1,769 research outputs found
Bis[[aqua(1H-imidazo[4,5-f][1,10]phenanthroline-κ2 N 6,N 7)cadmium]bis(μ-pyridine-2,3-dicarboxylato)-κ3 N,O 2:O 3;κ3 O 3:N,O 2]
In the title compound, [Cd2(C7H3NO4)2(C13H8N4)2(H2O)2], the CdII ion is six-coordinated by two N atoms from a 1H-imidazo[4,5-f][1,10]phenanthroline (IP) ligand, one N atom and one O atom from a pyridine-2,3-dicarboxylate (pdc) ligand, one O atom from another pdc ligand and one water molecule in a distorted octahedral geometry. Two CdII ions are bridged by a pair of pdc ligands, forming a centrosymmetric dinuclear structure. Neighboring dinuclear units are linked by the coordinated water molecules through O—H⋯N and O—H⋯O hydrogen bonds, forming a layer parallel to (011). The layers are further linked into a three-dimensional network through N—H⋯O hydrogen bonds. π–π interactions between the IP ligands further stabilize the supramolecular structure [centroid–centroid distances = 3.579 (3), 3.686 (3), 3.710 (3), 3.766 (3) and 3.841 (3) Å]
Species Recognition and Cryptic Species in the Tuber indicum Complex
Morphological delimitation of Asian black truffles, including Tuber himalayense, T. indicum, T. sinense, T. pseudohimalayense, T. formosanum and T. pseudoexcavatum, has remained problematic and even phylogenetic analyses have been controversial. In this study, we combined five years of field investigation in China with morphological study and DNA sequences analyses (ITS, LSU and β-tubulin) of 131 Tuber specimens to show that T. pseudohimalayense and T. pseudoexcavatum are the same species. T. formosanum is a separate species based on its host plants and geographic distribution, combined with minor morphological difference from T. indicum. T. sinense should be treated as a synonym of T. indicum. Our results demonstrate that the present T. indicum, a single described morphological species, should include at least two separate phylogenetic species. These findings are of high importance for truffle taxonomy and reveal and preserve the richness of truffle diversity
STDPG: A Spatio-Temporal Deterministic Policy Gradient Agent for Dynamic Routing in SDN
Dynamic routing in software-defined networking (SDN) can be viewed as a
centralized decision-making problem. Most of the existing deep reinforcement
learning (DRL) agents can address it, thanks to the deep neural network
(DNN)incorporated. However, fully-connected feed-forward neural network (FFNN)
is usually adopted, where spatial correlation and temporal variation of traffic
flows are ignored. This drawback usually leads to significantly high
computational complexity due to large number of training parameters. To
overcome this problem, we propose a novel model-free framework for dynamic
routing in SDN, which is referred to as spatio-temporal deterministic policy
gradient (STDPG) agent. Both the actor and critic networks are based on
identical DNN structure, where a combination of convolutional neural network
(CNN) and long short-term memory network (LSTM) with temporal attention
mechanism, CNN-LSTM-TAM, is devised. By efficiently exploiting spatial and
temporal features, CNNLSTM-TAM helps the STDPG agent learn better from the
experience transitions. Furthermore, we employ the prioritized experience
replay (PER) method to accelerate the convergence of model training. The
experimental results show that STDPG can automatically adapt for current
network environment and achieve robust convergence. Compared with a number
state-ofthe-art DRL agents, STDPG achieves better routing solutions in terms of
the average end-to-end delay.Comment: 6 pages,5 figures,accepted by IEEE ICC 202
Novel Microfiber Sensor and Its Biosensing Application for Detection of hCG Based on a Singlemode-Tapered Hollow Core-Singlemode Fiber Structure
A novel microfiber sensor is proposed and demonstrated based on a singlemode-tapered hollow core -singlemode (STHS) fiber structure. Experimentally a STHS with taper waist diameter of 26.5 μm has been fabricated and RI sensitivity of 816, 1601.86, and 4775.5 nm/RIU has been achieved with RI ranges from 1.3335 to 1.3395 , from 1.369 to 1.378, and from 1.409 to 1.4175 respectively, which agrees very well with simulated RI sensitivity of 885, 1517, and 4540 nm/RIU at RI ranges from 1.3335 to 1.337, from 1.37 to 1.374, and from 1.41 to 1.414 . The taper waist diameter has impact on both temperature and strain sensitivity of the sensor structure: (1) the smaller the waist diameter, the higher the temperature sensitivity, and experimentally 26.82 pm/°C has been achieved with a taper waist diameter of 21.4 μm; (2) as waist diameter decrease, strain sensitivity increase and 7.62 pm/με has been achieved with a taper diameter of 20.3 μm. The developed sensor was then functionalized for human chorionic gonadotropin (hCG) detection as an example for biosensing application. Experimentally for hCG concentration of 5 mIU/ml, the sensor has 0.5 nm wavelength shift, equivalent to limit of detection (LOD) of 0.6 mIU/ml by defining 3 times of the wavelength variation (0.06 nm) as measurement limit. The biosensor demonstrated relatively good reproducibility and specificity, which has potential for real medical diagnostics and other applications
