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Hybridizing grey wolf optimization with differential evolution for global optimization and test scheduling for 3D stacked SoC 被引量:93
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作者 Aijun Zhu Chuanpei Xu +2 位作者 Zhi Li Jun Wu Zhenbing Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第2期317-328,共12页
A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional (3D) stacked system-on-chip (SoC) by hybridizing grey wolf optimi... A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional (3D) stacked system-on-chip (SoC) by hybridizing grey wolf optimization with differential evo- lution (HGWO). Because basic grey wolf optimization (GWO) is easy to fall into stagnation when it carries out the operation of at- tacking prey, and differential evolution (DE) is integrated into GWO to update the previous best position of grey wolf Alpha, Beta and Delta, in order to force GWO to jump out of the stagnation with DE's strong searching ability. The proposed algorithm can accele- rate the convergence speed of GWO and improve its performance. Twenty-three well-known benchmark functions and an NP hard problem of test scheduling for 3D SoC are employed to verify the performance of the proposed algorithm. Experimental results show the superior performance of the proposed algorithm for exploiting the optimum and it has advantages in terms of exploration. 展开更多
关键词 META-HEURISTIC global optimization NP hard problem
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Directional hydraulic fracturing to control hard-roof rockburst in coal mines 被引量:32
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作者 Fan Jun Dou Linming +4 位作者 He Hu Du Taotao Zhang Shibin Gui Bing Sun Xinglin 《International Journal of Mining Science and Technology》 2012年第2期177-181,共5页
Hard roof is the main factor that induces rock-burst.In view of the present obvious weakness of control measures for hard roof rockburst in domestic collieries,the mechanism and field application of directional hydrau... Hard roof is the main factor that induces rock-burst.In view of the present obvious weakness of control measures for hard roof rockburst in domestic collieries,the mechanism and field application of directional hydraulic fracturing technology for rock-burst prevention have been investigated in this paper using theoretical analysis and numerical simulation.The results show that the weighting span of the main roof and the released kinetic energy as well as the total elastic energy decreased greatly after the directional fracturing of hard roof with the mining progression,thereby reducing the rockburst hazard degree to coal body.The directional hydraulic fracturing technology was carried out in 6305 working face of Jisan Coal Mine to prevent rockburst.Field practices have proved that this technology is much simpler and safer to operate with better prevention effect compared with blasting.By optimizing the operation procedures and developing a new technology of automated high-pressure delivery pipe,the maximum fracturing radius now reaches more than 9 m and the borehole depth exceeds 20 m.Additionally,drilling cutting method was applied to monitor the stress of the coal mass before and after the fracturing,and the drill cuttings dropped significantly which indicates that the burst prevention effect of directional hydraulic fracturing technology is very remarkable.The research results of this paper have laid a theoretical and practical foundation for the widespread application of the directional hydraulic fracturing technology in China. 展开更多
关键词 hard roofRockburstDirectional hydraulic fracturingSimulation
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TBM tunneling in extremely hard and abrasive rocks:Problems,solutions and assisting methods 被引量:32
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作者 ZHENG Yan-long HE Lei 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期454-480,共27页
