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Distribution law and susceptibility of geohazards across a gradient belt of the Western Sichuan Plateau
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作者 LI Tianbin WANG Jianfeng +4 位作者 HE Chaoyang MENG Lubo LI Chaofei MA Junjie WEI Daqiang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1849-1867,共19页
Across a gradient belt of the Western Sichuan Plateau,geohazards have seriously limited economic and social development.According to incomplete statistics,15,673 geohazards have been recorded in the study area.In orde... Across a gradient belt of the Western Sichuan Plateau,geohazards have seriously limited economic and social development.According to incomplete statistics,15,673 geohazards have been recorded in the study area.In order to mitigate the threat of geohazards to human engineering activities in the region,an overall understanding of the distribution pattern of geohazards and susceptibility assessment are necessary.In this paper,a gradient belt of the Western Sichuan Plateau and its zoning criteria were defined.Subsequently,on the basis of relief amplitude,distance to faults,rainfall,and human activities,three indicators of endogenic process were introduced:Bouguer gravity anomaly gradient,vertical deformation gradient,and horizontal deformation gradient.Thereafter,the distribution patterns of geohazards were investigated through mathematical statistics and ArcGIS software.By randomly selecting 10,449 hazards,a geohazard susceptibility map was generated using the Information Value(IV)model.Finally,the IV model was validated against 5224 hazards using the Area Under Curve(AUC)method.The results show that 47.6%of the geohazards were distributed in the zone of steep slope.Geohazards showed strong responses to distance to faults,human activities,and annual rainfall.The distribution of geohazards in the gradient belt of the Western Sichuan Plateau is more sensitive to vertical internal dynamics factors(such as vertical deformation gradient and Bouguer gravity anomaly gradient)without any apparent sensitivity to horizontal internal dynamics factors.The areas of high and very-high risk account for up to 32.22%,mainly distributed in the Longmenshan and Anning River faults.According to the AUC plot,the success rate of the IV model for generating the susceptibility map is 76%.This susceptibility map and geohazard distribution pattern can provide a reference for geological disaster monitoring,preparation of post-disaster emergency measures,and town planning. 展开更多
关键词 Gradient belt GEOHAZARDS Distribution law Bouguer Gravity anomaly gradient Vertical deformation gradient SUSCEPTIBILITY
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Hydrocarbon accumulation and orderly distribution of whole petroleum system in marine carbonate rocks of Sichuan Basin,SW China 被引量:1
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作者 GUO Xusheng HUANG Renchun +3 位作者 ZHANG Dianwei LI Shuangjian SHEN Baojian LIU Tianjia 《Petroleum Exploration and Development》 SCIE 2024年第4期852-869,共18页
Based on the situation and progress of marine oil/gas exploration in the Sichuan Basin,SW China,the whole petroleum system is divided for marine carbonate rocks of the basin according to the combinations of hydrocarbo... Based on the situation and progress of marine oil/gas exploration in the Sichuan Basin,SW China,the whole petroleum system is divided for marine carbonate rocks of the basin according to the combinations of hydrocarbon accumulation elements,especially the source rock.The hydrocarbon accumulation characteristics of each whole petroleum system are analyzed,the patterns of integrated conventional and unconventional hydrocarbon accumulation are summarized,and the favorable exploration targets are proposed.Under the control of multiple extensional-convergent tectonic cycles,the marine carbonate rocks of the Sichuan Basin contain three sets of regional source rocks and three sets of regional cap rocks,and can be divided into the Cambrian,Silurian and Permian whole petroleum systems.These whole petroleum systems present mainly independent hydrocarbon accumulation,containing natural gas of affinity individually.Locally,large fault zones run through multiple whole petroleum systems,forming a fault-controlled complex whole petroleum system.The hydrocarbon accumulation sequence of continental shelf facies shale gas accumulation,marginal platform facies-controlled gas reservoirs,and intra-platform fault-and facies-controlled gas reservoirs is common in the whole petroleum system,with a stereoscopic accumulation and orderly distribution pattern.High-quality source rock is fundamental to the formation of large gas fields,and natural gas in a whole petroleum system is generally enriched near and within the source rocks.The development and maintenance of large-scale reservoirs are essential for natural gas enrichment,multiple sources,oil and gas transformation,and dynamic adjustment are the characteristics of marine petroleum accumulation,and good preservation conditions are critical to natural gas accumulation.Large-scale marginal-platform reef-bank facies zones,deep shale gas,and large-scale lithological complexes related to source-connected faults are future marine hydrocarbon exploration targets in the Sichuan Basin. 展开更多
