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991.
Masayuki Yamaguchi Ken‐Ichi Suzuki Hiroshi Miyata 《Journal of Polymer Science.Polymer Physics》1999,37(7):701-713
The structure and mechanical properties of the injection‐molded products for the binary blends composed of an isotactic polypropylene (PP) and a rubbery ethylene‐1‐hexene copolymer (EHR) were studied. The following two types of blends were employed: one is the incompatible blend of PP and ethylene‐rich EHR; the other is the compatible blend of PP and 1‐hexene‐rich EHR. The incompatible blend shows a phase‐separated morphology, in which EHR domains in the skin layer highly orient to the flow direction. On the other hand, the compatible blend shows fairly homogeneous morphology in the skin and core regions, in which EHR molecules are dissolved into the amorphous PP region. The measurements of birefringence and infrared dichroism revealed that the magnitude of molecular orientation along the flow direction for the compatible blend is larger than that for the incompatible blend. Nevertheless, it was also found that anisotropy of the mechanical properties for the compatible blend is less prominent, which is attributed to lack of the mechanical connection between neighbor crystalline fragments aligned perpendicular to the flow direction. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 701–713, 1999 相似文献
992.
993.
994.
Masayuki Yamaguchi Hiroshi Miyata Koh-Hei Nitta 《Journal of Polymer Science.Polymer Physics》1997,35(6):953-961
Morphology and isothermal growth rates of spherulites for the binary blends consisting of an isotactic polypropylene (i-PP) and an ethylene-1-hexene rubber (EHR) were examined as a function of the crystallization temperature ranging from 388 K to 418 K. In this study, two types of EHR's were employed: “ethylene rich” EHR and “1-hexene rich” EHR. The blends of i-PP with the EHR of 51 mol % 1-hexene are miscible in the molten state, whereas the blends with the EHR of 33 mol % 1-hexene are immiscible in the molten state. It is found that the isothermal spherulite growth rate of the miscible i-PP/EHR blends decreases with increasing the EHR fraction, whereas the spherulite growth rate of the immiscible i-PP/EHR blends is independent of the blend composition and is the same as that of the i-PP. Optical microscope observation of the miscible blends crystallized isothermally shows that there are no rubber domains either in the intraspherulitic or in the interspherulitic contact regions. On the other hand, the immiscible i-PP/EHR blends show a phase-separated morphology. Furthermore, the number of tangential lamellae of the miscible i-PP/EHR blends is found to be increased by blending of the EHR, leading to the spherulite with negative birefringence. The sign of birefringence of spherulites is unaffected by the regime transition as well as by the fold surface free energy. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 953–961, 1997 相似文献
995.
Nobuhiro Kanomata Masayuki Suzuki Mamiko Yoshida Tadashi Nakata 《Angewandte Chemie (International ed. in English)》1998,37(10):1410-1412
Just like in biological systems , the GAPDH-catalyzed oxidation of aldehyde to carboxylate proceeds in conjunction with 1,4-selective reduction of NAD+ to NADH model compounds [Eq. (1)]. The combination of GAPDH- and LDH-type transfer reactions is also described here as a system mimic for the NAD+/NADH redox cycle in anaerobic glycolysis. GAPDH=D -glyceraldehyde-3-phosphate dehydrogenase, LDH=L -lactate dehydrogenase. 相似文献
996.
Masayuki Inoue Makoto Sasaki Kazuo Tachibana 《Angewandte Chemie (International ed. in English)》1998,37(7):965-969
Exceptional neurotoxicity is associated with ciguatoxin. The ciguatoxin mimic 1 , which contains the F–M framework of the natural product, has been prepared through a convergent synthesis. The two key steps were a Lewis acid mediated intramolecular reaction of a γ-alkoxyallylsilane with an acetal group and an SmI2-mediated intramolecular Reformatsky reaction that permitted construction of the annelated hexahydrooxonin ring system. 相似文献
997.
Takaomi Suzuki Naoki Sugihara Eiichi Iguchi Katsuya Teshima Shuji Oishi Masayuki Kawasaki 《Crystal Research and Technology》2007,42(12):1217-1221
The specific surface free energy of ruby and quartz single crystal was experimentally obtained using contact angle of water and formamide droplets on the crystal surfaces, and compared with the morphology of each crystal. The ruby crystals satisfied Wulff's relationship even though their shape were not equilibrium form. The specific surface free energies of the growing faces of synthetic quartz crystal, ‐X, +X, Z, and S faces were obtained as 51.9, 55.6, 57.4, and 58.9 mN/m, respectively. The growth rates of these faces were 0.09, 0.23, 0.28, and 0.33 mm/day, respectively. The growth rate of each face of the quartz crystal can be regarded as a function of the experimentally obtained specific surface free energy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
998.
Chikashi Nakamura Miki Hasegawa Masayuki Hara Jun Miyake 《Applied biochemistry and biotechnology》1999,77(1-3):169-179
A tetraheme cytochrome (BCytc) was isolated from the photosynthetic reaction centers (RC) of Rhodopseudomonas viridis while maintaining the redox activity. BCytc was removed from the H-subunit-detached RC by polyacrylamide electrophoresis using an alkyl ether sulfate mixed with sodium
dodecyl sulfate. Redox titration of BCytc showed a simple one-step redox titration curve and a lowered midpoint potential than that of one in RC. Direct electron transfer
between BCytc and electrode surfaces, such as indium tin oxide, was successfully performed, indicating a potential for molecular electronic
material. 相似文献
999.
Kenzo Hiraoka Akitaka Shimizu Akihito Minamitsu Masayuki Nasu Susumu Fujimaki Shinichi Yamabe 《Journal of the American Society for Mass Spectrometry》1995,6(12):1137-1142
The gas-phase stabilities of cluster ions SF+m (SF6)n with m = 0−5 were determined by using a high pressure mass spectrometer. The bond energies of SF+m (SF6)1 were found to be less than 10 kcal/mol and to decrease with m = 0 → 5. There appear to be rather large gaps in the bond energies between n = 1 and 2 for the clusters SF+m (SF6)n with m = 0−4. The structures of SF+5, SF+ (SF6)1, SF+3 (SF6)1, and SF+5 (SF6)1 were investigated by ab initio molecular orbital calculations. For SF+5, the D3h geometry is found to be most stable andC4v is a transition state of the Berry pseudorotation. For the ion-molecule complexes, the “on-top hat” models were found to be the most stable structures. 相似文献
1000.
Kenichi Kato Shunsuke Ohtani Masayuki Gon Kazuo Tanaka Tomoki Ogoshi 《Chemical science》2022,13(44):13147
Spatial arrangement of multiple planar chromophores is an emerging strategy for molecule-based chiroptical materials via easy and systematic synthesis. We attached five pyrene planes to a chiral macrocycle, pillar[5]arene, producing a set of chiroptical molecules in which pyrene-derived absorption and emission were endowed with dissymmetry by effective transfer of chiral information. The chiroptical response was dependent on linker structures and substituted patterns because of variable interactions between pyrene units. One of these hybrids showed larger dissymmetry factor and response wavelength (glum = 7.0 × 10−3 at ca. 547 nm) than reported pillar[5]arene-based molecules using the pillar[5]arene cores as parts of photo-responsive π-conjugated units.Chirality of a C5-symmetric pillar[5]arene was effectively transmitted to pyrene arrays in hybrid molecules. The pyrenes showed achiral monomer fluorescence and circularly polarized excimer emission. 相似文献