The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Han...The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.展开更多
“边界工作”是研究新闻从业者如何通过特定的话语策略来维护自身职业地位与合法性的经典理论框架。然而,ChatGPT和Sora等技术的开发应用表明生成式人工智能已具备多模态内容生产能力,套用“边界工作”理论中的扩张(expansion)、驱逐(ex...“边界工作”是研究新闻从业者如何通过特定的话语策略来维护自身职业地位与合法性的经典理论框架。然而,ChatGPT和Sora等技术的开发应用表明生成式人工智能已具备多模态内容生产能力,套用“边界工作”理论中的扩张(expansion)、驱逐(expulsion)和自主性保护(protection of autonomy)三条阐释维度已不足以说明生成式人工智能参与新闻生产的种种实践进路。受布尔迪厄“场域”理论启发,哥伦比亚大学教授伊亚尔(Gil Eyal)提出基于关系视角的“边界域”(Boundary zone)理论。本文认为,新闻“边界域”为毗邻新闻业的其他社会场域中的行动者提供了活动的机会空间,技术行动者和职业行动者获得平等的实践身份,新的社会场域由此得以诞生。媒体主导的新闻场域和科技公司主导的技术场域之间的“边界域”成为未来新闻实践的主体网络。展开更多
The active North China block consists of three second-order blocks: Ordos, North China Plain, and East Shandong-Huanghai Sea blocks. Two active tectonic zones, the Anyang-Heze- Linyi and Tangshan-Cixian zones, exist i...The active North China block consists of three second-order blocks: Ordos, North China Plain, and East Shandong-Huanghai Sea blocks. Two active tectonic zones, the Anyang-Heze- Linyi and Tangshan-Cixian zones, exist in the active North China Plain block and have separated the active block into 3 third-order active blocks, Taihangshan, Hebei-Shandong, and Henan-Huai blocks. The 3 third-order active blocks are characterized by their entire motion and are clearly different in their Cenozoic structures and deep structures. The active boundary tectonic zones between the third-order active blocks are less than those between the first- and second-order active blocks in their movement strength, extent, and seismic activity. The density of M ≥ 6 earthquakes in the boundary zones between active blocks is higher than that within the blocks by 9-22 times in the North China region, up to one order of magnitude on average. M ≥ 7 earthquakes occurred basically in the boundary zones between active blocks. The difference is not occasional, but reflects the nature of intraplate movement and the characteristics of strong seismic activity and is the powerful evidence for hypothesis of active blocks.展开更多
The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron ...The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron microscopy and transmission electron microscopy.For the Zr-free alloy,the strength increases to the highest value at 20 s with transfer time,and then decreases slightly.The elongation decreases slowly with transfer time within 20 s,and more rapidly after 20 s.For the Zr-containing alloy,prolonging transfer time within 20 s results in slight decrease in the strength and elongation,and rapid drop of which is observed after 20 s.For the Zr-free alloy,prolonging transfer time can increase the percentage of intergranular fracture,which is mainly caused by wide grain boundary precipitate free zone.The failure mode of the Zr-containing alloy is modified from the predominant transgranular void growth and intergranular fracture to transgranular shear and intergranular fracture with increase in the transfer time,which is attributed to the wider grain boundary precipitate free zone and coarse equilibrium η phases in the matrix.展开更多
This paper proposes design charts for estimating imperative input parameters for continuum approach analysis of the nonlinear dynamic response of piles.Experimental and analytical studies using continuum approach have...This paper proposes design charts for estimating imperative input parameters for continuum approach analysis of the nonlinear dynamic response of piles.Experimental and analytical studies using continuum approach have been conducted on single and 2×2 grouped piles under coupled and vertical modes of vibration,for different dynamic forces and pile depth.As these design charts are derived from model piles,the charts have been validated for prototype pile foundations using scaling law.The experimental responses of model piles are scaled up and these responses exhibit good agreement with analytical results.This study also extends to estimation of the errors in computing frequency–amplitude responses with an increase in pile length.It is found that,with an increase in pile length,the errors also increase.The effectiveness of the proposed design charts is also checked with data based on different field setups given in existing literature,and these charts are found to be valid.Thus,the developed design charts can be beneficial in estimating the input parameters for continuum approach analysis for determining the nonlinear responses of pile supported machine foundations.展开更多
