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(1-x)(Pb0.97La0.02)(Zr0.5Sn0.4Ti0.1)O3-x(Na0.5Bi0.5)0.94Ba0.06TiO3 (x = 0 ∼ 0.4) ceramics have been prepared and investigated. The ceramics consist of perovskite solid solution matrix and precipitated, isolated SnO2 particle, resulting in 0–3 type composite structure. With increasing x value, the room temperature crystal structure of perovskite solid solution transforms from tetragonal to pseudocubic, therefore, the electrical property evaluates form robust antiferroelectric at x = 0, metastable antiferroelectric at x = 0.1, and then relaxor ferroelectric at x > 0.1. Moreover, the breakdown strength is enhanced due to the composite structure and reaches maximum value of 190 kV/cm at x = 0.2. Both the phase transition and enhanced breakdown strength are helpful to improve energy storage property, the x = 0.2 ceramic shows largest recoverable energy density wrec of 1.84 J/cm3, discharge efficiency η of 86.6 %. Especially, both wrec and η illustrates significantly improved thermal stability within 25−125 °C.

Unquenched and quenched ceramics of 0.85Na0.5Bi0.5TiO3-0.11K0.5Bi0.5TiO3-0.04BaTiO3 have been prepared, and their crystal structure, temperature-dependent ferro-/piezoelectric properties and domain structure have been comparatively investigated. It is shown that quenching process can significantly improve the ferroelectric-relaxor transition temperature (TF-R), which is 130 °C for unquenched ceramics and 198 °C for quenched one. As the result, the thermal stability of ferro-/piezoelectric properties is highly enhanced. These observations are mainly attributed to the quenching induced stable rhombohedral ferroelectric phase and the defect altered domain evolution. This work may deepen the understanding of the effect of quenching on crystal structure, domain structure and their contributions to thermal stability of NBT-based ceramics.

The high-resolution transmission (HITRAN) database has been updated recently. Therefore, it is useful to analyze the effect of the updated data on radiative transfer calculations. This study identifies the impact of database updates that could affect climate models and satellite remote sensing applications. The fluxes and cooling rates of the longwave region are calculated by the line-by-line radiative transfer model based on the HITRAN08, HITRAN12 and HITRAN16 molecule spectroscopic databases under four typical atmospheric profiles. We show that the differences in cooling rates are mainly caused by the changes in the line parameters of H2O and CO2. The maximum difference in the upward fluxes at the top of the atmosphere between HITRAN08 and HITRAN16 is 0.6587 W m−2, whereas that between HITRAN12 and HITRAN16 is only 0.0406 W m−2, which is much smaller than the maximum difference between HITRAN08 and HITRAN16. Similar trends are also observed in the downward fluxes at the surface and cooling rates. Overall these differences are all less than the typical errors of radiative transfer schemes. On the contrary, we show that there are differences between the simulated brightness temperatures for the channels of hyperspectral measurements, such as FY-3D Hyperspectral Infrared Atmospheric Sounder (HIRAS), which are at least comparable to the noise equivalent temperature difference (NETD) of the corresponding channels. Therefore, it is necessary to consider the effect of using different HITRAN molecular spectroscopic databases in hyperspectral satellite remote sensing applications.

