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Secondary transfer length and residual prestress of fractured strand in post-tensioned concrete beams

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Frontiers of Structural and Civil Engineering 2022年第3期16卷 388-400页

作者： Lizhao DAI Wengang xu Lei WANG Shanchang yi Wen chen School of Civil Engineering Changsha University of Science and TechnologyChangsha 410114China Laboratory of Microstructures and Material Mechanics University of LorraineMetz 57045France

An experimental study is performed on five post-tensioned concrete beams to explore the effects of different fracture positions on secondary transfer length and residual prestress of fractured strand.A numerical model is developed and used to predict the secondary transfer length and residual prestress of fractured strand in post-tensioned concrete *** model change interaction,which can deactivate and reactivate the elements for simulating the removal and reproduction of parts of the model,is used to reproduce the secondary anchorage of fractured *** numerical model is verified by experimental *** shows that the fractured strand can be reanchored in concrete through the secondary anchorage,and the secondary transfer length of fractured strand with the diameter of 15.2 mm is 1133 *** residual prestress of fractured strand increases gradually in the secondary transfer length,and tends to be a constant beyond *** the fractured strand is fully anchored in concrete,a minor prestress loss will appear,and the average prestress loss is 2.28%in the present study.

关键词： post-tensioned concrete beams strand fracture secondary transfer length residual prestress

Single fundamental mode photonic crystal VCSEL with high power and low threshold current optimized by modal loss analysis

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Chinese Physics B 2017年第1期26卷 200-207页

作者： yi-Yang Xie Qiang Kan chen xu Kun xu Hong-Da chen Key Laboratory of Optoelectronics Technology (Ministry of Education) Beijing University of Technology Beijing 100124 China State Key Laboratory of Integrated Optoelectronics Institute of Semiconductor Chinese Academy of Sciences Beijing 100083 China Zhengzhou University of Aeronautics Zhengzhou 450046 China

The characteristics of the photonic crystal vertical cavity surface emitting lasers（PhC-VCSELs） were investigated by using the full vector finite-difference time-domain（FDTD） method through the transverse mode loss analysis. PhC-VCSELs with different photonic crystal structures were analyzed theoretically and experimentally. Through combining the dual mode confinement of oxide aperture and seven-point-defect photonic crystal structure, the PhC-VCSELs with low threshold current of 0.9 mA and maximum output power of 3.1 mW operating in single fundamental mode were demonstrated. Mode loss analysis method was proven as a reliable and useful way to analyze and optimize the PhC-VCSELs.

关键词： vertical cavity surface emitting lasers single fundamental mode mode loss

Iterative Android automated testing

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Frontiers of Computer Science 2023年第5期17卷 15-26页

作者： yi ZHONG Mengyu SHI Youran xu Chunrong FANG Zhenyu chen State Key Laboratory for Novel Software Technology Nanjing UniversityNanjing 210093China School of Big Data and Computer Science Chongqing College of Mobile CommunicationChongqing 400065China

With the benefits of reducing time and workforce,automated testing has been widely used for the quality assurance of mobile applications(APPs).Compared with automated testing,manual testing can achieve higher coverage in complex interactive *** the effectiveness of manual testing is highly dependent on the user operation process(UOP)of experienced *** on the UOP,we propose an iterative Android automated testing(IAAT)method that automatically records,extracts,and integrates UOPs to guide the test logic of the tool across the complex Activity *** feedback test results can train the UOPs to achieve higher coverage in each *** extracted 50 UOPs and conducted experiments on 10 popular mobile APPs to demonstrate IAAT’s effectiveness compared with Monkey and the initial automated *** experimental results show a noticeable improvement in the IAAT compared with the test logic without human *** the 60 minutes test time,the average code coverage is improved by 13.98%to 37.83%,higher than the 27.48%of Monkey under the same conditions.

关键词： quality assurance automated testing UOP test coverage

Control of Negative Gravitropism and Tension Wood Formation by Gibberellic Acid and Indole Acetic Acid in Fraxinus mandshurica Rupr. var. japonica Maxim Seedlings

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Journal of Integrative Plant Biology 2006年第2期48卷 161-168页

作者： Sha Jiang yi-Fan Li xu-Hui chen Ke xu College of Life Sciences Nankai University Tianjin 300071 China

In the present study, we Investigated the role of glbberelllc acid （GA3） and Indole acetic acid （IAA） In the gravity response of stems and tension wood formation using two-year-old stems of Fraxinus mandshurica Rupr. var. Japonica Maxim seedlings. Forty-five seedlings were used and divided Into nine groups that Included five seedlings In each group. Seedlings were treated with applications of GA3 alone at concentrations of 2.89×10^-8 and 2.89×10^-7 μmol/L, IAA alone at concentrations of 5.71×10^-8 and 5.71×10^-7 μmol/L, or their combination to the apical bud of the stem using a mlcroplpette. Seedlings were positioned horizontally after the first treatment. The same treatments were repeated six times per week. At the end of the experiment, all seedlings were harvested. Then, stem segments were cut under a light microscope. Application of exogenous GA3 at the higher concentration stimulated the upward bending of stems, whereas exogenous IAA had no effect. A synergistic effect of GA3 and IAA on upward stem bending was observed following application of the two combinations of GA3 and IAA. Moreover, application of exogenous GA3 at the higher dose stimulated wood formation on both the upper and lower sides of the stems, whereas the mixture of GA3 and IAA had a synerglstic effect on wood formation In horizontal stems. Application of exogenous IAA alone at the lower concentration （5.71×10^-8 μmol/L） or application of a mixture of the higher concentrations of GA3 （2.89×10^-7 μmol/L） and IAA （5.71×10^-7 μmol/L） Inhibited the development of gelatinous fibers （the G-layer） of tension wood on the upper side of the horizontal stems. The differentiation of gelatinous fibers of tension wood was not Inhibited by GA3 when It was applied alone, whereas the development of the gelatinous fibers of tension wood was strongly affected by the application of IAA. The findings of the present study suggest that the development of the G-layer Is not related to the dose of GA3, but needs a relat

