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91.
Samuel M. Blau Hetal D. Patel Evan Walter Clark Spotte-Smith Xiaowei Xie Shyam Dwaraknath Kristin A. Persson 《Chemical science》2021,12(13):4931
Modeling reactivity with chemical reaction networks could yield fundamental mechanistic understanding that would expedite the development of processes and technologies for energy storage, medicine, catalysis, and more. Thus far, reaction networks have been limited in size by chemically inconsistent graph representations of multi-reactant reactions (e.g. A + B → C) that cannot enforce stoichiometric constraints, precluding the use of optimized shortest-path algorithms. Here, we report a chemically consistent graph architecture that overcomes these limitations using a novel multi-reactant representation and iterative cost-solving procedure. Our approach enables the identification of all low-cost pathways to desired products in massive reaction networks containing reactions of any stoichiometry, allowing for the investigation of vastly more complex systems than previously possible. Leveraging our architecture, we construct the first ever electrochemical reaction network from first-principles thermodynamic calculations to describe the formation of the Li-ion solid electrolyte interphase (SEI), which is critical for passivation of the negative electrode. Using this network comprised of nearly 6000 species and 4.5 million reactions, we interrogate the formation of a key SEI component, lithium ethylene dicarbonate. We automatically identify previously proposed mechanisms as well as multiple novel pathways containing counter-intuitive reactions that have not, to our knowledge, been reported in the literature. We envision that our framework and data-driven methodology will facilitate efforts to engineer the composition-related properties of the SEI – or of any complex chemical process – through selective control of reactivity.A chemically consistent graph architecture enables autonomous identification of novel solid-electrolyte interphase formation pathways from a massive reaction network. 相似文献
92.
Frank W. Harris Steve O. Norris 《Journal of polymer science. Part A, Polymer chemistry》1973,11(9):2143-2151
A series of phenylated polydihydrophthalimides has been synthesized by the Diels-Alder reactions of 3,3′-(oxydi-p-phenylene)bis(2,4,5-triphenylcyclopentadienone) and 3,3′-(p-phenylene)bis(2,4,5-triphenylcyclopentadienone) with N,N′-o-, -m-, and -p-phenylenedimaleimide. The polydihydrophthalimides were soluble in dimethylformamide (DMF) and had intrinsic viscosities that ranged from 0.33 to 1.01, the polymers were dehydrogenated thermally and chemically to afford the corresponding phenylated polyphthalimides. The totally aromatic polyimides were also soluble in DMF but had intrinsic viscosities only as high as 0.41. The thermogravimetric analyses of the polyphthalimides showed breaks near 530°C in air and in nitrogen atmospheres. 相似文献
93.
Larry I. Amstutz Horst Meyer Samuel M. Myers
Robert L. Mills
《Journal of Physics and Chemistry of Solids》1969,30(12):2693-2697Measurements of T1 in the hep phase of H2, over the temperature range 2°–12°K and the ortho concentration range between 0.5 and 0.97 are presented. At temperatures below 10°K, the thermally activated self-diffusion is negligible and the mechanism for nuclear relaxation is that attributed by Moryia and Motizuki and by Harris to intramolecular dipolar interaction, modulated by intennolecular electric quadrupole-quadrupole (EQQ) interaction. The gaussian approximation for the correlation function was used by these authors to predict T1. From the comparison between experiment and theory, we determine the EQQ parameter Γ/kB to be 0.67°K. Above 10°K the effect of diffusion influences T1, and the experimental results for an 88 per cent ortho H2 sample up to the melting point suggest that the relaxation mechanisms resulting from EQQ interaction and diffusion are not independent of one another. 相似文献
94.
The positive cone of the K0-group of the non-commutative sphereB is explicitly determined by means of the four basic unboundedtrace functionals discovered by Bratteli, Elliott, Evans andKishimoto. The C*-algebra B is the crossed product A x Z2 ofthe irrational rotation algebra A by the flip automorphism defined on the canonical unitary generators U, V by (U) = U*,(V) = V*, where VU = e2i UV and is an irrational real number.This result combined with Rieffel's cancellation techniquesis used to show that cancellation holds for all finitely generatedprojective modules over B. Subsequently, these modules are determinedup to isomorphism as finite direct sums of basic modules. Italso follows that two projections p and q in a matrix algebraover B are unitarily equivalent if, and only if, their vectortraces are equal: [p] = [q]. These results will have the following ramifications. They areused (elsewhere) to show that the flip automorphism on A isan inductive limit automorphism with respect to the basic buildingblock construction of Elliott and Evans for the irrational rotationalgebra. This will, in turn, yield a two-tower proof of thefact that B is approximately finite dimensional, first provedby Bratteli and Kishimoto. 相似文献
95.
