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Self-centering seismic retrofit scheme for reinforced concrete frame structures:SDOF system study

Earthquake Engineering and Engineering Vibration 2010年第2期9卷 271-283页

作者： yunfeng zhang and Xiaobin Hu Department of Civil and Environmental Engineering,University of Maryland,College Park,MD 20742,USA Department of Civil and Environmental Engineering University of Maryland College Park 20742 USA

This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and minimal residual deformation. For comparison purpose,an alternate seismic retrofit scheme that uses a bilinear-hysteresis retrofit system such as buckling-restrained braces (BRB) is also considered in this paper. The parametric study was carried out in a single-degree-of-freedom (SDOF) system framework since a multi-story building structure may be idealized as an equivalent SDOF system and investigation of the performance of this equivalent SDOF system can provide insight into the seismic response of the multi-story building. A peak-oriented hysteresis model which can consider the strength and stiffness degradation is used to describe the hysteretic behavior of RC structures. The parametric study involves two key parameters -the strength ratio and elastic stiffness ratio between the seismic retrofit system and the original RC frame. An ensemble of 172 earthquake ground motion records scaled to the design basis earthquake in California with a probability of exceedance of 10% in 50 years was constructed for the simulation-based parametric study. The effectiveness of the two seismic retrofit schemes considered in this study is evaluated in terms of peak displacement ratio,peak acceleration ratio,energy dissipation demand ratio and residual displacement ratio between the SDOF systems with and without retrofit. It is found from this parametric study that RC structures retrofitted with the self-centering retrofit scheme (SCRS) can achieve a seismic performance level comparable to the bilinear-hysteresis retrofit scheme (BHRS) in terms of peak displacement and energy dissipation demand ratio while having negligible residual displacement after earthquake.

关键词： earthquake reinforced concrete frame structure nonlinear analysis SDOF system seismic retrofit self-centering

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Tetra-armed conjugated microporous polymers for gas adsorption and photocatalytic hydrogen evolution

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Science China Chemistry 2017年第8期60卷 1075-1083页

作者： yunfeng Xu Chong zhang Pan Mu Na Mao Xue Wang Qian He Feng Wang Jia-Xing Jiang Key Laboratory for Green Chemical Process of Ministry of Education Wuhan Institute of Technology Wuhan 430073 China

Two novel tetra-armed conjugated microporous polymers with different geometries have been designed and synthesized via Suzuki-Miyaura cross coupling polycondensation. Both polymers are stable in various organic solvents tested and are thermally stable. The pyrene-containing polymer of PrPy with the rigid pyrene unit shows a higher Brunauer-Emmet-Teller specific surface area of 1219m2g-1 than the tetraphenylethylene-containing polymer of PrTPE （770m2g 1）, which leads to a high CO2 uptake ability of 3.89mmolg I at 1.13bar/273K and a H2 uptake ability of 1.69wt% at 1.13bar/77K. The photocatalytic hydrogen production experiments revealed that PrPy also shows a better photocatalytic performance than PrTPE due to the higher conjugation degree and planar structure, the broader UV-visible （UV-Vis） absorption, the lower photoluminescence lifetime, and the higher specific surface area.

关键词： perylene conjugated mieroporous polymers gas adsorption hydrogen evolution

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置入微创椎间融合器高度对青少年腰椎间盘突出症患者腰椎生物力学的影响

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中国组织工程研究 2025年第21期29卷 4421-4429页

作者：张若帆关欢欢何卓群张云凤金凤王志强王建忠李筱贺祝勇王海燕张凯内蒙古医科大学研究生院内蒙古自治区呼和浩特市010110 内蒙古医科大学第二附属医院影像科内蒙古自治区呼和浩特市010010 内蒙古医科大学附属医院影像科内蒙古自治区呼和浩特市010010 内蒙古医科大学基础医学院人体解剖学教研室内蒙古自治区呼和浩特市010110 北京大学肿瘤医院内蒙古医院(内蒙古医科大学附属肿瘤医院) 内蒙古自治区呼和浩特市010010 乌兰察布市第二医院骨科内蒙古自治区乌兰察布市012000

