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Theoretical and experimental study on relationship between stress-strain and temperature variation

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Science China Earth Sciences 2009年第11期52卷 1825-1834页

作者： CHEN ShunYun liu LiQiang liu peixun MA Jin CHEN GuoQiang Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

Principle on temperature response to the stress-strain variation is fundamental to the relationship between thermal radiation variation and stress-strain field. Current research indicates that temperature has a sensitive response to rock deformation under the condition of normal temperature background. However, the basic physical relationship between deformation and temperature variation is not clear and need to be investigated further. In this paper, principle on temperature response to stress-strain variation is studied in detail, based on thermodynamics, elastic strain theory, and experiments on both ideal material and rock. In the stage of elastic deformation, results indicate that: 1) temperature increment is positively correlated with volume strain variation. Temperature rises with hydrostatic pressure increase. In other words, temperature rises when the specimen is under the compressive state whereas temperature drops under the tensile state. 2) Pure shear deformation does not contribute to tempera- ture variation. Namely, shape change of specimen does not produce temperature variation. However, there exist the relative tensile area and the compressive one in the specimen under the state of pure shear. Temperature drops within the relative tensile area while temperature rises within the compressive areas during the process of loading.

关键词： stress-strain temperature variation volume strain pure shear sine-wave load

Color image detail enhancement based on quaternion guided filter

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The Journal of China Universities of Posts and Telecommunications 2017年第4期24卷 40-50页

作者： Wu Kun Li Guiju Han Guangliang Yang Hang liu peixun Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China University of Chinese Academy of Sciences Beijing 100049 China

Color image enhancement is an active research field in image processing. Currently, many image enhancement methods are capable of enhancing the details of the color image. However, these methods only process the red, green and blue （RGB） color channels separately, which leads to color distortion easily. In order to overcome this problem, the paper presents an approach to integrate the quaternion theory into the traditional guided filter to obtain a quaternion guided filter （QGF）. This method makes full use of the color information of an image to realize the holistic processing of RGB color channels. So as to preserve color information while enhancing details, this paper proposes a color image detail enhancement algorithm based on the QGF. Experimental results show that the proposed algorithm is effective in the applications of the color image detail enhancement, and enables image＇s edges to be more prominent and texture clearer while avoiding color distortion. Compared with the existing image enhancement methods, the proposed method achieves better enhancement performance in terms of the visual quality and the objective evaluating indicators.

关键词： detail enhancement quaternion guided filter self-adaptive enhancement transfbrm

Experimental investigation of three-dimensional propagation process from surface fault

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Science China Earth Sciences 2008年第10期51卷 1426-1435页

作者： liu LiQiang liu peixun WONG HonChu MA ShaoPeng GUO YanShuang State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Department of Civil and Structural Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Mechanics School of ScienceBeijing Institute of TechnologyBeijing 100083China

Experimental study of the formation and propagation of three-dimensional (3D) faults is of great sig- nificance in the understanding of the propagation process developing from initial natural faults. In the study described in this paper, experimental investigations of 3D propagation processes of a type of surface fault are carried out under biaxial compression. The strain field near the surface fault is dy- namically measured and fully analyzed with a high-density Multi-Channel Digital Strain Gauge (MCDSG) and Digital Speckle Correlation Method (DSCM) based on the white-light image analysis. Simultane- ously the micro-fracture process involved in fault formation is observed by a 3D acoustic emission (AE) location system with a set of multi-channel whole-wave record equipment. The experimental results show that the 3D propagation process of surface fault differs greatly from that of the two-dimensional (2D) state and that a new more complicated type of 3D morphological characters and deformation mechanisms are produced. The 3D propagation process of surface faults may be divided into three stages: 1) the first stage of crack propagation initiated by wing cracks; 2) the conversion stage propa- gated by petal cracks; and 3) the second stage of crack propagation formed by shell-shaped fracture surface. The primary propagation patterns of the three stages are different. The corresponding defor- mation fields and micro-fracture distributions are likewise different. The fracture activities from petal cracks especially are of vital importance during surface fault propagation. This is also a key conversion state and marks an intrinsic difference between 2D-like and the 3D state in fault development.

