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The tail end: The Rh-catalyzed selective functionalization of commercial linear low-density polyethylene (LLDPE) with boron reagents is demonstrated. Subsequent oxidation and transformations of the boron-containing polymer yields materials that contain a variety of polar functionalities, such as hydroxy, amino, and formyl groups, at the termini of the side chains (see scheme). Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z501837_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
An analytical representation is introduced for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</tex> -dimensional piecewise-linear functions which are affine over convex polyhedral regions bounded by linear partitions. Explicit formulas are presented to compute the coefficients associated with this representation along with an example.
Three series of forced vibration tests were conducted on the intake tower located in Silverwood Lake near San Bernardino, California. In the first test series the water level in the reservoir was just above the base of the tower so the effects of water on its behavior were negligible. In the second and third series the water submerged nearly two-thirds of the tower. In the second test series the inside of the tower was empty, whereas in the third series the tower was filled with water to the same level as the water in the reservoir. During these tests seven modes of vibration were excited. Three of the modes were transverse modes of the bridge connecting the tower to land. Three more modes involved longitudinal movement of the bridge deck which can occur only at amplitudes of motion smaller than the clearances in the bridge supports. Thus, of the seven modes excited during the forced vibration tests, only one mode would be excited with significant amplitudes during strong earthquake ground motion.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
A novel photorespiratory mutant of Arabidopsis thaliana, designated gld2, was isolated based on a growth requirement for abnormally high levels of atmospheric CO2. Photosynthetic CO2 fixation was inhibited in the mutant following illumination in air but not in atmosphere containing 2% O2. Photosynthetic assimilation of 14CO2 in an atmosphere containing 50% O2 resulted in accumulation of 48% of the soluble label in glycine in the mutant compared to 9% in the wild type. The rate of glycine decarboxylation by isolated mitochondria from the mutant was reduced to 6% of the wild type rate. In genetic crosses, the mutant complemented two previously described photorespiratory mutants of A. thaliana that accumulate glycine during photosynthesis in air due to defects in glycine decarboxylase (glyD, now designated gld1) and serine transhydroxymethylase (stm). Because glycine decarboxylase is a complex of four enzymes, these results are consistent with a mutation in a glycine decarboxylase subunit other than that affected in the gld1 mutant. The two gld loci were mapped to chromosomes 2 and 5, respectively.
An electron moving in a magnetically ordered background feels an effective magnetic field that can be both stronger and more rapidly varying than typical externally applied fields. One consequence is that insulating magnetic materials in three dimensions can have topologically nontrivial properties of the effective band structure. For the simplest case of two bands, these "Hopf insulators" are characterized by a topological invariant as in quantum Hall states and Z2 topological insulators, but instead of a Chern number or parity, the underlying invariant is the Hopf invariant that classifies maps from the three-sphere to the two-sphere. This Letter gives an efficient algorithm to compute whether a given magnetic band structure has nontrivial Hopf invariant, a double-exchange-like tight-binding model that realizes the nontrivial case, and a numerical study of the surface states of this model.
A method for the preparation of heterobifunctional biodegradable dendrimers is described involving the preparation of a symmetric aliphatic ester dendrimer derived from 2,2-bis(hydroxymethyl)propanoic acid bearing a cyclic carbonate periphery, followed by opening of the carbonate moieties with a functional amine. This approach requiring no chromatographic purification steps was demonstrated with the preparation of a dendrimer bearing eight protected aldehydes and eight alkynes at its periphery.
People often use a variety of computing devices, such as PCs, PDAs, and cell phones, to access the same information. The user interface to this information needs to be different for each device, due to the different input and output constraints of each device. Currently designers designing such cross-device user interfaces either have to design a UI separately for each device, which is time consuming, or use a program to automatically generate interfaces, which often result in interfaces that are awkward. Each method also discourages iterative design, considered critical for creating good user interfaces. I have created a system called Damask to support the early-stage design of user interfaces targeted at multiple devices. Within Damask, designers use layers to specify which parts of a user interface is common across all devices and which are specific to one device. They use design patterns to specify higher-level concepts within a user interface. Design patterns in Damask include pre-built UI fragments that are already optimized for each device. Designers can instantiate patterns in their designs and then customize the instances to fit their particular requirements. Through a study performed with twelve professional web designers, we have found that, in the early stages of design, designers using patterns and layers in Damask create cross-device user interfaces that are as good as or better than those created without patterns and layers, in less time.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPoly(vinylpyridinium dichromate): an inexpensive recyclable polymeric reagentJean M. J. Frechet, Pauline Darling, and M. Jean FarrallCite this: J. Org. Chem. 1981, 46, 8, 1728–1730Publication Date (Print):April 1, 1981Publication History Published online1 May 2002Published inissue 1 April 1981https://pubs.acs.org/doi/10.1021/jo00321a042https://doi.org/10.1021/jo00321a042research-articleACS PublicationsRequest reuse permissionsArticle Views238Altmetric-Citations104LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
