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排序方式: 共有96条查询结果,搜索用时 15 毫秒
1.
M. V. Solovskii M. Yu. Eropkin E. M. Eropkina A. V. Slita M. Yu. Smirnova E. N. Vlasova E. B. Tarabukina A. I. Amirova 《Russian Journal of Applied Chemistry》2007,80(10):1703-1707
Nontoxic water-soluble low-molecular-weight (MW 14 000–36 000 Da) copolymers of acrylamide with 2-acrylamido-2-methylpropanesulfonic
acid, containing from 17.3 to 37.6 mol % sulfonate-containing monomeric units, were synthesized by heterophase radical polymerization
in isopropanol or ethanol at 50°C with azobis(isobutyronitrile) as an initiator.
Original Russian Text M.V. Solovskii, M.Yu. Eropkin, E.M. Eropkina, A.V. Slita, M.Yu. Smirnova, E.N. Vlasova, E.B. Tarabukina,
A.I. Amirova, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80, No. 10, pp. 1674–1678. 相似文献
2.
Dr. James P. Dombrowski Dr. Micah S. Ziegler Dr. Neelay M. Phadke Erum Mansoor Dr. Daniel S. Levine Dr. Ryan J. Witzke Prof. Dr. Martin Head-Gordon Prof. Dr. Alexis T. Bell Prof. Dr. T. Don Tilley 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(1):307-315
Anionic molecular models for nonhydrolyzed and partially hydrolyzed aluminum and gallium framework sites on silica, M[OSi(OtBu)3]4− and HOM[OSi(OtBu)3]3− (where M=Al or Ga), were synthesized from anionic chlorides Li{M[OSi(OtBu)3]3Cl} in salt metathesis reactions. Sequestration of lithium cations with [12]crown-4 afforded charge-separated ion pairs composed of monomeric anions M[OSi(OtBu)3]4− with outer-sphere [([12]crown-4)2Li]+ cations, and hydroxides {HOM[OSi(OtBu)3]3} with pendant [([12]crown-4)Li]+ cations. These molecular models were characterized by single-crystal X-ray diffraction, vibrational spectroscopy, mass spectrometry and NMR spectroscopy. Upon treatment of monomeric [([12]crown-4)Li]{HOM[OSi(OtBu)3]3} complexes with benzyl alcohol, benzyloxide complexes were formed, modeling a possible pathway for the formation of active sites for Meerwin–Ponndorf–Verley (MPV) transfer hydrogenations with Al/Ga-doped silica catalysts. 相似文献
3.
Micah I. Krichevsky 《Analytica chimica acta》1981,133(4):747-751
An interactive information system, MICRO-IS, is described. It comprises morphological, physiological, biochemical, and Chromatographic data describing microbial strains. A wide variety of retrieval, management, and editing functions can be invoked with easy-to-learn, user-oriented commands. 相似文献
4.
When a single DNA molecule is stretched beyond its normal contour length, a force-induced melting transition is observed. Ethidium binding increases the DNA contour length, decreases the elongation upon melting, and increases the DNA melting force in a manner that is consistent with the ethidium-induced changes in duplex DNA stability known from thermal melting studies. The DNA stretching curves map out a phase diagram and critical point in the force-extension-ethidium concentration space. Intercalation occurs between alternate base pairs at low forces and between every base pair at high forces. 相似文献
5.
We derive explicit, uniform, a priori interior Hessian and gradient estimates for special Lagrangian equations of all phases
in dimension two.
Y. Yuan is partially supported by an NSF grant. 相似文献
6.
7.
The Linear Search Problem concerns a search for a point in the real line by continuous motion starting at 0. The optimal turning
points for such a search under the hypothesis that the location of the target is distributed normally about 0 have been approximated
by mechanical calculation, but no proof has been given that there is only a single minimizing strategy or that the numbers
calculated do indeed approximate that strategy. Plausible arguments have been made before, both by these authors and others.
In this paper, the plausible arguments are supplanted by mathematical proofs.
The research of the senior author has been supported by the Wisconsin Alumni Research Foundation.
The research of the junior author has been supported by Hewlett Packard, Inc. under a Faculty Development Fellowship at Cornell
University. 相似文献
8.
Micah T. Nelp Vahe Bandarian 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(36):10773-10775
The biosynthesis of nitriles is known to occur through specialized pathways involving multiple enzymes; however, in bacterial and archeal biosynthesis of 7‐deazapurines, a single enzyme, ToyM, catalyzes the conversion of the carboxylic acid containing 7‐carboxy‐7‐deazaguanine (CDG) into its corresponding nitrile, 7‐cyano‐7‐deazaguanine (preQ0). The mechanism of this unusual direct transformation was shown to proceed via the adenylation of CDG, which activates it to form the newly discovered amide intermediate 7‐amido‐7‐deazaguanine (ADG). This is subsequently dehydrated to form the nitrile in a process that consumes a second equivalent of ATP. The authentic amide intermediate is shown to be chemically and kinetically competent. The ability of ToyM to activate two different substrates, an acid and an amide, accounts for this unprecedented one‐enzyme catalysis of nitrile synthesis, and the differential rates of these two half reactions suggest that this catalytic ability is derived from an amide synthetase that gained a new function. 相似文献
9.
Matthew Gursky Jeffrey Streets Micah Warren 《Calculus of Variations and Partial Differential Equations》2011,41(1-2):21-43
We show that on a compact Riemannian manifold with boundary there exists ${u \in C^{\infty}(M)}$ such that, u |?M ?? 0 and u solves the ?? k -Ricci problem. In the case k = n the metric has negative Ricci curvature. Furthermore, we show the existence of a complete conformally related metric on the interior solving the ?? k -Ricci problem. By adopting results of (Mazzeo and Pacard, Pacific J. Math. 212(1), 169?C185 (2003)), we show an interesting relationship between the complete metrics we construct and the existence of Poincaré?CEinstein metrics. Finally we give a brief discussion of the corresponding questions in the case of positive curvature. 相似文献
10.
Micah Stohlmann 《School science and mathematics》2019,119(5):287-296
Of the four subjects in an integrated science, technology, engineering, and mathematics (STEM) approach, mathematics has not received enough focus. This could be in part because mathematics teachers may be apprehensive or unsure about how to implement integrated STEM education in their classrooms. There are benefits to integrated STEM in a mathematics classroom though, including increased motivation, interest, and achievement for students. This article discusses three methods that middle school mathematics teachers can utilize to integrate STEM subjects. By focusing on open‐ended problems through engineering design challenges, mathematical modeling, and mathematics integrated with technology middle school students are more likely to see mathematics as relevant and valuable. Important considerations are discussed as well as recent research with these approaches. 相似文献