Stochastic cooling of the spectrometer ring (SRing) at the High Intensity Heavy-Ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, ...is applied to speed up the cooling process of a stored ion beam. In this study, both a Faltin traveling wave structure and a novel slot-ring standing wave structure based on a ceramic vacuum chamber are discussed and evaluated for the pickup/kicker of the SRing stochastic cooling system. The slot-ring structure should significantly improve the shunt impedance due to the Cherenkov effect. For the Faltin-type structure, the results for the pickup shunt impedance obtained from simulations and from beam measurements agree well. Good agreement is also found between the simulated and measured results for the pickup shunt impedance of the slot-ring structure. Cooling process simulations using the Fokker-Planck equation based on the shunt impedance results for the Faltin- and slot-ring-type pickups are also presented.
This research aims to investigate the control effect of asymmetric flow in a slab mold using a novel magnetic field arrangement: freestanding adjustable combination electromagnetic brake (FAC-EMBr). ...Three scenarios (submerged entry nozzle moves to the narrow face, wide face of the slab mold, and rotates 10°) were studied using three-dimensional numerical simulation. The results show that the magnetic field generated by the FAC-EMBr system can effectively cover three key zones in mold and that the magnetic flux density in the zone cover by a vertical magnetic pole can be adjusted according to the actual flow condition. The FAC-EMBr can effectively improve the asymmetric flow in a mold and near the narrow surface caused by the asymmetric arrangement of the nozzle and can effectively inhibit the occurrence of the flow deviation phenomenon and stabilize the steel/slag interface fluctuation. At the same time, FAC-EMBr has obvious inhibition effects on the surface velocity and can optimize the asymmetric distribution of the surface velocity and the upper reflux velocity caused by the asymmetric arrangement of the nozzle. This study can provide theoretical evidence for the development and utilization of a new electromagnetic brake technology.
A Co 3 O 4 –NiO composite electrode material in water–ethanol solution was synthesized in large scale via two steps: preparation of the precursor and a calcination process. The phase structure and ...morphology of the prepared Co 3 O 4 –NiO composites were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Cyclic voltammetry, chronopotentiometry, and electrochemical impedance measurements were applied in a mild aqueous electrolyte (2 mol L −1 KOH) to investigate the electrochemical performance of the Co 3 O 4 –NiO composites electrode. The results indicate that the molar ratio of Ni to Co and the water–ethanol ratio had a significant influence on the electrochemical capacitive behaviors of the products. The Co 3 O 4 –NiO composite electrode shows a maximum specific capacitance of 1832 F g −1 at 2 mA cm −2 under the conditions of n Co : n Ni = 1 : 1, V water : V alcohol = 1 : 2. In addition, the electrochemical stability was measured after 1000 continuous charge–discharge cycles at 2 mA cm −2 and only 1.863% was degraded, which shows the excellent electrochemical performance, indicating a kind of promising candidate for supercapacitors.
A BPM based beam loss monitoring scheme for the China initiative accelerator driven subcritical (CIADS) facility has been proposed for the MEBT section of its high power Linac. In this scheme, a ...differential beam monitoring algorithm is utilized that relies on beam intensity measurements using BPM electrodes. Discussions of the experimental results for the scheme are presented. Further experiments have been performed with some promising results. This paper describes the experimental results with some analyses on measurement errors of the system. The proposed physical design of this system is described and further development is presented.
Objectives. AQP7 and AQP9 represent glycerol channel in adipose tissue and liver and have been associated with metabolic diseases. We aimed to investigate the associations between genetic variants in ...AQP7 and AQP9 genes and the risk of type 2 diabetes (T2DM) in Chinese population. Methods. Blood samples were drawn from 400 T2DM patients and 400 age- and gender-matched controls. Genomic DNA was extracted by proteinase K digestion and phenol–chloroform extraction. Genotyping of 5 single nucleotide polymorphisms (SNPs) in AQP7 (rs2989924, rs3758269, and rs62542743) and AQP9 (rs57139208, rs16939881) was performed by the polymerase chain reaction assay with TaqMan probes. Results. The subjects with rs2989924 GA+AA genotypes had 1.47-fold increased risk of T2DM (odds ratio OR 1.47, 95% confidence interval CI 1.06-2.04), compared to those with GG genotype, and this association remained significant after adjustment for covariates (OR 1.66, 95% CI 1.07-2.57). When compared with rs3758269 CC genotype, the subjects with CT+TT genotypes had 45% decreased T2DM risk after multivariate adjustment (OR 0.55, 95% CI 0.35-0.85). The associations were evident in elder and overweight subjects and those with central obesity. No association was observed between AQP9 SNPs and T2DM risk. Conclusions. AQP7 SNP rs2989924 and rs3758269 were associated with T2DM risk in Chinese Han population.
