[en] The aim of this study was to evaluate acoustic radiation force impulse imaging for cervical lymphadenopathy in routine clinical practice and to correlate the acoustic radiation force impulse values with the morphological signs and the pathological results, which were used as the reference standard. The virtual touch tissue quantification values were analyzed in 123 patients (mean age 40.8 years, range 1–81 years) with 181 cervical lymph nodes (87 benign, 94 malignant). The diagnostic performance of acoustic radiation force impulse values were evaluated with respect to sensitivity, specificity, and area under the curve using a receiver operating characteristic curve analysis. The mean virtual touch tissue quantification values of the benign lesions (2.01 ± 0.95 m/s) differed from that of the malignant lesions (4.61 ± 2.56 m/s; P < 0.001). The cutoff level for virtual touch tissue quantification value for malignancy was estimated to be 2.595 m/s. Using the receiver operating characteristic curve curves with the cutoff value, the virtual touch tissue quantification value predicted malignancy with a sensitivity of 82.9%, specificity of 93.1% and gave an areas under the curve of 0.906 (95% CI 0.857–0.954). Acoustic radiation force impulse is feasible for cervical lymph nodes and provides quantitative elasticity measurements, which may complement B-mode ultrasound and potentially improve the characterization of cervical lymph nodes

[en] Highlights: • The isothermal sections of the Sn–Si–Ti system at 900 and 1200 °C were determined. • Ternary intermediate phase τ, with a tetragonal W_5Si_3-type structure, can be stable up to at least 1200 °C. • Eleven three-phase equilibria were determined at each temperature. - Abstract: Phase relations in the ternary Sn–Si–Ti system were established for the whole composition range for two temperatures, 900 and 1200 °C, by X-ray powder diffraction, scanning electron microscopy and energy dispersive spectroscopic. The results indicate that the previously reported compound τ is the only ternary intermediate phase, which can be stable up to at least 1200 °C and remains a tetragonal W_5Si_3-type structure. No Si solubility was found in Ti_6Sn_5 phase, and no Sn solubility was found in the Si–Ti binary phases except for Ti_5Si_3 at either temperature

[en] The NMR apparatus for measuring the laser enhanced thin gas NMR signal were sketched. The thin gas NMR signal in NMR spectrometers by spin exchange optical pumping methods using linearly polarized laser radiation have been greatly enhanced. The NMR signal of thin gas was first observed in this NMR spectrometer with high magnetic fields. A measured ¹²⁹Xe decay rates as the function of Cs density with a magnetic field of 1.879 tesla were shown out

[en] In view of the lack of relevant research on CNC grinders in the field of reliability research of CNC machine tools at present, This research collected reliability data based on 19 MSK series grinder machine tools of a machine tool factory., found out the crucial subsystem which is the most important component to the whole, and analyzed the reliability of the subsystem adopting FTA (Fault Tree Analysis) . Statistical researched on 438 reliability data collected, combining with the actual production situation, the results shows that cooling system is the key to the reliability of the whole grinder machine tool. The 29 minimum cut sets obtained by FTA can be adjusted to improve the reliability of the cooling system, what is more, the reliability of grinder machine tool would be improved as well. (paper)

[en] Conductive polymer composite, which can be used as the piezoresistive material of a flexible pressure sensor, has viscoelasticity. Therefore, the piezoresistivity is time dependent, introducing detrimental effects for sensor development. To reduce the time dependence, we designed a piezoresistive element with a novel structure called a ‘nonalignment electrodes element (NAEE)’, which is different from a traditional sandwich element (TSE). The experimental data under constant pressure show that the attenuation of the output resistance of a NAEE is much lower than that of a TSE, and the tend-to-stable-time (i.e. the shortest time needed to ensure that the output resistance of the element goes to a stable level) of a NAEE is far less than that of a TSE. The results verify the feasibility to reduce the time dependence substantially by using a NAEE. (paper)

[en] In this paper, follow-up grinding of crankshaft is studied and the mathematical model of follow-up grinding motion is established. Taking the double grinding wheel crankshaft follow-up grinder as the research object, the motion errors of the machine tool are obtained by analyzing the motion relations among the moving bodies. Based on the kinematics theory of multi-body system, the kinematics model of the whole machine tool is established. The position matrix of any cutting point is described according to the kinematic chain of “bed-workpiece” and “bed-tool”, and the precise machining model of double grinding wheel follow-up grinding machine tool is established by using the coincidence principle of tool actual trajectory and tool path. The coordinate system of each moving body is established, the transformation matrix between moving bodies is obtained, and the precision machining model of double grinding wheel follow-up crankshaft CNC grinding machine is solved, which lays a foundation for error compensation of the machine. (paper)

