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3D bicontinuous nanoporous copper (NPC) with tunable structure was facilely synthesized by one-step chemical dealloying of Ti-Cu amorphous alloys with minor Co addition (0, 4 and 6 at.%). As-dealloyed NPC shows a sandwich-like hierarchical porous structure with micropore in the inner layer and mesopore in the outer layer. The pore size of NPC can be adjusted by the Co content and corrosion time. In addition, the minor Co element in the matrix alloy can promote the formation of more uniform pore and ligament of NPC, which was evaluated by the surface diffusivity of NPC. The formation mechanism of NPC was discussed using phase separation theory. The NPC/Cu2O composite consists of a large number of 3D continuous ligaments and few tetrahedral Cu2O particles grown on the NPC substrate. As catalysts, NPC/Cu2O composite exhibits excellent degradation performance for methyl orange (MO) dye in the dark assisted by the ultrasonic irradiation due to hierarchical porous structure and the synergistic effect of Cu ligaments and Cu2O particles. The relationship between the efficient MO degradation rate of NPC/Cu2O catalysts and temperature has been discussed. Fenton-like reaction shows that NPC/Cu2O catalysts supplemented with hydrogen peroxide (H2O2) can generate HO· radicals, which resolve MO dye molecules into H2O, CO2 and inorganic species.

Shedding light on the dynamics of charge transfer is fundamental and important to understand the light-photocurrent power conversion in transition-metal dichalcogenide (TMD) heterostructures. Herein, based on time-dependent ab initio nonadiabatic molecular dynamics simulation, we studied the photoinduced carrier transfer dynamics in the WS2/WSe2 heterostructure and further analyzed the effects of stacking configuration and temperature. Our calculations show that the time scales of ultrafast hole transfer in the C7 and T stacking configurations are 35 fs and 30 fs, respectively, which are mainly caused by the adiabatic charge transfer mechanism. Meanwhile, the time scales of ultrafast electron transfer in the C7 and T stacking configurations are 12 fs and 40 fs, respectively, which are in good agreement with the experimental result. We also investigated in detail the photoinduced carrier transfer pathways of C7 and T stacking configurations, which appear to have some significant differences. In addition, we found that the temperature basically has no effect on the electron transfer dynamics of the WS2/WSe2 heterostructure; this is in excellent agreement with the experimental observation. In short, the reported findings can provide more in-depth insights into the photoinduced carrier transfer dynamics of TMD-based van der Waals heterostructures.

Three-dimensional bicontinuous nanoporous copper (NPC) with a pore size of 10–60 nm was fabricated by dealloying titanium–copper–cobalt amorphous ribbons in 0.23 M hydrofluoric acid (HF) solution for 1–12 h. It is found that dealloyed ribbons show sandwich-like layered structure in the cross-section and the pore size in the outer layer is larger than that in the core layer. The NPC ribbons, polarised in 1 M potassium hydroxide (KOH) solution for 30 min, delivered an excellent electrochemical performance with a specific capacitance of 202.3 mF/cm2 at the current density of 5 mA/cm2 in 1 M KOH electrolyte and good cycling stability of 90% capacitance retention after 5000 cycles at 20 mA/cm2.

Metal-organic frameworks (MOFs) derived porous carbons are promising electrode materials in electrochemical energy conversion and storage systems. However, the typical synthetic route of MOFs involving high temperature, organic solvent, massive energy consuming, and laboratory-scale production, hinders the realistic applications of MOFs serving as sacrificial templates for porous carbon. Herein, we demonstrate that highly crystalline MIL-100 (Fe) nanoparticles (MIL: Materials of Institute Lavoisier) can be synthesized in large scale with low cost under mild and green conditions. High-temperature pyrolysis of MIL-100(Fe) under argon atmosphere results in hollow carbon polyhedra (HCPs) featuring high degree of graphitization and hierarchical pore structures. The obtained HCPs are excellent electrode materials for electric double-layer capacitors (EDLCs), and show a specific capacitance of 214 F g−1 at current density 50 mA g−1. Moreover, the HCP-based supercapacitors can endure more than 5000 cycles without significant degradation of capacitance. The unique structure of HCPs, including hollow polyhedral shape, hierarchical micro/mesopore structures, and ultrathin layer of highly graphitized carbon shells, endows the superior performance of HCPs based EDLCs with specific capacitance and high rate capability.

