Reduced graphene oxide (rGO) aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials (EWAMs) due to their intrinsic conductive networks and ...intricate interior microstructure, as well as good compatibility with other electromagnetic (EM) components. Herein, we realized the decoration of rGO aerogel with Mo
2
C nanoparticles by sequential hydrothermal assembly, freeze-drying, and high-temperature pyrolysis. Results show that Mo
2
C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio. The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo
2
C nanoparticles, and more importantly, these nanoparticles regulate the EM properties of the rGO aerogel to a large extent. Although more Mo
2
C nanoparticles may decrease the overall attenuation ability of the rGO aerogel, they bring much better impedance matching. At a molar ratio of 1:1, a desirable balance between attenuation ability and impedance matching is observed. In this context, the Mo
2
C/rGO aerogel displays strong reflection loss and broad response bandwidth, even with a small applied thickness (1.7 mm) and low filler loading (9.0wt%). The positive effects of Mo
2
C nanoparticles on multifunctional properties may render Mo
2
C/rGO aerogels promising candidates for high-performance EWAMs under harsh conditions.
Carbon-based carbides have attracted tremendous attention for electromagnetic energy attenuation due to their adjustable dielectric properties, oxidation resistance, and good chemical stability. ...Herein, we reasonably regulate the growth of dopamine hydrochloride on the surface of the Mo-glycerate (Mo-GL) microsphere and then transform the resultant Mo-polydopamine (Mo-PD) microsphere into a dual-shell Mo2C/C (DS-Mo2C/C) microsphere in a high-temperature pyrolysis process under an inert atmosphere. It is found that the pyrolysis temperature plays an important role in the graphitization degree of the carbon matrix and internal architecture. The fabrication of a dual-shell structure can be propitious to the optimization of impedance matching, and the introduction of Mo2C nanoparticles also prompts the accumulation of polarization loss. When the pyrolysis temperature reaches 800 °C, the optimized composite of DS-Mo2C/C-800 exhibits good EM absorption performance in the frequency range of 2.0–18.0 GHz. DS-Mo2C/C-800′s qualified bandwidth can reach 4.4 GHz at a matching thickness of 1.5 mm, and the integrated qualified bandwidth (QBW) even exceeds 14.5 GHz with a thickness range of 1.5–5.0 mm. The positive effects of the dual-shell structure and Mo2C nanoparticles on EM energy attenuation may render the DS-Mo2C/C microsphere as a promising candidate for lightweight and broad bandwidth EM absorption materials in the future.
Anion exchange is an effective strategy to regulate the composition and optoelectronic properties of perovskite quantum dots (PQDs). Though promising, it is more desirable to synthesize PQDs to avoid ...the decrease of photoluminescence quantum yield (PLQY). Herein, we developed a ligand mediated anion exchange approach, in which the phase transition from CsPbBr3 QDs to CsPbI3 QDs was observed with the introduction of N-Acetyl-l-cysteine (NAC) and 1,3-dimethylimidazolium iodide (DMII) aqueous solution in CsPbBr3 QDs solution. NAC is expected to create more halogen vacancies in CsPbBr3 QDs, which provides sufficient adsorption sites for I− ions, resulting in accelerating the anion exchange rate in the process of DMII incorporation. Benefiting from the synergistic ligand mediated anion exchange, high PLQY of 97% and remarkable stability of CsPbI3 QDs are obtained. Furthermore, a white light-emitting diode (WLED) with a lumen efficiency (LE) of 116.82 lm/W is constructed, showing remarkable stability under continuous operation.
Background
This study aimed to explore the association of the presence and number of components of metabolic syndrome (MetS) with carotid atherosclerosis by measuring the presence of carotid plaque ...and total plaque area (TPA) in a population from a low-income area with high incidence of stroke of northern China.
Methods
A cross-sectional study was conducted in a rural area of Tianjin, China from April 2014 to January 2015. The presence of plaque and TPA measurement was determined by carotid ultrasound. The presence and number of components of MetS was ascertained using the modified International Diabetes Federation criteria for the Asian population.
Results
Among a total of 3,583 individuals aged ≥ 45 years, the overall prevalence of MetS was 54.5%. MetS and its components were related to the presence of carotid plaque as well as TPA. Multivariate analysis showed MetS was associated with a 20% higher risk of carotid plaque presence (95% confidence interval: 1.01, 1.42;
P
= 0.036) and an 18% increase in TPA (95% confidence interval: 0.08, 0.27;
P
< 0.001). The number of MetS components showed an increasing trend with the risk of carotid plaque presence and increased TPA. Among single components of MetS, high BP accounted for the largest proportion and was an independent risk factor of carotid plaque and increased TPA.
Conclusions
Among individuals aged 45 years or more, we confirmed MetS and its components were associated with carotid atherosclerosis in a low-income population of northern China. The presence of MetS and a higher number of MetS components exacerbated the risk of carotid atherosclerosis; among the five MetS components, high blood pressure was associated with the greatest risk. Targeted atherosclerosis prevention and intervention should include identification and treatment of MetS, especially high blood pressure.
