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1. Demonstration of electron cooling using a pulsed beam from an electrostatic electron cooler

Author

Bruker, M. W., Benson, S., Hutton, A., Jordan, K., Powers, T., Rimmer, R., Satogata, T., Sy, A., Wang, H., Wang, S., Zhang, H., Zhang, Y., Ma, F., Li, J., Ma, X. M., Mao, L. J., Sha, X. P., Tang, M. T., Yang, J. C., Yang, X. D., Zhao, H., and Zhao, H. W.

Subjects
Physics - Accelerator Physics
Abstract

Cooling of hadron beams is critically important in the next generation of hadron storage rings for delivery of unprecedented performance. One such application is the electron-ion collider presently under development in the US. The desire to develop electron coolers for operation at much higher energies than previously achieved necessitates the use of radio-frequency (RF) fields for acceleration as opposed to the conventional, electrostatic approach. While electron cooling is a mature technology at low energy utilizing a DC beam, RF acceleration requires the cooling beam to be bunched, thus extending the parameter space to an unexplored territory. It is important to experimentally demonstrate the feasibility of cooling with electron bunches and further investigate how the relative time structure of the two beams affects the cooling properties; thus, a set of four pulsed-beam cooling experiments was carried out by a collaboration of Jefferson Lab and Institute of Modern Physics (IMP). The experiments have successfully demonstrated cooling with a beam of electron bunches in both the longitudinal and transverse directions for the first time. We have measured the effect of the electron bunch length and longitudinal ion focusing strength on the temporal evolution of the longitudinal and transverse ion beam profile and demonstrate that if the synchronization can be accurately maintained, the dynamics are not adversely affected by the change in time structure., Comment: 13 pages, 19 figures. Submitted to Physical Review Accelerators and Beams

Published
2020
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3. Longitudinal Schottky spectra of a bunched Ne10+ ion beam at the CSRe

Author

Wen, W. Q., Ma, X., Zhang, D. C., Zhu, X. L., Meng, L. J., Li, J., Liu, H. P., Zhao, D. M., Wang, Z. S., Mao, R. S., Zhao, T. C., Wu, J. X., Ma, X. M., Yan, T. L., Li, G. H., Yang, X. D., Liu, Y., Yang, J. C., Yuan, Y. J., Xia, J. W., Xu, H. S., Xiao, G. Q., and Zhao, H. W.

Subjects
Physics - Accelerator Physics
Abstract

The longitudinal Schottky spectra of a radio-frequency (RF) bunched and electron cooled 22Ne10+ ion beam at 70 MeV/u have been studied by a newly installed resonant Schottky pick-up at the experimental cooler storage ring (CSRe), at IMP. For an RF-bunched ion beam, a longitudinal momentum spread of has been reached with less than 107 stored ions. The reduction of momentum spread compared with coasting ion beam was observed from Schottky noise signal of the bunched ion beam. In order to prepare the future laser cooling experiment at the CSRe, the RF-bunching power was modulated at 25th, 50th and 75th harmonic of the revolution frequency, effective bunching amplitudes were extracted from the Schottky spectrum analysis. Applications of Schottky noise for measuring beam lifetime with ultra-low intensity of ion beams are presented, and it is relevant to upcoming experiments on laser cooling of relativistic heavy ion beams and nuclear physics at the CSRe., Comment: to be published in Chinese Physics C

Published
2013
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4. Elastic and electronic properties of fluorite RuO_2 from first principle

Author

Yang, Z. J., Guo, A. M., Guo, Y. D., Li, J., Wang, Z., Liu, Q., Linghu, R. F., and Yang, X. D.

