A circular phased array antenna that can generate orbital angular momentum (OAM) radio beams in the 10 GHz band is described. The antenna consists of eight inset-fed patch elements and a microstrip ...corporate feeding network. A full-wave electromagnetic simulator is used to aid the antenna design and theoretical simulations are confirmed by measurements.
We present a semi-analytical formalism capable of handling the coupling of electromagnetic sources, such as point dipoles or free-propagating fields, with various kinds of dissipative resonances with ...radiation leakage, Ohmic losses or both. Due to its analyticity, the approach is very intuitive and physically-sound. It is also very economic in computational resources, since once the resonances of a plasmonic or photonic resonator are known, their excitation coefficients are obtained analytically, independently of the polarization, frequency or location of the excitation source. To evidence that the present formalism is very general and versatile, we implement it with the commercial software COMSOL, rather than with our in-house numerical tools.
Colletotrichum species are plant pathogens, saprobes, and endophytes on a range of economically important hosts. However, the species occurring on pear remain largely unresolved. To determine the ...morphology, phylogeny and biology of Colletotrichum species associated with
Pyrus plants, a total of 295 samples were collected from cultivated pear species (including P. pyrifolia, P. bretschneideri, and P. communis) from seven major pear-cultivation provinces in China. The pear leaves and fruits affected by anthracnose were sampled and
subjected to fungus isolation, resulting in a total of 488 Colletotrichum isolates. Phylogenetic analyses based on six loci (ACT, TUB2, CAL, CHS-1, GAPDH, and ITS) coupled with morphology of 90 representative isolates revealed that they belong to 10
known Colletotrichum species, including C. aenigma, C. citricola, C. conoides, C. fioriniae, C. fructicola, C. gloeosporioides, C. karstii, C. plurivorum, C. siamense, C. wuxiense, and two novel species, described
here as C. jinshuiense and C. pyrifoliae. Of these, C. fructicola was the most dominant, occurring on P. pyrifolia and P. bretschneideri in all surveyed provinces except in Shandong, where C. siamense was dominant. In contrast, only C. siamense
and C. fioriniae were isolated from P. communis, with the former being dominant. In order to prove Koch's postulates, pathogenicity tests on pear leaves and fruits revealed a broad diversity in pathogenicity and aggressiveness among the species and isolates, of which C. citricola,
C. jinshuiense, C. pyrifoliae, and C. conoides appeared to be organ-specific on either leaves or fruits. This study also represents the first reports of C. citricola, C. conoides, C. karstii, C. plurivorum, C. siamense, and C. wuxiense
causing anthracnose on pear.
All the Li metal anode-based batteries suffer from a high propensity to form Li dendrites. To prevent the formation of dendritic lithium on the electrodes, amorphous carbon coatings are deposited ...onto the surface of metallic lithium foil by magnetron sputtering technique. The electrochemical performances of the amorphous carbon-coated lithium (Li/C) electrodes are investigated by galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The compact carbon coatings on the surface of lithium foil can suppress the growth of dendritic lithium during charge–discharge process. The thickness of amorphous carbon coating affects the electrode from two aspects; the thick coating can prevent the formation of dendritic lithium much efficiently, but lead to a large impedance of Li+ transfer.
•Amorphous carbon coatings were deposited onto the surface of metallic lithium.•The formation of dendritic can be prevented according to the SEM photograph.•The electrochemical performance is promoted due to the existence of a-C coating.•The thickness of a-C coating affects the electrode performance from two aspects.
This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were ...investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5
min reached 68–96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca
2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30–34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO
4·2H
2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.
Species of Diaporthe (syn. Phomopsis) are important endophytes, saprobes and pathogens, infecting a wide range of plants and resulting in important crop diseases. However, the species occurring on ...pear remain largely unresolved. In this study, a total of 453 Diaporthe
isolates were obtained from branches of Pyrus plants (including P. bretschneideri, P. communis, P. pyrifolia and P. ussuriensis collected from 12 provinces in China) showing shoot canker symptoms. Phylogenetic analyses based on five loci (ITS, TEF,
CAL, HIS, and TUB) coupled with morphology of 113 representative isolates revealed that 19 Diaporthe species were isolated, representing 13 known species (including D. caryae, D. cercidis, D. citrichinensis, D. eres, D. fusicola,
D. ganjae, D. hongkongensis, D. padina, D. pescicola, D. sojae, D. taoicola, D. unshiuensis and D. velutina) and six new species described here as D. acuta, D. chongqingensis, D. fulvicolor, D. parvae, D.
spinosa and D. zaobaisu. Although Koch's postulates confirmed all species to be pathogenic, a high degree of variation in aggressiveness was observed. Moreover, these species have a high diversity, plasticity, and prevalence related to the geographical location and pear species
involved.
