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1. chinaXiv:202004.00001 [pdf]

Reappraisal of Serridentinus gobiensis Osborn & Granger and Miomastodon tongxinensis Chen:the validity of Miomastodon

WANG Shi-Qi; ZHANG Xiao-Xiao; LI Chun-Xiao 
Subjects: Biology >> Zoology

The elephantimorph proboscideans, Serridentinus gobiensis Osborn & Granger, 1932, and Miomastodon tongxinensis Chen, 1978, from the Middle Miocene of northern China, were revised as Zygolophodon gobiensis (Osborn & Granger, 1932). However, their phylogenetic positions are still being debated because of their intermediate morphology between the typical bunodont (Gomphotheriidae) and zygodont (Mammutidae) elephantimorphs. In the present paper, we compare their dental and mandibular morphology with that of the Eurasian Z. turicensis, Gomphotherium subtapiroideum, and G. tassyi, as well as the North American Mio. merriami and G. productum. It appears that S. gobiensis and Mio. tongxinensis share with Mio. merriami the slightly more bunodont molar morphology than that of Z. turicensis, e.g., the thicker enamel, thicker pretrite crescentoids, higher interlophid enamel pillars in buccal view, and the narrower contour majorly caused by the narrower posttrite half loph(id)s. S. gobiensis and Mio. merriami also possess an “erected oval cross-sectioned mandibular tusk”, in which the cross-section is mediolaterally compressed (dorsoventral diameter being larger than the mediolateral one). Whereas, in Z. turicensis and G. productum, the mandibular tusk is “laid oval cross-sectioned”, in which the cross-section is dorsoventrally compressed (dorsoventral diameter is smaller than the mediolateral one). Therefore, it is reasonable to revive the genus Miomastodon Osborn, 1922, which contains the species that were previously attributed to Zygolophodon, but they have relatively bunodont molar morphology (i.e., the robust type of the Z. turicensis group). The mandibular tusk with erected oval cross-section seems to be a synapomorphy of Miomastodon species. Furthermore, the molar morphology of G. subtapiroideum and G. tassyi also exhibits intermediate status between the typical bunodonts and zygodonts. However, the mandibular symphysis of G. subtapiroideum and G. tassyi is stronger than that of Miomastodon, and the mandibular tusk is pyriform cross-sectioned. The validity of Miomastodon and G. subtapiroideum/tassyi obscures the boundary between the Gomphotheriidae and Mammutidae, and suggests that the evolutions of the Gomphotheriidae and Mammutidae are deeply involved in with each other, rather than straightforwardly detached. This phenomenon has been revealed by a collagen sequence analysis among Notiomastodon, Mammut, and extant elephants, which should be further studied.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits47Downloads19 Comment 0

2. chinaXiv:202004.00002 [pdf]

New material of Cervidae (Artiodactyla, Mammalia) from Xinyaozi Ravine in Shanxi, North China

DONG Wei; BAI Wei-Peng; PAN Yue; LIU Wen-Hui
Subjects: Biology >> Zoology

Many cervid specimens were uncovered during the field exploration for Nihewan beds at the beginning of the 1980s from Taijiaping, Shuichongkou and Dazhuangke localities along Xinyaozi Ravine at Nangaoya Township of Tianzhen County, Shanxi Province in North China. Recent studies on the cervid material identified seven species of Cervidae in total: Muntiacus bohlini, Cervavitus cf. C. huadeensis, Axis shansius, Nipponicervus elegans, Elaphurus davidianus predavidianus, E. bifurcatus from the Early Pleistocene deposits at Taijiaping and Shuichongkou localities, and Cervus (Elaphus) elaphus from uncertain horizon at Dazhuangke. At least the previous six species of cervids were from Nihewan Formation (Nihewanian or equivalent to European middle and late Villafranchian), i.e. the Early Pleistocene, in Sangganhe Basin area.Cervavitus cf. C. huadeensis and A. shansius were survivors from the Late Neogene; M. bohlini,N. elegans, E. davidianus predavidianus and E. bifurcatus are new forms of the Early Pleistocene.If Dazhuangke horizon can be dated as those of Shuichongkou and Taijiaping localities, the appearance of elaphoid cervids could be traced back to the Early Pleistocene, and the evolution of elaphoid antler would start from absence to presence of bez tine. The presence of Elaphurus and Nipponicervus in mainland China and Japanese archipelago implies further that the sea level was dropped down that these cervids could migrate from the mainland to the islands. The abundance of folivorous cervid specimens in the Xinyaozi Ravine area indicates the existence of a certain scale of forested environment in Sangganhe Basin area during the Early Pleistocene.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits37Downloads14 Comment 0

3. chinaXiv:202004.00003 [pdf]

