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251.
On-chip fraction collection for multiple selected ssDNA fragments using isolated extraction channels
Li Z Sun K Sunayama M Matsuo Y Mizeikis V Araki R Ueno K Abe M Misawa H 《Journal of chromatography. A》2011,1218(7):997-1003
High efficiency and high-purity fraction collection is highly sought in analysis of fragments-of-interest from selective polymerase chain reaction (PCR) products generated by High Coverage Gene Expression Profiling (HiCEP) methods. Here we demonstrate a new electrophoretic chip device enabling automatic high-efficient fractionation of multiple ssDNA target fragments during a run of separation. We used thoroughly isolated extraction channels for each selected target to reduce the risk of cross-contamination between targets due to cross-talk of extraction channels. Fragments of 35, 108 and 138 b, were successfully isolated, then the recovery was PCR-amplified and assessed by capillary electrophoresis (CE) analysis. Total impurity level of the targets due to unwanted fragments of 0.7%, 2% and 6% respectively, was estimated. Difficulties in collecting multiple target factions are due to band diffusion and DNA adsorption to the walls for the fragments in the separation channel, which is generated by transferring the DNA target fraction from the extraction section to the target reservoir. Therefore, we have carefully measured band broadening and analyzed its influence on the separation resolution due to the delay. 相似文献
252.
253.
Macrocycles consisted of pyridine rings and acetylene bonds were prepared by Eglinton coupling from a tandem precursor bearing two terminal alkynyl groups. The composition of molecular size in the cyclized products changed by the reaction solvent. In pyridine, 9-meric and bigger macrocycles were obtained, while that of 6-mer was not. On the other hand, in pyridine/THF mixed solvent, the 6-mer was obtained as a major product. 相似文献
254.
A macrocyclic host molecule having pyridine-pyridone-pyridine modules for saccharide recognition was prepared by Cu(II)-mediated oxidative homocoupling of a tandem diethynyl precursor. In CH(2)Cl(2), the host molecule associated with dodecyl β-maltoside much more strongly (K(a) = 1.4 × 10(6) M(-1)) than with octyl monohexosides (K(a) = ca. 2 × 10(3) to 1 × 10(4) M(-1)), accompanied with induced CDs. An all-pyridine macrocyclic host was also studied, and its binding strength with saccharides was weaker than that for the pyridine-pyridone-pyridine host. 相似文献
255.
Pawlowska Z Lietard A Aloïse S Sliwa M Idrissi A Poizat O Buntinx G Delbaere S Perrier A Maurel F Jacques P Abe J 《Physical chemistry chemical physics : PCCP》2011,13(29):13185-13195
This work reports on the solvatochromic properties of a simple heterocyclic betaine pyridinium, 2-(1-pyridinio)benzimidazolate (SBPa), having promising potentialities in non-linear optics. From advanced PCM-TDDFT calculations, the solvatochromism of SBPa was found to be unusual, involving two different electronic states for absorption (S(0)→ S(2)) and emission (S(1)→S'(0)). To account for this behavior, we developed an innovative physical treatment which consists in a non-linear fit of the solvatochromic data using the Bilot-Kawski theoretical model and visualizing the least-square coefficient χ(2) on a 2D map as a function of the solute polarizability and gas phase absorption energy. In parallel, Kamlet-Taft correlations were undertaken to select a propitious set of electrostatic solvents usable in this treatment. Protic solvents that lead to specific interactions and nonpolar solvents that favor dimerization processes were excluded. From a choice of aprotic solvents with sufficiently high polarity, 4 dipole moments μ(g)(S(0)) = +9.1 D, μ(e)(S(2)) = -1.5 D, μ(e)(S(1)) = 0 D and μ(g)(S'(0)) = +3.31 D were determined, the 3 former values being in close agreement with TDDFT values, although the solute polarizability values seem underestimated. Anyhow, disregarding this discrepancy, we evaluated the static hyperpolarizability to β(0) = -64 × 10(-30) esu from the solvatochromic data in close agreement with DFT calculations. 相似文献
256.
This paper reports the summary of experiments performed to successive generate small-scale underwater shock waves by means
of shock-induced collapse of microbubbles confined in a narrow gap. The project is motivated to develop a method for efficient
inactivation of marine bacteria contained in ship ballast water by high impulsive pressure loading. The shock wave–air bubbles
interaction was visualized by shadowgraph; the images were recorded by ImaCon200, and simultaneous pressure measurements were
performed by using an optical fiber pressure transducer with higher temporal resolution. Attaching small air bubbles on a
single nylon fiber and placing it in a confined space, we demonstrated sequential generation of impulsive high pressures at
the successive collapses of small bubbles at incident and reflected shock loadings. The values of the very short impulsive
pressures that occurred repeatedly for a relatively long term are found high enough to inactivate marine bacteria. 相似文献
257.
258.
Takuo Okuchi Naotaka Tomioka Narangoo Purevjav Jun Abe Stefanus Harjo Wu Gong 《高压研究》2013,33(2):273-280
Neutron powder diffraction measurements of 0.9 mm3 of mixture of deuterated brucite and pressure medium were conducted at pressures to 2.8 GPa, using an opposed anvil cell and a medium-resolution diffractometer at Japan Proton Accelerator Research Complex pulsed neutron source. Spurious-free diffraction patterns were successfully obtained and refined to provide all structural parameters including Debye–Waller factors. Tilting of hydroxyl dipoles of brucite toward one of the three nearest-neighbor oxygen anions was confirmed to be substantial at pressure as low as 1.5 GPa. By this application, technical feasibility to analyze such a small sample has been newly established, which would be useful to extend the applications of neutron diffraction at high pressures. 相似文献
259.
We have investigated the pressure-induced Raman spectral changes of 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]). We found that [emim][BF4] did not crystallize up to 1.2 GPa. The Raman CH stretching spectra arising from the CH3 groups of the ethyl-chain and the CH3 group adjacent to the imidazolium-ring in [emim]+ cation largely changed against pressure. Moreover, the Raman intensity of the CH2 (N) bending band arising from the alkyl-chain drastically changes with increasing pressure, but that of the imidazolium-ring in-plane bending band arising from the imidazolium-ring is independent of pressure. Our results show that the environment around the alkyl-chain of [emim][BF4] is largely perturbed rather than that around the imidazolium-ring upon compression. 相似文献
260.
1,3-Dimethyl- or 1,3-divinyl-1,3-di-t-butoxydisiloxane-1,3-diol and 1,3-diphenyldisiloxane-1,1,3,3-tetraol were synthesized by hydrolysis of the corresponding diisocyanatodisiloxanes and tetrachlorodisiloxane. The disiloxanediols were soluble in common organic solvents and thermally very stable, therefore, they could be sublimed without decomposition. X-ray crystallography showed that the disiloxane-1,3-diols in the crystal feature a 1.21 nm diameter columnar array with intermolecular hydrogen bonding. The disiloxane-1,1,3,3-tetraol, on the other hand, revealed molecules with a gauche- and anti-conformation depending on crystallization method which formed a columnar array and a sheet-like array, respectively. It was confirmed that these silanols can be potential building blocks for ladder oligosilsesquioxanes. 相似文献