Purpose-This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.Design/methodology/approach-First,taking the Liuyuan Tunnel of Huangg...Purpose-This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.Design/methodology/approach-First,taking the Liuyuan Tunnel of Huanggang-Huangmei High-Speed Railway as an example and taking deflection of the third principal stress of the surrounding rock at a vault after tunnel excavation as the criterion,the critical buried depth of the large section tunnel was determined.Then,the strength reduction method was employed to calculate the tunnel safety factor under different rock classes and thickness-span ratios,and mathematical statistics was conducted to identify the relationships of the tunnel safety factor with the thickness-span ratio and the basic quality(BQ)index of the rock for different rock classes.Finally,the influences of thickness-span ratio,groundwater,initial stress of rock and structural attitude factors were considered to obtain the corrected BQ,based on which the stability of a large cross-section tunnel with a depth of more than 100 m during mechanized operation was analyzed.This evaluation method was then applied to Liuyuan Tunnel and Cimushan No.2 Tunnel of Chongqing Urban Expressway for verification.Findings-This study shows that under different rock classes,the tunnel safety factor is a strict power function of the thickness-span ratio,while a linear function of the BQ to some extent.It is more suitable to use the corrected BQ as a quantitative index to evaluate tunnel stability according to the actual conditions of the site.Originality/value-The existing industry standards do not consider the influence of buried depth and span in the evaluation of tunnel stability.The stability evaluation method of large section tunnel considering the correction of overburden span ratio proposed in this paper achieves higher accuracy for the stability evaluation of surrounding rock in a full or large-section mechanized excavation of double line high-speed railway tunnels.展开更多
In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation e...In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation equipments. For the construction of an extra-large section chamber in the Tangshan mine, we proposed an active support through a combination of bolting, anchor cables, lining, and a reinforced chamber floor by inverted arch pouring. ABAQUS software was used to analyze the surrounding rock deformation and the plastic zone development of the chamber under different excavation schemes.The best excavation scheme was determined, and the effectiveness of the combined supports was verified. In practice, the engineering installation showed good overall control of the movement of the surrounding rock, with roof-to-floor and side-to-side convergences of 154.6 and 77.5 mm, respectively,which meets the requirements for underground coal gangue separation.展开更多
Grain size traits, including grain length, grain width and grain thickness, are controlled by quantitative trait loci （QTLs）. Many QTLs relating to rice grain size traits had been reported, but their control mechani...Grain size traits, including grain length, grain width and grain thickness, are controlled by quantitative trait loci （QTLs）. Many QTLs relating to rice grain size traits had been reported, but their control mechanisms have not yet been elucidated. A recombinant inbred line （RIL） population of 240 lines, deriving from a cross between TD70, an extra-large grain size japonica line with 80 g of 1000-grain weight, and Kasalath, a small grain size indica variety, were constructed and used to map grain size QTLs to a linkage map by using 141 SSR markers in 2010 and 2011. Five QTLs for grain length, six for grain width and seven for grain thickness were detected distributing over chromosomes 2, 3, 5, 7, 9 and 12. Seven QTLs, namely qGL3.1, qGW2, qGW2.2, qGW5.1, qGW5.2, qGT2.3 and qGT3.1, were detected in either of the two years and explained for 56.19%, 4.42%, 29.41%, 10.37%, 7.61%, 21.19% and 17.06% of the observed phenotypic variances on average, respectively. The marker interval RM1347-RM5699 on chromosome 2 was found common for grain length, grain width and grain thickness; qGL3.1 and qGT3.1 were mapped to the same interval RM6080-RM6832 on chromosome 3. All 18 QTL alleles were derived from the large grain parent TD70. Most of the QTLs mapped in the present study were found the same as the genes previously cloned （GW2, GS3 or qGL3, GW5 and GS5）, and several were the same as the QTLs （GS7 and qGL-7） previously mapped. Three QTLs, qGL2.2 on chromosome 2, qGW9 and qGT9 on chromosome 9, were first detected. These results laid a foundation for further fine mapping or cloning of these QTLs.展开更多