Amino functionalized surfaces were selectively modified via the combination of a wet agarose stamping technique and microcontact printing technique. Because of the specific reaction environments and diffusion of HNO2 confined in agarose stamp, the reaction of amino groups in the edge of the strip pattern was much more intense than other areas. The modified amino groups in the edge areas show higher affinity to Au-NPs than other areas, consequently, edge enriched Au-NPs patterns were observed after the self-assembly of Au-NPs. A “cylindrical droplet” model, in a manner analogous to “coffee-ring” effect, was proposed to describe the diffusion of HNO2 from the bulk to the edge in agarose stamp. By using such density varied Au-NPs patterns as templates for the growth of ZnO nanorods, we observed high density of Au-NPs resulting in high density and highly (0 0 1) oriented ZnO nanorods. In contrast, sparse and non-oriented ZnO nanorods were grew on low density of Au-NPs areas. Our findings might open new routes for the fabrication of gradient patterns and extend applications of Au-NPs patterns in surface enhanced Raman scattering and catalysis.

Lithium ion capacitors (LIC), which can bridge the gap between lithium ion batteries and supercapacitors by combining the merits of the two systems, are thus considered as some of the most promising energy storage devices. However, the imbalances in specific capacity, high-rate behavior, and cycling lifespan between the two electrodes make it a challenge to develop LICs with high energy density at high power density output along with long cycle life. Herein, a LIC consisting of a three-dimensional carbon modified LTSO (3DC@LTSO) anode and a lignin-derived activated carbon (LDAC) cathode is designed and fabricated. These two electrode materials with desirable electrochemical properties will much favorably offset the imbalances between the two electrodes. Moreover, a novel electrode-matching strategic approach, which will further offset the imbalance between the two electrodes, is developed. Thereby, the assembled LDAC//3DC@LTSO LIC cell shows a high energy density of 115.3 W h kg−1 at 163.5 W kg−1 and a high power density of 6560 W kg−1 at 60 W h kg−1, coupled with an excellent cycling lifespan of 90% capacity retention after 6000 cycles at a current density of 2.0 A g−1. These combined results are impressive in terms of obtaining high energy density and long cycling lifespan LICs.

This paper introduces measurement of weak magnetic field using a novel design of chip-scale Spin Exchange Relaxation Free (SERF) atomic magnetometer based on a microfabricated Rubidium (Rb) vapor cell. The sensor, which integrates a micro-fabricated Rb vapor cell, a heater and related components, is fabricated by stacking printed circuit boards (PCB) and Micro Electro Mechanical Systems (MEMS) process technology. During the experiments, the noise of the measurement using the atomic magnetometer was obtained. In addition, a test of the simulated magnetic field was performed in a shielding cylinder, and the signal of the simulated magnetic field about 100 pT at 1.2 Hz was measured. The signal is processed by the software using a notch filter to suppress the Direct Current (DC) noise and 50Hz noise. This paper provides a novel micro-fabricated device for detecting weak magnetic field.

