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101.
Bioinspired Nacre‐Like Ceramic with Nickel Inclusions Fabricated by Electroless Plating and Spark Plasma Sintering 下载免费PDF全文
Zhe Xu Jiacheng Huang Cheng Zhang Soheil Daryadel Ali Behroozfar Brandon McWilliams Benjamin Boesl Arvind Agarwal Majid Minary‐Jolandan 《Advanced Engineering Materials》2018,20(5)
102.
Antony Jan Benjamin A. Reeves Yoeri van de Burgt Garrett J. Hayes Bruce M. Clemens 《Advanced Engineering Materials》2018,20(1)
103.
Romain Carron Enrico Avancini Thomas Feurer Benjamin Bissig Paolo A. Losio Renato Figi 《Science and Technology of Advanced Materials》2018,19(1):396-410
Cu(In,Ga)Se2-based solar cells have reached efficiencies close to 23%. Further knowledge-driven improvements require accurate determination of the material properties. Here, we present refractive indices for all layers in Cu(In,Ga)Se2 solar cells with high efficiency. The optical bandgap of Cu(In,Ga)Se2 does not depend on the Cu content in the explored composition range, while the absorption coefficient value is primarily determined by the Cu content. An expression for the absorption spectrum is proposed, with Ga and Cu compositions as parameters. This set of parameters allows accurate device simulations to understand remaining absorption and carrier collection losses and develop strategies to improve performances. 相似文献
104.
Qi Jia Xin Ou Manuel Langer Benjamin Schreiber Jörg Grenzer Pablo F. Siles Raul D. Rodriguez Kai Huang Ye Yuan Alireza Heidarian René Hübner Tiangui You Wenjie Yu Kilian Lenz Jürgen Lindner Xi Wang Stefan Facsko 《Nano Research》2018,11(7):3519-3528
A nanofabrication method for the production of ultra-dense planar metallic nanowire arrays scalable to wafer-size is presented. The method is based on an efficient template deposition process to grow diverse metallic nanowire arrays with extreme regularity in only two steps. First, III–V semiconductor substrates are irradiated by a low-energy ion beam at an elevated temperature, forming a highly ordered nanogroove pattern by a “reverse epitaxy” process due to self-assembly of surface vacancies. Second, diverse metallic nanowire arrays (Au, Fe, Ni, Co, FeAl alloy) are fabricated on these III–V templates by deposition at a glancing incidence angle. This method allows for the fabrication of metallic nanowire arrays with periodicities down to 45 nm scaled up to wafer-size fabrication. As typical noble and magnetic metals, the Au and Fe nanowire arrays produced here exhibited large anisotropic optical and magnetic properties, respectively. The excitation of localized surface plasmon resonances (LSPRs) of the Au nanowire arrays resulted in a high electric field enhancement, which was used to detect phthalocyanine (CoPc) in surface-enhanced Raman scattering (SERS). Furthermore, the Fe nanowire arrays showed a very high in-plane magnetic anisotropy of approximately 412 mT, which may be the largest in-plane magnetic anisotropy field yet reported that is solely induced via shape anisotropy within the plane of a thin film. 相似文献
105.
Andreas Förner Jan Vollhüter Anna Krapf Abdullah Jamjoom Daniel Hausmann Benjamin Wahlmann Zongwen Fu Carolin Körner Steffen Neumeier Mathias Göken 《Advanced Engineering Materials》2023,25(15):2300407
By increasing the density of interfaces in NiAl–CrMo in situ composites, the mechanical properties can be significantly improved compared to conventionally cast material. The refined microstructure is achieved by manufacturing through electron beam powder bed fusion (PBF-EB). By varying the process parameters, an equiaxed or columnar cell morphology can be obtained, exhibiting a plate-like or an interconnected network of the (Cr,Mo) reinforcement phase which is embedded in a NiAl matrix. The microstructure of the different cell morphologies is investigated in detail using scanning electron microscope, transmission electron microscopy, and atom probe tomography. For both morphologies, the mechanical properties at elevated temperatures are analyzed by compression and creep experiments parallel and perpendicular to the building direction. In comparison to cast NiAl and NiAl–(Cr, Mo), the yield strength of the PBF-EB fabricated specimens is significantly improved at temperatures up to 1,027 °C. While the columnar morphology exhibits the best improved mechanical properties at high temperatures, the equiaxial morphology shows nearly ideal isotropic mechanical behavior, which is a substantial advantage over directionally solidified material. 相似文献
106.
R Chalmers A Guhathakurta H Benjamin N Kleckner 《Canadian Metallurgical Quarterly》1998,93(5):897-908
Architectural protein IHF modulates Tn10 transposition in vitro. IHF stimulates transposon excision. Also, separately, IHF forces transposon end/target DNA interactions into a constrained pathway, "channeling," that yields only unknotted intratransposon inversion circles. Negative supercoiling influences both effects, differently. We infer that IHF is an architectural catalyst: it promotes initial transpososome assembly and is then ejected from the transpososome. IHF then rebinds, altering transpososome conformation to promote channeling. We also infer that the developing transpososome is a molecular spring: DNA provides basic elasticity; a conformational change in transposase provides force; and IHF and/or supercoiling provide conformational inputs. In vivo, IHF is a sensory transducer of chromosomal supercoiling status: with supercoiling absent, IHF is "supercoiling relief factor"; with supercoiling present, stimulation and channeling comprise a homeostatic pair such that modest changes in chromosome condition strongly influence transpositional outcome. 相似文献
107.