关键词 Sichuan Basin margin oil/gas whole petroleum system carbonate hydrocarbon accumulation hydrocarbon distribution law hydrocarbon exploration target
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Plastic zone distribution laws and its types of surrounding rock in large-span roadway 被引量:14
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作者 Li Chong Xu Jinhai +1 位作者 PanJianzhong Ma Chao 《International Journal of Mining Science and Technology》 2012年第1期23-28,共6页
In order to study the distribution laws and types of plastic zone of surrounding rock in large-span roadway, we analyzed the distribution laws with different spans and lateral pressures using FLAC3D numerical calcu- l... In order to study the distribution laws and types of plastic zone of surrounding rock in large-span roadway, we analyzed the distribution laws with different spans and lateral pressures using FLAC3D numerical calcu- lation software. Based on the roadway support difficulty and distribution laws of the plastic zone of sur- rounding rock, we defined the large-span roadway and classified the types of large-span rectangular roadways. As a result, the distribution laws of the plastic zone on surrounding rock in a rectangular roadway with different spans and lateral pressures were obtained. The results show that the area of the plastic zone on surrounding rock increased with the increase of the spans and lateral pressures, and the plastic zone was symmetrical to the center line of roadway. At λ=0.5, 1.0, 1.5, and 2.0, the plastic zone presented "addle- shape" distribution, "ellipse" distribution, "thin and high" distribution and "inverse trapezium" distribu- tion, respectively. In addition, we classified the roadways into four types according to the different lateral pressures and spans, including small-span, moderate-span, large-span and extreme-large-span roadways. 展开更多
关键词 Large-span roadway Plastic zone Distribution law TYPE
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Three-dimensional impact angle constrained distributed cooperative guidance law for anti-ship missiles 被引量:7
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作者 LI Wei WEN Qiuqiu +1 位作者 HE Lei XIA Qunli 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第2期447-459,共13页
This paper investigates the problem of distributed cooperative guidance law design for multiple anti-ship missiles in the three-dimensional(3-D)space hitting simultaneously the same target with considering the desired... This paper investigates the problem of distributed cooperative guidance law design for multiple anti-ship missiles in the three-dimensional(3-D)space hitting simultaneously the same target with considering the desired terminal impact angle constraint.To address this issue,the problem formulation including 3-D nonlinear mathematical model description,and communication topology are built firstly.Then the consensus variable is constructed using the available information and can reach consensus under the proposed acceleration command along the line-of-sight(LOS)which satisfies the impact time constraint.However,the normal accelerations are designed to guarantee the convergence of the LOS angular rate.Furthermore,consider the terminal impact angle constraints,a nonsingular terminal sliding mode(NTSM)control is introduced,and a finite time convergent control law of normal acceleration is proposed.The convergence of the proposed guidance law is proved by using the second Lyapunov stability method,and numerical simulations are also conducted to verify its effectiveness.The results indicate that the proposed cooperative guidance law can regulate the impact time error and impact angle error in finite time if the connecting time of the communication topology is longer than the required convergent time. 展开更多
关键词 distributed cooperative guidance law impact angle constraint communication topology nonsingular terminal sliding mode(NTSM)control finite time convergent
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Power Law Distributions in the Experiment for Adjustment of the Ion Source of the NBI System
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作者 韩筱璞 胡纯栋 《Plasma Science and Technology》 SCIE EI CAS CSCD 2005年第6期3102-3104,共3页
The experiential adjustment process in an experiment on the ion source of the neutral beam injector system for the HT-7 Tokamak is reported in this paper. With regard to the data obtained in the same condition, in arr... The experiential adjustment process in an experiment on the ion source of the neutral beam injector system for the HT-7 Tokamak is reported in this paper. With regard to the data obtained in the same condition, in arranging the arc current intensities of every shot with a decay rank, the distributions of the arc current intensity correspond to the power laws, and the distribution obtained in the condition with the cryo-pump corresponds to the double Pareto distribution. Using the similar study method, the distributions of the arc duration are close to the power laws too. These power law distributions are formed rather naturally instead of being the results of purposeful seeking. 展开更多
关键词 power law distribution adjustment experiment ion source double Pareto distribution
