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In this work, an ultra-wideband reflective polarization conversion metasurface (PCM) is proposed at first. Because the PCM is an anisotropic structure that is symmetric with respect to both x- and y-axes, and the reflection phase difference under x- and y-polarized incidences is close to 180° in an ultra-wide frequency range, the PCM can achieve both linear polarization conversion and circular-polarization (CP) maintaining reflection in the ultra-wide frequency band from 8.3 to 41.3 GHz except for near the frequency point of 38.8 GHz. Moreover, when its unit cell structure is rotated by 90°, its cross-polarized reflection coefficient under LP incidence, together with the co-polarized reflection coefficient under CP incidence, will be changed by almost 180° in phase. Thus, based on the PCM, an ultra-wideband coding diffusion metasurface (CDM) is further proposed for radar cross section (RCS) reduction. The simulation and experiment results indicate that the CDM can achieve effective RCS reduction in the ultra-wide frequency band of 8.2–41.7 GHz under normal incidence with arbitrary polarization; in addition, an ultra-wideband RCS reduction can still be realized under oblique incidence with an incident angle less than 45°, which shows that the CDM is of good application value in radar stealth technology. [ABSTRACT FROM AUTHOR]

Conversion from double rice cropping (RR) to maize-rice cropping (MR) have been occurring in recent years in Asia. However, effects on the environment by introducing maize into paddy still need more examination. The objective of this study was to assess differences in greenhouse gases emissions, carbon footprint and carbon neutrality between MR and RR cropping systems from 2016 to 2018. Results showed that the global warming potential (GWP) under MR cropping was 13.0 t CO2 eq ha−1, which was 20.0% higher than that of RR (10.8 t CO2 eq ha−1) due to its higher N2O emission. Although the GWP of MR increased, it significantly decreased carbon footprint by 17.3% in comparison with RR due to its higher gain yield. Simultaneously, MR had a substantial increase in net ecosystem economic efficiency by 62.5%. Nevertheless, carbon uptake was significantly higher in MR system, its carbon neutrality was lower than that of RR by 69.3% average. In conclusion, MR could be an effective sustainable cropping system with high yield and low carbon footprint in the subtropical regions. Considering the higher GWP of MR, further research is needed on appropriate agronomic practice to reduce carbon loss to realize higher carbon neutral potential. [ABSTRACT FROM AUTHOR]

In this study, an X-shaped metasurface composed of an array of X-shaped metal patches printed on a grounded dielectric substrate and covered by a top dielectric layer is proposed for both linear-to-circular (LTC) and circular-to-linear (CTL) polarization conversions. Theoretical analysis and numerical simulations indicate that the metasurface can be used as both LTC and CTL reflective polarization converters. Under u- and v-polarized incidences, it can achieve LTC polarization conversion in the ultra-wide frequency band from 7.5 to 25.8 GHz with a relative bandwidth of 110%, and the polarization conversion rate (PCR) can be kept larger than 99.7% in the frequency range of 7.9-24.7 GHz. Moreover, under CP incidence, a high-efficiency ultra-wideband CTL polarization conversion can be achieved, the bandwidth and PCR are almost the same as those of the LTC polarization conversion. Finally, one experimental verification is carried out, and a reasonable agreement is observed between the simulation and experimental results. [ABSTRACT FROM AUTHOR]

