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腹板中心开长圆孔可更换剪切耗能梁段的承载力研究

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建筑结构学报 2024年第10期45卷 193-205页

作者：冯大哲殷占忠吴宏凯任国超兰州理工大学土木工程学院兰州理工大学西部土木工程防灾减灾教育部工程研究中心

通过在腹板上开孔削弱耗能梁段截面的抗剪强度，可以达到在不改变梁段端部连接处截面大小的情况下调控梁段受剪承载力的目的。为此，对4个腹板中心开长圆孔的可更换剪切耗能梁段进行了循环加载试验及有限元分析，得到了梁段在剪切荷载... 详细信息

通过在腹板上开孔削弱耗能梁段截面的抗剪强度，可以达到在不改变梁段端部连接处截面大小的情况下调控梁段受剪承载力的目的。为此，对4个腹板中心开长圆孔的可更换剪切耗能梁段进行了循环加载试验及有限元分析，得到了梁段在剪切荷载作用下的应力分布、破坏模式、滞回性能以及承载力，探讨了水平加劲肋的布置对腹板开口角部局部屈曲的改善情况，研究了孔长变化对设置水平加劲肋的梁段的应力分布及破坏模式的影响，并基于破坏模式给出了该类构件的受剪承载力理论计算式。结果表明：梁段截面的极限塑性转角均超过了ANSI/AISC 341-16规定的塑性转角限值0.08 rad;无肋梁段最终在开口部位发生剪切屈曲破坏，体现为长圆孔边缘四个圆弧过渡区域形成屈曲拉力带；腹板水平加劲肋的布置可有效抑制长圆孔周边屈曲拉力带的形成，长圆孔宽度方向两侧的腹板均达到了钢材的抗拉强度，梁段的破坏模式表现为开口处的剪切和空腹破坏；设置水平加劲肋的腹板中心开长圆孔剪切耗能梁段比相同开口参数的无肋梁段具有更高的承载力和耗能能力，梁段的受剪承载力随孔长的增加而降低，实现了通过调整孔长控制梁段受剪承载力的目标。采用建议的受剪承载力计算式的计算结果与试验值比值的标准偏差为0.076,变异系数为0.075,可见，该计算式能够提供可靠的受剪承载力预测结果。

关键词：腹板开长圆孔可更换剪切耗能梁段循环加载试验有限元分析破坏模式受剪承载力

A simple fabricated thickness-based stiffness gradient for cell studies

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Science Bulletin 2017年第3期62卷 222-228页

作者： Yiwei Shu HO Nam Chan Dongshi Guan hongkai wu Lan Ma Division of Life Science & Health Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China Department of Chemistry The Hong Kong University of Science and Technology Hong Kong China Department of Physics The Hong Kong University of Science and Technology Hong Kong China

In this work, we developed a simple method to fabricate a thickness-based continuous stiffness gradient for biological studies. It was made by glass slides, polydimethylsiloxane （PDMS） pre-polymer, spacer and clips only, without any sophisticated equipment. It is easy to fabricate in any general biological and pharmaceutical laboratories. The stiffness gradient was characterized in terms of apparent Young＇s modulus by atomic force microscopy （AFM） and the Young＇s modulus along the gradient was found to be 8.5- 120 kPa, which is within the physiological relevant range. HeLa-C3 ceils were cultured on the gradient to study their morphological behavior according to the substrate stiffness. Furthermore, the drug efficiency of etoposide, an anti-cancer drug, was studied along the substrate stiffness gradient. It was found that HeLa-C3 cells cultured on the soft region of the gradient （8.5-11 kPa） are more sensitive to etoposide. We believe the proposed device could promote cell investigations and drug screenings on a substrate with comparable stiffness to the native tissue.