背景:青少年腰椎间盘突出症是引起青少年腰疼的主要病因,目前绝大多数患者通过保守治疗干预,而当长期的非手术治疗尝试后,患者的症状没有得到充分缓解或者当患者出现神经麻痹或马尾神经受压的症状时,手术可能是防止进一步损伤的必要手段... 详细信息

背景:青少年腰椎间盘突出症是引起青少年腰疼的主要病因,目前绝大多数患者通过保守治疗干预,而当长期的非手术治疗尝试后,患者的症状没有得到充分缓解或者当患者出现神经麻痹或马尾神经受压的症状时,手术可能是防止进一步损伤的必要手段,而选择合适的椎间融合器至关重要。目的:探究青少年腰椎间盘突出症患者置入不同高度微创椎间融合器固定后对腰椎生物力学的影响。方法:采集一名17岁男性青少年腰椎间盘突出症患者(L4-5节段突出)的CT扫描资料,MIMICS三维重建后,选择用与实验对象椎间隙等高和高于椎间隙3 mm椎间融合器进行分析,设计重建两种可膨胀混合材料椎间融合器:融合器L前高11 mm、后高9 mm、宽9 mm、长28 mm;融合器H前高14 mm、后高11 mm、宽11 mm、长28 mm,并对腰椎融合器进行建模。将融合器与腰椎模型经过优化处理,逆向建模后导入ABAQUS并最终得到腰椎融合三维模型。模拟人体腰椎后伸、前屈、右侧弯、左侧弯等生理活动,得到相应应力云图,观察L4-5椎体在7种不同工况下的生物力学特征。结果与结论;(1)两种融合器终板最大应力均在前屈和后伸工况,前屈工况H融合器上、下终板应力值为(18.27±3.80)MPa和(15.02±3.24)MPa;L融合器上、下终板应力值为(9.16±0.05)MPa和(9.17±1.83)MPa;后伸工况H融合器上、下终板应力值为(19.11±4.03)MPa和(16.32±3.72)MPa;L融合器上、下终板应力值为(9.13±0.01)MPa和(4.92±1.01)MPa;(2)除中立位L5上终板,其余不同工况下H型融合器终板应力值均大于L型融合器终板,差异有显著性意义(P<0.05);(3)同一椎间隙中选择高度超过椎间隙高度3 mm的椎间融合器更稳定。

关键词：青少年腰椎间盘突出症椎间融合器内固定融合器高度有限元分析生物力学

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Zebrafish Foxc1a controls ventricular chamber maturation by directly regulating wwtr1 and nkx2.5 expression

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Journal of Genetics and Genomics 2022年第6期49卷 559-568页

作者： Luqingqing He Qinxin zhang Dongya Jiang yunfeng zhang Yuxuan Wei Yuxi Yang Nan Li Shuang Wang Yunyun Yue Qingshun Zhao Model Animal Research Center Medical SchoolNanjing UniversityNanjingJiangsu 210061China Department of Prenatal Diagnosis Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical UniversityNanjing Maternity and Child Health Care HospitalNanjingJiangsu 210004China School of Traditional Chinese Pharmacy China Pharmaceutical UniversityNanjingJiangsu 210009China

