聚(3-羟基丁酸酯-3-羟基戊酸酯)/聚碳酸亚丙酯复合支架的构建与表征

分别采用反应性和非反应性熔融共混方法结合粒子沥滤技术以及碱处理技术构建不同质量比的聚(3-羟基丁酸酯-3-羟基戊酸酯)(PHBV)/聚碳酸亚丙酯(PPC)复合支架,通过表征支架的表面形态、孔隙率大小和体外降解性能,发现反应性共混法可显著改善支架的相容性和界面粘接。非反应性熔融共混法构建的支架孔隙率高于反应性共混法构建的复合支架。随着PPC含量的升高,复合支架的孔隙率升高。当PHBV/PPC质量比达50/50时,支架在PBS缓冲液中降解最快,反应性共混法构建的支架亲水性高于非反应性共混法,碱处理技术可显著改善复合支架的亲水性。这对功能重建的体内研究和临床实践具有潜在的理论价值和应用前景。     

光学经纬仪一测回水平方向标准偏差的测量不确定度评定

本文采用多齿分度台方法对DJ2级光学经纬仪一测回水平方向标准偏差进行测量,分析了测量结果不确定度的主要来源,并对测量值的不确定度进行评定,最后提出了用多齿分度台方法进行检定时应注意的问题。     

Endoplasmic Reticulum–Targeted Fluorescent Nanodot with Large Stokes Shift for Vesicular Transport Monitoring and Long‐Term Bioimaging

Herein, a highly stable aggregation‐induced emission (AIE) fluorescent nanodot assembled by an amphiphilic quinoxalinone derivative‐peptide conjugate, namely Quino‐1‐Fmoc‐RACR (also termed as Q1‐PEP), which exhibits large Stokes shift and an endoplasmic reticulum (ER)‐targeting capacity for bioimaging is reported. It is found that the resulting nanodot can effectively enter the ER with high fluorescent emission. As the ER is mainly involved in the transport of synthesized proteins in vesicles to the Golgi or lysosomes, the Q1‐PEP nanodot with ER‐targeting capacity can be used to monitor vesicular transport inside the cells. Compared to conventional fluorescent dyes with small Stokes shifts, the self‐assembled fluorescent nanodot shows superior resistance to photobleaching and aggregation‐induced fluorescence quenching, and elimination of the spectra overlap with autofluorescence of biosubstrate owning to their AIE‐active and red fluorescence emission characteristics. All these optical properties make the fluorescent nanodot suitable for noninvasive and long‐term imaging both in vitro and in vivo.     

A New Insight into Cross‐Sensitivity to Humidity of SnO2 Sensor

The efficiency of gas sensors varies enormously from fundamental study to practical application. This big gap comes mainly from the complex and unpredictable effect of atmospheric environment, especially in humidity. Here, the cross‐sensitivity to humidity of a SnO₂ sensor from local structural and lattice evolutions is studied. The sensing response of ethanol is found to be efficiently activated by adsorbing trace of water but inhibited as humidity increases. By X‐ray diffraction, pair distribution function of synchrotron and ab initio calculations, the independent effect of water and ethanol on lattice and local structure are clearly revealed, which elucidate the intricate sensing reactions. The formation of hydrogen bonds and repulsion of ethoxides play key roles in the structural distortions, and also in adsorption energies that are critical to the sensitive behavior. The results show the sensor performance coupled with local structural evolution, which provides a new insight into the controversial effects of humidity on SnO₂ sensors.     

Piezoresistive Pressure Sensor Based on Synergistical Innerconnect Polyvinyl Alcohol Nanowires/Wrinkled Graphene Film

Piezoresistive sensor is a promising pressure sensor due to its attractive advantages including uncomplicated signal collection, simple manufacture, economical and practical characteristics. Here, a flexible and highly sensitive pressure sensor based on wrinkled graphene film (WGF)/innerconnected polyvinyl alcohol (PVA) nanowires/interdigital electrodes is fabricated. Due to the synergistic effect between WGF and innerconnected PVA nanowires, the as‐prepared pressure sensor realizes a high sensitivity of 28.34 kPa^?1. In addition, the device is able to discern lightweight rice about 22.4 mg (≈2.24 Pa) and shows excellent durability and reliability after 6000 repeated loading and unloading cycles. What is more, the device can detect subtle pulse beat and monitor various human movement behaviors in real‐time.     

Electric Power Generation through the Direct Interaction of Pristine Graphene‐Oxide with Water Molecules

Converting ubiquitous environmental energy into electric power holds tremendous social and financial interests. Traditional energy harvesters and converters are limited by the specific materials and complex configuration of devices. Herein, it is presented that electric power can be directly produced from pristine graphene oxide (GO) without any pretreatment or additives once encountering the water vapor, which will generate an open‐circuit‐voltage of up to 0.4–0.7 V and a short‐circuit‐current‐density of 2–25 µA cm^?2 on a single piece of GO film. This phenomenon results from the directional movement of charged hydrogen ions through the GO film. The present work demonstrates and provides an extremely simple method for electric energy generation, which offers more applications of graphene‐based materials in green energy converting field.