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First experiment of liquid lithium limiter was successfully carried out on HT-7 tokamak and a few positive results were obtained. The results showed that by using lithium limiter, specially liquid lithium limiter, Hα intensity reduced 20–30%, the emission of CIII and OV decreased about 10–20%, loop voltage had a slight decline, the core electron temperature slightly increased, the particle confinement time increased by a factor of 2, and the energy confinement time increased 20%. After lithium coating, the hydrogen recycling decreased, and core electron temperature increased significantly by a factor of 2. At the same time, after lithium coating, electron density of edge plasmas obviously decreased while electron temperature slightly increased. These encouraging results are very useful for further research of long tray lithium limiter on HT-7 and liquid divertor on EAST.

The effect of melt undercooling on the γ phase is investigated in a two-phase Co2NiGa magnetic shape memory alloy by employing the method of glass fluxing combined with superheating cycling. A maximum bulk undercooling of 230 K is achieved. Microstructural evolution of the Co2NiGa alloy is investigated by optical microscopy with respect to different degrees of undercooling. Over the whole range of undercooling, it is found that both the size and the volume fraction of the γ phase are drastically influenced by undercooling. Especially, when the undercooling is in the range of 190–230 K, the alloy has an obvious preferred orientation.

Pulp quality changes of longan cv. 'Shixia' stored at 3-5°C were investigated and the activity of caspase-3 and autolysis index were determined during storage, and the roles of caspase-3 in longan pulp-autolysis and programmed cell death (PCD) were discussed. During cold storage stage of longan fruit, activity of caspase-3 fluctuated. At the beginning of storage, caspase-3 activity rose before the occurrence of pulp-autolysis. It increased quickly with enhanced pulp autolysis. The activity of caspase-3 in the autolytic pulp was significantly higher than that in the non-autolyzed pulp. The results indicated that caspase-3 may take part in the initiation and enhancement of the pulp autolysis, which maybe a result of PCD.

SummarySix wild species of Eriobotrya were evaluated as rootstocks for domesticated loquat. Twelve-month-old seedlings of Oak leaf loquat (an Oak Leaf loquat ‘Zaozhong No. 6’ hybrid) and wild Fragrant loquat (E. fragrans Champ) had higher root-to-shoot fresh weight (FW) ratios than other wild species. When the domesticated loquat, ‘Zaozhong No. 6’, was grafted onto seedlings of six different wild loquat species, differences in compatibility were observed. Graft compatibility was lower for all combinations compared to ‘Zaozhong No. 6’ grafted onto domesticated loquat seedlings. When wild Henry loquat was used as a rootstock, delayed incompatibility was observed. Differences in soluble sugar contents (SSC) between scion and rootstock were observed, and there was a significant negative correlation between graft compatibility and the difference in SSC values. The influence of the rootstock on anatomical changes at the graft union were observed using a scanning electron microscope (SEM). Wild rootstocks also i...

EAST is a non-circular advanced steady-state experimental device and the first entirely superconducting tokamak in the world. Vacuum system is one of the most important sub-systems of EAST device. Wall conditionings, such as baking, discharge cleaning and boronization, also play a very important role for the plasma operation. Due to Ion Cyclotron Resonance Frequency (ICRF) wall conditioning technique could be carried out in the presence of a high toroidal magnetic field, it is routinely used for wall cleanings on EAST. After the 2nd campaign in 2007, the plasma facing walls was modified to full carbon walls and vacuum system was upgraded to meet the requirement of particles exhaust. This paper will introduce the new statues of vacuum system, such as pumping, fueling and wall conditionings on EAST. Then the vacuum operation and wall conditioning in the 2008 campaign is introduced.

The effect of the fourth element Al on the martensitic transformation and magnetic properties of polycrystalline Ni–Fe–Ga alloys is investigated. A complete thermoelastic martensitic transformation in Ni–Fe–Ga–Al alloys was observed in a range of 309–394 K. Martensitic transformation temperatures of Ni–Fe–Ga alloys are obviously decreased by the substitution of Al for Ga element: the addition of 1% Al can decrease the martensitic transformation temperature by about 68 K. On the other hand, the substitution of Al for Ga increases the saturation magnetization and decreases the saturation magnetic field.

