Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

上海自貿區司法保障制度之建設

( Gang Chen ) 제주대학교 법과정책연구소 2014 국제법무 Vol.6 No.2

The reform of China (Shanghai) free trade zone needs to be secured by a relevant legal framework. However, the free trade zone will initially only be a trial for two to three years, as per the “Overall Plan" which is the legal base for the construction of Shanghai Free Trade Zone. Due to the strict and time-consuming of legislative procedures in China, the establishment of relevant legal framework for the free trade zone would be lagging. Under this circumstance, if the court system waited for all legislations being established, the development of free trade zone would lack any legal protection. As a result, the process of the free trade zone reform might well be blocked. Therefore, the current legal system needs to be adaptive to the new environment; to strive a balance between the resistivity and effectiveness and between the market autonomy and nation control, as well as business freedom and transaction security. In doing so would provide effective legal protection in the free trade zone. The priority for the legal system is to address new legal issues that require legal reform in the free trade zone. Only then could the free trade zone be successfully set up.

Hsa-miR-181a-5p Expression and Effects on Cell Proliferation in Gastric Cancer

Chen, Gang,Shen, Zhi-Li,Wang, Ling,Lv, Chun-Ye,Huang, Xin-En,Zhou, Rong-Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Purpose: MicroRNAs (miRNAs) are small endogenous, non-coding, single-stranded RNAs (approximately 22 nt). Accumulating evidence has shown that aberrant miRNA expression is pronounced and correlated with gastric cancer genesis and progression. Materials and Methods: Expression levels of miR-181a-5p in GC tissues and cell lines were assessed by qRT-PCR and tested for correlation with clinical features. In addition, effects of miR-181a-5p on GC cell growth were investigated. Results: Our findings indicate that miR-181a-5p is upregulated in GC, in correlation with lymph node invasion, nerve invasion and vascular invasion (P<0.05). Enforced expression of miR-181a -5p promoted cell proliferation ability. Conclusions: This study suggested that increased miR-181a-5p is related to GC progression. MiR-181a-5p may represent a potential therapeutic target for GC.

Construction and Characterization of a Full-length cDNA Library and Identification of Genes Involved in Salinity Stress in Wild Eggplant (Solanum torvum Swartz)

Gang Chen,Hua Wang,Jun-Yi Gai,Yue-Lin Zhu,Li-Fei Yang,Qian-Qian Liu,Gong-Chen Zhang,Guo-Hu Chen 한국원예학회 2012 Horticulture, Environment, and Biotechnology Vol.53 No.2

The objectives of this paper were to construct a full-length cDNA library and to isolate genes that confer salt tolerance from the leaves of salinity-tolerant wild eggplant variety, ‘Torvum Vigor’ (Solanum torvum Swartz). A full-length cDNA library from the leaves was successfully constructed by a switching mechanism at 5’-end of RNA transcript (SMART) approach and a long-distance PCR (LD-PCR) technique. The titer of the primary cDNA library was 3.6 ×106 cfu・mL-1 and that of the amplified library was 1.2 × 1010 cfu・mL-1. Gel electrophoresis results showed that most of the cDNA inserts ranged from 0.40 to 2.5 kb, with a recombination rate of 99%. A total of 427 randomly selected positive clones were sequenced. After removing the unsuccessful reads, 364 datasets were obtained and have been submitted to the NCBI Nucleotide Sequence Database under GenBank accession numbers JK265131-JK265494. Among the 364 submitted sequences, 74.45% of them contained full-length coding regions. BLASTX analysis revealed that 62.36% of the ‘Torvum Vigor’ expressed sequence tags (ESTs) possessed homology to known or putative proteins of other organisms. Seven genes that might be responsible for the encoding of known proteins in other organisms were identified to confer salt tolerance. This evidence demonstrated that the cDNA library constructed was a full-length library of high quality. It could be a useful resource for further research in the cloning of stress-related genes, which could be utilized in the genetic improvement of vegetable crops using transgenic technology.

Complex Mechanical Equipment Manufacturing Scheme Optimization Based on Multi-attribute Fuzzy Information Measurement Model

Gang Yang,Kangwei Chen 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

Design of complex mechanical equipment and scheme of manufacturing need a comprehensive consideration of constraints, and it embodies multiple layers, complexity, multiple types and uncertainty. This paper analyzes the question of scheme optimization for complex mechanical equipment and proposes a method of manufacturing scheme optimization for complex mechanical equipment based on multi -attribute fuzzy information measurement model. This method functions to build an indicator system of optimization scheme for manufacturing complex mechanical equipment. Three models are designed to evaluate all optimization indicators the system, namely model for computation of fuzzy interval indicator’s information quantity, model for computation of qualitative indicator information quantity and model for computation of fuzzy indicator’s information quantity with degree of membership. Weights are given to information quantity optimization indicators in different layers get total complex mechanical equipment scheme choose optimal strategy based on design manufacture.

