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The hydrogen absorbed on the first wall of the tokamak device will desorbed during the experiment. This additional hydrogen makes plasma density increase so that the plasma density cannot be controlled at experimental setting value. In this paper, in order to remove the adsorbed hydrogen on the first wall of the vacuum chamber as much as possible before the formal experiment, we measured the desorption rate of hydrogen in helium Taylor discharge cleaning and helium Taylor discharge cleaning with baking. Experimental results show that the use of helium Taylor discharge cleaning on J-TEXT can effectively remove hydrogen in the main vacuum chamber. The next experiments of adjusting the discharge cleaning parameters were carried out to measure the desorption rate change of hydrogen. And the best Taylor discharge cleaning parameters were determined according to the highest hydrogen desorption rate.

Sb2S3-based bulk/nano planar heterojunction (BnPHJ) films are promising photoelectric conversion materials for photovoltaics. Here, a solution-processing polymer/graphene composite film is employed as hole transporting layer in Sb2S3/TiO2-BnPHJ solar cells for the first time. The morphology and hole mobility of the composite film is investigated by SEM, AFM, SCLC techniques, and IMVS and EIS are applied to study the charge transport and recombination mechanism in the solar cells. The Sb2S3/TiO2-BnPHJ solar cells delivers a power conversion efficiency of 5.72% and a good stability.

The damage localization of rocks is an open issue in rock engineering. Moreover, it is difficult to observe directly the micro-scale process of damage localization and damage evolution of rocks. Therefore, in this paper, the General Particle Dynamic method (GPD) is developed to simulate the damage localization and failure process of 3D rock samples. The effect of the intermediate principal stress on the strength, the stress-strain curve and the damage localization modes of a cubical rock specimen subjected to the true triaxial compressive loads is investigated. The different failure modes including the single shear damage localization mode, axial splitting damage mode, X-shaped conjugate shear damage localization mode and Cone-shaped damage localization are found. It is found that the numerical results obtained from GPD are in good agreement with experimental observations. It is implied that the formation of damage localization band induced by the initiation and propagation and coalescence of micro-cracks in rocks can be well simulated using GPD.

In2S3 is a promising electron transporting material for solar cells. In this paper, In2S3 nanosheet arrays are grown on TiO2 films by a facile molecular precursor solution method for the first time. The composition, morphology and chemical valance states of the In2S3 nanosheet arrays are investigated by XRD, SEM, TEM and XPS techniques. Upon the in situ growth of CuInS2 nanoparticles into the In2S3 nanosheet arrays, the novel CuInS2 bulk heterojunction solar cells are obtained with a peak power conversion efficiency of 2.58% depending on the In2S3 nanosheet array height.

In this work, an extended finite element method with partial Heaviside function enrichment (XFEM-P) in the crack tip element is proposed for fracture analysis for the first time. In this method, the crack tip element is divided into cracked and uncracked domains naturally by the crack geometry. In the cracked domain, Heaviside function enrichment is employed to simulate the crack discontinuity across the crack surface. In the uncracked domain, the displacement from standard finite element method is employed. Ramp function is used to ensure the displacement continuity in the method. Through this way, the crack tip can be arbitrarily located inside the crack tip element, which is a great advantage over traditional counterpart, i.e., XFEM with only Heaviside function enrichment (XFEM-H). Thus the mesh work for the XFEM-P is much easier than that of the XFEM-H, resulting in great conveniences for crack propagation. The new method is applied to several examples. From the computed results, it is observed that the XFEM-P offers more accurate results than the XFEM-H in terms of strain energy and SIFs. The XFEM-P performs better than XFEM-H in numerical properties such as convergence rate and condition number.

