[en] This paper introduces the monitoring results of environmental gamma radiation air absorbed dose rate by Zhejiang Province Radiation Environmental Monitoring Center during Japan nuclear leakage accident. Monitoring includes continuous and instantaneous surveillance measurements in Hangzhou and Zhoushan areas and around Qinshan nuclear power base. The results indicated that Japan nuclear leakage accident caused by the earthquake did not significantly influence the environmental gamma radiation air absorbed dose rate level in Zhejiang Province. (authors)

[en] Beam profile and emittance are important parameters in storage ring. And progress the research of beam unstable on ring using beam profile monitoring system. The paper presents part reconstruction of the beam profile monitor system and its software update for Hefei light source. It is emphasizes on the software ROOT from CERN with its application in processing data and display

[en] We report both experimentally and numerically that ultra-broadband asymmetric acoustic transmission is realized by a brass plate and a right triangle reflector immersed in water. This exotic phenomenon arises from the asymmetric excitation of the leaky asymmetric zero-order Lamb mode in the brass plate induced by the incident angle of external bulk waves. The results show that the bandwidth of the asymmetric acoustic transmission could reach 2000 kHz, and the positive transmitted wave is only a single acoustic beam. The device has the advantages of ultra-broadband, single transmitted beam, and simpler structure, which has great potential applications in ultrasonic devices. (paper)

[en] Based on the structural design concept of ‘functional integration’, this paper proposes the principle of a power-generated magnetorheological energy absorber with velocity self-sensing capability (PGMREA), which realizes the integration of controllable damping mechanism and mechanical energy-electrical energy conversion mechanism in structure profile and multiple functions in function profile, including controllable damping, power generation and velocity self-sensing. The controllable damping mechanism consists of an annular gap and a ball screw. The annular gap fulfilled with MR fluid that operates in pure shear mode under controllable electromagnetic field. The rotational damping torque generated from the controllable damping mechanism is translated to a linear damping force via the ball screw. The mechanical energy-electrical energy conversion mechanism is realized by the ball screw and a generator composed of a permanent magnet rotor and a generator stator. The ball screw based mechanical energy-electrical energy conversion mechanism converts the mechanical energy of excitations to electrical energy for storage or directly to power the controllable damping mechanism of the PGMREA. The velocity self-sensing capability of the PGMREA is achieved via signal processing using the mechanical energy-electrical energy conversion information. Based on the principle of the proposed PGMREA, the mathematical model of the PGMREA is established, including the damping force, generated power and self-sensing velocity. The electromagnetic circuit of the PGMREA is simulated and verified via a finite element analysis software ANSYS. The developed PGMREA prototype is experimentally tested on a servo-hydraulic testing system. The model-based predicted results and the experimental results are compared and analyzed. (paper)

[en] Using the first-principles method based on the density functional theory, the adsorption energies, migration processes and electronic properties for the Li, Na, K and Rb adsorbed on the bilayer graphene (BLG) were calculated. The calculated adsorption energies indicate that both Li and Na atoms tend to aggregate into clusters, and the K and Rb atoms can dispersive on the BLG. The energy barriers for alkali-metal atoms migration decrease with the increasing of the atomic radius. The adsorption systems exhibit metallic character since the Fermi level shifts up into the conduction band due to the electrons transfer from adatoms to the BLG. Analysis of the charge density differences and electronic structures of these adsorption systems shows that ionic bond takes place between the alkali-metal atoms (Li, Na, K and Rb) and the BLG. (authors)

[en] The response to neoadjuvant chemotherapy has been proven to predict long-term clinical benefits for patients. Our research is to construct a nomogram to predict pathological complete response of human epidermal growth factor receptor 2 negative breast cancer patients. We enrolled 815 patients who received neoadjuvant chemotherapy from 2003 to 2015 and divided them into a training set and a validation set. Univariate logistic regression was performed to screen for predictors and construct the nomogram; multivariate logistic regression was performed to identify independent predictors. After performing the univariate logistic regression analysis in the training set, tumor size, hormone receptor status, regimens of neoadjuvant chemotherapy and cycles of neoadjuvant chemotherapy were the final predictors for the construction of the nomogram. The multivariate logistic regression analysis demonstrated that T4 status, hormone receptor status and receiving regimen of paclitaxel and carboplatin were independent predictors of pathological complete response. The area under the receiver operating characteristic curve of the training set and the validation set was 0.779 and 0.701, respectively. We constructed and validated a nomogram to predict pathological complete response in human epidermal growth factor receptor 2 negative breast cancer patients. We also identified tumor size, hormone receptor status and paclitaxel and carboplatin regimen as independent predictors of pathological complete response. The online version of this article (doi:10.1186/s12885-016-2652-z) contains supplementary material, which is available to authorized users

