[en] Based on the linearity of ablated area and laser pulse energy, the threshold fluence of sapphire is determined accurately in this paper. Meanwhile the dependences of F_th on pulse duration (τ<1 ps) with laser at 400 and 800 nm are presented, respectively. It is found that the experiment results agree well with the theoretical calculations based on avalanche model. And we discuss the photon absorption mechanism of the conduction band electrons in Al₂O₃ single crystal

[en] For biomass combustion to become a sustainable energy production system, it is crucial to minimise landfill of biomass ashes, to recycle the nutrients and to minimise the undesirable impact of hazardous substances in the ash. In order to test the plant availability of phosphorus (P) and cadmium (Cd) in four biomass ashes, we conducted two pot experiments on a P-depleted soil and one mini-plot field experiment on a soil with adequate P status. Test plants were spring barley and Italian ryegrass. Ash applications were compared to triple superphosphate (TSP) and a control without P application. Both TSP and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha"−"1 application, although the barley took up more P at higher applications. The apparent P use efficiency of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha"−"1 straw ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash-amended soil after harvest indicate that the ash may also contribute to P availability for the following crops. In conclusion, the biomass ashes in this study had P availability similar to the TSP fertiliser and did not contaminate the crop with Cd during the first year. - Highlights: • Effects of four biomass ashes vs. a P fertiliser (TSP) on two crops were studied. • Ashes increased crop yields with P availability similar to TSP on P-depleted soil. • Barley biomass and Cd uptake did not respond to high ash rates on a normal P soil. • Cd concentration of crops on ash-amended soil was in the range of TSP treatments. • High levels of soil available P remained after harvest at high ash applications.

[en] Highlights: • The low-power-laser was used to obtain the excellent coatings with different amount of Y_2O_3 addition. • The addition of rare earth oxide Y_2O_3 refined and purified the microstructure of the coatings, meanwhile, increased the thickness of the coatings and reduced the dilution of cladding materials from based alloy. • The primary phases in the coatings are Mg_3_2Al_4_7Cu_7, MgCu_6Al_5, Al_2CuMg and Al_1_2Mg_1_7. The A_l_4MgY and MgAl_2O_4 phase can be found in Y_2O_3-modified coatings. • The micro-hardness and the abrasion resistance of the coatings with Y_2O_3 had been improved obviously compared with the coatings without Y_2O_3. • The corrosion resistance of the AZ91D magnesium alloy had been improved by laser cladding. And the effect of Y_2O_3 on the corrosion potential of the coatings was less than the effect of Y_2O_3 on corrosion current density of the coatings. - Abstract: Due to the low-melting-point and high evaporation rate of magnesium at elevated temperature, high power laser clad coating on magnesium always causes subsidence and deterioration in the surface. Low power laser can reduce the evaporation effect while brings problems such as decreased thickness, incomplete fusion and unsatisfied performance. Therefore, low power laser with selected parameters was used in our research work to obtain Al–Cu coatings with Y_2O_3 addition on AZ91D magnesium alloy. The addition of Y_2O_3 obviously increases thickness of the coating and improves the melting efficiency. Furthermore, the effect of Y_2O_3 addition on the microstructure of laser clad Al–Cu coatings was investigated by scanning electron microscopy. The energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD) were used to examine the elemental and phase compositions of the coatings. The properties were investigated by micro-hardness test, dry wear test and electrochemical corrosion. It was found that the addition of Y_2O_3 refined the microstructure. The micro-hardness, abrasion resistance and corrosion resistance of the coatings was greatly improved compared with the magnesium matrix, especially for the Al–Cu coating with Y_2O_3 addition.

