In this article, a novel slot-array defected ground structure (DGS) for decoupling microstrip antenna array is proposed. The slot-array DGS is etched surrounding each antenna element on the ground ...plane and parallel to the radiating edges of each antenna element. The decoupling mechanism is elucidated via an equivalent circuit model and the coupled current field analysis, which reveals slot-array DGS has the spatial band-stop characteristic and changes the direction of the partially coupled current, respectively. Both characteristics of the slot-array DGS contribute to mutual coupling reduction. Three practical design examples of applying slot-array DGS to single-linearly polarized (LP), dual-LP, and compact circularly polarized (CP) antenna array are given to illustrate the design process and considerations. The simulated and measured results show that about 50 dB isolation enhancement is obtained by using the slot-array DGS when the edge-to-edge spacing between CP antenna elements is 0.057 wavelength. Additionally, a wheel-shaped absorber based on the electromagnetic loss material is designed and fabricated to reduce the backward radiation caused by slot-array DGS. The absorber has an absorptivity of more than 95% in the frequency range of 1.2-1.35 GHz and suppresses the backward radiation over 12.5 dB in the plane phi = 0° and 16.1 dB in the plane phi = 90° without deteriorating other antenna performances.
Status of the LHAASO experiment and its latest results in both
γ
-ray astronomic observations and charged cosmic ray (CR) measurements are reported in this paper. The discovery of photons around 1 ...PeV from the Crab, 12 PeVatrons in our galaxy and new sources with emissions above 100 TeV declare the onset of the utral-high-energy
γ
-ray astronomy. The capability of measurements of spectra of the individual species of CRs, e.g. protons and iron nuclei, starts the new era of the high precision measurement of CRs using the ground based extensive air shower technique. The detection of the highest energy photon at 1.4 PeV from the remote potential source in Cygnus region allows to test of the violation of fundamental physics rules, such as the Lorentz Invariance, and set the highest limits in the tests.
LHAASO on Cosmic Ray Knees Cao, Zhen
EPJ Web of Conferences,
2023, Letnik:
283
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
LHAASO construction was complete in July 2021. The full array is operating very stably since then. All arrays, KM2A, WCDA and WFCTA are calibrated, including the absolute energy scale at 21 TeV, ...which was measured by using WCDA and propagated to WFCTA, with the uncertainty will be reduced down <10% in 4 years. The knee of pure proton spectrum will be measured in the first phase of the hybrid measurements of showers using four types of EAS detection techniques started in 2019 winter. Sufficient data have been collected and the analysis is in progress. Since the last run, the second phase were started in 2021 winter. The knee of the iron spectrum is the goal which will take at least 3 years of data collection. CR all-particle spectrum, composition and anisotropy are under analysis.
Carbon-based nanomaterials, especially carbon nanotubes and graphene, have drawn wide attention in recent years as novel materials for environmental applications. Notably, the functionalized ...derivatives of carbon nanotubes and graphene with high surface area and adsorption sites are proposed to remove heavy metals via adsorption, addressing the pressing pollution of heavy metal. This critical revies assesses the recent development of various functionalized carbon nanotubes and graphene that are used to remove heavy metals from contaminated water, including the preparation and characterization methods of functionalized carbon nanotubes and graphene, their applications for heavy metal adsorption, effects of water chemistry on the adsorption capacity, and decontamination mechanism. Future research directions have also been proposed with the goal of further improving their adsorption performance, the feasibility of industrial applications, and better simulating adsorption mechanisms.
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•Removal of heavy metals from water has drawn wide attention.•Various functionalized carbon nanotube and graphene nanomaterials were stated.•Effects of water environmental chemistry on heavy metals removal were discussed.•Adsorption isotherms, kinetics, thermodynamics, and pathways were discussed.•Some research prospects were proposed for future studies and application.
