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981.
Manda S Nakanishi I Ohkubo K Yakumaru H Matsumoto K Ozawa T Ikota N Fukuzumi S Anzai K 《Organic & biomolecular chemistry》2007,5(24):3951-3955
Comparative study of electrochemical redox behaviour of five different nitroxyl radicals leads to the direct correlation between one-electron redox potentials and group electronegativity of the beta-substituent on the ring. Beta-substituents with an electron-donating effect caused a negative shift in the one-electron oxidation and one-electron reduction potentials of the nitroxyl radicals. In a similar aspect, beta-substituents with an electron-withdrawing effect behaved oppositely. 相似文献
982.
FEM calculation of an acoustic field in a sonochemical reactor 总被引:1,自引:0,他引:1
Yasui K Kozuka T Tuziuti T Towata A Iida Y King J Macey P 《Ultrasonics sonochemistry》2007,14(5):605-614
The spatial distribution of the acoustic amplitude in a sonochemical reactor has been numerically calculated using the finite element method (FEM). In the FEM program, the acoustic field in a sonochemical reactor is coupled with the vibration of the reactor's wall. The present calculations have revealed that the thin (thick) glass or stainless steel wall is nearly a free (rigid) boundary and that the glass wall is freer than the stainless steel wall. The influence of the attenuation coefficient of ultrasound on the acoustic field has also been studied in order to see the effect of bubbles on the acoustic field. As the attenuation coefficient increases, the vibration amplitude of the reactor's wall becomes smaller and the acoustic emission from the vibrating wall becomes weaker. The qualitative feature of the spatial pattern of sonochemiluminescence from an aqueous luminol solution has been reproduced by the calculation when the attenuation coefficient is in the range of 0.5-5m(-1). When the attenuation coefficient is less than about 0.05 m(-1), the standing wave pattern of an acoustic field in the liquid is very complex due to the acoustic emission from the vibrating wall. The present calculations have also revealed that some stripes of pressure antinodes have also been disconnected when the radius of the transducer is much smaller than the side length of the vibrating plate. The dependence of the acoustic field on the liquid height is also discussed. 相似文献
983.
Efficient Total Synthesis of Bongkrekic Acid and Apoptosis Inhibitory Activity of Its Analogues 下载免费PDF全文
Dr. Kenji Matsumoto Masaki Suyama Satoshi Fujita Takuya Moriwaki Yukiko Sato Yoshifumi Aso Satoshi Muroshita Hiroshi Matsuo Keishi Monda Dr. Katsuhiro Okuda Dr. Masato Abe Dr. Hiroyuki Fukunaga Prof. Arihiro Kano Prof. Mitsuru Shindo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11590-11602
Bongkrekic acid (BKA), isolated from the bacterium Burkholderia cocovenenans, is an inhibitor of adenine nucleotide translocator, which inhibits apoptosis, and is thus an important tool for the mechanistic investigation of apoptosis. An efficient total synthesis of BKA has been achieved by employing a three‐component convergent strategy based on Kocienski–Julia olefination and Suzuki–Miyaura coupling. It is noteworthy that segment B has been prepared as a new doubly functionalized coupling partner, which contributes to shortening of the number of steps. Torquoselective olefination with an ynolate has also been applied for the efficient construction of an unsaturated ester. Furthermore, it is revealed that 1‐methyl‐2‐azaadamantane N‐oxyl is an excellent reagent for final oxidation to afford BKA in high yield. Based on the total synthesis, several BKA analogues were prepared for structure–activity relationship studies, which indicated that the carboxylic acid moieties were essential for the apoptosis inhibitory activity of BKA. More easily available BKA analogues with potent apoptosis inhibitory activity were also developed. 相似文献
984.
985.
Polymeric Micelle Assembly with Inorganic Nanosheets for Construction of Mesoporous Architectures with Crystallized Walls 下载免费PDF全文
Dr. Bishnu Prasad Bastakoti Yunqi Li Dr. Masataka Imura Prof. Nobuyoshi Miyamoto Prof. Teruyuki Nakato Prof. Takayoshi Sasaki Prof. Yusuke Yamauchi 《Angewandte Chemie (International ed. in English)》2015,54(14):4222-4225
Here we propose a novel way to construct mesoporous architectures through evaporation‐induced assembly of polymeric micelles with crystalline nanosheets. As a model study, we used niobate nanosheets exfoliated by the direct reaction of K4Nb6O17?3 H2O crystals with an aqueous solution of propylamine. The electrostatic interaction between negatively charged nanosheets and positively charged polymeric micelles enable us to form composite micelles with the nanosheets. Removal of the micelles by calcination results in robust mesoporous oxides with the original crystalline structure. 相似文献
986.
