1 Introduction The uranium deposits related with Indosinian and Yanshanian granite have provided the abundant resource of uranium during the past several decades in China.The deposits are mainly distributing in the Gu...1 Introduction The uranium deposits related with Indosinian and Yanshanian granite have provided the abundant resource of uranium during the past several decades in China.The deposits are mainly distributing in the Guidong granite展开更多
The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan...The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials. Compound thermal activation was used to improve the cementitious properties of the tailings, while analyzing methods, such as X-ray diffraction （XRD）, infrared spectroscopy （IR）, nuclear magnetic resonance （NMR）, and X-ray photoelectron spectrometer （XPS）, were employed to study the changes in phase and structure under different activation conditions. The results reveal clear relationships between the binding energies of Si2p and O 1 s, polymerization degree, and cementitious activity of iron ore tailings.展开更多
Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the c...Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.展开更多
We report the applications of a low-cost and environmentally friendly chalcogenide glass, 75GeS2-15Ga2S3-10CsI, in building active microsphere laser oscillators. A silica fiber taper is used as the coupling mechanism....We report the applications of a low-cost and environmentally friendly chalcogenide glass, 75GeS2-15Ga2S3-10CsI, in building active microsphere laser oscillators. A silica fiber taper is used as the coupling mechanism. With an 808-nm laser diode as a pump source, we show that a high-Q （-, 6× 10^4） laser mode could be obtained from a 75-μm diameter microsphere that is coupled with a 1.77-μm waist-diameter fiber taper. The threshold of the incident pump power is 1.39 mW, which is considerably lower than those of previously reported free-space coupled chalcogenide microsphere lasers. We also note an apparent enhancement in laser power generated from this chalcogenide microsphere laser.展开更多
To investigate the process optimizationof Cu-en/AP composite microspheres preparation via electrostatic spraying,and to reveal the effects of droplet properties and flow rate variations on the experimental results dur...To investigate the process optimizationof Cu-en/AP composite microspheres preparation via electrostatic spraying,and to reveal the effects of droplet properties and flow rate variations on the experimental results during the electrostatic spraying process,the prepared process parameters of Cu-en/AP composite microspheres by electrostatic spray method under the orthogonal experimental design simulated by ANSYS(Fluent).The influence of flow rate,solvent ratio,and solid mass on the experimental results is examined using a controlled variable method.The results indicate that under the conditions of a flow rate of 2.67×10^(-3)kg/s an acetone-to-deionized water ratio of 1.5∶1.0,and a solid mass of 200 mg,the theoretical particle size of the composite microspheres can reach e nanoscale.Droplet trajectories in the electric field remain stable without significant deviation.The simulation results show that particle diameter decreases with increasing flow rate,with the trend leveling off around a flow rate of 1×10^(-3)kg/s.As the solvent ratio increases(with higher acetone content),particle diameter initially decreases,reaching a minimum around a ratio of 1.5∶1.0 before gradually increasing.Increasing the solid mass also reduces the particle diameter,with a linear increase in diameter observed at around 220 mg.Cu-en/AP composite microspheres with nanoscale dimensions were confirmed under these conditions by the final SEM images.展开更多
The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AF...The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AFE was studied. The results show that all kinds of dynamic recrystallization(DRX) behaviors can weaken the texture to vary degrees. The weakening effect of twinning-induced recrystallization(TDRX)behavior was particularly significant. During the interactive AFE process, the c-axis of most grains rotated under the external force, and tended to be 90° angle with the ED direction, forming a stable fiber texture. In addition, with the increase of loading passes, the starting of {0001} <11–20> basal slip system became more and more difficult. The(10–10) texture formed by {10–10} <11–20> prismatic slip system after sixth passes was the main texture type. With the increase of forming temperature, the starting ability of {10–10} <11–20>prismatic slip systems increased, and the(10–10) texture formed by prismatic slip system above 623 K dominated.展开更多
In the first half of 2006, growth of oil supplyan China slowed down and the growth rate of actual constmption was kept stable. Oil imports and apparent consmption increased rapidly, and the oil price went u to the his...In the first half of 2006, growth of oil supplyan China slowed down and the growth rate of actual constmption was kept stable. Oil imports and apparent consmption increased rapidly, and the oil price went u to the historical records. In the future, growth of oil snpply in China will still be restrained and oil import wil remain a relatively high growth rate in the latter half f 2006. Compared to actual consumption, which will still be stabilized, the growth rate of apparent consump on will be higher. The oil price will linger at high-level.展开更多
