Search

Catalytic hydrogenation of nitroarenes is a type of important reaction to get corresponding amines, the development of catalysts with outstanding catalytic performance is in urgent need. In this review, we summarize the breakthroughs in the development of supported metal catalysts in the past few decades, including the use of different metals and supports, improved metal utilization efficiency, adjustment of the structure, and the interaction. We focus on how to develop and innovate the structure of the catalyst, aiming at the contradiction between conversion and selectivity in selective hydrogenation of nitroarenes, from the perspective of the structure and the interaction to construct a kind of catalyst with low noble metal loading and high activity, stabilize the active components, and design and fabricate hybrid nanostructured catalysts with desired activity and selectivity. The development process and the catalytic performance of metal‐2D semiconductor hybrid nano‐structure catalyst are also discussed and provide a theoretical and practical basis for the precise design of supported metal catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hybrid nano-structured catalyst Pt/@-ZrO 2 /SBA-15 was fabricated. • Metal-metal oxide synergistic catalysis for high efficiency selective hydrogenation. • Metal oxide dispersed on the support at the state of the spontaneous mono-layer distribution. It is generally believed that noble metal catalysts exhibited higher activity for selective hydrogenation, while metal oxides were almost inactive. Here, we report metal-metal oxide synergistic catalysis for high efficiency selective hydrogenation by a hybrid nano-structure Pt/@-ZrO 2 /SBA-15 catalyst, which was fabricated by anchored Pt nanoparticles on the mono-layer dispersed ZrO 2 film layer coated in SBA-15 support via a photochemical route. This Pt/@-ZrO 2 /SBA-15 catalyst exhibited remarkable catalytic activity in the selective hydrogenation of C O bond, NO 2 , and C C bond. For the selective hydrogenation of benzaldehyde, conversion >99.9% was achieved with >99% selectivity, and the turnover frequency (TOF) can be achieved up to 4822 h−1, which was much higher than that of the atomically dispersed Pd 1 /TiO 2 -EG catalyst (1002 h−1) reported in the literature, no decay in the activity was observed by several cycles. Combined the experimental and characterization results, proved that the ZrO 2 was dispersed in a mono-layer in the channel of SBA-15, and the results showed that an appropriate loading of ZrO 2 in this catalyst could maximize the advantage of this hybrid nano-structure to achieve the best catalytic activity. The superior activity of Pt/@-ZrO 2 /SBA-15 was attributed to the synergistic catalysis, strong interface electronic effect, and the unique properties of the special hybrid nano-structure. This work demonstrated synergistic catalysis of metal Pt nanoparticles and monolayer dispersion ZrO 2 for high efficiency selective hydrogenation. [ABSTRACT FROM AUTHOR]

• A multi-field coupling model is based on COMSOL5.6 simulation platform and finite element method is applied to numerical simulation. • The effects of process parameters on coating polysilicon thin films are studied concurrently. • A new wafers placement strategy is proposed to achieve further improvements in deposition rate and uniformity. The high photoelectric conversion efficiency of tunnel oxide passivating contacts (TOPCon) photovoltaic (PV) cells and their process compatibility are increasingly recognized by the industry, making it of growing importance to develop deposition process technologies for high-capacity polysilicon thin films. Currently, the size of LPCVD reactors for preparing polysilicon thin films in the industry is getting enlarged, which directly leads to the degradation of axial uniformity of polysilicon thin films. In this paper, a coupled multi-physics field model is established to simulate the polysilicon thin-film Low Pressure Chemical Vapor Deposition (LPCVD) process based on COMSOL Multiphysics platform, and the validity of the model is verified by comparing experimental data with simulation results. By investigating the flow field, thermal field, chemical reaction field and surface reaction field, the effects of the process parameters such as chamber temperature and pressure are investigated, as well as characteristics of the polysilicon thin films deposition. The results show that the uniformity of thin films decreases with increasing temperature and pressure, and the deposition rate of thin films increases as temperature and pressure increase. With the help of optimized the process parameters, the deposition rate of polysilicon thin films was increased by 13.0% and the uniformity of thin films was controlled above 96%. The uniformity of the films can be further improved to 96.7% by optimizing the temperature zone parameters and adopting the wafers placement strategy. [ABSTRACT FROM AUTHOR]

A catalyst composed of La2O3/AC and Pd nanoparticles is constructed for precise synthesis of cyclohexanone from phenol hydrogenation with high conversion (>99 %) and selectivity (>95 %). The special structure and the synergistic effect remarkably facilitate the high conversion of phenol. The stability test results of the used Pd/@‐La2O3/AC catalyst showed that the phenol conversion decreased from 100 % to 24.5 %. The deactivation reason for the used catalyst was the agglomeration of Pd nanoparticles and the adsorption of organics. Three treatment methods, heat treatment, ethanol wash, and water wash, were regenerated the catalytic activity of the used Pd/@‐La2O3/AC catalyst. The regenerated method of water wash solved the problem of organic matter blockage and residue to a certain extent, but still can not fully recover its high activity. This deactivation mechanism provides important guidance to develop high stable Pd‐based catalyst for the selective hydrogenation of phenol. [ABSTRACT FROM AUTHOR]

