This article presents a Sub-6 GHz microstrip patch antenna(MPA)with enhanced gain using metamaterial(MTM)superstrate.The source MPA operates at 4.8 GHz and has a peak gain of 5.3 dBi at the resonance frequency.A windo...This article presents a Sub-6 GHz microstrip patch antenna(MPA)with enhanced gain using metamaterial(MTM)superstrate.The source MPA operates at 4.8 GHz and has a peak gain of 5.3 dBi at the resonance frequency.A window-shaped unit cell is designed and investigated through the material wave propagation technique.The unit cell shows an EpsilonNear Zero(ENZ)-Mu Very Large(MVL)behavior around 4.8 GHz.The unit cell has a fourfold geometry which makes it a polarization independent metamaterial.A double layer antenna is designed by placing a 4×4 MTM slab as a superstrate above the MPA at a height of 0.208λ0;whereλ0 is the free-space wavelength at the resonance frequency of the antenna.Impedance matching and gain of the source antenna is improved using the metamaterial.The simulation as well as measurement results show that novel antenna system has a peak gain of 7.68 dBi at 4.8 GHz and an impedance bandwidth of 0.22 GHz.The overall dimension of the antenna is 75×60×15 mm^(3).The proposed antenna operates in the Sub-6 GHz band and is suitable for 5G applications.展开更多
Organic acid composition has a major influence on fruit taste and quality.In general,the fruits of common citrus varieties accumulate more citrate than malate.Here,we report that a citrus variety,'Haruka'(Citr...Organic acid composition has a major influence on fruit taste and quality.In general,the fruits of common citrus varieties accumulate more citrate than malate.Here,we report that a citrus variety,'Haruka'(Citrus tamurana x natsudaidai),accumulates more malate than citrate at the ripening stage.However,the underlying mechanism is unclear.Organic acid profiles were compared between'Haruka'fruits and a common Ponkan cultivar,'Huagan 2'(Citrus reticulata),during fruit development and ripening.We found that'Haruka'fruit accumulated 75%less citrate than'Huagan 2'fruit and that the malate content was nearly 3-fold greater in'Haruka'fruit than in'Huagan 2'fruit.In addition,12 aluminum-activated malate transporter(ALMT)genes were identified in the citrus genome,with CsALMT9-like being predominantly expressed in'Haruka'fruit juice sacs.An analysis of genes associated with the accumulation of citrate/malate revealed that the expression levels of genes encoding a P-type proton pump(CsPH8),a citrate/H+symporter(CsCit),and CsALMT9-like were significantly greater in'Haruka'fruit than in'Huagan 2'fruit.Moreover,CsCit overexpression significantly decreased the citrate content,whereas overexpressing and silencing CsALMT9-like significantly increased and decreased the malate content.In addition,shading significantly increased the expression of CsPH8 but reduced the expression of CsCit and CsALMT9-like and significantly increased the citrate content but decreased the malate content,further confirming that CsCit and CsALMT9-like regulate the accumulation of citrate and malate in'Haruka'fruit,respectively.Taken together,these data indicate that the relatively low citrate content of'Haruka'is mainly due to increases in CsCit expression and that the relatively high malate content of'Haruka'is mainly due to increase in CsALMT9-like expression.This study provides insight into the mechanisms that influence malate content in citrus fruit.展开更多
基金This project was funded by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,Saudi Arabia under Grant No.(KEP-PhD-13-135-42).
文摘This article presents a Sub-6 GHz microstrip patch antenna(MPA)with enhanced gain using metamaterial(MTM)superstrate.The source MPA operates at 4.8 GHz and has a peak gain of 5.3 dBi at the resonance frequency.A window-shaped unit cell is designed and investigated through the material wave propagation technique.The unit cell shows an EpsilonNear Zero(ENZ)-Mu Very Large(MVL)behavior around 4.8 GHz.The unit cell has a fourfold geometry which makes it a polarization independent metamaterial.A double layer antenna is designed by placing a 4×4 MTM slab as a superstrate above the MPA at a height of 0.208λ0;whereλ0 is the free-space wavelength at the resonance frequency of the antenna.Impedance matching and gain of the source antenna is improved using the metamaterial.The simulation as well as measurement results show that novel antenna system has a peak gain of 7.68 dBi at 4.8 GHz and an impedance bandwidth of 0.22 GHz.The overall dimension of the antenna is 75×60×15 mm^(3).The proposed antenna operates in the Sub-6 GHz band and is suitable for 5G applications.
基金supported by the Hubei International Scientific and Technological Cooperation Program(Grant No.2022EHB032)the Earmarked Fund for CARS 26the Huazhong Agricultural University Seed Fund(Grant No.901/11050020115)。
文摘Organic acid composition has a major influence on fruit taste and quality.In general,the fruits of common citrus varieties accumulate more citrate than malate.Here,we report that a citrus variety,'Haruka'(Citrus tamurana x natsudaidai),accumulates more malate than citrate at the ripening stage.However,the underlying mechanism is unclear.Organic acid profiles were compared between'Haruka'fruits and a common Ponkan cultivar,'Huagan 2'(Citrus reticulata),during fruit development and ripening.We found that'Haruka'fruit accumulated 75%less citrate than'Huagan 2'fruit and that the malate content was nearly 3-fold greater in'Haruka'fruit than in'Huagan 2'fruit.In addition,12 aluminum-activated malate transporter(ALMT)genes were identified in the citrus genome,with CsALMT9-like being predominantly expressed in'Haruka'fruit juice sacs.An analysis of genes associated with the accumulation of citrate/malate revealed that the expression levels of genes encoding a P-type proton pump(CsPH8),a citrate/H+symporter(CsCit),and CsALMT9-like were significantly greater in'Haruka'fruit than in'Huagan 2'fruit.Moreover,CsCit overexpression significantly decreased the citrate content,whereas overexpressing and silencing CsALMT9-like significantly increased and decreased the malate content.In addition,shading significantly increased the expression of CsPH8 but reduced the expression of CsCit and CsALMT9-like and significantly increased the citrate content but decreased the malate content,further confirming that CsCit and CsALMT9-like regulate the accumulation of citrate and malate in'Haruka'fruit,respectively.Taken together,these data indicate that the relatively low citrate content of'Haruka'is mainly due to increases in CsCit expression and that the relatively high malate content of'Haruka'is mainly due to increase in CsALMT9-like expression.This study provides insight into the mechanisms that influence malate content in citrus fruit.
