全文获取类型
收费全文 | 112篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
化学 | 95篇 |
力学 | 3篇 |
数学 | 15篇 |
物理学 | 8篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 796 毫秒
91.
Synthesis of high quality zinc blende CdSe nanocrystals 总被引:1,自引:0,他引:1
Mohamed MB Tonti D Al-Salman A Chemseddine A Chergui M 《The journal of physical chemistry. B》2005,109(21):10533-10537
Highly homogeneous and luminescent CdSe colloidal nanocrystals in the less common zinc blende crystal structure have been obtained at high temperature in a noncoordinating organic solvent. The key parameter appears to be the addition of a phosphonic acid to the trioctylphosphine-selenium complex before its injection into the hot cadmium mixture, while the role of temperature is less relevant. Compared to standard (wurtzite) colloidal CdSe preparations, we find that the growth rate is considerably reduced, and the energy gap between the first two absorption bands becomes larger. 相似文献
92.
Kubo M Gruia F Benabbas A Barabanschikov A Montfort WR Maes EM Champion PM 《Journal of the American Chemical Society》2008,130(30):9800-9811
The low-frequency mode activity of metalloporphyrins has been studied for iron porphine-halides (Fe(P)(X), X = Cl, Br) and nitrophorin 4 (NP4) using femtosecond coherence spectroscopy (FCS) in combination with polarized resonance Raman spectroscopy and density functional theory (DFT). It is confirmed that the mode symmetry selection rules for FCS are the same as for Raman scattering and that both Franck-Condon and Jahn-Teller mode activities are observed for Fe(P)(X) under Soret resonance conditions. The DFT-calculated low-frequency (20-400 cm (-1)) modes, and their frequency shifts upon halide substitution, are in good agreement with experimental Raman and coherence data, so that mode assignments can be made. The doming mode is located at approximately 80 cm (-1) for Fe(P)(Cl) and at approximately 60 cm (-1) for Fe(P)(Br). NP4 is also studied with coherence techniques, and the NO-bound species of ferric and ferrous NP4 display a mode at approximately 30-40 cm (-1) that is associated with transient heme doming motion following NO photolysis. The coherence spectra of three ferric derivatives of NP4 with different degrees of heme ruffling distortion are also investigated. We find a mode at approximately 60 cm (-1) whose relative intensity in the coherence spectra depends quadratically on the magnitude of the ruffling distortion. To quantitatively account for this correlation, a new "distortion-induced" Raman enhancement mechanism is presented. This mechanism is unique to low-frequency "soft modes" of the molecular framework that can be distorted by environmental forces. These results demonstrate the potential of FCS as a sensitive probe of dynamic and functionally important nonplanar heme vibrational excitations that are induced by the protein environmental forces or by the chemical reactions in the aqueous phase. 相似文献
93.
Benoit Boulinguiez Abdelkrim Bouzaza Smail Merabet Dominique Wolbert 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):254-261
Photocatalytic treatment of polluted air by odorous contaminants – ammonia and butyric acid – is investigated in a plug-flow reactor covered by non-woven fiber textile coated with TiO2. For the first time, the single-component degradation pathway of ammonia by photocatalysis at ambient condition is highlighted. It appears fundamentally different compared to the butyric acid degradation pathway. The ammonia degradation pathway highlights a possible auto-accelerated behavior of the reaction. The chemical degradation kinetics follows the Langmuir–Hinshelwood model, though observed oxidation rates depend upon flow conditions in the reactor. Thus, interpretation of degradation results through a model considering the Langmuir–Hinshelwood approach and mass transfer phenomenon is presented. This model succeeds with a pair of determined kinetic constants and mass transfer coefficients to describe experimental results for different flow rates and for both pollutants, though they present wide dissimilarities in their degradation pathways. 相似文献
94.
95.
Abdelkrim Meddour Ccile Canlet Luis Blanco Jacques Courtieu 《Angewandte Chemie (International ed. in English)》1999,38(16):2391-2393
Unambiguous assignment of the resonances of different diastereomers in a nonracemic mixture is possible with 1H-decoupled 2H NMR spectroscopy in a chiral liquid crystalline solvent. This is demonstrated with, for example, the α,α′-dideuterated diol shown in the picture. Even diastereomers with centers of chirality up to nine bonds apart can be discriminated. 相似文献
96.