To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,...To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,174 teleseismic events recorded by 182 stations of Hi-CLIMB Project and 16 stations in the north of Hi-CLMB. Our tomographic images show the velocity structure significantly difference beneath northern and southern Qiangtang, which can further prove that the Longmu Co-Shuanghu ophiolitic belt is a significant tectonic boundary fault zone. There are two prominent high velocity anomalies and two prominent low velocity anomalies in our images. One obvious high velocity anomalies subduct beneath the Tibet at the long distance near 34°N, whereas it is broke off by an obvious low velocity anomaly under the IYS. We interpret them as northward subducting Indian lithosphere mantle and the low velocity anomanly under IYS likely reflects mantle material upwelling triggered by tearing of the northward subduction Indian lithosphere. The other prominent high velocity anomaly was imaged at a depth from 50 km to 200 km horizontal and up to the northern Qiangtang with its southern edge extending to about 34°N through Hoh Xil block. We infer it as the southward subducting Asia lithosphere mantle. The other widely low velocity anomaly beneath the Qiangtang block lies in the gap between the frontier of India plate and Asia plate, where is the channel of mantle material upwelling.展开更多
In this paper predecessors′achievements about the division between subtropical zone and warm temperate zone on the south slope of Funiu Mountain are firstly summarized, and the cause why these viewpoints about the di...In this paper predecessors′achievements about the division between subtropical zone and warm temperate zone on the south slope of Funiu Mountain are firstly summarized, and the cause why these viewpoints about the division are different also has been presented. Seven soil profiles at different heights above sea level are dug along the south slope of Funiu Mountain. Many compositions and properties of soil humus have been analyzed in laboratory. A comprehensive study has been made about the division according to the compositions and properties of soil humus with mathematical method. During the analysis process eight indexes have been used, such as altitude, organic carbon, humic acid (HA), fulvic acid (FA), the ratio of humic acid and fulvic acid (HA/FA), two extinction coefficients (E4,E6), and their ratio (E4/E6).The result indicates that the boundary is at about 1000 meters above sea level.展开更多
基金A subsidiary subject of the National Natural Science Fundation Project No. 9487001.
文摘The northern margin of the Alxa block is the junction of a tectonic units. Four first-order tectonic units are distinguished: 1. the Yagan structural zone characteristic of an immature island arc; 2. the Zhusileng-Hangwula structural zone, which was a passive continental margin in the Early Palaeozoic and was transformed into an active continental margin in the Late Palaeozoic;3. the Shalazha structural zone characteristic of a mature island arc; 4. the Nuru-Langshan structural zone, which was a Proterozoic orogenic belt and later evolved into an extensional transtional crust in the Palaeozoic. The above-mentioned tectonic units differ remarkably in sedimentary formations, magmatic rock associations, metamorphism and geochemistry and are bounded by faults between one another.
文摘“边界工作”是研究新闻从业者如何通过特定的话语策略来维护自身职业地位与合法性的经典理论框架。然而,ChatGPT和Sora等技术的开发应用表明生成式人工智能已具备多模态内容生产能力,套用“边界工作”理论中的扩张(expansion)、驱逐(expulsion)和自主性保护(protection of autonomy)三条阐释维度已不足以说明生成式人工智能参与新闻生产的种种实践进路。受布尔迪厄“场域”理论启发,哥伦比亚大学教授伊亚尔(Gil Eyal)提出基于关系视角的“边界域”(Boundary zone)理论。本文认为,新闻“边界域”为毗邻新闻业的其他社会场域中的行动者提供了活动的机会空间,技术行动者和职业行动者获得平等的实践身份,新的社会场域由此得以诞生。媒体主导的新闻场域和科技公司主导的技术场域之间的“边界域”成为未来新闻实践的主体网络。
文摘The active North China block consists of three second-order blocks: Ordos, North China Plain, and East Shandong-Huanghai Sea blocks. Two active tectonic zones, the Anyang-Heze- Linyi and Tangshan-Cixian zones, exist in the active North China Plain block and have separated the active block into 3 third-order active blocks, Taihangshan, Hebei-Shandong, and Henan-Huai blocks. The 3 third-order active blocks are characterized by their entire motion and are clearly different in their Cenozoic structures and deep structures. The active boundary tectonic zones between the third-order active blocks are less than those between the first- and second-order active blocks in their movement strength, extent, and seismic activity. The density of M ≥ 6 earthquakes in the boundary zones between active blocks is higher than that within the blocks by 9-22 times in the North China region, up to one order of magnitude on average. M ≥ 7 earthquakes occurred basically in the boundary zones between active blocks. The difference is not occasional, but reflects the nature of intraplate movement and the characteristics of strong seismic activity and is the powerful evidence for hypothesis of active blocks.
