We present here a pilot study to examine trophic level effects and migration patterns at the middle Shang Dynasty site of Xiaoshuangqiao in Henan Province using δD results combined with δ^13C and δ^15N values. A to...We present here a pilot study to examine trophic level effects and migration patterns at the middle Shang Dynasty site of Xiaoshuangqiao in Henan Province using δD results combined with δ^13C and δ^15N values. A total of 33 specimens（17 humans, 7 cattle, 5 pigs, 3 sheep, 1 dog） of bone collagen were isotopically analyzed for δ^13C, δ^15N, and dD values. A strong positive correlation（R^2 = 0.94）between mean δ^15N and δD values of herbivores（cattle and sheep）, omnivores（pig）, carnivores（dog）and humans was observed. The δD results were found to increase by -10‰ to 20‰ from herbivores to omnivores to carnivorous, evidence that collagen δD results are a useful indicator for the study of trophic levels and dietary patterns at archaeological sites. The δD results were also used to examine the origins of two different groups of individuals buried at Xiaoshuangqiao. Individuals buried in sacrificial pits of district V had mean δD values（-47.0 ± 2.9‰, n = 11） that were significantly（p =0.049） elevated compared to the people buried in the stratigraphy of district IX（-51.3 ± 3.3‰, n = 3）,indicating that they were ingesting water from different locations. In addition, the D values of the people buried in the stratigraphy were similar to the pigs（-54.5 ± 4.2‰, n = 5） at Xiaoshuangqiao,suggesting that they were most probably of the local population, and that the individuals buried in the sacrificial pits were most possibly from the coast and prisoners of the Dongyi（“东夷”）people. Thus,δD results have the potential to examine human origins and migration patterns and should be increasingly used in conjunction with δ^13C and δ^15N values at archaeological sites.展开更多
This paper undertook the C and N stable isotopic analysis of human bones unearthed at the Gouwan site in Xichuan,Henan,to reveal the human diets and to explore the lifestyle of humans and the development of rice and m...This paper undertook the C and N stable isotopic analysis of human bones unearthed at the Gouwan site in Xichuan,Henan,to reveal the human diets and to explore the lifestyle of humans and the development of rice and millet agriculture.The contribution of rice to human diets was almost equal to that of millet in this site though millet agriculture is the traditional economic model for the middle Yellow River Valley.On the other hand,the comparison of C and N stable isotopes in different cultural periods clearly indicates changes in millet and rice agriculture.Humans mainly depended on agriculture and gathering in the Yangshao Culture I. Millet agriculture,livestock rearing,and fishing were enhanced in the Yangshao Culture II.Millet agriculture and animal husbandry developed steadily in the Yangshao Culture III.After that the mixed rice and millet agriculture developed further.In addition,rice agriculture spread to the north in the climate suitable for cultural exchanges between north and south in the Yangshao Culture phases.In the Qujialing Culture period,under a colder climate,the rice farming was not dominant,though the Qujialing Culture played a key role in the site.展开更多
Historical records and archaeological remains indicate that the Chinese agricultural economy changed significantly from the Warring States （475-221 BC） to Han Dynasties （206 BC-220 AD）, i.e., from rice-millet base...Historical records and archaeological remains indicate that the Chinese agricultural economy changed significantly from the Warring States （475-221 BC） to Han Dynasties （206 BC-220 AD）, i.e., from rice-millet based agriculture to rice-millet-wheat based agriculture. However, the variation of human diets and the inner relationship between human diets and the agricultural transition during this period remain poorly understood. In this paper, the C and N stable isotopes from human and animal bones at the Shenmingpu site （SMPS）, Xichuan County, Henan Province were analyzed. If some outliers （M34, M36, M102） were excluded, the mean δ13C value （（-16.7±0.8）‰, n=15） of humans in Hart Dynasties was dramatically lower than that in the Warring States （（-12.7±0.8）‰, n=14）, indicating that the cultivation of rice and wheat, especially wheat, had been more widely popularized in Han Dynasties. Meanwhile, the range of 615N values of humans （6.6‰-9.3‰） in Hart Dynasties was narrower than that of the Warring States （6.2‰-10.4‰）, suggesting that the animal protein resources in human foods during Han Dynasties were more concentrated. The transition of human diets and the close relationship with the change of agricultural economy in SMPS were due to more stable society, the carryout of new agricultural policies, and the emergence of new agri- cultural tools in Han Dynasties.展开更多
