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Influence of soil to structure stiffness on the accuracy of the pushover method for underground structures

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Earthquake Research Advances 2022年第4期2卷 22-27页

作者： Qi wu yifeng Zhou Jiawei Jiang wuxi Institute of Technology Wuxi214021China Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing210009China

The pushover method for underground structures is a seismic analysis method featured by high calculation accuracy and a simple implementation process.The method has been widely used in seismic design and other related scientific research;however,the influence of different soil-structure flexibility ratios on the accuracy of this method is still not well understood.In this study,we select the cross-section structures beneath the Daikai subway station as the research object and establish 12 finite element analysis models with different soil-structure flexibility ratios using ABAQUS.All models are computed by the dynamic time-history method or the pushover method.Furthermore,the dynamic time-history solution result is taken as the standard solution,and the precision and application of the pushover analysis method are discussed based on the parameters of peak interlayer displacement and peak internal force of the middle column section.The results show that the soil-structure flexibility ratio has a significant influence on the calculation accuracy of the pushover method,and the calculation accuracy of this method is the most ideal when the soil-structure flexibility is equal to 1.The research results can provide significant references for the seismic design of underground structures or the improvement of simplified seismic analysis methods.

关键词： Underground structure Pushover Soil to structure flexibility Accuracy

顶空固相微萃取-气相色谱-质谱联用技术结合电子舌分析不同残糖含量蓝莓酒体风味

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食品与发酵工业 2024年第11期50卷 294-300页

作者：王利萍丁昱文吴颜欣邱树毅戴怡凤周鸿翔贵州大学酿酒与食品工程学院贵州省发酵工程与生物制药重点实验室贵州贵阳550025 贵州茅台(集团)生态农业产业发展有限公司贵州丹寨557500 北京食品营养与人类健康高精尖创新中心北京工商大学北京100048

蓝莓酒的风味会影响其质量与感官评价,因此研究蓝莓酒中的风味物质十分必要。该文利用顶空固相微萃取-气相色谱-质谱联用技术结合电子舌研究2种半甜、2种半干蓝莓酒风味,发现4种蓝莓酒的苦味、涩味均表现出随残糖含量下降而逐渐升高的趋... 详细信息

蓝莓酒的风味会影响其质量与感官评价,因此研究蓝莓酒中的风味物质十分必要。该文利用顶空固相微萃取-气相色谱-质谱联用技术结合电子舌研究2种半甜、2种半干蓝莓酒风味,发现4种蓝莓酒的苦味、涩味均表现出随残糖含量下降而逐渐升高的趋势,酸味、后苦味、后涩味无显著性差异。4种蓝莓酒中,半甜型蓝莓酒中酯类化合物含量高于半干型蓝莓酒,而半干型蓝莓酒中醇类化合物高于半甜型蓝莓酒。乙酸乙酯、萜品油烯、月桂酸乙酯等挥发性风味化合物在半甜型蓝莓酒中含量较高,肉桂酸乙酯、苯甲酸乙酯、苯乙酸乙酯等化合物在半干型蓝莓酒中含量较高,正辛醇、乙酸与发酵程度无显著性关联。此外,利用偏最小二乘法判别分析,分析发现4种蓝莓酒中13种潜在差异标志物,并结合香气活度值研究发现meso-2,3-丁二醇与芳樟醇分别仅为半甜型与半干型的整体风味做出贡献,而大马酮、苯乙醇、异戊醇、乙酸的香气活度值> 500,为不同残糖含量蓝莓酒的整体风味做出了重要贡献。

关键词：发酵蓝莓酒顶空固相微萃取-气相色谱-质谱联用技术电子舌偏最小二乘法判别分析香气活度值

Vehicle emissions of primary air pollutants from 2009 to 2019 and projection for the 14th Five-Year Plan period in Beijing, China

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Journal of Environmental Sciences 2023年第2期124卷 513-521页

