Using gradually regression analysis to establish the driving force model of utilized change of cultivated land in Gonghe County, and using path analysis, correlation analysis, partial correlation analysis and system d...Using gradually regression analysis to establish the driving force model of utilized change of cultivated land in Gonghe County, and using path analysis, correlation analysis, partial correlation analysis and system dynamics method to inspect the effect of driving changing on cultivated land change under different change situations. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed from the county territory scale level. At last, some corresponding policies and measures were put forward.展开更多
Using path analysis, correlation analysis, partial correlation analysis and system dynamics method to study the driving force of cultivated land in Qinghai Lake Area, and using gradually regression analysis to establi...Using path analysis, correlation analysis, partial correlation analysis and system dynamics method to study the driving force of cultivated land in Qinghai Lake Area, and using gradually regression analysis to establish the driving force model of utilized change of cultivated land. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed, and the differences during all factors were compared. The study provides some decision basis for sustainable utilization and management of land resources in Qinghai Lake Area.展开更多
report the circulation of a novel MERS-like coronavirus in Malayan pangolins, named Manis javanica HKU4-relatedcoronavirus (MjHKU4r-CoV). Among 86 animals, four tested positive by pan-CoV PCR, and seven tested seropos...report the circulation of a novel MERS-like coronavirus in Malayan pangolins, named Manis javanica HKU4-relatedcoronavirus (MjHKU4r-CoV). Among 86 animals, four tested positive by pan-CoV PCR, and seven tested seropositive (11 and12.8%). Four nearly identical (99.9%) genome sequences were obtained, and one virus was isolated (MjHKU4r-CoV-1). Thisvirus utilizes human dipeptidyl peptidase-4 (hDPP4) as a receptor and host proteases for cell infection, which is enhanced by afurin cleavage site that is absent in all known bat HKU4r-CoVs. The MjHKU4r-CoV-1 spike shows higher binding affinity forhDPP4, and MjHKU4r-CoV-1 has a wider host range than bat HKU4-CoV. MjHKU4r-CoV-1 is infectious and pathogenic inhuman airways and intestinal organs and in hDPP4-transgenic mice. Our study highlights the importance of pangolins as reservoirhosts of coronaviruses poised for human disease emergence.展开更多
The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of "...The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of " Two high and one early",which means high biomass and high efficiency of light energy conversion, as wellas fast growing in the early growth stage. The agronomic characters of 15 U. S展开更多
In 2022,China’ s actual utilized foreign capital reached a historical high.According to the data released by the State Council Information Office,China’s actual use of foreign capital continued to increase in 2022,r...In 2022,China’ s actual utilized foreign capital reached a historical high.According to the data released by the State Council Information Office,China’s actual use of foreign capital continued to increase in 2022,reaching RMB 1.2trillion,which is a new high historically.展开更多
In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is ...In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is about 2 million. In China as a whole, more than 20 million people enjoy eating food prepared according to Islamic guidelines, known as hal'al food.展开更多
It is unknown whether pangolins,the most trafficked mammals,play a role in the zoonotic transmission of bat coronaviruses.We report the circulation of a novel MERS-like coronavirus in Malayan pangolins,named Manis jav...It is unknown whether pangolins,the most trafficked mammals,play a role in the zoonotic transmission of bat coronaviruses.We report the circulation of a novel MERS-like coronavirus in Malayan pangolins,named Manis javanica HKU4-related coronavirus(MjHKU4r-CoV).Among 86 animals,four tested positive by pan-CoV PCR,and seven tested seropositive(11 and 12.8%).展开更多
Equilibrium moisture contents (EMC) of wood species are very necessary in the utilization of these in service. This study investigated the EMC of five lesser utilized species of Ghana and compared it with that of thre...Equilibrium moisture contents (EMC) of wood species are very necessary in the utilization of these in service. This study investigated the EMC of five lesser utilized species of Ghana and compared it with that of three European species. Sixteen randomly sampled specimens of each of the eight species (heartwood and sapwood) with dimensions 3 cm × 3 cm × 3 cm were exposed at various relative humidity conditions of 30%, 45%, 60%, 75% and 90% in a temperature and humidity-controlled climate chamber at a temperature of 25°C in accordance to German standard DIN 52182. The species are Albies alba, Fagus sylvatica and Picea abies which are European species and Amphimas pterocarpoides, Antiaris toxicaria, Canarium schweinfurthii, Celtis zenkeri and Cola gigantea are wood species from Ghana. Internal wood temperature and humidity were measured with datalogger. Samples were considered to have reached equilibrium at any given humidity when the daily weight changes were less than 0.1 mg according to German standard DIN 52183. After the last measurements of the weight changes, the samples were dried at 103°C until there was a constant weight. The five tropical hardwoods had low sorption values recorded and high sorption values for the European species and this could be attributed to differences in the microstructure of these woods.展开更多
