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21.
Oguro S Tanimoto A Jinzaki M Akita H Yashiro H Okuda S Kuribayashi S Kameyama K Mukai M 《Magnetic resonance imaging》2006,24(5):673-675
The imaging findings of a solitary fibrous tumor of the prostate are presented. A 35-year-old male presented with urinary retention and was found on transrectal ultrasonography to have a hypoechoic tumor of the prostate, measuring 5.5 cm in size. Magnetic resonance imaging on, the tumor showed low signal intensity on T1-weighted images and heterogeneous mixed signal intensity on T2-weighted images. Gadolinium-enhanced dynamic study showed gradual enhancement from the periphery to the center, and the enhancement is sustained. On immunohistochemistry, the spindle cells of the tumor showed positive staining for CD34 and bcl-2. Although the tumor was labeled as a low-grade malignancy on account of a low mitotic index (MIB-1 index) of about 5%, the patient developed local recurrence of the tumor with bladder wall invasion 12 months later. 相似文献
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Pressure effects on the Curie temperature and the crystallographic phase transition temperature of CeAg were determined from an electrical resistivity measurement from 4.2 to 300 K at hydrostatic pressures up to 5 kb. Results correspond to the alloying effect in Ce(Ag,In). 相似文献
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25.
Makio Ishiguro 《Annals of the Institute of Statistical Mathematics》1978,30(1):479-498
A new scheme of adaptive control is proposed. This scheme does not require a priori knowledge of the structure of the plant
to be controlled. The principal part of the scheme is a procedure which decides the order of the model of the plant. A criterion
for the order determination is developed. Using this criterion, we can decide whether to keep the current controller or to
adopt a new controller based on the information gathered during the operation of the system. The effectiveness of the scheme
is illustrated by a numerical example.
The Institute of Statistical Mathematics 相似文献
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Toshiharu Irisawa Kiiko Matsumoto Koichi Sudoh Hiroshi Iwasaki Makio Uwaha 《Surface science》2008,602(17):2880-2885
Smoothing of an atomically rough vicinal surface of SrTiO3 is studied by scanning tunneling microscope (STM) observation and by Monte Carlo (MC) simulation. A complex step pattern that resembles a two-dimensional phase separation pattern is observed on the surface. Analysis of the step pattern during annealing obtained by the STM in comparison with the MC simulation reveals an asymmetry of the relaxation pattern between islands and holes. The asymmetry is attributed to the difference of the mobility of an adatom and an atomic hole, and the asymmetry is enhanced by the step edge diffusion barrier. Values of an effective bond energy and an effective diffusion barrier as well as the surface diffusion coefficient are deduced from the relaxation pattern. 相似文献
28.
FI catalysts: new olefin polymerization catalysts for the creation of value-added polymers 总被引:4,自引:0,他引:4
Mitani M Saito J Ishii S Nakayama Y Makio H Matsukawa N Matsui S Mohri J Furuyama R Terao H Bando H Tanaka H Fujita T 《Chemical record (New York, N.Y.)》2004,4(3):137-158
This contribution reports the discovery and application of phenoxy-imine-based catalysts for olefin polymerization. Ligand-oriented catalyst design research has led to the discovery of remarkably active ethylene polymerization catalysts (FI Catalysts), which are based on electronically flexible phenoxy-imine chelate ligands combined with early transition metals. Upon activation with appropriate cocatalysts, FI Catalysts can exhibit unique polymerization catalysis (e.g., precise control of product molecular weights, highly isospecific and syndiospecific propylene polymerization, regio-irregular polymerization of higher alpha-olefins, highly controlled living polymerization of both ethylene and propylene at elevated temperatures, and precise control over polymer morphology) and thus provide extraordinary opportunities for the syntheses of value-added polymers with distinctive architectural characteristics. Many of the polymers that are available via the use of FI Catalysts were previously inaccessible through other means of polymerization. For example, FI Catalysts can form vinyl-terminated low molecular weight polyethylenes, ultra-high molecular weight amorphous ethylene-propylene copolymers and atactic polypropylenes, highly isotactic and syndiotactic polypropylenes with exceptionally high peak melting temperatures, well-defined and controlled multimodal polyethylenes, and high molecular weight regio-irregular poly(higher alpha-olefin)s. In addition, FI Catalysts combined with MgCl(2)-based compounds can produce polymers that exhibit desirable morphological features (e.g., very high bulk density polyethylenes and highly controlled particle-size polyethylenes) that are difficult to obtain with conventionally supported catalysts. In addition, FI Catalysts are capable of creating a large variety of living-polymerization-based polymers, including terminally functionalized polymers and block copolymers from ethylene, propylene, and higher alpha-olefins. Furthermore, some of the FI Catalysts can furnish living-polymerization-based polymers catalytically by combination with appropriate chain transfer agents. Therefore, the development of FI Catalysts has enabled some crucial advances in the fields of polymerization catalysis and polymer syntheses. 相似文献
29.
Akimoto S Yokono M Ohmae M Yamazaki I Tanaka A Higuchi M Tsuchiya T Miyashita H Mimuro M 《The journal of physical chemistry. B》2005,109(25):12612-12619
Ultrafast excitation relaxation dynamics and energy-transfer processes in the light-harvesting complex II (LHC II) of Arabidopsis thaliana were examined at physiological temperature using femtosecond time-resolved fluorescence spectroscopy. Energy transfer from lutein to Chl a proceeded with a rate constant of k(ET) = 1.8-1.9 x 10(13) s(-1) and a yield of approximately Phi(ET) = 0.70, whereas that from neoxanthin to Chl a had a rate constant of k(ET) = 6.5 x 10(11) s(-1) and a yield at the most of Phi(ET) = 0.09. Fluorescence anisotropic decay of lutein in LHC II showed a value larger than 0.4 at the initial state and decayed to approximately 0.1 in 0.3 ps, indicating that two lutein molecules interact with each other in LHC II. In solution, anisotropy of lutein remained constant (0.38) independent of time, and thus a new excited state inferred between the S(2) (1B(u)) state and the S(1) (2A(g)) state was not applicable for lutein in solution. Energy migration processes among Chl a or Chl b molecules were clearly resolved by kinetic analysis. On the basis of these results, relaxation processes and energy-transfer kinetics in LHC II of A. thaliana are discussed. 相似文献
30.
Masao Tomoi Makio Goto Hiroshi Kakiuchi 《Journal of polymer science. Part A, Polymer chemistry》1987,25(1):77-86
The acetylation of linalool with acetic anhydride was carried out in the presence of polystyrene-bound aminopyridines and triethylamine. The catalytic activity of the immobilized aminopyridines increased with decreasing percentage of ring substitution and with increasing spacer-chain length. The increased activity is attributed to an increase in the amount of aminopyridine units complexed with acetic anhydride. The acetylation could be successfully conducted by use of a mixture of the immobilized aminopyridines and polymer-supported benzyldiethylamine, which effectively trapped acetic acid formed in the reaction system. 相似文献