The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the...The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the half-cell test.However,here we find that contrary to consensus,the ester electrolyte shows better Na storage capability than the ether electrolyte in full cells.An in-depth analysis of three-electrode,symmetric cell,and in situ XRD tests indicates that traditional half-cell test results are unreliable due to interference from Na electrodes.In particular,Na electrodes show a huge stability difference in ester and ether electrolytes,and ester electrolytes suffer more severe interference than ether electrolytes,resulting in the belief that esters are far inferior to ether electrolytes.More seriously,the more accurate three-electrode test would also suffer from Na electrode interference.Thus,a“corrected half-cell test”protocol is developed to shield the Na electrode interference,revealing the very close super rate capability of hard carbon in ester and ether electrolytes.This work breaks the inherent perception that the kinetic properties of ester electrolytes are inferior to ethers in sodium-ion batteries,reveals the pitfalls of half-cell tests,and proposes a new test protocol for reliable results,greatly accelerating the commercialization of sodium-ion batteries.展开更多
By viewing satellite imagery, a striking large-scale dunefield can be clearly perceived, with a size of nearly 63 km long and 11 km wide, and trending NE-SW, on the right flank of the lower Laoha River, Northeast Chin...By viewing satellite imagery, a striking large-scale dunefield can be clearly perceived, with a size of nearly 63 km long and 11 km wide, and trending NE-SW, on the right flank of the lower Laoha River, Northeast China. By means of remote sensing imagery analysis and field observation as well as a comparison with a small-scale dunefield on the right flank of the lower Xiangshui River, analogous to the case of the lower Laoha River, this paper presents a new mechanism for its origin and development. The results show that: (1) the large-scale dunefield bears a tile-style framework overwhelmingly composed of transverse barchanoid ridges perpendicular to the predominant winds, and inlaid diverse blowouts. (2) The small-scale dunefield, referred to as a primary structural unit of the large one, is typical of an incipient dunefield, following the same rules of evolution as the larger. (3) A succession of barchanoid ridge chains can steadily migrate downwind in much the same manner as surface wave propagation in air or water stimulated by an incised valley, and ultimately tend to bear roughly the same wavelength and amplitude under stable climate and hydrologic regimes. (4) The first ridge chain acquires its sand source substantially from the downwind escarpments exposing the loose Quaternary sandy sediments to the air, while the ensuing ridges derive their sands dominantly from in situ deflation of the underlain Quaternary loose sandy sediments in blowouts, partly from the upwind ridges through northern elongated horns. Theoretically, the sands from riparian escarpments can be transported by wind to the downwind distal end of a dunefield after sufficient long du- ration. (5) The lower Laohahe region experienced probably three significant climatic changes in the past, corresponding to the three active dune belts, suggesting that once a large-scale dunefield occurs, it is nearly impossible to be completely stabilized, at least in its central portions. At present, seasonal shrinkage and stagnation of the lower Laoha River, wide-spread farming and afforestation in the valley, and establishing windbreaks downwind of the valley as well as surrounding the dunefield, appear to have significantly modified local flow fields and sand sources, engendering significant degradation of the dunefield.展开更多
Objective:To investigate the effectiveness of applying a multidisciplinary collaborative model for the diagnosis and treatment of patients with vertigo.Methods:The study was carried out in Xianyang Hospital of Yan’an...Objective:To investigate the effectiveness of applying a multidisciplinary collaborative model for the diagnosis and treatment of patients with vertigo.Methods:The study was carried out in Xianyang Hospital of Yan’an University,in which 100 patients with vertigo were selected from April 2021 to April 2022 and were divided into two groups:the control group was under the single diagnosis and treatment model,whereas the experimental group was under the multidisciplinary collaborative diagnosis and treatment model,with 50 cases in each group.The diagnostic effects of the two groups were compared.Results:The diagnostic and therapeutic efficiency of the patients in the experimental group were 94%and 98%,respectively,while those of the patients in the control group were 78%and 82%,respectively,with a significant difference between the two groups(p<0.05).The balance scores of the patients in both groups were low before the treatment,in which the difference was not significant(p>0.05);after the treatment,the scores improved,with those of the patients in the experimental group being significantly higher than those in the control group(p<0.05).Moreover,the satisfaction rate of patients in the experimental group(98%)was significantly higher than that of the control group(80%)(p<0.05).Conclusion:The application of the multidisciplinary collaborative diagnosis and treatment model in the diagnosis of patients with vertigo is effective.The multidisciplinary model can improve clinical diagnosis,enhance the treatment effect,improve the clinical symptoms of patients,and increase the satisfaction of patient care.Hence,it is of high clinical application value.展开更多