In this paper, magnetic and magnetocaloric properties of RCrO 4 (R=Gd and Er) oxides have been investigated. It is found that GdCrO 4 and ErCrO 4 exhibit a second-order magnetic transition from ferromagnetic to paramagnetic states at their Curie temperatures of 22.0 K and 14.9 K, respectively. The maximal magnetic entropy change (Δ S M ) for a field variation of 0–5 T have reached 22.8 J kg −1 K −1 for GdCrO 4 and 20.5 J kg −1 K −1 for ErCrO 4 . The collective magnetic contributions from R 3+ and Cr 5+ ions lead to the large Δ S M . For the same field variation, table-like Δ S M of ~19.5 J kg −1 K −1 and a large refrigerant capacity ( RC ) of 117 J kg −1 have been achieved for the composite material formed by GdCrO 4 and ErCrO 4 with the mass ratio of 1:1 from 16.0 K to 22.0 K. Since the liquid hydrogen temperature (20.3 K) locates within this range, large reversible magnetocaloric effect, high RC as well as the low cost make GdCrO 4 –ErCrO 4 composite material a potential candidate for magnetic refrigerant for the storage of liquid hydrogen.

The structure, magnetic properties and magnetocaloric effects of perovskite manganese oxides La1.4Ca1.6Mn2O7 and La1.3Eu0.1Sr0.05Ca1.55Mn2O7 have been investigated. They undergo a first-order ferromagnetic–paramagnetic phase transition around their respective Curie temperatures (235 K and 215 K, respectively). The doping of Eu and Sr atoms enhances greatly the value of magnetization, which leads to the large magnetocaloric effect. For a field change of 0–5 T, the maximum value of magnetic entropy change is only 4.5 J/kg K for La1.4Ca1.6Mn2O7 compound. However, it increases to 7.1 J/kg K for La1.3Eu0.1Sr0.05Ca1.55Mn2O7 compound. Meanwhile, a large refrigerant capacity of 240.4 J/kg is also achieved. Large reversible magnetocaloric effect and refrigerant capacity indicate the potentiality of La1.3Eu0.1Sr0.05Ca1.55Mn2O7 compound as a candidate for magnetic refrigerant.

Ultrathin Parylene-N (PPXN) films were prepared by using a home-made Knudsen Cell (KC). The PPXN films were identified by infrared (IR) spectra. The morphology and insulativity of PPXN films were measured by atomic force microscope (AFM) and current density versus voltage ( j – V ) characteristics. Well controlled 1-nm-thick PPXN thin films were inserted at different locations in the N′-bis(naphthalene-1-yl)-N, N′-bis(phenyl) benzidine (NPB) layers of organic light emitting diodes (OLEDs) with the structure of ITO/NPB/tris (8-hydroxyquinolato) aluminum (Alq 3 )/LiF/Al. For an optimized PPXN inserted structure, current efficiency of 6.27 cd/A was achieved, 11% higher than the 5.64 cd/A of the control one with 1-nm-thick PPXN buffer inserted at the anode interface. The device current efficiency improvement is due to the electron blocking of PPXN buffers, and the current density variation of devices under operation was explained by tunneling barrier reduction.

Extreme ultraviolet (EUV) source with short wavelength of 13.5 nm sets a solid foundation for extreme ultraviolet lithography (EUVL) that will provide distinguishable limited line width of 30 nm below and enough depth of focus in lithographic process. On the basis of a new scheme of EUV source from three plasmas to be coupled in capillary discharge, the demonstrative setup of three plasmas EUVL source in capillary discharge has been built and tested. By experiment, it is found that the single plasma source just emits very little power of radiation, while three independent plasmas source outputs intense radiation when three anode electrodes are concurrently discharged to the corresponding cathode electrodes. However, it is impossible for three independent plasmas to be coupled in capillary tube without the effect of the additional laser-produced plasma (LPP). As for the next work such as the weak positional coupling, the input of the laser beam and the delay time between the concurrent discharge and the ignition of the laser, it is worthy of doing.

