[en] Time-To-Count is a new measurement of GM tube. The author describes basic principle, operating model and characteristics of this measurement. A plan is given to bring about it, and detailed experiment data is also shown

[en] The glass-forming ability, thermal stability and magnetic properties of the Nd_60-xDy_xFe₃₀Al₁₀ (x=0, 2, 5) bulk amorphous alloys were investigated by X-Ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and the vibrating sample magnetometer (VSM). The results show that the glass forming ability of the Nd_60-xDy_xFe₃₀Al₁₀ (x=0,2,5) alloys decrease with increasing Dy content. The as-cast Nd_60-xDy_xFe₃₀Al₁₀ (x=0,2,5) alloys show hard magnetic behavior at room temperature. With increasing Dy content, the intrinsic coercivity of the alloys increase significantly while the saturation magnetization and remanence of the alloys decrease monotonously. With increasing annealed temperature, the intrinsic coercivity of the Nd₅₅Fe₃₀Al₁₀Dy₅ alloy decreased significantly, while the saturation magnetization and remanence decrease monotonously. The Nd₅₅Fe₃₀Al₁₀Dy₅ alloy shows soft magnetic behavior after annealed at 773 K for 30 min. (orig.)

[en] Most antiferroelectric ceramics are modified from the prototype PbZrO₃ by adding Sn and Ti in conjunction with small amount of Nb or La to optimize their properties. These modifiers introduce unique nanoscale structural feature to the ceramics in the form of incommensurate modulations. It was shown previously that the modulation is strongly responsive to a change in chemical composition or temperature. However, its response to an electric field, the driving force in real applications, has not been explored before. In the present work the dynamic evolution of the incommensurate modulation during the electric field-induced antiferroelectric-to-ferroelectric transformation was observed with an in situ transmission electron microscopy (TEM) technique. The results indicate that the incommensurate modulation exists as a transverse Pb-cation displacement wave. The wavelength was found to be quite stable against external electrical stimuli, in sharp contrast to the dramatic change under thermal stimuli reported previously. It is suggested that the appeared incommensurate modulation is an average effect of a mixture of two commensurate modulations. The electric field-induced antiferroelectric-to-ferroelectric transformation proceeds with aligning the Pb-cation displacements, which resembles the process of 90 deg. reorientation and 180 deg. reversal in normal ferroelectrics

[en] Highlights: • Evanescent wave tunneling spectrum in three bodies system with independent temperature has been calculated with the help of rigorous coupled wave analysis. • An intensive quasi-monochromatic tunneling peak has been induced in non-contact. • The tunneling mode originates from the coupling between cavity modes and spoof surface modes, and is further amplified by three bodies effect. • The spoof surface modes originate from surface phonon polariton in SiO₂, and is manipulated by subwavelength structure. - Abstract: In this study, a quasi-monochromatic photon tunneling peak has been achieved in substrate–comb–substrate three bodies system. The near-field tunneling peak results from coupling between spoof surface mode and cavity mode, which has been further amplified by three bodies effect. The spoof surface mode originates from phonon vibration, and is manipulated by the structure into new surface mode. As a non-contact approach to generate high intensity and narrow bandwidth tunneling mode, current study has many application points in near-field spectroscopy and energy-conversion.

[en] Highlights: • Asymmetric radiation transfer in a linear metamaterial with its physical meaning has been numerically demonstrated via Finite-Difference Time-Domain method and Rigorous Coupled Wave Analysis. • The physical picture of the asymmetric light-matter interaction has been investigated. • Dispersion relationship of surface plasmon polariton and temporal coupled mode theory have been employed to verify the results. - Abstract: In this paper, asymmetric radiation transfer based on linear light-matter interaction has been proposed. Two naturally different numerical methods, finite difference time domain (FDTD) and rigorous coupled wave analysis (RCWA), are utilized to verify that asymmetric radiation transfer can exist for linear plasmonic meta-material. The overall asymmetry has been introduced to evaluate bifacial transmission. Physics for the asymmetric optical responses have been understood via electromagnetic field distributions. Dispersion relation for surface plasmon polariton (SPP) and temporal coupled mode theory (TCMT) have been employed to verify the physics discussed in the paper. Geometric effects and the disappearing of asymmetric transmission have also been investigated. The results gained herein broaden the cognition of linear optical system, facilitate the design of novel energy harvesting device.

