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221.
Feasibility of carboxymethylcellulose with phenol moieties as a material for mammalian cell-enclosing subsieve-size capsules 总被引:1,自引:0,他引:1
Shinji Sakai Sho Ito Yuko Ogushi Ichiro Hashimoto Koei Kawakami 《Cellulose (London, England)》2008,15(5):723-729
Mammalian cell-enclosing capsules have been investigated as devices for bioproduction, cell therapy and stem cell research.
In this study, carboxymethylcellulose (CMC) with phenol moieties (CMC-Ph), synthesized through the conjugation reaction of
CMC and tyramine, was investigated as a material for these types of devices. Subsieve-size capsules of less than 100 μm in
diameter were prepared by extruding aqueous CMC-Ph solution into co-flowing liquid paraffin containing H2O2. The capsule diameter was controlled between 60–220 μm by changing the flow rate of liquid paraffin. There was no harmful
effect specific for CMC-Ph on mammalian cells enclosed in capsules. Feline kidney cells enclosed in subsieve-size CMC-Ph capsules
exhibited 87.0 ± 4.5% viability. In addition, the enclosed cells continued to grow over 13 days of study. These results demonstrated
the feasibility of CMC-Ph as a material for subsieve-size cell-enclosing capsules prepared via the droplet breakup technique
in a co-flowing water-immiscible fluid. 相似文献
222.
Yan Yong Sho Han-Ru Li De-Xin Li Guo-Dong Li Dong-Shen Zhen Jin-Shan 《Hyperfine Interactions》1986,28(1-4):635-638
Fe-xCr-8Co (x=24, 25, 27, 29 and 32 wt%) permanent magnetic alloys have been studied bv Mössbauer effect, magnetic balance and vibrating-sample magnetometer. It is indicated that the optimum permanent magnetic properties obtained for the composition of the alloys at about x=27. The value of Cr content in these alloys sigificantly influences the average hyperfine field, the saturation magnetic moment, the proportion of paramagnetic phase and orientation of magnetic moment in these alloys. The intrinsic coercive force is gradually reduced with the temperature decreasing from 290 to 77k. The paramagnetic peak in the spectrum disappars at about 125k. The certain mechanism has been suggested to explain the experimental results. 相似文献
223.
Hiroshi Maruoka Sho Nishida Nobuhiro Kashige Yuki Yoshimura Masahiko Omori Ryoko Tomita Eiichi Masumoto Fumi Okabe Fumio Miake Kenji Yamagata Toshihiro Fujioka 《Journal of heterocyclic chemistry》2012,49(5):1218-1223
As a part of systematic investigation of synthesis and biologically active compounds of pyrazole derivatives containing transition metal, several new pyrazole copper(II) complexes 3a?f were synthesized from pyrazole sodium salts 2a?f , which were produced from spiro‐pyrazoles 1a?f and sodium hydride by a ring‐opening reaction. All the synthesized compounds were characterized by spectroscopic analysis. Pyrazole copper(II) complexes 3a?d and 3f exhibited high DNA cleavage activity in vitro. Furthermore, compounds 3a?f were tested for their growth inhibitory activity in A549 lung cancer, B16F10 murine melanoma, and HeLa human uterine carcinoma cells. Compounds 3c,d displayed moderate B16F10 and HeLa inhibitory activity levels ( 3c : IC50 = 45 μM in B16F10 cells and 34 μM in HeLa cells, 3d : IC50 = 50 μM in B16F10 cells and 32 μM in HeLa cells). 相似文献
224.
La0.61Li0.17TiO3 microstructures have been studied by high resolution electron microscopy. A local lattice distortion occurs in the vicinity of the domain boundary region due to the twin with an angle of 89°. The average domain size of La0.61Li0.17TiO3 is greater than 20 nm. The domain size and structures of La0.61Li0.17TiO3 differ greatly from those of La-poor compounds, such as La0.55Li0.35TiO3. At a nanoscopic level, microdomains of 20–100 nm in size construct a two-dimensional structure in La-rich compounds, while microdomains of 5–10 nm in size construct a three-dimensional structure in La-poor compounds. In addition, the Li-ion conduction mechanisms for La-rich and La-poor compounds are two- and three-dimensional, respectively. 相似文献
225.
