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991.
992.
Supramolecular amphiphiles (SA), also named superamphiphiles, refer to amphiphiles that are formed by non-covalent interactions. This tutorial review focuses on the molecular architectures of SAs, including diversified topologies such as single chain, double chain, bolaform, gemini and rotaxane types. Non-covalent syntheses that have been employed to fabricate SAs are driven by hydrogen bonding, electrostatic attraction, host-guest recognition, charge transfer interaction, metal coordination and so on. It should be noted that SAs can be either small organic molecules or polymers. SAs allow for tuning of their amphiphilicity in a reversible fashion, leading to controlled self-assembly and disassembly. This line of research has been enriching traditional colloid chemistry and current supramolecular chemistry, and the application of SAs in the field of functional supramolecular materials is keenly anticipated. 相似文献
993.
Han P Li S Wang C Xu H Wang Z Zhang X Thomas J Smet M 《Langmuir : the ACS journal of surfaces and colloids》2011,27(23):14108-14111
We have prepared a UV-responsive polymeric superamphiphile, formed by a malachite green derivative and the double hydrophilic block copolymer methoxy-poly(ethylene glycol)(114)-block-poly(l-lysine hydrochloride)(200) (PEG-b-PLKC) on the basis of electrostatic interactions. The malachite green derivative undergoes photo-ionization upon UV irradiation, which makes it more hydrophilic, resulting in changes in the self-assembly behavior of the polymeric superamphiphile. For this reason, the polymeric superamphiphile originally self-assembles to form sheetlike aggregates, which disassemble after UV irradiation because of the increased solubility of the malachite green derivative. By use of Nile red as a probe, the polarity of the polymeric superamphiphile solution is confirmed to be increased after UV irradiation by fluorescence spectra, which also explains the disassembly of the polymeric superamphiphile. 相似文献
994.
Zhang J Liu Y Wu G Schönhoff M Zhang X 《Langmuir : the ACS journal of surfaces and colloids》2011,27(17):10370-10375
Stable multilayer films were fabricated on the basis of the alternating layer-by-layer assembly of a two-component bolaform supramolecular amphiphile and diazoresins, followed by photochemical cross-linking of the structure. UV-visible spectroscopy and atomic force microscopy revealed a uniform deposition process. Moreover, one component of the supramolecular amphiphile can be removed from the multilayer films after cross-linking between the second component and the diazoresin. The release and uptake of the imprinted supramolecular amphiphile component are shown to be reversible. Furthermore, uptake experiments of different molecules show the selectivity of the imprinted sites for the template molecule. Thus, surface-imprinted films can be formed by employing dissociable two-component supramolecular amphiphiles. This research reveals that supramolecular amphiphiles can be used as a novel concept for the construction of multilayer films, and it also provides a new method of generating surface-imprinted multilayers. 相似文献
995.
Adsorption of lead(II) ions from aqueous solution on low-temperature exfoliated graphene nanosheets 总被引:1,自引:0,他引:1
Huang ZH Zheng X Lv W Wang M Yang QH Kang F 《Langmuir : the ACS journal of surfaces and colloids》2011,27(12):7558-7562
Graphene nanosheets (GNSs) that were obtained by vacuum-promoted low-temperature exfoliation were used to adsorb lead ions from an aqueous system. The pristine and thermally modified GNSs were characterized with scanning electron microscopy observation and X-ray photoelectron spectroscopy analysis. It was interestingly found that the adsorption against lead ions was enhanced by heat treatment, although the oxygen complexes of GNSs showed a significant decrease. In addition, lead ion uptake resulted in an increase in the pH value of the solution. It is supposed that the Lewis basicity of GNSs is improved by heat treatment under a high vacuum, in favor of simultaneous adsorption of lead ions and protons onto GNSs. 相似文献
996.
