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61.
The recently proposed electron-hole potential (EHP) method for excited states is extended to the multi-configurational case. The variation equation is solved using the quadratic convergence method. The EHP methods are shown to be approximations to the complete singly excited configuration interaction (CSECI) in the variational sense. Extended Brillouin theorems are proved for the EHP methods. The excitation energies and wave functions obtained by one and two configurational EHP methods agree well with those of the CSECI method. The EHP methods have clear advantage in the computer time requirement over the CI method and are especially suited for a calculation of approximate excited states of large molecules. The EHP methods are applicable to excited states which belong to the same irreducible representation as the ground state. 相似文献
62.
J. Ahrens S. Altieri J. R. M. Annand H. -J. Arends R. Beck A. Braghieri N. d'Hose H. Dutz S. Goertz P. Grabmayr S. Hasegawa E. Heid H. Holvoet L. Van Hoorebeke N. Horikawa T. Iwata O. Jahn P. Jennewein R. Kondratiev J. Krimmer M. Lang B. Lannoy K. Livingston J. C. McGeorge W. Meyer A. Panzeri P. Pedroni T. Pinelli I. Preobrajenski G. Reicherz G. Rosner M. Rost T. Rostomyan D. Ryckbosch M. Schumacher B. Seitz G. Tamas A. Thomas R. van de Vyver Th. Walcher F. Zapadtka 《The European Physical Journal A - Hadrons and Nuclei》2005,26(1):135-140
The G asymmetry of the γp↦Nπ reaction has been measured for the first time for Eγ = 340±14 MeV. This observable, for which very scarce published data exist, plays an important role to disentangle the contributions
of the various nucleon resonances. The experiment, performed at the Mainz microtron MAMI, used a 4π-detector system, a linearly
polarized, tagged photon beam, and a longitudinally polarized proton target. 相似文献
63.
Keitaro Tanoi Natsuko I. Kobayashi Takayuki Saito Naoko Iwata Atsushi Hirose Yoshimi Ohmae Ren Iwata Hisashi Suzuki Tomoko M. Nakanishi 《Journal of Radioanalytical and Nuclear Chemistry》2013,296(2):749-751
The time course of Mg uptake and release using intact rice plants and 28Mg as a tracer is presented. Since there is no conventional Mg tracer available, 28Mg was produced via 27Al(α, 3p)28Mg reaction using a cyclotron. Using the purified 28Mg tracer, it was found that the uptake amount of 28Mg by the rice plants increased linearly during 30 min of application. After 28Mg treatment for 90 min, the roots were sequentially washed with iced solution for 120 min. Within about 10 min, almost all of the 28Mg, that was thought to be weakly bound to the apoplast, was washed away. 相似文献
64.
In order to increase the predictive ability of the PLS (Partial Least Squares) model, we have developed a new algorithm, by which uninformative samples which cannot contribute to the model very much are eliminated from a calibration data set. In the proposed algorithm, uninformative wavelength (or independent) variables are eliminated at the first stage by using the modified UVE (Uninformative Variable Elimination)-PLS method that we reported previously. Then, if the prediction error of the ith (1 < or =i< or = n) sample is larger than 3sigma, the corresponding sample is eliminated as uninformative, where n is the total number of calibration samples and sigma is the standard deviation calculated from the other n(-1) samples. Calculation of sigma by the leave-one-out manner enhances the ability to identify the uninformative samples. The final PLS model is constructed precisely because both uninformative wavelength variables and uninformative samples are eliminated. In order to demonstrate the usefulness of the algorithm, we have applied it to two kinds of mid-infrared spectral data sets. 相似文献
65.
Yukiko Furuhashi Pawel Sikorski Edward Atkins Tadahisa Iwata Yoshiharu Doi 《Journal of Polymer Science.Polymer Physics》2001,39(21):2622-2634
Poly(δ‐valerolactone) (PVL) crystals in the form of chain‐folded lamellae were prepared by isothermal crystallization from a 2‐methylbutane‐2‐ol solution. Wide‐angle and small‐angle X‐ray diffraction data, obtained from PVL lamellae sedimented to form oriented mats, were supplemented with morphological and structural data from electron microscopy, both imaging and diffraction. The diffraction signals index on an orthorhombic unit cell with the parameters a = 0.747 ± 0.002 nm, b = 0.502 ± 0.002 nm, and c (chain axis) = 0.742 ± 0.002 nm. Similar unit cell parameters were obtained from crystals grown from 1‐octanol and also from drawn melt‐pressed films. The evidence supports a model containing two antiparallel chain segments in the unit cell. The c value of 0.742 nm is appropriate for an all‐trans or onefold helical backbone conformation for the straight stems. Possible slight perturbations at the ester units from the all‐trans backbone conformation are discussed. Computerized modeling was used to optimize the adjacent‐reentry folded structure. The setting angles, with respect to the a axis, are ±58° for the corner and center chains. The lamellae are 7.26 ± 0.05 nm thick, and the chains run orthogonal to the lamellar surface. The chains fold in the diagonal (110) and (11¯0) planes in an alternating fashion. The X‐ray diffraction data suggest that a proportion of adjacent paired antiparallel entities, or hairpin units, are c‐axis‐sheared, and a relationship to the results obtained from drawn films is discussed. A brief comparison is also made with related polymer structures. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2622–2634, 2001 相似文献
66.
