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111.
Photodynamic therapy using 5-aminolevulinic acid-induced protoporphyrin IX has been developed as a very useful therapeutic modality. Recently, several authors have reported on the efficacy of this procedure for acne. This approach is based on the fact that 5-aminolevulinic acid-induced protoporphyrin IX has strong selectivity for sebaceous glands. We used the immortalized human sebaceous gland cell line SZ95 to investigate cellular mechanisms of photodynamic therapy using 5-aminolevulinic acid-induced protoporphyrin IX. Quantification of induced protoporphyrin IX production showed dependence on the applied 5-aminolevulinic acid dose. When SZ95 sebocytes were differentiated by arachidonic acid treatment, there was no difference between them and the control cells with respect to both the amount of 5-aminolevulinic acid-induced protoporphyrin IX and the phototoxic effects. We altered protoporphyrin IX formation rates by growing cells scattered as single cells in the culture dishes. Single cells produced significantly lower protoporphyrin IX levels than those grown with intercellular contacts. Intracellular localization of protoporphyrin IX was imaged using confocal laser scanning microscopy. The differentiation-specific lipid droplets were virtually excluded from protoporphyrin IX fluorescence. In addition to weak mitochondrial and strong membrane fluorescence, distinctive spots with strong fluorescence were observed. These did not colocalize with fluorescent probes for mitochondria, lysosomes or the Golgi apparati. 相似文献
112.
Samori S Tojo S Fujitsuka M Liang HJ Ho TI Yang JS Majima T 《The Journal of organic chemistry》2006,71(23):8732-8739
Emission from 9-cyano-10-phenylanthracene and 9-cyano-10-phenylethynylanthracenes having donor and acceptor substituents (RA = PA, PEA, OEA, NEA, and DEA) was studied with the time-resolved fluorescence measurement during the pulse radiolysis of RAs in benzene (Bz). PA and DEA showed only monomer emission, while other RAs (PEA, OEA, and NEA) showed both monomer and excimer emissions with much lower intensities. On the basis of the steady-state and transient absorption and emission measurements, the formation of RA in the singlet excited state ((1)RA*) can be attributed to the charge recombination between RA radical cation and anion (RA*+ and RA*-, respectively) which are initially generated from the radiolytic reaction in Bz. It is expected that for PA with a twisted geometry, the charge recombination between PA*+ and PA*- occurs to give (1)PA* during the pulse radiolysis in Bz. For PEA and OEA, pi-stacking interaction is possible for the formation of an encounter complex during the charge recombination between RA*+ and RA*-. For NEA, it is expected that NEA*+ and NEA*- collide neck-to-neck to generate the excimer due to the twisted geometry. For DEA, a considerably twisted structure is assumed to give (1)DEA* with strong ICT character but not (1)(DEA)2* because of the bulky donor substituent. 相似文献
113.
Tsukamoto I Constantinoiu E Furuta M Nishimura R Maeda Y 《Ultrasonics sonochemistry》2004,11(3-4):167-172
The inactivation effects of ultrasonic irradiation at 27.5 kHz and chlorination using sodium hypochlorite solution (NaOCl) on the growth of Saccharomyces cerevisiae (yeast cells) were investigated. In order to evaluate the effect of ultrasound on the growth of the yeast cells, calorimetric analysis was carried out in addition to colony counting. The heat evolution produced by the growth of yeast cells detected by calorimetry showed completely different patterns between sonication and chlorination. In case of sonication, the yeast cells were inactivated almost like a bactericidal effect, i.e. a quantitative change in cell number, at the beginning of sonication. It was similar to patterns obtained on simple dilution of yeast cells. In contrast, longer sonication increased the bacteriostatic effect, i.e. qualitative damage of the cell growth activity, together with the bactericidal effect. These results suggest that the cavitation caused by ultrasonic irradiation initially disrupted the cells located near the cavitation bubble which caused immediate cell death and the growth activity of the surviving cells was gradually damaged by further sonication. On the other hand, only a bacteriostatic effect was observed when the yeast cells were inactivated by chlorination. 相似文献
114.
J Choi M Fujitsuka S Tojo T Majima 《Journal of the American Chemical Society》2012,134(32):13430-13435
Pulse radiolysis is a powerful method to realize real-time observation of various redox processes, which induces various structural and functional changes occurring in biological systems. However, its application has been mainly limited to studies of the redox reactions of rather smaller biological systems such as DNA because of an undesired reaction due to various free radicals generated by pulse radiolysis. For application of pulse radiolysis to generate plenty of redox reactions of biological systems, selective redox reactions induced by electron pulses have to be developed. In this study, we report that in the presence of the high concentration of the denaturant, guanidine HCl (GdHCl), the selective reduction of the oxidized cytochrome c (Cyt c) takes place in time scales of a few microseconds by the electron transfer from the guanidine radical that is formed by the fast reaction of e(aq)(-) with GdHCl, consequently leading to folding kinetics of Cyt c. By providing insight into the folding dynamics of Cyt c, we show that the pulse radiolysis technique can be used to track the folding dynamics of various biomolecules in the presence of a denaturant including GdHCl. 相似文献
115.
