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861.
Kwon KW Choi JC Suh KY Doh J 《Langmuir : the ACS journal of surfaces and colloids》2011,27(7):3238-3243
We present new methods that enable the fabrication of multiscale, multicomponent protein-patterned surfaces and multiscale topologically structured surfaces by exploiting the merits of two well-established techniques: capillary force lithography (CFL) and microscope projection photolithography (MPP) based on a protein-friendly photoresist. We further demonstrate that, when hierarchically organized micro- and nanostructures were used as a cell culture platform, human colon cancer cells (cell line SW480) preferentially adhere and migrate onto the area with nanoscale topography over the one with microscale topography. These methods will provide many exciting opportunities for the study of cellular responses to multiscale physicochemical cues. 相似文献
862.
We report on a novel method for the quantitation of proteins specifically bound on a ligand-presenting biochip by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The bound protein was digested by trypsin, and the resulting peptide fragments were analyzed by MALDI-TOF MS in the presence of an isotope-labeled internal standard (IS). The IS has the same sequence as a reference peptide (RP) of the target protein digest, but a different molecular weight. The absolute amount of the specifically bound protein on a biochip is then quantitated by comparison of mass intensities between the RP and the IS. Because they have the same molecular milieu, the mass intensities of these two analytes represent the real amounts of analytes on the chip. As a model system, we tested glutathione s-transferase (GST) and a GST-fusion protein, which were captured on glutathione-presenting biochips. We observed that the glutathione densities on biochips showed a good correlation with the absolute quantity of the proteins. We believe that our method will provide an alternative to currently existing tools for the absolute quantitation of surface-bound proteins. 相似文献
863.
Md. Shamsuzzoha Sung Man Seo Young Hun Kim Woo Taik Lim 《Journal of inclusion phenomena and macrocyclic chemistry》2011,70(1-2):59-68
The single-crystal structure of a benzene sorption complex of fully dehydrated fully Mn2+-exchanged zeolite Y, |Mn37.5(C6H6)24|[Si117Al75O384]-FAU, has been determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd $ \overline{3} $ m at 100(1) K. A fully dehydrated and fully Mn2+-exchanged zeolite Y (|Mn37.5|[Si117Al75O384]-FAU, Si/Al = 1.56) was treated with zeolitically dried benzene at 297(1) K for 3 days. The structure was refined using all intensities to the final error indices (using the 544 reflections for which F o > 4??(F o)) R 1 = 0.050 (based on F) and wR 2 = 0.147 (based on F 2). In this structure, Mn2+ ions occupy four crystallographic sites: 13.5 Mn2+ ions are at the centers of the double 6-rings; 4 Mn2+ ions are in the sodalite cavity opposite to the double 6-rings; the remaining 20 Mn2+ ions are found at two non-equivalent threefold axes in the sodalite cavity and supercage with occupancies of 2 and 18, respectively. The 24 benzene molecules are found at two distinct positions within the supercages. Eighteen benzene molecules are found on the threefold axes in the supercages where each interacts facially with one of site-II Mn2+ ions (Mn2+-benzene center = ca. 2.53 Å). The remaining six benzene molecules lie on the planes of the 12-rings where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens. 相似文献
864.
Material segregation has been reported for industrial spray-dried milk powders, which indicates potential material migration during drying process. The relevant colloidal transport phenomenon and the underlying mechanism are still under debate. This study extended the glass-filament single droplet drying technique to observe not only the drying behaviour but also the dissolution behaviour of the correspondingly dried single particle. At progressively longer drying stage, a solvent droplet (water or ethanol) was attached to the semi-dried milk particle and the interaction between the solvent and the particle was video-recorded. Based on the different dissolution and wetting behaviours observed, material migration during milk drying was studied. Fresh skim milk and fresh whole milk were investigated using water and ethanol as solvents. Fat started to accumulate on the surface as soon as drying was started. At the initial stage of drying, the fat layer remained thin and the solubility of the semi-dried milk particle was much affected by lactose and protein present underneath the fat layer. Fat kept accumulating at the surface as drying progressed and the accumulation was completed by the middle stage of drying. The results from drying of model milk materials (pure sodium caseinate solution and lactose/sodium caseinate mixed solution) supported the colloidal transport phenomena observed for the milk drying. When mixed with lactose, sodium caseinate did not form an apparent solvent-resistant protein shell during drying. The extended technique of glass-filament single droplet approach provides a powerful tool in examining the solubility of individual particle after drying. 相似文献
865.
B. Roig I. DelplaE. Baurès A.V. Jung O. Thomas 《Trends in analytical chemistry : TRAC》2011,30(8):1243-1251
Heavy rainfall events, increasing in frequency and intensity with climate change, impact on the quality of the water resource used for drinking-water production. Small-scale water suppliers are particularly sensitive because of their management and the related difficulties of adapting treatment to variations. Decision-support systems, based on monitoring and analytical tools, need to be developed to improve crisis-management procedures related to such events. After presenting the issues related to heavy rainfall events, the article summarizes the tools currently used for quality control of drinking water within this framework, the need for developments and other requirements. 相似文献
866.
