Since the outbreak of the coronavirus disease 2019(COVID-19)pandemic,there have been a few variants of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),one of which is the Omicron variant(B.1.1.529).The...Since the outbreak of the coronavirus disease 2019(COVID-19)pandemic,there have been a few variants of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),one of which is the Omicron variant(B.1.1.529).The Omicron variant is the most mutated SARS-CoV-2 variant,and its high transmissibility and immune evasion ability have raised global concerns.Owing to its enhanced transmissibility,Omicron has rapidly replaced Delta as the dominant variant in several regions.However,recent studies have shown that the Omicron variant exhibits reduced pathogenicity due to altered cell tropism.In addition.展开更多
The central dogma states that genes encoded in the DNA should be first transcribed into messenger RNA(mRNA)and then translated into functional proteins(Crick,1970).This dogma has been written in numerous textbooks and...The central dogma states that genes encoded in the DNA should be first transcribed into messenger RNA(mRNA)and then translated into functional proteins(Crick,1970).This dogma has been written in numerous textbooks and learned by myriad students.However,along with the completion of the human genome project in June 2000,an astonishing fact was revealed:only 1.5%of the human genome encodes for proteins(Lander et al.,2001;Venter et al.,2001).This fact raised three fundamental questions:(i)why does the human genome have so few protein-coding genes?(ii)how to explain the apparent differences between humans and other species using the limited coding genes?(iii)what are the roles of the noncoding regions in our genome?展开更多
To identify a strategy for earlier sowing and harvesting of spring maize(Zea mays L.) in an alternative maize–maize double cropping system, a 2-year field experiment was performed at Quzhou experimental station of Ch...To identify a strategy for earlier sowing and harvesting of spring maize(Zea mays L.) in an alternative maize–maize double cropping system, a 2-year field experiment was performed at Quzhou experimental station of China Agricultural University in 2014 and 2015. A short-season cultivar, Demeiya number 1(KX7349), was used in the experiment. Soil temperature to 5 cm depth in the early crop growth stage, crop growth, crop yield, and water use of different treatments(plastic film-mulched raised bed(RF) and flat field without plastic film mulching(CK) in 2014; RF, plastic film-mulched flat field(FF), and CK in 2015)were measured or calculated and compared. Soil temperature in the film-mulched treatments was consistently higher than that in CK(1.6–3.5 °C in average) during the early growth stage. Crops in plastic film-mulched treatments used 214 fewer growing-degree days(GDDs) in 2014 and 262 fewer GDDs in 2015. In 2014, the RF treatment yielded 32.7%higher biomass than CK, although its 9.4% higher grain yield was not statistically significant. Also, RF used 17.9% less water and showed 33.1% higher water use efficiency(WUE) than CK. In 2015, RF and FF showed 56.2% and 49.5% higher yield, 15.0% and 4.5%lower water use(ET), and 63.4% and 75.7% higher WUE, respectively, than CK. RF markedly increased soil temperature in the early crop season, accelerated crop growth, reduced ET,and greatly increased crop yield and WUE. Compared with FF, RF had no obvious effect on crop growth rate, although soil temperature during the period between sowing and stem elongation was slightly increased. However, RF resulted in lower ET and higher WUE than FF. Effects of RF on soil water dynamics as well as its cost-effectiveness remain topics for further study.展开更多
This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. ...This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar （Wuyunjing 23） was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid （GA3） decreased while abscisic acid （ABA） content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale.展开更多
Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based o...Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based on a literature review and ifeld investigations, we analyzed the history and development, structure and characteristics, functions and values of the Xinghua Duotian Agrosystem in this research. The system has a long history, rich biodiversity, important ecosystem services, traditional adapted agricultural technologies and a folk culture. Altogether, these features form an attractive landscape created by its special water-land utilization. It also has great importance for the livelihood maintenance of the local people. However, the inheritance and conservation effort of Xinghua Duotian Agrosystem is facing great threats from modern agriculture, urbanization and labor loss. This paper wil provide insight into the Xinghua Duotian Agrosystem, and provide scientiifc support for the conservation and development of this special system. It will also provide a good example for similar areas in China and worldwide.展开更多
