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211.
212.
[reaction: see text] Bright green boradiazaindacene fluorescence is quenched by an oxidative photoinduced electron transfer (PET) from the excited state fluorophore to the bipyridyl unit complexed to metal cations. The closed shell diamagnetic cation Zn(II) is one of the most effective quenchers of fluorescence in this system, demonstrating that the quenching is not simply related to the facilitated intersystem crossing. The molecule also acts as a NOR logic gate with two chemical inputs, TFA and Zn(II). 相似文献
213.
Engin Şahin 《合成通讯》2020,50(4):549-557
AbstractAryl and heteroaryl chiral carbinols are useful precursors in the synthesis of drugs. Lactobacillus paracasei BD87E6, which is obtained from a cereal based fermented beverage, was investigated as whole cell biocatalyst for the bioreduction of different ketones (including aromatic, hetero-aromatic and fused bicyclic ketone) into chiral carbinols, which can be used as a pharmaceutical intermediate. The study shows that bioreduction of aryl, heteroaryl and fused bicyclic ketone (1-5) to their corresponding chiral carbinols (1a-5a) in excellent enantioselectivity (>99%) with high yields. This study gave the first example for an enantiopure production of (S)-6-chlorochroman-4-ol (3a), which has many antioxidant activity, by a biological method. For asymmetric bioreduction of other prochiral ketones, these results open way to use of L. paracasei BD87E6 as biocatalysts. Also, the present process shows a hopeful and alternative green synthesis for the production of enantiopure carbinols in a mild, inexpensive and environmentally friendly process. 相似文献
214.
A high resolution Raman spectrum of polycrystalline VOCl3 at –196 °C has been recorded. Besides the chlorine isotope splitting a further splitting of 3 of the 6 fundamentals has been observed. The number of the Raman lines in the 4 and 6 region and the intensity ratios in the 2 region will be explained by a factor group splitting of 2 VOCl3 molecules in the unit cell. 相似文献
215.
The temperature dependent behaviour of PCl4AsCl6, PCl4SbCl6 and AsCl4SbCl6 has been investigated byRaman spectroscopy. The As(V) containing complexes decompose into homogeneous molecular melts consisting of AsCl3, Cl2 and PCl5, respectively. In PCl4SbCl6 PCl4
+ and SbCl6
– complex ions were found in the solid as well as in the molten state. 相似文献
216.
Murat Yiğit Ismail Özdemir Engin Çetinkaya Bekir Çetinkaya 《Transition Metal Chemistry》2007,32(4):536-540
Reaction of 1,3-dialkylperhydrobenzimidazolinylidene, 1,3-dialkyl-4-methylimidazolinylidene and 1,3-dialkylimidazolinylidene
with [RhCl(COD)]2 yields {1,3-dialkylperhydrobenzimidazolin-2-ylidene}-, {1,3-dialkyl-4-methylimidazolin-2-ylidene}- {1,3-dialkylimidazolin-2-ylidene}chloro(η4-1,5-cyclooctadiene)rhodium(I) complexes (2a–c) and (4a, b). All compounds synthesised were characterised by elemental analysis, n.m.r. spectroscopy. Phenylboronic acid reacts with
aldehydes in the presence of a catalytic amount of the new rhodium(I)–carbene complexes (2a–c) and (4a, b), to give the corresponding aryl secondary alcohols in good yield (73–99%). 相似文献
217.
Hakan Gker Süreyya
lgen Rahmiye Ertand HÜLya Akgün Süheyla
zbey Engin Kendi GÜL Topu 《Journal of heterocyclic chemistry》1995,32(6):1767-1773
The title compounds, 1,2-dialkyl-benzimidazole-5(6)-carboxylic acids 34–45 were prepared at four steps; 1) preparation of mono amide derivatives 1–11 by the reaction of methyl 3,4-diaminobenzoate and substituted phenyl or phenoxyacetic acid chlorides; 2) preparation of the methyl benzimidazolecarboxyl-ates 12–22 , with zinc chloride and dry hydrogen chloride gas; 3) alkaline hydrolysis of the esters 23–33 ; and 4) substitution of the imidazole ring with benzyl or p-fluorobenzyl bromide, in alkali medium. 2-Aryl-benzimidazole-5(6)-carboxylic acids 50–53 were prepared via the oxidative condensation of 3,4-diaminobenzoic acid and aromatic aldehydes with cupric ion. 相似文献
218.
Electron spin resonance (ESR) spectroscopy was used to investigate the dosimetric properties of chicken egg shells. The ESR spectra of the irradiated egg shell were found to have an asymmetric absorption characterized by a major resonance at g=2.0019 and a minor resonance at g||=1.9980. The study was carried out on g=2.0019 signal because of the accuracy of measurements and the possibility of using it as ESR dosimeter. The activation energy (E), frequency factor (k0) and mean-life (τ) were calculated to be 1.50±0.10 eV, 2×1013 s−1 and (4.4±0.4)×104 year respectively. Dose–response was investigated between dose ranges of 1 Gy and 10 kGy for 60Co γ-rays. Dose–response was found to be appropriate for dosimetry in the range 3 Gy to 10 kGy. The lower limit of observable doses for egg shell sample was about 3 Gy. The other ESR dosimetric parameters of egg shell samples, fading characteristic, light effect, dose-rate dependence and energy dependence, have also been studied in detail. Apart from its non-tissue equivalence, egg shell has very good dosimetric properties with insignificant fading, light independence, linearity in dose–response (3 Gy–10 kGy), dose-rate independence and independence from energy above 500 keV. It suggests that egg shell may be used as a retrospective γ radiation dosimetry after nuclear accidents or other short accidental radiation events. 相似文献
219.
Süheyla Özbey Engin Kendi Hakan Göker Meral Tunçbilek 《Journal of chemical crystallography》1998,28(6):461-464
The crystal and molecular structure of the title compound has been determined by X-ray analysis. The 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole ion cocrystallizes with fumaric acid, (C19H22N4F+·C4H3O
4
–
), in space group P-1 with cell dimensions a = 9.938(1), b = 10.131(1), c = 12.712(1) Å, = 86.57(1), = 69.41(2), and = 67.22(2)°. The piperazine N4 atom is protonated and contacts the deprotonated O atom of the fumarate anion through a hydrogen bond. The benzimidazole ring is nearly planar and makes a dihedral angle of 111.25(12)° with the fluorophenyl ring. The piperazine ring adopts a chair conformation. 相似文献
220.
Latife Sahin Nurgül Hafızoğlu Hakan Çetinkaya Kaan Manisa Engin Bozkurt Ahmet Biçer 《Isotopes in environmental and health studies》2017,53(2):212-221
The analysis of natural radioactivity from 238U, 232Th and 40K in 357 soil samples collected from the province of Kütahya was carried out using a NaI(Tl) gamma-ray spectroscopy system at the Nuclear Physics Research Laboratory, Dumlup?nar University, Kütahya, Turkey. The specific activities of 238U, 232Th and 40K in the soil samples were evaluated. From the activity concentrations of 238U, 232Th and 40K, the total absorbed outdoor gamma-ray dose rates and the corresponding annual effective dose rates were determined. The corresponding values of the external and internal hazard indices of all the soil samples were also calculated. The external gamma-ray dose rate at 1 m above the ground was directly measured at each collected soil sample location. The results obtained in this study were compared within the limits of values obtained in other cities of Turkey, those in other countries. Radiological maps of Kütahya Province were constructed from the results of this study. 相似文献