Optimal design for hollow fiber inner-coated by dielectric layers with surface roughness

We report the optimal design for hollow fiber inner-coated with metallic and multidielectric layers by using ray-optics theory. Transmission characteristics of the multilayer hollow fiber are more dependent on the film surface roughness in the IR region. Comparisons of fibers with smooth and rough films are made and discussed in detail. The optimal design for film thickness, inner radius, and the number of layers and refractive indices is presented. The calculation results are important for structure design, material selection, and fabrication when considering imperfections in film-coating techniques. Multilayer fibers are fabricated based on the calculation and experimental results agree with the theoretical ones.     

Membrane fluidity altering and enzyme inactivating in sarcoma 180 cells post the exposure to sonoactivated hematoporphyrin in vitro

Sonodynamic therapy (SDT) is a novel tumor therapy method. We investigated membrane fluidity, activity of the enzymes and membrane morphology in vitro post hematoporphyrin-SDT treatment. Furthermore, the potential mechanisms behind the changes in membrane fluidity and enzymic activity were discussed. Tumor cells were exposed to ultrasound at 1.75 MHz for up to 3 min in the presence and absence of hematoporphyrin. Fluorescence polarization, contents of Malonaldehyde, and levels of free fatty acid were assessed. Activity of enzymes was checked by the plumbic nitrate detection method. For the morphologic study, a scanning electron microscope was used to observe the cellular surface. Ultrasonically induced cell damage increased in the presence of HPD (from 15% to 24%). Compared with ultrasound treatment alone, the fluidity decreased from 5.037 to 3.908, malonaldehyde content and free fatty acid level increased from 0.743 nmol/mL to 0.979 nmol/mL and from 237.180 μmol/L to 730.769 μmol/L, respectively, post ultrasound combined with HPD treatment. Inactivity of adenylate cyclase and guanylate cyclase and significant deformation of the cellular surface were also observed post SDT treatment. Our results suggested that alterations in membrane modality and lipid composition played important roles in SDT-mediated inhibition of tumor growth, even inducing tumor cell death, which might be attributed to a sono-chemical activation mechanism.     

Generation of 15-nJ bunched noise-like pulses with 93-nm bandwidth in an erbium-doped fiber ring laser

We report on the generation of high power superbroad spectrum bunched noise-like pulses from a passively mode-locked erbium-doped fiber ring laser without using the stretched-pulse technique. The maximum 3-dB spectral bandwidth of the noise-like pulses is about 93 nm with an energy of about 15 nJ. We further show numerically that the superbroad spectrum of the pulses is caused by the transform-limited feature of the pulses together with the Raman self-frequency shift effect. PACS 42.65.Dr; 42.55.Wd; 42.60.Fc; 42.81.Dp     

Multilayer dielectric cylindrical mirrors based on omnidirectional reflection from a one-dimensional photonic crystal

A multilayer dielectric cylindrical mirror (MDCM) based on the one-dimensional omnidirectional reflection of a photonic crystal is presented. In this case, the refractive indices of the two materials are 1.6 (polystyrene) and 4.6 (tellurium), and the corresponding optimized thicknesses are 0.75a and 0.25a. A very high reflectance over a wide frequency range is observed. In this case, a is the lattice constant of the photonic crystal. In this band, the MDCM has good reflection and focal properties. Therefore, it is feasible to use the MDCM for integrated waveguide devices. As an example, an etched diffraction grating demultiplexer based on the MDCM is also proposed. Both the operational principle and design of the device are introduced. This provides a method for designing compact integrated waveguide devices.     

Infinitely many solutions for a class of sublinear Schrodinger equation

In this paper, we investigate the Schr\"{o}dinger equation, which satisfies that the potential is asymptotical 0 at infinity in some measure-theoretic and the nonlinearity is sublinear growth. By using variant symmetric mountain lemma, we obtain infinitely many solutions for the problem. Moreover, if the nonlinearity is locally sublinear defined for $|u|$ small, we can also get the same result. In which, we show that these solutions tend to zero in $L^{\infty}(\mathbb{R}^{N})$ by the Br\"{e}zis-Kato estimate.     

Flower-like Ni3(NO3)2(OH)4@Zr-metal organic framework (UiO-66) composites as electrode materials for high performance pseudocapacitors

Zr-metal organic frameworks (Zr-MOFs, UIO-66) as a kind of crystalline porous material possess controllable porous structure and strong thermal stability up to 753 K. In this paper, we synthesized Ni₃(NO₃)₂(OH)₄, Zr-MOF with high specific surface area (1073 m² g⁻¹) and Ni₃(NO₃)₂(OH)₄@Zr-MOF composite for pseudocapacitor material. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were taken to characterize the structure and morphology of Ni₃(NO₃)₂(OH)₄, Zr-MOF, and Ni₃(NO₃)₂(OH)₄@Zr-MOF. The porous structure of Zr-MOF favors the utilization of the active material Ni₃(NO₃)₂(OH)₄ and interfacial charge transport and provides short diffusion paths for ions, which results in a high specific capacitance. Electrochemical properties are evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge measurement. A maximum specific capacitance (SC) of 992 F/g was obtained from CV at a scan rate of 5 mVs⁻¹, which is higher than Zr-MOF (∼134 F g⁻¹) and Ni₃(NO₃)₂(OH)₄ (∼753 F g⁻¹). Meanwhile, the Ni₃(NO₃)₂(OH)₄@Zr-MOF composite electrode exhibits a good cycling stability over 3000 cycles.

     

Spectral methods for pantograph-type differential and integral equations with multiple delays

We analyze the convergence properties of the spectral method when used to approximate smooth solutions of delay differential or integral equations with two or more vanishing delays. It is shown that for the pantograph-type functional equations the spectral methods yield the familiar exponential order of convergence. Various numerical examples are used to illustrate these results.      

Facile fabrication of novel cyclomatrix-type polyphosphazene nanotubes with active hydroxyl groups via an in situ template approach

Novel polyphosphazene nanotubes with active hydroxyl groups were fabricated via an in situ template approach under ultrasonic irradiation. SEM and TEM results indicated that the nanotubes were uniform with length of several micrometers, inner diameter of ca. 20 nm and outer diameter of 60-80 nm. FTIR spectra revealed that the content of the hydroxyl groups on the nanotube surface was dependent on the feed ratio of hexachlorocyclotriphosphazene (HCCP) to 4,4′-sulfonyldiphenol. The successful esterification of polymer nanotubes with benzoxy chloride demonstrated the high reactivity of the hydroxyl groups. The method employed here might provide a simple and effective way to prepare functional nanotubes used for biological applications.     

Structural and superconductivity study on α-FeSex

We have successfully synthesized the α-FeSe_x binary tetragonal superconductors with nominal composition of FeSe_x (x=0.6-1.0) via conventional solid state reactions between Fe and Se sealed in quartz tubes. Fe and β-FeSe are the most commonly seen impurities in this binary system. A low-temperature annealing at 400 °C is found to be crucial to remove β-FeSe, which is the thermodynamic stable phase with hexagonal symmetry. For all the samples of FeSe_x, superconductivity is confirmed by magnetic measurements as well as resistivity measurements with their T_c at around 8 K. We noticed that their T_c does not vary with the different nominal Se amount. High-resolution synchrotron X-ray diffraction analysis revealed that the unit cell parameters of all these samples do not change within the error range, and their structure only tolerate the same very small amount of Se deficiency. Based on this study, we concluded that the α-FeSe_x superconductor only exist in a very narrow deficiency range.