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排序方式: 共有241条查询结果,搜索用时 31 毫秒
111.
Rani U Oturak H Sudha S Sundaraganesan N 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,78(5):1467-1475
Quantum chemical calculations of energies, geometrical structural parameters, harmonic and anharmonic frequencies of 2,4-DCP and 4,6-DCP were carried out by HF and density functional theory methods with 6-311++G(d,p) as basis set. The assignment of each normal mode has been made using the observed and calculated frequencies, their IR and Raman intensities. A detailed interpretation of the FT-IR and FT-Raman spectra of 2,4-DCP and 4,6-DCP was reported on the basis of the calculated potential energy distribution (PED). A comparison of theoretically calculated vibrational frequencies at B3LYP/6-311++G(d,p) with FT-IR and FT-Raman experimental data shows good agreement between them. Natural atomic charges of 2,4-DCP and 4,6-DCP were calculated and compared with pyrimidine molecule. 相似文献
112.
Hakan Karadeniz Guliz Armagan Arzum Erdem Ezgi Turunc Ayfer Caliskan Lutfiye Kanit Ayfer Yalcin 《Electroanalysis》2009,21(22):2468-2476
A possible DNA damage after interaction of kainic acid (KA) with calf thymus double stranded DNA and genomic DNA was herein determined in in vitro and in vivo conditions using; electrochemical assay and agarose gel electrophoresis. The changes in guanine signal were detected as an indicator of DNA damage in genomic DNA samples isolated from 1 or 10 mg/kg KA‐treated animals. The decreased levels of guanine signal were found as 29% and 33% by 1 and 10 mg/kg KA treatment when compared to controls, respectively. The results of gel electrophoresis confirmed DNA damage obtained in identical samples by electrochemical method. 相似文献
113.
Christy D. Petruczok Efe Armagan Gozde Ozaydin Ince Karen K. Gleason 《Macromolecular rapid communications》2014,35(15):1345-1350
The first vapor‐phase deposition of poly(vinyl cinnamate) (PVCin) is reported. Initiated chemical vapor deposition (iCVD) is used to synthesize PVCin thin films with an average thickness of 100 nm. Free radical polymerization and cyclization reactions compete during the deposition process, with approximately 45% of the repeat units undergoing cyclization. Exposure to UV light (λ = 254 nm) induces dimerization (cross‐linking) of the PVCin, which is quantified using spectroscopic techniques. Approximately 90% of the free cinnamate moieties are dimerized at a UV dose of 300 mJ cm−2. PVCin is also incorporated into a copolymer with N‐isopropylacrylamide, which exhibits a characteristic change in hydrophilicity with temperature. The copolymer is selectively cross‐linked through a mask, and reversible swelling of patterns with 30 μm resolution is demonstrated by submerging the film in water.
114.
C(2)-Symmetric two bis(amino alcohol)oxalamides (diamidediols) were synthesized and fully characterized. A new method was developed and successfully applied for the simultaneous preconcentration of both trace and toxic metals in water, by using C(2)-symmetric compounds. Under the optimum experimental conditions (i.e. pH = 10.0 +/- 0.2, 2.75 x 10(-3) mol L(-1) N,N'-bis[(1R)-1-ethyl-2-hydroxyethyl]ethanediamide (DAD1), 1.75 x 10(-3) mol L(-1) N,N'-bis[(1S)-1-benzyl-2-hydroxyethyl]-ethanediamide (DAD2), 0.10% w/v octylphenoxy-polyethoxyethanol (Triton X-114)), calibration graphs were linear in the range of 2.5 - 25.0 ng mL(-1) for Cu and Cd, 5.0 - 25.0 ng mL(-1) for Co and Ni. The enrichment factors were 18, 23, 18 and 20 for Cd, Cu, Co and Ni in the case of DAD1, respectively; 20, 22, 17 and 20 for Cd, Cu, Co and Ni in the case of DAD2. The limits of detection for DAD1 were found to be 0.45, 0.50, 1.25 and 0.60 ng mL(-1) for Cd, Cu, Co and Ni, respectively, and for DAD2 were found to be 0.44, 0.25, 0.60 and 1.55 ng mL(-1) for Cd, Cu, Co and Ni, respectively. The developed method was applied to the determination of Cu, Cd, Co and Ni in water samples and certified reference materials with satisfactory results. 相似文献
115.
