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Strong metal/non-polar plastic dissimilar joints are highly demanded for the lightweight design in many fields, which, however, are rather challenging to achieve directly via welding. In this study, we designed a laser processing pretreatment on the Al alloy to create a deep porous Al surface structure, which was successfully joined to the polypropylene (PP) via friction spot welding. A maximum joint strength of 29 MPa was achieved, the same as that of the base PP (i.e. the joint efficiency reached 100%), much larger than ever reported. The joining mechanism of the Al alloy and the PP was mainly attributed to the large mechanical interlocking effect between the laser processed Al porous structure and the re-solidified PP and the formation of chemical bond at the interface. The deep porous Al surface structure modified by laser processing largely changed the Al‒PP reaction feature. The evidence of the C O Al chemical bond was first time found at the non-polar plastic/Al joint interface, which was the reaction result between the oxide on the Al alloy surface and thermal oxidization products of the PP during welding. This study provides a new way for enhancing metal-plastic joints via surface laser treatment techniques.

This work demonstrates a mid-infrared emitter based on Ge8Sb2Te11 (GST) and VO2. The results show that GST and VO2 have contrasting optical properties, which enable the emitter to reach a modulation depth of up to 82.5%. Continuous modulation of the resonant peak in the broad spectral range of 6.3–9.2 μm was achieved by modulating the crystallization ratio of the top GST layer. The structure can reach a controllable average emissivity of 11.5%–83.4% within 5–8 μm, 2.0%–19.0% at 8–14 μm, and 6.0%–47.3% at 3–5 μm, which is close to an ideal thermal emitter performance. Moreover, the structure is insensitive to both incident angle and polarization.

A complex structure consisting of ultrafine-grained processed zone and coarse-grained base material zone was developed in this study, aiming at improving the yield strength of a high nitrogen stainless steel without sacrificing corrosion resistance and ductility. The ultrafine-grained processed zone was produced by friction stir processing, leading to ultra-high strength and great pitting corrosion resistance, but significantly reduced ductility; the coarse-grained zone exhibited excellent ductility but a very low yield strength. The enhancement and coordination between the processed zone and coarse-grained zone resulted in significantly improved yield strength and ductility of the complex structure. Thus, a combination of excellent mechanical properties and corrosion resistance was successfully achieved.

The low temperature oxidation of n-pentane with nitric oxide (NO) addition has been investigated at 500–800 K in an atmospheric jet stirred reactor (JSR). The molar fraction of NO in the mixture is varied between 0 to 1070 ppm to study its chemical sensitization effect on low temperature oxidation of both fuel lean and rich n-pentane/oxygen mixtures. N-pentane, O2, CO, CO2, CH2O, C2H4, CH3CHO, NO, and NO2 are quantified simultaneously, in-situ by using an electron impact molecular beam mass spectrometer (MBMS), a micro-gas chromatograph (µ-GC), and a sensitive mid-IR dual-modulation faraday rotation spectrometer (DM-FRS). The experimental results reveal that NO addition delays the onset temperature of low temperature oxidation of n-pentane between 550–650 K, but reduces the negative temperature coefficient (NTC) behavior in the NTC region (650–750 K) and dramatically shifts the onset of high temperature fuel oxidation to an intermediate temperature (750–800 K). A recently developed n-pentane/NOx model by using Reaction Mechanism Generation (RMG) and a new n-pentane/NOx model in the present work were used to predict the experimental results. The results show that the three distinct temperature-dependent characteristics of NO sensitized n-pentane oxidation are captured appropriately by these two models at both fuel rich and lean conditions, while the onset temperature of low temperature oxidation is not accurately predicted by these two models. It shows that the RMG model has a better prediction of the onset delay of n-pentane oxidation than Zhao's model, while Zhao's model performs better at NTC and intermediate temperature regions. Besides RO2 + NO, additional fuel/NOx reaction pathway, like R + NO2, RO + NO, and RO + NO2, and the interconversion reactions among NO, NO2, and HONO may need to be further studied.

Thermal control materials are employed to adjust the temperature of a spacecraft operating in deep space. The spectral emissivity is a crucial factor in evaluating the thermal radiative properties of such materials. An apparatus, composed of a Fourier transform infrared spectrometer (FTIR), a sample cooling chamber and a mechanical modulation system was demonstrated to measure low temperature infrared spectral emissivity under vacuum. The mechanical modulation system, which includes a chopper and a lock-in amplifier, is employed to reduce the interference of background radiation during measurements. The limitation of the Fourier transform frequency on the chopper frequency can be eliminated by setting the FTIR on step-scan mode. The apparatus is separated into two parts and evacuated by different pumps. In this study, a high quality emission spectrum of a sample is measured by the apparatus. The spectral emissivity of thermal control materials are obtained in the wavelength range of 8 to 14 μm at 173 and 213 K. The combined standard uncertainty of the apparatus is 3.30% at 213 K.

