共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
利用DSC热分析法研究了Zr基及78Fe-9Si-13B非晶合金的比热容随温度的变化规律,发现Zr基非晶的比热容温度曲线与二级相变热容变化的规律十分相似,因此从热力学上证明了玻璃态与过冷液态之间的转变属于二级相变.78Fe-9Si-13B非晶合金的比热容温度曲线上仅存在一个λ形峰值,这显示居里温度与玻璃转变温度几乎相等,结构有序性与磁矩有序性的变化发生了重叠. 相似文献
3.
4.
《钢铁》2018,(11)
为了研究炉渣铁水脱硫速率,在实验室条件下进行了温度为1 673~1 773 K时CaO-SiO_2-Al_2O_3-Na_2O-TiO_2渣铁水脱硫的动力学试验。结果表明,随着温度的增加,脱硫速率加快,炉渣熔化效果更好。多数脱硫反应在约50 min后硫质量分数基本不变。通过建立铁水脱硫动力学的数学模型,计算脱硫过程中硫的传质系数和传质阻力。硫的传质系数范围为5.02×10-7~18.69×10-7m/s。温度为1 673~1 723 K时活化能为464.06 kJ/mol,温度为1 723~1 773 K时活化能为176.35 k J/mol。通过矿相解离分析仪(MLA)观察硫在渣铁界面附近的分布情况,结合MLA扫描图片,认为高温时硫在渣中的传质是脱硫过程的限制环节。 相似文献
5.
报道了用二 (2 乙基己基 )二硫代磷酸为萃取剂 ,以正庚烷为稀释剂萃取铟的热力学研究。在In2 (SO4 ) 3+Na2 SO4 +D2 EHDTPA +n C7H1 6 +H2 O体系中 ,在温度 2 78.15~ 3 0 3 .15K和离子强度 0 .1~ 2 .0mol·kg- 1 范围内 ,以Na2 SO4 为支持电解质 ,测定了萃取平衡水相中In3+浓度和pH值。计算了萃取反应的标准平衡常数K0 ,并得到经验公式logK0 =43 .93 -5 3 68.5 4 T -0 .0 699T ,同时计算了萃取反应的其他热力学量 ,并指出了焓和熵都是此萃取过程的推动力 相似文献
6.
DIBK-P204体系萃取锆铪的热力学研究 总被引:3,自引:0,他引:3
以二异丁基甲酮(DIBK)为萃取剂,二(2-乙基己基)磷酸酯(P204)为改质剂,利用对数函数外推法对DIBK-P204体系从HSCN介质中萃取锆和铪的热力学进行研究,结果表明:锆铪与SCN-所形成配合物的一级稳定性常数分别为1×1010.07和1×10-0.12,DIBK-P204体系萃取锆和铪的热力学平衡常数分别为lg(K12,Zr)=5.00和lg(K12,Hf)=-4.69,焓变分别为ΔHZr=-13.76 kJ·mol-1和ΔHHf=-13.05 kJ·mol-1,说明对锆铪的萃取反应为放热反应,升高温度不利于萃取反应的进行,并计算出常温下萃取反应的自由能变分别为ΔGZr=-28.06 kJ·mol-1和ΔGHf=26.32 kJ·mol-1,熵变分别为ΔSZr=48.78 J·(K.mol)-1和ΔSHf=-134.30 J·(K.mol)-1。 相似文献
7.
采用静态吸附法研究A12O3-P2O5-H2O反应体系产物三聚磷酸二氢铝Ⅰ型二水物[AlH2P3O10·2H2O(I)]吸附水中Ni2+的动力学和热力学.考察了温度、浓度、粒径、pH和搅拌速度对吸附过程的影响,通过不同温度下的吸附等温热力学性能的变化,计算了吸附焓、吸附熵和自由能.结果表明,在试验范围内,AlH2P3O10·2H2O(I)对Ni2+的吸附符合Langmuir吸附等温方程式,过程受颗粒扩散控制,反应级数为1.88,298.15K时的热力学数据为:Ea=11.561 kJ/mol,△H=35.75 kJ/mol,△S=190.58 J/(mol·K),△G=-21.07 kJ/mol,吸附为自发的吸热过程,其吸附动力学总方程为:1-2/3x-(1-x)2/3=0.36r0<'2>C0<'1.88>exp(-11 561/RT). 相似文献
8.
与块体材料相比,纳米材料尺寸小、界面能大,导致其溶解和熔化过程的热力学不同于块体材料.从理论上推导了Al2O3纳米颗粒在铁液中的元素平衡溶度积以及熔化温度与颗粒尺寸之间的关系,结果表明,随颗粒尺寸减小,平衡溶度积逐渐增加,熔化温度逐渐下降,而且粒径越小,平衡溶度积和熔化温度的变化率越大.经计算,1873K铁液中Al2O3的质量分数为0.01%时,半径为0.1nm的Al2O3颗粒比块体Al2O3的平衡溶度积增加了11.71%;半径为1nm的Al2O3颗粒在空气和铁液中的熔化温度分别为1849K和1267K,比块体Al2O3的熔化温度分别下降了454K和1036K. 相似文献
9.