Oil quality was upgraded more quickly, and alternative fuels for motor vehicles continued to grow rapidly （1） Gasoline and diesel were upgraded more quickly. China enacted specific measures and schedule requirement...Oil quality was upgraded more quickly, and alternative fuels for motor vehicles continued to grow rapidly （1） Gasoline and diesel were upgraded more quickly. China enacted specific measures and schedule requirement of oil quality upgrading in 2013. National IV gasoline began to be used throughout the country on January 1, 2014, with sulfur content dropping to 50ppm.展开更多
The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronav...The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronavirus genera.On January 30,2020,WHO re-evaluated the potential effects of 2019-nCoV infection in global public health,and declared this epidemic as a "Public Health Emergency of International Concern (PHEIC)".展开更多
This paper addresses the pressing necessity to align the regulatory capacity of renewable energy sources with their inherent fluctuations across various time scales.Emphasising the pivotal role of large-scale energy s...This paper addresses the pressing necessity to align the regulatory capacity of renewable energy sources with their inherent fluctuations across various time scales.Emphasising the pivotal role of large-scale energy storage technologies,the study provides a comprehensive overview,comparison,and evaluation of emerging energy storage solu-tions,such as lithium-ion cells,flow redox cell,and compressed-air energy storage.It outlines three fundamental principles for energy storage system development:prioritising safety,optimising costs,and realising value.Through analysis of two case studies-a pure photovoltaic(PV)power island interconnected via a high-voltage direct current(HVDC)system,and a 100%renewable energy autonomous power supply-the paper elucidates the critical role of energy storage in facilitating high levels of renewable energy integra-tion.Furthermore,it delves into the challenges inherent in the development of energy storage systems.展开更多
The Ordos Basin,the second largest sedimentary basin in China,contains the broad distribution of natural gas types.So far,several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin,ea...The Ordos Basin,the second largest sedimentary basin in China,contains the broad distribution of natural gas types.So far,several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin,each having over 1000×108 m 3 of proven gas reserves,and several gas pools have also been discovered in the Mesozoic.This paper collected the data of natural gases and elucidated the geochemical characteristics of gases from different reservoirs,and then discussed their origin.For hydrocarbons preserved in the Upper Paleozoic,the elevatedδ13C values of methane,ethane and propane indicate that the gases would be mainly coal-formed gases;the singular reversal in the stable carbon isotopes of gaseous alkanes suggests the mixed gases from humic sources with different maturity.In the Lower Paleozoic,theδ13C 1 values are mostly similar with those in the Upper Paleozoic,but theδ13C 2 andδ13C 3 values are slightly lighter,suggesting that the gases would be mixing of coal-type gases as a main member and oil-type gases.There are multiple reversals in carbon isotopes for gaseous alkanes,especially abnormal reversal for methane and ethane(i.e.δ13C 1>δ13C 2),inferring that gases would be mixed between high-mature coal-formed gases and oil-type gases.In the Mesozoic,theδ13Cvalues for gaseous alkanes are enriched in 12C,indicating that the gases are mainly derived from sapropelic sources;the carbon isotopic reversal for propane and butane in the Mesozoic is caused by microbial oxidation and mixing of gases from sapropelic sources with different maturity.In contrast to the Upper Paleozoic gases,the Mesozoic gases are characterized by heavier carbon isotopes of iso-butane than normal butane,which may be caused by gases generated from different kerogen types.Finally,according toδ13C 1-Ro relationship and extremely low total organic carbon contents,the Low Paleozoic gases would not be generated from the Ordovician source as a main gas source,bycontrast,the Upper Paleozoic source as a main gas source is contributed to the Lower Paleozoic gases.展开更多
Dear Editor,Acute Lymphoblastic Leukemia(ALL)is a potent malignancy,constituting 30%of all pediatric cancers.B-cell precursor ALL(BCP-ALL),which represents over 80%of ALL cases,is distinguished by chromosomal rearrang...Dear Editor,Acute Lymphoblastic Leukemia(ALL)is a potent malignancy,constituting 30%of all pediatric cancers.B-cell precursor ALL(BCP-ALL),which represents over 80%of ALL cases,is distinguished by chromosomal rearrangements that yield chimeric fusion proteins,which are unique from their normal counterparts.Among these,myocyte enhancer factor 2D(MEF2D)-fusion genes are found in both pediatric and adult populations and are associated with notably poor prognoses.展开更多
