Preparation and Performance Characterization of Exploding Foil Initiator Based on ODPA-ODA Polyimide Flyer.

The exploding foil initiator (EFI) system has been extensively used in ignition and detonation sequences and proved to be of high safety and reliability. Polyimide is considered the ideal flyer material for EFI due to its excellent performance, including thermal stability, outstanding mechanical properties, high radiation resistance, and excellent dielectric properties. In this study, we prepared the EFI based on a polyimide (ODPA-ODA) flyer, which is spin-coated and solidified on patterned copper film in situ. The electric explosion test shows that the prepared EFI has good working performance, and the 4000 V working voltage drove the flyer to reach a maximum velocity of 5096 m/s. The polyimide morphology and chemical structure after the electric explosion was observed by microscope, SEM, XPS, and FTIR, which showed that the polyimide flyer underwent thermal deformation and complex chemical reactions during an electric explosion. A large number of polyimide bonds broke to form new carbonyl compounds, and the opening of aromatic rings was accompanied by the formation of aliphatic hydrocarbon chains. The morphology and chemical structure analysis after the electric explosion test will lay a foundation for us to further understand the working principle and evolution process of polyimide (ODPA-ODA) flyer.

Ultra-Broadband High-Efficiency Solar Absorber Based on Double-Size Cross-Shaped Refractory Metals.

In this paper, a theoretical simulation based on a finite-difference time-domain method (FDTD) shows that the solar absorber can reach ultra-broadband and high-efficiency by refractory metals titanium (Ti) and titanium nitride (TiN). In the absorption spectrum of double-size cross-shaped absorber, the absorption bandwidth of more than 90% is 1182 nm (415.648-1597.39 nm). Through the analysis of the field distribution, we know the physical mechanism is the combined action of propagating plasmon resonance and local surface plasmon resonance. After that, the paper has a discussion about the influence of different structure parameters, polarization angle and angle of incident light on the absorptivity of the absorber. At last, the absorption spectrum of the absorber under the standard spectrum of solar radiance Air Mass 1.5 (AM1.5) is studied. The absorber we proposed can be used in solar energy absorber, thermal photovoltaics, hot-electron devices and so on.

Ordered array of Ag semishells on different diameter monolayer polystyrene colloidal crystals: An ultrasensitive and reproducible SERS substrate.

Ag semishells (AgSS) ordered arrays for surface-enhanced Raman scattering (SERS) spectroscopy have been prepared by depositing Ag film onto polystyrene colloidal particle (PSCP) monolayer templates array. The diversified activity for SERS activity with the ordered AgSS arrays mainly depends on the PSCP diameter and Ag film thickness. The high SERS sensitivity and reproducibility are proved by the detection of rhodamine 6G (R6G) and 4-aminothiophenol (4-ATP) molecules. The prominent enhancements of SERS are mainly from the "V"-shaped or "U"-shaped nanogaps on AgSS, which are experimentally and theoretically investigated. The higher SERS activity, stability and reproducibility make the ordered AgSS a promising choice for practical SERS low concentration detection applications.

[Fabrication and Surface-Enhanced Raman Scattering Research on Polystyrene Nanospheres Arrays].

To research surface-enhanced Raman scattering effect of different diameters' polystyrene nanospheres (Ag-coated) substrates, we had prepared a new surface-enhanced Raman scattering substrate. It was prepared by using spin-coating and self-assembled to form monolayer and hexagonal close-packed (HCP) order colloidal-crystal films with PS nanospheres of different diameters. Then, a 30 nm Ag film was deposited on the PS arrays with magnetron sputtering. We detected Raman scattered spectrum by means of Roman spectroscopy instrument with Rhodamine R6G as a probe molecule, and the conclusion was drawn that all the substrates of Ag-coated PS nanospheres displayed stronger Raman enhancement. With the increase of the diameter of the microspheres, the degree of fluctuation of polystyrene nanospheres array was continuously strengthened (increasing roughness), and the SERS signal was enhanced gradually. The signal peak reached a maximum when the ball diameter was 600 nm, and then we aquired an optimal SERS substrate. Simultaneously, we found that the SERS spectra of R6G of a high signal to noise ratio was obtained on the substrate, and associated with the benzene ring within a range of CC double bond stretching vibration characteristic spectrum and the inner surface and the outer surface deformation vibration characteristic spectra were significantly enhanced. The single and large-scale Raman scattering substrate presents especial nanostructure of high and low distribution. The depth and the gap between different PS microspheres show the obvious differences, which can significantly improve the surface morphology structure of Ag film and Raman scattering effect of PS nanospheres substrate. The substrate presenting special arrays' structure has significantly great potential in exploring molecule of chemical and biological filed.

Ratios of CD64 expressed on neutrophils, monocytes, and lymphocytes may be a novel method for diagnosis of neonatal sepsis.

INTRODUCTION: Neutrophil CD64 expression has been demonstrated as an improved diagnostic marker of infection and sepsis. The purpose of this study was to develop a new method to evaluate neutrophil CD64 expression for diagnosis of neonatal sepsis. METHODOLOGY: Eighty neonates with neonatal sepsis (21 culture positive, 59 negative) were enrolled in this prospective study along with 19 neonates with no symptoms or signs of infection as controls. Expressions of CD64 on monocytes, lymphocytes, and neutrophils were evaluated with flow cytometry (FCM). Ratios were calculated with these levels of CD64 expression. Blood culture and other laboratory exams were done at the same time for the diagnosis of neonatal sepsis. Results were compared between the neonatal sepsis and control groups. RESULTS: CD64 ratios showed significant difference between the groups (p < 0.01). Receiver operating curve (ROC) analysis showed that the CD64 ratios possessed high sensitivity (90%) and specificity (89.5%) in neonatal sepsis identification. CONCLUSIONS: The novel CD64 evaluation method, CD64 ratio, can be used as a supplementary method for diagnosis of neonatal sepsis.