[en] The effect of surface polar optical phonons (SOs) from the dielectric layers on electron mobility in dual-gated graphene field effect transistors (GFETs) is studied theoretically. By taking into account SO scattering of electron as a main scattering mechanism, the electron mobility is calculated by the iterative solution of Boltzmann transport equation. In treating scattering with the SO modes, the dynamic dielectric screening is included and compared to the static dielectric screening and the dielectric screening in the static limit. It is found that the dynamic dielectric screening effect plays an important role in the range of low net carrier density. More importantly, in-plane acoustic phonon scattering and charged impurity scattering are also included in the total mobility for SiO_2-supported GFETs with various high-κ top-gate dielectric layers considered. The calculated total mobility results suggest both Al_2O_3 and AlN are the promising candidate dielectric layers for the enhancement in room temperature mobility of graphene in the future

[en] Two new coordination complexes with tetrazole heterocycle ligands bearing acetate groups, [Co(L)_2]_n (1) and [Co_3(L)_4(N_3)_2·2MeOH]_n (2) (L=tetrazole-1-acetate) have been synthesized and structurally characterized. Single crystal structure analysis shows that the cobalt-complex 1 has the 3D 3,6-connected (4"2.6)_2(4"4.6"2.8"8.10)-ant topology. By introducing azide in this system, complex 2 forms the 2D network containing the [Co_3] units. And the magnetic properties of 1 and 2 have been studied. - Graphical abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with tetrazole heterocycle ligands bearing acetate groups are reported. - Highlights: • Two novel Cobalt(II) complexes with tetrazole acetate ligands were synthesized. • The magnetic properties of two complexes were studied. • Azide as co-ligand resulted in different structures and magnetic properties. • The new coordination mode of tetrazole acetate ligand was obtained.

[en] Highlights: • A novel gravity-assisted heat pipe thermal storage unit (GAHP-TSU) is presented and tested. • Composite granular solid–liquid PCM is piled up as the porous medium layer in GAHP-TSU. • GAHP-TSU avoids the major obstacle of low thermal conductivity of the PCM. • GAHP-TSU enables the thermal storage unit with outstanding heat transfer performance. - Abstract: In this study, a novel gravity-assisted heat pipe type thermal storage unit (GAHP-TSU) has been presented for the potential application in solar air conditioning and refrigeration systems, in which composite granular solid–liquid PCMs compounded by RT100 and high-density polyethylene with phase change temperature of 100 °C are piled up as a porous PCMs medium layer. Water is used as heat transfer fluid in the GAHP-TSU. The heat transfer mechanism of heat storage/release in the GAHP-TSU is similar to that of the gravity-assisted heat pipe, which is superior to traditional direct-contact or indirect-contact thermal storage units. The properties of start-up, heat transfer characteristics on the stages of heat absorption and release of the GAHP-TSU are studied in detailed, including necessary calculations based on heat transfer theory. The results show that the whole system is almost isothermal at the temperature over 70 °C and the heat transfer properties are excellent both for heat absorption and release stages. The GAHP-TSU device with low thermal conductivity of the PCMs is promising in potential industry applications

[en] It mainly introduced: The first, the primary sources in space radiation, which include Galactic Cosmic rays (GCRs), Solar Particle Events (SPEs), Trapped Radiation formed by charged particles trapped in geomagnetic field, secondary particles radiation produced due to interactions between charged particles and Earth's atmosphere. The second the contributions of mostly components to radiation dose. The third the methods for measuring space radiation, includes passive and active detectors, and their advantages and disadvantages. (authors)

