To address the problem of high lifespan loss and poor state of charge(SOC)balance of electric vehicles(EVs)participating in grid peak shaving,an improved golden eagle optimizer(IGEO)algorithm for EV grouping control s...To address the problem of high lifespan loss and poor state of charge(SOC)balance of electric vehicles(EVs)participating in grid peak shaving,an improved golden eagle optimizer(IGEO)algorithm for EV grouping control strategy is proposed for peak shaving sce-narios.First,considering the difference between peak and valley loads and the operating costs of EVs,a peak shaving model for EVs is constructed.Second,the design of IGEO has improved the global exploration and local development capabilities of the golden eagle optimizer(GEO)algorithm.Subsequently,IGEO is used to solve the peak shaving model and obtain the overall EV grid connected charging and discharging instructions.Next,using the k-means algorithm,EVs are dynamically divided into priority charging groups,backup groups,and priority discharging groups based on SOC differences.Finally,a dual layer power distribution scheme for EVs is designed.The upper layer determines the charging and discharging sequences and instructions for the three groups of EVs,whereas the lower layer allocates the charging and discharging instructions for each group to each EV.The proposed strategy was simulated and verified,and the results showed that the designed IGEO had faster optimization speed and higher optimization accuracy.The pro-posed EV grouping control strategy effectively reduces the peak-valley difference in the power grid,reduces the operational life loss of EVs,and maintains a better SOC balance for EVs.展开更多
The late Paleozoic evolution of the Wulijishanhen（WSH）-Shangdan（SD） area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biologic...The late Paleozoic evolution of the Wulijishanhen（WSH）-Shangdan（SD） area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biological associations, detrital materials, sandstone geochemistry and volcanic rocks indicates that the SD area was an epicontinental sea and rift during the late Paleozoic rather than a large-scale ocean undergoing spreading and closure. This study reveals that the actual evolution of the study area is from the late Carboniferous to the early Permian. The fusulinids Triticites sp. and Pseudoschwagerina sp.in the limestones demonstrate that the Amushan Formation develops during the late Carboniferous to the early Permian. The limestones at the base of the SD section indicate that it is a stable carbonate platform environment, the volcanic rocks in the middle of the sequence support a rift tectonic background, and the overlying conglomerates and sandstones are characteristic of an epicontinental sea or marine molasse setting. The rift volcanism made the differences in the fossil content of the SD and WSH sections and led to two sections expose different levels within the Amushan Formation and different process of tectonic evolution. Moreover, the geochemical characteristics and detrital materials of the sandstones show that the provenance and formation of the sandstones were related to the setting of active continental margin. The quartz-feldspar-lithic fragments distribution diagram indicates that the material source for the sandstones was a recycled orogenic belt. Thus, the source area of the sandstones may have been an active continental margin before the late Carboniferouseearly Permian. The characteristics of the regional tectonic evolution of the area indicate that the region may form a small part of the Gobie Tianshan rift of southern Mongolia.展开更多
Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been inves...Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However. the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.展开更多
Bitter gourd(Momordica charantia)is a popular cultivated vegetable in Asian and African countries.To reveal the characteristics of the genomic structure,evolutionary trajectory,and genetic basis underlying the domesti...Bitter gourd(Momordica charantia)is a popular cultivated vegetable in Asian and African countries.To reveal the characteristics of the genomic structure,evolutionary trajectory,and genetic basis underlying the domestication of bitter gourd,we performed whole-genome sequencing of the cultivar Dali-11 and the wild small-fruited line TR and resequencing of 187 bitter gourd germplasms from 16 countries.The major gene clusters(Bi clusters)for the biosynthesis of cucurbitane triterpenoids,which confer a bitter taste,are highly conserved in cucumber,melon,and watermelon.Comparative analysis among cucurbit genomes revealed that the Bi cluster involved in cucurbitane triterpenoid biosynthesis is absent in bitter gourd.Phylogenetic analysis revealed that the TR group,including 21 bitter gourd germplasms,may belong to a new species or subspecies independent from M.charantia.Furthermore,we found that the remaining 166 M.charantia germplasms are geographically differentiated,and we identified 710,412,and 290 candidate domestication genes in the South Asia,Southeast Asia,and China populations,respectively.This study provides new insights into bitter gourd genetic diversity and domestication and will facilitate the future genomics-enabled improvement of bitter gourd.展开更多
