The transition from a many-body localized phase to a thermalizing one is a dynamical quantum phase transition that lies outside the framework of equilibrium statistical mechanics. We provide a ...detailed study of the critical properties of this transition at finite sizes in one dimension. We find that the entanglement entropy of small subsystems looks strongly subthermal in the quantum critical regime, which indicates that it varies discontinuously across the transition as the system size is taken to infinity, even though many other aspects of the transition look continuous. We also study the variance of the half-chain entanglement entropy, which shows a peak near the transition, and find substantial variation in the entropy across eigenstates of the same sample. Furthermore, the sample-to-sample variations in this quantity are strongly growing and are larger than the intrasample variations. We posit that these results are consistent with a picture in which the transition to the thermal phase is driven by an eigenstate-dependent sparse resonant “backbone” of long-range entanglement, which just barely gains enough strength to thermalize the system on the thermal side of the transition as the system size is taken to infinity. This discontinuity in a global quantity—the presence of a fully functional bath—in turn implies a discontinuity even for local properties. We discuss how this picture compares with existing renormalization group treatments of the transition.
Despite intense studies into silicon anode materials, the large volume expansion of silicon remains a significant problem that reduces battery performance and shortens battery life. In this paper, a ...procedure to increase the cycle life of the silicon anode in full-cell configuration using a simple pre-lithiation method is proposed. By precisely controlling the thickness of the pre-deposited lithium through evaporation, the volume change of the silicon-containing anodes can be effectively reduced during discharge. A coin-cell fabricated with a high-capacity cathode and the pre-lithiated silicon–graphite anode shows improvements in cycling performance, as well as a higher discharge capacity. Electrochemical and microscopic analysis confirm that pre-lithiation successfully suppresses the volumetric changes. Thus, this work provides an effective method for the preparation of long-cycle-life Li-ion batteries containing silicon-based anodes.
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•The mechanism for improving cycle life through pre-lithiation was proposed and proved.•A pre-lithiation method is proposed by lithium evaporation on a Si-Gr anode.•Precisely controlled pre-lithiated cells prevent complete shrinkage of the silicon.•Enhanced cycle life and a high areal capacity were achieved at a high current densities.
Pseudo random number generator based on quantum chaotic map Akhshani, A.; Akhavan, A.; Mobaraki, A. ...
Communications in nonlinear science & numerical simulation,
January 2014, 2014-1-00, 20140101, Letnik:
19, Številka:
1
Journal Article
Recenzirano
•A novel pseudo-random number generator (PRNG) based on quantum logistic map is presented.•The Scale index analysis shows the generated sequence is more non-periodic.•The proposed PRNG is subjected ...to statistical tests using the well-known tests suites.•The PRNG successfully passed all statistical tests of the test suites for all runs.•There is no post-processing procedure which makes it an extremely simple generator.
For many years dissipative quantum maps were widely used as informative models of quantum chaos. In this paper, a new scheme for generating good pseudo-random numbers (PRNG), based on quantum logistic map is proposed. Note that the PRNG merely relies on the equations used in the quantum chaotic map. The algorithm is not complex, which does not impose high requirement on computer hardware and thus computation speed is fast. In order to face the challenge of using the proposed PRNG in quantum cryptography and other practical applications, the proposed PRNG is subjected to statistical tests using well-known test suites such as NIST, DIEHARD, ENT and TestU01. The results of the statistical tests were promising, as the proposed PRNG successfully passed all these tests. Moreover, the degree of non-periodicity of the chaotic sequences of the quantum map is investigated through the Scale index technique. The obtained result shows that, the sequence is more non-periodic. From these results it can be concluded that, the new scheme can generate a high percentage of usable pseudo-random numbers for simulation and other applications in scientific computing.
Abstract
Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well ...as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.
An image encryption scheme based on quantum logistic map Akhshani, A.; Akhavan, A.; Lim, S.-C. ...
Communications in nonlinear science & numerical simulation,
December 2012, 2012-12-00, 20121201, Letnik:
17, Številka:
12
Journal Article
Recenzirano
► A novel image encryption algorithm based on quantum logistic map is presented. ► The proposed scheme is subjected to the well-known security analysis. ► The results clearly demonstrate that the ...algorithm is more efficient and secure.
The topic of quantum chaos has begun to draw increasing attention in recent years. While a satisfactory definition for it is not settled yet in order to differentiate between its classical counterparts. Dissipative quantum maps can be characterized by sensitive dependence on initial conditions, like classical maps. Considering this property, an implementation of image encryption scheme based on the quantum logistic map is proposed. The security and performance analysis of the proposed image encryption is performed using well-known methods. The results of the reliability analysis are encouraging and it can be concluded that, the proposed scheme is efficient and secure. The results of this study also suggest application of other quantum maps such as quantum standard map and quantum baker map in cryptography and other aspects of security and privacy.
Summary
While many women with polycystic ovary syndrome (PCOS) are overweight, obese or centrally obese, the effect of excess weight on the outcomes of PCOS is inconsistent. The review aimed to ...assess the effects of overweight, obesity and central obesity on the reproductive, metabolic and psychological features of PCOS. MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting outcomes according to body mass index categories or body fat distribution. Data were presented as mean difference or risk ratio (95% confidence interval). This review included 30 eligible studies. Overweight or obese women with PCOS had decreased sex hormone‐binding globulin (SHBG), increased total testosterone, free androgen index, hirsutism, fasting glucose, fasting insulin, homeostatic model assessment‐insulin resistance index and worsened lipid profile. Obesity significantly worsened all metabolic and reproductive outcomes measured except for hirsutism when compared to normal weight women with PCOS. Overweight women had no differences in total testosterone, hirsutism, total‐cholesterol and low‐density lipoprotein‐cholesterol compared to normal weight women and no differences in SHBG and total testosterone compared to obese women. Central obesity was associated with higher fasting insulin levels. These results suggest that prevention and treatment of obesity is important for the management of PCOS.
With the continuous growth of internet usage, Google Trends has emerged as a source of information to investigate how social trends evolve over time. Knowing how the level of interest in conservation ...topics--approximated using Google search volume--varies over time can help support targeted conservation science communication. However, the evolution of search volume over time and the mechanisms that drive peaks in searches are poorly understood. We conducted time series analyses on Google search data from 2004 to 2013 to investigate: (i) whether interests in selected conservation topics have declined and (ii) the effect of news reporting and academic publishing on search volume. Although trends were sensitive to the term used as benchmark, we did not find that public interest towards conservation topics such as climate change, ecosystem services, deforestation, orangutan, invasive species and habitat loss was declining. We found, however, a robust downward trend for endangered species and an upward trend for ecosystem services. The quantity of news articles was related to patterns in Google search volume, whereas the number of research articles was not a good predictor but lagged behind Google search volume, indicating the role of news in the transfer of conservation science to the public.
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