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今日中国（法文版） 2022年第5期60卷 34-37页

作者： li CUNGEN 不详

A new interpretation for formation of orthogonal joints in quartz sandstone

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 289-299页

作者： le li Shaocheng Ji Département des Génies Civil Géologique et des MinesÉcole Polytechnique de MontréalMontréalQuébecH3C 3A7Canada

Two vertical and orthogonal systematic joint sets are generally arrayed in a grid pattern on the bedding surface,which are the significant features of flat-lying sandstone *** extensive researches are reported on this topic,many fundamental problems have still not been *** mutually perpendicular opening-mode fractures are an obvious manifestation of effective tensile stresses in two orthogonal directions in the horizontal bedding plane.A good understanding of these orthogonal joint systems is a key to structural analysis,landscape interpretation,and guidance of resolving a number of very practical problems in engineering,mining and hydrologic *** on an anatomic investigation on the orthogonal joints in the Potsdam sandstone of Cambrian age at Ausable Chasm(New York State,USA)and Beauharnois(Quebec,Canada),we proposed that the orthogonal joints may result from the auxetic effects of quartz-rich sandstone rather than local or regional rotation of the maximum tensile stress(σ_(3))direction by about 90°.The sandstone beds with negative Poisson's ratios are so fascinating that,when placed under vertical burial compression and layer-parallel extension in one direction(σ_(3)),it becomes stretched in the transverse direction(σ_(2)),producing two orthogonal sets of mutual abutting and intersecting joints(J1 and J2 normal toσ_(3) andσ_(2),respectively),and both are normal to the bedding *** set J1 is more closely-spaced than J2 by a factor of∼3.3,which is correlated with an average Poisson's ratio of−0.3 for the Potsdam sandstone at the time of joint formation.

关键词： Rock fractures Orthogonal joints Sandstone Auxetic effects Potsdam group

Primary dolostone related to the Cretaceous lacustrine hydrothermal sedimentation in Qingxi sag, Jiuquan Basin on the northern Tibetan Plateau： Discussion

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Science China Earth Sciences 2016年第4期59卷 866-870页

作者： li le YAO Guang Qing Key Laboratory of Tectonics & Petroleum Resources of the Ministry of Education China University of Geosciences Wuhan 430074 China Faculty of Resources China University ofGeosciences Wuhan 430074 China

Recently, a mechanism of hydrothermal sedimentation about a mantel-derived source was proposed to interpret the formation of lacustrine dolostone in the Cretaceous Xiagou Formation based on systematic petrological, mineralogical, and geochemical analyses （Wen et al., 2013）. Similar to the texture found in classic hydrothermal sediments （Zhang, 1988）, the breccia texture is characterized by certain hydro- thermal sedimentation features. With detailed analysis of the data and relevant explanations, however, we found that their data are not sufficient to support the mantle-derived hydrothermal genetic theory because the formation of ex- tensive laminated micritic ferruginous dolostone is not yet fully understood. We will review the model proposed by Wen et al. （2013） focusing on the following issues.

关键词：湖相白云岩热水沉积青藏高原北部白垩系青西凹陷酒泉盆地热液沉积物地球化学分析

Uranium comminution age responds to erosion rate semiquantitatively

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Acta Geochimica 2017年第3期36卷 426-428页

作者： le li Laifeng li Gaojun li MOE Key Laboratory of Surficial Geochemistry Department of Earth Sciences Nanjing University 163 Xianlindadao Nanjing 210023 China

Here we present(^(234)U/^(238)U)data from river sediments collected on the Tibetan ***(^(234)U/^(238)U)ratios of a specific grain size fraction show good correlation with erosion rates,which were determined by in-situ–produced cosmogenic *** correlation has previously been observed in a wide range of geomorphic settings,suggesting that(^(234)U/^(238)U)ratios of fluvial sediments have great potential to quantify erosion rates.

