Urea Detection of Electrochemical Transistor Sensors based on Polyanline (PANI)/MWCNT/Cotton Yarns

A cotton yarn biosensor based on electrochemical transistor functionalized with MWCNT and PANI was developed for the detection of urea. The transistors based on PANI/MWCNT/cotton yarns under optimized MWCNT concentration has been obtained, which exhibited high on/off current ratio, fast response time, and good operational stability. A transistor-based urea sensor was prepared from PANI/MWCNT/cotton yarns, which could monitor urea in the 1 nM–1 mM linear range with the correlation coefficient of 0.9716. Furthermore, the sensor showed superior reproducibility and high specificity. The practical applications of the proposed sensor were also confirmed. These results indicate the flexible transistor can be used as an efficient platform for biological detection in body fluids.     

Preparation and physicochemical properties of konjac glucomannan ibuprofen ester as a polysaccharide-drug conjugate

Abstract

A novel drug-polysaccharide conjugate with konjac glucomannan (KGM) as a drug carrier was fabricated through the esterification of ibuprofen (IBU), an anti-inflammatory drug, with KGM. The influences of the reaction conditions, such as the amount of ibuprofen acryl chloride, reaction time, reaction temperature, and the amount of catalyst, on the degree of substitution were investigated. KGM ibuprofen ester (KGM-IBU) was characterized by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), solid-state ¹³C NMR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The hydrophobic structure of IBU in KGM-IBU was proven by the fluorescence emission spectra of pyrene. In addition, by using commercially available ibuprofen sustained-release capsules (IBU-SRC) as a control, the in vitro controlled release performance of KGM-IBU was evaluated. The cumulative release of IBU-SRC within 36?h was 94%, while that of KGM-IBU within 36?h was 77%. The results showed that KGM-IBU had better sustained-release performance without a burst release effect. The obtained products could be used as a potential biocompatible sustained-release drug delivery system.     

大气环境下飞秒激光对铝靶烧蚀过程的研究

利用时间分辨的光阴影成像技术研究了在大气环境下飞秒激光烧蚀铝靶的动态过程. 在入射激光能量为4 mJ, 激光光斑超过1 mm时, 激光烧蚀区表面物质以近似平面冲击波形式向外喷射; 在同样激光能量下、激光光斑较小时(约0.6 mm), 激光烧蚀区以近似半球型冲击波形式向外喷射. 当激光能量比较大时(7 mJ), 发现空气的电离对于激光烧蚀靶材有着重要影响. 在光轴附近烧蚀产生的喷射物具有额外的柱状和半圆型的结构, 叠加在平面冲击波结构上.     

用于红外激光防护的高开关率VO2薄膜

采用反应离子束溅射和后退火处理技术在石英玻璃基底上制备了具有纳米粒子的二氧化钒(VO₂)薄膜. 该薄膜具有半导体-金属相变特性,在3 μm处的开关率达到76.6%。 热致相变实验结果给出了准确的最佳退火温度为465 ℃. 仿真、热致相变和光致相变实验都显示VO₂薄膜在红外波段具有很高的光学开关特性. 光电池防护实验结果显示VO₂薄膜将硅光电池的抗干扰能力提升了2.6倍, 证明了VO₂在激光防护中的适用性. 采用连续可调节系统研究得到VO₂在室温条件下的相变阈值功率密度为4.35 W/cm², 损伤阈值功率密度为404 W/cm²。 低相变阈值和高损伤阈值都进一步证明VO₂薄膜适用于激光防护系统。本实验制备的VO₂薄膜在光开关、光电存储器、智能窗等方面也具有广泛的应用价值.     