Chinese solar greenhouses are unique facility agriculture buildings and widely used in northeastern China, providing a favorable requirement for crop growth. The north wall configurations play an essential role in heat storage and thermal insulation and directly affect the management of the internal environment. This research is devoted to further improve the thermal performance of the greenhouse and explore the potential of the north wall. A mathematical model was designed to investigate the concave-convex wall configurations based on computational fluid dynamics. Four passive heat-storage north walls were analyzed by using the same constituent materials, including a plane wall, a vertical wall, a horizontal wall and an alveolate wall. The numerical model was validated by experimental measurements. The temperature distributions of the north walls were examined and a comparative analysis of the heat storage-release capabilities was carried out. The results showed that the heat-storage capacity of the north wall is affected by the surface structure. Moreover, the critical factor influencing the air temperature is the sum of the heat load released by the wall and the energy increment of greenhouse air. The results suggested that the alveolate wall has preferable thermal accumulation capacity. The concave-convex wall configurations have a wider range of heat transfer performance along the thickness direction, while the plane wall has a superior thermal environment. This study provides a basic theoretical reference to rationally design the internal surface structures of the north wall.

We report the spatial beam self-cleaning in bi-tapered conventional multimode fibers (MMFs) with different tapered lengths. Through the introduction of the bi-tapered structure in MMFs, the input beam with poor beam quality from a high-power fiber laser can be converted to a centered, bell-shaped beam in a short length, due to the strengthened nonlinear modes coupling. It is found that the bi-tapered MMF with longer tapered length at the same waist diameter shows better beam self-cleaning effect and larger spectral broadening. The obtained results offer a new method to improve the beam quality of high-power laser at low cost. Furthermore, it may be interesting for manufacturing bi-tapered MMF-based devices to obtain the quasi-fundamental mode beam in spatiotemporal mode-locked fiber lasers.

A series of poly(e-caprolactone)- b -poly( n -butyl acrylate)- b -polystyrene (PCL- b -P n BA- b -PS) triblock terpolymers with fixed PCL and P n BA block lengths but different PS block lengths were prepared. In all of these triblock terpolymers the P n BA block can be competitively dissolved in both the PCL and PS phases to form bi-phase structures in the melt, as revealed by atomic force microscopy (AFM). Due to the “competitive dissolution effect” of the P n BA middle block, the microphase separation and crystallization behaviors of these triblock terpolymers are different from those of common diblock copolymers to some extent. As revealed by the Flory-Huggins parameters, more P n BA segments tend to dissolved in the PS phase. Therefore, the volume fraction of the PS-rich phase ( f PS-rich ) is evidently larger than the calculated volume fraction of the PS block ( f PS ), and the phase boundaries between two different structures shift to lower f PS . There also exists a thick interphase layer between the PS-rich and PCL-rich phases due to competitive dissolution of the P n BA block. However, confined crystallization can only occur at a larger f PS-rich , though the measured glass transition temperature ( T g ) is high for the PS block. This can be attributed to a high fraction of the soft zone surrounding the PCL-rich phase and the lower volume fraction of the hard zone.

In the present work, crystallization-driven coassembly of micrometric polymer single crystals and nanometric block copolymer micelles was achieved. The hybrid single crystals are first formed by cocrystallization of polyethylene (PE) homopolymer and polyethylene-b-poly(tert-butyl acrylate) (PE-b-PtBA) block copolymer (BCP) in DMF or DMF/o-xylene mixed solvent. The morphology of the obtained hybrid single crystals can be regulated via changing the solvent composition, crystallization temperature and mass ratio of BCP/homopolymer. Because of the difference in crystallization rate, the distribution of PE-b-PtBA BCP in the hybrid single crystals may be inhomogeneous, leading to a concave gradient surface structure. The hybrid single crystals have a double-layer structure, in which PE homopolymer chains adopt extended conformation and the PE blocks in PE-b-PtBA are probably once-folded. After the PE homopolymer is consumed, cylindrical micelles of PE-b-PtBA can further epitaxially grow on the lateral surface o...