Ion cyclotron resonance discharge-associated oxidation (He/O-ICR) wall conditioning was successfully carried out on full metallic material walls for a divertor configuration in EAST. Within a range of He/O-ICR parameters (5–20 kW, 1.2–7 × 10−2 Pa) in EAST, the highest removal rates (7.8 × 1022 H-atoms/h, 4.2 × 1022 C-atoms/h) were obtained with 20 kW and 7 × 10−2 Pa He/O-ICR. These rates are about 10 times higher than those in HT-7. Oxygen retention rates were lower than HT-7 by a factor of >10. Results of O-ICR cleanings in both EAST and HT-7 showed that power density, working pressure, plasma-facing area and materials, and pumping speed are the main factors influencing the co-deposit removal rates during O-ICR wall conditioning.

TiC particles were fabricated in situ by self-propagating high-temperature synthesis reaction with 0–40 mass% Al in the total Al–Ti–C elemental powder mixtures. The reaction behavior and formation path of TiC were investigated. Because of the non-steady-state oscillatory propagation of combustion wave front, the typical swelled and layered reaction products were observed. With Al contents increasing, the reaction temperatures decreased and the TiC particles sizes evidently reduced. Al played an important role in controlling the reaction behavior and the morphology of products, serving not only as a diluent to inhibit the TiC particles from growing, but also as an intermediate reactant to participate in the reaction process.

ZrC particles were fabricated via self-propagating high-temperature synthesis (SHS) from 0 to 40 mass% Al–Zr–C elemental powder mixtures. The typical layered structures of the reaction products were observed due to the non-steady-state oscillatory motion of the combustion wave. With the Al content increasing, the reaction temperature decreased and the ZrC particle sizes evidently reduced from ~ 8 µm in Al free to ~ 50 nm in 40 mass% Al. The microstructures and formation mechanism of ZrC have been analyzed using XRD, SEM and quenched experiment. For Al free, including the low Al content, the formation of ZrC was controlled by the dissolution of C into a Zr melt or a solid ZrC layer. While for the high Al content, the formation of ZrC was controlled by the dissolution of C into a Zr–Al melt and the precipitation of ZrC, in which Al serves not only as a diluent to inhibit the ZrC particles from coarsening, but also as an intermediate reactant to participate in the reaction process.

A large amount of titanium carbide (TiC) octahedra were synthesized in situ by self-propagating high-temperature synthesis using Al, Ti, C elemental powders as source materials. The phase constituents and microstructure morphologies of as-product were characterized by X-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy. Due to the strong faceting tendency of the growing TiC crystal, the TiC grain grew as an octahedral morphology. If V [1 0 0] / V [1 1 1] =1.5, the TiC grain will grow as a perfect octahedral morphology. While if V [1 0 0] / V [1 1 1] >1.5, the TiC grain will grow as an imperfect octahedral morphology. According to the experimental results, the detailed microstructure and growth mechanism of TiC octahedron have been observed and analyzed. The models have been proposed to understand the formation and growth mode of TiC octahedron.

Tungsten has been considered as the primary candidate plasma-facing materials (PFM) for the EAST device. Three actively cooled W/Cu mock-ups with an interlayer made of tungsten–copper alloy (1.5 mm) were designed and manufactured. The tungsten armors, pure sintered tungsten plate (1 mm) and plasma-sprayed tungsten coatings (0.3 and 0.9 mm), were bonded to the interlayer by brazing and depositing respectively. All mock-ups can withstand high heat flux up to 5 MW/m 2 and no obvious failure was found after tests. The thermal performance experiments and microstructure analyses indicated the structure of mock-ups possess good thermal contact and high heat transfer capability. WCu alloy as an interlayer can largely reduce the stress due to the mismatch and improve the reliability. The mock-up with 0.9 mm coating had the highest surface temperature than the other two mock-ups, delaminations of this mock-up were found in the near surface by SEM. The primary results show that pure sintered tungsten brazed to WCu alloy is a possible way, and thick plasma-sprayed coating technique still need to be improved.

Normal plasma recoveries after various events, such as after shutdown, various boronization, oxidation and large air leak, were investigated in the 2007 campaign of HT-7. Plasma recoveries, including disruptive plasmas, would depend on the wall status, such as impurities content and hydrogen retention. After shutdown or air leak, impurities made plasma recovery very difficult. After boronization, plasma recoveries would depend on the procedures of the boronization (C2B10H12). After oxidation, boronization would effectively suppress impurities and would be beneficial for plasma recovery. ICRF cleanings in various working gases, such as He and D2, would be useful for impurities and hydrogen removal. This research is important for effective operation of HT-7 and would be useful for EAST and ITER operations.