Extremely hard and abrasive rocks pose great challenges to the past and ongoing TBM projects by increasing cutter wear and reducing penetration rates.A considerable amount of research has been conducted to improve the... Extremely hard and abrasive rocks pose great challenges to the past and ongoing TBM projects by increasing cutter wear and reducing penetration rates.A considerable amount of research has been conducted to improve the performance of TBMs in those challenging grounds by either improving the capacity of TBMs or developing assisting rock breakage methods.This paper first highlights the challenges of hard and abrasive rocks on TBM tunneling through case studies.It then presents the development of hard rock TBMs and reviews the technologies that can be used individually or as assistance to mechanical excavators to break hard rocks.Emphases are placed on technologies of high pressure waterjet,laser and microwave.The state of the art of field and laboratory research,problems and research directions of those technologies are discussed.The assisting methods are technically feasible;however,the main challenges of using those methods in the field are that the energy consumption can be over 10 times high and that the existing equipments have robustness problems.More research should be conducted to study the overall energy consumption using TBMs and the assisting methods.Pulsed waterjet,laser and microwave technologies should also be developed to make the assistance economically viable. 展开更多
关键词 hard and abrasive rocks tunnel boring machine waterjet laser microwave
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Non-explosive mining and waste utilization for achieving green mining in underground hard rock mine in China 被引量:29
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作者 Shao-feng WANG Li-cheng SUN +4 位作者 Lin-qi HUANG Xi-bing LI Ying SHI Jin-rui YAO Shao-lun DU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第9期1914-1928,共15页
Innovations of mining technologies were proposed by beneficial utilizations of unfavorable factors such as high geostress,high geotemperature and high mining depth to achieve green mining as mining depth increases ine... Innovations of mining technologies were proposed by beneficial utilizations of unfavorable factors such as high geostress,high geotemperature and high mining depth to achieve green mining as mining depth increases inevitably.Cuttability of deep hard rock was investigated by experimental and regressed analyses to find the reasonable stress adjustment method to improve non-explosive mechanized fragmentation for hard ore-rock.A non-explosive mechanized and intellectualized mining method was proposed to continuously and precisely exploit phosphate underground,which promoted the high-recovery,low-waste and high-efficiency exploitation of phosphate with recovery rate over 90%,dilution rate near 5%and cutting efficiency about 107.7 t/h.A circular economy model and the backfill system were proposed to conduct resource utilizations of solid waste,by which the utilization amount of waste increased year after year.In 2018,the utilization amounts of phosphogypsum,yellow phosphorus slag and waste rock increased to 1853.6×10^3 t/a,291.1×10^3 t/a and 1493.8×10^3 t/a,respectively. 展开更多
关键词 hard rock mine non-explosive mining waste backfilling circular economy waste utilization green mining
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Rockburst prediction in hard rock mines developing bagging and boosting tree-based ensemble techniques 被引量:29
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作者 WANG Shi-ming ZHOU Jian +3 位作者 LI Chuan-qi Danial Jahed ARMAGHANI LI Xi-bing Hani SMITRI 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期527-542,共16页
Rockburst prediction is of vital significance to the design and construction of underground hard rock mines.A rockburst database consisting of 102 case histories,i.e.,1998−2011 period data from 14 hard rock mines was ... Rockburst prediction is of vital significance to the design and construction of underground hard rock mines.A rockburst database consisting of 102 case histories,i.e.,1998−2011 period data from 14 hard rock mines was examined for rockburst prediction in burst-prone mines by three tree-based ensemble methods.The dataset was examined with six widely accepted indices which are:the maximum tangential stress around the excavation boundary(MTS),uniaxial compressive strength(UCS)and uniaxial tensile strength(UTS)of the intact rock,stress concentration factor(SCF),rock brittleness index(BI),and strain energy storage index(EEI).Two boosting(AdaBoost.M1,SAMME)and bagging algorithms with classification trees as baseline classifier on ability to learn rockburst were evaluated.The available dataset was randomly divided into training set(2/3 of whole datasets)and testing set(the remaining datasets).Repeated 10-fold cross validation(CV)was applied as the validation method for tuning the hyper-parameters.The margin analysis and the variable relative importance were employed to analyze some characteristics of the ensembles.According to 10-fold CV,the accuracy analysis of rockburst dataset demonstrated that the best prediction method for the potential of rockburst is bagging when compared to AdaBoost.M1,SAMME algorithms and empirical criteria methods. 展开更多
