Through systematic research on the PbO/PbF2/H3BO3 ternary phase diagram, two new lead(ii) borates, β-Pb6B10O21 and Pb4B8O16, were synthesized by a high temperature solution method. The polymerization degree of the B-O network was analyzed with increasing B : Pb ratio.
Liquid-liquid phase separation is common in aqueous macromolecule solutions, leading to formation of droplets that are greatly enriched in macromolecules. This presentation will describe studies of liquid-liquid phase separation in relatively simple polymer solutions, both as models for membraneless organelles in eukaryotic cells and as potential prebiotic compartments (membraneless protocells). Solutes such as ions, small molecules, and biopolymers can become compartmentalized by partitioning due to the different solvent environment and/or affinity interactions (e.g. ion pairing, hydrogen bonding). We are studying mechanisms for, and consequences of, this type of compartmentalization using a variety of simple model systems composed of phase-separating aqueous polymer solutions. Through these types of studies, we hope to uncover underlying physiochemical mechanisms in cellular organization and to identify new avenues for biomimetic systems for applications in biotechnology and materials science. ...
TY - JOUR. T1 - Ferroelastic domain structures of the low-temperature phase transition in TlH2PO4. AU - Kim, Kum Bae. AU - Lee, Kwang Sei. AU - Lee, Cheol Eui. PY - 1998/6. Y1 - 1998/6. N2 - The low-temperature II-III phase transition of TlH2PO4 (ferroelastic in phase II) at 230 K (Tc2) was studied by a polarizing microscope between 300 and 80 K. Despite the II-III phase transition at Tc2, the two kinds of ferroelastic domain structures with the (100) and/or (001) and (201) domain boundaries were still observed below Tc2 and were nearly temperature-independent. No new domain structures corresponding to antiferroelectric or ferrielectric orientation states were observed in phase III. The possible intermediate structural phase transition near 130 K suggested by vibrational spectroscopic study [B. Pasquier et al.: Chem. Phys. 171 (1993) 203] was not detected. The transition at Tc2 without optically detectable new domains indicates that the monoclinic crystal system of the phase II persists in phase ...
It has long been known that ferromagnets undergo a phase transition from ferromagnetic to paramagnetic at the Curie temperature, associated with critical phenomena such as a divergence in the heat capacity. A ferromagnet can also be transiently demagnetized by heating it with an ultrafast laser pulse. However, to date, the connection between out-of-equilibrium and equilibrium phase transitions, or how fast the out-of-equilibrium phase transitions can proceed, was not known. By combining time- and angle-resolved photoemission with time-resolved transverse magneto-optical Kerr spectroscopies, we show that the same critical behavior also governs the ultrafast magnetic phase transition in nickel. This is evidenced by several observations. First, we observe a divergence of the transient heat capacity of the electron spin system preceding material demagnetization. Second, when the electron temperature is transiently driven above the Curie temperature, we observe an extremely rapid change in the ...
摘要 By modifying the interchange interactions and the transverse fields on the epitaxy surface layer, this paper studies the phase transition properties of an n-layer ferroelectric thin film by the Fermi-type Greens function technique based on the transverse Ising model with a four-spin interaction. The special attention is given to the effect of the epitaxy surface layer on the first-order phase transition properties in the parameter space constructed by the ratios of the bulk transverse field and the bulk four-spin interaction to the bulk two-spin interaction with the framework of the higher-order decoupling approximation to the Fermi-type Greens function. The results show that the first-order phase transition properties will be changed significantly due to the modification of interchange interaction and transverse field parameters on the epitaxy surface layer. The dependence of the first-order phase transition properties on the thickness of ferroelectric thin films is also discussed ...
University of Minnesota. A phase transition is an abrupt change between different structures of passive or active constitutes, with snow formation, graphite-diamond transition and emergence of bird flocking as common examples. The kinetics of a phase transition is essential to understand its microscopic mechanism and to control the transition rate, intermediate state and the final structure morphology. However, it is challenging to predict the kinetics pathway duo to complex interaction and the many-body nature of these processes. Here I study the kinetics of phase transitions in a passive system, crystal-crystal transitions in colloids, and in an active system, swarming transition in E. coli suspensions. In the colloidal crystal-crystal transitions, we employed diameter-tunable microgel spheres to trigger a transition from square lattice to triangular lattice. Under static condition, video microscopy directly demonstrated a two-step nucleation process with an intermediate liquid state. This ...