A raised panel method based on NURBS (Non-Uniform Rational B-Splines) forfree-surface flows with forward speed is presented. In this generalized panel method, NURBS areemployed to represent the body geometry, disturbe...A raised panel method based on NURBS (Non-Uniform Rational B-Splines) forfree-surface flows with forward speed is presented. In this generalized panel method, NURBS areemployed to represent the body geometry, disturbed free surface, and to express the unknown sourcestrength distribution, on the body surface and above the free surface. Compared with commonhigher-order panel methods, it has no need of adopting local coordinates. NURBS make the geometryrepresentation of the body shape and the wave pattern more precise. Raised panels above the freesurface produce less numerical dispersion error, need less CPU consumption and are helpful andcombined with collocation-point shifting up-stream, can satisfy the radiation condition numerically.By using continuous and discrete Fourier analysis, numerical errors of this method are discussedand a general expression for the errors of numerical damping and dispersion, including the effectsof the vertical distance of singularities to the free surface, the order of singularity distributionrepresented by B-splines in panels, and collocation-point shifting is derived.展开更多
The no-till seeders of various soil opener configurations have been shown to produce various soil physical responses in relation to soil and climate conditions, thus affecting crop performance in permanent raised beds...The no-till seeders of various soil opener configurations have been shown to produce various soil physical responses in relation to soil and climate conditions, thus affecting crop performance in permanent raised beds （PRB） systems. This is particularly important in arid Northwest China where large volumes of residue are retained on the soil surface after harvest. In Zhangye, Gansu Province, China, a field trial assessed the effects of three typical （powered-chopper, powered-cutter and powered-disc） PRB no-till seeders and one traditional seeder on soil disturbance, residue cover index, bulk density, fuel consumption, plant growth, and subsequent yield. In general, seedbed conditions and crop performance for PRB no- till seeders seeded plots were better than for traditional seeded plots. In PRB cropping system, the powered-chopper seeder decreased mean soil disturbance and increased residue cover index compared to powered-disc and -cutter seeders. However, the results indicated that soil bulk density was 2.3-4.8% higher, soil temperature was 0.2-0.6℃ lower, and spring wheat emergence was 3.2-4.7% less. This was attributed to greater levels of residue cover and firmer seedbeds. Spring maize and wheat performance in the powered-cutter and -disc treatments was better （non-significant） than powered- chopper treatment. So powered disc no-till seeder, which generally provided the best planting condition and the highest yield, appeared to be the suitable seeder in heavy residue cover conditions. Considering the precision requirements for soil disturbance and residue cover, the powered strip-chopping no-till seeder could be a suitable option for PRB cropping system in Northwest China. Although these results are preliminary, they are still valuable for the design and selection of no-till seeders for PRB cropping systems in arid Northwest China.展开更多
China promotes integrated development of domestic,foreign tradeNChina,the world’s second-largest consumer market and the world’s biggest goods trader,is striving to accelerate the integrated development of both dome...China promotes integrated development of domestic,foreign tradeNChina,the world’s second-largest consumer market and the world’s biggest goods trader,is striving to accelerate the integrated development of both domestic and foreign trade.Introducing a circular released recently by the General Office of the State Council that raised 18 measures to speed up the integrated development,officials of multiple departments said that it is necessary to open up the domestic market as well as the international market,encourage foreign trade enterprises to switch to domestic sales,and domestic trade enterprises to engage in foreign trade.展开更多
A blind pianist builds his future with music.WHEN Liu Hao played the last note of French composer Claude Debussy’s Clair de Lune at the Lang Lang Master Class in Beijing on July 10 and slowly raised his hands in vale...A blind pianist builds his future with music.WHEN Liu Hao played the last note of French composer Claude Debussy’s Clair de Lune at the Lang Lang Master Class in Beijing on July 10 and slowly raised his hands in valediction,the audience erupted into thunderous applause.Many came up to him to give him flowers and take photos with him.展开更多
A two-year cycle of qualifying tournaments for the FIFA World Cup 2026 began in Africa on 15 November 2023.It is the first qualifying round after a significant change in FIFA rules that raised the number of teams comp...A two-year cycle of qualifying tournaments for the FIFA World Cup 2026 began in Africa on 15 November 2023.It is the first qualifying round after a significant change in FIFA rules that raised the number of teams competing at the finals of the World Cup to 48 from 32.This means more African teams can take part in the coveted tournament and,therefore,greater chance for Africa’s footballing stars to shine brightly.展开更多
