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1.
DTA investigations of glasses in the system Al2(SO4)3-H2O/55–65 mass% Al2(SO4)3 revealed effects at the glass transformation (T g), crystallization and melting temperature. During storage at ambient temperature,T g increased, probably due to an annealing process; the increase was the least at the stability maximum for the glasses, at 61–63% Al2(SO4)3.
Zusammenfassung Gläser des Systems Al2(SO4)3-H2O mit 55–65 Masse-% Al2(SO4)3 zeigen bei der DTA Effekte bei den Temperaturen von Glasumwandlung (T g), Kristallisation und Schmelzen. Aufbewahren bei Raumtemperatur führt zum Ansteigen vonT g, wahrscheinlich in Folge eines Temperprozesses; dieser Anstieg ist am geringsten bei der Zusammensetzung mit 61–63% Al2(SO4)3, d. h. am Stabilitätsmaximum der Gläser.

- 55–65 . % , g, . g, (61–63 .% ).
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2.
Five new steroid alcohols have been isolated in the form of their acetates from extracts of the spongeHalichondria sp 1 by column chromatography on silica gel and they have been identified as 24-isopropyl-5-cholest-22z-en-3-ol, 24-isopropylcholesta-5, 22Z-dien-3-ol, 24,24,26,26-tetramethylcholesta-5,25(27)-dien-3-ol, 24,24,26,26-tetramethylcholesta-5,22E,25(27)trien-3-ol, and 24-isopropenyl-25-methylcholesta-5,22E-dien-3-ol. The structures were established by an analysis of spectral characteristics.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 232–239, March–April, 1985.  相似文献   

3.
N-(2,3-Epoxypropyl)--pyrrolidone and N-(2,3-epoxypropyl)--suecinimide have been obtained for the first time. It has been shown that N-(2,3-epoxypropyl)--pyrrolidone readily reacts with ammonia and diethylamine to form the corresponding amino alcohols.  相似文献   

4.
Benzophenone analog 3 has been synthesized and characterized by the X-ray diffraction (XRD) method. The compound crystallizes in a monoclinic space group P21/c with cell parameters a = 7.701(8) Å, b = 7.151(5) Å, c= 28.323(3) Å, = 104.639(4)°, Z = 4. The structure exhibits intra- and intermolecular hydrogen bonding of the type N–HO, C–HO, and N–HN. The molecules are interlinked through hydrogen bonds forming an infinite chain. This polymeric-like structure may play an important role in biological activity.  相似文献   

5.
The simplest scheme of association reactions is suggested, whose mathematical model permits the existence of self-oscillations.
, .
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6.
Summary Vis spectrophotometry has been used to study various ligand substitution equilibria (1) and (2) involving four-coordinate copper(II) and nickel(II) his chelate complexes in methanol, propan-2-ol and toluene. MA2 + HB MAB+HA, K1 (1) MAB + HB MB2 + HA, K2 (2) The Schiff base ligands, HA and HB, which are monobasic and bidentate, represent salicylaldimine type N,O-ligands ( HSA=NR) (1) or pyrrole-2-aldimine type N,N-ligands ( HPA=NR) (2) with different branching at the - or (3-carbon of the organic group R. For both types of ligand the relative thermodynamic stability of their copper and nickel complexes is governed mainly by the steric demands of R, which determine the degree of tetrahedral distortion. The order of stability as given by = K1 K2 is: t-Bu < neo-Pent < i-Pr < i-Bu < Et < n-Pr. The K1/K2 ratio is strongly solvent dependent in the sense that the mixed ligand species MAB is stabilised in toluene relative to methanol. Such a solvent effect is not observed for . The MAB complexes could not be isolated. The vis spectrum of the mixed ligand species Ni(SA=NiPr, SA=NEt) was calculated by computer fitting of the experimental data.  相似文献   