We show a descent method for submodular function minimization based on an oracle for membership in base polyhedra. We assume
that for any submodular function f: ?→R on a distributive lattice ?⊆2
V
with ?,V∈? and f(?)=0 and for any vector x∈R
V
where V is a finite nonempty set, the membership oracle answers whether x belongs to the base polyhedron associated with f and that if the answer is NO, it also gives us a set Z∈? such that x(Z)>f(Z). Given a submodular function f, by invoking the membership oracle O(|V|2) times, the descent method finds a sequence of subsets Z
1,Z
2,···,Z
k
of V such that f(Z
1)>f(Z
2)>···>f(Z
k
)=min{f(Y) | Y∈?}, where k is O(|V|2). The method furnishes an alternative framework for submodular function minimization if combined with possible efficient
membership algorithms.
Received: September 9, 2001 / Accepted: October 15, 2001?Published online December 6, 2001 相似文献
67.
68.
Dr. M. Tanaka Prof. Dr. M. Hamada Prof. Dr. Y. Iwata 《Archive of Applied Mechanics (Ingenieur Archiv)》1982,52(1-2):95-104
Summary This paper presents a boundary element formulation for elastostatic problems. The formulation is expressed in terms of the matrix notation, so that it is easily applicable to an available system of matrix structural analysis. A computer program developed is used to calculate the stress intensity factor K
I for some example problems in plane elasticity. Comparison is made between the boundary element calculations and other solutions, whereby the effectiveness of the boundary element method is demonstrated.
Berechnung eines zweidimensionalen Spannungsintensitätsfaktors mit der Methode der Bandelemente
Übersicht Dieser Aufsatz bietet eine Formulierung elastostatischer Probleme durch die Methode der Randelemente an. Die Formulierung benutzt eine Darstellung in Matrizenbezeichnung, so daß sie auf ein verfügbares System für Matrizenstrukturberechnung einfach anwendbar ist. Ein ausgebautes Computerprogramm wird auf die Berechnung des Spannungsintensitätsfaktors K i für einige Beispiele in der ebenen Elastizität angewendet. Die mittels der Randelemente erhaltenen Ergebnisse werden mit anderen Lösungen verglichen. Dadurch zeigt sich die Wirksamkeit der Methode der Randelemente.相似文献
69.
When a mixture of o-alkynylaryl isocyanides and organic dichalcogenides such as diselenides or ditellurides was irradiated with light of wavelength over 300 or 400 nm, the intramolecular cyclization of the isocyanides took place to afford the corresponding 2,4-bischalcogenated quinolines selectively. The photochemical cyclization of 2-(phenylethynyl)phenyl isocyanide could also proceed in the presence of hydrogen transfer reagents such as tris(trimethylsilyl)silane, tributylgermyl hydride, alkanethiols, and benzeneselenol, providing the corresponding 3-phenylquinoline as the result of 2,4-dihydrogenation. 相似文献
70.
Two new cannabinoid-like chromane and chromene derivatives named anthopogocyclolic acid (1) and anthopogochromenic acid (2) and five related compounds (3-7) which are known as synthetic analogues of cannabinoids: cannabichromene (CBC) type, cannabicyclol (CBL) type, and cannabicitran (CBT) type, have been isolated together with geranyl orsellinic acid (8) from the Chinese medicinal plant Rhododendron anthopogonoides. Their structures were elucidated based on spectroscopic and chemical evidence. The absolute configuration of the asymmetric carbons at C-2 of 1-7 was determined to be S from their circular dichroism (CD) spectra. Compounds 2, 4 and 6 inhibited compound 48/80-induced histamine release from rat peritoneal mast cells. 相似文献