The effects of the surfactant sodium dodecyl sulfonate (SDS) on NiO–TiO 2 sols, xerogels and films have been studied. Xerogels and films with Ni concentration of 80 mol% have been prepared using sols containing 3, 6, 9 wt% of SDS added to nickel acetate tetrahydrate (Ni(CH 3 COO) 2 ·4H 2 O) and tetra- n -butyl titanate (TNBT) as precursors in a mixture of ethanol and n -butanol. The thermal analysis of dried xerogels has been measured by thermogravimetry (TG) and differential thermal analysis (DTA) in air up to 500 °C. The structural properties of xerogels sintered at 300 °C have been determined by XRD and the xerogels consist predominantly of bunsenite nanoparticles embedded in an amorphous TiO 2 phase. Single layers have been deposited by dip coating on FTO (fluorine doped tin oxide, SnO 2 :F) coated glasses and sintered at 300 °C. Their thickness is found to increase with the SDS amount while the roughness of the surface is reduced. The electrochromic properties of films deposited on FTO coated glasses have been studied in 1 M KOH aqueous electrolyte via cyclic voltammetry (CV), chronoamperometry (CA) and visible light transmission. The anodic and cathodic peaks in CV cycles and the charge intercalated during CA cycles increase with the SDS content. The transmission in the bleached and colored states as well as the change in optical density remain stable for the film prepared with 9 wt% SDS up to almost 18,000 CA cycles, a great improvement compared to films prepared without surfactant. The coloration efficiency of the film prepared with 9 wt% SDS is about 30 cm 2 /C, a value comparable to that obtained for pure NiO film.

The mechanical properties of both as-cast and as-extruded Zr-based metallic glass reinforced with tungsten composites with 33, 28, and 21 vol. % of metallic glass were investigated under quasi-static compression at strain rates from 10 −4 s −1 to 10 −1 s −1 . These two types of composites exhibited a strain rate sensitivity exponent that increased with the increase of the tungsten volume fraction. Compared to the composites with 33 and 21 vol. % of the metallic glass, the two types of composites with 28 vol. % of the metallic glass phase exhibited superior fracture energies. The in-situ compression test on the as-cast composites using high-energy synchrotron X-ray diffraction (HEXRD) revealed that the yield stress of the tungsten phase increased with a decrease in the metallic glass volume fraction. The as-cast composite with 28 vol. % of the metallic glass exhibited relatively great mechanical properties compared to the composites that contained 33 and 21 vol. % of the metallic glass. This result was attributed to the great coupling of the load distribution between the two phases and the high lattice strain in the tungsten phase.

A metal-plate monopole antenna for indoor digital television (DTV) signal coverage in the Ultra High Frequency (UHF) is presented. The proposed antenna is a planar metal-plate monopole with symmetrical bevels, which is easily fabricated by a single metal plate. Parametric study on the metal-plate parameters is conducted to achieve a return loss of 10 dB over the DTV band frequency range (470–860 MHz). The stability of the radiation pattern is also presented.

The uniaxial compressive responses of 3003 Al–Mn alloy upon strain rates ranging from 0.001/s to about 10 4 /s with initial temperatures from 77 K to 800 K were investigated. Instron servohydraulic testing machine and enhanced split Hopkinson bar facilities have been employed in such uniaxial compressive loading tests. The maximum true strain up to 80% has been achieved. The following observations have been obtained from the experimental results: 1) 3003 Al–Mn alloy presents remarkable ductility and plasticity at low temperatures and high strain rates; 2) its plastic flow stress strongly depends on the applied temperatures and strain rates; 3) the temperature history during deformation strongly affects the microstructure evolution within the material. Finally, paralleled with the systematic experimental investigations, a physically-based model was developed based on the mechanism of dislocation kinetics. The model predictions are compared with the experimental results, and a good agreement has been observed.

Surface plastic deformation form and residual stress distribution of nano-ceramics machined by ordinary grinding and two-dimensional ultrasonic grinding respectively were investigated. The obtained results show that machined surface residual stress in the two grinding modes is extrusion stress, and it decreased with the increasing of grinding depth. But the decrease of residual stress under two-dimensional ultrasonic grinding is less than that under normal grinding. In addition, under the same grinding parameters, the surface residual stress on two-dimensional ultrasonic vibration grinding is larger than that on ordinary grinding, and if other parameters unchanged, it is increased with the increase of wear particle granularity in the two grinding modes. It is produced by the reason that ductile regime of ceramic grinding become larger under ultrasonic grinding, so that material is still removed by plastic form at great depth. Plastic removal mode will produce greater surface extrusion stress, so with the increasing of grinding depth, the decreasing of residual stress under two-dimensional ultrasonic vibration grinding is less than that under the normal grinding. At the same time, the regular separating between wear particle and work piece improves the heat emission condition, which is also one of the reasons that the surface residual stress under two-dimensional ultrasonic grinding is larger than that under ordinary grinding.

