Abutment pressure distribution for longwall face mining through abandoned roadways

Abutment pressure distribution is different when a longwall panel is passing through the abandoned gate roads in a damaged coal seam. According to the geological condition of panel E13103 in Cuijiazhai Coal Mine in China, theoretical analysis and finite element numerical simulation were used to determine the front pressure distribution characteristics when the longwall face is 70, 50, 30, 20, 10, and 5 m from the abandoned roadways. The research results show that the influence range of abutment pressure is 40 to 45 m outby the face, and the peak value of front abutment pressure is related to the distance between the face and abandoned roadways. When the distance between the longwall face and abandoned roadways is reduced from 50 to 10 m, the front abutment pressure peak value kept increasing. When the distance is 10 m, it has reached the maximum. The peak value is located in 5 to 6 m outby the faceline. When the distance between the longwall face and abandoned roadways is reduced from 10 to 5 m, the front abutment pressure sharply decreases, the intact coal yields and is even in plastic state. The peak value transfers to the other side of the abandoned roadways. The research results provide a theoretical basis for determining the advance support distance of two roadways in the panel and the reinforcement for face stability when the longwall face is passing through the abandoned roadways.

Salubrinal alleviates traumatic spinal cord injury through suppression of the eIF2α/ATF4 pathway in mouse model

Spinal cord injury(SCI)remains an intractable clinical challenge of neurosurgery,it can be divided into two stages:uncontrollable primary injury induced by mechanical damage and controllable secondary injury regulated by continuous cell death.The apoptosis was the one of most important events in secondary injury,previous studies revealed that excessive endoplasmic reticulum(ER)stress breaks down the homeostasis and triggers apoptosis in the spinal cord.To deter or alleviate the secondary jury,we screen one of fat-soluble compounds,salubrinal,which was an inhibitor of eIF2αdephosphorylation can repair SCI by inhibiting ER stress in mice after SCI.Administration of salubrinal effectively represses apoptosis,protects neuronal cell,and promotes the restoration of locomotor function in mice SCI models.Furthermore,the level of phosphorylated eIF2αwas raised in the presence of salubrinal,but the protein expression of ATF4 and CHOP was downregulated.Unexpectedly,transcriptional expression of CHOPregulated pro-apoptotic genes was decreased.These data suggest salubrinal suppress ER stress by targeting eIF2α/ATF4 pathways and reduces cell death after SCI.It is suggested that the mitigation of secondary lesion by inhibiting ER stress induced apoptosis in the early phase of SCI is promising treatment strategy.

ADHESION STRENGTH AND MORPHOLOGIES OF r BMSCs DURING INITIAL ADHESION AND SPREADING

Cell adhesion plays an important role in cell physiology. A better understanding of this process could facilitate many clinical therapies. In this study, Rat bone marrow-derived mesenchymal stem cells （rBMSCs） were cultured on glass substrate, and the morphology and adhesion strength were characterized. The cell morphology was defined as spherical, adhesive, and spreading. The adhesion strengths of the different morphologies exhibited different distribu- tion patterns. The spherical cells exhibited low adhesion strength; the adhesive cells exhibited rapidly increasing adhesion strength while their diameters remained relatively constant. The ad- hesion strength increased with the cell diameter in the spreading cells. These findings suggest that adhesion strength can be quickly assessed by examining the cell morphology.

Embedding hollow Co3O4 nanoboxes into a three- dimensional macroporous graphene framework for high-performance energy storage devices

Carbon materials are widely used for supercapacitor applications thanks to their high surface area, good rate capability, and excellent cycling stability. However, the development of high energy density carbon supercapacitors still remains a challenge. In this work, hollow Co3O4 nanoboxes have been embedded into three-dimensional macroporous laser-scribed graphene （LSG） to produce composite electrodes with improved electrochemical performance. Here, Co3O4 provides high capacity through fast and reversible redox reactions, while LSG serves as a conductive network to maintain high power. The open nanobox morphology is a unique solution for extracting the maximum capacity from Co3O4, resulting in electrodes whose surfaces, both internal and external, are accessible to the electrolyte. The electrochemical performance of the composite material is promising with a volumetric capacity of 60.0 C/cm^3 and a specific capacity of 542.3 C/g, corresponding to 682.0 C/g of the constituent Co3O4. With a low equivalent series resistance of 0.9 Ω, the Co3O4/LSG electrode is able to maintain 113.1% of its original capacity after 10,000 cycles. This work provides new insights into the design of high-performance carbon/metal oxide nano- composites for next-generation energy storage devices.

140千年以来亚北极太平洋地区一直存在地磁场非偶极子行为吗?

Paleomagnetic records from globally distributed locations are essential for fully understanding geomagnetic field variations,particularly non-dipole field fluctuations[1].Paleomagnetic studies on historical time scales have demonstrated the existence of persistent geomagnetic flux patches,such as the Canadian(North America)and Siberian(East Asia)flux lobes,which may result from an organizing structure imposed on the geomagnetic field by lower mantle heterogeneity[2].Holocene paleomagnetic secular variations,reconstructed from the Alaskan margin of the Subarctic Pacific Ocean(SPO)[3]and revealed by dynamo modeling[4],further suggest that time-varying flux expulsions on the core-mantle boundary recurrently occur in high-latitude locations(Fig.la).

Optical coherence elastography of 3D bilayer soft solids using full-field and partial displacement measurements

Characterizing nonhomogeneous elastic property distribution of soft tissues plays a crucial role in disease diagnosis and treatment.In this paper,we will apply the optical coherence elastography to reconstruct the shear modulus elastic property distribution of a bilayer solid.In the computational aspect,we adopt a well-established inverse technique that solves for every nodal shear modulus in the problem domain(NO method).Additionally,we also propose a novel inverse method that assumes the shear moduli merely vary along the thickness of the bilayer solid(TO method).The inversion tests using simulated data demonstrate that TO method performs better in reconstructing the shear modulus distribution.Further,we utilize the experimental data obtained from the optical coherence tomography to reconstruct the shear modulus distribution of a bilayer phantom.We observe that the quality of the reconstructed shear modulus distribution obtained by the partial displacement measurement is better than that obtained by the full-field displacement measurement.Particularly,merely using the displacement component along the loading direction significantly improves the reconstructed results.This work is of great significance in applying optical coherence elastography(OCE)to characterize the elastic property distribution of layered soft tissues such as skins and corneas.