卷轴书画折痕产生的原因及防治对策研究

卷轴是书画艺术的一种独特展示与收藏形式,卷轴书画画芯表面的折痕不仅影响展陈效果,而且降低了书画文物的保存寿命。为此,利用超景深显微镜和扫描电镜分析了卷轴书画折痕的微观结构,探讨了折痕产生的机理,并提出了相应的预防措施。结果表明:小直径收卷是书画产生折痕的重要原因之一;收卷直径越小,书画出现折痕的现象越明显。通过在地杆处加轴管以增大收卷直径,能够有效减少折痕和断裂的产生。该方法保持了中国传统卷轴书画的装裱形式,维持了书画的原貌,并能够有效保存书画展示的传统韵味。研究结果为探讨书画折痕产生的机理和防治对策研究提供科学依据。     

Taphonomy of Corumbella werneri from the Ediacaran of Brazil: sinotubulitid tube or conulariid test?

Walde, D.H.-G., Weber, B., Erdtmann, B.-D. & Steiner, M. 20 June 2019. Taphonomy of Corumbella werneri from the Ediacaran of Brazil: sinotubulitid tube or conulariid test? Alcheringa 43, 335–350. ISSN 0311-5518

The problematic late Ediacaran tubular fossil Corumbella werneri is revised based on two-dimensional compressions, and new three-dimensionally preserved specimens from the Tamengo Formation of the Corumbá Region in Mato Grosso do Sul, west-central Brazil. These fossils represent some of the oldest skeletonized metazoans and were originally described from diagenetically compacted tubes that prompted conflicting interpretations as either Ediacaran coronate scyphozoan exoskeletons, or conulariid tests. Our new material from Corumbá permits a morphological and taphonomic revision of C. werneri, which we suggest was probably a calcareous sinotubulitid. Corumbella werneri closely resembles the late Ediacaran Sinotubulites from South China, as well as the Silurian worm tube Eoalvinellodes, which has similar exterior ornamentation. Ultrastructurally, the tubes of C. werneri exhibit a coarse sparitic microtexture, which we attribute to diagenetic alteration. Partial flexibility also supports interpretation as an originally weakly calcified, or entirely organic exoskeleton. We therefore reject placement of C. werneri as a conulariid scyphozoan, and instead, advocate possible relationships with marine annelids.

Detlef Hans-Gert Walde [walde.detlef@gmail.com], University of Brasília, Institute of Geosciences, Brasília-DF, Brazil; Bernd Weber [bweber@zedat.fu-berlin.de], Freie Universität Berlin, Institut für Geologische Wissenschaften, Malteserstr. 74–100, D-12249 Berlin, Germany; Bernd-D. Erdtmann [berni1739@gmail.com], 1165 N Mountain View Road, Apache Junction, AZ 85119, USA; *Michael Steiner [Michael.Steiner@FU-Berlin.de], Freie Universität Berlin, Institut für Geologische Wissenschaften (Haus D), Malteserstr. 74–100, D-12249 Berlin, Germany.     

Evidence for indigenous strip-drawing in production of wire at Mapungubwe Hill (1220-1290 AD): towards an interdisciplinary approach

Several cupreous conical tubes with unclear function are among some of the finds in the collections held at the University of Pretoria which were unearthed by archaeologists on Mapungubwe Hill. Most of these are poorly provenanced, particularly those connected with the activities of Guy Gardner (1935-1940) regarding the waste in northern dump. However, a redetermination of the context following the excavations of the 1970s suggests the funnels date to the period of the rise and development of Mapungubwe as a town and centre of a powerful state. The results from neutron tomography, stereomicroscope and SEM-EDS indicate that the tubes were most probably used in iron strip-drawing to produce wire.     

Frequency of Complete Cleft Sacra in a Native American Sample

The purpose of this paper is to contribute to the current understanding of the variability of complete sacral clefts in human populations by presenting new data on a large prehistoric and historic Native American skeletal sample (n = 1943). Results are examined by age, sex, time period, and regional distribution and compared with reported frequencies of complete sacral clefts in other modern, historic, and ancient populations. In all, 1.6% of the sample exhibited complete sacral clefts, including 2.1% of males and 1.1% of females. Although males exhibit a frequency twice as high as females, this difference is not statistically significant. However, within the Alaskan sample, the sex difference was significant (p = 0.002), with 3.4% of males and 0.5% of females exhibiting complete clefts; these differences may be related to mechanical influences during growth and development in males. Differences among age groups are not significant. Regional comparisons among Alaska, Eastern Woodlands, Great Basin/Northwest/California, Great Plains, and Southwest showed no significant differences overall, but Alaska (2.2%) and Great Plains (0.5%) do show a significant difference (p = 0.024). No significant differences were found between prehistoric, protohistoric, and historic/recent samples, suggesting a lack of a secular trend in frequency of complete sacral clefts in Native American populations. One individual exhibited an enlarged canal, which may be indicative of a more severe condition. Copyright © 2012 John Wiley & Sons, Ltd.