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91.
Sumiyoshi T Urabe D Tojo K Sakamoto M Niidome K Tsuboya N Nakajima T Tobe M 《Molecules (Basel, Switzerland)》2012,17(6):6507-6518
We describe in this study the asymmetric synthesis of radioisotope (RI)-labeled selective glucocorticoid receptor modulator. This synthesis is based on optimization of the cinchona alkaloid catalyzed addition of 6-bromoindole to ethyl trifluoropyruvate and Negishi coupling of zinc cyanide to the 6-bromoindole moiety. [1?C] Labeled (-)-{4-[(1-{2-[6-cyano-1-(cyclohexylmethyl)-1H-indol-3-yl]-3,3,3-trifluoro-2-hydroxypropyl}piperidin-4-yl)oxy]-3-methoxyphenyl}acetic acid (-)-1 was synthesized successfully with high enantioselectivity (>99% ee) and sufficient radiochemical purity. 相似文献
92.
Sasaki T Shizuki N Hiraishi E Hisaki I Tohnai N Miyata M 《Organic & biomolecular chemistry》2012,10(30):5985-5992
Molecular assemblies based on helical motifs are of substantial interest from the view point of fundamental science as well as application. In this study, we propose a new class of organic crystal, that is, heteroH-MOC (multi-component organic crystal containing different kinds of helical motifs consisted of different components), and describe successful construction of heteroH-MOCs with P2(1) and P2(1)2(1)2(1) space groups by using steroidal bile acids and cinchona alkaloids. In the P2(1) crystals, two kinds of helices composed of the steroid and alkaloid are arranged in a parallel fashion, while, in the P2(1)2(1)2(1) crystals, those are in a perpendicular fashion. It is remarkable that, in such systems, particularly in the latter crystals, components ingeniously achieved highly-ordered synchronization of periodicity (helical pitches r and periodic distances in the array of helices p), which is first demonstrated in this study through hierarchical interpretation of the crystal structures. 相似文献
93.
Esmail Vessally Ladan Edjlali Maryam Saber Soma Aryana 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(5):791-797
Geometrical structures, Hammett constants, 1H and 13C chemical shift values, molecular electrostatic potential maps, and several thermodynamic parameters of α-acyloxy carboxamide
derivatives (4a–o) were calculated using HF and DFT/B3LYP methods with 6-31G(d) basis set. The optimized structures were compared with analogous compound. The 1H and 13C NMR shielding tensors were computed with the Gauge-Independent Atomic Orbital (GIAO) method. Comparison of the experimental
1H and 13C NMR chemical shifts of 4a–o molecules with the theoretical data indicates good agreement. 相似文献
94.
Priyanka Poddar Soma Mitra Md. Mabud Hossain Debasish Biswas Pradip N. Ghosh 《Molecular physics》2013,111(15):1957-1964
The line shape parameters of rovibrational transitions of water vapour belonging to the (2ν1 + ν2 + ν3) overtone band due to collisions between absorber molecules and noble gas helium have been measured in the spectral range between 11988.494 cm?1 and 12218.829 cm?1 using NIR diode laser spectrometer. In addition nitrogen and air broadening effects on some water vapour transitions belonging to the same band have also been studied. Wavelength modulation spectroscopy along with phase sensitive detection technique are used to record first derivative (1f) signal of buffer gas broadened water vapour transitions. Observed line shapes are fitted to standard Voigt profiles by non-linear least squares fitting program to extract the line shape parameters, like line strength and pressure broadening coefficients. The broadening effects induced by different types of buffer gases on water vapour line shapes are compared. Rotational quantum number (J) dependence of broadening coefficients of water vapour transitions is also examined. 相似文献
95.
A Nag DS Chung DS Dolzhnikov NM Dimitrijevic S Chattopadhyay T Shibata DV Talapin 《Journal of the American Chemical Society》2012,134(33):13604-13615
Colloidal semiconductor nanocrystals (NCs) provide convenient "building blocks" for solution-processed solar cells, light-emitting devices, photocatalytic systems, etc. The use of inorganic ligands for colloidal NCs dramatically improved inter-NC charge transport, enabling fast progress in NC-based devices. Typical inorganic ligands (e.g., Sn(2)S(6)(4-), S(2-)) are represented by negatively charged ions that bind covalently to electrophilic metal surface sites. The binding of inorganic charged species to the NC surface provides electrostatic stabilization of NC colloids in polar solvents without introducing insulating barriers between NCs. In this work we show that cationic species needed for electrostatic balance of NC surface charges can also be employed for engineering almost every property of all-inorganic NCs and NC solids, including photoluminescence efficiency, electron mobility, doping, magnetic susceptibility, and electrocatalytic performance. We used a suite of experimental techniques to elucidate the impact of various metal ions on the characteristics of all-inorganic NCs and developed strategies for engineering and optimizing NC-based materials. 相似文献
96.
