Using literature,questionnaires,interviews,and mathematical statistics to investigate the current situation of sports public services in the Chengdu-Chongqing Twin-city Economic Circle.The results show that there are ...Using literature,questionnaires,interviews,and mathematical statistics to investigate the current situation of sports public services in the Chengdu-Chongqing Twin-city Economic Circle.The results show that there are some problems in Chengdu-Chongqing sports public services,such as big difference in the development level of supply between urban and rural areas,low supply level,low efficiency,supply mechanism defect,lack of social sports instructors,an outstanding contradiction between the quality of sports public service and residents’demand.To address the problems,government departments should accelerate the transformation of government functions,improve the relevant regulations and systems,increase the investment in sports public services,improve the quality of supply,cultivate the backbone team,integrate resources,and combine the national characteristics with regional characteristics,take into account the personalized needs of the residents,combine the sports public services with intelligence,and build the service system of“Internet+Fitness.”展开更多
The Microbial Fuel Cell (MFC) is a bioelectrical system that can convert chemical energy into electrical energy. The anode plays an important role in the improvement of power generation. Zeolite and carbon-based mater...The Microbial Fuel Cell (MFC) is a bioelectrical system that can convert chemical energy into electrical energy. The anode plays an important role in the improvement of power generation. Zeolite and carbon-based materials were coated in graphene felt anode in this study for proof of concept that the modified material could enhance power generation. Preliminary results showed that the maximum power density with the modified material was 2 - 2.5 times higher than the unmodified material using RAS as a substrate and 1.4 times higher using algae as a substrate in our single chamber model, whereas the dual-chamber model displayed a maximum power density of the modified material to be roughly 3 - 4 times higher than in the unmodified microbial fuel cell.展开更多
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
Identification of kiwifruit germplasm materials is the basis of protecting and utilizing these resources.However,identifying Actinidia arguta varieties based on morphology is difficult,especially for non-specialists.I...Identification of kiwifruit germplasm materials is the basis of protecting and utilizing these resources.However,identifying Actinidia arguta varieties based on morphology is difficult,especially for non-specialists.In this study,we collected 180 specimens comprising 60 varieties of three species(A.arguta,A.kolomikta,and A.polygama)from the Northeast of China.The emphasis of our study was on the feasibility of identifying A.arguta varieties.Here,we used common analysis methods(genetic distance,phylogenetic analysis and the DNA barcoding gap)and SNPs analysis to evaluate the discriminatory power of different DNA barcoding markers.The results revealed that common methods were insufficient to identify A.arguta varieties but SNPs analysis based on DNA barcoden was the potential method for identifying A.arguta varieties.Besides,Our study agree that DNA barcoding could be used to analysis the evaluation genetic relationship of the Actinidia plants.展开更多
Fruit of Lonicera caerulea L. is a rich source of phenolic compounds such as phenolic acids as well as anthocyanins,proanthocyanidins and other flavonoids,which display potential health-promoting effects. However,its ...Fruit of Lonicera caerulea L. is a rich source of phenolic compounds such as phenolic acids as well as anthocyanins,proanthocyanidins and other flavonoids,which display potential health-promoting effects. However,its genetics and genomic information is limited. Transcriptome and digital gene expression( DGE) profiles of fruit at four different development stages were compared. Related genes with anthocyanin biosynthesis were compared using real-time quantitative PCR( qRT-PCR). RNA-Seq generated 6. 26-Gb clean reads,which was then de novo assembled into 45,656 UniG enes with a mean length 837 bp. A total of 7 928 unigenes were annotated into 32 known metabolic or signaling pathways in which a few primary,intermediate,and secondary metabolic pathways are directly related to fruit quality. The result of DGE and qRT-PCR indicates that UFGT( comp20132_c0) may play a key role in honeysuckle coloration. This provides a reference for the study of complicated metabolism in non-model perennial species.展开更多
In the present study correlation, regression and path analyses were carried out to decide correlations among the agro- nomic traits and their contributions to seed yield per plant in Crambe abyssinica. Partial correla...In the present study correlation, regression and path analyses were carried out to decide correlations among the agro- nomic traits and their contributions to seed yield per plant in Crambe abyssinica. Partial correlation analysis indicated that plant height (X1) was significantly correlated with branching height and the number of first branches (P 2) was significantly correlated with pod number of primary inflorescence (P 3) was significantly correlated with number of secondary branches (P -grain weight (P 4) was significantly correlated with seed yield per plant (P 7) was significantly correlated with seed yield per plant (P -grain weight (P -grain weight (X8) was significantly correlated with seed yield per plant (P -grain weight contributed significantly to seed yield per plant at P 7) and 1000-grain weight (X8) to seed yield per plant (Y) is Y = 0.006 X7 + 1.222 X8 - 7.191. The path coefficient of pod number per plant to seed yield per plant was 0.967 and that of 1000-grain weight was 0.194. The determination coefficient of pod number per plant and 1000-grain weight to seed yield per plant was 0.983 and the determination coefficient of other agronomic traits was 0.130. Coefficient of variance indicated that the length of primary inflorescence showed the greatest variation, followed by seed yield per plant, pod number per plant, number of secondary branches, branching height, pod number of primary inflorescence, number of first branches, seed yield per plot, 1000-grain weight and plant height. It was suggested that seed yield per plant in Crambe might be improved by increasing the pod number per plant through selection or cultivation, but the negative correlation between pod number per plant and 1000-grain weight also needs to be considered.展开更多