• A multi-physics coupling model is established based on COMSOL Multiphysics for tubular LF-PECVD. • The effects of process parameters on coating SiN x :H are studied and the corresponding optimization results are obtained. • A new gas transport structure is proposed for further simulation research. In this paper, a coupled multi-physics field model based on the COMSOL Multiphysics platform is developed to simulate the deposition of SiN x :H thin films by LF-PECVD. The deposition process is simulated by combined analysis for the flow field, thermal field, chemical reaction field, and plasma field. The results have indicated that the temperature has the most significant effect on the deposition rate, the pressure and temperature are the major process parameter on the film uniformity. Through optimizing process parameters, the optimization range of the corresponding parameters is obtained. Compared with the original process, the coating rate of SiN x :H can be increased by 11.6%, and the uniformity performance can be controlled above 97%. By further optimizing the gas transport structure, the uniformity can be improved to 98.1%, the deposition rate can be increased by 1.44%. This paper provides a reference for solving the problems of low deposition rate and poor uniformity due to the increased size of tubular LF-PECVD equipment, which is conducive to improving the equipment capacity and the film quality, thus reducing the production cost and improving the performance of photovoltaic cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of a hybrid nanostructure Pt/@-ZrO 2 /SBA-15 catalyst by a photochemical route. • Strong interaction between Pt and ZrO 2 /SBA-15. • Efficient hydrogenation of nitroarenes over Pt/@-ZrO 2 /SBA-15 catalyst. • Special structure and synergistic effect of Pt/@-ZrO 2 /SBA-15 catalyst. A hybrid nanostructure Pt/@-ZrO 2 /SBA-15 catalyst was fabricated by coating ZrO 2 on SBA-15 (ZrO 2 /SBA-15), and then loaded Pt nanoparticles on the ZrO 2 /SBA-15 by a photochemical route at room temperature. This catalyst demonstrated outstanding activity and excellent selectivity (>99%) for hydrogenation of nitroarenes, outperforming conventional catalysts (Pt/SBA-15, Pt/ZrO 2 , Pt/AC, Pt/Al 2 O 3 , and Pt/SiO 2). For the hydrogenation of chloronitrobenzene, the Pt/@-ZrO 2 /SBA-15 catalyst achieved a turnover frequency (TOF) of 2.5–7.5 s−1. Particularly, the 0.07%Pt/@-ZrO 2 /SBA-15 catalyst yielded a TOF as high as 12 s−1 in the hydrogenation of nitrobenzene, much higher than the single-atom 0.08%Pt/FeO x -R200 (0.67 s−1) catalyst reported in the literature. Unlike single-atom (low metal loading) or conventional catalysts (high metal loading), this hybrid nanostructure catalyst with high or low Pt loading showed high activity. Moreover, the Pt/@-ZrO 2 /SBA-15 catalyst exhibited excellent recyclability; the catalytic activity did not decrease after six reaction cycles. The extraordinary activity and selectivity of this catalyst are attributed to the special structure and the synergistic effect. The catalysts also deliver high catalytic activity and selectivity for nitroarenes with various reducible substituents into the corresponding aminoarenes. Our findings provide a new perspective on developing a high-efficiency hybrid nanostructure catalyst for a variety of catalytic reactions. [ABSTRACT FROM AUTHOR]

• A hybird nano-structure catalyst Pd/@-ZrO 2 /AC is prepared by photochemical route. • Synergistic effect between Pd nanoparticles and nano-semiconductor(ZrO 2)/AC. • Pd/@-ZrO 2 /AC shows excellent activity and high benzyl alcohol selectivity in the hydrogenation of benzaldehyde. • Pd/@-Me x O y /AC catalysts exhibited synergistic catalysis and remarkable catalytic activity. Selective hydrogenation of benzaldehyde is a green and sustainable technology to produce benzyl alcohol. Herein, we report a hybrid nano-structure catalyst(Pd/@-ZrO 2 /AC) by photochemical route for selective hydrogenation of benzaldehyde under mild reaction conditions. The Pd/@-ZrO 2 /AC catalyst exhibited outstanding activity(100%) and high selectivity for benzyl alcohol (>98 %), much higher than that of Pd/ZrO 2 and Pd/AC. The high catalytic activity was attributed to the special structure and the synergistic effect. A series of Pd/@-Me x O y /AC(Me x O y : TiO 2 , CeO 2 , La 2 O 3) catalysts further confirmed the synergistic effect in this hybrid nano-structure for this reaction. This work clearly demonstrates that loading nano-metal on high specific surface area materials with nano-semiconductors can increase the catalytic activity and open up a new direction for the synergistic catalysis of hybrid nano-structure catalysts. [ABSTRACT FROM AUTHOR]

We report a novel hybrid nano-structure Pt catalyst, by coating rare metal oxide (CeO2 or La2O3) on the surface of SBA-15, then anchoring Pt nanoparticles on the CeO2/SBA-15 or La2O3/SBA-15 via a photochemical route. For the hydrogenation of benzaldehyde, the Pt/@-CeO2/SBA-15 and Pt/@-La2O3/SBA-15 catalysts demonstrated outstanding activity and excellent selectivity, much higher than that of Pt/CeO2, Pt/La2O3 and Pt/SBA-15. In particular, the TOF of Pt/@-La2O3/SBA-15 reached 2324 h−1, 2.3-fold higher than the atomically dispersed catalyst (Pd1/TiO2, 1002 h−1) in the literature. The superior catalytic performance was attributed to the special structure and the synergistic effect between the Pt nanoparticles and CeO2/SBA-15(La2O3/SBA-15). The content of metal oxide played an important role in the reaction, as only a suitable content of metal oxide could ensure that this hybrid structure would show the best performance. [ABSTRACT FROM AUTHOR]

• A multi-field coupling model and simulation platform are based on COMSOL5.3. • The effects of process parameters and reactor structure on coating silicon nitride film are studied concurrently. • Transforming dynamic coating problems into static problems for simulation research. This paper builds a physical model by using the finite element method on COMSOL simulation platform to simulate the in-line PECVD process. The in-line PECVD simulation model couples the flow field, thermal field, chemical reaction field and plasma field and is verified through experiments. In addition, a new simulation strategy is proposed to solve the problem of dynamic coating silicon nitride film. Through this simulation method, process parameters and structural parameters of the in-line PECVD equipment are optimized. Effects of microwave tube position, microwave shield size, total gas flow, pressure and temperature on main coating reaction region is studied. The results have shown that the position of microwave tube, the total gas flow and temperature have greater influence on the region of reaction zone, the concentration distribution of reactants and the thickness of SiN x H y film. Through optimizing process parameters and structural parameters, the coating rate of SiN x H y film can be increased from 0.0607 nm/s to 0.15 nm/s and the deposition thickness can be increased from 6.78 nm to 15.59 nm. The molar concentration of SiN x H y particles in the reaction region has grown by more than 23.5%. And the relative intensity of reaction field inside PECVD chamber has increased by 1.3–2.3, which is calculated by molar concentration ratio of SiN x H y particles. This paper provides a reference for the optimization of in-line PECVD equipment. [ABSTRACT FROM AUTHOR]

The removal behavior of the aluminum paste was investigated using thermogravimetric analyzer, and it was found that the mass loss curve could be divided into two main stages including low-temperature and high-temperature stages and a complex transition between them. The pre-exponential factors of the two main stages were calculated by Kissinger method. And the activation energies were determined using different methods named as Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sinose (KAS) and Kissinger. The dependence of the activation energy on the conversion has been analyzed in detail. The activation energy of the low-temperature stage keeps approximately constant, and the average value is 38.74 kJ mol−1 of FWO method and 33.86 kJ mol−1 of KAS method. According to KAS method, the activation energy for the high-temperature stage decreases from 157.03 to 94.65 kJ mol−1 with the temperature increasing from 596 to 675 K. The variation range of the activation energies indicates the existence of a complicated reaction mechanism during the high-temperature stage. Though high removal rate during the low-temperature stage is beneficial to reducing the processing time of silicon solar cells, the heating rate should be controlled when the temperature is close to the value resulting in the maximum mass loss rate to avoid causing defects in the aluminum back electrode. [ABSTRACT FROM AUTHOR]

