270,046 research outputs found
Supporting data for Primary data for Poly(4-ketovalerolactone) from Levulinic acid, Synthesis and Hydrolytic Degradation
No full textThe raw data files are organized within folders by the instrumentation used for characterization or by the chemdraw file. The characterization files are labeled by the number given to each molecule in the main text of the document.These files contain primary data along with associated output from instrumentation supporting all results reported in Xu et. al. Primary data for Poly(4-ketovalerolactone) from Levulinic acid, Synthesis and Hydrolytic Degradation. In Xu et al. we found: We report here the synthesis of poly(4-ketovalerolactone) (PKVL) via ring-opening transesterification polymerization (ROTEP) of the monomer 4-ketovalerolactone (KVL, two steps from levulinic acid). The polymerization of KVL proceeds to high equilibrium monomer conversion (up to 96% in the melt) to give the semicrystalline polyketoester PKVL with low dispersity. PKVL displays glass transition temperatures of 7 °C and two melting temperatures at 132 and 148 °C. This polyester can be chemically recycled through hydrolytic degradation. Under aqueous neutral or acidic conditions, the dominating pathway for polyester hydrolysis is through backbiting from the chain end. Under basic conditions, mid-chain cleavage, accelerated by the ketone carbonyl group in the backbone, promotes the hydrolysis of nearby backbone ester bonds. The final hydrolysis product is 5-hydroxylevulinic acid, the ring opened hydrolysis product of KVL. PKVL was also observed to degrade under the action of a Brønsted acid to a bis-spirocyclic dilactone natural product altaicadispirolactone, which is a dimer of KVL. This constitutes a rare example of a one-step synthesis of a secondary metabolite in which a polymer was the starting material and the sole source of matter. Analogous ROTEP of the isomeric 4-membered lactone 4-acetyl--propiolactone (APL) was also explored, although this chemistry was not as well-behaved as the KVL to PKVL polymerization.National Science Foundation, CHE-1901635Xu, Shu; Wang, Yuanxian; Hoye, Thomas R. (2020). Supporting data for Primary data for Poly(4-ketovalerolactone) from Levulinic acid, Synthesis and Hydrolytic Degradation. Retrieved from the University Digital Conservancy, https://doi.org/10.13020/jw1d-a958
A Fourier-related FE2 Multiscale Model for Instability Phenomena of Long Fiber Reinforced Materials
No full textA Novel FE2 Method Based Fourier Macroscopic Model for Instability Phenomena of Long Fiber Reinforced Composites
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Bolivaritettix platynotus Zheng, & Xu 2010
No full textBolivaritettix platynotus Zheng & Xu, 2010 Bolivaritettix platynotus Zheng, & Xu, 2010. In Zheng, Mao & Xu, Journal of Dali University, 9(4): 10 Specimens examined: 1♂, P. R. CHINA: Yunnan: Jiangcheng, 2009-VII-12. Distribution: P. R. CHINA: Yunnan.Published as part of Deng, Wei-An, Wei, Shi-Zhen, Xin, Lei & Chen, Ya-Zhen, 2018, Taxonomic revision of the genus Bolivaritettix Günther, 1939 (Orthoptera: Tetrigoidea: Metrodorinae) from China, with the descriptions of two new species, pp. 303-326 in Zootaxa 4434 (2) on page 310, DOI: 10.11646/zootaxa.4434.2.4, http://zenodo.org/record/129056
Thaumatodryinus moganensis Xu, He & Olmi 2001
No full textThaumatodryinus moganensis Xu, He & Olmi Thaumatodryinus moganensis Xu, He & Olmi, 2001: 64. Thaumatodryinus moganensis Xu, He & Olmi, 2001: He & Xu, 2002: 247. Description of female. Fully winged; length 6.2 mm. Head brown-black, except mandibles and clypeus testaceous-reddish; antennae with segments 1–4 testaceous (other segments missing in the only known specimen); mesosoma black, except pronotum testaceous-reddish with two brown-reddish stripes on lateral regions; petiole black; gaster testaceous-reddish; legs testaceous-reddish, except femora and proximal region of hind coxae brown-reddish. Antennae filiform; antennal segments in the following proportions: 28: 13: 57: 63 (other segments missing in the only known specimen). Head swollen, dull, granulated and rugose; frontal line complete; occipital carina complete; POL = 12; OL = 5.5; OOL = 17; OPL = 3.5; TL = 6; greatest breadth of posterior ocelli slightly longer than OL (6.5: 5.5). Pronotum dull, hairy, crossed by a transverse impression, granulated, with numerous little distinct transverse striae. Scutum dull, with median region granulated and lateral regions granulated and rugose. Notauli complete, posteriorly separated; minimum distance between notauli longer than POL (20: 12). Scutellum dull, granulated. Metanotum shiny, smooth. Propodeum reticulate rugose, without transverse or longitudinal keels. Forewing with a little distinct dark transverse band beneath the pterostigma; distal part of stigmal vein longer than proximal part (55: 34). Fore tarsal segments in the following proportions: 53: 7: 15: 42: 68. Enlarged claw with 2 subapical teeth and a row of about 30 lamellae (with distal lamella very long). Segment 5 of fore tarsus with 2 rows of approximately 60 lamellae; distal apex with a group of about 8 lamellae. Tibial spurs 1, 1, 2. Male. Unknown. Material examined. P. R. China, Zhejiang Province, Mt. Moganshan, 27.v. 1995, J. He coll., female holotype N. 978163 (ZJUC).Published as part of Xu, Zaifu, Olmi, Massimo & He, Junhua, 2009, A taxonomic revision of the Oriental species of Thaumatodryinus Perkins, with descriptions of two new species from P. R. China (Hymenoptera: Dryinidae), pp. 19-28 in Zootaxa 2175 on page 22, DOI: 10.5281/zenodo.18932
Calepitrimerus kunmingensis Xue, Luo, Xu 2011
No full text<p> <b> <i>Calepitrimerus kunmingensis</i> Xue, Luo, Xu & Hong, 2011: 63</b> </p> <p> <b>—</b> Holotype female (NJAU), from <i>Schefflera odorata</i> (Blanco) Merr. & Rolfe (Araliaceae), Campus of Yunnan Agricultural University, Kunming City, Yunnan Province, P. R. China.</p>Published as part of <i>LIU, DONG, YI, TIAN-CI, XU, YUN & ZHANG, ZHI-QIANG, 2013, new mite species described during 2007 to 2012 3663, pp. 1-102 in Zootaxa 3663 (1)</i> on page 42, DOI: 10.11646/zootaxa.3663.1.1, <a href="http://zenodo.org/record/5630595">http://zenodo.org/record/5630595</a>
On purely tree-colorable planar graphs
No full textA tree-k-coloring of a graph G is a k-coloring of G such that the subgraph induced by the union of any two color classes is a tree. G is purely tree-k-colorable if the chromatic number of G is k and any k-coloring of G is a tree-k-coloring. Xu [16] conjectured that there exist only two purely tree-4-colorable 4-connected maximal planar graphs. In this paper, we construct an infinite family of purely tree-colorable 4-connected maximal planar graphs, called dumbbell-maximal planar graphs, which disprove Xu's conjecture. Moreover, we give the enumeration of dumbbell-maximal planar graphs and propose a conjecture on such graphs. It turns out that the conjecture implies naturally the uniquely 4-colorable planar graph conjecture. (C) 2016 Elsevier B.V. All rights reserved.973 Program of China [2013CB329600]; National Natural Science Foundation of China [61372191, 61472012, 61472433, 61572046, 61502012, 61572492, 61572153]SCI(E)[email protected]; [email protected]; [email protected]
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