This study analyzes the current situation and problems of the school football competition system in Chongqing through literature search,interviews,and questionnaires.With this,a development model suitable for the esta...This study analyzes the current situation and problems of the school football competition system in Chongqing through literature search,interviews,and questionnaires.With this,a development model suitable for the establishment of a school football system for young people is proposed.Besides,this study aims to promote the construction and improvement and boost the competitiveness of school football competition system.展开更多
With China’s comprehensive development of information technology,it is now widely used in the field of higher vocational education,and online teaching has emerged at a critical juncture.In the information age,there a...With China’s comprehensive development of information technology,it is now widely used in the field of higher vocational education,and online teaching has emerged at a critical juncture.In the information age,there are challenges in meeting the actual needs of contemporary vocational students with traditional teaching methods,along with higher vocational training and school-enterprise cooperation and enrollment work taking place.Online teaching can stimulate students’interest in learning,break the limitation of time and space in conventional teaching,as well as improve the teaching efficiency.Therefore,taking higher vocational colleges in Chongqing as an example,this study explores the integration of online teaching into public physical education courses,in hope to provide some reference for higher vocational colleges.展开更多
Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in preci...Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in precisely controlling the inter-subcells carrier migration which determines the balance of charge transport across the entire device.The conductivity of"nanowires"-like conducting channel in interconnecting layer between sub-cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer.Here,we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSs.The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components.Based on our strategy,the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved.We believe our method might provide guidance for the manufacture of tandem organic solar cells.展开更多
Reasonable prediction of concrete creep is the basis of studying long-term deflection of concrete structures.In this paper,a hybrid model-driven and data-driven(HMD)method for predicting concrete creep is proposed by ...Reasonable prediction of concrete creep is the basis of studying long-term deflection of concrete structures.In this paper,a hybrid model-driven and data-driven(HMD)method for predicting concrete creep is proposed by using the sequence integration strategy.Then,a novel uncertainty prediction model(UPM)is developed considering uncertainty quantification.Finally,the effectiveness of the proposed method is validated by using the North-western University(NU)database of creep,and the effect of uncertainty on prediction results are also discussed.The analysis results show that the proposed HMD method outperforms the model-driven and three data-driven methods,including the genetic algorithm-back propagation neural network(GA-BPNN),particle swarm optimization-support vector regression(PSO-SVR)and convolutional neural network only method,in accuracy and time efficiency.The proposed UPM of concrete creep not only ensures relatively good prediction accuracy,but also quantifies the model and measurement uncertainties during the prediction process.Additionally,although incorporating measurement uncertainty into concrete creep prediction can improve the prediction performance of UPM,the prediction interval of the creep compliance is more sensitive to model uncertainty than to measurement uncertainty,and the mean contribution of variance attributed to the model uncertainty to the total variance is about 90%.展开更多
The characteristics of bioaerosols and their effects on human beings'health have become a major public concern in the recent years.This study compared the characteristics of bioaerosols under different types of po...The characteristics of bioaerosols and their effects on human beings'health have become a major public concern in the recent years.This study compared the characteristics of bioaerosols under different types of pollution(high-ozone[HO]episodes,haze episodes,and dust storms[DSs]),with those of bioaerosols on normal days(NDs)in Xi'an,China.The concentrations,diurnal variations,and size distribution of bacteria,fungi,and total airborne microbes(TAMs)were investigated.The results showed that the bacterial and fungal concentrations were the highest during DSs and on NDs,reaching 425.2 and 956.9 colony-forming units/m^(3),respectively.The concentration of TAMs was the highest during HO episodes,reaching 10.7×10^(6)cells/m^(3),which was significantly higher than that during the other