Previous studies on the Rice-Millet （foxtail millet and common millet） Blended Zone in Chinese Neolithic have not clearly addressed such questions as the importance of primitive rice-millet mixed agriculture to huma...Previous studies on the Rice-Millet （foxtail millet and common millet） Blended Zone in Chinese Neolithic have not clearly addressed such questions as the importance of primitive rice-millet mixed agriculture to human lifestyle and livestock managements within this region, the relationship among the development of the agriculture, paleoenvironment, and cultural interactions, and so on. Here stable carbon and nitrogen isotope analysis of human and pig bones from the Qinglongquan site was conducted, covering two cultural phases, namely the Qujialing Culture （3000 BC to 2600 BC） and the Shijiahe Culture （2600 BC to 2200 BC）. Based on this analysis, we further discussed the diets of ancient humans and pigs in the site, investigated the importance of rice-millet mixed agriculture to human and pig diets, and explored the relationship among the primitive rice agriculture and millet agriculture, cultural interactions, and paleoenvironment. The δ^13C values of human bone collagen （-16.7‰ to -12.4‰, averaging -14.6‰±1.3‰, n=24） revealed that both C3 and Ca foods were consumed, probably from the contribution of rice （C3 plant） and millets （C4 plants） due to the coexistence of these crops at this site. In addition, the human mean δ^13C value suggested that millet agriculture was only minor in human diets. The human δ^15N values （6.6‰ to 10.8‰, averaging 9.0‰±1.2‰, n=24） showed that animal resources played a significant role in human diets, and varied greatly. The mean δ^13C value of the pigs （-14.3‰±2.5‰, n=13） was quite similar to that of the humans, but the mean δ^15N value of the pigs was slightly less （1.3‰） The similar δ^13C and δ^15N values between humans and pigs suggested that the pigs consumed a lot of humans＇ food remains. No correlations of the δ^13C and δ^15N values between humans and pigs showed that both human and pig diets were based mainly on plant foods, which might be related to highly developed rice-millet mixed agriculture at that time. In comparison with the human and pig diets between the two periods, millet agriculture contributed more than 10% in the Shijiahe Culture, if a simple mixing model was used. This apparent dietary shift matched the climatic variation and agricultural development through the time. In warm and humid climate with the expansion of the Qujialing Culture northwards, rice was widely cultivated. However, when the climate was cold and add, northern culture was expanding southwards. Thus, millet agriculture became more important.展开更多
Central-south Inner Mongolia, China, is highly sensitive to the cultural interactions between sedentary agriculturalists and nomadic pastoralists during the Eastern Zhou Period(770–256 BC). The previous pattern of mu...Central-south Inner Mongolia, China, is highly sensitive to the cultural interactions between sedentary agriculturalists and nomadic pastoralists during the Eastern Zhou Period(770–256 BC). The previous pattern of multiple cultures and diverse ethnic groups has been transformed to the increasingly dominated cultural system of Central Plain since the middle and late Warring States Period, when the states of Zhao and Qin have conquered the most parts of central-south Inner Mongolia.However, the variation of subsistence strategies during this historical process has never been evaluated. Particularly, as the typical representative of Central Plain cultures, the effect of intensive millet agriculture is still unknown in the process of population integration and culture interaction. Thus, to explore the shift of subsistence pattern, carbon and nitrogen stable isotope analysis of bone collagen from Dabaoshan site(410–180 BC) have been performed. The isotopic result indicates a large amount of C_4-based animal protein consumed by Dabaoshan humans. According to the archaeological backgrounds, we propose the Dabaoshan persons intensively relied on the millet agriculture and developed the agro-pastoral economy, which hinted the comprehensive influences from Central plain civilizations in late Warring States Period. Further compared with other published isotopic data in the same region during different periods, we suggest the millet agriculture has played the positive role in the process of population integration and culture fusion in central-south Inner Mongolia during the Eastern Zhou Period.展开更多