Reconstructing the Holocene megaflood history is a key component of understanding the mechanism of past climate change and assessing the potential impact of future catastrophic events.The Pearl River is the longest wa...Reconstructing the Holocene megaflood history is a key component of understanding the mechanism of past climate change and assessing the potential impact of future catastrophic events.The Pearl River is the longest watercourse in southern China,and its lower reach has been identified as one of the world's most vulnerable regions for flood exposure.However,there is a complete lack of millennial-scale geological records of paleomegafloods for the future prediction of once-in-a-hundred(even once-in-a-thousand)year floods in southern China.Here,we identified a series of paleomegaflood deposits interbedded with wood-rich peat layers in the lower West Pearl River area.All paleoflood layers have been well dated using AMS~(14)C dating method.According to the regional correlation of the flood sequence,sediment characteristics and provenance analysis,there have been at least 7 megafloods corresponding to once-in-a-thousand-year events in the lower reaches of the West Pearl River during the past 6000 years,with an average return period of approximately 855 years.The identified paleomegafloods were coeval with periods of strong El Ni?o-Southern Oscillation(ENSO),indicating that weakening of the Asian summer monsoon,associated with enhanced ENSO variability,may have triggered abnormally high precipitation leading to flooding of exceptional magnitude in southern China.In addition,the most prominent paleomegafloods identified in the lower Pearl River coincided with intervals of lower precipitation and fewer storms in central-eastern China,indicating the intensification of the meridional“tripole”pattern of precipitation across eastern China during the latter half of the Holocene.Increased land use and deforestation over the last 2000 years have resulted in soil loss and rapid degradation of local primeval forest ecosystems,leading to more catastrophic flooding.Large amounts of rice pollen in the uppermost flood layer during the Song Dynasty indicate that this megaflood may have inundated a large area of cultivated land.The periodic occurrence of Holocene megafloods not only caused damage to human existence,but also affected the evolution of local civilization.This study reveals for the first time a series of Holocene millennial-scale megafloods and sheds new light on the importance of atmosphere-ocean interactions in the tropical Pacific and monsoon subtropical climate dynamics for precipitation anomalies in East Asia.Our data yield valuable information for future research into climate extremes and hazard prevention.展开更多
Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from...Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from stem cells have been obtained from studies on the dicot Arabidopsis thaliana. However, less is known about plant body specialization in monocots, another important branch of angiosperms. In this study, we analyzed stem cell lineage and differentiation during development of the root and leaf of the monocot model plant rice(Oryza sativa). Our results showed that three body layers of rice are established from stem cells accompanied by progressively reduced pluripotency. Layer 1(L1) is a single-cell layer of epidermis; L2 is the cortex/endodermis in the root and the mesophyll in the leaf; and L3 is the site of vascular initiation. At least two common steps in vascular development are shared between rice root and leaf. The preprocambium divides to form the procambium and root pericycle or leaf outer sheath. The procambium further differentiates into the xylem, phloem and circumambient cells. We found that the outer sheath of leaf vascular bundles originates not only from the preprocambium of L3,but also from the mesophyll precursor cells of L2. In addition, WUSCHEL-RELATED HOMEOBOX(WOX)genes are expressed in not only the stem cell niche but also metaxylem precursor in rice. This pattern differs from that of homologs in Arabidopsis, suggesting that WOX functions have been recruited in different stem cells in dicots and monocots.展开更多
De novo root regeneration(DNRR) has wide applications in agriculture such as those related to cutting technology. Detached Arabidopsis thaliana leaf explants can regenerate adventitious roots without added hormones. T...De novo root regeneration(DNRR) has wide applications in agriculture such as those related to cutting technology. Detached Arabidopsis thaliana leaf explants can regenerate adventitious roots without added hormones. The regenerative ability is highly dependent on the developmental status of the leaf. An immature leaf has a higher regenerative ability, while a mature leaf is difficult to regenerate. Using RNASeq analysis, we showed that the expression levels of many genes, including those in the auxin network,changed during leaf maturation. Particularly, the expression levels of many YUCCA(YUC) genes in the auxin biosynthesis pathway are responsive to leaf maturation. Overexpression of YUC1 in the yuc-1 D dominant mutant rescued the rooting defects caused by leaf maturation. In addition, YUC4 expression levels were also affected by circadian rhythms. The regenerative ability was reduced in both immature and mature mutant leaf explants from the new wuschel-related homeobox 11-3(wox11-3) and wox12-3 mutant alleles created by the CRISPR/Cas9 method. Overall, the transcriptome and genetic data, together with the auxin concentration analysis, indicate that the ability to upregulate auxin levels upon detachment may be reduced during leaf maturation. Thus, multiple developmental and environmental signals may converge to control auxin accumulation, which affects the efficiency of the WOX11/12-mediated DNRR from leaf explants.展开更多
