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1.
Le Xin Song Chuan Feng Teng Peng Xu Hai Ming Wang Zi Qiang Zhang Qing Qing Liu 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(3-4):223-233
The present work revealed there was a conceptual difference in the thermal decomposition behaviors between the complexed β-cyclodextrin
(CD) in an inclusion system and the β-CD complex of guest. The thermal decomposition behaviors of the solid inclusion complexes
of β-CD with ethylenediamine (Eda), diethylenetriamine (Dta) and triethylamine (Tea) were investigated using nonisothermal
thermogravimetry (TG) analysis based on weight loss as a function of temperature. In view of TG profiles, a consecutive mechanism
describing the formation and thermal decomposition of the three solid supermolecules of β-CD was presented. Heating rate has
very different effects on the thermal decomposition behaviors of these complexes. The faster the heating rate is, the higher
the melting-decomposition point of the complexed β-CD in an inclusion system is, and on the whole the bigger the rate constant
(k) of the thermal decomposition reaction of the complexed β-CD is. The thermal decomposition process of the complexed β-CD
for each inclusion system is determined to be simple first-order reaction using Ozawa method. The apparent activation energies
(E
a) and frequency factors (A) of the thermal decomposition reactions of the complexed β-CD molecules have been also calculated. It is found that when
the decomposition reaction of the complexed β-CD encountered a large value of E
a, such as that in Dta–β-CD system, an apparent compensation effect of A on E
a can provide enough energy to conquer the reaction barrier in prompting the k value of thermal decomposition reaction of the complexed β-CD according to Arrhenius equation. 相似文献
2.
H. X. Ma B. Yan Z. N. Li J. R. Song R. Z. Hu 《Journal of Thermal Analysis and Calorimetry》2009,95(2):437-444
The title compound 3,3-dinitroazetidinium (DNAZ) 3,5-dinitrosalicylate (3,5-DNSA) was prepared and the crystal structure has
been determined by a four-circle X-ray diffractometer. The thermal behavior of the title compound was studied under a non-isothermal
condition by DSC and TG/DTG techniques. The kinetic parameters were obtained from analysis of the TG curves by Kissinger method,
Ozawa method, the differential method and the integral method. The kinetic model function in differential form and the value
of E
a and A of the decomposition reaction of the title compound are f(α)=4α3/4, 130.83 kJ mol−1 and 1013.80s−1, respectively. The critical temperature of thermal explosion of the title compound is 147.55 °C. The values of ΔS
≠, ΔH
≠ and ΔG
≠ of this reaction are −1.35 J mol−1 K−1, 122.42 and 122.97 kJ mol−1, respectively. The specific heat capacity of the title compound was determined with a continuous C
p mode of mircocalorimeter. Using the relationship between C
p and T and the thermal decomposition parameters, the time of the thermal decomposition from initiation to thermal explosion (adiabatic
time-to-explosion) was obtained. 相似文献
3.
H. X. Ma B. Yan Y. H. Ren Y. Hu Y. L. Guan F. Q. Zhao J. R. Song R. Z. Hu 《Journal of Thermal Analysis and Calorimetry》2011,103(2):569-575
3,3-Dinitroazetidinium (DNAZ) salt of perchloric acid (DNAZ·HClO4) was prepared, it was characterized by the elemental analysis, IR, NMR, and a X-ray diffractometer. The thermal behavior
and decomposition reaction kinetics of DNAZ·HClO4 were investigated under a non-isothermal condition by DSC and TG/DTG techniques. The results show that the thermal decomposition
process of DNAZ·HClO4 has two mass loss stages. The kinetic model function in differential form, the value of apparent activation energy (E
a) and pre-exponential factor (A) of the exothermic decomposition reaction of DNAZ·HClO4 are f(α) = (1 − α)−1/2, 156.47 kJ mol−1, and 1015.12 s−1, respectively. The critical temperature of thermal explosion is 188.5 °C. The values of ΔS
≠, ΔH
≠, and ΔG
≠of this reaction are 42.26 J mol−1 K−1, 154.44 kJ mol−1, and 135.42 kJ mol−1, respectively. The specific heat capacity of DNAZ·HClO4 was determined with a continuous C
p mode of microcalorimeter. Using the relationship between C
p and T and the thermal decomposition parameters, the time of the thermal decomposition from initiation to thermal explosion (adiabatic
time-to-explosion) was evaluated as 14.2 s. 相似文献
4.