1.Introduction As the central organelle in the eukaryotic secretory pathway,the endoplasmic reticulum(ER)mediates cellular processes that include calcium homeostasis and protein processing[1,2].The infection of plants...1.Introduction As the central organelle in the eukaryotic secretory pathway,the endoplasmic reticulum(ER)mediates cellular processes that include calcium homeostasis and protein processing[1,2].The infection of plants by pathogens can induce ER stress and trigger the unfolded protein response(UPR).The UPR is a conserved protective signaling pathway that leads to programmed cell death(PCD)under extreme conditions[3–5],which can harm or benefit pathogens,depending on the timing and mode of cell death,and on whether the pathogen has physiologically adapted to benefit from the dying tissue[6].The biosynthesis and proper function of plant pattern recognition receptors(PRRs),which perceive pathogen-or microbe-associated molecular patterns(PAMPs or MAMPs)at the cell surface,also rely on N-glycosylation and the ER quality-control(ERQC)system[7–9].However,pathogens have evolved the capacity utilizing effectors to bind to the host ER stress pathway and manipulate it to their advantage during infection.展开更多
This paper aims to explore comprehensive utilization way of discarded fresh tobacco leaf. Based on modern tobacco demands on green,environmental protection and sustainable development,as well as actual situation of bi...This paper aims to explore comprehensive utilization way of discarded fresh tobacco leaf. Based on modern tobacco demands on green,environmental protection and sustainable development,as well as actual situation of biogas production facility in some villages of local tobacco area,this paper selects Longwan Village of Fengshiyan Town as the experimental site and explores the rational way of discarded fresh tobacco leaf biogas fermentation. Results show that cutting and fermentation of discarded fresh tobacco leaf before adding into biogas digester is conductive to improving p H in fermentation process,reducing crust amount,and effectively improving biogas production amount and rate. The study can provide reference for effective processing and rational utilization of discarded fresh tobacco leaf.展开更多
Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the bi...Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.展开更多
CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development o...CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.展开更多
The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon cap...A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.展开更多
Switched-capacitor/flying capacitor(FC)based multilevel converters have been gaining higher attention for their voltage-boosting ability.This feature makes them an attractive solution for renewable energy systems,such...Switched-capacitor/flying capacitor(FC)based multilevel converters have been gaining higher attention for their voltage-boosting ability.This feature makes them an attractive solution for renewable energy systems,such as low-voltage input photovoltaic power systems and electric vehicle systems.However,they usually require more high voltage rating switches and flying capacitors along with boosting capability.Furthermore,they suffer from high pulse currents at the switching transients.Aiming to solve these issues,this article proposes a new self-balancing three-phase five-level inverter based on the switched-capacitor(5L-SCTPNPC),which reduces the dc voltage requirement.The number of active switches is relatively smaller and seven active switches are required per phase.Especially,a soft-charging circuit for FC is designed to limit the impulse charging current.Compared to conventional multilevel inverters,the proposed five-level inverter reduces dc bus voltage by 50%.Significantly,the voltage stress of FC and the switches in parallel with FC are all reduced by 50%in comparison with some existing similar boosting five-level active-neutral-point-clamped(5L-BANPC)inverters.The operating principles,modulation strategy,and the design of the FC and charging inductor are provided in detailly.A comprehensive comparison study has been made to highlight the merits of the proposed inverter.Finally,the simulations and experiments validate the feasibility of the proposed topology.展开更多
BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Resear...BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.展开更多
