Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Polarized reflection and luminescence have been measured for the single crystals of [MA 2 ][MX 2 A 2 ](ClO 4 ) 4 (M=Pt, Pd, X=Cl, Br, I and A=ethylenediamine, cyclohexanediamine). The strong absorption bands due to the charge-transfer (CT) exciton transitions between the mixed-valent metal ions have been investigated…
Values for the thermal conductivity and thermopower of graphite fibers grown by pyrolysis of natural gas are reported between 10 and 370 K. The measurements were made along the fiber axis on both as-grown fibers and fibers heat treated to 3000 \ifmmode^\circ\else\textdegree\fi{}C. It is shown that heat treatment impro…
Properties of rf-sputtered molybdenum oxide films for electrochromic display devices have been investigated. This report mainly concerns the dependence of the properties on the oxygen concentration in the sputtering atmosphere. The oxide films were prepared by rf sputtering from a compressed powder MoO3 target under a…
We have performed a systematic investigation of empty electronic surface states on the (100), (110), and (111) faces of nickel, copper, and silver using momentum-resolved inverse photoemission spectroscopy at \ensuremath{\Elzxh}\ensuremath{\omega}=9.7 eV. We present the measured two-dimensional energy-band dispersions…
Dielectric properties, lattice- and microstructure of ceramic BaTiO3 showing grain sizes of 0.3–100 μm were studied. At grain sizes <10 μm the width of ferroelectric 90° domains decreases proportionally to the square root of the grain diameter. The decreasing width of the domains can be theoretically explained…
The method of natural localized molecular orbitals (NLMOs) is presented as a novel and efficient technique for obtaining LMOs for SCF and CI wave functions. It is an extension of the previously developed natural atomic orbital (NAO) and natural bond orbital (NBO) methods, and uses only the information contained in the…
In LiF:Mg, Ti dosimeters, gamma -irradiation at low temperature (77K) reduces the TL intensities of peaks 7 (260 degrees C) and 10 (450 degrees C) drastically whereas the TL intensity of peak 5 (200 degrees C) remains nearly the same as that after irradiation at room temperature (RT). This implies that during irradiat…
Abstract Various laterally fluoro‐substituted benzonitriles have been prepared containing a trans ‐4‐( n ‐alkyl)cyclohexane ring linked to the 4‐position of the benzonitriles either through a methyleneoxy (CH 2 O–) or an ethylene (CH 2 CH 2 ‐) bridge. The bridging group links the benzonitrile and cyclohexane rings e…
The Saddle Conformation of Hydroporphinoid Nickel(II) Complexes: Structure, Origin, and Stereochemical Consequences Thirteen crystal structures document the general phenomenon of coordination‐hole contraction in hexahydro‐ and tetrahydroporphinoid ligands of complexes with small metal ions such as low‐spin Ni(II). The…
Abstract The ferritic steels used for reactor pressure vessels undergo a marked transition from ductile to brittle fracture behaviour over a relatively narrow temperature range. For most unirradiated mild steels the ductile to brittle transition temperature (d.b.t.t.) is between — 50° and 20 °C. The process of irradia…
We have discovered a new form of Fr\'eedericksz transition in which uniform splay distortion is replaced by a complex periodic twist-splay pattern having a lower critical field than that for uniform splay. Experimental evidence is presented along with an exact calculation of both the critical field and the initial for…
We report the observation of an order-disorder transition in the semiconductor strained-superlattice system GeSi/Si, which doubles the lattice periodicity in a $〈111〉$ direction. This phenomenon may be representative of a class of order-disorder transitions in strained-semiconductor systems, even when the lattice mism…
The dispersion of the nonlinear susceptibilities of Ar, ${\mathrm{N}}_{2}$, and ${\mathrm{O}}_{2}$ have been measured for wavelengths from 700.0 to 457.9 nm. A comparison is made with phenomenological models used in the literature.
Yimengite is a new species of mineral discovered in Shandong Province in 1980, with crystal chemical formula K(Cr, Ti, Fe, Mg, Al, Si)12O19. It belongs to hexagonal system, and its cell parameters α 0=5.857 and c 0=22.940. 749 separate diffraction intensities of crystal were collected on RASA=IIS auto-four-circle sing…
The y-expansion as introduced by Barboy and Gelbart is applied to a system of hard ellipsoids-of-revolution. The expansion is truncated after the third order term yielding an approximate theory requiring the second- and third-virial coefficients as inputs. As the third virial coefficient is not known analytically, num…
The temperature dependence of the infrared reflectivity spectra of NaNO 3 is reported in the whole ordered phase, from 10 to 549K. Reflectivity spectra from 5 to 600 cm -1 , are fitted with a model of the factorised form of the dielectric function including the relaxation mode. The temperature dependence of the infrar…
Non-uniform uniaxial nematics systems are discussed using the Landaude Gennes and Frank formalisms. These formalisms are compared and extended in order that the description they provide be consistent. It is then possible to treat the spatial dependence of the main order parameter Q(r) and the local biaxiality P(r) ind…
We present the results of Monte Carlo simulations on a system of hard ellipsoids of revolution with length-to-breadth ratios a/b = 3, 2·75, 2, 1·25 and b/a = 3, 2·75, 2, 1·25. We identify four distinct phases, viz. isotropic fluid, nematic fluid, ordered solid and plastic solid. The coexistence points of all first ord…
The influence of thickness errors and boundary imperfections on the performance of a multilayer x-ray mirror is discussed and it is shown that both can be obtained separately from a measured reflectivity curve at a short x-ray wavelength. Multilayers have greatly reduced scattering compared to single films, and for th…
Soon after the discovery of x-rays and their property of constructive interference scattering (diffraction) by solids resulting from the ordered array of atoms forming the solids, it was proposed that man-made (synthetic) layered structures might extend the range of utility of this phenomena into spectral domains not…