We propose an alternative scheme for generation of atomic Schrodinger cat states in an optical cavity. In thescheme the atoms are always populated in the two ground states and the cavity remains in the vacuum state. T...We propose an alternative scheme for generation of atomic Schrodinger cat states in an optical cavity. In thescheme the atoms are always populated in the two ground states and the cavity remains in the vacuum state. Therefore,the scheme is insensitive to the atomic spontaneous emission and cavity decay. The scheme may be generalized to thedeterministic generation of entangled coherent states for two atomic samples. In contrast with the previously proposedschemes of [Commun. Theor. Phys. 40 (2003) 103 and Chin. Phys. B 18 (2009) 1045], the required interaction time inour scheme is greatly shortened and thus the decoherenee can be effectively suppressed.展开更多
目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分...目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分析颅骨表型变化。从小鼠颅骨中分离原代颅骨成骨细胞,进行体外培养并诱导成骨分化,同时通过实时荧光定量聚合酶链反应和RNA测序技术对基因表达及其功能进行分析。结果:实验结果显示,XLαs敲除小鼠颅缝宽度增加(P<0.05),颅骨未矿化区域明显增多(P<0.001),且成骨分化能力受抑制(P<0.01)。RNA测序进一步揭示XLαs缺失影响了线粒体功能。结论:本研究证实了XLαs在调节颅骨发育和成骨分化中的关键作用,特别是通过影响线粒体功能来发挥其调控效应。这一发现为针对GNAS突变导致的颅骨发育异常提供了新的治疗策略,具有潜在的临床应用价值。展开更多
基金supported by the NSFC HSR Fundamental Research Joint Fund (Grant No.U1934213)。
文摘Purpose-This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.Design/methodology/approach-First,taking the Liuyuan Tunnel of Huanggang-Huangmei High-Speed Railway as an example and taking deflection of the third principal stress of the surrounding rock at a vault after tunnel excavation as the criterion,the critical buried depth of the large section tunnel was determined.Then,the strength reduction method was employed to calculate the tunnel safety factor under different rock classes and thickness-span ratios,and mathematical statistics was conducted to identify the relationships of the tunnel safety factor with the thickness-span ratio and the basic quality(BQ)index of the rock for different rock classes.Finally,the influences of thickness-span ratio,groundwater,initial stress of rock and structural attitude factors were considered to obtain the corrected BQ,based on which the stability of a large cross-section tunnel with a depth of more than 100 m during mechanized operation was analyzed.This evaluation method was then applied to Liuyuan Tunnel and Cimushan No.2 Tunnel of Chongqing Urban Expressway for verification.Findings-This study shows that under different rock classes,the tunnel safety factor is a strict power function of the thickness-span ratio,while a linear function of the BQ to some extent.It is more suitable to use the corrected BQ as a quantitative index to evaluate tunnel stability according to the actual conditions of the site.Originality/value-The existing industry standards do not consider the influence of buried depth and span in the evaluation of tunnel stability.The stability evaluation method of large section tunnel considering the correction of overburden span ratio proposed in this paper achieves higher accuracy for the stability evaluation of surrounding rock in a full or large-section mechanized excavation of double line high-speed railway tunnels.
基金supported by the National Natural Science Foundation of China (No. 51304206)the Project of National Scientific and Technical Supporting Programs Foundation of China (No. 2012BAB13B03)the Program for New Century Excellent Talents in University of Ministry of Education of China (No. NCET-11-0728)
文摘In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation equipments. For the construction of an extra-large section chamber in the Tangshan mine, we proposed an active support through a combination of bolting, anchor cables, lining, and a reinforced chamber floor by inverted arch pouring. ABAQUS software was used to analyze the surrounding rock deformation and the plastic zone development of the chamber under different excavation schemes.The best excavation scheme was determined, and the effectiveness of the combined supports was verified. In practice, the engineering installation showed good overall control of the movement of the surrounding rock, with roof-to-floor and side-to-side convergences of 154.6 and 77.5 mm, respectively,which meets the requirements for underground coal gangue separation.
