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Refractory alloys such as tungsten and molybdenum based alloys with high strength, thermal/electrical conductivity, low coefficient of thermal expansion and excellent creep resistances are highly desirable for applications in nuclear facilities, critical components in aerospace and defense components. However, the serious embrittlement limits the engineering usability of some refractory alloys. A lot of research results indicate that the performances of refractory alloys are closely related to the physical/chemical status, such as the interface dimension, interface type, interface composition of their grain boundaries (GBs), phase boundaries (PBs) and other interface features. This paper reviewed the recent progress of simulations and experiments on interface design strategies that achieve high performance refractory alloys. These strategies include GB interface purifying/strengthening, PB interface strengthening and PB/GB synergistic strengthening. Great details are provided on the design/fabrication strategy such as GB interface controlling, PB interface controlling and synergistic control of multi-scaled interfaces. The corresponding performances such as the mechanical property, thermal conductivity, thermal load resistance, thermal stability, irradiation resistance, and oxidation resistance are reviewed in the aspect to the effect of interfaces. In addition, the relationships between these interfaces and material properties are discussed. Finally, future developments and potential new research directions for refractory alloys are proposed. [ABSTRACT FROM AUTHOR]

Surface that durably and anti-fouling are of interest for fundamental research and industrial application in the heat exchanger equipment. In the present study, hierarchical micro/nano structure (HMNS) is fabricated by electrical discharge machining (EDM) method. The morphology, metallographic and crystalline structures as well as corrosion resistance of the HMNS are characterized. The micro/nano structure improves the corrosion resistance and hydrophobic property of the surface. The HMNS, with the grain size dimension of 1.5–11 μm, shows an improved contact angle of 124.9° ± 5.4°. The co-effect of hydrophobic and corrosion resistance endows the HMNS with a superior anti-fouling property than that of polished surface. Fouling adhesion experiments shows that, after being immersed in CaCl2 + Na2CO3solution for 72 h at 50 ℃, there are only a few fouling adhere on the HMNS and the adhered fouling is loose and easy to fall off. Moreover, after 50 times of semitransparent tape adhesion, the HMNS still in the hydrophobic status with slightly decreases (4.09%–9.38%) of contact angle, which indicates that the HMNS is durably and suitable for industrial application. There is an industrial prospect for fabricating anti-fouling heat transfer surface by a low cost and environmentally friendly one-step EDM process.

During plasma spray forming, the forming quality is directly influenced by the flattening behavior of the droplet impacted onto the substrate, which is determined by the flattening configuration and solidification state of the droplet. In this study, according to the rule of Reynolds number and Peclet number, the flattening behavior of big-size molten droplet impacted onto the substrate with low-speed were experimentally simulated during flattening. The droplets of Sn30Pb70, Zn and ZA12 impacting onto the stainless steel substrate with different velocity were investigated. Splashing degree was introduced to evaluate the flattening profiles of the splats. The relationships between the splashing degree and the impact velocity, Reynolds number and Weber number of the droplet were established. Experimental results show that the flattening and diffusion are impeded by the dynamic viscosity and surface tension of the droplets, and the impeding effects are more remarkable when the impact velocity is lower. The research has a significant ap

Enterprises in Taiwan are facing global competition which requires enterprises to implement sound business models and maintain effective operational processes. The most pressing need is to develop global logistic processes and models that satisfy rapidly changing business and operational objectives. This research studies how the automotive industry in Taiwan has adopted its logistic hubs to improve international business operations and objectives. In the first phase of the study, Taiwan automotive firms were surveyed and their current (as-is) logistic models were derived. In the second phase, based on the industry characteristics and the company’s global strategy, the improved (to-be) logistic processes were derived. Further, a case of Taiwan automobile manufacturers is used to apply and demonstrate the to-be logistic models and evaluate the performance of the proposed models. The resulting framework for a global logistic hub is designed to improve the operations of automotive companies with respect to time and cost, as well as to ensure information sharing among automotive supply chain partners.

This paper worked on two dimensional ultrasonic grinding system with workpiece adhered to ultrasonic vibration. It analyzed the working locus of abrasive particle under two dimensional ultrasonic grinding (TDUG), and emulated the working course, and gave the key parameters affecting grinding efficiency and grinding locus’s characteristic under different grinding parameters, and brought forward the cutting course between abrasive particle and workpiece under TDUG belongs to an new rotating dynamic contact cutting model. At the same time, it put forward the theoretically critical speed condition under TDUG to obtain the optimum grinding effect, and verified good micro-feature of finished surface under TDUG by the means of grinding tests of nano ZrO2 ceramics.

