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91.
By using Darboux transformations, the authors give the explicit construction for local isometric immersions of space forms Mn(c) into space forms M2n-1(c + ε2) via purely algebraic algorithm. 相似文献
92.
For all minimal immersions of the 2-sphereS
2 into the unit 2m-sphereS
2m
with area 2π[m(m+1)+2], we are able to give an explicit representation by some real parameters. This representation is rather important in the
study of minimal 2-spheres inS
2m
because the parameters concerned are independent of each other. Particular examples are given and a classification theorem
is also obtained.
Supported by NNSF of China and NSF of Henan 相似文献
93.
Hailan Zhanguo Chen Gang Jia Xiaoting Zhang Yanchen Li 《Optics & Laser Technology》2004,36(4):331-335
A GaAs solid immersion lens has been applied to the external electric-optic measuring system. The spatial resolution of the system is improved to 0.7 μm because of the increased effective number aperture. We measured the electrical field distribution of ceramic microstrip lines transversely. The variation of electrical field with a submicrometre interval has been revealed experimentally and the results are in good agreement with the theoretical analysis. 相似文献
94.
Thomas Ivey 《Geometriae Dedicata》1997,64(2):125-144
The Pick cubic form is a fundamental invariant in the (equi)affine differential geometry of hypersurfaces. We study its role in the affine isometric embedding problem, using exterior differential systems (EDS). We give pointwise conditions on the Pick form under which an isometric embedding of a Riemannian manifold M
3 into
is rigid. The role of the Pick form in the characteristic variety of the EDS leads us to write down examples of nonrigid isometric embeddings for a class of warped product M
3's. 相似文献
95.
Dubinin"s theory for the volume filling of micropores (TVFM), originally developed for the adsorption of single vapours by microporous solids such as activated carbons and zeolites, has gradually been extended to other areas. They include immersion calorimetry, the adsorption of water vapour and of mixtures, as well as adsorption from aqueous solutions. Recent studies in the field of adsorption from aqueous solutions, by activated carbons, suggest that the principle of temperature invariance is fulfilled and in the case of phenolic compounds a modified DRK equation can be used to predict the adsorption equilibrium over a certain range of temperatures. Computer modelling of CO2 adsorption by carbons at 273 K leads to micropore distributions, which are in good agreement with those derived from other techniques. It also appears that the model isotherms in single slit-shaped micropores can be fitted to the Hill-de Boer isotherm, in agreement with mathematical studies of the origin of the Dubinin—Astakhov equation. 相似文献
96.
《Surface and interface analysis : SIA》2003,35(2):179-183
In this study sulphur hexafluoride (SF6) plasmas and argon plasma immersion ion implantation (ArPIII) techniques have been applied to improve the hydrophobicity of poly(tetrafluoroethylene) (PTFE), polyurethane and silicone surfaces. As evaluated by water contact angle measurements, all the treatments resulted in a significant enhancement in the hydrophobicity of the polymers. However, exposure of the treated samples to air induced a strong variation in their hydrophobicity as a consequence of post‐plasma reactions between atmospheric species and remnant surface free radicals. X‐ray photoelectron spectroscopy results strongly suggest that for polyurethane and silicone the surface fluorination by SF6 plasmas and the creation of new carbon bonds and radicals are the main agents for hydrophobicity enhancement. The PTFE exposed to ArPIII revealed increases in the contact angles after exposure to air. A significant incorporation of oxygen and the formation of new carbon bonds were revealed by XPS measurements. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
97.
241Am是极毒、亲骨超钚核素,主要发射5.49MeVα粒子和59.6keV的γ射线,半衰期为423年。曾经作为烟雾探测器广泛地应用于火灾报警器生产中,长期的生产造成了生产线各个部位,尤其是金属部件表面存在较为严重的放射性污染。在其生产线退役过程中,需要对这些污染表面进行去污以减少操作人员受照剂量和退役过程废物产生量。放射性污染的去污按去污机理可分为机械法、化学法、物理法和电化学法等[1]。其中化学浸泡去污在核设施退役中应用较为广泛[2]。NaF HNO3浸泡去污工艺早期由前苏联开发,针对的去污对象主要为不锈钢,开始采用的试剂组成为3… 相似文献
98.
Tadashi Sugiyama 《Geometriae Dedicata》2007,125(1):53-61
In this paper, we characterize of totally geodesic Kähler immersions by extrinsic shapes of some curves having points of order 2. 相似文献
99.
Realization of a near-field optical virtual probe based on an evanescent Bessel beam is strongly dependent on a radially polarized
beam; this makes it essential to study the focusing property of the beam. In this paper, two experimental setups based on
a fiber device and a liquid crystal device, respectively, are built to generate a radially polarized beam. This beam and an
annular radially polarized beam are focused by means of a high numerical aperture objective and a solid immersion lens (SIL).
Near-field distribution of the focus spot, the evanescent Bessel field, is experimentally measured with a scanning near-field
optical microscope (SNOM). The full width at half maximum (FWHM) of the central peak of the evanescent Bessel field is about
200 nm in the close vicinity of the bottom surface of SIL. This has potential for use as a near-field optical virtual probe. 相似文献
100.