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931.
Masaki Kurokiba Takayoshi Ogawa Futoshi Takahashi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,50(4):840-867
We show the global existence of small solution to the perturbed Keller–Segel system of simplified version. Our system has
a perturbed nonlinear term of worse sign, therefore the existence and uniqueness of solution is not really obvious. The local
existence theorem is obtained by a variational observation for the elliptic part. 相似文献
932.
Masaki Kurokiba Takayoshi Ogawa Futoshi Takahashi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(5):840-867
We show the global existence of small solution to the perturbed Keller–Segel system of simplified version. Our system has
a perturbed nonlinear term of worse sign, therefore the existence and uniqueness of solution is not really obvious. The local
existence theorem is obtained by a variational observation for the elliptic part.
相似文献
933.
Masaki Kasedou 《Journal of Geometry》2009,94(1-2):107-121
We define the notions of lightcone Gauss images of spacelike hypersurfaces in de Sitter space. We investigate the relationships between singularities of these maps and geometric properties of spacelike hypersurfaces as an application of the theory of Legendrian singularities. We classify the singularities and give some examples in the generic case in de Sitter 3-space. 相似文献
934.
Ryo Kobayashi Masaki Kurokiba Shuichi Kawashima 《Mathematical Methods in the Applied Sciences》2009,32(6):640-652
We study the stationary problem in the whole space ?n for the drift–diffusion model arising in semiconductor device simulation and plasma physics. We prove the existence and uniqueness of stationary solutions in the weighted Lp spaces. The proof is based on a fixed point theorem of the Leray–Schauder type. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
935.
Masaki Kawamoto 《Annali dell'Universita di Ferrara》2018,64(2):389-406
We consider a system associated to Klein–Gordon equations with homogeneous time-dependent electric fields. The upper and lower boundaries of a time-evolution propagator for this system were proven by Veseli? (J Oper Theory 25:319–330, 1991) for electric fields that are independent of time. We extend this result to time-dependent electric fields. 相似文献
936.
937.
Masaki Yoshida Dr. Shigeyuki Masaoka Prof. Dr. Jiro Abe Prof. Dr. Ken Sakai 《化学:亚洲杂志》2010,5(11):2369-2378
The mechanism of O2 evolution from water catalyzed by a series of mononuclear aquaruthenium complexes, [Ru(terpy)(bpy)(OH2)]2+, [Ru(tmtacn)(R2bpy)(OH2)]2+ (R=H, Me, and OMe; R2bpy=4,4′‐disubstituted‐2,2′‐bipyridines), and [Ru(tpzm)(R2bpy)(OH2)]2+ (R=H, Me, and OMe), is investigated, where terpy=2,2′:6′,2′′‐terpyridine, bpy=2,2′‐bipyridine, tmtacn=1,4,7‐trimethyl‐1,4,7‐triazacyclononane, and tpzm=tris(1‐pyrazolyl)methane. The kinetics of O2 evolution is investigated as a function of either the catalyst concentration or the oxidant concentration by employing Ce(NH4)2(NO3)6 as an oxidant; these catalysts can be classified into two groups that have different rate laws for O2 evolution. In one class, the rate of O2 evolution is linear to both the catalyst and Ce4+ concentrations, as briefly reported for [Ru(terpy)(bpy)(OH2)]2+ (S. Masaoka, K. Sakai, Chem. Lett. 2009 , 38, 182). For the other class, [Ru(tmtacn)(R2bpy)(OH2)]2+, the rate of O2 evolution is quadratic to the catalyst concentration and independent of the Ce4+ concentration. Moreover, the singlet biradical character of the hydroxocerium(IV) ion was realized by experimental and DFT investigations. These results indicate that the radical coupling between the oxygen atoms of a RuV?O species and a hydroxocerium(IV) ion is the key step for the catalysis of [Ru(terpy)(bpy)(OH2)]2+ and [Ru(tpzm)(R2bpy)(OH2)]2+, while the well‐known oxo‐oxo radical coupling among two RuV?O species proceeds in the catalysis of [Ru(tmtacn)(R2bpy)(OH2)]2+. This is the first report demonstrating that the radical character provided by the hydroxocerium(IV) ion plays a crucial role in the catalysis of such ruthenium complexes in the evolution of O2 from water. 相似文献
938.
Fukuda E Baba M Iwasaki N Uesawa Y Arifuku K Kamoe O Tsubono K Okada Y 《Natural product communications》2010,5(11):1755-1758
DART (Direct Analysis in Real Time)-MS is a novel mass spectrometric ion source, and allows the analysis of most compounds at ambient pressure and ground potential by producing [M+H]+ molecular ion species. Using this method, we examined the compounds characteristic of several kinds of licorices. For the analysis of Glycyrrhiza inflata Batalin, the peak at m/z 339 originates mainly from [M+H]+ of licochalcone A (LA), a species-specific compound. This peak was hardly detected in G. glabra Linné and G. uralensis Fischer. These results indicate that G. inflata can be differentiated from the other two species by detection of LA peaks using DART-MS analysis. 相似文献
939.
Dinesh Rangappa Dr. Koji Sone Dr. Mingsheng Wang Dr. Ujjal K. Gautam Dr. Dmitri Golberg Prof. Hiroshi Itoh Dr. Masaki Ichihara Dr. Itaru Honma Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(22):6488-6494
Graphene has attracted a great deal of attention in recent years due to its unusual electronic, mechanical, and thermal properties. Exploiting graphene properties in a variety of applications requires a chemical approach for the large‐scale production of high‐quality, processable graphene sheets (GS), which has remained an unanswered challenge. Herein, we report a rapid one‐pot supercritical fluid (SCF) exfoliation process for the production of high‐quality, large‐scale, and processable graphene for technological applications. Direct high‐yield conversion of graphite crystals to GS is possible under SCF conditions because of the high diffusivity and solvating power of SCFs, such as ethanol, N‐methyl‐pyrrolidone (NMP), and DMF. For the first time, we report a one‐pot direct conversion of graphite crystals to a high yield of graphene sheets in which about 90–95 % of the exfoliated sheets are <8 layers with approximately 6–10 % monolayers and the remaining 5–10 % are ≥10 layers. 相似文献
940.
Infrared predissociation spectroscopy of vacuum ultraviolet-pumped ion (IRPDS-VUV-PI) is performed on ammonia cluster cations (NH3)n+ (n=2-4) that are produced by VUV photoionization in supersonic jets. The structures of (NH3)2+ and (NH3)4+ are determined through the observation of infrared spectra and vibrational calculations based on ab initio calculations at the MP2/6-31G** and 6-31++G** levels. (NH3)2+ is found to be of the "hydrogen-transferred" form having the (H3N+-...NH2) composition. In contrast, (NH3)4+ exhibits the "head-to-head" dimer cation (H3...NH3+ core structure, where the positive charge is shared between two ammonia molecules in the core, and two other molecules are hydrogen bonded onto the core. An unequivocal assignment of the infrared spectrum of (NH3)3+ has not been achieved, because the presence of two isomeric structures could be suggested by the observed spectrum and theoretical calculations. 相似文献