Radiative cooling and evaporative cooling are sustainable cooling techniques without additional energy input. However, radiative cooling lacks dynamic cooling ability, while evaporative cooling demands external water replenishment, hindering their applications. Herein, a smart radiative/evaporative cooling bilayer combining a polydimethylsiloxane (PDMS) upper layer with a hydrogel lower layer is presented for efficient all‐day dynamic passive cooling. The PDMS layer with high solar reflectivity (0.930) and emissivity (0.952) provides excellent all‐day radiative cooling and protects the hydrogel from solar exposure, while the hydrogel layer demonstrates remarkable water evaporation and absorption, achieving dynamic evaporative cooling. Thus, the synergy of the two layers significantly enhances the overall cooling performance. Specifically, the bilayer can achieve the peak cooling power values of 424.4 and 650.6 W m−2 as well as the maximum subambient cooling temperatures of 10.4 and 3.7 °C during sunny and cloudy mid‐days, respectively. Moreover, the bilayer obtains 3.2 °C warmer temperature compared with the PDMS alone during cold nighttime, while the two structures exhibit comparable cooling performance during hot nighttime, indicating the self‐adaptive cooling property of the bilayer. In addition, the bilayer can achieve good cooling performance even under continuous cloudy days, offering a promising strategy for efficient all‐day dynamic passive cooling. [ABSTRACT FROM AUTHOR]

In this work, PbO-TeO 2 -Bi 2 O 3 -SiO 2 lead-containing glass and TeO 2 -Bi 2 O 3 -ZnO-Li 2 O lead-free glass were synthesized in order to investigate the difference between them and find out the reason why lead-free paste can't be used on monocrystalline wafer commercially. Their flowability and reactivity with SiN x were characterized. Lead-free glass presents lower flow temperature, better wettability and stronger etching ability to SiN x than lead-containing glass. Button test was carried out and large white particles was identified on the interface for lead-free glass. These results indicates the excessive flowability and etching to SiN x for lead-free glass. The morphology of grid line and interface between silver electrode and silicon wafer were investigated on dependence of temperature. The lead-containing and lead-free glasses went through similar evolution of silver sintering and interface microstructure with lead-free glass better facilitating silver sintering through liquid phase sintering due to its lower flow temperature. The thicker glass layer and more Ag crystallites with large size can be observed from cross-sectional micrographs for lead-free glass. Therefore, lead-free paste exhibits lower V oc and FF than lead-containing glass owing to its ecxessive corrosion of SiN x , thicker glass layer and large Ag crystallites. • Firing mechanism of lead-containing and lead-free silver paste was compared. • The two glasses show different flowability and reactivity with SiN x layer. • The lead-free glass can better facilitate the liquid phase sintering of silver. • The lead-free glass generates thicker glass layer and more Ag crystallites. • The lead-containing glass shows better U oc and FF than lead-free glass. [ABSTRACT FROM AUTHOR]

Hydrogenated silicon carbonitride (SiCN:H) thin films were deposited by sputtering of silicon carbide target in hydrogen-doped argon and nitrogen atmospheres. The properties of the SiCN:H films were analyzed by scanning electron microscopy with energy dispersive spectrometer, atomic force microscope, Fourier transform infrared spectroscopy, X-ray diffraction and fluorescence spectrophotometer. No distinct crystal was formed in the SiCN:H films as-deposited and annealed at 600∘C and 800∘C. The SiCN:H films were mainly composed of Si–N, Si–C, Si–O, C–C, C–N, C ≡ N, N–Hn bonds and SiCxNy network structure. The strong blue photoluminescence observed from the SiCN:H film annealed at 600∘C was attributed to SiCxNy network structure. [ABSTRACT FROM AUTHOR]

Abstract For thermal analysis of photovoltaic modules, single value absorbance model of solar cells has often been used. However, this model can't fully embody obvious selective absorption feature of solar cells. Aimed at this issue, a kind of segmented multi-waveband absorbance model was proposed. By simplifying the standard AM1.5 solar spectrum into 25 different wavebands, corresponding absorbance data were calculated. Combined with finite element method and this segmented absorbance model, temperature simulation of PV module was carried out and the temperature difference between the new model and the single value one used before got to 3.17 K. Then considering less calculated amount and the absorption characteristics, AM1.5 solar spectrum was taken into three wavebands and an alternative three-waveband absorbance model was put forward. The results showed the module temperature difference between the three-waveband absorbance model and multi-waveband absorbance model was only 0.20 K, which indicated the three-waveband absorbance model was more suitable in the PV module temperature simulation. Highlights • One kind of novel segmented waveband absorbance model was proposed considering solar cell selective absorption in the PV module. • Segmented absorbance data corresponding to different wavebands were calculated based on simplified standard solar spectrum of IEC. • Temperature accuracy using segmented waveband absorbance model were improved compared with single absorbance used before. • The modification of three-waveband absorbance model was a better choice considering both calculation and solar absorption. [ABSTRACT FROM AUTHOR]

Abstract Quaternary stannite semiconductor Cu 2 FeSnS 4 (CFTS), which is an ideal material for solar photovoltaic cells, has attracted widespread attention. CFTS crystals have been successfully synthesized by the co-electrochemical deposition method. The structure, morphology, and composition of as-synthesized samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), respectively. From the results, it was found that the properties of the sample can be improved by tuning the Cu2+ concentration in the electrolyte, and the best sample was obtained with the Cu2+ concentration of 0.01 M. For the best sample, the CFTS thin films have single phase and good crystallinity with even particle size. By the addition of ascorbic acid, an effective way has been found to enhance the Fe content in the sample, and the reason for the Fe-poor phenomenon has also been explored. Highlights • Cu 2 FeSnS 4 (CFTS) thin films have been successfully synthesized by the co-electrochemical deposition method. • The best sample of CFTS was obtained with the Cu2+ concentration of 0.01 M. • For the best sample, the CFTS thin films has optimal band gap, single phase and good crystallinity with even particle size. • Found an effective way to enhance the Fe content in the sample by the addition of ascorbic acid. [ABSTRACT FROM AUTHOR]

