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Accurate control of the layer number of orderly stacked 2D polymers has been an unsettled challenge in self-assembly. Herein we describe the fabrication of a bilayer 2D supramolecular organic framework from a monolayer 2D supramolecular organic framework in water by utilizing the cooperative coordination of a rod-like bipyridine ligands to zinc porphyrin subunits of the monolayer network. The monolayer supramolecular framework is prepared from the co-assembly of an octacationic zinc porphyrin monomer and cucurbit[8]uril (CB[8]) in water through CB[8]-encapsulation-promoted dimerization of 4-phenylpyridiunium subunits that the zinc porphyrin monomer bear. The bilayer 2D supramolecular organic framework exhibits structural regularity in both solution and the solid state, which is characterized by synchrotron small-angle X-ray scattering and high-resolution transmission electron microscopic techniques. Atomic force microscopic imaging confirms that the bilayer character of the 2D supramolecular organic framework can be realized selectively on the micrometer scale.

The creep properties of FGH96 superalloy were studied in the temperature range of 650 °C to 750 °C and stress range of 690MPa to 897MPa. The results show that the creep life of the alloy decreased significantly with the increase of stress and temperature. However, the temperature produced more effects than that of stress. The most suitable service temperature and stress were also obtained based on the creep results. A physical model base on crystal-plasticity theory was established, but the simplification of the Helmholtz free energy and the activation volume might reduce the accuracy of strain rate prediction. Based on the results of creep at different stresses and temperatures, the Helmholtz free energy and the activation volume of steady-state creep were obtained, which would play a key role in creep life prediction.

Low cycle fatigue (LCF) properties of a powder metallurgy(PM) nickel base superalloy FGH720Li were systematically studied in this work, including smooth LCF and notched LCF tested at various temperatures and different stress. The relationship between the fatigue life and applied stress was analyzed both for smooth fatigue and notch fatigue tests. The effects of loading frequency and stress ratio on LCF behavior were also studied. As an important influencing factor of the fatigue life in powder metallurgy superalloy, the effect of inclusions on LCF life was also investigated. The results showed that the fatigue properties of FGH720Li alloy was excellent, when tested at the temperature of 450°C and applied stress of 1230MPa, the fatigue life could exceed 5×104 cycles. When tested at 650°C and 1150MPa, the average fatigue life was still beyond 2×105 cycles.

The oxidation behavior of FGH720Li(P/M Udimet720Li) superalloy was investigated under static atmosphere in temperature ranging from 600°C to 730°C. The oxidation kinetics, composition and morphology of the oxidation layers were characterized by means of isothermal oxidation tests, X-ray diffraction(XRD), scanning electron microscopy（SEM）and energy dispersive X-ray spectroscopy(EDS). The results showed that the oxidation kinetics curves of FGH720Li superalloy followed the parabolic law. The results of cross-sectional morphology and elemental distribution indicated that the oxidation layer could be divided into three parts：porous Cr2O3 outer layer, dense Cr2O3 medium layer and oxidation affected zone with nail-like Al2O3 inner layer. The oxidation process was primarily controlled by the diffusion of chromium and oxygen through the oxide scale.

This work presents a novel process to form SiNx films and process for membranes with excellent mechanical properties for micro-electro-mechanical systems application as well as integration as IR waveguide for photonic application. The SiNx films were fabricated in SiNgen apparatus which is a single wafer chamber equipment compared to conventional low pressure chemical vapor deposition furnace process. The films showed low stress, good mechanical properties, but the synthesis also eradicates the issues of particle contamination. Through optimizing of the growth parameters and post annealing profile, low stress (40 Mpa) SiNx film could be finally deposited when annealing temperature rose up to 1150 °C. The stress relaxation is a result of more Si nano-crystalline which was formed during annealing, according to the FTIR results. The mechanical properties, Young’s modulus and hardness, were 210 Gpa and 20 Gpa respectively. For the waveguide application, a stack of three layers, SiO2/SiNx/SiO2 was formed where the optimized layer thicknesses were used for minimum optical loss according to simulation feedback. After deposition of the first two layers in the stack, the samples were annealed in range of 900–1150 °C in order to release the stress. Chemical mechanical polish technique was applied to planarize the nitride layer prior to the oxide cladding layer. Such wafers can be used to bond to Si or Ge to manufacture advanced substrates.