Glioblastoma (GBM) is the most common and aggressive intracranial tumor with poor prognosis. A large majority of clinical chemotherapeutic agents cannot achieve the desired therapeutic effect. Chelerythrine (CHE), a natural component with multitudinous pharmacological functions, has been proven to have outstanding antitumor effects in addition to antibacterial, anti-inflammatory, and hypotensive effects. However, the anti-GBM effect of CHE has not been reported to date. The purpose of this paper is to observe the anti-GBM effect of CHE and further explore the related mechanism.GBM cell lines (U251 and T98G) and BALB/c nude mice were used in the experiments. Methyl thiazolyl tetrazolium (MTT) and clone formation assays were applied to detect the viability, proliferation and stemness of GBM cells. Flow cytometry was utilized to identify the effect of CHE on GBM apoptosis. Scratch and Transwell experiments reflected the migration and invasion of cells. In vivo, xenograft tumors were implanted subcutaneously in nude mice. The progression of tumors was assessed by ultrasound and magnetic resonance imaging. Finally, western blot, bioinformatics, and immunohistochemistry experiments were used to explore the molecular mechanisms in depth.In vitro tests showed that CHE inhibited the proliferation, stemness, migration, and invasion of GBM cells and induced apoptosis. In vitro, CHE was observed to restrain the progression of xenograft tumors. We eventually proved that the cytotoxicity of CHE was relevant to the TGFB1-ERK1/2/Smad2/3-Snail/ZEB1 signaling pathway.CHE inhibited GBM progression by inhibiting the TGFB1-ERK1/2/Smad2/3-Snail/ZEB1 signaling pathway and is a potential chemotherapeutic drug for GBM.

The mechanical parameters of viscoelastic materials, such as storage modulus and loss factor, have frequency-dependent characteristic and the combination of different polymers usually exhibits various mechanical characteristics, which make the identification of the mechanical parameters of viscoelastic materials become a routine and challenging task. In this study, based on the measured resonance frequencies and frequency response functions (FRFs) of a viscoelastic damping plate, an inverse approach was developed to identify the aforementioned parameters with frequency-dependent characteristic. An analysis model was established with both the viscoelastic material damping and the remaining equivalent viscous damping considered. A response surface method was provided to achieve the matching calculation, which can identify the storage modulus and loss factor simultaneously. A cantilever plate attached with ZN_1 viscoelastic material was chosen to demonstrate the proposed method and the measured and the predicted FRFs were compared with the purpose of assessing the rationality of identification results. The results show that the loss factor of viscoelastic materials would be overestimated if only the material damping was included in the analysis model.

Several schemes have been proposed for handling gaseous overlapping bands in the context of the correlated k-distribution model (CKD), but they all require manual operation and the accuracy is limited. In this paper, we proposed two automatic methods for gas absorption calculation based on correlated k-distribution, namely finding point method (FPM) and re-optimized method (ROM), to improve the accuracy and the speed of gaseous absorption calculation. Compared with the line-by-line (LBL) results under standard profiles, the resulting accuracy of FPM is 0.09 Kday−1 in troposphere, -0.3 Kday−1 in stratosphere, -0.18 W/m2 for upward flux and -0.44 W/m2 for downward flux; the accuracy of ROM is 0.1 Kday−1 in troposphere, 0.3 Kday−1 in stratosphere, -0.35 W/m2 for upward flux and -0.18 W/m2 for downward flux. The accuracy of the two methods is higher than rapid radiative transfer model for general circulation models (RRTMG). Under realistic profiles, the accuracy of FPM and ROM is slightly lower than that their accuracy under standard profiles but still higher than RRTMG.

In this article, free vibration of the hard-coating cantilever cylindrical shell is investigated considering the elastic constraints at the clamped end. Love's first approximation theory and Rayleigh–Ritz method are applied to build the analytical model of hard-coating cylindrical shell. In the modeling process, orthogonal polynomials are used as admissible displacement functions to formulate the displacement field, and the elastic constraints are simulated by constrained springs whose stiffness values are determined using model updating technique. The developed model has been validated by the comparison between the natural frequencies obtained by analytical calculation and by experiment respectively. Finally, the influences of hard-coating parameters, including thickness, Young's modulus and loss factor, on the vibration characteristics of the cylindrical shell are studied.