Abstract A novel treatment technology of microwave catalytic oxidation degradation (MCOD) for nitrophenols (NPs) wastewater over green catalysts of g C 3 N 4 Bi 2 O 2 CO 3 and SiC Bi 2 O 2 CO 3 was developed. This process is eco-friendly because the only used Bi 2 O 2 CO 3 is non-toxic (which can be used as stomach medicine), and no heavy metal pollution exists in g-C 3 N 4 and SiC. The results show that these Bi 2 O 2 CO 3 based composites exhibited superior catalytic activity for the degradation of para -NP, as well as ortho -NP, with optimal removal ratio of 98.96%. In addition, the proportion of Bi 2 O 2 CO 3 and irradiation time were the key parameters that had greatly influenced the degradation performance. Moreover, O 2 − was confirmed to be primary contributor for the degradation, which was different from our previous work that OH was the main specie in carbon loaded metal oxide system. That is to say, the type of oxidative specie may be controlled by the type of catalyst system. Besides, separation and transfer efficiency of the charge carriers could be enhanced by the heterojunctions fabricated in the band structures of the composites. This work not only demonstrated that the Bi 2 O 2 CO 3 based composites coupled with MW irradiation can generate reactive oxidative species(ROS) which can degrade NPs high-effectively, but also developed a new and green idea for treating refractory industrial wastewater. Graphical abstract Image 1 Highlights • Green and secure Bi 2 O 2 CO 3 based composites were found to be superior MW catalysts. • High NPs and TOC removal ratios achieved without adding extra oxidants. • O 2 − generated by MW excited e− and h+ was the primary oxidative specie. • Heterojunction was introduced in the band structure of the synthesized catalysts. • Possible microwave catalytic mechanism over the catalysts was revealed. [ABSTRACT FROM AUTHOR]

Highlights • Multi-physics model for electrical, thermal based on FEM method is proposed. • The model is validated and calibrated on one real experiment study. • Simulation research is done on PVT modules from a new perspective of temperature distribution. • Temperature distribution is most strongly dependent on tube spacing. Abstract The issue of temperature distribution is significant in the research of PV/T collectors due to the inherent negative temperature characteristics of solar cells. In this paper, a three-dimensional thermal model of a water-cooled flat-panel PV/T collector with serpentine tube is established using the finite element method, which the simulation accuracy is verified by the experimental data. We investigate the effect of multiple factors on the temperature distribution, including tube spacing, absorber materials, inlet velocity and tube row arrangement, respectively. Our results show that reducing tube spacing is the most effective way to increase uniformity of temperature distribution, and using absorber materials with better thermal properties can improve the temperature distribution partly. However, increasing the fluid inlet velocity has little effect on establishing a uniform temperature field though it can reduce the plate temperature. Temperature is hardly affected by the tube row arrangement, and uniform temperature field cannot be obtained with more bends. [ABSTRACT FROM AUTHOR]

Abstract: Dysfunction of osteoblastic bone formation and matrix mineralization plays a key role in the pathological development of osteoporosis. The orexin peptide orexin‐A, a highly excitatory neuropeptide hormone, possesses various biological functions by activating its specific G protein‐coupled receptors, orexin‐1 receptor (OX1R) and orexin‐2 receptor (OX2R). Here, we report that OX1R but not OX2R was expressed in MC3T3‐E1 cells. Importantly, we found that orexin‐A accelerated osteoblast differentiation and matrix mineralization in MC3T3‐E1 cells, as manifested by elevation of physiological markers of osteoblastic differentiation [alkaline phosphatase (ALP) and osteogenic genes] and Alizarin Red staining, respectively. Importantly, our findings indicated that orexin‐A significantly increased the expression of runt‐related transcription factor 2 (Runx‐2), which is the central transcriptional factor. Orexin‐A treatment phosphorylated the kinase p38 mitogen‐activated protein kinase (MAPK) in a dose‐ and time‐dependent manner. Also, orexin‐induced increase in gene expression (Runx‐2, ALP, osteocalcin, and osterix) and matrix mineralization were prevented by the p38 MAPK specific inhibitor SB203580. Additionally, we also revealed that protein kinase D (PKD) is involved in the effects of Orexin‐A on p38 MAPK activation and Runx‐2 expression. Finally, we found that Orexin‐A‐induced osteoblastic formation and matrix mineralization and the activation of the PKD/p38 MAPK pathway are mediated by OX1R. Based on these findings, we concluded that activation of OX1R by orexin‐A might possess a therapeutic strategy for bone disease. © 2018 IUBMB Life, 70(7):633–641, 2018 [ABSTRACT FROM AUTHOR]

The junction temperature of LED (light emitting diode) has a significant impact on its performance and lifetime. In this paper, a simplified model based on the finite element analysis is developed to simulate the temperature distribution of the 200 W LED module using software ANSYS. The model contains LED package, the heat pipe radiator, as well as TIM (thermal interface material) between the LED package and radiator. The temperature distribution of the simulation agrees with that of the experimental measurement. Thickness of TIM affects the heat dissipation significantly, the chips temperature and the maximum temperature difference of chips increases sharply with TIM thickness increasing. Substituting aluminum fins with copper fins cannot improve the heat dissipation performance of heat pipe radiator, and the air velocity of heat pipe radiator plays a key role in the heat dissipation. Thermal conductivity of package submount directly affects the chip temperature and the uniformity of temperature distribution of package submount. [ABSTRACT FROM AUTHOR]

Microwave catalytic oxidation degradation (MCOD) process over microwave (MW) catalyst of pristine bismuth oxide (Bi 2 O 3 ) was developed to high-efficiently treat p-nitrophenol (PNP) polluted water. The facile prepared catalyst was characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and nitrogen adsorption. The major influencing parameters were investigated and the results showed that the degradation efficiency and the TOC removal ratio reached up to 99.74% and 94.20% respectively in the absence of extra oxidants or air bubbling under the optimal conditions. The PNP degradation efficiency of the seventh round still highly reached 97.80%. Furthermore, the reaction kinetics were studied which were accorded well with pseudo-first-order model and the rate constant was 0.883 min −1 . Moreover, the existence of hydroxyl radical ( OH) was confirmed by the fluorescent probe technique. The mechanism of the MCOD process was that the Bi 2 O 3 could be excited to generate electron–hole pairs by MW irradiation, then the H 2 O absorbed on the surface of the catalyst could be transformed into OH due to the holes. This work provides a clear demonstration that the MCOD method can high-efficiently degrade PNP and develops new MW catalytic pathways for the treatment of wastewater containing refractory organic contaminants. [ABSTRACT FROM AUTHOR]

