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141.
142.
3,6-diaryl-2,5-dihydro-1,4-diketopyrrolo[3,4-c]pyrrole-1,4-dione (DPPD) derivatives are used commercially as red pigments,
because of their color strength, brightness, and very low solubility in most common solvents. These products, although highly
colored, appear to be of limited value as dyes, since they show a tendency to form an aggregate when incorporated into a solvent.
Monoalkyl and dialkyl derivatives of DPPD were synthesized and then characterized with IR, 1HNMR, UV-Vis absorption and emission spectroscopy. Molar absorption coefficient, singlet energy level and Stokes’ shift values
of DPPD derivatives were declared. Monoalkyl and dialkyl derivatives of DPPD’s solubilities were measured from saturated solutions
of dimethylformamide (DMF), tetrahydrofuran (THF), dichloromethane (DCM), acetonitrile (ACN) and toluene and they are compared
with each other. 相似文献
143.
The purpose of this paper is to focus on the experimentally obtained results of impinging jet applications by the help of
two different analysis methods. Circular round pipes (D = 7.9, 10.8, 13.8 and 23.1 mm) have been used as the impinging jets. The heat transfer is calculated with Nusselt number
(Nu). The variable parameters are the dimensionless jet-to-impingement plate distance (z/D), Reynolds number (Re) and dimensionless temperature measurement points on the heated surface (x/L, y/L). Some important analysis methods such as artificial neural network (ANN), statistical regression, and uncertainty analysis
are applied to the obtained data. It is shown that the ANN application is not simply a classification analysis; it is actually
an application of the convergence of functions. As a result, by considering random data, 4.57% convergence level is obtained
regarding the pipe diameter. The software STATISTICA 5.0 is used to estimate new empirical correlations nonlinearly. The smallest
regression coefficient for the correlations is 0.87, while the highest value is 0.99. The result of the uncertainty analyses
showed that the total uncertainties are in the agreeable range; 8% for Nu, and 2.89% for Re.
Dr. Nevin Celik is a Post Doctoral Fellowship in University of Minnesota since August 2007. 相似文献
144.
Yaşar F Arkin H Celik T Berg BA Meirovitch H 《Journal of computational chemistry》2002,23(12):1127-1134
The advantage of the multicanonical (MUCA) simulation method of Berg and coworkers over the conventional Metropolis method is in its ability to move a system effectively across energy barriers thereby providing results for a wide range of temperatures. However, a MUCA simulation is based on weights (related to the density of states) that should be determined prior to a production run and their calculation is not straightforward. To overcome this difficulty a procedure has been developed by Berg that calculates the MUCA weights automatically. In a previous article (Ya?ar et al. J Comput Chem 2000, 14, 1251-1261) we extended this procedure to continuous systems and applied it successfully to the small pentapeptide Leu-enkephalin. To investigate the performance of the automated MUCA procedure for larger peptides, we apply it here to deltorphin, a linear heptapeptide with bulky side chains (H-Tyr(1)-D-Met(2)-Phe(3)-His(4)-Leu(5)-Met(6)-Asp(7)-NH(2)). As for Leu-enkephalin, deltorphin is modeled in vacuum by the potential energy function ECEPP. MUCA is found to perform well. A weak second peak is seen for the specific heat, which is given a special attention. By minimizing the energy of structures along the trajectory it is found that MUCA provides a good conformational coverage of the low energy region of the molecule. These latter results are compared with conformational coverage obtained by the Monte Carlo minimization method of Li and Scheraga. 相似文献
145.
Mehmet Karakus Dr. Yıldırım Aydogdu Omer Celik Veysel Kuzucu Semra Ide Evamarie Hey‐Hawkins Prof. Dr. 《无机化学与普通化学杂志》2007,633(3):405-410
Ferrocenyldithiodiphosphetane [FcPS(μ‐S)]2 [Fc = Fe(η5‐C5H4)(η5‐C5H5)] reacts with the aminoethanol derivatives 1‐ethyl‐3‐pyrrolidinol and 2‐(piperazin‐1‐yl)ethanol to give the zwitterionic (O‐ethylammonium)ferrocenyldithiophosphonates ( 2 ) and ( 3 ), which were fully characterized by elemental analysis, IR and NMR spectroscopy and mass spectrometry. The optical and electrical properties of 2 and 3 as well as those of the previously reported [FcP(S)S(OC2H4NHEt2)] ( 1 ) were studied. A molecular structure determination of 1 is also reported. 相似文献
146.
