When nano-fillers are used to enhance the thermal conductivity of organic phase change materials(PCMs),the naturally formed interface is considered to hinder thermal transport of the composite PCMs.However,the effect ...When nano-fillers are used to enhance the thermal conductivity of organic phase change materials(PCMs),the naturally formed interface is considered to hinder thermal transport of the composite PCMs.However,the effect of the interface on the thermal properties of surrounding PCM has not been fully studied.In this paper,three composite PCMs(Ery@SiC,Ery@SiO_(2) and Ery@Si_(3)N_(4))were prepared by melt-blending method.The local thermal conductivity and reduced Young’s modulus(E^(*))of the erythritol at the interface and far away from the interface in the composite PCMs were simultaneously measured by scanning thermal microscopy(SThM).The results revealed significant enhancement in local thermal conductivity of erythritol at the interface and its obvious positive correlation with E^(*).For different composite PCMs,molecular dynamics(MD)simulations suggested that the increase in intrinsic thermal conductivity and E^(*)of erythritol is attributed to the increase in interaction energy between erythritol and nanoparticles,as more erythritol phonon vibrations transform from localized mode to delocalized mode and erythritol has a higher density at the interface.These findings will provide new ideas for the design of PCM for energy storage.展开更多
We consider the effects of the aspect ratio L/H (where<em> L</em> is the length of a prism, and <em>H</em> is the height of a prism normal to the flow direction) and the size of additional stru...We consider the effects of the aspect ratio L/H (where<em> L</em> is the length of a prism, and <em>H</em> is the height of a prism normal to the flow direction) and the size of additional structures (which are a plate and a fin on the surface of a prism) on a vibration characteristic of a cantilevered rectangular prism. The present research is intended to support the analysis of energy harvesting research on the flow-induced vibration in water flow using a magnetostrictive phenomenon. The prisms are constructed from stainless steel and mounted elastically to a plate spring attached to the ceiling wall of the water tunnel. The prisms with aspect ratios of<em> L/H</em> ≥ 5 have reasonably identical vibration characteristics. However, the difference in the vibration characteristic appears distinctly on a rectangular prism with an aspect ratio of <em>L/H </em>= 2.5. The rectangular prism with an aspect ratio of <em>L/H</em> = 10 and a side ratio of <em>D/H</em> = 0.2 has a stable and large response amplitude and oscillates with a lower velocity. The length of the added plate and the size of the added fin influence the velocity of vibration onset. If the length of the added plate and fin size on the rectangular prism with <em>D/H</em> = 0.2 becomes large, the curve of the response amplitude shifts to that of the rectangular prism with <em>D/H</em>= 0.5. The response amplitude of the rectangular prism with/without plate or fin is found to be related to the second moment of area of the prism.展开更多
Considering the high filling ratios,high densities,and narrow absorbing bandwidths of the current electromagnetic wave(EMW) absorbers,in this work,we successfully synthesized a 3 D hierarchical NiCo_(2) O_(4) nanoflow...Considering the high filling ratios,high densities,and narrow absorbing bandwidths of the current electromagnetic wave(EMW) absorbers,in this work,we successfully synthesized a 3 D hierarchical NiCo_(2) O_(4) nanoflowers/reduced graphene oxide(NiCo_(2) O_(4)/RGO) composite foam by a simple method under gentle condition.The NiCo_(2) O_(4) nanoflowers and unique 3 D foam structure are beneficial to the refraction and scattering of EMW,which endows the prepared 3 D foam with highly efficient EMW absorption performance.When the ratio between NiCo_(2) O_(4) and RGO in the foam is 1:1,5% mass fraction of NiCo_(2) O_(4/)RGO foam in paraffin wax can reach a minimum reflection loss(RL_(min)) value of-52.2 dB with a thin thickness merely 2.6 mm.Simultaneously,the effective absorption bandwidth(EAB,RL exceeding-10 dB) is7.04 GHz that covers the whole Ku band(10.96-18 GHz).Moreover,the effects of the thickness of the absorber and the loading ratios of the foam in paraffin wax matrix on the EMW absorption properties are also carefully investigated.The results indicate that the optimum EMW absorption performance of NiCo_(2) O_(4/)RGO can be tuned in different bands.The EMW absorption mechanism is ascribed to the proper impedance matching and larger dielectric and magnetic loss produced by the synergy of NiCo_(2) O_(4) and RGO.Therefore,the NiCo_(2) O_(4/)RGO hybrid foam is ideal candidate to be used as high-efficient EMW absorbers with low filling ratio,light weight,and broad frequency bandwidths.展开更多