关键词 ROCKBURST hard rock PREDICTION BAGGING BOOSTING ensemble learning
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Predicting TBM penetration rate in hard rock condition:A comparative study among six XGB-based metaheuristic techniques 被引量:26
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作者 Jian Zhou Yingui Qiu +4 位作者 Danial Jahed Armaghani Wengang Zhang Chuanqi Li Shuangli Zhu Reza Tarinejad 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第3期201-213,共13页
A reliable and accurate prediction of the tunnel boring machine(TBM)performance can assist in minimizing the relevant risks of high capital costs and in scheduling tunneling projects.This research aims to develop six ... A reliable and accurate prediction of the tunnel boring machine(TBM)performance can assist in minimizing the relevant risks of high capital costs and in scheduling tunneling projects.This research aims to develop six hybrid models of extreme gradient boosting(XGB)which are optimized by gray wolf optimization(GWO),particle swarm optimization(PSO),social spider optimization(SSO),sine cosine algorithm(SCA),multi verse optimization(MVO)and moth flame optimization(MFO),for estimation of the TBM penetration rate(PR).To do this,a comprehensive database with 1286 data samples was established where seven parameters including the rock quality designation,the rock mass rating,Brazilian tensile strength(BTS),rock mass weathering,the uniaxial compressive strength(UCS),revolution per minute and trust force per cutter(TFC),were set as inputs and TBM PR was selected as model output.Together with the mentioned six hybrid models,four single models i.e.,artificial neural network,random forest regression,XGB and support vector regression were also built to estimate TBM PR for comparison purposes.These models were designed conducting several parametric studies on their most important parameters and then,their performance capacities were assessed through the use of root mean square error,coefficient of determination,mean absolute percentage error,and a10-index.Results of this study confirmed that the best predictive model of PR goes to the PSO-XGB technique with system error of(0.1453,and 0.1325),R^(2) of(0.951,and 0.951),mean absolute percentage error(4.0689,and 3.8115),and a10-index of(0.9348,and 0.9496)in training and testing phases,respectively.The developed hybrid PSO-XGB can be introduced as an accurate,powerful and applicable technique in the field of TBM performance prediction.By conducting sensitivity analysis,it was found that UCS,BTS and TFC have the deepest impacts on the TBM PR. 展开更多
关键词 TBM penetration rate hard rock XGB-based hybrid model Predictive model Metaheuristic optimization
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表浅肌肉腱膜皮瓣联合硬腭黏膜移植修复全层眼睑缺损 被引量:24
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作者 李冬梅 秦毅 +1 位作者 陈涛 赵颖 《中华眼科杂志》 CAS CSCD 北大核心 2007年第12期1064-1068,共5页
目的探讨利用眼周表浅肌肉腱膜系统(SMAS)皮瓣联合硬腭黏膜移植修复中、重度全层眼睑缺损的临床疗效。方法对26例(26只眼)大于或等于眼睑全长1/2的全层眼睑缺损患者,采用硬腭黏膜移植替代眼睑后层,即睑板和睑结膜层;利用眼周血... 目的探讨利用眼周表浅肌肉腱膜系统(SMAS)皮瓣联合硬腭黏膜移植修复中、重度全层眼睑缺损的临床疗效。方法对26例(26只眼)大于或等于眼睑全长1/2的全层眼睑缺损患者,采用硬腭黏膜移植替代眼睑后层,即睑板和睑结膜层;利用眼周血供丰富的SMAS皮瓣修复眼睑前层,即皮肤肌肉层。其中5例采用眼轮匝肌蒂皮瓣,5例为颞浅动脉皮瓣,7例为眉上皮瓣,9例为上睑皮肤轮匝肌双蒂瓣。手术操作中首先行硬腭黏膜移植,然后根据眼睑前层缺损的部位和范围设计眼周的SMAS转位皮瓣,术毕行睑缘缝合3个月。结果全部患者随访6~36个月,平均11个月。转位皮瓣全部成活,硬腭黏膜植片成活好,无收缩,眼睑外观及功能改善较满意。结论眼周SMAS皮瓣联合硬腭黏膜移植可一次性修复缺损的眼睑全层,效果肯定。 展开更多
关键词 粘膜 眼睑成形术 外科皮瓣 移植
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Understanding of the sodium storage mechanism in hard carbon anodes 被引量:24
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作者 Xiaoyang Chen Changyu Liu +4 位作者 Yongjin Fang Xinping Ai Faping Zhong Hanxi Yang Yuliang Cao 《Carbon Energy》 SCIE CAS 2022年第6期1133-1150,共18页
