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991.
Abbott T Akiba Y Beavis D Bloomer MA Bond PD Chasman C Chen Z Chu YY Cole BA Costales JB Crawford HJ Cumming JB Debbe R Engelage J Fung SY Grodzins L Gushue S Hamagaki H Hansen O Hayano RS Hayashi S Homma S Huang HZ Ikeda Y Juricic I Kang J Katcoff S Kaufman S Kimura K Kitamura K Kurita K Ledoux RJ Levine MJ Miake Y Morse RJ Moskowitz B Nagamiya S Olness J Parsons CG Remsberg LP Sakurai H Sarabura M Shor A Stankus P Steadman SG Stephans GS Sugitate T Tanaka M Tannenbaum MJ Torikoshi M 《Physical review letters》1991,66(12):1567-1570
992.
Dr. José I. Urgel Dr. Marco Di Giovannantonio Guido Gandus Qiang Chen Dr. Xunshan Liu Dr. Hironobu Hayashi Dr. Pascal Ruffieux Prof. Dr. Silvio Decurtins Dr. Akimitsu Narita Dr. Daniele Passerone Prof. Dr. Hiroko Yamada Shi-Xia Liu Prof. Dr. Klaus Müllen Dr. Carlo A. Pignedoli Prof. Dr. Roman Fasel 《Chemphyschem》2019,20(18):2360-2366
On-surface synthesis is a unique tool for growing low-dimensional carbon nanomaterials with precise structural control down to the atomic level. This novel approach relies on carefully designed precursor molecules, which are deposited on suitable substrates and activated to ultimately form the desired nanostructures. One of the most applied reactions to covalently interlink molecular precursors is dehalogenative aryl-aryl coupling. Despite the versatility of this approach, many unsuccessful attempts are also known, most of them associated to the poor capability of the activated precursors to couple to each other. Such failure is often related to the steric hindrance between reactants, which may arise due to their coplanarity upon adsorption on a surface. Here, we propose a copolymerization approach to overcome the limitations that prevent intermolecular homocoupling. We apply the strategy of using suitable linkers as additional reactants to the formation of fully conjugated polycyclic nanowires incorporating non-benzenoid rings. 相似文献
993.
Prof. Dr. Yujiro Hayashi Akira Takikawa Seitaro Koshino Keiichi Ishida 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(44):10319-10322
A three-pot synthetic method that features the use of an organocatalyst as the key step was developed for the preparation of biaryl atropisomers. The first reaction is an asymmetric domino Michael–Henry reaction catalyzed by diphenylprolinol silyl ether to afford the substituted nitrocyclohexanecarbaldehyde with four stereogenic centers and one defined configuration of a stereogenic axis with excellent enantioselectivity. Removal of the central chirality from the domino products afforded biaryl atropisomers having axial chirality with excellent enantioselectivity. 相似文献
994.
Koji Oohora Yuta Miyazaki Takashi Hayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(39):13951-13955
Myoglobin reconstituted with Ni tetradehydrocorrin was investigated as a model of F430‐containing methyl‐coenzyme M reductase, which catalyzes anaerobic methane generation. The NiII tetradehydrocorrin complex has a NiII/NiI redox potential of ?0.34 V vs. SHE and EPR spectroscopy indicates the formation of a NiI species upon reduction by dithionite. This redox potential is approximately 0.31 V more positive than that of F430. The NiI tetradehydrocorrin moiety is bound to the apo‐form of myoglobin to yield the reconstituted protein. Methane gas is generated in the reaction of the model with methyl iodide in the presence of the reconstituted protein under reductive conditions, whereas the NiI complex itself does not produce methane gas. This is the first example of a protein‐based functional model of F430‐containing methyl‐coenzyme M reductase. 相似文献
995.
Dr. Masanori Shigeno Kazutoshi Hayashi Dr. Kanako Nozawa-Kumada Prof. Dr. Yoshinori Kondo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(24):6077-6081
The organic superbase tBu-P4 catalyzes methoxy-alkoxy exchange reactions on (hetero)arenes with alcohols. The catalytic reaction proceeded efficiently with electron-deficient methoxy(hetero)arenes as well as with a variety of alcohols, including 3-amino-1-propanol, β-citronellol, menthol, and cholesterol. An intramolecular version of this reaction furnished six- and seven-membered ring compounds. 相似文献
996.
Yusuke Hotta Tsukasa Kaneko Ryuji Hayashi Akito Yamamoto Shota Morimoto Junya Chiba Takenori Tomohiro 《化学:亚洲杂志》2019,14(3):398-402
We developed a novel diazirine‐based photolabeling agent having a (coumarin‐4‐yl)methyl ester scaffold, which exhibited multiple photochemical properties of crosslinking, fluorogenicity and cleavage. These properties can be kinetically regulated via photoinduced electron transfer between diazirine and coumarin moieties. The C?O bond of (coumarin‐4‐yl)methyl ester can be cleaved via photochemical excitation of coumarin moiety, that function has been initially quenched by the diazirine moiety. Upon diazirine photolysis with 365‐nm light, interacting protein was stably captured with photoactivatable ligand probe. Then, the unlocked cleavage function was activated with 313 nm light, and the reaction was accelerated in a weakly‐basic solution. The crosslinked protein could be selectively isolated with attachment of a small coumarin tag on the surface. This multi‐functional labeling agent has a great potential to facilitate LC‐MS/MS‐based protein identification. 相似文献
997.
998.
Jens R. Stellhorn Shinya Hosokawa Naohisa Happo Hiroo Tajiri Tomohiro Matsushita Kenichi Kaminaga Tomoteru Fukumura Tetsuya Hasegawa Koji Kimura Kouichi Hayashi 《Surface and interface analysis : SIA》2019,51(1):70-73
We report on the characterization of a thin film of yttrium oxide by X-ray fluorescence holography. The sample has a layered structure with an YO base layer and an oxidized Y2O3 surface. Both layers are clearly observed in the atomic image reconstructions, and their local structure is analyzed. We show that by using incident energies close to the absorption edge of the fluorescing atom, it becomes possible to observe the thin surface layer clearly, even next to a base layer containing the same fluorescing element. 相似文献
999.
Ryosuke Matsubara Yuki Katsuragi Takaya Sakaguchi Shuhei Eguchi Masahiko Hayashi Akihiro Ando 《Tetrahedron》2018,74(27):3642-3651
Furoxans are distinctive heteroaromatic compounds in that they are potentially capable of releasing nitric oxide under physiological conditions. In order to utilize the furoxan scaffold for the development of functional molecules, synthetically relevant functional groups are required for access to diverse furoxans. In this report, a facile route to furoxans with sulfonyloxy groups, which are halide surrogates, has been developed. The key features of this strategy include the synthesis and utilization of bench-stable hydroxyfuroxan salts, the use of sulfonyl anhydrides in the sulfonylation step instead of sulfonyl chlorides, and the photochemical isomerization of one regioisomer to another in order to gain access to both. 相似文献
1000.