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1.
Papert's (1978) appeal to reconsider the power and possibilities of the aesthetic in mathematics learning is often ignored in mathematics education research. This paper begins with the premise, put forth by Dewey (1934), that the aesthetic structures many dimensions of inquiry and experience. In the same way that using particular paintings, musical compositions, or even everyday experiences has been instrumental to attempts by philosophers to understand the aesthetic dimensions of meaning and experience in artistic domains, I propose that analysing a particular encounter with mathematics may help reveal the nature and role of the often nebulous responses of elegance, beauty, and `fit' to which mathematicians lay claim in their mathematical activity. To achieve this, I draw on and adapt the defining features of the aesthetic character of experience set forth by the aesthetician Beardsley (1982). This, in turn, sheds light on the role thataesthetics can play in mathematical inquiry and experience, and provides initial categories and conjectures that can be used to investigate the potential roles of aesthetics in mathematics learning contexts.This revised version was published online in September 2005 with corrections to the Cover Date. 相似文献
2.
P.A. Sinclair 《Discrete Mathematics》2004,286(3):177-184
Let G be a connected graph with minimum degree at least 3. We prove that there exists an even circuit C in G such that G−E(C) is either connected or contains precisely two components one of which is isomorphic to a 1-bond. We further prove sufficient conditions for there to exist an even circuit C in a 2-connected simple graph G such that G−E(C) is 2-connected. As a consequence of this, we obtain sufficient conditions for there to exist an even circuit C in a 2-connected graph G for which G−E(C) is 2-connected. 相似文献
3.
Philip Sinclair 《Discrete Mathematics》2004,286(3):171-175
Let G be a 2-connected graph with minimum degree at least 3. We prove that there exists an even circuit C in G with factorization F={F1,F2} such that G−E(F1) is 2-connected. 相似文献
4.
Al2O3 incorporated HfO2 films grown by atomic layer deposition (ALD) were investigated by high-resolution X-ray photoelectron spectroscopy (HRXPS). The core level energy state of a 15 Å thick film showed a shift to higher binding energy, as the result of a silicate formation and Al2O3 incorporation. The incorporation of Al2O3 into the HfO2 film had no effect on silicate formation at the interface between the film and Si, while the ionic bonding characteristics and hybridization effects were enhanced compared to a pure HfO2 film. The dissociation of the film in an ultrahigh vacuum (UHV) is effectively suppressed compared to a pure HfO2 film, indicating an enhanced thermal stability of Hf-Al-O. Any dissociated Al2O3 on the film surface was completely removed into the vacuum by vacuum annealing treatment over 850 °C, while HfO2 contributed to Hf silicide formation on the film surface. 相似文献
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Ge segregation during the growth of Si1 − xGex alloys (x = 5, 10, 20, and 40%) was studied using X-ray photoelectron spectroscopy. The alloys were grown in thicknesses up to 20.0 nm at 500°C to measure quantitatively the amount of segregated surface Ge. The length of alloy needed to reach steady-state growth edge was found to decrease with increasing alloy concentration (4.8, 2.8, 2.4, and 2.0 nm, respectively). It was found that each alloy had a complete monolayer of Ge on the surface and an increasing amount of segregated Ge in the second layer (20, 55, 80, and 95%, respectively) during steady-state growth. An increase in the temperature of alloy growth (400–750°C) resulted in an increase in the leading edge of alloy growth but did not change the amount of segregated Ge during steady-state growth. We propose that film stress is responsible for the amount of Ge segregation. 相似文献
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9.
Sinclair JL 《Journal of AOAC International》2000,83(5):1108-1114
The occurrence of Cryptosporidium parvum or other pathogenic Cryptosporidium species in water must be known in order to assess risk and determine the treatment needed to reduce Cryptosporidium oocysts to acceptable levels in finished drinking water. Because Cryptosporidium oocyst occurrence may be sparse, methods must concentrate a large volume of water and correctly identify oocysts in the concentrate. The U.S. Environmental Protection Agency Information Collection Rule (ICR) protozoan method gives low and variable recoveries of Cryptosporidium oocysts, making risk assessment difficult. Therefore, a method giving better oocyst recovery and more consistent results was needed. Method 1622 was developed with existing materials and procedures, and improvements were made in filtration, cleanup, and detection. Absolute porosity filters were used, with cleanup by immunomagnetic separation and detection by direct fluorescent antibody stain with 4',6-diamidino-2-phenylindole (DAPI) staining for additional cell structures. Both the level and consistency of oocyst recovery were improved compared to recovery with the ICR method. 相似文献
10.
Phillip L. Kempster Jacobus F. Staden Henk R. Vliet 《Fresenius' Journal of Analytical Chemistry》1988,332(2):153-156
Summary Using an 11 ml centrifugal type spray chamber, a rapid sample introduction rate of 320 injections per hour may be achieved when interfacing flow injection analysis and inductively coupled plasma emission spectrometric techniques. Calcium was determined in water samples with a relative standard deviation of better than 3.5% over the analytical range of 10 to 200 mg · l–1 Ca. Mean recovery was 97%.
Calciumbestimmung im Wasser mit dem Flow-injection-Prinzip kombiniert mit der Induktions-gekoppelten Plasma-Emissions-Spektrometrie (FIA-ICP)相似文献