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91.
Ali Reza Harifi‐Mood Aziz Habibi‐Yangjeh Mohammad Reza Gholami 《Journal of Physical Organic Chemistry》2008,21(9):783-788
The second‐order rate constants for cycloaddition reaction of cyclopentadiene with naphthoquinone were determined spectrophotometrically in various compositions of 1‐(1‐butyl)‐3‐methylimidazolium terafluoroborate ([bmim]BF4) with water and methanol at 25 °C. Rate constants of the reaction in pure solvents are in the order of water > [bmim]BF4 > methanol. Rate constants of the reaction decrease sharply with mole fraction of the ionic liquid in aqueous solutions and increase slightly to a maximum in alcoholic mixtures. Multi‐parameter correlation of logk2 versus solute–solvent interaction parameters demonstrated that solvophobicity parameter (Sp), hydrogen‐bond donor acidity (α) and hydrogen‐bond acceptor basicity (β) of media are the main factors influencing the reaction rate constant. The proposed three‐parameter model shows that the reaction rate constant increases with Sp, α and β parameters. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
92.
Mohammad Reza R. Moghaddam All Reza Salemkar Ahmad Gholami 《Southeast Asian Bulletin of Mathematics》2000,24(2):255-261
Let be a variety of groups defined by the set of laws V. In this paper we study the concept of -isologism of groups in terms of -extensions and their connections with the Baer-invariant of groups are also discussed.AMS Subject Classification (2000): primary 20F14, 20F19, secondary 20E10 相似文献
93.
94.
Synthesis of Biginelli Compounds Using Cobalt Hydrogen Sulfate 总被引:1,自引:0,他引:1
Efficient synthesis of various 2‐oxo(thioxo)‐1,2,3,4‐tetrahydropyrimidines containing acetyl, carboethoxy, carbomethoxy and carboxamide groups on 5‐position of the N1‐substituted and N1‐unsubstituted heterocyclic ring was achieved using cobalt hydrogen sulfate Co(HSO4)2 under thermal conditions. Good to high yield, shorter reaction times, easy work up and simple preparation of Co(HSO4)2 are the advantages using this synthetic method. 相似文献
95.
Majid Montazer Mahbubeh Dastjerdi Maryam Azdaloo Mahnaz Mahmoudi Rad 《Cellulose (London, England)》2015,22(6):4049-4064
96.
Dr. Mojtaba Gholami Dr. Sharwatie Ramsaywack Dr. Manuel N. Chaur Dr. Adrian H. Murray Dr. Robert McDonald Dr. Michael J. Ferguson Prof. Dr. Luis Echegoyen Prof. Dr. Rik R. Tykwinski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15120-15132
Versatile, iterative synthetic protocols to form expanded [n]radialenes have been developed (n=3 and 4), which allow for a variety of groups to be placed around the periphery of the macrocyclic framework. The successful use of the Sonogashira cross‐coupling reaction to complete the final ring closure demonstrates the ability of this reaction to tolerate significant ring strain while producing moderate to excellent product yields. The resulting radialenes show good stability under normal laboratory conditions in spite of their strained, cyclic structures. The physical and electronic characteristics of the macrocycles have been documented by UV‐visible spectroscopy, electrochemical methods, and X‐ray crystallography (four derivatives), and these studies provide insight into the properties of these compounds as a function of pendent substitution in terms of conjugation and donor/acceptor functionalization. 相似文献
97.
A fast and efficient method is described for the one-pot synthesis of 2,4(1H,3H)-quinazolinediones by cyclization reaction of anthranilic acid derivatives with potassium cyanate and acetic acid in PEG.Good to high yields of the products obtain in short reaction times with simple work-up. 相似文献
98.
MohammadReza Elahifard Elham Fazeli Azadeh Joshani MohammadReza Gholami 《Surface and interface analysis : SIA》2013,45(7):1081-1087
Direct CO dissociation is seen the main path of the first step in the Fischer–Tropsch Synthesis (FTS) on the reactive iron surfaces. Cu/Fe alloy film is addressed with various applications over face‐centered‐cubic (fcc)‐Cu and body‐centered‐cubic (bcc)‐Fe in the FTS, i.e. preventing iron carbide formation (through direct CO dissociation) by moderating the surface reactivity and facilitating the reduction of iron surfaces, respectively. In this study by density functional theory, the stable configurations of CO molecule on various Cu/Fe alloys over fcc‐Cu(100) and bcc‐Fe(100) surfaces with different CO coverage (25% and 50%) have been evaluated. Our results showed that the ensemble effect plays a fundamental role to CO adsorption energy on the surface alloys over bcc‐Fe(100); on the other hand, the ligand effect determines the CO stability on the fcc‐Cu(100) surface alloys. CO dissociation barrier was also calculated on the surface alloys that showed although the CO dissociation process is thermodynamically possible on the more reactive surface alloys, but according to their high barrier, CO dissociation does not occur directly on these surfaces. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
99.
Abstract Monomers α-fluoroacrylonitrile (FAN) and ethyl α-fluoroacrylate (EFA) and homopolymers poly(α-fluoroacrylonitrile) (PFAN) and poly-(ethyl α-fluoroacrylate) (PEFA) have been synthesized and spectroscopi-cally characterized in detail for the first time. The 13C- and 19F-NMR spectroscopic results are reported, and the results are correlated to the tacticity and microstructure of both homopolymers. The major portion of the polymers is atactic. TGA analysis of PFAN indicates that the polymer is stable to about 200°C with subsequent loss of HF. PEFA is stable to 300 °C. Molecular weights determined by intrinsic viscosity (Mv ) are found to be about 130,000 for PFAN, and GPC analysis of PEFA indicates a molecular weight (Mn ) of about 36,000. Dielectric permittivities (ε) for PFAN and PEFA were determined to be 8.9 and 4.0, respectively, at 50 Hz. 相似文献
100.
Mahboubeh Tasviri Shahnaz Ghasemi Hedayatollah Ghourchian Mohammad Reza Gholami 《Journal of Solid State Electrochemistry》2013,17(1):183-189
By combination of 1-ethyl-3-methyl immidazolium ethyl sulfate as a typical room temperature ionic liquid (IL) and graphene oxide (GO) nanosheets, a nanocomposite was introduced for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase (GOx). The enzyme on the IL–GO-modified glassy carbon electrode exhibited a quasireversible cyclic voltammogram corresponding to the flavine adenine dinucleotide/FADH2 redox prosthetic group of GOx. At the scan rate of 100 mV?s?1, the enzyme showed a peak-to-peak potential separation of 82 mV and the formal potential of ?463 mV (vs Ag/AgCl in 0.1 M phosphate buffer solution, pH?7.0). The kinetic parameters of the charge transfer rate constant, the electron transfer coefficient, and the apparent Michaelis–Menten constant were calculated as 1.36 s?1 and 0.35 and 2.47 μM, respectively. When the modified electrode was examined as a biosensor for glucose determination, a linear range of 2.5–45 nM with detection limit of 0.175 nM (signal to noise?=?3) was obtained. The biosensor was stable for 2 months. 相似文献