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51.
Schulte T Drenkelforth S Kruse J Ertmer W Arlt J Sacha K Zakrzewski J Lewenstein M 《Physical review letters》2005,95(17):170411
We investigate, both experimentally and theoretically, possible routes towards Anderson-like localization of Bose-Einstein condensates in disordered potentials. The dependence of this quantum interference effect on the nonlinear interactions and the shape of the disorder potential is investigated. Experiments with an optical lattice and a superimposed disordered potential reveal the lack of Anderson localization. A theoretical analysis shows that this absence is due to the large length scale of the disorder potential as well as its screening by the nonlinear interactions. Further analysis shows that incommensurable superlattices should allow for the observation of the crossover from the nonlinear screening regime to the Anderson localized case within realistic experimental parameters. 相似文献
52.
A state of a quantum system can be regarded as classical (quantum) with respect to measurements of a set of canonical observables if and only if there exists (does not exist) a well defined, positive phase-space distribution, the so called Glauber-Sudarshan P representation. We derive a family of classicality criteria that requires that the averages of positive functions calculated using P representation must be positive. For polynomial functions, these criteria are related to Hilbert's 17th problem, and have physical meaning of generalized squeezing conditions; alternatively, they may be interpreted as nonclassicality witnesses. We show that every generic nonclassical state can be detected by a polynomial that is a sum-of-squares of other polynomials. We introduce a very natural hierarchy of states regarding their degree of quantumness, which we relate to the minimal degree of a sum-of-squares polynomial that detects them. 相似文献
53.
Numerical simulations for realistic experimental parameters demonstrate that laser cooling on the attractive side of the Feshbach resonance can drive fermions much below the superfluid transition. For the assumed set of experimental parameters the transition takes place at 0.35T(F), and laser cooling can drive the system down to at least 0.085T(F) in a time of a few seconds. Superfluid growth is self-consistently included in simulations. 相似文献
54.
Amihood Amir Yonatan Aumann Gad M. Landau Moshe Lewenstein Noa Lewenstein 《Journal of Algorithms in Cognition, Informatics and Logic》2000,37(2):247
Let a text string T of n symbols and a pattern string P of m symbols from alphabet Σ be given. A swapped version T′ of T is a length n string derived from T by a series of local swaps (i.e., t′ℓ ← tℓ + 1 and t′ℓ + 1 ← tℓ), where each element can participate in no more than one swap. The pattern matching with swaps problem is that of finding all locations i for which there exists a swapped version T′ of T with an exact matching of P in location i of T′. It has been an open problem whether swapped matching can be done in less than O(nm) time. In this paper we show the first algorithm that solves the pattern matching with swaps problem in time o(nm). We present an algorithm whose time complexity is O(nm1/3 log m log σ) for a general alphabet Σ, where σ = min(m,Σ). 相似文献
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56.
Noa?Cohen Pooja?SabhachandaniView authors OrcID profile Saheli?Sarkar Lindy?Kahanovitz Norman?Lautsch Steven?J.?Russell Tania?KonryEmail author 《Mikrochimica acta》2017,184(3):835-841
This paper describes a miniaturized microsphere-based immunoassay integrated into a microfluidic device for rapid quantitation of insulin. Analysis of bionic pancreas studies have revealed that the rates of absorption of insulin analogs vary from patient to patient, and even within patients on different occasions. Thus development of an approach to monitor insulin continuously allows the pharmacokinetic characteristics of insulin analogs to be determined in real-time. The authors have developed a microsphere-based continuous flow assay in a microfluidic chip that allows for the detection of insulin within seconds with high sensitivity and specificity. The method was applied to near real-time monitoring of clinical samples. Calibration plot were established for different insulin analogs such as insulin aspart (Novolog), insulin lispro (Humalog), and regular human insulin (RHI) and the insulin detection limit was 0.26 ng.mL?1 (44 pM). This sensitivity allows to detect the fasting insulin levels of T1D patients, which are reported in the range of 50–180 pM (0.3–1 ng.mL?1), after treatment with subcutaneous insulin administration. This fast approach was also applied to sera collected in intervals from T1D patients after a bolus of insulin aspart delivery. The insulin profile obtained by this method is similar to the basal and peak insulin levels as determined using the standard non-continuous ELISA reference method. In our perception, this assay will improve healthcare by personalizing diagnostics for better clinical outcome and provide real-time feedback on sensing and actuation. 相似文献
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58.
We present a general strategy to simulate a D+1-dimensional quantum system using a D-dimensional one. We analyze in detail a feasible implementation of our scheme using optical lattice technology. The simplest nontrivial realization of a fourth dimension corresponds to the creation of a bi-volume geometry. We also propose single- and many-particle experimental signatures to detect the effects of the extra dimension. 相似文献
59.
Stützer S Kartashov YV Vysloukh VA Tünnermann A Nolte S Lewenstein M Torner L Szameit A 《Optics letters》2012,37(10):1715-1717
We report Anderson localization in two-dimensional optical waveguide arrays with disorder in waveguide separation introduced along one axis of the array, in an uncorrelated fashion for each waveguide row. We show that the anisotropic nature of such disorder induces a strong localization along both array axes. The degree of localization in the cross-axis remains weaker than that in the direction in which disorder is introduced. This effect is illustrated both theoretically and experimentally. 相似文献
60.
We present a two-part systematic density functional theory (DFT) study of the electronic structure of selected transition
metal phthalocyanines. We use a semi-local generalized gradient approximation (GGA) functional, as well as several hybrid
exchange-correlation functionals, and compare the results to experimental photoemission data. Here, we study the intermediate
spin systems MnPc and FePc. We show that DFT calculations of these systems are extremely sensitive to the choice of functional
and basis set with respect to the obtained electronic configuration and to symmetry breaking. Interestingly, all simulated
spectra are in good agreement with experiment despite the differences in the underlying electronic configurations. 相似文献