全文获取类型
收费全文 | 141篇 |
免费 | 7篇 |
专业分类
化学 | 63篇 |
力学 | 1篇 |
数学 | 4篇 |
物理学 | 80篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 1篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 1篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 0 毫秒
1.
M. Mahjour-Shafiei H.R. Amir-Ahmadi J.C.S. Bacelar R. Castelijns K. Ermisch E.D. van Garderen I. Gašparić M.N. Harakeh N. Kalantar-Nayestanaki M. Kiš H. Löhner O. Scholten 《Physics letters. [Part B]》2006
A series of nucleon–nucleon bremsstrahlung (NNγ) experiments at 190 MeV incident beam energy have been performed at KVI in order to gain more insight into the dynamics governing the bremsstrahlung reaction. After initial measurements wherein the bremsstrahlung process was studied far away from the elastic limit, a new study was used to probe the process nearer to the elastic limit by measuring at lower photon energies. Measured cross sections and analyzing powers are compared with the predictions of a microscopic model and those of two soft-photon models. The theoretical calculations overestimate the data by up to ≈30%, for some kinematics. 相似文献
2.
3.
M. Adamus N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov H. Bia?kowska H. B?ttcher P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler W. Friebel H. Graessler P. van Hal J. K. Karamyan D. Kisielewska W. Kittel A. I. Kurnosenko B. B. Levchenko F. Meijers M. Merk A. B. Micha?owska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz V. M. Ronjin A. M. Rybin H. M. T. Saarikko Y. T. M. Saarikko W. Schmitz L. Scholten N. A. Sotnikova J. Stepaniak O. G. Tchikilev L. A. Tikhonova V. A. Uvarov F. Verbeure R. Wischnewski EHS/NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,37(2):215-229
The charged particle multiplicity distribution has been studied for non-single-diffractive π+ p andpp collisions at \(\sqrt s = 22\) GeV, for full phase space as well as for intervals in rapidity, azimuthal angle and transverse momentum. In general, the multiplicity distribution is well described by a negative binomial. From comparison of the distribution for negative or positive particles to that of all charged particles, cascading is favoured as an interpretation over stimulated emission. Interesting consequences follow from a comparison of our results to those at collider energies and toe + e ? data at comparable energy. Furthermore, evidence is given that the multiplicity distribution is not exactly of negative binomial type in every (connected or disconnected) phase space region. 相似文献
4.
V. V. Aivazyan I. V. Ajinenko Yu. A. Belokopytov P. C. Bosetti H. B?ttcher F. Botterweck P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf Th. Driever K. Dziunikowska A. Eskreys W. Friebel Z. C. Garutchava V. G. Gavrjusev H. Graessler P. van Hal T. Haupt W. Kittel S. S. Megrabyan F. Meijers A. B. Micha?owska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz L. P. Petrovikh E. Riipinen V. M. Ronjin A. M. Rybin H. M. T. Saarikko W. Schmitz L. Scholten R. Schulte O. G. Tchikilev L. A. Tikhonova A. G. Tomaradze V. A. Uvarov F. Verbeure R. Wischnewski A. Wróblewski S. A. Zotkin NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,42(4):533-542
Forward-backward multiplicity correlations in σ+,K + p andpp collisions at 250 GeV/c ( \(\sqrt s \) =22 GeV) are given for all charges and for the different charge combinations. The correlations are found to be caused predominantly by centrally produced particles. It is demonstrated that this result is an agreement with observations at the ISR and the CERNp \(\bar p\) -Collider. The results are compared to expectations from LUND, DPM and FRITIOF Monte Carlo models and a geometrical picture relating correlations in hadron-hadron collisions toe + e ? data in terms of impact parameters is tested. 相似文献
5.
Alexandre A.M. Lapis Jackson D. Scholten Marcos N. Eberlin 《Tetrahedron letters》2006,47(38):6775-6779
Intermolecular hydroamination or hydroarylation reactions of norbornene and cyclohexadiene performed with catalytic amounts of Brönsted or Lewis acid in ionic liquids were found to provide higher selectivity and yields than those performed in classical organic solvents. The ionic liquid increases the acidity of the media and stabilizes ionic intermediates through the formation of supramolecular aggregates. 相似文献
6.
7.
8.
Alex B. Scholten Jan W. de Haan Hans-Gerd Janssen Leo J. M. van de Ven Carel A. Cramers 《Journal of separation science》1997,20(1):17-23
Retention gape deactivated with Silicone OV-1701-OH show good chromatographic performance and remarkable stability against water induced stationary phase degradrdation. In an attempt to better understand the findamentals off the deactivation process using silanol terminated polysiloxanes, a fumed silica was deactivated with Silicon OV-1701-OH. In contrast to fused silic capillaries, fumed silica (Aerosil A-200) can be studied by 29Si cross-polarization magic-angle-spinning (CPMAS) NMR, thus serving as a model substrate for fused silica. Retention data from inverse gas chromatography at infinite dilurion and 29Si CP MAS NMR data of five Aerosil phases, differing in residual silanol surface concentration, are correlated with the aim of validating this approach for stationary phase characterization. A comparatively detailed model of the deactivating polymer layer that explains the observed absorption activities is deduced. Surface silanols are shown to play a key role in the polymer layer, the structure of which is of primary importance for the absorption behavior after deactivation. Contrary to common belief, the absolute silanol surface concentration after deativation is only of secondary importance for the overall absorption activity. High silanol surface concentrations enhance degradation of the polysiloxane chains into small cyclic fragments as well as subsequent absorption and immobolization to the silica substrate surface. The mobility of linear polysiloxane chains in the kHz regime (as determined bby NMR cross-polarization dynamics) appears to determine the extent which the residual silanols are accessible for analytes. It is therefore anticipated that there is an optimum silanol surface concentration of fused silica surfaces to be deactivated with silanol terminated polysiloxanes; it should be lazrge enough to adsord polymer fragments, but not large to avoid excessive residual silanol activity. 相似文献
9.
Testing polyethylene materials for stress cracking resistance at elevated temperatures in the presence of a detergent solution is relatively popular. The detergents used for these tests are—to our knowledge—only of the ethoxylated nonylphenol type (trade names: Igepal, Antharox, Arkopal). Extensive investigations of solutions of these nonionic detergents used at 80 °C have shown that they are very susceptible to oxidation. Oxidation has already started after about one day at 80 °C and leads to erroneous failure times of polyethylene test bars exposed to the detergent and to an unacceptably large scatter in the data.
An alternative anionic alkylbenzene sulphonate (ABS) detergent has been tested which, when dissolved in drinking water, produces reproducible failure times of welded polyethylene samples, if the age of the detergent solution does not exceed about 2000 h at 80 °C. 相似文献
10.
K. F. Hassan S. Spellerberg B. Scholten Z. A. Saleh S. M. Qaim 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):689-694
A novel anion-exchange chromatographic method for separation of radioiodine from an antimony target irradiated with 3He- or α-particles was developed, with separation yield of radioiodine amounting to 90 ± 5 % and its decontamination factor from the Te and Sb radionuclides to ~104. The optimized separation method developed was then applied to the production of 124I via the 121Sb(α,n)124I process using a highly enriched 121Sb target. Quality control tests showed that the separated 124I occurred >99 % as iodide and the longer lived impurities 126I and 125I amounted to 0.16 % and <0.05 %, respectively. The trace level of inactive Sb impurity was determined by ICP–OES. 相似文献