[en] Background and purpose: We conducted a meta-analysis of randomized controlled trials (RCTs) to compare the effects of recombinant human thyrotropin (rhTSH) and thyroid hormone withdrawal (THW) on thyrotropin stimulation prior to remnant ablation of differentiated thyroid cancer (DTC). Material and methods: A comprehensive search was conducted for articles discussing rhTSH and THW prior to December 2012. After applying the inclusion criteria, all the available data were summarized to analyze the efficacy of rhTSH and THW for stimulating TSH. Results: Seven RCTs that involved a total of 1535 patients, were included in the analysis. The ablation rates of the rhTSH group and the THW group were not significantly different (RR = 0.97, 95% CI: 0.94–1.01, p = 0.1). Patients in the rhTSH group had a better quality of life (QoL) than those in the THW group on the day of ablation (RR = 3.92, 95% CI: 3.44–5.40, p < 0.00001). However, there was no difference in the QoL 3 months after ablation (RR = −0.9, 95% CI: −2.20–0.39, p = 0.17). Additionally, there were no significant differences in serum thyroglobulin (Tg) levels measured just before radioiodine remnant ablation (preablation thyroglobulin levels) (RR = −0.14, 95% CI: −0.73–0.45, p = 0.65), or in days of hospital isolation (RR = −10.51, 95% CI: −32.79–11.73, p = 0.35) Conclusions: Our findings indicate that the administration of rhTSH had resulted in an ablation rate similar to that of THW for DTC patients, but rhTSH provided a better QoL at the time of ablation

[en] Zirconia nanopowders were prepared in the ultrasonic field by the sol-gel method and the sonochemical effect on the structure of zirconium hydroxide and the zirconia nanopowder properties were systematically investigated in this work. Ultrasound was introduced into the different stages of the synthesis of zirconia nanopowders in sol-gel reaction system, and zirconium hydroxides and the zirconia nanopowders with different properties were obtained. The results indicated that ultrasonic cavitation could not only disaggregate the agglomerates of zirconia colloidal particles but also reduce the amount of coordinated H₂O, free H₂O and free hydroxyl groups of the zirconium hydroxide colloidal particles, thus effectively preventing the formation of hard agglomerates in zirconia powders. Moreover, the effects of different ultrasonic output powers and treatment cycles on the structure and properties of ZrO₂ nanopowders were studied by TEM, XRD and SAXS. Zirconia nanopowders with an extremely small crystallite size (10.3 nm) and a narrow size distribution were yielded with 520 W ultrasound for 6 treatment cycles on the formation period and 600 W ultrasound for 2 treatment cycles on the washing period. It is concluded that the ultrasonic field is a potential method for nanopowder preparation. (orig.)

[en] Inertia cone crusher is a high-efficiency, super-fine crushing equipment with the unique principle and structure. It features high reduction ratio and low power consumption. The final product size can be within the narrow scope. The inertia cone crusher is suitable for crushing uranium ores. The application of the crusher in Fuzhou Uranium Mine is summarized. The result has shown that the inertia cone crusher has good application prospects in percolation leaching circuit of uranium ore. (authors)

[en] Two-dimensional (2D) materials have triggered enormous interest thanks to their interesting properties and potential applications, ranging from nanoelectronics to energy catalysis and biomedicals. In addition to other widely investigated 2D materials, GaTe, a layered material with a direct band gap of ~1.7 eV, is of importance for applications such as optoelectronics. However, detailed information on the transport properties of GaTe is yet to be explored, especially at low temperatures. Here, we report on electrical transport measurements on few-layered GaTe field effect transistors (FETs) encapsulated by h-BN at different temperatures. We find that by tuning the carrier density, ambipolar transport was realized in GaTe devices, and an electrical-field-induced metal to insulator transition (MIT) was observed when it was hole doped. The mobilities of GaTe devices show a clear dependence on temperature and increase with the decrease of temperature, reaching ~1200 cm²V⁻¹s⁻¹ at 3 K. Our findings may inspire further electronic studies in devices based on GaTe. (paper)