Experimental researches on material removal rate and surface roughness of Al2O3 engineering ceramic guide-pulley lapping were carried out using W20 and W5 fixed oilstones by self-developed ultrasonic lapping tool both with and without ultrasonic assistance. Experimental results show that lapping speed, lapping pressure and grain size produce different effects on the lapped surface roughness and material removal rate. The material removal rate in ultrasonic lapping process is two times as large as that in traditional lapping, and the ground surface roughness is superior to that in common machining method. The material removal rate increases along with the average diameter of grains and the lapping speed both in ultrasonic lapping and traditional lapping. In traditional lapping process the material removal rate becomes bigger along with the lapping force, while in ultrasonic lapping it gets the optimal value with the lapping force 450N. The value of lapped surface roughness increases along with the lapping speed in traditional lapping, on the contrary it decreases contrast to the lapping speed until 250rpm in the ultrasonic lapping. The value of traditionally lapped surface roughness decreases contrast to the lapping force, whereas it achieves the minimum with the lapping force 450N with ultrasonic assistance.

On the basis of analyzing the brittleness, ductileity, and the removal mechanisms of the^nano-ZrO2 Ceramics, the critical ductile grinding depth formula of the nano-ceramics was established. Due to superductileity of the nano-ZrO2 ceramics, it couldn’t apply the formula of the common engineering ceramic material according to experimental results. The value of material coefficient ζ has relations with not only the material characteristics but also the processing methods and the processing parameters. It was proved that ζ has great effects on the accuracy of theoretical calculation. Experimental results showed that the critical ductility grinding depth of the nano-ZrO2 ceramics is up to 12 µm in common grinding methods, while in ultrasonic grinding is up to 20µm. The grinding chips with and without ultrasonic vibration assistance were discussed.

Nano ceramics possessed ascendant mechanical property and physical characteristics contrast with engineering ceramics, so it has extensive application prospect in various industries. On the basis of applying the indentation fracture mechanics to analyze the removal mechanics of ceramic material, this paper analyzed the critical ductile grinding depth of the nano ZrO2 ceramics. Adopting ultrasonic composite processing we describe the influence of different processing parameters and grain size of diamond wheel on the grinding forces and surface roughness. Based on the grinding forces and surface roughness the grinding process with and without vibration is analyzed. By means of SEM and AFM the surface character and critical ductile grinding depth of nano ZrO2 ceramics are also discussed. The paper supplied the theoretical and experimental basis for the grinding of the large-sized ultraprecision plate structure of nano ZrO2 ceramics (nm).

Metal matrix composites（MMCs）is applied widely in recent years because of its excellent performances, but the machining is very difficult due to the rigidity of reinforced-phase in it, so, the application of MMCs is restricted much. In this paper the experiment of common and ultrasonic vibration drilling is performed to SiC particulate reinforced Al matrix composites （SiCp/Al）by use of carbide-alloy-twist-drill, and the surface roughness of hole is compared, furthermore, the wearing of twist drill and the feature of chips are analyzed by scanning electron microscope (SEM). From above, we can draw aconclusion that ultrasonic vibration drilling may meliorate the mechanism of drilling to some extent and it takes on much superiority that the common drilling is unmatched, so this method could provide a certain foundation for the posterior study and application.

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A perfect elastoplastic model for the relation of generalized stresses and their conjugate generalized strain rates is investigated in the paper. The exact solutions are solved for the model subjected to rectilinear generalized strain paths^1 and the concepts of response subspace and visualization are introduced such that the n-dimensional problem is reduced to a two-dimensional problem in the response subspace. The response path is found to be, geometrically speaking, a geodesic in the n-dimensional closed ball B^n of generalized stresses. The phase portrait of dissipation is studied and it is a remarkable fact that in the response subspace the coordinate x is exactly the dissipation power per unit generalized strain rate when x >= x"o"n [see eqn (63)]. The generalized stress-strain curves are classified by geometrical shapes into ten types, in contrast to the superficial impression of only one type of shape, an inclined straight line followed by a horizontal line. The existence of a limit strength vector and a limit power of dissipation is demonstrated by the long-term behavior based on the exact solutions, and the existence together with the response's stability is further verified by Lyapunov's direct method. The closeness to the limit strength point is also estimated and the exact formula accounted for prestress is derived. The dependence of the responses on the product space of initial values, input paths, property constants and closeness to the limit is thoroughly investigated with control parameters identified.