Weak gradient magnetic field detection is significant. This paper presents a novel micro-fabricated spin-exchange-relaxation-free (SERF) atomic magnetometer for weak gradient magnetic field detection, and the atomic vapor cell is fabricated by micro electro mechanical systems (MEMS) technology. Compared to the single-channel magnetometer, the novel magnetometer's signal-to-noise ratio has increased by 3.63 times. The magnetic field gradient noise of the novel magnetometer reaches 45.33 fToHz-1/2ocm-1 in the frequency range of 8 to 15 Hz, and the novel magnetometer has a CMRR (common mode rejection ratio) of 6.1. At the same time, the relationship between the magnitude of the magnetic field gradient and the peak of the dispersive signal has been verified, which provides an idea for the detection of weak gradient magnetic field.

Metal–organic frameworks (MOFs) featuring multiple catalytic units are excellent platforms for heterogeneous catalysis. However, the synergism between multiple catalytic units for catalysis is far from being well understood. Herein, we reported the synthesis of a robust 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) radical-functionalized Zr-MOF (UiO-68-TEMPO) in the form of single-crystalline and microsized crystals with varied missing linker defects. Detailed catalytic studies and theoretical calculations reveal that the synergistic effect between the TEMPO radicals and hydrophilic and defective Zr-nodes endows UiO-68-TEMPO with superior catalytic activity toward aerobic oxidation of alcohols. Our work not only offers a new route to design and synthesize highly effective MOF catalysts but also provides insights into the synergism between multiple catalytic sites.

Layer-by-layer integration of two-dimensional atomically thin materials provides an effective approach to the customized engineering of heteromaterials. Herein, first-principle calculations are employed to investigate the geometrical configurations and the electronic characteristics of 1T-XN2(X = S, Se, Te)/hBN van der Waals heterostructures (vdWHs). Our results demonstrate that the SN2/hBN vdWH possesses an obviously type-I band alignment. Whereas the 1T-XN2(X = Se, Te)/hBN vdWHs have a desired type-II band alignment, which may facilitate the spontaneous photogenerated electron-hole charge separation. The strain-induced semiconductor–metal transition can be realized in all the heterostructures. An intriguing type-II to type-I band alignment and indirect-direct bandgap transition takes place in 1T-TeN2/hBN under strain effect, which is a result of the different response behaviors of band-edge states with strain. The band alignment transition can be explained by the analysis of wave function topologies of band-edge states. The interlayer-coupling-tunable bandgap of 1T-XN2(X = S, Se)/hBN can also be found, and all the vdWHs always maintain their intrinsic band alignment type with the interlayer coupling effect. Overall, these findings will provide an avenue for applications of 1T-XN2(X = S, Se, Te)/hBN heterostructures in future electronic and optoelectronic devices, and strain engineering strategy can be utilized to regulate the carrier separation of the vdWHs.

Flower-like CuS/NiS microspheres grown on nanoporous copper were successfully prepared through dealloying Ti-Cu-Ni amorphous ribbons in H2SO4 solution. Each microsphere is composed of many nanosheets with thickness of 17–52 nm and its main composition is CuS. We also found the formation of nanosheets highly depended on the concentration of H2SO4 solution during dealloying and as its concentration reached to 15 M, flower-like microsphere clusters consisting of nanosheets can be obtained. Concentration-dependent and time-dependent formation mechanism of flower-like microsphere were discussed in this work. Its formation can be divided into three steps: nucleation and growth of nanoporous copper, precipitation of transition sulfide Cu2S and, nucleation and growth of flower-like CuS/NiS microsphere. Flower-like microsphere clusters were used as supercapacitor electrode material, which exhibit good electrochemical performance. Its specific capacitance can reach 122 F/g at current density of 1A/g and 95% capacitance retention can be maintained after 5000 cycles at 10 A/g. The high performance is due to its large specific surface area provided by the coexisting micro and nano pores.

Fe73.5Cu1Nb3Si15.5B7 nanocrystalline powder cores with different particle sizes ranging from 10 to 125 µm were fabricated by cold-pressing techniques. The cores exhibited increased core loss Pcv and decreased initial permeability µi with addition of fine powders below 50 µm in size, and the content should be less than 40 mass%. It was thought to be closely related to the high coercive force Hc due to the stresses generated during the crushing process and high demagnetization fields of small powders. Furthermore, modifying the alloy compositions by adding defined amount of Ni could improve the soft magnetic properties, including superior characteristics of permeability under high direct current (DC) bias field and comparable low core loss at high frequency.

