共查询到20条相似文献,搜索用时 93 毫秒
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采用密度泛函理论计算了缓蚀分子苯并三氮唑(BTA)和二巯基噻二唑(DMTD)的全局反应活性和局部反应活性. 采用分子动力学方法模拟了不同含量的BTA和DMTD对其热力学性质的影响. 同时通过腐蚀试验研究了缓蚀剂复配体系的缓蚀效果. 结果表明: 两种缓蚀分子的缓蚀效率关系为BTA小于DMTD, 活性主要集中于N和S原子上, 有多个活性位点, 因此, 缓蚀剂分子平卧式吸附在铜表面; 铜表面吸附单个缓蚀剂分子BTA和DMTD后, 室温下比热容基本相同, 但随缓蚀剂含量的增加, 比热容呈增大趋势. 这为铜箔轧制油缓蚀剂的选择提供理论指导. 通过腐蚀试验研究, 复配体系缓蚀具有很好的缓蚀效果, BTA和DMTD 的复配比例为1:1时最佳.
关键词:
密度泛函理论
分子动力学方法
反应活性
热力学性质 相似文献
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运用第一性原理方法结合准谐Debye-Grüneisen模型研究了高压下Ni3Al的热力学性质,拟合了Ni3Al的状态方程,计算了不同压强下Ni3Al的弹性模量及吉布斯自由能等热力学性质随温度的变化关系.计算结果表明:采用七阶Birch-Murnaghan方程拟合的晶格常数与实验测量结果吻合较好;零压下弹性模量、吉布斯自由能、焓、熵、热容和体膨胀系数随温度的变化与实验值符合较好;在特定压强下,Ni3Al的弹性模量和吉布斯自由能随温度升高而减小,焓、熵随温度升高而增加;预测的德拜温度约为500K,与实验值符合较好. 相似文献
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计算了广温度范围(300—30000 K)和广压力范围(0.1—10 atm, 1 atm=101.325 k Pa)下,不同混合物比例、碳和硅蒸气浓度的局域热力学平衡(LTE)和化学平衡(LCE)的氩-碳-硅等离子体组分、热力学性质和输运系数.等离子体气相平衡组分使用质量作用定律计算,同时凝聚相组分采用相平衡的方法计算.输运系数的计算包括黏度、电导率和热导率,使用拓展到高阶近似的Chapman-Enskog方法.采用文献中较新的数据得到了较为准确的碰撞积分,导出了Ar-C-Si等离子体的输运系数.结果表明,在相变温度以下,凝聚态物种的引入导致Ar-C-Si等离子体的热力学性质、输运系数与纯Ar等离子体接近,在相变温度点则会产生不连续点.压力、碳/硅蒸气浓度和比例对等离子体热力学性质和输运系数具有较大影响.最终计算值与文献数据对比符合良好,有望为氩-碳-硅等离子体传热流动数值模拟提供基础数据. 相似文献
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高压下Ni3Al热力学性质的第一性原理研究 总被引:1,自引:0,他引:1
运用第一性原理方法结合准谐Debye-Grüneisen模型研究了高压下Ni3Al的热力学性质,拟合了Ni3Al的状态方程,计算了不同压强下Ni3Al的弹性模量及吉布斯自由能等热力学性质随温度的变化关系. 计算结果表明:采用七阶Birch-Murnaghan方程拟合的晶格常数与实验测量结果吻合较好;零压下弹性模量、吉布斯自由能、焓、熵、热容和体膨胀系数随温度的变化与实验值符合较好;在特定压强下,Ni3Al的弹性模量和吉布斯自由能随温度升高而减小,焓、熵随温度升高而增加;预测的德拜温度约为500K,与实验值符合较好. 相似文献
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报道了掺Zn的重电子金属CeCu6-xZnx(x=0.05,0.1,0.15,0.2,0.3)样品的非常规制备方法以及低温电阻和低温比热容的测量结果,研究Zn含量对CeCu6-xZnx低温性质的影响及其物理原因.发现低温下Kondo散射项系数c随Zn含量的加大而减小,电阻极大值温度Tmax随Zn含量的加大而降低,CeCu6-xZnx的德拜温度ΘD随Zn含量的加大而略有上升
关键词:
重费密子系统
低温比热容
低温电阻
相干散射 相似文献
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建立了铁电/铁磁双层膜模型,铁电层的电矩用连续标量描述,而铁磁层的自旋应用经典矢量描述.利用蒙特卡罗方法模拟了体系的热力学性质和极化、磁化行为.给出了零场下体系的内能、比热、极化和磁化随温度变化的关系,并分别研究了体系在外磁场和外电场下的极化和磁化行为.模拟结果表明,双层膜体系的内能、比热、极化和磁化性质因层间耦合系数的不同而明显不同,当界面耦合较弱时,双层膜表现出各自的热力学性质,当层间耦合增强到一定程度时,双层膜耦合为一个整体,表现出统一的热力学性质.该双层膜在外场中形成电滞回线和磁滞回线,并表现出偏置特性,界面耦合强度和温度影响滞后回线和偏置现象. 相似文献
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苯的硝基和叠氮基衍生物是一类重要的含能材料,为了揭示其热力学性质与分子结构之间的关系,采用第一性原理进行了计算研究.通过计算平衡电负性连接指数,结合分子结构描述符,对苯的硝基和叠氮基衍生物的热力学性质建立了构效关系模型.模型检验结果表明,构建的模型具有良好的稳健性和预测能力,所得模型为苯的硝基和叠氮基衍生物的爆轰参数计算和分解机理研究提供了一种快速的热力学性质预测方法 . 相似文献
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刘晓静 《原子与分子物理学报》2017,34(6)
苯的硝基和叠氮基衍生物是一类重要的含能材料,为了揭示其热力学性质与分子结构之间的关系,采用第一性原理进行了计算研究。通过计算平衡电负性连接指数,结合分子结构描述符,对苯的硝基和叠氮基衍生物的热力学性质建立了构效关系模型。模型检验结果表明,构建的模型具有良好的稳健性和预测能力,所得模型为苯的硝基和叠氮基衍生物的爆轰参数计算和分解机理研究提供了一种快速的热力学性质预测方法。 相似文献
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Yu. A. Shevchenko A. G. Makarov P. D. Andriushchenko K. V. Nefedev 《Journal of Experimental and Theoretical Physics》2017,124(6):982-993
Problems of temperature behavior of specific heat are solved by the entropy simulation method for Ising models on a simple square lattice and a square spin ice (SSI) lattice with nearest neighbor interaction, models of hexagonal lattices with short-range (SR) dipole interaction, as well as with long-range (LR) dipole interaction and free boundary conditions, and models of spin quasilattices with finite interaction radius. It is established that systems of a finite number of Ising spins with LR dipole interaction can have unusual thermodynamic properties characterized by several specific-heat peaks in the absence of an external magnetic field. For a parallel multicanonical sampling method, optimal schemes are found empirically for partitioning the space of states into energy bands for Ising and SSI models, methods of concatenation and renormalization of histograms are discussed, and a flatness criterion of histograms is proposed. It is established that there is no phase transition in a model with nearest neighbor interaction on a hexagonal lattice, while the temperature behavior of specific heat exhibits singularity in the same model, in case of LR interaction. A spin quasilattice is found that exhibits a nonzero value of residual entropy. 相似文献