An affine de Casteljau type algorithm to compute q-Bernstein Bézier curves is introduced and its intermediate points are obtained explicitly in two ways. Furthermore we define
a tensor product patch, based on this algorithm, depending on two parameters. Degree elevation procedure is studied. The matrix
representation of tensor product patch is given and we find the transformation matrix between a classical tensor product Bézier
patch and a tensor product q-Bernstein Bézier patch. Finally, q-Bernstein polynomials B
n,m
(f;x,y) for a function f(x,y), (x,y)∈[0,1]×[0,1] are defined and fundamental properties are discussed.
AMS subject classification (2000) 65D17 相似文献
116.
Halil Aktaş Dr. J. Chris Slootweg Dr. Koop Lammertsma Prof. Dr. 《Angewandte Chemie (International ed. in English)》2010,49(12):2102-2113
Syntheses, properties, and reactivities of nucleophilic phosphinidene complexes [LnM?P? R] are reviewed. Emphasis is placed on the electronic tuning of this emerging class of phosphorus reagents, using different ancillary ligands and coordinatively unsaturated transition‐metal moieties. The difference in applicability of the established stable 18‐electron and transient 16‐electron phosphinidenes is addressed. 相似文献
117.
Aromatic chromophores; pyrene, phenanthrene, anthracene, naphtalene and benzene-tethered Schiff base ligands and their iron(III)/chromium(III) Salen and Saloph capped complexes have been synthesized. Compounds have been characterized by means of FT-IR Spectroscopy, (1)H-NMR Spectroscopy, Magnetic Susceptibility, Elementel Analsis, TG/DTA measurements. Their fluorescence and absorbance properties have been investigated by Luminescence Spectroscopy and UV-vis Spectroscopy. Generally, ligands show an intense excimer fluorescence emissions in acetonitrile-methanol medium while iron(III) and chromium(III) complexes exhibit low fluorescence's. Intensity compared to ligands iron and chromium centers act as an extra chromophore that quench the pyrene, phenanthrene, anthracene, naphtalene and benzene molecules' singlet state. The mechanism of quenching is attributed to a iron (or chromium)-to-pyrene (or phenanthrene, anthracene, naphtalene and benzene) electronic energy transfer process. 相似文献
118.
Laurent Pilon Halil Berbero?lu Razmig Kandilian 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(17):2639-2660
Solar radiation is the energy source driving the metabolic activity of microorganisms able to photobiologically fixate carbon dioxide and convert solar energy into biofuels. Thus, careful radiation transfer analysis must be conducted in order to design and operate efficient photobioreactors. This review paper first introduces light harvesting mechanisms used by microorganisms as well as photosynthesis and photobiological fuel production. It then provides a thorough and critical review of both experimental and modeling efforts focusing on radiation transfer in microalgae suspension. Experimental methods to determine the radiation characteristics of microalgae are presented. Methods for solving the radiation transfer equation in photobioreactors with or without bubbles are also discussed. Sample measurements and numerical solutions are provided. Finally, novel strategies for achieving optimum light delivery and maximizing sunlight utilization in photobioreactors are discussed including genetic engineering of microorganisms with truncated chlorophyll antenna. 相似文献
119.
Ayşegül Karaküçük-İyidoğan Zeliha Mercan Emine Elçin Oruç-Emre Demet Taşdemir Derya İşler İbrahim Halil Kılıç 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):661-673
Abstract The synthesis and characterization of 18 novel thiosemicarbazones have been investigated as part of a research program on development of compounds with antibacterial and antioxidant activities. Among the tested compounds, 2-(4-hydroxybenzylidene)-N-[4-(trifluoromethoxy)phenyl]hydrazine carbothioamide (3g) and 2-(thiophen-2-ylmethylidene)-N-[4-(morpholin-4-yl)phenyl]hydrazine carbothioamide (4b) showed excellent inhibition potency at low concentration (0.5 μg/mL) against Gram-positive pathogens (Enterococcus faecalis and Staphylococcus aureus). All tested compounds were also found to possess antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.] 相似文献
120.
Nalan Turkoz Karakullukcu Hasan Yakan Seyhan Ozturk Halil Kutuk 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):1576-1583
Abstract Some disulfide derivatives have been prepared by microwave assisted synthesis methodology from thiophthalimides(sulfenimides) and thiols in a modified microwave oven under reflux at 600 Watt in ethanol. Elucidation of the structures of the synthesized compounds has been performed by IR, 1H NMR, and 13C NMR spectroscopic methods. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional figures] 相似文献