关键词： surface fault 3D propagation strain field digital speckle acoustic emission

A thermal physical index to explore current tectonic activity with satellite remote sensing

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Science China Earth Sciences 2012年第2期55卷 290-295页

作者： CHEN ShunYun MA Jin liu peixun liu LiQiang HU XiaoYan State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

The use of satellite thermal infrared information is being developed as a method of exploring current tectonic activity. To realize real world application, an objective, stable and testable thermal physical index that is simultaneously related with tectonic activity must be established. From the viewpoint of the energy balance, the land surface is a boundary where energy is exchanged between outer space and the solid Earth. Regardless of how complex the influencing factors are, the land surface is mainly affected by the Sun, atmosphere and underground heat. In this paper, first, the relationships among land surface temperature, solar radiation, atmospheric temperature and thermal information from underground are obtained employing a mathematic physical method based on the equation of heat conduction and energy balance at the land surface. Second, a thermal physical index called the geothermal flux index (GFI), which can provide the activity state of underground heat, is constructed. Third, the theoretical basis of the thermal physical index is verified using stable annual variations in land surface temperature and solar radiation. Finally, combined with known crustal deformations derived using a global positioning system, the effectiveness of the GFI in extracting field tectonic motion is tested. The results indicate that the GFI is effective in providing information on current tectonic activity.

关键词： current tectonic activity thermal physical index geothermal flux index remote sensing

稀土萃取分离流程中Ce(Ⅳ)分布规律及抑制方法研究

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有色金属（冶炼部分） 2024年第5期 83-90页

作者：刘培勋胡广寿李虎平唐晓亮马旭花甘肃稀土新材料股份有限公司甘肃白银730922 兰州大学化学化工研究兰州730000

近年来,稀土冶炼分离企业在萃取提纯镨钕系列化合物的过程中普遍出现了铈组分分离顺序错位的现象。目前,尚未见到关于稀土萃取流程中各功能段有机相中Ce(Ⅳ)分布规律以及稀释剂选型与稀土冶炼过程铈组分分离顺序错位的关联性相关报道。... 详细信息

近年来,稀土冶炼分离企业在萃取提纯镨钕系列化合物的过程中普遍出现了铈组分分离顺序错位的现象。目前,尚未见到关于稀土萃取流程中各功能段有机相中Ce(Ⅳ)分布规律以及稀释剂选型与稀土冶炼过程铈组分分离顺序错位的关联性相关报道。鉴于此,以稀土分离流程中经典的铈镨分离工艺作为理论模型,系统研究了各萃取功能段Ce(Ⅳ)分布规律与影响因素,对稀释剂化学组成和化学特性进行了分析,同时测定了不同稀释剂对有机相中Ce(Ⅳ)的抑制作用。研究结果表明,稀土萃取分离过程中的水相酸度、元素配分、萃取级数等对各分离段有机相中Ce(Ⅳ)含量影响明显。稀释剂选型对稀土萃取分离过程有机相中Ce(Ⅳ)的抑制作用受其化学组成的影响,其抑制作用依次为:煤油>磺化煤油>溶解油,实际工业化生产过程中可通过补加适量的高溴值煤油或调整稀释剂中某些有效成分来抑制有机相中Ce(Ⅳ)的生成。该研究对后续工艺改进、确保稀土萃取分离过程镨钕系列产品质量稳定具有一定的指导意义。

关键词：稀土萃取 Ce(Ⅳ) 分布规律抑制

Near-surface Geothermal Gradient Observation and Geothermal Analyses in the Xianshuihe Fault Zone,Eastern Tibetan Plateau

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Acta Geologica Sinica(English Edition) 2017年第2期91卷 414-428页

作者： liu Qianqian SHI Yanan WEI Dongping HAN Peng CHEN Shunyun liu peixun liu Liqiang Key Laboratory of Computational Geodynamics Chinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake Administration

The Xianshuihe fault（XSHF） zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan and the 2013 Lushan earthquakes. This study analysed underground temperature sequence data for four years at seven measuring points at different depths（maximum depth： 18.9 m） in the southeastern section of the XSHF zone. High-frequency atmospheric noise was removed from the temperature sequences to obtain relatively stable temperature fields and heat fluxes near the measurement points. Our measurements show that the surrounding bedrock at（the seven stations distributed in the fault zone） had heat flux values range from-41.0 to 206 m W/m^2, with a median value of 54.3 m W/m^2. The results indicate a low heat flux in the northern section of DaofuKangting and a relatively high heat flux in the southern section of Kangting, which is consistent with the temperature distributions of the hot springs near the fault. Furthermore, our results suggest that the heat transfer in this field results primarily from stable underground heat conduction. In addition, the underground hydrothermal activity is also an obvious factor controlling the geothermal gradient.

