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Study of probability integration method parameter inversion by the genetic algorithm

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International Journal of Mining Science and Technology 2017年第6期27卷 1073-1079页

作者： li peixian Peng Di Tan Zhixiang Deng Kazhong College of Geoscience and Surveying Engineering China University of Mining and Technology (Beijing) School of Environment Science and Spatial Informatics China University of Mining and Technology

In order to obtain accurate probability integration method(PIM) parameters for surface movement of multi-panel mining, a genetic algorithm(GA) was used to optimize the parameters. As the measured surface movement is affected by more than one mining panel, traditional PIM parameter inversion model is difficult to ensure the reliability of the results due to the complexity of rock movement. With crossover,mutation and selection operators, GA can perform a global optimization search and has high computation efficiency. Compared with the pattern search algorithm, the fitness function can avoid falling into local minima traps. GA reduces the risk of local minima traps which improves the accuracy and reliability with the mutation mechanism. Application at Xuehu colliery shows that GA can be used to inverse the PIM parameters for multi-panel surface movement observation, and reliable results can be obtained. The research provides a new way for back-analysis of PIM parameters for mining subsidence under complex conditions.

关键词： Probability integration method GA Mining subsidence Parameter inversion Multiobjective optimization

Role of lateral growth on the structural properties of high temperature GaN layer

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Science China(Technological Sciences) 2009年第5期52卷 1242-1247页

作者： GAO ZhiYuan HAO Yue li peixian ZHANG JinCheng Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of MicroelectronicsXidian UniversityXi’an 710071China

The role of lateral growth on the structural properties of high temperature(HT) GaN epitaxial layer has been investigated by means of transmission electron microscopy(TEM) and X-ray diffraction(XRD).Variations of the lateral growth rate of HT GaN in metal-organic chemical vapor deposition(MOCVD) can be obtained by changing the V/Ⅲ ratio.It is found that under higher lateral growth rate,dislocation is easier to bend into subgrains away from c axis,and the position where bend occurs is closer to the buffer layer,however,dislocation density does not show to monotonically vary with increasing lateral growth rate.A model concerning the GaN growth dynamics and dislocation bending mechanics has been proposed to explain the correlation between lateral growth and the structural properties of GaN.

关键词： GaN lateral growth dislocation V/Ⅲ

Synergistic instability of coal pillar and roof system and filling method based on plate model

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International Journal of Mining Science and Technology 2013年第1期23卷 145-149页

作者： liu Congliang Tan Zhixiang Deng Kazhong li peixian Key Laboratory of Land Environment and Disaster Monitoring of SBSM China University of Mining & Technology Key Laboratory of Resources and Environmental Information Engineering China University of Mining & Technology

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.

关键词： Room and pillar gob Hard roof Synergetic instability Elastic foundation plate Box-filling

高校基层党组织引领青年思想的价值意涵、历史经验与创新路径

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南京理工大学学报（社会科学版） 2024年第2期37卷 87-92页

作者：李佩弦南京理工大学能源与动力工程学院江苏南京210094 南京理工大学电子工程与光电技术学院江苏南京210094

高校基层党组织是引领青年思想的核心力量,是高校培根铸魂、立德树人的生力军。立足新的时代方位,高校基层党组织引领青年思想呈现出多重价值意涵。因此,深刻认识高校基层党组织引领青年思想的价值意涵,总结百年来高校基层党组织的历史... 详细信息

高校基层党组织是引领青年思想的核心力量,是高校培根铸魂、立德树人的生力军。立足新的时代方位,高校基层党组织引领青年思想呈现出多重价值意涵。因此,深刻认识高校基层党组织引领青年思想的价值意涵,总结百年来高校基层党组织的历史经验,重点剖析新时代青年思想的新特征,进而从引领主客体、引领机制、引领模式与引领效果等方面,构建“立足政治认同,凝聚思想引领共识;完善工作格局,健全思想引领机制;多种方式并举,革新思想引领”模式;坚持问题导向,提升思想引领效果等新路径,为党培育担负民族复兴使命的接班人贡献力量。

关键词：高校基层党组织青年思想引领思想创新路径

Time series prediction of mining subsidence based on a SVM

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Mining Science and Technology 2011年第4期21卷 557-562页