ZrC hexagonal platelets were fabricated via self-propagating high-temperature synthesis (SHS) reaction from 20 mass% Al–Zr–C powder mixtures and a typical layered structure of the as-products was observed. The field emission scanning electron microscopy (FESEM) reveals that the thick ZrC hexagonal platelets (⩽1 μm) grew through the layer-by-layer growth mechanism of thin hexagonal monolayers along [1 1 1] direction, while the thin monolayer (⩽40 nm) was formed via two-dimensional (2D) nucleation mode along (1 1 1) plane. The formation and growth mechanism of the ZrC platelets have been discussed in detail. Al additive in the compact played an important role in determining the formation and growth of ZrC platelets, serving not only as a diluent to inhibit the ZrC grains from coarsening, but as an intermediate reactant to participate in the reaction process.

He–ICR cleanings were successfully carried out in 2006–2007 on the full superconducting tokamak (EAST), which is an ITER-relevant experimental tokamak. Factors influence on He–ICR efficiency, such as magnetic field, ICRF power and working pressure were investigated. In EAST, the breakdown pressure for He–ICR cleanings could reach 10 Pa. The removal efficiency for H during 20 kW 4.5 × 10−3 Pa He–ICR cleaning was same as that in He–GDC cleaning (2 Pa, 4A). Highest H removal rate in EAST with full metallic material walls, 1.7 × 1022 H/h in 20 kW 3 × 10−2 Pa He–ICR, was higher by a factor of four than that in HT-7 with carbon limiter configuration.

Carbon fibers (CF) were surface treated with air-oxidation and rare earth solution (RES), respectively. The friction and wear properties of the polyimide (PI) composites filled with differently surface-treated carbon fibers (20 vol.%), sliding against GCr15 steel under oil-lubricated condition, were investigated on a ball-on-block reciprocating UMT-2MT tribometer. Experimental results revealed that RES treatment largely reduced the friction and wear of CF reinforced PI (CF/PI) composites. Scanning electron microscope (SEM) investigation of worn surfaces of CF/PI composites showed that RES treated CF/PI composite had the strongest interfacial adhesion and the smoothest worn surface under given load and reciprocating sliding frequency. X-ray photoelectron spectroscopy (XPS) study of carbon fiber surface showed that the oxygen concentration was obviously increased after RES treatment. The increase in the amount of organic functional groups increased the interfacial adhesion between CF and PI matrix, and accordingly lowered coefficients of friction and wear rates.

The corrosion behavior of the quaternary Pr–Cu–Ni–Al bulk metallic glasses (BMGs) in 3.5 wt.% NaCl solution were investigated by potentiodynamic polarization and electrochemical impedance spectroscopic techniques. It is found that the there is a good correlation between the corrosion resistance and the glass-forming ability (GFA) in the BMGs, the larger the GFA, the stronger the corrosion resistance. In case of the representative Pr 55 Cu 15 Ni 15 Al 16 BMG, the isothermal heat treatment was conducted and it was found that the corrosion resistance became smaller with holding time at 483 K. The thermogravimetry measurement on the Pr–Cu–Ni–Al BMGs showed that the oxidation resistance was deteriorated by increasing the Cu content and no correlations were found with the GFA. The composition of the scales formed during the oxidation was confirmed by X-ray diffraction. The corrosion and oxidation mechanisms were also discussed based on the experimental results.

TiC ceramic particulates locally reinforced aluminum matrix composites were successfully fabricated via self-propagating high-temperature synthesis (SHS) reaction of Al–Ti–C system during aluminum melt casting. The SHS reaction could be initiated when Al contents in the green compacts ranged from 20 wt.% to 40 wt.%. With increasing Al contents, the ignition delay time was prolonged and the adiabatic combustion temperature was lowered. Using XRD and DSC analysis, the SHS reaction characteristic was discussed. The result showed that Al serves not only as a diluent but also as an intermediate reactant participating in the SHS reaction, determining the reaction process and its final producsts. The SEM images revealed a relatively uniform distribution and nearly spherical morphology of TiC particulates in the locally reinforced region, and excellent adhesion and gradient distribution between the TiC particulates reinforced region and Al-matrix. The size of the TiC particulates decreased obviously with increasing Al contents in the blends.

