检索结果-南通市图书馆

Dynamic prediction of landslide life expectancy using ensemble system incorporating classical prediction models and machine learning

引用

Geoscience Frontiers 2024年第2期15卷 202-219页

作者： Lei-Lei Liu Hao-Dong Yin Ting Xiao Lei Huang Yung-Ming Cheng Key laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China College of Civil Engineering and Architecture Wenzhou UniversityWenzhou 325035China Key laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of Zhejiang Province Wenzhou 325035China Wenzhou Key laboratory of Traffic Piezoelectric Engineering Technology Wenzhou 325035China Zhejiang International Science and Technology Cooperation Base of Ultra-soft Soil Engineering and Smart Monitoring Wenzhou 325035China School of Civil Engineering Qingdao University of TechnologyQingdao 266033China

With the development of landslide monitoring system,many attempts have been made to predict landslide failure-time utilizing monitoring data of *** models(e.g.,Verhulst,GM(1,1),and Saito models)that consider the characteristics of landslide displacement to determine the failuretime have been investigated *** practice,monitoring is continuously implemented with monitoring data-set updated,meaning that the predicted landslide life expectancy(i.e.,the lag between the predicted failure-time and time node at each instant of conducting the prediction)should be re-evaluated with *** manner is termed“dynamic prediction”.However,the performances of the classical models have not been discussed in the context of the dynamic prediction *** this study,such performances are investigated firstly,and disadvantages of the classical models are then reported,incorporating the monitoring data from four real ***,a more qualified ensemble model is proposed,where the individual classical models are integrated by machine learning(ML)-based *** evaluate the quality of the models under the dynamic prediction,a novel indicator termed“discredit index(b)”is proposed,and a higher value of b indicates lower prediction *** is found that Verhulst and Saito models would produce predicted results with significantly higher b,while GM(1,1)model would indicate results with the highest mean absolute ***,the ensemble models are found to be more accurate and qualified than the classical ***,the performance of decision tree regression-based ensemble model is the best among the various ML-based ensemble models.

关键词： Dynamic prediction Landslide life expectancy Machine learning Ensemble system

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pattern Formation in the Turing-Hopf Codimension-2 Phase Space in a Reaction-Diffusion System

引用

Chinese physics Letters 2009年第2期26卷 180-183页

作者：元旭津邵昕廖慧敏欧阳颀 State key laboratory for Mesoscopic physics and School of physics Peking University Beijing 100871

We systematicaily investigate the behaviour of pattern formation in a reaction-diffusion system when the system is located near the Turing-Hopf codimension-2 point in phase space. The chloride-iodide-malonic acid （CIMA） reaction is used in this study. A phase diagram is obtained using the concentration of polyvinyl alcohol （PVA ） and malonic acid （MA） as control parameters. It is found that the Turing-Hopf mixed state appears only in a small vicinity near the codimension-2 point, and has the form of hexagonal pattern overlapped with anti-target wave; the boundary line separating the Taring state and the wave state is independent of the concentration of MA, only relies on the concentration of PVA. The corresponding numerical simulation using the Lengyel-Epstein （LE） model gives a similar phase diagram as the experiment; it reproduces most patterns observed in the experiment. However, the mixed state we obtain in simulation only appears in the anti-wave tip area, implying that the 3-D effect in the experiments may change the pattern forming behaviour in the codimension-2 regime.

关键词： PATTERN formation (Physical sciences) REACTION-diffusion equations -- Numerical solutions CHEMICAL systems MALONIC acid POLYVINYL alcohol COMPUTER simulation PHASE diagrams MATHEMATICAL models

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Lengthening the Lifetime of Long Plasma Channel in Air Generated by Femtosecond Laser Pulse

引用

Chinese physics Letters 2006年第6期23卷 1482-1485页

作者：陈笑蒋红兵龚旗煌 State Key laboratory for Mesoscopic physics and Department of physics Peking University Beijing 100871