To improve the problem of low temperature at night in winter due to the lack of thermal storage in large-span plastic tunnels,an air thermal energy utilization system(ATEUS)was developed with fan-coil units to heat a ...To improve the problem of low temperature at night in winter due to the lack of thermal storage in large-span plastic tunnels,an air thermal energy utilization system(ATEUS)was developed with fan-coil units to heat a large-scale plastic tunnel covered with an external blanket(LPTEB)on winter nights.The ATEUS was composed of nine fan-coil units mounted on top of the LPTEB,a water reservoir,pipes,and a water circulation pump.With the heat exchange between the air and the water flowing through the coils,the thermal energy from the air can be collected in the daytime,or the thermal energy in the water can be released into the LPTEB at night.On sunny days,the collected thermal energy from the air in the daytime(E_(c))and released thermal energy at night(E_(r))were 0.25-0.44 MJ/m^(2) and 0.24-0.38 MJ/m^(2),respectively.Used ATEUS as a heating system,its coefficient of performance(COP),which is the ratio of the heat consumption of LPTEB to the power consumption of ATEUS,ranged from 1.6-2.1.A dynamic model was also developed to simulate the water temperature(T_(w)).Based on the simulation,E_(c) and E_(r) on sunny days can be increased by 60%-73%and 38%-62%,respectively,by diminishing the heat loss of the water reservoir and increasing the indoor air temperature in the period of collecting thermal energy.Then,the COP can reach 2.6-3.8,and the developed ATEUS can be applied to heating the LPTEB in a way that conserves energy.展开更多
基金supported by the National Natural Science Foundation of China(22179094)the Tianjin Research Program of Application Foundation and Advanced Technology of China(15ZCZDGX00270)
文摘The ether electrolytes usually outperform ester electrolytes by evaluating sodium-ion batteries(SIBs)rate performance,which is a near-unanimous conclusion of previous studies based on an essential configuration of the half-cell test.However,here we find that contrary to consensus,the ester electrolyte shows better Na storage capability than the ether electrolyte in full cells.An in-depth analysis of three-electrode,symmetric cell,and in situ XRD tests indicates that traditional half-cell test results are unreliable due to interference from Na electrodes.In particular,Na electrodes show a huge stability difference in ester and ether electrolytes,and ester electrolytes suffer more severe interference than ether electrolytes,resulting in the belief that esters are far inferior to ether electrolytes.More seriously,the more accurate three-electrode test would also suffer from Na electrode interference.Thus,a“corrected half-cell test”protocol is developed to shield the Na electrode interference,revealing the very close super rate capability of hard carbon in ester and ether electrolytes.This work breaks the inherent perception that the kinetic properties of ester electrolytes are inferior to ethers in sodium-ion batteries,reveals the pitfalls of half-cell tests,and proposes a new test protocol for reliable results,greatly accelerating the commercialization of sodium-ion batteries.
基金funded by NSFC(Grant No.41271025)the Construct Program of the Key Discipline in Hunan Province,China (2012001)
文摘By viewing satellite imagery, a striking large-scale dunefield can be clearly perceived, with a size of nearly 63 km long and 11 km wide, and trending NE-SW, on the right flank of the lower Laoha River, Northeast China. By means of remote sensing imagery analysis and field observation as well as a comparison with a small-scale dunefield on the right flank of the lower Xiangshui River, analogous to the case of the lower Laoha River, this paper presents a new mechanism for its origin and development. The results show that: (1) the large-scale dunefield bears a tile-style framework overwhelmingly composed of transverse barchanoid ridges perpendicular to the predominant winds, and inlaid diverse blowouts. (2) The small-scale dunefield, referred to as a primary structural unit of the large one, is typical of an incipient dunefield, following the same rules of evolution as the larger. (3) A succession of barchanoid ridge chains can steadily migrate downwind in much the same manner as surface wave propagation in air or water stimulated by an incised valley, and ultimately tend to bear roughly the same wavelength and amplitude under stable climate and hydrologic regimes. (4) The first ridge chain acquires its sand source substantially from the downwind escarpments exposing the loose Quaternary sandy sediments to the air, while the ensuing ridges derive their sands dominantly from in situ deflation of the underlain Quaternary loose sandy sediments in blowouts, partly from the upwind ridges through northern elongated horns. Theoretically, the sands from riparian escarpments can be transported by wind to the downwind distal end of a dunefield after sufficient long du- ration. (5) The lower Laohahe region experienced probably three significant climatic changes in the past, corresponding to the three active dune belts, suggesting that once a large-scale dunefield occurs, it is nearly impossible to be completely stabilized, at least in its central portions. At present, seasonal shrinkage and stagnation of the lower Laoha River, wide-spread farming and afforestation in the valley, and establishing windbreaks downwind of the valley as well as surrounding the dunefield, appear to have significantly modified local flow fields and sand sources, engendering significant degradation of the dunefield.