关键词： Stiffness gradient Cell analysis PDMS Etoposide

Fabrication of a hydroxyapatite-PDMS microfluidic chip for bone-related cell culture and drug screening

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Bioactive Materials 2021年第1期6卷 169-178页

作者： Qiangqiang Tang Xiaoyu Li Chen Lai Lei Li hongkai wu Yingjun Wang Xuetao Shi Peking University Shenzhen Institute Peking UniversityShenzhen518055PR China School of Materials Science and Engineering South China University of TechnologyGuangzhou510640PR China National Engineering Research Center for Tissue Restoration and Reconstruction South China University of TechnologyGuangzhou510006PR China Key Laboratory of Biomedical Engineering of Guangdong Province South China University of TechnologyGuangzhou510006PR China Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education South China University of TechnologyGuangzhou510006PR China Guangzhou Regenerative Medicine and Health Guangdong Laboratory 510005GuangzhouPR China CAS Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190PR China Department of Chemistry The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

Bone is an important part of the human body structure and plays a vital role in human health.A microfluidic chip that can simulate the structure and function of bone will provide a platform for bone-related biomedical ***(HA),a bioactive ceramic material,has a similar structure and composition to bone mineralization *** this study,we used HA as a microfluidic chip component to provide a highly bionic bone *** substrates with different microchannel structures were printed by using ceramic stereolithography(SLA)technology,and the minimum trench width was 50μ*** HA substrate with microchannels was sealed by a thin polydimethylsiloxane(PDMS)layer to make a HA-PDMS microfluidic *** culture experiments demonstrated that compared with PDMS,HA was more conducive to the proliferation and osteogenic differentiation of the human foetal osteoblast cell line(hFOB).In addition,the concentration gradient of the model drug doxorubicin hydrochloride(DOX)was successfully generated on a Christmas tree structure HA-PDMS chip,and the half maximal inhibitory concentration(IC50)of DOX was *** findings of this study indicate that the HA-PDMS microfluidic chip has great potential in the field of high-throughput bonerelated drug screening and bone-related research.

关键词： Hydroxyapatite(HA) Ceramic microfluidic chip Drug screening Biomimetic Bone-on-a-chip

高效液相色谱⁃串联质谱同位素内标法测定猪肉中5种磺胺类药物残留量

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广东畜牧兽医科技 2024年第1期49卷 43-50页

作者：李律雯刘燕伍宏凯梁祺琦高志敏伍绍登广东省农产品质量安全中心(广东省绿色食品发展中心) 广东广州510230

该方法采用高效液相色谱⁃串联质谱测定猪肉中5种磺胺类药物的残留量。猪肉样品经过乙腈提取,低温冷冻、高速离心脱脂,反向C18色谱柱分离,采用多反应监测正离子模式测定,使用同位素内标法定量。在优化条件下的结果显示,在5-200 ng/mL的... 详细信息

该方法采用高效液相色谱⁃串联质谱测定猪肉中5种磺胺类药物的残留量。猪肉样品经过乙腈提取,低温冷冻、高速离心脱脂,反向C18色谱柱分离,采用多反应监测正离子模式测定,使用同位素内标法定量。在优化条件下的结果显示,在5-200 ng/mL的质量浓度范围内线性良好,相关系数r均大于0.999。在空白猪肉样品中添加5、50、100、200μg/kg水平的药物回收试验中,平均回收率在60%-110%之间,RSD在1.03%-8.07%之间(n=6)。结果表明,此方法中样品的前处理简单,定量结果准确,重现性好,适用于猪肉中磺胺类药物残留的定性定量检测。

关键词：猪肉磺胺类药物同位素内标法高效液相色谱⁃串联质谱

Analysis of severe human adenovirus infection outbreak in Guangdong Province,southern China in 2019

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Virologica Sinica 2022年第3期37卷 331-340页

作者： Wenkuan Liu Shuyan Qiu Li Zhang hongkai wu Xingui Tian Xiao Li Duo Xu Jing Dai Shujun Gu Qian Liu Dehui Chen Rong Zhou State Key Laboratory of Respiratory Diseases National Clinical Research Center for Respiratory DiseaseGuangdong-Hong Kong-Macao Joint Laboratory of Respiratory Infectious DiseaseThe First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou Institute of Respiratory HealthGuangzhou Medical UniversityGuangzhou510040China Scientific Research Center The First Affiliated Hospital of Guangdong Pharmaceutical UniversityGuangzhou510062China Bioland Laboratory Guangzhou LaboratoryGuangzhou510320China

