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.

HIGH-PERFORMANCE Pt/CNTs CATALYSTS VIA HYDROGEN PLASMA FOR METHANOL ELECTROOXIDATION

J. L. XU,S. G. WANG,Q. R. DENG,Y. LIU,J. L. ZHU,C. B. XU,J. H. WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.2

High-performance carbon nanotubes-supported Pt catalysts (Pt/CNTs) catalysts were pre-pared on the basis of Pt precursors reduced by hydrogen plasma (Pt/CNTs-HP) generated bymicrowave. The other two Pt/CNTs catalysts prepared by hydrogen (Pt/CNTs-H) and NaBH 4(Pt/CNTs-N) reduction were also involved for comparison. The practical composition of thecatalysts was characterized with energy dispersive analysis of X-ray (EDAX). It was shown fromtransmission electron microscopy (TEM) and X-ray di®raction (XRD) that the Pt nanoparticlesin Pt/CNTs-HP were uniformly dispersed on CNTs with smaller particle size around 2 nmand narrower size distribution as compared with the other two catalysts. Additionally, X-rayphotoelectron spectrum (XPS) analysis indicated higher amount of zero-valence states of Pt inPt/CNTs-HP caused by hydrogen plasma treatment. The electrooxidation of liquid methanol onthese catalysts was investigated by cyclic voltammetry (CV), linear sweep voltammetry (LSV)and chronoamperometry. The long-time durability is very comparable to all the three catalysts. Remarkably, the Pt/CNTs-HP possessed the highest electrocatalytic activity, suggesting thatthe hydrogen plasma reduction approach can be a promising reduction method for preparinghigh-performance Pt-based electrocatalysts.

China Spallation Neutron Source: Accelerator Design Iterations and R&D Status

J. Wei,C.-D. Deng,C.-H. Wang,C.-T. Shi,H. Sun,H.-F. Ouyang,H.-M. Qu,H.-Y. Dong,J. Li,J. Zhang,J.-S. Cao,J.-Y. Tang,L. Dong,L.-L. Wang,Q. Qin,Q.-B. Wang,S. Wang,S.-N. Fu,S.-X Fang,T. -G. Xu,W. Kang,Y.- 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.I

The China Spallation Neutron Source (CSNS) is a high-power, accelerator-based project currently under preparation. The accelerator complex consists of an H$^-$ ion source, an H$^-$ linac, a rapid-cycling proton synchrotron, and the transport lines. During the past year, the design of most accelerator systems went through major iterations, and initial research and developments was started on the prototyping of several key components.

Fabrications and dielectric performances of novel composites: Calcium copper titanate / Polyvinylidene fluoride

Wang J.J.,Deng Q.J.,He Y.Y.,Feng Y.N.,Kang M.P.,Duan X.L.,Yang Y.L. 한국물리학회 2022 Current Applied Physics Vol.39 No.-

CCTO (Calcium copper titanate) powder as inorganic filler was synthesized by the Sol-gel method firstly. CCTO/ PVDF (Polyvinylidene fluoride) composite was fabricated by solution mixing based on high temperature resistance of PVDF and insulated property of CCTO. The composite of CCTO/PVDF were characterized by X-ray diffraction, Fourier Transform infrared spectroscopy, Scanning Electron Microscope and impedance analysis. The results showed that the addition of CCTO and increasing in its content did not affect the phase- and microstructure of the composites,but the increase of CCTO content can induce the generation of C–F new bonds. PVDF/CCTO composites were enhanced in performance of thermal and frequency-depended stability with increasing in the fraction of CCTO. The dielectric constant of CCTO/PVDF composite materials with 50% CCTO achieved to a maximum value of 50 almost, which is 5 times higher the pure PVDF. The conductivity felled into 10-8 to 10-1 S m-1 during the frequency of 102–108 Hz. The composite material would be expected to be applied in the field of integrated circuit.

