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221.
Thermal convection is observed in molecular dynamic simulations of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a square box. Boundaries introduce no shearing or time dependence, but the energy injection comes from a slip (shear-free) thermalizing base. The top wall is perfectly elastic and lateral boundaries are either elastic or periodic. The spontaneous temperature gradient appearing in the system due to the inelastic collisions, combined with gravity, produces a buoyancy force that, when dissipation is large enough, triggers convection. 相似文献
222.
223.
Diwa Reymar R. Tabora Estrellita U. Palattao Botvinnik L. Haneklaus Nils H. Vargas Edmundo P. Reyes Rolando Y. Ramirez Jennyvi D. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):967-974
Journal of Radioanalytical and Nuclear Chemistry - Phosphogypsum (PG) accumulates during wet-phosphoric acid production for fertilizers. In the Philippines, PG is partly (40%) utilized to produce... 相似文献
224.
Bence Mátyás Júlia Singer Máté Szarka Daniel A. Lowy Boglárka Döncző Péter Makleit Virgilio E. Failoc-Rojas Andrés Ramirez Pedro Martínez Zsolt Sándor Ida Kincses András Guttman 《Electrophoresis》2021,42(3):200-205
Although knowledge on glycan biosynthesis and processing is continuously maturing, there are still a limited number of studies that examine biological functions of N-glycan structures in plants, which remain virtually unknown. Here, the statistical correlation between nutrient (nitrogen) deficiency symptoms of crops and changes in 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled complex type free oligosaccharides is reported. While deficiency symptoms are predicted by multispectral images and Kjeldahl digestion, APTS-labeled complex type free oligosaccharides are identified by their glucose unit (GU) values in tomato xylem sap, using capillary electrophoresis with laser induced fluorescence detection (CE-LIF). Given the limited number of structures obtained from plants, archived in the literature, in the future, it is intended to create an open access database of promising indicators, namely, glycan structures that are presumably responsible for the nutrient deficiency caused stress in plants ( http://glycoplants.org ). 相似文献
225.
Pabón Rojas Jonathan Javier Ramón Valencia Bladimir Azdrubal Bolívar Osorio Francisco Javier Ramirez Daniel 《Cellulose (London, England)》2021,28(12):7845-7857
Cellulose - Utilization of raw natural fibers is a research topic of interest for achieving low-cost and ecofriendly composite materials with properties including low density and high specific... 相似文献
226.
Dmitri Sokolovski Daniel Alonso Ramirez Santiago Brouard Martin 《Annalen der Physik》2023,535(10):2300261
Quantum mechanics, in its orthodox version, imposes severe limits on what can be known, or even said, about the condition of a quantum system between two observations. A relatively new approach, based on so-called “weak measurements”, suggests that such forbidden knowledge can be gained by studying the system's response to an inaccurate weakly perturbing measuring device. It goes further to propose revising the whole concept of physics variables, and offers various examples of counterintuitive quantum behavior. Both views go to the very heart of quantum theory, and yet are rarely compared directly. A new technique must either transcend the orthodox limits, or just prove that these limits are indeed necessary. Both possibilities are studied and orthodoxy is vindicated. 相似文献
227.
H. Mizoguchi W.J. Marshall A.P. Ramirez A.W. Sleight M.A. Subramanian 《Journal of solid state chemistry》2007,180(12):3463-3468
Crystals of the mixed-valent compound were grown from a flux. The room temperature conductivity of a crystal was 3 S/cm but decreased smoothly with decreasing temperature to 10−5 S/cm at 25 K. Magnetic susceptibility data indicate a localized moment for Rh4+. A Seebeck coefficient at 200 K of +280 μV/K further confirms that this compound is a semiconductor rather than a metal with a partially filled 4d t2g band. A structure refinement based on single crystal X-ray diffraction data obtained at 173 and 296 K provided Rh–O distances sufficiently accurate to indicate the nature of the charge ordering between Rh3+ and Rh4+. The large Seebeck coefficient coupled with the high electrical conductivity indicates that this may be a promising low-temperature thermoelectric material. 相似文献
228.
A comprehensive overview of the irreversible port-Hamiltonian system’s formulation for finite and infinite dimensional systems defined on 1D spatial domains is provided in a unified manner. The irreversible port-Hamiltonian system formulation shows the extension of classical port-Hamiltonian system formulations to cope with irreversible thermodynamic systems for finite and infinite dimensional systems. This is achieved by including, in an explicit manner, the coupling between irreversible mechanical and thermal phenomena with the thermal domain as an energy-preserving and entropy-increasing operator. Similarly to Hamiltonian systems, this operator is skew-symmetric, guaranteeing energy conservation. To distinguish from Hamiltonian systems, the operator depends on co-state variables and is, hence, a nonlinear-function in the gradient of the total energy. This is what allows encoding the second law as a structural property of irreversible port-Hamiltonian systems. The formalism encompasses coupled thermo-mechanical systems and purely reversible or conservative systems as a particular case. This appears clearly when splitting the state space such that the entropy coordinate is separated from other state variables. Several examples have been used to illustrate the formalism, both for finite and infinite dimensional systems, and a discussion on ongoing and future studies is provided. 相似文献
229.
Costanza Vanni Anne Bodlenner Marco Marradi Jrmy P. Schneider Maria de los Angeles Ramirez Sergio Moya Andrea Goti Francesca Cardona Philippe Compain Camilla Matassini 《Molecules (Basel, Switzerland)》2021,26(19)
Among carbohydrate-processing enzymes, Jack bean α-mannosidase (JBα-man) is the glycosidase with the best responsiveness to the multivalent presentation of iminosugar inhitopes. We report, in this work, the preparation of water dispersible gold nanoparticles simultaneously coated with the iminosugar deoxynojirimycin (DNJ) inhitope and simple monosaccharides (β-d-gluco- or α-d-mannosides). The display of DNJ at the gold surface has been modulated (i) by using an amphiphilic linker longer than the aliphatic chain used for the monosaccharides and (ii) by presenting the inhitope, not only in monomeric form, but also in a trimeric fashion through combination of a dendron approach with glyconanotechnology. The latter strategy resulted in a strong enhancement of the inhibitory activity towards JBα-man, with a Ki in the nanomolar range (Ki = 84 nM), i.e., more than three orders of magnitude higher than the monovalent reference compound. 相似文献
230.
A. P. Ramirez C. L. Broholm R. J. Cava G. R. Kowach 《Physica B: Condensed Matter》2000,280(1-4):290-295
The idea that some systems could have a thermodynamically large number of accessible ground states was presaged in the work of Pauling on ice (Pauling, Cornell University Press, Ithaca, NY, 1945) [1]. With the advent of spin glasses, the methodology for describing ground states changed dramatically, and in particular it was realized that the observed slow dynamics were due to relaxation among a large number of nearly degenerate ground states. Now the accepted wisdom is that both “frustration”, as well as structural disorder, is responsible for spin glass behavior. However, well before spin-glasses were identified as a distinct class of systems, it had been appreciated that even for structurally periodic systems, bond frustration could lead to a thermodynamically large number of states. There is now a well-defined class of magnets which display effects of macroscopic ground state degeneracy. This class of geometrically frustrated magnets presents some new paradigms with which to view condensed matter systems – marginal underconstraint and downward shift of spectral weight. We discuss possible realizations of these phenomena in both in spin ice and also outside the context of local-moment magnetism. 相似文献