the effects of solid solution temperature on microstructure and properties in extruded and forged FGH95 superalloys are studied in this work. The superalloys with different micrtstructures are prepared through solid solution heat treatment at different temperature, and the microstructures were analyzed by SEM and EBSD. The results show that following with the increase of solid solution temperature, the grain size increase and the amount of primary γ′-phase located at the grain boundary decrease. When the solid solution temperature is higher than the solvus, the primary γ′-phase disappear completely, and as a result, the grain size grow significantly. The orientation of the FGH95 superalloys would not be influenced by the solid solution temperature, but the amount of twins increases following with the increase of solid solution temperature. The tensile and creep property is also studied in this work, the results show that the sub-solid solution heat treatment is suitable for Extruded and Forged FGH95 superalloys.

Aiming at the construction of novel platform for efficient light harvesting, the precise synthesis of a new family of AIEgen-branched rotaxane dendrimers was successful realized from an AIEgen-functionalized [2]rotaxane through a controllable divergent approach. In the resultant AIE macromolecules, up to twenty-one AIEgens located at the tails of each branches, thus making them the first successful example of AIEgen-branched dendrimers. Attributed to the solvent-induced switching feature of the rotaxane branches, the integrated rotaxane dendrimers displayed interesting dynamic feature upon the aggregation-induced emission (AIE) process. Moreover, novel artificial light-harvesting systems were further constructed based on these AIEgen-branched rotaxane dendrimers, which revealed impressive generation-dependent photocatalytic performances for both photooxidation reaction and aerobic cross-dehydrogenative coupling (CDC) reaction.

The construction of circularly polarized luminescence (CPL) switches with multiple switchable emission states and high dissymmetry factors (glum ) has attracted increasing attention due to their broad applications in diverse fields such as the development of smart devices and sensors. Herein, a new family of AIE-active chiral [3]rotaxanes were designed and synthesized, from which a novel CPL switching system was successfully constructed. The switching process was realized through the controlled motions of the chiral pillar[5]arene macrocycles along the axle through the addition or removal of the acetate anions, which not only modulated the chirality information transfer but also tuned the aggregations of the integrated [3]rotaxanes, thus resulting in reversible transformations between two emission states with both high photoluminescence quantum yields (PLQYs) and high dissymmetry factors (glum ) values.

The precise operation of molecular motion for constructing complicated mechanically interlocked molecules has received considerable attention and is still an energetic field of supramolecular chemistry. Herein, we reported the construction of two tris[2]pseudorotaxanes metallacycles with acid–base controllable molecular motion through self-sorting strategy and host–guest interaction. Firstly, two hexagonal Pt(II) metallacycles M1 and M2 decorated with different host–guest recognition sites have been constructed via coordination-driven self-assembly strategy. The binding of metallacycles M1 and M2 with dibenzo-24-crown-8 (DB24C8) to form tris[2]pseudorotaxanes complexes TPRM1 and TPRM2 have been investigated. Furthermore, by taking advantage of the strong binding affinity between the protonated metallacycle M2 and DB24C8, the addition of trifluoroacetic acid (TFA) as a stimulus successfully induces an acid-activated motion switching of DB24C8 between the discrete metallacycles M1 and M2. This research not only affords a highly efficient way to construct stimuli-responsive smart supramolecular systems but also offers prospects for precisely control multicomponent cooperative motion.

