The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge s...The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge separation process in organic photovoltaic(OPV) cells. This article provides an overview of interface energetics at typical planar and mixed donor-acceptor heterostructures, perovskite/organic hybrid interfaces, and their contact interfaces with charge collection layers. The substrate effect on energy level offsets at organic heterostructures and the processes that control and limit the OPV operation are presented. Recent efforts on interface engineering with electrical doping are also discussed.展开更多
Aims Environmental heterogeneity affects the performance of clonal aquatic plants.Few researchers integrated two aspects of heterogeneity into the study of clonal plant ecology.The aims of the present study are to(i)t...Aims Environmental heterogeneity affects the performance of clonal aquatic plants.Few researchers integrated two aspects of heterogeneity into the study of clonal plant ecology.The aims of the present study are to(i)test whether different substrate heterogeneity and submergence exert similar effects on plant performance and(ii)explore the foraging behaviour.Methods In this study,Scirpus yagara was subjected to multiple levels of substrate heterogeneity and submergence.Substrate treatments included one homogeneous substrate and three heterogeneous substrates(two-patch,four-patch and eight-patch).Water level treatments included 0,10 and 30 cm.Traits including ramet number,generation number,leaf number,bulb number,ramet height,culm length,rhizome length,clonal radius,spacer length,spacer thickness,total biomass,biomass of bulbs and biomass per bulb were measured.Important Findings Deeper water levels significantly reduced variables associated with growth such as ramet number,generation number,leaf number and bulb number,while substrate patchiness induced significant variations in traits such as spacer length and spacer thickness.Significant interactive effects of the two factors were found for ramet number,leaf number and spacer length.Scirpus yagara showed colonization towards the lake sediment patch in two-patch and four-patch substrates,and more structures were placed in the lake sediment patch.Especially for the two-patch substrate,all structures occupied the lake sediment patch.Two-sided intrusion was observed in the eight-patch substrate,which induced an even allocation of structures in different patches.The foraging behaviour was correlated with the patch size.展开更多
The addition of simple substrates could affect the microbial respiration in soils. This substrate-induced respiration is widely used to estimate the soil microbial biomass, but little attention has been paid to its in...The addition of simple substrates could affect the microbial respiration in soils. This substrate-induced respiration is widely used to estimate the soil microbial biomass, but little attention has been paid to its influence on the changes of community-level physiological profiles. In this study, the process of microbial communities responding to the added substrate using sole-carbon-source utilization （BIOLOG） was investigated. BIOLOG is biased toward fast-growing bacteria; this advantage was taken to detect the prompt response of the active microbial communities to the added substrate. Four soil samples from agricultural fields adjacent to heavy metal mines were amended with L-arginine, citric acid, or D-glucose. Substrate amendments could, generally, not only increase the metabolic activity of the microbial communities, but also change the metabolic diverse patterns compared with no-substrate control. By tracking the process, it was found that the variance between substrate-induced treatment and control fluctuated greatly during the incubation course, and the influences of these three substrates were different. In addition, the application of these induced changes to discriminate soil microbial communities was tested. The distance among all samples was greatly increased, which further showed the functional variance among microbial communities in soils. This can be very useful in the discrimination of microbial communities even with high similarity.展开更多
An improved analytical model for the current–voltage（I–V） characteristics of the 4H-SiC metal semiconductor field effect transistor（MESFET） on a high purity semi-insulating（HPSI） substrate with trapping and th...An improved analytical model for the current–voltage（I–V） characteristics of the 4H-SiC metal semiconductor field effect transistor（MESFET） on a high purity semi-insulating（HPSI） substrate with trapping and thermal effects is presented. The 4H-SiC MESFET structure includes a stack of HPSI substrates and a uniformly doped channel layer. The trapping effects include both the effect of multiple deep-level traps in the substrate and surface traps between the gate to source/drain. The self-heating effects are also incorporated to obtain the accurate and realistic nature of the analytical model. The importance of the proposed model is emphasised through the inclusion of the recent and exact nature of the traps in the 4H-SiC HPSI substrate responsible for substrate compensation.The analytical model is used to exhibit DC I–V characteristics of the device with and without trapping and thermal effects. From the results, the current degradation is observed due to the surface and substrate trapping effects and the negative conductance introduced by the self-heating effect at a high drain voltage. The calculated results are compared with reported experimental and two-dimensional simulations（Silvaco -TCAD）. The proposed model also illustrates the effectiveness of the gate–source distance scaling effect compared to the gate–drain scaling effect in optimizing 4H-SiC MESFET performance. Results demonstrate that the proposed I–V model of 4H-SiC MESFET is suitable for realizing SiC based monolithic circuits（MMICs） on HPSI substrates.展开更多
基金supported by the National Basic Research Program of China (2014CB932600)the National Natural Science Foundation of China (91433116, 11474214)+2 种基金Jiangsu Science and Technology Department (BK20140053)Bureau of Science and Technology of Suzhou Municipality (SYG201525, ZXG201422)the project of the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions
文摘The reliable information about interface energetics of organic materials, especially the energy level alignment at organic heterostructures is of pronounced importance for unraveling the photon harvesting and charge separation process in organic photovoltaic(OPV) cells. This article provides an overview of interface energetics at typical planar and mixed donor-acceptor heterostructures, perovskite/organic hybrid interfaces, and their contact interfaces with charge collection layers. The substrate effect on energy level offsets at organic heterostructures and the processes that control and limit the OPV operation are presented. Recent efforts on interface engineering with electrical doping are also discussed.