Hard carbon has been regarded as the most promising anode material for sodiumion batteries(SIBs)due to its low cost,high reversible capacity,and low working potential.However,the uncertain sodium storage mechanism hin... Hard carbon has been regarded as the most promising anode material for sodiumion batteries(SIBs)due to its low cost,high reversible capacity,and low working potential.However,the uncertain sodium storage mechanism hinders the rational design and synthesis of high-performance hard carbon anode materials for practical SIBs.During the past decades,tremendous efforts have been put to stimulate the development of hard carbon materials.In this review,we discuss the recent progress of the study on the sodium storage mechanism of hard carbon anodes,and the effective strategies to improve their sodium storage performance have been summarized.It is anticipated that hard carbon anodes with high electrochemical properties will be inspired and fabricated for large-scale energy storage applications. 展开更多
关键词 ANODE electrochemical energy storage hard carbon sodium-ion batteries sodium storage mechanism
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Facile Synthesis of Porous Carbon Nitride Spheres with Hierarchical Three-Dimensional Mesostructures for CO_(2) Capture 被引量:24
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作者 Qiang Li Jianping Yang +5 位作者 Dan Feng Zhangxiong Wu Qingling Wu Sung Soo Park Chang-Sik Ha Dongyuan Zhao 《Nano Research》 SCIE EI CSCD 2010年第9期632-642,共11页
Porous carbon nitride(CN)spheres with partially crystalline frameworks have been successfully synthesized via a nanocasting approach by using spherical mesoporous cellular silica foams(MCFs)as a hard template,and ethy... Porous carbon nitride(CN)spheres with partially crystalline frameworks have been successfully synthesized via a nanocasting approach by using spherical mesoporous cellular silica foams(MCFs)as a hard template,and ethylenediamine and carbon tetrachloride as precursors.The resulting spherical CN materials have uniform diameters of ca.4μm,hierarchical three-dimensional(3-D)mesostructures with small and large mesopores with pore diameters centered at ca.4.0 and 43 nm,respectively,a relatively high BET surface area of~550 m^(2)/g,and a pore volume of 0.90 cm^(3)/g.High-resolution transmission electron microscope(HRTEM)images,wide-angle X-ray diffraction(XRD)patterns,and Raman spectra demonstrate that the porous CN material has a partly graphitized structure.In addition,elemental analyses,X-ray photoelectron spectra(XPS),Fourier transform infrared spectra(FT-IR),and CO_(2) temperature-programmed desorption(CO_(2)-TPD)show that the material has a high nitrogen content(17.8 wt%)with nitrogen-containing groups and abundant basic sites.The hierarchical porous CN spheres have excellent CO_(2) capture properties with a capacity of 2.90 mmol/g at 25℃and 0.97 mmol/g at 75℃,superior to those of the pure carbon materials with analogous mesostructures.This can be mainly attributed to the abundant nitrogen-containing basic groups,hierarchical mesostructure,relatively high BET surface area and stable framework.Furthermore,the presence of a large number of micropores and small mesopores also enhance the CO_(2) capture performance,owing to the capillary condensation effect. 展开更多
关键词 Mesoporous materials carbon nitride NANOCASTING sphere hard template CO_(2)capture
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The Practice of Forward Prospecting of Adverse Geology Applied to Hard Rock TBM Tunnel Construction: The Case of the Songhua River Water Conveyance Project in the Middle of Jilin Province 被引量:22
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作者 Shucai Li Lichao Nie Bin Liu 《Engineering》 2018年第1期131-137,共7页
An increasing number of tunnels are being constructed with tunnel-boring machines (TBMs) due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse... An increasing number of tunnels are being constructed with tunnel-boring machines (TBMs) due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse geological conditions in the course of tunnel construction (e.g., karst caves, faults, or frac- tured zones), disasters such as water and mud inrush, collapse, or machine blockage may result, and may severely imperil construction safety. Therefore, the advance detection of adverse geology and water-bearing conditions in front of the tunnel face is of great importance. This paper uses the TBM tun- neling of the water conveyance project from Songhua River as a case study in order to propose a compre- hensive forward geological prospecting technical system that is suitable for TBM tunnel construction under complicated geological conditions. By combining geological analysis with forward geological prospecting using a three-dimensional (3D) induced polarization method and a 3D seismic method, a comprehensive forward geological prospecting technical system can accurately forecast water inrush geo-hazards or faults in front of the TBM tunnel face. In this way, disasters such as water and mud inrush, collapse, or machine blockage can be avoided. This prospecting technical system also has reference value for carrying out the forward prospecting of adverse geology for potential TBM tunneling and for ensuring that a TBM can work efficiently. 展开更多
