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Study on Late Cretaceous-Cenozoic exhumation of the Yanji area,NE China: insights from low-temperature thermochronology

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Acta Geochimica 2019年第6期38卷 815-833页

作者： xiaoming li Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences

The Yanji area,northeastern China,a part of the orogenic collage between the North China Block in the south and the Jiamusi-Khanka Massifs in the northeast,is the most likely location where the Pacific Plate subduction・related magmatic activities and subsequent exhumation processes ***,we report new low-temperature thermochronology of apatite and zircon data from the granitoid samples in the Yanji *** exhumation rates of Tianfozhishan,Yanji area,were〜0.049 and〜0.073 mm/year,interpreted from the elevations and apatite and zircon fission track ages,*** exhumation,integrated with the geological setting,suggested that the paleogeothermal gradient of the Tianfozhishan,even extending to the Yanji area,was possibly to be greater than 35℃/km in the Late *** thermal history modeling of the data indicates a basically similar pattern,but the various timing for different samples between the Oligocene-Early Miocene and the Middle Miocene in the Yanji *** hence conclude that a fourstages of cooling,from〜6.7℃/Ma(during the Late Cretaceous),to〜0.8℃/Ma(during the Late Cretaceous to the Oligocene-Early Miocene),then to〜2-3℃/Ma with varied styles(between the Oligocene-Early Miocene and the Middle Miocene),and finally to3 km under a reasonable paleogeothermal gradient(>35℃/km),speculated from the possible exhumation rate of *** with the tectonic setting,this exhumation,including two stages of pronounced tectonic uplift and denudation and two stages of weak exhumation driven by the low regional erosion rate,is possibly related to the subduction of the Pacific Plate beneath the Eurasian Plate since the Late *** study used more robust evidence to propose higher paleogeothermal gradient(>35℃/km),reflecting exhumation of>3 km in the Yanji area since the Late Cretaceous.

关键词： Low-temperature thermochronology Exhumation Pacific Plate subduction Yanji area Late Cretaceous-Cenozoic

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One family of 13315 stable periodic orbits of non-hierarchical unequal-mass triple systems

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Science China(Physics,Mechanics & Astronomy) 2021年第1期64卷 108-113页

作者： xiaoming li XiaoChen li ShiJun liao MOE Key Laboratory of Disaster Forecast and Control in Engineering School of Mechanics and Construction EngineeringJinan UniversityGuangzhou510632China Department of Earth Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridge02139USA School of Civil Engineering and Transportation South China University of TechnologyGuangzhou510641China Department of Engineering Science University of OxfordOxfordOX13PJUK Center of Advanced Computing School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai200240China

The three-body problem can be traced back to Newton in 1687,but it is still an open question *** that only a few periodic orbits of three-body systems were found in 300 years after Newton mentioned this famous *** triple systems are common in astronomy,practically all observed periodic triple systems are hierarchical(similar to the Sun,Earth and Moon).It has traditionally been believed that non-hierarchical triple systems would be unstable and thus should disintegrate into a stable binary system and a single star,and consequently stable periodic orbits of non-hierarchical triple systems have been expected to be rather ***,we report here one family of 135445 periodic orbits of non-hierarchical triple systems with unequal masses;13315 among them are *** with the narrow mass range(only 10-5)in which stable"Figure-eight"periodic orbits of three-body systems exist,our newly found stable periodic orbits have fairly large mass *** find that many of these numerically found stable non-hierarchical periodic orbits have mass ratios close to those of hierarchical triple systems that have been measured with astronomical *** implies that these stable periodic orbits of non-hierarchical triple systems with distinctly unequal masses quite possibly can be observed in *** investigation also suggests that there should exist an infinite number of stable periodic orbits of non-hierarchical triple systems with distinctly unequal *** that our approach has general meaning:in a similar way,every known family of periodic orbits of three-body systems with two or three equal masses can be used as a starting point to generate thousands of new periodic orbits of triple systems with distinctly unequal masses.

关键词： three-body problem non-hierarchical system periodic orbits

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More than six hundred new families of Newtonian periodic planar collisionless three-body orbits

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Science China(Physics,Mechanics & Astronomy) 2017年第12期60卷 63-69页

作者： xiaoming li ShiJun liao School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200240 China MoE Key Laboratory in Scientific and Engineering Computing Shanghai 200240 China

The famous three-body problem can be traced back to Isaac Newton in the 1680 s. In the 300 years since this "three-body problem"was first recognized, only three families of periodic solutions had been found, until 2013 when ˇSuvakov and Dmitraˇsinovi′c [***. Lett. 110, 114301(2013)] made a breakthrough to numerically find 13 new distinct periodic orbits, which belong to 11 new families of Newtonian planar three-body problem with equal mass and zero angular momentum. In this paper, we numerically obtain 695 families of Newtonian periodic planar collisionless orbits of three-body system with equal mass and zero angular momentum in case of initial conditions with isosceles collinear configuration, including the well-known figure-eight family found by Moore in 1993, the 11 families found by ˇSuvakov and Dmitraˇsinovi′c in 2013, and more than 600 new families that have never been reported, to the best of our knowledge. With the definition of the average period T = T=Lf, where Lf is the length of the so-called "free group element", these 695 families suggest that there should exist the quasi Kepler's third law T* ≈ 2:433 ± 0:075 for the considered case, where T*= T|E|^(3/2) is the scale-invariant average period and E is its total kinetic and potential energy,respectively. The movies of these 695 periodic orbits in the real space and the corresponding close curves on the "shape sphere"can be found via the website: http://***/three-body/***.

