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.

Solar Water Splitting with a Hydrogenase Integrated in Photoelectrochemical Tandem Cells

Nam, Dong Heon,Zhang, Jenny Z.,Andrei, Virgil,Kornienko, Nikolay,Heidary, Nina,Wagner, Andreas,Nakanishi, Kenichi,Sokol, Katarzyna P.,Slater, Barnaby,Zebger, Ingo,Hofmann, Stephan,Fontecilla‐,Ca John Wiley and Sons Inc. 2018 Angewandte Chemie Vol.57 No.33

<P><B>Abstract</B></P><P>Hydrogenases (H<SUB>2</SUB>ases) are benchmark electrocatalysts for H<SUB>2</SUB> production, both in biology and (photo)catalysis in vitro. We report the tailoring of a p‐type Si photocathode for optimal loading and wiring of H<SUB>2</SUB>ase through the introduction of a hierarchical inverse opal (IO) TiO<SUB>2</SUB> interlayer. This proton‐reducing Si|IO‐TiO<SUB>2</SUB>|H<SUB>2</SUB>ase photocathode is capable of driving overall water splitting in combination with a photoanode. We demonstrate unassisted (bias‐free) water splitting by wiring Si|IO‐TiO<SUB>2</SUB>|H<SUB>2</SUB>ase to a modified BiVO<SUB>4</SUB> photoanode in a photoelectrochemical (PEC) cell during several hours of irradiation. Connecting the Si|IO‐TiO<SUB>2</SUB>|H<SUB>2</SUB>ase to a photosystem II (PSII) photoanode provides proof of concept for an engineered Z‐scheme that replaces the non‐complementary, natural light absorber photosystem I with a complementary abiotic silicon photocathode.</P>

Optical properties of amorphous $Si_xC_yN_z$ ternary thin films prepared by plasma enhanced chemical vapor deposition

Zhang, Z.H.,Fan, X.J.,Guo, H.X.,Zhang, W.,Zhang, C.Y.,Luo, F.Y. The Korean Vacuum Society 1998 Applied Science and Convergence Technology Vol.7 No.1

Amorphous ternary $Si_xC_yN-z$ thin films were obtained by plasma enhanced chemical vapor deposition(PECVD) using $N_2, SiH_4 \;and \;C_2H_4$ as the reaction sources. The chemical state were characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy(FTIR). The optical properties of the thin films were investigated by UV-visible spectrophotometer and ellipsometer, and the optical band gaps of thin films were determined from corresponding transmittance spectra following Tauc equation.

Thermosensitive/superparamagnetic iron oxide nanoparticle-loaded nanocapsule hydrogels for multiple cancer hyperthermia

Zhang, Z.Q.,Song, S.C. IPC Science and Technology Press 2016 Biomaterials Vol.106 No.-

<P>Magnetic hyperthermia therapy (MHT) has been explored as an efficient and non-invasive treatment for cancer. However, the short retention time of magnetic nanoparticles localized within tumor targets hinders its potential for repeatable treatment. We report herein on the development of an injectable, biodegradable, thermosensitive and superparamagnetic iron oxide nanoparticle-loaded nanocapsule hydrogels (SPION-NHs) system for multiple MHT and long-term magnetic resonance imaging (MRI) contrast. Transmission electron microscopic images showed the core-shell structure of self-assembled poly(organophosphazene) nanocapsules and multiple embedded SPIONs within the core. The SPION-loaded nanocapusule solution can be transformed into hydrogel form at body temperature via the hydrophobic interaction. The cancer cells were killed efficiently using multiple MHT at moderate temperature through necrosis, as compared to single MHT-induced apoptosis. More than three weeks retention of SPIONs within tumors after a single injection of SPION-NHs facilitated successful multiple MHT, which was monitored by T-2-weighted MRI. Furthermore, excellent in vivo anti-cancer effect was observed after four cycles of MHT without severe damage on the surrounding healthy tissues, which was in contrast to single magnetic thermal ablation. (C) 2016 Elsevier Ltd. All rights reserved.</P>

STARTING SLIDING MODE VARIABLE STRUCTURE THAT COORDINATES THE CONTROL AND REAL-TIME OPTIMIZATION OF DRY DUAL CLUTCH TRANSMISSIONS

Z.-G. ZHAO,J.-L. JIANG,Z.-P. YU,T. ZHANG 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.6

This paper researches the coordination of control between an engine and clutch at the system level to adequately reflect a driver’s intention and improve the starting performance of a vehicle equipped with a dry dual clutch transmission (DCT). Four-degree-of-freedom (DOF) starting dynamic equations are established for a dry DCT with a single intermediate shaft, and a two-DOF model of the sliding friction process and a single-DOF in-gear model of stable operation are obtained after simplifying these equations. Taking advantage of predictive control and a genetic algorithm, target tracing curves of the engine’s speed and the vehicle’s velocity are optimally specified online, and the starting sliding mode variable structure (SMVS) coordinating control strategy is designed to track these curves. The starting performance of a prototype car equipped with a dry DCT is simulated under different starting cases on the MATLAB/Simulink software platform. The simulation results show that the designed SMVS coordinating controller not only embodies driver intention and effectively improves the dry DCT car’s starting performance but is also highly robust when subjected to variations in the vehicle parameters.