PurposeThe purpose of this paper is to investigate a new approach for making a bio‐based adhesive from a new resource, rice bran (RB) adhesive.Design/methodology/approachRB solution was prepared and its pHs were adjusted to either 8.5‐9.0 or 10.0‐10.5. The solid content of slurry was controlled at ≈18 per cent and then gelatinised in a water bath shaker at 60°C for 2 h or at 100°C for 1 h. The bonding strength of RB adhesive was determined by testing the strength of three‐layer plywood. A differential scanning calorimeter (DSC) was used for detecting the reaction energy and curing temperature. According to the DSC analysis, hot pressing at three temperatures was performed to select the best bonding conditions. Then, a two level split‐plot design was used to determine the effects of gelatinisation and pH on the bonding strength of RB adhesive. Thus, the formulation of RB adhesive was optimised. In order to improve the water resistance of RB adhesive, toluene diisocyanate (TDI) was used as a cross linking agent.FindingsIn the study reported here, a RB adhesive was developed by alkaline modification. Very high pH was not necessary, when RB adhesive with pH 10.0‐10.5 was gelatinised at 100°C for 1 h, its bonding strength was significantly lower than pH 8.5‐9.0 gelatinised at 60°C for 2 h. Water resistance of RB adhesive improved significantly when TDI was added as a cross linking agent. Compared to pure RB adhesive, the RB‐TDI mixed adhesive started curing at a higher temperature. For RB adhesive curing, 130°C was a suitable hot pressing temperature.Research limitations/implicationsThough the RB adhesive developed had a good bonding strength, its water resistance and dark colour was not satisfactory, which risks discolour of light colour wood. Further study is needed to solve this problem.Practical implicationsThe approach provided a bio‐adhesive with good bonding strength, reasonable working life, and without formaldehyde emission. Based on further study, RB adhesive could be considered a promising alternate adhesive in many applications such as paper board bonding and plywood.Originality/valueIt provided a potential way to utilise by‐product of agriculture, RB as industrial raw material. This will do farmers a great favour. Meanwhile, the modified RB adhesive is promising to partly or completely replace urea formaldehyde resin that mainly used in wood industry, avoiding formaldehyde emission and reducing the dependence on petroleum products.

PurposeTo investigate a new approach for making soy‐based adhesive having appropriate properties for potential application in wood industry.Design/methodology/approachThree chemicals were used for modifying protein contained in soy flour. According to orthogonal experiment design, nine soy‐based adhesives were prepared. Shearing strength of plywood bonded with these adhesives was measured to evaluate the bonding strength of nine formulas. Based on statistic analysis, the main effect factor and an optimised formula were determined. Further investigation on the modification effect to protein molecule was conducted by Fourier Transform Infrared Spectroscopy. In order to facilitate practical application, the viscosity of optimum formula adhesive was measured to determine possible working life. Three additives were added to optimise formula for reducing mould growth.FindingsBased on soy‐flour mass, the best combination of lime milk, sodium hydroxide (NaOH) and sodium silicate was 10, 2, and 20 per cent, respectively. NaOH was considered the main effect factor on bonding strength, and sodium silicate was of the second importance. The viscosity of the optimised adhesive changed lightly in 2 h, and significantly increased from 2 to 4 h. However, it still could spread on veneer, which indicated a reasonable working life for practical application. Based on soy flour mass, when 0.5 per cent sodium benzoate or 25 per cent phenol formaldehyde was added, mould growth could be restrained after early stage.Research limitations/implicationsThough the studied soy‐based adhesive had a good bonding strength and comparative water resistance, its pH was a little too high, which may cause risks of discolour of light coloured wood. Further study is needed to solve this problem.Practical implicationsThe approach provided a bio‐adhesive with good bonding strength, comparative water resistance, reasonable working life, and without formaldehyde emission. Soy‐based adhesive is considered a promising alternate adhesive in wood industry and other applications because of the above mentioned advantages.Originality/valueIt provided a potential way to utilise by‐product of agriculture, soy‐flour, as industrial raw material. This will benefit farmers significantly. Meanwhile, the modified soy‐based adhesive is promising to partly or completely replace urea formaldehyde resin that are mainly used in wood industry, avoiding formaldehyde emission and reducing the dependence on petroleum products.