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J.M. Carmona J. Richert P. Wagner 《The European Physical Journal A - Hadrons and Nuclei》2001,11(1):87-93
We test the influence of the Coulomb interaction on the thermodynamic and cluster generation properties of a system of classical
particles described by different lattice models. Numerical simulations show that the Coulomb interaction produces essentially
a shift in temperature of quantities like the specific heat but not qualitative changes. We also consider a cellular model.
The thermodynamic properties of the system are qualitatively unaltered.
Received: 7 November 2000 / Accepted: 17 May 2001 相似文献
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We employed ab-initio calculations to investigate the structural and thermodynamic properties of Massicot or orthorhombic phase of PbO named β-PbO using the projector augmented-wave(PAW) method within the generalized gradient approximation(GGA). The temperature and pressure dependence of bulk modulus, heat capacity at constant pressure and constant volume, entropy, thermal expansion coefficient and Grüneisen parameter were discussed. Accuracy of two different models, the Debye and Debye-Grüneisen which are based on the quasi-harmonic approximation(QHA) for producing thermodynamic properties of material were compared. According to calculation results, these two models can be used to designate thermodynamic properties for β-PbO with sensible accuracy over a wide range of temperatures and pressures, and our work on the properties of this structure will be useful for more deeply understanding various properties of this structure. 相似文献
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Francisco Gámez Benito Garzón Patrick J. Merkling Carlos Vega 《Molecular physics》2013,111(11):1331-1339
Gibbs ensemble Monte Carlo simulations are performed to obtain the vapour–liquid equilibrium of oblate-like fluids interacting through the Kihara intermolecular potential. Results confirm the validity of a perturbation theory for Kihara fluids, whose accuracy for prolate fluids was tested some years ago. As in the case of hard ellipsoids, the symmetry of the phase diagram of oblate and prolate models is analysed. An interesting relation of Boyle temperature and critical parameters with molecular volume is found for the considered models. As a particular application, this relation allows the prediction of some thermodynamic properties of a new promising biofuel 2,5dimethylfuran. 相似文献
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A general method, the method of variation under extension, is presented for expressing the thermodynamic properties of an inhomogeneous fluid as functionals of the local number density, when given a density functional for the total thermodynamic grand potential of the fluid. The method is demonstrated in detail for the van der Waals square-gradient density functional and for the nonlocal density functional which arises in the theory of fluids with long-ranged pair potentials or in the mean-field theory of penetrable-sphere models. As specific examples, we consider the planar and spherical interface between two fluid phases, the line of contact of three fluid phases, the contact line between two surface phases and the planar interface between a solid and fluid. 相似文献
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P. C. R. Rodrigues F. M. S. Silva Fernandes 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(3):353-359
A strategy to overcome some specific problems associated to the computation of free energies in clusters is presented. Free
energies and entropies of solid KCl nanoclusters are determined by thermodynamic integration, and Watanabe and Reinhardt’s
dynamical method, based on molecular dynamics simulations. The values are in good agreement with experimental data. From a
previous theoretical prediction of the caloric curve, T(E), for the coexistence region, an equation is derived to compute the free energies of the clusters at the solid-liquid coexistence.
The results are discussed in the context of the thermodynamic stability of phase coexistent states for finite and infinite
systems, yielding consistent conclusions. 相似文献