A new species of Amynodontopsis (Perissodactyla: Amynodontidae) from the Middle Eocene of Jiyuan, Henan, China

WANG Xiao-Yang; WANG Yuan-Qing; ZHANG Rui; ZHANG Zhong-Hui;  LIU Xiao-Ling; REN Li-Ping
Subjects: Biology >> Zoology

An adult amynodont skull, collected from the Middle Eocene Niezhuang Formation of Jiyuan Basin (Henan, China), is recognized as a new species Amynodontopsis jiyuanensis sp. nov. The specimen possesses the typical features of the genus Amynodontopsis, such as a dolichocephalic skull with elevated roof, premaxilla-nasal contact, large preorbital fossa extending posteriorly medial to the orbit, inner surface of anterior orbital bar concave in continuation with the preorbital fossa, antecrochet usually presented on M1, and metastyle of M3 strongly deflected labially. A. jiyuanensis is diagnosed by a combination of the following characters: long nasals, nasal process of premaxilla extending far back laterally below the nasal and excluding the maxilla from the border of external nares, nasal notch above the post-canine diastema, more transverse and proportionally longer protoloph and metaloph on upper molars. Comparison with known species of Amynodontopsis indicates that it is the most primitive one in the genus, due to the possession of primitive characters. Associated fossil mammals support a correlation of the strata bearing A. jiyuanensis with the Shara Murun Formation of the Erlian Basin, Nei Mongol, China, namely the Middle Eocene Sharamurunian Asian Land Mammal Age (ALMA), prior to all other known Amynodontopsis species. The earlier geologic age and primitive morphological features of A. jiyuanensis suggest that Amynodontopsis has an Asian origin in the Middle Eocene and later immigrated into North America.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits36Downloads16 Comment 0

4. chinaXiv:202004.00004 [pdf]

A Late Miocene Huerzelerimys (Rodentia: Muridae) skull from Hezheng, Gansu, China

WANG Ban-Yue; QIU Zhan-Xiang;  LI Lü-Zhou
Subjects: Biology >> Zoology

A skull with mandible and several cervicals of a new species of Huerzelerimys, H.asiaticus, collected from the Late Miocene Liushu Formation in Linxia Basin, Gansu Province,is described in this paper. The skull is the first one ever found for the genus Huerzelerimys. Its main characters are: size small; skull broad and short with stout rostrum; interorbital roof narrow;premaxillary laterodorsal crest well developed; frontal crests weak and subparallel; incisive foramina long, with their posterior ends lined up with anterior root of M1; posterior palatal foramina located mesial to M2; caudal border of hard palate lying posterior to M3;interpterygoid foramen absent; alisphenoid canal bony; bulla large and inflated; internal carotid foramen located near the basilar tubercle; mandible having low horizontal ramus and deeply concave diastema; anterior end of masseteric ridge lined up with anterior margin of m1; mental foramen situated slightly anterior to masseteric ridge and anteroventral to m1, near to mandibular diastema; upper incisors orthodont; M1 having slightly anteriorly located t1; in M1 and M2 t6 and t9 connected by distinct crest and t12 crest-like; t1 and t3 of M2 and t1 of M3 connected to t5; M3 having t3 and a large isolated t8; small Acc of m1 connected with both Alc and Abc; m1 and m2 having distinct buccal cingula, larger c2 attached to protoconid, and low crest-like posterior heel; m2 and m3 having isolated Abc; c1 absent in m3. The evolutionary level of the described skull tends to show that the age of the upper part of the Liushu Formation yielding H. asiaticus may belong to late Bahean, corresponding to European upper MN11 or lower MN12.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits37Downloads14 Comment 0

5. chinaXiv:202003.00083 [pdf]


江静; 董雅楠; 李艳; 杨百寅
Subjects: Psychology >> Management Psychology

员工高质量的建议是企业提质增效的重要途径。然而,以往研究主要聚焦在员工的“建言参与”和“建言数量”上,忽略了一个最本质的问题——员工的建言质量如何?为解决这一关键问题,分别从员工建言质量的内涵、测量、前因机制的角度构建一个关于员工建言质量的系统研究。研究一基于扎根理论,探讨员工建言质量的内涵与结构,开发员工建言质量的测量工具;研究二是基于内隐建言理论,从个体和团队两个层面探讨员工与领导的批判性思维对员工建言质量的影响机制。理论贡献在于推动员工建言质量的理论构建, 拓展批判性思维理论、内隐建言理论的应用。

submitted time 2020-03-30 Hits170Downloads126 Comment 0

6. chinaXiv:202003.00079 [pdf]