关键词： Fraxinus mandshurica gibberellic acid indole acetic acid interaction negative gravitropism tension wood.

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang xu ying-Tong Di Man-cheng Tang Ding-Kang chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei xu ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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既有公共建筑能效提升与全过程管理研究

江苏建筑 2020年第5期 121-123页

作者：朱文祥许锦峰陈龙季柳金李世宏徐亦陈江苏建科土木工程技术有限公司江苏南京210008 江苏建科鉴定咨询有限公司江苏南京210008 江苏建科工程咨询有限公司江苏南京210019

既有公共建筑能效提升实施过程复杂,提升后的实际效果与期望存在差距。文章对能效提升的实施方法与实施模式进行分析,提出了实施流程的全过程管理模式与方法,并对存在的问题进行探讨,为后续既有公共建筑的能效提升应用提供参考。

关键词：既有公共建筑能效提升全过程管理

Mechanism and application of an online intelligent evaluation model for energy consumption of a reheating furnace

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Journal of Iron and Steel Research International 2023年第1期30卷 102-111页

作者： Xiang-jun Bao Jing xu Guang chen xu chen Hong-guang Zhang yi-ming Shen Wei Zhai Department of Thermal Energy School of Energy and EnvironmentAnhui University of TechnologyMa’anshan 243002AnhuiChina Department of Metallurgical Engineering School of Energy and EnvironmentAnhui University of TechnologyMa’anshan 243002AuhuiChina Department of Construction and Environmental Engineering School of Architectural EngineeringAnhui University of TechnologyMa’anshan 243002AnhuiChina Ma’anshan Iron and Steel Co. Ltd.Ma’anshan 243003AnhuiChina

An online model was proposed to identify the reasons behind changes in the energy consumption of the reheating furnace of a steel processing *** heat conversion of the furnace was analyzed and integrated with the fuel consumption of the furnace to obtain a model of the energy *** with the mechanism analysis,the basic parameters affecting energy consumption were determined,and four key influencing factors were obtained:furnace output,furnace charging temperature,furnace tapping temperature,and steel *** specific calculation method of the contribution of each influencing factor was derived to define the conditions of the baseline energy consumption,while the online data were used to calculate the energy value and the actual performance value of the baseline energy *** contribution of each influencing factor was determined through *** cloud platform was used for database reconstruction and programming to realize the online intelligent evaluation of the energy consumption of the reheating ***,a case study of the evaluation of the practical energy consumption of a steel rolling furnace in a steel plant was *** intelligent evaluation results were quantified and displayed online,and the performance of the system in reducing production line energy consumption was demonstrated.

关键词： Online intelligent evaluation Model mechanism Contribution Data reconstruction

The effect of neural cell integrated into 3D co-axial bioprinted BMMSC structures during osteogenesis

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Regenerative Biomaterials 2021年第5期8卷 87-94页

作者： yi Zhang Haiyan chen Xiaoyan Long Tao xu Precision Medicine and Healthcare Research Center Tsinghua-Berkeley Shenzhen Institute(TBSI)Tsinghua UniversityShenzhen 518055People’s Republic of China East China Institute of Digital Medical Engineering Shangrao 334000People’s Republic of China Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China

A three-dimensional(3D)bioprinting is a new strategy for fabricating 3D cell-laden constructs that mimic the structural and functional characteristics of various tissues and provides a similar architecture and microenvironment of the native ***,there are few reported studies on the neural function properties of bioengineered bone ***,this study was aimed at investigating the effects of neural cell integration into 3D bioprinted bone *** bioprinted hydrogel constructs could maintain long-term cell survival,support cell growth for human bone marrow-derived mesenchymal stem cells(BMMSCs),reduce cell surface biomarkers of stemness,and enhance orthopedic differentiation with higher expression of osteogenesis-related genes,including osteopontin(OPN)and bone morphogenetic *** importantly,the bioprinted constructs with neural cell integration indicated higher OPN gene and secretory alkaline phosphatase *** results suggested that the innervation in bioprinted bone constructs can accelerate the differentiation and maturation of bone development and provide patients with an option for accelerated bone function restoration.

关键词： innervation 3D bioprinting co-axial BMMSC differentiation osteogenesis

Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation

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Nuclear Science and Techniques 2024年第5期35卷 99-108页

作者： You-Ming Deng Yong-Bin Leng Xing-yi xu Jian chen yi-Mei Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China University of Science and Technology of China Hefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle *** is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter ***,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this *** with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed *** basic principles of the method,simulation,and experimental comparison are also *** on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal *** results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed.

关键词： Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF