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101.
102.
Harrell Sellers 《International journal of quantum chemistry》1993,45(1):31-41
We present a theoretical and numerical comparison between two DIIS algorithms to which we refer herein as C 1-DIIS and C 2-DIIS . The C 2-DIIS algorithm is shown to be equivalent to the traditional C 1-DIIS algorithm near convergence and more stable numerically as regards the accumulation of round-off error when the C 1-DIIS equations become (nearly) singular. The C 2-DIIS algorithm also offers alternative solutions to the DIIS equations when anharmonicities or numerical difficulties are problematic. These properties of the C 2-DIIS algorithm allow the use of much larger DIIS spaces, obviating the need for truncation of the DIIS space, which, when done, usually results in a loss of information contained in the iterated subspace. The C 2-DIIS method can be considered to be a variant of the singular value decomposition method. © 1993 John Wiley & Sons, Inc. 相似文献
103.
S K Salzman M S Sellers A L Beckman R Naidu G D Macewen 《Journal of chromatography. A》1985,343(2):285-301
Liquid chromatography with electrochemical detection was used for the determination of norepinephrine and epinephrine in human plasma samples obtained prior to, after, and six times during the course of spinal fusion surgery for the correction of scoliosis. The catecholamines were extracted from plasma by alumina adsorption and chromatographed isocratically using a reversed-phase, ion-pairing system. Data obtained are compared to those obtained intraoperatively by other authors using a radioenzymatic method, and the mechanism of sympathetic activation during surgery is discussed. Preliminary data using 3-micron particle size columns and dual-parallel electrochemical detection are presented. 相似文献
104.
Lights, Camera, Action! systematic variation in 2-D difference gel electrophoresis images 总被引:1,自引:0,他引:1
2-D Difference gel electrophoresis (DIGE) circumvents many of the problems associated with gel comparison via the traditional 2-DE approach. DIGE's accuracy and precision, however, is compromised by the existence of other significant sources of systematic variation, including that caused by the apparatus used for imaging proteins (location of the camera and lighting units, background material, imperfections within that material, etc.). Through a series of experiments, we estimate some of these factors, and account for their effect on the DIGE experimental data, thus providing improved estimates of the true relative protein intensities. The model presented here includes 2-DE images as a special case. 相似文献
105.
An efficient and general procedure was developed for the direct alkylation of H-phosphinate esters with LHMDS at low temperature. The simplicity of the reaction allows the use of various H-phosphinate esters and takes place with a wide range of electrophiles. The approach can be employed to access some GABA analogues or precursors to GABA analogues. The isolated yields are moderate to good. This is the first report of an alkylation with a secondary iodide or a primary chloride. 相似文献
106.
C. Van Alsenoy J.N. Scarsdale H.L. Sellers Lothar Schäfer 《Chemical physics letters》1981,80(1):124-126
The structures of two unionized conformations of serine were refined without geometrical constraints using standard single determinant ab initio procedures on the 4-21G level. The results represent the best now available estimate for the unobserved equilibrium geometry of this system. 相似文献
107.
The well-known Rogers-Ramanujan identities have been a rich source of mathematical study over the last fifty years. In particular, Gordon’s generalization in the early 1960s led to additional work by Andrews and Bressoud in subsequent years. Unfortunately, these results lacked a certain amount of uniformity in terms of combinatorial interpretation. In this work, we provide a single combinatorial interpretation of the series sides of these generating function results by using the concept of cluster parities. This unifies the aforementioned results of Andrews and Bressoud and also allows for a strikingly broader family of q-series results to be obtained. We close the paper by proving congruences for a “degenerate case” of Bressoud’s theorem. 相似文献
108.
Hanell Sellers 《Chemical physics letters》1984,108(4):339-341
The adiabatic correction to the Hartree-Fock ring puckering potential of oxetane is presented along with the adiabatic correction to potential functions of H2, CO, and CO2. The oxetane calculation allows the identification of the source of the disagreement between theory and experiment for the barrier to ring planarity. 相似文献
109.
Motivated by the Debye theory of rotary diffusion in a dipolar fluid, we systematically develop a continuum mechanical theory
of rotary diffusion. This theory generalizes classical kinematics to include continuous rotary degrees of freedom and introduces
an additional balance law associated with the rotary degrees of freedom. Various constitutive relations are proposed in accordance
with standard procedures of nonlinear continuum mechanics. The resulting set of equations provides a properly invariant and
thermodynamically consistent theory that allows for constitutive nonlinearities. In particular, the classical Debye theory
along with the Nernst-Einstein relations are shown to follow from a special case of linear constitutive relations and an assumption
of ideality in which the free energy consists only of a classical entropic contribution. Within our theory, the notion of
osmotic pressure arises naturally as a consequence of accounting for
forces that act conjugate to the rotary degrees of freedom and serves as the driving force for rotary diffusion.
Accepted November 18, 2000?Published online April 23, 2001 相似文献
110.
Meredith C. K. Sellers Edmund G. Seebauer 《Applied Physics A: Materials Science & Processing》2011,104(2):583-586
Mn-doped anatase TiO2 (Mn: 1.2, 2.4 at%) thin films were grown on Si(100) via atomic layer deposition (ALD). The synthesis utilized Ti(OCH(CH3)2)4 and H2O as ALD precursors and Mn(DPM)3 as a dopant source. X-ray photoelectron spectroscopy measurements indicate that Mn is successfully doped in the TiO2 matrix and reveal information about film composition and elemental chemical states. Microstructure, crystallinity, and density
were investigated with scanning electron microscopy, X-ray diffraction, and X-ray reflectivity. All ALD-synthesized films
exhibited room-temperature ferromagnetism; the microstructure, density, and magnetic field-dependent magnetization of the
TiO2 varied with the concentration of Mn. ALD permits precise composition and thickness control, and much higher process throughput
compared to alternative techniques. 相似文献