Results 71 to 80 of about 4,362 (258)

Mechanism of grouped collapse of thick and hard roof for gob-side entry retaining combined backfill in fully-mechanized caving face

Meitan xuebao
A large range of caving roof of gob-side entry retaining is easy to cause impact damage of the roadside backfill body. In order to ensure the stability of gob-side entry retaining, different from the traditional large-angle inclined roof cutting method ...
Guorui FENG, Zijie MA, Wenda WU, Jianbiao BAI, Sunwen DU, Jinwen BAI, Lujin HE   +6 more
doaj   +1 more source

New craniodental materials of Falcarius utahensis (Theropoda: Therizinosauria) reveal patterns of intraspecific variation and cranial evolution in early coelurosaurians

The Anatomical Record, EarlyView.
Abstract Despite documented ecomorphological shifts toward an herbivorous diet in several coelurosaurian lineages, the evolutionary tempo and mode of these changes remain poorly understood, hampered by sparse cranial materials for early representatives of major clades. This is particularly true for Therizinosauria, with representative crania best known
William J. Freimuth, Lindsay E. Zanno
wiley   +1 more source

Mechanism and Control Technology of Rockburst Induced by Thick Hard Roof and Residual Coal Pillar: A Case Study

, 2023
Rockburst caused by the fracture of thick hard roof and the instantaneous instability of residual coal pillar seriously jeopardize the deep coal mining safety.
Wenjie Liu, Zhainan Zhang, Rijie Xu, Xiang He, Ke Yang   +4 more
core   +1 more source

Research on the bearing characteristics of brackets in thick hard roof mining sites and the effect of blasting on roof control

Geomechanics and Geophysics for Geo-Energy and Geo-Resources
AbstractDeep mining stress increase and thick hard rock layer endowment drive rock body fissure expansion, leading to sudden fracture of the roof plate accidents. The roof slab of 11,129 working face in Zhangji Mine is a 16 m thick sandstone composite roof slab, whose compressive strength reaches 89.8 MPa.
Jiaxin Dang, Min Tu, Xiangyang Zhang, Qingwei Bu   +3 more
openaire   +2 more sources

The coelurosaur theropods of the Romualdo formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica

The Anatomical Record, EarlyView.
Abstract The upper carbonate concretion levels of the Romualdo Formation (Aptian, Brazil) have yielded several theropod dinosaur remains, including spinosaurids and the coelurosaurs Santanaraptor placidus and Mirischia asymmetrica, the phylogenetic affinities of which are controversial.
Rafael Delcourt, Orlando Nelson Grillo, Christophe Hendrickx, Maximilian Kellermann, Max Cardoso Langer   +4 more
wiley   +1 more source

Study on the Mechanism of Weakening Thick and Hard Roof by Deep-Hole Blasting in Deep Coal Mines

Frontiers in Earth Science, 2022
In the mining process of deep coal mines with a thick and hard roof, it is easy to form a large overhanging roof and accumulate a lot of strain energy. The sudden breaking of the suspended roof may induce seisms, which seriously threaten the safety of underground miners and equipment.
Chen Zhang, Junpeng Zou, Xiufeng Zhang, Chao Wang, Yu-Yong Jiao   +4 more
openaire   +2 more sources

Re‐evaluation of a soft crested Edmontosaurin, with implications for hadrosaurid life appearance and diversity

The Anatomical Record, EarlyView.
Abstract Hadrosaurid dinosaurs are generally regarded as “crested” or “non‐crested” depending on the presence or absence of a bony cranial crest. At least one supposedly “non‐crested” hadrosaur is known to have possessed a soft tissue cranial crest (or comb), based on an exceptionally preserved “mummified” specimen. Here we redescribe this specimen and
Henry S. Sharpe, Phil R. Bell, Ian Baylatry, Robin Sissons, Corwin Sullivan   +4 more
wiley   +1 more source

The cranial, mandibular, and hyoid anatomy of softshell turtles (Trionychidae): A revised character list for phylogenetic analysis

The Anatomical Record, EarlyView.
Abstract Softshell turtles (Pan‐Trionychidae) are an early branching clade of hidden‐necked turtles (Cryptodira) with a rich fossil record extending back to the Early Cretaceous. The evolutionary history of softshell turtles is still unresolved because of their conservative morphology combined with high levels of polymorphism related to morphological ...
Léa C. Girard, Walter G. Joyce
wiley   +1 more source

Evolution Mechanism of Stress-Concentration Shell Structure and Stability Control of Thick–Hard Roofs Based on a Staged Thick-Plate Model

Eng
To address delayed roof fracture, severe stress concentration, and strong strata pressure under thick–hard roof conditions, this study investigated the 1014 mining face of Yushuquan Coal Mine.
Lili Xie, Zhibiao Guo, Jinglin You, Junao Zhu, Yuanxin Zhao   +4 more
doaj   +1 more source

Redescription of the Triassic cynodont Cistecynodon parvus and reassessment of its phylogeny

The Anatomical Record, EarlyView.
Abstract Cynodontia is an important subclade of Therapsida that first occurred in the late Permian. It includes extinct subclades which are the non‐mammaliaform cynodonts and Mammaliaformes, with the latter ultimately giving rise to crown mammals. The systematics of non‐mammaliaform cynodonts has been extensively studied and is relatively well‐resolved,
Erin S. Lund, Frederik P. Wolvaardt, Roger M. H. Smith, Jaganmoy Jodder, Julien Benoit   +4 more
wiley   +1 more source