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991.
This study focuses on the development of a new electric field responsive graphene oxide (GO) nanoparticle system for on-demand drug delivery. Today, GO is an attractive option adopted in various biological applications for its exclusive features such as flexibility, conductiveness, cost-effectiveness, and external stimuli-responsive nature. It is usual to utilize multiple drugs in cancer treatment. This kind of therapy has lesser side-effects, drug resistance, and is more effective than utilizing only one drug. This study aims to determine low-voltage-controlled dual drug (aspirin and doxorubicin) release from GO surface. Here, we have demonstrated how to control the drug release rate remotely with a handy mobile phone, with zero passive release at idle time. In addition, the study focused to estimate the synergism of aspirin with doxorubicin in the release mechanism from GO in the presence of external voltage, using the spectroscopic method. Moreover, we observed aspirin- and doxorubicin-induced synergistic antitumor activity in MDA-MB 231 (breast cancer cell) in vitro. Thus, our study presents a noble combination of aspirin and doxorubicin that could be utilized for remotely controlled on-demand drug delivery for triple negative breast cancer treatment, using GO as a carrier. 相似文献
992.
Dr. Mukulesh Mondal Dr. Shubhanjan Mitra Dylan J. Twardy Dr. Manashi Panda Prof. Kraig A. Wheeler Dr. Nessan J. Kerrigan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(21):e202104391
A versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid-catalyzed formal [3+2]- and [3+2+2]-cycloadditions of ketenes with azomethine imines is described. The methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (R=alkyl, OAc). The products were formed in good to excellent yields (71–99 % for 24 examples, 39 examples in all), with good to excellent diastereoselectivity in many cases (dr 3 : 1 to 27 : 1 for 22 examples), and with excellent enantioselectivity for most examples (≥93 % ee for 34 products). In the case of most disubstituted ketenes, the reaction proceeded through a [3+2+2]-cycloaddition to form structurally interesting bicyclic pyrazolo-oxadiazepinediones with moderate diastereoselectivity (dr up to 3.7 : 1) and as racemic mixtures (3 examples). The method represents the first unambiguous example of an enantioselective reaction between ketenes and a 1,3-dipole. 相似文献
993.
In the last decade, a few models of portfolio construction have been proposed which apply second order stochastic dominance (SSD) as a choice criterion. SSD approach requires the use of a reference distribution which acts as a benchmark. The return distribution of the computed portfolio dominates the benchmark by the SSD criterion. The benchmark distribution naturally plays an important role since different benchmarks lead to very different portfolio solutions. In this paper we describe a novel concept of reshaping the benchmark distribution with a view to obtaining portfolio solutions which have enhanced return distributions. The return distribution of the constructed portfolio is considered enhanced if the left tail is improved, the downside risk is reduced and the standard deviation remains within a specified range. We extend this approach from long only to long-short strategies which are used by many hedge fund and quant fund practitioners. We present computational results which illustrate (1) how this approach leads to superior portfolio performance (2) how significantly better performance is achieved for portfolios that include shorting of assets. 相似文献
994.
Wing-type vortex generators for fin-and-tube heat exchangers 总被引:3,自引:0,他引:3
The effect of wing-type vortex generators on heat transfer and pressure drop of a fin-and-tube heat exchanger element was investigated. Local heat transfer was measured by liquid crystal thermography on the fin in the Reynolds number range of 600–2700. Flow losses were estimated from the measured pressure drop of an element. Delta winglets were used as vortex generators. Four fin-and-tube configurations were tested, an inline and a staggered arrangement, each with plain fins and with fins with a pair of vortex generators behind each tube. For the inline tube arrangement the vortex generators increase the heat transfer by 55–65% with a corresponding increase of 20–45% in the apparent friction factor. Results indicate that the vortex generators have the potential to reduce considerably the size and mass of heat exchangers for a given heat load. 相似文献
995.
Zusammenfassung Der Einfluß von Sekundärflächen in der Form eines Delta-Halbflügelpaares auf Wärmeübergang und Strömungs-widerstand einer Rippenrohr-Konfiguration wurde untersucht. Die Halbflügelflächen wurden aus der Rippe ausgestanzt, die Sehne der Halbflügel blieb mit der Rippe verbunden. Die Flügelfläche war sehr klein gegenüber der Rippenfläche und bildete einen Winkel mit der Hauptströmungsrichtung, so daß die Vorderkanten starke Längswirbel erzeugten. Die Versuche wurden in einem geschlossenen Windkanal mit vertikaler Meßstrecke durchgeführt. Lokaler und mittlerer Wärmeübergang wurden durch instationäre Flüssigkristall-Thermografie bestimmt, die Widerstandsmessung erfolgte durch Wägung. Im Reynoldszahlbereich 2000 bis 5300 wurde die optimale Lage des Halbflügelpaares relativ zum Rohr ermittelt. Für ein Verhältnis der Fläche des Halbflügelpaares zur Rippenfläche von 0,003 wurden mittlere Wärmeübergangserhöhungen von 20% bei gleichzeitiger Widerstandsminderung der Rippenrohr-Konfiguration von 7% erzielt. Lokale Wärmeübergangserhöhungen von mehr als 70% wurden gemessen. Aus den Messungen folgt, daß Delta-Halbflügel den Wärmeübergang von Rippenrohr-Konfigurationen erhöhen und gleichzeitig den Strömungsverlust senken können.
