Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages...Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.展开更多
Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60...Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60× spotting-scope. A total of 310 herds of blue sheep and 1 336 individuals were observed during the study period. Blue sheep were frequently seen in small herds of 2 to 8 individuals, which represent 94.8% of total herds observed. Herds consisting of 9 individuals or more represented 5.2%. The largest herd we observed numbered 51 individuals. Mean group size was 4.2 individuals. Blue sheep herds can be divided into three types: male herds (composed solely of males), female herds (consisting of females with or without juveniles of both sexes), and mixed herds (including adult males, females, and subadults).Among the 310 herds, female herds were counted 150 times(48.4%), mixed herds 154 times(49.7%), and male herds 6 times(1.9%). Of 1 336 blue sheep classified by sex and age, adults, subadults and juveniles composed 64.1%,20.8%, and 15.1% respectively. The female:male ratio of adults was 1∶0.73. The ratio of adult females to juveniles was 1∶0.56, which is higher than the ratio recorded in spring (1∶0.43) or summer (1∶0.44).The results showed that the Helan Mountains State Nature Reserve has succeed in protecting blue sheep.展开更多
In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of ...In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones.展开更多
China’s energy system requires a thorough transformation to achieve carbon neutrality.Here,leveraging the highly acclaimed the Integrated MARKAL-EFOM System model of China(China TIMES)that takes energy,the environmen...China’s energy system requires a thorough transformation to achieve carbon neutrality.Here,leveraging the highly acclaimed the Integrated MARKAL-EFOM System model of China(China TIMES)that takes energy,the environment,and the economy into consideration,four carbon-neutral scenarios are proposed and compared for different emission peak times and carbon emissions in 2050.The results show that China’s carbon emissions will peak at 10.3–10.4 Gt between 2025 and 2030.In 2050,renewables will account for 60%of total energy consumption(calorific value calculation)and 90%of total electricity generation,and the electrification rate will be close to 60%.The energy transition will bring sustained air quality improvement,with an 85%reduction in local air pollutants in 2050 compared with 2020 levels,and an early emission peak will yield more near-term benefits.Early peak attainment requires the extensive deployment of renewables over the next decade and an accelerated phasing out of coal after 2025.However,it will bring benefits such as obtaining better air quality sooner,reducing cumulative CO_(2) emissions,and buying more time for other sectors to transition.The pressure for more ambitious emission reductions in 2050 can be transmitted to the near future,affecting renewable energy development,energy service demand,and welfare losses.展开更多
The previous phylogenies of Sordariomycetes by M.E.Barr,O.E.Eriksson and D.L.Hawksworth,and T.Lumbsch and S.Huhndorf,were mainly based on morphology and thus were somewhat subjective.Later outlines by T.Lumbsch and S....The previous phylogenies of Sordariomycetes by M.E.Barr,O.E.Eriksson and D.L.Hawksworth,and T.Lumbsch and S.Huhndorf,were mainly based on morphology and thus were somewhat subjective.Later outlines by T.Lumbsch and S.Huhndorf,and Maharachchikumbura and co-authors,took into account phylogenetic evidence.However,even these phylogenetic driven arrangements for Sordariomycetes,were somewhat subjective,as the arrangements in trees depended on many variables,such as number of taxa,different gene regions and methods used in the analyses.What is needed is extra evidence to help standardize ranking in the fungi.Estimation of divergence times using molecular clock methods has been proposed for providing additional rational for higher ranking of taxa.Thus,in Sordariomycetes,a divergence period(i.e.200–300 MYA)can be used as criteria to judge when a group of related taxa evolved and what rank they should be given.In this paper,we provide an updated classification of accepted subclasses,orders of Sordariomycetes and use divergence times to provide additional evidence to stabilize ranking of taxa in the class.We point out and discuss discrepancies where the phylogenetic tree conflicts with the molecular clock.展开更多