The non-oxidative aromatization of mixed CH4 with C3H8 over La-promoted Zn/HZSM-5 catalysts was studied in a fixed-bed reactor at 823 K with space velocity 600 h^-1 and CH4/C3H8(mol ratio)=5:l.The propane conversion a...The non-oxidative aromatization of mixed CH4 with C3H8 over La-promoted Zn/HZSM-5 catalysts was studied in a fixed-bed reactor at 823 K with space velocity 600 h^-1 and CH4/C3H8(mol ratio)=5:l.The propane conversion and the aromatic selectivities were up to 99%and 60%over the catalyst respectively,while methane conversion had an induction period with the highest conversion of 30%.The structure and surface acidity of the catalysts were characterized by XRD,NH3-TPD and TG-DTA.The influences of reaction and regenerative conditions on the activity and selectivity were also investigated.展开更多
The effect of vanadium addition to Cu/γ-Al2O3 catalyst used in the hydrogenation of CO2 to produce methanol was studied. It was found that the catalytic performance of the Cu-based catalyst improved after V addition....The effect of vanadium addition to Cu/γ-Al2O3 catalyst used in the hydrogenation of CO2 to produce methanol was studied. It was found that the catalytic performance of the Cu-based catalyst improved after V addition. The influence of reaction temperature, space velocity and the molar ratio of H2 to CO2 on the performance of 12%Cu-6%V/γ-Al2O3 catalyst were also studied. The results indicated that the best conditions for reaction were as follows： 240 ℃, 3600 h^-1 and a molar ratio of H2 to 602 of 3：1. The results of XRD and TPR characterization demonstrated that the addition of V enhanced the dispersion of the supported CuO species, which resulted in the enhanced catalytic performance of Cu-V/γ-Al2O3 binary catalyst.展开更多
Catalytic performances of the CO2 reforming of toluene on Co/MgO catalysts with different cobalt loadings were evaluated in a fluidized-bed reactor. The results showed that the conversion of toluene and the stability ...Catalytic performances of the CO2 reforming of toluene on Co/MgO catalysts with different cobalt loadings were evaluated in a fluidized-bed reactor. The results showed that the conversion of toluene and the stability of Co/MgO increased, but the apparent reaction rate decreased at the initial stage with increasing the amount of metallic Co formed from the reduction of Co/MgO catalysts at 700 ~C. The deactivation of Co/MgO catalysts was mainly resulted from that a part of the metallic Co was oxidized by CO2 and could not be re-reduced by H2 at reaction temperature. Therefore, the excess metallic Co on the higher Co loading catalysts was beneficial to the catalyst stability.展开更多
Sponge gourd(Luffa cylindrica)is an important cultivated vegetable and medicinal plant in the family Cucurbitaceae.In this study,a draft genome sequence of the sponge gourd inbred line P93075 was analyzed.Using Illumi...Sponge gourd(Luffa cylindrica)is an important cultivated vegetable and medicinal plant in the family Cucurbitaceae.In this study,a draft genome sequence of the sponge gourd inbred line P93075 was analyzed.Using Illumina,PacBio,and 10×Genomics sequencing techniques as well as new assembly techniques such as FALCON and chromatin interaction mapping(Hi-C),a chromosome-scale genome of approximately 656.19 Mb,with an N50 scaffold length of 48.76 Mb,was generated.From this assembly,25,508 protein-coding gene loci were identified,and 63.81%of the whole-genome consisted of transposable elements,which are major contributors to the expansion of the sponge gourd genome.According to a phylogenetic analysis of conserved genes,the sponge gourd lineage diverged from the bitter gourd lineage approximately 41.6 million years ago.Additionally,many genes that respond to biotic and abiotic stresses were found to be lineage specific or expanded in the sponge gourd genome,as demonstrated by the presence of 462 NBS-LRR genes,a much greater number than are found in the genomes of other cucurbit species;these results are consistent with the high stress resistance of sponge gourd.Collectively,our study provides insights into genome evolution and serves as a valuable reference for the genetic improvement of sponge gourd.展开更多
