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81.
Hisao Kato 《Transactions of the American Mathematical Society》1997,349(9):3645-3655
A homeomorphism of a compactum with metric is expansive if there is such that if and , then there is an integer such that . It is well-known that -adic solenoids () admit expansive homeomorphisms, each is an indecomposable continuum, and cannot be embedded into the plane. In case of plane continua, the following interesting problem remains open: For each , does there exist a plane continuum so that admits an expansive homeomorphism and separates the plane into components? For the case , the typical plane continua are circle-like continua, and every decomposable circle-like continuum can be embedded into the plane. Naturally, one may ask the following question: Does there exist a decomposable circle-like continuum admitting expansive homeomorphisms? In this paper, we prove that a class of continua, which contains all chainable continua, some continuous curves of pseudo-arcs constructed by W. Lewis and all decomposable circle-like continua, admits no expansive homeomorphisms. In particular, any decomposable circle-like continuum admits no expansive homeomorphism. Also, we show that if is an expansive homeomorphism of a circle-like continuum , then is itself weakly chaotic in the sense of Devaney.
82.
We previously found that a copolymer, poly(NIPAM- co-BP), consisting of N-isopropylacrylamide (NIPAM) and benzophenone (BP) units, behaves as a photosensitizer showing temperature-controlled oxygenation activity by singlet oxygen ( (1)O 2) in water ( J. Am. Chem. Soc. 2006, 128, 8751-8753 ). This polymer shows a heat-induced oxygenation enhancement at <20 degrees C, while showing suppression at >20 degrees C. This is driven by a heat-induced phase transition of the polymer from coil to micelle and then to globule state, controlling the stability and diffusion of (1)O 2 and the location of substrate. In the present work, effects of polymer concentration and BP content of the polymer on the oxygenation activity were studied at 5-35 degrees C. Increase in the polymer concentration leads to activity decrease at >20 degrees C due to strong polymer aggregation, suppressing incident light absorption of the BP units. With a decrease in BP content of the polymer, heat-induced oxygenation enhancement at <20 degrees C is more pronounced because formation of small size micelles accelerates (1)O 2 oxygenation. The obtained findings reveal that the polymer with low BP content, when used at high concentration, shows clear-cut off- on- off activity change against the temperature window: very low activity at <5 degrees C and >25 degrees C, and very high activity at middle temperature range. 相似文献
83.
Process design and energy requirement for a practical plant are investigated for an energy-saving drying (dewatering) process invented by the authors in 2002 for high-moisture porous materials. The basic concept of the process involves the extraction of water from a high-moisture porous material by bringing it in physical contact with liquefied dimethyl ether (DME) at room temperature. Water content of DME asymptotically increases to the saturation value and the high-moisture porous material is dried almost perfectly. DME from the DME-water mixture is vaporized by decompression. DME and water are separated by flash distillation. DME vapor is compressed and cooled in a heat exchanger, and the latent heat of condensation is reused to vaporize the DME in the heat exchanger. Multistage compression and multistage flash distillation are employed. After compression, the temperature of DME is less than 50?°C. Because specific heat ratio of DME is only 1.11, the energy consumption of the compressor is reduced. Considering the adiabatic efficiency of the compressor and the net thermal efficiency, the total energy for dewatering is about 1100 kJ per 1-kg-water-content of the material being dewatered This process has significant potential and is compact than the existing dewatering processes. 相似文献
84.
Medana C Calza P Carbone F Pelizzetti E Hidaka H Baiocchi C 《Rapid communications in mass spectrometry : RCM》2008,22(3):301-313
We have studied the photocatalytic transformation of atenolol, 4-[2-hydroxy-3-[(1-methyl)amino]propoxyl]benzeneacetamide, a cardioselective beta-blocking agent used to treat cardiac arrhythmias and hypertension, under simulated solar irradiation using titanium dioxide as photocatalyst. The investigation involved monitoring drug decomposition, identifying intermediate compounds, assessing mineralization, and evaluating toxicity. High-performance liquid chromatography (HPLC) coupled to high-resolution mass spectrometry (HRMS) via an electrospray ionization (ESI) interface was a powerful tool for the identification and measurement of the degradation products; 23 main species were identified. Intermediates were characterized through their chromatographic behavior and evolution kinetics, coupled with accurate mass information. Through the full analysis of MS and MS(n) spectra and a comparison with parent drug fragmentation pathways, the diverse isomers were characterized. Neither atenolol nor the intermediates formed exhibit acute toxicity. All intermediates are easily degraded and no compound identified could withstand 2 h irradiation. Photomineralization of the substrate in terms of carbon mineralization and nitrogen release was rapid and, within 4 h of irradiation, organic nitrogen and carbon were completely mineralized. 相似文献
85.