Fabaceae are the third largest angiosperm family,with 765 genera and~19500 species.They are important both economically and ecologically,and global Fabaceae crops are intensively studied in part for their nitrogen-fix...Fabaceae are the third largest angiosperm family,with 765 genera and~19500 species.They are important both economically and ecologically,and global Fabaceae crops are intensively studied in part for their nitrogen-fixing ability.However,resolution of the intrasubfamilial Fabaceae phylogeny and divergence times has remained elusive,precluding a reconstruction of the evolutionary history of symbiotic nitrogen fixation in Fabaceae.Here,we report a highly resolved phylogeny using>1500 nuclear genes from newly sequenced transcriptomes and genomes of 391 species,along with other datasets,for a total of 463 legumes spanning all 6 subfamilies and 333 of 765 genera.The subfamilies are maximally supported as mono-phyletic.The clade comprising subfamilies Cercidoideae and Detarioideae is sister to the remaining legumes,and Duparquetioideae and Dialioideae are successive sisters to the clade of Papilionoideae and Caesalpinioideae.Molecular clock estimation revealed an early radiation of subfamilies near the K/Pg boundary,marked by mass extinction,and subsequent divergence of most tribe-level clades within~15 million years.Phylogenomic analyses of thousands of gene families support 28 proposed putative whole-genome duplication/whole-genome triplication events across Fabaceae,including those at the ancestors of Fabaceae and five of the subfamilies,and further analyses supported the Fabaceae ancestral polyploidy.The evolution of rhizobial nitrogen-fixing nodulation in Fabaceae was probed by ancestral character reconstruction and phylogenetic analyses of related gene families and the results support the hypotheses of one or two switches)to rhizobial nodulation followed by multiple losses.Collectively,these results provide a foundation for further morphological and functional evolutionary analyses across Fabaceae.展开更多
The academic world is still uncertain about the classification of Taisui. It is debating whether Taisui is living or not, myxomycete complex or fungi. The passage studies the 228 finding reports of Taisui in modern Ch...The academic world is still uncertain about the classification of Taisui. It is debating whether Taisui is living or not, myxomycete complex or fungi. The passage studies the 228 finding reports of Taisui in modern China. It confirms that the first finding time of Taisui in modern China is 1963, and the first reported time is 1992. Taisui has been found in 25 administrative divisions. Taisui occurs the most times in Shandong Province. Besides, provinces where Taisui has been found most times are in northern China. Finding locations of Taisui vary from place to place. Taisui is most often found in normal earth layer, with different burying depth. Taisui is mainly found through seeing, tramping, and digging. Taisui findings lack subjective motivations and are connected with the life and production of the finders. Conclusion: Taisui is an object growing in earth layer.展开更多
Tectonically, the large-scale right-lateral strike-slip movement along the Red River fault zone is char-acterized at its late phase with the southeastward extension and deformation of the Northwestern Yunnan normal fa...Tectonically, the large-scale right-lateral strike-slip movement along the Red River fault zone is char-acterized at its late phase with the southeastward extension and deformation of the Northwestern Yunnan normal fault depression on its northern segment, and the dextral shear displacement on its central-southern segment. Research of the relations between stratum deformation and fault movement on the typical fault segments, such as Jianchuan, southeast Midu, Yuanjiang River, Yuanyang, etc. since the Miocene Epoch shows that there are two times dextral faulting dominated by normal shearing occurring along the Red River fault zone since the Miocene Epoch. The fission track dating (abbrevi-ated to FT dating, the same below) is conducted on apatite samples collected from the above fault segments and relating to these movements. Based on the measured single grain’s age and the con-fined track length, we choose the Laslet annealing model to retrieve the thermal history of the samples, and the results show that the fault zone experienced two times obvious shear displacement, one in 5.5 ± 1.5 MaBP and the other in 2.1± 0.8 MaBP. The central-southern segment sees two intensive uplifts of mountain mass in the Yuanjiang River-Yuanyang region at 3.6―3.8 MaBP and 1.6―2.3 MaBP, which correspond to the above-mentioned two dextral normal displacement events since the late Miocene Epoch.展开更多
文摘Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.
