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Resist-decreasing effects of rock bolts on strength of rock mass around roadway——insight from numerical modeling

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Mining Science and Technology 2009年第4期19卷 425-429页

作者： gao fu-qiang XIE Yao-she Mining and Designing Branch Central Coal Research Institute Beijing 100013 China Department of Earth Sciences Simon Fraser University Burnaby VSC2Z9 Canada School of Mines China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

To investigate the resist-decreasing effects of rock bolts on the strength of the rock mass around a roadway, a compara- tive study has been carded out using the numerical analysis code FLAC3D. An unsupported and a rock bolt supported model have been built for comparison. Two types of rock mass strength, the uniaxial compressive strength （UCS） and the wiaxial compressive strength （TCS） of rock mass have been obtained from each model, using a prepared Fish based on the Mohr-Coulomb criterion. The results indicate that when a roadway is excavated, both the UCS and TCS in a definite local rock mass around the roadway would inevitably decrease, no matter whether the roadway is supported or not. The major decreasing region did not settle in the middle of the roadway surface, but within a deeper horizon into the rock mass. The resist-decreasing effects of rock bolts both on the UCS and the TCS of rock mass around roadway are significant.

关键词： resist-decrease rock mass strength rock bolts numerical simulation

Intelligent modelling of clay compressibility using hybrid meta-heuristic and machine learning algorithms

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Geoscience Frontiers 2021年第1期12卷 441-452页

作者： Pin Zhang Zhen-Yu Yin Yin-fu Jin Tommy HTChan fu-Ping gao Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina School of Civil Engineering&Built Environment Science and Engineering FacultyQueensland University of Technology(QUT)BrisbaneQld4001Australia Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing100190China China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China

Compression index Ccis an essential parameter in geotechnical design for which the effectiveness of correlation is still a *** paper suggests a novel modelling approach using machine learning(ML)*** performance of five commonly used machine learning(ML)algorithms,***-propagation neural network(BPNN),extreme learning machine(ELM),support vector machine(SVM),random forest(RF)and evolutionary polynomial regression(EPR)in predicting Cc is comprehensively investigated.A database with a total number of 311 datasets including three input variables,*** void ratio e0,liquid limit water content wL,plasticity index Ip,and one output variable Cc is first *** algorithm(GA)is used to optimize the hyper-parameters in five ML algorithms,and the average prediction error for the 10-fold cross-validation(CV)sets is set as thefitness function in the GA for enhancing the robustness of ML *** results indicate that ML models outperform empirical prediction formulations with lower prediction *** yields the lowest error followed by BPNN,ELM,EPR and *** the ranges of input variables in the database are large enough,BPNN and RF models are recommended to predict ***,if the distribution of input variables is continuous,RF model is the best ***,EPR model is recommended if the ranges of input variables are *** predicted correlations between input and output variables using five ML models show great agreement with the physical explanation.

关键词： Compressibility Clays Machine learning Optimization Random forest Genetic algorithm

Resonant current in coupled inertial Brownian particles with delayed-feedback control

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Frontiers of physics 2017年第6期12卷 33-41页

作者： Tian-fu gao Zhi-Gang Zheng Jin-Can Chen College of Physical Science and Technology Shenyang Normal University Shenyang 110034 China College of Information Science and Engineering Huaqiao University Xiamen 361021 China Department of Physics Xiamen University Xiamen 361005 China

The transport of a walker in rocking feedback-controlled ratchets is investigated. The walker consists of two coupled ＂feet＂ that allow the interchange of the order of particles while the walker moves. In the underdamped case, tile deterministic dynamics of the walker in a tilted asymmetric ratchet with an external periodic force is considered. It is found that delayed feedback ratchets with a switching-on- and-off dependence of the states of the system can lead to absolute negative mobility. In such a novel phenomenon, the particles move against tile bias. Moreover, the walker can acquire a series of resonant steps for different values of the current. It is interesting to find that the resonant currents of the walker are induced by tile phase locked motion that corresponds to the synchronization of the motion with the change in the frequency of the external driving. These resonant steps can be well predicted in terms of time-space symmetry analysis, which is in good agreement with dynamics simulations. The transport performances can be optimized and controlled by suitably adjusting the parameters of tile delayed-feedback ratchets.

关键词： delayed-feedback control absolute negative mobility resonant steps phase locking

Haunted with and hunting for viruses

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Science China(Life Sciences) 2013年第8期56卷 675-677页

作者： George fu gao WU Ying Chinese Center for Disease Control and Prevention CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of Sciences Research Network of Immunity and Health Beijing Institutes of Life ScienceChinese Academy of Sciences

Early this year, a subtype influenza A virus （H7N9）, was found to cause severe human infections with a 29% case fatality rate （CFR）, making it a top-profile piece of news in the world （***）. The infection was shortly con- firmed to be related to live animal markets and poultry dealing , which led to a close-down of the markets and the outbreak has since been well controlled （***）.