Magnetic and magnetocaloric properties of ErAlO3 single crystal were investigated. Magnetization of ErAlO3 shows obvious anisotropy when magnetic field is applied along the a, b and c axes, which leads to large anisotropic magnetic entropy change. In particular, large rotating field entropy change from the b to c axis within the bc plane is obtained and reaches 9.7 J/kg K at 14 K in a field of 5 T. This suggests the possibility of using ErAlO3 single crystal for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.

Chemical synthesis is a versatile technique for fabricating novel nanostructured materials. In the Rieke process, a metal salt is reduced by an alkali in a hydrocarbon solvent to form small, highly reactive particles. Synthesis at an elevated temperature (200/spl deg/C) increases the as-synthesized particle size and produces higher coercivities and remanence ratios than observed in similar syntheses at room temperature. The ratio of synthesis temperature to solvent boiling point appears to be an important parameter in both coercivity and oxidation resistance.

We demonstrated the 1.55 /spl mu/m light emission at room temperature from self-assembled InAs quantum dots embedded inside the GaNAs strain-compensating layer. InAs quantum dots have been capped with tensile strained GaNAs instead of InGaAs and GaAs to compensate the compressive strain formed due to InAs QDs to keep the total strain of the system minimum; as a result the PL peak of InAs QDs shifts towards longer wavelength depending on the N% in GaNAs. The wavelength of 1.55 /spl mu/m is the longest wavelength so far achieved in self-assembled quantum dots grown on GaAs substrates, which would be promising for application to light source in long-wavelength optical-fiber communication system.

The authors present a new concept of a hybrid reactor: using a Joint-European-Torus-like device which works in the sub-breakeven condition as a source of high-energy neutrons makes it possible to induce a blanket fission of depleted-uranium, solid breeding material, and helium cooling so that one can produce 100 kg of nuclear fuel (/sup 239/Pu) per year. High temperature will be maintained by external ICRF and ECRF heating. A steady-state plasma current will be driven by LHCD. The plasma density will be maintained by pellet injection ICRF can produce a high-energy tail in the ion distribution function and lead to significant enhancement of D-T reaction rate by 2-5 times so that one can obtain a neutron source strength of 1*10/sup 19/ n/s, enough for the requirement of the hybrid reactor. >

Two kinds of III-V-N related quantum structures grown on GaAs are proposed, which have the capability to emit in the 1.5 /spl mu/m wavelength range. GaAsNSe is a new quaternary with high residual electron concentrations. It is shown that GaAsNSe/GaAs superlattices, with structural optimisation, give bright luminescence around 1.5 /spl mu/m at room temperature. A second structure is InAs quantum dots (QDs) grown on [001] GaAs. Instead of a conventional GaAs capping layer, a GaNAs strain-compensating layer (SCL) is proposed to minimise net compressive strain induced by InAs QDs. The application of a GaNAs SCL to cap InAs QDs improves the homogeneity and optical quality of the InAs QDs by the compensation of net strain. It is shown that 1.5 /spl mu/m emission from InAs QDs is made possible by increasing the N composition in the GaNAs SCL.

GaNAs strain compensating layers have been used to obtain 1.5 /spl mu/m luminescence from InAs quantum dots, and this fundamental scheme was demonstrated with light emitting diodes operating at room temperature.