The ability of the novel D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] analogues, L-chiro-inositol 1,4,6-trisphosphate [L-chrIns(1,4,6)P3] and the corresponding trisphosphorothioate compound [L-chrIns(1,4,6)PS3] to inhibit soluble inositol (1,4,5)P3/(1,3,4,5)P4-polyphosphate 5-phosphatase, potently and selectively, has been investigated. L-chrIns(1,4,6)P3competitively inhibited 5-phosphate specific dephosphorylation of Ins(1,4,5)P3and inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4] with apparent Kivalues of 6.35 and 1.76 μM, respectively. L-chrIns(1,4,6)PS3competitively inhibited hydrolysis of Ins(1,4,5)P3and noncompetitively inhibited dephosphorylation of Ins(1,3,4,5)P4with apparent Kivalues of 0.67 and 0.44 μM, respectively. L-chrIns(1,4,6)PS3did not affect Ins(1,4,5)P33-kinase activity. In the present investigation L-chrIns(1,4,6)P3and L-chrIns(1,4,6)PS3have been shown to be the most potent and selective inhibitors of inositol polyphosphate metabolism yet described.

Five polycyclic aromatic hydrocarbons (PAHs) were studied by means of chemical deoxygenation micelle-stabilized room temperature phosphorimetry (MS-RTP) with sodium sulfite as O2scavenger and with thallous nitrate as heavy atom perturbation in sodium dodeyl sulfate micellar media. Various factors of effect on room temperature phosphorescence are discussed. Analytical curves of five arenes give linear dynamic ranges (LDRs) of one and a half to two decades, and the limits of detection (LOD) of 1.7 × 10−7mol/liter to 3.4 × 10−7mol/liter. The relative standard deviations (RSDs) were between 0.51 and 3.2%.

This paper makes some systematic studies of the origination, the physical-mathematical characteristics and the disturbing function of the pressure wave in the inter-electrode gap, especially of the influence on the copying accuracy in PECM. Through the observation of high speed photograph to the real process in the gap and the analysis of precise measuring data for the pressure wave, we have recognized perceptually about the three respects.

The anomalous electron thermal transport model based on collisionless plasma instabilities driven by electron temperature gradient is applied to tokamak plasma with auxiliary heating. The steady state electron equation is solved and the results show good agreement with experimental observations including the principle of profile consitency, various scaling laws, and even some results for detached plasmas.

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Radiofrequency fields launched in the ion Bernstein mode in a plasma can stabilize the interchange mode by coupling it to ion Bernstein wave side-bands. A kinetic theory for non-linear coupling, based on the guiding centre formalism, is developed and conditions for stabilization are derived. Waves with ?0> ?ci, k0?vi/?ci1 are better suited for stabilization.

A theoretical investigation of the thermal equilibria of detached plasmas has been performed. The transport model used is that for the ?emodes. The model explains the scaling of the plasma radius, central electron temperature, impurity radiation, electron energy confinement time with plasma current and central density as observed on TFTR. Furthermore, assuming that the plasma disrupts when the safety factor reaches two at the edge of the detached plasma, a density limit ncris obtained. For the impurity density nIindependent of the plasma density, whereas for nI= fn(0), where f is the fraction of impurities, ncr? BT/R.

Parametric stabilization of the interchange mode by a fast magnetosonic pump wave through the magnetosonic sideband is calculated. Explicit threshold conditions are obtained. It is shown that the mechanism is significant at high densities. No singularity is, however, obtained at ?0= ?i.

The TFR group has recently employed radiofrequency powers in excess of 200 kW near the hydrogen cyclotron frequency in a predominantly deuterium plasma with some minority hydrogen. At low minority concentration, when ion-ion hybrid and hydrogen cyclotron resonance layers exist in the plasma, pronounced emissions have been observed at the hydrogen half-harmonics, accompanied by deuterium heating. It seems that the fast-wave pump decays parametrically into two short-wavelength deuterium Bernstein waves on the low field side of the cyclotron resonance layer, requiring a threshold power of less than 100 kW. The decay waves are eventually damped on the deuterium ions, thus heating them.

In high-temperature, weakly collisional plasmas, electron Doppler effects strongly modify the structure of the m = 1 internal kink mode, causing the growth rate ? to depend very weakly on the plasma resistivity ?: ? ~ ?1/7. The electron temperature gradient can also drive the m = 1 mode.