2,374 research outputs found
Finite-Size Scaling Analysis of the Eigenstate Thermalization Hypothesis in a One-Dimensional Interacting Bose gas
By calculating correlation functions for the Lieb-Liniger model based on the
algebraic Bethe ansatz method, we conduct a finite-size scaling analysis of the
eigenstate thermalization hypothesis (ETH) which is considered to be a possible
mechanism of thermalization in isolated quantum systems. We find that the ETH
in the weak sense holds in the thermodynamic limit even for an integrable
system although it does not hold in the strong sense. Based on the result of
the finite-size scaling analysis, we compare the contribution of the weak ETH
to thermalization with that of yet another thermalization mechanism, the
typicality, and show that the former gives only a logarithmic correction to the
latter.Comment: 5 pages, 3 figure
Regulation of CD1 Antigen-presenting Complex Stability
For major histocompatibility complex class I and II molecules, the binding of specific peptide antigens is essential for assembly and trafficking and is at the center of their quality control mechanism. However, the role of lipid antigen binding in stabilization and quality control of CD1 heavy chain (HC).beta(2)-microglobulin (beta(2)m) complexes is unclear. Furthermore, the distinct trafficking and loading routes of CD1 proteins take them from mildly acidic pH in early endososmal compartments (pH 6.0) to markedly acidic pH in lysosomes (pH 5.0) and back to neutral pH of the cell surface (pH 7.4). Here, we present evidence that the stability of each CD1 HC.beta(2)m complex is determined by the distinct pH optima identical to that of the intracellular compartments in which each CD1 isoform resides. Although stable at acidic endosomal pH, complexes are only stable at cell surface pH 7.4 when bound to specific lipid antigens. The proposed model outlines a quality control program that allows lipid exchange at low endosomal pH without dissociation of the CD1 HC.beta(2)m complex and then stabilizes the antigen-loaded complex at neutral pH at the cell surface
Pengaruh Model Pembelajaran Problem Solving Dan Problem Posing Terhadap Hasil Belajar Ditinjau Dari Kreativitas Siswa Pada Materi Termokimia Kelas XI SMA Negeri 1 Karanganyar Tahun Pelajaran 2015/216
Penelitian ini bertujuan untuk mengetahui: (1) pengaruh penggunaan model pembelajaran problem solving dan problem posing terhadap hasil belajar siswa; (2) pengaruh kreativitas terhadap hasil belajar siswa; dan (3) interaksi antara penggunaan model pembelajaran problem solving dan problem posing dengan kreativitas terhadap hasil belajar siswa pada materi termokimia di SMA Negeri 1 Karanganyar. Penelitian ini menggunakan metode eksperimen dengan desain faktorial 2x2. Populasi penelitian adalah seluruh siswa kelas XI MIA SMA Negeri 1 Karanganyar tahun pelajaran 2015/2016 sebanyak 9 kelas. Sampel penelitian ditentukan secara acak melalui teknik cluster random sampling dan diambil 2 kelas sebagai sampel. Teknik pengumpulan data menggunakan teknik tes untuk mengukur hasil belajar aspek pengetahuan dan kreativitas siswa dan teknik non tes untuk hasil belajar aspek sikap yang meliputi angket, observasi, jurnal guru dan untuk hasil belajar aspek keterampilan yang meliputi observasi dan penulisan laporan praktikum. Uji hipotesis penelitian menggunakan uji parametrik anava dua jalan untuk hasil belajar aspek pengetahuan dan keterampilan, dan uji non parametrik Kruskal Wallis untuk hasil belajar aspek sikap. Hasil penelitian menunjukkan bahwa: (1) ada pengaruh pembelajaran kimia menggunakan model problem solving dan problem posing terhadap hasil belajar aspek pengetahuan dan keterampilan, namun tidak ada pengaruh terhadap hasil belajar aspek sikap. Siswa yang dibelajarkan menggunakan model pembelajaran problem solving memiliki hasil belajar aspek pengetahuan dan sikap lebih baik dibandingkan siswa yang dibelajarkan dengan model pembelajaran problem posing; (2) ada pengaruh kreativitas tinggi dan rendah terhadap hasil belajar aspek sikap, namun tidak ada pengaruh terhadap hasil belajar aspek dan keterampilan. Siswa dengan kreativitas tinggi memiliki hasil belajar aspek pengetahuan, sikap, dan keterampilan lebih baik dibandingkan siswa dengan kreativitas rendah; (3) tidak ada interaksi antara penggunaan model pembelajaran problem solving dan problem posing dengan kreativitas siswa terhadap hasil belajar aspek pengetahuan, sikap, dan keterampilan