关键词 hard rock TBM TUNNELS Comprehensive FORWARD PROSPECTING Geological analysis3D induced polarization3D seismic methodAdverse GEOLOGY
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Hard carbon derived from cellulose as anode for sodium ion batteries:Dependence of electrochemical properties on structure 被引量:21
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作者 V.Simone A.Boulineau +3 位作者 A.de Geyer D.Rouchon L.Simonin S.Martinet 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第5期761-768,共8页
Cellulose, the most abundant organic polymer on Earth, is a sustainable source of carbon to use as a negative electrode for sodium ion batteries. Here, hard carbons(HC) prepared by cellulose pyrolysis were investigate... Cellulose, the most abundant organic polymer on Earth, is a sustainable source of carbon to use as a negative electrode for sodium ion batteries. Here, hard carbons(HC) prepared by cellulose pyrolysis were investigated with varying pyrolysis temperature from 700 °C to 1600 °C. Characterisation methods such as Small Angle X-ray Scattering(SAXS) measurements and N2adsorption were performed to analyse porosity differences between the samples. The graphene sheet arrangements were observed by transmission electron microscopy(TEM): an ordering of the graphene sheets is observed at temperatures above 1150 °C and small crystalline domains appear over 1400 °C. As the graphene sheets start to align, the BET surface area decreases and the micropore size increases. To correlate hard carbon structures and electrochemical performances, different tests in Na//HC cells with 1 M NaPF6ethylene carbonate/dimethyl carbonate(EC/DMC) were performed. Samples pyrolysed from 1300 °C to 1600 °C showed a 300 m Ah/g reversible capacity at C/10 rate(where C = 372 mA/g) with an excellent stability in cycling and a very good initial Coulombic efficiency of up to 84%. Furthermore, hard carbons showed an excellent rate capability where sodium extraction rate varies from C/10 to 5C. At 5C more than 80% of reversible capacity remains stable for hard carbons synthesized from 1000 °C to 1600 °C. 展开更多
关键词 Sodium ion battery ANODE hard carbon STRUCTURE
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“硬关井”水击压力计算及其应用 被引量:20
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作者 李相方 郑权方 《石油钻探技术》 北大核心 1995年第3期1-3,60,共4页
根据气侵后环空气液两相流分布特点及水击压力在气液两相流及单相流中传播特点,计算了“硬关井”情况下的水击压力变化情况。研究表明:对于气侵情况,硬关井引起的水击压力对井眼中下部影响很小,主要作用于井口装置;如果并口流速不... 根据气侵后环空气液两相流分布特点及水击压力在气液两相流及单相流中传播特点,计算了“硬关井”情况下的水击压力变化情况。研究表明:对于气侵情况,硬关井引起的水击压力对井眼中下部影响很小,主要作用于井口装置;如果并口流速不太大,可以采用硬关并,以便减少地层流体进一步侵入。 展开更多
关键词 hard shut-in water+pressure gas cutting well control
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Recent progress in plant-derived hard carbon anode materials for sodium-ion batteries:a review 被引量:22
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作者 Peng Yu Wei Tang +4 位作者 Fang-Fang Wu Chun Zhang Hua-Yun Luo Hui Liu Zhi-Guo Wang 《Rare Metals》 SCIE EI CAS CSCD 2020年第9期1019-1033,共15页
Sodium-ion batteries(SIBs)have been considered as a promising alternative to the commercialized lithium ion batteries(LIBs)in large-scale energy storage field for its rich reserve in the earth.Hard carbon has been exp... Sodium-ion batteries(SIBs)have been considered as a promising alternative to the commercialized lithium ion batteries(LIBs)in large-scale energy storage field for its rich reserve in the earth.Hard carbon has been expected to the first commercial anode material for SIBs.Among various of hard carbon materials,plant-derived carbon is prominent because of abundant source,low cost and excellent electrochemical performance.This review focuses on the recent progress in the development of plantderived hard carbon anodes for SIBs.We summarized the microstructure and electrochemical performance of hard carbon materials pyrolyzed from different parts of plants at different temperatures.It aims to present a full scope of plant-derived hard carbon anode materials and provide indepth understanding and guideline for the design of highperformance hard carbon for sodium ion anodes. 展开更多