(CoxNi1−x)0.85Se nanostructures (NSs) with different shapes (i.e., sheet-like, flower-like, and urchin-like) were synthesized by a sacrificial template method. As far as we know, this paper may be the first work that used (CoxNi1−x)0.85Se NSs as catalysts for reduction of 4-nitrophenol (4-NP) by NaBH4 in aqueous solution.

The reliable detection of composite material is dramatically important with its wide application in the aerospace industry. A new post-processing mode of ultrasonic array inspection, entitled total focusing method(TFM), offers significant advantages including high sensitivity and greater inspection coverage. Based on this mode, a wave velocity correction method for the elastic anisotropic of composites is put forward. Subsequently, practical application is carried out to image and locate the defect in a composite laminate sample to demonstrate the advantage of the described method. The results show that the proposed method can effectively improve the ability to detect and evaluate defects in composite laminates.

The FeSiBC amorphous powder cores were fabricated using powders of the FeSiBC amorphous ribbons which were mechanically crushed for a short time, and the relationship between magnetic properties and powder particle sizes was evaluated. The saturation magnetization Bs of the amorphous Fe82Si2B15C1 alloy was 1.62 T, which provided a superior dc-bias property for the powder cores. Meanwhile, a stable permeability up to high frequency range over 10 MHz and the low core loss of 400 kW/m3 at f = 50 kHz and Bm = 0.1 T were obtained. These excellent high-frequency magnetic properties of the FeSiBC amorphous powder cores could be attributed to the effective electrical insulation between the FeSiBC amorphous powders made by mechanical crushing.

Key parameters for thermomechanical control process (TMCP) and integrated welding operations have been determined to industrialize extra high strength micro-alloyed low carbon SiMnCrMoNiCu steel plates for bridge applications. Confocal Scanning Microscope was used to make In-situ observation on austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate transformation behavior of the TMCP conditioned austenite. Integrated industrial rolling trial was conducted to correlate the laboratory observations and commercial production of the plates. Microstructure factors affecting the toughness of the steel were analyzed. Submerged-Arc Welding (SMAW) trails were conducted and the structures and mechanical properties of the weld joints characterized. The representative plate with thickness of 60 mm consisted of acicular ferrite (AF) + refined polygonal ferrite (PF) + granular bainite (GB) across the entire thickness section exhibit yield strength (YS) greater than 560 MPa in transverse direction and excellent Charpy V Notch (CVN) impact toughness greater than 100 J at-40 °C in the parent metal and the weld joints. These provide useful integrated database for producing advanced high strength steel plates via TMCP. Keywords: Thermo-Mechanical Control Process;Weathering Steel Plate for Bridge; Submerged-Arc Welding without Preheating

Toroidal shape FeCuNbSiB nanocrystalline alloy powder cores were prepared by cold pressing using mechanically crushed and ball-milled powders, respectively. The morphologies and their effects on the magnetic properties of the compacted cores were investigated. Compared with ball-milled powders, mechanically crushed ones have more regular shapes and rounder edges, which lead to better inter-particle insulation. FeCuNbSiB nanocrystalline alloy powder cores fabricated from mechanically crushed powders exhibit remarkably lower core loss of about 248. 2 kW/m3 at 100 kHz for maximum flux density Bm=0. 1 T, and more stable permeability up to 10 MHz. Moreover, the dc-bias property could be improved significantly using mechanically crushed powders.