TeO 2 –Bi 2 O 3 –ZnO–Li 2 O–MgO lead-free glass was synthesized based on the consideration of environmental protection and the demand for further conversion efficiency improvement. Reactivity of Bi 2 O 3 powder with SiN x and Si as well as lead-free glass with SiN x and Si was investigated using differential thermal analysis. DSC curves show that Bi 2 O 3 doesn't react with SiN x or Si under 800 °C, whereas lead-free glass can react with SiN x and Si at approximately 600 °C indicating early softening and melting of glass facilitates the reaction between Bi 2 O 3 and SiN x or Si. The flowing behavior of lead-free glass at varied temperatures was studied and the morphology of the interface between the glass and the silicon wafer was examined. The white particles formed above silicon were identified as Bi–Te alloy or BiTeO x through stoichiometrically calculating. However, their formation was suppressed by the addition of silver powder. Ag crystallites and Ag particles start to generate on the interface, as the content of silver powder was increased to 8 wt%. These Ag particles and Ag crystallites were observed on the interface in the finished solar cell. • TeO 2 -based lead-free glass could replace leaded glass in silicon solar cells. • Bi–Te alloy or bismuth tellurite forms at the glass/Si wafer interface. • Addition of silver powder suppresses forming of Bi–Te alloy or bismuth tellurite. • Ag crystallites and Ag particles generate as more silver powder is added. • Ag crystallites and the glass layer play a decisive role in the contact formation. [ABSTRACT FROM AUTHOR]

A significant microwave selective effect on oxygen inhibition removal was found for NO decomposition through microwave catalysis over BaMnxMg1−xO3 catalysts. Especially, the NO conversion and N2 selectivity were up to 99.8% and 99.9%, respectively for the BaMn0.9Mg0.1O3 catalyst even with the coexistence of 10% oxygen and low temperature of 250 °C. [ABSTRACT FROM AUTHOR]

Cu 2 FeSnS 4 (CFTS) nanoparticles were synthesized by a liquid reflux method with a mixed solvent of triethylenetetramine-ethylene glycol(1:1.5, v/v) under the atmospheric pressure condition. Structure, morphology, composition and optical properties of as-synthesized samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer(EDS) and ultraviolet–visible absorption spectrophotometer (UV–vis), respectively. The results show that the CFTS nanoparticles have single phase, good crystallinity and fairly close to the stoichiometric ratio. Moreover, the size of primary CFTS nanoparticles is about 25.0 nm, and the nanoparticles are aggregated with size ranging from 100–300 nm. And their band gaps are 1.32 eV which is suitable for solar cell absorption material. [ABSTRACT FROM AUTHOR]

The direct catalytic decomposition of NO into N2 and O2 with high activity and N2 selectivity at low temperature under excess oxygen is a challenge. Herein, we report a new approach for the direct decomposition of NO into N2 and O2 by microwave catalysis over MeO x-Cu-ZSM-5 (Me=Mn, Ni) under excess oxygen. We observed that the microwave direct catalytic decomposition of NO over MeO x-Cu-ZSM-5 under excess oxygen is highly efficient, and the NO conversions are 94.3 % over MnO2-Cu-ZSM-5 at 300 °C and 92.3 % over Ni2O3-Cu-ZSM-5 at 350 °C. Meanwhile, the N2 selectivity remains more than 98 %. Importantly, the apparent activation energies of MnO2-Cu-ZSM-5 and Ni2O3-Cu-ZSM-5 are as low as 15.5 and 25.7 kJ mol−1, which suggests a significant microwave catalytic effect. Furthermore, microwave irradiation exhibits a microwave selective effect. The oxygen concentration has almost no influence on the activity of catalytic decomposition of NO over MeO x-Cu-ZSM-5 under microwave irradiation. [ABSTRACT FROM AUTHOR]

A three-dimension thermal model of typical polycrystalline photovoltaic (PV) module was performed in finite element software. Based on the model, the temperature distribution of the cell layer and module’s thickness direction were analyzed and simulated. The effects of environmental conditions such as solar irradiance, wind speed, ambient temperature and adjacent cell interval on the temperature distribution of PV module were investigated. The temperature distribution curves showed that the solar cell layer possessed the highest temperature of 331.76 K near the solar cell center. The increasing of adjacent solar cell interval decreased PV module temperature. Wider adjacent cell interval is recommended considering the electrical power output of PV module. The results also showed that higher solar irradiance is helpful for the heat dissipation of PV module but results in higher temperature. The effect of wind speed on PV module is obvious when it increases from 0 to 1 m/s and higher wind speed is helpful for the improving of PV module electrical efficiency. Lower ambient temperature is helpful for both the heat dissipation and the improving of PV module electrical efficiency, and this effect was obvious especially under high solar irradiance and low wind speed. [ABSTRACT FROM AUTHOR]

Using the density functional theory of first-principles calculations and the CASTEP module in Material Studio 5, the calculations of the structural and optical properties of the β-Si 12− n C n N 16 ( n =0, 4, 6, 8, 12) crystals were performed. The results show that the lattice constants a , c and cell volume of the silicon carbonitride crystals become smaller, while their a/c ratio is essentially unchanged when Si atoms are continually replaced by C atoms, and these confirm they maintain isotropic shrinkage in the lattice a and c direction. The band structures of the β-Si 12− n C n N 16 ( n =4, 6, 8) crystals are closer to β-Si 12 N 16 rather than β-C 12 N 16 . The β-Si 12 N 16 structure allows highest light transmission while the β-C 12 N 16 structure allows lowest light transmission, and there is no significant difference among the light transmission for the other three structures. The absorption peaks moves to shorter wavelength side with more C replacing Si of the β-Si 12 N 16 structure. [ABSTRACT FROM AUTHOR]

Cu 2 FeSnSe 4 (CFTSe) microparticles were successfully synthesized by an atmospheric pressure liquid reflux method in triethylenetetramine for the first time. The structure of prepared CFTSe microparticles was characterized by X-ray diffraction (XRD) and Raman spectra. The results clearly showed that the synthesized CFTSe microparticles had a single-phase stannite structure. The morphology and chemical composition of CFTSe microparticles were confirmed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The ratio of Cu/Fe/Sn/Se was about 2.00:0.88:1.02:4.29. Moreover, the prepared products with the size of 0.4–0.6 µm were spherical. Ultraviolet-visible spectrophotometry (UV–vis) analysis showed that the energy band gap was 1.47 eV. It indicated that the synthesized CFTSe microparticles were suitable for solar cell applications as absorption material. [ABSTRACT FROM AUTHOR]

Abstract: Cyclohexane oxidation using molecular oxygen as oxidant is one of the most challenge subjects. A novel photocatalytic reduction method to prepare Gold nanoparticles Au@TiO2/MCM-41 was proposed. The prepared samples were characterized by XRD, N2 adsorption isotherm, FT-IR, TEM and EDS. The results showed that gold nanoparticles were well-dispersed on TiO2/MCM-41, and TiO2 was dispersed on the surface of the support and the gold existed as Au0. Newly-developed catalyst was promising for the cyclohexane oxidation, achieving a turnover frequency (TOF) as high as 29,145h−1 with 9.87% conversion of cyclohexane. [Copyright &y& Elsevier]