Supramolecular cages/vesicles in biology display sophisticated structures and functions by utilizing a few types of protein subunit quasi-equivalently at distinct geometrical locations. However, synthetic supramolecular cages still lack comparable complexity to reach the high levels of functionality found in natural systems. Herein we report the self-assembly of giant pentagonal supramolecular prisms (molecular weight >50 kDa) with tetratopic pyridinyl subunits serving different geometrical roles within the structures, and their packing into a novel superstructure with unexpected three-fold rotational symmetry in a single two-dimensional layer of crystalline state. The formation of these complicated structures is controlled by both the predetermined angles of the ligands and the mismatched structural tensions created from the multi-layered geometry of the building blocks. Such a self-assembly strategy is extensively used by viruses to increase the volume and complexity of capsids and would provide a new approach to construct highly sophisticated supramolecular architectures.

In this study, cellulose and basalt fiber were introduced simultaneously to stone mastic asphalt (SMA) to investigate the effects of hybrid modification on performance improvement of asphalt mixture. The study consists of three parts. The first part investigated material properties of cellulose and basalt fiber, including microscope electrical scanning. The second part conducted a series of tests to evaluate the effects of different combinations of cellulose and basalt fiber on performance. With a total addition of fiber 0.4% by the weight of mixture, five different cellulose-basalt fiber ratios, 0 : 4, 1 : 3, 2 : 2, 3 : 1, and 4 : 0, were introduced to the asphalt mixtures. A series of tests including draindown, permanent deformation, low temperature bending, beam fatigue, and moisture damage resistance were conducted. In the final part, a benefit-cost ratio was designed to help determine the optimum cellulose-basalt fiber combination in the economic aspect. Results show that material properties of the two fibers are very different, including thermostability, modulus, surface, and microstructure, especially oil absorption. In general, all samples with fibers outperformed the control group in all the performance tests. Specifically, cellulose fiber improved draindown, ductility, and fatigue more significantly, whilst basalt fiber has more influence on improving permanent deformation, deflection strength, and stress sensitivity. Equal portion of cellulose and basalt fiber has the best moisture damage resistance. The mechanisms of the two fibers are different, resulting in different performance improvements on asphalt mixtures. Overall, an appropriate combination of the two fibers would produce paving materials with more balanced performance in an economical way.

surface plasmon resonance, which arises from collective oscillation of conduction band electrons induced by light radiations. Plasmon resonance can greatly modify the optical properties of nearby chromophores by enhancing their excitation efficiency, radiative and non-radiative decay rates [1, 2]. Aggregated metal NPs generally resulted in larger enhancement compared to monodispersed metal NPs [1, 3]. Our recent studies showed that aggregated metal NPs displayed significantly enhanced photo-thermal responses [4] and two-photon photoluminescence (2PPL) [1, 5-10]. Here I will present our recent effort on using single particle spectroscopy to investigated Plasmon enhanced optical responses. Published version

With the shortage of energy and the environmental problems becoming more and more serious, it has become one of the most urgent problems to find a new type of high specific energy. FeS2 has become ...

Thermal stabilities of microstructure and mechanical properties during long-term aging of 550°C/1500h, 650°C/1500h and 700°C/500h have been investigated on superalloy FGH95, in order to characterize the long-term properties of this alloy on service temperature. The results showed that the secondary and tertiary gamma-prime maintained good thermal stability at 550°C and 650°C with aging time up to 1500h. However, during 700°C aging for 500h, the secondary and tertiary γ′ both grew obviously, besides, the shape of secondary γ′ has turned from circular to square. The hardness, high-temperature tensile and creep residual strain had good stability at 550°C and 650°C with aging time up to 1500h. However, the creep residual strain apparently increased when the alloy aged at 700°C for 500h, which means that the FGH95 is suitable to be used for long time below 650°C, and short time at 700°C.

Two constitutive models, the modified Johnson-Cook model and the logarithm linear relation model based on empirical approach and data analysis, were presented to illustrate compressive deformation of magnesium alloys AZ80 under multiple loading directions and strain rates. The results of stress-strain curve analysis and sensitivity index analysis suggested that the stress held large fluctuations in loading direction of 90°. Model testing signified that the logarithm linear relation model was more proper than the modified Johnson-Cook model in view of relative mean square error and correlation coefficients. Moreover, numerical simulation building on established models also indicated that the logarithm linear model is more precise than the modified Johnson-Cook model.

