Nanjing University

About: Nanjing University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 85961 authors who have published 105504 publications receiving 2289036 citations. The organization is also known as: NJU & Nanking University.

Self-Templated Formation of Interlaced Carbon Nanotubes Threaded Hollow Co3S4 Nanoboxes for High-Rate and Heat-Resistant Lithium-Sulfur Batteries.

Abstract: Lithium–sulfur batteries (Li–S) have attracted soaring attention due to the particularly high energy density for advanced energy storage system. However, the practical application of Li–S batteries still faces multiple challenges, including the shuttle effect of intermediate polysulfides, the low conductivity of sulfur and the large volume variation of sulfur cathode. To overcome these issues, here we reported a self-templated approach to prepare interconnected carbon nanotubes inserted/wired hollow Co3S4 nanoboxes (CNTs/Co3S4–NBs) as an efficient sulfur host material. Originating from the combination of three-dimensional CNT conductive network and polar Co3S4–NBs, the obtained hybrid nanocomposite of CNTs/Co3S4–NBs can offer ultrahigh charge transfer properties, and efficiently restrain polysulfides in hollow Co3S4–NBs via the synergistic effect of structural confinement and chemical bonding. Benefiting from the above advantages, the S@CNTs/Co3S4–NBs cathode shows a significantly improved electrochemical...

The chandra deep field-south survey: 7 ms source catalogs

Abstract: We present X-ray source catalogs for the ≈7 Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 arcmin2. Utilizing wavdetect for initial source detection and ACIS Extract for photometric extraction and significance assessment, we create a main source catalog containing 1008 sources that are detected in up to three X-ray bands: 0.5-7.0 keV, 0.5-2.0 keV, and 2-7 keV. A supplementary source catalog is also provided, including 47 lower-significance sources that have bright (Ks ≤ 23) near-infrared counterparts. We identify multiwavelength counterparts for 992 (98.4%) of the main-catalog sources, and we collect redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, we identify 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ≈4 Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. We have achieved unprecedented X-ray sensitivity with average flux limits over the central ≈1 arcmin2 region of ≈1.9 ×10-17, 6.4 ×10-18, and 2.7 ×10-17 erg cm-2 s-1 in the three X-ray bands, respectively. We provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5-2.0 keV flux levels. The highest X-ray source density reaches ≈50,500 deg-2, and 47% ± 4% of these sources are AGNs (≈23,900 deg-2). (Less)

A Double Mass Extinction at the End of the Paleozoic Era

Abstract: Three tests based on fossil data indicate that high rates of extinction recorded in the penultimate (Guadalupian) stage of the Paleozoic era are not artifacts of a poor fossil record. Instead, they represent an abrupt mass extinction that was one of the largest to occur in the past half billion years. The final mass extinction of the era, which took place about 5 million years after the Guadalupian event, remains the most severe biotic crisis of all time. Taxonomic losses in the Late Permian were partitioned among the two crises and the intervening interval, however, and the terminal Permian crisis eliminated only about 80 percent of marine species, not 95 or 96 percent as earlier estimates have suggested.

Highly Ordered Platinum‐Nanotubule Arrays for Amperometric Glucose Sensing

Abstract: Direct glucose sensing on highly ordered platinum-nanotubule array electrodes (NTAEs) is systematically investigated. The NTAEs are fabricated by electrochemical deposition of platinum in a 3-aminopropyltrimethoxysilane-modified anodic alumina membrane. Their structures and morphologies are then characterized using X-ray diffraction and scanning electron microscopy, respectively. Electrochemical results show that NTAEs with different real surface areas could be achieved by controlling the deposition time or by using anodic alumina membranes with different pore size. Electrochemical responses of the as-synthesized NTAEs to glucose in a solutions of either 0.5 M H2SO4, or phosphate-buffered saline (PBS, pH 7.4) containing 0.1 M KCl are discussed. Based on the different electrochemical reaction mechanisms of glucose and interferents such as p-acetamedophenol and ascorbic acid, their high roughness factor makes NTAEs sensitive, selective, and stable enough to be a kind of biosensor for the non-enzymatic detection of glucose. Such a glucose sensor allows the determination of glucose in the linear range 2–14 mM, with a sensitivity of 0.1 μA cm–2 mM–1 (correlation coefficient 0.999), and a detection limit of 1.0 μM glucose, with neglectable interference from physiological levels of 0.1 mM p-acetamedophenol, 0.1 mM ascorbic acid, and 0.02 mM uric acid.