The core/shell structure was formed by GO self-assembled with amine-functionalized commercial ZnO (CZO) and preparative hexagonal ZnO (HZO), respectively. Graphene-coated CZO and HZO were obtained after being reduced in Ar at 500 °C. The mechanism of the coating procedure was investigated by measuring their respective zeta potential values. Our characterizations demonstrate that graphene on HZO has better quality and fewer layers. An obvious band gap decrease of ZnO was observed for coating with graphene. Photoluminescence spectra of ZnO@graphene core/shell composites display the fluorescence quenching property, which indicates its good application prospect in optoelectronics, photocatalytic and other fields.

How to coordinate the strength, ductility and electrical conductivity of Cu-Cr-Zr alloys has always been a difficult problem. Unlike most of previous reports on processing soft state (solution state) alloys, in the present study, a hard state (aged state) Cu-Cr-Zr alloy was subjected to one-step friction stir processing (FSP) at room temperature with more attentions paid to the evolution of grains and precipitates, and their effects on the mechanical and electrical properties. The results showed that the precipitates played a key role in grain refinement, and ultrafine grains (UFG) with an average size of 250 nm were produced after FSP. Many fine precipitates (average size of 3.1 nm) were uniformly distributed in the grains, neither dissolved nor obviously coarsened. Excellent comprehensive properties of high tensile strength (702 MPa), good elongation (16%) and electrical conductivity (74.3% IACS) were achieved in the FSP sample. Furthermore, this one-step FSP method does not need subsequent aging treatment which is indispensable for conventional processing methods, providing a simplified and efficient method for improving the performance of Cu-Cr-Zr alloys.

Atomic oxygen erosion is a significant threat to exterior spacecraft polymers. Polyhedral oligomeric silsesquioxane (POSS) is a potential kind of material in resisting AO diffusion erosion, but lack of mechanism studies for application supports. In this research, we used the first-principles calculations to investigate the mechanism based on two types of nominally hydrated POSS named T8 (Si8O12H8) and T10 (Si10O15H10). According to the results, we found that the minimum energy path (MEP) of AO diffusing inside POSS is the adjacent-edge-path rather than the center-path. We also found the energy barriers that hinder the diffusion motion of AO inside POSS are originated from the structural distortion of POSS, which are negatively correlated to Si-O bond length and positively correlated to structural compactness. Thus, compacter POSS structures with shorter Si-O bond length are expected to give better AO diffusion resistance properties.

Indium tin oxide (ITO) films with tunable epsilon-near-zero (ENZ) properties have attracted great interest among researchers. In this study, ITO films with tunable photoelectric properties were prepared by a magnetron sputtering technique under different oxygen flow rates, and their structures and optical properties are studied. The ENZ wavelength shift and electron accumulation layer were observed from their permittivity and carrier concentrations, which were calculated by a graded model combined with an oscillator model. This demonstrated that the variable carrier concentrations induced the tunable ENZ property of the ITO films. Meanwhile, the interface of the film and the substrate was found to have a significant influence on the loose lower layer by researching the profile of permittivity and carrier concentrations. Furthermore, the simulation of the transfer matrix method indicated that using ENZ materials as substrates can achieve zero reflection at an ENZ wavelength. ITO films serve as absorbers based on this characteristic. An absorption device was fabricated; its largest absorption rate was 97.41% at 1576 nm, and it maintained high absorption over a wide range of incident angles. The absorption mechanism in the ENZ film is illustrated by absorption maps and electric field distribution.

Ultrafine-grained (UFG) pure Al with uniform and stable microstructure produced by friction stir processing (FSP) significantly increased the high-cycle fatigue (HCF) strength compared with coarse-grained and other UFG materials prepared by severe plastic deformation (SPD). There was no obvious surface damage for FSP-UFG pure Al and the improved fatigue damage resistance can be attributed to the uniform microstructure and high microstructural stability. The ring-island stress distribution of FSP-UFG impeded the formation of large-scale shear bands, and enhanced the coordinated deformation during cyclic deformation. In addition to the enhanced tensile strength, increasing the fatigue strength exponent, which is decided by the microstructural stability, is also an effective method of improving the fatigue strength.