events.The maximum concentrations of bacteria and fungi during HO episodes were observed in the morning,while they appeared separately in the morning and evening during haze episodes.Bacteria and TAMs during DSs reached peak concentrations in the morning and evening,which is opposite to the particulate matter(PM)distribution pattern.On NDs,temperature and relative humidity had significant effects on bioaerosols.The size distributions of airborne bacteria exhibited bimodal patterns,whereas unimodal distributions were observed for fungi.Fungi mainly attached in fine particles(<2.1μm)with proportions of 67.4%and 60.5%during haze episodes and DSs,respectively,which means that fungi were easily penetrated into the human respiratory system.The evaluation of influence factors revealed that PM_(2.5) and PM10 had negative effects on fungal concentration during DSs,and ozone concentration and temperature were inversely correlated with fungal concentration during HO episodes.These results provide valuable reference data for elucidating the formation and evolution of bioaerosols under different types of pollution.展开更多
The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells,which require high-quality single crystals with controlled defect levels.Her...The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells,which require high-quality single crystals with controlled defect levels.Herein,we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates(MPs),and reported a defect-modulated photocurrent which is closely related to the growth sequence of the MPs.The MP synthesis initiates from island-like nano-disks,and subsequently transits to a layer-by-layer fashion,resulting in a defect-rich area at the center of the MPs.At elevated temperatures,these central defects may be thermally activated and become highly mobile,leading to photoluminescence quenching and degression of local and overall optoelectronic attributes,as evidenced by the spatial resolved optical and electrical scanning probe microscopy.Overall,this work shines light on the formation,proliferation and dynamics of defects in perovskites,and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability.展开更多
Successful coordination in multi-agent systems requires agents to achieve consensus.Previous works propose methods through information sharing,such as explicit information sharing via communication protocols or exchan...Successful coordination in multi-agent systems requires agents to achieve consensus.Previous works propose methods through information sharing,such as explicit information sharing via communication protocols or exchanging information implicitly via behavior prediction.However,these methods may fail in the absence of communication channels or due to biased modeling.In this work,we propose to develop dual-channel consensus(DuCC)via contrastive representation learning for fully cooperative multi-agent systems,which does not need explicit communication and avoids biased modeling.DuCC comprises two types of consensus:temporally extended consensus within each agent(inner-agent consensus)and mutual consensus across agents(inter-agent consensus).To achieve DuCC,we design two objectives to learn representations of slow environmental features for inner-agent consensus and to realize cognitive consistency as inter-agent consensus.Our DuCC is highly general and can be flexibly combined with various MARL algorithms.The extensive experiments on StarCraft multi-agent challenge and Google research football demonstrate that our method efficiently reaches consensus and performs superiorly to state-of-the-art MARL algorithms.展开更多
A three-year experiment was conducted in the middle-lower reaches of the Yangtze River in China to study the influence of continuous wheat straw return during the rice season and continuous rice straw return in wheat ...A three-year experiment was conducted in the middle-lower reaches of the Yangtze River in China to study the influence of continuous wheat straw return during the rice season and continuous rice straw return in wheat on methane (CH 4 ) emissions from rice fields in which, the rice-wheat rotation system is the most dominant planting pattern. The field experiment was initiated in October 2009 and has continued since the wheat-growing season of that year. The analyses for the present study were conducted in the second (2011) and third (2012) rice growing seasons. Four treatments, namely, the continuous return of wheat straw and rice straw in every season (WR), of rice straw but no wheat straw return (R), of wheat straw but no rice straw return (W) and a control with no straw return (CK), were laid out in a randomized split-plot design. The total seasonal CH 4 emissions ranged from 107.4 to 491.7 kg/ha (2011) and 160.3 to 909.6 kg/ha (2012). The increase in CH 4 emissions for treatments WR and W were 289% and 230% in the second year and 185% and 225% in the third year, respectively, in relation to CK. We observed less methane emissions in the treatment R than in CK by 14%-43%, but not statistically significant. Treatment R could increase rice productivity while no more CH 4 emission occurs. The difference in the total CH 4 emissions mainly related to a difference in the methane flux rate during the first 30-35 days after transplant in the rice growing season, which was caused by the amount of dissolved oxygen in paddy water and the amount of reducible soil materials.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 Chin...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 cortcentmdons. 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-eoncentration factor and the translocation factor of Cd in both cote 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
Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous st...Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous studies have shown that ions can migrate to form a conductive channel in perovskites under an external voltage. However, the exact resistance mechanism for Ag or halogens which dominate the resistive behavior is still controversial. Here, we demonstrate a resistive switching memory device based on Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/fluorine doped tin oxide (FTO). The migration of Ag cations and halide anions is demonstrated by energy dispersive X-ray spectroscopy (EDS) after the SET process (positive voltage on Ag). By comparing the I-V behavior of the Au-based devices, it is clear that the conductive channel formed by Ag is the main factor of the switching characteristics for Ag-based devices. Meanwhile, by controlling the appropriate SET voltage, two kinds of resistance characteristics of the analog switch and threshold switch can be realized in the Ag-based device. As a result, it may be possible to implement both data storage and neuromorphic computing in a single device.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 so...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
Understanding the damage behavior and cracking mechanism of brittle shale is crucial for hydraulic fracturing design.In this research,uniaxial compression tests are conducted on shale samples with different bedding pl...Understanding the damage behavior and cracking mechanism of brittle shale is crucial for hydraulic fracturing design.In this research,uniaxial compression tests are conducted on shale samples with different bedding plane orientations,and acoustic emission monitoring is implemented synchronously.The results indicate that the apparent elastic modulus increases with increasing bedding orientation.For the bedding orienta-tions of 45°and 90°,the lateral deformation is anisotropic due to the bedding structure,revealing the anisotropic Poisson effect.A shear failure surface and tensile failure surfaces form parallel to the bedding plane for bedding orientations of 45°and 90°,respectively.For the bedding orientation of 0°,shear failure mainly occurs through the bedding planes.Additionally,the damage mechanism of shale is investigated by crack classification based on AE parameters.It is found that crack initiation is induced by the generation of shear cracks for the bedding orientation of 45°,whereas by the generation of tensile cracks for other bedding orientations.According to damage attributable to different type cracks,shear cracks dominate the damage behavior for bedding orientations of 0°and 45°,whereas tensile cracks dominate the damage behavior for bedding orientation of 90°.Finally,the information entropy is calculated by AE energy.A low value of information entropy,approximately 0.36,predicts failure with a low degree of instability for the bedding orientation of 0°,whereas a high value of information entropy,more than 1.5,predicts failure with a high degree of instability for other bedding orientations.This finding indicates that the failure behavior is gradual progressive damage for bedding orientation of 0°,whereas sudden damage dominates failure behavior for other bedding orientations.展开更多
A number of studies have focused on the effects of rare earth elements(REEs) on crop plants,while little attention has been paid on how tolerant plant species respond to increasing mixed REE concentrations.In this stu...A number of studies have focused on the effects of rare earth elements(REEs) on crop plants,while little attention has been paid on how tolerant plant species respond to increasing mixed REE concentrations.In this study,ramie(Boehmeria nivea L.) was exposed to a series of REE concentrations prepared with equimolar mixtures of 16 REEs(i.e.0,1.6,8,16,80,160,400,800 μmol/L) in order to explore REE accumulation and fractionation characteristics in ramie and the responses of this plant to mixed REEs.Results show that ramie root and shoot biomasses are unaffected under lower REE concentrations(1.6-80 μmol/L),while the growth of ramie and the uptake of nutrients especially Ca and Mn are largely inhibited under higher REE concentrations(160-800 μmol/L).The P and Mo concentrations in the roots increase with the increasing REE concentrations in the solution,suggestive of an involvement of P and Mo in dealing with the high concentrations of REEs in this plant.The preferential uptake of Ce and heavy REEs(HREEs) and the preferential transport of HREEs within the plant lead to a positive Ce anomaly and a HREE enrichment in ramie leaves.Our study suggests that ramie could be a good candidate for the phyto re mediation of heavily REE-contaminated soils(e.g.,REE mine tailings in southern China).Our results also shed light on points of taking into account phytoremediation management strategies of REEcontaminated soils(e.g.,P and Mo fertilization).展开更多
文摘Using literature,questionnaires,interviews,and mathematical statistics to investigate the current situation of sports public services in the Chengdu-Chongqing Twin-city Economic Circle.The results show that there are some problems in Chengdu-Chongqing sports public services,such as big difference in the development level of supply between urban and rural areas,low supply level,low efficiency,supply mechanism defect,lack of social sports instructors,an outstanding contradiction between the quality of sports public service and residents’demand.To address the problems,government departments should accelerate the transformation of government functions,improve the relevant regulations and systems,increase the investment in sports public services,improve the quality of supply,cultivate the backbone team,integrate resources,and combine the national characteristics with regional characteristics,take into account the personalized needs of the residents,combine the sports public services with intelligence,and build the service system of“Internet+Fitness.”