Based on historical land use for eight periods from 1980 to 2020 and the projected land use under seven Shared Socioeconomic Pathways(SSPs:SSP1-1.9,SSP1-2.6,SSP2-4.5,SSP3-7.0,SSP4-3.4,SSP4-6.0,and SSP5-8.5)from 2021 t...Based on historical land use for eight periods from 1980 to 2020 and the projected land use under seven Shared Socioeconomic Pathways(SSPs:SSP1-1.9,SSP1-2.6,SSP2-4.5,SSP3-7.0,SSP4-3.4,SSP4-6.0,and SSP5-8.5)from 2021 to 2100,we conducted a study on past and future land use changes in the Qinghai-Tibet Plateau(QTP).This work aims to reveal the land use changes during the carbon peak(2021-2040)and carbon neutrality(2051-2070)periods and at the end of the 21st century(2081-2100).The results show that:(1)in the historical period(1980-2020),the land use types in the QTP were grassland(1475×10^(3)km^(2),58.2%),barren land(685×10^(3)km^(2),27.0%),forest land(243×10^(3)km^(2),9.6%),water(114×10^(3)km^(2),4.5%),cropland(18.6×10^(3)km^(2),0.7%)and urban land(0.3×10^(3)km^(2),0.01%).(2)Relative to the baseline period(1995-2014),the area of grassland is projected to decrease by 0.7%(SSP4-6.0)-5.4%(SSP2-4.5)(0.5-3.9%of the total area of the QTP),2.8%(SSP4-6.0)-12.5%(SSP3-7.0)(2.1-9.4%of the total area of the QTP)and 6.1%(SSP4-6.0)-21.7%(SSP4-3.4)(4.6-16.4%of the total area of the QTP)in the future three periods.In contrast,the forest land area is projected to increase,by approximately 2.5%(SSP4-6.0)to 30.1%(SSP3-7.0)(0.3-4.3%of the total area of the QTP),9.2%(SSP4-6.0)to 56.5%(SSP2-4.5)(1.3-8.0%of the total area of the QTP),and 21.2%(SSP4-6.0)to 72.8%(SSP2-4.5)(3.0-10.2%of the total area of the QTP)in the future three periods,respectively.(3)Approximately 0.4(SSP4-6.0)to 6.9%(SSP5-8.5),0.9(SSP4-6.0)to 2.7%(SSP4-3.4),and 0.04(SSP5-8.5)to 3.5%(SSP1-1.9)of land is expected to convert from grassland to forest land in the future three periods,respectively.The shift from grassland to forest land area is likely to enhance the carbon sink potential of the QTP in the future period.展开更多
Importance:The Coronavirus disease 2019(COVID-19)global pandemic poses a considerable challenge for pediatricians.Objective:This study aimed to identify the epidemiological characteristics and clinical features of ped...Importance:The Coronavirus disease 2019(COVID-19)global pandemic poses a considerable challenge for pediatricians.Objective:This study aimed to identify the epidemiological characteristics and clinical features of pediatric patients with COVID-19 in China.Methods:This multicenter retrospective study included pediatric patients from 46 hospitals in China,covering 12 provinces and two municipalities.Epidemiological,demographic,clinical,laboratory,treatment,and outcome data were analyzed.Results:In total,211 pediatric patients with COVID-19 were included in this study.The median age was 7.0 years(range:22 days to 18 years).Approximately 16.3%of the patients exhibited asymptomatic infections,23.0%had upper respiratory tract infections,and 60.7%had pneumonia,including two with severe pneumonia and one with critical illness.Approximately 78.7%of the pediatric patients occurred in familial clusters.The most three common symptoms or signs at onset in children with COVID-19 were fever(54.5%),cough(49.3%),and pharyngeal congestion(20.8%).Only 17.6%of the patients presented with decreased lymphocyte count,whereas 13.6%had increased lymphocyte count.Among the patients with pneumonia who exhibited abnormal chest computed tomography findings,18.2%(23/127)of the patients had no other symptoms.Generally,the chest radiographs showed abnormalities that affected both lungs(49.6%);ground-glass opacity(47.2%)was the most common manifestation.The cure and improvement rates were 86.7%(183/211)and 13.3%(28/211),respectively.Only one patient with an underlying condition received invasive mechanical ventilation;none of the patients died.Interpretation:Similar to adults,children of all age groups are susceptible to COVID-19.Fortunately,most pediatric patients have mild symptoms or remain asymptomatic,despite the high incidence of pneumonia.Decreased proportions of white blood cells and lymphocytes are less frequent in children than in adults.展开更多
基金supported by projects from Chinese Geological Survery Programme (12120115035601)
文摘1 Introduction The uranium deposits related with Indosinian and Yanshanian granite have provided the abundant resource of uranium during the past several decades in China.The deposits are mainly distributing in the Guidong granite
基金supported by the National Natural Science Foundation of China (No.50674062)the Key Project of the Ministry of Railway of China (No.2008G031-N)the Postdoctoral Science Foundation (No.20070420354)
文摘The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials. Compound thermal activation was used to improve the cementitious properties of the tailings, while analyzing methods, such as X-ray diffraction （XRD）, infrared spectroscopy （IR）, nuclear magnetic resonance （NMR）, and X-ray photoelectron spectrometer （XPS）, were employed to study the changes in phase and structure under different activation conditions. The results reveal clear relationships between the binding energies of Si2p and O 1 s, polymerization degree, and cementitious activity of iron ore tailings.