CuO-CeO2 catalyst prepared with co-precipitation showed high catalytic performance for the preferential oxidation of CO in excess hydrogen（PROX）.Influence of pH values in the preparation of CuO-CeO2 on its catalytic...CuO-CeO2 catalyst prepared with co-precipitation showed high catalytic performance for the preferential oxidation of CO in excess hydrogen（PROX）.Influence of pH values in the preparation of CuO-CeO2 on its catalytic performance was investigated in this work.The CuO-CeO2 catalyst prepared at pH = 13.03 had the smallest particle size（5.4 nm）,the largest surface areas（138m 2/g） and the highest activity with CO conversion of 99.6% at 130 ℃.The CuO-CeO2 catalyst was characterized using BET,XRD and TPR techniques.The results showed that when the pH value of the mixed solution containing Cu and Ce species was properly adjusted,both the adsorption layers and diffusion layers of the formed colloidal particles in hydroxide precursor of CuO-CeO2 were modified,resulting in the better catalytic performance for PROX on the final CuO-CeO2 catalyst展开更多
In the present study, we have investigated the reducibility of CuO species on CuO-CeO2 catalysts and the influence of CuO species on the catalytic performance for CO preferential oxidation （CO PROX） in excess hydrog...In the present study, we have investigated the reducibility of CuO species on CuO-CeO2 catalysts and the influence of CuO species on the catalytic performance for CO preferential oxidation （CO PROX） in excess hydrogen. It is revealed that the smaller the difference of reduction temperature （denoted as ？T） for two adjacent CuO species is, the higher the catalytic activity of CuO-CeO2 for the PROX in excess hydrogen may be obtained. It means that if the reduction energy of Cu0-Cu2＋ pairs matched better, the reduction-oxidation recycle of Cu0-Cu2＋ pairs would go on more easily, then the transferring energy of Cu0-Cu2＋ pairs would be lesser. Therefore, the CuO-CeO2 catalysts will be largely improved in their catalytic performance if the different CuO species on the catalysts have matched the reduction energy, which would allows them to cooperate effectively.展开更多
Doping of different rare-earth metals （Pr, Nd, Y and La） had an evident influence on the catalytic performance of CuO-CeO2 for the preferential oxidation （PROX） of CO in excess hydrogen. As for Pr, the doping enha...Doping of different rare-earth metals （Pr, Nd, Y and La） had an evident influence on the catalytic performance of CuO-CeO2 for the preferential oxidation （PROX） of CO in excess hydrogen. As for Pr, the doping enhanced the catalytic activity of CuO-CeO2 for PROX. For example, the CO conversion over the above catalyst for PROX was higher than 99% at 120 °C. Especially, the doping of Pr widened the temperature window by 20 °C over CuO-CeO2 with 99% CO conversion. For Nd, Y, and La, the doping depressed the catalytic activity of CuO-CeO2 for PROX. However, the doping of transition metals markedly improved the selectivity of CuO-CeO2 for PROX.展开更多
The cycle life of oxygen carrier（OC） is crucial to the practical applications of chemical looping combustion（CLC）. Cycle performance of Cu/SiO2 prepared with a mechanical mixing method was evaluated based on a CLC...The cycle life of oxygen carrier（OC） is crucial to the practical applications of chemical looping combustion（CLC）. Cycle performance of Cu/SiO2 prepared with a mechanical mixing method was evaluated based on a CLC process characterized with an added methane steam reforming step. The Cu/SiO2 exhibited high redox reactivity in the initial cycles, while the performance degraded with cycle number. Through characterization of the degraded Cu/SiO2, the performance degradation was mainly caused by the secondary particles＇ fragmentation and the fine particles＇ local agglomeration, which worsened the distribution and diffusion of the reactive gases in the packed bed. A regeneration method of the degraded OC based on re-granulation has been proposed, and its mechanism has been illustrated. With this method, the performance of the degraded OC through 420 redox cycles was recovered to a level close to the initial one.展开更多
