The Hexi Corridor,our study area,is located in Northwest China and is also the most developed area of oasis farming in arid regions of Northwestern China.However,the rapid development of metallurgy and chemical indust...The Hexi Corridor,our study area,is located in Northwest China and is also the most developed area of oasis farming in arid regions of Northwestern China.However,the rapid development of metallurgy and chemical industries in this region poses a great threat to the accumulation of heavy metals in crops.The objectives of this study are(1)to determine the influence of heavy metals on plant growth;(2)to assess the translocation capability of heavy metals in soil-plant system;and(3)to investigate the interaction between heavy metals.Pot experiments were conducted on cole(Brassica campestris L.)grown in the arid oasis soils singly and jointly treated with cadmium(Cd)and lead(Pb).Nine treatments were applied into the pots.Under the same planting conditions,three scenarios of Cd,Pb and Cd–Pb were designed to compare the interaction between Cd and Pb.The results showed that the response of cole weights to Cd,Pb and Cd–Pb treatments was slight,while Cd and Pb uptakes in cole were more sensitive to the single effects of Cd and Pb concentration in soils from the lower treatment levels.Under the influence of the single Cd,Pb and joint Cd–Pb treatments,Cd concentrations were lower in the cole roots than in the shoots,while for Pb,the results were opposite.Comparison studies revealed that the interaction of Cd and Pb could weaken the cole’s ability to uptake,concentrate and translocate heavy metals in arid oasis soils.展开更多
The articular cartilage(AC) can be seen as a biphasic poroelastic material.The cartilage deformation under compression mainly leads to an interstitial fluid flow in the porous solid phase.In this paper,an analytical p...The articular cartilage(AC) can be seen as a biphasic poroelastic material.The cartilage deformation under compression mainly leads to an interstitial fluid flow in the porous solid phase.In this paper,an analytical poroelastic model for the AC under laboratorial mechanical testing is developed.The solutions of interstitial fluid pressure and velocity are obtained.The results show the following facts.(i) Both the pressure and fluid velocity amplitudes are proportional to the strain loading amplitude.(ii) Both the amplitudes of pore fluid pressure and velocity in the AC depend more on the loading amplitude than on the frequency.Thus,in order to obtain the considerable fluid stimulus for the AC cell responses,the most effective way is to increase the loading amplitude rather than the frequency.(iii) Both the interstitial fluid pressure and velocity are strongly affected by permeability variations.This model can be used in experimental tests of the parameters of AC or other poroelastic materials,and in research of mechanotransduction and injury mechanism involved interstitial fluid flow.展开更多
The lacunar-canalicular system(LCS)is acknowledged to directly participate in bone tissue remodeling.The fluid flow in the LCS is synergic driven by the pressure gradient and electric field loads due to the electro-me...The lacunar-canalicular system(LCS)is acknowledged to directly participate in bone tissue remodeling.The fluid flow in the LCS is synergic driven by the pressure gradient and electric field loads due to the electro-mechanical properties of bone.In this paper,an idealized annulus Maxwell fluid flow model in bone canaliculus is established,and the analytical solutions of the fluid velocity,the fluid shear stress,and the fluid flow rate are obtained.The results of the fluid flow under pressure gradient driven(PGD),electric field driven(EFD),and pressure-electricity synergic driven(P-ESD)patterns are compared and discussed.The effects of the diameter of canaliculi and osteocyte processes are evaluated.The results show that the P-ESD pattern can combine the regulatory advantages of single PGD and EFD patterns,and the osteocyte process surface can feel a relatively uniform shear stress distribution.As the bone canalicular inner radius increases,the produced shear stress under the PGD or P-ESD pattern increases slightly but changes little under the EFD pattern.The increase in the viscosity makes the flow slow down but does not affect the fluid shear stress(FSS)on the canalicular inner wall and osteocyte process surface.The increase in the high-valent ions does not affect the flow velocity and the flow rate,but the FSS on the canalicular inner wall and osteocyte process surface increases linearly.In this study,the results show that the shear stress sensed by the osteocyte process under the P-ESD pattern can be regulated by changing the pressure gradient and the intensity of electric field,as well as the parameters of the annulus fluid and the canaliculus size,which is helpful for the osteocyte mechanical responses.The established model provides a basis for the study of the mechanisms of electro-mechanical signals stimulating bone tissue(cells)growth.展开更多