文摘The Microbial Fuel Cell (MFC) is a bioelectrical system that can convert chemical energy into electrical energy. The anode plays an important role in the improvement of power generation. Zeolite and carbon-based materials were coated in graphene felt anode in this study for proof of concept that the modified material could enhance power generation. Preliminary results showed that the maximum power density with the modified material was 2 - 2.5 times higher than the unmodified material using RAS as a substrate and 1.4 times higher using algae as a substrate in our single chamber model, whereas the dual-chamber model displayed a maximum power density of the modified material to be roughly 3 - 4 times higher than in the unmodified microbial fuel cell.
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Supported by the Jilin Scientific and Technological Development Program(20170203006NY)Central Public-interest Scientific Institution Basal Research Fund(1610342016019)
文摘Identification of kiwifruit germplasm materials is the basis of protecting and utilizing these resources.However,identifying Actinidia arguta varieties based on morphology is difficult,especially for non-specialists.In this study,we collected 180 specimens comprising 60 varieties of three species(A.arguta,A.kolomikta,and A.polygama)from the Northeast of China.The emphasis of our study was on the feasibility of identifying A.arguta varieties.Here,we used common analysis methods(genetic distance,phylogenetic analysis and the DNA barcoding gap)and SNPs analysis to evaluate the discriminatory power of different DNA barcoding markers.The results revealed that common methods were insufficient to identify A.arguta varieties but SNPs analysis based on DNA barcoden was the potential method for identifying A.arguta varieties.Besides,Our study agree that DNA barcoding could be used to analysis the evaluation genetic relationship of the Actinidia plants.
基金Supported by Agricultural Science and Technology Innovation Project of China
文摘Fruit of Lonicera caerulea L. is a rich source of phenolic compounds such as phenolic acids as well as anthocyanins,proanthocyanidins and other flavonoids,which display potential health-promoting effects. However,its genetics and genomic information is limited. Transcriptome and digital gene expression( DGE) profiles of fruit at four different development stages were compared. Related genes with anthocyanin biosynthesis were compared using real-time quantitative PCR( qRT-PCR). RNA-Seq generated 6. 26-Gb clean reads,which was then de novo assembled into 45,656 UniG enes with a mean length 837 bp. A total of 7 928 unigenes were annotated into 32 known metabolic or signaling pathways in which a few primary,intermediate,and secondary metabolic pathways are directly related to fruit quality. The result of DGE and qRT-PCR indicates that UFGT( comp20132_c0) may play a key role in honeysuckle coloration. This provides a reference for the study of complicated metabolism in non-model perennial species.
文摘In the present study correlation, regression and path analyses were carried out to decide correlations among the agro- nomic traits and their contributions to seed yield per plant in Crambe abyssinica. Partial correlation analysis indicated that plant height (X1) was significantly correlated with branching height and the number of first branches (P 2) was significantly correlated with pod number of primary inflorescence (P 3) was significantly correlated with number of secondary branches (P -grain weight (P 4) was significantly correlated with seed yield per plant (P 7) was significantly correlated with seed yield per plant (P -grain weight (P -grain weight (X8) was significantly correlated with seed yield per plant (P -grain weight contributed significantly to seed yield per plant at P 7) and 1000-grain weight (X8) to seed yield per plant (Y) is Y = 0.006 X7 + 1.222 X8 - 7.191. The path coefficient of pod number per plant to seed yield per plant was 0.967 and that of 1000-grain weight was 0.194. The determination coefficient of pod number per plant and 1000-grain weight to seed yield per plant was 0.983 and the determination coefficient of other agronomic traits was 0.130. Coefficient of variance indicated that the length of primary inflorescence showed the greatest variation, followed by seed yield per plant, pod number per plant, number of secondary branches, branching height, pod number of primary inflorescence, number of first branches, seed yield per plot, 1000-grain weight and plant height. It was suggested that seed yield per plant in Crambe might be improved by increasing the pod number per plant through selection or cultivation, but the negative correlation between pod number per plant and 1000-grain weight also needs to be considered.