[en] Experimental studies on single-phase real time flow resistance characteristics under unsteady flow condition were carried out. The experimental phenomena show fluctuation changes friction pressure drop characteristics. The friction pressure drop fluctuates with fluctuation flow and there is phase difference between two fluctuation signals. Based on analysis, such conclusions can be achieved that the acceleration may strongly influenced friction pressure drop, and with the same flow rate, the friction pressure drop is different with different directions of acceleration. When the direction of acceleration is same as that of flow rate, the friction pressure drop is large, when the acceleration is opposite with flow rate, the friction pressure drop is small. Based on theoretical analysis, an empirical correlation was obtained to calculate real time friction pressure drop of fluctuation conditions and calculated results fit well with experimental data. (authors)

[en] SiC film has been coated on surface of 316L stainless steel, using substrate bias-assisted radio frequency (RF) sputtering, as tritium permeation barrier (TPB) of first wall and blanket in fusion reactor. The microstructure of films was examined by SEM, XRD and FTIR. Results show that the film is compact, uniform and has good adherence with the substratum. The crystalline structure of the film is a microcrystalline cubic phase β-SiC and shows (111) preferred direction, the absorption peak corresponds to the stretch frequency peak of Si-C bond of β-SiC. A multiple transition layer (Ti and TiN) was deposited on stainless steel before depositing SiC film, and resulted in significant improving adhesion of SiC film to stainless steel. The tritium permeation reduction factor (PRF) of 316L with film evaluated at 500 degree C is up by a factor of 10⁴, compared with 316L with Pd film. It's found that bias voltage and RF power influence the quality of film and PRF. Appropriate technology has been selected through the preparation technologies

[en] Objective: To investigate the accuracy, reliability and convenience of 2-D ionization chamber array MatriXX system in daily quality control of radiation therapy. Methods: The percent depth dose (PDD), tissue maximum ratio (TMR), off-axis ratio profile, penumbra and field width of Varian 23EX linac were measured by MatriXX system combined with solid water phantom and compared with the data acquired by RFA300 three-dimensional water phantom. The dose distributions of static and dynamic intensity modulated radiation therapy (IMRT) plans created by Pinnac3 V8.0 m three-dimensional treatment planning system (3D-TPS) were validated by MatriXX combined with the dose phantom made in home. Results: The PDD and TMR of 6MV X-ray measured by MatriXX system were parallel to the curves acquired by RFA300, and the PDD curve of 15MV X-ray measured by MatriXX was nearly identic to that measured by RFA300. The values of penumbra measured by MatriXX were two or three times larger than those measured by RFA300, and when the field size was smaller than 3 cm x 3 cm the penumbra of it could not be automatically calculated out by the MatriXX system. The characteristic information of field, such as symmetry and flatness and field width, can be acquired at once in a single sampling, which can be completed in less than 20 mS. The qualitative and quantificational verification of 2-D dose distribution of IMRT plans can be quickly implemented by using MatriXX system. Conclusions: The MatriXX system is very accurate and convenient and effective in quality control of clinical radiotherapy, and it's a perfect tool for the quality control procedure of radiation therapy. (authors)

[en] Mg–Sr alloy has been studied as a potential biodegradable material with excellent bioactivity to promote the bone formation. However, its degradation behavior needs to be well controlled to avoid the negative effect, which is important for future application. Therefore in this study, the microstructure and its effect on corrosion behavior of an Mg–1.5Sr alloy were investigated. The microstructures of the alloy under different processing procedures were characterized by both optical and scanning electron microscopes. The corrosion performance was studied in Hank’s solution using immersion, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. The results showed that the grain size and the amount and distribution of β-Mg₁₇Sr₂ had obvious effects on the corrosion behavior of Mg–Sr alloy. The smaller the grain size was, the more the protective surface layer formed on Mg–Sr alloy, and the higher the corrosion resistance was. For the as-cast Mg–Sr alloy, the network-like second phases precipitated along the grain boundaries could not hinder the corrosion due to their own corrosion cracking accelerating the intergranular corrosion. However, the refinement of second phases increased the corrosion resistance of the as-extruded alloy. After solution treatment at 450 °C for 5 h, the grains in the alloy did not grow much and β-Mg₁₇Sr₂ phases homogenously distributed in the alloy, resulting in the increase in corrosion resistance. However, after aging treatment, large amount of precipitated second phases increased the galvanic corrosion of the alloy, accelerating the development of corrosion.

[en] 2D and 3D submicron periodic structures are first fabricated by red-induced photopolymerization using a common 635 nm semiconductor laser and specially developed red-sensitive polymer material. The principle of this new photopolymer material fabrication is explained and the absorption spectra of the material are measured. This fabrication technique allows a deeper penetration into volume and larger interference irradiation area which is more than 1 cm². The optical design, theoretical calculations and experimental results including diffraction patterns verifying the formation of periodic structures are presented. Compared with other fabrication technologies using high-power lasers, this approach has greatly reduced the demand for laser apparatus. Therefore, it is much more accessible to most laboratories and potentially usable in holographic fabrication of photonic crystals and devices in micro electro-mechanical systems (MEMS). (classical areas of phenomenology)