Background Intracerebral haemorrhage(ICH)is the most devastating form of stroke causing high morbidity and mortality.We aimed to develop a novel clinical score incorporating multisystem markers to predict functional d...Background Intracerebral haemorrhage(ICH)is the most devastating form of stroke causing high morbidity and mortality.We aimed to develop a novel clinical score incorporating multisystem markers to predict functional dependence at 90 days after ICH.Methods We analysed data from Chinese Cerebral Hemorrhage:Mechanism and Intervention study.Multivariable logistic regression analysis was used to identify the factors associated with 90-day functional dependency(the modified Rankin Scale≥3)after ICH and develop the ADVISING scoring system.To test the scoring system,a total of 2111 patients from Hubei province were included as the training cohort,and 733 patients from other three provinces in China were included as an external validation cohort.Results We found nine variables to be significantly associated with functional dependency and included in the ADVISING score system:age,deep location of haematoma,volume of haematoma,National Institutes of Health Stroke Scale,aspartate transaminase,international normalised ratio,neutrophil-lymphocyte ratio,fasting blood glucose and glomerular filtration rate.Individuals were divided into 12 different categories by using these nine potential predictors.The proportion of patients who were functionally dependent increased with higher ADVISING scores,which showed good discrimination and calibration in both the training cohort(C-statistic,0.866;p value of Hosmer-Lemeshow test,0.195)and validation cohort(C-statistic,0.884;p value of Hosmer-Lemeshow test,0.853).The ADVISING score also showed better discriminative performance compared with the other five existing ICH scores(p<0.001).Conclusions ADVISING score is a reliable tool to predict functional dependency at 90 days after ICH.展开更多
A pot experiment was conducted to study the bioaccumulation and translocation of cadmium (Cd) in cole (Brassica campestris L.) and celery (Apium graveolens) grown in the Cd-polluted oasis soil,Northwest of China.The r...A pot experiment was conducted to study the bioaccumulation and translocation of cadmium (Cd) in cole (Brassica campestris L.) and celery (Apium graveolens) grown in the Cd-polluted oasis soil,Northwest of China.The results showed that Cd in the unpolluted oasis soil was mainly bound to carbonate fraction (F2) and Fe-Mn oxide fraction (F3).However,marked change of Cd fractions was observed with increasing soil Cd concentrations,in which the concentration of Cd in F1 (exchangeable fraction),F2 and F3 increased significantly (p<0.001 for F1,F2 and F3).The growth of cole and celery could be facilitated by low concentrations of Cd,but inhibited by high concentrations.The correlation analysis between the fraction distribution coefficient of Cd in the soil and Cd concentration accumulated in the two vegetables showed that Cd in F1 in the soil made the greatest contribution on the accumulation of Cd in the two vegetables.The high bio-concentration factor and the translocation factor of Cd in both cole and celery were observed,and Cd had higher accumulation in the edible parts of the two vegetables.Therefore,both cole and celery grown in Cd-polluted oasis soil have higher risk to human health.And the two vegetables are not suitable to be cultivated as vegetables consumed by human in the Cd-polluted oasis soil.展开更多
A compact saturable absorber mirror（SAM） based on few-layer molybdenum disulfide（MoS2） nanoplatelets was fabricated and successfully used as an efficient saturable absorber（SA） for the passively Q-switched solid...A compact saturable absorber mirror（SAM） based on few-layer molybdenum disulfide（MoS2） nanoplatelets was fabricated and successfully used as an efficient saturable absorber（SA） for the passively Q-switched solid-state laser at 1 μm wavelength. Pulses as short as 182 ns were obtained from a ytterbium-doped（Yb:LGGG） bulk laser Q-switched by the MoS2 SAM, which we believe to be the shortest one ever achieved from the MoS2 SAs-based Q-switched bulk lasers. A maximum average output power of 0.6 W was obtained with a slope efficiency of 24%,corresponding to single pulse energy up to 1.8 μJ. In addition, the simultaneous dual-wavelength Q-switching at 1025.2 and 1028.1 nm has been successfully achieved. The results indicate the promising potential of few-layer MoS2 nanoplatelets as nonlinear optical switches for achieving efficient pulsed bulk lasers.展开更多
A pot experiment was conducted to study the relationship between distribution of cadmium (Cd) and zinc (Zn) and their availability to cole (Brassica campestris L.) grown in the multi-metal contaminated oasis soil in n...A pot experiment was conducted to study the relationship between distribution of cadmium (Cd) and zinc (Zn) and their availability to cole (Brassica campestris L.) grown in the multi-metal contaminated oasis soil in northwest of China.The results showed that Cd and Zn in the unpolluted oasis soil was mainly found in the residual fractionation,however,with increasing contents of Cd and Zn in the oasis soil,the distribution of Cd and Zn changed significantly.The growth of cole could be promoted by low Cd and Zn concentration,but significantly restrained by high concentrations.There was antagonistic effect among Cd and Zn in the multi-metals contaminated oasis soil.Stepwise regression analysis between fractionations distribution coefficients of the two meals in the soil and their contents in cole showed that both Cd and Zn in the exchangeable fractionation in the oasis soil made the most contribution on the uptake of Cd and Zn in cole.The bio-concentration factor (BCF) of Cd was greater than Zn in cole,and BCFs of the two metals in leaves were greater than those in roots.The translocation factors of the two metals in cole were greater than 1,and the two metals mainly accumulated in the edible parts in cole.Therefore,cole is not a suitable vegetable for the oasis soil because of the plants notable contamination by heavy metals.展开更多