Direct Detection of Pure ac Spin Current by X-Ray Pump-Probe Measurements

Li, J.,Shelford, L. R.,Shafer, P.,Tan, A.,Deng, J. X.,Keatley, P. S.,Hwang, C.,Arenholz, E.,van der Laan, G.,Hicken, R. J.,Qiu, Z. Q. American Physical Society 2016 Physical Review Letters Vol.117 No.7

Coronary Atherosclerosis T₁-Weighed Characterization With Integrated Anatomical Reference

Xie, Y.,Kim, Y.J.,Pang, J.,Kim, J.S.,Yang, Q.,Wei, J.,Nguyen, C.T.,Deng, Z.,Choi, B.W.,Fan, Z.,Bairey Merz, C.N.,Shah, P.K.,Berman, D.S.,Chang, H.J.,Li, D. Elsevier Science B.V. Amsterdam 2017 JACC CARDIOVASCULAR IMAGING Vol.10 No.6

Objectives: The aim of this work is the development of coronary atherosclerosis T<SUB>1</SUB>-weighted characterization with integrated anatomical reference (CATCH) technique and the validation by comparison with high-risk plaque features (HRPF) observed on intracoronary optical coherence tomography (OCT) and invasive coronary angiography. Background: T<SUB>1</SUB>-weighted cardiac magnetic resonance with or without contrast media has been used for characterizing coronary atherosclerosis showing promising prognostic value. Several limitations include: 1) coverage is limited to proximal coronary segments; 2) spatial resolution is low and often anisotropic; and 3) a separate magnetic resonance angiography acquisition is needed to localize lesions. Methods: CATCH acquired dark-blood T<SUB>1</SUB>-weighted images and bright-blood anatomical reference images in an interleaved fashion. Retrospective motion correction with 100% respiratory gating efficiency was achieved. Reference control subjects (n = 13) completed both pre- and post-contrast scans. Stable angina patients (n = 30) completed pre-contrast scans, among whom 26 eligible patients also completed post-contrast scans. After cardiac magnetic resonance, eligible patients (n = 22) underwent invasive coronary angiography and OCT for the interrogation of coronary atherosclerosis. OCT images were assessed and scored for HRPF (lipid-richness, macrophages, cholesterol crystals, and microvessels) by 2 experienced analysts blinded to magnetic resonance results. Results: Per-subject analysis showed none of the 13 reference control subjects had coronary hyperintensive plaques (CHIP) in either pre-contrast or post-contrast CATCH. Five patients had CHIP on pre-contrast CATCH and 5 patients had CHIP on post-contrast CATCH. Patients with CHIP had greater lipid abnormality than those without. Per-segment analysis showed elevated pre- and post-contrast plaque to myocardium signal ratio in the lesions with HRPF versus those without. Positive correlation was observed between plaque to myocardium signal ratio and OCT HRPF scoring. CHIP on pre-contrast CATCH were associated with significantly higher stenosis level than non-CHIP on invasive coronary angiography. Conclusions: CATCH provided accelerated whole heart coronary plaque characterization with simultaneously acquired anatomical reference. CHIP detected by CATCH showed positive association with high-risk plaque features on invasive imaging studies.

Effect of the Fuel Injection Strategy on First-cycle Firing and Combustion Characteristics during Cold Start in a TSDI Gasoline Engine

Q. FAN,J. BIAN,H. LU,L. LI,J. DENG 한국자동차공학회 2012 International journal of automotive technology Vol.13 No.4

The first firing cycle is very important during cold-start for all types of spark ignition engines. In addition, the combustion characteristics of the first firing cycle affect combustion and emissions in the following cycles. However, the firstcycle fuel-air mixing, combustion and emissions generation within the cylinder of a two-stage direct-injection (TSDI) engine during cold start is not completely understood. Based on the total stoichiometric air-fuel ratio and local richer mixture startup strategy, the first-cycle firing and combustion characteristic at cold start were investigated in a two-stage direct injection (TSDI) gasoline engine. In addition, the effects of the first injection timing, second injection timing, 1st and 2nd fuel injection proportion and total excess air ratio on the in-cylinder pressure, heat release rate and accumulated heat release were analyzed on the basis of a cycle-by-cycle analysis. It is shown that a larger 2nd fuel injection amount and later 2nd injection timing are more beneficial to the firing of the first cycle in the case of a total excess air ratio of 1.0. The optimum 1st and 2nd injection timing fuel injection proportions are 120oCA ATDC during the intake stroke, 60oCA BTDC during the compression stroke and 1:1. In addition, the firing boundary is a 2nd injection timing later than 90oCA BTDC during the compression stroke in the case of the 1st injection timing from 60oCA to 180oCA ATDC during an intake stroke and involves a 1st and 2nd fuel injection proportion of 1:1 and an excess air ratio of 1.0. The study provides a detailed understanding of cold-start combustion characteristics and a guide for optimizing the reliable first-cycle firing at cold start.