关键词 Sodium-ion battery Anode material hard carbon Plant derived Electrochemical performance
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Experimental investigation into stress-relief characteristics with upward large height and upward mining under hard thick roof 被引量:21
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作者 Ke Yang Xiang He +3 位作者 Litong Dou Wenjun Liu Li Sun Haisong Ye 《International Journal of Coal Science & Technology》 EI 2015年第1期91-96,共6页
According to geological conditions of No. 3 and No. 4 coal seams (namely A3 and B4) of the Pan'er coal mine and the parameters of panels 11223, 11224, and 11124 with fully-mechanical coal mining, we built 2D simila... According to geological conditions of No. 3 and No. 4 coal seams (namely A3 and B4) of the Pan'er coal mine and the parameters of panels 11223, 11224, and 11124 with fully-mechanical coal mining, we built 2D similar material simulation and FLAC3D numerical simulation models to investigate the development of mining-induced stress and the extraction effect of pressure-relief gas with large height and upward mining. Based on a comprehensive analysis of experimental data and observations, we obtained the deformation and breakage characteristics of strata overlying the coal seam, the development patterns of the mining-induced stress and fracture, and the size of the stress-relief area. The stress-relief effect was investigated and analyzed in consideration with mining height and three thick hard strata. Because of the group of three hard thick strata located in the main roof and the residual stress of mined panel 11124, the deformation, breakage, mining-induced stress and fracture development, and the stress-relief coefficient were discontinuous and asymmetrical. The breakage angle of the overlying strata, and the compressive and expansive zones of coal deformation were mainly controlled by the number, thickness, and strength of the hard stratum. Compared with the value of breakage angle derived by the traditional empirical method, the experimental value was lower than the traditional results by 3°-4°below the hard thick strata group, and by 13°-19° above the hard thick strata group. The amount of gas extracted from floor drainage roadway of B4 over 17 months was variable and the amount of gas per month differed considerably, being much smaller when panel 11223 influenced the area of the three hard thick strata. Generally, the stress-relief zone of No. 4 coal seam was small under the influence of the hard thick strata located in the main roof, which played an important role in delaying the breakage time and increasing the breakage space. In this study we gained understanding of the stress-relief mechanism in 展开更多
关键词 Integrated coal exploitation and gas extraction Large mining height Stress-relief effect hard thick strata Mining-induced stress
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Synergistic instability of coal pillar and roof system and filling method based on plate model 被引量:18
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作者 Liu Congliang Tan Zhixiang +1 位作者 Deng Kazhong Li Peixian 《International Journal of Mining Science and Technology》 SCIE EI 2013年第1期145-149,共5页
The security challenges from room and pillar gobs include land subsidence, spontaneous combustion of coal pillars and mine flood caused by gob water. To explore the instability mechanism of room and pillar gob, we est... The security challenges from room and pillar gobs include land subsidence, spontaneous combustion of coal pillars and mine flood caused by gob water. To explore the instability mechanism of room and pillar gob, we established a mechanical model of elastic plate on elastic foundation in which pillars and hard roofs were considered as continuous Winkler foundations and elastic plates, respectively. The synergetic instability of pillar and roof system was analyzed based on plate bending theory and catastrophe theory. In addition, mechanical conditions and math criterion of roof failure and overall instability of coal pillar and roof system were given. Through analyzing both advantages and disadvantages of some technologies such as induced caving, filling, gob sealing and isolation, we presented a new filling method named box-filling, in view of box foundation theory, to control the disasters of ground collapse, water inrush and mine fire. In a gob's treatment project in Ordos, safety assessment and filling design of a room and pillar gob have been done by the mechanical model. The results show that the gob will collapse when the pillars' average yield band is wider than 0.93 m, and box-filling can control land collapse, mine flood and mine fire economically and efficiently. So it is worth to study further and popularize. 展开更多