Subjects
Condensed Matter - Materials Science
Abstract

The elastic, thermodynamic, and electronic properties of fluorite RuO_2 under high pressure are investigated by plane-wave pseudopotential density functional theory. The optimized lattice parameters, elastic constants, bulk modulus, and shear modulus are consistent with other theoretical values. The phase transition from modified fluorite-type to fluorite is 88 GPa (by localized density approximation, LDA) or 115.5 GPa (by generalized gradient approximation, GGA). The Young's modulus and Lam\'e's coefficients are also studied under high pressure. The structure turned out to be stable for the pressure up to 120 GPa by calculating elastic constants. In addition, the thermodynamic properties, including the Debye temperature, heat capacity, thermal expansion coefficient, Gr\"uneisen parameter, and Poisson's ratio, are investigated. A small band gap is found in the electronic structure of fluorite RuO_2 and the bandwidth increases with the pressure. Also, the present mechanical and electronic properties demonstrate that the bonding nature is a combination of covalent, ionic, and metallic contributions., Comment: 9 pages, 6 figures

Published
2012
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11. Demonstration of electron cooling using a pulsed beam from an electrostatic electron cooler

Author

Bruker, M. W., primary, Benson, S., additional, Hutton, A., additional, Jordan, K., additional, Powers, T., additional, Rimmer, R., additional, Satogata, T., additional, Sy, A., additional, Wang, H., additional, Wang, S., additional, Zhang, H., additional, Zhang, Y., additional, Ma, F., additional, Li, J., additional, Ma, X. M., additional, Mao, L. J., additional, Sha, X. P., additional, Tang, M. T., additional, Yang, J. C., additional, Yang, X. D., additional, Zhao, H., additional, and Zhao, H. W., additional

Published
2021
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13. High air humidity causes atmospheric water absorption via assimilating branches in the deep-rooted tree Haloxylon ammodendron in an arid desert region of northwest China

Author

Gong, X.-W., Lü, G.-H., He, X.-M., Sarkar, B., and Yang, X.-D.

Abstract

Atmospheric water is one of the main water resources for plants in arid ecosystems. However, whether deep-rooted, tomentum-less desert trees can absorb atmospheric water via aerial organs and transport the water into their bodies remains poorly understood. In the present study, a woody, deep-rooted, tomentum-less plant, Haloxylon ammodendron (C.A. Mey.) Bunge, was selected as the experimental object to investigate the preconditions for and consequences of foliar water uptake. Plant water status, gas exchange, and 18O isotopic signatures of the plant were investigated following a typical rainfall pulse and a high-humidity exposure experiment. The results showed that a high content of atmospheric water was the prerequisite for foliar water uptake by H. ammodendron in the arid desert region. After atmospheric water was absorbed via the assimilating branches, which perform the function of leaves due to leaf degeneration, the plant transported the water to the secondary branches and trunk stems, but not to the taproot xylem or the soil, based on the 18O isotopic signatures of the specimen. Foliar water uptake altered the plant water status and gas exchange-related traits, i.e., water potential, stomatal conductance, transpiration rate, and instantaneous water use efficiency. Our results suggest that atmospheric water might be a subsidiary water resource for sustaining the survival and growth of deep-rooted plants in arid desert regions. These findings contribute to the knowledge of plant water physiology and restoration of desert plants in the arid regions of the planet.

Published
2019

18. An investigation and a proposal for handover decision-making in DVB-H

Author

Yang, X D, Song, Y H, Owens, T J, Cosmas, J, and Itagaki, T

Subjects
ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, DVB-H, Handover, Power consumption, ComputerApplications_COMPUTERSINOTHERSYSTEMS
Abstract

Digital Video Broadcasting for Handhelds (DVB-H) is a standard for broadcasting TV like IP data content to portable devices, such as mobile phones, personal digital assistants (PDAs), laptops, etc. Handover in unidirectional broadcasting networks is a novel issue. Since making accurate handover decisions can reduce the battery power consumed, this paper proposes and investigates different strategies that can assist the handover decision-making process in DVB-H networks. The benefits and drawbacks of the different algorithms are presented. A hybrid handover decision-making algorithm is proposed. Future research directions for handover in DVB-H are suggested.

Published
2005

19. Seamless soft handover in DVB-H networks

Author

Yang, X D, Song, Y H, Owens, T J, Cosmas, J, and Itagaki, T

Subjects
Data_CODINGANDINFORMATIONTHEORY
Abstract

DVB-H (Digital Video Broadcasting for Handhelds) is a standard specified by the DVB Organization specifically for the broadcast of TV-like content and data to handheld devices, such as mobile phones, which have unique requirements in terms of power consumption, screen-size and mobility. Seamless handover in such a unidirectional network is especially challenging. In this paper we describe the handover issues of DVB-H networks and propose a novel seamless soft handover mechanism based on measuring CDF (Cumulative Distribution Function) of the signal to noise ratio (SNR) in the DVB-H terminal receiver front-end . Details of the algorithm is given and simulation is done to prove the benefits of such soft handover scheme.