文摘Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61177087 and 61435009)the National Key Basic Research Program of China(Grant No.2012CB722703)+2 种基金the Program for Innovative Research Team of Ningbo City,China(Grant No.2009B21007)the K.C.Wong Magna Fund in Ningbo University,the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology),China(Grant No.2014-skllmd-01)the Natural Science Foundation of Ningbo City,China(Grant No.2014A610125)
文摘We report the applications of a low-cost and environmentally friendly chalcogenide glass, 75GeS2-15Ga2S3-10CsI, in building active microsphere laser oscillators. A silica fiber taper is used as the coupling mechanism. With an 808-nm laser diode as a pump source, we show that a high-Q （-, 6× 10^4） laser mode could be obtained from a 75-μm diameter microsphere that is coupled with a 1.77-μm waist-diameter fiber taper. The threshold of the incident pump power is 1.39 mW, which is considerably lower than those of previously reported free-space coupled chalcogenide microsphere lasers. We also note an apparent enhancement in laser power generated from this chalcogenide microsphere laser.
基金National Natural Science Foundation of China(No.2275150)。
文摘To investigate the process optimizationof Cu-en/AP composite microspheres preparation via electrostatic spraying,and to reveal the effects of droplet properties and flow rate variations on the experimental results during the electrostatic spraying process,the prepared process parameters of Cu-en/AP composite microspheres by electrostatic spray method under the orthogonal experimental design simulated by ANSYS(Fluent).The influence of flow rate,solvent ratio,and solid mass on the experimental results is examined using a controlled variable method.The results indicate that under the conditions of a flow rate of 2.67×10^(-3)kg/s an acetone-to-deionized water ratio of 1.5∶1.0,and a solid mass of 200 mg,the theoretical particle size of the composite microspheres can reach e nanoscale.Droplet trajectories in the electric field remain stable without significant deviation.The simulation results show that particle diameter decreases with increasing flow rate,with the trend leveling off around a flow rate of 1×10^(-3)kg/s.As the solvent ratio increases(with higher acetone content),particle diameter initially decreases,reaching a minimum around a ratio of 1.5∶1.0 before gradually increasing.Increasing the solid mass also reduces the particle diameter,with a linear increase in diameter observed at around 220 mg.Cu-en/AP composite microspheres with nanoscale dimensions were confirmed under these conditions by the final SEM images.
基金supported by National Natural Science Foundation of China (no. 51975166)。
文摘The interactive alternating forward extrusion(AFE) method can realize the change of texture type and the weakening of texture strength.Taking AZ31 magnesium alloy as an example, the texture evolution of interactive AFE was studied. The results show that all kinds of dynamic recrystallization(DRX) behaviors can weaken the texture to vary degrees. The weakening effect of twinning-induced recrystallization(TDRX)behavior was particularly significant. During the interactive AFE process, the c-axis of most grains rotated under the external force, and tended to be 90° angle with the ED direction, forming a stable fiber texture. In addition, with the increase of loading passes, the starting of {0001} <11–20> basal slip system became more and more difficult. The(10–10) texture formed by {10–10} <11–20> prismatic slip system after sixth passes was the main texture type. With the increase of forming temperature, the starting ability of {10–10} <11–20>prismatic slip systems increased, and the(10–10) texture formed by prismatic slip system above 623 K dominated.