China is the largest rice-producing country,but the genomic landscape of rice diversity has not yet been clarified.In this study,we re-sequence 1070 rice varieties collected from China(400)and other regions in Asia(67...China is the largest rice-producing country,but the genomic landscape of rice diversity has not yet been clarified.In this study,we re-sequence 1070 rice varieties collected from China(400)and other regions in Asia(670).Among the six major rice groups(aus,indica-I,indica-II,aromatic,temperate japonica,and tropical japonica),almost all Chinese varieties belong to the indica-II or temperate japonica group.Most Chinese indica varieties belong to indica-II,which consists of two subgroups developed during different phases of rice breeding.The genomic segments underlying the differences between these subgroups span36.32 Mb.The Chinese japonica rice varieties fall into the temperate japonica group,consisting of two subgroups based on their geographical distribution.The genomic segments underlying the differences between these subgroups span 27.69 Mb.These differentiated segments in the Chinese indica varieties span 45 genes with nonsynonymous mutations that are closely related to variations in plant height and grain width.Fifty-four genes with nonsynonymous mutations are associated with the differences in heading date between the two Chinese japonica subgroups.These findings provide new insights into rice diversity in China that will facilitate the molecular breeding.展开更多
In the past decades there have been many breakthroughs in low-dimensional materials,especially in two-dimensional(2D)atomically thin crystals like graphene.As structural analogues of graphene but with a sizeable band ...In the past decades there have been many breakthroughs in low-dimensional materials,especially in two-dimensional(2D)atomically thin crystals like graphene.As structural analogues of graphene but with a sizeable band gap,monolayers of atomically thin transition metal dichalcogenides(with formula of MX2,M=Mo,W;X=S,Se,Te,etc.)have emerged as the ideal 2D prototypes for exploring fundamentals in physics such as valleytronics due to the quantum confinement effects,and for engineering a wide range of nanoelectronic,optoelectronic,and photocatalytic applications.Transition metal trioxides as promising materials with low evaporation temperature,high work function,and inertness to air have been widely used in the fabrication and modification of MX2.In this review,we reported the fabrications of one-dimensional MoS2 wrapped MoO2 single crystals with varied crystal direction via atmospheric pressure chemical vapor deposition method and of 2D MoOx covered MoX2 by means of exposing MoX2 to ultraviolet ozone.The prototype devices show good performances.The approaches are common to other transition metal dichalcogenides and transition metal oxides.展开更多
Development of highly effective catalysts for one-stage conversion of methane with high selectivity to valuable products and energy efficiency will provide an efficient way to utilize natural gas and oil-associated ga...Development of highly effective catalysts for one-stage conversion of methane with high selectivity to valuable products and energy efficiency will provide an efficient way to utilize natural gas and oil-associated gases and to protect environment. In recent years, there have been many efforts on direct catalytic transformations of methane into higher hydrocarbons by feeding additives together with methane under non-oxidative conditions. This paper reviewed the advances in recent research on non-oxidative aromatization of methane in the presence of propane over different modified HZSM-5 catalysts. The thermodynamic consideration, the isotope verification and the mechanism of the activation of methane in the presence of propane are discussed in the paper in detail.展开更多
Xizang,previously known as Xizang,is located in the southwest region of China and is the highest region of the Qinghai-Tibet Plateau(QzP),with an average altitude of over 4000 m.With the development of modern agricult...Xizang,previously known as Xizang,is located in the southwest region of China and is the highest region of the Qinghai-Tibet Plateau(QzP),with an average altitude of over 4000 m.With the development of modern agriculture,the grain productivity in Xizang has been effectively improved.The total annual grain production has increased from 558,700 tons in 1988 to 1044,000 tons in 2018(Xizang Statistical Year Book).展开更多
As drastic climatic changes significantly impact global agricul-ture,the importance of conserving and utilizing wild germplasm has gained prominence.In this context,the conservation and sustainable utilization of wild...As drastic climatic changes significantly impact global agricul-ture,the importance of conserving and utilizing wild germplasm has gained prominence.In this context,the conservation and sustainable utilization of wild rice germplasm resources have become a high priority.Although efforts to conserve and sustain-ably utilize wild rice germplasm are underway globally,they are fragmented and require international cooperation to advance climate-resilient rice breeding and ensure future food security.展开更多
基金supported by the National Natural Science Foundation of China(52077078)China Southern Power Grid Company Limited 036000KK52220004(GDKJXM20220147).
