三种新激光染料的双光子吸收荧光和上转换激射

用实验方法研究了三种新激光染料PSPI,DEASPI和HEASPI的双光子吸收荧光和上转换激射。它们的二甲基酰胺溶液在锁模Nd∶YAG激光器 10 64nm红外光照射下 ,发射出很强的红色可见荧光和激射光。荧光峰值和激射波长分别位于～ 648nm和～ 62 4nm。实验测得DEASPI,PSPI和HEASPI的二甲基酰胺溶液的上转换激射效率高达 10 7% ,9 8%和 7 1%。     

Herschel,Talbot and Photography: Spring 1831 and Spring 1839

Abstract

The rich, productive, and enthusiastic interaction between Henry Talbot and John Herschel is a fascinating microcosm of early photographic research. An isolated experiment, shared by them in 1831, is a typical example of the tantalizing near-misses that pervade the chronicles of the pre-history of photography. Their correspondence in early 1839, before Herschel saw Daguerre's then superior productions, is a window for us today to learn from the initial thoughts of the excited pioneers. We face contemporary reports of discovery and hope, unedited and unrefined by the influence of time and later events.     

Magnetisation effects of multicore magnetite nanoparticles crystallised from a silicate glass

Magnetic multicore nanoparticles were produced by crystallisation of a glass with the composition Na₂O·Al₂O₃·B₂O₃·SiO₂·Fe₂O₃. During cooling of the melt, in a first step, phase separation occurred and droplets enriched in boron and iron oxide were formed. These droplets crystallised spontaneously during cooling. The phase-separated droplets had sizes in the range from 200 to 800 nm. Inside the droplets, magnetite crystals with a mean size of 33 nm occurred. Magnetometer measurements showed the occurrence of a small hysteresis which indicates predominantly superparamagnetic behaviour of the magnetite crystals. The magnetic domains of the phase-separated droplets were studied by magnetic force microscopy. In this article, a glass which is exposed to a magnetic field shows droplet-shape phase separations where the single-domain magnetite crystals do not have a preferred orientation of the magnetic dipoles. By contrast, the whole droplet shows one magnetic dipole parallel to the external field if the glass is exposed to a magnetic field during measurement.     

Hydrodynamical particle containment in a rotor‐stator spinning disk device

A novel type of rotor‐stator spinning disk device is proposed which allows for the entrapment of solid particles solely by hydrodynamic means. In this new configuration, the solid rotating disk is replaced with two conjoined rotors with a variable gap spacing. Liquid is fed through the top stator and can flow out again through the rotor‐rotor interior and the hollow rotation axis. Moreover, the volume between the two rotors is optionally filled with a highly porous reticulated carbon foam. It was found that particle containment was strongly improved by the presence of this reticulated foam as it hinders the buildup of centripetal boundary layer flow near the disks in the interior of the rotor‐rotor assembly. These centripetal boundary layers drag along particles resulting in a loss of containment. Experiments utilizing glass beads showed that particles with a diameter down to 17.8 µm can be completely entrapped when a carbon foam is placed between the two conjoined disks at rotor speeds up to the maximum investigated value of 178 rad s^?1. Additionally, the rotor‐rotor gap did not have an effect on the particle entrapment level when the reticulated carbon foam was omitted and can be ascribed to the build‐up of boundary layers, which is independent of rotor‐rotor distance. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3656–3665, 2015     

Genetically engineered brain drug delivery vectors: cloning, expression and in vivo application of an anti-transferrin receptor single chain antibodystreptavidin fusion gene and protein

A single chain Fv antibody–streptavidin fusion proteinwas expressed and purified from bacterial inclusion bodies followingcloning of the genes encoding the variable region of the heavychain and light chain of the murine OX26 monoclonal antibodyto the rat transferrin receptor. The latter undergoes receptormediated transcytosis through the brain capillary endothelialwall in vivo, which makes up the blood–brain barrier (BBB);therefore, the OX26 monoclonal antibody and its single chainFv analog may act as brain drug delivery vectors in vivo. Attachmentof biotinylated drugs to the antibody vector is facilitatedby production of the streptavidin fusion protein. The bi-functionalityof the OX26 single chain Fv antibody–streptavidin fusionprotein was retained, as the product both bound biotin and therat transferrin receptor in vitro and in vivo, based on pharmacokineticand brain uptake analyses in anesthetized rats. The attachmentof biotin–polyethyleneglycol–fluorescein to theOX26 single chain Fv antibody–streptavidin fusion proteinresulted in illumination of isolated rat brain capillaries inconfocal fluorescent microscopy. In conclusion, these studiesdemonstrate that genetically engineered single chain Fv antibody–streptavidinfusion proteins may be used for non-invasive neurotherapeuticdelivery to the brain using endogenous BBB transport systemssuch as the transferrin receptor.     

