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Study on the effect of ground motion direction on the response of engineering structure

Earthquake Engineering and Engineering Vibration 2016年第4期15卷 649-656页

作者： sun Menghan Fan feng sun Baitao Zhi Xudong Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology School of Civil Engineering Harbin Institute of Technology Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering Mechanics China Earthquake Administration

Due to the randomness of earthquake wave magnitude and direction, and the uncertain direction of strong axis and weak axis in the construction of engineering structures, the effect of the direction of ground motion on a structure are studied herein. Ground motion records usually contain three vertical ground motion data, which are obtained by sensors arranged in accordance with the EW （East -West） direction, NS （South- North） direction and perpendicular to the surface （z） direction, referring to the construction standard of seismic stations. The seismic records in the EW and NS directions are converted to Cartesian coordinates in accordance with the rotation of θ = 0°-180°, and consequently, a countless group of new ground motion time histories are obtained. Then, the characteristics of the ground motion time history and response spectrum of each group were studied, resulting in the following observations：（1） the peak and phase of ground motion are changed with the rotation of direction θ, so that the direction θ of the maximum peak ground motion can be determined; （2） response spectrum values of each group of ground motions change along with the direction θ, and their peak, predominant period and declining curve are also different as the changes occur; then, the angle θ in the direction of the maximum peak value or the widest predominant period can be determined; and （3） the seismic response of structures with different directions of ground motion inputs has been analyzed under the same earthquake record, and the results show the difference. For some ground motion records, such as the Taft seismic wave, these differences are significant. Next, the Lushan middle school gymnasium structure was analyzed and the calculation was checked using the proposed method, where the internal force of the upper space truss varied from 25% to 28%. The research results presented herein can be used for reference in choosing the ground motion when checking the actual damage to struct

关键词： direction of grotmd motion structure effect coordinate transformation response spectrum

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Automorphism Group and Representation of a Twisted Multi-loop Algebra

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Acta Mathematica Sinica,English Series 2010年第1期26卷 143-154页

作者： Cui CHEN Hai feng lian Shao Bin TAN Department of Mathematics and Physics Fujian University of Technology Fuzhou 350108 P. R. China Department of Computer and Information Fujian Agriculture and Forestry University Fuzhou 350002 P. R. China Department of Mathematics Xiamen University Xiamen 361005 P. R. China

Let G be the complexification of the real Lie algebra so（3） and A = C[t1^±1, t2^±1] be the Lau-ent polynomial algebra with commuting variables. Let L：（t1, t2, 1） = G c .A be the twisted multi-loop Lie algebra. Recently we have studied the universal central extension, derivations and its vertex operator representations. In the present paper we study the automorphism group and bosonic representations ofL（t1, t2, 1）.

关键词： Lie algebra automorphism group representation

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L^p-L^q decay estimates of solutions to Cauchy problems of thermoviscoelastic systems

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Applied Mathematics(A Journal of Chinese Universities) 2009年第4期24卷 473-482页

作者： YANG Lin HUANG Li-hong KUANG feng-lian College of Mathematics Hunan University Changsha 410082 China The fourth middle school Shaoyang Shaoyang 422000 China

L^p- L^q decay estimate of solution to Cauchy problem of a linear thermoviscoelastic system is studied. By using a diagonalization argument of frequency analysis, the coupled system will be decoupled micrologically. Then with the help of the information of characteristic roots for the coefficient matrix of the system, L^p- L^q decay estimate of parabolic type of solution to the Cauchy problem is obtained.

