The Element Segregation Between γ/γʹ Phases in a Ni-Based Single Crystal Superalloy Studied by 3D-APT and Its Potential Impact on Local Interfacial Misfit Strain

Wenchao Yang,Pengfei Qu,Ruirong Zhang,Jiarun Qin,Chen Liu,Jun Zhang,Lin Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Three-dimensional atom-probe tomography was used to characterize the γ/γʹ interface structure in a third-generation Nibasedsingle crystal superalloy with Re addition. It was found that an element-segregation layer with Re, Co and Cr wasformed in the γ phase close to the γ/γ′ interface, resulting in a more negative local interface misfit (− 0.29%) compared tothe measured result (− 0.16%) from high-resolution X-ray diffraction. Furthermore, the total reduction of interfacial freeenergy due to the solute atom segregation based on the Gibbsian interfacial excess was calculated to indicate that Re elementwas the most beneficial element in producing this more negative local misfit with the largest interfacial free energy reduction(13.67 ± 0.21 mJ/m2). Simultaneously, because of the co-segregation of Re, Co and Cr, and the depletion of Ni in the γphase close to the γ/γ′ interface, it was also deduced that some harmful topologically close-packed phases might be easierto nucleate and grow in the γ phase close to the γ/γ′ interface in service.

Investigation on Digital Media Image Processing Algorithm Based on Asynchronous and Inertia Adaptive Particle Swarm Optimization

Wenchao Zhang,Caigen Zhou,Xinxin Bao 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.2

With the continuous development of computer science and technology, image processing and analysis gradually form the scientific system. Although history of image processing is not long, it attracts many researchers study on it. Digital media image widely exists in many fields, such as education, video, advertisement, and so on. Process digital media image is an important part of image processing. When analyze the digital media image, we want to extract the image part we care from the original image and then method for image segmentation is quite important. That is to say that the image segmentation will divide the image into a number of regions with specific and unique nature. How to keep the original characteristics of the digital media image is quite important in the image segmentation. In this paper, we propose a new algorithm for digital media image segmentation, and it is also can be used in the image processing. The algorithm is based on asynchronous particle swarm optimization algorithm to obtain the adaptive threshold; take the inertia factor into the algorithm, the optimal threshold has been acquired for the image segmentation. Compared with other particle swarm optimization algorithm, the algorithm has the advantages of stable, easy to converge to the optimal solution, and high segmentation speed.

Novel Nucleotide Variations, Haplotypes Structure and Associations with Growth Related Traits of Goat AT Motif-Binding Factor (ATBF1) Gene

Zhang, Xiaoyan,Wu, Xianfeng,Jia, Wenchao,Pan, Chuanying,Li, Xiangcheng,Lei, Chuzhao,Chen, Hong,Lan, Xianyong Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.10

The AT motif-binding factor (ATBF1) not only interacts with protein inhibitor of activated signal transducer and activator of transcription 3 (STAT3) (PIAS3) to suppress STAT3 signaling regulating embryo early development and cell differentiation, but is required for early activation of the pituitary specific transcription factor 1 (Pit1) gene (also known as POU1F1) critically affecting mammalian growth and development. The goal of this study was to detect novel nucleotide variations and haplotypes structure of the ATBF1 gene, as well as to test their associations with growth-related traits in goats. Herein, a total of seven novel single nucleotide polymorphisms (SNPs) (SNP 1-7) within this gene were found in two well-known Chinese native goat breeds. Haplotypes structure analysis demonstrated that there were four haplotypes in Hainan black goat while seventeen haplotypes in Xinong Saanen dairy goat, and both breeds only shared one haplotype (hap1). Association testing revealed that the SNP2, SNP5, SNP6, and SNP7 loci were also found to significantly associate with growth-related traits in goats, respectively. Moreover, one diplotype in Xinong Saanen dairy goats significantly linked to growth related traits. These preliminary findings not only would extend the spectrum of genetic variations of the goat ATBF1 gene, but also would contribute to implementing marker-assisted selection in genetics and breeding in goats.

