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41.
Theodosis Giousis Georgia Potsi Antonios Kouloumpis Konstantinos Spyrou Yiannis Georgantas Nikolaos Chalmpes Konstantinos Dimos Myrsini‐Kiriaki Antoniou Georgios Papavassiliou Athanasios B. Bourlinos Hae Jin Kim Vijay Kumar Shankarayya Wadi Saeed Alhassan Majid Ahmadi Bart J. Kooi Graeme Blake Daniel M. Balazs Maria A. Loi Dimitrios Gournis Petra Rudolf 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2021,133(1):364-369
Germanane (GeH), a germanium analogue of graphane, has recently attracted considerable interest because its remarkable combination of properties makes it an extremely suitable candidate to be used as 2D material for field effect devices, photovoltaics, and photocatalysis. Up to now, the synthesis of GeH has been conducted by substituting Ca by H in a β‐CaGe2 layered Zintl phase through topochemical deintercalation in aqueous HCl. This reaction is generally slow and takes place over 6 to 14 days. The new and facile protocol presented here allows to synthesize GeH at room temperature in a significantly shorter time (a few minutes), which renders this method highly attractive for technological applications. The GeH produced with this method is highly pure and has a band gap (Eg) close to 1.4 eV, a lower value than that reported for germanane synthesized using HCl, which is promising for incorporation of GeH in solar cells. 相似文献
42.
43.
Dimitrios Dechouniotis Nikolaos Leontiou Xenofontas Dimitropoulos Andreas Kind Spyros Denazis 《International Journal of Network Management》2009,19(6):513-526
Nowadays traffic monitoring and analysis tools provide poor information about traffic volume without giving any clear view of what the hidden rules and relationships that govern these flows are. Since the majority of flows is generated by services (web browsing, email, p2p) and most of these applications are dependent on many network assets (servers and databases) we should discover the underlying relationships of every application. We present a technique that discovers the hidden relationships among components of a network that consist of parts of specific applications. From time information and flow attributes, such as IP addresses and service ports, our method using a novel hybrid genetic algorithm produces a small set of fuzzy rules that can reveal the underlying relationships over a network without any guidance. These dependencies build a service graph which can become a useful tool for fault localization, monitoring service performance, designing changes and anomaly detection. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
44.
The free (or open) boundary condition (FBC, OBC) was proposed by Papanastasiou et al. (A new outflow boundary condition, International Journal for Numerical Methods in Fluids, 1992; 14:587–608) to handle truncated domains with synthetic boundaries where the outflow conditions are unknown. In the present work, implementation of the FBC has been tested in several benchmark problems of viscous flow in fluid mechanics. The FEM is used to provide numerical results for both cases of planar and axisymmetric domains under laminar, isothermal or non‐isothermal, steady‐state conditions, for Newtonian fluids. The effects of inertia, gravity, compressibility, pressure dependence of the viscosity, slip at the wall, and surface tension are all considered individually in the extrudate‐swell benchmark problem for a wide range of the relevant parameters. The present results extend previous ones regarding the applicability of the FBC and show cases where the FBC is inappropriate, namely in the extrudate‐swell problem with gravity or surface‐tension effects. Particular emphasis has been given to the pressure at the outflow, which is the most sensitive quantity of the computations. In all cases where FBC is appropriate, excellent agreement has been found in comparisons with results from very long domains. The formulation for Picard‐type iterations is given in some detail, and the differences with the Newton–Raphson formulation are highlighted regarding some computational aspects. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
45.
46.
Nikolaos Efstathiou Sofronidis 《Proceedings of the American Mathematical Society》2002,130(4):1177-1182
The purpose of this paper is to show that given any non-negative real number , the set of entire functions whose order is equal to is -complete, and the set of all sequences of entire functions whose orders converge to is -complete.
47.
On , n?1 and n≠2, we prove the existence of a sharp constant for Sobolev inequalities with higher fractional derivatives. Let s be a positive real number. For n>2s and any function satisfies where the operator (?Δ)s in Fourier spaces is defined by . To cite this article: A. Cotsiolis, N.C. Tavoularis, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 801–804. 相似文献
48.
Nikolaos Kroupis Nikolaos Zervas Minas Dasygenis Konstantinos Tatas Antonios Argyriou Dimitrios Soudris Antonios Thanailakis 《The Journal of VLSI Signal Processing》2006,44(1-2):153-171
The continuous increase of the computational power of programmable processors has established them as an attractive design
alternative, for implementation of the most computationally intensive applications, like video compression. To enforce this
trend, designers implementing applications on programmable platforms have to be provided with reliable and in-depth data and
instruction analysis that will allow for the early selection of the most appropriate application for a given set of specifications.
To address this need, we introduce a new methodology for early and accurate estimation of the number of instructions required
for the execution of an application, together with the number of data memory transfers on a programmable processor. The high-level
estimation is achieved by a series of mathematical formulas; these describe not only the arithmetic operations of an application,
but also its control and addressing operations, if it is executed on a programmable core. The comparative study, which is
done using three popular processors (ARM, MIPS, and Pentium), shows the high efficiency and accuracy of the methodology proposed,
in terms of the number of executed (micro-)instructions (i.e. performance) and the number of data memory transfers (i.e. memory
power consumption). Using the proposed methodology we estimated an average deviation of 23% in our estimated figures compared
with the measurements taken from the real execution on the CPUs.