关键词： Uranium isotope Catchment erosion rate Tibetan Plateau Surface process

Double signal amplification sandwich-structured immunosensor based on TiO_2 nanoparticles enhanced CdSe@ZnS QDs electrochemiluminescence and the dramatic quenching effect of Au@polydopamine nanoparticles

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Science Bulletin 2016年第12期61卷 931-938页

作者： Qi-le li Shou-Nian Ding School of Chemistry and Chemical Engineering Southeast University

In this work, a double signal amplified immunosen- sor based on the enhanced CdSe@ZnS quantum dots （QDs） electrochemiluminescence （ECL） via TiO2 nanoparticles （TiO2 NPs） and the outstanding quencher of polydopamine （PDA） decorated Au nanoparticles （Au@PDA NPs） for ultrasensitive detection of carcinoembryonic antigen （CEA） has been successfully achieved. The ECL of CdSe@ZnS QDs with different sizes has been investigated carefully, especially cooperation with TiO2 NPs. Au@PDA NPs have been synthesized and characterized by transmission electron microscopy （TEM） and UV-Vis spectrum, which acted as ECL quenchers to label the secondary antibody （Ab2） of CEA to form Ab2/Au@PDA NPs conjugates. The sandwich-structured immunosensor was formed between capture antibody （Abl） on CdSe@ZnS QDs/TiO2 NPs/glassy carbon electrode, CEA and Ab2/Au@PDA NPs conjugates, resulting in a proportional ECL quenching signal relevant to the CEA concentration. Thus, CEA as a model biomarker has been detected in the linear range from 0.001 to 100 ng mL^-1 with a limit of detection of 0.35 pg mL^-1 （S/N = 3）.

关键词： Electrochemiluminescence CdSe@ZnSQDs TiO2 NPs Au@PDA nanoparticles Immunosensor

Two types of dynamic cool coronal structures observed with STEREO and Hinode

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Research in Astronomy and Astrophysics 2009年第12期9卷 1368-1376页

作者： Jun Zhang le-Ping li Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Solar coronal loops show significant plasma motions during their formation and eruption stages. Dynamic cool coronal structures, on the other hand, are often observed to propagate along coronal loops. We report on the discovery of two types of dynamic cool coronal structures, and characterize their fundamental properties. Using the EUV 304 A images from the Extreme UltraViolet Imager （EUVI） telescope on the Solar TErrestrial RElation Observatory （STEREO） and the Ca Ⅱ filtergrams from the Solar Optical Telescope （SOT） instrument on Hinode, we study the evolution of an EUV arch and the kinematics of cool coronal structures. The EUV 304A observations show that a missile-like plasmoid moves along an arch-shaped trajectory, with an average velocity of 31 km s^- 1. About three hours later, a plasma arch forms along the trajectory, subsequently the top part of the arch fades away and disappears; meanwhile the plasma belonging to the two legs of the arch flows downward to the arch＇s feet. During the arch formation and disappearance, SOT Ca Ⅱ images explore dynamic cool coronal structures beneath the arch. By tracking these structures, we classify them into two types. Type I is thread- like in shape and flows downward with a greater average velocity of 72 km s-l; finally it combines with a loop fibril at a chromospheric altitude. Type Ⅱ is shape-transformable and sometimes rolling as it flows downward with a smaller velocity of 37 km s-1, then disappears insularly in the chromosphere. It is suggested that the two types of structures are possibly controlled by different magnetic configurations.

关键词： Sun: chromosphere -- Sun: UV radiation -- Sun: activity

A Finite Difference Scheme for Solving the Undamped Timoshenko Beam Equations with Both Ends Free

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Acta Mathematicae Applicatae Sinica 2012年第4期28卷 691-704页

作者： Fu-le li Zong-hu XIU College of Science and Information Qingdao Agricultural University

In this paper, a boundary feedback system of a class of non-uniform undamped Timoshenko beam with both ends free is considered. A linearized three-level difference scheme for the Timoshenko beam equations is derived by the method of reduction of order on uniform meshes. The unique solvability, unconditional stability and convergence of the difference scheme are proved by the discrete energy method. The convergence order in maximum norm is of order two in both space and time. The validity of this theoretical analysis is verified experimentally.