文摘To address the problem of high lifespan loss and poor state of charge(SOC)balance of electric vehicles(EVs)participating in grid peak shaving,an improved golden eagle optimizer(IGEO)algorithm for EV grouping control strategy is proposed for peak shaving sce-narios.First,considering the difference between peak and valley loads and the operating costs of EVs,a peak shaving model for EVs is constructed.Second,the design of IGEO has improved the global exploration and local development capabilities of the golden eagle optimizer(GEO)algorithm.Subsequently,IGEO is used to solve the peak shaving model and obtain the overall EV grid connected charging and discharging instructions.Next,using the k-means algorithm,EVs are dynamically divided into priority charging groups,backup groups,and priority discharging groups based on SOC differences.Finally,a dual layer power distribution scheme for EVs is designed.The upper layer determines the charging and discharging sequences and instructions for the three groups of EVs,whereas the lower layer allocates the charging and discharging instructions for each group to each EV.The proposed strategy was simulated and verified,and the results showed that the designed IGEO had faster optimization speed and higher optimization accuracy.The pro-posed EV grouping control strategy effectively reduces the peak-valley difference in the power grid,reduces the operational life loss of EVs,and maintains a better SOC balance for EVs.
基金financially supported by the China Geological Survey (Grant No. [2010] 01-09-11)
文摘The late Paleozoic evolution of the Wulijishanhen（WSH）-Shangdan（SD） area near to the Chaganchulu Ophiolite belt is reinterpreted. Analysis of the upper Carboniferous to lower Permian sedimentary sequence, biological associations, detrital materials, sandstone geochemistry and volcanic rocks indicates that the SD area was an epicontinental sea and rift during the late Paleozoic rather than a large-scale ocean undergoing spreading and closure. This study reveals that the actual evolution of the study area is from the late Carboniferous to the early Permian. The fusulinids Triticites sp. and Pseudoschwagerina sp.in the limestones demonstrate that the Amushan Formation develops during the late Carboniferous to the early Permian. The limestones at the base of the SD section indicate that it is a stable carbonate platform environment, the volcanic rocks in the middle of the sequence support a rift tectonic background, and the overlying conglomerates and sandstones are characteristic of an epicontinental sea or marine molasse setting. The rift volcanism made the differences in the fossil content of the SD and WSH sections and led to two sections expose different levels within the Amushan Formation and different process of tectonic evolution. Moreover, the geochemical characteristics and detrital materials of the sandstones show that the provenance and formation of the sandstones were related to the setting of active continental margin. The quartz-feldspar-lithic fragments distribution diagram indicates that the material source for the sandstones was a recycled orogenic belt. Thus, the source area of the sandstones may have been an active continental margin before the late Carboniferouseearly Permian. The characteristics of the regional tectonic evolution of the area indicate that the region may form a small part of the Gobie Tianshan rift of southern Mongolia.
文摘Influence of three different preparation methods, i.e. impregnation, coprecipitation, and inverse coprecipitation, on the preferential oxidation of CO in excess hydrogen （PROX） over CuO-CeO2 catalysts has been investigated and CuO-CeO2 catalysts are characterized using BET, XPS, XRD, UV Raman, and TPR techniques. The results show that the catalysts prepared by coprecipitation have smaller particle sizes, well-dispersed CuOx species, more oxygen vacancies, and are more active in the PROX than those prepared by the other methods. However. the inverse coprecipitation depresses the catalytic performance of CuO-CeO2 catalysts and causes the growth of CuO-CeO2 because of different pH value in the precipitation process.
文摘Bitter gourd(Momordica charantia)is a popular cultivated vegetable in Asian and African countries.To reveal the characteristics of the genomic structure,evolutionary trajectory,and genetic basis underlying the domestication of bitter gourd,we performed whole-genome sequencing of the cultivar Dali-11 and the wild small-fruited line TR and resequencing of 187 bitter gourd germplasms from 16 countries.The major gene clusters(Bi clusters)for the biosynthesis of cucurbitane triterpenoids,which confer a bitter taste,are highly conserved in cucumber,melon,and watermelon.Comparative analysis among cucurbit genomes revealed that the Bi cluster involved in cucurbitane triterpenoid biosynthesis is absent in bitter gourd.Phylogenetic analysis revealed that the TR group,including 21 bitter gourd germplasms,may belong to a new species or subspecies independent from M.charantia.Furthermore,we found that the remaining 166 M.charantia germplasms are geographically differentiated,and we identified 710,412,and 290 candidate domestication genes in the South Asia,Southeast Asia,and China populations,respectively.This study provides new insights into bitter gourd genetic diversity and domestication and will facilitate the future genomics-enabled improvement of bitter gourd.