The thermal decomposition of benzoic acid and its derivatives containing —OH, —NH2, —COOH and —SO3H functional groups as substituents in ortho, meta and (or) para position together with sulphanilic acid was investigated.
The analyses were performed using derivatograph, sample mass ranged from 50 to 200 mg, heating rates from 3 to 15 K min−1 and static air atmosphere. It has been established that thermal decomposition of these aromatic acids proceeds through three
common stages. In the first stage the phase transformations occur. The following two stages are due to the formation of intermediate
products of the thermal decomposition and their combustion. Principal component analysis (PCA) was applied for evaluation
of the results. Thanks to this method the influence of specific functional groups and their positions on the benzene ring
on the thermal decomposition of the compounds under investigation was determined.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
S. -X. Wang Z. -C. Tan Y. -S. Li L. -X. Sun Y. Li 《Journal of Thermal Analysis and Calorimetry》2008,92(2):483-487
Synthesis, characterization and thermal analysis of polyaniline (PANI)/ZrO2 composite and PANI was reported in our early work. In this present, the kinetic analysis of decomposition process for these
two materials was performed under non-isothermal conditions. The activation energies were calculated through Friedman and
Ozawa-Flynn-Wall methods, and the possible kinetic model functions have been estimated through the multiple linear regression
method. The results show that the kinetic models for the decomposition process of PANI/ZrO2 composite and PANI are all D3, and the corresponding function is ƒ(α)=1.5(1−α)2/3[1−(1-α)1/3]−1. The correlated kinetic parameters are E
a=112.7±9.2 kJ mol−1, lnA=13.9 and E
a=81.8±5.6 kJ mol−1, lnA=8.8 for PANI/ZrO2 composite and PANI, respectively. 相似文献
6.
S. Y. Sawant V. M. S. Verenkar S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2007,88(3):669-672
Samples of water based commercial acrylic resin paints were spread in a film form on slides, dried at room temperature and
exposed to solar radiation for up to eight months.
The characterization and quantification of resins and charges in the white paint emulsion were carried out for the thermal
decomposition. Besides this, X-ray diffractometry was used to identify CaCO3 as charge and TiO2 (rutile phase) as pigment.
It was observed through thermal techniques similar behavior to the samples even though with varied exposure time.
Kinetic studies of the samples allowed to obtain the activation energy (E
a) and Arrhenius parameters (A) to the thermal decomposition of acrylic resin to three different commercial emulsion (called P1, P2, P3) through non-isothermal procedures. The values of E
a varied regarding the exposition time (eight months) and solar radiation from 173 to 197 kJ mol−1 (P1 sample), from 175 to 226 kJ mol−1 (P2 sample) and 206 to 197 kJ mol−1 (P3 sample).
Kinetic Compensation Effect (KCE) observed for samples P2 and P3 indicate acrylic resin s present in these may be similar in nature. This aspect could be observed by a small difference in the thermal behavior of
the TG curves from P1 to P2 and P3 sample.
The simulated kinetic model to all the samples was the autocatalytic Šesták-Berggreen. 相似文献
7.
A. I. Kazakov Yu. I. Rubtsov G. B. Manelis L. P. Andrienko 《Russian Chemical Bulletin》1997,46(12):2015-2020
Kinetic regularities of thermal decomposition of dinitramide in aqueous and sulfuric acid solutions were studied in a wide
temperature range. The rate of the thermal decomposition of dinitramide was established to be determined by the rates of decomposition
of different forms of dinitramide as the acidity of the medium increases: first, N(NO2)− anions, then HN(NO2)2 molecules, and finally, protonated H2N(NO2)2
+ cations. The temperature dependences of the rate constants of the decomposition of N(NO2)− (k
an) and HN(NO2)2 (k′ac) and the equilibrium constant of dissociation of HN(NO2)2 (K
a) were determined:k
an=1.7·1017 exp(−20.5·103/T), s−1,k′ac=7.9·1016 exp(−16.1·103/T), s−1, andK
a=1.4·10 exp(−2.6·103/T). The temperature dependences of the decomposition rate constant of H2N(NO2)2
+ (k
d) and the equilibrium constant of the dissociation of H2N(NO2)2
+ (K
d) were estimated:k
d=1012 exp(−7.9·103/T), s−1 andK
d=1.1 exp(6.4·103/T). The kinetic and thermodynamic constants obtained make it possible to calculate the decomposition rate of dinitramide solutions
in a wide range of temperatures and acidities of the medium.
