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81.
Maiti M Weiner S Buldyrev SV Stanley HE Sastry S 《The Journal of chemical physics》2012,136(4):044512
Using the Jagla model potential we calculate the potential of mean force (PMF) between hard sphere solutes immersed in a liquid displaying water-like properties. Consistent estimates of the PMF are obtained by (a) umbrella sampling, (b) calculating the work done by the mean force acting on the hard spheres as a function of their separation, and (c) determining the position dependent chemical potential after calculating the void space in the liquid. We calculate the PMF for an isobar along which cold denaturation of a model protein has previously been reported. We find that the PMF at contact varies non-monotonically, which is consistent with the observed cold denaturation. The Henry constant also varies non-monotonically with temperature. We find, on the other hand, that a second (solvent separated) minimum of the PMF becomes deeper as temperature decreases. We calculate the solvent-solvent pair correlation functions for solvents near the solute and in the bulk, and show that, as temperature decreases, the two pair correlation functions become indistinguishable, suggesting that the perturbation of solvent structure by the solute diminishes as temperature decreases. The solvent-solute pair correlation function at contact grows as the temperature decreases. We calculate the cavity correlation function and show the development of a solvent-separated peak upon decrease of temperature. These observations together suggest that cold denaturation occurs when the solvent penetrates between hydrophobic solutes in configurations with favorable free energy. Our results thus suggest that cold denatured proteins are structured and that cold denaturation arises from strong solvent-solute interactions, rather than from entropic considerations as in heat denaturation. 相似文献
82.
For a tensor triangulated category which is well generated in the sense of Neeman, it is shown that the collection of Bousfield classes forms a set. This set has a natural structure of a complete lattice which is then studied, using the notions of stratification and support. 相似文献
83.
S Chandra A Biswas S Datta B Ghosh V Siruguri AK Raychaudhuri MH Phan H Srikanth 《J Phys Condens Matter》2012,24(36):366004
We report a detailed investigation of the magnetocaloric properties of self-doped polycrystalline LaMnO(3+δ) with δ?=?0.04. Due to the self-doping effect, the system exhibits a magnetic transition from a paramagnetic to ferromagnetic-like canted magnetic state (CMS) at ~120?K, which is associated with an appreciably large magnetocaloric effect (MCE). The CMS is an inhomogeneous magnetic phase developing due to a steady growth of antiferromagnetic correlation in its predominant ferromagnetic state below ~120?K. The stabilization of CMS in this material is concluded from a comprehensive analysis of magnetocaloric data using Landau theory, which is in excellent agreement with our neutron diffraction study. The magnetic entropy change versus temperature curves for different applied fields collapse into a single curve, revealing a universal behavior of MCE. Our studies suggest that investigation of MCE is an effective technique to acquire fundamental understanding about the basic magnetic structure of a system with complex competing interactions. 相似文献
84.
We obtain monatomic glass formers in simulations by modifying the tetrahedral character in a silicon potential to explore a triple point zone between potentials favoring diamond (dc) and bcc crystals. dc crystallization is always preceded by a polyamorphic transformation of the liquid, and is frustrated when the Kauzmann temperature of the high temperature liquid intersects the liquid-liquid coexistence line. The glass forming liquids are extraordinarily fragile. Our results suggest that Si and Ge liquids may be vitrified at a pressure close to the diamond-beta-tin-liquid triple point. 相似文献
85.
Mohammad Asadikiya Yuexing Zhu Srikanth Gopalan Yu-cheng Chuang Ping-chun Tsai Ralph Nicolai Nasara Shih-kang Lin Yu Zhong 《Ionics》2018,24(3):707-713
The Li4Ti5O12 is applied in lithium ion batteries as anode material, which can be synthesized by various synthesis techniques. In this study, the molten salt synthesis technique at low temperatures, i.e. 350 °C, was applied to synthesize Li4Ti5O12. Surprisingly, the Li4Ti5O12 was not formed according to XRD analysis, which raised question about the stability range of Li4Ti5O12. To investigate the stability of Li4Ti5O12 at low temperatures, the high-temperature calcined Li4Ti5O12 powder was equilibrated in the LiCl-KCl eutectic salt at 350 °C. The result of experiment revealed that the Li4Ti5O12 is not decomposed. Results of ab initio calculations also indicated that the Li4Ti5O12 phase is a stable phase at 0 K. The products of molten salt synthesis technique were then annealed at 900 °C, which resulted in the Li4Ti5O12 formation. It was concluded that the Li4Ti5O12 is a stable phase at low temperatures and the reasons for not forming the Li4Ti5O12 by molten salt technique at low temperature are possibly related to activation energy and kinetic barriers. The Li4Ti5O12 formation energy is also very small, due to the results of ab initio calculations. 相似文献
86.
R. Srikanth S. Banerjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(2):217-227
We develop an information theoretic interpretation of the number-phase complementarity in atomic systems, where phase is treated
as a continuous positive operator valued measure (POVM). The relevant uncertainty principle is obtained as an upper bound
on a sum of knowledge of these two observables for the case of two-level systems. A tighter bound characterizing the uncertainty
relation is obtained numerically in terms of a weighted knowledge sum involving these variables. We point out that complementarity
in these systems departs from mutual unbiasededness in two significant ways: first, the maximum knowledge of a POVM variable
is less than log (dimension) bits; second, surprisingly, for higher dimensional systems, the unbiasedness may not be mutual
but unidirectional in that phase remains unbiased with respect to number states, but not vice versa. Finally, we study the
effect of non-dissipative and dissipative noise on these complementary variables for a single-qubit system. 相似文献
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90.
Harper AS Leone AM Lee D Wang W Ranganathan S Williams ME Murray RW 《The journal of physical chemistry. B》2005,109(40):18852-18859
A room-temperature redox molten salt for the study of electron transfers in semisolid media, based on combining bis(cyclopentadienyl)cobalt with oligomeric polyether counterions, [Cp2Co](MePEG350SO3), is reported. The transport properties of the new molten salt can be varied (plasticized) by varying the polyether content. The charge transport rate during voltammetric reduction of the ionically conductive [Cp2Co](MePEG350SO3) molten salt exceeds the actual physical diffusivity of [Cp2Co]+ because of rapid [Cp2Co](+/0) electron self-exchanges. The measured [Cp2Co](+/0) electron self-exchange rate constants (k(EX)) are proportional to the diffusion coefficients (D(CION)) of the counterions in the melt. The electron-transfer activation barrier energies are also close to those of ionic diffusion but are larger than those derived from optical intervalent charge-transfer results. Additionally, the [Cp2Co](+/0) rate constant results are close to those of dissimilar redox moieties in molten salts where D(CION) values are similar. All of these characteristics are consistent with the rates of electron transfers of [Cp2Co](+/0) (and the other donor-acceptor pairs) being controlled not by the intrinsic electron-transfer rates but by the rate of relaxation of the ion atmosphere around the reacting pair. In the low driving force regime of mixed-valent concentration gradients, the ion atmosphere relaxation is competitive with electron transfer. The results support the generality of the recently proposed model of ionic atmosphere relaxation control of electron transfers in ionically conductive, semisolid materials. 相似文献