[en] Selective oxidation of Fe–3Al–6Cr alloy exposed to Zn/ZnO Rhines pack was conducted at 900 °C, 950 °C, and 1000 °C for 1–5 h. Results indicate that when the oxidation temperature reached or exceeded 950 °C, a complete external oxide film was obtained. Zn would vaporize and condense on the surface of the alloys. Zn uniformly distributed on the surface could dissolve in the α–Fe phase and Zn could be oxidized to ZnO and continue to react with the oxides of aluminum and chromium on the surface layer to form ZnM₂O₄ (M: Al + Cr) spinel. After selective oxidation for 1 h at 900 °C, Fe–3Al–6Cr alloy produced ZnM₂O₄ + M₂O₃ + α–Fe on the top surface and ZnM₂O₄, Al₂O_3, Fe₂Al₅, FeAl phases appeared on the subsurface. When the selective oxidation temperature reached 950 °C, a complete external oxide film was obtained, which completely covered the surface. ZnM₂O₄ + M₂O₃ oxides and α–Fe containing Zn appeared on the surface. External oxides ZnM₂O₄ and internal oxides of Al₂O₃ were found when Fe–3Al–6Cr alloy was oxidized at 1000 °C for 1 h. (paper)

[en] The microstructure and microhardness of the arc-melted Co_xNi_2−xCrFeTi multi-component alloys, in both as-cast state and after annealing at 800 and 1000 °C for 30 days, were experimentally investigated by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The volume fraction of the C14 phase increased with the Co content. The microstructure and microhardness of the alloys greatly changed after annealing at 800 or 1000 °C for 30 days. The eutectic structure appears in the as-cast alloys containing 5 ∼ 15 at% Co. The BCC phase exists in the as-cast and 800 °C annealed Co_0.25Ni_1.75CrFeTi alloy, while it transforms to the σ phase at 1000 °C. With the increase of the Co content, the D0₂₄ phase gradually transforms to the C14 phase and the alloy hardness increased. The microhardness of the alloy gradually decreases with the increase of annealing temperature. The maximum hardness of the as-cast alloys can achieve 1044 HV, while that for 800 and 1000 °C annealed alloys is 1027 and 956 HV, respectively. (paper)

[en] Highlights: • The surface oxidation products of the Zn-Al-Mg melt were analyzed with XPS. • Certain Al must be added in bath containing Mg to get stable galvanizing melts. • The oxidation products vary with the bath composition. • Oxidation can be predicted in galvanizing by using the calculated phase diagrams. • The thermodynamic analysis can be used to design the practical bath melts. - Abstract: Surface oxidation of molten Zn-6Al baths containing 0.0, 3.0 and 6.0 wt. % Mg were analyzed using X-ray photoelectron spectroscopy. γ-Al_2O_3 is formed on the surface of the Zn-6Al bath, while MgAl_2O_4 and MgO occur at 460 °C in the Zn-6Al-3Mg and Zn-6Al-6Mg baths, respectively. Thermodynamic analysis on the oxidation of the Zn-Al-Mg baths was performed. Calculated phase diagrams at 460 °C and 560 °C show good agreements with the experimental results. MgO or MgAl_2O_4 exists in almost the entire composition range of the calculated oxidation diagrams. According to the calculation, oxidation products depend on the composition and temperature of the baths. The primary and secondary oxidation products of the Zn-Al-Mg baths can be reasonably explained by oxidation phase diagrams. Utilizing these results, the favorable practical bath melts and operating conditions can be designed.

[en] The corrosion behaviors of pure magnesium (Mg) and three Mg alloys with different Al contents were investigated in a modified simulated body fluid (m-SBF) through immersion tests, Tafel experiments, and electrochemical impedance spectroscopic (EIS) experiments. The immersion results show that the corrosion rates (CRs) of the four samples were in an order of AZ91D < AZ61 < AZ31 < pure Mg after immersion for 1 day. With an increase in immersion time, their corrosion rates decreased and then a stable stage was reached after 16 days. The order of CRs of the four samples changed to AZ91D < pure Mg < AZ61 < AZ31 after immersion for 24 days. The results of EIS experiments indicate that the charge transfer resistance (R_ct) of the three magnesium alloys initially increased and then decreased while the R_ct of pure Mg was kept lower within 24 h. The results of a scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) show that pure Mg and three alloys were heterogeneously corroded in the m-SBF. The corrosion of pure Mg, which showed a more uniform corrosion appearance, resulted from localized corrosion over the entire surface. Alloy AZ91D (of 8.5-9.5 wt.% Al) showed relatively uniform corrosion morphology and the β-Mg₁₂Al₁₇ precipitates in alloy AZ91D were more homogeneously and continuously distributed along the grain boundaries. Obvious corrosion pits were found on the surface of alloy AZ61 and AZ31. The corrosion pits of alloy AZ61 were shallower than those of alloy AZ31. Alloy AZ61 (of 5.8-7.2 wt.% Al) possessed more Al₈Mn₅ and a little β-Mg₁₂Al₁₇ presented along the grain boundary heterogeneously and discontinuously. Al₈Mn₅ was the main phase of the AZ31 alloy (of 2.5-3.5 wt.% Al) dispersed into the matrix. In conclusion, the microstructure and the Al content in the α-Mg (Al) matrix significantly affected the corrosion properties of the alloys in the m-SBF. With the increase in Al content, the corrosion resistances of the samples were improved.