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41.
The consequences of 50 MeV Li3+ ion irradiation (fluence: 5×1013 ions/cm2) on the structural and electrical properties of the Y3+xFe5?xO12 (x=0.0, 0.2, 0.4 and 0.6) garnet system have been investigated over the temperature range of 300–673 K. It is found that the percentage formation of an additional yttrium orthoferrite phase observed along with the bcc garnet phase considerably reduces for x=0.4 and 0.6 compositions after swift heavy ion (SHI) irradiation. The nature of thermal variation of DC resistivity curves for x=0.0 and 0.2 compositions is different from that for x=0.4 and 0.6 compositions. The SHI irradiation influences the magnitude of DC resistivity and conduction mechanism for the single-phase compositions while for mixed-phase compositions they remain unaffected. The results have been explained in the light of replacement of magnetic (5μB), smaller (0.64 Å), Fe3+ ion by nonmagnetic (0μB), larger (0.89 Å), Y3+ ion, the presence of the yttrium orthoferrite phase and swift heavy ion irradiation-induced paramagnetic centers in the system. 相似文献
42.
In this article, we look beyond convexity and introduce the four new classes of functions, namely, approximate pseudoconvex functions of type I and type II and approximate quasiconvex functions of type I and type II. Suitable examples illustrating the non emptiness of the newly defined classes and distinguishing them from the existing classical notions of pseudoconvexity and quasiconvexity are provided. These newly defined concepts are then employed to establish sufficient optimality conditions for the quasi efficient solutions of a vector optimization problem. 相似文献
43.
The structural and elastic properties of praseodymium monochalcogenides (PrX: X = S, Se, Te) and monopnictides (PrY: Y = P, As, Sb, Bi) with NaCl-type structure have been investigated by using an interionic potential theory with necessary modification to include the effect of Coulomb screening due to the delocalized f-electrons of rare earth ion. The calculations are done at ambient as well as at high pressure. The structure of the high pressure phase of PrX compounds is CsCl-type while all the PrY compounds have been found to undergo from their initial NaCl-type structure to high pressure body centered tetragonal (BCT) structure, which can be seen as the distorted CsCl-type with c/a ratio ≈ 0.82–0.87. The calculated transition pressures are in good agreement with the experimental results. The elastic properties like second-order elastic constants for PrX, Y compounds are calculated for the first time. The nature of the bonding is also predicted by calculating the distance between the ions with the increasing pressure. 相似文献
44.
Abstract The infrared and ultraviolet absorption spectra of toluene-d have been investigated for the first time in the regions 400 - 4000 cm?1 and 2350 ?2750 A° respectively. The intense band at 2666.3 A°(37494 cm?1) in the u.v. vapour absorption spectrum has been identified as the o,o band and others have been interpreted in terms of the three (519,632 and 785 cm?1) ground state and the six (454,526,743,935,963 and 1180 cm?1 excited state fundamentals. The correlation of the various frequencies of the ground and excited states of toluene and toluene-d has been done. The observed isotopic shift for toluene-d is 14 cm?1. 相似文献
45.
Priti Tagde Pooja Tagde Fahadul Islam Sandeep Tagde Muddaser Shah Zareen Delawar Hussain Md. Habibur Rahman Agnieszka Najda Ibtesam S. Alanazi Mousa O. Germoush Hanan R. H. Mohamed Mardi M. Algandaby Mohammed Z. Nasrullah Natalia Kot Mohamed M. Abdel-Daim 《Molecules (Basel, Switzerland)》2021,26(23)
Curcumin is the primary polyphenol in turmeric’s curcuminoid class. It has a wide range of therapeutic applications, such as anti-inflammatory, antioxidant, antidiabetic, hepatoprotective, antibacterial, and anticancer effects against various cancers, but has poor solubility and low bioavailability. Objective: To improve curcumin’s bioavailability, plasma concentration, and cellular permeability processes. The nanocurcumin approach over curcumin has been proven appropriate for encapsulating or loading curcumin (nanocurcumin) to increase its therapeutic potential. Conclusion: Though incorporating curcumin into nanocurcumin form may be a viable method for overcoming its intrinsic limitations, and there are reasonable concerns regarding its toxicological safety once it enters biological pathways. This review article mainly highlights the therapeutic benefits of nanocurcumin over curcumin. 相似文献
46.