Foundation of Statistical Mechanics under experimentally realistic conditions
We demonstrate the equilibration of isolated macroscopic quantum systems,
prepared in non-equilibrium mixed states with significant population of many
energy levels, and observed by instruments with a reasonably bound working
range compared to the resolution limit. Both properties are fulfilled under
many, if not all, experimentally realistic conditions. At equilibrium, the
predictions and limitations of Statistical Mechanics are recovered.Comment: Accepted in Phys. Rev. Let
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Impact of aircraft emissions on reactive nitrogen over the North Atlantic Flight Corridor region
Equilibration of isolated macroscopic quantum systems
We investigate the equilibration of an isolated macroscopic quantum system in
the sense that deviations from a steady state become unmeasurably small for the
overwhelming majority of times within any sufficiently large time interval. The
main requirements are that the initial state, possibly far from equilibrium,
exhibits a macroscopic population of at most one energy level and that
degeneracies of energy eigenvalues and of energy gaps (differences of energy
eigenvalues) are not of exceedingly large multiplicities. Our approach closely
follows and extends recent works by Short and Farrelly [2012 New J. Phys. 14
013063], in particular going beyond the realm of finite-dimensional systems and
large effective dimensions.Comment: 19 page
Metal-organic vapor-phase epitaxial growth of InGaN and InAlN for multi-junction tandem solar cells
MOVPE growth of InGaN and InAlN has been studied to prepare a wanted band gap from 0.65 to 2.5 eV for multi-junction tandem solar cells. The main subjects in the growth of InGaN are the suppression of phase separation and metallic In incorporation and the control of composition in grown films. Both phase separation and metallic In segregation can be avoided by choosing the appropriate substrate position on the susceptor. By optimizing growth temperature and TMI/(TMI+TEG) molar ratio, InGaN films with full composition range are successfully grown. The Mg-doping behavior of MOVPE InGaN (In composition 0.1~0.4) is also studied using Cp2Mg as a Mg source. The growth behavior of InAlN is studied with the dominant parameters such as growth pressure, TMI/(TMI+TMA) molar ratio and substrate position on the susceptor. The major difficulty in the InAlN growth is found to be the adduct formation by the parasitic reaction of TMA and NH3. By employing the atmospheric-pressure growth, adduct-free InAlN films are grown with a reasonable growth rate (~ 1m/h). This enables us to grow InAlN films with an In content from 0.3 to 1, corresponding to band gaps from 3.6 to 0.65 eV. In order to demonstrate an ability to prepare these different alloys sequentially, InAlN/InGaN hetero-structures are prepared and the photo-response is observed for the first time for an n-InAlN/p-InGaN hetero-junction
Tests and applications of self-consistent cranking in the interacting boson model
The self-consistent cranking method is tested by comparing the cranking
calculations in the interacting boson model with the exact results obtained
from the SU(3) and O(6) dynamical symmetries and from numerical
diagonalization. The method is used to study the spin dependence of shape
variables in the and boson models. When realistic sets of parameters
are used, both models lead to similar results: axial shape is retained with
increasing cranking frequency while fluctuations in the shape variable
are slightly reduced.Comment: 9 pages, 3 ps figures, Revte
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