Intermetallic compounds produced in laser additive manufacturing are the main factors restricting the joint performance of dissimilar metals.To solve this problem,a dual molten pool interface interlocking mechanism wa...Intermetallic compounds produced in laser additive manufacturing are the main factors restricting the joint performance of dissimilar metals.To solve this problem,a dual molten pool interface interlocking mechanism was proposed in this study.Based on a dual molten pool interface interlocking mechanism,the dissimilar metals,aluminum alloy and stainless steel,were produced as single-layer and multilayer samples,using the wire-feed laser additive manufacturing directed energy deposition technology.The preferred parameters for the dual molten pool interface interlocking mechanism process of the dissimilar metals,aluminum alloy and stainless steel,were obtained.The matching relationship between the interface connection of dissimilar metals and the process parameters was established.The results demonstrated excellent mechanical occlusion at the connection interface and no apparent intermetallic compound layer.Good feature size and high microhardness were observed under a laser power of 660 W,a wire feeding speed of 55 mm/s,and a platform moving speed of 10 mm/s.Molecular dynamics simulations demonstrated a faster rate of aluminum diffusion in the aluminum alloy substrate to stainless steel under the action of the initial contact force than without the initial contact force.Thus,the dual molten pool interface interlocking mechanism can effectively reduce the intermetallic compound layer when dissimilar metals are connected in the aerospace field.展开更多
C and N stable isotope ratios of 19 human bones in Sanxingcun Site, Jintan, Jiangsu Province, were measured to explore the lifestyle and social economic structure. Although the bone collagen degraded to different exte...C and N stable isotope ratios of 19 human bones in Sanxingcun Site, Jintan, Jiangsu Province, were measured to explore the lifestyle and social economic structure. Although the bone collagen degraded to different extents, the atomic ratio of C/N was located in the range of 2.9-3.6, indicating that they were preserved very well. Average δ13C value (20.05±0.21‰), average δ 15N value (9.69 ±0.33‰) and poor positive correlation between each other suggested that rice agriculture was dominant with hunt-ing-fishing supplemented in human lifestyle. Poor negative correlation between δ 15N values and C3 percentages of foods implied relative independence of rice agriculture and hunting-fishing. Compared to Hemudu Site and Qingpu Site, rice agriculture was developed further, but hunting-fishing decreased. The mode for people in Sanxingcun Site to get the meat was still in the initial exploitation.展开更多
In order to explore subsistence patterns in northern Shaanxi Province around 4,000 yr BP,28 human and 24 animal bones from the Shengedaliang site were sampled for stable carbon and nitrogen isotope ratio analysis.The ...In order to explore subsistence patterns in northern Shaanxi Province around 4,000 yr BP,28 human and 24 animal bones from the Shengedaliang site were sampled for stable carbon and nitrogen isotope ratio analysis.The results show that most people primarily subsisted on C_4 resources,e.g.millet and millet-related animal products,despite the fact that there was some intake of C_3 plants by some individuals.Stable nitrogen isotope values indicate that there were differences in meat consumption between individuals at the site.Pigs were mainly foddered with millet and millet byproducts,as well as some cattle,according to their highδ^(13)C values.However,most cattle and the sheep/goats consumed wild C_3 plants at Shengedaliang.Our above findings indicates that subsistence patterns in northern Shaanxi around 4,000 yr BP were characterized by millet farming,while the grassland animal husbandry,e.g.cattle and sheep/goats raising,displayed very little contribution to local economy.The intensive millet farming in northern Shaanxi provided enough food for population growth,ensured the accumulation of wealth,and consequently accelerated social differentiation and complexity.展开更多