基金supported by the Key Research and Development Program of Shaanxi Province(Grant Number:2020SF-146)the Science and Technology Project of Xianyang City(Project Number:2021ZDYF-SF-0062).
文摘Objective:To investigate the effectiveness of applying a multidisciplinary collaborative model for the diagnosis and treatment of patients with vertigo.Methods:The study was carried out in Xianyang Hospital of Yan’an University,in which 100 patients with vertigo were selected from April 2021 to April 2022 and were divided into two groups:the control group was under the single diagnosis and treatment model,whereas the experimental group was under the multidisciplinary collaborative diagnosis and treatment model,with 50 cases in each group.The diagnostic effects of the two groups were compared.Results:The diagnostic and therapeutic efficiency of the patients in the experimental group were 94%and 98%,respectively,while those of the patients in the control group were 78%and 82%,respectively,with a significant difference between the two groups(p<0.05).The balance scores of the patients in both groups were low before the treatment,in which the difference was not significant(p>0.05);after the treatment,the scores improved,with those of the patients in the experimental group being significantly higher than those in the control group(p<0.05).Moreover,the satisfaction rate of patients in the experimental group(98%)was significantly higher than that of the control group(80%)(p<0.05).Conclusion:The application of the multidisciplinary collaborative diagnosis and treatment model in the diagnosis of patients with vertigo is effective.The multidisciplinary model can improve clinical diagnosis,enhance the treatment effect,improve the clinical symptoms of patients,and increase the satisfaction of patient care.Hence,it is of high clinical application value.
基金supported by the National Natural Science Foundation of China(Grant Nos.42072205&41301582)the National Key R&D Program of China(Grant No.2022YFF0801501)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311022010)。
文摘Reconstructing the Holocene megaflood history is a key component of understanding the mechanism of past climate change and assessing the potential impact of future catastrophic events.The Pearl River is the longest watercourse in southern China,and its lower reach has been identified as one of the world's most vulnerable regions for flood exposure.However,there is a complete lack of millennial-scale geological records of paleomegafloods for the future prediction of once-in-a-hundred(even once-in-a-thousand)year floods in southern China.Here,we identified a series of paleomegaflood deposits interbedded with wood-rich peat layers in the lower West Pearl River area.All paleoflood layers have been well dated using AMS~(14)C dating method.According to the regional correlation of the flood sequence,sediment characteristics and provenance analysis,there have been at least 7 megafloods corresponding to once-in-a-thousand-year events in the lower reaches of the West Pearl River during the past 6000 years,with an average return period of approximately 855 years.The identified paleomegafloods were coeval with periods of strong El Ni?o-Southern Oscillation(ENSO),indicating that weakening of the Asian summer monsoon,associated with enhanced ENSO variability,may have triggered abnormally high precipitation leading to flooding of exceptional magnitude in southern China.In addition,the most prominent paleomegafloods identified in the lower Pearl River coincided with intervals of lower precipitation and fewer storms in central-eastern China,indicating the intensification of the meridional“tripole”pattern of precipitation across eastern China during the latter half of the Holocene.Increased land use and deforestation over the last 2000 years have resulted in soil loss and rapid degradation of local primeval forest ecosystems,leading to more catastrophic flooding.Large amounts of rice pollen in the uppermost flood layer during the Song Dynasty indicate that this megaflood may have inundated a large area of cultivated land.The periodic occurrence of Holocene megafloods not only caused damage to human existence,but also affected the evolution of local civilization.This study reveals for the first time a series of Holocene millennial-scale megafloods and sheds new light on the importance of atmosphere-ocean interactions in the tropical Pacific and monsoon subtropical climate dynamics for precipitation anomalies in East Asia.Our data yield valuable information for future research into climate extremes and hazard prevention.