文摘In the first half of 2006, growth of oil supplyan China slowed down and the growth rate of actual constmption was kept stable. Oil imports and apparent consmption increased rapidly, and the oil price went u to the historical records. In the future, growth of oil snpply in China will still be restrained and oil import wil remain a relatively high growth rate in the latter half f 2006. Compared to actual consumption, which will still be stabilized, the growth rate of apparent consump on will be higher. The oil price will linger at high-level.
文摘Oil quality was upgraded more quickly, and alternative fuels for motor vehicles continued to grow rapidly （1） Gasoline and diesel were upgraded more quickly. China enacted specific measures and schedule requirement of oil quality upgrading in 2013. National IV gasoline began to be used throughout the country on January 1, 2014, with sulfur content dropping to 50ppm.
文摘The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronavirus genera.On January 30,2020,WHO re-evaluated the potential effects of 2019-nCoV infection in global public health,and declared this epidemic as a "Public Health Emergency of International Concern (PHEIC)".
基金State Grid Corporation of China under-Technology Project,Grant/Award Number:5100-202355765A-3-5-YS。
文摘This paper addresses the pressing necessity to align the regulatory capacity of renewable energy sources with their inherent fluctuations across various time scales.Emphasising the pivotal role of large-scale energy storage technologies,the study provides a comprehensive overview,comparison,and evaluation of emerging energy storage solu-tions,such as lithium-ion cells,flow redox cell,and compressed-air energy storage.It outlines three fundamental principles for energy storage system development:prioritising safety,optimising costs,and realising value.Through analysis of two case studies-a pure photovoltaic(PV)power island interconnected via a high-voltage direct current(HVDC)system,and a 100%renewable energy autonomous power supply-the paper elucidates the critical role of energy storage in facilitating high levels of renewable energy integra-tion.Furthermore,it delves into the challenges inherent in the development of energy storage systems.
基金the Science and Technology Project of PetroChina(Grant No.07-01C-01-07)
文摘The Ordos Basin,the second largest sedimentary basin in China,contains the broad distribution of natural gas types.So far,several giant gas fields have been discovered in the Upper and Lower Paleozoic in this basin,each having over 1000×108 m 3 of proven gas reserves,and several gas pools have also been discovered in the Mesozoic.This paper collected the data of natural gases and elucidated the geochemical characteristics of gases from different reservoirs,and then discussed their origin.For hydrocarbons preserved in the Upper Paleozoic,the elevatedδ13C values of methane,ethane and propane indicate that the gases would be mainly coal-formed gases;the singular reversal in the stable carbon isotopes of gaseous alkanes suggests the mixed gases from humic sources with different maturity.In the Lower Paleozoic,theδ13C 1 values are mostly similar with those in the Upper Paleozoic,but theδ13C 2 andδ13C 3 values are slightly lighter,suggesting that the gases would be mixing of coal-type gases as a main member and oil-type gases.There are multiple reversals in carbon isotopes for gaseous alkanes,especially abnormal reversal for methane and ethane(i.e.δ13C 1>δ13C 2),inferring that gases would be mixed between high-mature coal-formed gases and oil-type gases.In the Mesozoic,theδ13Cvalues for gaseous alkanes are enriched in 12C,indicating that the gases are mainly derived from sapropelic sources;the carbon isotopic reversal for propane and butane in the Mesozoic is caused by microbial oxidation and mixing of gases from sapropelic sources with different maturity.In contrast to the Upper Paleozoic gases,the Mesozoic gases are characterized by heavier carbon isotopes of iso-butane than normal butane,which may be caused by gases generated from different kerogen types.Finally,according toδ13C 1-Ro relationship and extremely low total organic carbon contents,the Low Paleozoic gases would not be generated from the Ordovician source as a main gas source,bycontrast,the Upper Paleozoic source as a main gas source is contributed to the Lower Paleozoic gases.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government[2022R1A5A1026413 to H.-D.Y.,H.J.,and 2021R1A2C3006559 to H.-D.Y.].
文摘Dear Editor,Acute Lymphoblastic Leukemia(ALL)is a potent malignancy,constituting 30%of all pediatric cancers.B-cell precursor ALL(BCP-ALL),which represents over 80%of ALL cases,is distinguished by chromosomal rearrangements that yield chimeric fusion proteins,which are unique from their normal counterparts.Among these,myocyte enhancer factor 2D(MEF2D)-fusion genes are found in both pediatric and adult populations and are associated with notably poor prognoses.