7.
We have synthesized the organic conductor (BEDT-TTF)AgXIY (X 1.8 and Y 2.9). This compound has, in addition to high electronic conductivity (300 k 5–10 –1 · cm–1), significant ionic conductivity connected with the motion of silver ions. The value of this ionic conductivity at room temperature is 10–3 –1 · cm–1. The activation energy for diffusion of Ag ions is equal to 0.2 eV.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 247–249, March–April, 1989.  相似文献   

8.
A thermodynamic study is presented for the simultaneous synthesis of C1–C4 alcohols from synthesis gas. The equilibrium composition was calculated for the gaseous mixture containing Co, H2, CH3OH, C2H5OH, C3H7OH, n-C4H9OH and H2O. Operating industrial conditions were specifically considered.
C1–C4 -. , CO, H2, CH3OH, C2H5OH, C3H7OH, -C4H9OH H2O. .
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9.
The chlorination kinetics of pure vanadia was studied via isothermal thermogravimetric measurements, with CCl4, CoCl2 and Cl2 as chlorinating agents. At temperatures where chemical control was predominant, apparent activation energies of 77, 48 and 126 kJ: mol–1 were obtained for chlorination by CCl4, COCl4 and Cl2, respectively. For interpretation of the conversion vs. time curves in the whole conversion range, a non-uniform particle size distribution was assumed, where the reacting solid phase was considered to be composed of thin plates of different thicknesses. With this model, a fairly good correspondence was obtained between the measured and calculated kinetic curves. Selected thermodynamic calculation data on the V2O5 + CCl4, V2O5 + COCl2 and V2O5 + Cl2 systems are presented.
Zusammenfassung Mittels isothermen Thermogravimetriemessungen wurde die Kinetik der Chlorierung von reinem Vanadiumoxid mit CCl4, COCl2 und Cl2 als Chlorierungsmittel untersucht. Bei Temperaturen mit vorherrschender chemischer Kontrolle wurde für die Chlorierung mit CCl4, COCl2 bzw. Cl2 Bruttoaktivierungsenergien von 77, 48 bzw. 126 kJ/mol erhalten. Zur Interpretation der Konversion-Zeit-Diagramme im gesamten Conversionsbereich wurde eine nichteinheitliche Teilchengrösseverteilung angenommen, namentlich den Bestand der reagierenden Festphase aus dünnen Plättchen unterschiedlicher Dicke. Mit diesem Modell konnte eine recht gute Übereinstimmung zwischen errechneten und ermittelten kinetischen Kurven erhalten werden. Einige thermodynamische Rechenbeispiele für die Systeme V2O5 + CCl4, V2O5 + COCl2 und V2O5+Cl2 wurden gegeben.

, l4, l2 l2. , l4, l2 l2, 77, 48 126 ·–1. — , . , . - . V2O5+CCl4, V2O5+COCl2 V2O5+Cl2.
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10.
Based on investigations of temperature-programmed desorption of CO2 from -Al2O3 surface, three forms of CO2 adsorption differing considerably in quantitative contributions and temperature ranges of desorption have been distinguished. A significant inhibiting influence of water on CO2 adsorption has been observed. Water adsorption results in gradual blocking of high and medium-energy adsorptive centers of CO2 on -Al2O3.
- CO2 -Al2O3 CO2, . CO2. CO2 Al2O3 .
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11.
    