Ethiopian artist presents the 64 characters of the ancient Chinese classic divination text the I Ching in a series of unique paintings Dawit Muluneh,50,found his calling for painting and sculpture at an early age.Born...Ethiopian artist presents the 64 characters of the ancient Chinese classic divination text the I Ching in a series of unique paintings Dawit Muluneh,50,found his calling for painting and sculpture at an early age.Born and raised in Ethiopia’s capital Addis Ababa,he abandoned the playground and became obsessed with watching his uncle paint.展开更多
"Who will feed China?"This was a question raised by Lester Brown,the director of the World Watch Institute in the United States,in 1994.He predicted that China's grain production would decrease from 340 ..."Who will feed China?"This was a question raised by Lester Brown,the director of the World Watch Institute in the United States,in 1994.He predicted that China's grain production would decrease from 340 million tons in 1990 to 272 million tons by 2030,a 20%decrease,while China's population would reach 1.6 billion(Brown,1995).If the dietary structure was not improved,China would need to import 200-369 million tons of grain,equivalent to the global grain trade at the time.He projected the high possibility of a food crisis in China,which might further trigger a global food crisis.However,with the joint efforts of national agricultural researchers,represented by Yuan Longping,and the Chinese government,China's grain production has achieved 18 consecutive increases from 2004 to 2021.In 2022,grain production in China reached 633 million tons(NBS and Statistics,2022),while the population remained stable at 1.4 billion.As a result,China has achieved complete self-sufficiency in its staple food supply and has demonstrated to the international community through practical actions that the Chinese people can feed themselves.展开更多
主题语境:传统铁路技艺篇幅:357词建议用时:7分钟。1 Howard Jones,now silver-haired and 71,was born and raised in London.His father took him to see a rare Clan Stewart steam railway engine at Liverpool Street Station when...主题语境:传统铁路技艺篇幅:357词建议用时:7分钟。1 Howard Jones,now silver-haired and 71,was born and raised in London.His father took him to see a rare Clan Stewart steam railway engine at Liverpool Street Station when he was five.He would sneak into train sheds to admire the engines.When the last regular steam-train passenger service ended in Britain in 1968,“It was almost like losing a close friend,”said Jones.展开更多
After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluen...After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluent Mandarin?”Well,not only can we speak and write Mandarin,but many of us are also proficient in dialects such as Hakka,Cantonese,Hokkien,and Teochew.Our mastery of these dialects transcends mere convenience in communication;more importantly,it is about our strong desire to preserve the culture and language of our ancestral homeland:China.Indeed,as an ethnic Chinese person born and raised in Malaysia,my roots are forever tied to China.展开更多
Emerging and reemerging human-infecting viruses have been representing a massive threat to public health and have raised global concerns in recent years[1,2].While scientists and the public have worried and prepared f...Emerging and reemerging human-infecting viruses have been representing a massive threat to public health and have raised global concerns in recent years[1,2].While scientists and the public have worried and prepared for the emerging influenza-induced pandemic,the recognized first coronavirus caused pandemic raided the humans.As the new disease's etiology recognized as coronavirus disease 2019(COVID-19),severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)has spread throughout the world in a fewmonths since late 2019 and thus far has causedmore than 50 million infections with over 1 million deaths.In front of this severe and complicated new infectious disease,many countries,including China,have well-controlled the domestic transmission of COVID-19,based on positive attitudes,practical strategies,and scientific measures.The two primary forefronts in combating the new virus are epidemiological intervention and laboratory investigation.The field surveillance and intervention strategies comprise the origin tracing,the transmission route investigation,quarantine of the contacts,and other epidemiological emergency disposals.展开更多
Linqu County in Weifang of Shandong Province has recently risen to fame as China's largest producer of foie gras,the liver of specially fattened geese and ducks,which is a French delicacy.Last year,the county rais...Linqu County in Weifang of Shandong Province has recently risen to fame as China's largest producer of foie gras,the liver of specially fattened geese and ducks,which is a French delicacy.Last year,the county raised more than 5 million Landes geese,a breed developed in France specifically for their large,fatty livers;and produced more than 5,000 tons of foie gras for the domestic and international markets,accounting for more than 70 percent of domestic goose liver production.展开更多