For 13.56 MHz large-area capacitively coupled plasma (CCP) discharges, the increase of plasma enhanced chemical vapor deposition (PECVD) chamber radius to 500 mm is likely to exacerbate the impact of edge effect. In this paper, based on COMSOL Multiphysics, a two-dimensional fluid model combined with the full set of Maxwell's equations is developed and validated. Simulation results indicate that the existence of the edge effect destroys the radial plasma uniformity of large-area discharges. The decrease of the RF voltage amplitude or chamber pressure causes an improvement in plasma radial uniformity, but the plasma density reduces. Only by adjusting the process parameters, the optimization of plasma uniformity degree is not obvious and the edge effect cannot be eliminated. Furthermore, the chamber structure has a significant influence on plasma uniformity. And enlarging the electrode gap or extending the grounded electrode length could help to obtain a uniform deposition by impairing the edge effect. The experiment results show that the film uniformity is improved by optimizing. The results obtained in this work could play a useful role in weakening the edge effect and raising the plasma uniformity of large-area CCP discharge. • A Large-area capacitively coupled PECVD discharge model is established based on COMSOL Multiphysics. • We demonstrated the edge effect impact on plasma distributions in PECVD. • RF voltage amplitude, chamber pressure, electrode gap, and lower electrode length influenced plasma uniformity. • The chamber structure has more impact on the edge effect and the influences on edge effect are obtained. [ABSTRACT FROM AUTHOR]

TS-1 has been synthesized from an inorganic reactant system using Ti(SO4)2 as the titanium source, TPABr as the templating agent, and ammonia as the base to provide the alkalinity needed for crystallization. The effects of preparation parameters, such as titanium sources, crystallization temperature and time, SiO2/TiO2, TPABr/SiO2, ammonia/SiO2 and seed crystals on the physicochemical and catalytic properties of TS-1 were investigated in detail. The TS-1 samples were characterized by XRD, FT-IR, UV–vis, SEM, and ICP-AES, and the catalytic performance of TS-1 was evaluated in the epoxidation of allyl chloride. The results show that the catalytic performance of TS-1 synthesized using Ti(SO4)2 was excellent, and the crystal size of the catalyst was small. The synthesis conditions had a great influence on the properties of TS-1. The optimum synthesis conditions for the present system should employ a gel composition of SiO2/TiO2/NH3/TPABr/H2O = 1:0.022:2.5:0.15:35 and carry out the crystallization at 443 K for 3 days; the addition of seed in the synthesis gel played an important role in the crystallization of TS-1. Moreover, the stability and reusability of TS-1 prepared from this system was fine. [ABSTRACT FROM AUTHOR]

Abstract: A fluorinated polyimide (PI) was synthesized by a two-step reaction from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride and 2,2′-bis(trifluoromethyl)-4,4′diaminobiphenyl. A series of PI composites with various mass fractions of multi-walled carbon nanotubes (MWNTs) were prepared by either an in situ polymerization or blending process. To increase the chemical compatibility of carbon nanotubes with the PI matrix, MWNTs were treated with an acid mixture and sulfoxide chloride by turns. Results show that the dispersion of the MWNTs is highly improved in the PI by modification. The modified MWNTs are dispersed homogeneously in the matrix, while the structures of the PI and MWNTs are stable in the preparation process. The thermal stability of the nanocomposites is slightly lower than that of the pure PI. With incorporating MWNTs, the storage modulus and glass transition temperature of the composite films enhanced comparing to that of PI matrix. The dielectric constants of the composites increase sharply, which is favorable to their practical use in anti-static materials and embedded capacitors. [Copyright &y& Elsevier]

Silicon oxycarbide (SiCO) thin films were prepared by the RF reactive sputtering technique on n-type silicon substrates with the target of sintered silicon carbide (SiC), and high purity oxygen was used as the reactant gas. The as-deposited films were annealed at temperatures of 600°C, 800°C, and 1000°C under nitrogen ambient, respectively. The films were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and photoluminescence (PL) spectrophotometer. The results show that annealing temperature plays an important role in the structure and photoluminescence of the films. The temperature 600°C is the most favorable annealing temperature for SiO2 crystallization and the formation of 6H-SiC crystal phase in the SiCO films. The intense PL peaks located at 375 nm and 470 nm are observed at room temperature. The origin of the PL was discussed. [ABSTRACT FROM AUTHOR]

SiCO thin-films doped with aluminum (Al) prepared by alternate deposition of SiC and Al thin layers using Ar and O2 as sputtering gas were deposited on n-Si substrates. The as-deposited thin-films were annealed under 600°C in nitrogen ambient. The thin-films have been characterized by atomic force microscopy, energy dispersive spectrometer, X-ray diffraction, fourier transform infrared spectroscopy, and photoluminescence spectra. The results showed that the introduction of Al promotes the formation of Si-C bonds, but hinders amorphous SiC to further transform to crystalline SiC. The doped Al would react with SiOx in the thin-films to form more Si particles which strongly affect the optical properties. After Al doped, there presented a seven times of enhancement emission band centered around 412 nm, which is ascribed to nanostructure Si-related defect centers embedded in the SiCO thin-films. The obtained results are expected to have important applications in modern optoelectronic devices. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 thin films were deposited by DC reactive magnetron sputtering. Some TiO2 thin films samples were annealed for 5min at different temperatures from 300 to 900°C. The structure and optical properties of the films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM) and ultraviolet–visible (UV–vis) spectrophotometry, respectively. The influence of the annealing temperature on the structure and optical properties of the films was investigated. The results show that the as-deposited TiO2 thin films are mixtures of anatase and rutile phases, and possess the column-like crystallite texture. With the annealing temperature increasing, the refractive index and extinction coefficient increase. When the annealing temperature is lower than 900°C, the anatase phase is the dominant crystalline phase; the weight fraction of the rutile phase does not increase significantly during annealing process. As the annealing temperature rises to 900°C, the rutile phase with the large extinction coefficient becomes the dominant crystalline phase, and the columnar structure disappears. The films annealed at 300°C have the best optical properties for the antireflection coatings, whose refractive index and extinction coefficient are 2.42 and 8×10−4 (at 550nm), respectively. [Copyright &y& Elsevier]

