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41.
42.
Aishabibi Kassymbek Prof. Dmitry G. Gusev Dr. Anton Dmitrienko Prof. Melanie Pilkington Prof. Georgii I. Nikonov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(4):e202103455
Reaction of the Ga(I) compound NacNacGa ( 9 ) with the diazo compound N2CHSiMe3 affords the nitrilimine compound NacNacGa(N-NCSiMe3)(CH2SiMe3) ( 10 ). Carrying out this reaction in the presence of pyridine does not lead to C−H activation on the transient alkylidene NacNacGa=CHSiMe3 but generates a metallated diazo species NacNacGa(NHN=CHSiMe3)(CN2SiMe3) ( 13 ) that further rearranges into the isonitrile compound NacNacGa(NHN=CHSiMe3)(N(NC)SiMe3) ( 15 ). Reactions of 10 with the silane H3SiPh and the borane HBcat furnished products of 1,3 addition to the nitrilimine moiety NacNacGa{N(ERn)NCSiMe3}(CH2SiMe3), whereas reaction with the diborane B2cat2 gave the product of formal nitrene insertion into the B−B bond. DFT calculations suggest that the interaction of 9 with N2CHSiMe3 proceeds through intermediate formation of an alkylidene compound that undergoes CH activation with a second molecule of N2CHSiMe3. Insertion into the B−B bond likely proceeds through an initial 1,3-addition of the diborane, followed by boryl migration to the former nitrene center. 相似文献
43.
Dr. Joseph N. Capilato Stefan A. Harry Dr. Maxime A. Siegler Prof. Thomas Lectka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202103922
As appreciation for nonclassical hydrogen bonds has progressively increased, so have efforts to characterize these interesting interactions. Whereas several kinds of C−H hydrogen bonds have been well-studied, much less is known about the R3N+−C−H⋅⋅⋅X variety. Herein, we present crystallographic and spectroscopic evidence for the existence of these interactions, with special relevance to Selectfluor chemistry. Of particular note is the propensity for Lewis bases to engage in nonclassical hydrogen bonding over halogen bonding with the electrophilic F atom of Selectfluor. Further, the first examples of 1H NMR experiments detailing R3N+−C−H⋅⋅⋅X (X=O, N) hydrogen bonds are described. 相似文献
44.
Chikako Matsuda Ryo Igarashi Prof. Dr. Hiroshi Katagiri Dr. Takashi Murase 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200132
Tri- and tetra-fluorinated [7]helicenes are photolabile and undergo a double fluorine atom transfer. Herein, we show that the transferred product further undergoes a skeletal transformation on silica gel. The transformation begins with activation of the allylic C−F bond on the silanol surface. Then, the resulting carbocation readily undergoes a regioselective nucleophilic aromatic substitution with water, depending on the position of the fluorine substituents. Hexafluoro-2-propanol also activated the allylic C−F bond and acted as a nucleophile. These findings support the generation of a highly reactive cationic electrophilic intermediate in the successive transformations involving fluorine atoms. 相似文献
45.
《Mendeleev Communications》2022,32(4):452-453
New (E)-5-[2-(5-nitrofuran-2-yl)vinyl]-1,2,4-oxadiazoles and 5-(5-nitrofuran-2-yl)-1,2,4-oxadiazoles were synthesized via the base-promoted condensation of nitrofuran-containing acyl chlorides with amidoximes. Testing these compounds against Gram-negative E. coli, Gram-positive B. subtilis and S. aureus as well as M. tuberculosis HRv37 strain revealed three compounds being selectively antimycobacterial. None of these compounds displayed any cytotoxicity towards human pancreatic epithelioid carcinoma cell line, PANC-1. 相似文献
46.
An efficient catalyst-free, alternative method for the C–N bond formation reaction of alkyl electrophiles using formamides as the N-sources was achieved under mild conditions. The reaction possesses the advantages of a broad range of substrates scope and wide functional group tolerance. It should also be noted that this process was performed using the environmentally benign water as the sole solvent, and high yield can also be achieved in ten-gram scale. 相似文献
47.
TBAI‐Catalyzed/Water‐Assisted Double C−S Bond Formations: An Efficient Approach to Sulfides through Metal‐Free Three‐Component Reactions 下载免费PDF全文
Xue‐Qiang Chu Prof. Dr. Xiao‐Ping Xu Prof. Dr. Shun‐Jun Ji 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14181-14185
An aqueous catalytic method for double C?S bond formations that involves alcohol derivatives, organic halides, and sodium thiosulfate has been developed. A diverse range of functionalized sulfides, including pharmaceutical and biological derivatives, can be obtained in an efficient and eco‐friendly manner under air. The mechanistic studies revealed that this tetrabutylammonium‐iodide‐catalyzed/water‐assisted reaction generated a mercaptan species as the key intermediate. 相似文献
48.
Aromaticity Relocation in Perylene Derivatives upon Two‐Electron Oxidation To Form Anthracene and Phenanthrene 下载免费PDF全文
Akinobu Matsumoto Dr. Mitsuharu Suzuki Dr. Hironobu Hayashi Dr. Daiki Kuzuhara Dr. Junpei Yuasa Prof. Dr. Tsuyoshi Kawai Prof. Dr. Naoki Aratani Prof. Dr. Hiroko Yamada 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14462-14466
We prepared perylene dications 1 2+ and 2 2+ by using “capped” perylene derivatives, and for the first time, successfully obtained single crystals of a perylene dication 1 2+ that enabled us to perform its structural analysis. We realized that the substituted aryl groups on perylene control the positions of positive charges, thus the remaining electronic system satisfies Clar's sextet rule toward the highest number of localized sextets. Experimental and theoretical evidence proved that Clar's aromatic π‐sextet rule could be applied even for the dicationic perylenes in a very simple way. 相似文献
49.
Dr. Hajime Kameo Tatsuya Kawamoto Prof. Shigeyoshi Sakaki Prof. Didier Bourissou Prof. Hiroshi Nakazawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(7):2370-2375
Si?F bond cleavage of fluoro‐silanes was achieved by transition‐metal complexes under mild and neutral conditions. The Iridium‐hydride complex [Ir(H)(CO)(PPh3)3] was found to readily break the Si?F bond of the diphosphine‐ difluorosilane {(o‐Ph2P)C6H4}2Si(F)2 to afford a silyl complex [{[o‐(iPh2P)C6H4]2(F)Si}Ir(CO)(PPh3)] and HF. Density functional theory calculations disclose a reaction mechanism in which a hypervalent silicon species with a dative Ir→Si interaction plays a crucial role. The Ir→Si interaction changes the character of the H on the Ir from hydridic to protic, and makes the F on Si more anionic, leading to the formation of Hδ+???Fδ? interaction. Then the Si?F and Ir?H bonds are readily broken to afford the silyl complex and HF through σ‐bond metathesis. Furthermore, the analogous rhodium complex [Rh(H)(CO)(PPh3)3] was found to promote the cleavage of the Si?F bond of the triphosphine‐monofluorosilane {(o‐Ph2P)C6H4}3Si(F) even at ambient temperature. 相似文献
50.
A simple, highly efficient synthetic protocol is developed for the synthesis of unsymmetrical diaryl vinyl selenides from diaryldiselenide and β-bromo styrene under transition-metal free conditions in N,N′-dimethyl propylene urea and 130 °C to afford high yields and excellent selectivities. This method provides a new strategy to fabricate a wide variety of important substituted molecular skeletons and an alternative to conventionally used metal salts, additives, and ligands. 相似文献