While the world was still looking to Paris for Olympic glory in early August,New York City orchestrated its own symphony of cultural exchange.In the heart of Manhattan,the renowned Carnegie Hall raised the curtain on ...While the world was still looking to Paris for Olympic glory in early August,New York City orchestrated its own symphony of cultural exchange.In the heart of Manhattan,the renowned Carnegie Hall raised the curtain on World Orchestra Week(WOW!),a melodious celebration of international communication that rivaled the grandeur of any sporting spectacle.展开更多
After careful consideration,with the consent of Editor-inChief Weiyan Zhang(张维岩)and Editor-in-Chief Ho-kwang Mao(毛河光),I have decided to step down as the Executive Editor-inChief of MRE to focus on my health and ...After careful consideration,with the consent of Editor-inChief Weiyan Zhang(张维岩)and Editor-in-Chief Ho-kwang Mao(毛河光),I have decided to step down as the Executive Editor-inChief of MRE to focus on my health and research.I will be succeeded by the next Executive Editor-in-Chief,Professor Jinren Sun(孙今人)of the Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,and Professor Hongbo Cai(蔡洪波)of the Institute of Applied Physics and Computational Mathematics in Beijing.With the help of both of these excellent and experienced physicists,I believe that MRE and its community can be raised to a higher level.展开更多
Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia....Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices.展开更多
Dear Editor,Embryonic stem cells(ESCs)have been assumed to possess immature mitochondria and to favor anaerobic glycolysis over oxidative phosphorylation(OXPHOS)for energy production.This proposition is largely based ...Dear Editor,Embryonic stem cells(ESCs)have been assumed to possess immature mitochondria and to favor anaerobic glycolysis over oxidative phosphorylation(OXPHOS)for energy production.This proposition is largely based on the findings that ESCs possess globular mitochondria with blurred cristae,and the facts that ESCs have higher glycolysis activity and lower mitochondrial respiration capacity than somatic cells(Kondoh et al.,2007;Folmes et al.,2011,2012;Zhang et al.,2012;Xu et al.,2013;Ito and Suda,2014;Gu et al.,2016).However,recent studies have shown that mitochondrial autophagy and mitochondrial dynamics are pivotal for ESC self-renewal and pluripotency(Todd et al.,2010;Liu et al.,2016,2020;Wang et al.,2019;Zhong et al.,2019).These studies have raised a fundamental question:what is the contribution and functional mechanism of mitochondrial respiration in pluripotency regulation?展开更多
基金We would like to apologize to those researchers whose related work we were not able to cite in this review.This work was supported by a special program from the Ministry of Science and Technology of China(2021YFA1101000)the Chinese National Natural Science Funds(31925013 and U20A20393 to L.Z.,31871405,32125016 and 82041009 to F.Z.)+5 种基金Zhejiang Provincial Natural Science Foundation of China under Grant(LBY21H060001 to L.Z.)the Medical and the Medical and Health Research Project of Zhejiang Province(2020RC115 to L.Z.)Jiangsu National Science Foundation(BK20180043 and 19KJA550003 to F.Z.)the Zhejiang Natural Science Fund(LD19C070001to L.Z.)the Key Project of University Natural Science Foundation of Jiangsu Province(19KJA550003)A project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,and the Medical and Health Research Project of Zhejiang Province(2020RC155 to L.Z.).
文摘Since the outbreak of the coronavirus disease 2019(COVID-19)pandemic,there have been a few variants of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),one of which is the Omicron variant(B.1.1.529).The Omicron variant is the most mutated SARS-CoV-2 variant,and its high transmissibility and immune evasion ability have raised global concerns.Owing to its enhanced transmissibility,Omicron has rapidly replaced Delta as the dominant variant in several regions.However,recent studies have shown that the Omicron variant exhibits reduced pathogenicity due to altered cell tropism.In addition.
基金This work was supported by the National Natural Science Foundation of China(91940000).We thank Drs.Xiaorong Zhang and Jing Hu for critical reading of this manuscript.We are sorry for the excellent works supported by the Major Research Program that are not highlighted in this comment due to space limitations.
文摘The central dogma states that genes encoded in the DNA should be first transcribed into messenger RNA(mRNA)and then translated into functional proteins(Crick,1970).This dogma has been written in numerous textbooks and learned by myriad students.However,along with the completion of the human genome project in June 2000,an astonishing fact was revealed:only 1.5%of the human genome encodes for proteins(Lander et al.,2001;Venter et al.,2001).This fact raised three fundamental questions:(i)why does the human genome have so few protein-coding genes?(ii)how to explain the apparent differences between humans and other species using the limited coding genes?(iii)what are the roles of the noncoding regions in our genome?
