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Vertical cavity surface emitting laser (VCSELs) as the ideal light source for rubidium (Rb) and cesium (Cs) atomic clocks is analyzed for its mode and polarization control. We fabricated three kinds of shapes: triangular, elliptic, and circular oxidation apertures which also have different sizes. We formed three different shape oxide apertures by wet-oxidation with 36 μm–39 μm circular mesa. Our results show that triangular oxidized-VCSEL has the advantages of mode and polarization selection over elliptic and circular oxide apertures. When triangular oxide-confined VCSELs emit in single mode, the measured side mode suppression ratio (SMSR) is larger than 20 dB and orthogonal polarization suppression ratio achieves 10 dB. Resonant blueshift of VCSELs with triangular and elliptic apertures is observed with the decrease of aperture size.

Corrosion inhibition effect of AHA film formed on the copper surface by self-assembled monolayers technique was estimated in 3 wt% NaCl solution by electrochemical impedance spectroscopy and polarization methods. Polarization data indicated that AHA was an anodic inhibitor. The maximum inhibition efficiency reached 93.5% in the case of assembly 3 h in 10 mM AHA solution. The adsorption of AHA on the copper surface fits Langmuir adsorption isotherm. Surface-enhanced Raman scattering together with quantum chemical studies demonstrated that N–O and C=O groups were attached to the copper surface, predicting the feasible adsorption centers and confirming the relationship between the molecular structures of AHA and its inhibition property.

In this work, we examined the relationship between the anticorrosion behavior and the structure of the cysteamine/ l -cysteine layer-by-layer coating on the copper surface via the self-assembled monolayers (SAMs) technique with electrochemistry and surface-enhanced Raman scattering (SERS) spectroscopy. SERS results elucidated the layer-by-layer adsorption mechanism of cysteamine/ l -cysteine at the copper surface. Electrochemical investigations explored the inhibition behavior of cysteamine/ l -cysteine for copper from corrosion with a high protection efficiency of 91.4%.

The adsorption and corrosion protection effect of phytic acid calcium (PAC) film on the copper surface in 3 wt% NaCl solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Raman spectroscopy. Polarization curves indicate that PAC is a mixed inhibitor, affecting both cathodic and anodic corrosion currents. The inhibition efficiency of PAC film reached 92.53% at an optimized condition. Adsorption of PAC molecules on the surface followed Langmuir adsorption isotherm and the standard Gibbs energy of −37.32 kJ mol−1 indicated a chemisorptive way. Raman studies suggested that PAC molecule chemically anchored at the surface via P O groups.

TiSi2 (Titanium disilicide) has attracted great research interest due to its large silicon content, remarkably low electrical resistivity (about13–16μΩcm), good photocatalytic property, high temperature stability, and good corrosion resistance. It is an excellent electronic material and potential photocatalyst and high temperature structure material. In this work, TiSi2 was prepared by using the “chemical oven” enhanced self-propagating combustion method from the elemental powder compact. The mixture of Si and Ti (atomic ratio 3:5) were ignited as chemical oven. The composition of product was detected by XRD. Result shows the product is a single phase titanium disilicide with trace impurities. The maximum combustion temperature of Ti+2Si compact was up to 1472°C, which exceeds the lowest eutectic point (1330°C) of the Ti-Si binary mixture. Thus it can be predicted the formation of TiSi2 is primarily dominated by the solid-liquid mechanism, which includes dissolving solid reactants and precipitating silicide product. It could also be convinced by SEM photos of the combustion product and reacting zone of the compact.

Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS. Potentiometric titration results indicated that the acidic constants (pKa) of the EPS fell into three ranges of 3.5–4.0, 5.9–6.7, and 8.9–9.8. The adsorption site concentrations of the surface functional groups also increased. Adsorption results suggested that EPS had a specific binding affinity for the dosed heavy metal, and that EPS extracted from the Zn2+-dosed system had a higher binding affinity for all heavy metals. Additionally, Zn2+ decreased the inhibitory effects of Cd2+ and Cu2+ on the SRB.

Perventricular device occlusion and minimally invasive surgical repair for perimembranous ventricular septal defect (pmVSD) are two typical methods to reduce the invasiveness of the conventional operation through median sternotomy. However, few comparative studies have been made between them in terms of effectiveness and cost. A review was made of the inpatients with isolated pmVSD, who had undergone perventricular device occlusion or minimally invasive surgical repair from June 2011 and January 2013 for a comparative investigation between the two procedures. The two treatment groups had similar baseline characteristics. Procedural success was achieved in 163 (94.8 %) of the perventricular and 137 (98.6 %) of the surgical (P = 0.136). Major complications occurred in 2 (1.2 %) of the perventricular and 4 (2.9 %) of the surgical (P = 0.497), and minor complications, in 57 (33 %) of the percutaneous and 49 (35.2 %) of the surgical (P = 0.696). In cost, the surgical repair was 30.5 % cheaper than the device occlusion (Yuan 20139 ± 3760 vs. 28970 ± 3343, P