Superconductivity in potassium and ammonia co-intercalated FeSe_(1-x)Te_x

The origin of the ～40 and ～30 K superconducting phases in the metal-intercalated FeSe superconductors is still unclear. We report the synthesis of K_(0.3)(NH_3)_y(FeSe_(1-x)Te_x)_2 and K_(0.6)(NH_3)_y(FeSe_(1-x)Te_x)_2 with x=0-0.6 by using the liquid ammonia method at room temperature. The superconducting transition temperature Tcof the former remains about 43 K for all the nominal Te content less than 0.3, while that of the latter is about 30 K and obviously decreases with Te doping. Superconductivity disappears for x ≥0.4 in both systems. Except for the different chemical pressure induced by substitution of Te for Se in both systems, we also observed distinct external pressure effect on superconductivity for both systems, with much more efficiency of suppressing Tcby external pressure in the former system. These dramatic differences of both chemical and external pressure effects on Tc between the ～30 and ～40 K superconducting phases revealed that the existence of the two superconducting phases can be ascribed to the moderate and negligible coupling between FeSe layers, respectively.     

Comparative analysis of the main active components and hypoglycemic effects after the compatibility of Scutellariae Radix and Coptidis Rhizoma

In this study, a rapid and highly sensitive ultra high performance liquid chromatography with triple quadrupole mass spectrometry method with the mobile phase of acetonitrile and 0.1% aqueous formic acid was established and successfully applied to comparatively analyze main active components after their compatibility. Besides, the effects of Scutellariae Radix, Coptidis Rhizoma and combined extracts on type 2 diabetic rats induced by high‐fat diet along with low dose of streptozocin were investigated. Under the optimized chromatographic conditions, good separation of seven target components was achieved within 12 min. All calibration curves exhibited good linearity (R² ≥ 0.999). The relative standard deviation of precision, repeatability and stability varied from 0.69 to 2.23, 0.98 to 2.56, and 0.92 to 2.57%, respectively. The recovery ranged from 91.11 to 105.35%. The contents of seven active components were notably reduced after compatibility; however, the hypoglycemic effect of combined extracts was stronger than single drug by decreasing the activities of fructose‐1,6‐bisphosphatase, glucose 6‐phosphatase, phosphoenolpyruvate carboxykinase and increasing the activities of glucokinase, phosphofructokinase, pyruvate kinase. Accordingly, the established analytical method was accurate and sensitive enough for quantitative evaluation of seven investigated compounds. Moreover, the combined extract had definite effects on type 2 diabetes through multiple components against multiple targets.     

Analysis of time series in the cumulative residual entropy plane based on oscillation roughness exponent

Nonlinear Dynamics - In this work, we propose the cumulative residual entropy (CRE) plane and CRE curve based on the weighted-multiscale cumulative residual Rényi/Tsallis permutation entropy...     

Multiscale cumulative residual distribution entropy and its applications on heart rate time series

Nonlinear Dynamics - Distribution entropy has been proved to reveal stability for short time series and to distinguish different classes of series by complexity. However, there still exists some...     

Hypoxia-Induced Pro-Protein Therapy Assisted by a Self-Catalyzed Nanozymogen

The success of intracellular protein therapy demands efficient delivery and selective protein activity in diseased cells. Therefore, a cascaded nanozymogen consisting of a hypoxia-activatable pro-protein, a hypoxia-inducing protein, and a hypoxia-strengthened intracellular protein delivery nanovehicle was developed. RPAB, an enzymatically inactive pro-protein of RNase, reversibly caged with hypoxia-cleavable azobenzene, was delivered with glucose oxidase (GOx) using hypoxia-responsive nanocomplexes (NCs) consisting of azobenzene-cross-linked oligoethylenimine (AOEI) and hyaluronic acid (HA). Upon NC-mediated delivery into cancer cells, GOx catalyzed glucose decomposition and aggravated tumoral hypoxia, which drove the recovery of RPAB back to the hydrolytically active RNase and expedited the degradation of AOEI to release more protein cargoes. Thus, the catalytic reaction of the nanozymogen was self-accelerated and self-cycled, ultimately leading to a cooperative anti-cancer effect between GOx-mediated starvation therapy and RNase-mediated pro-apoptotic therapy.     

Tribological behaviors of DLC films in sulfuric acid and sodium hydroxide solutions

Tribological behaviors of three typical kinds of diamond-like carbon (DLC) films (a-C, a-C:Cr, and a-C:H) in sulfuric acid and sodium hydroxide solutions were investigated. The a-C film showed the lowest stable coefficients of friction (COF) in both sulfuric acid and sodium hydroxide solutions but the worst wear resistance in sulfuric acid solution. The a-C:H film showed the highest COF in sulfuric acid solution and the best wear resistance in both sulfuric acid and sodium hydroxide solutions. The a-C:Cr film exhibited superior comprehensive tribological performance in sulfuric acid solution, while in sodium hydroxide solution, high COF and very poor wear resistance was observed. What is more, friction and wear mechanism was revealed by investigating the friction-induced material evolutions on the sliding surface.     

N-Doped Graphdiyne Coating for Dendrite-Free Lithium Metal Batteries

Nonuniform nucleation is one of the major reasons for the dendric growth of metallic lithium, which leads to intractable problems in the efficiency, reversibility, and safety in Li-based batteries. To improve the deposition of metallic Li on Cu substrates, herein, a freestanding current collector (NGDY@CuNW) is formed by coating pyridinic nitrogen-doped graphdiyne (NGDY) nanofilms on 3D Cu nanowires (CuNWs). Theoretical predictions reveal that the introduction of nitrogen atoms in the 2D GDY can enhance the binding energy between the Li atom and GDY, therefore improving the lithiophilicity on the surface for uniform lithium nucleation and deposition. Accordingly, the deposited metallic Li on the NGDY@CuNW electrode exhibits a dendrite-free morphology, resulting in significant improvements in terms of the reversibility with a high coulombic efficiency (CE) and a long lifespan at high current density. Our research provides an efficient method to control the surface property of Cu, which also will be instructive for other metal batteries.     

Highly efficient AgNO3‐catalyzed approach to 2‐(benzo[d]azol‐2‐yl)phenols from salicylaldehydes with 2‐aminothiophenol, 2‐aminophenol and benzene‐1,2‐diamine

A new, convenient and efficient AgNO₃‐catalyzed strategy for the preparation of 2‐(benzo[d]azol‐2‐yl)phenol derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2‐aminothiophenol, 2‐aminophenol or benzene‐1,2‐diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO₃ as a readily available and low‐cost benign oxidant at low catalyst loadings with excellent functional group tolerance.     

Vector sampling expansions in shift invariant subspaces

Multi-input multi-output (MIMO) sampling scheme which is motivated by applications in multi-channel deconvolution and multi-source separation has been investigated in many aspects. Common for most of results on MIMO systems is that the input signals are supposed to be band-limited. In this paper, we study vector sampling expansions on general finitely generated shift-invariant subspaces. Necessary and sufficient conditions for a vector sampling theorem to hold are given. We also give several examples to illustrate the main result.     

液体光击穿阈值的研究

运用声学基础理论,讨论了激光入射到液体中,激光能量与声信号强度间的变化关系.发现激光能量与声信号强度之间存在着对数线形关系.根据液体中光声信号的连续性,得到了一种求取液体光击穿阈值的新方法.