Biaxially textured Ni–5 at.%W substrates have been prepared by cold rolling, followed by three different annealing routes. In this paper, the processes of melting Ni and W metals, flat rolling, various annealing methods are described in detail. The Ni–5 at.%W tapes annealed under either high vacuum or flowing Ar (7% H2) gas were characterized by X-ray pole figures, ODF, EBSD as well as AFM analysis. The texture analysis indicated that as fabricated tapes have a sharp cube texture formed after annealing at a wide temperature range of 800–1100 °C. The high quality of cube orientation on tapes was obtained after a two-step annealing (TSA), where the percentage of the cube texture component was as high as 93.5% within a misorientation angle smaller than 8° from EBSD analysis. Furthermore, it was also observed that the number of twin boundaries in this tape decreased with respect to that of tapes annealed both in vacuum and one-step gas annealing. From AFM on 1 μm2 areas, it was concluded that the roughness (RMS) on the tape surface reached 0.98 nm. 相似文献
We consider the extended trust-region subproblem with two linear inequalities. In the “nonintersecting” case of this problem, Burer et al. have proved that its semi-definite programming relaxation with second-order-cone reformulation (SDPR-SOCR) is a tight relaxation. In the more complicated “intersecting” case, which is discussed in this paper, so far there is no result except for a counterexample for the SDPR-SOCR. We present a necessary and sufficient condition for the SDPR-SOCR to be a tight relaxation in both the “nonintersecting” and “intersecting” cases. As an application of this condition, it is verified easily that the “nonintersecting” SDPR-SOCR is a tight relaxation indeed. Furthermore, as another application of the condition, we prove that there exist at least three regions among the four regions in the trust-region ball divided by the two intersecting linear cuts, on which the SDPR-SOCR must be a tight relaxation. Finally, the results of numerical experiments show that the SDPR-SOCR can work efficiently in decreasing or even eliminating the duality gap of the nonconvex extended trust-region subproblem with two intersecting linear inequalities indeed. 相似文献
Antifouling coatings are used to improve the speed and energy efficiency of ships by preventing organisms, such as barnacles
and weed, building up on the underwater hull and helping the ships movement through the water. Typically, marine coatings
are tributyltin self-polishing copolymer paints containing toxic molecules called biocides. They have been the most successful
in combating biofouling on ships, but their widespread use has caused severe pollution in the marine ecosystem. The low surface
energy marine coating is an entirely non-toxic alternative, which reduces the adhesion strength of marine organisms, facilitating
their hydrodynamic removal at high speeds. In this paper, the novel low surface energy non-toxic marine antifouling coatings
were prepared with modified acrylic resin, nano-SiO2, and other pigments. The effects of nano-SiO2 on the surface structure and elastic modulus of coating films have been studied, and the seawater test has been carried out
in the Dalian Bay. The results showed that micro-nano layered structures on the coating films and the lowest surface energy
and elastic modulus could be obtained when an appropriate mass ratio of resin, nano-SiO2, and other pigments in coatings approached. The seawater exposure test has shown that the lower the surface energy and elastic
modulus of coatings are, the less the marine biofouling adheres on the coating films.
Supported by High-Tech Research and Development Program of China (Grant No. 2004AA001520) 相似文献
So far, all existing quantum oblivious transfer protocols focused on realization of the oblivious transfer of a classical bit or classical bit-string. In this paper, p-Rabin quantum oblivious transfer of a qubit protocol is achieved by using a probabilistic teleportation protocol. As the probabilistic teleportation protocol is able to transfer an (un)known pure state with a certain probability, this feature makes the probabilistic teleportation protocol well fit for Rabin oblivious transfer. Here, this is the first time that the concept of qubit oblivious transfer is presented. Furthermore, p-Rabin quantum oblivious transfer of a qubit protocol can also be used for oblivious of a bit by encoding classical bit with two pre-agreed orthogonal states. Finally, security analysis shows that the protocol satisfies the security requirements of oblivious transfer, and what’s more, the discussion of relationship with no-go theorem demonstrates that the probabilistic teleportation protocol is able to evade the no-go theorem.
A new arbitrated quantum signature of quantum messages with a semi-honest arbitrator is designed by utilizing the chained control-NOT(CNOT) operations encryption and the classical public board. Detailed theoretical analysis show that the proposed scheme satisfies the requirements of unforgeable and undeniable properties. The novelty is that the feasibility of signing quantum messages under the control of a semi-honest arbitrator is demonstrated. And with the help of the decoy technique, shared keys can be reused. 相似文献
We present an efficient three-party quantum secure direct communication (QSDC) protocol with single photos in both polarization and spatial-mode degrees of freedom. The three legal parties’ messages can be encoded on the polarization and the spatial-mode states of single photons independently with desired unitary operations. A party can obtain the other two parties’ messages simultaneously through a quantum channel. Because no extra public information is transmitted in the classical channels, the drawback of information leakage or classical correlation does not exist in the proposed scheme. Moreover, the comprehensive security analysis shows that the presented QSDC network protocol can defend the outsider eavesdropper’s several sorts of attacks. Compared with the single photons with only one degree of freedom, our protocol based on the single photons in two degrees of freedom has higher capacity. Since the preparation and the measurement of single photon quantum states in both the polarization and the spatial-mode degrees of freedom are available with current quantum techniques, the proposed protocol is practical. 相似文献
The effect of minor alloying on several bulk metallic glasses and high-entropy alloys was studied. It was found that minor
Nb addition can optimize the interface structure between the W fiber and the Zr-based bulk metallic glass in the composites,
and improve the mechanical properties. Minor Y addition can destabilize the crystalline phases by inducing lattice distortion
as a result to improve the glass-forming ability, and the lattice distortion energy is closely related to the efficiency of
space filling of the competing crystalline phases. A long-period ordered structure can precipitate in the Mg-based bulk metallic
glass by yttrium alloying. For the high-entropy alloys, solid solution can be formed by alloying, and its mechanical properties
can be comparable to most of the bulk metallic glasses. 相似文献