In this study,two fullerenes(C60,C70)and their methano-substitutions(PC61BM,PC71BM),as electron transport materials(ETMs)in perovskite solar cells(Pero-SCs),were systematically studied.As being used as ETMs,methanoful...In this study,two fullerenes(C60,C70)and their methano-substitutions(PC61BM,PC71BM),as electron transport materials(ETMs)in perovskite solar cells(Pero-SCs),were systematically studied.As being used as ETMs,methanofullerenes,though with lower electron mobility compared to the counterpart pristine fullerenes,lead to higher power conversion efficiencies(PCEs)of Pero-SCs.The difference is likely caused by the fill-out vacancies and smoother morphology of the interfaces between ETM and perovskite layers,as they were prepared by different methods.In addition,compared to C60 and PC61BM,C70 and PC71BM showed priority in terms of short-circuit current density,which should be attributed to fast free charge extraction abilities.展开更多
A methanol-soluble diamine-modified fullerene derivative(denoted as PCBDANI)was applied as an efficient cathode buffer layer(CBL)in planar p-i-n perovskite solar cells(pero-SCs)based on the CH_3NH_3PbI_(3-x)Cl_x absor...A methanol-soluble diamine-modified fullerene derivative(denoted as PCBDANI)was applied as an efficient cathode buffer layer(CBL)in planar p-i-n perovskite solar cells(pero-SCs)based on the CH_3NH_3PbI_(3-x)Cl_x absorber.The device with PCBDANI single CBL exhibited significantly improved performance with a power conversion efficiency(PCE)of 15.45%,which is approximately17%higher than that of the control device without the CBL.The dramatic improvement in PCE can be attributed to the formation of an interfacial dipole at the PCBM/Al interface originating from the amine functional group and the suppression of interfacial recombinationby the PCBDANI interlayer.To further improve the PCE of pero-SCs,PCBDANI/LiF double CBLs were introduced between PCBM and the top Al electrode.An impressive PCE of 15.71%was achieved,which is somewhat higher than that of the devices with LiF or PCBDANI single CBL.Besides the PCE,the long-term stability of the device with PCBDANI/LiF double CBLs is also superior to that of the device with LiF single CBL.展开更多
To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxi...To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxide,and carbon dioxide,a method for the simultaneous determination of methanol,ethanol,n−propanol,and η-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry.The measured results show that the determination limits of the four alcohol characterizers can be controlled to 10μg/kg level.Based on this method,the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research.Ethanol,η-propanol,and η-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization,similar to that of methanol.By analyzing 52 sets of measured data of 500 kV EHV transformers in operation,η-butanol is found to have excellent performance,and a new method to evaluate the aging state of oil-paper insulation employing η-butanol and methanol is proposed along with the aging attention value model.The measured data of 500 kV EHV transformers in operation indicate that the combination of η-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging,and the feasibility of the method is verified.Two possible pathways for the generation of η-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.展开更多
基金supported by the National Natural Science Foundation of China(51178209,91025015)the Fundamental Research Funds for the Central Universities in Lanzhou University(lzujbky-2011-66)
文摘The Hexi Corridor,our study area,is located in Northwest China and is also the most developed area of oasis farming in arid regions of Northwestern China.However,the rapid development of metallurgy and chemical industries in this region poses a great threat to the accumulation of heavy metals in crops.The objectives of this study are(1)to determine the influence of heavy metals on plant growth;(2)to assess the translocation capability of heavy metals in soil-plant system;and(3)to investigate the interaction between heavy metals.Pot experiments were conducted on cole(Brassica campestris L.)grown in the arid oasis soils singly and jointly treated with cadmium(Cd)and lead(Pb).Nine treatments were applied into the pots.Under the same planting conditions,three scenarios of Cd,Pb and Cd–Pb were designed to compare the interaction between Cd and Pb.The results showed that the response of cole weights to Cd,Pb and Cd–Pb treatments was slight,while Cd and Pb uptakes in cole were more sensitive to the single effects of Cd and Pb concentration in soils from the lower treatment levels.Under the influence of the single Cd,Pb and joint Cd–Pb treatments,Cd concentrations were lower in the cole roots than in the shoots,while for Pb,the results were opposite.Comparison studies revealed that the interaction of Cd and Pb could weaken the cole’s ability to uptake,concentrate and translocate heavy metals in arid oasis soils.
