排序方式: 共有67条查询结果,搜索用时 15 毫秒
21.
T. D. Kieu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(1):115-128
We introduce a class of quantum heat engines which consists of
two-energy-eigenstate systems, the simplest of quantum mechanical
systems, undergoing quantum adiabatic processes and energy exchanges
with heat baths, respectively, at different stages of a cycle. Armed
with this class of heat engines and some interpretation of heat
transferred and work performed at the quantum level, we are able to
clarify some important aspects of the second law of thermodynamics.
In particular, it is not sufficient to have the heat source hotter
than the sink, but there must be a minimum temperature difference
between the hotter source and the cooler sink before any work can be
extracted through the engines. The size of this minimum temperature
difference is dictated by that of the energy gaps of the quantum
engines involved. Our new quantum heat engines also offer a
practical way, as an alternative to Szilard's engine, to physically
realise Maxwell's daemon. Inspired and motivated by the Rabi
oscillations, we further introduce some modifications to the quantum
heat engines with single-mode cavities in order to, while respecting
the second law, extract more work from the heat baths than is
otherwise possible in thermal equilibria. Some of the results above
are also generalisable to quantum heat engines of an infinite number
of energy levels including 1-D simple harmonic oscillators and 1-D
infinite square wells, or even special cases of continuous spectra. 相似文献
22.
We show that a glass microsphere resonator can be used as a wavelength-selective mirror in fiber lasers. Due to their high quality factor (Q approximately 10(8)), microsphere resonators possess a narrow reflection bandwidth. This feature enables construction of single-frequency fiber lasers even when the laser cavity is long. Nonlinear effects (such as stimulated Raman lasing) were also observed in our setup at relatively low pump powers. 相似文献
23.
In this work, we will prove the Dugundji extension theorem for the cone metric space. It is heavily reliant on the paracompactness of the cone topology that is proved by Ayse Sönmez in the paper Sönmez (2010) [11]. 相似文献
24.
Consistent temperature control in an on-chip flow-through polymerase chain reaction (PCR) employing two or more heaters is one of the main obstacles for device miniaturization and integration when realizing micro total analysis systems (μTAS), and also leads to operational complexity. In this study, we propose a qiandu (right triangular prism)-shaped polydimethylsiloxane (PDMS) microdevice with serpentine microchannels fabricated on its slanted plane, and apply the device for an on-chip flow-through PCR employing a single heater. The inclined nature of the qiandu-shaped microdevice enables the formation of a surface temperature gradient along the slanted plane of the microdevice in a height-dependent manner by the use of a single heater, and enables liquid to traverse over wide ranges of temperatures, including the three temperature zones--denaturation, annealing, and extension temperatures--required in a typical PCR. The feasibility of the qiandu-shaped PDMS microdevice as a versatile platform for performing a flow-through PCR was examined by employing multiple templates and varying the inclination angle of the device. In addition, the potential of performing a multiplex PCR using a single qiandu-shaped PDMS microdevice was explored. A 409 bp long gene fragment effective as a marker for diagnosing lung cancer and a 230 bp long gene fragment from a plasmid vector were simultaneously amplified in less than 25 min on a single microdevice, paving the way for a microscale, multiplex PCR on a single device employing a single heater. 相似文献
25.
26.
Tuan Dao Anh Ke Nguyen Huu Thi Kieu Loan Phan Hung Le Vu Tuan 《Journal of Sol-Gel Science and Technology》2018,87(1):245-253
Journal of Sol-Gel Science and Technology - In this work, a fabrication process of high crystallinity CZTSSe absorber layer is presented. The CZTS structure is firstly prepared by spin-coating... 相似文献
27.
