The properties of the same pigments in murals are affected by different concentrations and particle diameters,which cause the shape of the spectral reflectance data curve to vary,thus influencing the outcome of matchi...The properties of the same pigments in murals are affected by different concentrations and particle diameters,which cause the shape of the spectral reflectance data curve to vary,thus influencing the outcome of matching calculations.This paper proposes a spectral matching classification method of multi-state similar pigments based on feature differences.Fast principal component analysis(FPCA)was used to calculate the eigenvalue variance of pigment spectral reflectance,then applied to the original reflectance values for parameter characterization.We first projected the original spectral reflectance from the spectral space to the characteristic variance space to identify the spectral curve.Secondly,the relative distance between the eigenvalues in the eigen variance space is combined with the JS(Jensen-Shannon)divergence to express the difference between the two spectral distributions.The JS information divergence calculates the relative distance between the eigenvalues.Experimental results showthat our classification method can be used to identify the spectral curves of the same pigment under different states.The value of the root means square error(RMSE)decreased by 12.0817,while the mean values of the mean absolute percentage error(MAPE)and R2 increased by 0.0965 and 0.2849,respectively.Compared with the traditional spectral matching algorithm,the recognition error was effectively reduced.展开更多
Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of so...Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of southern East Asians.However,large-scale genetic studies on ancient populations in this region are hindered by limited sample preservation.Here,using highly efficient DNA capture techniques,we obtain 48 complete mitochondrial genomes of individuals from Guangxi and Fujian in China and reconstruct their maternal genetic history over the past 12,000 years.We find a strong connection between southern East Asians dating to~12,000-6000 years ago and present-day Southeast Asians.In addition,stronger genetic affinities to northern East Asians are observed in historical southern East Asians than Neolithic southern East Asians,suggesting increased interactions between northern and southern East Asians over time.Overall,we reveal dynamic connections between ancient southern East Asians and populations located in surrounding regions,as well as a shift in maternal genetic structure within the populations over time.展开更多
Phyto-groups on 5 remained city wall sections of the Ming Dynasty in Nanjing City was investigated through on-the-spot survey,99 species of 93 genera,60 families were found,and species of Asteraceae and Poaceae accoun...Phyto-groups on 5 remained city wall sections of the Ming Dynasty in Nanjing City was investigated through on-the-spot survey,99 species of 93 genera,60 families were found,and species of Asteraceae and Poaceae accounted for the largest ratio.Plants on the city wall are characterized by strong drought resistance and precocity,their seeds can grow out of the wall cracks,and roots secrete acidoid and obtain nutrients from wall bricks.Plants on different wall sections are different,and human interventions influence phyto-groups on the city wall greatly.On this basis,it was concluded that plants had negative influence on city wall,especially plant roots destroyed the wall seriously.Corresponding researches were carried out and prevention suggestions proposed to provide scientific support for the protection of ancient city walls in Nanjing City.展开更多
South China preserves a rich archaeological record elucidating the evolution of early modern humans during the Late Pleistocene.However,few studies on plant utilization were conducted in this region.We used phytolith ...South China preserves a rich archaeological record elucidating the evolution of early modern humans during the Late Pleistocene.However,few studies on plant utilization were conducted in this region.We used phytolith analysis from Yahuai Cave,Guangxi,to infer human use of plant resources over the past 30000 years.AMS 14C dating was used to constrain the chronological framework.Results indicate that several economically essential species were present throughout the sequence including Urticineae(cf.Ulmus sp.),which appears in the lower layers of the sequence(Marine Isotope Stage 3 through Heinrich 1);bamboo and palm which appear throughout the sequence,and wild rice which appears in a clear archaeological context dating to 16000 years ago.This is the earliest record of wild rice in South China and a prerequisite for rice domestication.The unique stone tool assemblages,which resemble those in north China as opposed to South China,point to the possibility that humans,seeking refuge from the colder north,brought their tool kit with them and utilized familiar northern taxa.Warmer South China would have served as a refuge for human populations escaping the cold,harsh climate in the north with more ameliorate conditions in the south.展开更多
基金This work was supported in part by the National Science Foundation of China:Shaanxi Natural Science Basic Research Project(2021JM-377)Science and Technology Cooperation Project of Shaanxi Provincial Department of Science and Technology(2020KW-012)University Talent Service Enterprise Project of Xi’an Science and Technology Bureau(GXYD10.1)。
文摘The properties of the same pigments in murals are affected by different concentrations and particle diameters,which cause the shape of the spectral reflectance data curve to vary,thus influencing the outcome of matching calculations.This paper proposes a spectral matching classification method of multi-state similar pigments based on feature differences.Fast principal component analysis(FPCA)was used to calculate the eigenvalue variance of pigment spectral reflectance,then applied to the original reflectance values for parameter characterization.We first projected the original spectral reflectance from the spectral space to the characteristic variance space to identify the spectral curve.Secondly,the relative distance between the eigenvalues in the eigen variance space is combined with the JS(Jensen-Shannon)divergence to express the difference between the two spectral distributions.The JS information divergence calculates the relative distance between the eigenvalues.Experimental results showthat our classification method can be used to identify the spectral curves of the same pigment under different states.The value of the root means square error(RMSE)decreased by 12.0817,while the mean values of the mean absolute percentage error(MAPE)and R2 increased by 0.0965 and 0.2849,respectively.Compared with the traditional spectral matching algorithm,the recognition error was effectively reduced.
