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981.
Yasuhiro Yamada Kenichi Tanabe Naoki Nishida Yoshio Kobayashi 《Hyperfine Interactions》2016,237(1):105
Iron films were deposited on porous alumina substrates using an arc plasma gun. The pore sizes (120 – 250 nm) of the substrates were controlled by changing the temperature during the anodic oxidation of aluminum plates. Iron atoms penetrated into pores with diameters of less than 160 nm, and were stabilized by forming γ-Fe, whereas α-Fe was produced as a flat plane covering the pores. For porous alumina substrates with pore sizes larger than 200 nm, the deposited iron films contained many defects and the resulting α-Fe had smaller hyperfine magnetic fields. In addition, only a very small amount of γ-Fe was obtained. It was demonstrated that the composition and structure of an iron film can be affected by the surface morphology of the porous alumina substrate on which the film is grown. 相似文献
982.
A tunable supramolecular phenylacetylene host system with a chiral channel-like cavity is developed by using (1R,2S)-2-amino-1,2-diphenylethanol. This host system possesses a chiral 21-helical columnar structure; chiral cavities are constructed by the self-assembly of the 21-helical column, and guest molecules are included by varying the packing of this column. 相似文献
983.
Manabu Miyamoto Kaori Nagata Takanori Maruo Norikazu Nishiyama Katsunori Yogo Yasuyuki Egashira Korekazu Ueyama 《Journal of membrane science》2008
Mesoporous silica membranes were prepared on porous alumina substrates by a vapor infiltration of tetraethoxysilane (TEOS) into a non-ionic poly(oxyethylene) (Brij56) surfactant film. Periodic mesostructured silica membranes were formed on both α- and γ-alumina substrates pre-treated with polystyrene. The polystyrene polymer plugged the pores of the alumina substrates and inhibited the deposition of silica in the alumina pores, resulting in the formation of a very thin silica membrane without a silica/alumina composite layer at the interface between mesoporous silica and the alumina substrates. The calcined mesoporous silica membrane showed very high nitrogen permeance (>10−6 mol m−2 s−1 Pa−1). The single gas permeation was governed by the Knudsen diffusion mechanism. The durability of the mesoporous silica membrane against moisture in air was improved by a silylation with trimethylethoxysiliane. 相似文献
984.
Wang W Bando Y Zhi C Fu W Wang E Golberg D 《Journal of the American Chemical Society》2008,130(26):8144-8145
Noncovalent functionalization of boron nitride nanotubes (BNNTs) in aqueous solution was achieved by means of pi-stacking of an anionic perylene derivative, through which carboxylate-functionalized BNNTs were prepared for the first time. Starting from the functionalized nanotubes, an innovative methodology was designed and demonstrated for the controlled near-surface carbon doping of BNNTs. As a result of such delicate doping, novel B-C-N/BN coaxial nanotubes have been fabricated, and their p-type semiconducting behaviors were elucidated through gate-dependent transport measurements. 相似文献
985.
Shintaro Morisada Hiroko Suzuki Saki Emura Yoshitsugu Hirokawa Yoshio Nakano 《Adsorption》2008,14(4-5):621-628
The adsorption property of the polyampholyte gel composed of sodium styrene sulfate (SSS) and vinylbenzyl trimethylammonium chloride (VBTA) has been investigated with several hydrophobic aromatic compounds as adsorbate. Using the N-isopropylacrylamide (NIPA) gel, the corresponding experiments were also performed for comparison. At room temperature, the NIPA gel hardly adsorbed the aromatic compounds, while it adsorbed them at higher temperatures. As for the SSS-VBTA gel, the adsorption amounts of the polyaromatic compounds decreased with increasing temperature, while the adsorption amounts of the monoaromatic compounds were almost independent of temperature and smaller than those of the polyaromatic compounds. These results indicate that the aromatic rings in the SSS-VBTA gel may play an important role in the adsorption of the aromatic compounds. Also, it has been demonstrated that the SSS-VBTA gel can repeatedly adsorb bisphenol-A at room temperature and desorb it at higher temperature by the temperature-swing operation: this behavior is diametrically opposite to that of the NIPA gel. This shows that the SSS-VBTA gel is much more suitable for the adsorption removal of the hydrophobic aromatic compounds from very dilute aqueous solutions, because a vast amount of energy is required for heating a large amount of water when using the NIPA gel. 相似文献
986.
Haisong Qi Jie Cai Lina Zhang Yoshiharu Nishiyama Aurélie Rattaz 《Cellulose (London, England)》2008,15(1):81-89
Cellulose multi-filament fibers have been spun successfully on a pilot plant scale, from a cellulose dope in 7 wt% NaOH/12 wt%
urea aqueous solution pre-cooled to −12 °C. Coagulation was accomplished in a bath with 10 wt% H2SO4/12 wt% Na2SO4 and then 5 wt% H2SO4 aqueous solution. By using different finishing oil, including H2O, 4% glycerol aqueous solution, 2% polyvinyl alcohol (PVA) aqueous solution, 2% polyethylene glycol octyl phenylether (OP)
aqueous solution, mobol and 2%glycerol/1%PVA/1%OP aqueous solution (PGO), we prepared six kinds of the cellulose multi-filaments,
with tensile strength of 1.7–2.1 cN/dtex. Their structure and properties were investigated with scanning electron microscope
(SEM), 13C NMR solid state, wide-angle X-ray diffraction (WAXD) and tensile testing. The cellulose fibers treated with PGO possessed
higher mechanical properties and better surface structure than others. Interestingly, although the orientation of the cellulose
multi-filaments is relatively low, the tensile strength of the single-fiber was similar to that of Lyocell. It was worth noting
that the dyeability of the multi-filament fibers was superior to viscose rayon. 相似文献
987.
We investigated the quantum beats, the oscillation between singlet and triplet states of radical pairs induced by the microwave field resonant to one of the component radicals. They were observed as the alternation of the yields of the component radicals by a nanosecond time-resolved optical absorption with the X-band (9.15 GHz) resonant microwave pulse. This technique was applied to the photochemical reaction of benzophenone, benzophenone-d(10), and benzophenone-carbonyl-(13)C in a sodium dodecylsulfate micellar solution with a step-by-step increase of the resonant microwave pulse width. The yields of the component radicals showed alternation with an increase of the microwave pulse width. This indicates that the radical pair retains spin coherence in the micellar solution. The magnetic isotope effect on the amplitude of the quantum beat was observed. The MW effect on the quantum beat of BP-(13)C decreases from 80% to 60% of that of BP by irradiation of the pi-pulse MW due to spin-locking. The kinetic parameters were also determined using the X- or Ku-band (17.44 GHz) region. They are almost similar to each other except for the intersystem recombination rate in the system of BP-(13)C, which may be slightly higher than those in other systems. 相似文献
988.
Hayashi Y Regnier T Nishiguchi S Sydnes MO Hashimoto D Hasegawa J Katoh T Kajimoto T Shiozuka M Matsuda R Node M Kiso Y 《Chemical communications (Cambridge, England)》2008,(20):2379-2381
Herein, we describe an efficient strategy for the total synthesis of (+)-negamycin using commercially available achiral N-Boc-2-aminoacetaldehyde as starting material with 42% overall yield for a limited number of steps. 相似文献
989.
990.