Purpose： This study was to present national estimates of participating in moderate-to-vigorous physical activity （MVPA） and adherence to the recommendations of 60 rain/day of MVPA among Chinese ...school-aged children and to assess demographic differences in MVPA. Methods： Cross-sectional analyses of data from the 2016 Physical Activity and Fitness in China--The Youth Study. Participants were 90,712 primary, junior middle, and junior high school children （boy： 47%; girl： 53%）, recruited from 1204 rural and urban schools across 32 administrative provinces and regions in the Mainland of China. Main outcomes were （a） average MVPA minutes per day in the previous 7 days by self-reports and （b） percentage meeting MVPA recommendations. Results： Average MVPA time was 45.4 rain/day, with boys having more MVPA （47.2 min/day） than girls （43.7 min/day） overall and across the 3 school grade categories. About 30% of participants met MVPA recommendations, with a higher percentage of boys （32%） than girls （28%） overall and across the 3 grades categories. Urban school children outperformed rural children in terms of MVPA time. Overall, boys were more likely to meet MVPA recommendations （adjusted odds ratio （aOR） = 1.19, 95% confidence interval （CI）： 1.16-1.22） compared with girls; children in higher grades （junior middle （aOR = 0.92, 95%CI： 0.87-0.98） and junior high （aOR = 0.59, 95%CI： 0.53-0.66）） were less likely to meet recommenda- tions compared with primary school children. The odds of meeting recommendations did not differ between urban and rural children （p = 0.07）, but urban boys were found to be more likely to meet recommendations compared with rural boys （aOR = 1.14, 95%CI： 1.06-1.19）. Conclusion： Overall, the average MVPA minutes per day among Chinese school-aged children is low, and less than one-third of them meet MVPA recommendations. These results were most evident among junior middle and junior high school children and those living rural areas. 2017 Production and hosting by Elsevier B.V on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
The engineering of catalysts with desirable properties can be accelerated by computer-aided design. To achieve this aim, features of molecular catalysts can be condensed into numerical descriptors ...that can then be used to correlate reactivity and structure. Based on such descriptors, we have introduced topographic steric maps that provide a three-dimensional image of the catalytic pocket-the region of the catalyst where the substrate binds and reacts-enabling it to be visualized and also reshaped by changing various parameters. These topographic steric maps, especially when used in conjunction with density functional theory calculations, enable catalyst structural modifications to be explored quickly, making the online design of new catalysts accessible to the wide chemical community. In this Perspective, we discuss the application of topographic steric maps either to rationalize the behaviour of known catalysts-from synthetic molecular species to metalloenzymes-or to design improved catalysts.
Vitamin D may play a role in skeletal muscle because of the discovery of VDR in skeletal muscle. However, vitamin D deficiency is a global problem, including athletes. Studies examining the effect of ...vitamin D supplementation on muscle function in athletes have inconsistent results. Therefore, we aimed to quantitatively summarize the evidence for the effect of vitamin D supplementation on skeletal muscle strength and explosive power of athletes using a meta-analysis.
PubMed, EMBASE, Cochrane Library, and Web of Science were searched for studies to identify randomized controlled trials or controlled trials meeting the inclusion criteria. By a meta-analysis, effect sizes (standardized mean differences, SMD) with 95% confidence intervals (CI) was calculated to compare reported outcomes across studies, I2 index was used to assessing heterogeneity, and heterogeneity factors were identified by regression analysis. The potential publication and sensitivity analyses were also assessed.
Eight RCTs involving 284 athletes were included. The protocols used to evaluate the muscle strength of athletes were inconsistent across the included studies, and muscle explosive power was assessed via vertical jump tests. The results indicated that vitamin D supplementation had no impact on overall muscle strength outcomes (SMD 0.05, 95% CI: -0.39 to 0.48, p = 0.84). In subgroup analysis, vitamin D supplementation had an effect on lower-limb muscle strength (SMD 0.55, 95% CI:0.12 to 0.98, p = 0.01) but not upper-limb muscle strength (SMD -0.19, 95% CI:-0.73 to 0.36, p = 0.50) or muscle explosive power (SMD 0.05, 95% CI:-0.24 to 0.34, p = 0.73). Vitamin D supplementation was more effective for athletes trained indoors (SMD 0.48, 95% CI:0.06 to 0.90, p = 0.02).