This work was supported by the project PENED ’99 ED501 funded by GSRT of the Greek Ministry of Development, and the project
PRENED ’99 KE 874 funded by the Research Committee of the Democritus University of Thrace. This work was partially sponsored
by a scholarship from the Public Benefit Foundation of Alexander S. Onassis (Minas Dasygenis).
Nikolaos Kroupis was born in Trikala in 1976. He receiver the engineering degree and Ms.C. degree in Department of Electrical and Computer
Engineering from Democritous University of Thrace, Greece, in 2000 and 2002, respectively. Since 2002 he has been a Ph.D.
student at the Laboratory of Electrical and Electronic Materials Technology. His research interests are in software/hardware
co-design of embedded system for signal processing applications.
Nikos D. Zervas received a Diploma in Electrical & Computer Engineering from University of Patras, Greece in 1997. He received the Ph.D.
degree in the Department of Electrical and Computer Engineering of the same University in 2004. His research interests are
in the area of high-level, power optimization techniques and methodologies for multimedia and telecommunication applications.
He has received an award from IEEE Computer Society in the context of Low-Power Design Contest of 2000 IEEE Computer Elements
Mesa Workshop. Mr. Zervas is a member of the IEEE, ACM and of the Technical Chamber of Greece.
Minas Dasygenis was born in Thessaloniki in 1976. He received his Diploma in Electrical and Computer Engineering in 1999, from the Democritus
University of Thrace, Greece, and for his diploma Thesis he was honored by The Technical Chamber of Greece and Ericsson Hellas.
In 2005, he received his PhD Degree from the Democritus University of Thrace. His research interests include low-power VLSI
design of arithmetic circuits, residue number system, embedded architectures, DSPs, hardware/ software codesign and IT security.
He has published more than 20 papers in international journals and conferences and he has been a principal researcher in three
European research projects.
Konstantinos Tatas received his degree in Electrical and Computer Engineering from the Democritus University of Thrace, Greece in 1999. He received
his Ph.D. in the VLSI Design and Testing Center in the same University by June 2005. He has been employed as an RTL designer
in INTRACOM SA, Greece between 2000 and 2003. His research interests include low-power VLSI design of DSP and multimedia systems,
computer arithmetic, IP core design and design for reuse.
Antonios Argyriou received the degree in Electrical and Computer engineering from the Democritous University of Thrace, Greece, in 2001, and
the M.S. and Ph.D. degrees in Electrical and Computer engineering from the Georgia Institute of Technology, Atlanta, in 2003
and 2005, respectively. His primary research interests include wireless networks, mobile computing and multimedia communications.
He is a member of the IEEE and ACM.
Dimitrios Soudris received his Diploma in Electrical Engineering from the University of Patras, Greece, in 1987. He received the Ph.D. Degree
in Electrical Engineering, from the University of Patras in 1992. He is currently working as Ass. Professor in Dept. of Electrical
and Computer Engineering, Democritus University of Thrace, Greece. His research interests include low power design, parallel
architectures, embedded systems design, and VLSI signal processing. He has published more than 140 papers in international
journals and conferences. He was leader and principal investigator in numerous research projects funded from the Greek Government
and Industry as well as the European Commission (ESPRIT II-III-IV and 5th and 6th IST). He has served as General Chair and
Program Chair for the International Workshop on Power and Timing Modelling, Optimisation, and Simulation (PATMOS). He received
an award from INTEL and IBM for the project results of LPGD #25256 (ESPRIT IV). He is a member of the IEEE, the VLSI Systems
and Applications Technical Committee of IEEE CAS and the ACM.
Antonios Thanailakis was born in Greece on August 5, 1940. He received B.Sc. degrees in physics and electrical engineering from the University
of Thessaloniki, Greece, 1964 and 1968, respectively, and the Msc. and Ph.D. Degrees in electrical engineering and electronics
from UMIST, Manchester, U.K. in 1968 and 1971, respectively. He has been a Professor of Microelectronics in Dept. of Electrical
and Computer Eng., Democritus Univ. of Thrace, Xanthi, Greece, since 1977. He has been active in electronic device and VLSI
system design research since 1968. His current research activities include microelectronic devices and VLSI systems design.
He has published a great number of scientific and technical papers, as well as five textbooks. He was leader for carrying
out research and development projects funded by Greece, EU, or other organizations on various topics of Microlectronics and
VLSI Systems Design (e.g. NATO, ESPRIT, ACTS, STRIDE). 相似文献
49.
Nikolaos Halidias 《Journal of Mathematical Analysis and Applications》2002,276(1):13-27
In this paper we prove two existence theorems for elliptic problems with discontinuities. The first one is a noncoercive Dirichlet problem and the second one is a Neumann problem. We do not use the method of upper and lower solutions. For Neumann problems we assume that f is nondecreasing. We use the critical point theory for locally Lipschitz functionals. 相似文献
50.
In this paper we study the relaxation of optimal control problems monitored by subdifferential evolution inclusions. First
under appropriate convexity conditions, we establish an existence result. Then we introduce the relaxed problem and show that
it always has a solution under fairly general hypotheses on the data. Subsequently we examine when the relaxation is admissible.
So we show that every relaxed trajectory can be approximated by extremal original ones (i.e. original trajectories generated
by bang-bang controls) and that the values of the original and relaxed problems are equal. Some examples are also presented. 相似文献