[en] We report both experimentally and numerically that a flow-free pseudospin-dependent acoustic topological insulator (ATI) is realized by two honeycomb sonic crystals with direct and indirect band gaps. By simply rotating triangular rods of the sonic crystals, the band inversion is realized, which arises from the change of the coupling strength between the triangular rods and leads to a topological phase transition. Moreover, a direct band gap is converted into an indirect band gap when the rotation angle is larger than 32.18°. By using the triangular rods with the rotation angles of 0°, 30°, and 60°, we design two topological insulators which include a topological nontrivial sonic crystal with the direct band gap (30°) and the indirect band gap (60°), respectively. In the topological insulator composed of the sonic crystal with the indirect band gap, the pseudospin-dependent edge modes also support acoustic propagation, in which the clockwise (anticlockwise) acoustic energy flux emulates pseudospin− (pseudospin+) state. Furthermore, these edge modes are topologically protected and remain high transmission after transmitting through topological waveguides with defects. The results provide diverse concepts to design ATIs with versatile applications. (paper)

[en] The ER321 stainless steel was fabricated by laser and wire additive manufacturing (LWAM) assisted with ultrasonic vibration (UV) under synchronous motion conditions. It was found that the grain structure of ER321 stainless steel varied from coarse columnar dendrites (without UV) to equiaxed dendrites (with UV). And, the UV effectively weakened the texture strength and homogenized the grain structure of the deposition layers. The improvement of grain structure enhanced the microhardness (~10.7%) and yield strength (~11.9%) of ER321 stainless steel. These results show that this innovative manufacturing approach can effectively improve the problem of coarse columnar dendrites in the additive manufactured complex large-scale components.

[en] An abnormal aging phenomenon is reported for GaN-based near-ultraviolet laser diodes (LDs). Under an electrical stress for several minutes, the threshold current of the LDs decreased, while the light output power and the operation voltage increased. The amplitude of the abnormal aging phenomena was found to be mainly related to the excess Mg concentration in the p-AlGaN electron blocking layer (EBL). It almost disappeared when the Mg concentration in the AlGaN EBL was reduced to 2  ×  10¹⁹ cm⁻³. We propose that this phenomenon was related to the Mg–V_N–H complex defects formed in highly doped AlGaN EBL ([Mg]  >  3  ×  10¹⁹ cm⁻³). (paper)

[en] Highlights: • The plasticity is strongly dependent on strain rate in Ti1023 single crystal micropillars containing brittle ω-precipitates; • Micropillar plasticity is closely related to the width of deformation band; • The improvement of micropillar plasticity upon high strain rate is ascribed to the wider deformation band; • Cross slip governs plasticity improvement, which is validated by crystallographic analysis and first-principles calculation. Brittle ω-precipitates in bcc β-Ti alloys are well known to dramatically degrade material plasticity and even trigger macroscopic premature fracture, posing an obstacle for structural applications. The embrittlement mechanism is intimately related to dislocation pile-up at the ω/β interface that leads to stress concentration and undesirable failure. The underlying physics of improving ductility remains to be further uncovered. Here we report a new finding in β-Ti alloy single crystal micropillar compression that the plasticity can be substantially improved by means of increasing strain rate, while mechanical strength simultaneously exhibits striking “faster is stronger” fashion. The results reveal that the improvement of micropillar plasticity upon higher loading rate can be ascribed to the wider deformation band, in contrast to equivalents under quasi-static mode. The microscopic examination shows that cross slip induced by screw dislocations governs the plasticity improvement, which is further validated by crystallographic analysis and first principle energy landscape calculations. This “dynamic self-toughening” behavior advances our fundamental understanding to the plastic deformation mechanism of ω-precipitate contained bcc β-Ti alloys.