During 2018–2019,a severe human adenovirus(HAdV)infection outbreak occurred in southern ***,we screened 18 respiratory pathogens in 1704 children(≤14 years old)hospitalized with acute respiratory illness in Guangzhou,China,in *** total,151 patients had positive HAdV test results;34.4%(52/151)of them exhibited severe *** infection occurred throughout the year,with a peak in *** median patient age was 3.0(interquartile range:1.1–5.0)*** with severe HAdV infection exhibited increases in12 clinical indexes(P≤0.019)and decreases in four indexes(P≤0.007),compared with patients exhibiting nonsevere *** significant differences were found in age or sex distribution according to HAdV infection severity(P>0.05);however,the distributions of comorbid disease and HAdV co-infection differed according to HAdV infection severity(P0.05);the HAdV-7 isolate exhibited stronger virulence and infectivity,compared with HAdV-3(P<0.001).Overall,comorbid disease,HAdV co-infection,and high virulence and infectivity of HAdV-7 were critical risk factors for severe HAdV infection;these data can facilitate treatment,control,and prevention of HAdV infection.

关键词： Human adenovirus(HAdV) Human adenovirus type 7(HAdV-7) Severe illness Epidemiology Acute respiratory illness Virulence and infectivity Risk factor

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嵌入弹性波纹环的轴承挤压油膜特性分析

机械工程学报 2022年第13期58卷 185-193页

作者：武洪凯吴承伟大连理工大学工业装备结构分析国家重点实验室大连116024

设计了一种弹性波纹环轴承挤压油膜阻尼器,建立了弹性波纹环挤压油膜阻尼器的流固耦合分析模型,基于ABAQUS软件分析弹性波纹环的压缩力学性质,利用MATLAB编程分析弹性波纹环间隙的挤压油膜流动阻尼特性,通过Python脚本进行数据交换实现... 详细信息

设计了一种弹性波纹环轴承挤压油膜阻尼器,建立了弹性波纹环挤压油膜阻尼器的流固耦合分析模型,基于ABAQUS软件分析弹性波纹环的压缩力学性质,利用MATLAB编程分析弹性波纹环间隙的挤压油膜流动阻尼特性,通过Python脚本进行数据交换实现了阻尼器的流固耦合动力学分析。研究了轴承冲击挤压速度、挤压位移、弹性环厚度、波纹周期数和波纹幅值对阻尼器动力特性系数的影响。结果表明,挤压速度对阻尼器压缩刚度和阻尼特性影响较小,挤压位移和波纹幅值对油膜阻尼有着显著影响,弹性波纹环厚度对挤压刚度影响明显,波纹周期对挤压刚度和阻尼特性影响显著。

关键词：弹性波纹环挤压膜阻尼器流固耦合雷诺方程动力特性

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弹性波纹环减振轴承设计与分析

航空动力学报 2023年第2期38卷 482-490页

作者：武洪凯吴承伟大连理工大学工程力学系工业装备结构分析国家重点实验室辽宁大连116024

设计了一种圆周周向呈现正弦波纹状的弹性圆环轴承阻尼器,与滚动轴承耦合到一起,实现轴承减振吸能功能。建立了弹性波纹环减振轴承的力学模型,利用有限元方法对该减振轴承进行力学性能分析,研究了弹性波纹环几何参数对其应力分布和径向... 详细信息

设计了一种圆周周向呈现正弦波纹状的弹性圆环轴承阻尼器,与滚动轴承耦合到一起,实现轴承减振吸能功能。建立了弹性波纹环减振轴承的力学模型,利用有限元方法对该减振轴承进行力学性能分析,研究了弹性波纹环几何参数对其应力分布和径向压缩刚度的影响以及弹性波纹环的减振吸能效果。结果表明:与弹性凸台环比较,弹性波纹环的应力分布有了很大改善,在给定工况下,最大Mises应力从1356 MPa降低到464 MPa,应力减小了64%,消除了应力集中现象;弹性波纹环的厚度、波纹周期数和弹性环直径对弹性环的应力和刚度影响显著。弹性波纹环的引入大幅度降低了轴承在振动冲击时受到的冲击力。