Recently, water has been employed as a supportive agent for the preparation of multiple suppressing agents including aqueous film forming foams (AFFF), which is combined with different kinds of gases for its various applications. In this study, the water mist is chosen for the gas-suppressing agent such as carbon dioxide. Our work investigated the suppression effects of water droplets on the n-heptane pool fire, and its mixture with carbon dioxide, respectively. The size and frequency of droplets with their effect on temperature and suppression was compared to observe the difference in the suppression. Initially, it was found that the droplets having a larger droplet size were found to be more efficient as compared to the smaller droplets with respect to the heat release rate, temperature, and radiation. Afterwards, a mixture of water droplets and carbon dioxide was simultaneously discharged to compare the difference between these two suppressing agents. It was found that the synergistic effect of the mixture has higher advantages over the use of only water suppression. It helps reduce the hot gases that surround the pool fire and allows the water mist to travel efficiently towards the fuel. Both suppression mechanisms were set to similar initial parameters that lead to different outcomes.

This paper is focused on a new self-supporting inorganic membrane prepared by a one-time cast molding process with geopolymer paste. This new preparation method has the advantages of easy fabrication, free sintering and low cost compared with the conventional inorganic membrane preparation methods. This work explores the influence of the H 2 O/Na 2 O molar ratio on the strength and porous structure of the inorganic membrane. A linear relationship between the permeated water flux and the membrane thickness or operating pressure was observed after a filtration test. By optimizing processing parameters, this study obtained an inorganic membrane (with the H 2 O/Na 2 O molar ratio of 18) between the ultrafiltration membrane and the microfiltration membrane with a high compressive strength of 20 MPa, a pore size distribution of 20 to 100 nm, a rejection rate of 100% for nano-Al 2 O 3 particles and a permeated water flux of 185 kg/m 2 h when the operating pressure was 0.3 MPa and the membrane thickness was 5.0 mm. This membrane will be a good choice for the field of water treatment with membranes.

Mechanically interlocked molecules, such as catenanes, rotaxanes, and knots, have applications in information storage, switching devices, and chemical catalysis. Rotaxanes are dumbbell-shaped molecules that are threaded through a large ring, and the relative motion of the two components along each other can respond to external stimuli. Multiple rotaxane units can amplify responsiveness, and repetitively branched molecules--dendrimers--can serve as vehicles for assembly of many rotaxanes on single, monodisperse compounds. Here, we report the synthesis of higher-generation rotaxane dendrimers by a divergent approach. Linkages were introduced as spacer elements to reduce crowding and to facilitate rotaxane motion, even at the congested periphery of the compounds up to the fourth generation. The structures were characterized by 1D multinuclear ((1)H, (13)C, and (31)P) and 2D NMR spectroscopy, MALDI-TOF-MS, gel permeation chromatography (GPC), and microscopy-based methods including atomic force microscopy (AFM) and transmission electron microscopy (TEM). AFM and TEM studies of rotaxane dendrimers vs. model dendrimers show that the rotaxane units enhance the rigidity and reduce the tendency of these assemblies to collapse by self-folding. Surface functionalization of the dendrimers with ferrocenes as termini produced electrochemically active assemblies. The preparation of dendrimers with a well-defined topological structure, enhanced rigidity, and diverse functional groups opens previously unidentified avenues for the application of these materials in molecular electronics and materials science.

Oxidation behavior of FGH91 superalloy in air and the temperature range of 540 to 980 °C for period up to 100h has been studied. The results indicate that oxidation kinetics obeyed parabolic law, and the activation energy of oxidation was calculated to be 98.2 KJ/mol. The scales on the surface were determined by SEM, EDS and XRD, the results show that the oxidation scales were composed of three layers: the outer layer was composed of Cr2O3 layer with a small amount of TiO and NiCr2O4 spinel; the intermediate layer was made up of Al2O3 and matrix alloy; and a small amount of titanium-nitride disperse in the inner layer. Besides, γ’-free layer was formed under the oxidation scales due to the impoverishment of Al in this layer, which was induced by the formations of Al2O3.

