Dipole resonances have been excited in 121?124Sn isotopes using (3He,t) charge exchange reaction at E3He=177 MeV and the cross sections were related to the neutron-skin thicknesses. The well understood correlation may be used to determine the neutron-skin thicknesses in the future. 相似文献
About 25 years ago, Bogdanovic and Schwickardi (B. Bogdanovic, M. Schwickardi: J. Alloys Compd. 1–9, 253 (1997) discovered the catalyzed release of hydrogen from NaAlH4. This discovery stimulated a vast research effort on light hydrides as hydrogen storage materials, in particular boron hydrogen compounds. Mg(BH4)2, with a hydrogen content of 14.9 wt %, has been extensively studied, and recent results shed new light on intermediate species formed during dehydrogenation. The chemistry of B3H8−, which is an important intermediate between BH4− and B12H122−, is presented in detail. The discovery of high ionic conductivity in the high-temperature phases of LiBH4 and Na2B12H12 opened a new research direction. The high chemical and electrochemical stability of closo-hydroborates has stimulated new research for their applications in batteries. Very recently, an all-solid-state 4 V Na battery prototype using a Na4(CB11H12)2(B12H12) solid electrolyte has been demonstrated. In this review, we present the current knowledge of possible reaction pathways involved in the successive hydrogen release reactions from BH4− to B12H122−, and a discussion of relevant necessary properties for high-ionic-conduction materials. 相似文献
The organothiol 4-mercaptopyridine (pyS) has been used extensively as facilitator for the assessment of heterogeneous electron transfer reaction of cytochrome c (cyt c). Its efficiency, however, is strongly affected by the instability of the adlayer due to the C-S bond cleavage. The K(4)[Ru(CN)(5)(pyS)].3H(2)O complex was synthesized and characterized aiming its utilization as an inorganic self-assembled monolayer (SAM) that would enhance the gold adlayer stability. The SAM formed by this complex onto gold (RupySAu) was characterized by spectroscopic (FTIRRAS and SERS) and electrochemical (LSV) techniques. The ex situ vibrational SERS and FTIRRAS spectra data of this SAM formed onto gold suggest a sigma interaction between the gold and sulfur atoms of the complex, inducing a perpendicular arrangement in relation to the surface normal. Additionally, SERS and FTIRRAS spectra performed for freshly prepared RupySAu adlayer and for large immersion times in the precursor solution have not shown any significant change that would reflect the degradation of the adlayer. The LSV desorption curves of this SAM indicate an enhancement in the C-S bond strength of the pyS ligand when coordinated to the [Ru(CN)(5)](3-) moiety. Comparatively to the data obtained for the desorption process of the pyS monolayer, the reductive desorption potential, E(rd), of the RupySAu presents a shift of -17 mV. This bond strength intensification leads to an increase in the stability of the monolayer. The voltammetric curves of cyt c carried out with the RupySAu electrode showed electrochemical parameters consistent with those reported for the native protein, as well as the maintenance of the electrochemical kinetic data after repetitive cycles. The results all together suggest that the pi back-bonding effect from the [Ru(CN)(5)](3-) metal center plays an important role in the stability of the RupySAu adlayer, improving the assessment of the cyt c heterogeneous electron transfer reaction. 相似文献
We have studied the solid-liquid equilibrium of the system Sr1–yBayFCl1–xBrx using DTA and X-ray diffraction techniques. The entire composition range in this system yields solid solutions which crystallize in the PbFCl (Matlockite) structure type. The melting points of the entire composition range have been parametrized (within 5°C rms error) using a biquadratic fit of the available data obtained by experiment and from the literature.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
Abstract Two peptides, H-Gly-Lys-Thr-Gly-Pro-Gly-OH (1) and Leu-enkephalin (2) FAB-PI spectra in normal and deuterated glycerol have been studied. Two C-deuterated and D2O exchanged analogs have been used to compare their fragmentation to unlabelled peptides. The mass spectrometry of peptides has become a particularly interesting field with the wide spread adoption of the FAB technique. This technique enables one to record the quasi-molecular ion (in both positive and negative modes as M+1 or M?1 respectively) and to extract from the spectrum valuable information on the peptide sequence. 相似文献
The idea of underground storage of hydrogen exists today in several forms. One of the most promising methods is the option of underground methanation, which consists of injecting H2 and CO2 into an underground porous reservoir (aquifer) and converting them into methane by means of methanogenic bacteria that initiate the methanation reaction. However, due to their activities, the high accumulation of bacteria in the
pore walls causes pore-clogging (microbial-induced clogging); one of the main problems that can become an
obstacle to the implementation of this idea. In this paper, we develop a conceptual model of bio-clogging, which consists of several stages of attachment to pore walls, detachment from the walls and pore plugging by the biomass growth. This model was built into the numerical model of multicomponent two-phase flow. The effect of bio-clogging on gas movement in the storage was analyzed numerically. It has been found that bio-clogging reduces vertical rise of hydrogen and results in more uniform radial gas penetration into the reservoir.
High-spin states of the doubly-odd 112Sb were studied by in-beam spectroscopy using the 88Sr (28Si, p3n) and 89Y (29Si, α2n) fusion-evaporation reactions at beam energies of 120 and 108 MeV, respectively. γ?γ, charged particle-γ?γ coincidences, and γ?γ angular correlation analyses were employed for determining the level scheme of 112Sb. In the present work, all the levels except for low-lying states in 112Sb were newly established. Two ΔI = 1 strongly coupled bands were observed; one is a negative-parity band that is similar to those observed in the neighboring doubly-odd Sb isotopes and the other is a positive-parity band that has a new type structure not observed in the other isotopes. From the similarity of the properties of these ΔI = 1 bands to the bands built on 9/2+ 2p?1h states in the odd-A Sb isotopes, we suggest that these two ΔI = 1 bands should be associated with the [π(g9/2)?1 ? νh11/2] and [π(g9/2)?1νg7/2] configurations, respectively. 相似文献