作者： li peixian Tan Zhixiang Yan lili Deng Kazhong Jiangsu Key Laboratory of Resources and Environmental Information Engineering China University of Mining Technology Xuzhou 221116 China Key Laboratory of Land Environment and Disaster Monitoring of SBSM China University of Mining ＆ Technology Xuzhou 221116 China

In order to study dynamic laws of surface movements over coal mines due to mining activities,a dynamic prediction model of surface movements was established,based on the theory of support vector machines(SVM) and times-series analysis.An engineering application was used to verify the correctness of the model.Measurements from observation stations were analyzed and processed to obtain equal-time interval surface movement data and subjected to tests of stationary,zero means and normality.Then the data were used to train the SVM model.A time series model was established to predict mining subsidence by rational choices of embedding dimensions and SVM parameters.MAPE and WIA were used as indicators to evaluate the accuracy of the model and for generalization performance.In the end,the model was used to predict future surface movements.Data from observation stations in Huaibei coal mining area were used as an example.The results show that the maximum absolute error of subsidence is 9 mm,the maximum relative error 1.5%,the maximum absolute error of displacement 7 mm and the maximum relative error 1.8%.The accuracy and reliability of the model meet the requirements of on-site engineering.The results of the study provide a new approach to investigate the dynamics of surface movements.

关键词：时间序列预测 SVM模型采煤沉陷基础动态预测模型最大相对误差地表移动采矿活动

在大肠杆菌体内外调控一致的5′-UTR序列挖掘

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中国生物工程杂志 2024年第5期44卷 20-31页

作者：李佩贤李娇娇刘倩张婕齐浩天津大学化工学院天津300350 天津大学系统生物工程教育部重点实验室天津300350

基因元件的标准化和模块化为日益复杂的遗传系统改造设计提供了参考。目的:通过探究5′-非翻译区(5′-untranslated region,5′-UTR)在大肠杆菌体内外对翻译起始调控的一致性,挖掘通用型5′-UTR序列为模块化工程增添具有良好特征的遗传... 详细信息

基因元件的标准化和模块化为日益复杂的遗传系统改造设计提供了参考。目的:通过探究5′-非翻译区(5′-untranslated region,5′-UTR)在大肠杆菌体内外对翻译起始调控的一致性,挖掘通用型5′-UTR序列为模块化工程增添具有良好特征的遗传元件。方法:构建包含25 nt的5′-UTR随机文库化转至大肠杆菌中,通过测量样品荧光值(Flu)和OD600来量化其体内的相对活性值;利用大肠杆菌BL21 Star(DE3)细胞抽提物进行体外蛋白质表达,通过测定样品Flu来量化体外的相对活性值;依据5′-UTR的碱基分布、最小自由能等对文库序列特征进行分析;将得到的体内外真实活性值进行相关性分析并计算皮尔逊相关系数。结果:成功构建的554个5′-UTR变体文库在体内外蛋白质表达系统中表现出中等相关性(Pearson’r=0.64);其中,相对活性值高的5′-UTR序列富含AG,并且其在体内外均呈现自身最小自由能较大,而与16S rRNA杂交的自由能较小;文库数据量大小使体内外相关性分析产生一定的波动性但较为微弱;最后,发现高活性区间内的5′-UTR序列在体内外相关性较高,并从文库中优选出3条作为通用型5′-UTR应用于代谢工程与合成生物学领域。结论:体内外蛋白质表达的中等相关性推动了体外快速表征在研究体内生物合成中的拓展与应用,筛选出的通用型5′-UTR为基因线路的遗传设计提供了选择。

关键词： 5′-非翻译区大肠杆菌基因表达调控无细胞蛋白表达合成生物学

High efficiency and enhanced ESD properties of UV LEDs by inserting p-GaN/p-AlGaN superlattice

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Science China(Physics,Mechanics & Astronomy) 2014年第5期57卷 887-891页

作者： HUANG Yong li peixian YANG Zhuo HAO Yue WANG XiaoBo State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology Xidian University Zoomview Optoelelectronic Co. Ltd.