Abstract: Silicon carbonitride (SiCN) thin films were deposited on n-type Si (100) and glass substrates by reactive magnetron sputtering of a polycrystalline silicon target in a mixture of argon (Ar), nitrogen (N2) and acetylene (C2H2). The properties of the films were characterized by scanning electron microscope with an energy dispersive spectrometer, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometry and ultraviolet-visible spectrophotometer. The results show that the C2H2 flow rate plays an important role in the composition, structural and optical properties of the films. The films have an even surface and an amorphous structure. With the increase of C2H2 flow rate, the C content gradually increases while Si and N contents have a tendency to decrease in the SiCN films, and the optical band gap of the films monotonically decreases. The main bonds are Si–O, N–H n , C–C, C–N, Si–N, Si–C and Si–H in the SiCN films while the chemical bonding network of Si–O, C–C, C–O, C–N, N–Si and Ced in the surface of the SiCN films. [ABSTRACT FROM AUTHOR]

Abstract: Silicon carbonitride (SiCN) films were prepared by means of reactive magnetron sputtering of a sintered SiC target on n-type Si (1 0 0) substrates in the reactant gas of nitrogen, and then the films were respectively annealed at 600, 800 and 1100°C for 5min in nitrogen ambient. The films were characterized by energy dispersive spectrometer, X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence (PL) spectrophotometry. Intense PL peaks at 370, 400 and 440nm were observed at room temperature. The results show that annealing temperature and composition play an important role in the structures and PL properties of the films. The annealing temperature of 600°C favors the formation of the SiC (1 0 9) crystal in the SiCN films, and results in a maximal PL peak. The intensity of the 440nm PL peak can be improved by increasing the abundance of the Si–C bond. [ABSTRACT FROM AUTHOR]

Ta-Si-N thin films and Cu/Ta-Si-N thin films were deposited on p-type Si (111) substrates by magnetron reactive sputtering. Then the films were characterized by four-point probe sheet resistance measurement, atomic force microscopy, X-ray diffraction method and scanning electron microscope, respectively. The experimental results show that the sheet resistance of Ta-Si-N thin film increases with N content. And the surface roughness of the thin film first decreases and then increases with N content. By increasing the N content, the diffusion barrier property of Ta-Si-N thin film can be improved; however, this improvement is not evident when N content beyond 56%. The as-deposited Ta-Si thin film is nano-crystalline. When doped with N, the as-deposited thin film becomes amorphous. The crystallization of Ta-Si-N thin film occurs again at high temperature. Cu atoms diffuse through grain boundaries of Ta-Si-N thin film into Si, and this leads to failure of the diffusion barrier. [ABSTRACT FROM AUTHOR]

Abstract: Many attempts have been made to increase the efficiency of solar cells by introducing a deep impurity level in the semiconductor band gap. Since Tl may be the most suitable impurity for crystalline Si solar cells, the impurity photovoltaic (IPV) effect in silicon solar cell doped with thallium as impurity was investigated by the numerical solar cell simulator SCAPS. Results show that the IPV effect of thallium extends the spectral sensitivity in the sub-band gap range from 1000 to about 1400nm. When the Tl concentration (N t ) is lower than the base doping density (N D ), the short-circuit current density and efficiency increase with increasing N t . But they decrease rapidly as the impurity density exceeds the shallow base doping density (N t >N D ). The optimum Tl concentration is about equal to the base doping density. For the Si solar cells with high internal reflection coefficients, the IPV effect becomes appreciable (ΔJ sc≈9mA/cm2 and Δη≈2%). [ABSTRACT FROM AUTHOR]

Abstract: The red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae) is a widespread pest that lives in, and feeds on, wheat flour. Here, we studied the effects of low-intensity microwave radiation (LIMR; ≤2.0kW/kg) on physiological and biochemical characteristics of T. castaneum, and compared them to the effects of heat conduction treatment, to provide a theoretical basis for using LIMR for pest control. Lethal model equations with respect to temperature were shown to provide acceptable fitting accuracy for the effects of LIMR treatment. Semi-lethal and lethal temperatures induced through LIMR (48°C and 50°C, respectively) for T. castaneum were lower than those induced through heat conduction (50°C and 52°C). When T. castaneum were subjected to LIMR, the insects’ moisture content, pH values, alkaline phosphatase and acetyl cholinesterase activity were all lower than when the insects were subjected to heat conduction. Peroxide values and total free amino acid content were higher, and protein subunits molecular weights were lower when T. castaneum were exposed to LIMR than to heat; moreover, after LIMR exposure, the amino acid composition of T. castaneum was changed and the insect''s DNA was damaged. [Copyright &y& Elsevier]

Abstract: The silicon carbonitride (SiCN) films were deposited on n-type Si (100) and glass substrates by the radiofrequency (RF) reactive magnetron sputtering of polycrystalline silicon target under mixed reactive gases of acetylene and nitrogen. The films have been characterized by energy dispersive spectrometer (EDS), atomic force microscope (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible spectrophotometer (UVS). The influence of RF power on the compositional, morphological, structural and optical properties of the SiCN films was investigated. The SiCN films deposited at room temperature are amorphous, and the C, Si and O compositions except N in the films are sensitive to the RF power. The surface roughness and optical band gap decrease as the RF power increases. The main bonds in the SiCN films are C–N, N–H n , C–H n , C–C, C013;H and Si–C, and the intensities of the C013;H and C–H n bonds increase with increment of the RF power. The mechanisms of the influence of RF power on the characteristics of the films are discussed in detail. [Copyright &y& Elsevier]

To investigate the effects of glass frits in aluminum paste on the formation of back surface field (BSF), two kinds of aluminum paste with different glass frits were prepared, and two sets of multi-crystalline silicon solar cell were produced by applying those two aluminum pastes under the same process condition. The composition of glass frits and the morphology of dried aluminum pastes and the solar cell cross sections were investigated. The photoelectric properties and bowing deformation of the solar cell were also explored. The results showed that glass frits rich in lead and barium could markedly promote the formation of BSF due to the intensification of Al-Si mutual diffusion. The mechanism could be attributed to the enhanced utilization rate of aluminum powders. The glass frits with optimized content would reduce the warping degree of solar cells and keep the conversion efficiency unchanged at the same time. [ABSTRACT FROM AUTHOR]

Ta2O5 thin films were deposited at different oxygen flow ratio (O2/(O2+Ar) = 10 ~ 80%) by DC reactive magnetron sputtering. Influence of oxygen flow ratio on depositing rate, surface characteristics, microstructure, and optical properties are discussed in this paper. With the increasing of oxygen, deposition rate decreases exponentially, the root mean square roughness and the maximum roughness decrease according to the atom force microscope images. XRD patterns indicate the as-deposited Ta2O5 films are amorphous. Based on the envelop method, the samples' optical constants are calculated from the curve of transmission spectrum. The results indicate that refractive index n increases from 2.01 to 2.20 (λ = 500 nm) for the oxygen flow ratio increases from 20% to 60%, the extinction coefficient k appears to decrease. [ABSTRACT FROM AUTHOR]