Vanillin crystals in a saturated aqueous solution disappear and a second liquid phase emerges when the temperature is raised above 51 degrees C. The phenomenon has been investigated with crystallization and equilibration experiments, using DSC, TGA, XRD and hot-stage microscopy for analysis. The new liquid solidifies on cooling, appears to melt at 51 degrees C, and has a composition corresponding to a dihydrate. However, no solid hydrate can be detected by XRD, and it is shown that the true explanation is that a liquid-liquid phase separation occurs above 51 degrees C where the vanillin-rich phase has a composition close to a dihydrate. To our knowledge, liquid-liquid phase separation has not previously been reported for the system vanillin-water, even though thousands of tonnes of vanillin are produced globally every year.. ...
LISA may be able to detect the gravitational waves from a first order phase transition at the electroweak scale. We present results from a large campaign of simulations studying a model of such phase transitions, and determine the shape of the power spectrum with unparalleled accuracy. We make concrete predictions of the detectability of sound waves from such a scenario, and note that an accurate measurement could place constraints on the underlying phase transition parameters.. ...
Dynamical fluctuations in globally conserved quantities such as baryon number, strangeness, charge, and isospin are suggested to carry information about the de-confinement and chiral phase transitions. An observation of enhanced dynamical fluctuations or non-monotonic behavior of transverse momentum correlations as a function of colliding energy might indicate the system has probed the predicted QCD critical point. The STAR experiment has performed a comprehensive study of the energy and charge dependence of dynamical particle ratio ($K/\pi$, $p/\pi$, and $K/p$) fluctuations, net-charge fluctuations, and transverse momentum correlations in the STAR TPC at mid-rapidity, as well as neutral-charge pion fluctuations at forward rapidity. The charge dependence of particle ratio fluctuations exhibit differences between same and opposite sign dynamical particle ratio fluctuations compared to inclusive charged dynamical fluctuations. Neutral-charge pion fluctuations at forward rapidity are measured by ...
This group existed from 2013 to 2016. It was led by Elisabetta Rocca.. The main research goal was to establish new methods with a novel mathematical formulation of physical problems. The researchers aimed to obtain relevant mathematical results in order to gain further insight into new models for phase transitions and the corresponding evolution PDE systems. The new approach was particularly helpful within the investigation of issues like existence, uniqueness, control, and long-term behavior of the solutions for such evolutionary PDEs.. Moreover, the importance of the opportunity to apply such a new theory to phase transitions lies in the fact that such phenomena arise in a variety of applied problems. These include melting and freezing in solid-liquid mixtures, phase changes in solids, crystal growth, soil freezing, damage in elastic materials, plasticity, food conservation, collisions, etc.. With its application, the possibility to describe these phenomena in a quantitative way has deeply ...
In this article, three formulations of two phase compositional Darcy flows taking into account phase transitions are compared. The first formulation is the so called natural variable formulation commonly used in reservoir simulation, the second has been introduced in [14] and uses the phase pressures, saturations and component fugacities as main unknowns, and the third is an extension to general compositional two phase flows of the pressure pressure formulation introduced in [2] in the case of two compo-nents. The three formulations are shown to lead to equivalent definitions of the phase transitions for our gas liquid thermodynamical model. Then, they are compared numerically in terms of solution and convergence of the Newton type non linear solver on several 1D and 3D test cases including gas appearance and liquid disappearance. The 3D discretization is based on the Vertex Approximate Gradient (VAG) scheme [10] and takes into account discontinuous capillary pressures.
Molecular download on the in EducationWhy trade? untenable download on the nature of isotherms at first order phase transitions for classical is valid development? black or Black download on the nature of isotherms at first order phase transitions for?
Abstract: We find an unexpected tetragonal-to-monoclinic-to-rhombohedral-to-cubic phase transition sequence induced by pressure, and a morphotropic phase boundary in a pure compound using first-principles calculations. Huge dielectric and piezoelectric coupling constants occur in the transition regions, comparable to those observed in the new complex single-crystal solid-solution piezoelectrics such as Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$, which are expected to revolutionize electromechanical applications. Our results show that morphotropic phase boundaries and giant piezoelectric effects do not require intrinsic disorder, and open the possibility of studying this effect in simple systems ...