Pooja Singla Manoj Sharma O. P. Pandey K. Singh 《Applied Physics A: Materials Science & Processing》2014,116(1):371-378
Undoped and Zn-doped TiO2 nanoparticles were synthesized by the sol gel method. The dopant (Zn) was taken at 0.1, 0.2, 0.5, 0.7, and 1.0 mol%. The initial precursors were titanium tetraisopropoxide and zinc acetate. The samples were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and UV–vis diffuse reflectance. The photocatalytic activity of the prepared nanoparticles was studied by observing their role in degradation of two azo dyes, i.e., Eriochrome Black T and Methyl Red under UV–visible light. The results revealed that Zn-doped TiO2 nanoparticles exhibited better degradation as compared to undoped TiO2 nanoparticles. In this study, 0.7 mol% Zn-doped TiO2 showed highest photocatalytic activity. Doping of Zn allowed better separation of electron–hole pairs which results in increased oxidation and reduction reactions. 相似文献
47.
Sathyanarayanan Jayashree Sharma Pooja Muthuirulan Pushpanathan Jeyaprakash Rajendhran Paramasamy Gunasekaran 《Applied biochemistry and biotechnology》2014,174(2):855-866
Lactobacillus fermentum is a lactic acid bacterium of probiotic importance, which is found ubiquitously in fermented milk products. Bile salt hydrolase (BSH) has a significant role in affording probiotic properties to lactobacilli. In the present study, two bsh genes encoding BSH1 and BSH2 were identified from the draft genome sequence of L. fermentum MTCC 8711. Nucleotide comparison revealed no significant similarity between bsh1 and bsh2 genes, whereas the deduced amino acid sequences showed 26 % sequence similarity between both BSH1 and BSH2. Pfam analysis revealed the presence of cys-2 active site residues in the catalytic pocket of both BSH1 and BSH2 highly essential for catalysis. Phylogentic analysis of BSH1 and BSH2 revealed the possible independent origin of these proteins in Lactobacillus. We cloned these genes in pSLp111.3, a Lactobacillus expression vector with signal peptide A (slpA) and expressed in the native L. fermentum strain for overexpression and extracellular secretion. The bsh1 gene failed to express and to produce promising BSH activity. However, bsh2 gene was overexpressed and the recombinant strain showed improved BSH activity. Induction of the recombinant strain with an optimal 2 % xylose concentration secreted 0.5 U/ml of the BSH into extracellular medium. Furthermore, the recombinant strain was able to completely assimilate the 100-μg/ml cholesterol within 24 h, whereas the native strain took 72 h for the complete assimilation of cholesterol. 相似文献
48.
J. E. Drake M. B. Hursthouse M. E. Light R. Maheshwari K. G. Ojha R. Ratnani 《Journal of chemical crystallography》2008,38(7):553-556
Abstract Bis(2-amino-5-fluoro-3-methylphenyl)disulfide was obtained by oxidation of 2-amino-5-fluoro-3-methylbenzenethiol and was characterized
by elemental analysis, IR and 1H-NMR spectroscopy. The X-ray structure was determined. Crystal data: C14H14N2F2S2: Monoclinic, P21
/n, a = 11.8268(3), b = 9.5770(3), c = 12.3977(3) ?, β = 98.079(2)°, V = 1390.29(7) ?, Z = 4. The supramolecular structure arises because the NH2 groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds.
Index Abstract Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide
J. E. Drake1, M. B. Hursthouse2, M. E. Light2, R. Maheshwari3, K.G. Ojha3, R. Ratnani3*
Bis(2-amino-5-fluoro-3-methylphenyl)disulfide is linked into a three-dimensional frame work by a combination of intermolecular
N–H···F and N–H···N and intramolecular N–H···S hydrogen bonds. The supramolecular structure arises because the NH2 groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds.
相似文献
49.
A. K. Maheshwari Dr. D. S. Jain J. N. Gaur 《Monatshefte für Chemie / Chemical Monthly》1977,108(2):279-283
The reduction of Cd(II) in propylenediamine was found to be reversible and diffusion controlled. The complexes of Cd(II) with propylenediamine in 25%, 50%, and 75% dimethylformamide have been studied polarographically using theDeFord andHume's treatment as extended byIrving. Increase in the stability constants was observed with increase in dimethylformamide percentage. The percentage composition of the various complexed and uncomplexed species in 25% and 50% dimethylformamide are presented. 相似文献
50.