Various genesis of epithermal veins as well as host rock cause complication in the modeling process. Thus LINEST and controlling function were applied to improve the accuracy and the quality of the model.The LINEST is...Various genesis of epithermal veins as well as host rock cause complication in the modeling process. Thus LINEST and controlling function were applied to improve the accuracy and the quality of the model.The LINEST is a model which is based on multiple linear regression and refers to a branch of applied statistics.This method concerns directly to the application oft-test (TINV and TDIST to analyses of variables in the model)and F- test (FDIST,F-statistic to compare different models) analysis.Backward elimination technique is applied to reduce the number of variables in the model through all the borehole data.After 18 steps,an optimized reduced model (ORM)was constructed and ranked in order of importance as Pb >Ag >P >Hg>Mn>Nb >U>Sr>Sn>As > Cu,with the lowest confidence level (CL)of 92% for Cu.According to the epigenetic vein genesis of Glojeh polymetallic deposit,determination of spatial pattems and elemental associations accompanied by anomaly separation were conducted by K-means cluster and robust factor analysis method based on centered log-ratio (clr)transformed data.Therefore,12 samples (cluster 2)with the maximum distance from centroid,indicates the intensity of vein polymetallic mineralization in the deposit.In addition, an ORM for vein population was extracted for Sb >A1 > As >Mg >Pb >Cu >Ag elements with the R2 up to 0.99. On the other hand,after 23 steps of optimization process at the host rock population,an ORM Was conducted by Ag >Te >Hg >Pb >Mg >A1 >Sb >As represented in descending order oft-values.It revealed that Te and Hg can be considered as pathfinder elements for Au at the host rock.Based on the ORMs at each population Ag,Pb,and As were often associated with Au mineralization.The concentration ratio of (tSb × tA1)vein/(tSb × tA1)baekground as an enrichment index can intensify the mineralization detection.Finally,Glojeh deposit was evaluated to be classified as a vein-style Au (Ag,Pb,As)-polymetallic mineralization.展开更多
Salinity is a major abiotic stress affecting plant growth and productivity. Considerable genetic variation is present in rice in response to salt stress, with higher sensitivity during early seedling and reproductive ...Salinity is a major abiotic stress affecting plant growth and productivity. Considerable genetic variation is present in rice in response to salt stress, with higher sensitivity during early seedling and reproductive stage. In this study, physiological changes in leaves and developing panicles of rice genotypes (IR686, Sadri, Rc222, CSR28, IR670 and Pokkali) contrasting in salt tolerance at the reproductive stage were evaluated in greenhouse experiment under salt stress. The results showed that IR670 and the tolerant-check Pokkali maintained lower Na^+/K^+ ratio, less reduction in chlorophyll concentration, lower malondialdehyde (MDA) production, higher concentrations of reduced ascorbate (reduced AsA), higher proline accumulation and lower percentage reduction in pollen viability than the salt-sensitive genotypes under salt stress. The higher concentration of reduced AsA suggests an efficient ROS-scavenging system. Physiological measurements and pollen viability analysis revealed that Sadri (moderately tolerant at the seedling stage) is sensitive to salt stress at the flowering stage. The findings will be useful in breeding salt tolerant varieties at both seedling and reproductive stages by selecting appropriate genotypes and phenotypes.展开更多
基金supported by the National Key R&D Program of China(No.2023YFF0612804)the National Natural Science Foundation of China(Nos.52222602,52236006,and 22293043)+3 种基金Beijing Nova Program(No.20220484170)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-001C1 and FRF-EYIT-23-05)Foundation of the Youth Innovation Promotion Association of CAS(No.2020048)IPE Project for Frontier Basic Research(No.QYJC-2023-08).