Photochemical reactions on the surface of -Al2O3 and V/-Al2O3 in the presence of H2+CO and CH4+CO gaseous mixtures have been investigated by IR and mass spectroscopy methods. It has been revealed that UV irradiation of V/-Al2O3 in CH4+CO produces surface formates and acetates, whereas after irradiation of V/-Al2O3 in H2+CO and -Al2O3 in both mixtures only surface formates are formed.
- -Al2O3 V/-Al2O3 H2+CO CH4+CO. - V/-Al2O3 CH4+CO , V/-Al2O3 H2+CO -Al2O3 - .
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12.
Zusammenfassung Aus Mono-und Dihalogen-essigsäuren bilden sich mitSchiff-schen Basen in Dimethylformamid (DMF) und POCl3 (bzw. POBr3) über labile Addukte -Lactame. Analog reagieren -Chlor-und -Brom-propionsäure.
The reaction of -chloro and -bromo acetic or propionic acids withSchiff bases inDMF in the presence of POCl3 or POBr3 yields -lactames via unstable adducts.
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13.
The preconcentration of Au and Pd on Duolite GT-73 chelating resin with the thiol functional group was investigated prior to determination of these noble metals by means of inductively coupled plasma atomic emission spectrometry. It was found that AuIII and PdII were retained on the resin along with other concomitant metals (Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) from different HCl-containing media. A two-step elution procedure was developed for the release of the noble metals. First 4.0molL–1 HNO3 solution was used to elute the base metals. The recovery of Au and Pd was performed afterwards using 0.50molL–1 solution of (NH2)2CS. Retrieval of Au and Pd retained on Duolite GT-73 was also carried out by decomposition of the resin in the open vessel system using H2SO4 with H2O2. The detection limits of Au and Pd evaluated for the devised protocol, with a preconcentration factor of 50, were 0.085µgL–1 and 0.28µgL–1, respectively. The proposed method was applied to the determination of Au and Pd in spiked electrolytic bath samples.  相似文献   

14.
The thermal decomposition of crystalline PI3 and P2I4 in nitrogen and oxygen is reported. The oxidation of PI3 leads mainly to the formation of phosphorus pentoxide and iodine together with PxI polymeric species as a minor product. The decomposition of the polymeric species P3I2O6 in oxygen and nitrogen follows a two-stage route which precludes its involvement in the oxidation of P2I4.
Zusammenfassung Es wurde die thermische Zersetzung von kristallinem PI3 und P2I4 in Stickstoff und Sauerstoff untersucht. Die Oxydation von PI3 führt zur Bildung von Phosphorpentoxyd und Jod mit wenig Polymeren der Zusammensetzung PxI. Die Zersetzung der Polymeren P3I2O4 in Sauerstoff und Stickstoff erfolgt in zwei Stufen, die eine Beteiligung in der Oxydation von P2I4 ausschließen.

Résumé On décrit la décomposition thermique, dans l'azote et dans l'oxygène, de PI3 et de P2I2 cristallins. L'oxydation de PI3 conduit principalement à la formation d'iode et de pentoxyde de phosphore, avec de petites quantités de PxI de type polymère. La décomposition de l'espèce polymère P3I2O6, dans l'oxygène et dans l'azote, s'effectue suivant un processus en deux étapes excluant sa participation à l'oxydation de P2I4.

I3 P2I4 . I3, , , — — xI . 3I26 , 2I4.


The author is indebted to Mrs. I. M. Walker for practical assistance with the thermoanalysis studies.  相似文献   