Novel soft materials,Eu(III)-containing complex dissolved in [C8mim][X](X=Cl-,PF6-and Tf2N-) ionic liquids,were synthesized.FT-IR and elementary analysis of complex proved that the molecular formula is [C8mim][Eu(TTA)4].The complex and ionic liquids had highthermal stability according to TGA.The photoluminescence spectra showed that the [C8mim][Eu(TTA)4] exhibited typical red emission deriving from 5D0-7F2 transition.After dissolving the complex in [C8mim][X](X=Cl-,PF6-and Tf2N-) ionic liquids,the luminescence intensitydecreased in the following order:[C8mim][Tf2N]≈[C8mim][PF6 ]>[C8mim][Cl].This was because Tf2N-and PF6-anions had larger molecularvolume and weaker coordination ability than Cl-. 相似文献
10.
与块体材料相比,纳米材料尺寸小、界面能大,导致其溶解和熔化过程的热力学不同于块体材料.从理论上推导了Al2O3纳米颗粒在铁液中的元素平衡溶度积以及熔化温度与颗粒尺寸之间的关系,结果表明,随颗粒尺寸减小,平衡溶度积逐渐增加,熔化温度逐渐下降,而且粒径越小,平衡溶度积和熔化温度的变化率越大.经计算,1873K铁液中Al2O... 相似文献
11.
12.
13.
An analysis of the Li2O-SiO2 and Li2O-GeO2 systems in the temperature range from 298 to 1373 K has been performed by Raman spectroscopy. A comparison of the spectroscopic data for the crystalline phases, glasses, and melts allowed us to determine the main anion groups existing in these systems and to establish the structural changes induced by changes in the temperature and composition. 相似文献
14.
15.
16.
The Gq/phospholipase C-linked human P2Y2 receptor was tagged at its amino terminus with the hemagglutinin A (HA) epitope sequence (P2Y2-HA) and stably expressed in 1321N1 human astrocytoma cells. Neither the pharmacological selectivity nor the signaling properties of the receptor were altered by the presence of the epitope. An enzyme-linked immunosorbent assay was developed to quantify cell surface levels of P2Y2-HA receptors using an anti-HA antibody. Incubation of cells with P2Y2 receptor agonists resulted in a concentration of agonist- and time-dependent decrease in cell surface immunoreactivity. Methodology for indirect immunofluorescence confocal microscopy was developed and applied to demonstrate that the agonist-promoted decreases in cell surface immunoreactivity paralleled increases in intracellular immunoreactivity. Agonist-induced internalization of P2Y2 receptors was demonstrated directly by prelabeling P2Y2-HA receptors with antibody before agonist challenge and then quantifying the movement of receptors from a cell surface to intracellular localization in the presence of agonist. Removal of agonist from the medium resulted in recovery of cell surface immunoreactivity to control levels within approximately 1 hr. Incubation of P2Y2-HA receptor-expressing cells with P2Y2 receptor agonists also resulted in receptor-specific desensitization of nucleotide-promoted inositol phosphate accumulation. This loss of responsiveness occurred more rapidly and to a greater extent than did the agonist-promoted loss of surface receptors. Inhibition of receptor internalization by reduction of temperature to 16 degrees had no effect on the capacity of nucleotides to induce P2Y2 receptor-specific desensitization. These results illustrate that the P2Y2 receptor undergoes agonist-promoted movement to an intracellular compartment. This receptor internalization is not required for agonist-induced desensitization. 相似文献
17.
18.
Hisao Kimura Fumitaka Tsukihashi Nobuo Sano 《Metallurgical and Materials Transactions B》1995,26(3):553-556
The activity of a few percent of Na2O in the CaO-CaF2-SiO2 system doubly saturated with CaO and 3CaO·SiO2 has been determined between 1423 and 1623 K by a chemical equilibration technique. The temperature dependence of the activity
coefficient of Na2O may be expressed as follows. {fx553-01}
It was found that Henry’s law holds up to 5 mass pct of Na2O in the flux at 1473 K. The activity of a small amount of Na2O in the CaO-CaF2-SiO2 flux is discussed in comparison with that for the Na2O-SiO2 system in terms of their refining characteristics. 相似文献
19.
20.
All available thermodynamic and phase diagram data have been critically assessed for all phases in the MnO-TiO2, MgO-TiO2, FeO-TiO2, Ti2O3-TiO2, Na2O-TiO2, and K2O-TiO2 systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable thermodynamic and phase diagram data
have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid
slag as a function of composition and temperature and equations for the Gibbs energies of all compounds as functions of temperature.
The modified quasichemical model was used for the molten slag phases. 相似文献