基金This work is supported by the National Science Foundation of China(Grant Nos 2034300220433030)and PetroChina.
文摘The non-oxidative aromatization of mixed CH4 with C3H8 over La-promoted Zn/HZSM-5 catalysts was studied in a fixed-bed reactor at 823 K with space velocity 600 h^-1 and CH4/C3H8(mol ratio)=5:l.The propane conversion and the aromatic selectivities were up to 99%and 60%over the catalyst respectively,while methane conversion had an induction period with the highest conversion of 30%.The structure and surface acidity of the catalysts were characterized by XRD,NH3-TPD and TG-DTA.The influences of reaction and regenerative conditions on the activity and selectivity were also investigated.
基金This work is supported by the Natural Science Foundation of Zhejiang Province (No. 405088)
文摘The effect of vanadium addition to Cu/γ-Al2O3 catalyst used in the hydrogenation of CO2 to produce methanol was studied. It was found that the catalytic performance of the Cu-based catalyst improved after V addition. The influence of reaction temperature, space velocity and the molar ratio of H2 to CO2 on the performance of 12%Cu-6%V/γ-Al2O3 catalyst were also studied. The results indicated that the best conditions for reaction were as follows： 240 ℃, 3600 h^-1 and a molar ratio of H2 to 602 of 3：1. The results of XRD and TPR characterization demonstrated that the addition of V enhanced the dispersion of the supported CuO species, which resulted in the enhanced catalytic performance of Cu-V/γ-Al2O3 binary catalyst.
基金supported by the National Basic Research Program of China(2013CB228104)the Hi-Tech Research and Development Program of China(2007AA05Z415)
文摘Catalytic performances of the CO2 reforming of toluene on Co/MgO catalysts with different cobalt loadings were evaluated in a fluidized-bed reactor. The results showed that the conversion of toluene and the stability of Co/MgO increased, but the apparent reaction rate decreased at the initial stage with increasing the amount of metallic Co formed from the reduction of Co/MgO catalysts at 700 ~C. The deactivation of Co/MgO catalysts was mainly resulted from that a part of the metallic Co was oxidized by CO2 and could not be re-reduced by H2 at reaction temperature. Therefore, the excess metallic Co on the higher Co loading catalysts was beneficial to the catalyst stability.
基金funded by the National Natural Science Foundation of China(31872093,31401865,31902011)the Science and Technology Program of Guangdong Province(2018B020202007,2019KJ110,2019A050507003,2019A050520002,2019A1515010723),the Science and Technology Program of Guangzhou of China(201807010033)the National Modern Agricultural Technology System Construction Project(CARS-25-G-36).
文摘Sponge gourd(Luffa cylindrica)is an important cultivated vegetable and medicinal plant in the family Cucurbitaceae.In this study,a draft genome sequence of the sponge gourd inbred line P93075 was analyzed.Using Illumina,PacBio,and 10×Genomics sequencing techniques as well as new assembly techniques such as FALCON and chromatin interaction mapping(Hi-C),a chromosome-scale genome of approximately 656.19 Mb,with an N50 scaffold length of 48.76 Mb,was generated.From this assembly,25,508 protein-coding gene loci were identified,and 63.81%of the whole-genome consisted of transposable elements,which are major contributors to the expansion of the sponge gourd genome.According to a phylogenetic analysis of conserved genes,the sponge gourd lineage diverged from the bitter gourd lineage approximately 41.6 million years ago.Additionally,many genes that respond to biotic and abiotic stresses were found to be lineage specific or expanded in the sponge gourd genome,as demonstrated by the presence of 462 NBS-LRR genes,a much greater number than are found in the genomes of other cucurbit species;these results are consistent with the high stress resistance of sponge gourd.Collectively,our study provides insights into genome evolution and serves as a valuable reference for the genetic improvement of sponge gourd.