The discrete ordinates particle transport codes (SN codes) are widely used in reactor design, radiation shielding, nuclear detection and other fields. SN automatic modeling system (SNAM) is an integrated interface program between CAD systems and SN codes, which makes full use of CAD technology to improve SN modeling and perform the conversion between CAD models and SN code input files. The modeling capability of SNAM has been tested by the International Thermonuclear Experimental Reactor (ITER) benchmark model in this paper. The benchmark process includes geometric model processing, material assignment, model normalizing, converting to SN code input file, calculating and analysis with SN code system VisualBUS. The neutron flux radial distribution of the inboard blanket modules is given and compared with the results calculated by MCNP.

A series of Pr–Ni–Al bulk metallic glasses (BMGs) was prepared by a copper mold casting method. The effect of the alloy composition on the glass transition temperatures ( T g ) and supercooled liquid regions (Δ T x ) was studied. It showed that the increase in Pr content to a certain degree, though at which the alloy remained fully amorphous, caused the disappearance of T g and Δ T x . Continuous and isothermal annealing methods were used to investigate the disappearance mechanism of T g and Δ T x on the representative Pr 55 Ni 25 Al 20 and Pr 65 Ni 25 Al 10 BMGs. X-ray diffraction (XRD) analysis on crystallization products showed that the disappearance of T g and Δ T x for Pr 65 Ni 25 Al 10 was not due to the precipitation of different kinds of crystalline products but due to the decrease in glass stability (GS) resulted from the larger quantities of the first precipitating Pr 7 Ni 3 phase at relative lower temperatures. As a whole, the alloy composition dependence of T g and Δ T x was also discussed in the framework of the three empirical rules for achievement of high glass-forming ability glasses.

Many technical improvements were achieved recently in the HT-7 superconducting tokamak, such as ICRF boronization, new water cooling graphite limiters which is instead of molybdenum limiter, and application of ferritic steel for reducing the magnetic ripple, and so on. The global impurity content and impurity components were measured and studied by using of spectroscopy diagnostics in the HT-7 tokamak. Experimental results of the effective ionic charge Zeff and impurity behaviors before and after technical improvements mentioned above are compared in this paper. It is observed that the integrated plasma performance is enhanced while the global impurity content and Zeff drops with these technical improvements. Steady state plasma with higher performance and 5-min long pulse plasma were obtained.

Doped graphites containing B, Si and Ti dopants with improved mechanical and thermal properties are developed as divertor plates in experimental advanced superconducting tokamak (EAST) device. SiC coatings with a grading distribution along the depth up to 100 μm from the surface were applied on the doped graphites by chemical vapor reaction (CVR) method in order to reduce the carbon impurities emitted from the surface of doped graphites during long pulse plasma discharge. High heat flux test on SiC coated graphites were carried out with an active cooling test (ACT) facility. Results show that SiC coated doped graphites can handle heat flux up to 6 MW/m 2 while keeping structural integrity. The abrupt increase of surface temperature and the eroded pot on the surface implied that SiC coatings acted as a heat transfer barrier when irradiated with heat flux of 6 MW/m 2 .

Oxidation experiments at wall temperatures of 400–470 K, including O-ICR, O-GDC conditioning and thermal-oxidation have been carried out for removal of deposits and hydrogen in HT-7. Thermal-oxidation seems ineffective to remove co-deposited layers and hydrogen at these temperatures. O-GDC oxidation appeared to be the most efficient on HT-7. However O-ICR was almost as good and could be applied with the magnetic field in ITER. Both O-ICR and O-GDC have a deposits removal rates ∼20 times that of He-ICR and He-GDC cleaning. Higher pressures and conditioning power during oxygen wall conditioning are favorable for removal of deposits and hydrogen. The oxygen retention after O-GDC oxidations was much higher than that after O-ICR oxidations. High power low oxygen pressure and He in O-ICR oxidation are beneficial for reducing oxygen retention. To remove the retained oxygen on walls both He-ICR and He-GDC were found to be effective. Plasma discharges could be recovered after a few tens of disruptive plasmas.