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A Theoretical Explanation of the Causes of Popular Elements and Income Power Law Distribution Based on Data Analysis
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作者 DONG Chun 《Psychology Research》 2022年第6期362-368,共7页
The known statistical data show that the distribution of popular elements and people’s income presents the characteristics of power law distribution.At present,the explanation for this phenomenon is mostly through th... The known statistical data show that the distribution of popular elements and people’s income presents the characteristics of power law distribution.At present,the explanation for this phenomenon is mostly through the“rich get richer”theory,but the author believes that this theory has major flaws and fails to provide a reasonable explanation for many phenomena.Therefore,the author expands some empirical and recognized theories in a similar direction in logic,and derives a logical mathematical model through the derivation of mathematical formulas,so as to explain the phenomenon that the distribution of popular elements and people’s income presents a power-law distribution.Then,by analyzing various characteristics of social networks and comparing them with some phenomena in nature,the conclusion can be extended to all self-organizing groups in nature. 展开更多
关键词 social network POPULARITY INCOME power law distribution
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Power Law for the Rates of Different Numbers of Chronic Diseases among Elderly Chinese People
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作者 Handong Li Ping Gao 《Open Journal of Statistics》 2016年第6期1155-1165,共12页
Chronic disease is an important factor that affect the health of elderly people. We analyzed the 2006 and 2010 data from the Chinese Urban and Rural Elderly Population Surveys, which are nationally representative surv... Chronic disease is an important factor that affect the health of elderly people. We analyzed the 2006 and 2010 data from the Chinese Urban and Rural Elderly Population Surveys, which are nationally representative surveys of elderly people aged 60 years and above. We found that there existed a typical power-law distribution for the rates of different numbers of chronic diseases among elderly Chinese people. A Kolmogorov-Smirnov test indicated that the result was robust, and the power exponents were approximately ?2.5. In addition, a paired t-test was conducted, which demonstrated that the rates of different numbers of chronic diseases did not have significant urban-rural differences, time differences or gender differences. 展开更多
关键词 Chronic Disease Power law Distribution Elderly People Kolmogorov-Smirnov Test (K-S Test) Paired T-Test
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Study on the Geohazard Distribution Laws and Hazard-Causing Mechanism in Menghai County of Yunnan Province
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作者 Mingchang Hei Xuegang Dai +2 位作者 Xukai Yuan Jia Xiong Xiaobo Kang 《Journal of World Architecture》 2021年第5期14-21,共8页
The study area is located at the southwest border of Yunnan Province and the southward extended part of Nushan Mountain,with complex and fragile geo-environmental conditions.Deep geological survey and mathematical ana... The study area is located at the southwest border of Yunnan Province and the southward extended part of Nushan Mountain,with complex and fragile geo-environmental conditions.Deep geological survey and mathematical analytical investigation on the geohazard distribution and hazard-causing mechanisms in this area were carried out in this study.The results revealed that:(1)The development of geohazards was affected differently by difierent slope shapes,slope structures and elevations;(2)Most of the geohazards were developed in medium shallow cut ridge-like medium-height mountainous geomorphological region and shallow cut steamed bun-like low and medium-height mountainous geomorphological region,and they were relatively concentrated on tectonic zones like fault zones;(3)The slopes formed by loose earth piling up on the surface of Indo-Chinese magmatic rock and Lancang Group metamorphic rock formations were most prone to slope instability and even landslide.The deep study on the geohazard distribution and hazard-causing mechanisms can provide geoscientific basis and reference for the prevention and mitigation work of geohazards under similar geo-environmental conditions. 展开更多
关键词 Menghai County GEOHAZARD Distribution law Hazard-causing mechanism
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Low complexity joint source-channel decoding for transmission of wavelet compressed images
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作者 殷玮玮 梅中辉 吴乐南 《Journal of Southeast University(English Edition)》 EI CAS 2006年第2期148-152,共5页