Objectives
Although recombinant tissue plasminogen activator (r‐tPA) is currently the most effective treatment for brain ischemic stroke, the 3‐h narrow therapeutic windows severely limits its ...clinical efficacy. We aim to investigate the effect of resveratrol on improving treatment outcomes of delayed r‐tPA administration.
Materials & methods
Patients were randomly divided according to their onset‐to‐treatment time (OTT), as early OTT or delayed OTT. Then, they were either treated with r‐tPA + placebo or with r‐tPA + resveratrol. Twenty‐four hours after the treatment, outcomes were assessed with NIH stroke scale (NIHSS), and plasma levels of MMP‐2 and MMP‐9 were also examined with ELISA.
Results
In patients receiving delayed r‐tPA treatment, co‐administration of resveratrol significantly improves their treatment outcomes compared with those receiving placebo, as indicated by improved NIHSS scores. This improved outcome was be caused by resveratrol‐induced reduction in plasma levels of both matrix metalloproteinase (MMP)‐2 and MMP‐9, as a positive correlation was observed between reductions in both MMPs and patient NIHSS scores.
Conclusions
Resveratrol could be potentially administered as an adjuvant with r‐tPA treatment, which extends the clinical therapeutic window of r‐tPA, therefore improving the outcome of patients receiving late stroke treatment.
This paper deals with the magnetic properties magnetic susceptibility, saturation isothermal remanent magnetization (SIRM), magnetomineralogicl parameters, the contents of heavy metals (Fe, Mn, Cd, ...Cr, Cu, Pb and Zn) and their mutual relationship in the urban topsoils of Luoyang, China. Magnetic susceptibility measured on 215 urban topsoil samples ranged from 31 × 10−8 to 1128 × 10−8 m3 kg−1 (average 215 × 10−8 m3 kg−1) and showed that high magnetic susceptibility values were obtained on topsoil samples from industrial areas (average 313 × 10−8 m3 kg−1) and roadside (236 × 10−8 m3 kg−1), whereas lower susceptibility values were observed in parks and green areas (123 × 10−8 m3 kg−1). The urban topsoils were enriched with Cd, Cr, Cu, Pb and Zn, with average contents of 1.71, 30.51, 85.40, 65.92 and 215.75 mg kg−1, respectively. The heavy metals Cr, Cu, Pb and Zn show a statistically significant correlation with magnetic susceptibility and SIRM. The Tomlinson Pollution Load Index (PLI) also shows significant correlation with magnetic susceptibility and SIRM, indicating that the magnetic parameters can provide a proxy method for identifying the heavy metal pollution in urban topsoils. Rock magnetism and X-ray diffraction analyses revealed that the dominant magnetic mineral in the urban topsoils is anthropogenic pseudo-single domain (PSD)-multidomain (MD) magnetite. These magnetic particles are associated with the industrial activities, traffic exhaust and deposition of atmospheric particulate.
Abstract
The rotating detonation characteristics of high-temperature hydrogen-rich gas were studied. Hydrogen-rich gas was generated by the pre-combustion of hydrogen, and a rotating detonation ...experiment of hydrogen-rich gas and air was subsequently performed. The auto-initiation of high-temperature hydrogen-rich gas was observed in the experiment, and the influence of pre-detonation tube ignition on the steady propagation of the detonation wave was analyzed. The results show that high-temperature hydrogen-rich gas and air have the ability to spontaneously form rotating detonation waves. The operation of the pre-detonation tube has a significant influence on the propagation mode and propagation velocity of the continuous rotating detonation wave after auto-initiation. The rotational detonation wave formed by the auto-initiation of hydrogen-rich gas and air has a short instability in the propagation process. The propagation velocity of the detonation wave before and after the unstable state is 1345.4 m/s and 1425.3 m/s, respectively, the unstable state is 1345.4 m/s and 1425.3 m/s, respectively.
A study of direct forging process for powder superalloys Bai, Q.; Lin, J.; Jiang, J. ...
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
01/2015, Letnik:
621
Journal Article
Recenzirano
Odprti dostop
Powder metallurgy (PM) processing of nickel-based superalloys has been used for a wide range of near net-shape fine grained products. In this paper a novel forming process, i.e. direct forging of ...unconsolidated powder superalloys is proposed. In this process, encapsulated and vacuumed powder particles are heated up to a forming temperature and forged directly at high speed to the final shape, by using a high forming load. Experiments of direct powder forging have been conducted on an upsetting tool-set. Microstructure, relative density and hardness of the formed specimen have been investigated. A finite element model of the direct powder forging process has been established in DEFORM and validated by the comparisons of experimental with simulation results of load variation with stroke as well as relative density distribution. The stress state and the relative density variation have been obtained from FE simulation. The correlation between the stress and consolidation condition has been rationalised. The developed FE model can provide a guide to design the geometry and thickness of preform for direct powder forging.
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