A New Chromone Glycoside from Rhododendron spinuliferum

Gang Chen,Xue Feng Li,Qi Zhang,Hui Zi Jin,Yun Heng Shen,Shi Kai Yan,Wei Dong Zhang 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.8

A new chromone glycoside, 3,5,7-trihydroxylchromone-3-O-α-L-arabinopyranoside (1), together with quercetin (2), (+)-catechin (3), (-)-epi-catechin (4) were isolated from the aerial parts of Rhododendron spinuliferum. The structure of 1 was elucidated on the basis of spectroscopic and 2D-NMR spectral analysis. In addition, 1 exhibited mild inhibitory effect on NO production in LPS-stimulated RAW264.7 cells.

Tripod gait-based turning gait of a six-legged walking robot

Gang Chen,Bo Jin,Ying Chen 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

The turning gait planning and improvement methods of a six-legged walking robot on the basis of tripod gait are presented in this study. A projection method that considers an unstructured environment is proposed for the turning gait planning of the six-legged walking robot. The body and foot motion trajectories of the swing legs are planned with polynomial curves to keep the robot steady while walking. Two basic turning gaits, namely, circling and spinning gaits, are successfully designed with the planning method. An optimized method is proposed to improve the turning angle, which is subjected to stability, kinematics, and relief amplitude constraints in the unstructured environment. The turning ability of the turning gait is improved with the optimized turning angle. The circling and spinning gaits are implemented in simulations and experiments. Results demonstrate that the planning and improvement methods for the turning gait are valid and correct.

Enhanced Locality Sensitive Clustering in High Dimensional Space

Chen, Gang,Gao, Hao-Lin,Li, Bi-Cheng,Hu, Guo-En The Korean Institute of Electrical and Electronic 2014 Transactions on Electrical and Electronic Material Vol.15 No.3

A dataset can be clustered by merging the bucket indices that come from the random projection of locality sensitive hashing functions. It should be noted that for this to work the merging interval must be calculated first. To improve the feasibility of large scale data clustering in high dimensional space we propose an enhanced Locality Sensitive Hashing Clustering Method. Firstly, multiple hashing functions are generated. Secondly, data points are projected to bucket indices. Thirdly, bucket indices are clustered to get class labels. Experimental results showed that on synthetic datasets this method achieves high accuracy at much improved cluster speeds. These attributes make it well suited to clustering data in high dimensional space.

Enhanced Locality Sensitive Clustering in High Dimensional Space

Gang Chen,Hao-Lin Gao,Bi-Cheng Li,Guo-En Hu 한국전기전자재료학회 2014 Transactions on Electrical and Electronic Material Vol.15 No.3

A dataset can be clustered by merging the bucket indices that come from the random projection of locality sensitivehashing functions. It should be noted that for this to work the merging interval must be calculated first. To improvethe feasibility of large scale data clustering in high dimensional space we propose an enhanced Locality SensitiveHashing Clustering Method. Firstly, multiple hashing functions are generated. Secondly, data points are projected tobucket indices. Thirdly, bucket indices are clustered to get class labels. Experimental results showed that on syntheticdatasets this method achieves high accuracy at much improved cluster speeds. These attributes make it well suited toclustering data in high dimensional space.

Microstructure Evolution and Tensile Mechanical Properties of Thixoformed High Performance Al-Zn-Mg-Cu Alloy

Gang Chen,Qiang Chen,Bo Wang,Zhi-ming Du 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.5

Al-Zn-Mg-Cu alloys are the strongest aluminum alloys which have been widely used for aerospace applications. They are usually machined from the wrought state usually with a high waste percentage. To reduce waste, it is important to thixoform these alloys in near net shape. In this work, the thixoformability of a commercial high performance Al-Zn-Mg-Cu alloy 7075 was studied. A novel multistep reheating regime was developed in recrystallization and partial melting (RAP) route to obtain spheroidal semi-solid microstructures. The as-extruded 7075 alloy was fully recrystallized for a short holding time using the multistep reheating regime. Semi-solid microstructures with fine and spherical solid grains with a grain size of 40-50 μm embedded in liquid matrix were obtained. The advantage of the multistep reheating regimes over those conventional routes was also discussed. Some wheel-shaped components were thixoformed from the as-received 7075 alloy. The ultimate tensile strength, yield strength and elongation to fracture of the thixoformed component based on multistep reheating regime, are 510 MPa, 446 MPa and 17.5% respectively. These values are superior to those of the products manufactured with the conventional RAP route. As the results indicated, thixoforming could be conducted based on commercial extruded Al-Zn-Mg-Cu alloys, which has important practical significance.