In this work, a high-efficiency ultra-wideband ellipse-shaped linear-to-circular polarization conversion metasurface is proposed. The metasurface is composed of a square array of ellipse-shaped metal patches printed on grounded dielectric substrate and covered by a dielectric layer, because it is an orthogonal anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along the directions ±45° with respect to the vertical y-axis, and the reflection phase difference under u- and v-polarized incidences is very close to −90° in an ultra-wide frequency ranges, both theoretical prediction and numerical simulation show that the metasurface can achieve high-efficiency ultra-wideband linear-to-circular polarization conversion under x- and y-polarized incidences, its 3-dB axial-ratio (AR) band is between 7.08 and 25.86 GHz with a relative bandwidth of 114%, in particular, the AR of its reflected wave can be kept lower than 0.89 dB in the frequency range 7.65–25.32 GHz, in which the polarization conversion rate (PCR) is always larger than 99.73%. Finally, one effective experimental verification is carried out, and a reasonable agreement is observed between the simulation and experimental results. Therefore, the polarization conversion metasurface has great potential application values in various polarization-controlled devices. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of different enzymatic hydrolysis and different microwave pretreatment durations on the sugar yield of Chinese spirits distillers residues (CSDR). Addition of both α-amylase and cellulase in the enzymatic hydrolysis of distillers grains resulted in a higher yield of reducing sugar (145.74 ± 4.20 mg·g–1). Fourier transform infrared spectroscopy (FTIR) revealed that different enzyme treatments degraded different functional groups of the cellulose structure. Subsequently, the highest reducing sugar yield (181.33 ± 6.42 mg·g–1) was achieved at microwave pretreatment time of 6 min and was 1.29-fold higher than that of the untreated sample. The differences in the structural features of CSDRs under various microwave pretreatment durations were characterized by scanning electron microscopy, FTIR spectroscopy, and X-ray diffraction. The data revealed that the optimal microwave pretreatment time at 6 min could obviously remove lignin, and then obtain the highest CrI value, achieving the highest reducing sugar yield. [ABSTRACT FROM AUTHOR]

In this paper, an ultra-wideband circular polarization (CP) maintaining reflector is proposed based on an anisotropic metasurface, which is an orthogonal anisotropic structure with a pair of symmetrical axes u and v perpendicular to each other. The simulated results show that the reflector can realized CP-maintaining reflection under both right-handed and left-handed CP (RHCP and LHCP) incidences in the frequency band between 8.79 and 27.09 GHz, the fractional bandwidth is up to 102%. In addition, the physical mechanism of the CP-maintaining reflection has been analyzed in detail, and one useful formula has been derived, which can be used to calculate the cross- and co-polarization reflection coefficients under CP incidence according to the phase differences between the two reflection coefficients under u and v-polarized incidences. Finally, one effective experimental validation was carried out. [ABSTRACT FROM AUTHOR]

Context:Polymorphisms ofIL-32related closely to tumoregenesis. Materials and methods:TwoIL-32polymorphisms (rs12934561 and rs28372698) and mRNA expression were conducted by SNP genotype assay and real-time PCR in 423 lung cancer patients and 437 controls. Results:T allele of rs28372698 associated significantly with poor prognosis in moderate and well-differentiated lung cancer patients. TT genotype of rs12934561 related closely to poor survival status in squamous carcinoma.IL-32mRNA expression decreased in lung cancer. Discussion and conclusion:Our study indicates the importance ofIL-32polymorphism and mRNA expression in susceptibility and influence of survival status in lung cancer. [ABSTRACT FROM AUTHOR]

Background: There has been an increase in non-daily smoking, alternative tobacco product and marijuana use among young adults in recent years. Objectives: This study examined perceptions of health risks, addictiveness, and social acceptability of cigarettes, cigar products, smokeless tobacco, hookah, electronic cigarettes, and marijuana among young adults and correlates of such perceptions. Methods: In Spring 2013, 10,000 students at two universities in the Southeastern United States were recruited to complete an online survey (2,002 respondents), assessing personal, parental, and peer use of each product; and perceptions of health risks, addictiveness, and social acceptability of each of these products. Results: Marijuana was the most commonly used product in the past month (19.2%), with hookah being the second most commonly used (16.4%). The least commonly used were smokeless tobacco products (2.6%) and electronic cigarettes (4.5%). There were high rates of concurrent product use, particularly among electronic cigarette users. The most positively perceived was marijuana, with hookah and electronic cigarettes being second. While tobacco use and related social factors, related positively, influenced perceptions of marijuana, marijuana use and related social factors were not associated with perceptions of any tobacco product. Conclusions/ Importance: Marketing efforts to promote electronic cigarettes and hookah to be safe and socially acceptable seem to be effective, while policy changes seem to be altering perceptions of marijuana and related social norms. Research is needed to document the health risks and addictive nature of emerging tobacco products and marijuana and evaluate efforts to communicate such risks to youth. [ABSTRACT FROM AUTHOR]