Three kinds of Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3O10 ((Bi,Pb)-2223) monofilamentary tapes were fabricated by powder-in-tube (PIT) process under different conditions. The phase evolutions during melting and reformation of (Bi,Pb)-2223 core in them have been investigated by ex-situ X-ray diffraction (XRD) analysis. The short tapes were melted at 855°C, 858°C in 7.5% O2 balanced with argon, and then slowly cooled to 801°C and 804°C at 1.5°C/h, respectively. The results show that the (Bi,Pb)-2223 phase can reform directly from the melt in all three tapes if the appropriate melting temperatures are used. However, the ceramic cores underneath the silver sheath exhibit different melting and recrystalization behaviors, as the differences of phase compositions in the original tapes before melted.

The present work proposed a rapid solidification process based on suction casting method to fabricate bulk Co–Ni–Al alloys. The main purpose is to seek a balance between functional characteristics (pseudoelasticity and shape memory effect) and mechanical properties (strength and ductility) in this system. The results revealed that two grain refinement transitions occurred in the quenched alloys with the variation of the cooling rate. Under the cooling rate of about 24–50 K/s, rapidly solidified Co–Ni–Al alloys exhibited the divorced β + γ eutectic structure. It is confirmed by magnetic force microscopy observation that the γ phase surrounded by the β grains showed a strong stripe-like magnetic contrast whereas the intracrystalline β phase possessed weak magnetic anisotropy. The divorced eutectic structure weakened the hindrance of the γ phase to the reversible motion of martensitic variants of the matrix, and thus offered good shape memory recovery and pseudoelasticity. At the same time, the ductility was significantly improved owing to the presence of the γ phase distributed at the grain boundaries. It is believed that the rapidly solidified Co–Ni–Al alloys are promising smart materials for practical application.

The kinetic viscosity (η) of AlNiPr(Si,Cu) superheated melts has been measured by an oscillating crucible method in temperature range from melting temperature up to about 1500 K, and the temperature dependence of the viscosity is discussed in the framework of Arrhenius models. Superheated fragility parameter was deduced from Angell's fragility concept and super-Arrhenius equation. It is found that there is a good correlation between the superheated fragility and glass-forming ability. The resultant relationships of the correlation are also discussed.

The effectiveness of D2-ICR cleaning with a pressure up to 0.18 Pa was surveyed on hot walls of 400–470 K for oxygen removal after oxidation experiment in the HT-7 superconducting tokamak. The oxygen removal rate in D2-ICR cleaning was about (7–9) × 1021 O-atoms/h, about 5–10 times higher that that He-ICR cleanings before and after the D2-ICR cleaning. In about 130 min He-ICR and D2-ICR cleanings, about 8 × 1021 O-atoms were removed. After the cleanup, a lot of water still retained in HT-7 vessel and 67 disruptive plasmas were required before obtaining normal plasma. In present experiment, the recovered plasmas were easily controlled and much better than previous report in HT-7 oxidation experiments.

It is shown that the martensitic transformation temperatures of Co 50 Ni 22− x Ga 28 Fe x ( x = 0, 1, 2, 5) alloys decrease as Ni is gradually substituted by Fe. The volume fraction of the second phase is also reduced with increasing Fe content, which impairs the mechanical properties. Two-phase Co–Ni–Ga–Fe alloys exhibit complete superelastic behaviors in a wide temperature interval between room temperature and 200 °C. Moreover, the stress hysteresis in two-phase alloy shows much stronger sensitivity to temperature than that in single-phase alloy.

Fly ash is the waste emissions of burning coal powder from coal-fired power plants, the annual emissions of fly ash exceed 100,000,000t in China (Li 2004). But the reutilization rate of fly ash is only 30%, and more than 70% of that are used in building materials, construction engineering, road engineering etc. Fly ash can be processed to synthetic zeolite (Xu et al. 2006). The fly ash zeolite has very good adsorption properties because its’ very large specific surface area. And the fly ash zeolite has good removal effect of =Hg2+, Pb2+, Cu2+, Ni2+, Zn2+ and other heavy metal ions in wastewater on (Li 2004, Luo 2004). Its unique physical and chemical properties along with its low cost lead to broad application prospect in wastewater treatment.

This study investigated the magnetic domain morphologies of Co–Ni–Ga and Co–Ni–Al alloys with the β + γ two-phase structures by magnetic force microscopy. In the rapidly solidified state, the martensite in a grain refined Co 45 Ni 25 Ga 30 alloy exhibited sharp magnetic contrast, whereas the parent phase in a Co 38 Ni 34 Al 28 alloy with divorced eutectic structure had weak magnetic anisotropy. After annealing at 1173 K, the γ phase showed fulgurous magnetic domains in the annealed Co 45 Ni 25 Ga 30 , and stripe-like 180° domain walls in regularly eutectic Co 38 Ni 34 Al 28 .