关键词： three-body problem periodic orbits clean numerical simulation(CNS)

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Clean numerical simulation:a new strategy to obtain reliable solutions of chaotic dynamic systems

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Applied Mathematics and Mechanics(English Edition) 2018年第11期39卷 1529-1546页

作者： xiaoming li Shijun liAO School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai 200240China Collaborative Innovative Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China Ministry-of-Education Key Laboratory of Scientific and Engineering Computing Shanghai 200240China

It is well-known that chaotic dynamic systems, e.g., three-body system and turbulent flow, have sensitive dependence on the initial conditions(SDIC). Unfortunately,numerical noises, i.e., truncation error and round-off error, always exist in practice. Thus,due to the SDIC, the long-term accurate prediction of chaotic dynamic systems is practically impossible. In this paper, a new strategy for chaotic dynamic systems, i.e., the clean numerical simulation(CNS), is briefly described, and applied to a few Hamiltonian chaotic systems. With negligible numerical noises, the CNS can provide convergent(reliable) chaotic trajectories in a long enough interval of time. This is very important for Hamiltonian systems, and thus should have many applications in various fields. It is found that the traditional numerical methods in double precision cannot give not only reliable trajectories but also reliable Fourier power spectra and autocorrelation functions(ACFs). In addition, even the statistic properties of chaotic systems cannot be correctly obtained by means of traditional numerical algorithms in double precision, as long as these statistics are time-dependent. The CNS results strongly suggest that one had better be very careful on the direct numerical simulation(DNS) results of statistically unsteady turbulent flows, although DNS results often agree well with experimental data when the turbulent flow is in a statistical stationary state.

关键词： chaos numerical noise clean numerical simulation(CNS) reliability of computation

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Response of stomatal conductance of two tree species to vapor pressure deficit in three climate zones

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Journal of Arid Land 2014年第6期6卷 771-781页

作者： Jing li xiaoming li School of Environmental Science and Engineering Shandong University

Stomatal behavior is a central topic of plant ecophysiological research under global environmental change. However, the physiological mechanism controlling the response of stomata to vapor pressure deficit （VPD） or relative humidity （RH） has been inadequately understood till now. In this study, responses of stomatal conduc- tance （gs） to VPD in two species of trees （Fraxinus chinensis Roxb., Populus alba L. var. pyramidalis Bge.）in three different climate zones （Jinan with typical warm humid/semi-humid climate, Urumqi with temperate continental arid climate and Turpan with extreme arid desert climate） were measured. Levels of two phytohormones （abscisic acid, ABA; indole-3-acetic acid, IAA） in the leaves of the two tree species at these three sites were also measured by high performance liquid chromatography. The results showed that the responses of gs to an increasing VPD in these two tree species at the three sites had peak curves which could be fitted with a Log Normal Model （gs=***（-O.5（In（DIc）lb）2）. The VPD/RH values corresponding to the maximum g, can be calculated using the fitting models for the two tree species in the three sites. We found that the calculated g, -VPD correlated nega- tively with relative air humidity in the three sites during the plant growth period （April to October 2010）, which showed the values of g,-max-VPD were related to the climate conditions. The prevailing empirical stomatal model （Leuning model） and optimal stomatal behavior model could not properly simulate our measured data. The water use efficiency in the two tree species did not show obvious differences under three very different climatic conditions, but the highest gs, photosynthetic and transpiration rates occurred in P. alba var. of Turpan. The sensitivity in re- sponse of g~ to VPD in leaves of the two trees showed positive correlations with the concentration of ABA, which implied that ABA level could be used as an indicator of the sensitivity of stomatal response to VPD

关键词： abscisic acid relative humidity stomatal conductance stomatal model vapor pressure deficit

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On the periodic solutions of the three-body problem

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National Science Review 2019年第6期6卷 1070-1071页

作者： Shijun liao xiaoming li Advanced Center of Computing School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong University School of Physics and Astronomy Shanghai Jiao Tong University MOE Key Laboratory of Disaster Forecast and Control in Engineering School of Mechanics and Construction Engineering Jinan University

The motion of three bodies that attract each other by universal gravitation was first investigated by Newton [1] and was reconsidered by many great mathematicians and scientists, including Euler, Lagrange, Poincaré [2] and Hilbert. The famous three-body problem has had a great influence on physics, mathematics and non-linear dynamics. It has led to a new

关键词： On the periodic solutions of the three-body problem

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Pattern transition of two-dimensional Faraday waves at an extremely shallow depth

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Science China(Physics,Mechanics & Astronomy) 2016年第11期59卷 58-60页