Jean-Paul Laval Abdelkrim Taoudi 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(11):1488-1493
The first ternary BaF2–Ln(Y)F3–ZrF4 phases crystallizing near the composition range of fluoride glasses, namely Ba4YZr3F23 (barium yttrium fluoridozirconate) and isotypic Ba4LnZr3F23 (Ln = Yb, Er and Nd), have been synthesized. The crystal structure of Ba4YZr3F23 cannot be correctly determined in the centrosymmetric space group Pnma (R1 = 0.09); it is preferably described in the noncentrosymmetric space group Pn21a (R1 = 0.028). All cations are located at y = 0.25–0.29 and 0.75–0.79. This new structure type is formed by infinite {[YZr3F23]8?}n columns associating, along [001], YF9 tricapped trigonal prisms, ZrF8 dodecahedra and ZrF7 polyhedra. These columns are interconnected via BaF10+1 and BaF12 irregular polyhedra. 相似文献
97.
Amani Jaafar Adeline Fix-Tailler Najwa Mansour Magali Allain Wassim N. Shebaby Wissam H. Faour Sima Tokajian Abdelkrim El-Ghayoury Daoud Naoufal Jean-Philippe Bouchara Gérald Larcher Ghassan Ibrahim 《应用有机金属化学》2020,34(12):e5988
The reactions of Cu (II), Zn (II) and Cd (II) chloride or bromide with (E)-1-(3,4-dimethoxybenzylidene)-4-methylthiosemicarbazone (MTSVT) lead to the formation of new complexes. They were characterized by spectroscopic studies: IR, 1H and 13C NMR. The crystal structures of the compounds [MTSVT] ( L ), [ZnBr2(MTSVT)2] ( 2 ), [CdCl2(MTSVT)2] ( 3 ) and [CdBr2(MTSVT)2.H2O] ( 4 ) were determined by X-ray diffraction. For complexes 2 – 4 , the ion is coordinated through the sulfur atom. All compounds were tested for their antifungal activity against human pathogenic fungi Candida albicans and Aspergillus fumigatus, and for their antibacterial activity against Gram (+) Bacillus subtilis and Enterococcus faecalis as well as against Gram (−) bacteria such as Paracoccus yeei and Acinetobacter baumanii. The results indicated that the metal complexes exhibited a marked enhancement in antibacterial activity compared with the parent Schiff base. 相似文献
98.
Ziti Ahmed Hartiti Bouchaib Labrim Hicham Batan Abdelkrim Fadili Salah Ridah Abderraouf Tahri Mounia Belafhaili Amine Thevenin Philippe 《Journal of Sol-Gel Science and Technology》2021,99(1):252-262
Journal of Sol-Gel Science and Technology - Quaternary semiconductor Cu2ZnSnS4 absorber material was synthesized by the sol-gel method deposited by the dip-coating technique on ordinary glass... 相似文献
99.
Frontispiece: Synthesis of Onion‐Peel Nanodendritic Structures with Sequential Functional Phosphorus Diversity
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
100.
Farid Nâamoune Bouzid Messaoudi Abdelkrim Kahoul Nabila Cherchour Alain Pailleret Hisasi Takenouti 《Ionics》2012,18(4):365-370
In this investigation, Mn3O4 spinel-type oxide was synthesized at low temperature using the Pechini process. We employed a sol-gel route, in which a solution
of Mn(II) in a mixture of citric acid and ethylene glycol was heated to form a polymeric precursor, followed by annealing
at lower temperature. The oxide obtained was identified by X-ray diffraction, scanning electron spectroscopy, and Raman spectroscopy.
The results revealed that the formation of Mn3O4 hausmannite structure with a minor secondary phase of MnSO4 occurred at or above 280 °C. The sample powder consisted of fine grains with homogeneous morphology and an average size close
to 1 μm was obtained. This new preparation procedure yielded an electrode oxide which appears to be a promising cathode material
for fuel cells and metal-air batteries. 相似文献