关键词： A型流感病毒狩猎交易市场人类感染新闻网站 CFR 病死率家禽

Comparison of spatial-temporal distribution characteristics of water temperatures between Lancang River and Mekong River

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Chinese Science Bulletin 2007年第A02期52卷 141-147页

作者： ZHANG YiPing gao fu HE DaMing LI ShaoJuan Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming 650223 China Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China Asian International Rivers Center Yunnan University Kunming 650014 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

水温度(WT ) 是水身体物理性质的重要指示物之一。在河连续统在 WT 上理解空间时间的变化的特征将帮助开发合理 river-water-resource 利用，以避免可能的生态学危机，并且在深奥区域充分利用自然资源计划。作为在亚洲的最大的国际河连... 详细信息

水温度(WT ) 是水身体物理性质的重要指示物之一。在河连续统在 WT 上理解空间时间的变化的特征将帮助开发合理 river-water-resource 利用，以避免可能的生态学危机，并且在深奥区域充分利用自然资源计划。作为在亚洲的最大的国际河连续统， Lancang 湄公河河分区(作为更大的湄公河分区知道，公克) 成为了著名经济、政治、生态的自然领土。这研究检验了 Lancang 河水的空间时间的分发特征。温度，用从 11 的 WT 价值的观察数据，水文学在 1960 年代驻扎。而且， Yunjinghong 水文学之间的 WT 差别驻扎(在中国的一个代表性的车站) 并且 Chiang Saen 水文学车站(在泰国的一个代表性的车站) 被分析。结果显示了那：1 ) 水温度比上面的部分在河连续统的更低的部分是更高的。纬度变化是主要影响因素。这效果比在雨季在旱季是更明显的，在冬季更明显比在夏天，和平均最小的 WT 明显的更多比平均最大的 WT ， 2 )之间的 WT 差别上面并且河连续统的更低的部分在研究时期期间由于更低的部分( Chiang Saen 水文学车站)的上面的部分( Yunjinghong 水文学车站)和 WT 的明显的减少的 WT 的小增加是减少。因此， WT 的参数被纬度影响，并且Lancang湄公河河连续统躺在纵贯的方向因此热带水的动物例如热带水的鱼，不能在冬季季节在这河连续统的上面的部分幸存，当时在里面夏天季节，热带水的动物适当地游泳到上面的溪流。更低的湄公河河里的水温度被地区性的水温度和地区性的气候变化主要影响。

关键词：澜沧江湄公河水温分布情况

nsights into battles between Mycobacterium tuberculosis and macrophages

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Protein & Cell 2014年第10期5卷 728-736页

作者： Guanghua Xu Jing Wang George fu gao Cui Hua Liu CAS key Laboratory of Pathogenic Microbiology and Immunology Institute of Microbiology Chinese Academy of Sciences Beijing 100101. China School of Life Sciences Anhui University Hefei 230039 China

As the first line of immune defense for Mycobacterium tuberculosis （Mtb）, macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant since ancient times. Triggered upon Mtb infection, multiple cellular pathways in macrophages are activated to initiate a tailored immune response toward the invading pathogen and regulate the cellular fates of the host as well. Toll-like receptors （TLRs） expressed on macrophages can recognize pathopatterns （PAMPs） on Mtb and mediate the production of immune-regulatory cytokines such as tumor necrosis factor （TNF） and type I Interferons （IFNs）. In addition, Vitamin D receptor （VDR） and Vitamin D-1- hydroxylase are up-regulated in Mtb-infected macrophages, by which Vitamin D participates in innate immune respon- ses. The signaling pathways that involve TNF, type I IFNs and Vitamin D are inter-connected, which play critical roles in the regulation of necroptosis, apoptosis, and autophagy of the infected macrophages. This review article summarizes cur- rent knowledge about the interactions between Mtb and macrophages, focusing on cellular fates of the Mtb-infected macrophages and the regulatory molecules and cellular pathways involved in those processes.