基金supported by the National Natural Science Foundation of China (Grant No. 31271678)the Jiangsu Agricultural Scientific Self-Innovation Fund (Grant No. CX[11]4023)the Super Rice Breeding and Demonstration Program of the Ministry of Agriculture in China
文摘Grain size traits, including grain length, grain width and grain thickness, are controlled by quantitative trait loci （QTLs）. Many QTLs relating to rice grain size traits had been reported, but their control mechanisms have not yet been elucidated. A recombinant inbred line （RIL） population of 240 lines, deriving from a cross between TD70, an extra-large grain size japonica line with 80 g of 1000-grain weight, and Kasalath, a small grain size indica variety, were constructed and used to map grain size QTLs to a linkage map by using 141 SSR markers in 2010 and 2011. Five QTLs for grain length, six for grain width and seven for grain thickness were detected distributing over chromosomes 2, 3, 5, 7, 9 and 12. Seven QTLs, namely qGL3.1, qGW2, qGW2.2, qGW5.1, qGW5.2, qGT2.3 and qGT3.1, were detected in either of the two years and explained for 56.19%, 4.42%, 29.41%, 10.37%, 7.61%, 21.19% and 17.06% of the observed phenotypic variances on average, respectively. The marker interval RM1347-RM5699 on chromosome 2 was found common for grain length, grain width and grain thickness; qGL3.1 and qGT3.1 were mapped to the same interval RM6080-RM6832 on chromosome 3. All 18 QTL alleles were derived from the large grain parent TD70. Most of the QTLs mapped in the present study were found the same as the genes previously cloned （GW2, GS3 or qGL3, GW5 and GS5）, and several were the same as the QTLs （GS7 and qGL-7） previously mapped. Three QTLs, qGL2.2 on chromosome 2, qGW9 and qGT9 on chromosome 9, were first detected. These results laid a foundation for further fine mapping or cloning of these QTLs.
基金supported partially by Research Institute for Astronomy and Astrophysics of Maragha,Iran
文摘We propose an alternative scheme for generation of atomic Schrodinger cat states in an optical cavity. In thescheme the atoms are always populated in the two ground states and the cavity remains in the vacuum state. Therefore,the scheme is insensitive to the atomic spontaneous emission and cavity decay. The scheme may be generalized to thedeterministic generation of entangled coherent states for two atomic samples. In contrast with the previously proposedschemes of [Commun. Theor. Phys. 40 (2003) 103 and Chin. Phys. B 18 (2009) 1045], the required interaction time inour scheme is greatly shortened and thus the decoherenee can be effectively suppressed.
文摘目的:本研究旨在探究超大型刺激性G蛋白α亚单位(extra-large stimulatory G protein alpha subunit, XLαs)在小鼠颅骨发育和成骨分化中的功能及分子机制。方法:通过构建XLαs第一外显子敲除的小鼠模型,运用阿尔新蓝茜素红染色技术分析颅骨表型变化。从小鼠颅骨中分离原代颅骨成骨细胞,进行体外培养并诱导成骨分化,同时通过实时荧光定量聚合酶链反应和RNA测序技术对基因表达及其功能进行分析。结果:实验结果显示,XLαs敲除小鼠颅缝宽度增加(P<0.05),颅骨未矿化区域明显增多(P<0.001),且成骨分化能力受抑制(P<0.01)。RNA测序进一步揭示XLαs缺失影响了线粒体功能。结论:本研究证实了XLαs在调节颅骨发育和成骨分化中的关键作用,特别是通过影响线粒体功能来发挥其调控效应。这一发现为针对GNAS突变导致的颅骨发育异常提供了新的治疗策略,具有潜在的临床应用价值。
