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31.
Thermodynamic properties of quaternary aqueous solutions of mixed chlorides of 1-1*1-1*2-1 charge type with the cations (Na+, NH4
+; Mg2+, Ca2+, Ba2+) were determined using the hygrometric method. The quaternary systems NH4Cl + NaCl + MgCl2 + H2O, NH4Cl + NaCl + CaCl2+ H2O, and NH4Cl + NaCl + BaCl2 + H2O have been studied at 25 °C. The water activities were measured at total molalities from 0.44 mol⋅kg−1 to saturation for different ionic-strength fractions y of NH4Cl, y=(0.20,0.50,0.80), and different ionic strength ratios z for other solutes, z=(0.20,0.50 and 0.80) for each value of y. The obtained data allows the calculation of osmotic coefficients. 相似文献
32.
Ludivine Louise‐Leriche Emilia Pǎunescu Géraldine Saint‐André Rachid Baati Anthony Romieu Alain Wagner Pierre‐Yves Renard 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(11):3510-3523
A new pro‐fluorescent probe aimed at a HTS assay of scavengers is able to selectively and efficiently cleave the P? S bond of organophosphorus nerve agents and by this provides non‐toxic phosphonic acid has been designed and synthesised. The previously described pro‐fluorescent probes were based on a conventional activated P? Oaryl bond cleavage, whereas our approach uses a self‐immolative linker strategy that allows the detection of phosphonothioase activity with respect to a non‐activated P? Salkyl bond. Further, we have also developed and optimised a high‐throughput screening assay for the selection of decontaminants (chemical or biochemical scavengers) that could efficiently hydrolyse highly toxic V ‐type nerve agents. A preliminary screening, realised on a small α‐nucleophile library, allowed us to identify some preliminary “hits”, among which pyridinealdoximes, α‐oxo oximes, hydroxamic acids and, less active but more original, amidoximes were the most promising. Their selective phosphonothioase activity has been further confirmed by using PhX as the substrate, and thus they offer new perspectives for the synthesis of more potent V nerve agent scavengers. 相似文献
33.
Souad Chaouche Rachid Ouarsal Brahim El Bali Mohammed Lachkar Michael Bolte Michal Dusek 《Journal of chemical crystallography》2010,40(6):526-530
Abstract
Crystal structure of Li2HPO3,H2O was determined by single-crystal X-Ray diffraction analysis at 173(2) K. It crystallizes in the monoclinic system (P21/c) with the parameters: a = 5.0322(9) ?, b = 8.9795(17) ?, c = 17.088(4) ?, β = 92.672(16)° and Z = 8. The structure was refined to R = 0.0237 and ωR = 0.0650 for 1449 reflexions. The framework of Li2HPO3, H2O can be described as layers perpendicular to the crystallographic c axis. The structure contains two types of Li-tetrahedrons. In one kind each O atom belongs to one HPO3 group, while in the second kind one apex is an O from water. A network of hydrogen bonds interactions insures the connection between the layers. 相似文献34.
Souad Chaouche Rachid Ouarsal Mohammed Lachkar Francesco Capitelli Brahim El Bali 《Journal of chemical crystallography》2010,40(6):486-490
Abstract
A new hybrid phosphate, (C6H5NH3)[ZnCl(HPO3)], has been synthesized and its structure characterized from single-crystal X-ray diffraction. The title compound crystallizes in the orthorhombic space group Pbca (n. 61) with the unit-cell parameters: a = 9.8635(2) ?, b = 9.4516(10) ?, c = 22.2430(4) ?, Z = 8 and V = 2,073.62(6) ?3. The final R factors were R/ωR = 0.0361/0.0924. Its framework might be described as a layered structure with two (010)-parallel cationic and anionic layers. The IR spectrum of this phase shows characteristic bands of phosphite and anilinium groups. 相似文献35.
36.
The expansion of a plasma induced by laser ablation is investigated using a single-fluid model combined with Saha?s equation. The space coordinates x and time t are combined to a one self-similar variable ξ=x/(ct). To obtain ordinary differential equations, two different transformations for the density are used. The density profiles during the expansion are found to be completely different, one corresponds to the common results i.e., the density decreases monotonically with ξ, while with the second transformation, the profile shows a density increasing for certain interval of the self-similar variable. This effect is enhanced with higher initial ionization fraction. The role of the initial velocity which corresponds to the start of the expansion from an unperturbed plasma or from an expansion already going on is pointed out. 相似文献
37.
Rachid Touzani Michael HaibachAgnieszka J. Nawara-Hultzsch Sghir El KadiriThomas J. Emge Alan S. Goldman 《Polyhedron》2011,30(15):2530-2534
The complexation of the simple 1-hydroxymethyl-3,5-dimethylpyrazole (HL) ligand with Fe and Ni salts leads to interesting polynuclear complexes in good yield. X-ray diffraction reveals that the resulting complexes (μ4-L)4Ni4Cl4(H2O)4 and (μ2-L)4(μ3-L)2Fe8Cl16(μ4-O)6 adopt cubane-type and open-cubane-type structures in the solid state. 相似文献
38.
Kashinath D Tisserand S Puli N Falck JR Baati R 《European journal of organic chemistry》2010,2010(10):1869-1874
Nucleophilic mixed chromium(II) and chromium(III) acetylides are generated from the smooth reduction of primary 1,1,1-trichloroalkanes with chromium(II) chloride in the presence of an excess amount of triethylamine at room temperature. These species arise from chromium(III) vinylidene carbenoids. It has been demonstrated that uncommon low-valent Cr(II) acetylides are formed by C-H insertion of Cr(II)Cl(2) into terminal alkynes, formed in situ through the Fritsch- Buttenberg-Wiechell (FBW) rearrangement, whereas Cr(III) acetylides are concomitantly generated by HCl elimination from the chromium(III) vinylidene carbenoid. Both divergent pathways result, overall, in the formation of nucleophilic acetylides. In situ trapping with electrophilic aldehydes afforded propargyl alcohols. Furthermore, deuteration experiments and the use of deuterium labeled 1,1,1-trichloroalkane substrates demonstrated the prevalence of low-valent Cr(II) acetylides, potentially useful, yet highly elusive synthetic intermediates. 相似文献
39.
40.
We design and analyze an unconditionally convergent nonstandard finite-difference method to study transmission dynamics of a mathematical model of HIV-TB co-infection. The dynamics of this model are studied using the qualitative theory of dynamical systems. These qualitative features of the continuous model are preserved by the numerical method that we propose in this paper. This method also preserves positivity of the solution which is one of the essential requirements when modelling epidemic diseases. Furthermore, we show that the numerical method is unconditionally stable. Competitive numerical results confirming theoretical investigations are provided. Comparisons are also made with other conventional approaches that are routinely used to solve these types of problems. 相似文献