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排序方式: 共有62条查询结果,搜索用时 31 毫秒
1.
We investigate analytical properties of a measure geometric Laplacian which is given as the second derivative w.r.t. two atomless finite Borel measures μ and ν with compact supports supp μ ? supp ν on the real line. This class of operators includes a generalization of the well‐known Sturm‐Liouville operator as well as of the measure geometric Laplacian given by . We obtain for this differential operator under both Dirichlet and Neumann boundary conditions similar properties as known in the classical Lebesgue case for the euclidean Laplacian like Gauß‐Green‐formula, inversion formula, compactness of the resolvent and its kernel representation w.r.t. the corresponding Green function. Finally we prove nuclearity of the resolvent and give two representations of its trace. 相似文献
2.
The determination by neutron activation of trace quantities of calcium, strontium and barium in single crystals of alkali halides has been studied. The matrix is eliminated before the irradiation by an ion-exchange procedure. Gamma spectroscopy after radiochemical separation is used to determine strontium and barium. Calcium is determined by measuring the β-activity of 49Sc formed by the decay of 49Ca. Long-lived radioactive tracers are used to determine the chemical yields. 相似文献
3.
Analysis and fragmentation mechanisms of hirsutinolide‐type sesquiterpene lactones by ultra‐high‐performance liquid chromatography/electrospray ionization linear ion trap Orbitrap mass spectrometry
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4.
Stefano Gialanella Fabrizio Girardi Gloria Ischia Ivan Lonardelli Maurizio Mattarelli Maurizio Montagna 《Journal of Thermal Analysis and Calorimetry》2010,102(3):867-873
This study deals with some microstructural and crystallographic aspects of the thermally induced transformation of goethite
(α-FeOOH) into hematite (α-Fe2O3), occurring at about 300 °C. Powder specimens of goethite have been annealed in air at different temperatures, ranging from
200 °C up to 1,000 °C. The resulting products have been analyzed for a complete characterization of the changes brought about
by the thermal treatments, using a multianalytical approach, based on: thermogravimetry, differential thermal analysis, transmission
electron microscopy, Raman spectroscopy, and X-ray diffraction. At lower temperatures, the transition to hematite produces
no important changes in size and shape of the original goethite grains. Recrystallization, and partial sintering, occurs only
at temperatures in excess of 800 °C. The relevant evolution of pores present in both phases has been also considered, as it
may provide important indications on the actual formation mechanism of hematite. 相似文献
5.
This paper gives the optimal order l of smoothness in the Mihlin and Hörmander conditions for operator-valued Fourier multiplier theorems. This optimal order l is determined by the geometry of the underlying Banach spaces (e.g. Fourier type). This requires a new approach to such multiplier theorems, which in turn leads to rather weak assumptions formulated in terms of Besov norms. 相似文献
6.
A bounded linear operator between Banach spaces is calledcompletely continuous if it carries weakly convergent sequences into norm convergent sequences. Isolated is a universal operator for the class
of non-completely-continuous operators fromL
1 into an arbitrary Banach space, namely, the operator fromL
1 into ⊆∞ defined byT
0(f) = (∫r
n
f
d
μ)
n>-0, wherer
n
is thenth Rademacher function. It is also shown that there does not exist a universal operator for the class of non-completely-continuous
operators between two arbitrary Banach spaces. The proof uses the factorization theorem for weakly compact operators and a
Tsirelson-like space.
Supported in part by NSF grant DMS-9306460. Participant, NSF Workshop in Linear Analysis & Probability, Texas A&M University
(supported in part by NSF grant DMS-9311902).
Supported in part by NSF grant DMS-9003550. 相似文献
7.
8.
F. Girardi E. Marafante R. Pietra E. Sabbioni A. Marchesini 《Journal of Radioanalytical and Nuclear Chemistry》1977,37(1):427-440
Some typical applications of long-term/low-level exposure (LLE) is presented including in vivo LLE study on rats and in vitro
experiments on some metal binding components as well as on cadimium binding protein. 相似文献
9.
F. Girardi R. Pietra E. Sabbioni 《Journal of Radioanalytical and Nuclear Chemistry》1970,5(1):141-171
The retention of different radio-ions on columns of eleven ionic precipitates from different acid media was studied, in view
of possible applications for radiochemical separations. The results of about 2,000 adsorption experiments, carried out in
a standardized way, are presented schematically in periodic tables. 相似文献
10.
The possibility of observing a Higgs particle via high pT bremsstrahlung from a weak Z0 in p and pp collisions is examined. It appears that, although very weak, some signal might be observed in the future p collision experiments. 相似文献