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81.
Murat Cakici Mustafa Catir Semistan Karabuga Hamdullah Kilic Sabri Ulukanli Medine Gulluce Furkan Orhan 《Tetrahedron: Asymmetry》2010,21(16):2027-2031
A simple synthetic method for the preparation of enantiomerically pure (S)-4-aminoquinazoline alcohols from (S)-quinazolinone alcohols by key steps including chlorination, nucleophilic ipso substitution, and deacetylation is presented. Mutagenic and antimutagenic properties of the (S)-4-aminoquinazoline alcohols were investigated by using Salmonella typhimurium TA1535, and Escherichia coli WP2uvrA tester strains at 0.01, 0.1, and 1 μg/plate concentrations. (S)-4-aminoquinazoline alcohols were found to be genotoxically safe at the tested concentrations. Among the tested (S)-4-aminoquinazoline alcohols, the best antimutagenic activity was obtained with a methyl derivative at 0.1 μg/plate dose. 相似文献
82.
Long Li N. Murat Karabacak Jennifer S. Cobb Qi Wang Pengyu Hong Jeffrey N. Agar 《Rapid communications in mass spectrometry : RCM》2010,24(18):2689-2696
Our previous work postulated a transition concept among different isotopic mass states (i.e., isotopic species) of a molecule, and developed a hierarchical algorithm for accurately calculating their masses and abundances. A theoretical mass spectrum can be generated by convoluting a peak shape function to these discrete mass states. This approach suffers from limited memory if a level in the hierarchical structure has too many mass states. Here we present a memory efficient divide‐and‐recursively‐combine algorithm to do the calculation, which also improves the truncation method used in the previous hierarchical algorithm. Instead of treating all of the elements in a molecule as a whole, the new algorithm first ‘strips’ each element one by one. For the mass states of each element, a hierarchical structure is established and kept in the memory. This process reduces the memory usage by orders of magnitude (e.g., for bovine insulin, memory can be reduced from gigabytes to kilobytes). Next, a recursive algorithm is applied to combine mass states of elements to mass states of the whole molecule. The algorithm described above has been implemented as a computer program called Isotope Calculator, which was written in C++. It is freely available under the GNU Lesser General Public License from http://www.cs.brandeis.edu/~hong/software.html or http://people.brandeis.edu/~agar . Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
83.
The catalytic potential of imidazolium salts in the benzoin condensation was investigated. Various aromatic aldehydes were tested in the benzoin condensation under the optimised protocol to afford α-hydroxyketones using N-heterocyclic carbenes derived from mono- and dicationic imidazolium salts. The products were obtained in good yields within short reaction times. Dicationic imidazolium salts with a long aliphatic chain between the imidazole rings were found to be more effective pre-catalysts for the benzoin condensation in comparison to the corresponding monocationic salts having the same aliphatic chain length. 相似文献
84.
Murat Aydemir Nermin Meric Akın Baysal Bahattin Gümgüm Mahmut Toğrul Yılmaz Turgut 《Tetrahedron: Asymmetry》2010,21(6):703-710
Hydrogen-transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. The new chiral C2-symmetric ligands N,N′-bis-[(1S)-1-sec-butyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 1 and N,N′-bis-[(1S)-1-phenyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 2 and the corresponding ruthenium complexes 3 and 4 have been prepared and their structures have been elucidated by a combination of multi-nuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. 1H–31P NMR, DEPT, 1H–13C HETCOR, or 1H–1H COSY correlation experiments were used to confirm the spectral assignments. The catalytic activity of complexes 3 and 4 in transfer hydrogenation of acetophenone derivatives by iso-PrOH has also been studied. Under optimized conditions, these chiral ruthenium complexes serve as catalyst precursors for the asymmetric transfer hydrogenation of acetophenone derivatives in iso-PrOH and act as excellent catalysts, giving the corresponding chiral alcohols in 99% yield and up to 75% ee. This transfer hydrogenation is characterized by low reversibility under these conditions. 相似文献
85.
Esabi B. Kurbanoglu Kani Zilbeyaz Namudar I. Kurbanoglu Murat Ozdal Mesut Taskin Omer F. Algur 《Tetrahedron: Asymmetry》2010,21(4):461-464
A specially designed process for the continuous production of a chiral alcohol by immobilized Rhodotorula glutinis was prepared and is reported. The performance of the process with immobilized cells was also investigated. The run time of the immobilized cells, the flow rates of the substrate, and tris buffer containing 4% glucose in the process were optimized. The immobilized R. glutinis biocatalyst could be used for 15 days with maximum reaction activity. Under the optimized conditions, the continuous production process was operated for 30 days and resulted in 10.8 mL (S)-1-phenylethanol [(S)-1-PE]. The process has been demonstrated on a multigram scale in 75% overall yield with a purity of >99%. 相似文献
86.
Murat Tonga Nergiz Cengiz Meliha Merve Kose Tuna Dede Amitav Sanyal 《Journal of polymer science. Part A, Polymer chemistry》2010,48(2):410-416
A modular approach toward the synthesis of polymers containing dendron groups as side chains is developed using the Diels–Alder “click” reaction. For this purpose, a styrene‐based polymer appended with anthracene groups as reactive side chains was synthesized. First through third‐generation polyester dendrons containing furan‐protected maleimide groups at their focal point were synthesized. Facile, reagent‐free, thermal Diels–Alder cycloaddition between the anthracene‐containing polymer and latent‐reactive dendrons leads to quantitative functionalization of the polymer chains to afford dendronized polymers. The efficiency of this functionalization step was monitored using 1H and 13C NMR spectroscopy and FTIR and UV–vis spectrometry. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 410–416, 2010 相似文献
87.
Homogenization and optimal bounds in linear elasticity 总被引:5,自引:0,他引:5
88.
M. Murat Koksalan Paul N. S. Sagala 《The Journal of the Operational Research Society》1992,43(3):259-263
In this paper we address the problem of choosing the most preferred alternative among a large number of alternatives where each alternative is defined by multiple criteria. We assume that the decision maker has a quasiconcave utility function. We develop an exact approach that combines the ideas that have appeared in the literature regarding the use of different types of dummy alternatives in conjunction with real alternatives. Our experimental results indicate that the new approach is comparable to leading existing approaches. 相似文献
89.
Cover Picture: Intracellular Modulation of Excited‐State Dynamics in a Chromophore Dyad: Differential Enhancement of Photocytotoxicity Targeting Cancer Cells (Angew. Chem. Int. Ed. 18/2015) 下载免费PDF全文
90.
Aluminum is one of the most toxic metals causing a variety of neurologic diseases, especially Alzheimer's disease. It is impossible to avoid contact with aluminum because of its existence in food to medications. Therefore, removal of aluminum from the blood or wastewater is urgently important. The cost-effective and easy-to-prepare adsorbents are needed to get efficient aluminum removal. For that purpose, the poly(2-hydroxyethylmethacrylate-co-acrylic acid), poly(HEMA-co-AA), microparticles was synthesized to remove aluminum in a very short interaction time. The achievement of the desired polymeric structure was confirmed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM), etc. Additionally, particle features such as swelling ratio, size, and surface area were determined. The microparticles synthesized in this study have been determined with very good adsorption capacity even in small aluminum concentrations. 相似文献