High-performance high nitrogen stainless steel (HNS) with ultra-high strength up to ∼1.7 GPa and excellent corrosion resistance was successfully obtained by friction stir processing. The simultaneous enhancement in strength and corrosion resistance was mainly attributed to the grain ultra-refinement. Uniform ultrafine-grained microstructure (∼225 nm) significantly improved the repassivation behavior of HNS. With significantly increased element diffusion rate and element content, the passive film formed on the ultrafine-grained HNS showed high resistance to the nucleation and growth of pits. Grain ultra-refinement was confirmed to be an effectual method for improving corrosion resistance of HNS without sacrificing strength.

AuPd nanoparticle-decorated graphene-coated ZnO nanorod (ZNR) array electrodes (ZNR@Gr/AuPd) were synthesized via electrostatic self-assembly followed by solution reduction methods. The morphologies of ZNR@Gr/AuPd were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), which indicated that ZNR was well-coated by graphene with 3–5 layers and uniformly decorated with AuPd nanoparticles (about 5 nm). UV-Vis diffuse reflectance and photoluminescence spectra were obtained to analyze the optical properties. The photoelectrochemical (PEC) properties were also evaluated; the results indicated that the photocurrent density was 2.27 mA cm−2 at 0.8 V versus Ag/AgCl, which was 7.1 times that of bare ZNR. The sample also displayed enhanced PEC stability (91.3%), which prevented photocorrosion. Finally, a proposed PEC mechanism of ZNR@Gr/AuPd was illustrated to explain the charge transfer and the role of graphene and AuPd nanoparticles in the improvement of PEC performance and stability. The ZNR@Gr/AuPd electrode shows excellent PEC performance and stability, exhibiting promising potential in the generation of H2.

Technology innovation capability is a main driver in improving a country’s industrial competitiveness. Development prospects and development speed are strongly dependent on industry innovation capability. Therefore, how to effectively and correctly evaluate the innovation capability of industry is of great importance. On the basis of previous research, this paper establishes an index system for evaluating the technology innovation capability of China’s high-tech industries. The index is characterized by the objective evaluation of objects with measurable indexes. The fuzzy Borda method uses precise digital methods to handle fuzzy evaluation objects; therefore, more scientific and pragmatic quantitative criteria are obtained with qualitative and quantitative evaluation results. This paper is the first attempt to apply the fuzzy Borda combination method to high-tech industry innovation capability evaluation. We establish a fuzzy Borda combination model based on four kinds of single evaluation models. By making a combination evaluation, the disadvantages of a single evaluation method are avoided. In the end, based on the fuzzy Borda combination evaluation model, the real technology innovation data of 2013 is analyzed and the innovation capability of individual industry is ranked, which will provide useful guidance for decision-making administrators.

A graphene coated hexagonal ZnO (HZO@Gr) with enhanced activity in photocatalysis was synthesized. However, the photoinduced charge transfer behavior and the beneficial role of graphene in promoting photocatalytic reactions have not been sufficiently investigated experimentally. In this paper, the surface potentials of the ±(0001)-polar plane of HZO (Zn-polar plane and O-polar plane), graphene, graphene/Zn-polar plane and graphene/O-polar plane were measured using Kelvin probe force microscopy (KPFM). On the basis of the KPFM results, the respective Fermi levels were calculated and the internal electric field (IEF) of HZO was confirmed. Taking the IEF of HZO into consideration, the three-dimensional band diagrams of the HZO@Gr composites in methyl blue (MB) solution in the dark and under UV-visible irradiation after equilibrium were proposed. Accordingly, it is found that there could emerge different interactions between graphene and HZO at the ±(0001)-polar plane of HZO. Furthermore, the photogenerated holes and electrons tend to migrate to opposite directions. With the participation of graphene and IEF, the composites show a decrease in possibility of charge recombination. As a result, the active groups, namely ˙OH and ˙O2− radicals, could be mainly generated at/near the O-polar plane and Zn-polar plane, respectively. This work can serve as a supplemental explanation of the charge transfer during the photocatalytic process at the polar ZnO/graphene composite surface.