Micro-electrodialysis (μED) and CE were combined for rapid pretreatment and subsequent determination of inorganic cations in biological samples. Combination of μED with CE greatly improved the analytical performance of the latter as the adsorption of high molecular weight compounds present in real samples on the inner capillary wall was eliminated. Fifty microliter of 80-fold diluted human body fluids such as plasma, serum and whole blood was used in the donor compartment of the μED system requiring less than 1?μL of the original body fluid per analysis. Inorganic cations that migrated through a cellulose acetate dialysis membrane with molecular weight cut-off value of 500?Da were collected in the acceptor solution and were then analyzed using CE-C?D. Baseline separation of inorganic cations was achieved in a BGE solution consisting of 12.5?mM maleic acid, 15?mM L-arginine and 3?mM 18-crown-6 at pH 5.5. Repeatability of the CE-C?D method was better than 0.5% and 2.5% for migration times and peak areas, respectively; limits of detection of all inorganic cations in the presence of 2?mM excess of Na(+) were around 1?μM and calibration curves were linear with correlation coefficients better than 0.998. Repeatability of the sample pretreatment procedure was calculated for six independent electrodialysis runs of artificial and real samples and was better than 11.8%. Recovery values between 96.3 and 110% were achieved for optimized electrodialysis conditions of standard solutions and real samples; lifetime of the dialysis membranes for pretreatment of real samples was estimated to 100 runs. 相似文献
28.
Conor T. Riley Tien A. Kieu Joseph S. T. Smalley Si Hui Athena Pan Sung Joo Kim Kirk W. Post Alireza Kargar Dimitri N. Basov Xiaoqing Pan Yeshaiahu Fainman Deli Wang Donald J. Sirbuly 《固体物理学:研究快报》2014,8(11):948-952
Currently there is a strong interest in plasmonic materials operating in the near‐infrared (NIR), however, conventional metals such as gold and silver possess high optical losses in this region. In this work we demonstrate localized surface plasmon resonances (LSPRs) with low loss in the NIR region by utilizing atomic layer deposition to deposit thin films of aluminium doped zinc oxide onto silicon nanopillars created via nanopshere lithography. The deposited films have excellent conformality and the LSPRs can be tuned from the mid‐infrared to the NIR by controlling the doping concentration, deposition temperature and nanostructure morphology. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
29.
A. Sokolov T. Kieu A. Melatos 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,76(4):637-642
The gauge theory of arbitrage was introduced by Ilinski in [K. Ilinski, preprint arXiv:hep-th/9710148 (1997)]
and applied to fast money flows in [A. Ilinskaia, K. Ilinski, preprint arXiv:cond-mat/9902044 (1999); K. Ilinski,
Physics of finance: gauge modelling in non-equilibrium pricing (Wiley, 2001)]. The theory of fast money flow dynamics
attempts to model the evolution of currency exchange rates and stock prices on short, e.g. intra-day, time scales.
It has been used to explain some of the heuristic trading rules, known as technical analysis, that are used by professional
traders in the equity and foreign exchange markets. A critique of some of the underlying assumptions of the gauge theory of
arbitrage was presented by Sornette in [D. Sornette, Int. J. Mod. Phys. C 9, 505 (1998)]. In this paper, we present a
critique of the theory of fast money flow dynamics, which was not examined by Sornette. We demonstrate that the choice of
the
input parameters used in [K. Ilinski, Physics of finance: gauge modelling in non-equilibrium pricing (Wiley, 2001)]
results in sinusoidal oscillations of the exchange rate, in conflict with the results presented in [K. Ilinski,
Physics of finance: gauge modelling in non-equilibrium pricing (Wiley, 2001)]. We also find that the dynamics
predicted by the theory are generally unstable in most realistic situations, with the exchange rate tending to zero or
infinity exponentially. 相似文献
30.
New parameter values are proposed for the empirical potentials used to describe SiO2-B2O3-Na2O alkali borosilicate glass systems. They are based on Buckingham potentials, but include dependence between the fitting parameters and the glass chemical composition to improve the representation of the complex environment around the boron atoms. In particular, the boron anomaly (observed when the [Na2O]/[B2O3] ratio varies) is correctly reproduced. The structural and mechanical properties of a wide range of glass compositions and of reedmergnerite crystals are correctly simulated: bond distances, mean angles, densities, elastic moduli. The deviations from the experimental values are small. 相似文献