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Driving forces of continental lithospheric deformation

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Science China Earth Sciences 2024年第12期67卷 3950-3956页

作者： Zebin CAO lijun liu State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

*** The lithosphere is a fundamental component of Earth’s layered structure,and its stress state and deformation mechanisms are critical to understanding Earth’s tectonic evolution(Ghosh and Holt,2012)and managing natural resources(Heidbach et al.,2018).According to the classical theory of plate tectonics,significant lithospheric deformation is expected near active plate boundaries due to the relative motion between tectonic plates.

关键词： tectonic lithospheric Earth

葡萄牙栖盐田菌LLJ914的全基因组测序和比较基因组分析

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中国海洋大学学报（自然科学版） 2025年第1期55卷 51-65页

作者：李娟娟刘子涵王雅楠刘莉君张晓华于敏中国海洋大学海洋生命学院山东青岛266003 青岛海洋科技中心海洋生态与环境科学功能实验室山东青岛266237 中国海洋大学进化与海洋生物多样性研究所山东青岛266003

栖盐田菌属细菌因具有较强渗透压耐受能力而备受关注。然而,目前对其适应高盐或其他海洋极端环境的机制尚未探明。为揭示分离自冲绳海槽热液区的葡萄牙栖盐田菌(Salinicola lusitanus)LLJ914与其同属菌株之间的遗传特征及代谢潜力的差异... 详细信息

栖盐田菌属细菌因具有较强渗透压耐受能力而备受关注。然而,目前对其适应高盐或其他海洋极端环境的机制尚未探明。为揭示分离自冲绳海槽热液区的葡萄牙栖盐田菌(Salinicola lusitanus)LLJ914与其同属菌株之间的遗传特征及代谢潜力的差异,探究其在极端海洋生境下的适应机制。通过全基因组测序获得葡萄牙栖盐田菌LLJ914全基因组序列,选取同属其他菌株的基因组进行比较基因组学分析,探究栖盐田菌属各菌株及不同环境来源的葡萄牙栖盐田菌代谢潜力的差异。菌株LLJ914基因组大小为4781556 bp,GC含量为64.0%,共编码4229个蛋白,69个tRNA,12个rRNA。通过构建系统发育树,并进行平均核苷酸和平均氨基酸一致性分析,发现该菌株与马齿苋(Halimione portulacoides)内共生的葡萄牙栖盐田菌CR50^(T)亲缘关系最近。通过功能基因注释分析,发现葡萄牙栖盐田菌具有抵抗各种重金属的相关基因和利用甲基膦酸产生甲烷的phn基因簇;相比于植物内共生菌CR50^(T),菌株LLJ914基因组中包含更多与氨基酸和碳水化合物的运输代谢、能量生产和转换以及转录相关的功能基因。此外,菌株LLJ914基因组中还包含特有的与重金属抵抗、免疫防御及有氧呼吸相关的基因,这可能与其适应复杂极端的深海热液环境有关。本研究揭示了葡萄牙栖盐田菌LLJ914适应深海热液环境的遗传特征及代谢潜力,为更好地认识热液微生物的生态功能提供了参考。

关键词：葡萄牙栖盐田菌极端环境热液区冲绳海槽全基因组测序比较基因组分析

Integrated wellbore-reservoir-geomechanics modeling for enhanced interpretation of distributed fiber-optic strain sensing data in hydraulicfracture analysis

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3136-3148页

作者： lijun liu Xinglin Guo Xiaoguang Wang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China Tianfu Yongxing Laboratory Chengdu610213China College of Energy Chengdu University of TechnologyChengdu610059China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu610059China

Fiber-optic distributed strain sensing(FO-DSS)has been successful in monitoring strain changes along horizontal wellbores in hydraulically fractured ***,the mechanism driving the various FO-DSS responses associated with near-wellbore hydraulic fracture properties is still *** address this knowledge gap,we use coupled wellbore-reservoir-geomechanics simulations to study measured strain-change behavior and infer hydraulic fracture *** crossflow among fractures is captured through explicit modeling of the transient wellbore *** addition,local grid refinement is applied to accurately capture strain changes along the fiber.A Base Case model was designed with four fractures of varying properties,simulating strain change signals when the production well is shut-in for 10 d after 240 d of production and reopened for 2 ***-pressure plots for different fracture clusters were used to gain insights into inferring fracture properties using DSS *** comparing the model with and without the wellbore,distinct strain change signals were observed,emphasizing the importance of incorporating the wellbore in FO-DSS *** effects of fracture spacing and matrix permeability on strain change signals were thoroughly *** results of our numerical study can improve the understanding of the relation between DSS signals and fracture hydraulic properties,thus maximizing the value of the dataset for fracture diagnostics and characterization.

