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51.
52.
The hierarchically structured mesoporous LiMn2O4 (LMO) nanospheres were synthesized using a template-free self-assembly process that was coupled with ultrasound (U). The ultrasound technique suggested here is very powerful for controlling an ordered nanostructure and improving crystallinity with large single-crystalline domains. Owing to the hierarchical mesoporous structure and high crystallinity, U-LMO provides an excellent rate capability and cycle stability with a capacity retention of more than 98% up to 50 cycles at a 0.2 C rate. Here, we demonstrate that mesoporous U-LMO nanospheres were fabricated to enhance the electrochemical performance and protect it from structurally significant collapsing because of high crystallinity. 相似文献
53.
In a recent paper, the first author proved the log-concavity of the coefficients of the characteristic polynomial of a matroid realizable over a field of characteristic 0, answering a long-standing conjecture of Read in graph theory. We extend the proof to all realizable matroids, making progress towards a more general conjecture of Rota?CHeron?CWelsh. Our proof follows from an identification of the coefficients of the reduced characteristic polynomial as answers to particular intersection problems on a toric variety. The log-concavity then follows from an inequality of Hodge type. 相似文献
54.
By means of a technique of corona excited supersonic expansion coupled with a pinhole-type glass nozzle, we generated vibronically excited but jet-cooled benzyl-type radicals from precursor 2-chloro-4-fluorotoluene seeded in a large amount of inert carrier gas He. From an analysis of the visible vibronic emission spectrum, we found evidence of the formation of the 2-chloro-4-fluorobenzyl and 4-fluorobenzyl radicals. A possible pathway for the formation of these benzyl-type radicals is herein proposed. Also, the electronic energy in the D(1) → D(0) transition and the vibrational mode frequencies of the 2-chloro-4-fluorobenzyl radical in the ground electronic state were accurately determined, for the first time, by comparison with ab initio calculations and the known vibrational data of the precursor. 相似文献
55.
Seong Huh Young Jun Park Alan. J. Lough Moo‐Jin Jun 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):416-417
The title compound, [RuH(C6H8BN4)(C21H21P)2(CO)], possesses two trans‐disposed tri‐p‐tolylphosphines in axial positions and the remaining ligands in equatorial positions. The overall geometry of the RuII ion is a distorted octahedral structure. The P—Ru—P axis deviates from linearity by about 13°. This distortion arises mainly from the steric congestion between the bulky phosphine moieties and the tetrahedral dihydrobis(pyrazol‐1‐yl)borate ligands. 相似文献
56.
In-Hwan Choi Sukbin Yoon Prof. Dr. Seong Huh Prof. Dr. Sung-Jin Kim Dr. Youngmee Kim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(64):14580-14584
Metal–organic frameworks (MOFs) with negatively charged frameworks are suitable for selectively encapsulating cationic guest ions via a cation-exchange process. Encapsulating photoactive [RuL3]2+ polypyridine complexes into the preorganized mesoscale channels of a MOF is a good method for stabilizing the excited states of the complexes. Three new RuL3@InBTB MOFs were prepared by encapsulating cationic [Ru(bpy)3]2+ (bpy=2,2′-bipyridine), [Ru(phen)3]2+ (phen=1,10-phenanthroline), and [Ru(bpz)3]2+ (bpz=2,2′-bipyrazine) into the mesopores of a three-dimensional (3D) InBTB MOF (H3BTB=1,3,5-benzenetribenzoic acid). The photophysical properties of the resulting materials were investigated by photoluminescence (PL) analysis. The photoredox catalytic activities were also investigated for the aza-Henry reaction, hydrogenation of dimethyl maleate, and decomposition of methyl orange under visible light irradiation at room temperature. RuL3@InBTB MOFs were found to be very stable and highly recyclable photoredox catalytic systems. 相似文献
57.
Junji Nakano Moon Yul Huh Yoshikazu Yamamoto Takeshi Fujiwara Ikunori Kobayashi 《Computational Statistics》2004,19(1):137-146
Summary Jasp is an experimental general purpose Java-based statistical system which adopts several new computing technologies. It
has a function-based and object-oriented language, an advanced user interface, flexible extensibility and a server/client
architecture with distributed computing abilities. DAVIS is, on the other hand, a stand-alone Java-based system, and is designed
for providing advanced data visualization functions with easy operations by a GUI. In this paper, it is made possible to use
tools of DAVIS from within Jasp, in order that the new integrated system can handle not only data filtering and statistical
analysis but also data visualization. We develop a mechanism for extending the server/client system of Jasp to realize an
efficient collaboration with DAVIS in the client-side. It is shown that the mechanism is straightforward and simple. 相似文献
58.
Woonghee Tim Huh Ganesh JanakiramanPeter L. Jackson Nidhi Sawhney 《Operations Research Letters》2003,31(5):366-374
This paper studies minimizing the flow time of a cyclic schedule for repeated identical jobs, where one job is started/completed in each cycle, subject to the schedule achieving maximum throughput. We propose a branch and bound method for a single machine problem, and use this method to derive an improved lower bound for the multiple machine problem. 相似文献
59.
In vivo magnetic resonance detection of cancer by using multifunctional magnetic nanocrystals 总被引:8,自引:0,他引:8
Huh YM Jun YW Song HT Kim S Choi JS Lee JH Yoon S Kim KS Shin JS Suh JS Cheon J 《Journal of the American Chemical Society》2005,127(35):12387-12391
The unique properties of magnetic nanocrystals provide them with high potential as key probes and vectors in the next generation of biomedical applications. Although superparamagnetic iron oxide nanocrystals have been extensively studied as excellent magnetic resonance imaging (MRI) probes for various cell trafficking, gene expression, and cancer diagnosis, further development of in vivo MRI applications has been very limited. Here, we describe in vivo diagnosis of cancer, utilizing a well-defined magnetic nanocrystal probe system with multiple capabilities, such as small size, strong magnetism, high biocompatibility, and the possession of active functionality for desired receptors. Our magnetic nanocrystals are conjugated to a cancer-targeting antibody, Herceptin, and subsequent utilization of these conjugates as MRI probes has been successfully demonstrated for the monitoring of in vivo selective targeting events of human cancer cells implanted in live mice. Further conjugation of these nanocrystal probes with fluorescent dye-labeled antibodies enables both in vitro and ex vivo optical detection of cancer as well as in vivo MRI, which are potentially applicable for an advanced multimodal detection system. Our study finds that high performance in vivo MR diagnosis of cancer is achievable by utilizing improved and multifunctional material properties of iron oxide nanocrystal probes. 相似文献
60.
Racemic fluids of chiral calamitic molecules are investigated with molecular dynamics simulations. In particular, the phase behavior as a function of density is examined for eight racemates. The relationship between chiral discrimination and orientational order in the phase is explored. We find that the transition from the isotropic phase to a liquid crystal phase is accompanied by an increase in chiral discrimination, as measured by differences in radial distributions. Among ordered phases, discrimination is largest for smectic phases with a significant preference for heterochiral contact within the layers. 相似文献