In current palaeodietary research, gelatinization is the main method to extract insoluble collagen （ISC） from ancient bones. However, the degradation products of ISC, i.e., soluble collagen （SC）, is often neglecte...In current palaeodietary research, gelatinization is the main method to extract insoluble collagen （ISC） from ancient bones. However, the degradation products of ISC, i.e., soluble collagen （SC）, is often neglected and abandoned. In this work, we try to separate the extracts of ancient bones using gel chromatography and compare the contents of carbon and nitrogen, atomic C/N ratio, and stable carbon and nitrogen isotopic values of the extracts from three peaks to determine which peak can be at- tributed to SC. At last, the potential application of SC in palaeodietary research is discussed based on the comparison of stable isotopic values between ISC and SC. Among the three peaks, the second with the retention time between 17.5 min and 27.5 min had the most broad peak shape, indicating that the molecular weights of proteins collected were most variable. Besides, the contents of carbon and nitrogen and atomic C/N ratio of extracts in this peak were closest to the corresponding ISC. Based on the above, we conclude that the extract in second peak is SC. More important, the δ13c and δ15N values of ISC and SC are very similar. For ISC and SC with atomic C/N ratios within the normal range （2.9-3.6）, the mean difference of δ13C value was only （0.3±0.2）%o （n=2） while δ15N value was （0.6±0.1）‰ （n=2）. Although the atomic C/N ratios of some SC are slightly be- yond the normal range, the mean differences of δ13C and δ15N values were still only （0.4±0.1）‰and （0.3±0）‰ （n=2） respec- tively. These isotopic differences are quite below the isotope fractionation in one trophic level δ13C values of 1‰-1.5‰ and 615N values of 3‰-5‰）, suggesting that SC had great application potentials in palaeodietary research.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41603009)MOE(Ministry of Education in China) Project of Humanities and Social Sciences(No.16YJCZH100)+1 种基金Origin of Chinese Civilisation and Mount Songshan Civilisation Zhengzhou Research Association(No.Q2015-1)Humanities and Social Science Research Foundation of Jiangsu Normal University(No.15XWR025)
文摘We present here a pilot study to examine trophic level effects and migration patterns at the middle Shang Dynasty site of Xiaoshuangqiao in Henan Province using δD results combined with δ^13C and δ^15N values. A total of 33 specimens（17 humans, 7 cattle, 5 pigs, 3 sheep, 1 dog） of bone collagen were isotopically analyzed for δ^13C, δ^15N, and dD values. A strong positive correlation（R^2 = 0.94）between mean δ^15N and δD values of herbivores（cattle and sheep）, omnivores（pig）, carnivores（dog）and humans was observed. The δD results were found to increase by -10‰ to 20‰ from herbivores to omnivores to carnivorous, evidence that collagen δD results are a useful indicator for the study of trophic levels and dietary patterns at archaeological sites. The δD results were also used to examine the origins of two different groups of individuals buried at Xiaoshuangqiao. Individuals buried in sacrificial pits of district V had mean δD values（-47.0 ± 2.9‰, n = 11） that were significantly（p =0.049） elevated compared to the people buried in the stratigraphy of district IX（-51.3 ± 3.3‰, n = 3）,indicating that they were ingesting water from different locations. In addition, the D values of the people buried in the stratigraphy were similar to the pigs（-54.5 ± 4.2‰, n = 5） at Xiaoshuangqiao,suggesting that they were most probably of the local population, and that the individuals buried in the sacrificial pits were most possibly from the coast and prisoners of the Dongyi（“东夷”）people. Thus,δD results have the potential to examine human origins and migration patterns and should be increasingly used in conjunction with δ^13C and δ^15N values at archaeological sites.