Grigoraviciute I Yamauchi H Karppinen M 《Journal of the American Chemical Society》2007,129(9):2593-2596
Among high-Tc superconductive copper oxides, there have been known phases that contain fluorite-structured layers as an additional "blocking block" between adjacent CuO2 planes. Here, we report that even a phase with the CuO2 planes separated by a 12-A thick quadruple-fluorite-layer block can be synthesized in a single phase and strongly oxygenated form to exhibit superconductivity with a Tc value as high as 55 K. The new phase is the fourth member of the (Cu,Mo)Sr2(Ce,Y)sCu2O(5+2s+delta) or (Cu,Mo)-12s2 homologous series. Comparison with the previously known s = 1, 2, and 3 members of the series reveals the amazing conclusion that Tc remains essentially unaffected upon inserting additional fluorite-structured layers between the two CuO2 planes as long as the hole-doping level of the planes is kept constant. 相似文献
86.
Koizumi H Kimata Y Shiraishi Y Hirai T 《Chemical communications (Cambridge, England)》2007,(18):1846-1848
A polymeric photosensitizer, poly(NIPAM-co-RB), consisting of N-isopropylacrylamide and rose bengal units, demonstrates a temperature-controlled changeable oxygenation selectivity by singlet oxygen in water. 相似文献
87.
Serizawa T Sawada T Matsuno H 《Langmuir : the ACS journal of surfaces and colloids》2007,23(22):11127-11133
We investigated polymer-binding 7-mer peptides that recognize differences in the polymer stereoregularity of all-purpose poly(methyl methacrylate)s (PMMAs) with simple chemical structures. Quantitative surface plasmon resonance measurements detected association/dissociation processes of the peptides against PMMA film surfaces, followed by an estimation of kinetic parameters such as association/dissociation rate constants and affinity constants. Greater association and smaller dissociation constants of the peptides were observed against a target isotactic PMMA than the structurally similar reference syndiotactic PMMA, followed by greater affinity constants against the target. A c02 peptide composed of the Glu-Leu-Trp-Arg-Pro-Thr-Arg sequence showed the greatest affinity constant (2.8x10(5) M(-1)) for the target, which was 41-fold greater than that for the reference, thus demonstrating extremely high peptide specificities. The substitution of each amino acid of the c02 peptide to Ala (Ala scanning) clearly revealed the essential amino acids for the affinity constants; the essential order was Pro5>Thr6>Arg7>Glu1>Arg4. In fact, the shorter 4-mer peptide composed of the C-terminal Arg-Pro-Thr-Arg sequence of the c02 peptide still demonstrated strong target specificity, although the N-terminal 4-mer peptide Glu-Leu-Trp-Arg completely lost its specificity. The possible conformations modeled with Molecular Mechanics supported the significance of the Arg-Pro-Thr-Arg sequence. The thermodynamic parameters of the c02 peptide suggested an induced fit mechanism for the specific affinity. The present affinity analyses of polymer-recognizing peptides revealed significant and general information that was essential for potential applications in peptidyl nanomaterials. 相似文献
88.
89.
Ryuta Nishida Katsuyoshi Kakinuma Hanako Nishino Takeo Kamino Hisao Yamashita Masahiro Watanabe Hiroyuki Uchida 《Solid State Ionics》2009,180(14-16):968-972
Aiming at SOFC anode applications, we have synthesized nanometer-sized nickel catalysts supported on hollow spherical particles of samaria-doped ceria (Ni/SDC) by spraying a mixed solution of nickel, samarium, and cerium nitrates into an atmospheric pressure plasma. The as-prepared particles consisted of SDC (average diameter dSDC = ca. 0.8 µm) and uniformly dispersed nanometer-sized NiO particles. When reduced in H2 at 800 °C or 1000 °C, Ni nanoparticles (average diameter dNi = 34 nm) were found to be embedded uniformly into the SDC surface. 相似文献
90.
To model electron transport through a molecular junction, we propose an efficient method using an ab initio self-consistent nonequilibrium Green's function theory combined with density functional theory. We have adopted a model close to the extended molecule approach, due to its flexibility, but have improved on the problems relating to molecule-surface couplings and the long-range potential via a systematic procedure for the same ab initio level as that of Green's function. The resulting algorithm involves three main steps: (i) construction of the embedding potential; (ii) perturbation expansion of Green's function in the molecular orbital basis; and (iii) truncation of the molecular orbital space by separating it into inactive, active, and virtual spaces. The above procedures directly reduce the matrix size of Green's function for the self-consistent calculation step, and thus, the algorithm is suitable for application to large molecular systems. 相似文献