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| 1 | Damage characteristics and constitutive modeling of the 2D C/Si C composite: Part I – Experiment and analysis显示文摘This paper reports an experimental investigation on the macroscopic mechanical behaviors and damage mechanisms of the plain-woven(2D) C/Si C composite under in-plane on- and offaxis loading conditions. Specimens with 15, 30, and 45 off-axis angles were prepared and tested under monotonic and incremental cyclic tension and compression loads. The obtained results were compared with those of uniaxial tension, compression, and shear specimens. The relationships between the damage modes and the stress state were analyzed based on scanning electronic microscopy(SEM) observations and acoustic emission(AE) data. The test results reveal the remarkable axial anisotropy and unilateral behavior of the material. The off-axis tension test results show that the material is fiber-dominant and the evolution rate of damage and inelastic strain is accelerated under the corresponding combined biaxial tension and shear loads. Due to the damage impediment effect of compression stress, compression specimens show higher mechanical properties and lower damage evolution rates than tension specimens with the same off-axis angle. Under cyclic tension–compression loadings, both on-axis and off-axis specimens exhibit progressive damage deactivation behaviors in the compression range, but with different deactivation rates. | Li Jun Jiao Guiqiong Wang Bo Yang Chengpeng Wang Gang | 2014 | Chinese Journal of Aeronautics2014，27，6： | 10 |
| 2 | Damage characteristics and constitutive modeling of the 2D C/SiC composite: Part Ⅱ–Material model and numerical implementation显示文摘In this work, a macroscopic non-linear constitutive model accounting for damage, inelastic strain and unilateral behavior is proposed for the 2D plain-woven C/Si C composite. A set of scalar damage variables and a new thermodynamic potential expression are introduced in the framework of continuum damage mechanics. In the deduced constitutive equations, the material's progressive damage deactivation behavior during the compression loading is described by a continuous function, and different deactivation rates under uniaxial and biaxial compression loadings are also considered. In damage evolution laws, the coupling effect among the damage modes and impediment effect of compression stress on the development of shear damage in different plane stress states are taken into account. Besides, the general plasticity theory is applied to describing the evolution of inelastic strain in tension and/or shear stress state. The Tsai–Wu failure criterion is adopted for strength analysis. Additionally, the material model is implemented as a user-defined material subroutine(UMAT) and linked to the ABAQUS finite element software, and its performance is demonstrated through several numerical examples. | Li Jun Jiao Guiqiong Wang Bo Li Liang Yang Chengpeng | 2015 | Chinese Journal of Aeronautics2015，28，1： | 10 |
| 3 | The response of deltaic systems to climatic and hydrological changes in Daihai Lake rift basin,Inner Mongolia,northern China显示文摘Delta systems are ubiquitous around lacustrine rift basins. Its peripheral ge-ometry, progradation structures and sedimentary successions were controlled by both tec-tonic settings and climatic changes. Peripheral geometry of a delta was strongly influenced by depositional gradients which formed the fan-shape delta on the steep slopes and developed the lobe-shape delta on the gentle slopes. Due to the discharge feed rivers can change rapidly driven by climatic variations, and the nearshore area of deltas display considerable facies variability. The rise of annual rainfall, which suggests the rivers feeding deltas are continuous, and result in distributary mouth bars that are prevalent in the front of deltas since the down-slope flows are greater than the along-slope currents. On the contrary, when the annual rainfall decreases and evaporation increases, the rivers only can feed deltas ephemerally. If the along-slope currents were in a dominant position, the distal bars were deposited. Progra-dation structure and sedimentary successions of deltas were controlled by the gradients of slopes. On gentle depositional slopes, shingle foreset beds predominate with fine sediments and small-scale sedimentary structures or vice versa. | Yu Xinghe Li Shunli Tan Chengpeng Xie Jing Chen Bintao Yang Fan | 2013 | Journal of Palaeogeography2013，2，1： | 6 |
| 4 | An efficient CRISPR/Cas9 platform for targeted genome editing in rose(Rosa hybrida)显示文摘The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-related nuclease 9(Cas9)system enables precise,simple editing of genes in many animals and plants.However,this system has not been applied to rose(Rosa hybrida)due to the genomic complexity and lack of an efficient transformation technology for this plant.Here,we established a platform for screening single-guide RNAs(sgRNAs)with high editing efficiency for CRISPR/Cas9-mediated gene editing in rose using suspension cells.We used the Arabidopsis thaliana U6-29 promoter,which showed high activity for driving sgRNA expression,to modify the CRISPR/Cas9 system.We used our highly efficient optimized CRISPR/Cas9 system to successfully edit RhEIN2,encoding an indispensable component of the ethylene signaling pathway,resulting in ethylene insensitivity in rose.Our optimized CRISPR/Cas9 system provides a powerful toolbox for functional genomics,molecular breeding,and synthetic biology in rose. | Chengpeng Wang Yang Li Na Wang Qin Yu Yonghong Li Junping Gao Xiaofeng Zhou Nan Ma | 2023 | Journal of Integrative Plant Biology2023，65，4： | 1 |
