Parameter-tuning Networks: Experiments and Active Walk Model

The tuning process of a large apparatus of many components could be represented and quantified by constructing parameter-tuning networks. The experimental tuning of the ion source of the neutral beam injector of HT-7 Tokamak is presented as an example. Stretched-exponential cumulative degree distributions are found in the parameter-tuning networks. An active walk model with eight walkers is constructed. Each active walker is a particle moving with friction in an energy landscape; the landscape is modified by the collective action of all the walkers. Numerical simulations show that the parameter-tuning networks generated by the model also give stretched exponential functions, in good agreement with experiments. Our methods provide a new way and a new insight to understand the action of humans in the parameter-tuning of experimental processes, is helpful for experimental research and other optimization problems.Comment: 4 pages, 5 figure

Quantum electrodynamics in a whispering-gallery microcavity coated with a polymer nanolayer

Quasi-transverse-electric and -transverse-magnetic fundamental whispering gallery modes in a polymer-coated silica microtoroid are theoretically investigated and demonstrated to possess very high-quality factors. The existence of a nanometer-thickness layer not only evidently reduces the cavity mode volume but also draws the maximal electric field's position of the mode to the outside of the silica toroid, where single quantum dots or nanocrystals are located. Both effects result in a strongly enhanced coherent interaction between a single dipole (for example, a single defect center in a diamond crystal) and the quantized cavity mode. Since the coated microtoroid is highly feasible and robust in experiments, it may offer an excellent platform to study strong-coupling cavity quantum electrodynamics, quantum information, and quantum computation

High-Q exterior whispering gallery modes in a metal-coated microresonator

We propose a kind of plasmonic whispering gallery modes highly localized on the exterior surface of a metal-coated microresonator. This exterior (EX) surface mode possesses high quality factors at room temperature, and can be efficiently excited by a tapered fiber. The EX mode can couple to an interior (IN) mode and this coupling produces a strong anti-crossing behavior, which not only allows conversion of IN to EX modes, but also forms a long-lived anti-symmetric mode. As a potential application, the EX mode could be used for a biosensor with a sensitivity high up to 500 nm per refraction index unit, a large figure of merit, and a wide detection range

Simultaneous determination of captopril and hydrochlorothiazide by time-resolved chemiluminescence with artificial neural network calibration

AbstractThe combined use of chemometrics and chemiluminescence (CL) measurements, with the aid of the stopped-flow mixing technique, developed a simple time-resolved CL method for the simultaneous determination of captopril (CPL) and hydrochlorothiazide (HCT). The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium (IV)-rhodamine 6G CL system. After the flow was stopped, an initial rise of CL signal was observed for HCT standards, while a direct decay of CL signal was obtained for CPL standards. The mixed CL signal was monitored and recorded on the whole process of continuousflow/stopped-flow, and the obtained data were processed by the chemometric approach of artificial neural network. The relative prediction error (RPE) of CPL and HCT was 5.9% and 8.7%, respectively. The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%. The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation

Current Situation of PC12 Cell Use in Neuronal Injury Study

The nervous system diseases are easy to get and hard to cure. The mechanism is bound up with nervous cells injure, so it’s significant to study medicine protect nervous cells injure. We need find an ideal model to study these diseases. PC12 cell is a pheochromocytoma cell line from RattusNorvegicus, because it has some characters of nerve cells and easy to cultivate and passage, these cells have been proved to be a useful cell model to study nervous physiology and pharmacology. There are several of PC12 cells, American type culture collection supply two kinds of PC12 cell named PC12 cell and PC12Adh. There are high differentiation, low differentiation and undifferentiating in domestic. Although they are very similar, there are still some differences, and not every PC12 cell is effective for every experimental model. After compared, we hold that PC12Adh cell line is more suitable for neurite outgrowth studies under ROCK inhibitor than the PC12 cell line, PC12 cells that induced by NGF and high differentiated PC12 cell are similar to cerebral cortical neurons, they are suitable for various physiological and pathological study of nervous system. Undifferentiated PC12 cells due to low levels of dopamine, therefore it is not suitable for study on neural cells

Oxygen Vacancy Induced Ferromagnetism in V2_2O5−x_{5-x}

{\it Ab initio} calculations within density functional theory with generalized gradient approximation have been performed to study the effects of oxygen vacancies on the electronic structure and magnetism in undoped V$_2$O$_{5-x}$ ($0 < x < 0.5$). It is found that the introduction of oxygen vacancies would induce ferromagnetism in V$_2$O$_{5-x}$ with the magnetization being proportional to the O vacancy concentration $x$. The calculated electronic structure reveals that the valence electrons released by the introduction of oxygen vacancies would occupy mainly the neighboring V $d_{xy}$-dominant band which then becomes spin-polarized due to intra-atomic exchange interaction, thereby giving rise to the half-metallic ferromagnetism.Comment: To be published as a Letter in J. Phys. Soc. Japa

Movable Fiber-Integrated Hybrid Plasmonic Waveguide on Metal Film

A waveguide structure consisting of a tapered nanofiber on a metal film is proposed and analyzed to support highly localized hybrid plasmonic modes. The hybrid plasmonic mode can be efficiently excited through the in-line tapered fiber based on adiabatic conversion and collected by the same fiber, which is very convenient in the experiment. Due to the ultrasmall mode area of plasmonic mode, the local electromagnetic field is greatly enhanced in this movable waveguide, which is potential for enhanced coherence light emitter interactions, such as waveguide quantum electrodynamics, single emitter spectrum and nonlinear optics