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931.
Chenghai Yang 《Geography Compass》2009,3(5):1717-1731
Information concerning the spatial variation in crop yield has become necessary for site‐specific crop management. Traditional satellite imagery has long been used to monitor crop growing conditions and to estimate crop yields over large geographic areas. However, this type of imagery has limited use for assessing within‐field yield variability because of its coarse spatial resolution. Therefore, high‐resolution airborne multispectral and hyperspectral imagery has been used for this purpose. This study presents an overview on the use of remote sensing imagery for mapping crop yield variability and illustrates how airborne hyperspectral imagery can be used for crop yield estimation based on the work conducted at the US Department of Agriculture’s Kika de la Garza Subtropical Agricultural Research Center at Weslaco, Texas. Some of the challenges and considerations on the use of hyperspectral imagery for yield mapping are discussed. 相似文献
932.
933.
Chun Yang 《European Planning Studies》2013,21(7):1046-1063
The global production networks (GPNs) perspective, especially its focal concept of “strategic coupling” has been widely applied to regional studies in the era of globalization. The 2000s, especially the aftermath of the 2008 global financial crisis, has witnessed a dramatic restructuring of the governance structure of GPNs; the effects on regional evolution have, however, been understudied. Echoing to MacKinnon's [(2012) Beyond strategic coupling: Reassessing the firm-region Nexus in global production networks, Journal of Economic Geography, 12, pp. 227–245] recent plea for conceptualizing the types, degree and depth of strategic coupling in the GPNs framework, this paper postulates that regional trajectories have been reshaped by the transition from strategic coupling to recoupling and decoupling, as a result of regional selection and abandonment of transnational corporations (TNCs) in host regions in China. Based on updated field investigation and in-depth interviews during the period of mid-2008 and early 2012, this paper examines and compares the transformation of the cross-border production networks driven by Hong Kong and Taiwan-based TNCs, particularly their divergent engagements in decoupling from source regions in coastal China, e.g. the Pearl River Delta and recoupling with the inland provinces, such as Sichuan and Hubei. Particular attention is paid to the changing power relations among TNCs and concerned regions with the emergence of key supplier-led domestic market-oriented production networks in China. Through developing an evolutionary framework on strategic coupling, the paper puts forward pertinent topics on the research agenda to explore dynamic interaction between GPN restructuring and regional evolution in the contemporary global economy. 相似文献
934.
Zhong-Qiang Chen Fengqing Yang 《Alcheringa: An Australasian Journal of Paleontology》2013,37(2):163-183
O’Gorman, J.P. &; Gasparini, Z., 2013. Revision of Sulcusuchus erraini (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina. Alcheringa 37, 161–174. ISSN 0311-5518. Sulcusuchus erraini, from the upper Campanian–lower Maastrichtian of Patagonia, Argentina, is the only polycotylid from the Southern Hemisphere for which the skull and mandible are known. The diagnosis of the species and genus is emended based on new observations. Sulcusuchus is characterized by the following autapomorphies: (1) deep and broad rostral and mandibular grooves and (2) a wide notch on the posterior margin of the pterygoids that are combined with a part of the body of the basioccipital, forming a wide plate. Several hypotheses about the identity of the structures that could have been housed in the rostral and mandibular grooves are evaluated. Only two of several hypotheses were not discarded. The first is that the grooves may have accommodated oral glands (supralabial and sublabial), but the biological role of such glands could not be inferred. The second hypothesis is the presence of special structures of an electrosensitive and/or mechanosensitive nature, which might allow the detection of infaunal or semi-infaunal food in soft substrates, as is represented in modern analogues, such as dolphins. José P. O’Gorman [joseogorman@fcnym.unlp.edu.ar] and Zulma Gasparini [zgaspari@fcnym.unlp.edu.ar], División Paleontología Vertebrados, Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n., B1900FWA La Plata, Argentina. Also affiliated with Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917 (C1033AAJ), Ciudad Autónoma de Buenos Aires, Argentina and CONICET: Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina Received 5.6.2012; revised 31.7.2012; accepted 4.9.2012. 相似文献
935.
Zhang, Y., He, W.-H., Shi, G.R. & Zhang, K.-X., 2013. A new Changhsingian (Late Permian) Rugosochonetidae (Brachiopoda) fauna from the Zhongzhai section, southwestern Guizhou Province, South China. Alcheringa 37, 221–245. ISSN 0311-5518. This paper describes 20 species (including three undetermined species) of Rugosochonetidae (Brachiopoda) in an upper offshore fauna from the Permian–Triassic Boundary Zhongzhai section, southwestern Guizhou Province, South China. New taxa are Tethyochonetes sheni, Tethyochonetes cheni, Neochonetes (Huangichonetes) archboldi, Neochonetes (Sommeriella) waterhousei, Neochonetes (Sommeriella) rectangularis and Neochonetes semicircularis. Yang Zhang [zyan@deakin.edu.au] and G.R. Shi [guang.shi@deakin.edu.au] (corresponding author), School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; Weihong He [whzhang@cug.edu.cn] (corresponding author) and Kexin Zhang [kx_zhang@cug.edu.cn], State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Road, Hongshan, Wuhan 430074, PR China. Received 8.6.2012; revised 19.9.2012; accepted 7.10.2012. 相似文献
936.
Fired bricks are a hard and durable masonry material that has played a major role in the emergence of early human urban civilization. In China, fired clay bricks have been widely used as a building and flooring material since the Qin Dynasty (476?206 bc ), although a few lines of evidence show that fired clay bricks might have been invented as early as 5500 years ago in eastern central China. However, these burnt clumps of clay appear not to be bricks in the strict sense, and our knowledge about the origin of fired clay bricks in China still remains fragmentary. Archaeological excavations at a Middle Neolithic cultural site in northwestern China reveal that the making of fired clay bricks began some 5000 years ago. Our findings also open a window into the process of prehistoric brickmaking in East Asia. 相似文献
937.
金沙遗址玉器的材质来源探讨 总被引：1，自引：0，他引：1
成都金沙遗址是迄今为止我国发现玉器最多的遗址,通过对其中551件玉器材质鉴定的结果发现,最主要的材质类型为透闪石集合体构成的软玉。通过对软玉型玉器的宏观特征、显微特征、玉器和石器的矿物及岩石组合特征研究,以及与四川汶川龙溪玉、新疆和田玉特征的对比,并且采用ICPMS进行主要玉器类型和玉料的微量元素特征的研究,同时结合现代资料和古代史料,认为金沙出土的玉器主要的材质应该来自于汶川的龙溪玉,与新疆和田玉、良渚玉器没有关系,但同时也存在其他地区玉料甚至是玉器交流的可能。 相似文献
938.
939.
南北朝时期襄阳地区集中出现了一批砌筑考究、图像精美的画像砖墓,具有鲜明的时代性和地方特色。本文主要以襄阳南朝画像砖墓为研究对象,以视觉分析的研究方法讨论其营建特点,并发现画像砖的垒砌与墓葬中图像的布局直接相关。 相似文献
940.
本文就书画展室的文物保护问题进行了探讨,着重分析了影响书画寿命的几项因素,包括温度、湿度、光照、虫霉害等,并据此提出了多方面的保护措施。 相似文献