Published
2004

20. Dielectronic recombination experiment of P-like Tin on HIRFL-CSRm at Lanzhou

Author

Xu, W Q, primary, Ma, X, additional, Wen, W Q, additional, Zhu, X L, additional, Gao, Y, additional, Wang, S L, additional, Zhang, P J, additional, Zhang, R T, additional, Li, B, additional, Zhang, Y, additional, Zhao, D M, additional, Liu, H P, additional, Parkhomchuk, V V, additional, Reva, V B, additional, Yang, X D, additional, Li, J, additional, Ma, X M, additional, Yan, T L, additional, Yang, J C, additional, Xia, J W, additional, Yuan, Y J, additional, Xu, H S, additional, Xiao, G Q, additional, Li, C Y, additional, Wang, J G, additional, Zhut, L F, additional, and Badnell, N R, additional

Published
2014
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21. Growth hormone improves growth in pediatric renal transplant recipients-a systemic review and meta-analysis of randomized controlled trials.

Author

Wu Y., Xiang B., Yang X.-D., Cheng W., Wu Y., Xiang B., Yang X.-D., and Cheng W.

Abstract

Background: Growth hormone had been applied to treat pediatric renal allograft recipients with growth retardation. In this systemic review and meta-analysis, we assess the efficiency and safety of growth hormone use in post-renal transplant children. Method(s): A literature search revealed five prospective randomized controlled trials assessing this therapy, with a total of 401 patients. The outcomes, including the baseline height standard deviation score (HSDS), HSDS after a 1-year therapy, delta height standard deviation score (DELTAHSDS), allograft rejection rates and changes in the glomerular filtration rates (GFR) were analyzed. Result(s): Pooled data of the five studies showed that 1 year after the randomized controlled trials, the experimental group receiving growth hormone had a significantly higher growth velocity than the control group, with a mean HSDS difference of 0.68 [95 % confidence interval (CI) 0.25-1.11, P=0.002] between the two groups. The mean difference in the DELTAHSDS between the treated and control group was 0.52 (95 % CI 0.37-0.68, P<0.00001). The rejection episode rates were 35/205 and 19/185, respectively (number of patients with rejection/ total number of patients) (risk ratio 1.56, 95 % CI 0.97-2.53, P=0.07), and the mean difference in the DELTAGFR was 3.27 ml/min per 1.73 m2 (95 % CI -3.54-10.09, P=0.35), which was not statistically significant. Conclusion(s): Based on these studies, we suggest that the application of growth hormone is an effective treatment to promote the growth velocity of children after kidney transplantation. However, the safety of this treatment needs further evaluation. © 2012 IPNA.

Published
2012

23. Analysis of genetic and genotype x environment interaction effects on heterosis of nutrient quality traits in indica hybrid rice

Author

Shi, C. H., Zhu, J., Yu, Y. G., Yang, X. D., and Xue, J. M.

Subjects
Indica rice, Hybrid rice, Genetic analysis, Heterosis, Genotypic environment interaction, Restorer genes, Cytoplasmic male sterility, Traits
Abstract

This article 'Analysis of genetic and genotype x environment interaction effects on heterosis of nutrient quality traits in indica hybrid rice' appeared in the International Rice Research Notes series, created by the International Rice Research Institute (IRRI) to expedite communication among scientists concerned with the development of improved technology for rice and rice-based systems. The series is a mechanism to help scientists keep each other informed of current rice research findings. The concise scientific notes are meant to encourage rice scientists to communicate with one another to obtain details on the research reported.