Jürgen R. Reichenbach Marco Essig E. Mark Haacke Benjamin C. Lee Christian Przetak Werner A. Kaiser Lothar R. Schad 《Magma (New York, N.Y.)》1998,6(1):62-69
The purpose of this study was to evaluate a non-flow related magnetic resonance imaging method to visualize small veins independent of arteries in the human brain. A long TE, high-resolution 3D gradient echo MR acquisition was used to highlight venous information. The method is based on the paramagnetic property of deoxyhemoglobin and the resulting phase difference between veins and brain parenchyma at long echo times. The MR magnitude images were masked with a phase mask filter to enhance small structure visibility.. Venous information down to sub-pixel vessel diameters of several hundred microns is visible. Venous data are displayed in an angiographic manner using a minimum intensity projection algorithm. Both superficial veins and deep white matter veins are visible. The method has been successfully applied in volunteers. Preliminary results in patients with cerebral arteriovenous malformations indicate its potential in clinical applications. The proposed method is easy to implement and does not require administration of a contrast agent or application of specially designed rf pulses to highlight the veins. Rather it exploits the intrinsic magnetic properties (BOLD-effect) and the prolonged T 2* of venous blood. The method may be of diagnostic potential in the assessment of arteriovenous malformations or other vascular venous lesions. © 1998 Elsevier Science B.V. All rights reserved. 相似文献
108.
The smart car seat: personalized monitoring of vital signs in automotive applications 总被引:1,自引:1,他引:0
Marian Walter Benjamin Eilebrecht Tobias Wartzek Steffen Leonhardt 《Personal and Ubiquitous Computing》2011,15(7):707-715
Embedded wireless sensors are important components of mobile distributed computing networks, and one of the target applications
areas is health care. The preservation of mobility for senior citizens is one of the key issues in maintaining an independent
lifestyle. Thus health technologies inside a car can contribute both to safety issues (supervision of driver fitness) as well
as healthcare issues by monitoring vitals signs imperceptibly. In this paper, three embedded measurement techniques for non-contact
monitoring of vital signals have been investigated. Specifically, capacitive electrocardiogram (cECG) monitoring, mechanical
movement analysis (ballistocardiogram, BCG) using piezo-foils and inductive impedance monitoring were examined regarding their
potential for integration into car seats. All three sensing techniques omit the need for electroconductive contact to the
human body, but require defined mechanical boundary conditions (stable distances or, in the case of BCG, frictional connection).
The physical principles of operation, the specific boundary conditions regarding automotive integration and the results during
wireless operation in a running car are presented. All three sensors were equipped with local intelligence by incorporating
a microcontroller. To eliminate the need for additional cabling, a wireless Bluetooth communication module was added and used
to transmit data to a measurement PC. Finally, preliminary results obtained during test drives on German city roads and highways
are discussed. 相似文献
109.
A Modern Graphics Processing unit (GPU) is able to perform massively parallel scientific computations at low cost. We extend our implementation of the checkerboard algorithm for the two-dimensional Ising model [T. Preis et al., Journal of Chemical Physics 228 (2009) 4468-4477] in order to overcome the memory limitations of a single GPU which enables us to simulate significantly larger systems. Using multi-spin coding techniques, we are able to accelerate simulations on a single GPU by factors up to 35 compared to an optimized single Central Processor Unit (CPU) core implementation which employs multi-spin coding. By combining the Compute Unified Device Architecture (CUDA) with the Message Parsing Interface (MPI) on the CPU level, a single Ising lattice can be updated by a cluster of GPUs in parallel. For large systems, the computation time scales nearly linearly with the number of GPUs used. As proof of concept we reproduce the critical temperature of the 2D Ising model using finite size scaling techniques. 相似文献
110.
We conduct a rigorous analysis of the (1+1) evolutionary algorithm for the single source shortest path problem proposed by Scharnow, Tinnefeld, and Wegener (The analyses of evolutionary algorithms on sorting and shortest paths problems, 2004, Journal of Mathematical Modelling and Algorithms, 3(4):349-366). We prove that with high probability, the optimization time is O(n2 max{?, log(n)}), where ? is the smallest integer such that any vertex can be reached from the source via a shortest path having at most ? edges. This bound is tight. For all values of n and ? we provide a graph with edge weights such that, with high probability, the optimization time is of order Ω(n2 max{?, log(n)}). To obtain such sharp bounds, we develop a new technique that overcomes the coupon collector behavior of previously used arguments. Also, we exhibit a simple Chernoff type inequality for sums of independent geometrically distributed random variables, and one for sequences of random variables that are not independent, but show a desired behavior independent of the outcomes of the previous random variables. We are optimistic that these tools find further applications in the analysis of evolutionary algorithms. 相似文献