关键词 Room and pillar gob hard roof Synergetic instability Elastic foundation plate Box-filling
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德国历史学派与19世纪经济学方法论之争的启示 被引量:17
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作者 何蓉 《社会》 北大核心 2005年第3期167-186,共20页
In the mid-19th century, out of their dissatisfaction with the neglect of the economic theories about other countries’ experiences in the British classic economics, the economists in the German Historical School wo... In the mid-19th century, out of their dissatisfaction with the neglect of the economic theories about other countries’ experiences in the British classic economics, the economists in the German Historical School worked hard to construct an economic theory that was congruent to the developmental stage in their own country’s culture and history. Their deeply-cherished concern about the reality in a transitional era when Germany was approaching modernization drove them to propose that the living condition of the working class be improved by the power of the state. In the late 80’s of the same century, the Methodenstreit of German Historical School versus the Austrian School broke out, after which the mainstream economics was well on its way in terms of theoretical refinement and scrutiny, whereas the influence from the Historical School gradually subsided. Even so, the lessons from the Historical School are still enlightening to research in contemporary social sciences. This paper describes the unique basics in the theory building of the Historical School; explains the background and meaning of its academic origin, research methodology, and the Methodenstreit; and from there, discusses implications for contemporary social sciences. 展开更多
关键词 经济学方法论 19世纪 历史学派 School ACADEMIC culture science about 德国 from origin that other and power after which STILL there with hard when LATE well This its of to way are for In be on so
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改良小切口非超声乳化术治疗高龄硬核白内障 被引量:18
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作者 郎雪华 陈明华 《中华眼外伤职业眼病杂志》 2013年第12期935-938,共4页
目的探讨改良式小切口非超声乳化白内障摘出人工晶状体植入术在高龄硬核白内障的中的临床应用。方法对82例高龄患者104眼硬核白内障施行改良式小切口非超声乳化白内障摘出人工晶状体植入术,并与同期81例高龄患者103眼硬核白内障施行晶... 目的探讨改良式小切口非超声乳化白内障摘出人工晶状体植入术在高龄硬核白内障的中的临床应用。方法对82例高龄患者104眼硬核白内障施行改良式小切口非超声乳化白内障摘出人工晶状体植入术,并与同期81例高龄患者103眼硬核白内障施行晶状体超声乳化吸出人工晶状体植入术对比,术后随访12个月,比较两种手术时间、角膜内皮细胞的密度、丢失率,以及术后视力。结果两种手术方式的手术时间差异无统计学意义(P〉0.05),在角膜内皮细胞密度、丢失率和术后视力的比较差异有统计学意义(P〈0.05)。结论高龄硬核白内障适宜行改良式小切口非超声乳化白内障摘出人工晶状体植入术,且有损伤小、恢复快等优点。 展开更多
关键词 白内障摘出 改良式 小切El 白内障 硬核 内皮细胞 角膜
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Etching‐assisted femtosecond laser modification of hard materials 被引量:18
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作者 Xue-Qing Liu Ben-Feng Bai +1 位作者 Qi-Dai Chen Hong-Bo Sun 《Opto-Electronic Advances》 2019年第9期1-14,共14页
With high hardness, high thermal and chemical stability and excellent optical performance, hard materials exhibit great potential applications in various fields, especially in harsh conditions. Femtosecond laser ablat... With high hardness, high thermal and chemical stability and excellent optical performance, hard materials exhibit great potential applications in various fields, especially in harsh conditions. Femtosecond laser ablation has the capability to fabricate three-dimensional micro/nanostructures in hard materials. However, the low efficiency, low precision and high surface roughness are the main stumbling blocks for femtosecond laser processing of hard materials. So far, etching- assisted femtosecond laser modification has demonstrated to be the efficient strategy to solve the above problems when processing hard materials, including wet etching and dry etching. In this review, femtosecond laser modification that would influence the etching selectivity is introduced. The fundamental and recent applications of the two kinds of etching assisted femtosecond laser modification technologies are summarized. In addition, the challenges and application prospects of these technologies are discussed. 展开更多
关键词 FEMTOSECOND laser hard materials WET ETCHING DRY ETCHING
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A novel true triaxial test system for microwave-induced fracturing of hard rocks 被引量:15