基金The present work was financially supported by the National Natural Science Foundation of China(31800299,31170339)the general financial grant from the China Postdoctoral Science Foundation(2017M622184)the Special Foundation of National Science and Technology Basic Research(2013FY112300).
文摘Aims Environmental heterogeneity affects the performance of clonal aquatic plants.Few researchers integrated two aspects of heterogeneity into the study of clonal plant ecology.The aims of the present study are to(i)test whether different substrate heterogeneity and submergence exert similar effects on plant performance and(ii)explore the foraging behaviour.Methods In this study,Scirpus yagara was subjected to multiple levels of substrate heterogeneity and submergence.Substrate treatments included one homogeneous substrate and three heterogeneous substrates(two-patch,four-patch and eight-patch).Water level treatments included 0,10 and 30 cm.Traits including ramet number,generation number,leaf number,bulb number,ramet height,culm length,rhizome length,clonal radius,spacer length,spacer thickness,total biomass,biomass of bulbs and biomass per bulb were measured.Important Findings Deeper water levels significantly reduced variables associated with growth such as ramet number,generation number,leaf number and bulb number,while substrate patchiness induced significant variations in traits such as spacer length and spacer thickness.Significant interactive effects of the two factors were found for ramet number,leaf number and spacer length.Scirpus yagara showed colonization towards the lake sediment patch in two-patch and four-patch substrates,and more structures were placed in the lake sediment patch.Especially for the two-patch substrate,all structures occupied the lake sediment patch.Two-sided intrusion was observed in the eight-patch substrate,which induced an even allocation of structures in different patches.The foraging behaviour was correlated with the patch size.
基金supported by the National Natural Science Foundation of China(No.30470289,30670039).
文摘The addition of simple substrates could affect the microbial respiration in soils. This substrate-induced respiration is widely used to estimate the soil microbial biomass, but little attention has been paid to its influence on the changes of community-level physiological profiles. In this study, the process of microbial communities responding to the added substrate using sole-carbon-source utilization （BIOLOG） was investigated. BIOLOG is biased toward fast-growing bacteria; this advantage was taken to detect the prompt response of the active microbial communities to the added substrate. Four soil samples from agricultural fields adjacent to heavy metal mines were amended with L-arginine, citric acid, or D-glucose. Substrate amendments could, generally, not only increase the metabolic activity of the microbial communities, but also change the metabolic diverse patterns compared with no-substrate control. By tracking the process, it was found that the variance between substrate-induced treatment and control fluctuated greatly during the incubation course, and the influences of these three substrates were different. In addition, the application of these induced changes to discriminate soil microbial communities was tested. The distance among all samples was greatly increased, which further showed the functional variance among microbial communities in soils. This can be very useful in the discrimination of microbial communities even with high similarity.
文摘An improved analytical model for the current–voltage（I–V） characteristics of the 4H-SiC metal semiconductor field effect transistor（MESFET） on a high purity semi-insulating（HPSI） substrate with trapping and thermal effects is presented. The 4H-SiC MESFET structure includes a stack of HPSI substrates and a uniformly doped channel layer. The trapping effects include both the effect of multiple deep-level traps in the substrate and surface traps between the gate to source/drain. The self-heating effects are also incorporated to obtain the accurate and realistic nature of the analytical model. The importance of the proposed model is emphasised through the inclusion of the recent and exact nature of the traps in the 4H-SiC HPSI substrate responsible for substrate compensation.The analytical model is used to exhibit DC I–V characteristics of the device with and without trapping and thermal effects. From the results, the current degradation is observed due to the surface and substrate trapping effects and the negative conductance introduced by the self-heating effect at a high drain voltage. The calculated results are compared with reported experimental and two-dimensional simulations（Silvaco -TCAD）. The proposed model also illustrates the effectiveness of the gate–source distance scaling effect compared to the gate–drain scaling effect in optimizing 4H-SiC MESFET performance. Results demonstrate that the proposed I–V model of 4H-SiC MESFET is suitable for realizing SiC based monolithic circuits（MMICs） on HPSI substrates.
