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排序方式: 共有119条查询结果,搜索用时 10 毫秒
1.
Doz. Dr. P. Bukovec B. Orel J. Šiftar 《Monatshefte für Chemie / Chemical Monthly》1974,105(6):1299-1305
The IR- and Raman Spectra of several compounds of the stoichiometryM 2 I M IIIF5H2O and their deuterated analogs have been interpreted on the basis of their crystal structures. The compounds studied were divided into two classes regarding the bonding of water molecules. The main spectroscopic difference between the two classes was found in the region of H2O vibrations in good agreement with theoretical predictions. The metal—fluorine and metal—oxygene vibrations gave no direct information concerning the two types of water. 相似文献
2.
Summary Optically pure (+)-beta-eudesmol is a possible starting material for the synthesis of several termite defense compounds. A
two step procedure for the isolation of gram quantities of (+)-beta-eudesmol from commercially availableAmyris balsamifera oil (syn. West Indian sandalwood oil), containing 8% beta-eudesmol, was developed. Step one consisted of an efficient vacuum
distillation of the total oil. Step two was a medium pressure LC separation with an AgNO3 impregnated silica gel stationary phase. Several other separation procedures failed due to the presence of many closely related
sesquiterpene alcohols (75% of the oil). 相似文献
3.
4.
Zorica?Crnjak Orel Egon?Matijevi? Dan?V.?GoiaEmail author 《Colloid and polymer science》2003,281(8):754-759
Uniform, spherical CuCl particles were obtained by mixing aqueous solutions of CuCl 2 and ascorbic acid in the presence of polyvinylpyrrolidone (PVP) as dispersing agent. The size and the uniformity of the resulting particles depended on the volume ratio of the reactant solutions, their concentrations, the distribution of the stabilizers, and the mixing method. The single jet precipitation yielded large spheres of broad size distributions, while the particles obtained by the double jet technique were rather uniform in size. The final colloidal CuCl particles were formed by the aggregation of nanocrystals, initially generated in the system. Depending on the pH of the reaction mixture, these particles slowly change to large CuCl crystals on aging in the mother liquor. 相似文献
5.
Jelena Vasiljević Samira Hadžić Ivan Jerman Lidija Černe Brigita Tomšič Jožef Medved Matjaž Godec Boris Orel Barbara Simončič 《Polymer Degradation and Stability》2013
The aim of this study was to introduce a non-formaldehyde inorganic–organic hybrid sol–gel flame-retardant precursor (SiOP) containing phosphorous, nitrogen, and silicon and to compare its functional properties with those of the conventional formaldehyde-containing organic flame-retardant agent, organophosphonate (OP). SiOP was used at concentrations of 2%, 4%, and 8%, and OP was used at a concentration of 200 g/dm3. Both agents were applied to 100% cotton (CO) woven fabric by the pad-dry-cure method under the appropriate conditions. The presence of the SiOP and OP coatings on the CO fabric was confirmed by scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. The results of the vertical tests of flammability and the thermogravimetric analyses showed that the presence of the SiOP coating changed the thermal degradation pathway of the CO fabric and resulted in an increase in the thermo-oxidative stability of the cellulose fibres. The thermo-oxidative stability was enhanced by the addition of higher amount of dry solids. At comparable dry solids contents, OP preserved significantly greater flame retardancy and thermo-oxidative stability than did SiOP. These results indicated that the SiOP precursor could not act as an effective alternative to the OP agent in the flame-retardant protection of CO fabric. 相似文献
6.
Thin solid films of mixed Fe/Ti oxide composition (Fe/Ti molar ratios: 0.5∶1, 1∶1, 1.5∶1) have been made from Fe(NO3)3 alcoholic solution to which Ti(OiPr)4 was added. Films have been deposited by the dip-coating technique and heat-treated at 300°C and 500°C. Powders of Fe/Ti oxide
heat-treated at 300°C are amorphous, while powders annealed at 500°C for 40 hours transformed to mixed rutile, pseudobrookite
and hematite phases. The structure of the XRD amorphous films was identified with the help of near-normal reflection absorption
(6°) (IRRA) and near-grazing incidence angle (NGIA) spectroscopy. NGIA FT-IR spectra of films are characterised with a single
phonon mode appearing in the spectral range 600–950 cm−1 which shifts with increasing Ti concentration from 675 cm−1 (Fe2O3) to 904 cm−1 (TiO2) thus exhibiting one-mode behavior.