关键词： L^p- L^q decay estimate Cauchy problem thermoviscoelastic system

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The balance of acidity and redox capability over modified CeO_2 catalyst for the selective catalytic reduction of NO with NH_3

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Journal of Environmental Sciences 2019年第5期31卷 273-279页

作者： Zhihua lian Wenpo Shan Meng Wang Hong He Qingcai feng Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Sciences Research Center for Eco-Environmental Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences

The effect of acidity and redox capability over sulfuric acid-modified CeO_2 catalysts were studied for the selective catalytic reduction of NO_x with NH_3(NH_3-SCR). The deposition of sulfate significantly enhanced the catalytic performance over CeO_2. NO_x conversion over4H_2SO_4/CeO_2 at 230–440 °C was higher than 90%. The strong redox capability of CeO_2 could result in unselective NH_3 oxidation and decrease high temperatures catalytic activity and N_2 selectivity. The deposition of sulfate increased the acidity and weakened the redox capability, and then increased the high temperature NO_x conversion and N_2 selectivity. An appropriate level of acidity also promoted the activity at 190–250 °C over ceria-based catalysts, and with further increase in the acidity, the SCR activity decreased slightly. Weak redox capability lowered the low-temperature catalytic activity. Excellent SCR activity requires a balance of acidity and redox capability on the catalysts.

关键词： NH3-SCR CeO2 Acidity Redox capability H2SO4

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Effects of selenium and sulfur on antioxidants and physiological parameters of garlic plants during senescence

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Journal of Integrative Agriculture 2016年第3期15卷 566-572页

作者： CHENG Bo lian Hai-feng LIU Ying-ying YU Xin-hui sun Ya-li sun Xiu-dong SHI Qing-hua LIU Shi-qi State Key Laboratory of Crop Biology Ministry of Science and Technology/Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Huanghuai Region) Ministry of Agriculture/College of Horticultural Science and Engineering Shandong Agricultural University Institute of Science and Technology Information Shandong Academy of Agricultural Sciences

A hydroponic study was conducted to determine the effects of selenium（Se： 0, 3, 6 μmol L^-1） on senescence-related oxidative stress in garlic plants grown under two sulfur（S） levels. We evaluated the yields of plants harvested at 160 and 200 days after sowing. Plants grown under a low Se dose（0.3 μmol L^-1） at low S level showed higher yields（12.0% increase in fresh weight yield, 13.7% increase in dry weight yield） than the controls, despite a decrease in chlorophyll concentration. Compared with control plants, the Se-treated plants showed lower levels of lipid peroxidation. The Se-treated plants also showed higher activities of glut athione peroxidase and catalase, but lower superoxide dismutase activities. Changes in Fv/Fm values and proline contents were affected more strongly by S than by Se. On the basis of our results, we can conclude that Se plays a key role in the antioxidant systems in garlic seedlings. It delays senescence by alleviating the peroxide stress, but it can be toxic at high levels. A high S level may increase tolerance to high Se concentrations through reducing Se accumulation in plants.

关键词： selenium sulfur garlic antioxidant activity oxidative stress senescence

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Crystallinity and stability of covalent organic frameworks

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Science China Chemistry 2020年第10期63卷 1367-1390页

作者： Xin Huang Chao sun Xiao feng Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster ScienceMinistry of EducationSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Covalent organic frameworks(COFs)are a class of organic porous polymers with high crystallinity,and their structures can be precisely tailored via topology *** to the characteristics of permanent pores,periodic structures and rich building blocks,COFs have triggered tremendous attention in the past fifteen years and are extensively investigated in various *** and stability are two crucial features for practical *** general,these two features are contradictory for COFs formed via dynamic covalent chemistry(DCC).High thermodynamic reversibility is usually required to attain exceptional crystallinity of COFs,often resulting in limited *** first two reported COFs are based on the boroxine and boronate ester linkages,which are unstable in water and even in humid ***,many researchers doubt the stability of COFs for real ***,in these years,various novel linkages have been developed for the construction of COFs,and numerous newly synthesized COFs are robust towards strong acid/base and even some of them can resist the attack of strong oxidizing and reducing *** this review,we focus on the linkage chemistry of the COFs in terms of crystallinity and stability,further extending it to the investigation in the mechanisms of the crystal growth and the overall regulation of the contradiction between stability and *** strategies for improving the crystallinity,including selecting building units,introducing non-covalent interactions and slowing nucleation and growth rate,are described in the third section,while the methodologies for increasing the stability from the viewpoints of chemical modification and non-covalent interactions are summarized in the fourth ***,the challenges and perspectives are presented.