We theoretically investigate the lifetime of self-guided plasma channel in air by launching an auxiliary delayed long-pulsed laser beam following an ultrashort laser. A detailed model makes the electron-ion recombination, the attachment of electrons on neutral particles, and particularly the impact ionization and electron-detachment mechanism incorporate. The calculated results show that the temporal evolution of electron density is greatly flattened and broadened. When the auxiliary laser intensity exceeds the threshold 3.32 × 10^4 Wcm^-2, the channel lifetime is distinctly prolonged from nanosecond to microsecond, or even longer due to the electrical field enhancement. Furthermore, with the laser intensity up to 109 Wcm^-2, the impact ionization overwhelms the detachment in effect. Thus, it is an effective way to extend the channel lifetime and provides a real opportunity for applications.

关键词： ELECTRICAL-CONDUCTIVITY CONICAL EMISSION

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Retrieval of original signals for superconducting quantum interference device operating in flux locked mode

引用

Chinese physics B 2015年第4期24卷 421-424页

作者：刘当婷田野赵士平任育峰陈赓华 Beijing National laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences

We discuss a simple relation between the input and output signals of a superconducting quantum interference device magnetometer operating in flux locked mode in a cosine curve approximation. According to this relation, an original fast input signal can be easily retrieved from its distorted output response. This technique can be used in some areas such as sensitive and fast detection of magnetic or metallic grains in medicine and food security checking.

关键词： SQUID magnetometer signal retrieval

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Neutron matter properties from relativistic Brueckner-Hartree-Fock theory in the full Dirac space

引用

Science China(physics,Mechanics & Astronomy) 2023年第4期66卷 67-74页

作者： Xiaoying Qu Hui Tong Chencan Wang Sibo Wang School of Mechatronics Engineering Guizhou Minzu UniversityGuiyang 550025China College of physics and Materials Science Tianjin Normal UniversityTianjin 300387China Strangeness nuclear physics laboratory RIKEN Nishina CenterWako 351-0198Japan School of physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Department of physics Chongqing UniversityChongqing 401331China

A novel description of the strongly interacting pure neutron matter(PNM)was carried out by the relativistic Brueckner-HartreeFock(RBHF)theory in the full Dirac space with Bonn A *** scalar and vector components of the single-particle potentials are shown as functions of the momentum and the density,and are compared with the results obtained by the RBHF calculations in the Dirac space without negative-energy *** benchmarking the binding energies of PNM to those predicted by several ab initio methods in the nonrelativistic framework with two-and three-body forces,we find our results are softer than those from the Brueckner-Hartree-Fock theory with the inclusion of three-body force,and in harmony with the ones obtained by the Monte Carlo method and many-body perturbation theory within *** addition,the equation of state for neutron star matter is consistent with the constraints from multi-messenger astrophysical observation and heavy-ion collision *** tidal deformabilities of a binary neutron star system are calculated and found consistent with the constraints from GW170817.

关键词： neutron matter properties relativistic Brueckner-Hartree-Fock full Dirac space

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characterization,spectroscopic investigation of defects by positron annihilation,and possible application of synthesized PbO nanoparticles

引用

Chinese physics B 2021年第2期30卷 400-407页

作者： Sk Irsad Ali Anjan Das Apoorva Agrawal Shubharaj Mukherjee Maudud Ahmed P M G Nambissan Samiran Mandal Atis Chandra Mandal Department of physics University of BurdwanGolapbagBurdwan 713104West BengalIndia Department of physics A.P.C.Roy Government CollegeSiliguriDarjeeling 734010West BengalIndia Applied nuclear physics Division Saha Institute of Nuclear Physics1/AF BidhannagarKolkata 700064India Department of physics Government General Degree College at PedongKalimpong 734311West BengalIndia

Nanocrystalline samples of highly pure lead oxide were prepared by the sol-gel route of synthesis.X-ray diffraction and transmission electron microscopic techniques confirmed the nanocrystallinity of the samples,and the average sizes of the crystallites were found within 20 nm to 35 *** nanocrystallites exhibited specific anomalous properties,among which a prominent one is the increased lattice parameters and unit cell *** optical band gaps also increased when the nanocrystallites became smaller in *** latter aspect is attributable to the onset of quantum confinement effects,as seen in a few other metal oxide *** annihilation was employed to study the vacancy type defects,which were abundant in the samples and played crucial roles in modulating their *** defect concentrations were significantly larger in the samples of smaller crystallite *** results suggested the feasibility of tailoring the properties of lead oxide nanocrystallites for technological applications,such as using lead oxide nanoparticles in batteries for better performance in discharge rate and *** also provided the physical insight into the structural build-up process when crystallites were formed with a finite number of atoms,whose distributions were governed by the site stabilization energy.