基金supported by the Qinghai Province Key Research and Development and Transformation Program Project(Grant No.2022-SF-173).
文摘Based on historical land use for eight periods from 1980 to 2020 and the projected land use under seven Shared Socioeconomic Pathways(SSPs:SSP1-1.9,SSP1-2.6,SSP2-4.5,SSP3-7.0,SSP4-3.4,SSP4-6.0,and SSP5-8.5)from 2021 to 2100,we conducted a study on past and future land use changes in the Qinghai-Tibet Plateau(QTP).This work aims to reveal the land use changes during the carbon peak(2021-2040)and carbon neutrality(2051-2070)periods and at the end of the 21st century(2081-2100).The results show that:(1)in the historical period(1980-2020),the land use types in the QTP were grassland(1475×10^(3)km^(2),58.2%),barren land(685×10^(3)km^(2),27.0%),forest land(243×10^(3)km^(2),9.6%),water(114×10^(3)km^(2),4.5%),cropland(18.6×10^(3)km^(2),0.7%)and urban land(0.3×10^(3)km^(2),0.01%).(2)Relative to the baseline period(1995-2014),the area of grassland is projected to decrease by 0.7%(SSP4-6.0)-5.4%(SSP2-4.5)(0.5-3.9%of the total area of the QTP),2.8%(SSP4-6.0)-12.5%(SSP3-7.0)(2.1-9.4%of the total area of the QTP)and 6.1%(SSP4-6.0)-21.7%(SSP4-3.4)(4.6-16.4%of the total area of the QTP)in the future three periods.In contrast,the forest land area is projected to increase,by approximately 2.5%(SSP4-6.0)to 30.1%(SSP3-7.0)(0.3-4.3%of the total area of the QTP),9.2%(SSP4-6.0)to 56.5%(SSP2-4.5)(1.3-8.0%of the total area of the QTP),and 21.2%(SSP4-6.0)to 72.8%(SSP2-4.5)(3.0-10.2%of the total area of the QTP)in the future three periods,respectively.(3)Approximately 0.4(SSP4-6.0)to 6.9%(SSP5-8.5),0.9(SSP4-6.0)to 2.7%(SSP4-3.4),and 0.04(SSP5-8.5)to 3.5%(SSP1-1.9)of land is expected to convert from grassland to forest land in the future three periods,respectively.The shift from grassland to forest land area is likely to enhance the carbon sink potential of the QTP in the future period.
基金This study was supported by CAMS Innovation Fund for Medical Sciences(CIFMS,2019-12M-5-0262020-I2M-C&T-B-098).
文摘Importance:The Coronavirus disease 2019(COVID-19)global pandemic poses a considerable challenge for pediatricians.Objective:This study aimed to identify the epidemiological characteristics and clinical features of pediatric patients with COVID-19 in China.Methods:This multicenter retrospective study included pediatric patients from 46 hospitals in China,covering 12 provinces and two municipalities.Epidemiological,demographic,clinical,laboratory,treatment,and outcome data were analyzed.Results:In total,211 pediatric patients with COVID-19 were included in this study.The median age was 7.0 years(range:22 days to 18 years).Approximately 16.3%of the patients exhibited asymptomatic infections,23.0%had upper respiratory tract infections,and 60.7%had pneumonia,including two with severe pneumonia and one with critical illness.Approximately 78.7%of the pediatric patients occurred in familial clusters.The most three common symptoms or signs at onset in children with COVID-19 were fever(54.5%),cough(49.3%),and pharyngeal congestion(20.8%).Only 17.6%of the patients presented with decreased lymphocyte count,whereas 13.6%had increased lymphocyte count.Among the patients with pneumonia who exhibited abnormal chest computed tomography findings,18.2%(23/127)of the patients had no other symptoms.Generally,the chest radiographs showed abnormalities that affected both lungs(49.6%);ground-glass opacity(47.2%)was the most common manifestation.The cure and improvement rates were 86.7%(183/211)and 13.3%(28/211),respectively.Only one patient with an underlying condition received invasive mechanical ventilation;none of the patients died.Interpretation:Similar to adults,children of all age groups are susceptible to COVID-19.Fortunately,most pediatric patients have mild symptoms or remain asymptomatic,despite the high incidence of pneumonia.Decreased proportions of white blood cells and lymphocytes are less frequent in children than in adults.