15.
The support and mixing effects of Fe2O3 for the activity of 1-butene oxidative dehydrogenation were examined. Alumina and titania which were able to catalyze the isomerization of butene via an allyl intermediate, stimulated remarkably the formation of butadiene from butene when they were used as support or mixing component of Fe2O3 catalyst. Otherwise Fe2O3 supported on SO 4 2– ion containing Al2O3 or TiO2–Al2O3, which catalyze the isomerization via a cationic intermediate, is almost inactive for the formation of butadiene.
Fe2O3 1-. , , , Fe2O3. , Fe2O3, Al2O3, SO 4 –2 , TiO2–Al2O3, , .
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16.
Iron(II) tartrate two and a half hydrate (FeC4H4O6·2.5H2O) was prepared and its thermal dehydration and decomposition were studied with a simultaneous thermal analyser (TG/DTA/DTG) under atmospheres of static air, dynamic dry nitrogen and dynamic air. This study was supplemented with the two-probe d.c. electrical conductivity technique under the same atmospheres. Under all the above atmospheres, the thermal dehydration was found to be a two-step process. However, the thermal decomposition process was quite complicated, involving the formation of various metastable intermediates, including-Fe2O3. The final product of decomposition under all atmosphere was-Fe2O3.Studies on the physical properties of-Fe2O3 were also undertaken.
Zusammenfassung Es wurde Eisen(II)-tartrathydrat (FeC4H4O6 · 2,5H2O) hergestellt und seine thermische Dehydratation bzw. Zersetzung in statischer Luftatmosphäre bzw. im Stickstoff- und Luftstrom mittels eines Simultanthermoanalysators (TG/DTA/DTG) untersucht, ergänzt durch Untersuchungen nach dem Gleichstromleitfähigkeitsverfahren in den gleichen Atmosphären. Die thermische Dehydratation wurde in jedem Falle als zweistufig befunden. Der thermische Zersetzungsprozeß ist jedoch wegen der Bildung verschiedener metastabiler Zwischenprodukte, z. B.-Fe2O3, recht kompliziert. Das Endprodukt der Zersetzung war in allen Fällen-Fe2O3. Weiterhin wurden die physikalischen Eigenschaften von-Fe2O3 untersucht.

, FeC4H4O6 · 2,52. . , . , y-Fe2O3. -Fe2O3. -Fe2O3.


Now deceased.

Financial assistance for this work was given by Grants-in-aid (Defence Ministry), Govt. of India. One of the authors (A.V.R.) is grateful to the Head, Dept. of Chemistry, Sardar Patel University, for his interest and encouragement.  相似文献   

17.
The thermal properties of coordination compounds of the composition Cu(NCS)2L2 (whereL=pyridine, 2-, 3- and 4-picoline, and 2,3-, 2,4-, 2,5-, 2,6-, 3,4- and 3,5-lutidine) are dealt with. The thermal decomposition of these compounds begins with the release of the ligandL. The compounds with pyridine derivatives containing a methyl substituent at position 2 show a markedly decreased initial decomposition temperature. It was found that X-ray irradiation caused a reduction of the central atom Cu(II) in the coordination compounds under investigation. X-ray electron spectra data showed the stability of the compounds Cu(NCS)2L2 withL=picoline or lutidine having a methyl substituent at position 2 to be distinctly lower in the surface layers. From the given series, the compounds Cu(NCS)2(pyridine)2 and Cu(NCS)2(3,5-lutidine)2 exhibit an analogous course of thermal decomposition in nitrogen atmosphere up to 600°. The stoichiometries of thermal decomposition are discussed.
Zusammenfassung Der Artikel befaßt sich mit den thermischen Eigenschaften von Koordi-nationsverbindungen der Zusammensetzung Cu(NCS)2 L 2 (L= Pyridin, 2-, 3-, 4-Pikolin, 2,3-, 2.4-, 2,5-, 2,6-, 3,4- und 3,5-Lutidin). Die thermische Zersetzung dieser Verbindungen beginnt mit der Abspaltung des LigandenL. Die Verbindungen mit Pyridinderivaten, welche einen Methylsubstituenten in Position 2 im Pyridinring enthalten, zeigen eine deutlich herabgesetzte anfängliche Zersetzungstemperatur. Es wurde gefunden, daß die Röntgenbestrahlung eine Reduktion des zentralen Cu(II)-Atoms bei den untersuchten Koordinationsverbindungen herbeiführte. Die Daten der Röntgen-Elektronenspektren zeigten, daß die Stabilität der Verbindungen Cu(NCS)2L2 mitL=Pikolin oder Lutidin, welche einen Methylsubstituenten in Position 2 enthalten, in den Oberflächenschichten wesentlich geringer ist. Von der gegebenen Reihe der Verbindungen zeigen Cu(NCS)2(Pyridin)2 und Cu(NCS)2(3,5-Lutidin)2 in Stickstoff-Atmosphäre bis zu 600° einen ähnlichen Verlauf der thermischen Zersetzung. Die Stöchiometrie ihrer thermischen Zersetzung wird beschrieben.