A Fluorinated Polythiophene Derivative with Stabilized Backbone Conformation for Highly Efficient Fullerene and Non-Fullerene Polymer Solar Cells

Zhang, Shaoqing,Qin, Yunpeng,Uddin, Mohammad Afsar,Jang, Bomee,Zhao, Wenchao,Liu, Delong,Woo, Han Young,Hou, Jianhui American Chemical Society 2016 Macromolecules Vol.49 No.8

<P>Here, taking a polythiophene derivative (PBDD4T) as a starting polymer, we tried to increase the rotation barrier and hence stabilize its backbone conformation by introducing fluorine into the beta and beta'-position of the alpha-linked bithiophene segments and then synthesized a new polymer named as PBDD4T-2F. Our results demonstrate that the rotation barrier between the a-linked bithiophene significantly increases after the fluorination, so PBDD4T-2F has a more stable backbone conformation than PBDD4T. Compared to PBDD4T, PBDD4T-2F shows stronger aggregation effect in solution state and more compact pi-pi stacking in solid thin film and also possesses deeper HOMO level. These properties make PBDD4T-2F being an ideal donor material in PSCs. When blended with PC71BM, a fullerene acceptor, the PBDD4T-2F-based device showed a power conversion efficiency (PCE) of 9.04%, which is 38% higher than that of the PBDD4T-based device; when blended with ITIC, a non-fullerene acceptor, the PBDD4T-2F-based device showed a PCE of 8.69%, which is almost 20 times higher than that of the PBDD4T-based device. What is more, the tandem cell, in which the blend of PBDD4T-2F:PC61BM was used for making the front subcell, exhibited a high PCE of 10.12%. The photovoltaic results indicate that the fluorination is an effective method to enhance interchain pi-pi interaction for the polythiophene and hence to tune its photovoltaic properties in PSCs, especially for the fullerene-free device based on ITIC.</P>

Novel Nucleotide Variations, Haplotypes Structure and Associations with Growth Related Traits of Goat AT Motif-Binding Factor (ATBF1) Gene

Xiaoyan Zhang,Xianfeng Wu,Wenchao Jia,Chuanying Pan,Xiangcheng Li,Chuzhao Lei,Hong Chen,Xianyong Lan 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.10

The AT motif-binding factor (ATBF1) not only interacts with protein inhibitor of activated signal transducer and activator of transcription 3 (STAT3) (PIAS3) to suppress STAT3 signaling regulating embryo early development and cell differentiation, but is required for early activation of the pituitary specific transcription factor 1 (Pit1) gene (also known as POU1F1) critically affecting mammalian growth and development. The goal of this study was to detect novel nucleotide variations and haplotypes structure of the ATBF1 gene, as well as to test their associations with growth-related traits in goats. Herein, a total of seven novel single nucleotide polymorphisms (SNPs) (SNP 1-7) within this gene were found in two well-known Chinese native goat breeds. Haplotypes structure analysis demonstrated that there were four haplotypes in Hainan black goat while seventeen haplotypes in Xinong Saanen dairy goat, and both breeds only shared one haplotype (hap1). Association testing revealed that the SNP2, SNP5, SNP6, and SNP7 loci were also found to significantly associate with growth-related traits in goats, respectively. Moreover, one diplotype in Xinong Saanen dairy goats significantly linked to growth related traits. These preliminary findings not only would extend the spectrum of genetic variations of the goat ATBF1 gene, but also would contribute to implementing marker-assisted selection in genetics and breeding in goats.

REGENERATIVE BRAKING CONTROL STRATEGY OF ELECTRIC VEHICLES BASED ON BRAKING STABILITY REQUIREMENTS

Jiang Biao,Zhang Xiangwen,Wang Yangxiong,Hu Wenchao 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.2

