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。
In the presence of catalysts, polycarboxylic acids such as meso -1,2,3,4-butanetetracarboxylic acid (BTCA) can cross-link cellulose in a process believed to involve cyclic anhydrides as intermediates. This study was undertaken to explore, in the absence of cellulose, interactions between catalysts and polycarboxylic a…
The binary phase diagram between (R) and (S) N-acetyl-α-methylbenzylaminehas been established by using differential scanning calorimetry and X-ray diffraction. Up to 337 K, the two enantiomers form an eutectic mixture without partial solid solution (i.e. conglomerate). At 337 K, the eutectoid equilibrium: conglomerate…
A highly sensitive flow injection technique involving oxidative cleavage and spectrofluorimetric detection was developed for the determination of methotrexate. Cerium(IV) trihydroxyhydroperoxide (CTH) was introduced as a packed reactor for the construction of a derivatization column which is used in a flowing system f…
Microcrystalline La2O3 outgassed at 873 K has a UV absorption edge centred at ca. 250 nm on which absorption ascribable to surface states is superimposed. This latter absorption is diminished by CO2 adsorption, which produces surface carbonate. UV reflectance and IR results with CO are correlated to show that CO adsor…
The effect of TiO2, ZrO2 and P2O5 as nucleating agents was discussed in a SiO2-Al2O3-MgO-CaO-Na2O glass system. Crystallization study of glass system containing these oxides indicated that only surface crystallization and not volume crystallization occurred. The crystals that were formed were wollastonite and a small…
The oxidation of CaS and SrS powders and thin films was studied in situ up to 1300 °C by thermoanalytical techniques (TG, DTA and high-temperature XRD) while FTIR and powder XRD were used to analyse ex situ the solid reaction intermediates and products. CaS powder starts to oxidize to CaSO4 around 500 °C but the oxida…
A self-propagated combustion technique for the synthesis of zirconia-doped barium titanate (BZT) is reported. The technique involves autocombustion of a citrate-nitrate gel at relatively low temperature (150–200 °C). The product is obtained after calcination of the resulting ash at ca. 800 °C. The method is very simpl…
Parameters of strength of isotropic high-density graphite are thought to be strongly correlated to pore structure of the graphite from experimental results on fracture toughness. Until now the pore structure has not been analyzed quantitatively, and the relation between the parameters of strength and the pore structur…
Models are presented for the family of n,3 polyamides. They have an organization in space quite different from the usual α and γ forms of polyamides. Hydrogen-bonded sheets are not present in the n,3 polyamides. The molecules are linked by an unique network of hydrogen bonds with two spatial orientations which form an…
Asymmetric biphenyl type polyimides (PI) were prepared by thermal imidization of polyamic acids (PAA) derived from 2, 3, 3′, 4′- biphenyltetracarboxylic dianhydride (a-BPDA) and p-phenylenediamine (PDA) or 4, 4′-oxydianiline (ODA). The degrees of molecular orientation, film densities, and dynamic mechanical properties…
Phase relations in the Sm–Fe–V system, especially around the compound Sm3(Fe,V)29, have been studied. Isothermal sections of the iron-rich corner of the Sm–Fe–V system were constructed from X-ray diffraction studies and microstructural observations. α-(Fe,V), γ-(Fe,V), Sm2(Fe,V)17, Sm(Fe,V)12 and liquid phases are pre…
Electrochemical noise measurements (ENM), linear polarization tests and mass loss measurements were performed in sulfuric acid, acetic acid and other solutions. The ENM data were converted to corrosion rates by calculating the noise resistance, Rn = σV/σI where σV and σI are the standard deviations of the potential an…
The surface structure of a clean MoS 2 (0002) and an in situ Cs surface-doped MoS 2 (0002) has been studied using high-resolution X-ray photoemission spectroscopy. The X-ray photoelectron diffraction (XPD) patterns of the Mo 3d 5/2 and S 2p core levels from a clean, well-ordered MoS 2 (0002) show forward focusing inte…
Methylene Blue adsorption isotherms from aqueous solution at 25 °C, and diffuse reflectance spectra of the adsorbed dye have been used to examine aluminosilicate gels and zeolite X formed during hydrothermal synthesis. These techniques require little sample pretreatment, and during the measurements the dye cannot pene…
Tetrahedral pentaerythritol tetra(3,4-dialkoxybenzoates) and tetra(3,4,5-trialkoxybenzoates) can display columnar liquid-crystalline phases despite the fact that they are neither disc-like nor amphiphilic.
The AC electrical behaviour of sandwich devices fabricated entirely in vacuum using thermally evaporated thin films of lead phthalocyanine and gold electrodes is observed over the frequency range to Hz and the temperature range 160 to 440 K. In the high-frequency region the AC conductivity is proportional to . Capacit…
Throughout the author's research on “Drying Theory”, emphasis has been placed on the observation of phenomena. Regarding the simultaneous transport of mass (water and water vapor)-heat-momentum during drying. it is represented by “drying basic equations” which take the form of simultaneous differential equations, whil…
Partial discharges in high voltage metal-clad switchgear can result in catastrophic failure of the individual plant and in some cases of the substation. There has been a need for detection and location of the damaging discharges without the plant or substation being taken out of service. The conventional partial disch…
The short-range structure in amorphous and liquid GexTe1−x alloys with x≤0.33 has been investigated through time-of-flight neutron diffraction measurements. The first sharp diffraction peak (FSDP) in the structure factor was observed in the amorphous state, implying that the structural units are partially connected ea…
As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether pyrimidine)s have been prepared with 4,6-bis(4-(trimethylsiloxy)phenyl)pyrimidine and a series of activated bis(aryl fluoride)s using a catalytic amount of cesium fluoride in diphenyl sulfone. These polymers…