关键词： Mycobacterium tuberculosis,macrophages necroptosis apoptosis autophagy tumornecrosis factor (TNF) type I Interl:erons (IFNs)

Numerical Analysis and Verification of the Gas Jet from Aircraft Engines Impacting a Jet Blast Deflector

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Chinese Journal of Mechanical Engineering 2018年第5期31卷 127-137页

作者： fu-Dong gao De-Xin Wang Hai-Dong Wang Ming-Ming Jia Department of Carrier Aviation Security and Station Management Naval Aeronautical University

The process of the gas jet from aircraft engines impacting a jet blast deflector is not only a complex fluid–solid coupling problem that is not easy to compute, but also a safety issue that seriously interferes with flight deck envi?ronment. The computational fluid dynamics(CFD) method is used to simulate numerically the impact e ect of gas jet from aircraft engines on a jet blast deflector by using the Reynolds?averaged Navier?Stokes(RANS) equations and turbulence models. First of all, during the pre?processing of numerical computation, a sub?domains hybrid meshing scheme is adopted to reduce mesh number and improve mesh quality. Then, four di erent turbulence models includ?ing shear?stress transport(SST) k-w, standard k-w, standard k-ε and Reynolds stress model(RSM) are used to compare and verify the correctness of numerical methods for gas jet from a single aircraft engine. The predicted values are in good agreement with the experimental data, and the distribution and regularity of shock wave, velocity, pressure and temperature of a single aircraft engine are got. The results show that SST k?w turbulence model is more suitable for the numerical simulation of compressible viscous gas jet with high prediction accuracy. Finally, the impact e ect of gas jet from two aircraft engines on a jet blast deflector is analyzed based on the above numerical method, not only the flow parameters of gas jet and the interaction regularity between gas jet and the jet blast deflector are got, but also the thermal shock properties and dynamic impact characteristics of gas jet impacting the jet blast deflector are got. So the dangerous activity area of crew and equipments on the flight deck can be predicted qualitatively and quantitatively. The proposed research explores out a correct numerical method for the fluid–solid interaction during the impact process of supersonic gas jet, which provides an e ective technical support for design, thermal ablation and structural damage analysis

关键词： Aircraft engine Gas jet Computational fluid dynamics Jet blast deflector Impact effect

Microstructures and Mechanical Property of MoSi2/TSi2(T=Cr,V,Nb,Ta,Ti)Two-Phase Alloys

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材料科学与工程学报 2000年第Z2期20卷 736-742页

作者： fu-gao Wei Department of Materials Science and Engineering Interdisciplinary Graduate School of Science and Engineering Tokyo Institute of Technology 4259 Nagatsuta Midori-ku Yokohama 226-8502 Japan

In order to improve the low temperature ductility and high temperature strength ofMoSi2 while keeping its superior high temperature oxidation resistance, the present work attempts to combine MoSi2with the C40 type disilicides of transition metals including Cr, V, Nb, Ta and Ti. The possibility of producing a thermally compatible composite of MoSi2 and the C40 disilicides is discussed by critical assessment of MoSi2-TSi2(T=Cr, V,Nb,Ta, Ti) pseudo-binary phase diagrams. Relative phase stability between the CIIb MoSi2 and the C40 TSi2 is investigated and lamellar MoSi2/TSi2 two-phase microstructures are obtained by appropriate choice of composition and heat-treament. Preliminary result on the microhardness of MoSi2/TSi2two-phase alloys is also discussed.

关键词： Phase stability phase diagram lamellar structure lattice parameter microhardness

FLOW-PIPE-SEEPAGE COUPLING ANALYSIS OF SPANNING INITIATION OF A PARTIALLY-EMBEDDED PIPELINE

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Journal of Hydrodynamics 2010年第4期22卷 478-487页

作者： gao fu-ping LUO Cheng-cai Key Laboratory for Hydrodynamics and Ocean Engineering Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China Centre for Offshore Foundation Systems The University of Western Australia Nedlands WA 6907 Australia

The initiation of pipeline spanning involves the coupling between the flow over the pipeline and the seepage-flow in the soil underneath the *** pipeline spanning initiation is experimentally observed and discussed in this *** is qualitatively indicated that the pressure-drop induced soil seepage failure is the predominant cause for pipeline spanning initiation.A flow-pipe-seepage sequential coupling Finite Element Method（FEM） model is proposed to simulate the coupling between the water flow-field and the soil seepage-field.A critical hydraulic gradient is obtained for oblique seepage failure of the sand in the direction tangent to the *** study is performed to investigate the effects of inflow velocity,pipe embedment on the pressure-drop,and the effects of soil internal friction angle and pipe embedment-to-diameter ratio on the critical flow velocity for pipeline spanning *** is indicated that the dimensionless critical flow velocity changes approximately linearly with the soil internal friction angle for the submarine pipeline partially-embedded in a sandy seabed.

关键词： submarine pipeline pipeline spanning seepage failure flow-pipe-seepage coupling