In the next generation of fusion device in China, e.g., the Experimental Advanced Superconducting Tokamak (EAST), the divertor target will be exposed to high heat loads up to 5 MW/m 2 for about 1000 s. An actively water-cooled target plate element with flat tungsten tile armored on CuCrZr heat sink was designed for EAST. A two-dimensional finite element method (FEM) code was used to analyze its thermal and mechanical properties under high heat flux of 10 MW/m 2 for the selection of an appropriate cross section. To meet the integrated requirements of temperature and stress in the target element, twisted tapes have to be inserted into the cooling channels to strengthen the heat transfer efficiency, and a tungsten armor thickness of 4 mm and a distance of 2 mm from the interface to the vertex of the cooling channel were ultimately selected. The thermal and mechanical properties of two kinds of tungsten armor (sintered and plasma sprayed) were also analyzed and discussed in the FEM calculations. The designed structure can be used under the 5 MW/m 2 heat load expected for normal operation of EAST device, but it would suffer from cracks/ failure danger under higher heat load, up to 10 MW/m 2 .

Effect of solidification rate on the solidified microstructure and crystal orientation based on a new type ferromagnetic shape memory Co-Ni-Al alloys have been studied by the liquid metal cooling directional solidification. The results show that at the lower rate of 5 μm/s for the Co 32 Ni 40 Al 28 alloys, worm-like γ' phase precipitated in martensite matrix and faceted γ particles were introduced under the rate of 10 μm/s. For a rather faster growth rate of 150 μm/s, interdendritic β + γ eutectic lamella appears after the dendritic β formed. The single austenite phase was observed in the Co 38 Ni 34 Al 28 alloy at the rate of 5 μm/s. At the same time, the preferred orientations changed with the variation of the solidification conditions. It is found that (111) oriented martensite crystal can be obtained in the Co 32 Ni 40 Al 28 alloy at the rate of 5 μm/s, while (110) and (100) orientations become stronger at the rate of 10,m/s. But the preferred orientation degree at 150 μm/s is very poor. The Co 38 Ni 34 Al 28 rod with (110) oriented austenite can be prepared at the rate of 5 μm/s.

The effectiveness of several types of oxygen removal, including baking, ion cyclotron resonant discharge cleaning, glow discharge cleaning and disruptive plasma cleaning were surveyed on hot walls of 402–470 K in the HT-7 machine. Oxygen removal from ‘clean’ walls and from walls with oxygen contamination has been examined. The wall conditions, such as material, structure of plasma facing components and oxygen retention, would influence the oxygen removal efficiency of ICR cleanings. On ‘clean’ metal walls before 2000, high power He-ICR produced high oxygen removal. However, on ‘clean’ walls with carbon limiters after 2004, both He-ICR and D 2 -ICR cleanings would induce oxygen retention but not removal. On heavy contaminated walls, such as after oxidation experiment, the removal rate of oxygen during He-ICR cleanings depended on oxygen retained on the walls, ICR power and pressure. Filling helium promoted oxygen removal during baking. He-GDC cleaning possibly has oxygen removal efficiency at far position, but comparison between it and He-ICR cleaning also depended on oxygen retention status. Disruptive plasma discharges with cryo-pumping are essentially for removal of the remained oxygen from the walls after wall cleanings and for re-building normal plasma. To apply those oxygen removal techniques in a superconducting tokamak device, such as EAST and ITER, should depend on oxygen retention and their distribution on walls.

The martensitic microstructure and crystal structure evolution of Co 46 Ni 27 Ga 27 alloys under different undercooling condition was investigated. The increase of reverse martensitic transformation temperature was found with undercooling in 22 to 165 °C undercooling range, but decreased with further high undercooling. The reasons for these have been discussed using the elastic strain energy mechanism and grain refinement caused by internal stress during rapid solidification.

