全文获取类型
收费全文 | 424篇 |
免费 | 6篇 |
专业分类
化学 | 195篇 |
晶体学 | 5篇 |
力学 | 14篇 |
数学 | 43篇 |
物理学 | 173篇 |
出版年
2020年 | 7篇 |
2019年 | 4篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1998年 | 3篇 |
1997年 | 11篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1971年 | 4篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 3篇 |
1934年 | 3篇 |
1915年 | 6篇 |
1890年 | 4篇 |
1886年 | 4篇 |
1884年 | 3篇 |
排序方式: 共有430条查询结果,搜索用时 345 毫秒
101.
Robert Thayer Sataloff Joseph R. Spiegel Mary Hawkshaw Deborah C. Rosen Reinhardt J. Heuer 《Journal of voice》1997,11(2):238-246
New insights into the anatomy and physiology of phonation, along with technological advances in voice assessment and quantification, have led to dramatic improvements in medical voice care. Techniques to prevent vocal fold scar have been among the most important, especially scarring and hoarseness associated with voice surgery. Nevertheless, dysphonia due to vocal fold scar is still encountered all too frequently. Although it is not generally possible to restore such injured voices to normal, patients with scar-induced dysphonia can usually be helped. Voice improvement is optimized through a team approach. Treatment may include sophisticated voice therapy and vocal fold surgery. Although experience with collagen injection has been encouraging in selected cases (particularly in those involving limited areas of vocal fold scar), there is no consistently successful surgical technique. Attempts to treat massive vocal fold scar, such as may be seen following vocal fold stripping, have been particularly unsuccessful. This paper reports preliminary experience with the implantation of autologous fat into the vibratory margin of the vocal fold of patients with severe, extensive scarring. Using this technique, it appears possible to recreate a mucosal wave and improve voice quality. Additional research is needed. 相似文献
102.
T. de Reus J. Reinhardt B. Müller U. Müller G. Soff W. Greiner 《Zeitschrift für Physik A Hadrons and Nuclei》1985,321(4):589-592
We show that emission of high-energy electrons and photons in nuclear collisions at intermediate energies is sensitive to the space-time evolution of the reaction. The electron and photon spectra measure related but complementary quantities connected with the nuclear charge distribution. We show that at 60 MeV/u beam energy production of 50 MeV electrons is predicted to measurable probability. 相似文献
103.
H. J. Wollersheim P. Egelhof H. Emling J. Gerl W. Henning R. Holzmann R. Schmidt R. S. Simon N. Martin G. Eckert Th. W. Elze K. Stelzer R. Kulessa G. Duchene B. Haas J. C. Merdinger J. P. Vivien J. de Boer E. Hauber K. Kaiser P. von Brentano R. Reinhardt R. Wirowski R. Julin C. Fahlander I. Thorslund H. Kluge 《Zeitschrift für Physik A Hadrons and Nuclei》1992,341(2):137-144
Collective properties of206,208Pb have been investigated with gamma-ray spectroscopy using nuclear and electromagnetic excitation by208Pb projectiles. From the measurement of particle-particle- and particle-particle- coincidences a new energy level in208Pb at 5.683 MeV was observed and the data suggest an interpretation as a 2-phonon octupole vibrational state with spin 4+ or 6+. For this state one finds the same dynamical deformation parameter
3 as for the first-excited collective 3– state. The results are compared to predictions of models which consider, in particular, the aspects of the quadrupole interaction and the interaction of the 2-particle pairing vibration with the 2-phonon octupole vibration. For the206Pb+208Pb system at 6.2 MeV/u the nuclear potential could be determined from the measured inelastic cross sections.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday 相似文献
104.