Oxygen(O_(2))is essential for life support and rocket propulsion in Mars exploration missions,and in situ oxygen production from the Martian atmosphere is of profound scientific and engineering significance.In this ar...Oxygen(O_(2))is essential for life support and rocket propulsion in Mars exploration missions,and in situ oxygen production from the Martian atmosphere is of profound scientific and engineering significance.In this article,we propose a novel method for O_(2) production from the Martian atmosphere by using glow discharge ionization combined with a self-developed oxygen-permeable membrane(OPM).Experiments under simulated Martian atmospheric conditions examined parameter impacts on the O_(2) production rate and assessed the operating characteristics and glow discharge plasma tolerance of the OPM.Results indicate that(1)the proportion of O_(2) produced positively correlates with the ionization voltage under fixed discharge electrode spacing,pressure,and flow rate,reaching a maximum of 8.18%(saturating at 4600–5400 V);(2)O_(2) yield rises with the carbon dioxide(CO_(2))flow rate at a constant pressure,with the maximum value reaching 0.5 g/h;(3)titanium(Ti)and molybdenum(Mo)electrodes exhibit higher application potential under high voltage conditions;(4)the OPM operates at temperatures above 800℃ and shows few changes in the main body sections after 24 h of plasma tolerance testing.This study lays the foundation for future development of a mature Mars oxygen production prototype with lower energy consumption and higher efficiency.展开更多
Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biolo...Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.展开更多
The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps...The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps conducted under harsh reaction conditions.Herein,we report a cyclic catalytic process for the production of NH_(3) by directly utilizing earth-abundant CH_(4) as a hydrogen source for N_(2) hydrogenation while simultaneously co-producing H_(2) over an alumina-supported iron catalyst(Fe/Al_(2)O_(3)).It achieves exceptional productivities of 2300μmol g^(-1)h^(-1)for NH_(3) and 400 mmol g^(-1)h^(-1)for H_(2) at700℃.By eliminating the coke that results from CH_(4) pyrolysis through a reaction with the greenhouse gas CO_(2) to produce valuable CO,we establish an atom-economic cyclic catalytic process while producing a CO stream intrinsically separated in the regeneration step.Mechanistic investigations indicate that the iron species in Fe/Al_(2) O_(3) serve as tri-functional active sites for CH_(4) pyrolysis,N_(2) hydrogenation,and coke elimination to produce CO,thus enabling an efficient and environmentally friendly cyclic catalytic process.展开更多
基金Supported by the National Social Science Fund(06XMZ014)~~
文摘Using gradually regression analysis to establish the driving force model of utilized change of cultivated land in Gonghe County, and using path analysis, correlation analysis, partial correlation analysis and system dynamics method to inspect the effect of driving changing on cultivated land change under different change situations. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed from the county territory scale level. At last, some corresponding policies and measures were put forward.
基金Supported by The Regional Sustainable Development of the Qing-TibetPlateau(2004)~~
文摘Using path analysis, correlation analysis, partial correlation analysis and system dynamics method to study the driving force of cultivated land in Qinghai Lake Area, and using gradually regression analysis to establish the driving force model of utilized change of cultivated land. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed, and the differences during all factors were compared. The study provides some decision basis for sustainable utilization and management of land resources in Qinghai Lake Area.
文摘report the circulation of a novel MERS-like coronavirus in Malayan pangolins, named Manis javanica HKU4-relatedcoronavirus (MjHKU4r-CoV). Among 86 animals, four tested positive by pan-CoV PCR, and seven tested seropositive (11 and12.8%). Four nearly identical (99.9%) genome sequences were obtained, and one virus was isolated (MjHKU4r-CoV-1). Thisvirus utilizes human dipeptidyl peptidase-4 (hDPP4) as a receptor and host proteases for cell infection, which is enhanced by afurin cleavage site that is absent in all known bat HKU4r-CoVs. The MjHKU4r-CoV-1 spike shows higher binding affinity forhDPP4, and MjHKU4r-CoV-1 has a wider host range than bat HKU4-CoV. MjHKU4r-CoV-1 is infectious and pathogenic inhuman airways and intestinal organs and in hDPP4-transgenic mice. Our study highlights the importance of pangolins as reservoirhosts of coronaviruses poised for human disease emergence.
文摘The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of " Two high and one early",which means high biomass and high efficiency of light energy conversion, as wellas fast growing in the early growth stage. The agronomic characters of 15 U. S
文摘In 2022,China’ s actual utilized foreign capital reached a historical high.According to the data released by the State Council Information Office,China’s actual use of foreign capital continued to increase in 2022,reaching RMB 1.2trillion,which is a new high historically.