Chamber maturation is a significant process in cardiac development. Disorders of this crucial process lead to a range of congenital heart defects. Foxc1a is a critical transcription factor reported to regulate the specification of cardiac progenitor cells. However, little is known about the role of Foxc1a in modulating chamber maturation. Previously, we reported that foxc1a-null zebrafish embryos exhibit disrupted heart structures and functions. In this study, we observe that ventricle structure and cardiomyocyte proliferation are abolished during chamber maturation in foxc1a-null zebrafish embryos. To observe the endogenous localization of Foxc1a in the hearts of living embryos, we insert eyfp at the foxc1a genomic locus using TALEN. Analysis of the knockin zebrafish show that foxc1a is widely expressed in ventricular cardiomyocytes during chamber development. Cardiac RNA sequencing analysis reveals the downregulated expression of the Hippo signaling effector wwtr1. Dual-luciferase and chromatin immunoprecipitation assays reveal that Foxc1a can bind directly to three sites in the wwtr1 promoter region. Furthermore, wwtr1m RNA overexpression is sufficient to reverse the ventricle defects during chamber maturation. Conditional overexpression of nkx2.5 also partially rescues the ventricular defects during chamber development. These findings demonstrate that wwtr1 and nkx2.5 are direct targets of Foxc1a during ventricular chamber maturation.

关键词： Zebrafish Foxc1a Cardiac ventricular development wwtr1 nkx2.5

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Nitrogen fluorescence induced by the femtosecond intense laser pulses in air

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High Power Laser Science and Engineering 2016年第1期4卷 45-51页

作者： He Li Suyu Li Shuchang Li Dunli Liu Dan Tian Anmin Chen Ying Wang Xiaowei Wang yunfeng zhang Mingxing Jin Institute of Atomic and Molecular Physics Jilin University Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University)

Our experiments show that external focusing and initial laser energy strongly influences filament generated by the femtosecond Ti–sapphire laser in air. The experimental measurements show the filament length can be extended both by increasing the laser energy and focal length of focusing lens. On the other hand, the plasma fluorescence emission can be enhanced by increasing the laser energy with fixed focal length or decreasing the focal length. In addition, the collapse distance measured experimentally are larger than the calculated ones owing to the group-velocity-dispersion effect. In addition, we find that the line widths of the spectral lines from N2 is independent of filament positions, laser energies and external focusing.

关键词： femtosecond laser filament fluorescence

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Semi-interpenetrating polymer networks toward sulfonated poly(ether ether ketone) membranes for high concentration direct methanol fuel cell

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Chinese Chemical Letters 2019年第2期30卷 299-304页

作者： Xupo Liu yunfeng zhang Shaofeng Deng Cuicui Li Jiaming Dong Jiaying Wang Zehui Yang Deli Wang Hansong Cheng Sustainable Energy Laboratory Faculty of Materials Science and Chemistry China University of Geosciences (Wuhan) Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education Hubei Key Laboratory of Material Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.

关键词： Direct methanol fuel cell Proton exchange membrane Semi-interpenetrating polymer networks Sulfonated poly(ether ether ketone) Bromomethylated poly(phenylene oxide)

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On English Vocabulary Learning and Teaching in Middle Schools

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曲靖师范学院学报 1999年第S1期19卷 30-33页

作者： zhang yunfeng 曲靖市麒麟区第四中学云南曲靖655000

Vocabulary is basic to language learing It would be imposssible to learn a language without learning vocabulary. Vocabulary learning is considered to be a big task in foreign language leaming. As foreign language teachers, in order to help stdend learn English efficiently, it is necessary for us to discuss how vocabulary teaching and learning strategies can be improved. In this paper three aspects will be dicussed: Firstly, traditiasl Enhlish vocabulary teaching techniquesand itS pesible negative conse quencas; Secondly, how to leam vocabulary;And thirdly, how to teach vocabulary.

