The selection of a non-shattering phenotype is a pivotal change in the process of rice domestication. However, current research is heavily restricted by the preservation conditions of macro-plant remains in early and middle Neolithic sites, as very limited well-preserved rice spikelet bases could be retrieved. We present a non-destructive method based on micro-computed tomographic (CT) scanning, which could provide detailed visualization of the internal structures of charred spikelet bases and efficiently discriminate the shattering and non-shattering phenotypes of rice spikelet bases according to the abundance of fusiform echinate phytoliths. It could be widely applied in different contexts, especially those poorly preserved specimens and tempers in pottery sherds, greatly improving our knowledge of rice domestication. 相似文献
In archaeology, strontium isotope analysis is developing into an efficient scientific technique for tracing the movement of prehistoric humans and animals. Determining the local bioavailable 87Sr/86Sr ratio range is the key to distinguishing whether the human or animal is indigenous to the local area. It has been shown that the 87Sr/86Sr ratio in the enamel of pigs can be an excellent sample to determine the range of local strontium isotope ratio at the site. However, pigs may not be all local at the site, and there is no special study on whether pigs’ different ages and tooth types impact the local strontium isotope characteristics. In this paper, the tooth enamel of 19 pigs from the Zaoshugounao site for strontium isotope ratio (87Sr/86Sr) by multicollector–inductively coupled plasma mass spectrometry. There were no significant differences in 87Sr/86Sr ratios of local pigs at different months and different molar types, which did not affect the determination of the local strontium isotope standard. Based on the local strontium isotope ratio range (0.711056–0.711476), we found that five pigs were non-local. The Jing and Wei river basins (in Guanzhong basin) and northern Shaanxi are likely sources of non-pigs. 相似文献
Geographical distance constitutes friction in searching for research collaborators. Taking advantage of a quasinatural experiment featured by High-Speed Railway (HSR) lines in China, this paper employs the difference-in-differences model to identify the causal impact of a substantial improvement in the intercity transportation infrastructure on collaborative innovation across cities. The data pertain to a universe of patent applications filed by Chinese universities and their citations. We find that HSR contributes to a substantial increase in the innovation quantity and quality of collaborative patenting innovation between universities and corporates. It contributes to industry collaboration by utilizing university academic disciplines in the related technology fields. Lastly, HSR facilitates universities to search for new research partners with better quality beyond the geographical boundary. 相似文献
Shear walls are important lateral force-resistant components of tall buildings. Hence, a reliable numerical model that can accurately represent the mechanical characteristics and large deformations of shear walls is critical for realistic collapse simulation of tall buildings. Based on the theory of generalized conforming element, a high-performance quadrilateral flat shell element, NLDKGQ, accounting for the large deformation using the updated Lagrangian formulation, is proposed herein and implemented in OpenSees. The reliability of NLDKGQ is validated using classical benchmark problems and reinforced concrete specimens. In addition, its capability in simulating the collapse of a tall building is also demonstrated. 相似文献
Wang, Q., Wang, Y., Qi, Y., Wang, X., Choh, S.J., Lee, D.C. & Lee, D.J., November 2017. Yeongwol and the Carboniferous–Permian boundary in South Korea. Alcheringa 42, 245–258. ISSN 0311-5518
Six conodont and one fusuline zones are recognized on basis of a total of 25 conodont and 13 fusuline species (including seven unidentified species or species given with cf. or aff. in total) from the Bamchi Formation, Yeongwol, Korea. The conodont zones include the Streptognathodus bellus, S. isolatus, S. cristellaris, S. sigmoidalis, S. fusus and S. barskovi zones in ascending order, which can be correlated with the conodont zones spanning the uppermost Gzhelian to Asselian Age of the Permian globally. The fusuline zone is named the Rugosofusulina complicata–Pseudoschwagerina paraborealis zone. The co-occurrence of the conodont Streptognathodus isolatus (the Global Boundary Stratotype Section and Point index for the base of Permian) and Pseudoschwagerina (a Permian inflated fusuline) indicates that the Carboniferous–Permian boundary can be placed in the lower part of the Bamchi Formation in South Korea.
Qiulai Wang* [qlwang@nigpas.ac.cn] CAS Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, East Beijing Road 39, Nanjing 210008, PR China; Yue Wang* [yuewang@nigpas.ac.cn] LPS, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, East Beijing Road 39, Nanjing 210008, PR China; Yuping Qi* [ypqi@nigpas.ac.cn] Xiangdong Wang* [xdwang@nigpas.ac.cn] CAS Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, East Beijing Road 39, Nanjing 210008, PR China; Suk-Joo Choh [sjchoh@korea.ac.kr] Department of Earth and Environmental Sciences, Korea University, Seoul 02841, Republic of Korea; Dong-Chan Lee [dclee@chungbuk.ac.kr] Department of Earth Sciences Education, Chungbuk National University, Cheongju 28644, Republic of Korea; Dong-Jin Lee [djlee@andong.ac.kr] Department of Earth and Environmental Sciences, Andong National University, Andong 36729, Republic of Korea. *Also affiliated with: University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, PR China.相似文献