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91.
Piotr Oprocha Dawoud Ahmadi Dastjerdi Maryam Hosseini 《Journal of Mathematical Analysis and Applications》2014
In recent years many new definitions of shadowing, using a notion of ergodic (or average) pseudo-orbit were introduced. While, under the assumption of chain mixing, average pseudo-orbit usually can be equivalently replaced by pseudo-orbit in these definitions of shadowing, it is not completely clear when these shadowing properties (i.e. approximation of a pseudo-orbit by a real orbit on a sufficiently large set of indices) can or cannot occur. In this paper we analyze necessary and sufficient conditions for shadowing over a set with positive density (or syndetic). While we do not provide full characterization, a few relations to standard notions from topological dynamics are obtained. 相似文献
92.
Using direct recoil spectrometry (DRS), the shadowing of surface H atoms by neighboring O atoms can differentiate between full and partial dissociation routes of water molecules on the surface as well as point to the geometrical arrangements of hydroxyl surface groups. The H2O/U and H2O/Ti systems were compared. It has been found that different mechanisms control the water-surface interactions in these systems.For the H2O/U system, a simple direct-collision (Langmuir-type) dissociative chemisorption controls the process. Two consecutive stages were identified: (i) below ∼70% monolayer coverage, a complete dissociation of water into oxygen ion and two H atoms, which chemisorb on the remaining unreacted metallic surface and (ii) above about 70% of a full layer coverage, three dimensional oxide islands start to form, causing partial dissociation of water and the formation of surface hydroxyls.For the H2O/Ti system, a more complicated mechanism, which involves a precursor state, seems to control the process. In that case, two concurrent routes act simultaneously. In addition to the simple direct-collision mechanism, water precursor clusters (bound by hydrogen bonds), which partly dissociate, result in chemisorbed tilted hydroxyl clusters (even at low-coverage). The relative contributions of the precursor route and the direct-collision route are pressure dependent, with the former being dominant at higher exposure pressures. 相似文献
93.
本文证明了Riemann流形上的微分同胚f在其双曲不变集附近具有相对于C1小扰动一致的极限 跟踪性.还证明了如果f是C1-结构稳定的,则,具有极限跟踪性. 相似文献
94.
Brian?A.?Coomes Hüseyin?Ko?akEmail author Kenneth?J.?Palmer 《Journal of Dynamics and Differential Equations》2005,17(1):175-215
A new method for rigorously establishing the existence of a transversal homoclinic orbit to a periodic orbit (or a fixed point) of diffeomorphisms in Rn is presented. It is a computer-assisted technique with two main components. First, a global Newton’s method is devised to compute a suitable pseudo (approximate) homoclinic orbit to a pseudo periodic orbit. Then, a homoclinic shadowing theorem, which is proved herein, is invoked to establish the existence of a true transversal homoclinic orbit to a true periodic orbit near these pseudo orbits. 相似文献
95.
This paper studies the M0-shadowing property for the dynamics of diffeomorphisms defined on closed manifolds. The C1 interior of the set of all two dimensional diffeomorphisms with the M0-shadowing property is described by the set of all Anosov diffeomorphisms. The C1-stably M0-shadowing property on a non-trivial transitive set implies the diffeomorphism has a dominated splitting. 相似文献
96.
97.
98.
The nuclear shadowing and antishadowing effects are explained by a unitarized BFKL equation.The Q2-and x-variations of the nuclear parton distributions are detailed based on the level of the unintegrated gluon distribution.In particular,the asymptotical behavior of the unintegrated gluon distribution near the saturation limit in nuclear targets is studied. Our results in the nuclear targets are insensitive to the input distributions if the parameters are fixed by the data of a flee proton. 相似文献
99.
M. Vazquez‐Castro F. Perez‐Fontan S. R. Saunders 《International Journal of Satellite Communications and Networking》2002,20(2):151-166
Non‐geostationary orbit satellite networks have dynamic, yet deterministic topologies. This paper deals with the consequences of relying on the use of multiple visible satellites to improve availability with time/locations through satellite diversity techniques. The assumption of independent blockage events in two different satellite‐to‐mobile links is generally not accurate and information on shadowing correlation should be taken into account in the assessment of availability.In this paper a shadowing correlation study for urban environments is presented and a model for the real environments, as well as for a generic urban environment is inferred. The model proposed here is simple and can be run on a computer. It also relates urban and constellation geometries thus allowing the identification of those cases for which satellite diversity gain should be expected. As a result of this analysis and modelling, we present empirical analytical expressions describing positive correlation coefficient as a function of satellite angular separation (azimuth and elevation). We also show that an angle exists above which correlation can be negative and satellite diversity can sensibly improve link availability. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
100.
Miguel García Jose Miguel Maruri Luis Marroyo Eduardo Lorenzo Miguel Prez 《Progress in Photovoltaics: Research and Applications》2008,16(6):529-536
When analysing the influence of shade on photovoltaic (PV) systems, the intuitive assumption is that conversion architectures with more inverters, such as string‐ and module‐inverters, will have lower energy losses associated with partial shading of the generators. However, other phenomena which can affect a system's response to shade, for example, the way in which the inverter performs the maximum power point tracking (MPPT), mean that modular configurations are not always the least susceptible to shade effects. We present a case in which the general tendency of many of the currently available commercial inverters to remain in local power maxima results in a string‐inverter configuration behaving worse in response to shade than a central‐inverter configuration. Experimental data were collected throughout 2005 and 2006 from PV plants in Arguedas and Sesma (Spain). We interpret our observations with theoretical analysis based on the results of simulation experiments. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献