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151.
Hyunji Jung Dr. Abhishek Dubey Hyun Jung Koo Dr. Vaishali Vajpayee Dr. Timothy R. Cook Dr. Hyunuk Kim Prof. Se Chan Kang Prof. Peter J. Stang Prof. Ki‐Whan Chi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6709-6717
The synthesis of six new [2+2] metallarectangles through the coordination‐driven self‐assembly of octahedral RuII‐based acceptors with ambidentate pyridyl‐carboxylate donors is described. These molecular rectangles are fully characterized by 1H NMR spectroscopy, high‐resolution electrospray mass spectrometry, and single‐crystal X‐ray diffraction. In each case, despite the possible formation of multiple isomers, based on the relative orientation of the pyridyl and carboxylate groups (head‐to‐head versus head‐to‐tail), evidence for the formation of a single preferred ensemble (head‐to‐tail) was found in the 1H NMR spectra. Furthermore, the cytotoxicities of all of the rectangles were established against A549 (lung), AGS (gastric), HCT‐15 (colon), and SK hep 1 (liver) human cancer cell lines. The cytotoxicities of rectangles that contained the 5,8‐dihydroxy‐1,4‐naphthaquinonato bridging moiety between the Ru centers ( 9 – 11 ) were particularly high against AGS cancer cells, with IC50 values that were comparable to that of reference drug cisplatin. 相似文献
152.
An efficient procedure for conversion of alcohols to the corresponding carbonyl compounds, an alternative to the classical Swern oxidation, is described. Pivaloyl chloride is employed as a mild and inexpensive electrophile. A possible reaction mechanism is proposed. 相似文献
153.
Synthesis and Spectral Characterization of Related Substances of Lacidipine,an Antihypertensive Drug
V. V. N. K. V. Prasada Raju Ganta Madhusudhan Reddy Vedantham Ravindra Vijayavitthal T. Mathad P. K. Dubey 《合成通讯》2013,43(12):2137-2145
Five related substances (impurities) were detected in lacidipine bulk drug substance by a simple high-performance liquid chromatographic method (HPLC) and were identified by liquid chromatography–mass spectrometry (LC-MS). These related substances were independently synthesized, characterized, and co-injected with the sample containing impurities. 相似文献
154.
Facile Syntheses of Histamine- and Imidazole-4-propionic Acid–Derived Room-Temperature Ionic Liquids
We report synthesis of histamine- and imidazole-4-propionic acid–based ionic liquids containing a variety of alkyl and aryl groups placed at the two different positions of the constituent imidazole ring in convenient steps in good yields. 相似文献
155.
R. M. Tripathi S. K. Sahoo S. Mohapatra P. Lenka J. S. Dubey V. D. Puranik 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1195-1200
Uranium concentration in groundwater reflect both redox conditions and uranium content in host rock. In the present study an attempt has been made to study the uranium concentration and activity ratios of uranium isotopes to present the geochemical conditions of the groundwater in Malwa region of Punjab state, India and the reason for high uranium levels and variation of activity ratios from secular equilibrium conditions. Uranium concentration in groundwater samples was found to be in the range of 13.9 ± 1.2 to 172.8 ± 12.3 μg/l with an average value of 72.9 μg/l which is higher than the national and international guideline values. On the basis of uranium concentration, the groundwater of the study region may be classified as oxidized aquifer on normal uranium content strata (20 %) or oxidized aquifer on enhanced uranium content strata (80 %). The 238U, 235U and 234U isotopic concentration in groundwater samples was found to be in the range of 89.2–1534.5, 4.4–68.5, and 76.4–1386.2 mBq/l, respectively. Activity ratios of 234U/238U varies from 0.94 to 1.85 with a mean value of 1.11 which is close to unity that shows secular equilibrium condition. High value of 234U isotope than 238U may be due to alpha recoil phenomenon. The plot of AR of 234U/238U against the total uranium content in log scale reveals that the groundwaters of the study region either belongs to stable accumulation or normal oxidized aquifer. 相似文献
156.