关键词： Distributed strain sensing Fracture diagnostic Coupled flow and geomechanics Transient wellbore flow

Simulating land-use change and its effect on biodiversity conservation in a watershed in northwest China

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Ecosystem Health and Sustainability 2017年第5期3卷 13-23页

作者： Youjia Liang lijun liu School of Resources and Environmental Engineering Wuhan University of TechnologyWuhanChina School of Navigation Wuhan University of TechnologyWuhanChina

Introduction:Land-use management strategies play a major role in biodiversity *** many parts of the world,local governments are under increasing pressure to regulate human activity to mitigate negative impacts on ***/other:This study aimed to analyze the effects of different land-use patterns on biodiversity change across a typical artificial desert *** first analyzed land-cover change based on past and future management scenarios in a watershed spanning Gaotai,Linze,and Ganzhou counties in northwest *** then analyzed the effect of different land-use patterns on biodiversity change in the *** found that the crucial landcover changes are likely to occur in the wetland reserves and areas established for the Grain for Green Project around the oases,and such changes could affect biodiversity throughout the entire watershed ***:The use of spatial analysis to illustrate explicit changes in ecosystems is useful in fostering biodiversity awareness and the need for decision-making at different ***:Thus,these findings indicate that land-use management strategies for the middle and southeast parts of the watershed are particularly important for future management of biodiversity and the integrated ecosystem services of the entire watershed landscape.

关键词： Land-use management biodiversity scenario analysis spatial modeling

VIBRATION CONTROL OF FLUID-FILLED PRISMATIC SHELL WITH ACTIVE CONSTRAINED LAYER DAMPING TREATMENTS

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 101-105页

作者： liu lijun ZHANG Zhiyi HUAHongxing ZHANG Yi State Key Laboratory of Vibration Shock and Noise Shanghai Jiaotong University Shanghai 200240 China 704 Research Department China Ship and Heavy Industry Group Corporation Shanghai 200030 China

Active constrained layer damping （ACLD） combines the simplicity and reliability of passive damping with the light weight and high efficiency of active actuators to obtain high damping over a wide frequency band. A fluid-filled prismatic shell is set up to investigate the validity and efficiency of ACLD treatments in the case of fluid-structure interaction. By using state subspace identification method, modal parameters of the ACLD system are identified and a state space model is established subsequently for the design of active control laws. Experiments are conducted to the fluid-filled prismatic shell subjected to random and impulse excitation, respectively, For comparison, the shell model without fluid interaction is experimented as well. Experimental results have shown that the ACLD treatments can suppress vibration of the fluid-free and fluid-filled prismatic shell effectively. Under the same control gain, vibration attenuation is almost the same in both cases.

关键词： Active constrained layer damping Subspace identification method Vibration control

Feature Extraction and Dimensionality Reduction of Arc Sound under Typical Penetration Status in Metal Inert Gas Welding

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Chinese Journal of Mechanical Engineering 2012年第2期25卷 293-298页

作者： liu lijun LAN Hu ZHENG Hongyan JIAN Xiaoxia Ningbo Institute of Technology Zhejiang UniversityNingbo 315100China School of Material Science ＆ Engineering Harbin University of Science and TechnologyHarbin 150080China Rongcheng College Harbin University of Science and TechnologyRongcheng 264300China

Arc sound is well known as the potential and available resource for monitoring and controlling of the weld penetration status,which is very important to the welding process quality control,so any attentions have been paid to the relationships between the arc sound and welding *** non-linear mapping models correlating the arc sound to welding parameters have been established with the help of neural ***,the research of utilizing arc sound to monitor and diagnose welding process is still in its infancy.A self-made real-time sensing system is applied to make a study of arc sound under typical penetration status,including partial penetration,unstable penetration,full penetration and excessive penetration,in metal inert-gas（MIG） flat tailored welding with spray *** sound is pretreated by using wavelet de-noising and short-time windowing technologies,and its characteristics,characterizing weld penetration status,of time-domain,frequency-domain,cepstrum-domain and geometric-domain are ***,high-dimensional eigenvector is constructed and feature-level parameters are successfully fused utilizing the concept of primary principal component analysis（PCA）.Ultimately,60-demensional eigenvector is replaced by the synthesis of 8-demensional vector,which achieves compression for feature space and provides technical supports for pattern classification of typical penetration status with the help of arc sound in MIG welding in the future.

