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排序方式: 共有548条查询结果,搜索用时 15 毫秒
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Shen NH Massaouti M Gokkavas M Manceau JM Ozbay E Kafesaki M Koschny T Tzortzakis S Soukoulis CM 《Physical review letters》2011,106(3):037403
We experimentally demonstrate, for the first time, an optically implemented blueshift tunable metamaterial in the terahertz (THz) regime. The design implies two potential resonance states, and the photoconductive semiconductor (silicon) settled in the critical region plays the role of intermediary for switching the resonator from mode 1 to mode 2. The observed tuning range of the fabricated device is as high as 26% (from 0.76 THz to 0.96 THz) through optical control to silicon. The realization of broadband blueshift tunable metamaterial offers opportunities for achieving switchable metamaterials with simultaneous redshift and blueshift tunability and cascade tunable devices. Our experimental approach is compatible with semiconductor technologies and can be used for other applications in the THz regime. 相似文献
3.
Walter?Oelert Magnus?Wolke Pawe??Moskal COSY- collaboration at COSY-Jülich 《Czechoslovak Journal of Physics》2000,50(4):69-90
During the actual lectures, features of the COSY-Jülich accelerator were presented, followed by a short summary of ongoing experiments at the COoler SYnchrotron COSY using internal as well as external beams in the range of 45 MeV to 2.5 GeV. Here the research of the COSY-11 collaboration is presented. This °0 facility studies the hidden and open strangeness production observing the ν and η′ as well the K+Y and K+K? production in the proton—proton interactions at the respective thresholds. 相似文献
4.
The paper deals with the numerical treatment of stochastic differential-algebraic equations of index one with a scalar driving
Wiener process. Therefore, a particularly customized stochastic Runge-Kutta method is introduced. Order conditions for convergence
with order 1.0 in the mean-square sense are calculated and coefficients for some schemes are presented. The proposed schemes
are stiffly accurate and applicable to nonlinear stochastic differential-algebraic equations. As an advantage they do not
require the calculation of any pseudo-inverses or projectors. Further, the mean-square stability of the proposed schemes is
analyzed and simulation results are presented bringing out their good performance. 相似文献
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Purpose
To prospectively evaluate diffusion-weighted (DW) magnetic resonance (MR) imaging for differentiation of postobstructive consolidation from centrally located lung carcinomas by using apparent diffusion coefficients (ADCs).Materials and Methods
An institutional review board approved this study; informed consent was obtained from patients. Forty-nine consecutive patients (3 women, 46 men; mean age, 63.6 years; age range, 42–85 years) with lung carcinoma underwent DW MR imaging. Forty patients had central and nine patients had peripheral lung carcinomas. ADC of each lung carcinoma was calculated from DW MR images obtained with two different b values (0, 1000 s/mm2).In the final study group including 27 patients with central lung carcinoma accompanying distal lung consolidation (mean age, 67.2 years; 3 women, 24 men), ADCs of lung carcinomas were statistically compared among cytologic/histologic types and accompanying postobstructive consolidations. Unpaired t test was used for measurable variables with normal distribution, and Kruskal–Wallis variance analysis and Mann–Whitney U tests were used for the measurable variables without normal distribution.Results
There was no significant difference between mean ADC values of all types of carcinomas (P=.302) and also between mean ADC values of central (1.91 ± 0.7×10−3 mm2/s) and peripheral carcinomas (1.58 ± 0. 6×10−3 mm2/s) (P=.224). The mean ADC value for the masses of central lung carcinoma with postobstructive consolidations was 1.83 ± 0.75×10−3 mm2/s, and for consolidation was 2.50 ± 0.76×10−3 mm2/s. ADC of central carcinoma masses was significantly lower than that of postobstructive consolidations (P=.003).Conclusions
ADC values of central lung carcinoma masses appear to be lower than accompanying postobstructive consolidations. ADC values could be considered useful as a differentiating parameter among central lung carcinomas and accompanying postobstructive consolidations. 相似文献7.
Ayta? Gültekin Arzu Ers?z Nalan Y?lmaz Sar??zlü Adil Denizli R?dvan Say 《Journal of nanoparticle research》2010,12(6):2069-2079
Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP nanoclusters have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamido-cysteine (MAC) attached to gold–silver nanoclusters, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloylamidoantipyrine–terbium ((MAAP)2–Tb(III)) has been used as a new metal-chelating monomer via metal coordination–chelation interactions and dipicolinic acid (DPA) which is main participant of Bacillus cereus spores used as a model. Nanoshell sensors with templates give a cavity that is selective for DPA. The DPA can simultaneously chelate to Tb(III) metal ion and fit into the shape-selective cavity. Thus, the interaction between Tb(III) ion and free coordination spheres has an effect on the binding ability of the gold–silver nanoclusters nanosensor. The binding affinity of the DPA imprinted nanoclusters has been investigated by using the Langmuir and Scatchard methods, and the respective affinity constants (K affinity) determined were found to be 1.43 × 104 and 9.1 × 106 mol L?1. 相似文献
8.
Boris?ShapiroEmail author Kouichi?Takemura Milo??Tater 《Communications in Mathematical Physics》2012,311(2):277-300
The well-known Heun equation has the form
ll{Q(z)\frac d2dz2+P(z)\fracddz+V(z)}S(z)=0,\begin{array}{ll}\left\{Q(z)\frac {d^2}{dz^2}+P(z)\frac{d}{dz}+V(z)\right\}S(z)=0,\end{array} 相似文献
9.
Przemyslaw W. Wachulak Andrzej Bartnik Henryk Fiedorowicz Dalibor Pánek Petr Br??a 《Applied physics. B, Lasers and optics》2012,109(1):105-111
Laser-produced plasma sources of short-wavelength radiation offer an interesting alternative to synchrotron and free-electron laser installations. Recently, we reported on a newly developed desktop EUV microscope based on plasma generated from a gas-puff target and diffractive optics. The half-pitch resolution of the microscope approached 50?nm. Compared to analogous microscopes based on synchrotron sources, our system is compact and cost-effective. In this paper, we present the results of imaging experiments on a thin polycrystalline object that was carried out in order to further examine the applicability of the microscope. We have demonstrated here that EUV microscopy can provide structural information that cannot be accessed by conventional optical microscopy or SEM. 相似文献
10.
In this paper, we study pseudo-Riemannian submanifolds of a pseudo-hyperbolic space \(\mathbb H^{m-1}_s (-1) \subset \mathbb E^m_{s+1}\) with 2-type pseudo-hyperbolic Gauss map. We give a characterization of proper pseudo-Riemannian hypersurfaces in \(\mathbb H^{n+1}_s (-1) \subset \mathbb E^{n+2}_{s+1}\) with non-zero constant mean curvature and 2-type pseudo-hyperbolic Gauss map. For \(n=2\), we prove classification theorems. In addition, we show that the hyperbolic Veronese surface is the only maximal surface fully lying in \(\mathbb H^4_2 (-1) \subset \mathbb H^{m-1}_2 (-1)\) with 2-type pseudo-hyperbolic Gauss map. Moreover, we prove that a flat totally umbilical pseudo-Riemannian hypersurface \(M^n_t\) of the pseudo-hyperbolic space \(\mathbb {H}^{n+1}_t(-1) \subset \mathbb E^{n+2}_{t+1}\) has biharmonic pseudo-hyperbolic Gauss map. 相似文献
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