In this reported work Ni-riched NiO-Co3O4 sheet-like nanocomposites (SNCs) were obtained through a facile solvothermal method in a mixed solvent and subsequently calcinated in air. Galvanostatic charge-discharge measurement revealed that the Ni-riched NiO-Co3O4 SNCs electrode has an impressive specific capacitance as high as 836 F g−1 at 4 A g−1 in 3 M KOH solution. The as-obtained Ni-riched NiO-Co3O4 SNCs product showed a weak cycling stability, but the higher capacitance (424 F g−1) was retained after 1000 cycles at 4 A g−1.

In this paper, based on finite element (FE) software MSC.Marc, a multi-field coupled FE model is established to investigate the 18-pass hot rolling process of GCr15 steel rod. Thermal, mechanical and microstructural phenomena during the rolling process are coupled in the model. In this model, the microstructure evolution of GCr15 Steel is described by some empirical equations which are obtained using the Gleeble-3800 thermomechanical simulator, and a MSC.Marc subprogram is designed to predict the evolution of recrystallization behavior and austenite grain size. With the aid of the model, the paper analyzes detailedly the distribution and evolution of microscopic field-variables in rolled piece during the whole rolling process of GCr15 steel rod. Predicted values of grain size show good agreement with measured ones. The current model is beneficial to understand the effect of recrystallization behavior and control the microstructure evolution during hot rod rolling process.

During the inertia friction welding (IFW) process of superalloy GH4169, the main mechanism for microstructural evolution is dynamic recrystallization (DRX). In order to investigate the microstructural evolution during the process, a finite element (FE) model coupled with the DRX model of the alloy was developed on the platform of MSC.Marc. Equivalent strain was introduced into the DRX model to improve the computational precision. As a result, the IFW process with microstructural evolution was simulated. Simulated results reveal that DRX region is very small. Fully recrystallized region and fine grains appear near the weld line. Dynamically recrystallized fraction (DRXF) decreases and grain size increases with the increase of the distance from the weld line. Predicted results of microstructural distribution agree well with experimental ones.

In this paper, four 3-D finite element models are developed to simulate the whole rod rolling process of GCr15 steel. The distribution and evolution of different field-variables, such as effective strain, effective strain rate and temperature, are obtained. Based on the simulated results and the microstructure evolution models of the steel, the paper designs a FORTRAN program to predict the evolution of recrystallization behavior and austenite grain size in rolled piece during the rolling. The surface temperatures of rolled piece calculated by FEM agree well with measured values. Comparison between calculated values and measured ones of grain size shows the validity of the program.

Impurity segregation at grain boundary (GB) can significantly affect the mechanical behaviors of polycrystalline metal. The effect of nickel impurity segregated at Cu GB on the deformation mechanism relating to loading direction is comprehensively studied by atomic simulation. The atomic structures and shear responses of Cu Σ9(114) 110 and Σ9(221) 110 symmetrical tilt grain boundary with different quantities of nickel segregation are analyzed. The results show that multiple accommodative evolutions involving GB gliding, GB shear-coupling migration, and dislocation gliding can be at play, where for the shear of Σ9(114) 110 the segregated GBs tend to maintain their initial configurations and a segregated GB with a higher impurity concentration is more inclined to be a dislocation emission source while maintaining the high mechanical strength undergone plastic deformation for the shear of Σ9(221) 110. It is found that the nickel segregated GB exerts a cohesion enhancement effect on Cu under deformation: strong nickel segregation increases the work of separation of GB, which is proved by the first-principles calculations.

The objective of this study is to develop a set of mathematical models which can predict the austenite grain size of GCr15 steel in hot working process. The models can describe the evolution of grain size during dynamic recrystallization (DRX), metadynamic recrystallization (MDRX), static recrystallization (SRX), and grain growth process after recrystallization, respectively. The DRX behavior in GCr15 steel was investigated by the single hot compression tests, and the double compression tests with different inter-stage delay times were used to research the kinetics of MDRX and SRX. The tests were performed on the Gleeble-3800 thermo-mechanical simulation machine at temperature from 950 to 1150 °C, strain rate from 0.01 to 50 s −1 and initial austenite grain size from 26.3 to 90.0 μm. In addition, a set of specimens were heated to 950, 1050, 1100 and 1150 °C for 0–480 s to determine the grain growth model after recrystallization. The predicted results of grain size are in good agreement with the measured ones.