[en] Highlights: • A novel open heat pipe thermal storage unit is design to improve its performance. • Mechanism of its operation is phase-change heat transfer. • Tubular canisters with phase change material were placed in thermal storage unit. • Experiment and analysis are carried out to investigate its operation properties. - Abstract: A novel open thermosyphon-type thermal storage unit is presented to improve design and performance of heat pipe type thermal storage unit. In the present study, tubular canisters filled with a solid–liquid phase change material are vertically placed in the middle of the thermal storage unit. The phase change material melts at 100 °C. Water is presented as the phase-change heat transfer medium of the thermal storage unit. The tubular canister is wrapped tightly with a layer of stainless steel mesh to increase the surface wettability. The heat transfer mechanism of charging/discharging is similar to that of the thermosyphon. Heat transfer between the heat resource or cold resource and the phase change material in this device occurs in the form of a cyclic phase change of the heat-transfer medium, which occurs on the surface of the copper tubes and has an extremely high heat-transfer coefficient. A series of experiments and theoretical analyses are carried out to investigate the properties of the thermal storage unit, including power distribution, start-up performance, and temperature difference between the phase change material and the surrounding vapor. The results show that the whole system has excellent heat-storage/heat-release performance

[en] In order to evaluate the safety of helium cooled blanket system of China Fusion Engineering Test Reactor (CFETR) and optimize the blanket design, this study presents the initial events of accidents, and determines the accident list and design basis accidents based on the design characteristics of CFETR helium cooled blanket. The thermal hydraulic steady-state analysis of CFETR helium cooled blanket module is carried out by using the best transient estimation program RELAP5. The preliminary safety analysis of accident transient is carried out according to the requirements of design basis accident. The results show that the LOCA accidents in different positions should be focused on in the accident safety analysis of helium cooled blanket system;The in-vessel LOCA large break accident is analyzed and calculated, and the maximum temperature of the first wall and the maximum pressure in the vacuum vessel are given, which meet the requirements of the acceptance criteria. (authors)

[en] Objective: To develop a new automatic detection algorithm of the diaphragm motion based on Canny edge detection and wavelet transform. Methods: On-line fluoroscopic images under free breathing were enhanced by using the wavelet transform. After the wavelet transform, edge detection was carried out for the enhanced image. Canny edge detection algorithm was used to achieve the diaphragm edge. Programs were written in Matlab to track the position of the diaphragm. The diaphragm movement curves were derived to evaluate the characteristics of patients respiratory motion. Results: Under calm free breathing,the amplitude and period of diaphragm motion acquired by means of the wavelet transform and Canny edge detection were in good agreement with manual measurement. There were six to seven respiratory cycles in a XVI Motion-View^TM. The magnitude of diaphragm movement was not exactly the same in the cranio-caudal (CC) direction. The magnitude was from 6.7 mm to 8.0 mm with an average of 7.4 mm. The movements of the respiratory motion cycles had little variations in amplitude and period for the same patient between fractions except emotional excitement or cough. Conclusions: The automatic diaphragm detection methods developed in this paper are precise, and can effectively reflect the characteristics of the respiratory motion. The method can save much time and improve the measure precision greatly compared with the manual measurement. (authors)

[en] Based on the research of X-ray fluorescence spectral lines of the Jiajika ore specimen, combined with the geochemical theory of the pegmatite lithium deposit, come up with the method of using the Rb, Nb, Y elements which is the associated elements of Li element and the main elements of surrounding rock Fe, St, Zr as the basis for distinguishing the ore from non-ore layers. Applying this research result, a full-hole X-ray fluorescence spectral measurement was performed on the three boreholes in Jiajika, and the possible mineralized layers were given one by one. Core sampling analysis in late stage in the exploration area confirmed the reliability of the X-ray fluorescence spectral measurement results. Statistics show that using X-ray fluorescence spectral measurement as a guide can reduce core sampling by about 30%, and the economic benefits are significant. (authors)

[en] Textured diamond films were deposited on (100) Si substrates via microwave plasma CVD (MWCVD) with bias-enhanced nucleation or without substrate bias. The samples were identified by means of scanning electron microscopy (SEM) and X ray diffraction (XRD) to be textured. The nucleation and growth process of textured diamond films were investigated, the mechanism of nucleation and growth were discussed

[en] It mainly deals with the theory of particle measurement in a method of ion collection and probes the prospect of its application in alpha surface contamination measurement. (authors)