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| 1 | Formability of AA 2219-O sheet under quasi-static,electromagnetic dynamic,and mechanical dynamic tensile loadings显示文摘The mechanism by which electromagnetic forming(EMF)enhances the formability of metals is unclear owing to the coupling effect of multi-physics fields.In the present work,the associated formability improvement mechanisms were qualitatively categorized and illustrated.This was realized by comparing the formability of fully annealed 2219 aluminum alloy(AA 2219-O)sheet under quasi-static(QS),electromagnetic dynamic(EM),and mechanical dynamic(MD)tensile loadings.It was found that the forming limit of AA 2219-O sheet under EM tensile loading was significantly(45.4%)higher than that under QS tensile loading,and was marginally(3.7%–4.3%)higher than that under MD tensile loading.In addition,the forming limit of AA 2219-O sheet demonstrated a negative dependency on the strain rate within the range of the dynamic tensile tests conducted.The deformation conditions common to EM and MD tensile loadings were responsible for the significant formability improvement compared with QS tensile loading.In particular,the inertial effect was dominant.The different deformation conditions that distinguish EM tensile loading from MD tensile loading resulted in the marginal improvement in formability.This was caused by the absence of a sustaining contact force at the later deformation stage and the lower strain rate.The body force exerted little influence on the formability improvement,and the thermal effect under the two dynamic tensile loadings was negligible. | Hongliang Su Liang Huang Jianjun Li Wang Xiao Hui Zhu Fei Feng Hongwei Li Siliang Yan | 2021 | Journal of Materials Science & Technology2021，，11： | 13 |
| 2 | Role of the inter-pass cooling rate in recrystallization behaviors of Ni-based superalloy during interrupted hot compression显示文摘The microstructural evolution of a Ni-based superalloy under interrupted hot compressive deformation with different cooling rates in the inter-pass stage is investigated. It is found that metadynamic recrystallization(MDRX) in the inter-pass stage is more sensitive to the accumulated strain than the deformation temperature which is above the recrystallization temperature. The variations of both the grain distribution and the texture intensity caused by MDRX during the interpass stage result in variations of the yield stress(YS) and the work hardening(WH) rate in each stage. Results also show that the MDRX process in the inter-pass stage has a considerable influence on the final microstructure of three-pass compression. The final grain distribution is more uniform,and the compression texture gradually transforms into recrystallization texture with an increasing degree of MDRX. In order to predict the MDRX fraction in the inter-pass cooling stage, a modified kinetic equation is established, which can reasonably predict the MDRX behavior under multi-pass compression with different conditions in the inter-pass stage. Meanwhile, the influence of the interpass cooling stage on the mechanism of dynamic recrystallization(DRX) is studied. It is universally acknowledged that the discontinuous dynamic recrystallization(DDRX) process is the major deformation mechanism for the Ni-based superalloy. However, the continuous dynamic recrystallization(CDRX) process is promoted in the compression stage with a decrease of the cooling rate in each inter-pass stage. | Xin ZHANG Hongwei LI Mei ZHAN Siliang YAN Ning ZHANG | 2019 | Chinese Journal of Aeronautics2019，32，5： | 5 |
| 3 | Plastic wrinkling prediction in thin-walled part forming process: A review显示文摘The precision forming of thin-walled components has been urgently needed in aviation and aerospace field. However, the wrinkling induced by the compressive instability is one of the major defects in thin-walled part forming. The initiation and growth of the wrinkles are interactively affected by many factors such as stress states, mechanical properties of the material, geometry of the workpiece and boundary conditions. Especially when the forming process involves complicated boundary conditions such as multi-dies constrains, the perturbation of clearances between workpiece and dies and the contact conditions changing in time and space, etc., the predication of the wrinkling is further complicated. In this paper, the current prediction methods were summarized including the static equilibrium method, the energy method, the initial imperfection method,the eigenvalue buckling analysis method, the