基金Project(2005CB623706) supported by the Major State Basic Research Development Program of ChinaProject(50230310) supported by the National Natural Science Foundation of China
文摘The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron microscopy and transmission electron microscopy.For the Zr-free alloy,the strength increases to the highest value at 20 s with transfer time,and then decreases slightly.The elongation decreases slowly with transfer time within 20 s,and more rapidly after 20 s.For the Zr-containing alloy,prolonging transfer time within 20 s results in slight decrease in the strength and elongation,and rapid drop of which is observed after 20 s.For the Zr-free alloy,prolonging transfer time can increase the percentage of intergranular fracture,which is mainly caused by wide grain boundary precipitate free zone.The failure mode of the Zr-containing alloy is modified from the predominant transgranular void growth and intergranular fracture to transgranular shear and intergranular fracture with increase in the transfer time,which is attributed to the wider grain boundary precipitate free zone and coarse equilibrium η phases in the matrix.
文摘This paper proposes design charts for estimating imperative input parameters for continuum approach analysis of the nonlinear dynamic response of piles.Experimental and analytical studies using continuum approach have been conducted on single and 2×2 grouped piles under coupled and vertical modes of vibration,for different dynamic forces and pile depth.As these design charts are derived from model piles,the charts have been validated for prototype pile foundations using scaling law.The experimental responses of model piles are scaled up and these responses exhibit good agreement with analytical results.This study also extends to estimation of the errors in computing frequency–amplitude responses with an increase in pile length.It is found that,with an increase in pile length,the errors also increase.The effectiveness of the proposed design charts is also checked with data based on different field setups given in existing literature,and these charts are found to be valid.Thus,the developed design charts can be beneficial in estimating the input parameters for continuum approach analysis for determining the nonlinear responses of pile supported machine foundations.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFC0600301)the Geological Investigation Project of China Geological Survey(Grant No.DD20190448,DD20190370)the Natural Science Foundation of China(Grant No.41374101,4171101169,41274095)。
文摘To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,174 teleseismic events recorded by 182 stations of Hi-CLIMB Project and 16 stations in the north of Hi-CLMB. Our tomographic images show the velocity structure significantly difference beneath northern and southern Qiangtang, which can further prove that the Longmu Co-Shuanghu ophiolitic belt is a significant tectonic boundary fault zone. There are two prominent high velocity anomalies and two prominent low velocity anomalies in our images. One obvious high velocity anomalies subduct beneath the Tibet at the long distance near 34°N, whereas it is broke off by an obvious low velocity anomaly under the IYS. We interpret them as northward subducting Indian lithosphere mantle and the low velocity anomanly under IYS likely reflects mantle material upwelling triggered by tearing of the northward subduction Indian lithosphere. The other prominent high velocity anomaly was imaged at a depth from 50 km to 200 km horizontal and up to the northern Qiangtang with its southern edge extending to about 34°N through Hoh Xil block. We infer it as the southward subducting Asia lithosphere mantle. The other widely low velocity anomaly beneath the Qiangtang block lies in the gap between the frontier of India plate and Asia plate, where is the channel of mantle material upwelling.
文摘In this paper predecessors′achievements about the division between subtropical zone and warm temperate zone on the south slope of Funiu Mountain are firstly summarized, and the cause why these viewpoints about the division are different also has been presented. Seven soil profiles at different heights above sea level are dug along the south slope of Funiu Mountain. Many compositions and properties of soil humus have been analyzed in laboratory. A comprehensive study has been made about the division according to the compositions and properties of soil humus with mathematical method. During the analysis process eight indexes have been used, such as altitude, organic carbon, humic acid (HA), fulvic acid (FA), the ratio of humic acid and fulvic acid (HA/FA), two extinction coefficients (E4,E6), and their ratio (E4/E6).The result indicates that the boundary is at about 1000 meters above sea level.