文摘When nano-fillers are used to enhance the thermal conductivity of organic phase change materials(PCMs),the naturally formed interface is considered to hinder thermal transport of the composite PCMs.However,the effect of the interface on the thermal properties of surrounding PCM has not been fully studied.In this paper,three composite PCMs(Ery@SiC,Ery@SiO_(2) and Ery@Si_(3)N_(4))were prepared by melt-blending method.The local thermal conductivity and reduced Young’s modulus(E^(*))of the erythritol at the interface and far away from the interface in the composite PCMs were simultaneously measured by scanning thermal microscopy(SThM).The results revealed significant enhancement in local thermal conductivity of erythritol at the interface and its obvious positive correlation with E^(*).For different composite PCMs,molecular dynamics(MD)simulations suggested that the increase in intrinsic thermal conductivity and E^(*)of erythritol is attributed to the increase in interaction energy between erythritol and nanoparticles,as more erythritol phonon vibrations transform from localized mode to delocalized mode and erythritol has a higher density at the interface.These findings will provide new ideas for the design of PCM for energy storage.
文摘We consider the effects of the aspect ratio L/H (where<em> L</em> is the length of a prism, and <em>H</em> is the height of a prism normal to the flow direction) and the size of additional structures (which are a plate and a fin on the surface of a prism) on a vibration characteristic of a cantilevered rectangular prism. The present research is intended to support the analysis of energy harvesting research on the flow-induced vibration in water flow using a magnetostrictive phenomenon. The prisms are constructed from stainless steel and mounted elastically to a plate spring attached to the ceiling wall of the water tunnel. The prisms with aspect ratios of<em> L/H</em> ≥ 5 have reasonably identical vibration characteristics. However, the difference in the vibration characteristic appears distinctly on a rectangular prism with an aspect ratio of <em>L/H </em>= 2.5. The rectangular prism with an aspect ratio of <em>L/H</em> = 10 and a side ratio of <em>D/H</em> = 0.2 has a stable and large response amplitude and oscillates with a lower velocity. The length of the added plate and the size of the added fin influence the velocity of vibration onset. If the length of the added plate and fin size on the rectangular prism with <em>D/H</em> = 0.2 becomes large, the curve of the response amplitude shifts to that of the rectangular prism with <em>D/H</em>= 0.5. The response amplitude of the rectangular prism with/without plate or fin is found to be related to the second moment of area of the prism.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. 202065001)the National Natural Science Foundation of China (No. 51572249)+1 种基金the National Natural Science Foundation Joint Fund (No. U1806223)the State Key Laboratory of Marine Coatings (GZ-19-0004)。
文摘Considering the high filling ratios,high densities,and narrow absorbing bandwidths of the current electromagnetic wave(EMW) absorbers,in this work,we successfully synthesized a 3 D hierarchical NiCo_(2) O_(4) nanoflowers/reduced graphene oxide(NiCo_(2) O_(4)/RGO) composite foam by a simple method under gentle condition.The NiCo_(2) O_(4) nanoflowers and unique 3 D foam structure are beneficial to the refraction and scattering of EMW,which endows the prepared 3 D foam with highly efficient EMW absorption performance.When the ratio between NiCo_(2) O_(4) and RGO in the foam is 1:1,5% mass fraction of NiCo_(2) O_(4/)RGO foam in paraffin wax can reach a minimum reflection loss(RL_(min)) value of-52.2 dB with a thin thickness merely 2.6 mm.Simultaneously,the effective absorption bandwidth(EAB,RL exceeding-10 dB) is7.04 GHz that covers the whole Ku band(10.96-18 GHz).Moreover,the effects of the thickness of the absorber and the loading ratios of the foam in paraffin wax matrix on the EMW absorption properties are also carefully investigated.The results indicate that the optimum EMW absorption performance of NiCo_(2) O_(4/)RGO can be tuned in different bands.The EMW absorption mechanism is ascribed to the proper impedance matching and larger dielectric and magnetic loss produced by the synergy of NiCo_(2) O_(4) and RGO.Therefore,the NiCo_(2) O_(4/)RGO hybrid foam is ideal candidate to be used as high-efficient EMW absorbers with low filling ratio,light weight,and broad frequency bandwidths.