Electrochemical investigations made with the help of cyclic voltammetry (CV) and chronocoulometry (CPC) performed in 0.01M LiOH and in 1M LiClO4/propylene carbonate electrolytes revealed that films are able to uptake reversibly Li+ ions with a charge capacity (Q) per film thickness (d) in the range 0.1–0.26 mC/cm2nm and 0.06 mC/cm2nm, respectively. The temperature at which the films were prepared alters the rate of Li+ insertion which is faster for less compact films obtained at 300°C. In situ UV-VIS spectroelectrochemical measurements revealed
that Fe/Ti oxide films bleached in the UV spectral region (300 nm<λ<450 nm) and colored in the VIS spectral region (450 nm<λ<800
nm), thus exhibiting mixed anodic and cathodic electrochromism. 相似文献
7.
An application of symplectic implicit Runge–Kutta (RK ) integration schemes, the s-stage Gauss–Legendre Runge–Kutta (GLRK ) methods of order 2s, for the numerical solution of molecular dynamics (MD ) equation is described. The two-stage fourth-order GLRK method, the implicit midpoint rule, and the three-stage diagonally implicit RK method of order four are studied. The fixed-point iteraction was used for solving the resulting nonlinear system of equations. The algorithms were applied to a complex system of N particles interacting through a Lennard-Jones potential. The proposed symplectic methods for MD integration permit a wide range of time steps, are highly accurate and stable, and are thus suitable for the MD integration. © 1994 John Wiley & Sons, Inc. 相似文献
8.
Jelena Vasiljević Brigita Tomšič Ivan Jerman Boris Orel Gregor Jakša Barbara Simončič 《Cellulose (London, England)》2014,21(4):2611-2623
This research aimed to prepare cotton fibres with novel multifunctional water- and oil-repellent, antibacterial, and flame-retardant properties. A three-component equimolar sol mixture, which included 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride, and P,P-diphenyl-N-(3-(trimethoxysilyl)propyl) phosphinic amide, was applied to the cotton fabric using the sol–gel process. The presence of the coating on the cotton fibres was confirmed by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy. The functional properties of the coated cotton fabric were determined from liquid contact angle measurements and antibacterial activity, burning behaviour, and thermo-oxidative stability studies. The results demonstrate that a unique, compatible, and uniform organic-inorganic hybrid polymer network was formed on the fabric surface, which preserved its simultaneous hydrophobic (water contact angle of 135 ± 2°), oleophobic (n-hexadecane contact angle of 117 ± 1°), and bactericidal (bacterial reduction of 100 %) properties and incorporated the enhanced thermo-oxidative stability of the modified cellulose fibres. 相似文献
9.
Additive mappings, which do not increase the minimal rank of symmetric matrices are classified in characteristic two or three. 相似文献
10.
Zusammenfassung Die Analyse der IR-Spektren einer Auswahl der Verbindungen des TypsM
2
I
M
IIIF5·H2O bzw.M
I
M
IIIF4·2 H2O und der entsprechenden Deuterohydrate führt zum Ergebnis, daß das Wasser nicht koordinativ gebunden, sondern als Gitterwasser auftritt. Bei den hydratisierten Fluorogallaten ist die Wasserstoffbindung stärker ausgeprägt als bei den entsprechenden Fluoro-aluminaten und-indaten.
3. Mitt.: Mh. Chem.102, 885 (1971). 相似文献
Fluoro metallates (III), IV: IR-Spectra of some hydrated fluoro-aluminates,-gallates, and-indates
Interpretation of the IR spectra of several compounds of the stoichiometryM 2 I M IIIF5·H2O,M I M IIIF4·2H2O and their deuterated analogs proves the presence of the lattice water. Hydrogen bond is stronger in the case of fluorogallates in comparision to the similar fluoroaluminates and indates.
3. Mitt.: Mh. Chem.102, 885 (1971). 相似文献