The kinetic viscosity ( η ) of superheated melts, thermal properties ( T x , T m , T L ) and X-ray diffraction analysis on the Pr-based bulk metallic glasses (BMG) are reported and discussed. A new refined concept, the superheated fragility defined as M ′ = E S δ x / k B , has been developed based on common solidification theory and the Arrhenius equation. The interrelationship between this kind of fragility and the glass-forming ability (GFA) is elaborated on and evaluated in Pr-based BMG and Al-based amorphous ribbon alloys. Using viscosity data of superheated melts, it is shown, theoretically and experimentally, that the fragility parameter M ′ may be used as a GFA indicator for metallic alloys.

The fusion-driven subcritical system (named FDS-I) was previously proposed as an intermediate step toward the final application of fusion energy. A conceptual design of the FDS-I is presented, which consists of the fusion neutron driver with relatively easy-achieved plasma parameters, and the He-gas/liquid lithium–lead Dual-cooled subcritical Waste Transmutation (DWT) blanket used to transmute long-lived radioactive wastes and to generate energy on the basis of self-sustainable fission and fusion fuel cycle. An overview of the FDS-I is given and the specifications of the design analysis are summarized.

The evolution of recycling behaviour has been investigated during long pulse discharges in the HT-7 tokamak after ICRF boronization (C2B10H12) using the H/(H+D) ratio and the edge recycling coefficient R. After boronization, impurity reduction is observed, attributed to the fresh boron film, but the recycling coefficient can exceed unity due to a large amount of hydrogen absorbed in the film, leading to an uncontrollable density rise and discharge termination. When the H/(H+D) ratio was reduced to less than 25%, the electron density was easily controlled. The longest discharge, up to 240 s with central electron temperature Te(0) of about 1.0 keV and central electron density ne(0) of 0.8 × 1019 m−3, was achieved following boronization. After many discharges the effectiveness of boron film was weakened, and the density rise was correlated with an increase in both carbon and oxygen radiation which limited the duration of long pulse discharges.

A series of samples of CoNiGa were studied with regard to their structure, martensitic transformation, magnetic properties, and thermally induced strains. Optical microscopy shows that a single martensite phase exists in the alloys, which accords with the X-ray diffraction result. The martensitic transformation temperature (higher than 350 K) decreases with increasing Co content when keeping the ratio of Ni/Ga constant; this was attributed to the size factor. The saturation magnetization, about 30 emu/g, increases with increasing Co content. In addition, a complete shape recovery with a phase transformation strain of 1% appears in the oriented martensitic variants.

The effect of the fourth element Ta on the microstructure, crystal structure and martensitic transformation of (Co 45 Ni 25 Ga 30 ) 1− x Ta x ( x = 0, 0.5, 2, 5) alloys was investigated. Some Ta-rich precipitates were observed in the higher Ta-addition samples, which lead to the decrease of the martensitic transformation temperatures and thermal hysteresis. In addition, 1423 K annealing temperature is not high enough to impede the presence of the γ phase in Co–Ni–Ga–Ta alloys, and 1473 K heat treatment temperature is needed.

Ni–Fe–Ga alloys were highly undercooled by using molten glass purifier and superheating cycle. Effects of the undercooling on the temperatures of martensitic transformation, microstructures and phase structures were investigated. Compared with the as-melted alloy, there is little effect of the undercooling on the temperatures of the martensitic transformation and the undercooled Ni56Fe17Ga27 alloy retained the 14M martensitic structure within the achieved undercooling range of 0–200 K, while in the Ni60Fe17.5Ga22.5 alloy, the γ phase formed as primary phase during the stage of rapid solicitation, in addition, the γ phase became more refined and the volume fraction increased up to 76% under the undercooling of 220 K.

The aim is to investigate the effect of the substitution of Ag for Ni and Co for Ga on the martensitic transformation in Ni–Fe–Ga magnetic shape memory alloy. A complete thermoelastic intermartensitic transformation in the Ni 56.5 Fe 19.0 Ga 24.5 alloy was observed in the vicinity of 300 K and the intermartenisitic transformation diminished with alloying with Ag and Co. Substitution of 1.0 at% Ag for Ni results in the M S temperature decreasing slightly, while substituting 4.5 at% Co for Ga, the M S temperature increases dramatically from 300.54 K to 388.24 K.

