Time-dependent Ginzburg–Landau equations for multi-gap superconductors

We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size samples tend to form clusters or other disorder structures. When the sample size is large, stripes appear in the pattern. These results are in good agreement with the previous experimental observations of the intriguing anomalous vortex pattern, providing a reliable theoretical basis for the future applications of multi-gap superconductors.     

Surface passivation in n-type silicon and its application in silicon drift detector

Based on the surface passivation of n-type silicon in a silicon drift detector(SDD), we propose a new passivation structure of SiO2/Al2O3/SiO2 passivation stacks. Since the SiO2 formed by the nitric-acid-oxidation-of-silicon(NAOS)method has good compactness and simple process, the first layer film is formed by the NAOS method. The Al2O3 film is also introduced into the passivation stacks owing to exceptional advantages such as good interface characteristic and simple process. In addition, for requirements of thickness and deposition temperature, the third layer of the SiO2 film is deposited by plasma enhanced chemical vapor deposition(PECVD). The deposition of the SiO2 film by PECVD is a low-temperature process and has a high deposition rate, which causes little damage to the device and makes the SiO2 film very suitable for serving as the third passivation layer. The passivation approach of stacks can saturate dangling bonds at the interface between stacks and the silicon substrate, and provide positive charge to optimize the field passivation of the n-type substrate.The passivation method ultimately achieves a good combination of chemical and field passivations. Experimental results show that with the passivation structure of SiO2/Al2O3/SiO2, the final minority carrier lifetime reaches 5223 μs at injection of 5×10¹⁵ cm^-3. When it is applied to the passivation of SDD, the leakage current is reduced to the order of nA.     

运用三维离散元技术模拟落锤撞击下奥克托今颗粒的点火燃烧过程

炸药颗粒的点火燃烧过程一直是人们关注的热点问题。近年来，三维离散元技术在中尺度观测颗粒材料的动力学过程中拥有显著优势。炸药燃烧属于颗粒材料的反应动力学，运用三维离散元技术(DM3)可以有效地观测炸药燃烧传播的过程。以奥克托今(HMX)颗粒为例，本文成功模拟并观测到了HMX颗粒的燃烧反应程度，确定了颗粒开始燃烧反应的时间，以及燃烧反应传播的时间。同时，结合落锤冲击颗粒的三维图像以及其表观压强和放热功率，得到了HMX颗粒燃烧反应、燃烧传播的整个反应动力学过程，包括颗粒在冲击加载下碎化塑性变形的过程，颗粒燃烧反应放热的过程，落锤回弹颗粒喷射的过程等。同时，进一步说明了尖顶颗粒更利于颗粒点火，平顶颗粒有抑制颗粒点火的能力。     

Propylphosphonic anhydride(T3P~) catalyzed one-pot synthesis of α-aminonitriles

The Strecker reaction was performed via a one-pot three component condensation of hetero aromatic/aromatic aldehydes, secondary amines and trimetylsilyl cyanide in the presence of propylphosphonic anhydride(T3P~) to accomplish the corresponding a-aminonitriles. The main advantages of this method are very short reaction time and excellent yields.     

Chloride‐Selective Electrodes Based on “Two‐Wall” Aryl‐Extended Calix[4]Pyrroles: Combining Hydrogen Bonds and Anion–π Interactions to Achieve Optimum Performance

The performance of chloride‐selective electrodes based on “two‐wall” aryl‐extended calix[4]pyrroles and multiwall carbon nanotubes is presented. The calix[4]pyrrole receptors bear two phenyl groups at opposite meso‐positions. When the meso‐phenyl groups are decorated with strong electron‐withdrawing substituents, attractive anion–π interactions may exist between the receptor’s aromatic walls and the sandwiched anion. These anion–π interactions are shown to significantly affect the selectivity of the electrodes. Calix[4]pyrrole, bearing a p‐nitro withdrawing group on each of the meso‐phenyl rings, afforded sensors that display anti‐Hofmeister behavior against the lipophilic salicylate and nitrate anions. Based on the experimental data, a series of principles that help in predicting the suitability of synthetic receptors for use as anion‐specific ionophores is discussed. Finally, the sensors deliver excellent results in the direct detection of chloride in bodily fluids.     

New soft porous frameworks based on lambda-zirconium phosphate and aliphatic dicarboxylates: Synthesis and structural characterization

New dicarboxylate-functionalized pillared materials with a general formula of λ-ZrPO₄(OH)_1-x(OOC(CH₂)_nCOO)_x/2(dmso) (n=6, 8 and 10) have been prepared by post-synthesis modification of the inorganic layers of λ-zirconium phosphate (λ-ZrP), where the superficial Chloride monovalent anionic ligands of λ-layer are partially exchanged with the divalent anionic ligands of a series of long-chain aliphatic dicarboxylic acids, namely octanedioic acid, decanedioic acid and dodecanedioic acid. The synthesized materials are characterized by X-ray diffractometry, FT-IR spectrophotometry, elemental and thermogravimetric analyses. The X-ray diffraction patterns show that the obtained solid phases are pure. Furthermore, the interlayer distance of λ-ZrP systematically increases from 1.02 to 1.59 nm as a result of the incorporation of the mentioned acids inside the interlayer gallery.     

Highly Luminescent Red Phosphorescent OLED with Interfacial Layers for Hole Transport and Electron Injection

Four kinds of red phosphorescent organic light-emitting devices were fabricated and compared to investigate the effect of interfacial layers for hole transport and electron injection. 1 nm-thick LiF in the device A and C and 1 nm-thick Cs₂CO₃ in the device B and D were deposited as an electron injection layer between the anode and the electron transport layer, and 5 nm-thick layer of dipyrazion[2,3-f:2′,2′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile[HATCN] was inserted as a hole transport interfacial layer between the hole injection layer and the hole transport layer only in the device C and D. Under a luminance of 1000 cd/m², the power efficiencies were 7.6 lm/W and 8.5 lm/W in the device A and B, and 8.6 lm/W and 13.4 lm/W in the device C and D. The quantum efficiency of the device D was 15.8% under 1000 cd/m² which was somewhat lower than those of the device A and C, but a little higher than that of the device B. The luminance of the device D was much higher than those of the other devices at a given votage. The luminance of the device D at 7 V was 23,710 cd/m², which was 13.0, 3.4, and 4.0 times higher than those of the device A, B, and C at the same voltage, respectively.     

Study of blood collection and sample preparation for analysis of vitamin D and its metabolites by liquid chromatography–tandem mass spectrometry

The analysis of vitamin D status, with special emphasis on 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, is gaining interest in clinical studies due to the classical and non-classical effects attributed to this prohormone. In this research, the influence of the two steps preceding determination (viz. sample collection and preparation) on the quantitative analysis of vitamin D and its more important metabolites has been studied. Two preparation approaches, deproteination and solid-phase extraction (SPE), have been evaluated in terms of sensitivity to delimit their application, thus establishing that detection of 1,25-dihydroxyvitamin D cannot be addressed by protein precipitation. Concerning sample collection, serum and plasma reported high accuracy (above 83.3%) for vitamin D and metabolites, while precision, expressed as relative standard deviation, was below 12.9% for all analytes in both samples. Statistical analysis revealed that serum and plasma provided similar physiological levels for vitamin D₃, 24,25-dihydroxyvitamin D₃ and 25-hydroxyvitamin D₃, while significantly different levels were obtained for 1,25-dihydroxyvitamin D₃, always higher in plasma than in serum. Sample collection and treatment have proved to be significant in the analysis of vitamin D and its relevant metabolites.