文摘This study analyzes the current situation and problems of the school football competition system in Chongqing through literature search,interviews,and questionnaires.With this,a development model suitable for the establishment of a school football system for young people is proposed.Besides,this study aims to promote the construction and improvement and boost the competitiveness of school football competition system.
基金Project of“Innovation of Teaching Mode of Public Physical Education in Chongqing”(Project Number:203675).
文摘With China’s comprehensive development of information technology,it is now widely used in the field of higher vocational education,and online teaching has emerged at a critical juncture.In the information age,there are challenges in meeting the actual needs of contemporary vocational students with traditional teaching methods,along with higher vocational training and school-enterprise cooperation and enrollment work taking place.Online teaching can stimulate students’interest in learning,break the limitation of time and space in conventional teaching,as well as improve the teaching efficiency.Therefore,taking higher vocational colleges in Chongqing as an example,this study explores the integration of online teaching into public physical education courses,in hope to provide some reference for higher vocational colleges.
基金the National Natural Science Foundation of China(NSFC)(22275016,21835006,22122905)Beijing Municipal Science&Technology Commission(2232078)+2 种基金Beijing National Laboratory for Molecular Sciences(BNLMS)Junior Fellow(2019BMS20014,BNLMS-CXXM-201903)National Research Council of Science and Technology of Korea(Global20-004)the Key Research Program of the Chinese Academy of Sciences(XDPB13-3).
文摘Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in precisely controlling the inter-subcells carrier migration which determines the balance of charge transport across the entire device.The conductivity of"nanowires"-like conducting channel in interconnecting layer between sub-cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer.Here,we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSs.The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components.Based on our strategy,the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved.We believe our method might provide guidance for the manufacture of tandem organic solar cells.
基金supported by the National Natural Science Foundation of China(Grant Nos.52208166 and 52108135)the National Key Research and Development Program of China(No.2021YFB2600900)+1 种基金the Science and Technology Innovation Program of Hunan Province(No.2022RC1186)the Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province.
文摘Reasonable prediction of concrete creep is the basis of studying long-term deflection of concrete structures.In this paper,a hybrid model-driven and data-driven(HMD)method for predicting concrete creep is proposed by using the sequence integration strategy.Then,a novel uncertainty prediction model(UPM)is developed considering uncertainty quantification.Finally,the effectiveness of the proposed method is validated by using the North-western University(NU)database of creep,and the effect of uncertainty on prediction results are also discussed.The analysis results show that the proposed HMD method outperforms the model-driven and three data-driven methods,including the genetic algorithm-back propagation neural network(GA-BPNN),particle swarm optimization-support vector regression(PSO-SVR)and convolutional neural network only method,in accuracy and time efficiency.The proposed UPM of concrete creep not only ensures relatively good prediction accuracy,but also quantifies the model and measurement uncertainties during the prediction process.Additionally,although incorporating measurement uncertainty into concrete creep prediction can improve the prediction performance of UPM,the prediction interval of the creep compliance is more sensitive to model uncertainty than to measurement uncertainty,and the mean contribution of variance attributed to the model uncertainty to the total variance is about 90%.
基金the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences(grant No.SKLLQG2236)Natural Science Foundation of Shaanxi Province,China(grant No.2021JQ-027).