Hydrogeochemical investigations were carried out in the Datong Basin, northern China to understand the sources and mechanisms of fluoride enrichment in the groundwater. The re- sults indicate that ...fluoride concentrations reached up to 7.2 mg/L, and the hydrochemical type changed from Ca-HCO3, Ca-Mg-HCO3 water in the recharge areas to Na-HCO3, Na-Mg-HCO3 in the flow-through area and ultimately to Na-CI-HCO3, Na-SO4-CI and Na-CI in the discharge areas. The to- tal fluorine contents in the soils ranged between 277.6 and 1 292.5 mg/kg, which can provide large amounts of fluorine from fluorine-bearing minerals, such as fluorite, biotite and amphibole. The con- centration of water-soluble fluorine ranged from 3.9 to 49.9 mg/kg （mostly less than 1% of the total fluorine） in the soils and rocks that, may have released sufficient fluorine into the groundwater. The results of PHREEQC simulations indicate that most of the analyzed samples are under-saturated with respect to fluorite （CaFz） from the recharge area to the discharge area. The fluctuation of F concentra- tion in the 11 months indicates that the seasonal variation and the agricultural activity also affect the fluoride content in the groundwater. Fluoride enrichment in groundwater is predominantly controlled by fluorite solubility, residence time, evapotranspiration intensity and seasonal variation in this arid and semi-arid area.
A four-vane continuous wave (CW) RFQ has been designed for the injector II LINAC of China ADS project. To acquire the experience of a CW RFQ on design, tuning, conditioning, running, etc., a 1-m-long ...RFQ accelerator prototype has been built. Working at 162.5MHz, the RFQ prototype accelerates protons of 10mA from 20keV to 560keV in one meter length with a low inter-vane voltage of 65kV and a safe Kilpatric factor of 1.3. Conditioning and beam test of the accelerator prototype have been completed, and it shows the transmission efficiency can reach 90% with a 10mA CW proton beam. Design, fabrication and tests of the RFQ prototype will be presented in detail in the paper.
A Co sub(3)O sub(4)-NiO composite electrode material in water-ethanol solution was synthesized in large scale viatwo steps: preparation of the precursor and a calcination process. The phase structure ...and morphology of the prepared Co sub(3)O sub(4)-NiO composites were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Cyclic voltammetry, chronopotentiometry, and electrochemical impedance measurements were applied in a mild aqueous electrolyte (2 mol L super(-1) KOH) to investigate the electrochemical performance of the Co sub(3)O sub(4)-NiO composites electrode. The results indicate that the molar ratio of Ni to Co and the water-ethanol ratio had a significant influence on the electrochemical capacitive behaviors of the products. The Co sub(3)O sub(4)-NiO composite electrode shows a maximum specific capacitance of 1832 F g super(-1) at 2 mA cm super(-2) under the conditions of n sub(Co) : n sub(Ni) = 1 : 1, V sub(water) : V sub(alcohol) = 1 : 2. In addition, the electrochemical stability was measured after 1000 continuous charge-discharge cycles at 2 mA cm super(-2) and only 1.863% was degraded, which shows the excellent electrochemical performance, indicating a kind of promising candidate for supercapacitors.
Although arsenic-contaminated groundwater in the Datong Basin has been studied for more than 10 years, little has been known about the complex patterns of solute transport in the aquifer systems. ...Field monitoring and transient 3D unsaturated groundwater flow modeling studies were car- ried out on the riparian zone of the Sanggan River at the Datong Basin, northern China, to better un- derstand the effects of groundwater flow on As mobilization and transport. The results indicate that ir- rigation is the primary factor in determining the groundwater flow paths. Irrigation can not only in- crease groundwater level and reduce horizontal groundwater velocity and thereby accelerate vertical and horizontal groundwater exchange among sand, silt and clay formations, but also change the HS concentration, redox conditions of the shallow groundwater. Results of net groundwater flux estimation suggest that vertical infiltration is likely the primary control of As transport in the vadose zone, while horizontal water exchange is dominant in controlling As migration within the sand aquifers. Recharge water, including irrigation return water and flushed saltwater, travels downward from the ground surface to the aquifer and then nearly horizontally across the sand aquifer. The maximum value of As enriched in the riparian zone is roughly estimated to be 1 706.2 mg.d-1 for a horizontal water exchange of 8.98 m3.d-1 close to the river and an As concentration of 190 μg.L-1.
An adaptive marker extraction-based watershed algorithm is proposed to overcome the over-segmentation problem. By combining local minima depth and water basin scale information, markers are ...adaptively extracted for local minima, and the threshold for marker-extraction is automatically calculated according to the statistics of local extreme points in the gradient map. These markers are imposed on the original gradient map as its local minima. The watershed algorithm is applied on the modified gradient map to segment the image. Simulation results show that the proposed method can efficiently reduce over-segmentation with scarcely computational complexity increase. It has better anti-noise performance and edge-location capability as well.
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