Analytical result on the supercurrent through a superconductor/quantum-dot/superconductor junction

We present an analytical result for the supercurrent across a superconductor/quantum-dot/superconductor junction. By converting the current integration into a special contour integral, we can express the current as a sum of the residues of poles. These poles are real and give a natural definition of the Andreev bound states. We also use the exact result to explain some features of the supercurrent transport behavior.Comment: 8 pages, 2 figure

Nonlinear transport theory for hybrid normal-superconducting devices

We report a theory for analyzing nonlinear DC transport properties of mesoscopic or nanoscopic normal-superconducting (N-S) systems. Special attention was paid such that our theory satisfies gauge invariance. At the linear transport regime and the sub-gap region where the familiar scattering matrix theory has been developed, we provide confirmation that our theory and the scattering matrix theory are equivalent. At the nonlinear regime, however, our theory allows the investigation of a number of important problems: for N-S hybrid systems we have derived the general nonlinear current-voltage characteristics in terms of the scattering Green's function, the second order nonlinear conductance at the weakly nonlinear regime, and nonequilibrium charge pile-up in the device which defines the electrochemical capacitance coefficients

Ni/Ni3C Core-Shell Nanochains and Its Magnetic Properties: One-Step Synthesis at low temperature

One-dimensional Ni/Ni3C core-shell nanoball chains with an average diameter by around 30 nm were synthesized by means of a mild chemical solution method using a soft template of trioctylphosphineoxide (TOPO). It was revealed that the uniform Ni nanochains were capped with Ni3C thin shells by about 1 to 4 nm in thickness and each Ni core consists of polygrains. The coercivity of the core-shell nanochains is much enhanced (600 Oe at 5 K) and comparable with single Ni nanowires due to the one-dimensional shape anisotropy. Deriving from the distinctive structure of Ni core and Ni3C shell, this architecture may possess a possible bi-functionality. This unique architecture is also useful for the study on the magnetization reversal mechanism of one-dimensional magnetic nanostructure.Comment: 17 pages, 6 figur

Lateral retroperitoneoscopic adrenalectomy for complicated adrenal tumor larger than 5 centimeters

Background: The role of lateral retroperitoneoscopic adrenalectomy (LRA) for complicated tumor with large diameter remains controversial, this study aimed to evaluate the effectiveness of this procedure on the management of tumor larger than 5cm in diameter.Methods: A retrospective comparison was conducted of 67 patients with large complicated adrenal tumor (>5cm). 41 patients received LRA, and 26 received open adrenalectomy (OA) in our hospital between January 2011 and June 2015. Basic characteristics regarding mean age, gender, body mass index (BMI), tumor size, tumor side, previous abdominal surgery, resection method, pathology were preferentially analyzed. Operative indicators regarding operation time, estimated blood loss (EBL), conversion to ICU, complications, post-operative hospitalization, duration of drain, time to first oral intake and ambulation were compared between groups.Results: There were no significant differences between the two groups in the basic characteristics. The mean operation time for LRA was shorter than OA (98.7±32.3 min vs 152.7±72.3 min, P = 0.001). EBL was 31.9±20.0 ml for LRA and 590.0±1181.1 ml for OA (P = 0.03). There was no complication in LRA group and one patient in OA group had complications, but this difference was not significant (P = NS). The post-operative hospitalization in LRA was 7.4±2.8 days, and shorter than 9.8±2.7 days in OA group (P = 0.00). The time to first oral intake and ambulation for LRA was shorter than OA (first oral intake, 1.9±0.8 days vs 3.1±1.3 days, P = 0.00; time to ambulation, 2.6±1.4 days vs 4.2±1.6 days, P = 0.00). While the difference between groups were not significant in terms of ICU conversion (3/41 vs 4/26, P = NS) and duration of drain (3.9±2.2 days vs 4.7±1.9 days, P = NS).Conclusion: Our study shows that LRA can be performed safely and effectively for complicated adrenal tumors larger than 5 cm in diameter, but it remains technically demanding.Keywords: Retroperitoneoscopic adrenalectomy; adrenal tumor; lateral positio