关键词： temperature sequence records geothermal gradient heat flow heat flux Xianshuihe fault zone Tibet Plateau Proto-Tethys

Effect of fault jogs on frictional behavior: An experimental study

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Science China Earth Sciences 2008年第10期51卷 1436-1445页

作者： MA ShengLi CHEN ShunYun liu peixun HU XiaoYan WANG KaiYing HUANG YuanMin State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

Studying the effect of geometrically irregular bodies on the mechanical behavior of fault activity is of significance in understanding the seismic activity along a fault zone. By using rock mechanics ex- periment with medium-scale samples, we have studied the effect of fault jogs, the most common irregularity along fault zones, on frictional behavior. The research indicates that extensional fault jog can be easily fractured because of its low strength and the fractured jog has no obvious resistance to fault sliding, and the micro-fractures occurring in the jog are indicative of stick-slip along the faults. The fault zone containing extensional jogs is characterized by velocity weakening and can be described by rate and state friction law. Compressional fault jog makes fault sliding more difficult because of its high fracturing strength, but the micro-fractures occurring in the tensile areas around fault ends at higher stress level can provide necessary condition for occurrence of stick-slip along the faults before the jog is fractured and thus act as precursors of fault instability. Compression jog can be taken as a stable indicator of fault segmentation until the jog is completely fractured and two faults are linked.

关键词： en-echelon faults extensional jog compression jog micro-fracture stick-slip

Spatial-temporal variation of the land surface temperature field and present-day tectonic activity

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Geoscience Frontiers 2010年第1期1卷 57-67页

作者： Jin Ma Shunyun Chen Xiaoyan Hu peixun liu Liqiang liu State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

This study attempts to acquire information on tectonic activity in western China from land surface temperature （LST） field data. On the basis of the established relationship between heat and strain, we analyzed the LSTdistribution in western China using the satellite data product MODIS/Terra. Our results show that： 1. There are departures from annual changes of LSTin some areas, and that these changes are associated with the activity of some active tectonic zones. 2. When annual-change background values caused by climate factors are removed, the long-period component （LSTLow） of temperature residual （AT） of the LSTis able to serve as an indicator for tectonic activity. We have found that a major earthquake can produce different effects on the/ST fields of surrounding areas. These effects are characterized by both rises and drops in temperature. For example, there was a noteworthy temperature decline associated with the Sumatran M9 earthquake of 2004 in the Bayan Har-Songpan block of central Tibetan Plateau. 3. On the other hand, the LST field of a single area may respond differently to major shocks occurring in different areas in the regions surrounding China. For instance, the Kun- lun M 8.1 event made the LSTon the Longmen Mountains fault zone increase, whereas the Zaisan Lake M 7.9 quake of 2003, and the Sumatran M 9 event of 2004, caused decreases in the same area＇s LST. 4. The variations of land surface temperature （LST） over time are different in different tectonic areas. These phenomena may provide clues for the study of tectonic deformation processes. On the basis of these phenomena, we use a combi- nation of temperature data obtained at varied depths, regional seismicity and strain results obtained with GPS measurements, to test the information related to tectonic activity derived from variations of the LST field, and discuss its implications to the creation of models of regional tectonic deformation.

关键词： Land surtace temperature(LST) field North-south seismic zone(N-S seismic zone) Bayan Har - Songpanblock Present-day tectonicactivity Earthquake

An experimental study on variation of thermal fields during the deformation of a compressive en echelon fault set

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Progress in Natural Science:Materials International 2007年第3期17卷 298-304页

作者： liu peixun, MA Jin, liu Liqiang, MA Shengli and CHEN Guoqiang (Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China) Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

The temperature variations during deformation of a compressive en echelon fault set in a rock sample were measured by a surface measurement system with multi-point platinum resistance thermometers and an infrared thermal image system. The measurements obtained by the two systems were in agreement with each other, indicating a relationship between temporal-spatial variations of the thermal field and changes of stress and strain. At varied structural positions of the rock sample, the rising of the temperature was different, implying distinct stress distributions at these positions. In the experiment, the deformation process of the sample included three stages: elastic deformation, stick-slip, and rupture. Correspondingly, the variation process of temperature had also three stages, each of which had its own temperature rising profile. And the thermal radiation field showed a similar process. These phenomena mean that the dominant mechanisms of temperature rising in all stages of deformation are different. Experimental results provide a physical basis for the study of current fault activities by using data of satellite infrared images.

关键词： en echelon fault set stick-slip thermal infrared radiation temperature mechanism of temperatnre rising.