Chloroform is available as not only an organic solvent but also photochemical molecular storage for synthetically important chemicals such as Cl(2), HCl, and COCl(2). We have succeeded in synthesizing organochlorine compounds, hydrochloric salt of amines, ureas, organic carbonates, and polycarbonate in practical high yields with photodecomposed chloroform. 相似文献
97.
Soma Nag 《Applied Surface Science》2009,256(2):353-355
We study squeeze flow of two different fluids (castor oil and ethylene glycol) between a pair of glass plates and a pair of perspex plates, under an applied load. The film thickness is found to vary with time as a power-law, where the exponent increases with load. After a certain time interval the area of fluid-solid contact saturates to a nearly steady value. This saturation area, increases with load at different rates for different fluid-solid combinations. 相似文献
98.
Dra Lakk-Bogth Patrik Trk Flra Viktria Csendes Soma Keszei Beatrix Gantner Jzsef Kaizer 《Molecules (Basel, Switzerland)》2021,26(15)
Heme iron and nonheme dimanganese catalases protect biological systems against oxidative damage caused by hydrogen peroxide. Rubrerythrins are ferritine-like nonheme diiron proteins, which are structurally and mechanistically distinct from the heme-type catalase but similar to a dimanganese KatB enzyme. In order to gain more insight into the mechanism of this curious enzyme reaction, non-heme structural and functional models were carried out by the use of mononuclear [FeII(L1–4)(solvent)3](ClO4)2 (1–4) (L1 = 1,3-bis(2-pyridyl-imino)isoindoline, L2 = 1,3-bis(4′-methyl-2-pyridyl-imino)isoindoline, L3 = 1,3-bis(4′-Chloro-2-pyridyl-imino)isoindoline, L4 = 1,3-bis(5′-chloro-2-pyridyl-imino)isoindoline) complexes as catalysts, where the possible reactive intermediates, diiron-perroxo [FeIII2(μ-O)(μ-1,2-O2)(L1-L4)2(Solv)2]2+ (5–8) complexes are known and well-characterized. All the complexes displayed catalase-like activity, which provided clear evidence for the formation of diiron-peroxo species during the catalytic cycle. We also found that the fine-tuning of iron redox states is a critical issue, both the formation rate and the reactivity of the diiron-peroxo species showed linear correlation with the FeIII/FeII redox potentials. Their stability and reactivity towards H2O2 was also investigated and based on kinetic and mechanistic studies a plausible mechanism, including a rate-determining hydrogen atom transfer between the H2O2 and diiron-peroxo species, was proposed. The present results provide one of the first examples of a nonheme diiron-peroxo complex, which shows a catalase-like reaction. 相似文献
99.
Controlled release technology addresses problems associated with excessive use of toxic agricultural chemicals. This paper reviews the studies on the use of carbohydrate polymers as controlled release matrices for pesticides. Alginates, starch and its derivatives, chitosan, carboxymethylcellulose and ethylcellulose are some of the natural polymers discussed in this review. The advantages and disadvantages of these polymeric systems as well as the factors that affect pesticide release are presented. A discussion on the polymers’ encapsulation efficiency and release profile is also included, which will aid future researchers in identifying the suitable formulation for controlled release of pesticides. Combination of two polymers, incorporation of sorbents into polymer matrices, and modification of polymer systems are some of the strategies also discussed herein. Recent trends in this area of research include nanoformulation, nanoencapsulation, and the development of polymeric systems with dual properties such as controlled release with photo-protective property and the attract-and-kill strategy. Cytotoxicity studies are being conducted to address safety issues of pesticide handlers as well as to determine the toxicity of the formulation to non-target organisms such as the plant itself. 相似文献
100.
Thin silicon phthalocyanine dichloride films on HOPG were prepared and the 相似文献