Effects of Vanadium doping on BaFe2As2
We report an investigation of the structural, magnetic and electronic
properties of Ba(Fe(1-x)V(x))2As2 using x-ray, transport, magnetic
susceptibility and neutron scattering measurements. The vanadium substitutions
in Fe sites are possible up to 40\%. Hall effect measurements indicate strong
hole-doping effect through V doping, while no superconductivity is observed in
all samples down to 2K. The antiferromagnetic and structural transition
temperature of BaFe2As2 is gradually suppressed to finite temperature then
vanishes at x=0.245 with the emergence of spin glass behavior, suggesting an
avoided quantum critical point (QCP). Our results demonstrate that the avoided
QCP and spin glass state which were previously reported in the superconducting
phase of Co/Ni-doped BaFe2As2 can also be realized in non-superconducting
Ba(Fe(1-x)V(x))2As2.Comment: 5 pages, 6 figure
Open Vocabulary Object Detection with Pseudo Bounding-Box Labels
Despite great progress in object detection, most existing methods work only
on a limited set of object categories, due to the tremendous human effort
needed for bounding-box annotations of training data. To alleviate the problem,
recent open vocabulary and zero-shot detection methods attempt to detect novel
object categories beyond those seen during training. They achieve this goal by
training on a pre-defined base categories to induce generalization to novel
objects. However, their potential is still constrained by the small set of base
categories available for training. To enlarge the set of base classes, we
propose a method to automatically generate pseudo bounding-box annotations of
diverse objects from large-scale image-caption pairs. Our method leverages the
localization ability of pre-trained vision-language models to generate pseudo
bounding-box labels and then directly uses them for training object detectors.
Experimental results show that our method outperforms the state-of-the-art open
vocabulary detector by 8% AP on COCO novel categories, by 6.3% AP on PASCAL
VOC, by 2.3% AP on Objects365 and by 2.8% AP on LVIS. Code is available at
https://github.com/salesforce/PB-OVD.Comment: ECCV 202
Di-μ-sulfato-bis[diaqua(1H-imidazo[4,5-f][1,10]phenanthroline)iron(II)] dihydrate
The title dinuclear FeII complex, [Fe2(SO4)2(C13H8N4)2(H2O)4]·2H2O, is centrosymmetric. Two sulfate anions bridge two FeII cations to form the binuclear complex. Each FeII cation is coordinated by two N atoms from a 1H-imidazo[4,5-f][1,10]phenanthroline (IP) ligand, two O atoms from two sulfate anions and two water molecules in a distorted octahedral geometry. Extensive O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonding is present in the crystal structure. Weak π–π stacking is observed between parallel IP ring systems, the face-to-face separation being 3.428 (14) Å
The capsid protein p38 of turnip crinkle virus is associated with the suppression of cucumber mosaic virus in Arabidopsis thaliana co-infected with cucumber mosaic virus and turnip crinkle virus
AbstractInfection of plants by multiple viruses is common in nature. Cucumber mosaic virus (CMV) and Turnip crinkle virus (TCV) belong to different families, but Arabidopsis thaliana and Nicotiana benthamiana are commonly shared hosts for both viruses. In this study, we found that TCV provides effective resistance to infection by CMV in Arabidopsis plants co-infected by both viruses, and this antagonistic effect is much weaker when the two viruses are inoculated into different leaves of the same plant. However, similar antagonism is not observed in N. benthamiana plants. We further demonstrate that disrupting the RNA silencing-mediated defense of the Arabidopsis host does not affect this antagonism, but capsid protein (CP or p38)-defective mutant TCV loses the ability to repress CMV, suggesting that TCV CP plays an important role in the antagonistic effect of TCV toward CMV in Arabidopsis plants co-infected with both viruses
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