文摘In China, 10 ethnic minorities with a combined population of over 20 million people are followers of Islam. In Ningxia Hui Autonomous Region, the population is nearly 6 million, a-mong which the Islamic population is about 2 million. In China as a whole, more than 20 million people enjoy eating food prepared according to Islamic guidelines, known as hal'al food.
文摘It is unknown whether pangolins,the most trafficked mammals,play a role in the zoonotic transmission of bat coronaviruses.We report the circulation of a novel MERS-like coronavirus in Malayan pangolins,named Manis javanica HKU4-related coronavirus(MjHKU4r-CoV).Among 86 animals,four tested positive by pan-CoV PCR,and seven tested seropositive(11 and 12.8%).
文摘Equilibrium moisture contents (EMC) of wood species are very necessary in the utilization of these in service. This study investigated the EMC of five lesser utilized species of Ghana and compared it with that of three European species. Sixteen randomly sampled specimens of each of the eight species (heartwood and sapwood) with dimensions 3 cm × 3 cm × 3 cm were exposed at various relative humidity conditions of 30%, 45%, 60%, 75% and 90% in a temperature and humidity-controlled climate chamber at a temperature of 25°C in accordance to German standard DIN 52182. The species are Albies alba, Fagus sylvatica and Picea abies which are European species and Amphimas pterocarpoides, Antiaris toxicaria, Canarium schweinfurthii, Celtis zenkeri and Cola gigantea are wood species from Ghana. Internal wood temperature and humidity were measured with datalogger. Samples were considered to have reached equilibrium at any given humidity when the daily weight changes were less than 0.1 mg according to German standard DIN 52183. After the last measurements of the weight changes, the samples were dried at 103°C until there was a constant weight. The five tropical hardwoods had low sorption values recorded and high sorption values for the European species and this could be attributed to differences in the microstructure of these woods.
基金This work was supported by the National Natural Science Foundation of China(31430073,31721004,and 31801715)the Natural Science Foundation of Jiangsu Province,China(BK20180518)the Fundamental Research Funds for the Central Universities,China(KJQN201913).
文摘1.Introduction As the central organelle in the eukaryotic secretory pathway,the endoplasmic reticulum(ER)mediates cellular processes that include calcium homeostasis and protein processing[1,2].The infection of plants by pathogens can induce ER stress and trigger the unfolded protein response(UPR).The UPR is a conserved protective signaling pathway that leads to programmed cell death(PCD)under extreme conditions[3–5],which can harm or benefit pathogens,depending on the timing and mode of cell death,and on whether the pathogen has physiologically adapted to benefit from the dying tissue[6].The biosynthesis and proper function of plant pattern recognition receptors(PRRs),which perceive pathogen-or microbe-associated molecular patterns(PAMPs or MAMPs)at the cell surface,also rely on N-glycosylation and the ER quality-control(ERQC)system[7–9].However,pathogens have evolved the capacity utilizing effectors to bind to the host ER stress pathway and manipulate it to their advantage during infection.
文摘This paper aims to explore comprehensive utilization way of discarded fresh tobacco leaf. Based on modern tobacco demands on green,environmental protection and sustainable development,as well as actual situation of biogas production facility in some villages of local tobacco area,this paper selects Longwan Village of Fengshiyan Town as the experimental site and explores the rational way of discarded fresh tobacco leaf biogas fermentation. Results show that cutting and fermentation of discarded fresh tobacco leaf before adding into biogas digester is conductive to improving p H in fermentation process,reducing crust amount,and effectively improving biogas production amount and rate. The study can provide reference for effective processing and rational utilization of discarded fresh tobacco leaf.
基金supported by CARS(CARS-21),the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-032)the Science and Technology Department of Xizang(XZ202401ZY0020)+2 种基金the Science and Technology Department of Sichuan Province(2023YFH0044,2023YFH0018)the Sichuan Province Science Foundation for Distinguished Young Scholars(2022JDJQ0006)the Doctoral Fund of Southwest University of Science and Technology(19ZX7117,21ZX7116).
文摘Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.
基金Supported by National Key R&D Program of China(2025YFE0109700)the National Natural Science Foundation of China(52106150)。
文摘CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
文摘A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.