关键词： Timoshenko beam nonhomogeneous undamped partial differential equation finite difference

Multicolor electrochemiluminescence of core-shell CdSe@ZnS quantum dots based on the size effect

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Science China Chemistry 2016年第11期59卷 1508-1512页

作者： Qi-le li Shou-Nian Ding Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research School of Chemistry and Chemical Engineering Southeast University

Multicolor electrochemiluminescence(ECL) of semiconductor nanocrystals tuned by size effect has been successfully achieved using quantum dots(QDs) with core-shell structure for the first time. It would open a new way and provide a guidance for design and preparation of stable and strong multicolor ECL emitters for simultaneous multicomponent analysis application.

关键词： CdSe@ZnSQDs electrochemiluminescence size effect multicolor

Finite-difference time-domain studies of low-frequency stop band in superconductor-dielectric superlattice

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Chinese Physics B 2010年第8期19卷 374-378页

作者：王身云刘少斌 le-Wei Joshua li College of Information Science and Technology Nanjing University of Aeronautics & Astronautics Department of Electrical and Computer Engineering National University of Singapore

The transmission coefficients of electromagnetic （EM） waves due to a superconductor-dielectric superlattice are numerically calculated. Shift operator finite difference time domain （SO-FDTD） method is used in the analysis. By using the SO-FDTD method, the transmission spectrum is obtained and its characteristics are investigated for different thicknesses of superconductor layers and dielectric layers, from which a stop band starting from zero frequency can be apparently observed. The relation between this low-frequency stop band and relative temperature, and also the London penetration depth at a superconductor temperature of zero degree are discussed, separately. The low-frequency stop band properties of superconductor-dielectric superlattice thus are well disclosed.

关键词： shift operator finite difference time domain method superconductor superconductor- dielectric superlattice high-pass filter

The relationship between diameter and depth of potholes eroded by running water

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 818-831页

作者： Shaocheng Ji le li Wei Zeng Departement des COnies Civil Geologique et des Mines Ecole Polytechnique de Montreal Montreal Quebec H3C 3A7 Canada Faculty of Architecture and Urban Planning Chongqing University Chongqing 430045 China

Geometrical analyses of 3930 potholes （3565 fluvial potholes, 237 marine potholes and 128 hillside potholes） from 33 localities in the world reveal a consistent, linear relationship： D Nh ＋ M, where h and D are, respectively, the depth and mean diameter of pothole, M is a critical size of the initial concavities （seminal potholes） that subsequently underwent growth, and N is the ratio of diameter expanding （wall erosion） speed to deepening （floor abrasion） speed. For the stream potholes, N is generally less than 1 with an average value of 0.67, M varies from 5.3 cm to 40.5 cm with an average of 20 cm, and N decreases gently with increasing M. However, the marine and hillside potholes are generally characterized by N 〉 1 and M 〈 10-14 cm, and a power-law relationship N 4.24M o.78 （coefficient of determination R2 0.75, M is in cm） exists. The results indicate that depth increases faster than diameter for stream potholes due to the larger size of grinding stones （〉5-10 cm）, while depth increases slower than diameter for marine potholes and hillside potholes due to the smaller size of grinding stones （〈5-10 cm）. The pothole h-D relationship is nearly independent of rock type. Knowledge of the pothole depth-diameter relationship is useful in a number of contexts, including simulation of hydraulic dynamics, theoretical considerations of erosion, comprehension of channel incision and development of canyons and gorges, and accurate estimation of excavation volume and mechanical strength ofpotholed bedrock in the design and stability analysis of hydraulic and environmental engineering projects （e.g. dam construction and river dredging）.

关键词： Potholes Erosion Rock excavation Hydraulic engineering River dredging