文摘Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60× spotting-scope. A total of 310 herds of blue sheep and 1 336 individuals were observed during the study period. Blue sheep were frequently seen in small herds of 2 to 8 individuals, which represent 94.8% of total herds observed. Herds consisting of 9 individuals or more represented 5.2%. The largest herd we observed numbered 51 individuals. Mean group size was 4.2 individuals. Blue sheep herds can be divided into three types: male herds (composed solely of males), female herds (consisting of females with or without juveniles of both sexes), and mixed herds (including adult males, females, and subadults).Among the 310 herds, female herds were counted 150 times(48.4%), mixed herds 154 times(49.7%), and male herds 6 times(1.9%). Of 1 336 blue sheep classified by sex and age, adults, subadults and juveniles composed 64.1%,20.8%, and 15.1% respectively. The female:male ratio of adults was 1∶0.73. The ratio of adult females to juveniles was 1∶0.56, which is higher than the ratio recorded in spring (1∶0.43) or summer (1∶0.44).The results showed that the Helan Mountains State Nature Reserve has succeed in protecting blue sheep.
基金Project supported by the National Natural Science Foundation of China (No. 60474064), and the Natural Science Foundation of Zhejiang Province (No. Y105694), China
文摘In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones.
基金supported by the National Natural Science Foundation of China (71690243 and 51861135102)the Ministry of Science and Technology of the People’s Republic of China (2018YFC1509006)the World Bank Group (7202065)
文摘China’s energy system requires a thorough transformation to achieve carbon neutrality.Here,leveraging the highly acclaimed the Integrated MARKAL-EFOM System model of China(China TIMES)that takes energy,the environment,and the economy into consideration,four carbon-neutral scenarios are proposed and compared for different emission peak times and carbon emissions in 2050.The results show that China’s carbon emissions will peak at 10.3–10.4 Gt between 2025 and 2030.In 2050,renewables will account for 60%of total energy consumption(calorific value calculation)and 90%of total electricity generation,and the electrification rate will be close to 60%.The energy transition will bring sustained air quality improvement,with an 85%reduction in local air pollutants in 2050 compared with 2020 levels,and an early emission peak will yield more near-term benefits.Early peak attainment requires the extensive deployment of renewables over the next decade and an accelerated phasing out of coal after 2025.However,it will bring benefits such as obtaining better air quality sooner,reducing cumulative CO_(2) emissions,and buying more time for other sectors to transition.The pressure for more ambitious emission reductions in 2050 can be transmitted to the near future,affecting renewable energy development,energy service demand,and welfare losses.
基金K.D.Hyde thanks the Chinese Academy of Sciences,Project Number 2013T2S0030for the award of Visiting Professorship for Senior International Scientists at Kunming Institute of Botany.The authors extend their appreciation to the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP#0089+2 种基金K.D.Hyde would like to thank the Thailand Research Fund(TRF)Grant No.RSA5980068 entitled Biodiversityphylogeny and role of fungal endophytes on above parts of Rhizophora apiculata and Nypa fruticans and National Research Council of Thailand(NRCT)entitled Diseases of mangrove trees and maintenance of good forestry practice(Grant Number:60201000201)The authors would like to thank NRCT for the grant to study the Biodiversity,phylogeny and role of fungal endophytes of Pandanaceae(Grant No.:592010200112).
文摘The previous phylogenies of Sordariomycetes by M.E.Barr,O.E.Eriksson and D.L.Hawksworth,and T.Lumbsch and S.Huhndorf,were mainly based on morphology and thus were somewhat subjective.Later outlines by T.Lumbsch and S.Huhndorf,and Maharachchikumbura and co-authors,took into account phylogenetic evidence.However,even these phylogenetic driven arrangements for Sordariomycetes,were somewhat subjective,as the arrangements in trees depended on many variables,such as number of taxa,different gene regions and methods used in the analyses.What is needed is extra evidence to help standardize ranking in the fungi.Estimation of divergence times using molecular clock methods has been proposed for providing additional rational for higher ranking of taxa.Thus,in Sordariomycetes,a divergence period(i.e.200–300 MYA)can be used as criteria to judge when a group of related taxa evolved and what rank they should be given.In this paper,we provide an updated classification of accepted subclasses,orders of Sordariomycetes and use divergence times to provide additional evidence to stabilize ranking of taxa in the class.We point out and discuss discrepancies where the phylogenetic tree conflicts with the molecular clock.