We have performed electron spin resonance measurements over a wide frequency and magnetic field range on a single crystal of the S=1 quasi-one-dimensional Heisenberg antiferromagnet Ni(C5H14N2)2N3(PF6). We observed gapped excitation branches above the critical field H(c) where the Haldane gap closes. These branches are analyzed by a phenomenological field theory using the complex-field phi(4) model. A satisfactory agreement between experiment and theory is obtained. 相似文献
226.
Mizuno K Adachi E Imamura Y Katsumata O Hayashi T 《Micron (Oxford, England : 1993)》2001,32(3):317-323
Although the triple-helical structure of fibrillar collagen is regarded in general as being quite similar, each type of collagen molecule has inherent characteristics in the triple-helical domain. Few studies have ever been performed in terms of the aggregate structure of the triple-helical domain of fibrillar collagen. Reconstituted aggregates from the purified triple-helical domain of each type of fibrillar collagen might amplify the subtle differences in the structural characteristics of each type of collagen molecule. In this study, the reconstituted aggregate structure of pepsin-treated type V collagen (type Vp collagen), that is, virtually its triple-helical domain was characterized by transmission electron microscopy. Pepsin-treated type I (type Ip) and type II (type IIp) collagen were compared with type Vp collagen. Unique features of the aggregate structure of the triple-helical domain of the type V collagen can be summarized as follows:These results suggested that the lateral packing of the triple-helical domain of type V collagen is determined by its molecular structure. The characteristics of type Vp collagen fibrils might be explained by their characteristic amino acid composition. A significant feature of the triple-helical domain of type V collagen is the high content of glycosylated hydroxylysine residues. Molecular model building of the collagenous structure suggests that a change in surface roughness is conspicuous by incorporating the glycosylated hydroxylysine residues. More than a ten-fold content of bulky glycosylated hydroxylysine residues in type V collagen compared to that of type I might have a significant influence on both the intermolecular and interfibrillar interactions of the triple-helical domain of type V collagen molecule. 相似文献
227.
Isobe H Sugiyama S Fukui Ki Iwasawa Y Nakamura E 《Angewandte Chemie (International ed. in English)》2001,40(18):3364-3367
228.
229.
Tomoko Yamazaki Shunji Katsumata Katsumi Kimura 《Journal of Electron Spectroscopy and Related Phenomena》1973,2(3):335-340
The He I photoelectron (PE) spectra of C2H5F and n-C3H7F have been obtained. The PE spectra indicate that the first ionization potentials are about 0.4 eV higher than those of the parent alkanes owing to the inductive effect of fluorine. All the PE bands obtained here have been interpreted in terms of appropriate p-type localized MO's using the sum rule described previously by the authors. Orbital energy diagrams involving the inductive effect of fluorine are illustrated. The semi-empirical CNDO/2 and MINDO/2 methods were also employed to help confirm the present orbital assignments. 相似文献
230.
A.?YokoyamaEmail author H.?Ohba M.?Hashimoto K.?Katsumata H.?Akagi T.?Ishii A.?Ohya S.?Arai 《Applied physics. B, Lasers and optics》2004,79(7):883-889
Silicon isotope separation has been performed utilizing the infrared multiphoton dissociation (IRMPD) of Si2F6 irradiated with two-frequency CO2 laser lights. The two-frequency excitation method improved the separation efficiency by keeping the high enrichment factors. For example, Si2F6 with the 28Si fraction of 99.4% was obtained at 40.0% dissociation of Si2F6 after the simultaneous irradiation of 100 pulses with 966.23 cm-1 photons (0.089 J/cm2) and 954.55 cm-1 photons (0.92 J/cm2), while 1000 pulses were needed to obtain 99.0% of 28Si at 27.2% dissociation in the case of single frequency irradiation at 954.55 cm-1 (0.92 J/cm2). The single-step enrichment factors of 29Si and 30Si increased with increasing Si2F6 pressure. The reason for this enhancement has been discussed in terms of the rotational and vibrational relaxations by collisions with ambient gases. PACS 42.62.Cf; 82.30.Lp; 82.50.Bc 相似文献