Here we demonstrate a tunable broadband near-infrared absorber composed of VOalt;subagt;2alt;/subagt; /Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt;/ITO layers with a facile lithography-free method. Simulated and experimental spectra show absorption bands with above 90% absorptance can be tuned from 1.62 ~2.42 μm to 1.2~1.5 μm by thermally induced VOalt;subagt;2alt;/subagt; phase transition. Furthermore, the absorber with VOalt;subagt;2alt;/subagt; in the intermediate state can yield a broadband perfect absorption over the wavelength range of 1.2~2.5 μm. Besides high absorption performance can still be remained at the incident up to 70° for both polarizations due to the presence of ultrathin layer of VOalt;subagt;2alt;/subagt; (λ/52) in the absorber.

Optical properties and electronic structures of VO2 films obtained by magnetron sputtering method on quartz and sapphire substrates were analyzed by transmission spectrum and spectroscopic ellipsometry (SE). The metal-to-insulator transition (MIT) characteristics of the two thin films were compared and discussed correlating with their structural details. By fitting spectroscopic ellipsometric data, the dielectric functions, electronic transitions, and optical bandgap of VO2 films can be tuned by substrate effects. On quartz substrate, the VO2 film exhibits a lower transition temperature and broader thermal hysteresis (ΔH). It is found that the lowest order transition (E1) on quartz substrate does not reduce to zero in the metallic phase as expected. There are two reasons: one is the slight decrease in the filled a1g bands compared to the bands due to a greater compressive stress in the quartz films; the other is associated with the donor level (ED) and acceptor level (EA).

Tantalum pentoxide films were deposited on BK7 glass substrates using oxygen plasma enhanced pulsed laser deposition (OPE-PLD). X-ray diffraction, atomic force microscopy, ultraviolet–visible–near infrared scanning spectrophotometry, and spectroscopic ellipsometry were used to characterize the crystallinity, microscopic morphology and optical properties of films. Results show that the film roughness increased with the increase of oxygen pressure, and decreased with the application of OPE. Meanwhile the use of oxygen plasma in a 2 Pa O2 pressure resulted in the transmittance of the thin film of 91.8% at its peak position (the transmittance of bare substrate). Moreover, the root-mean-square roughness as low as 0.736 nm, and refractive index of 2.18 at 633 nm wavelength, close to the refractive index of bulk Ta2O5 (~ 2.20 at 633 nm wavelength), were obtained.

Silicon dioxide (SiO 2 ) thin films were deposited on BK7 substrates by pulsed laser deposition (PLD) method using ceramic SiO 2 targets (C-SiO 2 -Ts), which was sintered by solid state sintering. The reason for using C-SiO 2 -T instead of the silicon target is to reduce the oxygen-deficiency phenomenon in deposited SiO 2 thin films. The influence of substrate-temperatures, oxygen-pressures and oxygen-plasma-assistance on the properties of synthesized films was studied. X-ray diffraction, atomic force microscopy, ultraviolet–visible–near-infrared scanning spectrophotometry were used to characterize the crystallinity, morphology and optical properties of deposited films. Results show that the root-mean-square roughness of films increased with the increase of oxygen-pressure, substrate-temperature and with the employment of oxygen-plasma. The transmittance of films increased with the increase of oxygen-pressure and decreased with the increase of substrate-temperature and with the employment of oxygen-plasma. Stoichiometric SiO 2 thin film with high optical quality was synthesized at room-temperature and 20 Pa oxygen-pressure using C-SiO 2 -T.

The amorphous silicon oxide SiO 2− x thin films were prepared by the plasma-assisted pulsed laser deposition (PLD) method. X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-VIS-NIR scanning spectrophotometry and ellipsometry were used to characterize the crystallinity, microscopic morphology and optical properties of obtained thin films. The influences of substrate temperatures, oxygen partial pressures and oxygen plasma assistance on the compositions of silicon oxide (SiO 2− x ) thin films were investigated. Results show that the deposited thin films are amorphous and have high surface quality. Stoichiometric silicon dioxide (SiO 2 ) thin film can be obtained at elevated temperature of 200 °C in an oxygen plasma-assisted atmosphere. Using normal incidence transmittance, a novel and simple method has been proposed to evaluate the value of x in transparent SiO 2− x thin films on a non-absorbing flat substrate.

Al2O3 coatings, with a Ni-based buffer layer (Ni or NiAl), were deposited on a Cu substrate by electron beam evaporation (EBE). The Al2O3 coatings were amorphous of good stoichiometry and their surface was undulated and continuous. The Ni-based buffer layer played a key role on improving the adhesion of the Al2O3 coatings to the substrate. The diffusion of Cu from the substrate into the Al2O3 coating at high temperature was suppressed by the buffer layer. Excellent resistivity (1015 Ω cm) and high breakdown voltage (110 kV/mm) have been obtained.