Mehmet Sirin Tutgun Deniz Sinirlioglu Sevim Unugur Celik Ayhan Bozkurt 《Ionics》2015,21(10):2871-2878
The preparation, thermal, morphological, and ion-conducting properties of new composite membranes based on poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) and nitrilotri(methylphosphonic acid) (NMPA)/hexagonal boron nitride (hBN) were carried out throughout this work. Fourier transform infrared (FTIR) spectroscopy was used to characterize the interactions between host polymer, NMPA, and inorganic additive, hBN. Thermal properties of the materials were examined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) tests. TGA results illustrated that all composite membranes are thermally stable up to 200 °C. The surface topography of the films was investigated by scanning electron microscopy (SEM) and verified that hBN uniformly dispersed into the PAMPS-NMPA matrix. The crystallinity of the membranes was characterized by using X-ray diffraction (XRD). X-ray patterns support semicrystalline nature of the composite materials. At anhydrous conditions, the maximum proton conductivity was found as 3.2?×?10?5 S cm?1 at 150 °C for PAMPS-NMPA-3hBN via impedance analyzer. 相似文献
147.
Formisano C Rigano D Senatore F Celik S Bruno M Rosselli S 《Natural product research》2008,22(10):833-839
The volatile constituents of the aerial parts of Centaurea amanicola Hub.-Mor., Centaurea consanguinea DC. and Centaurea ptosimopappa Hayek were extracted by hydrodistillation and analysed by GC and GC-MS. Altogether 94 components were identified. Sesquiterpenoids, fatty acids and carbonylic compounds were the most abundant components in the oils. Hexadecanoic acid and (Z,Z )-9,12-octadecadienoic acid were the main fatty acids in all the examined samples, that showed different patterns of composition. The study on the biological activity of the oils showed an action mainly against the Gram-positive pathogens. 相似文献
148.
Prof. Dr. Holger Braunschweig Dr. Mehmet Ali Celik Florian Hupp Dr. Ivo Krummenacher Lisa Mailänder 《Angewandte Chemie (International ed. in English)》2015,54(21):6347-6351
Herein, we present the results of our investigations on the effect of ortho substitution of aryl azides on the ring‐expansion reaction of boroles, five‐membered unsaturated boron heterocycles. These studies led to the isolation of the first 1,2‐azaborinine‐substituted azo dyes, which are bright yellow solids. One of the derivatives, (E)‐2‐mesityl‐1‐(mesityldiazenyl)‐3,4,5,6‐tetraphenyl‐1,2‐azaborinine, was found to be unstable in solution and to transform through a Jacobsen‐like reaction into an indazole and 1‐hydro‐1,2‐azaborinine. DFT calculations were performed to shed light on possible mechanisms to rationalize the unexpected azo‐azaborinine formation and to draw conclusions about the role played by the ortho substituents in the reaction. 相似文献
149.
Prof. Dr. Holger Braunschweig Dr. Qing Ye Dr. Mehmet Ali Celik Dr. Rian D. Dewhurst Dr. Krzysztof Radacki 《Angewandte Chemie (International ed. in English)》2015,54(17):5065-5068
A 1,4‐dibora‐1,3‐butadiene iron complex was successfully synthesized through the stoichiometric reaction of an iron bis(borylene) complex with diphenylacetylene. This complex was treated with CO and PMe3, which led to the formation of an unusual six‐membered B2C3O ylidic ring bound to both the PMe3 group and zerovalent iron center. The reaction is a very rare example of the incorporation of both atoms of CO into a ring system. 相似文献
150.