基金supported by the National Natural Science Foundation of China(51977069)the National Natural Science Foundation Youth Project of China(52107195)the First Key Research and JieBang Headed Program,Hunan Province,China(2021GK1250).
文摘Switched-capacitor/flying capacitor(FC)based multilevel converters have been gaining higher attention for their voltage-boosting ability.This feature makes them an attractive solution for renewable energy systems,such as low-voltage input photovoltaic power systems and electric vehicle systems.However,they usually require more high voltage rating switches and flying capacitors along with boosting capability.Furthermore,they suffer from high pulse currents at the switching transients.Aiming to solve these issues,this article proposes a new self-balancing three-phase five-level inverter based on the switched-capacitor(5L-SCTPNPC),which reduces the dc voltage requirement.The number of active switches is relatively smaller and seven active switches are required per phase.Especially,a soft-charging circuit for FC is designed to limit the impulse charging current.Compared to conventional multilevel inverters,the proposed five-level inverter reduces dc bus voltage by 50%.Significantly,the voltage stress of FC and the switches in parallel with FC are all reduced by 50%in comparison with some existing similar boosting five-level active-neutral-point-clamped(5L-BANPC)inverters.The operating principles,modulation strategy,and the design of the FC and charging inductor are provided in detailly.A comprehensive comparison study has been made to highlight the merits of the proposed inverter.Finally,the simulations and experiments validate the feasibility of the proposed topology.
文摘BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.
基金supported by the Open Fund of the National Key Laboratory of Deep Space Exploration(No.NKDSEL2024004-2)the National Natural Science Foundation of China(No.42173045)supported by the Shandong Provincial Natural Science Foundation(No.ZR2025QC448).
文摘Oxygen(O_(2))is essential for life support and rocket propulsion in Mars exploration missions,and in situ oxygen production from the Martian atmosphere is of profound scientific and engineering significance.In this article,we propose a novel method for O_(2) production from the Martian atmosphere by using glow discharge ionization combined with a self-developed oxygen-permeable membrane(OPM).Experiments under simulated Martian atmospheric conditions examined parameter impacts on the O_(2) production rate and assessed the operating characteristics and glow discharge plasma tolerance of the OPM.Results indicate that(1)the proportion of O_(2) produced positively correlates with the ionization voltage under fixed discharge electrode spacing,pressure,and flow rate,reaching a maximum of 8.18%(saturating at 4600–5400 V);(2)O_(2) yield rises with the carbon dioxide(CO_(2))flow rate at a constant pressure,with the maximum value reaching 0.5 g/h;(3)titanium(Ti)and molybdenum(Mo)electrodes exhibit higher application potential under high voltage conditions;(4)the OPM operates at temperatures above 800℃ and shows few changes in the main body sections after 24 h of plasma tolerance testing.This study lays the foundation for future development of a mature Mars oxygen production prototype with lower energy consumption and higher efficiency.
基金supported by National Natural Science Foundation of China(22278241)a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016).
文摘Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.
基金financial support from the National Key R&D Program of China(2022YFA1504500 and 2023YFA1506300)the National Natural Science Foundation of China(22588201,22225204,and 22472169)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0600100)Liaoning Binhai Laboratory(LBLG-2024-03)。
文摘The traditional ammonia synthesis via the Haber–Bosch process requires large consumption of highpurity H_(2) and causes significant carbon emissions owing to the energy-intensive and complex hydrogen production steps conducted under harsh reaction conditions.Herein,we report a cyclic catalytic process for the production of NH_(3) by directly utilizing earth-abundant CH_(4) as a hydrogen source for N_(2) hydrogenation while simultaneously co-producing H_(2) over an alumina-supported iron catalyst(Fe/Al_(2)O_(3)).It achieves exceptional productivities of 2300μmol g^(-1)h^(-1)for NH_(3) and 400 mmol g^(-1)h^(-1)for H_(2) at700℃.By eliminating the coke that results from CH_(4) pyrolysis through a reaction with the greenhouse gas CO_(2) to produce valuable CO,we establish an atom-economic cyclic catalytic process while producing a CO stream intrinsically separated in the regeneration step.Mechanistic investigations indicate that the iron species in Fe/Al_(2) O_(3) serve as tri-functional active sites for CH_(4) pyrolysis,N_(2) hydrogenation,and coke elimination to produce CO,thus enabling an efficient and environmentally friendly cyclic catalytic process.
