摘要：Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied *** electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex *** this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of *** using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was ***,the perspective related to application of TEM techniques in HEAs are also discussed.

摘要：This paper introduces the design and simulation of a Wire Position Monitor （WPM） used in the cryogenic system of an Accelerator Driven System （ADS）. The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.

摘要：Parametric X-ray Radiation （PXR） can be used as a novel, quasi-monochromatic energy-tunable and high-yield X-ray source. It is produced at the Bragg angle by a relativistic electron beam passing through the periodic structure of crystal materials. This article concerns the PXR experiment using low energy electrons （10 MeV） from NCEL （Novel Compact Electron-Linac）. The difficulty of the experiment is to distinguish the PXR photons form the background. The design of the experiment relies mainly on the yield of PXR, the Bremsstrahlung background of the X-rays and the capability of the detector.

摘要：The small angle neutron scattering （SANS） instrument is presently being constructed at chinese Spal- lation Neutron Source （CSNS） in China, and the biological shielding design is needed to prevent the instrument from causing excessive dose rates in accessible locations. In this paper, the study of shielding design for SANS that relies on Monte Carlo simulation is introduced. Beam line shielding calculations are performed considering both scenarios of closed versus open TO chopper. The basic design scheme of the beam stop is discussed. The size of the TO chopper rotor is also estimated.

摘要：Cooling water is an important part in a Spallation Neutron Source target cooling system, but the unstable vortexes at the exits of the slits between every two tungsten target slices have a negative impact on the stable running of the target system. We apply the field synergy principle for fluid flow to obtain the optimal flow field, which has a uniform velocity distribution without eddy, and then, optimize the geometrical structure of the cooling water flow channel based on the optimal flow field. The results show that when the cooling water flows in the optimized channel, the eddy sizes decrease, the time fluctuations of velocity and pressure almost vanish, and the volume flow rates of the cooling water in each parallel slit are uniform. Therefore, it effectively improves the running stability of the target system with the premise of satisfying the target heat load.

摘要：K-ion batteries(KIBs)hold great promise for large-scale energy ***,the absence of suitable cathode materials limits their practical ***,rationally designing advanced cathode materials for KIBs remains an open *** this work,based on density functional theory calculations,we find that the bond stability of Fe–O is higher than that of Co–O in layered transitional metal(TM)***,the K-ion migration in the Fe-based layered TM oxide has a significantly lower activation energy barrier than that in the Co-based *** on this theoretical prediction,we successfully synthesized a low-cost K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode,which shows excellent structural stability and superior K-storage properties,including durable cycle life and high-rate ***,the designed K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode possesses a great full-cell performance with a discharge capacity of~75 mA h g^(-1) and capacity retention of~80%after 100 *** results show that Fe has better structural stability and K-ion diffusion than high-cost Co in layered oxide cathodes,and this finding provides new insights into the design of low-cost and high-performance KIB layered *** work highlights the feasibility of a theory-guided experiment in screening promising battery materials.

摘要：A prototype of large-area position sensitive neutron detector was designed and constructed according to the requirements of the Small-Angle Scattering spectrometer of China Spallation Neutron Source(CSNS).The detector was based on the 3He neutron convertor and MWPC with an effective area of 650 mm×650 mm.A prototype was completed and tested with 55Fe *** high-pressure vessel was designed and constructed with high-strength aluminum alloy.A position resolution of about 4.6mm×2.3 mm(FWHM)and efficiency>65%for neutrons with wavelength of 1.8?was determined after the operational gas filled.

摘要：Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator （PA） beam loss monitor （BLM） system is reported. The low leakage current （〈0.1 pA）, good plateau （≈800 V） and linearity range up to 200 Roentgen/h are obtained in the first prototype. All of these give us good experience for further improving the ionization chamber construction.

摘要：The rational design of efficient single-atomic(SA)catalysts is essential and highly desirable but impeded by the lack of sufficient acknowledge between structure and *** this end,it is critical to clarify the effect of the coordination structure of active metal centers on the catalytic activities for the design of such ***,we report that different coordination structures of SA Pt catalysts can dramatically influence their activities for anti-Markovnikov hydroboration of *** with the other two coordination structures(Pt-N4 and Pt-O2),the SA Pt species coordinated with three O atoms(Pt-O3)display the highest turnover number value of 3288 for the hydroboration reaction to access the important alkylboronic *** functional theory calculations reveal that a superior catalytic activity can be expected for alkene hydroboration over the three O coordinated Pt species due to the lowest reaction energy(ΔG)limiting step from the reaction phase diagram.

摘要：Chang'E-1 is the first lunar mission in China,which was successfully launched on Oct.24th,*** was guided to crash on the Moon on March 1,2009,at 52.36°E,1.50°S,in the north of Mare *** total mission lasted 495 days,exceeding the designed life-span about four months.1.37Terabytes raw data was received from Chang'*** was then processed into 4Terabytes science data at different levels.A series of science results have been achieved by analyzing and applicating these data,especially "global image of the Moon of China's first lunar exploration mission".Four scientific goals of Chang'E-1 have been *** provides abundant materials for the research of lunar sciences and *** these results will serve for China's future lunar missions.