High-entropy alloys (HEAs) have been extensively studied in recent years. However, yield strength of HEAs in which austenite is the dominating phase is usually low, far from satisfying the engineering demands. Improving performance-cost ratio of such alloys will help for their practical structural applications. Here we report a novel strategy to produce ultrastrong, tough, and low-cost HEAs, in which heavy nitrogen-doping (2.6 at.%) was applied to an inexpensive metastable FeMnCoCr HEA. Coupled with simple thermomechanical processing, we produced a multi-heterostructure, which consisted of fine α-martensite laths, deformed austenite with dense dislocations, recrystallized ultrafine grains and nano-nitride precipitates. Our novel FeMnCoCrN HEA exhibits a high yield strength of 1310 MPa which is ~5.2 times stronger than its base alloy without nitrogen doping. In particular, the highly dislocated body-centered cubic (bcc) martensite laths formed in the austenitic deformation matrix has an unexpected area fraction up to 24%. The hetero-deformation induced strengthening then reaches 750 MPa at the yield point, leading to a remarkable yield strength elevation of the material. Moreover, the high nitrogen content changes the dominant deformation mechanism from martensitic transformation to twinning, which contributes to a satisfactory uniform elongation of 16.5%, while the material is further strengthened by the dynamically refined microstructure. The high-nitrogen duplex alloy design strategy developed here provides a new paradigm for developing high-performance fcc HEAs.

Highly efficient broadband light management to enhance the light trapping inside active layer is critical for many energy conversion devices such as thin film solar cells and photoelectrochemical cells. In this work, we demonstrate highly transparent, mesoporous wood composite via fast extraction of lignin along naturally formed low tortuosity channels followed by fast filling of polymers. The transparent wood displays a high optical transmittance and at the same time a high haze in a broad wavelength range between 400 nm and 1100 nm. With such unique optical properties, the transparent wood composite with cellulose nanofibers can be utilized for a range of optoelectronics, especially for solar cells and wide-angle lighting where light management is crucial to enhance device operation efficiency. We demonstrate that the newly developed transparent wood composite can function as a broad range light management layer and substantially improve the overall energy conversion efficiency by as much as 18% when simply coated with a GaAs thin film solar cell. Our research on wood based light management material provides an attractive platform for future development embracing green, disposable optoelectronic devices with efficient light management.

Aims Glioblastoma multiforme (GBM) is characterized by aggressive infiltration and terrible lethality. The overwhelming majority of chemotherapeutic drugs fail to exhibit the desired treatment effects. Polydatin (PD), which was initially extracted from Polygonum cuspidatum, is distinguished for its outstanding cardioprotective, hepatoprotective, and renal protective effects, as well as significant anticancer activities. However, the anti-GBM effect of PD is unclear. Materials and methods Cell proliferation and apoptosis after PD intervention were estimated using MTT, colony formation and flow cytometry assays in vitro, while wound-healing and Transwell assays were applied to assess cell migration and invasion. In addition, the anti-GBM effects of PD in vivo were detected in the subcutaneous tumor model of nude mice. Moreover, Western blot, immunofluorescence and immunohistochemical staining assays were employed to elaborate the relevant molecular mechanisms. Key findings The present study demonstrated that PD repressed cell proliferation, migration, invasion and stemness and promoted apoptosis in GBM cells. Moreover, by correlating the molecular characteristics of cancer cells with different sensitivities to PD and employing diverse analytical methods, we ultimately verified that the cytotoxicity of PD was related to EGFR-AKT/ERK1/2/STAT3-SOX2/Snail signaling pathway inhibition, in which multiple components were vital therapeutic targets of GBM. Significance This work demonstrated that PD could inhibit proliferation, migration, invasion and stemness and induce apoptosis by restraining multiple components of the EGFR-AKT/ERK1/2/STAT3-SOX2/Snail signaling pathway in GBM cells.