Long plasma discharges require in-vessel integration of actively cooled plasma facing components (PFC) in order to operate the HT-7 tokamak at the steady state. To promote power removing capacity, two flat toroidal limiters with high heat removal capability have been designed and installed in the HT-7 tokamak. The high performance toroidal limiters, 1.7 m 2 area, were located at top and bottom of the HT-7 vessel, covering 265 ◦ and 285 ◦ , respectively, in the toroidal direction. The bolted structure for the graphite tile has been adopted. Employing flexible graphite sheet interlayer between the graphite tile and copper alloy heat sink has been demonstrated to be an effective way to improve heat transfer. The water cooling in the heat sink has been specially designed with large channel. The geometry of the array bars in the water cooling channel accelerates the turbulent flow of the cooling water and provided higher heat removing capacity. The experiences accumulated in the process of design of the HT-7 toroidal limiter will be helpful to design high thermal conductive plasma facing components with easy maintenance. Its heat removal capacity has been increased by a factor of 5 compared with the previous the HT-7 poloidal limiter with stainless steel heat sink, which were served as the main limiter. © 2004 Elsevier B.V. All rights reserved.

The effects of the Ni and Ga content on the martensitic transformation of Ni–Fe–Ga alloys with composition close to Ni 55 Fe 17.5 Ga 27.5 were investigated. The DSC results show that the martensitic transformation temperatures increase with Ni addition or Ga depletion. A complete thermoelastic intermartensitic transformation and retransformation in Ni 58 Fe 17.5 Ga 27.5 alloy in the vicinity of 370 K was observed, the hysterisis of martensitic and intermartensitic transformation are 10.54 and 5.07 K, respectively.

In order to stay competitive with international markets, companies must deliver new products with higher quality in a shorter time with a broader variety of versions at minimum costs. Virtual manufacturing (VM) is quickly becoming an interesting strategy for product development. Primarily aimed at reducing the lead times to market and costs associated with new product development, VM offers a test-bed for the time-consuming and expensive physical experimentation. In this paper, several key issues for developing a virtual turning test-bed by using virtual manufacturing technology are discussed, i.e., representation of a workpiece with the capability of transferring error data used for machining accuracy prediction and reflecting the machining accuracy, representation of the swept volume of a tool for simulating turning process with high efficiency. The construction of surface topography, a basic model for machining accuracy prediction is also highlighted. The representations and relevant algorithms discussed in this paper are implemented in a virtual turning test-bed. A virtual machining and inspection system (VMIS) for ultra-precision diamond turning is presented and experiments are carried out to demonstrate it.

Welding is a common method for repairing damaged ship propellers, especially by cavitation erosion. Reports on cavitation erosion and corrosion behavior of copper–manganese–aluminum (CMA) alloy weldment are sparse. In this paper, CMA weldment was prepared by tungsten inert gas welding (TIG), and its cavitation erosion behavior and corrosion behavior in 3.5% NaCl aqueous solution were studied by magnetostrictive vibratory device for cavitation erosion and electrochemical device, respectively. Results show that the weld zone (WZ) of the weldment exhibits better cavitation erosion and corrosion resistance than the heat-affected zone (HAZ) and the base metal. The cumulative mass loss of the WZ is only 1/4 that of the base metal. SEM analysis of eroded specimens reveals that the base metal is attacked most severely; the HAZ less and the WZ least. The microcracks causing cavitation damage initiate at the phase boundaries. Among the three zones of the weldment, the WZ is the noblest, its corrosion potential is −266 mV, while the HAZ, −284 mV, and the base metal, −279 mV, in about 60 h exposure to 3.5% NaCl aqueous solution. And its corrosion current density is the lowest, about 0.035 A m−2, while the HAZ, 0.078 A m−2, and the base metal, ±0.79 A m−2.

Ultrafine-grained (UFG) materials have extensive prospects for engineering application due to their excellent mechanical properties. However, the grain size decrease reduces their strain hardening ability and makes UFG materials more susceptible to deformation instability such as shear localization. In most cases, critical shear strain is taken as the criterion for formation of shear localization under impact loading or adiabatic shear band (ASB). Recently, some researchers found that the formation of ASB was determined only by the dynamic loading process and had nothing to do with its static loading history. They proposed for coarse-grained metals a dynamic stored energy-based criterion for ASB and verified it by some experiments. In this study, we will focus on the shear localization behavior of UFG metals such as UFG titanium and magnesium alloy AZ31. Quasi-static loading and dynamic loading will be applied on the same specimen alternately. The shear localization behavior will be analyzed and the criterion of its formation will be evaluated.