[en] Objective: To asses the clinical effect of stent-graft in the treatment of pseudoaneurysms. Methods: During the period from March 2008 to June 2011, 86 patients with pseudoaneurysms were admitted to the hospital, of whom stent-graft implantation was carried out in 12. The pseudoaneurysms were located at the thoracic aorta (n=4), abdominal aorta (n=3), common carotid artery (n=3), internal carotid artery (n=1) and right subclavian artery (n=1). All the patient were followed up for 5-43 months. The clinical results were analyzed. Results: The technical success rate for stent delivery was 100%. The pseudoaneurysms was immediately isolated after the procedure in all 12 cases. After endovascular exclusion with stent-graft, no leakage occurred and the blood flow distal to the parent artery was normal. All patients were followed up for a mean period of 23.5 months except one who lost in touch with the authors. One patient with coexisting Behcet's disease died of massive bleeding due to abdominal aortic rupture four months after operation. The other patients were in good clinical condition, and no complications such as stent stenosis, displacement, internal leakage etc. were observed in the follow-up period. Conclusion: The implantation of stent-graft has satisfactory short-term effect in treating pseudoaneurysms, although its long-term efficacy needs to be further observed. (authors)

[en] Highlights: • 2-yrs CH₄ and N₂O emissions were examined in the Three Gorges Reservoir's drawdown area. • CH₄ emission was increased in the drawdown area after the impounding of the TGR's dam. • CH₄ emission was increased with decreasing of 175–155 m elevations in the drawdown area. • The impounding of the TGR's dam had no effects on N₂O emission in the drawdown area. • N₂O emission was similar among 155, 165 and 175 m elevations in the drawdown area. -- Abstract: To investigate the effect of dam impounding on CH₄ and N₂O emissions from the drawdown area of the Three Gorges Reservoir (TGR), CH₄ and N₂O fluxes were measured at the elevations of 180 m, 175 m, 165 m and 155 m (above the sea level) from September 2010 to August 2012 using the static chamber technique. The elevations of 175 m, 165 m and 155 m were located in the drawdown area and the non-flooded elevation of 180 m was taken as the control for the drawdown area. The drawdown area studied here acted as the sources of CH₄ and N₂O as a whole. Seasonal, inter-annual and spatial CH₄, but not N₂O, fluxes varied significantly between September 2010 and August 2012. The CH₄ fluxes were highest in winter but lowest in summer, and significantly higher in the wet year than in the dry year. The annually cumulative CH₄ emissions were 14.09 ± 4.27, 12.61 ± 3.59, 68.92 ± 13.09 and 77.41 ± 9.42 kg CH₄ ha⁻¹ from the elevations of 180 m, 175 m, 165 m and 155 m, respectively. Compared with 180 m elevation, the annual CH₄ emission was insignificantly decreased by 11% at 175 m elevation (P > 0.05), and substantially increased by 389% and 449% at 165 m (P < 0.05) and 155 m elevations (P < 0.05), respectively. The annually cumulative N₂O emissions were 4.74 ± 1.78, 7.43 ± 2.57, 3.39 ± 1.05 and 8.83 ± 1.95 kg N₂O ha⁻¹ from the above corresponding elevations, respectively, and there were no significant differences among the four elevations (P > 0.05). These results showed that CH₄ emissions were increased but N₂O emissions were not affected in the drawdown area after the dam impounding in the TGR, and CH₄ emissions were increased with the decrease in the elevations while N₂O emissions were not affected by the elevation in the drawdown area.

[en] The magnetization of a ferrimagnetic mixed-spin nanoparticle for a series of different single-ion anisotropies D1 and D2 with increasing external magnetic field is studied by the use of the effective-field theory with correlations. At low temperature, the magnetization exhibits an obvious step effect for different anisotropies, exchange couplings, and external magnetic field. The results show that the positive single-ion anisotropy D1 (or D2) is a necessary element for the emergence of the accessional magnetization plateaus for the ferrimagnetic mixed-spin nanoparticle. However, for the stronger D2 the magnetization plateaus dissatisfy the 2S+1 criterion in such a ferrimagnetic nanoparticle system.