Significantly improved electrostatic discharge(ESD)properties of InGaN/GaN-based UV light-emitting diode(LED)with inserting p-GaN/p-AlGaN superlattice(p-SLs)layers(instead of p-AlGaN single layer)between multiple quantum wells and Mg-doped GaN layer are reported.The pass yield of the LEDs increased from 73.53%to 93.81%under negative 2000 V ESD pulses.In addition,the light output power(LOP)and efficiency droop at high injection current were also improved.The mechanism of the enhanced ESD properties was then investigated.After excluding the effect of capacitance modulation,high-resolution X-ray diffraction(XRD)and atomic force microscope(AFM)measurements demonstrated that the dominant mechanism of the enhanced ESD properties is the material quality improved by p-SLs,which indicated less leakage paths,rather than the current spreading improved by p-SLs.

关键词：紫外发光二极管 ESD LED 超晶格性能 InGaN 原子力显微镜 X-射线衍射

A method to calculate displacement factors using SVM

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Mining Science and Technology 2011年第3期21卷 307-311页

作者： li peixian Tan Zhixiang Yan lili Deng Kazhong Key Laboratory of Land Environment and Disaster Monitoring of SBSM China University of Mining ＆ Technology Xuzhou 221116 China Jiangsu Key Laboratory of Resources and Environmental Information Engineering Chino University of Mining ＆ Technology Xuzhou 221116 China

In order to improve the precision of mining subsidence prediction, a mathematical model using Support Vector Machine (SVM) was established to calculate the displacement factor. The study is based on a comprehensive analysis of factors affecting the displacement factor, such as mechanical properties of the cover rock, the ratio of mining depth to seam thickness, dip angle of the coal seam and the thickness of loose layer. Data of 63 typical observation stations were used as a training and testing sample set. A SVM regression model of the displacement factor and the factors affecting it was established with a kernel function, an insensitive loss factor and a properly selected penalty factor. Given an accurate calculation algorithm for testing and analysis, the results show that an SVM regression model can calculate displacement factor precisely and reliable precision can be obtained which meets engineering requirements. The experimental results show that the method to calculation of the displacement factor, based on the SVM method, is feasible. The many factors affecting the displacement factor can be considered with this method. The research provides an efficient and accurate approach for the calculation of displacement in mining subsidence prediction.

关键词： SVM方法位移计算计算算法煤层厚度回归模型开采沉陷支持向量机沉陷预测

大型煤炭基地生态系统服务功能遥感评估及演变分析

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遥感学报 2024年第4期28卷 926-939页

作者：孙灏高金华崔希民王国瑞李培现中国矿业大学(北京)地球科学与测绘工程学院北京100083 宁夏回族自治区国土资源调查监测院银川750000

生态系统服务功能是人类从生态系统中获得的直接收益,因此从服务功能角度评估矿区生态系统状况具有重要意义。以大型煤炭基地宁东为例,在阐述矿区生态系统状况遥感监测研究现状和进展的基础上,设计了遥感数据驱动的气候调节、防风固沙... 详细信息

生态系统服务功能是人类从生态系统中获得的直接收益,因此从服务功能角度评估矿区生态系统状况具有重要意义。以大型煤炭基地宁东为例,在阐述矿区生态系统状况遥感监测研究现状和进展的基础上,设计了遥感数据驱动的气候调节、防风固沙、固碳释氧、水源涵养和土壤保持5项生态系统服务功能计算方案,利用长时间序列连续数据评估了上述功能的时空演变,衡量了矿区生产活动对地表生态系统的影响。应用Mann-Kendall非参数检验实现对研究区生态系统服务功能的时空动态评估。研究结果表明:(1)从2001年—2019年,宁东基地生态系统服务功能整体呈改善趋势,其中气候调节、固碳释氧、防风固沙改善趋势非常显著,水源涵养出现轻微下降现象,土壤保持处于基本不变的状态。(2)空间分布上,远离采煤工作面的区域生态系统服务功能比较强,反之则比较弱。(3)矿区与非矿区对照分析表明,矿区生产活动迟滞了生态系统服务功能的增加,其中非矿区的气候调节功能的上升速率约为矿区上升速率的两倍,非矿区防风固沙和固碳释氧功能的上升速率约为矿区上升速率的1.5倍。研究区生态系统服务功能的整体改善,可能是气候环境变化和人工修复活动的综合结果,但鉴于其整体改善速率明显低于非矿区,说明煤炭开采活动造成了一定的负面影响,仍然需要加大对生态系统保护和修复的力度。

关键词：煤炭基地遥感生态系统服务功能动态监测生态环境矿区采矿影响