基金Project supported by the National Natural Science Foundation of China(Nos.11632013,11472185,and 11702183)the Natural Science Foundation of Shanxi Province(No.2016021145)+1 种基金the Program for the OIT of Higher Learning Institutions of Shanxi,the State Key Laboratory of Fine Chemicals(No.KF 1511)the Scientific and Technological Innovation Projects of Colleges and Universities in Shanxi Province(No.2017135)
文摘The articular cartilage(AC) can be seen as a biphasic poroelastic material.The cartilage deformation under compression mainly leads to an interstitial fluid flow in the porous solid phase.In this paper,an analytical poroelastic model for the AC under laboratorial mechanical testing is developed.The solutions of interstitial fluid pressure and velocity are obtained.The results show the following facts.(i) Both the pressure and fluid velocity amplitudes are proportional to the strain loading amplitude.(ii) Both the amplitudes of pore fluid pressure and velocity in the AC depend more on the loading amplitude than on the frequency.Thus,in order to obtain the considerable fluid stimulus for the AC cell responses,the most effective way is to increase the loading amplitude rather than the frequency.(iii) Both the interstitial fluid pressure and velocity are strongly affected by permeability variations.This model can be used in experimental tests of the parameters of AC or other poroelastic materials,and in research of mechanotransduction and injury mechanism involved interstitial fluid flow.
基金supported by the National Natural Science Foundation of China(Nos.11972242 and 11632013)the China Postdoctoral Science Foundation(No.2020M680913)。
文摘The lacunar-canalicular system(LCS)is acknowledged to directly participate in bone tissue remodeling.The fluid flow in the LCS is synergic driven by the pressure gradient and electric field loads due to the electro-mechanical properties of bone.In this paper,an idealized annulus Maxwell fluid flow model in bone canaliculus is established,and the analytical solutions of the fluid velocity,the fluid shear stress,and the fluid flow rate are obtained.The results of the fluid flow under pressure gradient driven(PGD),electric field driven(EFD),and pressure-electricity synergic driven(P-ESD)patterns are compared and discussed.The effects of the diameter of canaliculi and osteocyte processes are evaluated.The results show that the P-ESD pattern can combine the regulatory advantages of single PGD and EFD patterns,and the osteocyte process surface can feel a relatively uniform shear stress distribution.As the bone canalicular inner radius increases,the produced shear stress under the PGD or P-ESD pattern increases slightly but changes little under the EFD pattern.The increase in the viscosity makes the flow slow down but does not affect the fluid shear stress(FSS)on the canalicular inner wall and osteocyte process surface.The increase in the high-valent ions does not affect the flow velocity and the flow rate,but the FSS on the canalicular inner wall and osteocyte process surface increases linearly.In this study,the results show that the shear stress sensed by the osteocyte process under the P-ESD pattern can be regulated by changing the pressure gradient and the intensity of electric field,as well as the parameters of the annulus fluid and the canaliculus size,which is helpful for the osteocyte mechanical responses.The established model provides a basis for the study of the mechanisms of electro-mechanical signals stimulating bone tissue(cells)growth.
