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排序方式: 共有342条查询结果,搜索用时 31 毫秒
321.
322.
We analyze the stability of a variety of uniform textures in superfluid 3HeA in the presence of superflow p. We find below Tins a class of stable helical l? textures, where l? is no longer aligned with p but winds around it with a constant pitch . 相似文献
323.
Metallic contacts between superconducting and normal films are known to have a pair-breaking effect on the electron pairs. By limiting our considerations to the gapless regime and to contacts between superconducting and paramagnetic metals the features of this pair-breaking mechanism are investigated. We compute the normalization of the order parameter and with it such quantities as the tunneling conductance, electrical and thermal conductivity and the critical current parallel to the contact. Furthermore we investigate the influence of a magnetic field. By calculating the? 2(t)-parameter we demonstrate the interplay between the different pair-breaking mechanisms in perpendicular and parallel fields. In the latter case we discuss the influence of the contact on the superconducting sheath proposed bySaint-James andde Gennes. Experiments to test the present theory are suggested. 相似文献
324.
Mamoru Nomura Xiang Liu Kouichi Ishitani Kazumi Fujita 《Journal of Polymer Science.Polymer Physics》1994,32(15):2491-2498
The saturation swelling behavior of styrene and acrylonitrile (SAN) copolymer particles with a styrene (St) and acrylonitrile (AN) comonomer mixture was investigated experimentally. The effects of the copolymer composition and the compositional inhomogeneity in SAN Copolymer particles on their swelling behavior were examined. The experimental results show that both the copolymer composition and the compositional inhomogeneity in SAN copolymer particles have little or no influence on the swellability of SAN copolymer particles with a St and AN comonomer mixture, as long as the weight fraction of AN monomer units in SAN copolymer particles is less than a certain value between 0.6 and 0.8. With increasing AN content in the copolymer particles beyond this value, however, the swellability of SAN copolymer particles gradually decreases. Semiempirical equations are proposed, which correlate the saturation concentration of each monomer in SAN copolymer particles as a function of the comonomer composition in the monomer droplets and the overall copolymer composition in SAN copolymer particles. © 1994 John Wiley & Sons, Inc. 相似文献
325.
Direct Evaluation of Transition Amplitude Using Determinant of Wave Operator in One-Dimensional Potential Scattering System
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Itsuki Banno Kazumi Fujima 《中国物理快报》2007,24(11):3032-3035
A determinantal formula is developed for direct evaluation of transition amplitude without solving the wave equation in a one-dimensional potential scattering system. Our formulation is 5ased on the principle that a desired quantity can be extracted from the wave operator, which is the master operator maintaining all the information of the system. This principle is tested in a simplified system, i.e,, in a one-dimensional potential scattering system. We are now developing a formula for direct evaluation of near-field amplitude to design a system, in which local field enhancement is desired. 相似文献
326.
Inagaki K Takatsu A Watanabe T Aoyagi Y Yarita T Okamoto K Chiba K 《Analytical and bioanalytical chemistry》2007,387(7):2325-2334
A new marine sediment certified reference material, NMIJ CRM 7306-a, for butyltin and phenyltin analysis has been prepared
and certified by the National Metrological Institute of Japan at the National Institute of Advanced Industrial Science and
Technology (NMIJ/AIST). Candidate sediment material was collected at a bay near industrial activity in Japan. After air-drying,
sieving, and mixing the material was sterilized with γ-ray irradiation. The material was re-mixed and packaged into 250 glass
bottles (15 g each) and these were stored in a freezer at −30 °C. Certification was performed by use of three different types
of species-specific isotope-dilution mass spectrometry (SSID–MS)—SSID–GC–ICP–MS, SSID–GC–MS, and SSID–LC–ICP–MS, with 118Sn-enriched organotin compounds synthesized from 118Sn-enriched metal used as a spike. The 118Sn-enriched mono-butyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were synthesized as a mixture whereas the 118Sn-enriched di-phenyltin (DPhT) and triphenyltin (TPhT) were synthesized individually. Four different extraction methods,
mechanical shaking, ultrasonic, microwave-assisted, and pressurized liquid extraction, were adopted to avoid possible analytical
bias caused by non-quantitative extraction and degradation or inter-conversion of analytes in sample preparations. Tropolone
was used as chelating agent in all the extraction methods. Certified values are given for TBT 44±3 μg kg−1 as Sn, DBT 51 ± 2 μg kg−1 as Sn, MBT 67 ± 3 μg kg−1 as Sn, TPhT 6.9 ± 1.2 μg kg−1 as Sn, and DPhT 3.4 ± 1.2 μg kg−1 as Sn. These levels are lower than in other sediment CRMs currently available for analysis of organotin compounds. 相似文献
327.
328.
Numerical simulations of sonochemical production of nanoparticles have been performed for the first time under the experimental condition of Dang et al. [Jpn. J. Appl. Phys. 48 (2009) 09KC02] on the production of BaTiO(3). The results of the numerical simulations have suggested that only primary particles aggregate with other particles. It is also shown that larger aggregates are produced for lower initial concentration of BaCl(2) and TiCl(4). This is caused by longer reaction time as the reaction rate is lower for lower concentration and by lower viscosity which results in higher rate of aggregation. 相似文献
329.
Itoh N Inagaki K Narukawa T Aoyagi Y Narushima I Koguchi M Numata M 《Analytical and bioanalytical chemistry》2011,401(9):2909-2918
The National Metrology Institute of Japan has issued a certified reference material of tunnel dust for polycyclic aromatic
hydrocarbons (PAHs) and toxic element analyses. PAH certification was performed using isotope dilution mass spectrometry with
deuterium-labeled PAHs as internal standards. Three extraction techniques (microwave-assisted extraction with toluene/methanol,
Soxhlet extraction with toluene, and pressurized liquid extraction with toluene) were used, and the extracts were measured
by gas chromatography/mass spectrometry with two different columns. For values of PAHs, 11 PAHs are provided as certified
values between 0.294 and 20.3 mg/kg, and five PAHs are provided as information values. Certified values of five toxic elements
(Cr, Ni, Pb, Mn, and Cd) obtained from microwave-assisted digestions and a combination of measurement techniques are also
provided between 43.4 and 10.71 × 103 mg/kg. 相似文献
330.
Triplet superconductors such as Sr2RuO4 and NaxCoO2·yH2O are now found to be p-wave (px±ipy) or f-wave ((px±ipy)coscpz) superconductors. In conventional singlet superconductors, vortices are quantized because phase of order parameter must rotate by 2π around a vortex. But triplet superconductors have a degree of freedom of spin, which is described by d-vector. The d-vector and phase can rotate by π around a vortex, separately. Therefore appearance of HQVs is predicted. Theoretically, it is found that a pair of HQVs is more stable than a singly quantized vortex, for several parameter regions.In this study, in order to investigate quasi-particle bound states around two vortices in s-wave superconductors, we have developed a new numerical method to solve the BdG equation for two vortices state, using Mathieu functions. We confirmed the validity of this method for two vortices state and applied it in case of a pair of vortices. And we solved it. 相似文献