In this series of articles, we report the results of studies of the thermal decomposition of dinitramide performed in 1974–1978
and not published previously.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2129–2133, December, 1997. 相似文献
8.
Ammonium nitrate (AN) is one of the main nitrogen fertilizers used in fertilization programs. However, AN has some serious
disadvantages — being well soluble in water hardly 50% of the N-species contained are assimilated by plants. The second disadvantage
of AN is associated with its explosive properties. The aim of this paper was to clarify the influence of different lime-containing
substances — mainly Estonian limestone and dolomite — as internal additives on thermal behaviour of AN.
Commercial fertilizer grade AN was under investigation. The amount of additives used was 5, 10 or 20 mass%, or calculated
on the mole ratio of AN/(CaO, MgO)=2:1 in the blends. Experiments were carried out under dynamic heating condition up to 900°C
(10°C min−1) in a stream of dry air or N2 by using Setaram Labsys 2000 equipment coupled to Fourier transform infrared spectrometer (FTIR).
The results of analyses of the gaseous compounds evolved at thermal treatment of neat AN indicated some differences in the
decomposition of AN in air or in N2. At the thermal treatment of AN’s blends with CaCO3, MgCO3, limestone and dolomite samples the decomposition of AN proceeds through a completely different mechanism — depending on
the origin and the content of additives, partially or completely, through the formation of Mg(NO3)2 and Ca(NO3)2. 相似文献
9.
Kelei Zhuo Qiufen Zhang Xiaopeng Xuan Hucheng Zhang Jianji Wang 《Frontiers of Chemistry in China》2007,2(2):193-198
Densities have been measured for Glucose + HCl +Water at 10-degree intervals from 278.15 to 318.15 K. The apparent molar volumes
(V
Φ,G) and standard partial molar volumes (V
Φ,G
0
) for Glucose in aqueous solution of 0.2, 0.4, 0.7, 1.1, 1.6, 2.1 mol·kg−1 HCl have been calculated as well as volumetric interaction parameters (V
EG) for Glucose — HCl in water and standard partial molar expansion coefficients (∂V
Φ,G
0
/ ∂T)p. Results show that (1) the apparent molar volume for Glucose in aqueous HCl solutions increases lineally with increasing
molality of Glucose and HCl; (2) V
Φ,G/0 for Glucose in aqueous HCl solutions increases lineally with increasing molality of HCl; (3) the volumetric interaction parameters
for Glucose — HCl pair in water are small positive and vary slightly with temperature; (4) the relation between V
Φ,G
0
and temperature exists as V
Φ,G
0
= a
0 + a
1(T − 273.15 K)2/3; (5) values of (∂V
Φ,G
0
/ ∂T)p are positive and increase as temperatures rise, and at given temperatures decrease slightly with increasing molalities of
HCl, indicating that the hydration of glucose decreases with increasing temperature and molality of HCl. These phenomena are
interpreted successfully by the structure interaction model.
Translated from Acta Chimica Sinica, 2006, 64(16): 1635–1641 (in Chinese) 相似文献
10.
