共查询到20条相似文献,搜索用时 31 毫秒
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嵌段共聚物在乳液聚合和分散聚合中的应用 总被引:4,自引:0,他引:4
综述了嵌段共聚物在乳液聚合和分散聚合中作为稳定剂应用的进展,主要讨论了共聚物化学组成,比例,分子量,浓度以及胶束形成等因素对聚合体系的影响。 相似文献
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文献中未见MCl-HCl-H2O(M=Li、Na、K、Rb、Cs)三元体系25℃时在HCl全浓度范围内溶解度预测的报道。本文报道应用Pitzer的离子相互作用模型,系统地对0.1~16.0 mol·kg-1浓度范围内HCl的活度系数和渗透系数值进行最小二乘法拟合,得到一套优于文献上报道的作用参数。用这一套参数和本文报道中五个三元体系得到的θmn和φmnx,对溶解度预测获得满意结果。本方法可以推广到其它任何温度时、甚至相关四元和五元体系的溶解度预测,可以减少繁琐的实验测定,并对于利用HCl从盐卤中盐析分离LiCl、RbCl和CsCl的相化学工艺计算具有实际意义。 相似文献
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R. Kandan B. Prabhakara Reddy G. Panneerselvam 《Journal of Thermal Analysis and Calorimetry》2018,132(3):1639-1644
Enthalpy measurements have been taken on GdSmTi2O7 and DySmTi2O7 by using a high-temperature differential calorimeter at temperature between 800 and 1655 K. Thermodynamic function, such as heat capacity, entropy and Gibbs energy functions of GdSmTi2O7 and DySmTi2O7, was derived using the data obtained in this study. The results are presented and compared with the data available in the literature. The polynomial expression of enthalpy increments obtained for GdSmTi2O7(s) and DySmTi2O7(s) in the temperature range 298–1700 K is given as: \(\begin{aligned} H_{\text{T}}^{0} - H_{298}^{0} / {\text{J}}\,{\text{mol}}^{ - 1} & = 252.961\,T \, + 1.596 \times 10^{ - 2} \,T^{2} + 3.705 \times 10^{6} \,T^{ - 1} - 89{,}265\quad ({\text{GdSmTi}}_{2} {\text{O}}_{7} ) \\ H_{\text{T}}^{0} - H_{298}^{0} / {\text{J}}\,{\text{mol}}^{ - 1} & = 256.504\,T \, + 1.576 \times 10^{ - 2} \,T^{2} + 3.531 \times 10^{6} \,T^{ - 1} - 89{,}721\quad \left( {{\text{DySmTi}}_{2} {\text{O}}_{7} } \right). \\ \end{aligned}\) 相似文献
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新型光活性串型液晶共聚物合成与表征 总被引:1,自引:0,他引:1
以对苯二甲酰氯,2 ,5 二[4 ((S) 2 甲基丁氧基) 苯甲酰氧基] 对苯二酚和己二醇为单体,采用溶液共缩聚的方法,合成了一系列新的光活性串型液晶共聚物.共聚物通过GPC、DSC、TG、WAXD、偏光显微镜和旋光仪等方法表征.发现所有的共聚物加热至各自的熔点以上都能形成液晶态,在液晶态可以观察到沙地织构或破碎焦锥织构.通过变温X 射线衍射证明它们为手性近晶C(S*C) 相.所有共聚物的熔点( Tm) 和液晶态清亮点( Ti) 随共聚物中己二醇用量的改变呈规律性变化.共聚物有很高的旋光性,在合成反应中旋光性保持. 相似文献
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M.R.M. Witwit 《Journal of mathematical chemistry》1997,22(1):11-23
Energy eigenvalues of double‐well potentials for two‐dimensional systems are calculated by the approach of expanding the potential functions such as $V(x,y;Z^2 ,\lambda ) = - Z^2 [x^2 + y^2 ] + \lambda [x^4 + 2x^2 y^2 + y^4 ]$ around their minima, using the inner product technique, for various values of perturbation parameters Z2 and λ. Some of the results calculated by the inner product technique are compared with the results produced by other means. 相似文献
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升温淋洗分级技术是根据结晶性聚合物的结晶度进行分级和表征的一项分析和制备技术,在聚烯烃非均匀性的表征和窄组成分布样品的制备中有重要应用。本文主要介绍升温淋洗分级原理、热力学模型、装置技术特点、分析方法以及在聚乙烯研究中最新应用进展。 相似文献
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Stefano Bosisio Antonia S. J. S. Mey Julien Michel 《Journal of computer-aided molecular design》2017,31(1):61-70
In the context of the SAMPL5 blinded challenge standard free energies of binding were predicted for a dataset of 22 small guest molecules and three different host molecules octa-acids (OAH and OAMe) and a cucurbituril (CBC). Three sets of predictions were submitted, each based on different variations of classical molecular dynamics alchemical free energy calculation protocols based on the double annihilation method. The first model (model A) yields a free energy of binding based on computed free energy changes in solvated and host-guest complex phases; the second (model B) adds long range dispersion corrections to the previous result; the third (model C) uses an additional standard state correction term to account for the use of distance restraints during the molecular dynamics simulations. Model C performs the best in terms of mean unsigned error for all guests (MUE \(3.2\,<\,3.4\,<\,3.6\,\text{kcal}\,\text{mol}^{-1}\)—95 % confidence interval) for the whole data set and in particular for the octa-acid systems (MUE \(1.7\,<\,1.9\,<\,2.1\,\text{kcal}\,\text{mol}^{-1}\)). The overall correlation with experimental data for all models is encouraging (\(R^2\, 0.65\,<\,0.70<0.75\)). The correlation between experimental and computational free energy of binding ranks as one of the highest with respect to other entries in the challenge. Nonetheless the large MUE for the best performing model highlights systematic errors, and submissions from other groups fared better with respect to this metric. 相似文献
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M.R.M. Witwit 《Journal of mathematical chemistry》1998,22(1):11-23
Energy eigenvalues of double‐well potentials for two‐dimensional systems are calculated by the approach of expanding the potential
functions such as
