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51.
Given a real polynomial in one variable such that , we consider the maximal operator in ,
We prove that is bounded on for 1$"> with bounds that only depend on the degree of .
0\,,\,i,j\in \mathbb{Z}}\frac{1... ...t f\big (x_{1}-2^{i}p(t),x_{2}-2^{j}p(t)\big )\big \vert\,dt . \end{displaymath}">
We prove that is bounded on for 1$"> with bounds that only depend on the degree of .
52.
Kathryn Lesh 《Transactions of the American Mathematical Society》2000,352(7):3211-3237
Let be a family of subgroups of which is closed under taking subgroups and conjugates. Such a family has a classifying space, , and we showed in an earlier paper that a compatible choice of for each gives a simplicial monoid , which group completes to an infinite loop space. In this paper we define a filtration of the associated spectrum whose filtration quotients, given an extra condition on the families, can be identified in terms of the classifying spaces of the families of subgroups that were chosen. This gives a way to go from group theoretic data about the families to homotopy theoretic information about the associated spectrum. We calculate two examples. The first is related to elementary abelian -groups, and the second gives a new expression for the desuspension of as a suspension spectrum.
53.
The use of a nitrogen electron cyclotron resonance (ECR) plasma source has allowed the growth of GaAsN at GaAs substrate temperatures as high as 600 °C, unlike the case for growth using radio frequency (RF) plasma sources, for which there is significant loss of nitrogen at substrate temperatures as low as 480-520 °C. Photoluminescence (PL) intensities are significantly improved at a substrate temperature of 600 °C and are further improved slightly by using an ion trap to extract charged species from the beam. As the trap voltage is increased there is a reduction in the total nitrogen concentration, as measured by secondary ion mass spectrometry (SIMS), and a slight increase in the active nitrogen concentration, as measured by PL. These observations are consistent, for example, with charged and active nitrogen species together being involved in the formation of point defects, however more work is needed to clarify what may well prove to be a complex situation. 相似文献
54.
Kathryn A. Dowsland 《Discrete Applied Mathematics》2008,156(3):313-324
The focus of this paper is an ant colony optimisation heuristic for the graph colouring problem. We start by showing how a series of improvements enhance the performance of an existing ant colony approach to the problem and then go on to demonstrate that a further strengthening of the construction phase, combined with a tabu search improvement phase, raise the performance to the point where it is able to compete with some of the best-known approaches on a series of benchmark problems. 相似文献
55.
Bruce W. Tattershall Kathryn E. Holmes Catherine Tweedy Gina C. Valks 《无机化学与普通化学杂志》2008,634(10):1703-1710
Reaction of a mixture of bicyclic phosphorus sulfide selenide iodides α‐P4SnSe3−nI2 (n = 0–3) with PriNH2 and Et3N gave corresponding diamides α‐P4SnSe3−n(NHPri)2 (n = 0–3) and imides α‐P4SnSe3−n(μ‐NPri) (n = 2–3), identified in solution by 31P NMR. In one isomer of α‐P4S2Se(μ‐NPri), the C2 symmetry of imides such as α‐P4S3(μ‐NPri) was broken, allowing relative assignment of 2J NMR couplings to the PNP bridge and the PSP bridge opposite to it. The coupling through the sulfur bridge was found to be reduced to ca. zero, in contrast to previous assumptions for this class of compounds. Ab initio models were calculated at the MPW1PW91/svp level for the sulfide selenide imides and for a selection of bond rotamers of the diamides, and at the MPW1PW91/LanL2DZ(d) level for the sulfide selenide diiodides. Different skeletal isomers were prevalent for the mixed chalcogenide diamides than for the diiodides, showing that exchange of chalcogen between skeletal positions took place in the amination reaction even at room temperature. Similar differences to those observed were predicted by the models, suggesting that equilibrium was attained. 相似文献
56.
An Algebraic Thinking Test was given to 116 students aged 12–14, at the end of each of three years. This age span crosses two levels of school in New Zealand. This test assessed their ability to represent compensation in the four arithmetic operations both numerically and with letters for variables. The analyses of these results, together with the results from separate interviews designed to report individual progress of students in the New Zealand Numeracy Project, showed that students who had developed advanced mental strategies for dealing with additive, multiplicative and proportional operations, were the students who were capable of making full use of the alphanumeric symbols of algebra. These results, taken together with earlier studies by the authors, led to a proposal for a “pathway for algebraic thinking” accessible to all students. 相似文献
57.
Kathryn L. Gilroy Sarah A. Cumming Andrew R. Pitt 《Analytical and bioanalytical chemistry》2010,398(1):547-554
Quantum dots (Qdots) are fluorescent nanoparticles that have great potential as detection agents in biological applications.
Their optical properties, including photostability and narrow, symmetrical emission bands with large Stokes shifts, and the
potential for multiplexing of many different colours, give them significant advantages over traditionally used fluorescent
dyes. Here, we report the straightforward generation of stable, covalent quantum dot–protein A/G bioconjugates that will be
able to bind to almost any IgG antibody, and therefore can be used in many applications. An additional advantage is that the
requirement for a secondary antibody is removed, simplifying experimental design. To demonstrate their use, we show their
application in multiplexed western blotting. The sensitivity of Qdot conjugates is found to be superior to fluorescent dyes,
and comparable to, or potentially better than, enhanced chemiluminescence. We show a true biological validation using a four-colour
multiplexed western blot against a complex cell lysate background, and have significantly improved previously reported non-specific
binding of the Qdots to cellular proteins. 相似文献
58.
Xiang B Macisaac S Lardizabal K Li B 《Rapid communications in mass spectrometry : RCM》2010,24(23):3447-3455
A new method for the determination of N- and C-termini of a protein isolated in a polyacrylamide gel is introduced. In-gel partial protein hydrolysis by hydrochloric acid is used to generate N- and C-terminal peptides for identification. This new method is complementary to existing techniques. The application of the in-gel protein termini identification technique to the characterization of the transgenic protein diacylglycerol acyltransferase (UrDGAT2A) purified from soybean seeds is also reported here. Both N- and C-termini of UrDGAT2A were successfully identified and the N-terminus was found to be blocked by acetylation. The analysis results of UrDGAT2A and two commercial proteins (bovine serum albumin (BSA) and alcohol dehydrogenase) are used to demonstrate the effectiveness of the method in identifying actual N- and C-termini, terminal truncation and blocking. 相似文献
59.
In this paper we propose a model-independent method to extract the resonance parameters on the lattice directly from the Euclidean 2-point correlation functions of the field operators at finite times. The method is tested in case of the two-point function of the Δ-resonance, calculated at one loop in Small Scale Expansion. Further, the method is applied to a 1+1-dimensional model with two coupled Ising spins and the results are compared with earlier ones obtained by using Lüscher's approach. 相似文献
60.