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131.
A 27-year experience with 252 popliteal artery aneurysms in 167 patients is reviewed. Long-term results with respect to graft patency and limb salvage rates are analyzed. The results emphasize the importance of early surgical intervention and demonstrate the superiority of autologous saphenous vein over other graft materials. 相似文献
132.
133.
Zr
100-xA1x (x ≤ 40) metastable alloys were synthesized by high- energy ball milling of elemental Zr and Al powders: supersaturated
substitutional cph solid solution for x ≤ 15 and an amorphous phase for x ≥ 17.5. We performed a calorimetric study of the
thermodynamics and kinetics of the metastable- to- equilibrium transformations of these phases. Their stability range (temperature/composition),
as well as the apparent activation energies associated with the transformations, were determined. The transformation enthalpies
were measured and used to determine the enthalpy of formation for these metastable phases. For both as- milled and relaxed
amorphous phases, the measured enthalpy of crystallization is compared with those estimated for an undercooled liquid. Different
amounts of retained entropy at the glass transition temperature were used to estimate the enthalpy loss upon undercooling
due to the excess specific heat.
This paper was presented at the Thermodynamics and Phase Equilibria of Metastable Phases Symposium at the Spring TMS Meeting,
March 1-4,1992, in San Diego. The symposium was organized by Philip Nash, Illinois Institute of Technology, and Ricardo Schwarz,
Los Alamos National Laboratory. 相似文献
134.
Dr. H. Brunner 《Computing》1979,23(2):179-187
It has been shown that if a Volterra integral equation of the first kind with continuous kernel is solved numerically in a given intervalI by collocation in the space of piecewise polynomials of degreem≧0 and possessing finite discontinuities at their knotsZ N then a careful choice of the collocation points yields convergence of orderp=m+2 on a certain finite subset ofI (while the global convergence order ism+1; this subset does not contain the knotsZ N . In this note it will be shown that superconvergence onZ N can be attained only if some of the collocation points coalesce (Hermite-type collocation). 相似文献
135.
136.
HG Brunner T Hulsebos PM Steijlen DJ der Kinderen A vd Steen BC Hamel 《Canadian Metallurgical Quarterly》1993,46(4):472-474
We have performed linkage analysis in a small family with autosomal dominant inheritance of multiple café-au-lait spots (CLS) in order to clarify its relationship to classical von Recklinghausen disease (NF 1). We found that an affected woman had transmitted a different haplotype for markers flanking the NF1 gene to both of her affected daughters. These results exclude an allelic mutation of the NF 1 gene on chromosome 17 as the cause for inherited café-au-lait spots in this family. 相似文献
137.
138.
139.
This paper surveys machine induction techniques for database management and analysis. Our premise is that machine induction facilitates an evolution from relatively unstructured data stores to efficient and correct database implementations. 相似文献
140.
A theory of weak stability for linear multistep methods for the numerical solution of Volterra integro-differential equations is developed, and a connection between this theory and the corresponding theory for ordinary differential equations is established. In addition, the order of such methods is discussed, and a new starting procedure is proposed and analyzed. 相似文献