关键词： covalent organic frameworks crystallinity stability dynamic covalent chemistry linkage chemistry

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General optimal design of solar-powered unmanned aerial vehicle for priority considering propulsion system

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Chinese Journal of Aeronautics 2020年第8期33卷 2176-2188页

作者： Xinhua LI Kaijun sun feng LI School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China CH UAV Technology Co. LtdChina Academy of Aerospace AerodynamicsBeijing 100()74China

This paper describes the general optimization design method of Solar-Powered Unmanned Aerial Vehicle which priority considering propulsion system planning. Based on the traditional solar powered aircraft design method, the propulsion system top-level target parameters which affect the path planning are integrated into the general optimization design. According to the typical mission requirements of Solar-Powered Unmanned Aerial Vehicle, considering the design variables such as wing area, aspect ratio, design mission date and so on, the general optimization is carried out with the minimum aircraft weight as the optimization objective. The influence of wing area and aspect ratio on the optimal design results is analyzed and compared with the traditional design method. The results show that the general design method of Solar-Powered Unmanned Aerial Vehicle for priority considering propulsion system can greatly reduce the electricity demand of energy storage battery, greatly reduce the aircraft weight of Solar-Powered Unmanned Aerial Vehicle.

关键词： Aircraft design optimization General design technology Route analysis Solar-powered Unmanned aerial vehicle

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Probing electron and lattice dynamics by ultrafast electron microscopy: Principles and applications

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International Journal of Mechanical System Dynamics 2023年第3期3卷 192-212页

作者： Yiling lian Jingya sun Lan Jiang Laser Micro/Nano Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijingP.R.China Yangtze Delta Region Academy of Beijing Institute of Technology JiaxingP.R.China Chongqing Innovation Center Beijing Institute of TechnologyChongqingP.R.China

Microscale charge and energy transfer is an ultrafast process that can determine the photoelectrochemical performance of ***,nonlinear and nonequilibrium properties hinder our understanding of ultrafast processes;thus,the direct imaging strategy has become an effective means to uncover ultrafast charge and energy transfer *** to diffraction limits of optical imaging,the obtained optical image has insufficient spatial ***,electron beam imaging combined with a pulse laser showing high spatial–temporal resolution has become a popular area of research,and numerous breakthroughs have been achieved in recent *** this review,we cover three typical ultrafast electron beam imaging techniques,namely,time-resolved photoemission electron microscopy,scanning ultrafast electron microscopy,and ultrafast transmission electron microscopy,in addition to the principles and characteristics of these three *** outstanding results related to photon–electron interactions,charge carrier transport and relaxation,electron–lattice coupling,and lattice oscillation are also *** summary,ultrafast electron beam imaging with high spatial–temporal resolution and multidimensional imaging abilities can promote the fundamental under-standing of physics,chemistry,and optics,as well as guide the development of advanced semiconductors and electronics.

关键词： ultrafast electron imaging charge transfer time-resolved photoemission electron microscopy scanning ultrafast electron microscopy ultrafast transmission electron microscopy

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基于干性指数模型对肉瘤预后、免疫浸润和铁死亡调控的分析

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中国组织工程研究 2025年第19期29卷 4151-4160页

作者：魏婧娴孟莲孙皓张田田刘春霞石河子大学医学院病理学系/石河子大学第一附属医院病理科新疆维吾尔自治区石河子市832000 广州医科大学附属第二医院病理科广东省广州市510260

背景:干性指数可能与肉瘤预后、免疫浸润有关,但具体调控机制与特征基因尚不清楚。目的:利用基因干性指数模型探究肉瘤干细胞与患者预后和免疫浸润的关系,并识别肉瘤干细胞铁死亡特征基因。方法:从癌症基因组图谱(TCGA)中获取肉瘤RNA测... 详细信息

