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排序方式: 共有98条查询结果,搜索用时 15 毫秒
81.
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
82.
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
83.
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
84.
A new method for calculating matrix elements of the collision integral is used for solving problems of the mobility of ions
against the background of atoms and for constructing the distribution functions for ions upon an abrupt application of an
electric field. It is shown how the stationary distribution function can be constructed using the nonstationary moments method
in the case when the stationary moments method is completely inapplicable. The solution to the nonstationary problem for the
CEM model corresponding to resonant charge exchange with a constant collision frequency, which is constructed analytically,
is used for analyzing the limits of applicability of the nonstationary moments method. 相似文献
85.
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
86.
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
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.
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
90.
A new method for calculating the matrix elements of the collision integral in the Boltzmann equation is used for studying the behavior of an ion impurity upon an abrupt application of an electric field. For five models of interaction, the behavior of mobility is analyzed and the evolution of the distribution function for various values of the electric field is illustrated. The initial stage of runaway of ions is studied in the case of the Coulomb interaction. Two methods for improving the convergence of the polynomial expansions of the distribution function are considered. 相似文献