基金supported by the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No. KJCX3.SYW.N12)National Natural Science Foundation of China(Grant No.40702003)+4 种基金Relics Preservation Project of South-to-North Water Diversion(Grant No.A.07015)Cooperative Research Project between Chinese Academy of Sciences and Zhengzhou UniversityPartner group program of Max Plank Institute and Chinese Academy of SciencesProgram of Bureau of Planning & StrategyChinese Academy of Sciences (Grant No.KACX1-YW-0830)
文摘This paper undertook the C and N stable isotopic analysis of human bones unearthed at the Gouwan site in Xichuan,Henan,to reveal the human diets and to explore the lifestyle of humans and the development of rice and millet agriculture.The contribution of rice to human diets was almost equal to that of millet in this site though millet agriculture is the traditional economic model for the middle Yellow River Valley.On the other hand,the comparison of C and N stable isotopes in different cultural periods clearly indicates changes in millet and rice agriculture.Humans mainly depended on agriculture and gathering in the Yangshao Culture I. Millet agriculture,livestock rearing,and fishing were enhanced in the Yangshao Culture II.Millet agriculture and animal husbandry developed steadily in the Yangshao Culture III.After that the mixed rice and millet agriculture developed further.In addition,rice agriculture spread to the north in the climate suitable for cultural exchanges between north and south in the Yangshao Culture phases.In the Qujialing Culture period,under a colder climate,the rice farming was not dominant,though the Qujialing Culture played a key role in the site.
基金supported by grants from CAS Knowledge Innovation Directional Project (Grant No.KZCX2-YW-Q1-04)CAS Strategic Priority Research Program (Grant Nos.XDA05130303, XDA05130501)+2 种基金Chinese Academy of Sciences & Max-Planck Institute Partnership Group Project (Grant No.KACX1-YW-0830)National Science and Technology Ministry (Grant No.2010BAK67B03)Relic Preservation Project of South-to-North Water Diversion
文摘Historical records and archaeological remains indicate that the Chinese agricultural economy changed significantly from the Warring States （475-221 BC） to Han Dynasties （206 BC-220 AD）, i.e., from rice-millet based agriculture to rice-millet-wheat based agriculture. However, the variation of human diets and the inner relationship between human diets and the agricultural transition during this period remain poorly understood. In this paper, the C and N stable isotopes from human and animal bones at the Shenmingpu site （SMPS）, Xichuan County, Henan Province were analyzed. If some outliers （M34, M36, M102） were excluded, the mean δ13C value （（-16.7±0.8）‰, n=15） of humans in Hart Dynasties was dramatically lower than that in the Warring States （（-12.7±0.8）‰, n=14）, indicating that the cultivation of rice and wheat, especially wheat, had been more widely popularized in Han Dynasties. Meanwhile, the range of 615N values of humans （6.6‰-9.3‰） in Hart Dynasties was narrower than that of the Warring States （6.2‰-10.4‰）, suggesting that the animal protein resources in human foods during Han Dynasties were more concentrated. The transition of human diets and the close relationship with the change of agricultural economy in SMPS were due to more stable society, the carryout of new agricultural policies, and the emergence of new agri- cultural tools in Han Dynasties.
基金supported by the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KJCX3.SYW.N12)National Natural Science Foundation of China(Grant No.40702003)+1 种基金Partner group program of Max Plank Institute and Chinese Academy of Sciences(Grant No.KACX1-YW-0830)Relics Preservation Project of South-to-North Water Diversion
文摘Previous studies on the Rice-Millet （foxtail millet and common millet） Blended Zone in Chinese Neolithic have not clearly addressed such questions as the importance of primitive rice-millet mixed agriculture to human lifestyle and livestock managements within this region, the relationship among the development of the agriculture, paleoenvironment, and cultural interactions, and so on. Here stable carbon and nitrogen isotope analysis of human and pig bones from the Qinglongquan site was conducted, covering two cultural phases, namely the Qujialing Culture （3000 BC to 2600 BC） and the Shijiahe Culture （2600 BC to 2200 BC）. Based on this analysis, we further discussed the diets of ancient humans and pigs in the site, investigated the importance of rice-millet mixed agriculture to human and pig diets, and explored the relationship among the primitive rice agriculture and millet agriculture, cultural interactions, and paleoenvironment. The δ^13C values of human bone collagen （-16.7‰ to -12.4‰, averaging -14.6‰±1.3‰, n=24） revealed