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991.
992.
993.
Takeru Iwamura Ikuyoshi Tomita Masato Suzuki Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2000,38(18):3440-3449
The chemical modification of polymers having amide moieties was carried out with p‐toluenesulfonyl isocyanate. The resulting polymers revealed high hydrolytic character. For example, poly(acrylamide) was refluxed with an excess amount of p‐toluenesulfonyl isocyanate in THF for 50 h to obtain a structurally modified polymer in 76% yield, whose sulfonylurea functionality was 100%. The resulting polymer was subjected to hydrolysis in a 1 M NaOH solution at 50 °C to convert 90% of the sulfonylurea in the side chain to the carboxylic acid moieties. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3440–3449, 2000 相似文献
994.
Takahito Itoh Masato Miyachi Masataka Kubo 《Journal of polymer science. Part A, Polymer chemistry》1999,37(9):1285-1292
2,5‐Bis(dicyanomethylene)‐2,5‐dihydrofuran (TCNF) is not homopolymerizable with any initiators, but copolymerizable with styrene (St) in an alternating fashion. Reactivity of TCNF was compared with that of 2,5‐bis(dicyanomethylene)‐2,5‐dihydrothiophene (TCNT) on the basis of the terpolymerization of the TCNT‐TCNF‐St system and the rates of addition reactions of AIBN with TCNT and with TCNF. TCNF was found to be lower in reactivity than TCNT. The relative reactivity was explained with the energy difference between quinonoid structure and benzenoid one. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1285–1292, 1999 相似文献
995.
Shigeo Nakamura Masato Amano 《Journal of polymer science. Part A, Polymer chemistry》1997,35(16):3359-3363
Nitrogen-containing cellulose derivatives hydrazinodeoxycellulose (HDC) and carboxyalkyl hydrazinodeoxycelluloses (α- and β-CAHDCs) were prepared from 6-chlorodeoxycellulose (CDC). Their adsorption of divalent transition metal ions was determined from dilute aqueous solutions and compared with that of aminoalkyl celluloses (AmACs) reported previously. HDC scarcely adsorbs metal ions in the pH range of 1–2, whereas α- and β-CAHDCs adsorb metal ions in this pH range. However, the adsorption of metal ions on HDC increases rapidly with increasing pH and HDC more effectively adsorbs metal ions than α- and β-CAHDCs in weakly acidic conditions. The ability to adsorb Cu2+ ions was in the order of AmAC (carbon number in the diamine moiety m = 2) > HDC > α-CAHDC > β-CAHDC in the weakly acidic region. These adsorbents selectively adsorb Cu2+ ions from the solutions containing other metal ions such as Mn2+, Co2+, and Ni2+, and the Irving–Williams series is obeyed in these adsorbent/metal ion systems. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3359–3363, 1997 相似文献
996.
Masaaki Sakai Masato Ueda Norio Miyaura 《Angewandte Chemie (International ed. in English)》1998,37(23):3279-3281
Highly inert to ionic additions to aldehydes , aryl- and 1-alkenylboronic acids succumb to a catalytic variant mediated by a [Rh(acac)(CO)2]–diphosphane complex in aqueous phase at 80–95°C to yield secondary alcohols [Eq. (a)]. A key step in the catalytic cycle is the transmetalation between the boron reagent and the rhodium complex. Ln=diphosphane (e.g. 1,1′-bis(diphenylphosphanyl)ferrocene); R=aryl, 1-alkenyl; R′=alkyl, aryl; acac=acetylacetonate. 相似文献
997.
998.
Dr. Steffen Greßies Masato Ito Mika Sakai Dr. Hiroshi Osaki Dr. Ju Hyun Kim Dr. Tobias Gensch Dr. Constantin Daniliuc Dr. Naoki Ando Prof. Dr. Shigehiro Yamaguchi Prof. Dr. Frank Glorius 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(8):2753-2759
The synthesis and photophysical properties of a soluble amide-embedded coronene is reported. The key step in this synthesis is the twofold C−H activation of diazaperylene by a rhodium(III)Cp* catalyst. This unprecedented structural motif shows intense fluorescence in the near infrared region with a small Stokes shift and a distinct vibronic structure, which exhibits a slight extent of negative solvatochromism. Comparison of this compound with some relevant compounds revealed the importance of the amide incorporation in the peripheral concave region including an angular position to retain high aromaticity reflecting that of parent coronene. Treatment of this compound with Lewis acid B(C6F5)3 formed a bis-adduct, which exhibited enhanced aromaticity as a consequence of the increased double bond character of the amide C−N bonds. 相似文献
999.
Masato Sakabe Prof. Dr. Soichi Sato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(18):5658-5665
The hexacoordinated antimony(V) dication [(ppy)3Sb]2+ ([ 1 ]2+; ppy=2-(2-pyridyl)phenyl), stabilized by three intramolecular donor–acceptor interactions, has been isolated as its hexachloroantimonate salt [ 1 ][SbCl6]2, prepared by the oxidative addition of chlorine to the neutral stibine [(ppy)3Sb] ( 1 ), followed by the abstraction of chloride. Air-stable [ 1 ][SbCl6]2 exhibits remarkable thermal stability and the three ppy ligands on the antimony atom are shown to be magnetically inequivalent in the 1H and 13C NMR spectra. A hexacoordinated, meridional octahedral bonding geometry has been determined for [ 1 ][SbCl6]2 by X-ray crystallographic analysis. Theoretical calculations were performed to investigate why the meridional form was generated preferentially over the facial form. In addition, the dynamics of the ppy ligands were investigated by variable-temperature 1H NMR spectroscopy. The potential to generate dications by using a single-electron-transfer reagent has also been investigated. The dication [ 1 ]2+ is the first [12–Sb–6]2+ chemical species to have been structurally determined. 相似文献
1000.
Dr. Naoto Yamasaki Ikumi Iwasaki Kazu Sakumi Dr. Rei Hokari Dr. Aki Ishiyama Dr. Masato Iwatsuki Masataka Nakahara Prof. Dr. Shuhei Higashibayashi Prof. Dr. Takeshi Sugai Prof. Dr. Hiroshi Imagawa Prof. Dr. Miwa Kubo Prof. Dr. Yoshiyasu Fukuyama Prof. Dr. Satoshi Ōmura Prof. Dr. Hirofumi Yamamoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(17):5555-5563
The total synthesis of dehydroantofine was achieved by employing a novel, regioselective, azahetero Diels–Alder reaction of easily accessible 3,5-dichloro-2H-1,4-oxazin-2-one with 14 a as a key step. Furthermore, it is demonstrated that dehydroantofine is a promising candidate as a new antimalarial agent in a biological assay with chloroquine-resistant Plasmodium falciparum. 相似文献