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81.
Nonlinear Dynamics - Quasi-zero stiffness (QZS) isolators, a nonlinear vibration isolation technique, enhance the isolation performance, by lowering the natural frequencies of an isolation system... 相似文献
82.
Semiha akr Ender Bier Katsuyuki Aoki Emine Cokun 《Crystal Research and Technology》2006,41(3):314-320
A new nicotinamide complex of Fe(II) cation was prepared by reaction between ferrous sulfate and nicotinamide in aqueous solution. The complex was characterized on the basis of elemental analysis, FT IR and UV–VIS spectroscopy, electrochemistry (cyclic voltammetry) and X–ray crystallography. The complex consists of the molecular composition of [Fe(nicotinamide)2(H2O)4]· [Fe(H2O)6]·(SO4)2·2H2O. The complex crystallizes in the monoclinic space group P 21/c [a = 12.862(3), b = 7.110(3), c = 16.382(3) Å; β = 95.79(2)°]. It has been proven that nicotinamide is coordinated to Fe(II) through the nitrogen atom of its heterocyclic ring. © 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim 相似文献
83.
I. A. Ender L. A. Bakaleinikov E. Yu. Flegontova A. B. Gerasimenko 《Technical Physics》2017,62(8):1148-1155
We have proposed an algorithm for the sequential construction of nonisotropic matrix elements of the collision integral, which are required to solve the nonlinear Boltzmann equation using the moments method. The starting elements of the matrix are isotropic and assumed to be known. The algorithm can be used for an arbitrary law of interactions for any ratio of the masses of colliding particles. 相似文献
84.
Metin Gençten Koray B. Dönmez Yücel Şahin Kadir Pekmez Ender Suvacı 《Journal of Solid State Electrochemistry》2014,18(9):2469-2479
The gel electrolyte is an important component of the valve-regulated lead-acid (VRLA) batteries. In this study, fumed silica-based gel electrolyte systems were prepared. In this concept, several important parameters controlling the performance of the GEL-VRLA battery, such as the sulfuric acid and fumed silica concentrations, gel formulation, gelling time and rate, and different additives (Na2SO4 and MgSO4), were scientifically investigated. The gel formulations were characterized by cyclic voltammetric and electrochemical impedance spectroscopic methods. The optimum parameters were determined by using the results of anodic peak currents and redox capacities, R s and R ct values. Addition of 6 % (w/w) fumed silica to 30 % (w/w) sulfuric acid, for preparation of gelled electrolyte, increased the battery performance significantly. According to the results of the transmission electron and optic microscope images of the gel electrolytes, the three-dimensional gel structure was prepared successfully. The optimization of sulfuric acid concentration and amount of Na2SO4 and MgSO4 additives were examined for the first time in detail by cyclic voltammetry, electrochemical impedimetry, and battery test. Na2SO4 and MgSO4 additives make a good combination with a gelled-electrolyte system and improve the charge/discharge capacity according to sulfuric acid electrolytes. According to the experimental results, the fumed silica-based gel electrolyte system has a great potential for application in gelled electrolyte VRLA batteries. 相似文献
85.
A two-dimensional microslip friction model with normal load variation induced by normal motion is presented in this paper.
The model is a distributed parameter model, which characterizes the stick-slip-separation of the contact interface and determines
the resulting friction force, including its time variance and spatial distribution, between two elastic structures. When the
relative motion is simple harmonic motion, the stick-slip-separation transition angles associated with any point in the contact
area can be analytically determined within a cycle of motion. In addition, if the relative motion is given, stick-slip-separation
transition boundaries inside the contact area and their time variances can be determined. Along with an iterative multi-mode
solution approach utilizing harmonic balance method (HBM), the developed model can be employed to determine the forced response
of frictionally constrained structures. In the approach, the forced response is constructed in terms of the free mode shapes
of the structure; consequently, it can be determined at any excitation frequency and for any type of normal load distribution.
Two examples, a one-dimensional beam like damper and a more realistic blade to ground damper, are employed to illustrate the
predictive abilities of the developed model. It is shown that while employing a single mode model, transition boundaries for
the beam like damper agrees with the results given in the literature, the developed method identifies the phase difference
along the slip to stick transition boundary when a multi-mode model is employed. Moreover, while partial slip is illustrated
in the two examples, typical softening and hardening effects, due to separation of the contact surface, are also predicted
for the blade to ground damper. 相似文献
86.