S Monari G Battistuzzi CA Bortolotti S Yanagisawa K Sato C Li I Salard D Kostrz M Borsari A Ranieri C Dennison M Sola 《Journal of the American Chemical Society》2012,134(29):11848-11851
The hydrophobic patch of azurin (AZ) from Pseudomonas aeruginosa is an important recognition surface for electron transfer (ET) reactions. The influence of changing the size of this region, by mutating the C-terminal copper-binding loop, on the ET reactivity of AZ adsorbed on gold electrodes modified with alkanethiol self-assembled monolayers (SAMs) has been studied. The distance-dependence of ET kinetics measured by cyclic voltammetry using SAMs of variable chain length, demonstrates that the activation barrier for short-range ET is dominated by the dynamics of molecular rearrangements accompanying ET at the AZ-SAM interface. These include internal electric field-dependent low-amplitude protein motions and the reorganization of interfacial water molecules, but not protein reorientation. Interfacial molecular dynamics also control the kinetics of short-range ET for electrostatically and covalently immobilized cytochrome c. This mechanism therefore may be utilized for short-distance ET irrespective of the type of metal center, the surface electrostatic potential, and the nature of the protein-SAM interaction. 相似文献
116.
Sumiko Tsukamoto Mayank Jain Andrew Murray Christine Thiel Esther Schmidt Lara Wacha Reiner Dohrmann Manfred Frechen 《Radiation measurements》2012,47(9):903-908
The IRSL and post-IR IRSL (pIRIR) signal characteristics of polymineral fine grains are investigated and compared with those of K- and Na-rich feldspar extracts. TL signal loss after IR and pIRIR stimulations occurs mainly at around 320 °C for polymineral and Na-feldspar samples and around 410 °C for K-feldspar samples, when a preheat temperature of 250 °C for 60 s is used. After preheating to a higher temperature (320 °C for 60 s) all samples show a TL reduction around 410 °C in the blue detection window. Pulse annealing experiments for IRSL and pIRIR signals for preheats between 320 °C and 500 °C indicate that the signal stabilities are similar among the different feldspar types, when a higher preheat temperature (>320 °C) is used. Thermal activation energies for IRSL and pIRIR signals are largest in K-feldspar and smallest in polymineral fine grains, in both blue and UV detection windows for both fast time-resolved (TR) and continuous wave (CW) signals. These results suggest that IRSL and pIRIR signals in polymineral fine grains originate mainly from Na-feldspar grains; these signals are less thermally stable than those from K-feldspar, but a more stable signal (presumably from K-feldspar grains) can be obtained using a higher preheat temperature. 相似文献
117.
Tsutomu Furuta Toshihiro IsobeMunetoshi Sakai Sachiko MatsushitaAkira Nakajima 《Applied Surface Science》2012,258(7):2378-2383
During evaporation, shape changes of nanoliter-scale (80-100 nL) water droplets were evaluated on two superhydrophobic surfaces with different random roughness (nm-coating, μm-coating). The square of the contact radius and the square of the droplet height decreased linearly with evaporation time. However, trend changes were observed at around 170 s (nm-coating) and around 150 s (μm-coating) suggesting a wetting mode transition. The calculated droplet radii for the wetting mode transition from the average roughness distance and the average roughness height of these surface structures were approximately equal to the experimental values at these trend changes. A certain level of correlation between the roughness size and droplet radius at the wetting mode transition was confirmed on surfaces with random roughness. 相似文献
118.
Macahig RA Harinantenaina L Sugimoto S Matsunami K Otsuka H Takeda Y Shinzato T 《Natural product communications》2012,7(4):467-470
Phytochemical investigation of the leaves of Fraxinus griffithii has led to the isolation of two new glucosylated acyclic sesquiterpene alcohols, griffithosides D (1) and E (2), along with iridoid and secoiridoid glycosides. The molecular structures of these compounds were elucidated using NMR, MS and other spectroscopic techniques, as well as comparison with literature data. The isolated compounds were tested for radical-scavenging activity and cytotoxicity against A549 human lung adenocarcinoma cells and Leishmania major parasites. 相似文献
119.
The metabolism of anti-breast cancer drug, tamoxifen, in a single human hepatocellular carcinoma cell, HepG2, was directly monitored by a video-mass spectroscope. The cytoplasm, a vacuole or nucleus of the cell was directly sucked by a nano-spray tip under a video-microscope, and then was introduced into a mass spectrometer. Unchanged drug molecules were found in cytoplasm and a vacuole, but the metabolites were only found in the cytoplasm. This direct detection of drug metabolites in a live single cell is useful for speedy drug metabolism monitoring. 相似文献
120.
Masashi?BanEmail author Sachiko?Kitajima Fumiaki?Shibata 《International Journal of Theoretical Physics》2012,51(8):2419-2426
The time-evolution of the trace distance between two qubit states in the presence of an initial correlation with an environment is investigated by means of the exactly solvable model of qubit and environmental system, where there is at most one excitation in the whole system, It is found that the trace distance can exceed its initial value during the time-evolution under certain conditions if the qubit is initially entangled with the environment. Furthermore the Bures distance between two qubit states is investigated. It is seen that the time-evolution of the Bures distance is quite different from that of the trace distance. 相似文献