基金supported by the Heavy Oil National Key Laboratory (No.2008-03)the Ministry of Science and Technology of China (No.2004 CB719504)the Starting Foundation of Hunan University
文摘CuO-CeO2 catalyst prepared with co-precipitation showed high catalytic performance for the preferential oxidation of CO in excess hydrogen（PROX）.Influence of pH values in the preparation of CuO-CeO2 on its catalytic performance was investigated in this work.The CuO-CeO2 catalyst prepared at pH = 13.03 had the smallest particle size（5.4 nm）,the largest surface areas（138m 2/g） and the highest activity with CO conversion of 99.6% at 130 ℃.The CuO-CeO2 catalyst was characterized using BET,XRD and TPR techniques.The results showed that when the pH value of the mixed solution containing Cu and Ce species was properly adjusted,both the adsorption layers and diffusion layers of the formed colloidal particles in hydroxide precursor of CuO-CeO2 were modified,resulting in the better catalytic performance for PROX on the final CuO-CeO2 catalyst
基金supported by the State Key Laboratory of Heavy Oil Processing (No. 200803)the Ministry of Science and Technology of China (No.2005CB221406)
文摘In the present study, we have investigated the reducibility of CuO species on CuO-CeO2 catalysts and the influence of CuO species on the catalytic performance for CO preferential oxidation （CO PROX） in excess hydrogen. It is revealed that the smaller the difference of reduction temperature （denoted as ？T） for two adjacent CuO species is, the higher the catalytic activity of CuO-CeO2 for the PROX in excess hydrogen may be obtained. It means that if the reduction energy of Cu0-Cu2＋ pairs matched better, the reduction-oxidation recycle of Cu0-Cu2＋ pairs would go on more easily, then the transferring energy of Cu0-Cu2＋ pairs would be lesser. Therefore, the CuO-CeO2 catalysts will be largely improved in their catalytic performance if the different CuO species on the catalysts have matched the reduction energy, which would allows them to cooperate effectively.
基金the National Basic Research Program of China (973 program, No. 2004 CB 7195040)
文摘Doping of different rare-earth metals （Pr, Nd, Y and La） had an evident influence on the catalytic performance of CuO-CeO2 for the preferential oxidation （PROX） of CO in excess hydrogen. As for Pr, the doping enhanced the catalytic activity of CuO-CeO2 for PROX. For example, the CO conversion over the above catalyst for PROX was higher than 99% at 120 °C. Especially, the doping of Pr widened the temperature window by 20 °C over CuO-CeO2 with 99% CO conversion. For Nd, Y, and La, the doping depressed the catalytic activity of CuO-CeO2 for PROX. However, the doping of transition metals markedly improved the selectivity of CuO-CeO2 for PROX.
基金supported by the Beijing Science and Technology Program(Grant no.Z131100005613045)the National Natural Science Foundation of China(Grant no.51306015)the Fundamental Research Funds for the Central Universities(Grant no.FRF-SD-12-013A)
文摘The cycle life of oxygen carrier（OC） is crucial to the practical applications of chemical looping combustion（CLC）. Cycle performance of Cu/SiO2 prepared with a mechanical mixing method was evaluated based on a CLC process characterized with an added methane steam reforming step. The Cu/SiO2 exhibited high redox reactivity in the initial cycles, while the performance degraded with cycle number. Through characterization of the degraded Cu/SiO2, the performance degradation was mainly caused by the secondary particles＇ fragmentation and the fine particles＇ local agglomeration, which worsened the distribution and diffusion of the reactive gases in the packed bed. A regeneration method of the degraded OC based on re-granulation has been proposed, and its mechanism has been illustrated. With this method, the performance of the degraded OC through 420 redox cycles was recovered to a level close to the initial one.
基金supported by the National Key Research and Development Program of China(2016YFD0100301 to Z.X.M.)the National Natural Science Foundation of China(31670211 and31970237 to Z.X.M.)+3 种基金Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-001 to Z.X.M.)the Central Public-interest Scientific Institution Basal Research Fund(S2021ZD01 to Z.X.M.)the Major Incubation Project of Shenyang Normal University(ZD20210 to P.H.B.)the Hundred Talent Program of Shenyang Normal University(SSDBRJH2002012 to P.H.B.)。
文摘China is the largest rice-producing country,but the genomic landscape of rice diversity has not yet been clarified.In this study,we re-sequence 1070 rice varieties collected from China(400)and other regions in Asia(670).Among the six major rice groups(aus,indica-I,indica-II,aromatic,temperate japonica,and tropical japonica),almost all Chinese varieties belong to the indica-II or temperate japonica group.Most Chinese indica varieties belong to indica-II,which consists of two subgroups developed during different phases of rice breeding.The genomic segments underlying the differences between these subgroups span36.32 Mb.The Chinese japonica rice varieties fall into the temperate japonica group,consisting of two subgroups based on their geographical distribution.The genomic segments underlying the differences between these subgroups span 27.69 Mb.These differentiated segments in the Chinese indica varieties span 45 genes with nonsynonymous mutations that are closely related to variations in plant height and grain width.Fifty-four genes with nonsynonymous mutations are associated with the differences in heading date between the two Chinese japonica subgroups.These findings provide new insights into rice diversity in China that will facilitate the molecular breeding.