Convective condensation in a stator–rotor–stator spinning disc reactor

Centrifugal intensification of condensation heat transfer in the rotor–stator cavities of a stator–rotor–stator spinning disc reactor (srs‐SDR) is studied, as a function of rotational velocity ω, volumetric throughflow rate , and average temperature driving force . For the current range of ω, heat transfer from the vapor bubbles to the condensate liquid is limiting, due to a relatively low gas–liquid interfacial area a_GL. For rad s^?1, a strong increase of a_GL, results in increasing the reactor‐average condensation heat transfer coefficient h_c from 1600 to 5600 W m^?2 K^?1, for condensation of pure dichloromethane vapor. Condensation heat transfer in the srs‐SDR is enhanced by rotation, independent of the vapor velocity. The intensified condensation comes at the cost of relatively high energy dissipation rates, indicating condensation in the srs‐SDR is more suited as a means to supply heat (e.g. in an intensified reactor‐heat exchanger), rather than for bulk cooling purposes. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3784–3796, 2016     

Facilitation of consumer loyalty toward branded applications: The dual-route perspective

Although many brands develop mobile applications (apps) to build relationships with consumers, most branded apps fail to retain consumers’ loyalty. This study examines the facilitation of consumer loyalty toward branded apps (continuance intention, in-app purchase intention, and word-of-mouth intention) from the dual-route perspective. One route is the affective (relationship) route, where brand benefits (functional benefits, experiential benefits, symbolic benefits, and monetary benefits) drive parasocial interactions between consumers and the brand, which, in turn, influences branded app loyalty. The other route is the utility route, where system characteristics (system quality and information quality) affect perceived usefulness, which, in turn, facilitates branded app loyalty. An online survey was conducted, and the research model was empirically tested using partial least squares structural equation modeling. The findings support the dual-route perspective according to which both affective and utilitarian paths facilitate branded app loyalty. The key theoretical contribution of this study is that it moves beyond the utilitarian path and finds the affective (relationship) path to give a more complete picture of the facilitation of consumer loyalty in the branded app context. A strategy is provided to suggest to practitioners how to design branded apps to facilitate consumer loyalty.     

Defective Thyroglobulin: Cell Biology of Disease

The primary functional units of the thyroid gland are follicles of various sizes comprised of a monolayer of epithelial cells (thyrocytes) surrounding an apical extracellular cavity known as the follicle lumen. In the normal thyroid gland, the follicle lumen is filled with secreted protein (referred to as colloid), comprised nearly exclusively of thyroglobulin with a half-life ranging from days to weeks. At the cellular boundary of the follicle lumen, secreted thyroglobulin becomes iodinated, resulting from the coordinated activities of enzymes localized to the thyrocyte apical plasma membrane. Thyroglobulin appearance in evolution is essentially synchronous with the appearance of the follicular architecture of the vertebrate thyroid gland. Thyroglobulin is the most highly expressed thyroid gene and represents the most abundantly expressed thyroid protein. Wildtype thyroglobulin protein is a large and complex glycoprotein that folds in the endoplasmic reticulum, leading to homodimerization and export via the classical secretory pathway to the follicle lumen. However, of the hundreds of human thyroglobulin genetic variants, most exhibit increased susceptibility to misfolding with defective export from the endoplasmic reticulum, triggering hypothyroidism as well as thyroidal endoplasmic reticulum stress. The human disease of hypothyroidism with defective thyroglobulin (either homozygous, or compound heterozygous) can be experimentally modeled in thyrocyte cell culture, or in whole animals, such as mice that are readily amenable to genetic manipulation. From a combination of approaches, it can be demonstrated that in the setting of thyroglobulin misfolding, thyrocytes under chronic continuous ER stress exhibit increased susceptibility to cell death, with interesting cell biological and pathophysiological consequences.     

MOCVD Growth of Doped GaAs/AlGaAs Quantum Heterostructures

The influences of growth techniques of AP-MOCVD GaAs/AlGaAs silicon-doped multi-quantum wells(MQWs), heterostructure bipolar transistors (HBTs), double barrier resonant tunneling diodes(DBRTDs) ontheir structures and performances were studied. Continuously grown MQWs, that is, no growth interruption atthe heterointerfaces, shown blue-shifted, narrower and stronger photoluminescence(PL) compared withinterruptedly grown ones.TEM examination of the interrupted interfaces revealed a bright line correspondingto the compositional fluctuation and impurity adsorption, and indicated noncommutative structures ofAlGaAs/GaAs and GaAs/AlGaAs interfaces. High performance HBTs and DBRTDs were obtained bycontinuously grown method while growth interruption caused performance degradation. It was concluded thatgrowth interruption may cause accumulation of residua1 impurities in the ambient as well as compositionalfluctuation while continuous growth at very low growth rates can overcome such problems.