作者： Tongran wu Yangyang Cui Aiping Lian Ye Tian Renfei Li Xinyu Liu Jing Yan yifeng Xue Huan Liu Bobo wu National Engineering Research Center of Urban Environmental Pollution Control Beijing Municipal Research Institute of Environmental ProtectionBeijing 100037China Beijing Municipal Ecology and Environment Bureau Beijing 100048China State Key Joint Laboratory of ESPC School of EnvironmentTsinghua UniversityBeijing 100084China School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China

Over the past decade,the emission standards and fuel standards in Beijing have been upgraded twice,and the vehicle structure has been improved by accelerating the elimination of 2.95 million old vehicles.Through the formulation and implementation of these policies,the emissions of carbon monoxide(CO),volatile organic compounds(VOCs),nitrogen oxides(NO_(x)),and fine particulate matter(PM_(2.5))in 2019 were 147.9,25.3,43.4,and 0.91 kton in Beijing,respectively.The emission factor method was adopted to better understand the emissions characteristics of primary air pollutants from combustion engine vehicles and to improve pollution control.In combination with the air quality improvement goals and the status of social and economic development during the 14th Five-Year Plan period in Beijing,different vehicle pollution control scenarios were established,and emissions reductions were projected.The results show that the emissions of four air pollutants(CO,VOCs,NO_(x),and PM_(2.5))fromvehicles in Beijing decreased by an average of 68% in 2019,compared to their levels in 2009.The contribution of NOx emissions from diesel vehicles increased from 35% in 2009 to 56% in 2019,which indicated that clean and energy-saving diesel vehicle fleets should be further improved.Electric vehicle adoption could be an important measure to reduce pollutant emissions.With the further upgrading of vehicle structure and the adoption of electric vehicles,it is expected that the total emissions of the four vehicle pollutants can be reduced by 20%-41% by the end of the 14th Five-Year Plan period.

关键词： Emission variations Vehicle structure Electric vehicle 14th Five-Year Plan Air pollution

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均布荷载下双中空玻璃的荷载分配研究

建筑结构学报 2024年第6期45卷 85-96页

作者：王智远刘军进陈美合杨轲昕李滇李建辉刘强吴宜峰中国建筑科学研究院有限公司北京100013 同济大学土木工程学院上海200092 中建研科技股份有限公司北京100013 北京建筑大学大型多功能振动台阵实验室北京100013

双中空玻璃被广泛应用于门窗及幕墙工程领域,但目前国内外相关规范中仍缺少精简有效的设计方法。为研究均布荷载作用下双中空玻璃的荷载分配情况,对4块中空玻璃试件开展堆载试验。基于理想气体状态方程和ANSYS挠度场分析,建立适用于双... 详细信息

双中空玻璃被广泛应用于门窗及幕墙工程领域,但目前国内外相关规范中仍缺少精简有效的设计方法。为研究均布荷载作用下双中空玻璃的荷载分配情况,对4块中空玻璃试件开展堆载试验。基于理想气体状态方程和ANSYS挠度场分析,建立适用于双中空玻璃的高精度有限元模型,模拟分析与试验结果吻合良好。通过有限元参数分析,揭示各玻璃面板分荷比例随内、外中空层厚度的变化规律。研究表明:随着内中空层厚度的增加,外、中片分荷比例呈近似线性关系增长;随着外中空层厚度的增加,中、内片分荷比例呈近似线性关系减小;当内、外侧中空层厚度等幅增加时,外片分荷比例显著增大,内片分荷比例明显降低,中片分荷比例则降低缓慢。结合面板的尺寸因素,提出了考虑长宽比和面积补充系数的适用于双中空玻璃荷载分配的中空层系数计算公式,拟合公式的适用性和有效性较好,可供相应标准规范修订参考使用。

关键词：双中空玻璃中空层系数堆载试验有限元分析荷载分配

Back in time:digital restoration techniques for the millennium Dunhuang murals

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The Journal of China Universities of Posts and Telecommunications 2022年第2期29卷 13-23页