Electric vehicles are effective way to solve energy and environmental problems, but the promotion and application of electric vehicles are suppressed by their limited endurance range seriously. The regenerative braking technology is an important method to increase the endurance range of the electric vehicle. During the braking process, the kinetic energy of the electric vehicle can be converted into electric energy and stored in the energy source device with the regenerative braking system, so the endurance range of the electric vehicle can be increased accordingly. In order to increase the efficiency of energy recovery, a regenerative braking strategy with the optimization distribution algorithm is proposed in this paper, and the braking forces of the front and rear axles are distributed optimally with variable ratios based on the braking strength. With the optimal braking force distribution ratio and related constraint conditions, the regenerative braking control strategy was designed to meet the braking stability and the maximum braking energy recovery. And then a simulation model of the braking control strategy was built with MATLAB/Simulink software, and the simulation tests on UDDS and NEDC cycle conditions were done to verify the effectiveness of the designed regenerative braking control strategy. Compared with the control strategy of ADVISOR software, the braking energy recovery efficiency was improved more than 51.9 % while maintaining the braking stability.

A Comparative Test Study of the Impact Performances of Stainless-Steel Rebar Equal-Strength Replacement Piers

Xiwu Zhou,Wenchao Zhang,Yushen Gao,Guoxue Zhang,Ruisheng Xiong 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.1

It has been found that there are rebar instability and construction complexity phenomena associated with the replacements of ordinary pier rebars with stainless-steel rebars of equal piece numbers and strength. Therefore, this study explored the issues of the equal-strength replacements of stainless-steel pier rebars with diff erent distributions. The study utilized the most advanced domestic multi-function super-high heavy hammer impact test system available, and conducted a comparative test of the horizontal impact results of two groups of pier models with 1/5 contraction scales. The purpose of the testing was to analyze the impact force, impact displacement, strain time history curve, crack propagation and distribution, ultrasonic damages to the concrete, and so on. The test results showed the following: The original specimen displayed a consistent variation trend with the equal replacement specimen of the stainless-steel rebar of diff erent distributions from the aspects of the maximum impact force, strain of the rebar and concrete, displacement peak, and so on, under the conditions of continuous multiple impacts. The relative variation rate was found to be within the scope of ± 10% under equal impact energy. The quantity and distribution of the cracks, as well as the concrete damages, were also found to be approximately consistent under equal impact energy. Therefore, in this study, it was considered to be feasible for the solution of the problems related to rebar corrosion, strength surplus, resource waste, and so on, to replace ordinary pier rebars with stainless-steel rebars with equal-strength and diff erent distributions.

Molecular Design of Photovoltaic Polymers for Efficient Organic Solar Cells

Jianhui HOU,Wenchao ZHAO,Shaoqing ZHANG,Huifeng YAO 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

A Study of the Cumulative Impact Forces of Stainless-Steel Reinforced Concrete Pier

Xiwu Zhou,Wenchao Zhang,Yushen Gao,Fei Huang,Guoxue Zhang 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.1

Stainless-steel reinforcement is used to replace the common reinforcement of RC pier in the marine environment, so as to solve the corrosion issue of reinforcement. According to the collision force of stainless-steel reinforced concrete bridge pier under cumulative impact, in this paper the cumulative impact loss factors of the pier is considered to analyze the relationship between the pier stiff ness and ultrasonic sound velocity by numerical simulation. The calculation formula of the collision force considering the cumulative impact damage of the pier is then created with the experimental verifi cation and comparative analysis of relevant norms. The results show that the formula of the collision force proposed in this paper is able to better refl ect the actual force of the cumulative impact of the pier.

A Method for Microgrid Connected Fuel Cell Inverters Seamless Transitions Between Voltage Source and Current Source Modes

Rongliang Shi,Xing Zhang,Haizhen Xu,Fang Liu,Wenchao Li,Fubin Mao,Yong Yu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper proposes a novel seamless transfer method for microgrid connected fuel cell inverters (FCIs) between voltage source and current source modes. In order to protect the fuel cell, the FCI output power should be restricted when the microgrid frequency is greatly disturbed. In this sense, the FCI is transfered from voltage source mode to constant current source mode. Meanwhile, the FCI is transfered from constant current source mode to voltage source mode until service can be restored. The proposed method can cooperatively work with well developed virtual synchronous generator (VSG) control algorithm so that these FCIs are able to share load among them as well as subsist under transient events of the system. Theoretical analysis and experimental results validate effectiveness of the proposed method.