Association between Single Nucleotide Polymorphisms in the Dgat2 Gene and Beef Carcass and Quality Traits in Commercial Feedlot Steers

Li, J.,Xu, X.,Zhang, Q.,Wang, X.,Deng, G.,Fang, X.,Gao, X.,Ren, H.,Xu, S. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.7

Diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyzes the final and rate-limiting step of triglyceride synthesis. Both DGAT1 and DGAT2 genes code proteins with DGAT activity. Studies have shown DGAT1 polymorphisms associate with intramuscular fat deposition in beef cattle, but fewer associations between DGAT2 and beef cattle economic traits have been reported. The objective of this study was to investigate single nucleotide polymorphism (SNP) in intron3 of bovine DGAT2 and evaluate the associations of that with carcass, meat quality, and fat yield traits. Test animals were 157 commercial feedlot steers belonging to 3 Chinese native breeds (22 for Luxi, 24 for Jinnan, and 23 for Qinchuan), 3 cross populations (20 for Charolais${\times}$Fuzhou, 18 for Limousin ${\times}$Luxi, and 17 for Simmental${\times}$Jinan) and 1 Taurus pure breed population (16 Angus steers). In the current study, 15 SNP were discovered in intron3 and exon4 of DGAT2 at positions 65, 128, 178, 210, 241, 255, 270, 312, 328, 334, 365, 366, 371, 415, and 437 (named as their positions in PCR amplified fragments). Only 7 of them (128, 178, 241, 270, 312, 328, and 371) were analyzed, because SNP in three groups (65-128-255, 178-210-365 and 241-334-366) were in complete linkage disequilibrium within the group, and SNP 415 was a deletion and 437 was a null mutation. Frequencies for rare alleles in the 3 native breed populations were higher than in the 3 cross populations for 178 (p = 0.04), 270 (p = 0.001), 312 (p = 0.03) and 371 (p = 0.002). A general linear model was used to evaluate the associations between either SNP genotypes or allele substitutions and the measured traits. Results showed that SNP 270 had a significant association with the fat yield associated with kidney, pelvic cavity, heart, intestine, and stomach (KPHISY). Animals with genotype CC and CT for 270 had less (CC: -7.71${\pm}$3.3 kg and CT: -5.34${\pm}$2.5 kg) KPHISY than animals with genotype TT (p = 0.02). Allele C for 270 was associated with an increase of -4.26${\pm}$1.52 kg KPHISY (p = 0.006) and $-0.92{\pm}0.45%$ of retail cuts weight percentage (NMP, Retail cuts weight/slaughter body weight) (p = 0.045); allele G for 312 was associated with an increase of -5.45${\pm}$2.41 kg KPHISY (p = 0.026). An initial conclusion was that associations do exist between DGAT2 gene and carcass fat traits. Because of the small sample size of this study, it is proposed that further effort is required to validate these findings in larger populations.

Efficient Conditional Proxy Re-encryption with Chosen-Ciphertext Security

Weng, J.,Yang, Y.,Tang, Q.,Deng, R.H.,Bao, F. SPRINGER-VERLAG 2009 Lecture Notes in Computer Science Vol.5735 No.-

Choice of dispersants for the nano-apatite filler of polylactide-matrix composite biomaterial

C. Deng,J. Weng,Q.Y. Cheng,S.B. Zhou,X. Lu,J.X. Wan,S.X. Qu,B. Feng,X.H. Li 한국물리학회 2007 Current Applied Physics Vol.7 No.6

The aim of this study is to compare de-aggregative ability of common organic dispersants for the acicular nano-apatite crystallite withmain composition of calcium hydroxyapatite (HA) as a ller of composite containing polylactide (PLA) matrix. Firstly, the acicularnano-apatite powders with an average length of 70120 nm were synthesized based on traditional chemical co-precipitation andfreeze-drying techniques. Common organic dispersants including tetrahydrofuran, acetone, chloroform,N,N-dimethyl formamideiments showed that nano-apatite suspension dispersed by DMF and ethanol presented homogeneous and stable colloid after vigorly stir-red for 24 h and then kept still for same time, respectively. Results of particle measurements and viscosity measurement illuminated that alarge number of the nano-apatite particles with an average dimension of 297.86 nm and viscosity of 0.8872 cP in DMF suspension couldbe dispersed up to 91.28 nm by the DMF dispersant and the DMF dispersant could minimize agglomeration between the apatite ultra-furan, acetone and ethanol, when the nano-apatite/PLA composite biomaterials were prepared.