Chittipaka Rajitha P. K. Dubey Venkataiah Sunku Venugopal Rao Veeramaneni Manojit Pal 《Journal of heterocyclic chemistry》2013,50(3):630-637
The synthesis of novel 1,2,3‐thiadiazol derivatives containing 2H‐benzo[b][1,4]oxazin‐3(4H)‐one moiety as one of the substituents has been reported. A combined application of H3PO4/(CF3CO)2O mediated acylation followed by Hurd–Mori reaction has been explored to synthesize these compounds. The scope and limitation of this strategy along with the reaction mechanism of the key step is discussed. 相似文献
157.
The title compound (5) has been prepared in one pot by refluxing 1‐(1‐alkyl/aralkyl‐1H‐benzimidazole‐2‐yl)‐ethanone (1) with substituted o‐phenylenediamine (2) in ethanol in the presence of iodine. Alternatively, 5 could also be prepared by treating 2‐bromo‐1‐(1‐ alkyl/aralkyl‐1H‐benzimidazole‐2‐yl)‐ethanone (3A) with 2 in refluxing ethanol. The formation of 5 from 1 and 2 probably occurs through the intermediacy of 3B (i.e., 3, X=I) and 4. 相似文献
158.
P. Praveen Kumar Y. Dathu Reddy Ch. Venkata Ramana Reddy B. Rama Devi P.K. Dubey 《Green Chemistry Letters and Reviews》2014,7(4):322-329
Green synthesis of novel title compounds (6) has been developed from 3-(1,4-dioxo-3,4-dihydrophthalazin-(1H)-yl)-3-oxopropanenitrile (3) and indole-3-aldehyde (4) using Knoevenagel condensation followed by alkylation with alkylating agents. Compound 6 could also be synthesised by alkylation of 4 followed by condensation with 3. In an alternate sequence of reactions, 6 could be synthesised either from treatment of 3 with N,N-dimethylformamide dimethyl acetal to form (E)-3-(dimethlamino)-2-(1,4-dioxo-1,2,3,4-tetrahydrophthalazine-2-carbonyl)acrylonitrile 8 followed by reaction with 10 or by the reaction 8 with 9 followed by alkylation. 相似文献
159.
New complexes of iron(III) of the type [(μ-Cl)2Fe2{η
2-(opbz)4] (1) and [(Cl)2Fe{η
2-(opbz)] (2) [Hopbz = {2-(o-hydroxyphenyl)}-benzimidazole, η
2 = Number of connectivity sites involved in bonding the metal] have been synthesized by the interactions of iron(III) chloride
with the corresponding ligand (Hopbz) in 1:2 and 1:1 molar ratio(s) in hot EtOH. The complex (1) was further treated with various sodium salts of Schiff bases (sb) [Na(o-smab), Na(p-smab) and Na(sap)], alkoxo-Na(OPri), aryloxo-Na(OAr) and tetraisopropoxyaluminate [Na{Al(OPri)4] in a 1:1 molar ratio (in THF–benzene medium) to produce derivatives of the type: {(η
2-(sb) Fe{η
2-opbz)2] (3), (4) and (5), [(μ-OPri)2Fe2{η-(opbz)4}] (6) [(μ-OAr)2Fe2{η-(opbz)4}] (7) and [(μ-OPri)2Al(OPri)2-Fe{η-(opbz)2}] (8). All these derivatives were characterised by elemental analysis, spectral (IR, UV–visible and FAB-mass) and magnetic susceptibility
measurements. On the basis of these studies, a distorted octahedral (dimeric) geometry around iron(III) for the complexes
(1), (6), (7) and (8) have been suggested. 相似文献
160.
S. Thamotharan V. Parthasarathi S. Dubey D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o110-o112
In the title compound, C29H36O2, the outer cyclohexene ring of the steroid nucleus has a conformation that lies about half‐way between a half‐chair and an envelope, while the central and outer cyclohexane rings of the steroid nucleus have slightly distorted chair conformations. The steroidal cyclopentane ring adopts a 13β,14α‐half‐chair conformation. The benzylidene moiety has an E configuration with respect to the carbonyl group on the cyclopentane ring. The dihedral angle between the mean planes of the steroid nucleus and the benzylidene moiety is 35.54 (9)°. The packing of the molecules is assumed to be dictated mainly by weak intermolecular C—H⋯O interactions. 相似文献