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261.
The half- and fully-ammonium ion exchanged forms of α- and γ-zirconium phosphates and of α-zirconium arsenate have been prepared. Their modes of thermal decomposition were studied by thermal methods of analysis, including simultaneous DTA/mass spectrometry. The samples heated to various temperatures were also characterized by X-ray diffraction analysis together with IR spectroscopy. The loss of water and ammonia of the various exchanged samples is compared in terms of the changes taking place in the layer lattice upon heating. The use of DTA/MS for a system involving water and ammonia as volatiles is demonstrated  相似文献   
262.
AStudyofSynthesis,ImmobilizationandCatalyticCapabilityofMetaloporphyrin*WANGXing-qiao**,GAOShuang,CAChang-shengYULian-xiang,G...  相似文献   
263.
In some circumstances, P-nBu3 pr P-nBu3/CC14 desulphurises [Fe(CO)2{P(OPh)3}2(CS2)] to give [Fe(CO)2{P(OPh)3}2(CS)] which has trigonal bipyramidal coordination about the iron atom with the phosphite ligands in axial positions.  相似文献   
264.
The bridging vinyl clusters [HOs3(CHCHR)(CO)10] (R = H, Ph, or n-Bu) react with PMe2Ph to give the zwitterionic adducts [HOs3(CHCHRPMe2Ph)(CO)10] which contain μ2-alkylidene ligands. The adducts are not formed so readily when R = Ph or n-Bu but most readily when polar solvents are used. All three CHCHR complexes add cyanide ion irreversibly to give the anionic clusters which were isolated as [N(PPh3)2][HOs3(CHCHRCN)(CO)10]. There is infrared evidence for the addition of various other anions. Acid reverses the addition of methoxide but HCl reacts with the cyanide adduct [HOs3(CHCH2CN)(CO)10]? to give [HOs3Cl(CO)10] and EtCN. No evidence for nucleophilic addition at [HOs3(PhCCHPh)(CO)10] was obtained.  相似文献   
265.
The production of a novel two-dimensional bimolecular surface structure using weak noncovalent interactions is demonstrated and observed by scanning tunneling microscopy. This work follows the three-dimensional (3D) ideas of crystal engineering and applies the concepts of supramolecular synthons to molecular systems constrained to 2D by physisorption on a conducting surface. We demonstrate a well-ordered planar structure that self-assembles through the influence of fluorine-phenyl interactions. This study provides a concrete example of the "bottom up" construction of nanostructures and of the systematic design of self-organized layers. To our knowledge, this is the first in a new class of fully 2D materials based both upon weak intermolecular interactions and upon image charges and weak interactions associated with adsorption on metal surfaces.  相似文献   
266.
267.
The simultaneous analysis of evolved gases and the determination of stable isotope composition (delta13C) as part of a thermal analysis experiment have been used to (a) distinguish bulk chemical hosts for carbon (C) and nitrogen (N) within a soil and (b) track labelled C within a soil sequestration experiment. C3 and C4 dung was applied to a pasture soil, and soil samples taken for analysis. The results of thermogravimetry-differential scanning calorimetry-quadrupole mass spectrometry-isotope ratio mass spectrometry (TG-DSC-QMS-IRMS) show that the proportion of more refractory C (lignin-like) is greater for the dungs than for the soil organic matter (SOM), and that this increases with time within the soil. Analysis of evolved gases shows that nitrogen is associated with the decomposition of more refractory C, and is not so strongly associated with the labile C component. IRMS analysis distinguished C3 and C4 dung, and allowed the amount of C from these sources to be estimated for the soil samples. Most dung C enters the refractory SOM fraction. This paper demonstrates the potential of TG-DSC-QMS-IRMS in the investigation of SOM.  相似文献   
268.
Troy D. Manning  Ivan P. Parkin   《Polyhedron》2004,23(18):3087-3095
The dual source atmospheric pressure chemical vapour deposition (APCVD) reaction of VOCl3 and H2O was used to prepare thin films of vanadium oxides on glass and silicon substrates. The thin films were characterised by X-ray diffraction, Raman spectroscopy X-ray photoelectron spectroscopy and scanning electron microscopy. At reactor temperatures above 600 °C with a gas-phase excess of water over VOCl3, vanadium(IV) oxide thin films were produced which show a thermochromic transition temperature of 67 °C. The APCVD process is directly compatible with high throughput float-glass production enabling the use of a thin film of VO2 as an intelligent window coating. With reactor temperatures below 600 °C or with a gas-phase excess of VOCl3 over water, V2O5 thin films were produced. Vanadium(IV) oxide thin films could also be prepared on silicon substrates from the APCVD reaction of VOCl3 and H2O, which opens up further technological applications for the APCVD of VO2 thin films.  相似文献   
269.
[Fe(CO)2 {P(OR)3}2 (SO2)] complexes (R = aryl) exist in solution as equilibrium mixtures of two isomers; both have been shown by X-ray diffraction studies (where R = Ph or o-MeC6H4) to have planar coordination about SO2 and trigonal bipyramidal coordination about Fe, but in one isomer (R = Ph) the equatorial plane is occupied by SO2 and two CO ligands whilst in the other one (R = o-MeC6H4) it is occupied by the SO2 and two P ligands.  相似文献   
270.
A new low temperature differential scanning calorimeter is described which operates over the temperature range –150 °C to 700 °C. The equipment features a chromel heat flux DSC sensor plate located in a cobalt alloy heating chamber, enabling work to be carried out in oxidizing atmospheres to above 600 °C. Full data processing and programme control facilities are provided by an IBM compatible computer system. The performance of the instrument is illustrated by experiments on indium and poly (vinyl chloride).
Zusammenfassung Ein neues Tieftemperatur-Differential-Scanning-Kalorimeter für den Bereich von –120 °C bis+700 °C wird beschrieben. Das Gerät enthält eine Wärmefluss-DSC-Sensorplatte aus Chromel in einer Heizkammer aus einer Kobaltlegierung, was Arbeiten in oxidierender Atmosphäre bis über 600 °C ermöglicht. Ein IBM-kompatibles Computersystem bietet alle Möglichkeiten der Datenverarbeitung und Programmregelung. Die Leistungsfähigkeit des Geräts wird an Hand von Experimenten mit Indium und Polyvinylchlorid demonstriert.

, —150° 700°. , 600°. IBM . .
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