Résumé L'article a trait aux propriétés thermiques des composés de coordination de composition Cu(SCN)2L2 (L=pyridine, 2-, 3-, 4-picoline, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-lutidine). La décomposition thermique de ces composés commence avec la libération du ligandL. Les composés avec des dérivés de la pyridine contenant un substituant méthyle en position 2 sur le cycle de la pyridine présentent une température initiale de décomposition qui se trouve abaissée de manière appréciable. On observe que le traitement aux rayons X provoque une réduction de l'atome central Cu(II) dans les composés de coordination étudiés. Les données fournies par les spectres électroniques des rayons X ont montré que la stabilité des composés Cu(SCN)2L2 avecL= picoline ou lutidine, ayant un substituant méthyle en position 2, est nettement plus faible dans les couches superficielles. Dans cette série de composés, Cu(SCN)2 (pyridine)2 et Cu(SCN)2(3,5-lutidine)2 montrent, en atmosphère d'azote, jusqu'à 600°, un processus analogue de décomposition thermique. La stoechiométrie de leur réaction de décomposition thermique est examinée.

Cu(NCS)2L2 L=, 2-, 3-, 4- , 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-. L. 2- . , , Cu(II). , Cu(NCS)2L2 c L= , 2, . Cu(NCS)2 ( )2 Cu(NCS)2 (3,5-)2 600°. .
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18.
Casein phosphopeptides (CPP) are phosphorylated casein-derived peptides that can be released by in-vitro or in-vivo enzymatic hydrolysis of s1-casein, s2-casein, and -casein (CN). Many of these peptides contain a highly polar acidic sequence of three phosphoseryl groups followed by two glutamic acid residues. These domains are binding sites for minerals such as calcium, iron, and zinc and play an important role in mineral bioavailability. The aim of this study was speciation analysis of calcium, iron, and zinc in CPP fractions from the soluble fraction of a toddler milk-based formula. Methods for CPP separation by anion-exchange high-performance liquid chromatography (AE-HPLC) were combined with CPP identification by reversed-phase high performance liquid chromatography–electrospray ionization mass spectrometry and determination of the calcium, iron, zinc, and phosphorus content of the fractions obtained by AE-HPLC. Calcium and phosphorus were detected in all the analyzed AE-HPLC fractions. Calcium and zinc could be bound to CPP derived from s1-CN and s2-CN in fraction 3. Iron could be bound to CPP in fraction 4 in which -CN(15-34)4P was present with the cluster sequence S(P)S(P)S(P)EE. The results obtained prove the different distribution of calcium, iron, and zinc in heterogeneous CPP fractions.  相似文献   

19.
    
The replacement of triphenylphosphine by triphenylarsine or triphenylbismuthine in the systems -C3H5NiCl–(C2H5)nAlCl3–n-Lig strongly affects the isomerization activity of the catalytic complex and the distribution of hexanes in propylene dimerization. Systems with (C6H5)3As and (C2H5)2AlCl represent the highest isomerization activity and the highest selectivity to 2-methylpentene-2.
, -C3H5NiCl–(C2H5)n–AlCl3–n-Lig . (C6H5)3As (C2H5)2AlCl 2--2.
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20.
The tail-end purification of Am from Pu loading effluents in 7.5M HNO3 containing 160 mg l–1 Am and 1.2 mg l–1 Pu has been carried out. With 0.2M CMPO+1.2M TBP in dodecane as the extractant and stripping by 0.04M HNO3+0.05M NaNO2, the Pu level is brought down to 31.2 g l–1. When the acidity was reduced to 4.2M HNO3, one contact with 20% TLA/dodecane and subsequent extraction by a mixture of CMPO and TBP and stripping with 0.04M HNO3+0.05M NaNO2 gave Am samples without any detectable amounts of Pu. The recovery of Am was 90% by the first procedure and 98% by the second one.  相似文献   

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