关键词： English learning Vocubulary eguivalents linguistics

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Aerosol deposition technology and its applications in batteries

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Nano Materials Science 2024年第1期6卷 24-37页

作者： Xinyu Wang Ramon Alberto Paredes Camacho Xiaoyu Xu Yumei Wang Yi Qiang Hans Kungl Ruediger-AEichel yunfeng zhang Li Lu National University of Singapore(Chongqing)Research Institute Chongqing401123PR China National University of Singapore Singapore117576 Fundamental Electrochemistry(IEK-9) Institute of Energy and Climate ResearchForschungszentrum Jülich52425JülichGermany

Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room *** resolves the challenge of integrating ceramic films onto temperaturesensitive substrates,including metals,glasses,and *** should be emphasized that the AD is a spray coating technology that uses powder without thermal assistance to generate films with high *** to the traditional sputter-based approach,the AD shows several advantages in efficiency,convenience,better interfacial bonding and so ***,it opens some possibilities to the field of batteries,especially all-solidstate batteries(ASSBs)and draws much attention not only for research but also for large scale *** purpose of this work is to provide a critical review on the science and technology of AD as well as its applications in the field of *** process,mechanism and effective parameters of AD,and recent developments in AD applications in the field of batteries will be systematically reviewed so that a trend for AD will be finally provided.

关键词： Aerosol deposition Room temperature impact consolidation Ceramic film All-solid-state battery Spray coating technology

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Characterization and mapping of a new male sterility mutant of anther advanced dehiscence(t) in rice

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Journal of Genetics and Genomics 2008年第3期35卷 177-182页

作者： Yi zhang yunfeng Li Jian zhang Fucheng Shen Yuanxin Huang Zhiwei Wu Key Laboratory of Biotechnology and Crop Quality Improvement Ministry of Agriculture Southwest University Chongqing 400716 China

Anther dehiscence is very important for pollen maturation and release. The mutants of anther dehiscence in rice （Oryza sativa L.） are few, and related research remains poor. A male sterility mutant of anther dehiscence in advance, add（t）, has been found in Minghui 63 and its sterility is not sensitive to thermo-photo. To learn the character of sterilization and the function of the add（t） gene, the morphological and cytological studies on the anther and pollen, the ability of the pistil being fertilized, inheritance of the mutant, and mapping of add（t） gene have been conducted. The anther size is normal but the color is white in the mutant against the natural yellow in the wild-type. The pollen is malformed, unstained, and small in the KI-I2 solution. The anther dehiscence is in advance at the bicellular pollen stage. A crossing test indicated that the grain setting ratio of the add（t） is significantly lower than that of the CMS line 2085A. The ability of the pistil being fertilized is most probably decreased by the add（t） gene. The male sterility is controlled by a single recessive gene of add（t）. This gene is mapped between the markers of R02004 （InDel） and RM300 （SSR） on chromosome 2, and the genetic distance from the add（t） gene to these markers is 0.78 cM and 4.66 cM, respectively.

关键词： male sterility sterility character gene mapping rice

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Animal Modelling of Lumbar Corpectomy and Fusion and in vivo Growth of Spine Supporting Bone by Titanium Cage Implants: An Experimental Study

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Journal of Bionic Engineering 2010年第4期7卷 329-336页

作者： Qingxian Hou,Qingsan Zhu,Yuntao Wu,Ran Li,Dan Li,yunfeng zhang,Qing Ruan First Hospital of Jilin University,Changchun 130021,P.R.China [a] First Hospital of Jilin University Changchun 130021 P. R. China

In this study a lumbar spinal fusion animal model is established to assess the effect of spinal fusion cage,and explore theminimum area ratio of titanium cage section to vertebral section that ensures bone healing and biomechanical *** was conducted by posterolateral approach with titanium cage implantation combined with plate *** with the same length but different diameters were *** implantation of titanium cages,the progress of bone healingwas observed and the bone biomechanical properties were measured,including deformation and displacement in axial compression,flexion,extension,and lateral bending *** factors affecting the in vivo growth of spine supporting body *** results show that the area ratio of titanium cage section to vertebral section should reach 1/2 to ensure the bonehealing,sufficient bone intensity and biomechanical *** bone healing indicators,such as BMP,suggest that there isa relationship between the peak time and the peak value of bone formation and metabolism markers and the bone healing strength.

关键词： lumbar corpectomy titanium cage implantation spinal fusion biomechanics bone metabolism markers

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