基金Funding This study was funded by the Research and Development Program of China(2018YFC1312200)the National Natural Science Foundation of China(81820108010,81901214,82071335).
文摘Background Intracerebral haemorrhage(ICH)is the most devastating form of stroke causing high morbidity and mortality.We aimed to develop a novel clinical score incorporating multisystem markers to predict functional dependence at 90 days after ICH.Methods We analysed data from Chinese Cerebral Hemorrhage:Mechanism and Intervention study.Multivariable logistic regression analysis was used to identify the factors associated with 90-day functional dependency(the modified Rankin Scale≥3)after ICH and develop the ADVISING scoring system.To test the scoring system,a total of 2111 patients from Hubei province were included as the training cohort,and 733 patients from other three provinces in China were included as an external validation cohort.Results We found nine variables to be significantly associated with functional dependency and included in the ADVISING score system:age,deep location of haematoma,volume of haematoma,National Institutes of Health Stroke Scale,aspartate transaminase,international normalised ratio,neutrophil-lymphocyte ratio,fasting blood glucose and glomerular filtration rate.Individuals were divided into 12 different categories by using these nine potential predictors.The proportion of patients who were functionally dependent increased with higher ADVISING scores,which showed good discrimination and calibration in both the training cohort(C-statistic,0.866;p value of Hosmer-Lemeshow test,0.195)and validation cohort(C-statistic,0.884;p value of Hosmer-Lemeshow test,0.853).The ADVISING score also showed better discriminative performance compared with the other five existing ICH scores(p<0.001).Conclusions ADVISING score is a reliable tool to predict functional dependency at 90 days after ICH.
基金supported by the National Environmental Protection Commonweal Project of China (No. NEPCP 200809098)the Fundamental Research Funds for the Central Universities in Lanzhou University (No. lzujbky-2009-65)the National Natural Science Foundation of China (No. 91025015)
文摘A pot experiment was conducted to study the bioaccumulation and translocation of cadmium (Cd) in cole (Brassica campestris L.) and celery (Apium graveolens) grown in the Cd-polluted oasis soil,Northwest of China.The results showed that Cd in the unpolluted oasis soil was mainly bound to carbonate fraction (F2) and Fe-Mn oxide fraction (F3).However,marked change of Cd fractions was observed with increasing soil Cd concentrations,in which the concentration of Cd in F1 (exchangeable fraction),F2 and F3 increased significantly (p<0.001 for F1,F2 and F3).The growth of cole and celery could be facilitated by low concentrations of Cd,but inhibited by high concentrations.The correlation analysis between the fraction distribution coefficient of Cd in the soil and Cd concentration accumulated in the two vegetables showed that Cd in F1 in the soil made the greatest contribution on the accumulation of Cd in the two vegetables.The high bio-concentration factor and the translocation factor of Cd in both cole and celery were observed,and Cd had higher accumulation in the edible parts of the two vegetables.Therefore,both cole and celery grown in Cd-polluted oasis soil have higher risk to human health.And the two vegetables are not suitable to be cultivated as vegetables consumed by human in the Cd-polluted oasis soil.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51321091, 61275142, 61308042, and 91022003)China Postdoctoral Science Foundation (Grant Nos. 2013M531594, 2014T70633)
文摘A compact saturable absorber mirror（SAM） based on few-layer molybdenum disulfide（MoS2） nanoplatelets was fabricated and successfully used as an efficient saturable absorber（SA） for the passively Q-switched solid-state laser at 1 μm wavelength. Pulses as short as 182 ns were obtained from a ytterbium-doped（Yb:LGGG） bulk laser Q-switched by the MoS2 SAM, which we believe to be the shortest one ever achieved from the MoS2 SAs-based Q-switched bulk lasers. A maximum average output power of 0.6 W was obtained with a slope efficiency of 24%,corresponding to single pulse energy up to 1.8 μJ. In addition, the simultaneous dual-wavelength Q-switching at 1025.2 and 1028.1 nm has been successfully achieved. The results indicate the promising potential of few-layer MoS2 nanoplatelets as nonlinear optical switches for achieving efficient pulsed bulk lasers.