基金supported by National Basic Research Program of China(2014CB943500/2012CB910500)the National Natural Science Foundation of China(91419302/31422005)Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from stem cells have been obtained from studies on the dicot Arabidopsis thaliana. However, less is known about plant body specialization in monocots, another important branch of angiosperms. In this study, we analyzed stem cell lineage and differentiation during development of the root and leaf of the monocot model plant rice(Oryza sativa). Our results showed that three body layers of rice are established from stem cells accompanied by progressively reduced pluripotency. Layer 1(L1) is a single-cell layer of epidermis; L2 is the cortex/endodermis in the root and the mesophyll in the leaf; and L3 is the site of vascular initiation. At least two common steps in vascular development are shared between rice root and leaf. The preprocambium divides to form the procambium and root pericycle or leaf outer sheath. The procambium further differentiates into the xylem, phloem and circumambient cells. We found that the outer sheath of leaf vascular bundles originates not only from the preprocambium of L3,but also from the mesophyll precursor cells of L2. In addition, WUSCHEL-RELATED HOMEOBOX(WOX)genes are expressed in not only the stem cell niche but also metaxylem precursor in rice. This pattern differs from that of homologs in Arabidopsis, suggesting that WOX functions have been recruited in different stem cells in dicots and monocots.
基金supported by grants from the National Natural Science Foundation of China (31630007, 31770399 and 21375066)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB27030103)+1 种基金the Key Research Program of CAS (QYZDB-SSWSMC010)the National Key Laboratory of Plant Molecular Genetics
文摘De novo root regeneration(DNRR) has wide applications in agriculture such as those related to cutting technology. Detached Arabidopsis thaliana leaf explants can regenerate adventitious roots without added hormones. The regenerative ability is highly dependent on the developmental status of the leaf. An immature leaf has a higher regenerative ability, while a mature leaf is difficult to regenerate. Using RNASeq analysis, we showed that the expression levels of many genes, including those in the auxin network,changed during leaf maturation. Particularly, the expression levels of many YUCCA(YUC) genes in the auxin biosynthesis pathway are responsive to leaf maturation. Overexpression of YUC1 in the yuc-1 D dominant mutant rescued the rooting defects caused by leaf maturation. In addition, YUC4 expression levels were also affected by circadian rhythms. The regenerative ability was reduced in both immature and mature mutant leaf explants from the new wuschel-related homeobox 11-3(wox11-3) and wox12-3 mutant alleles created by the CRISPR/Cas9 method. Overall, the transcriptome and genetic data, together with the auxin concentration analysis, indicate that the ability to upregulate auxin levels upon detachment may be reduced during leaf maturation. Thus, multiple developmental and environmental signals may converge to control auxin accumulation, which affects the efficiency of the WOX11/12-mediated DNRR from leaf explants.
基金financially supported by China Agriculture Research System of MOF and MARA(Grant No.CARS-23-D02)the Key Research and Development Plan,Science Technology Department of Zhejiang Province(Grant No.2019C02009).
文摘To improve the problem of low temperature at night in winter due to the lack of thermal storage in large-span plastic tunnels,an air thermal energy utilization system(ATEUS)was developed with fan-coil units to heat a large-scale plastic tunnel covered with an external blanket(LPTEB)on winter nights.The ATEUS was composed of nine fan-coil units mounted on top of the LPTEB,a water reservoir,pipes,and a water circulation pump.With the heat exchange between the air and the water flowing through the coils,the thermal energy from the air can be collected in the daytime,or the thermal energy in the water can be released into the LPTEB at night.On sunny days,the collected thermal energy from the air in the daytime(E_(c))and released thermal energy at night(E_(r))were 0.25-0.44 MJ/m^(2) and 0.24-0.38 MJ/m^(2),respectively.Used ATEUS as a heating system,its coefficient of performance(COP),which is the ratio of the heat consumption of LPTEB to the power consumption of ATEUS,ranged from 1.6-2.1.A dynamic model was also developed to simulate the water temperature(T_(w)).Based on the simulation,E_(c) and E_(r) on sunny days can be increased by 60%-73%and 38%-62%,respectively,by diminishing the heat loss of the water reservoir and increasing the indoor air temperature in the period of collecting thermal energy.Then,the COP can reach 2.6-3.8,and the developed ATEUS can be applied to heating the LPTEB in a way that conserves energy.