THREE-SPEED TRANSMISSION SYSTEM FOR PURELYELECTRIC VEHICLES

Z. ZHANG,C. ZUO,W. HAO,Y. ZUO,X. L. ZHAO,M. ZHANG 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.5

This paper discusses the necessity of using a transmission system to improve the energy efficiency of purelyelectric vehicles (EVs). The energy efficiency of an electric motor varies at different operating points to meet the output powerdemand. The three gear ratios of a transmission system can maintain the motor speed within a stable region with relativelyhigh energy efficiency, while various vehicle speeds are needed. This work is based on a light EV prototype. The optimizedgear ratios of this transmission result in a considerably reduced energy consumption of 9.3% compared with conventional EVswith single-speed reducers under the condition of the Urban Dynamometer Driving Schedule driving cycle. Thus, thetransmission system is necessary to improve the energy efficiency of EVs.

Transport of liquid mercury under pressure in double-walled carbon nanotubes

Z.Q. Zhang,H.W. Zhang,Y.G. Zheng,J.B. Wang,L. Wang 한국물리학회 2008 Current Applied Physics Vol.8 No.2

In this paper, transport of liquid mercury under pressure through double-walled carbon nanotubes is studied using classical moleculardynamics simulations in conjunction with a pressure control model. The results indicate that wetting of double-walled carbon nanotubesby mercury occurs above a threshold pressure of liquid mercury. Liquid mercury can be transported through the inner tube of double-port eciency increases greatly with enlarging the inner tube size. The space between the two walls of double-walled carbon nanotubescan also transport the liquid mercury while the distance between the two walls is much larger than the radius of the inner tube. Transporteciency of double-walled carbon nanotubes is a little lower than that of single-walled carbon nanotubes while double-walled carbonnanotubes transport liquid more steadily than single-walled carbon nanotubes.

Evaluation of the representativeness of ground-based visibility for analysing the spatial and temporal variability of aerosol optical thickness in China

Zhang, Z.Y.,Wong, M.S.,Lee, K.H. Pergamon Press ; Elsevier [distribution] 2016 Atmospheric environment Vol.147 No.-

<P>Although visibility is a widely-used indicator to quantify the aerosol loadings, only a few studies have been analyzed the representativeness of visibility in deriving Aerosol Optical Thickness (AOT). In this paper, ground-based visibility, MODerate-resolution Imaging Spectroradiometer (MODIS) and Multi angle Imaging SpectroRadiometer (MISR) monthly AOT products between July 2002 and December 2014 were analyzed in order to extract the dominant modes of variability using the Singular Value Decomposition (SVD) method. The method has significant merit to reduce data dimension and examine both spatial and temporal variability simultaneously. Results indicated that the satellite retrieved AOTs agreed well with ground-based visibility in terms of inter-annual variability. The correlation coefficients in the first deseasonalized mode are greater than 0.65 between visibility and satellite AOT products. However, large differences were observed in the seasonal variability between ground-based visibility and AOT. In addition, Aerosol vertical distribution from LIdar climatology of Vertical Aerosol Structure for space-based lidar simulation studies (LIVAS) and cloud data from ground-based meteorological station were used to investigate the seasonal variability disagreement. The AOT values derived from LIVAS extinction coefficients between 0 and 500 m above surface have a stronger relationship with visibility, than total column AOT with visibility. It also indicates that seasonal variation of aerosol vertical distribution is the main cause of the disagreement between two parameters, and the uncertainties of satellite products also contribute to the disagreement. Results in this study highlighted that the visibility observation could only be used to depict the inter-annual AOT and more ancillary information could be used for studying seasonal AOT variation. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Perturbation Theory for a Nonlinear Two-level System

Z. J. Zhang,D. G. Jiang,X. X. Yi 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.3

Perturbation theory is an important tool in quantum mechanics, it can help to find solutions to the Schr¨odinger equation and has been proven to be a good approximation for linear quantum systems. In this paper, we examine whether the perturbation theory is available for nonlinear systems by exemplifying a nonlinear two-level system. The results show that the ratio (r) of the nonlinear rate C to the tunneling coefficient V determines the validity of the perturbation theory. For small ratio r, the perturbation theory is available; otherwise, it yields wrong results.

Summation formulas of q-series by modified Abel's lemma

Z. Zhang,Y. Zhang 장전수학회 2008 Advanced Studies in Contemporary Mathematics Vol.17 No.2

By means of Abel's lemma on summation by parts, we revisit several basic hypergeometric series identities. Furthermore, some new summation formulas are also established.