A low specific on-resistance ( \(R_{{{\rm \mathrm{{\scriptstyle ON}},sp}}}\) ) silicon-on-insulator (SOI) p-channel LDMOS (pLDMOS) with an enhanced reduced surface field (RESURF) effect and self-shielding effect of the back-gate (BG) bias is proposed and investigated. It features an oxide trench and the p-drift region surrounding the trench, which is built on the n-SOI layer. In the OFF-state, first, the extended trench gate also acts as a gate field plate; second, the p-drift and the n-SOI layer forms a folded RESURF structure. Both increase the doping dose of the p-drift and modulate electric field (E-field) distribution; third, the oxide trench not only reduces the device pitch but also enhances the E-field strength. All of them result in a low \(R_{\rm {\scriptstyle {ON,SP}}}\) and a high breakdown voltage (BV) with a reduced device pitch. The free charges induced on the SOI/buried oxide (BOX) interface not only enhance the E-field strength in the BOX but also effectively shield the influence of BG bias effect in a wide range. The proposed pLDMOS achieves state-of-the-art improvement in the tradeoff between BV and \(R_{\rm {\scriptstyle {ON,SP}}}\) . Compared with the p-top SOI pLDMOS, the proposed device reduces the \(R_{\rm {\scriptstyle {ON,SP}}}\) by 79% at the same BV. A strong immunity to the BG bias effect is demonstrated and analyzed in detail.

0.7Pb(ZrxTi1−x)O3–0.1Pb(Zn1/3Nb2/3)O3–0.2Pb(Ni1/3Nb2/3)O3 (0.7PZT–0.1PZN–0.2PNN, x = 0.44–0.47) piezoelectric powders and ceramics have been prepared through conventional solid-state reaction method. Outstanding piezoelectric and dielectric properties occurred at the morphotropic phase boundary (MPB), which was characterized by the X-ray diffraction spectrum. The MPB composition (x = 0.46) performed high d33 value (641 pC/N), indicating that the system suited large-strain application. The field-induced strain reached 0.25% under a considerably low electric field (0.8 kV/mm) according to the bipolar strain *S–E loops. The effect of the grain size on the aging phenomenon and temperature stability has also been investigated. Due to higher Curie temperature and smaller grain size, the 0.7PZT–0.1PZN–0.2PNN ceramics maintained a high d33 level after depoling treatment, revealing a superior strain capacity for high-temperature application.

In order to study the effect of stray current on the compressive strengths of concrete and rebar corrosion under different cementitious systems, a set of test device is designed to simulate the migration of stray current in the concrete. The compressive strength of the concrete is tested in the 4th week and 7th week after electrification to evaluate the compressive strength ratio of the concrete with different cementitious materials under the influence of stray current. The polarization curve of the rebar is measured to evaluate the electrochemical properties of the rebar. The result shows that: The influence laws of stray currents on the strength of concrete with different cementitious materials and rebar corrosion are consistent. The reduction extent of the compressive strength of concrete and corrosion extent of rabars follows the sequence: pure cement > fly ash+mineral powder+fiber>fly ash ≥ fly ash+mineral powder+swelling agent≥fly ash+mineral powder.With the increase of current time, The longer the current time is, the more significant the reduction of compressive strength is, and the more serious the rebar corrosion is.

The mechanical behaviour of as-cast AZ31 Mg alloy has been investigated at strain rates up to 2.0×103s-1. Dynamic tests were carried out at room temperature using a Split Hopkinson Pressure Bar (SHPB) apparatus. Microstructural characteristic were analysed by Image MAT A1 optical microscopy. The results demonstrated that AZ31 Mg alloy exhibited obvious yield phenomena and strain hardening behaviour at high strain rates. The basically same curvature of stress-strain curves exhibited an similar strain hardening rate. The dynamic yield strength changes little and the peak stress increases with the strain rates. An examination by optical microscopy after high strain rate deformation reveals the occurrence of twinning and twin area percentage increases with the strain rate increasing.