Protein–protein interactions, particularly weak and transient ones, are often mediated by peptide recognition domains. Characterizing
the interaction interface of domain–peptide complexes and analyzing binding specificity for modular domains are critical for
deciphering protein–protein interaction networks. In this article, we report the successful use of an integrated computational
protocol to dissect the energetic profile and structural basis of peptide binding to third PDZ domain (PDZ3) from the PSD-95
protein. This protocol employs rigorous quantum mechanics/molecular mechanics (QM/MM), semi-empirical Poisson–Boltzmann/surface
area (PB/SA), and empirical conformational free energy analysis (CFEA) to quantitatively describe and decompose systematic
energy changes arising from, respectively, noncovalent interaction, desolvation effect, and conformational entropy loss associated
with the formation of 30 affinity-known PDZ3–peptide complexes. We show that the QM/MM-, PB/SA-, and CFEA-derived energy components
can work together fairly well in reproducing experimentally measured affinity after a linearly weighting treatment, albeit
they are not compatible with each other directly. We also demonstrate that: (1) noncovalent interaction and desolvation effect
donate, respectively, stability and specificity to complex architecture, while entropy loss contributes modestly to binding;
(2) P0 and P−2 of peptide ligand are the most important positions for determining both the stability and specificity of the PDZ3–peptide
complex, P−1 and P−3 can confer substantial stability (but not specificity) for the complex, and N-terminal P−4 and P−5 have only a very limited effect on binding. 相似文献
997.
Xin-Long Ni Masashi Takimoto Zeng Xi Takehiko Yamato 《Journal of inclusion phenomena and macrocyclic chemistry》2011,71(1-2):231-237
Hexahomotrioxacalix[3]arene having [(5′-methyl-2,2′-bipyridyl)-5-yl]oxycarbonylmethoxy group with cone conformation was prepared, which shows strong Ag+ affinity and acts as a ditopic receptor for Ag+ and nBuNH3 +. A conformational change of 2,2′-bipyridyl moiety from the original outward orientation of the ring nitrogen to the inside orientation toward the thiacalixarene cavity was observed in the process of Ag+ complexation. 相似文献
998.
Bo?Xiao Yulu?Zhang XinXiang?Zhang Haibing?Lv Lianghong?Yan Bo?JiangEmail author 《Journal of Sol-Gel Science and Technology》2011,60(1):11-16
The poly(isopropylene oxide) glycerolether (PO) modified silica antireflective (AR) coating films were prepared by sol–gel
method. The properties of the silica sols and AR films were characterized by particle size analyzer, transmission electron
microscope, UV–Vis spectro-photometry, spectroscopic ellipsometer and contact angle measurement. The results show that PO
addition has inconspicuous effect on the transmittance of AR coatings; the maximum transmittance reached 99.5%. Thicknesses
of films increase and refractive index decrease with increase of PO concentration. The contact angle with water for the silica
films with and without PO was 68.5o and 28.5o, respectively, which indicates an increase of hydrophobicity of the modified coating. When the films were placed in 95% relative
humidity at room temperature for 30 days, transmittance loss for the unmodified and modified silica films were 2.5 and 0.6%
respectively. Moisture-resistance of the film is greatly improved by PO addition. 相似文献
999.
Jin‐Peng Geng Prof. Dr. Zhao‐Xi Wang Qiong‐Fang Wu Ming‐Xing Li Prof. Dr. Hong‐Ping Xiao 《无机化学与普通化学杂志》2011,637(2):301-305
A new manganese(II) complex [Mn3(bidc)2(C2O4)(H2O)10]n ( 1 ) (bidc = benzimidazole‐5,6‐dicarboxylate) was synthesized and characterized by X‐ray crystallography. X‐ray diffraction shows that complex 1 has a neutral, one‐dimensional (1D) brick wall chain structure. With the intramolecular and intermolecular hydrogen bonding interactions, the adjacent chains are joined into a 3D suparmolecular architecture. IR spectroscopy and variable temperature magnetic susceptibility measurements were made, which indicated weak antiferromagnetic coupling between the MnII ions in complex 1 . 相似文献
1000.
Gel electrophoresis (GE) is a very common analytical technique for proteome research and protein analysis. Despite being developed decades ago, there is still a considerable need to improve its precision. Using the fluorescence of Colloidal Coomassie Blue -stained proteins in near-infrared (NIR), the major error source caused by the unpredictable background staining is strongly reduced. This result was generalized for various types of detectors. Since GE is a multi-step procedure, standardization of every single step is required. After detailed analysis of all steps, the staining and destaining were identified as the major source of the remaining variation. By employing standardized protocols, pooled percent relative standard deviations of 1.2-3.1% for band intensities were achieved for one-dimensional separations in repetitive experiments. The analysis of variance suggests that the same batch of staining solution should be used for gels of one experimental series to minimize day-to-day variation and to obtain high precision. 相似文献