作者： Tao yifeng Song Yucheng Xu Mengqiu Zhang Chuang wu Ming Bai Sule School of Artificial Intelligence Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China

In the long history of more than 1 500 years,Dunhuang murals suffered from various deteriorations causing irreversible damage such as falling off,fading,and so on.However,the existing Dunhuang mural restoration methods are time-consuming and not feasible to facilitate cultural dissemination and permanent inheritance.Inspired by cultural computing using artificial intelligence,gated-convolution-based dehaze net(GD-Net) was proposed for Dunhuang mural refurbishment and comprehensive protection.First,a neural network with gated convolution was applied to restore the falling off areas of the mural to ensure the integrity of the mural content.Second,a dehaze network was applied to enhance image quality to cope with the fading of the mural.Besides,a Dunhuang mural dataset was presented to meet the needs of deep learning approach,containing 1 180 images from the Cave 290 and Cave 112 of the Mogao Grottoes.The experimental results demonstrate the effectiveness and superiority of GD-Net.

关键词： image inpainting image enhancement mural restoration

基于预制孔的SiCf/SiC复合材料微小孔超声振动辅助钻削加工研究

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电加工与模具 2024年第3期 54-60页

作者：肖培乾汪文虎吴晓锋蒋松山熊一峰西北工业大学机电学院航空发动机高性能制造工业和信息化部重点实验室航空发动机先进制造技术教育部工程研究中心陕西西安710072 中国航发动力股份有限公司陕西西安710021

SiCf/SiC复合材料是典型的硬脆性难加工材料。为解决SiCf/SiC复合材料微小孔(<1 mm)加工难题,提高加工精度和改善加工质量,先采用脉冲激光预制SiCf/SiC微小孔,再在不同预制孔尺寸和加工参数下开展直径0.5 mm的SiCf/SiC微小孔超声振动辅... 详细信息

SiCf/SiC复合材料是典型的硬脆性难加工材料。为解决SiCf/SiC复合材料微小孔(<1 mm)加工难题,提高加工精度和改善加工质量,先采用脉冲激光预制SiCf/SiC微小孔,再在不同预制孔尺寸和加工参数下开展直径0.5 mm的SiCf/SiC微小孔超声振动辅助钻削加工试验,最终确定了合适的激光预制孔尺寸及超声振动辅助钻削加工参数域。结果表明:脉冲激光预制孔时存在的较大热影响区和微裂纹等缺陷,会明显影响后续超声辅助钻削微小孔的入、出口质量,推荐的预制孔直径为0.3 mm;超声振动辅助钻削加工时,选择主轴转速为11000~15000 r/min、进给速度为2~10mm/min,可获得加工质量较好的SiCf/SiC微小孔。

关键词：陶瓷基复合材料激光预制孔超声辅助钻削微小孔

宁波市江北区≥60岁人群流感病毒裂解疫苗安全性监测

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中国预防医学杂志 2024年第2期25卷 234-238页

