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Ni L.,Shandong University of Science and Technology | Zhang J.,Shandong University of Science and Technology | Guo X.,China University of Mining and Technology | Guo X.,Shandong Energy Group Company Ltd
Advanced Materials Research | Year: 2013

TMS320F2812 is widely used in the design of embedded control system. Based on DSP TMS320F2812, the colliery high-voltage integrated protector which has setting protection, measurement, controlling and communication is developed. The design of AD module, CAN bus communication module and protection module of the integrated protector is elaborated. The structure design of its internal circuit and realization algorithms of part of modules are also given. Experimental results show that the protector achieves a good performance. © (2013) Trans Tech Publications, Switzerland.


Zheng T.,North China Electrical Power University | Zhu X.,Hefei Power Supply Company | Xu Z.,Shandong Energy Group Co. | Liu L.,North China Electrical Power University
Dianwang Jishu/Power System Technology | Year: 2013

The impacts of grid-connected resistance-type of DC bias suppression devices on distance relay of transmission line is analyzed in this paper. Based on the analysis of mal-operation of distance relay caused by the insertion of DC bias suppression devices, a protective scheme which combines zero sequence reactance relay with phase-to-phase impedance relay has been put forward. phase-to-phase impedance relay is used to protect phase-to-phase fault and zero sequence reactance relay is applied for protecting the ground fault. Corresponding setting criteria are also given in this paper. Finally, PSCAD simulation results show that the proposed scheme can provide effective protection for the asymmetrical fault of transmission line with the insertion of resistance-type of DC bias suppression device.


Li W.,China University of Mining and Technology | Li W.,Shandong energy group co. | Yang R.S.,China University of Mining and Technology
Advanced Materials Research | Year: 2014

Loose blasting technology is applied to the problem of fully mechanized coal face passing through fault. The paper gets safe and practical loose blasting parameters and blasting process, achieves no re-open-off cut for the fully mechanized coal face, reduces loss of coal pillars for faults and improves the coal recovery rate. At last, the goal of high yield, steady yield, and increasing yield for fully mechanized mining face is realized. © (2014) Trans Tech Publications, Switzerland.


Guo X.,China University of Mining and Technology | Guo X.,Shandong Energy Group Co. | Liu J.,North China Institute of Science and Technology | Jiang F.,University of Science and Technology Beijing
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2015

By using the in-situ observation and numerical simulation, the roof moving features of fully-mechanized sublevel caving face with deep alluvium has been studied. The results can be drawn as follows: 1) The time effect of the load of supports in the fully mechanized caving face with deep alluvium is significant. 2) While with advance of working face, the break of the immediate roof forms "rock-gangue" structure periodically and the break of the basic roof induces weighting of working face. 3) The weighting order along incline direction of the working face follows roof fracture characteristics of general working face. 4) The area of overlying strata area to be controlled by supports is large, and the strength of weighting induced by the upper basic roof breaking is large. 5) The advance stress fluctuation monitoring technology offers a new method for weighting prediction in working face. Finally, the suggestion about roof accident prevention of fully-mechanized sublevel caving face with deep alluvium was proposed. The study results can be useful for roof control design and roof accidents prevention in fully-mechanized sublevel caving face with deep alluvium. ©, 2015, China University of Mining and Technology. All right reserved.


Guo X.,China University of Mining and Technology | Guo X.,Shandong Energy Group Co Ltd | Zhu S.,University of Science and Technology Beijing | Zhai M.,Shandong Energy Group Co Ltd
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2015

Taking the LW 2031N of Xinjulong mine as an example, the reasonable support resistance of fully-mechanized sublevel caving face with deep alluvium thin bedrock was investigated by the numerical simulation. The results show that the support load had a significant time effect and came from the weight of top coal and immediate roof, the impact load induced by basic roof destruction and the additional load induced by the slow deformation of deep alluvium. The model for determination of the reasonable support resistance was proposed. Considering the remarkable time effect of support load and the variety of rock structure model, the reasonable support resistance of the test face is 13700 kN. Microseismic monitoring reveals the thickness of bedrock in test face is 50 m, immediate roof thickness is 30 m, and basic roof thickness is 20 m. The support load monitoring shows that the support resistance is 10000-14000 kN basically, which verified the support resistance. The results above can provide a reference for support selection of fully-mechanized sublevel caving face with deep alluvium thin bedrock. ©, 2015, China University of Mining and Technology. All right reserved.


Li J.,Shandong University | Ren N.,Shandong University | Qiu J.,Shandong University | Jiang H.,Shandong University | And 5 more authors.
International Journal of Biological Macromolecules | Year: 2013

Naturally-derived collagens for tissue engineering are limited by low mechanical strength and rapid degradation. In this study, carbodiimide is used to chemically modify the collagen derived from porcine acellular dermal matrix (PADM). The results show that the strength and resistance of PADM to enzymatic digestion can be adjusted by the reconnection of free amino and carboxyl groups of the collagen fibers. The cytocompatibility of the crosslinked PADM was evaluated by cell adhesion and proliferation assays. The cell culture studies on crosslinked and uncrosslinked PADM showed that the modification does not affect the scaffold's biocompatibility. These results demonstrate that the PADM collagen materials can be strengthened through a low-cost, non-toxic crosslinking method for potential use in biomedical applications. © 2013 Elsevier B.V.