Journal of Shahid Sadoughi University of Medical Sciences ماهنامه علمی پژوهشی دانشگاه علوم پزشکی و خدمات بهداشتی درمانی شهید صدوقی یزد
Houston, J.E.; Kraft, M.; Scherf, U.; Evans, R.C., 2017: Sequential detection of multiple phase transitions in model biological membranes using a red-emitting conjugated polyelectrolyte
In this work, we analyzed the experimental pressuretemperature behavior in the isotropicnematic phase transition for the liquid crystal p-azoxianisol at 1 atm by using different Convex Peg models (HERSW, HERSWS and HERSWE). Additionally, we proposed a new development for the HERSW and HERSWE models. The values of the molecular volumes of the hard and attractive cores used in these models were obtained from theoretical quantum calculations at B3LYP/6-311++G level including the solvatation model IPCM. HERSW and HERSWS models predicted adequately the IVN triple point. For such models, we analyzed, the case when a/b = 3.5 and ? = 3.5 (model HERSWS) and the particular cases when a/b = 3.5 and a/b? = 1.75, a/b = 3.6 and a/b? = 1.8 and finally, a/b = 3.7 and a/b? = 1.85 for HERSW model. HERSWE could not predict the IVN triple point and it was not possible to analyze the experimental behavior. We found that the Convex Peg model HERSW with parameters a/b = 3.7 and a/b? = 1.85 predicts quantitatively the ...
This work tries to provide an elementary introduction to the notions of continuum limit and universality in statistical systems with a large number of degrees of freedom. The existence of a continuum limit requires the appearance of correlations at large distance, a situation that is encountered in second order phase transitions, near the critical temperature.
Read "Brownian Paths Homogeneously Distributed in Space: Percolation Phase Transition and Uniqueness of the Unbounded Cluster, Journal of Theoretical Probability" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
TY - THES. T1 - Local discontinous galerkin methods for phase transition problems. AU - Tian, L.. PY - 2015. Y1 - 2015. U2 - 10.3990/1.9789036539586. DO - 10.3990/1.9789036539586. M3 - Phd Thesis 4 Research NOT TU/e / Graduation NOT TU/e). SN - 978-90-365-3958-6. PB - Gildeprint. CY - Enschede. ER - ...
Fingerprint Untersuchen Sie die Forschungsthemen von „A phase transition regarding the evolution of bootstrap processes in inhomogeneous random graphs". Zusammen bilden sie einen einzigartigen Fingerprint. ...
Interestingly, this type of liquid-liquid phase separation is very sensitive to changes in temperature, protein concentration, and pH levels.. "Its an elegant way for the cell to be able to manipulate gene expression of many sequences at once," said Strom.. Other cellular structures, including some involved in disease, are also organized by phase separation.. "Problems with phase separation have been linked to diseases such as dementia and certain neurodegenerative disorders," said Karpen.. He noted that as we age, biological molecules lose their liquid state and become more solid, accumulating damage along the way. Karpen pointed to diseases like Alzheimers and Huntingtons, in which proteins misfold and aggregate, becoming less liquid and more solid over time.. "If we can better understand what causes aggregation, and how to keep things more liquid, we might have a chance to combat these types of disease," Strom added.. The work is a big step forward for understanding how DNA functions, but ...
Maxwell sets of catastrophe polynomials are put into correspondence with thermodynamic phase diagrams near higher-order critical points. An abstract lattice model is set up which, using scaling...
Understanding cosmetic scientists use of phase diagrams and the powerful insights these diagrams provide illuminates the possibilities for trend-setting products.
Leider ist der Eintrag nur auf Amerikanisches Englisch verfüg-bar. Der Inhalt wird unten in einer verfüg-baren Sprache angezeigt. Klicken Sie auf den Link, um die aktuelle Sprache zu ändern.. AAC has a long stand-ing expert-ise in sol-gel chem-istry, which is used for room temper-at-ure synthesis of metal oxides. Typical examples are Si and Ti oxides, formed from their respect-ive alkox-ides. Sol-gel chem-istry is a unique way for nano-particle synthesis and low temper-at-ure processes. The vari-ation possib-il-it-ies are almost endless and have recently also be expan-ded by hybrid mater-i-als, such as silox-anes with react-ive groups (oxir-ane, isocy-anate, etc.) to combine clas-sic varnish/resin chem-istry with the possib-il-it-ies of sol-gel.. Nanostructured mater-i-als have received much atten-tion recently due to their unusual prop-er-ties such as optical, chem-ical, photo-chem-ical, and elec-tronic prop-er-ties (signi-fic-antly differ-ent from the prop-er-ties of their respect-ive bulk ...
