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161.
1Introduction Archaeologicalfindingsdatingbacktothe4thcentury BCshowedthatmissinghumanteethhavebeenreplaced bymaterialswhichincluded:animalteeth,coral,shells,ivory(elephanttusk),wood,andmetals[1].Inmodern times,autografts(boneobtainedfromanothersiteinthe … 相似文献
162.
Product optimization involves selecting design, manufacturing, and support attributes that can produce the best system. Producibility or manufacturability is the term often used to describe the relative ease of manufacturing a product. In complex systems, productibility optimization is a very difficult process, particularly when the values of many attributes are restricted by constraints. One challenge is to develop more universal producibility metrics for the conceptual design phase when design information is limited and drawings are nondimensional. This paper develops a new method for producibility optimization in conceptual design based on a combination of both decision theoretic and expert system techniques. Decision theoretic techniques provide the means to model the design for producibility problem in a manner that can deal with risk, uncertainty, and user (or corporate) preferences, and can effectively integrate diverse factors to provide a measure of the overall worth of a design. The particular decision theoretic approach employed is based on multi-attribute utility theory. An illustrative example of the methodology is applied to the conceptual design of a structural composite part. 相似文献
163.
John Tsinias 《Systems & Control Letters》1991,17(1)
In this paper we generalize the Vidyasagar's well known theorem on the local stabilizability problem of nonlinear systems using state detection [11]. Our purpose is to prove that if a system is weakly detectable and stabilizable by means of a continuous state feedback u = γ(x), for which no differentiability assumption is imposed, then the system is also stabilized by the law u = γ(z), where z is the output of a weak detector for the state x. The result above is applicable to several cases not covered by other works. 相似文献
164.
165.
叙述了从铅阳极泥回收金银后的渣料中综合回收有价金属的生产实践。根据渣料性质,将火法和湿法工艺相互结合,使渣料中的锑、铋、金、银、铅、铜得以较彻底的分离和回收。 相似文献
166.
Acid Green 25, which is a diazoic dye bearing two sulfonic groups, is efficiently sorbed on chitosan. The protonation of chitosan may explain the electrostatic attraction of this anionic dye and that its optimum pH is close to 3. Preliminary protonation of amine groups (obtained by contact with a sulfuric acid solution) reduced the variation of solution pH following sorbent addition but significantly reduced sorption performance: the maximum sorption capacity of raw chitosan, 525 mg dye/g (0.84 mmol dye/g), was halved by acidic preconditioning. The acidic conditioning also reduced the kinetic rate—the time necessary to reach equilibrium increased up to threefold depending on the experimental conditions. The size of sorbent particles influenced sorption kinetics and equilibrium because of resistance to intraparticle diffusion, but the sorption appeared to occur not only at the surface of the sorbent but also in the intraparticle network of the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1073–1080, 2003 相似文献
167.
John R. Clem Zhidong Hao Ljiljana Dobrosavljević-Grujić Zoran Radović 《Journal of Low Temperature Physics》1992,88(3-4):213-219
We present a generalized variational model of an isolated vortex, valid in the anisotropic case when the external magnetic field is along one of the symmetry directions. We discuss the effects of the field anisotropy on the core and magnetic pinning of individual vortices. 相似文献
168.
John McCarthy 《International Planning Studies》2004,9(1):43-64
The emergence of new tourism‐related land uses within historic port cities has brought a range of physical, economic and social benefits. However, there are often associated tensions between the need for economic development and the need to maintain the unique heritage resource that may be a large part of the attraction for visitors. The case of Malta's Cottonera Project—for the waterfront of part of the historic ‘Grand Harbour’—throws these tensions into sharp relief; indeed, the controversy generated by the proposal led to a successful vote of no confidence in the Maltese government. The case illustrates the problematic role of the spatial planning system in seeking to mediate between interests with opposing aims in historic port cities, and the need to apply principles of sustainable regeneration. 相似文献
169.
170.
High-performance liquid chromatography of human milk triacylglycerols and gas chromatography of component fatty acids 总被引:1,自引:0,他引:1
Human milk triacylglycerols were separated by high-performance liquid chromatography. A 5-μ Supelcosil LC-18 column (Supelco,
Inc., Bellefonte, PA) was used with acetone/acetonitrile (64∶36, vol/vol) as mobile phase. Triacylglycerols were tentatively
identified based on theoretical carbon number and relative retention time. Despite changes resulting from dietary fat variation,
the major component triacylglycerols were those composed of palmitic, oleic and linoleic acids. Triacylglycerols with palmitic,
stearic and oleic acids were present as minor components. Fatty acids were quantified by gas chromatography relative to an
internal standard. Ratios of n−6/n−3 fatty acids were found to be high than previously reported.
Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献