关键词： lead oxide nanocrystals positron annihilation sol-gel processes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New layered metal oxides as positive electrode materials for room-temperature sodium-ion batteries

引用

Chinese physics B 2015年第3期24卷 10-13页

作者：穆林沁胡勇胜陈立泉 Beijing National laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of Sciences

In order to achieve better Na storage performance, most layered oxide positive electrode materials contain toxic and expensive transition metals Ni and/or Co, which are also widely used for lithium-ion batteries. Here we report a new quaternary layered oxide consisting of Cu, Fe, Mn, and Ti transition metals with O3-type oxygen stacking as a positive electrode for room-temperature sodium-ion batteries. The material can be simply prepared by a high-temperature solidstate reaction route and delivers a reversible capacity of 94 m Ah/g with an average storage voltage of 3.2 V. This paves the way for cheaper and non-toxic batteries with high Na storage performance.

关键词： layered oxides positive electrode sodium-ion battery energy storage

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Shear Banding Driven by Electric Field and Shear Flow

引用

Chinese physics Letters 2013年第9期30卷 80-84页

作者： ZHENG Jie FU Wei-Juan ZHOU Lu-Wei State Key laboratory of Surface physics and Department of PhysicsFudan UniversityShanghai 200433

The shear banding is explored in a granular suspension driven by electric field and shear *** find that,given an imposed electric field,there is a critical shear rate determining whether shear banding emerges.A phase diagram of shear banding and fluidization is constructed by using the present experimental *** evolution in different shear banding phases constitutes an apparent shear thinning phenomenon,probably reflecting an underlying perspective of shear *** the two-phase model,combining with mean field approach and the Onsager least dissipation principle,we give a qualitative explanation of our experimental *** results suggest that the stress heterogeneity plays a crucial role for the physical origin of shear banding in this system.

关键词： flow. Shear qualitative

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Significant effect of electron transfer between current collector and active material on high rate performance of Li_4Ti_5O_(12)

引用

Chinese physics B 2011年第11期20卷 9-12页

作者：潘慧霖胡勇胜李泓陈立泉 Beijing National laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of Sciences

The rate and cycling performances of the electrode materials are affected by many factors in a practical complicated electrode process. Learning about the limiting step in a practical electrochemical reaction is very important to effectively improve the electrochemical performances of the electrode materials. Li4Ti5O12, as a zero-strain material, has been considered as a promising anode material for long life Li-ion batteries. In this study, our results show that the Li4Ti5O12 pasted on Cu or graphite felt current collector exhibits unexpectedly higher rate performance than on A1 current collector. For Li4Ti5O12, the electron transfer between current collector and active material is the critical factor that affects its rate and cycling performances.

关键词： Li4Ti5O12 current collector electron transfer Li-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Temperature-driven spin reorientation transition of magnetron sputtered nickel thin film

引用

Chinese physics B 2008年第9期17卷 3495-3498页

作者：宋小会张殿琳 Beijing National laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of Sciences

The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si （111） systems has been studied. The relationship between ac initial susceptibility and temperature of nickel films with different thicknesses shows that the magnetization orientation changes from in-plane to out-of-plane with the increase of temperature. The temperature dependence of mugnetoelastic, magneto-crystalline, and magnetostatic anisotropies determines the direction of the reorientation transition. The temperature-driven spin reorientation transition is supported by Hall coefficient measurements which show that its temperature dependence is similar to that of susceptibility.

关键词： magnetic anisotropy spin reorientation transition ac initial susceptibility

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：