B. K. Kasenov E. S. Mustafin M. A. Akubaeva S. T. Edil’baeva Sh. B. Kasenova Zh. I. Sagintaeva S. Zh. Davrenbekov 《Russian Journal of Inorganic Chemistry》2010,55(9):1454-1457
Manganites DyM3IMg3Mn4O12 and DyM3IBa3Mn4O12 (MI = Li, Na, K) were synthesized by the solid-state reaction of dysprosium and manganese(III) oxides and magnesium and corresponding alkali metal carbonates. The X-ray powder diffraction studies showed that the crystals
are orthozhombic with the following unit cell parameters and densities: DyLi3Mg3Mn4O12—a = 10.88 ?, b = 10.73 ?, c = 19.63 ?, V
0 = 1656.2 ?3, Z = 8, ρcalc = 5.36 g/cm3, ρpycn = 5.11 ± 0.05 g/cm3; DyNaMg3Mn4O12—a = 10.55 ?, b = 10.72 ?, c = 18.28 ?, V
0 = 2067.4 ?3, Z = 8, ρcalc = 4.60 g/cm3, ρpycn = 4.88 ± 0.09 g/cm3; DyK3Mg3Mn4O12—a = 10.56 ?, b = 10.72 ?, c = 20.89 ?, V
0 = 2206.0 ?3, Z = 8, ρcalc = 4.60 g/cm3, ρpycn = 4.92 ± 0.06 g/cm3; DyLi3Ba3Mn4O12—a = 10.53 ?, b = 10.69 ?, c = 21.28 ?, V
0 = 2395.4 ?3, Z = 8, ρcalc = 5.58 g/cm3, ρpycn = 5.98 ± 0.12 g/cm3; DyNa3Ba3Mn4O12—a = 10.53 ?, b = 10.74 ?, c = 23.00 ?, V
0 = 2602.3 ?3, Z = 8, ρcalc = 5.39 g/cm3, ρpycn = 5.30 ± 0.07 g/cm3; DyK3Ba3Mn4O12—a = 10.52 ?, b = 10.75 ?, c = 25.69 ?, V
0 = 2905.2 ?3, Z = 8, ρcalc = 5.04 g/cm3, ρpycn = 5.00 ± 0.18 g/cm3. 相似文献
11.
Kinetics of thermal decomposition of CeO2 nanocrystalline precursor prepared by precipitation method
Xiaolan Song Xi He Haiping Yang Dayu Xu Nan Jiang Guanzhou Qiu 《Frontiers of Chemistry in China》2008,3(2):182-185
The thermal decomposition of CeO2 nanocrystalline precursor prepared by chemical precipitation method was investigated using thermo-gravimetric/differential
scanning calorimetry (TG/DSC) and X-ray powder diffraction (XRD). In particular, the differential thermal analysis curves
for the decomposition of CeO2 nanocrystalline precursor were measured at different heating rates in air by a thermal analyzer (NETZSCH STA 449C, Germany).
The kinetic parameters of the thermal decomposition of CeO2 nanocrystalline precursor were calculated using the Kissinger method and the Coats-Redfern method. Results show that the
apparent active energy E of the reaction is 105.51 kJ/mol, the frequency factor lnA is 3.602 and the reaction order n is 2. This thermal decomposition process can be described by the anti-Jander equation and a three-dimensional diffusion mechanism.
Tanslated from Journal of Central South University (Science and Technology), 2007, 38(3): 428–432 [译自: 中南大学学报(自然科学版] 相似文献
12.
Shashi B. Kalia Priyanka Sankhyan R. Puri J. Christopher 《Journal of Thermal Analysis and Calorimetry》2012,107(2):597-605
Non-isothermal techniques, i.e. thermogravimetry (TG) and differential scanning calorimetry (DSC), have been applied to investigate
the thermal behaviour of carbaryl (1-naphthyl-N-methylcarbamate = 1-Naph-N-Mecbm) and its complexes, M(1-Naph-N-Mecbm)4X2, where M = Cu, X = Cl, NO3 and CH3COO and M = Zn, X = Cl. Carbaryl and Zn(1-Naph-N-Mecbm)4Cl2 complex exhibit two-stage thermal decomposition while the copper(II) complexes exhibit three and four-stage decomposition
in their TG curves. The nature of the metal ion has been found to play highly influential role on the nature of thermal decomposition
products as well as energy of activation ‘E*’. The presence of different anions does not seem to alter the thermal decomposition patterns. The complexes display weak
to medium intensity exothermic and endothermic DSC curves, while the free ligand exhibits two endothermic peaks. The kinetic
and thermodynamic parameters namely, the energy of activation ‘E*’, the frequency factor ‘A’ and the entropy of activation ‘S*’ etc. have been rationalized in relation to the bonding aspect of the carbaryl ligand. The nature and chemical composition
of the residues of the decomposition steps have been studied by elemental analysis and FTIR data. 相似文献
13.