New-type silica Λ-shape wedge arrays (SWAs) were fabricated by a combined process of template fabrication, hot embossing and sol–gel replication. Using silica needle arrays (SNAs) as template, the configuration of Λ-shape was transferred from SNAs to PMMA/PC molds by hot-pressing process. Then they were casted to form silica Λ-shape wedge arrays by sol–gel process. Using this procedure, high quality silica Λ-shape wedge arrays can be obtained with designed sizes and shapes over a large area. The taper height and interspace of SWAs can be tuned by the imprint depth during the hot-embossing process. This technology provides a cost-effective method to fabricate Λ-shape silica wedges. By changing the primal template, other patterned silica substrate can also be fabricated, such as grating, pillar and spherical structures. These silica based microstructure can find many applications in semiconductor devices, solar cells and optics etc.

The positive effects of the vacuum assistant dye adsorption (VADA) process on the performances of the dye-sensitized solar cells (DSSCs) were investigated experimentally. Using commonly used materials and processes as a demonstration, nanoporous films and the resulted solar cells with different dye adsorption processes were fabricated and characterized for comparison. The amounts of dyes adsorbed by the TiO2 nanoporous films were found to be enhanced greatly compared with dyes adsorbed in ambient condition. In accordance, a relative increase of about 29% for the short-circuit currents (Isc) and 32% for the efficiencies (η) were observed for the resulted DSSCs. Photocurrent-voltage measurement indicated that the lifetime of the photogenerated charge carriers changed little. Hence, such improvements were originated from the application of VADA process, which realized full contact between the dye solution and TiO2 nanoparticles by driving away the air bubbles concealed in the nanoporous film. The VADA process may be also applied in other kinds of solar cells, such as solid state DSSCs and organic or flexible solar cells to enhance the dye adsorption and further increase their efficiencies.

A simple method to fabricate silica micro/nano-needle arrays (SNAs) is presented based on tube-etching mechanism. Using silica fibers as templates, highly aligned and free-standing needle arrays are created over large area by simple processes of polymer infiltration, cutting, chemical etching and polymer removal. Their sizes and orientations can be arbitrarily and precisely tuned by simply selecting fiber sizes and the cutting directions, respectively. This technique enables the needle arrays with special morphology to be fabricated in a greatly facile way, thereby offers them the potentials in various applications, such as optic, energy harvesting, sensors, etc. As a demonstration, the super hydrophobic property of PDMS treated SNAs is examined.

The junction temperature of homoepitaxial green and blue GaInN/GaN quantum well light emitting diode (LED) dies is analyzed by micro-Raman, photoluminescence, cathodoluminescence mapping, and forward-voltage methods and compared to finite element simulations. Dies on GaN substrate and sapphire were analyzed under variable drive current up to 200 mA (246 A/cm2). At 100 mA, dies on bulk GaN remain as cool as 355 K (83 °C) while dies on sapphire heat up to 477 K (204 °C). The efficiency droop and spectral line shift in green LEDs with increasing current density can now be separated into electrical and thermal contributions.

An enhancement of radiative recombination in GaInN/GaN heterostructures is being pursued by a reduction of defects associated with threading dislocations and a structural control of piezoelectric polarization in the active light-emitting regions. First, in conventional heteroepitaxy on sapphire substrate along the polar c-axis of GaN, green and deep green emitting light-emitting diode (LED) wafers are being developed. By means of photoluminescence at variable low temperature and excitation density, internal quantum efficiencies of 0.18 for LEDs emitting at 530 nm and 0.08 for those emitting at 555 nm are determined. Those values hold for the high current density of 50 A/cm 2 of high-power LED lamps. In bare epi dies, we obtain efficacies of 16 lm/W. At 780 A/cm 2 we obtain 22 lm when measured through the substrate only. The 555 nm LED epi material under pulsed photoexcitation shows stimulated emission up to a wavelength of 485 nm. This strong blue shift of the emission wavelength can be avoided in homoepitaxial multiple quantum well (MQW) and LED structures grown along the non-polar a- and m-axes of low-dislocation-density bulk GaN. Here, wavelength-stable emission is obtained at 500 and 488 nm, respectively, independent on excitation power density opening perspectives for visible laser diodes.