| 5 | Effects of the Northeast China Revitalization Strategy on Regional Economic Growth and Social Development显示文摘Measuring the economic and social effects of the Northeast China Revitalization Strategy is critical to addressing regional sustainable development in China. To shed light on this issue, an integrated perspective was adopted that is combined with the difference-in-differences method to measure the effects of the strategy on economic growth and social development in Northeast China. The findings suggest that the strategy has significantly improved regional economic growth and per-capita income by increasing its gross domestic product(GDP) and GDP per capita by 25.70% and 46.00%, respectively. However, the strategy has significantly worsened the regional employment in the secondary industry of the region. In addition, the strategy has not significantly improved regional infrastructural road, education investment or social security, and has had no significant effect on mitigating regional disparity. In addition, the policy effects are highly heterogeneous across cities based on city size and characteristics. Therefore, there is no simple answer regarding whether the Northeast China Revitalization Strategy has reached its original goals from an integrated perspective. The next phase of the strategy should emphasize improving research and development(R&D) and human capital investments based on urban heterogeneity to prevent conservative path-dependency and the lock-in of outdated technologies. | REN Wanxia XUE Bing YANG Jun LU Chengpeng | 2020 | Chinese Geographical Science2020，30，5： | 1 |
| 6 | Achieving highest Young’s modulus in Al-Li by tracing the size and bonding evolution of Li-rich precipitates显示文摘For decades,it has been well accepted that every 1 wt.%Li addition to Al will reduce Al alloy’s density by 3%and increase its Young’s modulus by 6%.However,the fundamental mechanism of modulus improve-ments stays controversial though all studies agreed that the contribution of such a substantial boosting comes from Li-rich clusters either in solid solution or precipitations.In this study,we experimentally produce nano-sized Li-rich clusters by non-equilibrium solidification using centrifugal casting and trace their evolutions as a function of subsequent heat treatments.High-resolution transmission electron mi-croscopy(HRTEM)reveals a further decrease in the lattice constants of Li-rich regions from the as-cast(0.406 nm),solid solution(0.405 nm)to the aged state(0.401 nm),while Young’s modulus of the Al-Li al-loy reaches 89.16 GPa.Small-angle neutron scattering(SANS)experiments and first-principle calculations based on density functional theory have shown both the bond strength around precipitates and the size of those Li-rich region dominate Young’s modulus.At the beginning,it is volumetric compression due to Li addition that increases modulus,tightening the Al-Al potential curves.In the end,it is the Al-Al and Al-Li valence bonds in Al 3 Li at large size and high-volume fraction which increase its second derivative of internal energy and thus Young’s modulus. | Chengpeng Xue Yuxuan Zhang Shuo Wang Guangyuan Tian Xinghai Yang Yubin Ke Zhenhua Xie Junsheng Wang | 2023 | Journal of Materials Science & Technology2023，，14： | 1 |
| 7 | Direct laser writing breaking diffraction barrier based on two-focus parallel peripheralphotoinhibition lithography显示文摘Direct laser writing(DLW)enables arbitrary three-dimensional nanofabrication.However,the diffraction limit poses a major obstacle for realizing nanometer-scale features.Furthermore,it is challenging to improve the fabrication efficiency using the currently prevalent single-focal-spot systems,which cannot perform high-throughput lithography.To overcome these challenges,a parallel peripheral-photoinhibition lithography system with a sub-40-nm two-dimensional feature size and a sub-20-nm suspended line width was developed in our study,based on two-photon polymerization DLW.The lithography efficiency of the developed system is twice that of conventional systems for both uniform and complex structures.The proposed system facilitates the realization of portable DLW with a higher resolution and throughput. | Dazhao Zhu Liang Xu Chenliang Ding Zhenyao Yang Yiwei Qiu Chun Cao Hongyang He Jiawei Chen Mengbo Tang Lanxin Zhan Xiaoyi Zhang Qiuyuan Sun Chengpeng Ma Zhen Wei Wenjie Liu Xiang Fu Cuifang Kuang Haifeng Li Xu Liu | 2022 | Advanced Photonics2022，4，6： | 1 |