around their minima, using the inner product technique, for various values of perturbation parameters Z2 and λ. Some of the results calculated by the inner product technique are compared with the results produced by other means.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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E. Makrlík P. Selucký P. Vaňura 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):467-470
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+ (aq) + 1·Na+ (org) $ \Leftrightarrow $ 1·M+ (org) + Na+ (aq) taking place in the two-phase water–phenyltrifluoromethyl sulfone (abbrev. FS 13) system (M+ = Li+, H3O+, NH4 +, Ag+, Tl+, K+, Rb+, Cs+; 1 = benzo-18-crown-6; aq = aqueous phase, org = FS 13 phase) were evaluated. Further, the stability constants of the 1·M+ complexes in FS 13 saturated with water were calculated; they were found to increase in the series of $ {\text{Cs}}^{ + } \, < \,{\text{Rb}}^{ + } \, < \,{\text{H}}_{ 3} {\text{O}}^{ + } \, < \,{\text{Ag}}^{ + } \, < \,{\text{Li}}^{ + } \, < \,{\text{NH}}_{4}^{ + } \, < \,{\text{K}}^{ + } \, < \,{\text{Tl}}^{ + } $ . 相似文献
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Let H{\mathcal{H}} be a set of disjoint faces of a cubic bipartite polyhedral graph G. If G has a perfect matching M such that the boundary of each face of H{\mathcal{H}} is an M-alternating cycle (or in other words, G-H{G-\mathcal{H}} has a perfect matching), then H{\mathcal{H}} is called a resonant pattern of G. Furthermore, G is k-resonant if every
i (1 \leqslant i \leqslant k){i\,(1\,\leqslant\, i\, \leqslant\, k)} disjoint faces of G form a resonant pattern. In particular, G is called maximally resonant if G is k-resonant for all integers
k \geqslant 1{k\,\geqslant\, 1}. In this paper, all the cubic bipartite polyhedral graphs, which are maximally resonant, are characterized. As a corollary,
it is shown that if a cubic bipartite polyhedral graph is 3-resonant then it must be maximally resonant. However, 2-resonant
ones need not to be maximally resonant. 相似文献
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《Physics and Chemistry of Liquids》2012,50(3):295-316
A cage model is used to calculate the shear viscosity m s and the thermal conductivity s for insulating monatomic liquids and for liquid alkali metals. Three empirical laws: (i) $ \eta_s \, \propto \, (1/\sqrt T ) $ for liquid alkalis; (ii) s / m s ~ constant for Rb and Cs respectively; (iii) $ ({\gamma / {\eta _s }})\sim \sqrt {{{k_B T_m } / M}} $ for liquid alkalis at the melting temperature T m , where n is the surface tension and M the ionic mass, are naturally explained. 相似文献
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A. A. Altynnikov L. T. Tsikoza V. F. Anufrienko 《Journal of Structural Chemistry》2006,47(6):1161-1169
Two types of ESR spectrum (A and B) of exchange-coupled Cu2+ ions have been found for Cu-Ti-O catalysts at 77 K and 300 K. In associates A and B, the Cu2+ ions form a system with orbital ordering. The difference between the spectra is due to the difference between the ground states of adjacent Cu2+ ions in the associates: the ground states are $d_{x^2 } $ and $d_{y^2 } $ for A type associates and $d_{x^2 - y^2 } $ and $d_{z^2 - x^2 } $ for B type associates. The copper associates lie on the surface of the TiO2 (anatase) support microparticles. 相似文献
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Hemlata V. Khadilkar S. M. Bhojane Jayanthi Kulkarni S. G. Kulkarni 《Journal of Thermal Analysis and Calorimetry》2013,111(1):939-942
Molar heat capacity measurement on Na2TeO4(s) and TiTe3O8(s) were carried out using differential scanning calorimeter. The molar heat capacity values were least squares analyzed and the dependence of molar heat capacity with temperature for Na2TeO4(s) and TiTe3O8(s) can be given as, $$ \begin{gathered} {\text{C}}^{\text{o}}_{{{\text{p}},{\text{m}}}} \left\{ {{\text{Na}}_{ 2} {\text{TeO}}_{ 4} \left( {\text{s}} \right)} \right\} \,={159}.17 { } + 1.2\,\times\,10^{-4}T-{55}.34\,\times\,10^{5}/T^{2};\hfill \\ C^{\text{o}}_{{{\text{p}},{\text{m}}}} \left\{ {{\text{TiTe}}_{ 3} {\text{O}}_{ 8} \left( {\text{s}} \right)} \right\}\,=\,{ 275}.22{ }+{4}.0\,\times\, 10^{-5}T-{58}.28\,\times\,10^{5}/T^{2};\hfill \\ \end{gathered} $$ From this data, other thermodynamic functions were evaluated. 相似文献
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Mahboubi Davoud Jafari Gavzan Iraj Saidi Mohammad Hassan Ahmadi Naghi 《Journal of Thermal Analysis and Calorimetry》2022,147(21):12253-12267
Journal of Thermal Analysis and Calorimetry - Lithium-ion batteries should continuously be operated at the optimum temperature range $$\left( {15 \sim 40 \,^\circ C} \right)$$ for the best... 相似文献
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The phytosteroids 3ß-hydroxy-(24S)-stigmast-5, 22E-dien-7-one and (24S)-stigmasta-5, 22E-diene-3\, 7ß-diol have been synthesized from stigmasterol. 相似文献