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矩形巷道围岩应力分布及其破坏机理研究 被引量:48
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作者 侯化强 王连国 +1 位作者 陆银龙 张蓓 《地下空间与工程学报》 CSCD 北大核心 2011年第S2期1625-1629,共5页
将煤矿矩形巷道围岩的应力求解简化为弹性力学中的求解矩形孔口区域的应力问题。首先利用复变函数理论中的保角变换,求得矩形孔口向单位圆的映射函数,然后将其应用到弹性力学中的孔口应力问题的求解中,最终求得了方形孔口区域及矩形巷... 将煤矿矩形巷道围岩的应力求解简化为弹性力学中的求解矩形孔口区域的应力问题。首先利用复变函数理论中的保角变换,求得矩形孔口向单位圆的映射函数,然后将其应用到弹性力学中的孔口应力问题的求解中,最终求得了方形孔口区域及矩形巷道围岩的弹性解析解。通过弹塑型理论提出矩形巷道围岩具有塑性滑动区、裂隙扩展区及围岩稳定区的"三区"理论,求解出塑性区围岩裂隙的扩展方向。 展开更多
关键词 复变函数 映射 矩形巷道 “三区”理论 安全系数 裂隙扩展角
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基于Aspen Plus的地下煤气化平衡模型建模与优化分析
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作者 张骏驰 吕存彬 张龙 《煤化工》 CAS 2022年第4期46-52,共7页
为了实现对地下煤气化过程中合成气组成及低位热值的合理预测,以“三区”理论为基础,使用流程模拟软件Aspen Plus建立了地下煤气化平衡模型,通过与工业试验结果进行对比,验证了模型的可靠性;使用平衡模型探讨了操作压力和氧化剂类型对... 为了实现对地下煤气化过程中合成气组成及低位热值的合理预测,以“三区”理论为基础,使用流程模拟软件Aspen Plus建立了地下煤气化平衡模型,通过与工业试验结果进行对比,验证了模型的可靠性;使用平衡模型探讨了操作压力和氧化剂类型对合成气组成及低位热值的影响。结果表明:气化通道内操作压力越高,合成气中CO_(2)、H_(2)含量越低,CH_(4)、CO含量越高,合成气低位热值越高;在O_(2)含量相同的条件下,富氧水蒸气作为氧化剂时,合成气的低位热值最高,O_(2)最佳体积分数为60%~80%。 展开更多
关键词 地下煤气化 平衡模型 “三区”理论 Aspen Plus 操作压力 氧化剂类型
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Influential Factors in Employment Location Selection Based on “Push-Pull” Migration Theory—A Case Study in Three Gorges Reservoir Area in China 被引量:10
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作者 XU Ding-de ZHANG Ji-fei +3 位作者 XIE Fang-ting LIU Shao-quan CAO Meng-tian LIU En-lai 《Journal of Mountain Science》 SCIE CSCD 2015年第6期1562-1581,共20页
In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull"... In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies. 展开更多
关键词 Off-farm employment Location selection Migrants Push-Pull migration theory Three Gorges Reservoir region China
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Cluster Partition Function and Invariants of 3-Manifolds
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作者 Mauricio ROMO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2017年第4期937-962,共26页
The author reviews some recent developments in Chern-Simons theory on a hyperbolic 3-manifold M with complex gauge group G. The author focuses on the case of G = SL(N, C) and M being a knot complement: M = S^3\ K. The... The author reviews some recent developments in Chern-Simons theory on a hyperbolic 3-manifold M with complex gauge group G. The author focuses on the case of G = SL(N, C) and M being a knot complement: M = S^3\ K. The main result presented in this note is the cluster partition function, a computational tool that uses cluster algebra techniques to evaluate the Chern-Simons path integral for G = SL(N, C). He also reviews various applications and open questions regarding the cluster partition function and some of its relation with string theory. 展开更多
关键词 Chern-Simons theory KNOTS Cluster algebras
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