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1.
R. Bernabei P. Belli F. Montecchia F. Nozzoli F. Cappella A. Incicchitti D. Prosperi R. Cerulli C.J. Dai H.L. He H.H. Kuang J.M. Ma X.H. Ma X.D. Sheng Z.P. Ye R.G. Wang Y.J. Zhang 《The European Physical Journal C - Particles and Fields》2008,53(2):205-213
The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the
framework of corollary investigations on WIMP dark matter candidates. In fact, the modeling of this existing effect implies
a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological
arguments are developed and possible implications are discussed at some extent.
PACS 95.35.+d 相似文献
2.
Daniela Belli Dell’Amico Luca Labella Fabio Marchetti Simona Samaritani 《Coordination chemistry reviews》2010,254(5-6):635-645
In this review we summarize some recent literature data concerning synthetic procedures, properties, structure, reactivity and applications of halo-carbonyl complexes of palladium, platinum and gold, taking into consideration that the organometallic chemistry of these metals, with a particular attention to the halo-carbonyls, has been reviewed 20 years ago [F. Calderazzo, J. Organomet. Chem. 400 (1990) 303]. A brief overview of the early studies is provided. 相似文献
3.
M. Rizzotto J. Toso H. Velasco M. Belli U. Sansone 《Journal of Radioanalytical and Nuclear Chemistry》2009,280(1):193-197
In the present paper the contribution to the external gamma dose rate due to 137Cs in soil as a function of time is presented. Sampling sites were selected along the Calabria and Basilicata Regions coastal
beaches (southern part of Italy) to assess the external gamma dose rate in air, 1 m above the ground level. A convection-dispersion
model, with constant parameters was used to approximate the radiocesium soil vertical migration. The model was calibrated
using the initial 137Cs activity deposition in this region (Chernobyl fallout) and 137Cs activity concentration down the soil profile, measured 10 years later. The dispersion coefficient and the advection velocity
values, were respectively: 2.17 cm2 y−1 and 0.32 cm y−1. The Radionuclide Software Package (RSP), which uses a Monte Carlo simulation code, was used to determine the primary 137Cs gamma dose contribution in air 1 m above the ground surface. The resulting 137Cs external dose rate ranged from 0.42 nGy h−1 in 1986, to 0.05 nGy h−1 in 2007. 相似文献
4.
Stefania?Gaudino Chiara?Galas Maria?Belli Sabrina?Barbizzi Paolo?de?Zorzi Radojko?Ja?imovi? Zvonka?Jeran Alessandra?Pati Umberto?SansoneEmail author 《Accreditation and quality assurance》2007,12(2):84-93
The measurement of trace-element concentration in soil, sediment and waste, is generally a combination of a digestion procedure
for dissolution of elements and a subsequent measurement of the dissolved elements. “Partial” and “total” digestion methods
can be used in environmental monitoring activities. To compare measurement results obtained by different methods, it is crucial
to determine and to maintain control of the bias of the results obtained by these methods. In this paper, ICP-MS results obtained
after matrix digestion with modified aqua regia (HCl+HNO3+H2O2) method and two “total” digestion methods (microwave aqua regia+HF and HNO3+HF) are compared with those obtained by instrumental neutron activation analysis, a non-destructive analytical method for
the determination of the total mass concentrations of inorganic components in environmental matrices. The comparison was carried
out on eight agricultural soil samples collected in one test area and measured by k0-INAA and ICP-MS to determine As, Co, Cr, Sb and Zn mass concentration. The bias of results for As, Cd, Co, Cr, Cu, Ni, Pb,
Sb and Zn of the three digestion methods were assessed using selected measurement standards. This paper highlights that the
digestion procedure is an integral part of the measurement and can affect the measurement result in environmental analysis. 相似文献
5.
Destructive adsorption of CCl4 over lanthanum-based solids: linking activity to acid-base properties
van der Heijden AW Bellière V Alonso LE Daturi M Manoilova OV Weckhuysen BM 《The journal of physical chemistry. B》2005,109(50):23993-24001
The relative activities of a low-surface crystalline and high-surface amorphous LaOCl, further denoted as S1 and S2, have been compared for the destructive adsorption of CCl4. It was found that the intrinsic activity of S2 is higher than that of S1. Both samples were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2-physisorption, and Raman and infrared (IR) spectroscopy. IR was used in combination with CO2, CO, and methanol as probe molecules. The CO2 experiments showed that different carbonate species are formed on both materials. For S1, a high surface concentration of bidentate carbonate species and a lower concentration of monodentate carbonate were observed. In the case of S2, bulk carbonates were present together with bridged carbonates. CO adsorption shows that S2 and S1 have very similar Lewis acid sites. However, methanol adsorption experiments showed that S2 had a higher number of stronger Lewis acid sites than S1 and that twofold coordinated methoxy species were more strongly bound than threefold coordinated methoxy species. Because of the analogy between methanol dissociation and the removal of the first chlorine atom in the destructive adsorption of CCl4, the sites enabling twofold coordination were likely to be the same Lewis acid sites actively involved in the destructive adsorption of CCl4. La2O3 was less active than the two LaOCl materials, and therefore, the intrinsic activity of the catalyst increases as the strength of the Lewis acid sites increases. S2 contains more chlorine at the surface than S1, which is expressed by the higher number of sites enabling twofold coordination. Moreover, this explains the difference in destructive adsorption capacity for CCl4 that was observed for the samples S1 and S2. Since LaCl3, being the most acidic phase, is not active for the destructive adsorption of CCl4, basic oxygen atoms, however, remain needed to stabilize the reaction intermediate CCl3 as La-O-CCl3. 相似文献
6.
