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。
Assuming the existence of stationary metastable states (SMS's), and using general thermodynamic arguments, we prove that a positive Kauzmann temperature exists for SMS's provided the ideal glass energy is higher than the crystal energy at absolute zero. We confirm the general predictions by two exact calculations, one…
We have fabricated MgxZn1−xO epitaxial composition spreads where the composition across the chip is linearly varied from ZnO to MgO. By using a scanning x-ray microdiffractometer and transmission electron microscopy, we have mapped the phase evolution across the spread. We have discovered a unique growth relationship…
Silicatein, an enzymatic biocatalyst purified from the glassy skeletal elements of a marine sponge, and previously shown capable of catalyzing and structurally directing the hydrolysis and polycondensation of silicon alkoxides to yield silica and silsesquioxanes at low temperature and pressure and neutral pH, is shown…
We report on the observation of field-effect transistor (FET) behavior in electrospun camphorsulfonic-acid-doped polyaniline/polyethylene oxide (PEO) nanofibers. Saturation channel currents are observed at surprisingly low source–drain voltages. The hole mobility in the depletion regime is 1.4×10−4 cm2/V s, while the…
Ceria nanoparticles are a widely used nanomaterial for applications in catalysts, fuel cell, and microelectronics. An important factor that influences the performance of CeO 2 is the particle shape. In this paper, a systematic study has been carried out to determine the shapes of CeO 2 nanoparticles. For particles in…
The reactions of single-walled carbon nanotubes (SWNTs) with succinic or glutaric acid acyl peroxides in o-dichlorobenzene at 80-90 degrees C resulted in the addition of 2-carboxyethyl or 3-carboxypropyl groups, respectively, to the sidewalls of the SWNT. These acid-functionalized SWNTs were converted to acid chloride…
An image-plate (IP) detector coupled with high-energy synchrotron radiation was used for atomic pair distribution function (PDF) analysis, with high probed momentum transfer Q max ≤ 28.5 Å −1 , from crystalline materials. Materials with different structural complexities were measured to test the validity of the quanti…
A model, based on the theory of nonlocal continuum mechanics, on the column buckling of multiwalled carbon nanotubes is presented. The present analysis considers that each of the nested concentric tubes is an individual column and that the deflection of all the columns is coupled together through the van der Waals int…
CRYSTALS version 12 contains a modern crystallographic user interface, and novel strategies that incorporate chemical knowledge and crystallographic guidance into the crystal structure analysis software.
X-ray crystallography provides one of the most important tools for understanding structure-function relationships in proteins. Over the last several years, the scientific community has accumulated a great deal of experience making crystals and solving protein structures by X-ray diffraction. However, often the X-ray a…
In the past decade macromolecular crystallography has undergone major advances in crystallization, data collection by synchrotron X-ray sources and area detectors, and data analysis by high performance computers and new computational techniques. In addition, recombinant gene technology in many cases allows the express…
The primary functional role of collagen is as a supporting tissue and it is now well established that the aggregated forms of the collagen monomers are stabilized to provide mechanical strength by a series of intermolecular crosslinks. These links are formed by oxidative deamination of the ε-amino group of the single…
Abstract The new trihydrate diphosphate, MnNH 4 NaP 2 O 7 ·3H 2 O, were synthesized and investigated by X‐ray diffraction and vibrational spectroscopy. Single crystal structure has been obtained using 1361 reflections with a final R value of 0.0564. This salt crystallizes in the monoclinic system, space group Cc, with…
Through comparison with the high-resolution structure of Clostridium symbiosum glutamate dehydrogenase, the different substrate specificities of the homologous enzymes phenylalanine dehydrogenase and leucine dehydrogenase were attributed to two residues, glycine 124 and leucine 307, in Bacillus sphaericus phenylalanin…
We present ab initio studies of $2\ifmmode\times\else\texttimes\fi{}1$ reconstructions of the diamond, Si, and Ge(113) surfaces. For all group-IV elements tetramers stabilize the (113) surface due to the tendency for opening of a surface-state gap. In the case of diamond, the symmetric tetramer structure with semicond…
Ni 81 Fe 19 was sputter deposited onto Si single-crystal wafers which had the native oxide layer intact. Dc hysteresis loops were measured using the magneto-optic Kerr effect, and anisotropy fields determined from the susceptibility. Saturation magnetostriction constants were deduced from the change in anisotropy fiel…
The incorporation of trans -cyclohexylene (C-ring) groups into the main chains of glassy polymers increases polymer chain dynamics. With the increase in trans-C-ring content in the main chain, both the coefficient of thermal expansion (CTE) of bulk specimens and the CTE of nanosized holes in these glasses increase. Tr…
We summarize our correlated scanning tunnelling microscopy and optical spectroscopy investigations of the electronic level structure and single-electron charging effects in CdSe quantum rods. Both optical and tunnelling spectra show that the level structure depends primarily on rod diameter and not on length. With inc…
A new approach to introduce polymers to cellulosic materials was developed by using the ability of a cellulose-binding module-Candida antarctica lipase B conjugate to catalyze ring-opening polymerization of epsilon-caprolactone in close proximity to cellulose fiber surfaces. The epsilon-caprolactone was introduced to…
Imidazole glycerol-phosphate dehydratase (IGPD) catalyzes the sixth step of histidine biosynthesis. The enzyme is of fundamental biochemical interest, because it catalyzes removal of a non-acidic hydrogen atom in the dehydration reaction. It is also a potential target for development of herbicides. IGPD is a metalloen…