Published
1997
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24. Progress of dielectronic recombination experiment at CSRm

Author

Meng, L J, primary, Ma, X, additional, Yang, X D, additional, Xu, H S, additional, Xia, J W, additional, Yuan, Y J, additional, Yang, J C, additional, Zhu, X L, additional, Mao, L J, additional, Li, J, additional, Ma, X M, additional, Yan, T L, additional, Qian, D B, additional, Xiao, G Q, additional, Parkhomchuk, V V, additional, and Reva, V B, additional

Published
2012
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27. News from the CSR storage ring

Author

Ma, X, primary, Xu, H S, additional, Xia, J W, additional, Yang, X D, additional, Meng, L J, additional, Wang, M, additional, Tu, X L, additional, Liu, H P, additional, Hu, Z G, additional, Zhu, X L, additional, Mao, R S, additional, Zhang, D C, additional, Mao, L J, additional, Li, J, additional, Li, G H, additional, Liu, Y, additional, Yang, J C, additional, Yuan, Y J, additional, Cai, X H, additional, Zheng, J H, additional, Yang, X T, additional, Xiao, G Q, additional, and Zhan, W L, additional

Published
2009
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29. The first test experiment performed at the electron cooler of storage rings in Lanzhou

Author

Meng, L J, primary, Ma, X, additional, Liu, H P, additional, Yang, X D, additional, Xia, J W, additional, Xu, H S, additional, Hu, Z G, additional, Zhu, X L, additional, Wang, M, additional, Mao, R S, additional, Zhang, D C, additional, Mao, L J, additional, Li, J, additional, Li, G H, additional, Liu, Y, additional, Yang, J C, additional, Yuan, Y J, additional, Zheng, J H, additional, Yang, X T, additional, Xiao, G Q, additional, and Zhan, W L, additional

Published
2009
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31. Stability in parametric resonance of axially moving viscoelastic beams with time-dependent speed

Author

Chen, L.-Q. and Yang, X.-D.

Subjects
Resonance -- Research, Viscoelastic materials -- Research, Engineering and manufacturing industries, Research
Abstract

Chen, L.-Q., and X.-D. Yang. Stability in parametric resonance of axially moving viscoelastic beams with timedependent speed. Journal of Sound and Vibration (United Kingdom) 284(3-5):879-891, June 21, 2005 (www.idealibrary. com). [...]

Published
2006

42. ANALYSIS AND INVESTIGATION OF A CANTOR SET FRACTAL UWB ANTENNA WITH A NOTCH-BAND CHARACTERISTIC.

Author

Li, Y. S., Yang, X. D., Liu, C. Y., and Jiang, T.

Subjects
WAVEGUIDES, ELECTRICAL conductors, ELECTROMAGNETISM, ANTENNAS (Electronics), WIRELESS communications
Abstract

A coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna with a notch band characteristic is presented in the paper. The radiation patch of the proposed UWB antenna is designed using cantor set fractal technology. The bandwidth is broadened by setting two symmetrical triangular tapered corners at the bottom of the wide slot of the proposed UWB antenna. The notched band characteristic is achieved by employing a T-shaped tuning stub at the top of the wide slot. The notched band can be controlled by adjusting the length and the width of the T-shaped tuning stub to give tunable notched band function. The proposed cantor set fractal wide slot UWB antenna has been designed in details and optimized. Experimental and numerical results show that the proposed antenna, with compact size of 26 x 21mm², has an impedance bandwidth range from 2.8GHz to 11GHz for voltage standing-wave ratio (VSWR) less than 2, except the notch band frequency 5.0GHz-6.3GHz for HIPERLAN/2 and IEEE 802.11a (5.1GHz-5.9GHz). [ABSTRACT FROM AUTHOR]

Published
2011

45. Effects of 1α-hydroxycholecalciferol on growth performance, parameters of tibia and plasma, meat quality, and type lib sodium phosphate cotrans porter gene expression of one- to twenty-one-day-old broilers.

Author

Han, J. C., Yang, X. D., Zhang, T., Li, H., Li, W. L., Zhang, Z. Y., and Yao, J. H.