Dr. Kazuhiko Matsumoto M. Sc. Jamie Haner Dr. Hélène P. A. Mercier Prof. Gary J. Schrobilgen 《Angewandte Chemie (International ed. in English)》2015,54(47):14169-14173
Acetonitrile and the potent oxidative fluorinating agent XeF6 react at ?40 °C in Freon‐114 to form the highly energetic, shock‐sensitive compounds F6XeNCCH3 ( 1 ) and F6Xe(NCCH3)2?CH3CN ( 2 ?CH3CN). Their low‐temperature single‐crystal X‐ray structures show that the adducted XeF6 molecules of these compounds are the most isolated XeF6 moieties thus far encountered in the solid state and also provide the first examples of XeVI? N bonds. The geometry of the XeF6 moiety in 1 is nearly identical to the calculated distorted octahedral (C3v) geometry of gas‐phase XeF6. The C2v geometry of the XeF6 moiety in 2 resembles the transition state proposed to account for the fluxionality of gas‐phase XeF6. The energy‐minimized gas‐phase geometries and vibrational frequencies were calculated for 1 and 2 , and their respective binding energies with CH3CN were determined. The Raman spectra of 1 and 2 ?CH3CN were assigned by comparison with their calculated vibrational frequencies and intensities. 相似文献
987.
Dr. Jun Matsumoto Prof. Dr. Masayuki Nakamori Tatsumasa Okamoto Prof. Dr. Asako Murata Prof. Dr. Chikara Dohno Prof. Dr. Kazuhiko Nakatani 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(63):14305-14309
Expanded CUG repeat RNA in the dystrophia myotonia protein kinase (DMPK) gene causes myotonic dystrophy type 1 (DM1) and sequesters RNA processing proteins, such as the splicing factor muscleblind-like 1 protein (MBNL1). Sequestration of splicing factors results in the mis-splicing of some pre-mRNAs. Small molecules that rescue the mis-splicing in the DM1 cells have drawn attention as potential drugs to treat DM1. Herein we report a new molecule JM642 consisted of two 1,3-diaminoisoquinoline chromophores having an auxiliary aromatic unit at the C5 position. JM642 alternates the splicing pattern of the pre-mRNA of the Ldb3 gene in the DM1 cell model and Clcn1 and Atp2a1 genes in the DM1 mouse model. In vitro binding analysis by surface plasmon resonance (SPR) assay to the r(CUG) repeat and disruption of ribonuclear foci in the DM1 cell model suggested the binding of JM642 to the expanded r(CUG) repeat in vivo, eventually rescue the mis-splicing. 相似文献
988.
Kazuyuki Matsumoto 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(2):1-4
This paper investigates an anisotropy of the adiabatic relaxation time T 2′ for single crystalline bcc 3He. No difference in the calculation of T 1(0) was revealed between the nearest-neighbor anti-ferromagnetic Heisenberg model and the multiple exchange model. However, we may distinguish these two models by the anisotropy of the adiabatic relaxation time T 2′. The results presented in this paper are compared with experimental observations. 相似文献
989.
Nishi K Matsumoto N Iijima S Halcrow MA Sunatsuki Y Kojima M 《Inorganic chemistry》2011,50(22):11303-11305
A series of spin-crossover (SCO) iron(II) compounds, fac-[Fe(II)(HL(R))(3)]Cl·PF(6) [R = methyl (Me, 1), ethyl (Et, 2), n-propyl (n-Pr, 3), n-butyl (n-Bu, 4), and n-pentyl (n-Pen, 5)], were synthesized, where HL(R) denotes a series of [(2-methylimidazol-4-yl)methylidene]monoalkylamines. The cations fac-[Fe(II)(HL(R))(3)](2+) and chloride anions associate through 3:3 imidazole···chloride hydrogen bonding. This hydrogen-bonding motif gives rise to a variety of assembly structures consisting of a one-dimensional ladder for 3 and 4, two kinds of two-dimensional networks for 1 and 2, and a cubane-like structure for 5. The compounds exhibit various types of SCO transitions between high-spin (S = 2) and low-spin (S = 0) states as a result of their intermolecular interactions. 相似文献
990.
A novel amphiphilic branched peptide (1), in which three β-sheet formable peptides (L(4)K(8)L(4)) were connected by Lys residue, was newly prepared as a building block for self-assembly. A detailed analysis of the conformation and self-assembling property of 1 in water at various pH conditions was performed by using circular dichroism, FTIR, atomic force and transmission electron microscopies. The experimental results revealed that the branched peptide showed a pH-dependent conformation forming a shape-specific β-sheet-based nanofiber with morphologically kinked structures under specific pH conditions. Exploring a novel peptide building unit that has the ability to self-assemble into designed and complicated nano-objects is valuable to facilitate a bottom-up nanotechnology. 相似文献