结果与结论:①运动能力:与假手术组比较,心肌梗死组最高跑速和最大负重下降(P0.05)。③骨骼肌重塑:与假手术组比较,心肌梗死组腓肠肌质量、腓肠肌质量指数、细胞横截面积、超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性、活化的卫星细胞数量下降(PmaFbx蛋白表达量上调(PmaFbx蛋白表达量降低(P<0.05);与有氧运动组比较,抗阻运动组腓肠肌质量、腓肠肌质量指数、细胞横截面积、活性氧水平、丙二醛含量、活化的卫星细胞数量升高(P<0.05),超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性下调(P<0.05)。结果表明:有氧运动和抗阻运动均可提升心力衰竭大鼠的运动能力,其机制与减轻氧化应激、抑制泛素-蛋白酶体系统活性以及激活卫星细胞进而改善骨骼肌重塑有关。有氧运动对于改善骨骼肌氧化应激作用更佳,而抗阻运动促进骨骼肌再生方面效果更为显著。

关键词：心肌梗死心力衰竭运动心脏骨骼肌重塑

Finite Element Prediction of the Thermal Conductivity of GNP/Al Composites

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Acta Metallurgica sinica(English letters) 2022年第5期35卷 825-838页

作者： X.s.Yang l.Zhou K.Y.liu Z.Y.liu Q.Z.Wang B.l.Xiao Z.Y.ma school of Electromechanical and Automotive Engineering Yantai UniversityYantai264005China shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

A 3 D multi-scale finite element model was developed to predict the effective thermal conductivity of graphene nanoplatelet(GNP)/Al *** factors influencing the effective thermal conductivity of the GNP/Al composites were investigated,including the orientation,shape,aspect ratio,configuration and volume fraction of *** results show that GNPs shape has a little influence on the thermal conductivity of GNP/Al composites,and composites with elliptic GNPs have the highest thermal *** addition,with increasing the aspect ratio of GNPs,the thermal conductivity of GNP/Al composites increases and finally tends to be *** GNPs configuration strongly influences the thermal conductivity of GNP/Al composites,and the thermal conductivity of the composites with layered GNPs is the highest among the five *** effective thermal conductivity is sensitive to volume fraction of ***,when the volume fraction of layered GNPs reaches 1.54%,the thermal conductivity of GNP/Al composites is as high as 400 W/m *** findings of this study could provide a good theoretical basis for designing high thermal conductivity GNP/Al composites.

关键词： Multi-scale finite element model Thermal conductivity GNP/Al composites shape Aspect ratio Configuration

Assessing the spatiotemporal distributions of evapotranspiration in the Three Gorges Reservoir Region of China using remote sensing data

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Journal of Mountain science 2018年第12期15卷 2676-2692页

作者： ma Ze-zhong RAY Ram l HE Yi-ping Chongqing Institute of surveying and Planning for land Resource and Housing Chongqing 400020China Cooperative Agricultural Research Center College of Agriculture and Human SciencesPrairie View A&M UniversityPrairie ViewTX 77446USA EDF Renewal Energy San DiegoCA 92118USA

Evapotranspiration(ET) is a critical component of the global hydrological cycle, and it has a large impact on water resource management as it affects the availability of freshwater resources. It is important to understand the hydrological cycle for the water resources planning and management. This study used Moderate Resolution Imaging spectroradiometer(MODIs) satellite derived ET, and potential evapotranspiration(PET) and Tropical Rainfall Measuring Mission(TRMM) satellite derived precipitation datasets to assess the spatial and temporal distributions of ET, PET, and precipitation during the study period at Three Gorges Reservoir(TGR) region. Based on the topographic variations and land-use/land-cover distributions, the study region which includes five counties of Hubei Province and nineteen counties of Chongqing Municipality was divided into four study zones. The ET and precipitation data were evaluated using in situ observations. The ET, PET, and precipitation data were compared to analyze the spatial and long-term(2001-2016) temporal distributions of average annual ET, PET, and precipitation, and to understand the relationships between them in the study region. The results showed that each selected zone had highest ET at the counties with the Yangtze River passing through whereas lowest at the counties which were located away from the river. Results also showed increasing trends in ET and PET from south-west to north-east in the study region. Analysis showed TGR had a significant impact on spatial and temporal distributions of ET and PET in the study region. Therefore, this study helps to understand the impact of TGR on spatial and temporal distributions of ET and PET during and after the construction.

