Research on Powder Metallurgy Technology in Fusion Materials in China

Ge Chang-Chun,Zhou Zhang-Jian,Du Juan,Song Shu-Xiang 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

STRUCTURES OF Ni(II) OCTAETHYLPORPHYRIN AND C60 AT Au(111) SURFACE INVESTIGATED BY STM

GE-BO PAN,LI-JUN WAN,HUI-JUAN YAN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2006 NANO Vol.1 No.1

In situ scanning tunneling microscopy (STM) was employed to investigate the adsorption of C60 on a Ni(II) octaethylporphyrin (NiOEP) adlayer at liquid/Au(111) interface. It was found that C60 molecules tend to form small islands without defined coordination to the underlying NiOEP array. Moreover, increasing the surface coverage of C60 resulted in the formation of multilayers. The mixture of C60 and NiOEP prepared in solution formed separated domains. The results suggested that the C60–C60 interaction is stronger than that of C60–NiOEP and dominated the adsorption of C60 on NiOEP-modified Au(111) surface. This work provides a direct evidence at molecular scale for the coordination of C60 with NiOEP in a two-dimensional assembly, demonstrating that immobilizing C60 at the geometric center of NiOEP on an Au(111) surface in solution is complicated.

Quantitative Indirect ELISA for Determination of Walnut Proteins in Foods

Juan Fang,Dan Chen,Chaoyin Chen,Feng Ge,Diqiu Liu,Benyong Han,Xiangfeng Xiong 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.6

An indirect enzyme-linked immunosorbent assay (ELISA) capable of detecting walnut proteins in commercial products was developed. Polyclonal antibodies against soluble walnut protein were used. Specific epitopes of walnut protein were analyzed for cross activity with peanut, soybean, sesame, rice, wheat, jujube, and defatted milk protein. Epitopes of walnut proteins had no cross activity. The indirect ELISA was highly specific for soluble walnut proteins. Recovery values from walnut protein solutions ranged from 88.47 to 115%, and low coefficients of variation (<10%) indicated good repeatability. Intra and inter-assay precisions were <6 and <7 %, respectively. The limit of detection was 10 ng/mL of soluble walnut protein. The method was applied to detect some commercial food products in China and the results showed that indirect ELISA could be promisingly used to quantify adulteration of walnut processed foods.

CONVERGENCE OF MODIFIED MULTI-STEP ITERATIVE FOR A FINITE FAMILY OF ASYMPTOTICALLY QUASI-NONEXPANSIVE MAPPINGS

Xiao, Juan,Deng, Lei,Yang, Ming-Ge Korean Mathematical Society 2014 대한수학회논문집 Vol.29 No.1

In a uniformly convex Banach space, we introduce a iterative scheme for a finite family of asymptotically quasi-nonexpansive mappings and utilize a new inequality to prove several convergence results for the iterative sequence. The results generalize and unify many important known results of relevant scholars.

Step-up and Step-down Asymmetrical 24-Pulse Autotransformer Rectifier

Zhang, Lu,Ge, Hong-juan,Jiang, Fan,Yang, Guang,Lin, Yi The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

The existing 24-pulse autotransformer rectifier unit (ATRU) needs interphase reactors for parallel work of the rectifier bridges, and its output voltage cannot be regulated. Aiming at these problems, a step-up and step-down asymmetrical 24-pulse ATRU is proposed in this paper. The connections and turns ratios among transformer windings are well designed. In addition, a 15-degree phase difference is formed between two of the 24 voltage vectors produced by the transformer, which makes the four rectifier bridge groups produce a 24-pulse DC voltage without interphase reactors. Meanwhile, by adding extended winding to each phase of the transformer, wide-range regulation of the ATRU output voltage can be realized, and the reasonable voltage regulation range is between 0.2 and 1.6. The superposition of the voltage vectors and the principle of the voltage regulation are analyzed in detail. Furthermore, the turns ratio of the windings, winding current, output voltage, and kilovolt-ampere rating are all derived. Finally, the simulations and experiments are carried out, and the correctness of the principle and theoretical analysis of the new 24-pulse ATRU are verified.

CCNG2 Suppressor Biological Effects on Thyroid Cancer Cell through Promotion of CDK2 Degradation

Li, Wei-Juan,Liu, Ge-Ling,Yu, Fang,Xiang, Xiu-Xiu,Lu, Yi-Fang,Xiao, Hong-Zhen,Shi, Yan-Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