To utilize residual redundancy to reduce the error induced by fading channels and decrease the complexity of the field model to describe the probability structure for residual redundancy, a simplified statistical mode... To utilize residual redundancy to reduce the error induced by fading channels and decrease the complexity of the field model to describe the probability structure for residual redundancy, a simplified statistical model for residual redundancy and a low complexity joint source-channel decoding(JSCD) algorithm are proposed. The complicated residual redundancy in wavelet compressed images is decomposed into several independent 1-D probability check equations composed of Markov chains and it is regarded as a natural channel code with a structure similar to the low density parity check (LDPC) code. A parallel sum-product (SP) and iterative JSCD algorithm is proposed. Simulation results show that the proposed JSCD algorithm can make full use of residual redundancy in different directions to correct errors and improve the peak signal noise ratio (PSNR) of the reconstructed image and reduce the complexity and delay of JSCD. The performance of JSCD is more robust than the traditional separated encoding system with arithmetic coding in the same data rate. 展开更多
关键词 joint source-channel decoding sum-product algorithm generalized distribution law wavelet compressed image
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The occurrences and geochemical characteristics of thorium in iron ore in the Bayan Obo deposit, Northern China 被引量:1
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作者 Xiaozhi Hou Zhanfeng Yang +1 位作者 Zhenjiang Wang Wencai Wang 《Acta Geochimica》 EI CAS CSCD 2020年第1期139-154,共16页
The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analy... The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis,field emission scanning electron microscopy,energy dispersive spectrometer,and automatic mineral analysis software.Results identified that 91.69%of ThO2 in the combined samples was mainly distributed in rare earth minerals(bastnaesite,huanghoite,monazite;56.43%abundance in the samples),iron minerals(magnetite,hematite,pyrite;20.97%),niobium minerals(aeschynite;14.29%),and gangue minerals(aegirine,riebeckite,mica,dolomite,apatite,fluorite;4.22%).An unidentified portion(4.09%)of ThO2 may occur in other niobium minerals(niobite,ilmenorutile,pyrochlore).Only a few independent minerals of thorium occur in the iron ore samples.Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution.Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism,which provided source material and favorable porosity for hydrothermal mineralization.Trace elements such as Sc,Nb,Zr,and Ta have higher correlation coefficients with thorium,which resulted from being related to the relevant minerals formed during thorium mineralization.In addition,correlation analysis of ThO2 and TFe,and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals,and the main occurrence minerals of ThO2 were closely related to iron ore types. 展开更多
关键词 THORIUM Occurrence state Distribution law Geochemical characteristics Iron ore Bayan Obo deposit
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Balmer H_α,H_β and H_γ Spectral Lines Intensities in High-Power RF Hydrogen Plasmas 被引量:1
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作者 王松柏 雷光玖 +1 位作者 刘东平 杨思泽 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第3期219-222,共4页
Hα(Balmer-alpha), Hβ (Balmer-beta) and Hγ (Balmer-gamma) spectral line inten- sities in atomic hydrogen plasma are investigated by using a high-power RF source. The intensities of the Hα, Hβ and Hγ spectra... Hα(Balmer-alpha), Hβ (Balmer-beta) and Hγ (Balmer-gamma) spectral line inten- sities in atomic hydrogen plasma are investigated by using a high-power RF source. The intensities of the Hα, Hβ and Hγ spectral lines are detected by increasing the input power (0-6 kW) of ICPs (inductively coupled plasmas). With the increase of net input power, the intensity of Hα im- proves rapidly (0-2 kW), and then reaches its dynamic equilibrium; the intensities of Hβ can be divided into three processes: obvious increase (0-2 kW), rapid increase (2-4 kW), almost constant (4-6 kW); while the intensities of Hγ increase very slowly. The energy levels of the excited hydro- gen atoms and the splitting energy levels produced by an obvious Stark effect play an important role in the results. 展开更多
关键词 Keywords: high-power RF (radio frequency) source ICPs (inductively coupled plasmas) and spectral lines intensity Boltzmann distribution law Stark effect transitionprobability
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Evolution of two properties for scale-free network 被引量:1
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作者 Li Shouwei Qian Xingsan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第3期535-540,共6页
Fitness of node can denote its competing power and clustering denotes the transitivity of network. Because the fitness of node is uncertain or fuzzy in some social networks, an explicit form of the degree distribution... Fitness of node can denote its competing power and clustering denotes the transitivity of network. Because the fitness of node is uncertain or fuzzy in some social networks, an explicit form of the degree distribution on fuzzy fitness is derived within a mean field approach. It is a weighted sum of different fuzzy fitness. It can be found that the fuzzy fitness of nodes may lead to multiscaling. Moreover, the clustering coefficient of node decays as power law and clustering coefficient of network behavior not-decrease-but-increase’ phenomenon after some time. Some computer simulation results of these models illustrate these analytical results. 展开更多
关键词 fuzzy fitness clustering coefficient power law distribution scale-free.