关键词： Evapotranspiration Precipitation Tropical Rainfall Measuring Mission (TRMM) Moderate Resolution Imaging spectroradiometer (MODIs) Three Gorges Reservoir Potential Evapotranspiration

Metallurgical properties of CaO–siO_(2)–Al_(2)O_(3)–4.6wt%MgO–Fe_(2)O_(3)slag system pertaining to spent automotive catalyst smelting

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International Journal of Minerals,Metallurgy and materials 2023年第5期30卷 886-896页

作者： Ruili Zheng Jianfang lü Weifeng song Mudan liu Huashan li Yong liu Xianjin lü Zhiyuan ma school of Environmental science and Engineering Guangdong University of TechnologyGuangzhou 510006China Institute of Resources Utilization and Rare Earth Development Guangdong Academy of SciencesGuangzhou 510650China state Key laboratory of Rare Metals separation and Comprehensive Utilization Guangzhou 510650China Guangdong Key laboratory of Mineral Resources Development and Comprehensive Utilization Guangzhou 510650China

The metallurgical properties of the CaO–siO_(2)–Al_(2)O_(3)–4.6wt%Mg O–Fe_(2)O_(3)slag system,formed by the co-treatment process of spent automotive catalyst(sAC)and copper-bearing electroplating sludge(CBEs),were studied systematically in this *** slag structure,melting temperature,and viscous characteristics were investigated by Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,Fact sage calculation,and viscosity *** results show that the increase of Fe_(2)O_(3)content(3.8wt%–16.6wt%),the mass ratio of CaO/siO_(2)(m(CaO)/m(siO_(2)),0.5–1.3),and the mass ratio of siO_(2)/Al_(2)O_(3)(m(siO_(2))/m(Al_(2)O_(3)),1.0–5.0)can promote the depolymerization of silicate network,and the presence of a large amount of Fe_(2)O_(3)in form of tetrahedral and octahedral units ensures the charge compensation of Al^(3+)ions and makes Al_(2)O_(3)only behave as an acid *** calculation and viscosity measurements show that with the increase of Fe_(2)O_(3)content,m(Ca O)/m(siO_(2)),and m(siO_(2))/m(Al_(2)O_(3)),the depolymerization of silicate network structure and low-melting-point phase transformation first occur within the slag,leading to the decrease in melting point and viscosity of the slag,while further increase causes the formation of high-melting-point phase and a resultant re-increase in viscosity and melting *** on experimental analysis,the preferred slag composition with low polymerization degree,viscosity,and melting point is as follows:Fe_(2)O_(3)content of 10.2wt%–13.4wt%,m(CaO)/m(siO_(2))of 0.7–0.9 and m(siO_(2))/m(Al_(2)O_(3))of 3.0–*** work provides a theoretical support for slag design in co-smelting process of sAC and CBEs.

关键词： spent automotive catalyst co-treatment slag system slag structure melting temperature phase transformation viscosity

Recycling and recovery of spent copper-indium-gallium-diselenide(CIGs)solar cells:A review

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International Journal of Minerals,Metallurgy and materials 2023年第6期30卷 989-1002页

作者： Xiang li Baozhong ma Chengyan Wang Die Hu Yingwei lü Yongqiang Chen state Key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China school of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

Copper-indium-gallium-diselenide(CIGs)is a fast-evolving commercial solar *** firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGs solar cell *** this paper,the sources and characteristics of valuable metals in spent CIGs solar cells were *** potential environmental impacts of CIGs,including service life,critical material,and material toxicity,were *** main recovery methods of valuable metals in the various types of spent CIGs,including hydrometallurgy,pyrometallurgy,and comprehensive treatment processes,were compared and *** mechanism of different recovery processes was *** challenges faced by different recycling processes of spent CIGs were also covered in this ***,the economic viability of the recycling process was *** purpose of this review is to provide reasonable suggestions for the sustainable development of CIGs and the harmless disposal of spent CIGs.

关键词： spent solar cells recycling technology valuable component separation metallurgy progress urban mining

What′s new with the XYZ mesons?

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Chinese Physics C 2008年第6期32卷 455-462页

作者： s.l.Olsen Institute of High Energy Physics Chinese Academy of Sciences

I review some of the recent experimental results on the so-called XYZ mesons.

关键词： charmonium multiquark mesons quark-gluon hybrids