This study aimed to analyze the expression and clinical significance of cyclin G2 (CCNG2) in thyroid carcinoma and the biological effects of CCNG2 overexpression in a cell line. Immunohistochemistry and Western blotting were used to analyze CCNG2 protein expression in 63 cases of thyroid cancer and normal tissues to allow the relationship with clinical factors to be assessed. CCNG2 lentiviral and empty vectors were transfected into the thyroid cancer K1 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were applied to detect the mRNA and protein levels of CCNG2. MTT assay and cell cycle were also conducted to assess the influence of up-regulated expression of CCNG2 on K1 cell biology. The level of CCNG2 protein expression was found to be significantly lower in thyroid cancer tissue than normal tissues (P<0.05). Western blot: The relative amount of CCNG2 protein in thyroid cancer tissue was respectively found to be significantly lower than in normal tissues (P<0.05), correlating with lymph node metastasis, clinic stage and histological grade (P<0.05), but not gender, age or tumor size (P>0.05). Loss of CCNG2 expression correlated significantly with poor overall survival time on Kaplan-Meier analysis (P<0.05). The results for biological functions showed that K1 cell transfected CCNG2 had a lower survival fraction, a greater percentage in the G0/G1 phases, and lower cyclin-dependent kinase 2 (CDK2) protein expression compared with K1 cells non-transfected with CCNG2 (P<0.05). CCNG2 expression decreased in thyroid cancer and correlated significantly lymph node metastasis, clinic stage, histological grade and poor overall survival, suggesting that CCNG2 may play important roles as a negative regulator in thyroid cancer K1 cells by promoting degradation of CDK2.

Research on a New 12-Pulse Step-Up and Step-Down Aviation Auto-Transformer Rectifier

Jiang, Fan,Ge, Hong-juan,Dong, Xiao-xu,Zhang, Lu The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper presents a new step-up and step-down multi-pulse auto-transformer rectifier unit (ATRU) topology. This structure can achieve a wide range of output voltages, which solves the problem of auto-transformer output voltage being difficult to regulate. Adding middle taps to the primary winding and reasonably setting the number of auto-transformer windings, constituted two groups of three-phase output voltages with a $30^{\circ}$ phase difference. Multi-pulse output DC voltage is obtained after a three-phase output voltage across two rectifier bridges and inter-phase reactor. Thus, the output DC voltage is related to the number and configuration of the auto-transformer winding. In this paper, the relationship between the voltage ratio of the auto-transformer and the ratio of winding, input current and auto-transformer kilovoltampere rating are deduced and validated by simulations. On this basis, the output voltage range is optimized. An experiment on two different voltage ratio principle prototypes was carried out to verify the correctness of the analysis design.

Parameterized Modeling of Spatially Varying PSF for Lens Aberration and Defocus

Wang Chao,Chen Juan,Jia Hongguang,Shi Baosong,Zhu Ruifei,Wei Qun,Yu Linyao,Ge Mingda 한국광학회 2015 Current Optics and Photonics Vol.19 No.2

Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existingpoint spread function (PSF) models in the literature corresponding to lens aberrations and defocus are eitherparameterized and spatially invariant or spatially varying but discretely defined. In this paper, aparameterized model is developed and presented for a PSF which is spatially varying due to lens aberrationsand defocus in an imaging system. The model is established from the Seidel third-order aberrationcoefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometrystructure. The accuracy of the model is demonstrated with simulations and measurements for a defocusedinfrared camera and a single spherical lens digital camera. Compared with optical software Code V, thevisual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model

Step-up and Step-down Asymmetrical 24-Pulse Autotransformer Rectifier

Lu Zhang,Hong-juan Ge,Fan Jiang,Guang Yang,Yi Lin 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

The existing 24-pulse autotransformer rectifier unit (ATRU) needs interphase reactors for parallel work of the rectifier bridges, and its output voltage cannot be regulated. Aiming at these problems, a step-up and step-down asymmetrical 24-pulse ATRU is proposed in this paper. The connections and turns ratios among transformer windings are well designed. In addition, a 15-degree phase difference is formed between two of the 24 voltage vectors produced by the transformer, which makes the four rectifier bridge groups produce a 24-pulse DC voltage without interphase reactors. Meanwhile, by adding extended winding to each phase of the transformer, wide-range regulation of the ATRU output voltage can be realized, and the reasonable voltage regulation range is between 0.2 and 1.6. The superposition of the voltage vectors and the principle of the voltage regulation are analyzed in detail. Furthermore, the turns ratio of the windings, winding current, output voltage, and kilovolt-ampere rating are all derived. Finally, the simulations and experiments are carried out, and the correctness of the principle and theoretical analysis of the new 24-pulse ATRU are verified.

Fabrication of Pure Refractory Metals by Resistance Sintering under Ultra High Pressure

Zhou Zhang-Jian,Du Juan,Song Shu-Xiang,Ge Chang-Chun 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Refractory materials, such as W and Mo, are very useful elements for use in high-temperature applications. But it is not easy to fabricat pure W and Mo with very high density and retaining very fine grain size because of their high melting point. In this paper, a newly developed method named as resistance sintering under ultra high pressure was use to fabricate pure fine-grained W and Mo. The microstructure was analysis by SEM. The sintering mechanism is primary analyzed. Basic physical property of these sintered pure W and Mo, such as hardness, bend strength, are tested.