S. F. Santos M. C. de Andrade J. A. Sampaio A. B. da Luz T. Ogasawara 《Journal of Thermal Analysis and Calorimetry》2007,87(3):743-746
TiO2–CeO2 oxides
for application as ceramic pigments were synthesized by the Pechini method.
In the present work the polymeric network of the pigment precursor was studied
using thermal analysis. Results obtained using TG and DTA showed the occurrence
of three main mass loss stages and profiles associated to the decomposition
of the organic matter and crystallization. The kinetics of the degradation
was evaluated by means of TG applying different heating rates. The activation
energies (E
a) and
reaction order (n) for each stage were
determined using Horowitz–Metzger, Coats–Redfern, Kissinger and
Broido methods. Values of E
a
varying between 257–267 kJ mol–1 and n=0–1 were found. According to the kinetic
analysis the decomposition reactions were diffusion controlled. 相似文献
14.
The interaction of C60 fullerite and C60—NH4Cl mixture (8 wt. % of NH4Cl, promoter of reaction) with ammonia was investigated at a starting NH3 pressure of 0.6—0.7 MPa in the temperature range 423—773 K. Raising the temperature to 723 K is accompanied by hydrogenation
and nitrogenation of the C60 matrix. Treatment of fullerite with ammonia at 773 K is followed by the decomposition of the fullerene framework and formation
of X-ray amorphous product. The physico-chemical properties of hydride-nitride phases formed during the interaction were investigated.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 217—219, February, 2006. 相似文献
15.
O. A. Plyusnina V. A. Emel’yanov I. A. Baidina I. V. Korol’kov S. A. Gromilov 《Journal of Structural Chemistry》2007,48(1):114-121
Double complex [RuNO(NH3)4OH][PtCl4] (I) and [RuNO(NH3)4OH][PdCl4] (II) salts have been prepared and explored with TGA, IR spectroscopy, powder and single crystals X-ray diffraction. Crystal phases
of I and II are isostructural (space group Cmc21) and have the following crystal chemical characteristics: a = 8.106 Å, b = 18.190(3) Å, c = 8.097 Å, V = 1194.0 Å3, Z = 4, ρcalc = 3.077 g/cm3 (I), and a = 8.116 Å, b = 18.135 Å, c = 8.062 Å, V = 1186.5 Å3, Z = 4, ρcalc = 2.600 g/cm3 (II). The product of thermal decomposition of I in inert and hydrogen atmospheres is a substitution solid solution Pt0.5Ru0.5 with the parameter of the FCC unit cell a = 3.856(3) Å. Thermolysis of II affords two-phase mixtures of limited solid solutions of the metals featuring Ru-based HCP and Pd-based FCC cells.
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.1, pp.114–121, January–February, 2007. 相似文献
16.
Milena Pintarič Svetozar Milićev Bogdan Volavšek 《Monatshefte für Chemie / Chemical Monthly》1990,121(5):357-360
Summary Two microcristalline phases have been isolated from aqueous solutions: (NH3OH)2AlF5(A) and (NH3OH)AlF4·H2O(B). They crystallize in the orthorhombic system with cell parameters for A:a=6.475 (3) Å,b=7.295 (3) Å,c=10.827 (5) Å, and for B:a=7.003 (3) Å,b=8.489 (4) Å,c=10.745 (5) Å. The Hydroxylammonium-aluminates were characterized by vibrational spectroscopy and their thermal decomposition studied by DSC and TG analysis. 相似文献
17.
D. V. Pinakov V. A. Logvinenko Yu. V. Shubin G. N. Chekhova 《Journal of Thermal Analysis and Calorimetry》2010,100(1):163-169
Inclusion compounds (intercalates) of fluorinated graphite matrix with methylene dichloride (C2F
x
Br
z
·yCH2Cl2, x = 0.49, 0.69, 0.87, 0.92, z ≈ 0.01) were synthesized by guest substitution from acetonitrile to methylene dichloride. The kinetics of the thermal decomposition
(the first stage of filling → the second stage of filling) was studied under isothermal conditions at 291–303 K. The relationship
between the structure of host matrices with thermal properties and kinetic parameters of inclusion compounds is discussed. 相似文献
18.