张田; 孙卉
Subjects: Psychology >> Social Psychology


submitted time 2020-03-29 Hits130Downloads50 Comment 0

7. chinaXiv:202003.00078 [pdf]


温芳芳 Wen, Fangfang; 佐斌 Zuo,Bin; 马书瀚 Ma,Shuhan; 谢志杰 Xie,Zhijie
Subjects: Psychology >> Social Psychology


submitted time 2020-03-28 Hits104Downloads47 Comment 0

8. chinaXiv:202002.00017 [pdf]


李世峰; 吴艺玲; 张福民; 许琼英; 周爱保
Subjects: Psychology >> Social Psychology


submitted time 2020-03-27 Hits2690Downloads77 Comment 0

9. chinaXiv:202003.00081 [pdf]


赵宇; 胡良博; 蒋宇; 唐俊峰; 黄栋; 薛华庆; 周尚文
Subjects: Geosciences >> Geology

本文通过原位分析计算,获得滑面、邻近面特征粘土矿物种类及其相对含量、矿物粒径及孔隙率,实验以清晰可靠的物理图像和测试数据揭示滑面、邻近面矿物成分、结构的空间分布特征和差异,从而揭示土质斜坡破坏、滑面强度降低的物理路径和机制。实验采取新鲜未经后期风化滑带土,用AMICSCAN矿物分析电镜集高分辨场发射扫描电镜、最新一代(第三代)的矿物自动分析软件AMICS(Automatic Mineral Identification and Characterization System,分辨率可达0.5μm像素)和超大面积高分辨成像软件为一体的矿物分析和结构分析系统,依据矿物原子比例的唯一性,在识别矿物种类及其分布情况。其次,利用 FEI 公司的Helios NanoLab-650 聚焦电子束扫描电镜(FIB-SEM)并结合X 射线能谱仪(EDS)/以电镜的高分辨率背散射电子二维图像与能谱仪测得的特征谱相结合,借助Avizo Fire 软件基于能谱的点、线元素扫描图像和每间隔一微米扫描得出500帧聚焦电子束扫描电镜图像结合,可视化重建并计算滑带土的孔隙空间三维分布状态,并通过体积比近似折算成含量比,为揭示滑面形成路径和机理提供真实、准确可靠的证据。实验显示:1)微米尺度上,滑面、邻近面之间可见明显的分界,滑面厚度不均匀,在10纳米分辨率的背散射图像上,滑面结构致密孔隙小且较难分辨;2) 宽17微米,高19微米的立方体扫描切割3维立体滑带土样中,滑面部分孔隙率0.0331,邻近面部分孔隙率0.0754,邻近面孔隙率约为滑面的2.3倍;3)能谱仪特征谱图像和数据显示,滑面上蒙脱石特征元素Na、Ca、Mg峰明显,并且在分界线附近出现跳水式的陡降,证明滑面上蒙脱石富集,而邻近面却未检出蒙脱石;4)邻近面伊利石特征元素K高于滑面,即邻近面伊利石含量明显高于滑面。实验用清晰的物理图像和准确的能谱数据证实:滑面、邻近面存在矿物成分和结构的显著差异,滑面孔隙率低有可能是因为滑面上覆土体压力造成的。本文首次以原位实验的方法揭示滑面、邻近面矿物成分、孔隙率和结晶度及粒度空间差异,为揭示滑面演化路径提供了可靠的依据,为最终建立滑面、土体跨尺度演化模型,我们需要进行更多的滑面、邻近面成分结构差异、宏观强度、微纳尺度结构对比分析、以及矿物演化动力学过程分析。

submitted time 2020-03-26 Hits72Downloads39 Comment 0

10. chinaXiv:202003.00082 [pdf]

Measuring colloidal forces between clay microparticles with optical tweezers

赵宇; 武京治; 胡良博; 蒋宇
Subjects: Geosciences >> Geology

The interaction forces between clay micro-particles play an important role in the macroscopic strength behavior of clayey soils. Optical tweezers were used in the present study to explore the interaction between clay micro- particles. This technology uses a highly focused laser beam to manipulate small objects and can also be used as a force transducer for the measurement of forces on the order of pico-Newtons (pN). Polystyrene beads were first used to measure the surface interactions between polystyrene beads and clay particles for accurate calibration of the system because of their perfectly spherical shape and optical homogeneity, and were successful in obtaining force mea- surements within the range of 20 pN. Subsequently the interactive force was measured when a small clay particle was moved along the surface of a large clay particle. The force measured varies as the interaction of clay surfaces may evolve along their relative motion, leading to force measurements up to 40 ∼ 80 pN. The present study shows a promising potential of optical tweezers in exploring the complex micro-scale phenomena in clay minerals.

submitted time 2020-03-26 Hits137Downloads64 Comment 0

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