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排序方式: 共有1010条查询结果,搜索用时 62 毫秒
951.
D. Kameda H. Ueno K. Asahi D. Nagae M. Takemura K. Shimada A. Yoshimi T. Nagatomo T. Sugimoto M. Uchida T. Arai K. Takase S. Suda T. Inoue J. Murata H. Kawamura H. Watanabe Y. Kobayashi M. Ishihara 《Hyperfine Interactions》2007,180(1-3):61-64
The electric quadrupole moments for the ground states of 32Al and 31Al have been measured by the β ray-detected nuclear quadrupole resonance method. Spin-polarized 32Al and 31Al nuclei were obtained from the fragmentation of 40Ar projectiles at E/A?=?95 MeV/nucleon, and were implanted in a single crystal α-Al2O3 stopper. The measured Q moment of 32Al, |Q(32Al)|?=?24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of 31Al is considerably smaller than the sd calculations. 相似文献
952.
Ryoichi Nishimura Shunsuke Hayashi Masao Fukushima 《Computational Optimization and Applications》2013,55(1):21-47
In a real situation, optimization problems often involve uncertain parameters. Robust optimization is one of distribution-free methodologies based on worst-case analyses for handling such problems. In this paper, we first focus on a special class of uncertain linear programs (LPs). Applying the duality theory for nonconvex quadratic programs (QPs), we reformulate the robust counterpart as a semidefinite program (SDP) and show the equivalence property under mild assumptions. We also apply the same technique to the uncertain second-order cone programs (SOCPs) with “single” (not side-wise) ellipsoidal uncertainty. Then we derive similar results on the reformulation and the equivalence property. In the numerical experiments, we solve some test problems to demonstrate the efficiency of our reformulation approach. Especially, we compare our approach with another recent method based on Hildebrand’s Lorentz positivity. 相似文献
953.
Ryoichi Kase 《代数通讯》2013,41(10):4376-4391
Happel and Unger defined a partial order on the set of basic tilting modules. We study the poset of basic preprojective tilting modules over path algebras of representation-infinite type. First we will give a criterion for Ext-vanishing for preprojective modules. With the using of this result, we will give combinatorial characterizations of the poset of basic preprojective tilting modules. Finally, we will see the structure of a preprojective part of tilting quivers. 相似文献
954.
955.
High-resolution electron spectroscopy is used to explore the role played by molecular symmetry in determining the morphology of the energy spectra of electrons ejected when N2 and O2 are irradiated by intense laser fields. In O2, the low-energy part of the electron spectrum is curtailed due to the destructive interference brought about by the antibonding nature of the O2 valence orbital. The high-energy tail of the spectrum is also suppressed by virtue of electron rescattering being of little consequence in O2. In contrast, in N2, which has a bonding valence orbital, the electron dynamics follow the pattern that has been established for atomic ionization in strong optical fields. 相似文献
956.
Ishimatsu R Nishi N Kakiuchi T 《Langmuir : the ACS journal of surfaces and colloids》2007,23(14):7608-7611
The specific interaction of N-tetradecylisoquinolinium (C(14)Iq+) with Cl- and Br- has been detected in the voltammetry of ion transfer and electrocapillarity at the interface between an aqueous solution (W) and a room-temperature ionic liquid (RTIL), N-tetradecylisoquinolinium bis(pentafluoroethylsulfonyl)imide ([C(14)Iq+][C(2)C(2)N-]). This specific interaction also makes the transfer of Cl- and Br- into [C(14)Iq+][C(2)C(2)N-] energetically more favorable in comparison with that of F- and SO(4)(2-). The width of the polarized potential window in ion-transfer voltammetry at the [C(14)Iq+][C(2)C(2)N-]|W interface is significantly narrower because of the transfer of anions from W to RTIL. The degree of affinity of the anion with C(14)Iq+ agrees with the Hofmeister series. Such an ion-pair formation of anions in W with cations in the RTIL is much weaker when the cation constituting the RTIL is a symmetric tetraheptylammonium ion. 相似文献
957.
Sakakibara N Nakatsubo T Suzuki S Shibata D Shimada M Umezawa T 《Organic & biomolecular chemistry》2007,5(5):802-815
The present study established a system for comprehensive metabolic analysis of the cinnamate/monolignol and lignan pathways by the use of a stable-isotope-dilution method. The system was successfully applied to characterization of the pathways in Carthamus tinctorius cv. Round-leaved White maturing seeds in combination with administration of stable-isotope-labelled precursors. Experimental results obtained using this technique strongly suggested the intermediacy of ferulic acid in lignan biosynthesis in the plant. 相似文献
958.