作者：李萍萍张冰凌叶莉霞吴一峰宁波市江北区疾病预防控制中心浙江宁波315020 宁波市江北区庄桥街道社区卫生服务中心宁波市疾病预防控制中心

目的监测分析在宁波市江北区≥60岁人群中接种三价流感病毒裂解疫苗(trivalent influenza splitvirion vaccine,TIV)和四价流感病毒裂解疫苗(quadrivalent influenza split-virion vaccine,QIV)的疑似预防接种异常反应(adverse events following immunization,AEFI)发生率。方法选择2020年9月—2021年4月在宁波市江北区预防接种门诊接种流感病毒裂解疫苗并符合纳入标准的研究对象,采用主动监测方式收集接种后30 d内发生的AEFI,分析AEFI发生率。结果宁波市江北区≥60岁人群流感病毒裂解疫苗发生AEFI409例(33.39‰),其中一般反应、异常反应、偶合症分别为389例(31.76‰)、11例(0.90‰)、9例(0.73‰)。TIV、QIV的AEFI发生率分别为34.34‰、29.58‰,差异无统计学意义(χ^(2)=1.366,P=0.257);TIV、QIV一般反应分别为32.81‰、27.53‰,差异无统计学意义(χ^(2)=2.456,P=0.117);异常反应分别为0.82‰、1.23‰,差异无统计学意义(χ^(2)=0.056,P=0.812)。TIV(χ^(2)=16.441,P<0.01)、QIV(χ^(2)=5.354,P=0.021)的AEFI发生率均为女性高于男性,差异有统计学意义;60~<70岁人群TIV的AEFI发生率低于70~<80岁和≥80岁,差异有统计学意义(χ^(2)=7.655、6.164,P=0.006、0.016),三个年龄组QIV的AEFI发生率差异无统计学意义(χ^(2)=0.975,P=0.601)。结论TIV和QIV在≥60岁人群中AEFI发生率较低,症状通常较轻微,具有良好的安全性。

关键词：流感病毒裂解疫苗预防接种异常反应安全性评价

Effects of surface grinding for scratched alloy 690TT tube in PWR nuclear power plant:Microstructure and stress corrosion cracking

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Journal of Materials Science & Technology 2022年第18期113卷 229-245页

作者： Bin wu Hongliang Ming Fanjiang Meng yifeng Li Guangqing He Jianqiu Wang En-Hou Han School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shanghai Nuclear Engineering Research and Design Institute Ltd.Co. Shanghai 200233China Instrumental Analysis and Research Center Shanghai UniversityShanghai 200444China Department of Materials Science Fudan UniversityShanghai 200433China Shanghai Electric Nuclear Power Equipment Co. Ltd.Shanghai 201306China

Alloy 690TT tube samples with different scratch depths were repaired by grinding treatments using abra-sive papers of two different particle sizes.The microstructure and stress corrosion cracking(SCC)behavior were studied in detail.During grinding,the plastic accumulation zone vulnerable to SCC was removed.Meanwhile,some residual slip steps remained in the scratched area.Corrosion tests lasting 1000,2000,3000,and 4000 h show that the sensitivity and risk of SCC in the scratched area are decreased by grind-ing.Treatment using abrasive particles of a smaller size is more effective.Nevertheless,deep scratches remained hazardous even after the grinding.

关键词： Alloy 690TT Scratch Surface Stress corrosion High temperature corrosion Intergranular corrosion

A paradigm for high-throughput screening of cell-selective surfaces coupling orthogonal gradients and machine learning-based cell recognition

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Bioactive Materials 2023年第10期28卷 1-11页

作者： Hongye Hao Yunfan Xue Yuhui wu Cong Wang yifeng Chen Xingwang Wang Peng Zhang Jian Ji MOE Key Laboratory of Macromolecule Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027PR China International Research Center for X Polymers International CampusZhejiang UniversityHaining314400PR China

The combinational density of immobilized functional molecules on biomaterial surfaces directs cell behaviors. However, limited by the low efficiency of traditional low-throughput experimental methods, investigation and optimization of the combinational density remain daunting challenges. Herein, we report a high-throughput screening set-up to study biomaterial surface functionalization by integrating photo-controlled thiol-ene surface chemistry and machine learning-based label-free cell identification and statistics. Through such a strategy, a specific surface combinational density of polyethylene glycol (PEG) and arginine-glutamic acid-aspartic acid-valine peptide (REDV) leads to high endothelial cell (EC) selectivity against smooth muscle cell (SMC) was identified. The composition was translated as a coating formula to modify medical nickel-titanium alloy surfaces, which was then proved to improve EC competitiveness and induce endothelialization. This work provided a high-throughput method to investigate behaviors of co-cultured cells on biomaterial surfaces modified with combinatorial functional molecules.

关键词： alloy coating high