| 8 | Ultra-high strength yet superplasticity in a hetero-grain-sized nanocrystalline Au nanowire显示文摘Nanocrystalline metals often display a high strength up to the gigapascal level,yet they suffer from poor plasticity.Previous studies have shown that the development of hetero-sized grains can efficiently overcome the strength-ductility trade-off of nanocrystalline metals.However,whether this strategy can lead to the fabrication of nanocrystalline nanowires exhibiting both high strength and superplasticity is unclear,similar to the atomistic deformation mechanism.In this paper,we show that ultra-small nanocrystalline Au nanowires comprising grains in both the Hall–Petch and inverse Hall–Petch grain-size regions can exhibit extremely high uniform elongation(236%)and high strength(2.34 gigapascals)at room temperature.In situ atomic-scale observations revealed that the plastic deformation underwent two stages.In the first stage,the super-elongation ability originated from the intergrain plasticity of small grains via mechanisms such as grain boundary migration and grain rotation.This intergrain plasticity caused the grains in the heterogeneous-structured nanowires to grow very large.In the second stage,the superelongation ability originated from intragrain plasticity accompanied by the diffusion of surface atoms.Our results show that the hetero-grain-sized nanocrystalline nanowires,comprising grains with sizes both in the strongest Hall–Petch effect region and the inverse Hall–Petch effect region,were simultaneously ultrastrong and ductile.They displayed neither a strength-ductility trade-off nor plastic instability. | Libo Fu Deli Kong Chengpeng Yang Jiao Teng Yan Lu Yizhong Guo Guo Yang Xin Yan Pan Liu Mingwei Chen Ze Zhang Lihua Wang Xiaodong Han | 2022 | Journal of Materials Science & Technology2022，，6： | 1 |
| 9 | Identifying the crystal structure of T 1 precipitates in Al-Li-Cu alloys by ab initio calculations and HAADF-STEM imaging显示文摘Controversial experimental reports on the crystal structure of T 1 precipitates in Al-Li-Cu alloys have ex-isted for a long time,and all of them can be classified into five models.To clarify its ground-state atomic structure,herein,we have combined high-throughput first-principles calculations and CALPHAD,as well as aberration-corrected HAADF-STEM experiments.Employing the special quasi-random structure(SQS)and supercell approximation(SPA)methods to simulate the local disorder on Al-Cu sub-lattices,we find that none of the present models can satisfy the phase stability in Al-Li-Cu ternary system based on temperature-dependent convex hull analysis.Using the cluster expansion(CE)formulas,structural predic-tions derived from the five-frame models were performed.Subsequently,by introducing the vibrational contribution to the free energy at aging temperatures,we proposed a novel ground-state T 1 structure that maintains a coherent relationship with Al-matrix at the<112>Al orientation.The underlying phase transition between the variants of T 1 precipitates was further discussed.By means of ab initio molecular dynamics(AIMD)simulations,we resolved the controversy regarding the number of atomic layers con-stituting the T 1 phase and acknowledged the existence of Al-Li corrugated layers.The root cause of this structural distortion is triggered by atomic forces and bondings.Our work can have an positive impact on the novel fourth generation of Al-Cu-Li alloy designs by engineering the T 1 strengthening phase. | Shuo Wang Xianghai Yang Junsheng Wang Chi Zhang Chengpeng Xue | 2023 | Journal of Materials Science & Technology2023，，2： | 1 |
| 10 | Failure criteria for C/SiC composites under plane stress state显示文摘The applicability and limitation of several quadratic strength theories were investigated with respect to 2D-C/SiC and 2.5D-C/SiC composites. A kind of damage-based failure criterion, referred to as D-criterion, is proposed for nonlinear ceramic composites. Meanwhile, the newly developed criterion is preliminarily validated under tension-shear combined loadings. The prediction shows that the failure envelope given by D-criterion is lower than that from Tsai–Hill and Hoffman criteria. This reveals that the damage-based criterion is reasonable for evaluation of damage-dominated failure strength. | Chengpeng Yang Guiqiong Jiao Hongbao Guo | 2014 | Theoretical & Applied Mechanics Letters2014，4，2： | 1 |
| 11 | Analysis of Unstarted Hypersonic Flow Unsteadiness Based on Schlieren Image Processing显示文摘The unstarted flow field in a hypersonic inlet model at a design point of Ma 6 is studied experimentally.The time-resolved spatial flow characteristics of the separation shock oscillation,which is induced by the unstarted flow,are analyzed based on a high-speed Schlieren system and an image processing method.The motion of the separation shock detected by the shock-detection algorithm is compared to the results of fast-response wall-pressure measurements,and good agreement is demonstrated by comparing the frequency components in the power spectral density contours between shock oscillation and pressure fluctuation.The hysteresis of the pressure and separation shock during oscillation cycles is observed from the time history of the shock motion,which means that the unsteady flow pattern of the unstarted hypersonic flow can be accurately clarified by time-resolved Schlieren image processing.These results convincingly demonstrate that the shock-detection technique is successfully applied to an unstarted hypersonic flow case. | WANG Chengpeng WANG Wenshuo XUE Longsheng XU Pei YANG Jinfu | 2019 | Transactions of Nanjing University of Aeronautics and Astronautics2019，36，5： | 0 |