文摘The characteristics of bioaerosols and their effects on human beings'health have become a major public concern in the recent years.This study compared the characteristics of bioaerosols under different types of pollution(high-ozone[HO]episodes,haze episodes,and dust storms[DSs]),with those of bioaerosols on normal days(NDs)in Xi'an,China.The concentrations,diurnal variations,and size distribution of bacteria,fungi,and total airborne microbes(TAMs)were investigated.The results showed that the bacterial and fungal concentrations were the highest during DSs and on NDs,reaching 425.2 and 956.9 colony-forming units/m^(3),respectively.The concentration of TAMs was the highest during HO episodes,reaching 10.7×10^(6)cells/m^(3),which was significantly higher than that during the other events.The maximum concentrations of bacteria and fungi during HO episodes were observed in the morning,while they appeared separately in the morning and evening during haze episodes.Bacteria and TAMs during DSs reached peak concentrations in the morning and evening,which is opposite to the particulate matter(PM)distribution pattern.On NDs,temperature and relative humidity had significant effects on bioaerosols.The size distributions of airborne bacteria exhibited bimodal patterns,whereas unimodal distributions were observed for fungi.Fungi mainly attached in fine particles(<2.1μm)with proportions of 67.4%and 60.5%during haze episodes and DSs,respectively,which means that fungi were easily penetrated into the human respiratory system.The evaluation of influence factors revealed that PM_(2.5) and PM10 had negative effects on fungal concentration during DSs,and ozone concentration and temperature were inversely correlated with fungal concentration during HO episodes.These results provide valuable reference data for elucidating the formation and evolution of bioaerosols under different types of pollution.
基金supported by the National Natural Science Foundation of China(Nos.11804042,62004022)the China Postdoctoral Science Foundation(No.2023M730479).
文摘The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells,which require high-quality single crystals with controlled defect levels.Herein,we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates(MPs),and reported a defect-modulated photocurrent which is closely related to the growth sequence of the MPs.The MP synthesis initiates from island-like nano-disks,and subsequently transits to a layer-by-layer fashion,resulting in a defect-rich area at the center of the MPs.At elevated temperatures,these central defects may be thermally activated and become highly mobile,leading to photoluminescence quenching and degression of local and overall optoelectronic attributes,as evidenced by the spatial resolved optical and electrical scanning probe microscopy.Overall,this work shines light on the formation,proliferation and dynamics of defects in perovskites,and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences,China(No.XDA27030300)the Program for National Nature Science Foundation of China(62073324).
文摘Successful coordination in multi-agent systems requires agents to achieve consensus.Previous works propose methods through information sharing,such as explicit information sharing via communication protocols or exchanging information implicitly via behavior prediction.However,these methods may fail in the absence of communication channels or due to biased modeling.In this work,we propose to develop dual-channel consensus(DuCC)via contrastive representation learning for fully cooperative multi-agent systems,which does not need explicit communication and avoids biased modeling.DuCC comprises two types of consensus:temporally extended consensus within each agent(inner-agent consensus)and mutual consensus across agents(inter-agent consensus).To achieve DuCC,we design two objectives to learn representations of slow environmental features for inner-agent consensus and to realize cognitive consistency as inter-agent consensus.Our DuCC is highly general and can be flexibly combined with various MARL algorithms.The extensive experiments on StarCraft multi-agent challenge and Google research football demonstrate that our method efficiently reaches consensus and performs superiorly to state-of-the-art MARL algorithms.
基金supported by the National Science and Technology Support Plan Project in China (No. 2012BAD04B08, 2011BAD16B14)
文摘A three-year experiment was conducted in the middle-lower reaches of the Yangtze River in China to study the influence of continuous wheat straw return during the rice season and continuous rice straw return in wheat on methane (CH 4 ) emissions from rice fields in which, the rice-wheat rotation system is the most dominant planting pattern. The field experiment was initiated in October 2009 and has continued since the wheat-growing season of that year. The analyses for the present study were conducted in the second (2011) and third (2012) rice growing seasons. Four treatments, namely, the continuous return of wheat straw and rice straw in every season (WR), of rice straw but no wheat straw return (R), of wheat straw but no rice straw return (W) and a control with no straw return (CK), were laid out in a randomized split-plot design. The total seasonal CH 4 emissions ranged from 107.4 to 491.7 kg/ha (2011) and 160.3 to 909.6 kg/ha (2012). The increase in CH 4 emissions for treatments WR and W were 289% and 230% in the second year and 185% and 225% in the third year, respectively, in relation to CK. We observed less methane emissions in the treatment R than in CK by 14%-43%, but not statistically significant. Treatment R could increase rice productivity while no more CH 4 emission occurs. The difference in the total CH 4 emissions mainly related to a difference in the methane flux rate during the first 30-35 days after transplant in the rice growing season, which was caused by the amount of dissolved oxygen in paddy water and the amount of reducible soil materials.
