2,783 research outputs found
Detailed Componential Characterization of Extractable Species with Organic Solvents from Wheat Straw
Componential analysis of extractives is important for better understanding the structure and utilization of biomass. In this investigation, wheat straw (WS) was extracted with petroleum ether (PE) and carbon disulfide (CS2) sequentially, to afford extractable fractions EFPE and EFCS2, respectively. Detailed componential analyses of EFPE and EFCS2 were carried out with Fourier transform infrared (FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), and electron probe microanalysis (EPMA). Total extractives were quantified 4.96% by weight compared to the initial WS sample. FTIR and GC/MS analyses results showed that PE was effective for the extraction of ketones and waxes derived compounds; meanwhile CS2 preferred ketones and other species with higher degrees of unsaturation. Steroids were enriched into EFPE and EFCS2 with considerable high relative contents, namely, 64.52% and 79.58%, respectively. XPS analysis showed that most of the C atoms in extractives were contained in the structures of C-C, C-COOR, and C-O. TEM-EDS and EPMA analyses were used to detect trace amount elements, such as Al, Si, P, S, Cl, and Ca atoms. Detailed characterization of extractable species from WS can provide more information on elucidation of extractives in biomass
(E)-Ethyl N′-(3-hydroxybenzylidene)hydrazinecarboxylate dihydrate
The asymmetric unit of the title compound, C10H12N2O3·2H2O, contains two organic molecules with similar conformations and four water molecules. Each organic molecule is close to planar (r.m.s. deviations = 0.035 and 0.108 Å) and adopts a trans conformation with respect to its C=N bond. In the crystal, the components are linked into a three-dimensional network by N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, some of which are bifurcated. An R
2
2(8) loop occurs between adjacent organic molecules
Analytical Strategies Involved in the Detailed Componential Characterization of Biooil Produced from Lignocellulosic Biomass
Elucidation of chemical composition of biooil is essentially important to evaluate the process of lignocellulosic biomass (LCBM) conversion and its upgrading and suggest proper value-added utilization like producing fuel and feedstock for fine chemicals. Although the main components of LCBM are cellulose, hemicelluloses, and lignin, the chemicals derived from LCBM differ significantly due to the various feedstock and methods used for the decomposition. Biooil, produced from pyrolysis of LCBM, contains hundreds of organic chemicals with various classes. This review covers the methodologies used for the componential analysis of biooil, including pretreatments and instrumental analysis techniques. The use of chromatographic and spectrometric methods was highlighted, covering the conventional techniques such as gas chromatography, high performance liquid chromatography, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectrometry. The combination of preseparation methods and instrumental technologies is a robust pathway for the detailed componential characterization of biooil. The organic species in biooils can be classified into alkanes, alkenes, alkynes, benzene-ring containing hydrocarbons, ethers, alcohols, phenols, aldehydes, ketones, esters, carboxylic acids, and other heteroatomic organic compounds. The recent development of high resolution mass spectrometry and multidimensional hyphenated chromatographic and spectrometric techniques has considerably elucidated the composition of biooils
Co-contributorship Network and Division of Labor in Individual Scientific Collaborations
Collaborations are pervasive in current science. Collaborations have been
studied and encouraged in many disciplines. However, little is known how a team
really functions from the detailed division of labor within. In this research,
we investigate the patterns of scientific collaboration and division of labor
within individual scholarly articles by analyzing their co-contributorship
networks. Co-contributorship networks are constructed by performing the
one-mode projection of the author-task bipartite networks obtained from 138,787
papers published in PLoS journals. Given a paper, we define three types of
contributors: Specialists, Team-players, and Versatiles. Specialists are those
who contribute to all their tasks alone; team-players are those who contribute
to every task with other collaborators; and versatiles are those who do both.
We find that team-players are the majority and they tend to contribute to the
five most common tasks as expected, such as "data analysis" and "performing
experiments". The specialists and versatiles are more prevalent than expected
by a random-graph null model. Versatiles tend to be senior authors associated
with funding and supervisions. Specialists are associated with two contrasting
roles: the supervising role as team leaders or marginal and specialized
contributions.Comment: accepted by JASIS
AlphaPose: Whole-Body Regional Multi-Person Pose Estimation and Tracking in Real-Time
Accurate whole-body multi-person pose estimation and tracking is an important
yet challenging topic in computer vision. To capture the subtle actions of
humans for complex behavior analysis, whole-body pose estimation including the
face, body, hand and foot is essential over conventional body-only pose
estimation. In this paper, we present AlphaPose, a system that can perform
accurate whole-body pose estimation and tracking jointly while running in
realtime. To this end, we propose several new techniques: Symmetric Integral
Keypoint Regression (SIKR) for fast and fine localization, Parametric Pose
Non-Maximum-Suppression (P-NMS) for eliminating redundant human detections and
Pose Aware Identity Embedding for jointly pose estimation and tracking. During
training, we resort to Part-Guided Proposal Generator (PGPG) and multi-domain
knowledge distillation to further improve the accuracy. Our method is able to
localize whole-body keypoints accurately and tracks humans simultaneously given
inaccurate bounding boxes and redundant detections. We show a significant
improvement over current state-of-the-art methods in both speed and accuracy on
COCO-wholebody, COCO, PoseTrack, and our proposed Halpe-FullBody pose
estimation dataset. Our model, source codes and dataset are made publicly
available at https://github.com/MVIG-SJTU/AlphaPose.Comment: Documents for AlphaPose, accepted to TPAM
N′-(4-Hydroxy-3-methoxybenzylidene)acetohydrazide monohydrate
In the title compound, C10H12N2O3·H2O, the Schiff base molecule is approximately planar [within 0.189 (1) Å]. The interplanar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, molecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydroxy H atom deviates from the 4-hydroxy-3-methoxyphenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R
1
2(4) motif. A weak C—H⋯π interaction is also present
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