R&D Status of High-current Accelerators at IFP

J. J. Deng,J. S. Shi,W. P. Xie,L. W. Zhang,K. Z. Zhang,S. P. Feng,J. Li,M. Wang,Y. He,L. S. Xia,Z. Y. Dai,H. T. Li,L. Wen,S. F. Chen,X. Li,Q. G. Lai,M. H. Xia,Y. C. Guan,S. Y. Song,L. Chen 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.61

High-current accelerators have many important applications in Z-pinches, high-power microwaves, and free electron lasers, imploding liners and radiography and so on. Research activities on Zpinches, imploding liners, radiography at the Institute of Fluid Physics (IFP) are introduced. Several main high-current accelerators developed and being developed at IFP are described, such as the Linear Induction Accelerator X-Ray Facility Upgrade (LIAXFU, 12 MeV, 2.5 kA, 90 ns), the Dragon-I linear induction accelerator (20 MeV, 2.5 kA, 60 ns), and the Primary Test Stand for Z-pinch (PTS, 10 MA, 120 ns). The design of Dragon-II linear induction accelerator (20 MeV, 2.5 kA, 3 × 60 ns) to be built will be presented briefly.

재래 흑돼지와 중국 재래돈간의 Melanocortin Receptor 1(MC1R) 유전자의 유전자형 분석

이성수,양보석,정진관,고서봉,오성종,양영훈,김규일,이찬동,풍서당 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.1

PCR-RFLP analysis of Melanocortin receptor 1 (MC1R) gene was carried out to investigate the genotype distribution in Korean-Native and Chinese-Native pig breeds(Neijiang, Putian, Wannanhua and Jinhua). Allelic variants of MC1R in pigs were analyzed by digestion of BspH I , AccII and Hha I . Ncijiang. Wannanhua and Jinhua had only MC1R*2 allele which is considered to be typical genotype for Meishan and Large Black. Among 20 Korean-Native Pigs and 5 Putian pigs, 10 and 2 heads had the MC1R*3 allele (*2/3 or 3/3), respectively, which was detected in European pig breeds such as Hampshire, Large White, and Pietrain. The remaining animals possessed the genotype MC1R*2/2, probably reflecting the genetic introgression of MC1R*3 allele into Korean-Native and Putian pig breeds by the crossbreeding for improvement. The alleles MC1R*l and MC1R*4, which are considered to be typical allele for European Wild Boar with wild-type coat color and Duroc with red coat color, respectively, were not detected in pig breeds used in this experiment. These results indicate that the analysis of genotype frequencies of MC1R gene may be a useful tool for the conservation of Korean-Native and Chinese-Native pig breeds.

Effects of Betaine on Performence, Carcass Characteristics and Hepatic Betaine-homocysteine Methyltransferase Activity in Finishing Barrows

Feng, J.,Liu, X.,Wang, Y.Z.,Xu, Z.R. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.3

This experiment was conducted to determine the effect of dietary betaine (0, 0.125%) on performance, carcass composition, pork quality and hepatic betaine-homocysteine methyltransferase (BHMT) activity of crossbred finishing barrows. Three replicates of ten pigs were used for each treatment. The results showed that average daily gain, feed intake and feed conversion were not affected by betaine. Compared with the control group, pigs treated with betaine had a 8.17% (p<0.05) decrease in carcass fat percentage, and a 8.84% (p<0.05) reduction in 10th-rib backfat thickness, but dressing percentage, percentage lean, longissimus muscle area, and average backfat thickness were not affected. There were also no significant differences in muscle color score, marbling score, pork pH value and water loss rate between the control and betaine-treated groups. Hepatic betaine-homocysteine methyltransferase (BHMT) activity was significantly increased by 13.97% (p<0.05) when pigs were offered 0.125% betaine.

NANOSIZED HYDROXYAPATITE/COLLAGEN COMPOSITE

Feng, Feng, Q,L,Cui, Cui, F.Z,Wang, Wang, R.Z,Du, Du, C,Li, Li, H.D 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.1 No.2

This paper reported the synthesis of a nano-Hydroxyapatite(HAp)/collagen biocomposite and its biological performances. A thoroughly mixed slurry of type I collagen in supersaturated HAp solution was obtained. HAp was then controlled to precipitate on collagen by adjusting the solution properly. SEM, XRD and TEM analysis reveals that HAp in the composite was nanometer sized and uniformly dispersed oncollagen matrix. In vitro biocompatibility of this new biomaterial was evaluated in terms of its biodegradation and bioactivity. The mice macrophage and osteoblast were used for the study, and the behavior of the cells in contact with the composite was investigated by means of SEM. The observations showed that the composite can be degraded through extracellular resorption process mediated by macrophage, and they can also be well-contact with osteoblast cells, in vitro.