We demonstrate homoepitaxial growth of GaInN/GaN-based green (500–560 nm) light emitting diodes (LEDs) on a-plane and m-plane quasi-bulk GaN prepared by hydride vapor phase epitaxy (HVPE). We find that in order to achieve an emission peak wavelength beyond 500 nm, a minimum InN-fraction of ∼14% is needed for both, a- and m-plane quantum wells (QWs), while ∼8% are enough for c-plane-oriented QWs. Besides increasing the InN-fraction in these non-polar QWs, widening the QW also proves to effectively shift the emission to longer wavelengths without loosing efficiency with the benefit of maintaining a low InN-fraction.

GaInN/GaN multiple quantum well light-emitting diode structures in polar c -axis and non-polar m -axis growth have been compared in terms of luminescence properties. Grown under identical conditions, under low excitation density the c -axis structure has a luminescence maximum at 558 nm while the m -axis structure shows a maximum at 488 nm and shows superluminescence at 485 nm under high photoexcitation density. Under the same conditions, on increasing the excitation power, the peak intensity increases 40 fold in the m -axis structure without any variation of the emission wavelength. In similar but separately grown c -axis structures without a p-side, luminescence shifts from 555 nm at low excitation density to superluminescence at 485 nm under high excitation. The coincidence, of the superluminescence wavelength in the polar structure with the stable peak wavelength in the non-polar one, suggests that the wavelength shift in the polar structure is due to its piezoelectric polarization. The absence of such effects in the m -axis-grown structure therefore suggests a stronger dipole matrix element, potentially enabling higher quantum efficiencies and suitability for high efficiency light-emitting diode and laser diode designs in the green spectral region.

We demonstrate homoepitaxial growth of GaInN/GaN-based light emitting diodes (LED) on quasi-bulk GaN with an atomically flat polished surface. The threading dislocation densities of the epitaxial layers were 2-5 x 10 8 cm -2 which was one order of magnitude less than those grown on c-plane sapphire substrate. The growth defects introduced during the epitaxial process were also one order of magnitude smaller than those grown on the sapphire substrate. The crystalline quality and the optical properties of the epitaxial layer and device performance were much improved. The optical output power of the light emitting diode increased by more than one order of magnitude compared to those on sapphire substrate.

A two-step silica deposition process, including prefunctionalization with poly(vinylpyrrolidone) and the following silica deposition, has been used to fabricate silica layer on the surface of nanoscaled silver shell. The influencing parameters of silica coating process were optimized to prevent the precoated silver nanoparticles from desquamating from silica spheres, finally to obtain mono-dispersed silica spheres with silver and silica multilayer films. The resulted silica layer was dense and uniform, its thickness was controllable in the range of 20–50 nm. Such coated silica layer can provide improved thermal stability of the SiO 2 -Ag core-shell structural spheres.

Silver nanoparticles of 20 and 70 nm, respectively, were deposited on the surfaces of submicron silica spheres. Plasma resonances of the submicron silica spheres with dense and uniform silver layer were investigated using UV/vis absorption spectra. It was found that the silver plasma resonance band of the silica–silver core-shell spheres was broadened and shifted to longer wavelength several hundreds nanometers. The dipole–dipole interactions of neighboring silver particles and Mie scattering of silver shell as a whole may serve as the mechanism of such shift and broadening.

Dense, uniform and thickness controllable silver layers were successfully coated on the mono-dispersed submicrometer silica spheres to obtain silica–silver core-shell structural spheres. The growth process of nanoscaled silver layer on silica spheres mainly includes two steps, i.e. nanoscaled nuclei formation and controllable layer growth process. The nuclear-growth mechanism is responsible for the deposition processes. The reagent concentrations and reaction time were found to be the key factors for the formation of controllable silver layer. High quality silver layer with dense and uniform structure was verified by transmission electron microscopy, X-ray diffraction and Energy Dispersive X-ray microanalysis.