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 cortcentmdons. 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-eoncentration factor and the translocation factor of Cd in both cote 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the financial supports from the National Natural Science Foundation of China(51872036,51773025)Dalian Science and Technology Innovation Fund(2018J12GX033)National Key R&D Program of China(2017YFB0405604)
文摘Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous studies have shown that ions can migrate to form a conductive channel in perovskites under an external voltage. However, the exact resistance mechanism for Ag or halogens which dominate the resistive behavior is still controversial. Here, we demonstrate a resistive switching memory device based on Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/fluorine doped tin oxide (FTO). The migration of Ag cations and halide anions is demonstrated by energy dispersive X-ray spectroscopy (EDS) after the SET process (positive voltage on Ag). By comparing the I-V behavior of the Au-based devices, it is clear that the conductive channel formed by Ag is the main factor of the switching characteristics for Ag-based devices. Meanwhile, by controlling the appropriate SET voltage, two kinds of resistance characteristics of the analog switch and threshold switch can be realized in the Ag-based device. As a result, it may be possible to implement both data storage and neuromorphic computing in a single device.
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supported by the National Natural Science Foundation of China(Grant No.51704198)the Department of Science and Technology of Sichuan Province(No.2021YFH0030).
文摘Understanding the damage behavior and cracking mechanism of brittle shale is crucial for hydraulic fracturing design.In this research,uniaxial compression tests are conducted on shale samples with different bedding plane orientations,and acoustic emission monitoring is implemented synchronously.The results indicate that the apparent elastic modulus increases with increasing bedding orientation.For the bedding orienta-tions of 45°and 90°,the lateral deformation is anisotropic due to the bedding structure,revealing the anisotropic Poisson effect.A shear failure surface and tensile failure surfaces form parallel to the bedding plane for bedding orientations of 45°and 90°,respectively.For the bedding orientation of 0°,shear failure mainly occurs through the bedding planes.Additionally,the damage mechanism of shale is investigated by crack classification based on AE parameters.It is found that crack initiation is induced by the generation of shear cracks for the bedding orientation of 45°,whereas by the generation of tensile cracks for other bedding orientations.According to damage attributable to different type cracks,shear cracks dominate the damage behavior for bedding orientations of 0°and 45°,whereas tensile cracks dominate the damage behavior for bedding orientation of 90°.Finally,the information entropy is calculated by AE energy.A low value of information entropy,approximately 0.36,predicts failure with a low degree of instability for the bedding orientation of 0°,whereas a high value of information entropy,more than 1.5,predicts failure with a high degree of instability for other bedding orientations.This finding indicates that the failure behavior is gradual progressive damage for bedding orientation of 0°,whereas sudden damage dominates failure behavior for other bedding orientations.
基金Project supported by the Key R&D Program of Jiangxi Province(20192ACB70016)the National Natural Science Foundation of China(41771343)+1 种基金the 111 Project(B18060)the Sino-French Cai Yuanpei Programme(38896SC)。
文摘A number of studies have focused on the effects of rare earth elements(REEs) on crop plants,while little attention has been paid on how tolerant plant species respond to increasing mixed REE concentrations.In this study,ramie(Boehmeria nivea L.) was exposed to a series of REE concentrations prepared with equimolar mixtures of 16 REEs(i.e.0,1.6,8,16,80,160,400,800 μmol/L) in order to explore REE accumulation and fractionation characteristics in ramie and the responses of this plant to mixed REEs.Results show that ramie root and shoot biomasses are unaffected under lower REE concentrations(1.6-80 μmol/L),while the growth of ramie and the uptake of nutrients especially Ca and Mn are largely inhibited under higher REE concentrations(160-800 μmol/L).The P and Mo concentrations in the roots increase with the increasing REE concentrations in the solution,suggestive of an involvement of P and Mo in dealing with the high concentrations of REEs in this plant.The preferential uptake of Ce and heavy REEs(HREEs) and the preferential transport of HREEs within the plant lead to a positive Ce anomaly and a HREE enrichment in ramie leaves.Our study suggests that ramie could be a good candidate for the phyto re mediation of heavily REE-contaminated soils(e.g.,REE mine tailings in southern China).Our results also shed light on points of taking into account phytoremediation management strategies of REEcontaminated soils(e.g.,P and Mo fertilization).