Progress of Jinping Underground laboratory for Nuclear Astrophysics (JUNA)

Jinping Underground laboratory for Nuclear Astrophysics(JUNA) will take the advantage of the ultra-low background of CJPL lab and high current accelerator based on an ECR source and a highly sensitive detector to directly study for the first time a number of crucial reactions occurring at their relevant stellar energies during the evolution of hydrostatic stars. In its first phase, JUNA aims at the direct measurements of~(25)Mg(p,γ)~(26)Al,~(19)F(p,α)~(16)O,~(13)C(α,n)~(16)O and ~(12)C(α,γ)~(16)O reactions. The experimental setup,which includes an accelerator system with high stability and high intensity, a detector system, and a shielding material with low background, will be established during the above research. The current progress of JUNA will be given.     

Magnetic interactions in the geometrically frustrated triangular lattice antiferromagnet CuFeO2

The spin-wave excitations of the geometrically frustrated triangular lattice antiferromagnet CuFeO2 have been measured using high resolution inelastic neutron scattering. Antiferromagnetic interactions up to third nearest neighbors in the ab plane (J1, J2, J3, with J{2}/J{1} approximately 0.44 and J{3}/J{1} approximately 0.57), as well as out-of-plane coupling (J{z}, with J{z}/J{1} approximately 0.29) are required to describe the spin-wave dispersion relations, indicating a three-dimensional character of the magnetic interactions. Two energy dips in the spin-wave dispersion occur at the incommensurate wave vectors associated with multiferroic phase and can be interpreted as dynamic precursors to the magnetoelectric behavior in this system.     

Observation of two resonant structures in e+ e- -->pi+ pi- psi(2S) via initial-state radiation at Belle

The cross section for e+ e- --> pi+ pi- psi(2S) between threshold and sqrt[s]=5.5 GeV is measured using 673 fb(-1) of data on and off the Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant-mass distribution, one at 4361 +/- 9 +/- 9 MeV/c2 with a width of 74 +/- 15 +/- 10 MeV/c2, and another at 4664 +/- 11 +/- 5 MeV/c2 with a width of 48 +/- 15 +/- 3 MeV/c2, if the mass spectrum is parametrized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.     

Molecular theory of physical aging in polymer glasses

A molecular level theory for the physical aging of polymer glasses is proposed. The nonequilibrium time evolution of the amplitude of long wavelength density fluctuations, and its influence on activated barrier hopping, plays an essential role. The theory predicts temperature-dependent apparent power-law aging of the segmental relaxation time and logarithmic aging of thermodynamiclike properties, in good accord with experiments. A physical origin for the quantitative nonuniversal aspects based on the amplitude of quenched density fluctuations is suggested.     

Measurement of Einstein-Podolsky-Rosen-type flavor entanglement in Upsilon(4S) --> B0 B0 decays

The neutral B meson pair produced at the Upsilon(4S) should exhibit a nonlocal correlation of the type discussed by Einstein, Podolsky, and Rosen. We measure this correlation using the time-dependent flavor asymmetry of semileptonic B(0) decays, which we compare with predictions from quantum mechanics and two local realistic models. The data are consistent with quantum mechanics, and inconsistent with the other models. Assuming that some B pairs disentangle to produce B(0) and B(0) with definite flavor, we find a decoherent fraction of 0.029 +/ -0.057, consistent with no decoherence.     

First-principles study on the metallic antiferromagnet Co[PhPO3]·H2O

The electronic structure and the magnetic properties of transition metal phosphonate Co(PhPO₃)·H₂O have been studied by first-principles within the density-functional theory (DFT) and the full potential linearized augmented plane wave (FP-LAPW) method. The total energy, the total magnetic moment, the atomic spin magnetic moments and the density of states(DOS) of Co(PhPO₃)·H₂O were all calculated. The calculations reveal that the title compound is a metallic antiferromagnet and has a metallic ferromagnetic metastable state, which are in good agreement with the experiment. The spin magnetic moment of Co(PhPO₃)·H₂O is about 4.93 _μB${\mu }_{\mathrm{B}}$ per molecule, and it is mainly assembled at the cobalt atom, at the same time, with a little contribution from the P, O1, O2, O3.