WEDM (Wire Cut Electrical Discharge Machining) is a kind of spark cutting machining processes by using the linear movable electrode (known electrode wire).With the development of science and technology and the emergence of a large number of new materials, EDM wire cutting start to face new challenges. The characteristics of these new materials such as multiphase materials processing, electrical conductivity, thermal conductivity inhomogeneity, as well as processing of large thickness of the workpiece result in low efficiency of EDM wire cutting and high frequent wire broken. Recent years, seldom research on the introduction of ultrasonic vibration into medium-speed EDM wire cutting has been done. This article aimed to analyze the influence on the cutting efficiency and workpice suface roughness by using self-made ultraconic assisted appratus on Medium-speed EDM. The results showed that ultrasonic vibration can improve the efficiency of wire electric discharge machining , and it can alao reduce the surface roughness Ra value of the workpiece. What's more, the cutting speed is higher when the direction of ultrasonic vibration and cutting direction is vertical rather than parallel.

The blends of poly(trimethylene terephthalate) (PTT) with maleated styrene-butylene-co-ethylene-styrene copolymer (SEBS-g-MA) were prepared by melt blending. Their morphologies and crystallization behavior were investigated. Morphology observation shows the well-dispersed phase of SEBS-g-MA in PTT matrix and the partical size of SEBS-g-MA increased as the content of SEBS-g-MA increasing. Differential scanning colorimetry(DSC) experiments showed that the melting point of pure PTT and their blends was almost constant. Addition of 5-30wt% SEBS-g-MA in blends increased crystallization points of PTT phase and the crystallinity of the blends were higher than that of PTT.

To explore and develop scaffold for bone regeneration or tissue engineering with the capacity of controlled drug delivery, the feasibility of hydroxyapatite/polyurethane (HA/PU) scaffold containing drug-loaded microspheres for controlled drug delivery system was demonstrated. Ciprofloxacin hydrochlorid as a model drug was encapsulated in ethyl cellulose (EC) microspheres, which were subsequently incorporated into HA/PU composite scaffold to generate an antibiotic drug delivery system. The results show that EC microspheres are uniformly distributed in the HA/PU scaffold matrix and display no significant effect on the pore structure of the scaffold. Compared with incorporating ciprofloxacin hydrochlorid into scaffolds directly, embedding microspheres into scaffolds significantly reduces the initial burst drug release and extends the release time of drug delivery. In vitro drug delivery tests and antibacterial activity tests prove that drug-loaded microsphere/scaffold system has good drug delivery properties and effective antibacterial properties. These results suggest that the novel drug-loaded microsphere/ scaffold composites developed in this study is a good candidate scaffold with the function of bone repair and infection treatment for bone tissue engineering.

The mechanical properties and microstructures were investigated for AZ80 Mg alloy during plane strain compression and extrusion processing. The results show the tensile strength increases with the increasing deformation degree in the two-phase zone due to sufficient dynamic recrystallization and work-hardening effect. In single-phase zone, the tensile strength increases firstly and then does not varies basically when the deformation degree is greater than a certain critical value. This is very beneficial to optimize processing parameters to obtain microstructure with improved mechanical behavior.