R. Gvishi P.N. Prasad B.A. Reinhardt J.C. Bhatt 《Journal of Sol-Gel Science and Technology》1997,9(2):157-167
We have investigated the nonlinear optical performance of new UV photostable dyes, didecyl and didecyloxy substitutedpara-polyphenyl heptamers (DDPPH and DDOPPH hereafter, respectively) using the techniques of degenerate four-wave mixing (DFWM)
and optical Kerr gate (OKG). The studies were performed on the dyes dissolved in THF solution and doped in sol-gel processed
composite-glass. The magnitudes and the signs of the real and the imaginary components of the complex third-order optical
susceptibilities were determined by the heterodyned OKG method and compared to the values obtained from concentration dependent
homodyne Kerr gate and DFWM measurements. The observed effective second hyperpolarizability γ values are dependent on the
optical intensity and the pulse width of the pumping source beam. Doping of the dyes in composite-glass allows to increase
the interaction length providing the prospect of using them as building blocks for photonic devices. 相似文献
105.
H. Nölle A. Horn J. Hüve B. Nölle J. Reinhardt J. Schmand H. J. Andrä E. W. Weber 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,30(2):227-229
Cooling and optical pumping by a circularly polarized two mode laser is applied to a Na atomic beam in transverse geometry. The low velocity components of the beam are transversly cooled to the Doppler limit temperature of 240 µK and are simultaneously spin polarized for more than 90%. 相似文献
106.
F. -W. Breitbarth H. -J. Tiller R. Reinhardt 《Plasma Chemistry and Plasma Processing》1985,5(4):293-316
For the case of weak feed gas decomposition, where the concentration of CCl4 exceeds those of decomposition and built-up products, the emission of CCl* is shown to originate from dissociative excitation of CCl4. With electron concentration measured independently, the kinetics of CCl4 decomposition has been extracted from the time dependence of the CCl* intensity. Supported by EPR determinations of radical concentrations in rapidly flowing CCl4 and CCl4/O2 afterglows, the primary decomposition reaction is shown to be the electron impact dissociation into CCl3 and Cl. Its rate constant (k
1=4×10–8 cm3s–1) indicates strongly that dissociative electron attachment is the main reaction channel at least at r.f. power densities just above the threshold of a self-maintaining discharge. At extremely low mean electron energies the emission of a continuum is observed, which is tentatively ascribed to the radiative CCl3-Cl recombination. 相似文献
107.
108.
Summary The separation of racemic side-chain fluorinated alkylbenzenes and bromofluorinated analogues by capillary gas chromatography using permethylated , and -cyclodextrins dissolved in polysiloxanes of different polarity as stationary phases is described. The influence of the achiral polysiloxane matrices on the separation of enantiomers is discussed in the light of the results obtained with the different phases. For a part of the tested compounds thermodynamic data are determined which describe the interaction of enantiomers with the stationary phase. The mechanism of separation is discussed on this basis and by comparison with data for structurally similar compounds. 相似文献
109.
Reinhardt Euler 《Mathematical Programming》1982,24(1):269-283
Let (E,I) be an independence system over the finite setE = {e
1, ,e
n
}, whose elements are orderede
1 e
n
. (E,I) is called regular, if the independence of {e
l
, ,e
l
k
},l
1 < <l
k
, implies that of {e
m
l
, ,e
m
k
}, wherem
l
< ··· <m
k
andl
1 m
1, ,l
k
m
k
. (E,I) is called a 2-system, if for anyI I,e E I the setI {e } contains at most 2 distinct circuitsC, C I and the number 2 is minimal with respect to this property. If, in addition, for any two independent setsI andJ the family (C J, C
C
(J, I)), whereC(J, I) denotes {C C:e J I C
{e}}, can be partitioned into 2 subfamilies each of which possesses a transversal, then (E,I) is called a (2, 2)-system. In this paper we characterize regular 2-systems and we show that the classes of regular 2-systems resp. regular (2, 2)-systems are identical. 相似文献
110.
C. Reinhardt 《Fresenius' Journal of Analytical Chemistry》1886,25(1):11-19
Ohne Zusammenfassung 相似文献