that both C3 and Ca foods were consumed, probably from the contribution of rice （C3 plant） and millets （C4 plants） due to the coexistence of these crops at this site. In addition, the human mean δ^13C value suggested that millet agriculture was only minor in human diets. The human δ^15N values （6.6‰ to 10.8‰, averaging 9.0‰±1.2‰, n=24） showed that animal resources played a significant role in human diets, and varied greatly. The mean δ^13C value of the pigs （-14.3‰±2.5‰, n=13） was quite similar to that of the humans, but the mean δ^15N value of the pigs was slightly less （1.3‰） The similar δ^13C and δ^15N values between humans and pigs suggested that the pigs consumed a lot of humans＇ food remains. No correlations of the δ^13C and δ^15N values between humans and pigs showed that both human and pig diets were based mainly on plant foods, which might be related to highly developed rice-millet mixed agriculture at that time. In comparison with the human and pig diets between the two periods, millet agriculture contributed more than 10% in the Shijiahe Culture, if a simple mixing model was used. This apparent dietary shift matched the climatic variation and agricultural development through the time. In warm and humid climate with the expansion of the Qujialing Culture northwards, rice was widely cultivated. However, when the climate was cold and add, northern culture was expanding southwards. Thus, millet agriculture became more important.
基金supported by National Natural Science Foundation of China (Grant No. 41373018)National Social Science Foundation of China (Grant No. 10CKG001)
文摘Central-south Inner Mongolia, China, is highly sensitive to the cultural interactions between sedentary agriculturalists and nomadic pastoralists during the Eastern Zhou Period(770–256 BC). The previous pattern of multiple cultures and diverse ethnic groups has been transformed to the increasingly dominated cultural system of Central Plain since the middle and late Warring States Period, when the states of Zhao and Qin have conquered the most parts of central-south Inner Mongolia.However, the variation of subsistence strategies during this historical process has never been evaluated. Particularly, as the typical representative of Central Plain cultures, the effect of intensive millet agriculture is still unknown in the process of population integration and culture interaction. Thus, to explore the shift of subsistence pattern, carbon and nitrogen stable isotope analysis of bone collagen from Dabaoshan site(410–180 BC) have been performed. The isotopic result indicates a large amount of C_4-based animal protein consumed by Dabaoshan humans. According to the archaeological backgrounds, we propose the Dabaoshan persons intensively relied on the millet agriculture and developed the agro-pastoral economy, which hinted the comprehensive influences from Central plain civilizations in late Warring States Period. Further compared with other published isotopic data in the same region during different periods, we suggest the millet agriculture has played the positive role in the process of population integration and culture fusion in central-south Inner Mongolia during the Eastern Zhou Period.
基金supported by the National Natural Science Foundation of China(Grant No.51901162)the support of the National Talent Program of China。
文摘Intermetallic compounds produced in laser additive manufacturing are the main factors restricting the joint performance of dissimilar metals.To solve this problem,a dual molten pool interface interlocking mechanism was proposed in this study.Based on a dual molten pool interface interlocking mechanism,the dissimilar metals,aluminum alloy and stainless steel,were produced as single-layer and multilayer samples,using the wire-feed laser additive manufacturing directed energy deposition technology.The preferred parameters for the dual molten pool interface interlocking mechanism process of the dissimilar metals,aluminum alloy and stainless steel,were obtained.The matching relationship between the interface connection of dissimilar metals and the process parameters was established.The results demonstrated excellent mechanical occlusion at the connection interface and no apparent intermetallic compound layer.Good feature size and high microhardness were observed under a laser power of 660 W,a wire feeding speed of 55 mm/s,and a platform moving speed of 10 mm/s.Molecular dynamics simulations demonstrated a faster rate of aluminum diffusion in the aluminum alloy substrate to stainless steel under the action of the initial contact force than without the initial contact force.Thus,the dual molten pool interface interlocking mechanism can effectively reduce the intermetallic compound layer when dissimilar metals are connected in the aerospace field.