A new amphiphilic copolymer (copoly-(MR-BMA-HEA-MAA), PRBHM) containing multihydroxyl segments was designed and synthesized for application in drug carrier. PRBHM can be dissolved in water to form aggregates directly with a critical aggregate concentration (CAC) of 0.0138 mg mL−1. The chains of PRBHM can be collapsed into hydrophobic globules when pH decreases from neutral to slightly acid condition (pH = 5.0–7.0) in water. Since the hydrophilic hydroxyl group is independent on pH, PRBHM can keep stable both in neutral and slightly acid aqueous solutions. The hydrophobic small molecules such as 5-(4-(4-vinylbenzyloxy) phenyl)-4,5-dihydro-1,3-diphenyl-1H-pyrazole (PY) can be loaded into PRBHM aggregates via ultrasonic treatment in water, and can be internalized into BEL-7402 cancer cells. The cytotoxicity determination also indicates the good biocompatibility of PRBHM in potential application as a drug carrier. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A simple and versatile method has been invented to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations. As-prepared hydrogels composed of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) (PEDOT-PSS) exhibit expanded-coil conformation in polymer chains, phase-separate at nanometer scale, possess controllable microstructure, and is responsive to external stimulus. The conducting PEDOT-PSS hydrogels have then been introduced into multiple-network hydrogels to obtain composite hydrogels combining enhanced mechanical strength and excellent electrical activity. Triple-network (TN) and special double-network (sDN) hydrogels, containing poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) as the matrix respectively, are successfully prepared. Finally, PEDOT-PSS hydrogels with self-strengthening function are directly fabricated via a one-step process under optimized conditions. The strengthening mechanisms for each kind of hydrogels are proposed, and the applicability in electrosensors, supercapacitors and electromechanical actuators are briefly demonstrated.

Recrystallization and microstructural changes of an electropulsing treated (EPT) Fe-3%Si alloy strip were studied using optical microscopy and electron backscattering diffraction (EBSD) techniques. Microstructural evolution and misorientation angle distribution were detected during recrystallization in both EPT and traditional heat treated (THT) alloy specimens. The results indicate electropulsing tremendously accelerated movement of dislocation and vacancies, which is in favors of recrystallization. The temperature of recrystallization was reduced. A sufficient high temperature became a dominant factor in speeding up recrystallization. The mechanism of electropulsing induced recrystallization is discussed from the point view of dislocation dynamics, microstructural changes and electropulsing kinetics. (doi:10.2320/matertrans.M2010044) Grain-oriented Fe-3% Si steels are used as cores in electrical transformers due to their soft magnetic properties. In order to develop a new production technology for grain- oriented silicon steel heat treatment, EPT is use to cold rolling Fe-3% Si strip. As an alternative to the traditional thermal and mechanical processes, EPT has been recognized for its high efficiency and attracted attention for use in extensive studies in materials science and engineering, such as electroplasticity, 1-4) electromigation, 5) recrystallization, 6) phase transformation 7-11) and mechanism of interaction between electrons and lattice atoms and dislocation move- ment. 12,13) In our previous studies indicated that EPT enhanced rates of recrysytallization of AZ31 alloy. 14) Compared with the conventional processes, microstructure and grain size were remarkably different, and the material properties were improved. But so far little has been done on the effects of electropulsing on the microstructural evolution of the Fe-Si alloy. The material selected in the research was a commercial Fe-Si alloy with a composition of Al(0.024 mass%), N(0.026 mass%), Cu(0.10), Si(3 mass%), Fe in balance. The as-received Fe-Si alloy strip of 6 mm in width and 0.3 mm in thickness was produced after 75% final reduction of cold rolling at room temperature. The schematic view of EPT process is shown in Fig. 1. Multiple pulses current generated continuously are applied to the alloy strip directly when the Fe-Si alloy strip was moving at a speed of 1 m/min through a distance of 200 mm between the two electrodes. An electropulsing generator was applied to discharge positive- directional multiple pulses with various pulse voltage through adjusting controlling parameters. It took about 12 s to move the strip from anode to cathode. An infrared thermoscope was adopted near the cathodes to test the surface maximum temperature of material directly. The current parameters such as amplitude and root-mean-square density

ZnO, as a wide-band gap semiconductor, has recently become a new research focus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy (L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition (PLD). Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond (ns) pulsed laser ablation of ZnO ceramic target, the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.

