Materials Literature
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We study the electronic structure and the optical properties of germanium clusters up to about 103 atoms, by using a semi-empirical tight-binding approach. Germanium nanocrystals are related to quantum dots growing, by a self-organization process, in sapphire matrices. The optical properties of such dots are experimen…
A new method to extract quantitative information from poorly resolved 29 Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of natural mixed-layer illite-smectite (I-S) clays is presented. The Si-Al distribution in layered aluminosilicates are used to link the intensities of 29 Si resonances from a…
Beim Einengen einer Lösung von Er2(SO4)3 in Wasser erhält man Er2(SO4)3 · 8 H2O in Form von blaßrosa Einkristallen. Nach Auskunft der Einkristallstrukturanalyse kristallisiert die Verbindung monoklin (C2/c, Z = 8, a = 1346,1(3), b = 667,21(1), c = 1816,2(6) pm, β = 101,90(3)°, Rall = 0,0169) mit achtfacher Koordinatio…
This simple experiment illustrates the main features of excited oxygen in the singlet state 1 O 2 ( 1 D g ): (i) its high oxidizing power and its selectivity towards unsaturated organic compounds, (ii) its low excitation energy which allows its access by various chemical processes and (iii) its long lifetime compared…
The structure of human insulin mutant B9 (Ser-->Glu) was determined by an X-ray crystallographic method at 2.5 A resolution with an R factor of 0.165 under non-crystallographic restraints. The crystals were grown at low pH (<3.8) and belong to the orthorhombic P2(1)2(1)2(1) space group with unit-cell dimensions a = 44…
Sso7d is a basic 7-kDa DNA-binding protein from Sulfolobus solfataricus, also endowed with ribonuclease activity. The protein consists of a double-stranded antiparallel beta-sheet, onto which an orthogonal triple-stranded antiparallel beta-sheet is packed, and of a small helical stretch at the C-terminus. Furthermore,…
Creation of an autologous heart valve by tissue engineering offers a promising approach to cardiac surgery. Although we have demonstrated successful formation of native valve analogous tissue in vitro, hemodynamic competence remains a serious problem. The aim of this study was to optimize in vitro formation of collage…
The realization of electrooptic coefficients leading to digital drive voltage levels is an important objective if polymeric electrooptic materials are to achieve significant commercial application. Polymeric materials characterized by electrooptic coefficients somewhat greater than those of the dominant commercial mat…
Summary Much of the Paris Basin is covered with loess, dominated by particles 2–50 μm in diameter, which has undergone strong pedogenesis. We have investigated the mineralogical changes that have accompanied the development of a Podzoluvisol in such material. Four silt‐size and two clay‐size fractions from five horizo…
Spark plasma sintering (SPS) was applied to the production of non-lead ferroelectric Bi 4 Ti 3 O 12 ceramics. A powder compact of a calcined oxide mixture was embedded in a mixture of ZrO 2 and Sb-doped SnO 2 powders in a carbon die and heated for a very short duration under a constant current of 450 A. This process l…
A series of SiC‐AlN compositions of 0, 10, 25, 50, 75, 90, and 100 mol% AlN were hot pressed at 2100°C for a 1 h soak at a pressure of 35 MPa under vacuum. 2H‐wurtzite SiC‐AlN solid‐solution structures were formed for compositions with 25‐100 mol% AlN. The associated lattice parameters for these solid solutions follow…
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Thermal and Structural Studies of Phase Transitions in Layered Perovskite SrBi2Ta2O9 , Myint, Akira Onodera, Seiji Kojima, Seiji Kojima, Haruyasu Yamashita, Haruyasu Yamashita, Toshihiko Takama, Toshihiko Takama
Site-directed mutagenesis was used to determine the efficacy of changing surface residues to improve crystal quality. Nine mutants of the 24 kDa fragment of the Escherichia coli DNA gyrase B subunit were produced, changing residues on the protein's surface. The mutations changed either the charge or the polarity of th…
We report here the results of magnetic susceptibility, electrical resistivity, magnetoresistance (MR), heat-capacity, and ${}^{151}\mathrm{Eu}$ M\"ossbauer-effect measurements on the compound ${\mathrm{Eu}}_{2}{\mathrm{CuSi}}_{3},$ crystallizing in an ${\mathrm{AlB}}_{2}$-derived hexagonal structure. The results estab…
To prevent crystals from moving in orbit and sedimenting upon their return to earth, the model protein thaumatin was crystallized in agarose gel in the Advanced Protein Crystallization Facility during the eight-day Space Shuttle mission STS-95 (November 1998). The quality of tetragonal crystals grown in microgravity w…
Surface-stabilized ferroelectric liquid crystals (SSFLCs) fabricated by adopting polymer stabilization in terms of the UV photocure of doped photocurable monoacrylates with mesogenic side chains at a temperature where the LC medium is in the SmC * phase under the simultaneous application of a monopolar electric field,…
The use of agricultural residues for power production has generated increasing interest in the conversion of rice husks to higher quality fuels by thermochemical conversion processes such as pyrolysis, combustion, and gasification. However, the reliable design and operation of thermochemical conversion systems require…
Atomic structures, energies, and stress distributions of symmetrical 〈011〉 tilt grain boundaries (GB's) and selected GB triple junctions (TJ's) in diamond as well as a multiply twinned diamond particle have been calculated using an analytic bond order potential function. In general, energies of 〈011〉 tilt GB's are abo…
Thirteen pedons representing the mountains, the upper footslopes, the lower footslopes, and the alluvial terraces of a volcanic slope in Mindanao, the Philippines were studied to understand relationships between the degree of soil development and fertility characteristics. Soils in the upper and the lower footslopes w…