基金financially supported by the Special Fund for Agro-scientific Research in the Public Interest (No. 201103001)
文摘To identify a strategy for earlier sowing and harvesting of spring maize(Zea mays L.) in an alternative maize–maize double cropping system, a 2-year field experiment was performed at Quzhou experimental station of China Agricultural University in 2014 and 2015. A short-season cultivar, Demeiya number 1(KX7349), was used in the experiment. Soil temperature to 5 cm depth in the early crop growth stage, crop growth, crop yield, and water use of different treatments(plastic film-mulched raised bed(RF) and flat field without plastic film mulching(CK) in 2014; RF, plastic film-mulched flat field(FF), and CK in 2015)were measured or calculated and compared. Soil temperature in the film-mulched treatments was consistently higher than that in CK(1.6–3.5 °C in average) during the early growth stage. Crops in plastic film-mulched treatments used 214 fewer growing-degree days(GDDs) in 2014 and 262 fewer GDDs in 2015. In 2014, the RF treatment yielded 32.7%higher biomass than CK, although its 9.4% higher grain yield was not statistically significant. Also, RF used 17.9% less water and showed 33.1% higher water use efficiency(WUE) than CK. In 2015, RF and FF showed 56.2% and 49.5% higher yield, 15.0% and 4.5%lower water use(ET), and 63.4% and 75.7% higher WUE, respectively, than CK. RF markedly increased soil temperature in the early crop season, accelerated crop growth, reduced ET,and greatly increased crop yield and WUE. Compared with FF, RF had no obvious effect on crop growth rate, although soil temperature during the period between sowing and stem elongation was slightly increased. However, RF resulted in lower ET and higher WUE than FF. Effects of RF on soil water dynamics as well as its cost-effectiveness remain topics for further study.
基金provided by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2016YFD0300505 and 2015BAD01B03)the Public Welfare and Industry,Ministry of Agriculture,China(201403039 and 201303102)the Fundamental Research Funds for the Central Universities,China(KYTZ201402)
文摘This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings （HLMS） on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar （Wuyunjing 23） was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid （GA3） decreased while abscisic acid （ABA） content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale.
基金National Natural Science Fund of China (31200376)Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (2013T2Z0011)
文摘Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based on a literature review and ifeld investigations, we analyzed the history and development, structure and characteristics, functions and values of the Xinghua Duotian Agrosystem in this research. The system has a long history, rich biodiversity, important ecosystem services, traditional adapted agricultural technologies and a folk culture. Altogether, these features form an attractive landscape created by its special water-land utilization. It also has great importance for the livelihood maintenance of the local people. However, the inheritance and conservation effort of Xinghua Duotian Agrosystem is facing great threats from modern agriculture, urbanization and labor loss. This paper wil provide insight into the Xinghua Duotian Agrosystem, and provide scientiifc support for the conservation and development of this special system. It will also provide a good example for similar areas in China and worldwide.
文摘A raised panel method based on NURBS (Non-Uniform Rational B-Splines) forfree-surface flows with forward speed is presented. In this generalized panel method, NURBS areemployed to represent the body geometry, disturbed free surface, and to express the unknown sourcestrength distribution, on the body surface and above the free surface. Compared with commonhigher-order panel methods, it has no need of adopting local coordinates. NURBS make the geometryrepresentation of the body shape and the wave pattern more precise. Raised panels above the freesurface produce less numerical dispersion error, need less CPU consumption and are helpful andcombined with collocation-point shifting up-stream, can satisfy the radiation condition numerically.By using continuous and discrete Fourier analysis, numerical errors of this method are discussedand a general expression for the errors of numerical damping and dispersion, including the effectsof the vertical distance of singularities to the free surface, the order of singularity distributionrepresented by B-splines in panels, and collocation-point shifting is derived.