Vitamin D supplementation positively affected lower limb muscle strength in athletes, but not upper limb muscle strength or muscle power. Different muscle groups and functions may respond differently to vitamin D supplementation. Additional studies should focus on determining the appropriate vitamin D supplementation methods and optimal serum 25(OH)D levels for athletes.
The protocol for our study is registered in the international prospective register of systematic reviews (PROSPERO registration number CRD42016045872).
Bioactivity of soy-based fermented foods: A review Cao, Zhen-Hui; Green-Johnson, Julia M.; Buckley, Nicole D. ...
Biotechnology advances,
January-February 2019, 2019 Jan - Feb, 2019-01-00, 20190101, Letnik:
37, Številka:
1
Journal Article
Recenzirano
For centuries, fermented soy foods have been dietary staples in Asia and, now, in response to consumer demand, they are available throughout the world. Fermentation bestows unique flavors, boosts ...nutritional values and increases or adds new functional properties. In this review, we describe the functional properties and underlying action mechanisms of soy-based fermented foods such as Natto, fermented soy milk, Tempeh and soy sauce. When possible, the contribution of specific bioactive components is highlighted. While numerous studies with in vitro and animal models have hinted at the functionality of fermented soy foods, ascribing health benefits requires well-designed, often complex human studies with analysis of diet, lifestyle, family and medical history combined with long-term follow-ups for each subject. In addition, the contribution of the microbiome to the bioactivities of fermented soy foods, possibly mediated through direct action or bioactive metabolites, needs to be studied. Potential synergy or other interactions among the microorganisms carrying out the fermentation and the host's microbial community may also contribute to food functionality, but the details still require elucidation. Finally, safety evaluation of fermented soy foods has been limited, but is essential in order to provide guidelines for consumption and confirm lack of toxicity.
The evolution of extensive air shower detection as a technique for γ-ray astronomical instrumentation for the last three decades is reviewed. The first discoveries of galactic PeVatrons by the Large ...High Altitude Air Shower Observatory demonstrate the importance of this technique in ultra-high energy γ-ray astronomy. Utilizing this technique, the origins of high energy cosmic rays may be discovered in the near future.
Sulfur (S) fertilizer application in rice (Oryza sativa L.) is crucial in determining rice grain productivity and quality. However, little information is available concerning the effect of S supply ...on cadmium (Cd) uptake and translocation in rice. In this study, both hydroponic and soil experiments were conducted to investigate the influence of S supply on Cd accumulation in rice under two Cd levels (0 and 50 μM), combined with three S concentrations (0, 2.64 and 5.28 mM). The moderate and excessive S supply (2.64 and 5.28 mM) tended to increase plant growth, root length, root and shoot dry weights of rice seedlings, and significantly decreased Cd concentrations in rice plants and grains in the absence or presence of Cd. The subcellular distribution and chemical forms of Cd in roots and shoots also varied with S supply levels. The decreased Cd uptake and translocation in rice grains could be ascribed to the enhanced formation of iron (Fe) plaque on the root surfaces and increased Cd chelation and vacuolar sequestration in roots, since Fe, Mn concentrations in Fe plaque, glutathione and phytochelatins contents, as well as phytochelatin synthase (OsPCS) and tonoplast heavy metal ATPase (OsHMA3) expressions in roots significantly increased with increased S supply. This work provides more insight into the mechanisms of Cd uptake and translocation in rice, and will be helpful for developing strategies to reduce rice grain Cd through S fertilizer application in Cd-contaminated soil.
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•S supply reduces health risk to humans by decreasing Cd accumulation in rice grains.•S supply restrains Cd uptake by enhancing Fe plaque formation on the root surfaces.•S supply reduces Cd translocation by increasing Cd chelation and vacuolar sequestration in roots.
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