基金supported by the National Environmental Protection Commonweal Project of China(No. NEPCP200809098)the Fundamental Research Funds for the Central Universities in Lanzhou University(No. lzujbky-2009-65)the National Natural Science Foundation of China(No. 91025015)
文摘A pot experiment was conducted to study the relationship between distribution of cadmium (Cd) and zinc (Zn) and their availability to cole (Brassica campestris L.) grown in the multi-metal contaminated oasis soil in northwest of China.The results showed that Cd and Zn in the unpolluted oasis soil was mainly found in the residual fractionation,however,with increasing contents of Cd and Zn in the oasis soil,the distribution of Cd and Zn changed significantly.The growth of cole could be promoted by low Cd and Zn concentration,but significantly restrained by high concentrations.There was antagonistic effect among Cd and Zn in the multi-metals contaminated oasis soil.Stepwise regression analysis between fractionations distribution coefficients of the two meals in the soil and their contents in cole showed that both Cd and Zn in the exchangeable fractionation in the oasis soil made the most contribution on the uptake of Cd and Zn in cole.The bio-concentration factor (BCF) of Cd was greater than Zn in cole,and BCFs of the two metals in leaves were greater than those in roots.The translocation factors of the two metals in cole were greater than 1,and the two metals mainly accumulated in the edible parts in cole.Therefore,cole is not a suitable vegetable for the oasis soil because of the plants notable contamination by heavy metals.
基金the National Natural Science Foundation of China(51303118,91333204)the Natural Science Foundation of Jiangsu Province(BK20130289)+3 种基金the Ph.D.Programs Foundation of Ministry of Education of China(20133201120008)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Scientific Research Foundation for Returned Scholars,Ministry of Education of ChinaBeijing National Laboratory for Molecular Sciences,State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
文摘In this study,two fullerenes(C60,C70)and their methano-substitutions(PC61BM,PC71BM),as electron transport materials(ETMs)in perovskite solar cells(Pero-SCs),were systematically studied.As being used as ETMs,methanofullerenes,though with lower electron mobility compared to the counterpart pristine fullerenes,lead to higher power conversion efficiencies(PCEs)of Pero-SCs.The difference is likely caused by the fill-out vacancies and smoother morphology of the interfaces between ETM and perovskite layers,as they were prepared by different methods.In addition,compared to C60 and PC61BM,C70 and PC71BM showed priority in terms of short-circuit current density,which should be attributed to fast free charge extraction abilities.
基金the National Natural Science Foundation of China(21204054,51303118,91333204)the Natural Science Foundation of Jiangsu Province(BK20130289)+3 种基金the Ph.D.Programs Foundation of Ministry of Education of China(20133201120008)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Scientific Research Foundation for Returned Scholars,Ministry of Education of ChinaBeijing National Laboratory for Molecular Sciences,State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
文摘A methanol-soluble diamine-modified fullerene derivative(denoted as PCBDANI)was applied as an efficient cathode buffer layer(CBL)in planar p-i-n perovskite solar cells(pero-SCs)based on the CH_3NH_3PbI_(3-x)Cl_x absorber.The device with PCBDANI single CBL exhibited significantly improved performance with a power conversion efficiency(PCE)of 15.45%,which is approximately17%higher than that of the control device without the CBL.The dramatic improvement in PCE can be attributed to the formation of an interfacial dipole at the PCBM/Al interface originating from the amine functional group and the suppression of interfacial recombinationby the PCBDANI interlayer.To further improve the PCE of pero-SCs,PCBDANI/LiF double CBLs were introduced between PCBM and the top Al electrode.An impressive PCE of 15.71%was achieved,which is somewhat higher than that of the devices with LiF or PCBDANI single CBL.Besides the PCE,the long-term stability of the device with PCBDANI/LiF double CBLs is also superior to that of the device with LiF single CBL.
基金supported by Innovation Foundation of China Electric Power Research Institute(GY83-18-006).
文摘To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxide,and carbon dioxide,a method for the simultaneous determination of methanol,ethanol,n−propanol,and η-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry.The measured results show that the determination limits of the four alcohol characterizers can be controlled to 10μg/kg level.Based on this method,the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research.Ethanol,η-propanol,and η-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization,similar to that of methanol.By analyzing 52 sets of measured data of 500 kV EHV transformers in operation,η-butanol is found to have excellent performance,and a new method to evaluate the aging state of oil-paper insulation employing η-butanol and methanol is proposed along with the aging attention value model.The measured data of 500 kV EHV transformers in operation indicate that the combination of η-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging,and the feasibility of the method is verified.Two possible pathways for the generation of η-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.