Zhang M.,University of Science and Technology Beijing | Jiang F.,University of Science and Technology Beijing | Li K.,University of Science and Technology Beijing | Zhai M.,Shandong Energy Group Co Ltd | Yang G.,Gaozhuang Coal Industry Co Ltd
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2016

The morphological characteristics, caving and movement regularity of super-thick overlying key strata were analysed in the process of repeated mining based on the key strata theory. The results show that the mine-quake mechanism near the stopping line is concluded as the following two forms. 1) The increase of roof caving height resulting from the increase of mining height causes the instability of articulated balance structures in highstand key rock strata, which can induce mine quakes. 2) The outward extension of roof strata movement line due to repeated mining results in the increase of roof movement scope near the stope boundary, which can break the highstand key strata and then induce mine quakes. Several prevention and control methods of dynamic disasters such as lowering the mining speed to lower the influence scope, and optimizing mining boundary to lower the stress according to the mechanism of mine quakes were proposed. The mining practice in Longwall Panel 3 lower 510 shows that mine quakes and disasters near the stope boundary are prevented and controlled, and workface safety and surface stability are guaranteed. © 2016, Editorial Board of Journal of CUMT. All right reserved.


Wang G.,Shandong Energy Group Co. | Wang G.,Shandong University | Qiu J.,Shandong University | Zheng L.,Shandong University | And 4 more authors.
Journal of Biomaterials Science, Polymer Edition | Year: 2014

The surface characteristics of biomaterials, especially regarding the sustained delivery of bone morphogenetic protein-2 (BMP-2), can possibly provide a novel and effective drug delivery system that can enhance osteogenesis. In this study, we evaluated the BMP-2 adsorption and release ability of the surface biomimetic hydroxyapatite (HAp) nanostructure on a new HAp-coated genipin-chitosan conjugation scaffold (HGCCS), and the resulting osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. HGCCS exhibited a loading efficiency of 65% (1.30 g), which is significantly higher than 28% (0.56 g, p < 0.01) for the genipin cross-linked chitosan framework, as quantified by an enzyme-linked immunosorbent assay. More importantly, we found that the release of BMP-2 from HGGCS sustained for at least 14 days in simulated body fluid in vitro, which is much better than the burst release within 3 days for CGF. Moreover, the BMP-2 release from HGCCS induced an increase in alkaline phosphatase activity as an indicator of osteogenic differentiation of seeded BMSCs for 14 days in vitro. HGCCS also stimulated a high mRNA expression of osteogenic differentiation makers, runt-related transcription factor 2 for 14 days, osteopontin for 3 days, and osteocalcin for 14 days. The results of this study suggest that the surface biomimetic HAp nanostructure of HGCCS used as a delivery system for BMP-2 is capable of promoting osteogenic differentiation in vitro. These findings demonstrated that HAp nanostructure assembled on organic porous scaffold could work as both calcium source and absorption/release platform, which opened a new research avenue for cell growth factor release, and provided a promising strategy for design and preparation of bioactive scaffold for bone tissue engineering. © 2014 © 2014 Taylor & Francis.


Qiu J.,Shandong University | Li J.,Shandong University | Wang G.,Shandong Energy Group Co. | Zheng L.,Shandong University | And 5 more authors.
ACS Applied Materials and Interfaces | Year: 2013

As a biocompatible and bioactive natural tissue engineering scaffold, porcine acellular dermal matrix (PADM) has limitations for the application in tissue regeneration due to its low strength and rapid biodegradation. Here, purified PADM was modified by a nontoxic cross-linker (genipin) to enhance its mechanical properties and improve its resistance to enzymatic degradation. In vitro testing results demonstrated that the stiffness of the genipin cross-linked PADM was improved and biodegradation rate was decreased. Results of cell proliferation assays showed that the cross-linking reaction by genipin did not undermine the cytocompatibility of PADM. Furthermore, genipin cross-linking imparted an observable fluorescence allowing visualization of the scaffold's three-dimensional (3D) porous structure and cell distribution by confocal laser scanning microscopy (CLSM). Immunostaining of the cell nuclei and cytoskeleton indicated that MC3T3-E1 preosteoblasts were tightly adhered to and uniformly distributed onto the cross-linked PADM scaffold. Results of this study suggest that the 3D porous genipin cross-linked PADM with intrinsic fluorescence may have broader applications for tissue engineering scaffolds where higher mechanical stiffness is needed. © 2012 American Chemical Society.


PubMed | Shandong Energy Group Co.
Type: Journal Article | Journal: Journal of biomaterials science. Polymer edition | Year: 2014

The surface characteristics of biomaterials, especially regarding the sustained delivery of bone morphogenetic protein-2 (BMP-2), can possibly provide a novel and effective drug delivery system that can enhance osteogenesis. In this study, we evaluated the BMP-2 adsorption and release ability of the surface biomimetic hydroxyapatite (HAp) nanostructure on a new HAp-coated genipin-chitosan conjugation scaffold (HGCCS), and the resulting osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. HGCCS exhibited a loading efficiency of 65% (1.30 g), which is significantly higher than 28% (0.56 g, p < 0.01) for the genipin cross-linked chitosan framework, as quantified by an enzyme-linked immunosorbent assay. More importantly, we found that the release of BMP-2 from HGGCS sustained for at least 14 days in simulated body fluid in vitro, which is much better than the burst release within 3 days for CGF. Moreover, the BMP-2 release from HGCCS induced an increase in alkaline phosphatase activity as an indicator of osteogenic differentiation of seeded BMSCs for 14 days in vitro. HGCCS also stimulated a high mRNA expression of osteogenic differentiation makers, runt-related transcription factor 2 for 14 days, osteopontin for 3 days, and osteocalcin for 14 days. The results of this study suggest that the surface biomimetic HAp nanostructure of HGCCS used as a delivery system for BMP-2 is capable of promoting osteogenic differentiation in vitro. These findings demonstrated that HAp nanostructure assembled on organic porous scaffold could work as both calcium source and absorption/release platform, which opened a new research avenue for cell growth factor release, and provided a promising strategy for design and preparation of bioactive scaffold for bone tissue engineering.

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