We report the extraordinarily large positive magnetoresistances (MR, 69400% at 4.5 K under a magnetic field of 8.15 T), de Hass–van Alphen oscillations effect at 10 K and the semimetal-insulator-like transition in a wide range of temperature in highly oriented pyrolitic graphite (HOPG). Besides a dominating ordinary MR (OMR) mechanism in the free-electron mode, it is realized from qualitative analysis that the Coulomb interacting quasiparticles within graphite layers play some roles. However it is difficult to associate the transition with the simple OMR theory. In order to investigate the possible origins of the transition, further analysis is carried out. It is revealed that the magnetic-field-induced behaviour is responsible for the semimetal-insulator-like transitions in HOPG.

La0.7 Ca0.3 CrO3 powder consisting of superfine and uniform particles (100-200 nm) were synthesized using a glycine-nitrate process (GNP). The sintering and electronic conducting properties of La0.7 Ca0.3 CrO3 were investigated in the sintering temperature range of 1 200–1450 °C. The desired morphology of the powder significantly improved its sinterability. La0.7 Ca0.3 CrO3 ceramics sintered at 1 250–1450 °C show high relative densities above 95%. The ceramics sintered at 1 250–1400 °C have very similar electronic conducting properties, providing electronic conductivities around 55 Ω−1 cm−1 at a measuring temperature of 800 °C. Further increasing the sintering temperature to 1450 °C led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La0.7 Ca0.3 CrO3 with respect to the enhanced sintering properties and superior electronic conducting properties.

Poly ethylene oxide (PEO)x−V2O5−V2O5−MoO3 (x=0, 0.5, 1) films were prepared by the sol-gel method. The synthesis and structure of the films were investigated by XRD, TG-DTA, FTIR, etc. The results show that V2O5−MoO3 xerogel has a layered structure and its interlayer space increased from 1.3181 nm at x=0 to 1. 7898 nm at x=1 after the nanocomposite films were dried, and PEO in the interlayer changes the interface structure by forming hydrogen bonds with V=0 bands. CV measurement indicates that the intercalation of PEO improves insertion/extration properties of Li+ ions in the interlayer.

Infrared radiant powder was synthesized by conventional ceramic processing techniques by using Fe2O3, MnO2, CuO, Co2O3 and kaolin as raw materials. A novel infrared radiant glaze was developed by introducing the infrared radiant powder into glazing as a functional additive. Infrared radiant characteristics of the powder and the glaze were investigated. The optimum content of infrared radiant powder in glazing was ascertained to be 5%. The infrared radiant glaze exhibits significant antibacterial and antifungal functions due to the thermal effect of infrared radiation. Antibacterial percentages of the glaze reach 91%–100% when Escherichia coli, Staphylococcus aureus and Bacillus subtilis are used as model bacterium respectively, while antifungal percentage of the glaze exceeds 95% when Penicillum citrinum is used as model fungus.

Anomalous transport behaviour, i.e. the dependence of the tunnel resistance on the injection current, has been discovered in Ta/Co/Al2O3/FeNi tunnel junctions. The zero-field voltage-current characteristic of the magnetic tunnelling junction obeys the transport principle of the normal tunnel junction at low injection current, but it exhibits a negative resistance behaviour when the injection current is raised to the break-over current level. The physics of the restorable electric breakdown has been initially studied.

Using the ion-beam-sputtering technique, we have fabricated Fe/Al2O3/Fe magnetic tunnelling junctions (MTJs). We have observed double-peaked shapes of curves, which have a level summit and a symmetrical feature, showing the magnetoresistance of the junction as a function of applied field. We have measured the tunnel conductance of MTJs which have insulating layers of different thicknesses. We have studied the dependence of the magnetoresistance of MTJs on tunnel conductance. The microstructures of hard- and soft-magnetic layers and interfaces of ferromagnets and insulators were probed. Analysing the influence of MJT microstructures, including those having clusters or/and granules in magnetic and non-magnetic films, a magnetization reversal mechanism (MRM) is proposed, which suggests that the MRM of tunnelling junctions may be explained by using a group-by-group reversal model of magnetic moments of the mesoscopical particles. We discuss the influence of MTJ microstructures, including those with clusters or/and granules in the ferromagnetic and non-magnetic films, on the MRM.