96.
Samuel Jurkiewicz 《Annals of Operations Research》1994,50(1):281-293
If a graph has too many edges, it must be Hamiltonian. We show how to construct graphs near the threshold: they have as many edges as possible without sacrificing planarity but are not Hamiltonian. We base our construction on the concepts of independent sets and 1-toughness.The work of the author was partially supported by CNPq-Brasil. 相似文献
97.
We study perturbative QCD at the five-loop level. In particular we considerR =
tot(e
+
e
– hadrons)/(e
+
e
–
+
–) andR
= ( v+hadrons)/( ev). We use our method to estimate the five-loop coefficients. As a result, we obtain
s
(M
z
) = 0.1186(11) and
s
(34 GeV) = 0.1396(16), which are accurate at the 1% level. We also findR = 3.8350(18), which is consistent withR
and is accurate to 0.05%. 相似文献
98.
99.
Hanfei Li Fei Han Lulu Wang Laixin Huang Oluwarotimi Williams Samuel Hang Zhao Ruijie Xie Ping Wang Qiong Tian Qingsong Li Yang Zhao Mei Yu Jing Sun Ruofan Yang Xiaomeng Zhou Fei Li Guanglin Li Yi Lu Peizhi Guo Zhiyuan Liu 《Advanced functional materials》2023,33(29):2300859
Stretchable ultra-narrow (e.g., 10 µm in width) microelectrodes are crucial for the electrophysiological monitoring of single cells providing the fundamental understanding to the working mechanism of neuro network or other electrically functional cells. Current fabrication strategies either focus on the preparation of normal stretchable electrodes with hundreds of micrometers or millimeters in width by using inorganic conductive materials or develop conductive organic polymer gel for ultra-narrow electrodes which suffer from low stretchability and instability for long-term implantation, therefore, it is still highly desirable to explore bio-interfacial ultra-narrow stretchable inorganic electrodes. Herein, a hybrid strategy is reported to prepare ultra-narrow multi-channel stretchable microelectrodes without using photolithography or laser-assisting etching. A 10 µm × 10 µm monitoring window is fabricated with enhanced interfacial impedance by the special rough surface. The stretchability achieves to 120% for this 10 µm-width stretchable electrode. Supported by these superior properties, it is demonstrated that the stretchable microelectrodes can detect electrophysiological signals of single cells in vitro and collect electrophysiological signals more precisely in vivo. The reported strategy will open up the accessible preparation of the fine-size stretchable microelectrode. It will significantly improve the resolution of monitoring and stimulation of inorganic stretchable electrodes. 相似文献
100.
Ivona Kafedjiska Igal Levine Artem Musiienko Natalia Maticiuc Tobias Bertram Amran Al-Ashouri Christian A. Kaufmann Steve Albrecht Rutger Schlatmann Iver Lauermann 《Advanced functional materials》2023,33(34):2302924
The performance of five hole-transporting layers (HTLs) is investigated in both single-junction perovskite and Cu(In, Ga)Se2 (CIGSe)-perovskite tandem solar cells: nickel oxide (NiOx,), copper-doped nickel oxide (NiOx:Cu), NiOx+SAM, NiOx:Cu+SAM, and SAM, where SAM is the [2-(3,-6Dimethoxy-9H-carbazol-9yl)ethyl]phosphonic acid (MeO-2PACz) self-assembled monolayer. The performance of the devices is correlated to the charge-carrier dynamics at the HTL/perovskite interface and the limiting factors of these HTLs are analyzed by performing time-resolved and absolute photoluminescence ((Tr)PL), transient surface photovoltage (tr-SPV), and X-ray/UV photoemission spectroscopy (XPS/UPS) measurements on indium tin oxide (ITO)/HTL/perovskite and CIGSe/HTL/perovskite stacks. A high quasi-Fermi level splitting to open-circuit (QFLS-Voc) deficit is detected for the NiOx-based devices, attributed to electron trapping and poor hole extraction at the NiOx-perovskite interface and a low carrier effective lifetime in the bulk of the perovskite. Simultaneously, doping the NiOx with 2% Cu and passivating its surface with MeO-2PACz suppresses the electron trapping, enhances the holes extraction, reduces the non-radiative interfacial recombination, and improves the band alignment. Due to this superior interfacial charge-carrier dynamics, NiOx:Cu+SAM is found to be the most suitable HTL for the monolithic CIGSe-perovskite tandem devices, enabling a power-conversion efficiency (PCE) of 23.4%, Voc of 1.72V, and a fill factor (FF) of 71%, while the remaining four HTLs suffer from prominent Voc and FF losses. 相似文献