关键词：弹性波纹环有限元分析应力集中应力分布减振效果

A review on the transformation of birnessite in the environment:Implication for the stabilization of heavy metals

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Journal of Environmental Sciences 2024年第5期139卷 496-515页

作者： Miao Shi Qingzhu Li Qingwei Wang Xuelei Yan Bensheng Li Linhai Feng Chao wu Rongrong Qiu hongkai Zhang Zhihui Yang Weichun Yang Qi Liao Liyuan Chai School of Metallurgy and Environment Central South UniversityChangsha 410083China National Engineering Research Centre for Control and Treatment ofHeavy Metal Pollution Central South UniversityChangsha 410083China Water Pollution Control Technology Key Lab of Hunan Province Changsha 410083China

Birnessite is ubiquitous in the natural environment where heavy metals are retained and easily *** surface properties and structure of birnessite change with the changes in external environmental conditions,which also affects the fate of heavy *** the effect and mechanism of the birnessite phase transition process on heavy metals is the key to taking effective measures to prevent and control heavy metal ***,the four transformation pathways of birnessite are summarized first in this ***,the relationship between transformation pathways and environmental conditions is *** relevant environmental conditions include abiotic(e.g.,co-existing ions,pH,oxygen pressure,temperature,electric field,light,aging,pressure)and biotic factors(e.g.,microorganisms,biomolecules).The phase transformation is achieved by the key intermediate of Mn(Ⅲ)through interlayer-condensation,folding,neutralizationdisproportionation,and dissolution-recrystallization *** AOS(average oxidation state)of Mn and interlayer spacing are closely correlated with the phase transformation of *** but not least,the mechanisms of heavy metals immobilization in the transformation process of birnessite are summed *** involve isomorphous substitution,redox,complexation,hydration/dehydration,*** transformation of birnessite and its implication on heavy metals will be helpful for understanding and predicting the behavior of heavy metals and the crucial phase of manganese oxides/hydroxides in natural and engineered environments.

关键词： Birnessite Transformation Heavy metals Pathways Mechanism

The divergence of brassinosteroid sensitivity between rice subspecies involves natural variation conferring altered internal auto-binding of OsBSK2

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Journal of Integrative Plant Biology 2022年第8期64卷 1614-1630页

作者： Wenchao Yin Lulu Li Zhikun Yu Fan Zhang Dapu Liu hongkai wu Mei Niu Wenjing Meng Xiaoxing Zhang Nana Dong Yanzhao Yang Jihong Liu Yongqiang Liu Guoxia Zhang Jianlong Xu Shimei Wang Chengcai Chu Qian Qian Hongning Tong National Key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China Rice Research Institute of Anhui Academy of Agricultural Sciences Hefei 230001China State Key Laboratory of Plant Genomics Institute of Genetics and Developmental Biologythe Innovative Academy for Seed DesignChinese Academy of SciencesBeijing 100101China

Japonica/geng and indica/xian are two major rice(Oryza sativa)subspecies with multiple divergent traits,but how these traits are related and interact within each subspecies remains ***(BRs)are a class of steroid phytohormones that modulate many important agronomic traits in ***,using different physiological assays,we revealed that japonica rice exhibits an overall lower BR sensitivity than *** screening of BR signaling genes led to the identification of a set of genes distributed throughout the primary BR signaling pathway with divergent *** these,we demonstrate that the C38/T variant in BR Signaling Kinase2(OsBSK2),causing the amino acid change P13L,plays a central role in mediating differential BR signaling in japonica and indica ***2in indica plays a greater role in BR signaling than OsB SK2in japonica by affecting the auto-binding and protein accumulation of ***,we determined that OsBSK2 is involved in a number of divergent traits in japonica relative to indica rice,including grain shape,tiller number,cold adaptation,and nitrogen-use *** study suggests that the natural variation in OsB SK2 plays a key role in the divergence of BR signaling,which underlies multiple divergent traits between japonica and indica.

关键词： brassinosteroid divergence grain shape natural variation rice