Donor-acceptor pi-conjugated benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorescent dyes 3a, 3b, 8a, and 8b with a carboxyl group at different positions of the chromophore skeleton have been designed and synthesized. The absorption and fluorescence spectra and cyclic voltammograms of the fluorescent dyes agree very well, showing that the position of the carboxyl group has a negligible influence on the photophysical and electrochemical properties of these dyes. When these dyes are used in dye-sensitized solar cells, however, their photovolatic performances are considerably different. The short-circuit photocurrents and energy conversion efficiencies under a simulated solar light increase in the order: 3a (2.12 mA cm(-2), 1.00%) approximately 3b (2.10 mA cm(-2), 1.06%) > 8b (1.50 mA cm(-2), 0.67%) > 8a (0.84 mA cm(-2), 0.34%). Based on semi-empirical molecular orbital calculations (AM1 and INDO/S) together with spectral analyses and their photovolatic performance, the relationships between the observed photovolatic properties and the chemical structures of the benzofuro[2,3-c]oxazolo[4,5-a]carbazole-type fluorescent dyes are discussed. It is found that strong interaction between a TiO(2) surface and the electron accepting moiety of the dye leads to a high photovoltaic performance. 相似文献
959.
Shigeru Amemiya Yushin Kim Ryoichi Ishimatsu Benjamin Kabagambe 《Analytical and bioanalytical chemistry》2011,399(2):571-579
The monitoring of heparin and its derivatives in blood samples is important for the safe usage of these anticoagulants and
antithrombotics in many medical procedures. Such an analytical task is, however, highly challenging due to their low therapeutic
levels in the complex blood matrix, and it still relies on classical, indirect, clot-based assays. Here we review recent progress
in the direct electrochemical sensing of heparin and its analogs at liquid/liquid interfaces and polymeric membranes. This
progress has been made by utilizing the principle of electrochemical ion transfer at the interface between two immiscible
electrolyte solutions (ITIES) to voltammetrically drive the interfacial transfer of polyanionic heparin and monitoring the
resulting ionic current as a direct measure of heparin concentration. The sensitivity, selectivity, and reproducibility of
the ion-transfer voltammetry of heparin are dramatically enhanced compared to those of traditional potentiometry. This voltammetric
principle was successfully applied for the detection of heparin in undiluted blood samples, and was used to develop highly
sensitive ion-selective electrodes based on thin polymeric membranes that are intended for analytical applications beyond
heparin detection. The mechanism of heparin recognition and transfer at liquid/liquid interfaces was assessed quantitatively
via sophisticated micropipet techniques, which aided the development of a powerful ionophore that can extract large heparin
molecules into nonpolar organic media. Moreover, the reversible potentiometric detection of a lethal heparin-like contaminant
in commercial heparin preparations was achieved through the use of a PVC membrane doped with methyltridodecylammonium chloride,
which enables charge density dependent polyanion selectivity. 相似文献
960.
Higashi T Suzuki M Hanai J Inagaki S Min JZ Shimada K Toyo'oka T 《Journal of separation science》2011,34(7):725-732
Vitamin D deficiency in an infant is associated with a wide range of adverse health outcomes in later life. A method for the quantification of 25‐hydroxyvitamin D3 [25(OH)D3, the best‐established indicator of vitamin D status] in neonatal dried blood spots (DBSs) using LC/ESI‐MS/MS has been developed and validated. The method employed two steps of derivatization, a Diels–Alder reaction with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione followed by acetylation, to enhance the detectability of 25(OH)D3 in ESI‐MS/MS and to separate 25(OH)D3 from 3‐epi‐25‐hydroxyvitamin D3 [3‐epi‐25(OH)D3], a potent interfering metabolite. 25(OH)D3 was extracted from two DBS punches (3 mm in diameter, equivalent to 5.3 μL of whole blood), purified using an Oasis HLB® cartridge, and subjected to derivatization prior to analysis with LC/ESI‐MS/MS. 25‐Hydroxyvitamin D4 was used as the internal standard. This method was reproducible (intra‐ and inter‐assay RSDs, <6.9%) and accurate (analytical recovery, 95.2–102.7%), and the LOQ was 3.0 ng/mL. The developed method enabled specific quantification of 25(OH)D3 in neonatal DBSs and detection of vitamin D deficiency without interference from 3‐epi‐25(OH)D3. 相似文献