Resonant perfect absorption of molybdenum disulfide beyond the bandgap

Light absorption and radiation are fundamental processes in optical science and engineering.Materials with perfect absorption properties play an important role in numerous optical applications.Following the meteoric rise of MoS_(2)material,global opportunities and challenges coexist due to its extremely weak light-matter interaction capability beyond its energy band.In this work,we designed a kind of sandwich resonance structure and investigated MoS_(2)as a perfect absorber in the infrared spectrum that should be transparent according to the optical band theory.The infrared absorption properties of W or Au/MoS_(2)/Au models at 800 nm-2400 nm were systematic simulated.By optimizing the structural parameters,the resonant wavelength of perfect absorption can be modulated from 830 nm to 1700 nm with angle insensitivity and polar independence.Moreover,we discovered that the bandwidth of absorption exceeding 50%of the W-top model reaches500 nm,while that of the Au-top model is less than 100 nm,indicating that the top metal material has a great influence on the resonance absorption spectrum.Our work provides a practical route for enhancing and manipulating the light-matter interactions of low-dimensional materials beyond their own band gaps,which will be critical in the future design and implementation of optoelectronic devices and systems.

Effects of dietary supplementation of nucleotides from late gestation to lactation on the performance and oxidative stress status of sows and their offspring

Increased metabolic burdens in breeding sows,which are induced by elevated systemic oxidative stress,could increase the need for nucleotides to repair lymphocyte DNA damage;however,de novo synthesis of nucleotides may be insufficient to cover this increased need.This study investigated the effects of dietary nucleotides on milk composition,oxidative stress status,and the reproductive and lactational performance of sows.Forty multiparous sows were assigned to 2 dietary treatments(Control group,and 1 g/kg Nucleotides group)based on a randomized complete block design using their BW at 85 d of gestation as a block.Sows from 2 groups were fed a restricted diet during gestation and ad libitum during lactation.The experiment lasted from 85 d of gestation to 21 d of lactation.The reproductive perfor-mance of sows and the growth performance of suckling piglets were measured.Oxidative stress pa-rameters and milk components were also analysed.Data were analyzed using contrasts in the MIXED procedure of SAS.Sows in the Nucleotides group consumed more feed during the first week(P<0.01)and from 1 to 21 d(P<0.05)of lactation than those in Control group.Correspondingly,the litter weight gain of piglets showed a tendency to increase from cross-fostering to 9 d(P=0.09)and from cross-fostering to 20 d(P=0.10)in the Nucleotides group relative to the Control group.Additionally,the Nucleotides group was higher(P<0.01)than the Control group in the concentrations of uridine 5'monophosphate,guanosine 5'monophosphate,inosine 5'monophosphate,adenosine 5'mono-phosphate and total nucleotides in milk.Furthermore,the Nucleotides group was higher(P<0.01)than the Control group in the serum levels of total antioxidant capacity(P<0.01)for sows at 109 d of gestation and glutathione peroxidase for weaning piglets,but lower at the levels of thiobarbituric acid-reactive substances(P<0.05)in serum of weaning piglets.This study indicated that maternal dietary nucleotides could promote piglet growth,probably due to the higher lactational feed intake and higher concentration of nucleotides in the milk of sows,and lower oxidative stress for both sows and piglets.

Optical performance analysis of an innovative linear focus secondary trough solar concentrating system

The parabolic trough solar concentrating system has been well developed and widely used in commercial solar thermal power plants. However, the conventional system has its drawbacks when connecting receiver tube parts and enhancing the concentration ratio. To overcome those inherent disadvantages, in this paper, an innovative concept of linear focus secondary trough concentrating system was proposed, which consists of a fixed parabolic trough concentrator, one or more heliostats, and a fixed tube receiver. The proposed system not only avoids the end loss and connection problem on the receiver during the tracking process but also opens up the possibility to increase the concentration ratio by enlarging aperture. The design scheme of the proposed system was elaborated in detail in this paper.Besides, the optical performance of the semi and the whole secondary solar trough concentrator was evaluated by using the ray tracing method. This innovative solar concentrating system shows a high application value as a solar energy experimental device.