背景:干性指数可能与肉瘤预后、免疫浸润有关,但具体调控机制与特征基因尚不清楚。目的:利用基因干性指数模型探究肉瘤干细胞与患者预后和免疫浸润的关系,并识别肉瘤干细胞铁死亡特征基因。方法:从癌症基因组图谱(TCGA)中获取肉瘤RNA测序数据及相关临床信息。利用肉瘤干性指数,对获取的肉瘤RNA测序数据进行分组。利用生存数据进行组间预后情况分析,获取组间差异表达基因后进行通路富集和免疫浸润分析。获得铁死亡相关差异基因,构建蛋白互作网络并进行预后相关性分析。培养横纹肌肉瘤细胞系,分为贴壁细胞组和干细胞组,贴壁细胞组不予任何干预,干细胞组通过无血清培养处理以诱导横纹肌肉瘤干细胞富集,qRT-PCR验证干细胞相关标志物、铁死亡相关差异基因以及铁死亡相关标志物的mRNA表达。结果与结论:①以干性指数中位数为界将患者分成高干性指数组和低干性指数组,通过患病风险预测显示高干性指数组患者的无进展生存期低于低干性指数组,提示预后不佳;②GO、KEGG分析显示肉瘤高、低干性指数组差异表达基因参与不同的细胞通路;高干性指数组和低干性指数组之间免疫浸润存在差异;差异基因中有23个铁死亡相关基因,其中9个可构成相关性较强的蛋白互作网络,其中IDO1、IFNG、AQP5高表达的肉瘤患者预后更好,CA9高表达的肉瘤患者预后不佳;③qRT-PCR结果显示,与贴壁细胞组相比,干细胞组干细胞相关标志物NANOG、SOX2和OCT4 mRNA表达显著升高(P<0.05);与贴壁细胞组相比,干细胞组铁死亡相关标志物SLC7A11的mRNA表达显著降低(P<0.05),ACSL4、GPX4、FTH1和COX2的mRNA表达显著升高(P<0.05);与贴壁细胞组相比,干细胞组差异基因CA9的mRNA表达显著降低,IDO1、IFNG、AQP5的mRNA表达显著升高(P<0.05)。经上述生物信息学分析与实验验证,干细胞与肉瘤生存、铁死亡过程密切相关,CA9、IDO1、IFNG、AQP5在肉瘤干细胞中异常表达,可能成为肉瘤诊断标志物和治疗新靶点。

关键词：肉瘤干细胞干性指数铁死亡生存预后免疫浸润

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基于一阶差分光谱的海水硝酸盐氮与亚硝酸盐氮测量方法

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光谱学与光谱分析 2025年第1期45卷 45-51页

作者：梁星辉冯巍巍蔡宗岐王焕卿杨剑炼中国科学院烟台海岸带研究所中国科学院海岸带环境过程与生态修复重点实验室山东烟台264003 山东省海岸带环境过程重点实验室山东烟台264003 中国科学院大学北京100049

硝酸盐氮与亚硝酸盐氮是海洋水质监测的重点参数,也是研究海洋氮循环的重要参考。紫外吸收光谱法操作简单,响应快速,适用于多种水质参数监测,但测量中硝酸盐氮与亚硝酸盐氮存在混叠干扰以及海水离子干扰。提出了一种硝酸盐氮与亚硝酸盐... 详细信息

硝酸盐氮与亚硝酸盐氮是海洋水质监测的重点参数,也是研究海洋氮循环的重要参考。紫外吸收光谱法操作简单,响应快速,适用于多种水质参数监测,但测量中硝酸盐氮与亚硝酸盐氮存在混叠干扰以及海水离子干扰。提出了一种硝酸盐氮与亚硝酸盐氮快速测量方法,对光谱进行一阶差分等预处理,使用相关系数搜索进行波段优化,使用BP神经网络进行浓度反演,模型的预测值与真实值线性相关系数为0.998。与国外同类设备进行了比对测试,两者线性相关系数为0.982。参加了烟台市海洋环境监测预报中心2023年夏季航次,进行了应用测试,与实验室方法进行了比对分析,两者线性相关系数为0.902,说明本方法能够实现海水硝酸盐氮与亚硝酸盐氮的快速测量,为后续原位监测仪器的研制提供参考。

关键词：硝酸盐氮亚硝酸盐氮紫外吸收光谱一阶差分 BP神经网络

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