| 12 | Development of Integrated Computational Materials Engineering(ICME)Model for Mg Alloy Design and Process Optimization显示文摘Integrated computational materials engineering(ICME)has emerged to be one of the most powerful materials genome engineering(MGE)approaches in designing new materials and manufacturing processes in recent years.It has successfully deployed many new products for the electronic,automotive,and aerospace industries.This paper reviews the current status of research on first principles in the design of high-strength Mg alloys,discusses the application of crystal plasticity finite element models to the microscale slip,twinning,microstructure morphology,texture evolution,and macroscopic forming of Mg alloys,and introduces the research progress of crystal plasticity finite element models and phase field models,meta cellular automata models and first principles coupled models respectively,around the need for multi-scale coupled simulations of Mg alloys.The key technology obstacles of integrating the first principles,crystal plasticity finite element,and microstructure models for Mg alloys have been solved.This paper can provide a reference for the design of new Mg alloy compositions and the development of high-performance Mg alloys. | Hui Su Zhifei Yan Yingchun Tian Chengpeng Xue Shuo Wang Guangyuan Tian Xinghai Yang Quan Li Xuelong Wu Zhongyao Li Junsheng Wang | 2023 | Journal of Beijing Institute of Technology2023，32，4： | 0 |
| 13 | Integrated Computational Materials Engineering for the Development and Design of High Modulus Al Alloys显示文摘Integrated computational materials engineering(ICME)is to integrate multi-scale computational simulations and key experimental methods such as macroscopic,mesoscopic,and microscopic into the whole process of Al alloys design and development,which enables the design and development of Al alloys to upgrade from traditional empirical to the integration of compositionprocess-structure-mechanical property,thus greatly accelerating its development speed and reducing its development cost.This study combines calculation of phase diagram(CALPHAD),Finite element calculations,first principle calculations,and microstructure characterization methods to predict and regulate the formation and structure of composite precipitates from the design of highmodulus Al alloy compositions and optimize the casting process parameters to inhibit the formation of micropore defects in the casting process,and the final tensile strength of Al alloys reaches420 MPa and Young's modulus reaches more than 88 GPa,which achieves the design goal of the high strength and modulus Al alloys,and establishes a new mode of the design and development of the strength/modulus Al alloys. | Chengpeng Xue Xinghai Yang Shuo Wang Junsheng Wang | 2023 | Journal of Beijing Institute of Technology2023，32，4： | 0 |
| 14 | Evaluation on the fresh eating quality of tree peony flowers显示文摘Tree peony(Paeonia suffruticosa)is an ornamental and medicinal plant in China.The fresh eating of flower petals has gradually become a new idea for further development.This study analyzed the sensory indexes,nutritional indexes and antioxidant indexes of fresh flowers of five cultivars,namely,‘Fengdan’(P.ostia‘Fengdan’),‘Xiangyu’(P.suffruticosa‘Xiangyu’),‘Zhaofen’(P.suffruticosa‘Zhanfen’),‘Luoyanghong’(P.suffruticosa‘Luoyanghong’)and‘High Noon’(P.‘High Noon’),to provide a theoretical basis for eating fresh tree peony flowers.The aroma volatiles of petals mainly comprised terpenes,alcohols and alkanes.‘Luoyanghong’and‘High Noon’have brighter colors.The taste test showed that‘Luoyanghong’,‘High Noon’and‘Xiangyu’were the most palatable.‘High Noon’contained the highest soluble sugar content,‘Luoyanghong’contained the highest starch and vitamin C(VC)levels,and‘Zhaofen’contained the highest soluble protein content.The contents of bioactive compounds were the highest in‘Luoyanghong’,and superoxide dismutase(SOD)activity was the highest in‘Xiangyu’.The petals were rich in essential amino acids,with the highest amount in‘Xiangyu’.‘Luoyanghong’and‘High Noon’showed strong antioxidant capacity.Therefore,tree peony flowers have excellent sensory qualities,abundant nutrients and strong antioxidant activity and could be further developed as a food to be eaten fresh.The results showed that tree peony flowers had great edible potential.Flowers of red and yellow cultivars can be considered for fresh eating on the basis of the traditional consumption of white and pink tree peony flowers. | Chengpeng Yin Xinwen Zhang Kun Li Yang Bai Ping Yang Chuanrong Li Xiuhua Song | 2022 | Food Bioscience2022，47，3： | 0 |
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