基金financed by the National Natural Science Foundation of China (51175499)the Beijing Natural Science Foundation, China (6112015)the Australian Centre for International Agricultural Research (ACIAR)
文摘The no-till seeders of various soil opener configurations have been shown to produce various soil physical responses in relation to soil and climate conditions, thus affecting crop performance in permanent raised beds （PRB） systems. This is particularly important in arid Northwest China where large volumes of residue are retained on the soil surface after harvest. In Zhangye, Gansu Province, China, a field trial assessed the effects of three typical （powered-chopper, powered-cutter and powered-disc） PRB no-till seeders and one traditional seeder on soil disturbance, residue cover index, bulk density, fuel consumption, plant growth, and subsequent yield. In general, seedbed conditions and crop performance for PRB no- till seeders seeded plots were better than for traditional seeded plots. In PRB cropping system, the powered-chopper seeder decreased mean soil disturbance and increased residue cover index compared to powered-disc and -cutter seeders. However, the results indicated that soil bulk density was 2.3-4.8% higher, soil temperature was 0.2-0.6℃ lower, and spring wheat emergence was 3.2-4.7% less. This was attributed to greater levels of residue cover and firmer seedbeds. Spring maize and wheat performance in the powered-cutter and -disc treatments was better （non-significant） than powered- chopper treatment. So powered disc no-till seeder, which generally provided the best planting condition and the highest yield, appeared to be the suitable seeder in heavy residue cover conditions. Considering the precision requirements for soil disturbance and residue cover, the powered strip-chopping no-till seeder could be a suitable option for PRB cropping system in Northwest China. Although these results are preliminary, they are still valuable for the design and selection of no-till seeders for PRB cropping systems in arid Northwest China.
文摘China promotes integrated development of domestic,foreign tradeNChina,the world’s second-largest consumer market and the world’s biggest goods trader,is striving to accelerate the integrated development of both domestic and foreign trade.Introducing a circular released recently by the General Office of the State Council that raised 18 measures to speed up the integrated development,officials of multiple departments said that it is necessary to open up the domestic market as well as the international market,encourage foreign trade enterprises to switch to domestic sales,and domestic trade enterprises to engage in foreign trade.
文摘A blind pianist builds his future with music.WHEN Liu Hao played the last note of French composer Claude Debussy’s Clair de Lune at the Lang Lang Master Class in Beijing on July 10 and slowly raised his hands in valediction,the audience erupted into thunderous applause.Many came up to him to give him flowers and take photos with him.
文摘A two-year cycle of qualifying tournaments for the FIFA World Cup 2026 began in Africa on 15 November 2023.It is the first qualifying round after a significant change in FIFA rules that raised the number of teams competing at the finals of the World Cup to 48 from 32.This means more African teams can take part in the coveted tournament and,therefore,greater chance for Africa’s footballing stars to shine brightly.
文摘Ethiopian artist presents the 64 characters of the ancient Chinese classic divination text the I Ching in a series of unique paintings Dawit Muluneh,50,found his calling for painting and sculpture at an early age.Born and raised in Ethiopia’s capital Addis Ababa,he abandoned the playground and became obsessed with watching his uncle paint.
基金supported by the National Natural Science Foundation of China(32171453)the National Key R&D Program of China(2023ZD0403005)the Central Public-interest Scientific Institution Basal Research Fund(1610392020001).
文摘"Who will feed China?"This was a question raised by Lester Brown,the director of the World Watch Institute in the United States,in 1994.He predicted that China's grain production would decrease from 340 million tons in 1990 to 272 million tons by 2030,a 20%decrease,while China's population would reach 1.6 billion(Brown,1995).If the dietary structure was not improved,China would need to import 200-369 million tons of grain,equivalent to the global grain trade at the time.He projected the high possibility of a food crisis in China,which might further trigger a global food crisis.However,with the joint efforts of national agricultural researchers,represented by Yuan Longping,and the Chinese government,China's grain production has achieved 18 consecutive increases from 2004 to 2021.In 2022,grain production in China reached 633 million tons(NBS and Statistics,2022),while the population remained stable at 1.4 billion.As a result,China has achieved complete self-sufficiency in its staple food supply and has demonstrated to the international community through practical actions that the Chinese people can feed themselves.
文摘主题语境:传统铁路技艺篇幅:357词建议用时:7分钟。1 Howard Jones,now silver-haired and 71,was born and raised in London.His father took him to see a rare Clan Stewart steam railway engine at Liverpool Street Station when he was five.He would sneak into train sheds to admire the engines.When the last regular steam-train passenger service ended in Britain in 1968,“It was almost like losing a close friend,”said Jones.
文摘After a two-year gap year following high school,I finally departed my hometown in Malaysia for a solo journey to China.Upon arrival,the most frequent question I encountered was:“Why do you Malaysians speak such fluent Mandarin?”Well,not only can we speak and write Mandarin,but many of us are also proficient in dialects such as Hakka,Cantonese,Hokkien,and Teochew.Our mastery of these dialects transcends mere convenience in communication;more importantly,it is about our strong desire to preserve the culture and language of our ancestral homeland:China.Indeed,as an ethnic Chinese person born and raised in Malaysia,my roots are forever tied to China.