Subjects
*BROILER chickens, *SODIUM phosphates, *POULTRY feeding, *ANIMAL nutrition, *ANIMAL genetics, *GENE expression, *MEAT quality
Abstract

This experiment was conducted to investigate the effects of 1α-hydroxycholecalciferol (1α-OH D3) on the growth performance, tibia and plasma parameters, nutrient utilization, meat quality of the breast and thigh, and type IIb sodium phosphate cotranspoter gene expression of broilers. A total of 96 males of l-d-old Arbor Acres broilers were randomly assigned to 8 cages of 12 birds each. Two dietary treatments were applied to 4 cages each. Diet 1 was prepared as the basal diet (nonphytate phosphorus, 021%), whereas diet 2 was the basal diet supplemented with 5 μg/kg of 1α-OH D3. Results showed that supplementation of the basal diet with 1α-OH D3 increased growth performance, tibia ash and strength, plasma inorganic phosphate concentration, utilization of total phosphorus and nonphytate phosphorus, lightness and yellowness of the breast and thigh meat, and intestinal type IIb sodium phosphate cotranspoter mRNA expression, whereas it decreased the shear force and water-holding capacity of the thigh meat. These data suggest that the addition of 1α-OH D3 might improve growth performance, tibia development, and meat quality in 1- to 21-d-old broilers by increasing the absorption and retention of phosphorus. [ABSTRACT FROM AUTHOR]

Published
2009
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49. Evaluation of equivalency values of microbial phytase to inorganic phosphorus in 22- to 42-day-old broilers

Author

Han, J. C., Yang, X. D., Qu, H. X., Xu, M., Zhang, T., Li, W. L., Yao, J. H., Liu, Y. R., Shi, B. J., Zhou, Z. F., and Feng, X. Y.

Abstract

This experiment was conducted to evaluate the equivalency values of microbial phytase to inorganic phosphorus (Pi) in 22- to 42-d-old broilers fed a corn-soybean meal diet. Ten dietary treatments were designed in which diet 1 was the basal diet [calcium 0.90%, total phosphorus 0.35%, nonphytate phosphorus (NPP) 0.13%] and diet 4 was control (calcium 0.90%, total phosphorus 0.57%, NPP 0.35%). Diets 2 and 3 included 0.20 and 0.27% of NPP, and diets 5 to 10 contained graded levels of microbial phytase (125, 250, 500, 1,000, 2,000, and 4,000 U/kg of diet). Body weight gain, feed intake, phosphorus retained, plasma Pi concentration, tibia ash content, and tibia-breaking strength increased, but plasma calcium concentration decreased with increasing dietary NPP content (from 0.13 to 0.35%) or phytase activity. Microbial phytase caused an increase, whereas dietary NPP caused a decrease in phytate phosphorus (PP) retention. When 4,000 U of phytase was added to the basal diet with 0.13% NPP, 95% PP was released based on tibia ash content, and broiler BW gain and feed intake were equal to those of broilers fed the control diet (NPP 0.35%). Microbial phytase at 125, 250, 500, 1,000, 2,000, and 4,000 U/kg of diet was determined to be equivalent to the addition of 0.035 to 0.208% of Pi from dicalcium phosphate in 22- to 42-d-old broilers. These data suggest that high levels of microbial phytase could release almost all dietary PP and replace all supplemental Pi in growing-finishing broilers.

Published
2009
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50. Elastic and electronic properties of fluorite RuO2 from first principle.

Author

Yang, Z. J., Guo, A. M., Guo, Y. D., Li, J., Wang, Z., Liu, Q., Linghu, R. F., and Yang, X. D.

Subjects
*ELECTRIC properties of metals, *ELASTICITY, *RUTHENIUM oxides, *THERMODYNAMICS, *FLUORITE, *HIGH pressure (Science), *PLANE wavefronts
Abstract

The elastic, thermodynamic, and electronic properties of fluorite RuO2 under high pressure are investigated by plane-wave pseudopotential density functional theory. The optimized lattice parameters, elastic constants, bulk modulus, and shear modulus are consistent with other theoretical values. The phase transition from modified fluorite-type to fluorite is 88 GPa (by localized density approximation, LDA) or 115.5 GPa (by generalized gradient approximation, GGA). The Young's modulus and Lamé's coefficients are also studied under high pressure. The structure turned out to be stable for the pressure up to 120 GPa by calculating elastic constants. In addition, the thermodynamic properties, including the Debye temperature, heat capacity, thermal expansion coefficient, Grüneisen parameter, and Poisson's ratio, are investigated. A small band gap is found in the electronic structure of fluorite RuO² and the bandwidth increases with the pressure. Also, the present mechanical and electronic properties demonstrate that the bonding nature is a combination of covalent, ionic, and metallic contributions. [ABSTRACT FROM AUTHOR]

Published
2012
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