Summary Recent observations of CGRO satellite challenged the almost universally accepted galactic origin of gamma-ray bursts and have
revived the extragalactic, cosmological models. This hypothesis should imply some variations of the morphological and energetic
characteristics of the weaker events to which we think the farthest ones might belong. The existence of such variations due
to the cosmological red-shift should be tested. In this paper we examine the possible correlations between temporal morphology
of the gamma-ray bursts, peak intensity and photon energy spectra when the red-shift effects do not yet occur. We examine
the peak intensities and the energy spectral-hardness distributionversus rise times for events observed by previous space missions, with a logN-logS shape free of cosmological effects. The results of this analysis suggest that a wide range of values of the temporal and
spectral characteristic parameters is an intrinsic property of the sources.
Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992. 相似文献
7.
M. Belli A. Scafati A. Bianconi E. Burattini S. Mobilio C. R. Natoli L. Palladino A. Reale 《Il Nuovo Cimento D》1983,2(5):1281-1304
Summary The binding of Mn2+ ions to ATP molecules has been studied by means of the fine-structure analysis of X-ray absorption spectra (EXAFS and XANES)
at theK-edge of Mn using the synchrotron, radiation facility PULS in Frascati. The results obtained in both freeze-dried and liquid
samples of aqueous solutions at room temperature of the Mn-ATP complex under diffrent values ofpH and Mn:ATP ratio are reported and discussed. The Mn2+ ion appears to be octahedrally coordinated, the phosphate oxygen atoms being in the first co-ordination shell. Values of
(2.15±0.05) ? and (3.4±0.05) ?, respectively, have been found for Mn-O and Mn-P distances. Theoretical considerations together
with experimental results do not support the existence of a direct binding of the Mn to the N(7) atom of the adenine ring.
The coordination numbers for the first and second shell are consistent with the formation of a Mn(ATP)2 complex in solution atpH=9 and Mn: ATP=1:10, while a Mn-ATP 1:1 complex is found at lowerpH and higher Mn: ATP ratios.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
8.
Summary We investigate by a statistical analysis possible correlations among the observational parameters of the γ-ray bursts: the
rise time, the decay time and spectral hardness. We discuss the physical constraints implied by the results.
To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee. 相似文献
9.
Dell'Amico DB Calderazzo F Marchetti F Ramello S Samaritani S 《Inorganic chemistry》2008,47(3):1237-1242
The hexanuclear Pd6Cl12, i.e., the crystal phase classified as beta-PdCl2, was obtained by reacting [TBA]2[Pd2Cl6] with AlCl3 (or FeCl3) in CH2Cl2. The action of AlCl3 on PtCl42-, followed by digestion of the resulting solid in 1,2-C2H4Cl2 (DCE), CHCl3, or benzene, produced Pt6Cl12.DCE, Pt6Cl12.CHCl3, or Pt6Cl12.C6H6, respectively. Treating [TBA]2[PtCl6] with a slight excess of AlCl3 afforded [TBA][Pt2Cl9], whose anion was established crystallographically to be constituted by two "PtCl6" octahedra sharing a face. Dehydration of H2PtCl6.nH2O with SOCl2 gave an amorphous compound closely analyzing as PtCl4, reactive with [Q]Cl in SOCl2 to yield [Q][Pt2Cl9] or [Q]2[Pt2Cl10], depending on the [Q]Cl/Pt molar ratio (Q=TBA+, PPN+). A single-crystal X-ray diffraction study has shown [PPN]2[Pt2Cl10].C7H8 to contain dinuclear anions formed by two edge-sharing PtCl6 octahedra. 相似文献
10.
Daniela Belli Dell'Amico Fausto Calderazzo Luca Labella Fabio Lorenzini Fabio Marchetti 《无机化学与普通化学杂志》2002,628(8):1868-1872
The hydrogensulfato‐carbonyl derivative [Cu(CO)(SO4H)]n, as obtained from the Cu2O/ H2SO4/CO system and recrystallized from H2SO4/(CH3O)2SO2 has been shown to possess a crystal structure organised in infinite chains built up by corner sharing of {CuO3(CO)} and {S(OH)O3} tetrahedra. The chains are connected by hydrogen bonds in layers, with CO groups leaning out on both sides. The absorption of CO by CuSO4/Cu or by Cu2O in sulfuric acid was quantified as a function of concentration. The CuSO4/Cu system in water absorbs carbon monoxide (CO/Cu molar ratio = 1.0). 相似文献