Ni–Al intermetallic compounds nanocrystalline thin films were deposited by direct current magnetron co-sputtering from elemental Ni and Al targets. The integrity of the thin films and their elemental compositions were assessed using a scanning electron microscope (SEM) equipped with an energy dispersive spectroscope analyzer. The morphologies of thin alloy films are density and smoothing characterized by atomic force microscope and SEM. The preferred (111) orientation in both as-deposited and annealed films are identified using X-ray diffractometer (XRD). The electrical properties of the alloy films were studied, and show good metallic conduction characteristics. From room temperature to 200°C, the resistance of the thin films are assumed to be linear as a function of varying temperature. All the thin films show a positive temperature coefficient of resistance (TCR). As 1% O2 was introduced into the vacuum chamber during sputtering, the root mean square roughness of the films increased, grain size turned out to be smaller, and the crystallization process was blocked. The amorphous Al2O3 phase was found in XRD patterns. The results of TCR measurement show a different electric conduction mechanism compared with alloy films. [ABSTRACT FROM AUTHOR]

By controlling the sputtering power, rotational speed of the substrate and sputtering time, Ni–Cr thin films with appropriate composition were fabricated by double-target magnetron co-sputtering techniques. The homogeneity and oxidation of Ni–Cr thin film has been studied by Auger electron spectroscopy (AES). The structures of Ni–Cr thin films were determined by an X-ray diffractometer (XRD). The oxidation and the resistance stability of the Ni–Cr thin film after rapid thermal process (RTP) have been studied. The relations between TCR and RTP techniques of Ni–Cr thin films were discussed. [ABSTRACT FROM AUTHOR]

The electromechanical properties of nichrome (Ni–Cr 80/20 wt.%) used as a common material for application in thin film strain gauges have been studied. The surface topography and chemical composition of Ni–Cr thin films grown on the glass substrate by magnetron sputtering have been analyzed by atomic force microscope (AFM) and energy dispersive spectroscopy (EDS), respectively. The temperature coefficient of resistance (TCR) has been determined by a Nano-volt/Micro ohm meter. The gauge factor (FG) has been determined by the cantilever method. Low stable TCR values (22 ppm to 46 ppm in the 50–150°C temperature range) have been obtained. Resistance stability is achieved by rapid thermal annealing (RTA) at 300°C for 10 min combined with a 24 h thermal annealing (TA) at 150°C. The desired 45 Ω/m sheet resistance and a gauge factor of 2.6 have been attained for 40-nm-thickness films. The films have very small roughness of 2.1~4.4 nm. [ABSTRACT FROM AUTHOR]

By controlling the sputtering power, rotated speed of substrate and sputtering time, Ni–Cr films with appropriate composition were fabricated by double-target magnetron co-sputtering techniques. The cross-sectional micrograph and element diffusion of Ni–Cr films deposited on stainless steel substrates by magnetron sputtering have been analyzed by scanning electron microscope (SEM) and energy dispersive spectroscope (EDS). The results indicate that the according compositions of Ni–Cr films are 58 wt.% Ni and 42 wt.% Cr when the sputtering powers of Ni and Cr targets are 288 W and 280 W, respectively. In the same time, the diffusions of Ni, Fe and Cr were revealed and the diffusion distances of Ni and Cr are calculated by Fick's second law with a Pile-Up law model. The largest diffusion distance is about 885 nm, beyond which the content of Ni and Cr detected by EDS is the same as the substrate. [ABSTRACT FROM AUTHOR]

A powder extrusion moulding (PEM) process based on a novel binder system, and a 92 wt.% tungsten carbide +8 wt.% cobalt composite powder as a test material, are described. The binder system is comprised of major fraction of a mixture of low molecular weight components (LMWCs) and a minor fraction of very finely dispersed polymer. The feedstocks are mixed as a thick slurry at a suitable temperature and are rapidly homogenized by stirring at an adequate shear force. The binders are removed by thermal debinding. The thermal debinding mechanism has been investigated by thermogravimetry (TG) and differential thermogravimetry (DTG). In the first stage of debinding, the LMWCs are removed. These open up pore channels which allows much faster removal of the remaining polymer component during the subsequent stage. The microstructures of the moulded green parts are observed by SEM. The debinded samples are sintered or sinter/HIPed at different temperatures. The properties of the sintered samples are measured. [Copyright &y& Elsevier]

Abstract: Cu2ZnSnSe4(CZTSe) microparticles were successfully synthesized by the one-step solution-chemical method in a novel solvent triethylenetramine under the open-air condition. The characterization of its phase constituents, morphology, structure and optical properties were done using powder X-ray diffraction(XRD), Raman spectra, Scanning electron microscope(SEM), Energy Dispersive Spectrometer(EDS) and ultraviolet–visible (UV–vis) spectrophotometry, respectively. The X-ray diffraction and Raman pattern showed that the CZTSe microparticles had single phase with a stannite structure. Moreover, the prepared products showed the morphology of microparticles with size ranging from 2000–4000nm. The composition of the CZTSe microparticles was basically corresponds with the theoretical value. The observed band gap of 1.44eV matched well with the bulk CZTSe material which made them promising candidates as absorber materials for photovoltaic applications. [Copyright &y& Elsevier]

The direct decomposition of hydrogen sulfide into hydrogen and sulfur has attracted plenty of attention due to its capability of recovering hydrogen and sulfur from a hazardous waste gas simultaneously. Nevertheless, it remains a tough challenge to achieve the direct decomposition of hydrogen sulfide at high conversion. In this work, we report the highly effective direct decomposition of hydrogen sulfide by microwave catalysis over the CoNi 2 S 4 /CNTs and CoMoS 3.13 /CNTs composite microwave catalysts. CoMoS 3.13 /CNTs exhibits excellent catalytic activity under microwave irradiation. The best H 2 S conversion of CoNi 2 S 4 /CNTs and CoMoS 3.13 /CNTs are respectively up to 58.15% and 71.77% at 750 °C under microwave irradiation, which far exceed the corresponding equilibrium conversion under conventional heating mode. Moreover, the apparent activation energies of CoNi 2 S 4 /CNTs and CoMoS 3.13 /CNTs are reduced to 17.88 and 15.83 kJ/mol, respectively, indicating an excellent microwave selective catalytic effect. Our finding is believed to provide a novel method to achieve direct H 2 S decomposition reaction. [ABSTRACT FROM AUTHOR]