Herrn Prof. Klaus Gersten zum 60. Geburtstag gewidmet 相似文献
Influence of punched-out delta-winglet vortex generators on heat transfer and drag of fin-tubes
Fin-tube configurations with a small delta-winglet pair punched out from the fins have been investigated with regard to heat transfer and drag. The winglets were punched out in such a way that their chords stayed connected with the fin. The winglet area was small compared to the fin area, it formed an angle with the main flow direction, so that the leading edges generated strong longitudinal vortices. The experiments were performed in a wind tunnel with vertical test section. Local and global heat transfer were determined by liquid crystal thermography, drag was measured by a scale. For Reynolds numbers between 2000 and 5300 the optimal winglet position relative to the tube was determined. For a winglet to fin area ratio of 0.003 an overall heat transfer enhancement on the fin of 20% resulted with a simultaneous drag reduction of 7%. Local heat transfer enhancements of more than 70% were measured. From the measurements follows that winglet pairs can increase the heat transfer in fin-tube configurations while simultaneously decreasing the flow losses.
Herrn Prof. Klaus Gersten zum 60. Geburtstag gewidmet 相似文献
996.
Vijay Bhatt Surabhi Yadav Pradip K. Jha Aranya B. Bhattacherjee 《Annalen der Physik》2023,535(2):2200484
A theoretical model is presented to study the hybrid optomechanical system comprising an ensemble of N number of quantum dots (QDs). Utilizing the Holstein–Primakoff (H-P) transformation formalism, the calculations become easily scalable. The bistability in this hybrid optomechanical system is studied in the presence of third order nonlinear χ(3) medium using the H-P transformation method and to verify the results, numerical method has also been utilized. It is also demonstrated that the system's parameters may be tuned to alter the bistability phenomenon and absorption spectrum's response, which exhibits both positive and negative absorption (emission). This alternative approach (H-P transform) is demonstrated to solve analytically the system containing multiple QDs in an elegant manner. 相似文献
997.
Interior local null controllability of one‐dimensional compressible flow near a constant steady state
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Debanjana Mitra Mythily Ramaswamy Michael Renardy 《Mathematical Methods in the Applied Sciences》2017,40(10):3445-3478
We consider the one‐dimensional compressible Navier–Stokes equations with periodic boundary conditions, with initial conditions in a small neighborhood of a state of uniform density and uniform nonzero velocity. We prove that, with a control given only by a body force localized in a subinterval, we can steer the system to uniform density and velocity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
998.
Singh C Ghorai PK Horsch MA Jackson AM Larson RG Stellacci F Glotzer SC 《Physical review letters》2007,99(22):226106
We perform atomistic and mesoscale simulations to explain the origin of experimentally observed stripelike patterns formed by immiscible ligands coadsorbed on the surfaces of gold and silver nanoparticles. We show that when the conformational entropy gained via this morphology is sufficient, microphase-separated stripelike patterns form. When the entropic gain is not sufficient, we instead predict bulk phase-separated Janus particles. We also show corroborating experimental results that confirm our simulational predictions that stripes form on flat surfaces as well as on curved nanoparticle surfaces. 相似文献
999.
M. Marchetto Z. T. Ang K. Jayamanna R. E. Laxdal A. Mitra V. Zvyagintsev 《The European physical journal. Special topics》2007,150(1):241-242
ISAC at TRIUMF is a world-class facility for the production and post-acceleration of radioactive ion beams (RIB).
Commissioned in 2002 the ISAC I linear accelerator serves three different beam lines delivering
both stable and radioactive species.
Two of them are permanent experiments (DRAGON and TUDA); the third one is a general purpose station (GPS).
The maximum energy we can reach in ISAC I is 1.8 MeV/u.
ISAC II is a phased upgrade of the ISAC facility. The beam coming from ISAC I is injected at 1.5 MeV/u into
a new superconducting LINAC. In `Phase I' the LINAC adds 20 MV to the beam energy
and 20 MV more will be added in `Phase II'.
The paper will give an overview of both the ISAC I and ISAC II accelerators.
Operational experience with accelerating RIBs in ISAC I is summarized.
First ISAC II commissioning results are presented. 相似文献
1000.
Light scattering measurements made at visible wavelengths have the ability to quantify subcellular morphology. Apoptosis, or programmed cell death, is associated with distinct morphological signatures such as mitochondrial swelling and nuclear condensation as well as characteristic biochemical signaling pathways, many of which are initiated by the release of cytochrome c from the mitochondria into the cytosol. In this Letter, we examine the time course of mitochondrial morphology changes as reported by light scattering and the subcellular location of cytochrome c measured by immunofluorescence microscopy in response to intracellular cell death signaling induced by photodynamic damage to lysosomes. We report that within this system, release of cytochrome c from the mitochondria into the cytosol occurs approximately simultaneously with mitochondrial-morphology-induced light scattering changes, providing further evidence that light scattering has the potential to play an important role in future studies of cell death biology. 相似文献