作者： XiaoChen li xiaoming li ShiJun liao School of Naval Architecture Ocean and Civil EngineeringShanghai Jiaotong UniversityShanghai 200240China Collaborative Innovative Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China State Key Laboratory of Ocean Engineering Shanghai 200240China

In this paper, we experimentally investigate the pattern transition of two-dimensional Faraday waves at an extremely shallow depth in a Hele-Shaw cell. Several patterns of Faraday waves are observed, which have some significant differences in wave profile,wave height and wave length. It is found that, in a wide range of the forcing frequency f, there always exists a region of the acceleration amplitude A, in which there exist the so-called hysteretic jumps between different patterns of Faraday waves. All of these experimental observations could enrich our knowledges about the Faraday waves and would be helpful to the further theoretical studies on the related topic in future.

关键词： Faraday waves extremely shallow water experimental observation

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On the stability of the three classes of Newtonian three-body planar periodic orbits

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Science China(Physics,Mechanics & Astronomy) 2014年第11期57卷 2121-2126页

作者： li xiaoming liAO ShiJun School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong University Ministry-of-Education Key Laboratory in Scientific Computing Nonlinear Analysis and Applied Mathematics Research Group (NAAM) King Abdulaziz University (KAU)JeddahSaudi Arabia

Currently,the fifteen new periodic orbits of Newtonian three-body problem with equal mass were found by Suvakov and Dmitra sinovi[Phys Rev Lett,2013,110:114301]using the gradient descent method with double *** this paper,these reported orbits are checked stringently by means of a reliable numerical approach(namely the"Clean Numerical Simulation",CNS),which is based on the arbitrary-order Taylor series method and data in arbitrary-digit precision with a procedure of solution *** is found that seven among these fifteen orbits greatly depart from the periodic ones within a long enough interval of time,and are thus most possibly unstable at *** is suggested to carefully check whether or not these seven unstable orbits are the so-called"computational periodicity"mentioned by Lorenz in *** work also illustrates the validity and great potential of the CNS for chaotic dynamic systems.

关键词： unstable Newtonian verification chaotic digit carefully periodicity Clean enough arbitrary

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基于SAE和LSTM神经网络的深部未钻地层可钻性预测方法

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西安石油大学学报(自然科学版) 2025年第1期40卷 39-46,64页

作者：朱亮李晓明纪慧楼一珊油气钻完井技术国家工程研究中心(长江大学) 湖北武汉430100 油气钻采工程湖北省重点实验室(长江大学) 湖北武汉430100 中国石油川庆钻探工程有限公司四川成都610051

在制定深部地层钻进提速方案时,对地层可钻性进行钻前预测是十分必要的,现有的岩石可钻性预测方法精度低,难以满足钻井设计的要求。为此,提出一种基于SAE和LSTM神经网络相结合的组合模型对深部未钻地层的可钻性进行预测。并将SAE-LSTM... 详细信息

在制定深部地层钻进提速方案时,对地层可钻性进行钻前预测是十分必要的,现有的岩石可钻性预测方法精度低,难以满足钻井设计的要求。为此,提出一种基于SAE和LSTM神经网络相结合的组合模型对深部未钻地层的可钻性进行预测。并将SAE-LSTM组合模型的训练时间和预测结果与BP神经网络、支持向量机、随机森林和单一的LSTM模型进行了对比分析。结果表明:所构建的SAE-LSTM组合模型预测地层可钻性训练用时最短,预测值与实际测量值误差最小,拟合结果的均方根误差RMSE仅为0.081,平均绝对百分比误差MAPE为1.189,决定系数R^(2)为0.966,其RMSE和MAPE最小,R 2最大,较其他模型预测精度更高。该方法为地层参数预测提供了新的途径,能改善以往预测方法在处理复杂地层问题时预测效率低、预测精度不高等问题。

关键词：深部地层钻探岩石可钻性预测模型栈式自动编码器 LSTM神经网络深度学习

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Thinopyrum ponticum and Th. intermedium: the promising source of resistance to fungal and viral diseases of wheat

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Journal of Genetics and Genomics 2009年第9期36卷 557-565页

作者： Hongjie li xiaoming Wang The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCR1) Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

Thinopyrum ponticum and Th. intermedium provide superior resistance against various diseases in wheat （Ttricum aestivum）. Because of their readily crossing with wheat, many genes for disease resistance have been introduced from the wheatgrasses into wheat. Genes for resistance to leaf rust, stem rust, powdery mildew, Barley yellow dwarf virus, Wheat streak mosaic virus, and its vector, the wheat curl mite, have been transferred into wheat by producing chromosome translocations. These genes offer an opportunity to improve resistance of wheat to the diseases; some of them have been extensively used in protecting wheat from damage of the diseases. Moreover, new resistance to diseases is continuously detected in the progenies of wheat-Thinopyrum derivatives. The present article summaries characterization and application of the genes for fungal and viral disease-resistance derived from Th. ponticum and Th. intermedium.

关键词： wheat disease resistance gene Thinopyrum pontieum Th. intermedium wheatgrass

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