基金Supported by Knowledge Innovation Project of Chinese Academy of Sciences (KJCX3.SYW.N12), Startup Fund for Returnees of Ministry of Education, President Fund of Chinese Academy of Sciences, and President Fund from Graduate Univer-sity of Chinese Academy of Sciences
文摘C and N stable isotope ratios of 19 human bones in Sanxingcun Site, Jintan, Jiangsu Province, were measured to explore the lifestyle and social economic structure. Although the bone collagen degraded to different extents, the atomic ratio of C/N was located in the range of 2.9-3.6, indicating that they were preserved very well. Average δ13C value (20.05±0.21‰), average δ 15N value (9.69 ±0.33‰) and poor positive correlation between each other suggested that rice agriculture was dominant with hunt-ing-fishing supplemented in human lifestyle. Poor negative correlation between δ 15N values and C3 percentages of foods implied relative independence of rice agriculture and hunting-fishing. Compared to Hemudu Site and Qingpu Site, rice agriculture was developed further, but hunting-fishing decreased. The mode for people in Sanxingcun Site to get the meat was still in the initial exploitation.
基金supported by the Knowledge Innovation Fund of the Chinese Academy of Social Sciencesthe National Natural Science Foundation of China(Grant Nos.41373018&41471167)
文摘In order to explore subsistence patterns in northern Shaanxi Province around 4,000 yr BP,28 human and 24 animal bones from the Shengedaliang site were sampled for stable carbon and nitrogen isotope ratio analysis.The results show that most people primarily subsisted on C_4 resources,e.g.millet and millet-related animal products,despite the fact that there was some intake of C_3 plants by some individuals.Stable nitrogen isotope values indicate that there were differences in meat consumption between individuals at the site.Pigs were mainly foddered with millet and millet byproducts,as well as some cattle,according to their highδ^(13)C values.However,most cattle and the sheep/goats consumed wild C_3 plants at Shengedaliang.Our above findings indicates that subsistence patterns in northern Shaanxi around 4,000 yr BP were characterized by millet farming,while the grassland animal husbandry,e.g.cattle and sheep/goats raising,displayed very little contribution to local economy.The intensive millet farming in northern Shaanxi provided enough food for population growth,ensured the accumulation of wealth,and consequently accelerated social differentiation and complexity.
基金supported by CAS Strategic Priority Research Program (Grant No. XDA05130303)Chinese Academy of Sciences & Max-Planck Institute Partnership Group Project (Grant No. KACX1-YW-0830)
文摘In current palaeodietary research, gelatinization is the main method to extract insoluble collagen （ISC） from ancient bones. However, the degradation products of ISC, i.e., soluble collagen （SC）, is often neglected and abandoned. In this work, we try to separate the extracts of ancient bones using gel chromatography and compare the contents of carbon and nitrogen, atomic C/N ratio, and stable carbon and nitrogen isotopic values of the extracts from three peaks to determine which peak can be at- tributed to SC. At last, the potential application of SC in palaeodietary research is discussed based on the comparison of stable isotopic values between ISC and SC. Among the three peaks, the second with the retention time between 17.5 min and 27.5 min had the most broad peak shape, indicating that the molecular weights of proteins collected were most variable. Besides, the contents of carbon and nitrogen and atomic C/N ratio of extracts in this peak were closest to the corresponding ISC. Based on the above, we conclude that the extract in second peak is SC. More important, the δ13c and δ15N values of ISC and SC are very similar. For ISC and SC with atomic C/N ratios within the normal range （2.9-3.6）, the mean difference of δ13C value was only （0.3±0.2）%o （n=2） while δ15N value was （0.6±0.1）‰ （n=2）. Although the atomic C/N ratios of some SC are slightly be- yond the normal range, the mean differences of δ13C and δ15N values were still only （0.4±0.1）‰and （0.3±0）‰ （n=2） respec- tively. These isotopic differences are quite below the isotope fractionation in one trophic level δ13C values of 1‰-1.5‰ and 615N values of 3‰-5‰）, suggesting that SC had great application potentials in palaeodietary research.