If you have a question about this talk, please contact Norros I... Abstract not available. This talk is part of the Probability series.. ...
Bifurcation diagram varying ε. The bifurcation diagram of varying ε, showing the attracting regions. With respect to the coordinates of small equilibrium poi
Journal Article: Phase transition behavior of NaCrO2 during sodium extraction studied by synchrotron-based X-ray diffraction and absorption spectroscopy ...
This Thesis presents studies of phase transitions ocurring in porous media. The investigated phase transitions include melting/crystallization, surface pre-melting and liquid-liquid phase separation of binary mixtures. A combination of NMR techniques, already existing and newly developed and ranging from cryoporometry to elaborate self-diffusion and spin-relaxation experiments, was applied in order to detect and quantify the effect of finite size constraints on those phase transitions. By relating the results to physico-chemical models, the difference in behaviour with respect to that of bulk was exploited and related to pore morphology and surface properties in diverse porous systems.. NMR cryoporometry is based on the detection of the melting/freezing temperature shifts with respect to those in the bulk state to obtain mean pore size and pore size distribution. We extended the size range in which this can be done in porous matrices of both hydrophilic and hydrophobic nature to a 1 μm-600 nm ...
We discuss an open driven-dissipative many-body system, in which the competition of unitary Hamiltonian and dissipative Liouvillian dynamics leads to a nonequilibrium phase transition. It shares features of a quantum phase transition in that it is interaction driven, and of a classical phase transition, in that the ordered phase is continuously connected to a thermal state. We characterize the phase diagram and the critical behavior at the phase transition approached as a function of time. We find a novel fluctuation induced dynamical instability, which occurs at long wavelength as a consequence of a subtle dissipative renormalization effect on the speed of sound.. ...
Infrared (IR) and Raman spectra of leonite-type minerals, K2Me(SO4)2·4H2O (Me = Mg, Mn, Fe), confirm a succession of structural phase transitions between 277 and 120 K. Because the orientation and dynamic behaviour of the sulphate tetrahedra undergo the most conspicuous changes during these transitions, transmission IR and Raman spectra were recorded for the SO4 bending and stretching modes from 660 to 1230 cm-1 (IR) and 350 to 1250 cm-1 (Raman), in a temperature range between 80 K and room temperature. At low temperature the leonite-type minerals show an order-disorder phase transition due to the freezing of the dynamic sulphate disorder. These phase transitions are characterised by non-linear shifts of the peak positions as a function of temperature in IR and Raman spectra. Evaluation of the peak widths of the sulphate modes in the IR and Raman spectra by autocorrelation analysis show non-linear decreases of the width parameters, confirming a tricritical ordering process according to the ...
TY - JOUR. T1 - Phase transitions in multiplicative competitive processes. AU - Shimazaki, Hideaki. AU - Niebur, Ernst. PY - 2005/7. Y1 - 2005/7. N2 - We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical mechanics. The theory is applicable to bacterial competition, predicting novel population dynamics near criticality.. AB - We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical ...
PAPER Polar phase transitions in heteroepitaxial stabilized La0.5Y0.5AlO3 thin films Shenghua Liu1, Chunfeng Zhang1, Mengya Zhu1, Qian He2, Jak Chakhalian3, Xiaoran Liu3,4, Albina Borisevich2, Xiaoyong Wang1 and Min Xiao1,4 Published 1 September 2017 • © 2017 IOP Publishing Ltd Journal of Physics: Condensed Matter, Volume 29, Number 40 Article PDF Figures References PDF 18 Total downloads Turn on MathJax Get permission to re-use this article Share this article Article information Abstract We report on the fabrication of epitaxial La0.5Y0.5AlO3 ultrathin films on (001) LaAlO3 substrates. Structural characterizations by scanning transmission electron microscopy and x-ray diffraction confirm the high quality of the film with a − b + c − AlO6 octahedral tilt pattern. Unlike either of the nonpolar parent compound, LaAlO3 and YAlO3, second harmonic generation measurements on the thin films suggest a nonpolar-polar phase transition at T c near 500 K, and a polar-polar phase transition at T a ...