Polyol-mediated solvothermal synthesis and luminescence properties of CeF3, and CeF3:Tb nanocrystals
Xuesong Qu Hyun Kyoung Yang Byung Kee Moon Jung Hyun Jeong Kwang Ho Kim 《Journal of solid state chemistry》2011,184(2):246-251
CeF3 and CeF3:Tb3+ nanocrystals were successfully synthesized through a facile and effective polyol-mediated route with ethylene glycol (EG) as solvent. Various experimental techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence (PL) spectra as well as decay dynamics were used to characterize the samples. The results indicated that the content of NH4F and reactant concentrations were key factors in the product shape and size. Excessive NH4F was necessary for the formation of hexagonal nanoplates. The specific morphology of product can be controlled by changing the NH4F content and reactant concentrations. In addition, Tb3+ doped-CeF3 sample shows strong green emission centered at 544 nm corresponding to the 5D4-7F5 transition of Tb3+. Due to the decrease of nonradiative decay rate, the lifetime of 5D4 level of Tb3+ become longer gradually upon increasing the size of product. 相似文献
867.
Blue-emitting Eu2+-doped CaMgSi2O6 phosphors were prepared by the reverse micelle method. The resultant particles were nanocrystalline with a grain size of about <300 nm and exhibited a characteristic blue emission spectrum centered at 445 nm induced by the oxygen coordinated Eu2+ ions. By using the corresponding nanophosphors followed by the formation of a uniform phosphor layer, we have demonstrated the mini-sized transparent plasma-discharge panels and investigated their luminance characteristics. Phosphor coated panel is properly transparent, ≥65%, at the visible wavelength region and illuminates a characteristic blue emission under Ne/Xe plasma discharge conditions. Thus, we can obtain a fast decaying, robust blue-emitting silicate phosphor layer under excited plasma radiation for upcoming emissive display devices like as transparent and three-dimensional plasma display panels. 相似文献
868.
Park JH Mamun MI Abd El-Aty AM Na TW Choi JH Ghafar MW Choi WJ Kim KS Kim SD Shim JH 《Biomedical chromatography : BMC》2011,25(1-2):155-163
In a continuation of our earlier work, a multiresidual analytical method using 48 frequently used neutral pesticides in a water matrix was developed and validated in this study. The samples were extracted with dichloromethane and the pesticides were analyzed via GC-NPD followed by confirmation with GC-MS. Good linearity was detected over a concentration range of 0.01-1.0 microg/mL with correlation coefficients (r(2) ) in excess of 0.982. The recoveries were measured between 70.7 and 111.4% for the majority of the targeted pesticides with relative standard deviations (RSDs) of less than 20%. The LODs and LOQs were in ranges of 0.1-2 and 0.33-6.6 microg/L, respectively. A total of 66 water samples were collected from different locations in Yeongsan and the Sumjin River, Republic of Korea, and were analyzed in accordance with the developed method. None of the water samples were determined to contain any of the targeted pesticides. The method has been shown to be simpler, faster, and more cost-effective than the method established by the Environmental Protection Agency (EPA). 相似文献
869.
Da Jung Kim Sang-deok Mun Sungwoo YoonChang Hwa Oh Hyoung-Ryun ParkTae-Soo You Junseong Lee Youngjo Kim 《Polyhedron》2011,30(6):1076-1079
Three monomeric boratranes B[(OCH2CH2)nN(CH2CMe2O)3−n] (n = 0, 1; n = 1, 2; n = 2, 3) have been synthesized by the reaction of B(OMe)3 with a series of triethanolateamines such as [(OCH2CH2)nN(CH2CMe2O)3−n]3− (n = 0, L1; n = 1, L2; n = 2, L3), where the number of CMe2 groups adjacent to the OH functionality varied from 3 (L1H3) to 2 (L2H3) to 1 (L3H3). These boratranes 1-3 have been characterized by solution 1H, 13C{1H} and 11B NMR, and the crystal structures of 1 and 2 have been determined by single crystal X-ray diffraction. 相似文献
870.
Jung Hee MoonSo Han Kim Kang Mun LeeTae-Soo You Youngkyu DoYoungjo Kim 《Polyhedron》2011,30(13):2333-2338
Three monomeric germatranes, 1-isopropoxy-3,3,7,7,10,10-hexamethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (1), 1-isopropoxy-3,3,7,7-tetramethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (2), and 1-isopropoxy-3,3-dimethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (3) have been synthesized by the reaction of Ge(O-i-Pr)4 in refluxing toluene with corresponding triethanolamines, (HOCH2CH2)nN(CH2CMe2OH)3−n (n = 0, L1H3; n = 1, L2H3; n = 2, L3H3), where the number of CMe2 groups adjacent to a OH functionality varied from 3 (L1H3) to 2 (L2H3), and to 1 (L3H3). These germatranes 1-3 have been characterized by solution 1H and 13C{1H} NMR and the solid state structure of 2 has been determined by single crystal X-ray diffraction. 相似文献