基金supported by funds from the National Natural Science Foundation of China(31770242 and 31970224)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31010000)+1 种基金funds from the State Key Laboratory of Genetic Engineering and the Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering at Fudan Universityfunds from the Pennsylvania State University.
文摘Fabaceae are the third largest angiosperm family,with 765 genera and~19500 species.They are important both economically and ecologically,and global Fabaceae crops are intensively studied in part for their nitrogen-fixing ability.However,resolution of the intrasubfamilial Fabaceae phylogeny and divergence times has remained elusive,precluding a reconstruction of the evolutionary history of symbiotic nitrogen fixation in Fabaceae.Here,we report a highly resolved phylogeny using>1500 nuclear genes from newly sequenced transcriptomes and genomes of 391 species,along with other datasets,for a total of 463 legumes spanning all 6 subfamilies and 333 of 765 genera.The subfamilies are maximally supported as mono-phyletic.The clade comprising subfamilies Cercidoideae and Detarioideae is sister to the remaining legumes,and Duparquetioideae and Dialioideae are successive sisters to the clade of Papilionoideae and Caesalpinioideae.Molecular clock estimation revealed an early radiation of subfamilies near the K/Pg boundary,marked by mass extinction,and subsequent divergence of most tribe-level clades within~15 million years.Phylogenomic analyses of thousands of gene families support 28 proposed putative whole-genome duplication/whole-genome triplication events across Fabaceae,including those at the ancestors of Fabaceae and five of the subfamilies,and further analyses supported the Fabaceae ancestral polyploidy.The evolution of rhizobial nitrogen-fixing nodulation in Fabaceae was probed by ancestral character reconstruction and phylogenetic analyses of related gene families and the results support the hypotheses of one or two switches)to rhizobial nodulation followed by multiple losses.Collectively,these results provide a foundation for further morphological and functional evolutionary analyses across Fabaceae.
文摘The academic world is still uncertain about the classification of Taisui. It is debating whether Taisui is living or not, myxomycete complex or fungi. The passage studies the 228 finding reports of Taisui in modern China. It confirms that the first finding time of Taisui in modern China is 1963, and the first reported time is 1992. Taisui has been found in 25 administrative divisions. Taisui occurs the most times in Shandong Province. Besides, provinces where Taisui has been found most times are in northern China. Finding locations of Taisui vary from place to place. Taisui is most often found in normal earth layer, with different burying depth. Taisui is mainly found through seeing, tramping, and digging. Taisui findings lack subjective motivations and are connected with the life and production of the finders. Conclusion: Taisui is an object growing in earth layer.
基金the National Natural Science Foundation of China (Grant No.40272087)
文摘Tectonically, the large-scale right-lateral strike-slip movement along the Red River fault zone is char-acterized at its late phase with the southeastward extension and deformation of the Northwestern Yunnan normal fault depression on its northern segment, and the dextral shear displacement on its central-southern segment. Research of the relations between stratum deformation and fault movement on the typical fault segments, such as Jianchuan, southeast Midu, Yuanjiang River, Yuanyang, etc. since the Miocene Epoch shows that there are two times dextral faulting dominated by normal shearing occurring along the Red River fault zone since the Miocene Epoch. The fission track dating (abbrevi-ated to FT dating, the same below) is conducted on apatite samples collected from the above fault segments and relating to these movements. Based on the measured single grain’s age and the con-fined track length, we choose the Laslet annealing model to retrieve the thermal history of the samples, and the results show that the fault zone experienced two times obvious shear displacement, one in 5.5 ± 1.5 MaBP and the other in 2.1± 0.8 MaBP. The central-southern segment sees two intensive uplifts of mountain mass in the Yuanjiang River-Yuanyang region at 3.6―3.8 MaBP and 1.6―2.3 MaBP, which correspond to the above-mentioned two dextral normal displacement events since the late Miocene Epoch.