static-implicit finite element method and the dynamicexplicit finite element method. Then, a systematical comparison and summary of these methods in terms of their advantages and limitations are presented. By using a combination of explicit FE method, initial imperfection and energy conservation, a hybrid method is recommended to predict plastic wrinkling in thin-walled part forming. Finally, considering the urgent requirements of complex thin-walled structures' part in aviation and aerospace field, the trends and challenges in wrinkling prediction under complicated boundary conditions are presented. | Liu Nan Yang He Li Heng Yan Siliang | 2016 | Chinese Journal of Aeronautics2016，29，1： | 5 |
| 4 | Spatial characters of nutrients in Wujiangdu Reservoir in karst river,SW China显示文摘A preliminary assessment of the Wujiangdu Reservoir examined nutrient distribution and transport.Water samples were collected in the summer(July) of 2004, during the high-flow season. Inorganic nutrients(N,P, Si) and chlorophyll a(chl a) concentrations of the Wujiangdu Reservoir and its inflow rivers were analyzed.Other water parameters(dissolved oxygen, p H, temperature, and electrical conductivity) were measured as well.The results show gradually decreasing concentrations of NO_3^--N and dissolved silicate in the surface water moving downstream to the dam of the Wujiangdu Reservoir.Additionally, soluble reactive phosphorus concentrations measured very low, with most falling below the sensitivity threshold of the method used in surface waters. Particulate phosphorus and NO_3^--N were the predominant species of phosphorus and nitrogen in the reservoir, respectively. The concentration of nutrients in the Yeji River was the largest of all inflow rivers. The maximum concentration of chl a was found near the dam. These results reflect upstream conditions similar to that of a river, and reservoir conditions near the dam similar to that of a natural lake system. | Jun Zhu Siliang Li Yuchun Wang Haiyu Yan Limin Liao Jun Zhong | 2017 | Acta Geochimica2017，36，4： | 1 |
| 5 | 泰文和中文阅读过程中的眼动控制(中文)显示文摘This paper analyses some aspects of the eye movement behaviour of readers of Thai and Chinese. The main focus is on readers′landing site distributions on words and how these are affected by the lack of clear word boundary information due to the absence of inter-word spaces. Empirical evidence from Thai and Chinese readers suggest that readers can relatively accurately target word centres. We make the case that this accuracy can be accounted for by a default targetting model(effectively, the prior landing site distribution, in Bayesian terms)modulated by statistical cues about word beginnings available from word-initial character frequencies. | Ronan G. Reilly Inthraporn Aranyanak Lili Yu Guoli Yan Siliang Tang | 2011 | 心理与行为研究2011，9，1： | 0 |
| 6 | The partitioning patterns of nutrients between pods and seeds of Zanthoxylum fruits impacted by environmental factors显示文摘The nutritive quality in plant organs is related to the different partitioning patterns of nutrient resources among the organs under various environmental conditions.This study examined the relationship between the nutritive quality of pods and seeds in Zanthoxylum and environmental factors, such as temperature and preciptation by using numerous samples collected from Southwest China to the East China of Shandong peninsula. The increasing accumulations of N, P and C in seeds implied that the nutritive quality in seeds was higher at the regions with relative higher mean annual temperature(MAT) and mean annual precipitation(MAP), while that in pods was on the contrary. By contrast, pod nutritive content was relatively high, but seed nutritive content was relatively low at the regions with relative high MAT and MAP. In addition, C:N ratio in pods was significantly and negatively correlated with MAT and MAP, while that in seed was significantly and positively correlated with MAT and MAP. The partitioning patterns of N-compounds between pods and seeds reflected different nitrogen translocations in the plant organs under various climate condition. The N:P ratios were negatively correlated with MAP, implying a higher proportional allocation of P to seeds than that of N in the areas with a relative high MAP. Therefore, the strategies to assess pod nutritional quality should be taken into accountfor nutritive translocation under various environmental conditions. | Hechun Piao Siliang Li Zhifeng Yan | 2018 | Acta Geochimica2018，37，5： | 0 |
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