The triethanolamine complexes, [M(tea)2]sq·nH2O, (n=2 for Co(II), n=0 for Ni(II), Cu(II) and n=1 for Cd(II), tea=triethanolamine, sq2−=squarate), have been synthesized and characterized by elemental analyses, magnetic susceptibility and conductivity measurements,
UV-Vis and IR spectra, and thermal analyses techniques (TG, DTG and DTA). The Co(II), Ni(II) and Cu(II) complexes possess
octahedral geometry, while the Cd(II) complex is monocapped trigonal prismatic geometry. Dianionic squarate behaves as a counter
ion in the complexes. The thermal decomposition of these complexes takes place in three stages: (i) dehydration, (ii) release of the tea ligands and (iii) burning of organic residue. On the basis of the first DTGmax of the decomposition, the thermal stability of the anhydrous complexes follows the order: Ni(II), 289°C>Co(II), 230°C>Cu(II),
226°C>Cu(II), 170°C in static air atmosphere. The final decomposition products — the respective metal oxides — were identified
by FTIR spectroscopy. 相似文献
19.
Z. Fengqui H. Rongzu S. Jirong G. Hongxu 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(7):1034-1036
The kinetic parameters of the exothermic decomposition of the title compound in a temperatureprogrammed mode have been studied
by means of DSC. The DSC data obtained are fitted to the integral, differential, and exothermic rate equations by the linear
least-squares, iterative, combined dichotomous, and least-squares methods, respectively. After establishing the most probable
general expression of differential and integral mechanism functions by the logical choice method, the corresponding values
of the apparent activation energy (E
a), preexponential factor (A), and reaction order (n) are obtained by the exothermic rate equation. The results show that the empirical kinetic model function in differential
form and the values of E
a and A of this reaction are (1 − α)−4.08, 149.95 kJ mol−1, and 1014.06 s−1, respectively. With the help of the heating rate and kinetic parameters obtained, the kinetic equation of the exothermic
decomposition of the title compound is proposed. The critical temperature of thermal explosion of the compound is 155.71°C.
The above-mentioned kinetic parameters are quite useful for analyzing and evaluating the stability and thermal explosion rule
of the title compound.
The text was submitted by the authors in English. 相似文献
20.
Thermal explosion simulation and incompatible reaction of dicumyl peroxide by calorimetric technique
Sun-Ju Shen Sheng-Hung Wu Jen-Hao Chi Yih-Wen Wang Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2010,102(2):569-577
Dicumyl peroxide (DCPO) is usually employed as an initiator for polymerization, a source of free radicals, a hardener, and
a linking agent. In Asia, due to its unstable reactive nature, DCPO has caused many thermal explosions and runaway reaction
incidents in the manufacturing process. This study was conducted to elucidate its essentially thermal hazard characteristics.
In order to analyze the runaway behavior of DCPO in a batch reactor, thermokinetic parameters, such as heat of decomposition
(ΔH
d) and exothermic onset temperature (T
0), were measured via differential scanning calorimetry (DSC). Thermal runaway phenomena were then thoroughly investigated
by DSC. The thermokinetics of DCPO mixed with acids or bases were determined by DSC, and the experimental data were compared
with kinetics-based curve fitting of thermal safety software (TSS). Solid thermal explosion (STE) and liquid thermal explosion
(LTE) simulations of TSS were applied to determine the fundamental thermal explosion behavior in large tanks or drums. Results
from curve fitting indicated that all of the acids or bases could induce exothermic reactions at even an earlier stage of
the experiments. In order to diminish the extent of hazard, hazard information must be provided to the manufacturing process.
Thermal hazard of DCPO mixed with nitric acid (HNO3) was more dangerous than with other acids including sulfuric acid (H2SO4), phosphoric acid (H3PO4), and hydrochloric acid (HCl). By DSC, T
0, heat of decomposition (ΔH
d), and activation energy (E
a) of DCPO mixed with HNO3 were calculated to be 70 °C, 911 J g−1, and 33 kJ mol−1, respectively. 相似文献