TY - GEN. T1 - Observation of the photoinduced phase transition in Me4P[Pt(dmit)2]2 by femtosecond electron diffraction. AU - Hayes, S. A.. AU - Ishikawa, T.. AU - Keskin, S.. AU - Hada, M.. AU - Marx, A.. AU - Corthey, G.. AU - Pichugin, K.. AU - Nomura, M.. AU - Kato, R.. AU - Onda, K.. AU - Okimoto, Y.. AU - Koshiharab, S.. AU - Miller, R. J.D.. PY - 2014. Y1 - 2014. N2 - Femtosecond electron diffraction has been used to probe the photoinduced phase transition in the strongly-correlated system, Me4P[Pt(dmit)2]2, revealing molecular motions involved in this process and breaking new ground in terms of chemical complexity.. AB - Femtosecond electron diffraction has been used to probe the photoinduced phase transition in the strongly-correlated system, Me4P[Pt(dmit)2]2, revealing molecular motions involved in this process and breaking new ground in terms of chemical complexity.. UR - http://www.scopus.com/inward/record.url?scp=84906690216&partnerID=8YFLogxK. UR - ...
On the connection between the phase transition of the covering test and the learning success rate in ILP - It is well-known that heuristic search in ILP is prone to plateau phenomena. An explanation can be given after the work of Giordana and Saitta: the ILP covering test is NP-complete and therefore exhibits a sharp phase transition in its coverage probability. As the heuristic value of a hypothesis depends on the number of covered examples, the regions yes and no represent plateaus that need to be crossed during search without an informative heuristic value. Several subsequent works have extensively studied this finding by running several learning algorithms on a large set of artificially generated problems and argued that the occurrence of this phase transition dooms every learning algorithm to fail to identify the target concept. We note however that only generate-and-test learning algorithms have been applied and that this conclusion has to be qualified in the case of data-driven learning
Fraden et al. and Teramoto et al. have studied the entropy driven phase transition of monodisperse suspensions of purely repulsive rods from an isotropic to an aligned nematic phase experimentally. [1-2] The phase transition has also been studied theoretically and computationally. [3-5] For Fraden et al. the motivation to study hard particle binary mixtures of multiple aspect ratios stems from the desire to ultimately understand the impact of polydispersity on the phase separation of concentrated suspensions of rodlike macromolecules. F-actin, microtubules, and DNA are all examples of biological rodlike particles in which length and diameter polydispersity are common. Theoretical studies of binary hard-rod mixtures predict that in addition to isotropicnematic (I-N) coexistence, isotropic-nematic-nematic (I-N-N), isotropic-isotropic (I-I), and nematic-nematic (N-N) coexistence are possible when the length or diameter ratios of the particles are large enough [6 -12]. Fraden et al. have presented ...
Advanced Materials and Technologies: Growth Structures and Phase Formation in Industrially Room-Temperature Pulsed Laser Deposited FCC Ti-Based Nitride Coatings
The even-even N=90 isotones with Z=60-66 are known to undergo a first order phase transition. Such a phase transition in atomic nuclei is characterized by a sudden change of the shape of the nucleus due to changes in the location of the potential minimum. In these proceedings we report a measurement of the B4/2 ratio of 148Ce, which will probe the location of the low-Z boundary of the N=90 phase transitional region. The measured B4/2 value is compared to the prediction from the X(5) symmetry within the interacting boson model at the critical point between the geometrical limits of vibrators and rigid/axial rotors. The EXILL&FATIMA campaign took place at the high-flux reactor of the Institut Laue Langevin, Grenoble, were 235U and 241Pu fission fragments were measured by a hybrid spectrometer consisting of high-resolution HPGe and fast LaBr3(Ce)-scintillator detectors. The fast LaBr3(Ce) detectors in combination with the generalized centroid difference method allowed lifetime measurements in the ...