关键词： metal inert gas welding penetration arc sound feature extraction dimensionality reduction

Recovery of coupled networks after cascading failures

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Journal of Systems Engineering and Electronics 2018年第3期29卷 650-657页

作者： GAO Jiazi YIN Yongfeng FIONDELLA Lance liu lijun School of Reliability and Systems Engineering Beihang University Department of Electrical & Computer Engineering University of Massachusetts

With society＇s increasing dependence on critical infrastructure such as power grids and communications systems, the robustness of these systems has attracted significant *** of some nodes can trigger a cascading failure, which completely fragments the network, necessitating recovery efforts to improve robustness of complex systems. Inspired by real-world scenarios, this paper proposes repair models after two kinds of network failures, namely complete and incomplete collapse. In both models, three kinds of repair strategies are possible, including random selection（RS）, node selection based on single network node degree（SD）, and node selection based on double network node degree（DD）. We find that the node correlation in each of the two coupled networks affects repair efficiency. Numerical simulation and analysis results suggest that the repair node ratio and repair strategies may have a significant impact on the economics of the repair process. The results of this study thus provide insight into ways to improve the robustness of coupled networks after cascading failures.

关键词： networks reliability interdependent networks recovery strategy cascading failure

NUMERICAL VALIDATION OF COMPUTATIONAL MODEL FOR SHEET CAVITATING FLOWS

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Chinese Journal of Mechanical Engineering 2006年第1期19卷 45-49页

作者： LI Jun liu lijun FENG Zhenping School of Energy ＆ Power Engineering Xi＇ an Jiaotong University Xi＇ an 710049 China Research Institute for Applied Mechanics Kyushu University Fukuoka 816-8580 Japan

A computational modeling for the sheet cavitating flows is presented. The cavitation model is implemented in a viscous Navier-Stokes solver. The cavity interface and shape are determined using an iterative procedure matching the cavity surface to a constant pressure boundary. The pressure distribution, as well as its gradient on the wall, is taken into account in updating the cavity shape iteratively. Numerical computations are performed for the sheet cavitating flows at a range of cavitation numbers across the hemispheric headform/cylinder body with different grid numbers. The influence of the relaxation factor in the cavity shape updating scheme for the algorithm accuracy and reliability is conducted through comparison with other two cavity shape updating numerical schemes. The results obtained are reasonable and the iterative procedure of cavity shape updating is quite stable, which demonstrate the superiority of the proposed cavitation model and algorithms.

关键词： Sheet cavitation Liquid/vapor tracking method Numerical simulation

Trajectory tracking anti-disturbance control for unmanned aerial helicopter based on disturbance characterization index

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Control Theory and Technology 2023年第2期21卷 233-245页

作者： Linbo Chen Tao Li lijun liu Zehui Mao College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106JiangsuChina

This work studies the trajectory tracking control for unmanned aerial helicopter(UAH)system under both matched disturbance and mismatched ***,to tackle the strong coupling,an input-output feedback linearization method is utilized to simplify the nonlinear UAH ***,a set of finite-time disturbance observers(FTDOs)are proposed to estimate mismatched disturbances with their successive derivatives,which are utilized to design the feedforward controller via ***,as for matched disturbance,by defining the disturbance characterization index(DCI)to determine whether the disturbance is harmful or not for the UAH system,a feedback controller is proposed and a sufficient condition is established to ensure the convergence of the tracking ***,some numerical simulations and comparisons illustrate the validity and advantages of our control scheme.

关键词： Unmanned aerial helicopter(UAH) Trajectory tracking control Finite-time disturbance observer(FTDO) Backstepping control Disturbance characterization index(DCI)