The growth behavior of austenite grains in GCr15 steel was investigated through the isothermal annealing tests of the steel under different heating temperatures and holding times. The tests were performed on a Gleeble-3800 thermo-mechanical simulation machine. Austenitizing temperatures 1223, 1323, 1373, and 1423 K were chosen, and holding time varied from 0 to 480 s. Experimental results suggest that austenite grains grow gradually with the increase of heating temperature, and holding time has an important effect on the growth of austenite grains. The time exponent for the growth is bigger at higher temperature, and the growth rate decreases with increasing time. On the basis of previous models and experimental results, a mathematical model that can describe the growth behavior of austenite grains in the tested steel under different heating temperatures and holding times was obtained using regression analysis. The predicted grain sizes by the model are in good agreement with measured ones.

The dynamical recrystallization (DRX) of GCr15 steel was investigated at deformation temperatures of 950–1150 °C and strain rates of 0.1–10 s −1 on a Gleeble-3800 thermo-mechanical simulator. The stress–strain curves at lower strain rates are typical of the occurrence of DRX and exhibit a peak in the flow stress before reaching steady state. The flow stress at higher strain rates increases rapidly to the maximum too, but followed by a steady region. The microstructures after deformation certify that DRX takes place in all specimens. And the results show that DRX occurs more easily with the decrease of strain rate and the increase of deformation temperature. Using regression analysis, the DRX activation energy of the steel, the relationship of critical strain and deformation conditions were determined. In order to determine the recrystallized fraction under different conditions, an approximate model based on the stress–strain curves was investigated, and the kinetic model for DRX was established.

The present study combined clodronate, one of bisphosphonates, to the surface of HA scaffold by chelation. The cell culture test and gene expression test were performed and evaluated the effect of clodronate modifying the HA on co-culturing osteoblast with HA scaffold in vitro. Characteristic peaks in XPS and FT-IR spectra indicated clodronate being immobilized on the surface of HA. The cell culture test indicated that the cells actively proliferated on the scaffolds. The results of RT-PCR showed there was no significant difference between two groups in expression of RANKL gene, while the expression of OPG gene showed higher expression in Clodronate-HA group. Clodronate had no obvious effect on the cytocompatibility of HA, and Clodronate-HA might be used as bone scaffold with potential ability to improve osteogenesis.

The hot deformation behaviors of GCr15 bearing steel were investigated by isothermal compression tests, performed on a Gleeble-3800 thermal-mechanical simulator at temperatures between 950 °C and 1 150 °C and strain rates between 0.1 and 10 s−1. The peak stress and peak strain as functions of processing parameters were obtained. The dependence of peak stress on strain rate and temperature obeys a hyperbolic sine equation with a Zener-Hollomon parameter. By regression analysis, in the temperature range of 950−1 150 °C and strain rate range of 0.1−10 s−1, the mean activation energy and the stress exponent were determined to be 351 kJ/mol and 4.728, respectively. Meanwhile, models of flow stress and dynamic recrystallization (DRX) grain size were also established. The model predictions show good agreement with experimental results.

In this paper, we use the a-plane InGaN interlayer to improve the property of a-plane GaN. Based on the a-InGaN interlayer, a template exhibits that a regular, porous structure, which acts as a compliant effect, can be obtained to release the strain caused by the lattice and thermal mismatch between a-GaN and r-sapphire. We find that the thickness of InGaN has a great influence on the growth of a-GaN. The surface morphology and crystalline quality both are first improved and then deteriorated with increasing the thickness of the InGaN interlayer. When the InGaN thickness exceeds a critical point, the a-GaN epilayer peels off in the process of cooling down to room temperature. This is an attractive way of lifting off a-GaN films from the sapphire substrate.