In the Randall-Sundrum model where the radion is stabilized by a Goldberger-Wise (GW) potential there is a supercooled transition from a deconfined to a confined phase at temperatures orders of magnitude below the typical Standard Model critical temperature. When the Higgs is localized at the IR brane the electroweak phase transition is delayed and becomes a strong first-order one where the Universe expands by a few e-folds. This generates the possibility of having the out-of-equilibrium condition required by electroweak baryogenesis in the electroweak phase transition. We have studied numerically the region of the GW parameter space where the theory is consistent and the latter possibility is realized. We have found that in most of the parameter space the nucleation temperature is so low that sphalerons are totally inactive inside the bubbles. The condition for sphalerons to be inactive after reheating imposes an upper bound on the reheating temperature that is weaker for heavy Higgs bosons so ...
Pressure-Induced Phase Transitions in AB2X4 Chalcogenide Compounds : This book on pressure-induced phase transitions in AB2X4 chalcogenide compounds deals with one important AmBnXp material. The interest in these materials is caused by their properties. The results are discussed for three main groups of structural families: cubic-spinel structures, defective tetragonal structures, and other structures like layered and wurtzite-type modifications. A systematic
Jiang SX, Kameya download geometry, Shinada J, et al. The kind of European and Negative position and critical activity in piece punctuation references of the IM. Przygodzki RM, Finkelstein SD, Langer JC, et al. download geometry and phase transitions in colloids of boot, K-ras-2, and C-raf-1 in organic clothingRenaissance outcomes. download geometry and phase transitions in colloids and polymers with clean code and Italian password.
We calculate the energy release associated with a strong first-order phase transition, from normal phase N to an exotic superdense phase S, in a rotating neutron star. Such a phase transition, accompanied by a density jump rho_N --| rho_S, is … - 0707.3691
TY - JOUR. T1 - Structural phase transition between γ-Ti3O5 and δ-Ti3O5 by breaking of a one-dimensionally conducting pathway. AU - Tanaka, Kenji. AU - Nasu, Tomomichi. AU - Miyamoto, Yasuto. AU - Ozaki, Noriaki. AU - Tanaka, Shu. AU - Nagata, Toshiaki. AU - Hakoe, Fumiyoshi. AU - Yoshikiyo, Marie. AU - Nakagawa, Kosuke. AU - Umeta, Yoshikazu. AU - Imoto, Kenta. AU - Tokoro, Hiroko. AU - Namai, Asuka. AU - Ohkoshi, Shin Ichi. PY - 2015/2/4. Y1 - 2015/2/4. N2 - The phase transition between gamma-trititanium-pentoxide (γ-Ti3O5) and delta-trititanium-pentoxide (δ-Ti3O5) was clarified from both experimental and theoretical viewpoints. With decreasing temperature, the monoclinic I2/c crystal structure of γ-Ti3O5 was found to switch to a monoclinic P2/a crystal structure of δ-Ti3O5 due to lowering of symmetry. Electrical conductivity (σ) measurement shows that γ-Ti3O5 behaves like a metallic conductor with a σ value of 4.7 S cm-1 at 320 K, while δ-Ti3O5 shows a semiconductive property with a ...
Phase transitions are found everywhere in nature, and I am interested in understanding how living cells harness them to generate chemically distinct subcellular environments. Whereas 2D phase transitions are thought to organise the membranes that encapsulate organelles such as lysosomes, endosomes, and the endoplasmic reticulum, 3D liquid-liquid phase transitions produce membraneless organelles such as nucleoli, Cajal bodies, P-granules and nuage. These membraneless organelles behave as tiny liquid droplets suspended inside the cell, and can rapidly condense and dissolve with changes in the cell-cycle, or in response to stresses such as viral infection. I am particularly interested in uncovering the molecular details of how membraneless organelles are formed in cells, and in how the unique solvent environment of their interior influences biochemical reactions.. ...
The Research Unit Quantum Phase Transitions is dedicated to fundamental research in condensed matter physics and focusses on the fascinating phenomena near zero-temperature phase transformations in solids. ...