文摘Various genesis of epithermal veins as well as host rock cause complication in the modeling process. Thus LINEST and controlling function were applied to improve the accuracy and the quality of the model.The LINEST is a model which is based on multiple linear regression and refers to a branch of applied statistics.This method concerns directly to the application oft-test (TINV and TDIST to analyses of variables in the model)and F- test (FDIST,F-statistic to compare different models) analysis.Backward elimination technique is applied to reduce the number of variables in the model through all the borehole data.After 18 steps,an optimized reduced model (ORM)was constructed and ranked in order of importance as Pb >Ag >P >Hg>Mn>Nb >U>Sr>Sn>As > Cu,with the lowest confidence level (CL)of 92% for Cu.According to the epigenetic vein genesis of Glojeh polymetallic deposit,determination of spatial pattems and elemental associations accompanied by anomaly separation were conducted by K-means cluster and robust factor analysis method based on centered log-ratio (clr)transformed data.Therefore,12 samples (cluster 2)with the maximum distance from centroid,indicates the intensity of vein polymetallic mineralization in the deposit.In addition, an ORM for vein population was extracted for Sb >A1 > As >Mg >Pb >Cu >Ag elements with the R2 up to 0.99. On the other hand,after 23 steps of optimization process at the host rock population,an ORM Was conducted by Ag >Te >Hg >Pb >Mg >A1 >Sb >As represented in descending order oft-values.It revealed that Te and Hg can be considered as pathfinder elements for Au at the host rock.Based on the ORMs at each population Ag,Pb,and As were often associated with Au mineralization.The concentration ratio of (tSb × tA1)vein/(tSb × tA1)baekground as an enrichment index can intensify the mineralization detection.Finally,Glojeh deposit was evaluated to be classified as a vein-style Au (Ag,Pb,As)-polymetallic mineralization.
基金the International Rice Research InstituteDOST-ASTHRDPUniversity of the Philippines Visayas for providing support
文摘Salinity is a major abiotic stress affecting plant growth and productivity. Considerable genetic variation is present in rice in response to salt stress, with higher sensitivity during early seedling and reproductive stage. In this study, physiological changes in leaves and developing panicles of rice genotypes (IR686, Sadri, Rc222, CSR28, IR670 and Pokkali) contrasting in salt tolerance at the reproductive stage were evaluated in greenhouse experiment under salt stress. The results showed that IR670 and the tolerant-check Pokkali maintained lower Na^+/K^+ ratio, less reduction in chlorophyll concentration, lower malondialdehyde (MDA) production, higher concentrations of reduced ascorbate (reduced AsA), higher proline accumulation and lower percentage reduction in pollen viability than the salt-sensitive genotypes under salt stress. The higher concentration of reduced AsA suggests an efficient ROS-scavenging system. Physiological measurements and pollen viability analysis revealed that Sadri (moderately tolerant at the seedling stage) is sensitive to salt stress at the flowering stage. The findings will be useful in breeding salt tolerant varieties at both seedling and reproductive stages by selecting appropriate genotypes and phenotypes.
