[en] Due to the need to reduce electronic device sizes, it is very important to consider the depth and lateral distribution of ions implanted into a crystalline target. This paper reports that Nd ions with energies of 200 keV to 500 keV and dose of 5×10¹⁵ ions/cm² are implanted into Si single crystals at room temperature under the angles of 0deg , 30deg , and 45deg , respectively. The lateral spreads of 200keV–500keV Nd ions implanted in Si sample are measured by Rutherford backscattering technique. The results show that the measured values are in good agreement with those obtained from the prediction of SRIM2010 codes. (condensed matter: structural, mechanical, and thermal properties)

[en] The multiple filamentation of terawatt femtosecond (fs) laser pulses is experimentally studied in a natural environment. A more than 30-m long plasma filament with a millimeter diameter is formed by the collimated fs laser pulse freely propagating in an open atmosphere. This study provides the first quantitative experimental data about the electron density of a long range light filament in the atmosphere. The electron density of such a filament is quantitatively detected by using an electric method, showing that it is at the 10¹¹-cm⁻³ level. (paper)

[en] Ferroelectric polymers are widely used in wearable energy conversion electronics for their favorable flexibility and pyroelectric properties, such as infrared sensors and energy harvesting devices. In this work, we report a method to greatly enhance the pyroelectric properties of polyvinylidene fluoride (PVDF) by spin-coating. Under the shear stress induced by spin-coating, the crystallization behavior of PVDF has been distinctly improved. As a result, the crystallinity and relative content of β phase achieve 40% and 97% in PVDF and the polarization reaches up to 28.2 µC/cm² at 80 MV/m². Consequently, the pyroelectric coefficient of spin-coated PVDF film has been raised to as high as 0.92 × 10⁻⁸ C/cm² K at 35 °C, which is significantly superior to those of cast PVDF film, stretched PVDF film, P(VDF-TrFE) film and the PVDF-PZT composite film. This achievement will enable the practically potential for PVDF based pyroelectric polymers in wearable infrared sensors and energy harvesting devices.

[en] Highlights: • Hybrid heterostructure of p-type CuPc and n-type porous GaN was fabricated by electrophoretic deposition. • The influence of concentration, electric field intensity, and deposition time on the growth of CuP film was explored. • Prototype devices of CuPc/PGaN heterostructures showed photovoltaic response. • The biggest I_on/I_off ratio of CuPc/PGaN hybrid heterostructure can reach 162. A new hybrid heterostructure of p-type copper phthalocyanine (CuPc) and n-type porous GaN (PGaN) has been fabricated by electrophoretic deposition. The influence of CuPc concentration, electric field intensity, and deposition time on the growth of CuPc film has been explored. The as-prepared CuPc films are made of numerous nanorods. The X-ray diffraction (XRD) spectra revealed that the CuPc films are the β phase and amorphous type on pristine and porous GaN, respectively. Moreover, the prototype devices were fabricated on the basis of the CuPc/PGaN heterostructures. The devices exhibited excellent photodetector performance under ultraviolet (UV) light illumination.

[en] Dendritic Pd nanoarchitectures were electrochemically deposited on single-crystal n-GaN(0001) by cyclic voltammetry and employed as anode electrocatalyst for direct formic acid fuel cells. The Pd deposition on n-GaN(0001) was found to commence at 0.2 V vs. Ag/AgCl without underpotential deposition process and follow the typical instantaneous nucleation in large overpotential region. High-resolution transmission electron microscope images revealed that numerous small branches were formed around the trunk of dendritic structures and grew along the <111> directions. The as-obtained dendritic Pd nanoarchitectures showed good catalytic performance for formic acid and the oxidation peak potential appeared at 0.45 V vs. Ag/AgCl. The maximum current density and mass activity were 19.7 mA cm"−"1 and 904 mA mg"−"1, respectively, for the dendritic Pd nanocrystals obtained by cycling the potentials from -0.25 to 1.0 V for 5 times

[en] Highlights: • Availability of labile organic carbon is driving factor of sulfate reduction. • Labile iron is low in the sediment due to iron-poor nature of source materials. • Human perturbations have no significant impact on sulfur and iron diagenesis. • The Yellow River estuary exerts important influences on sulfur cycling. Natural processes and human activities exert important impacts on elemental cycling in coastal sediments, which has not been well documented. Sediments in the Bohai Sea and North Yellow Sea were investigated to assess the impacts of the Yellow River inputs and/or anthropogenic perturbations on diagenesis of iron and sulfur. Labile iron (0.5 M HCl-extractable iron) in the sediments is low due to iron-poor nature of source materials. Dynamic regimes and low availability of labile organic carbon (OC) result in relatively low sulfide contents in deltaic sediments. However, low but continuous supply of labile OC exported from an anthropogenically impacted bay could substantially elevate sulfide burial in sediments near the bay. Neither offshore oil exploitations nor frequent algal blooms in the seas have detectable influences on iron and sulfur diagenesis in the sediments. The sediments are capable of quickly consuming porewater sulfide by reaction with reactive iron under the current conditions.

[en] We report on a 520-µJ, 1-kHz mid-infrared femtosecond optical parametric amplifier system driven by a Ti:sapphire laser system. The seeding signal was generated from white-light continuum in YAG plate and then amplified in four non-collinear amplification stages and the idler was obtained in the last stage with central wavelength at 2.8 µm and bandwidth of 525 nm. To maximize the bandwidth of the idler, a theoretical method was developed to give an optimum non-collinear angle and estimate the conversion efficiency and output spectrum. As an experimental result, laser pulse energy up to 1.8 mJ for signal wave and 520 µJ for idler wave were obtained in the last stage under 10-mJ pump energy, corresponding to a pump-to-idler conversion efficiency of 5.2%, which meets well with the numerical calculation.