In this study, Al2O3 films with an Ni-based buffer layer were prepared on a Cu substrate by plasma-ion assisted deposition (PIAD). The main purpose of this study is to develop a novel electrical insulating film to be used at high temperature. X-ray diffraction (XRD) spectra show the Al2O3 films prepared by this method are amorphous. The results of atomic force microscopy (AFM), scanning electron microscopy (SEM), and auger electron spectroscopy (AES) analyses reveal that the Al2O3 films perfectly adhere to the substrate through the buffer layer, no visible defects were observed, and no impurity from Ni or Cu was detected. The diffusion of Cu into the Al2O3 film at high temperature is suppressed. Al2O3 films with an Ni-based buffer layer exhibit excellent resistivity (>1010Ω·cm) even after experiencing a high temperature environment as high as 600°C 10 times.

Networked rectangular MgO nanostructures have been prepared through direct reaction of Mg with flowing oxygen. The nanostructures consist of the branches that have square cross sections and grow in a right-angled zigzag manner to elongate in three dimensions, which form the networked rectangular nanostructures. The edge dimension of their cross-sections is in the range of 50–150 nm. A growth mechanism based on the vapor–solid process is proposed for the formation of the networked nanostructures.

Two-photon absorption (TPA) spectra of three organic compounds have been directly measured by an approach of using tunable laser from an optical parameter amplifier as an excitation source. The output intensity of the optical parameter amplifier can cover a broad spectral range 400–2000 nm, and the same intensity in the whole spectral range can be easily adjusted. Therefore, the measurement based on this method is direct and reliable. The experimental results show that the profiles of the TPA spectra are quite similar to those of the linear absorption spectra. All of these compounds exhibit large TPA cross-section in a broad spectral range from 750 to 1100 nm.

The emission and optical limiting properties of two new organic compounds have been experimentally investigated. Pumping by picosecond and nanosecond lasers, respectively, these two compounds possess strong two-photon absorption and optical limiting effects. The results of time-resolved fluorescence of them in DMF solvent at the different concentrations and small quantum yields indicate that the non-radiation process and reabsorption result in the low emission efficiency of these new molecules with large two-photon absorption (TPA) cross-sections.

The present investigation examines the effect of buffer layer and film thickness on the thermal fatigue behaviour of Al2O3 films. Al2O3 films with a Ni-based buffer layer were deposited on Cu substrates by plasma ion assisted deposition (PIAD) technique. SEM image and AES depth profile indicated that the Ni-based buffer layer effectively improved the adhesion of the Al2O3 film to the Cu substrate and suppressed the diffusion of Cu from the substrate into the Al2O3 film at 600 °C, which was beneficial for the insulating properties of Al2O3 films and therefore was favored for the improvement of thermal fatigue behaviour. The thermal cycle test results demonstrated that the Ni-based buffer layer greatly enhanced the thermal fatigue behaviour with decreasing buffer layer thickness and the increasing Al2O3 film thickness, therefore increasing the lifetime of Al2O3 films.

Silicon dioxide (SiO 2 ) film is an important material for semiconductor industry as the gate dielectric material, and optical industry as antireflective coatings, and so on. The sol-gel method has been widely used for the deposition of oxide thin films due to several advantages such as simple and low-cost equipment, normal atmospheric conditions, and ease control of the precursor composition doping. In this work, SiO 2 thin film was deposited on BK7 glass substrate by spin-coating and dip-coating techniques, respectively. Three precursor concentrations were investigated, i.e., tetraethylorthosilicate (TEOS): ethanol: water= 1:7:7, 1:10:10 and 1:15:15 (molar ratio). X-Ray Diffraction spectrometry (XRD), scanning electron microscopy (SEM), and UV-VIS-NIR scanning spectrophotometry were used to characterize the crystallinity, morphological and optical properties of deposited SiO 2 thin films. Results show that all the SiO 2 thin films deposited by the spin-coating and dip-coating are amorphous. SEM analysis confirms that the deposited SiO 2 thin films have high surface quality and tight adherence with the substrate. The transmittance measurements indicate that dip-coated SiO 2 thin film from gel of low precursor concentration represents better transmittance than that from high concentrations at the range of 600-1200nm. SiO 2 thin film spin-coated from gel of high precursor concentration has better transmittance than that by dip-coating, but of opposite results for the films deposited from gels of low precursor concentrations.