文摘Emerging and reemerging human-infecting viruses have been representing a massive threat to public health and have raised global concerns in recent years[1,2].While scientists and the public have worried and prepared for the emerging influenza-induced pandemic,the recognized first coronavirus caused pandemic raided the humans.As the new disease's etiology recognized as coronavirus disease 2019(COVID-19),severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)has spread throughout the world in a fewmonths since late 2019 and thus far has causedmore than 50 million infections with over 1 million deaths.In front of this severe and complicated new infectious disease,many countries,including China,have well-controlled the domestic transmission of COVID-19,based on positive attitudes,practical strategies,and scientific measures.The two primary forefronts in combating the new virus are epidemiological intervention and laboratory investigation.The field surveillance and intervention strategies comprise the origin tracing,the transmission route investigation,quarantine of the contacts,and other epidemiological emergency disposals.
文摘Linqu County in Weifang of Shandong Province has recently risen to fame as China's largest producer of foie gras,the liver of specially fattened geese and ducks,which is a French delicacy.Last year,the county raised more than 5 million Landes geese,a breed developed in France specifically for their large,fatty livers;and produced more than 5,000 tons of foie gras for the domestic and international markets,accounting for more than 70 percent of domestic goose liver production.
文摘While the world was still looking to Paris for Olympic glory in early August,New York City orchestrated its own symphony of cultural exchange.In the heart of Manhattan,the renowned Carnegie Hall raised the curtain on World Orchestra Week(WOW!),a melodious celebration of international communication that rivaled the grandeur of any sporting spectacle.
基金supported by the National Natural Science Foundation of China(Grant No.12035002).
文摘After careful consideration,with the consent of Editor-inChief Weiyan Zhang(张维岩)and Editor-in-Chief Ho-kwang Mao(毛河光),I have decided to step down as the Executive Editor-inChief of MRE to focus on my health and research.I will be succeeded by the next Executive Editor-in-Chief,Professor Jinren Sun(孙今人)of the Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,and Professor Hongbo Cai(蔡洪波)of the Institute of Applied Physics and Computational Mathematics in Beijing.With the help of both of these excellent and experienced physicists,I believe that MRE and its community can be raised to a higher level.
文摘Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices.
基金We thank Dr Masaru Okabe at Osaka University Japan for providing the B6D2-Tg(CAG/Su9-DsRed2,Acr3-EGFP)RBGS002Osb mice(mito-red)the National Institute for Basic Biology Japan for providing the B6.Cg-Tg(CAG-GFP/LC3)53Nmz/NmzRbrc mice.+3 种基金the National Key R&D Program of China 2018YFA0108402the Strategic Priority Research Program of the Chinese Academy of Sciences XDA16030302the Strategic Collaborative Research Program of the Ferring Institute of Reproductive Medicine Grant No.33,and the National Natural Science Foundation of China Program(31720103907,31570995,31621004),to T.Z.and(31400831)to J.C.The raw data FASTQ files for the RNA sequencing data are deposited in NCBI GEO,GEO:GSE140712(Fig.1D,1E and S4)and ScienceDB,China National Standard GB/T 7714-2015(Fig.S8A,S8F and S8G)The metabolomic data files are deposited in ScienceDB,China National Standard GB/T 7714-2015.
文摘Dear Editor,Embryonic stem cells(ESCs)have been assumed to possess immature mitochondria and to favor anaerobic glycolysis over oxidative phosphorylation(OXPHOS)for energy production.This proposition is largely based on the findings that ESCs possess globular mitochondria with blurred cristae,and the facts that ESCs have higher glycolysis activity and lower mitochondrial respiration capacity than somatic cells(Kondoh et al.,2007;Folmes et al.,2011,2012;Zhang et al.,2012;Xu et al.,2013;Ito and Suda,2014;Gu et al.,2016).However,recent studies have shown that mitochondrial autophagy and mitochondrial dynamics are pivotal for ESC self-renewal and pluripotency(Todd et al.,2010;Liu et al.,2016,2020;Wang et al.,2019;Zhong et al.,2019).These studies have raised a fundamental question:what is the contribution and functional mechanism of mitochondrial respiration in pluripotency regulation?