基金Project supported by the National Natural Science Foundation of China(Grant No.11874427)the National Science Foundation DMR-1903962the Fundamental Research Funds for the Central Universities of Central South University(Grant No.2019zzts429).
文摘In the past decades there have been many breakthroughs in low-dimensional materials,especially in two-dimensional(2D)atomically thin crystals like graphene.As structural analogues of graphene but with a sizeable band gap,monolayers of atomically thin transition metal dichalcogenides(with formula of MX2,M=Mo,W;X=S,Se,Te,etc.)have emerged as the ideal 2D prototypes for exploring fundamentals in physics such as valleytronics due to the quantum confinement effects,and for engineering a wide range of nanoelectronic,optoelectronic,and photocatalytic applications.Transition metal trioxides as promising materials with low evaporation temperature,high work function,and inertness to air have been widely used in the fabrication and modification of MX2.In this review,we reported the fabrications of one-dimensional MoS2 wrapped MoO2 single crystals with varied crystal direction via atmospheric pressure chemical vapor deposition method and of 2D MoOx covered MoX2 by means of exposing MoX2 to ultraviolet ozone.The prototype devices show good performances.The approaches are common to other transition metal dichalcogenides and transition metal oxides.
文摘Development of highly effective catalysts for one-stage conversion of methane with high selectivity to valuable products and energy efficiency will provide an efficient way to utilize natural gas and oil-associated gases and to protect environment. In recent years, there have been many efforts on direct catalytic transformations of methane into higher hydrocarbons by feeding additives together with methane under non-oxidative conditions. This paper reviewed the advances in recent research on non-oxidative aromatization of methane in the presence of propane over different modified HZSM-5 catalysts. The thermodynamic consideration, the isotope verification and the mechanism of the activation of methane in the presence of propane are discussed in the paper in detail.
基金funded by the Heilongjiang Key Research and Development Program(2022ZX02B03)the Talent Program of Xizang Department of Science and Technology(2020Wz002)+1 种基金Science and Technology Service Network Initiative,Chengdu Branch,Chinese Academy of Sciences(KFJ-STS-QYZD-2021-22-005)the 2nd Tibetan Plateau Scientific Expedition Program(2019QZKK0502030402).
文摘Xizang,previously known as Xizang,is located in the southwest region of China and is the highest region of the Qinghai-Tibet Plateau(QzP),with an average altitude of over 4000 m.With the development of modern agriculture,the grain productivity in Xizang has been effectively improved.The total annual grain production has increased from 558,700 tons in 1988 to 1044,000 tons in 2018(Xizang Statistical Year Book).
基金supported by the Project of Hainan Province Science and Technology Special Fund(ZDYF2022XDNY260)the Nanfan special project,CAAS(YBXM2404 and YBXM2403)+4 种基金the Project of Sanya Yazhouwan Science and Technology City(SCKJ-JYRC-2023-47 and SKJC-2023-02-001)the National Natural Science Foundation of China(32261143465 and 32350710198)National Key Research and Development Program of China(2021YFD1200101)the Project of Hainan Province Nature and Science Fund(2021JJLH0075)the Project of Hainan Province Science and Technology Innovation(KJRC2023A01)the Hainan Province International Scientific and Technological Cooperation Talent and Exchange Project(Foreign Expert Program)Plan(G20241024007E).
文摘As drastic climatic changes significantly impact global agricul-ture,the importance of conserving and utilizing wild germplasm has gained prominence.In this context,the conservation and sustainable utilization of wild rice germplasm resources have become a high priority.Although efforts to conserve and sustain-ably utilize wild rice germplasm are underway globally,they are fragmented and require international cooperation to advance climate-resilient rice breeding and ensure future food security.