基金This work was supported by the Chinese Academy of Sciences(CAS,XDB26000000,YSBR-019,XDA1905010,QYZDB-SSW-DQC003)National Natural Science Foundation of China(41925009,41630102,41672021)+2 种基金“Research on the roots of Chinese civilization”of Zhengzhou University(XKZDJC202006)Tencent Foundation through the XPLORER PRIZEthe Howard Hughes Medical Institute(55008731).
文摘Southern East Asia,including Guangxi and Fujian provinces in China,is home to diverse ethnic groups,languages,and cultures.Previous studies suggest a high complexity regarding population dynamics and the history of southern East Asians.However,large-scale genetic studies on ancient populations in this region are hindered by limited sample preservation.Here,using highly efficient DNA capture techniques,we obtain 48 complete mitochondrial genomes of individuals from Guangxi and Fujian in China and reconstruct their maternal genetic history over the past 12,000 years.We find a strong connection between southern East Asians dating to~12,000-6000 years ago and present-day Southeast Asians.In addition,stronger genetic affinities to northern East Asians are observed in historical southern East Asians than Neolithic southern East Asians,suggesting increased interactions between northern and southern East Asians over time.Overall,we reveal dynamic connections between ancient southern East Asians and populations located in surrounding regions,as well as a shift in maternal genetic structure within the populations over time.
基金Supported by Program of National Natural Science Foundation of China(NSFC J0730641)Phase-III Innovative Undergraduate Cultivation Program of "985 Project" of Nanjing University
文摘Phyto-groups on 5 remained city wall sections of the Ming Dynasty in Nanjing City was investigated through on-the-spot survey,99 species of 93 genera,60 families were found,and species of Asteraceae and Poaceae accounted for the largest ratio.Plants on the city wall are characterized by strong drought resistance and precocity,their seeds can grow out of the wall cracks,and roots secrete acidoid and obtain nutrients from wall bricks.Plants on different wall sections are different,and human interventions influence phyto-groups on the city wall greatly.On this basis,it was concluded that plants had negative influence on city wall,especially plant roots destroyed the wall seriously.Corresponding researches were carried out and prevention suggestions proposed to provide scientific support for the protection of ancient city walls in Nanjing City.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB26000000)the National Natural Science Foundation of China(Grant Nos.41877427&41730319)+1 种基金the National Basic Research Program of China(Grant No.2015CB953803)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2018099)。
文摘South China preserves a rich archaeological record elucidating the evolution of early modern humans during the Late Pleistocene.However,few studies on plant utilization were conducted in this region.We used phytolith analysis from Yahuai Cave,Guangxi,to infer human use of plant resources over the past 30000 years.AMS 14C dating was used to constrain the chronological framework.Results indicate that several economically essential species were present throughout the sequence including Urticineae(cf.Ulmus sp.),which appears in the lower layers of the sequence(Marine Isotope Stage 3 through Heinrich 1);bamboo and palm which appear throughout the sequence,and wild rice which appears in a clear archaeological context dating to 16000 years ago.This is the earliest record of wild rice in South China and a prerequisite for rice domestication.The unique stone tool assemblages,which resemble those in north China as opposed to South China,point to the possibility that humans,seeking refuge from the colder north,brought their tool kit with them and utilized familiar northern taxa.Warmer South China would have served as a refuge for human populations escaping the cold,harsh climate in the north with more ameliorate conditions in the south.