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作者 Xia-Ting Feng Jiuyu Zhang +4 位作者 Chengxiang Yang Jun Tian Feng Lin Shiping Li Xiangxin Su 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第5期961-971,共11页
This study introduces a test system for microwave-induced fracturing of hard rocks under true triaxial stress.The test system comprises a true triaxial stress loading system,an open-ended microwaveinduced fracturing s... This study introduces a test system for microwave-induced fracturing of hard rocks under true triaxial stress.The test system comprises a true triaxial stress loading system,an open-ended microwaveinduced fracturing system,a data acquisition system,an acoustic emission(AE)monitoring system,and an auxiliary specimen loading system.Microwave-induced surface and borehole fracturing tests under true triaxial stress were fulfilled for the first time,which overcomes the problem of microwave leakage in the coupling loading of true triaxial stress and microwave.By developing the dynamic monitoring system,the thermal response and fracture evolution were obtained during microwave irradiation.The monitoring system includes the infrared thermometry technique for monitoring rock surface temperature,the distributed optic fiber sensing technique for monitoring temperature in borehole in rock,the AE technique and two-dimensional digital speckle correlation technique for monitoring the evolution of thermal damage and the rock fracturing process.To validate the advantages of the test system and investigate the characteristics of microwave-induced fracturing of hard rocks,the study demonstrates the experimental methods and results for microwave-induced surface and borehole fracturing under true triaxial stress.The results show that thermal cracking presented intermittent characteristics(calm eactiveecalm)during microwave-induced surface and borehole fracturing of basalt.In addition,true triaxial stress can inhibit the development and distribution of thermal cracks during microwave-induced surface fracturing.When microwave-induced borehole fracturing occurs,it promotes the distribution of thermal cracks in rock,but inhibits the width of cracks.The results also prove the reliability of the test system. 展开更多
关键词 Deep hard rock engineering True triaxial apparatus Microwave-induced fracturing of hard rocks Electromagnetic compatibility Dynamic monitoring Evolution of rock fracturing
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Hierarchical porous hard carbon enables integral solid electrolyte interphase as robust anode for sodium-ion batteries 被引量:16
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作者 Xu-Kun Wang Juan Shi +5 位作者 Li-Wei Mi Yun-Pu Zhai Ji-Yu Zhang Xiang-Ming Feng Zi-Jie Wu Wei-Hua Chen 《Rare Metals》 SCIE EI CAS CSCD 2020年第9期1053-1062,共10页
Hard carbon is the most promising anode for sodium-ion battery applications due to the wide availability and low work voltage.However,it often delivers worse electrochemical performance in ester-based electrolytes.Her... Hard carbon is the most promising anode for sodium-ion battery applications due to the wide availability and low work voltage.However,it often delivers worse electrochemical performance in ester-based electrolytes.Herein,a hierarchically porous loose sponge-like hard carbon with a highly disordered phase,prepared from the biomass of platanus bark,exhibits superior rate performance with a capacity of 165 mAh·g-1 at a high current of1 A·g-1,and high retention of 71.5%after 2000 cycles in an ester-based electrolyte.The effect of the hierarchically porous loose sponge-like structure on the formation dynamics of solid electrolyte interphase(SEI),and related properties,was studied via cyclic voltammetry(CV),galvanostatic intermittent titration technique(GITT),X-ray photoelectron spectroscope(XPS),Fourier transform infrared spectroscopy(FTIR)and electrochemical impedance spectroscopy(EIS)analysis.These results reveal that the hierarchically porous structure can construct continued connecting channels and accelerate the electrolyte transport,which is beneficial to the reaction kinetics of SEI.Moreover,the mesoporous structure is conducive to good contact between electrolyte and materials and shortens the Na+diffusion path,which in turn facilitates the charge transfer kinetics in the material. 展开更多
关键词 Sodium-ion battery hard carbon Hierarchically porous structure SEI Ester-based electrolyte
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