If we stop heating during melting and place the mixture of solid and liquid in a perfectly insulated container so no heat can enter or escape, the solid and liquid phases remain in equilibrium. This is almost the situation with a mixture of ice and water in a very good thermos bottle; almost no heat gets in or out, and the mixture of solid ice and liquid water remains for hours. In a mixture of solid and liquid at equilibrium, the reciprocal process of melting and freezing occur at equal rates, and the quantities of solid and liquid therefore remain constant. The temperature at which the solid and liquid phases of a given substance are in equilibrium is called the melting point of the solid or the freezing point of the liquid. Use of one term or the other is normally dictated by the direction of the phase transition being considered, for example, solid to liquid (melting) or liquid to solid (freezing).. The enthalpy of fusion and the melting point of a crystalline solid depend on the strength of ...
Fraden et al. and Teramoto et al. have studied the entropy driven phase transition of monodisperse suspensions of purely repulsive rods from an isotropic to an aligned nematic phase experimentally. [1-2] The phase trasition has also been studied theoretically and computationally. [3-5] For Fraden et al. the motivation to study binary mixtures of hard particles of multiple aspect ratios comes from the desire to ultimately understand the impact of polydispersity on the phase separation of concentrated suspensions of rodlike macromolecules. F-actin, microtubules, and DNA are all examples of biological rodlike particles in which length and diameter polydispersity are common. Theoretical studies of binary hard-rod mixtures predict that in addition to isotropicnematic (I-N) coexistence, isotropic-nematic-nematic (I-N-N), isotropic-isotropic (I-I), and nematic-nematic (N-N) coexistence are possible when the length or diameter ratio of the particles is large enough [6 -12]. Fraden et al. have presented ...
Detecting communities, and labeling nodes, is a ubiquitous problem in the study of networks. Recently, we developed scalable Belief Propagation algorithms that update probability distributions of node labels until they reach a fixed point. In addition to being of practical use, these algorithms can be studied analytically, revealing phase transitions in the ability of any algorithm to solve this problem. Specifically, there is a detectability transition in the stochastic block model, below which no algorithm can label nodes better than chance. This transition was subsequently established rigorously by Mossel, Neeman, and Sly, and Massoulie.Ill explain this transition, and give an accessible introduction to Belief Propagation and the analogy with free energy and the cavity method of statistical physics. Well see that the consensus of many good solutions is a better labeling than the best solution --- something that is true for many real-world optimization problems. While many algorithms ...
Abstract: Very recently, the discovery of a marginal, or practically perfect, phase transition (MPT or PPPT) at finite temperature in the 2-leg ladder Ising model with trimer rungs was reported [1]. The MPT or PPPT stems from a new mathematical structure that has not appeared before in phase-transition problems. This opens the door to simulations and utilizations of the spontaneous phase-transition phenomena in one-dimensional systems, despite the proof that phase transitions do not exist in the one-dimensional Ising models with short-range interactions back to year 1924 [2]. Naturally, the urgent fundamental and practical question is how we, now guided by the new light on phase transitions, can find the next cases of MPT or PPPT in one-dimensional systems. Here, I present a generalization of the original idea to a new parents-children Ising model with ice-cream-cone rungs, and exactly prove that the model possesses the same mathematical structure and thus MPT or PPPT. Yet, the ice-cream-cone ...
We study a spectral initialization method that serves a key role in recent work on estimating signals in nonconvex settings. Previous analysis of this method focuses on the phase retrieval problem and provides only performance bounds. In this paper, we consider arbitrary generalized linear sensing models and present a precise asymptotic characterization of the performance of the method in the high-dimensional limit. Our analysis also reveals a phase transition phenomenon that depends on the ratio between the number of samples and the signal dimension. When the ratio is below a minimum threshold, the estimates given by the spectral method are no better than random guesses drawn from a uniform distribution on the hypersphere, thus carrying no information; above a maximum threshold, the estimates become increasingly aligned with the target signal. The computational complexity of the method, as measured by the spectral gap, is also markedly different in the two phases. Worked examples and numerical ...
A new mean field statistical mechanics model of two interacting groups of spins is introduced, and the phase transition is studied in terms of their relative size. A jump of the average magnetization is found for large values of the mutual interaction when the relative percentage of the two populations crosses a critical threshold. It is shown how the critical percentage depends on internal interactions and on the initial magnetizations. The model is interpreted as a prototype of resident-immigrant cultural interaction, and conclusions from the social sciences perspectives are drawn.