Background
To date, the relationship between thyroid dysfunction and subcortical ischemic vascular disease (SIVD)‐induced cognitive impairments still remains elusive.
Methods
Cognitive performances ...were examined in 215 participants, including 54 healthy participants, 52 SIVD patients with no dementia (SIVDND), 55 patients with mild cognitive impairment (SVMCI), and 54 patients with vascular dementia (VD). Serum thyroid‐stimulating hormone (TSH), total triiodothyronine (TT3), free triiodothyronine (FT3), total thyroxine (TT4) and free thyroxine (FT4), thyroglobulin antibody (TGA), and antithyroid peroxidase antibody (TPO‐Abs) were quantified by radioimmunoassay or ELISA.
Results
A close correlation between thyroid status and cognitive dysfunction in SIVD was observed. Serum TT3 and FT3 levels decreased, whereas serum TSH level increased, with the decline in cognitive functions. Furthermore, TT3 levels showed a positive correlation, whereas TSH level showed a negative correlation, with the Mini‐Mental State Examination (MMSE) scores. Our results suggested that thyroid function was associated with cognitive impairments induced by SIVD. Also, thyroid function and thyroid hormone level could be a risk factor in the development of SIVD. Serum TT3 and TSH levels might also be used as biomarkers for cognitive dysfunction.
Conclusions
These findings might contribute to a more accurate clinical diagnosis and differentiation among normal controls, SIVDND, SVMCI, and VD patients, in order to develop appropriate intervention approaches for SIVD therapeutic treatment.
Thyroid function was associated with cognitive impairments induced by SIVD. Thyroid function and thyroid hormone level could be a risk factor in the development of SIVD. Serum TT3 and TSH levels can be used as biomarkers for cognitive dysfunction.
The Chinese urban minimum living-standard guarantee system, mainly functions to guarantee the poor people to have minimum living-standard life; at same time it can make some people to get rid of ...poverty by some poverty lines. But how much of the rates can be reduced? What differences among provinces, and what impact on all kind of families? The paper tries to answer these questions by using Chinese Household Income Project (CHIP) 2002 and 2007, taking international poverty line, minimum living standard line, Martin’s poverty line and relative poverty line respectively to measure the poverty reduction impact of urban minimum living standard guarantee. On the whole, the urban minimum living standard guarantee is effective to alleviate absolute poverty and even part of relative poverty. For example, taking international poverty line as standard, in 2002 the urban minimum living guarantee respectively decreased absolute poverty rate, poverty gap and squared poverty gap of national urban area by 4.58%, 11.41% and 16.32%, while in 2007 decreased respectively by 47.24%, 70.87% and 83.04%. Taking relative poverty line as standard, in 2002 respectively poverty rate, poverty gap and squared poverty gap of national urban area decreased by 1.92%, 4.65% and 8.37%, while in 2007 the 3 indices reached by 3.28%, 11.63% and 22.57% respectively, but which are lower than by international poverty line. On the whole, according to different poverty lines and indices, the urban citizen in different provinces and families gained different poverty reduction effects brought by the urban minimum living standard guarantee.
The propagation of high-power microwave (HPM) in a double-line containing plasma filaments produced by intense femtosecond laser pulses is investigated with the electromagnetic simulation software ...CST. The results show that HPM can propagate around the surface of the line rather than in the plasma with a velocity near the speed of light. We can also obtain that the amplitude of the induced current and the electric field is inversely proportional to the HPM propagation length and the spacing between the two channels. Besides, the electric field near the transmission line is larger than that far away from the line. Furthermore, the attenuation of the HPM in the double line is 0.39 dB/m, which is lower than that in the free space. The research results show that the double line can provide efficient transport of the HPM energy.
In future, HELPD would provide valuable platform for investigating the issue in the W impurity control, towards the wall conditioning requirements in tokamak.The tungsten (W) impurity caused by ...sputtering of the first wall is considered as an issue influencing the plasma safe operation of EAST, ITER and other future fusion devices. As a supplement to the experiments on the tokamak, the linear plasma device (LPD) serves as an effective divertor simulator for the W impurity control research. This work presents the design and construction of High-parameters Experimental Linear Plasma Device (HELPD) in detail, including its layout and operation parameters. Besides the function of plasma exposure, the target sample could be exchanged in a separate material pretreatment vessel for wall conditioning, such as lithium coating and glow discharge cleaning (GDC) without breaking vacuum conditions. And the preliminary results show that the device could produce a steady state plasma of 1∼10 eV, and its flux could reach 1022 m−2s−1 with 10 kW helicon wave. In the future, HELPD would provide valuable platform for investigating the issue in the W impurity control，towards the wall conditioning requirements in tokamak.
•The new designed LPD, named HELPD, has been employed for plasma-wall interactions research.•It presents the design and operation experience of essential subsystems, such as wall conditioning, magnet coil, vacuum system, and diagnostics.•The preliminary results show that the device could produce a steady state Ar helicon plasma of 1∼10 eV and the flux of 1022 m−2/s.
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