In the present study, the interaction between cinchonine (CCN) and human serum albumin (HSA) was investigated using differential pulse polarography (DPP), cyclic voltammetry (CV) and spectroscopic techniques in Britton-Robinson (B-R) buffer pH 7.4. CCN displayed a main cathodic peak at ?1.228 V (vs. Ag|AgCl|KClsat) on mercury working electrode. The addition of HSA into CCN sulfate solution resulted in the decrease of the main reduction peak current of CCN and no new peaks appeared. The decay in the peak current of CCN, after the addition of HSA, showed a decrease in free drug concentration and formation of a biocomplex. The peak current changes of CCN in the presence of HSA were followed by DPP to determine the binding parameters. The logarithm of binding constant and binding ratio between CCN and HSA were 6.128 and 1: 1, respectively. This interaction was also confirmed by UV-Vis and FTIR-ATR spectroscopic measurements. 相似文献
87.
Özlem Türker Bayrak Ender Okandan Hale Üçkardeş 《Accreditation and quality assurance》2009,14(8-9):497-502
Fuel sector is one of the powerful sectors in Turkish industry. The implementation of a new law for regulating the fuel sector had enforced the quality control of fuels sold to public. This resulted in several accredited fuel-testing laboratories to emerge. Thus, a scheme to evaluate their proficiency in measurements became an important requirement. The inter-laboratory comparison scheme LABKAR for gasoline, diesel oil, LPG, lubricating oil and biodiesel samples have evolved to fulfill this need. In this paper, LABKAR is introduced; the results obtained from the program are analyzed and discussed. The kernel densities of the participants’ results show that the use of robust mean as a consensus value is appropriate for fuel samples. Although the number of rounds is not enough to derive strict conclusions, it is seen that the performance of the scheme based on the standard deviations and coefficient of variations is improving in each round. It has been observed that the number of laboratories receiving “action” or “warning” is decreasing, which indicates that they are benefiting from the scheme. 相似文献
88.
The electrochemical behaviors of copper ions complexed with picolinic, nicotinic and isonicotinic acids (2-, 3- and 4-pyridinecarboxylic acids) in Britton–Robinson buffer (pH 7.4) was studied by polarographic and voltammetric techniques on a mercury electrode. This study showed that the reduction of complexed copper ions in the presence of nicotinic acid (NA) was carried out in two one-electron steps [Cu(II)/Cu(I) and Cu(I)/Cu(0)] whereas this cathodic process in the presence of picolinic acid (PA) or isonicotinic acid (INA) occurred in one two-electron step [Cu(II)/Cu(0)]. The stability of the Cu(I) complex can be sourced from the positions of carboxylate substituents on these isomeric ligands, binding to the copper center. 相似文献
89.
The kinetics of C-S coupling of phenylmagnesium bromide with phenyl arenesulfonates has been studied in THF:toluene (7:10) at 90 °C. Kinetic data and Hammett relationship are consistent with an asynchronous SNa mechanism in which rate determining thiophilic attack of carbanion takes place much ahead of phenoxy group departure. 相似文献
90.
A single-stage swelling and polymerization method was proposed for the synthesis of monodisperse porous poly(vinyl acetate-co-divinylbenzene) [poly(VAc-co-DVB)] particles with different VAc/DVB feed ratios. The particles obtained with the VAc/DVB feed ratio of 50:50 v/v had a narrow pore size distribution exhibiting a sharp peak at 30 nm. Based on this distribution the mean pore size and the specific volume were determined as 12 nm and 1.39 mL/g, respectively. The specific surface area of poly(VAc-co-DVB) particles was found to be 470 m2/g. These properties make poly(VAc-co-DVB) particles a promising support for potential HPLC applications. Poly(vinyl alcohol-co-divinylbenzene) [poly(VA-co-DVB)] particles were then obtained by the basic hydrolysis of poly(VAc-co-DVB) particles. The hydroxyl groups on poly(VA-co-DVB) particles have a suitably reactive functionality for surface grafting or derivatization protocols aiming at synthesizing various HPLC packings. The examination of poly(VA-co-DVB) particles by confocal laser scanning microscopy showed the homogeneous distribution of hydroxyl functionality in the particle interior. As a starting point, the chromatographic performance of plain material, poly(VAc-co-DVB) particles produced with VAc/DVB feed ratio of 50:50 (v/v) was tested by a commonly utilized chromatographic mode, reversed phase chromatography. Poly(VAc-co-DVB) particles were successfully used as packing material in the RP separation of alkylbenzenes with resolutions higher than 1.5. Theoretical plate numbers up to 17 500 plates/m were achieved. No significant change both in the chromatographic resolution and column efficiency was observed with increasing flow rate. The chromatography showed that poly(VAc-co-DVB) particles were a suitable starting material for the synthesis of chromatographic packings for different modes of HPLC. 相似文献