Fabrication and Field-Emission Properties of Vertically-Aligned Tapered [110]Si Nanowire Arrays Prepared by Nanosphere Lithography and Electroless Ag-Catalyzed Etching

Z. Feng,K. Q. Lin,Y. C. Chen,S. L. Cheng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.09

In this study, the controllable fabrication of a variety of vertically aligned, single-crystalline [110]-oriented Si nanowire arrays with sharp tips on (110)Si substrates is achieved using a combined self-assembled nanosphere lithography and multiple electroless Ag-catalyzed Si etching processes. All of the experiments were performed at room temperature. The morphological evolution and formation mechanism of long tapered [110]Si nanowire arrays during the multiple tip-sharpening cycle processes have been investigated by scanning electron microscopy, transmission electron microscopy and water contact angle measurements. Field emission measurements demonstrate that the field-emission behaviors of all nanowire samples produced in this study agree well with the Fowler–Nordheim theory, and the produced long tapered [110]Si nanowire array possesses superior electron emission characteristics, with a very low turn-on field of 1.4 V/ m and a high field enhancement factor of 3816. The simple and room temperature fabrication of the well-ordered long tapered [110]Si nanowire array and its excellent electron field emission performance suggest that it can serve as a good candidate for applications in high-performance. Si-based vacuum electronic nanodevices.

GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

Feng, J.-Z.,Li, J.,Yu, F. The Korean Society of Automotive Engineers 2003 International journal of automotive technology Vol.4 No.4

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

Naphthalene-based poly(arylene ether ketone) anion exchange membranes

Liu, Z.,Li, X.,Shen, K.,Feng, P.,Zhang, Y.,Xu, X.,Hu, W.,Jiang, Z.,Liu, B.,Guiver, M. Royal Society of Chemistry 2013 Journal of materials chemistry. A, Materials for e Vol.1 No.21

GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

J. Z. FENG,J. LI,F. YU 한국자동차공학회 2003 International journal of automotive technology Vol.4 No.4

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-or-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.<br/>

Numerical investigation on residual stress in photovoltaic laminates after lamination

Q. Z. Zhang,B. F. Shu,M. B. Chen,Q. B. Liang,C. Fan,Z. Q. Feng,P. J. Verlinden 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

A series of simulations were carried out to investigate the residual stress induced in the photovoltaic laminate during the cooling processafter lamination with a global model and several submodels. The simulations focus separately on the effects of the cooling rate, thecell layout and anisotropy on the residual stress and deformation of the photovoltaic laminate in a comparative manner with the finiteelement method. The results have shown that significant stress concentration and twist occurs in the interconnection region in the cell. Inaddition, different cooling rates, cell layouts and anisotropy only influence the largest stress rather than the stress distribution and deformation. Therefore, the results of a uniform stationary isotropic model with fewer cells can provide enough insight into the stress distributionin real photovoltaic laminates and the modified largest first principal stress can be used for design and verification.

Spectroscopic Ellipsometric Study of Size-Controlled Silicon Nano-Crystals in SiO2 Composite Thin Film

S.-Z. Feng,L.-Y. Chen,J. Li,P.-H. Mao,R.-J. Zhang,X.-F. Li,Y.-X. Zheng 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.II

In this work, a series of SiO$_x$/SiO$_2$ superlattices were prepared, by using reactive evaporation, with different thicknesses of the SiO$_x$ layers. After being annealed at 1100 $^\circ$C, composite thin films with the nano-crystals of silicon (nc-Si) embedded in the SiO$_2$ layers were formed. The optical properties of the films were measured by using the spectroscopic ellipsometric (SE) method in the photon energy range from 1.5 to 4.5 eV at three different incidence angles of 65$^\circ$, 70$^\circ$ and 75$^\circ$. In terms of the ellipsometric data, the effective medium approximation (EMA) with the four-parameter Lorentz oscillator model was used to fit the spectra and to extract the optical dispersion of the nc-Si particles. We found that the dielectric functions of the composite films strongly depended on the volume fraction of nc-Si and the constant of the SiO$_2$ layers, which changed with the composition in the investigated spectrum range