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Landslide and Rockfall Distribution by Reservior of Stepped Hydropower Station in the Jinsha River 被引量:1
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作者 LI Yong FAN Xiaoyi CHENG Genwei 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第4期801-805,共5页
The landslides and rockfalls were studied in this paper from Xiangjiaba to Baihetan in the lower reach of Jinsha river. Their volume, distribution density and landslide index were studied which indicated that there ex... The landslides and rockfalls were studied in this paper from Xiangjiaba to Baihetan in the lower reach of Jinsha river. Their volume, distribution density and landslide index were studied which indicated that there existed close relationships between landslides and rockfalls and geological structure, stratum. The fold and faultage influenced on the stability of slope and offered the geological condition to landslides and rockfalls. The physiognomy controlled their distribution. Slope angles of landslides were 10 °-50°and slope angles of rockfalls were mainly 35°-50° in the valley in the studied area. The results indicated the geology and physiognomy of distribution area of the landslides and rockfalls in the studied area. They offered the theoretical foundation to prevent and cure geological disaster and protect the water power engineering. 展开更多
关键词 lower reach of Jinsha River reservoir area landslide and rockfall distribution characteristics and laws
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Study on numerical simulation of organic pollutant transport in groundwater northwest of Laixi 被引量:2
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作者 ZHU Heng-hua JIA Chao +2 位作者 XU Yu-liang YU Ze-min YU Wei-jiang 《Journal of Groundwater Science and Engineering》 2018年第4期293-305,共13页
The construction and hydrogeological area in the low hill, which is northwest of Laixi City and in the east of Shandong Province more precisely, is one of Dagu River's groundwater source. Regarding COD as the typi... The construction and hydrogeological area in the low hill, which is northwest of Laixi City and in the east of Shandong Province more precisely, is one of Dagu River's groundwater source. Regarding COD as the typical pollutant according to general situation of groundwater pollution in aforementioned area, a three-dimensional advection-dispersion model was established to simulate the transport of organic pollutants under two accident conditions. In addition, the effect of corresponding dispersity was analyzed. The results show that COD transport is mainly in accordance with the direction of groundwater flow, pollutant concentration and its gradient as well as the rule of narrower pollution range in deeper stratum. Moreover, COD is mainly transported and diffused in groundwater of sandy soil in the first and second layers. However, under accident condition II, the pollutant concentration begins to decay gradually after its transport and diffusion tends to be stable. Besides, in terms of dominance, dispersion is to transverse transport of pollutants what advection is to longitudinal transport. If considering random dispersion, the final results see higher peak concentration of COD and longer transverse distance from pollution center compared to transport route. What's more, the pollution plume changes and concentration isocline becomes slightly irregular. 展开更多
关键词 COD Advection-dispersion model law of transport and distribution DISPERSIVITY
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Thermodynamic properties of a finite Bose gas in a harmonic trap
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作者 王建辉 马永利 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第5期78-84,共7页
We have investigated the thermodynamic behaviour of ideal Bose gases with an arbitrary number of particles confined in a harmonic potential. By taking into account the conservation of the total number N of particles a... We have investigated the thermodynamic behaviour of ideal Bose gases with an arbitrary number of particles confined in a harmonic potential. By taking into account the conservation of the total number N of particles and using a saddle-point approximation, we derive analytically the simple explicit expression of mean occupation number in any state of the finite system. The temperature dependence of the chemical potential, specific heat, and condensate fraction for the trapped finite-size Bose system is obtained numerically. We compare our results with the usual treatment which is based on the grand canonical ensemble. It is shown that there exists a considerable difference between them at sufficiently low temperatures, especially for the relative small numbers of Bose atoms. The finite-size scaling at the transition temperature for the harmonically trapped systems is also discussed. We find that the scaled condensate fractions for various system sizes and temperatures collapse onto a single scaled form. 展开更多
关键词 trapped finite bosons simple explicit distribution law thermodynamics finite-size scaling
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Size Distribution of Submarine Landslides Along the Middle Continental Slope of the East China Sea
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作者 HU Guanghai YAN Tong +2 位作者 LIU Zhenxia Maarten Vanneste DONG Lifeng 《Journal of Ocean University of China》 SCIE CAS 2009年第4期322-326,共5页
This paper investigates the size distribution of submarine landslides on the middle continental slope of the East China Sea (ECS) using the size of the landslide source regions. Geomorphometric mapping is used to iden... This paper investigates the size distribution of submarine landslides on the middle continental slope of the East China Sea (ECS) using the size of the landslide source regions. Geomorphometric mapping is used to identify 102 mass movements from multibeam bathymetric data and to extract morphological information about the head scarps and side walls. These mass movements have areas ranging between 0.06 km2 and 15.51 km2 and volumes between 0.002 km3 and 2 km3. The area vs volume relationship of these failure scarps is approximately linear, suggesting a fairly uniform failure thickness in each event with scarce deep excavating landslides. The cumulative area distribution of the slope failures can be described by an inverse power law. The submarine landslides on the mid-ECS continental slope could be considered as a large-scale self-organizing system because they have the characteristics of a dissipative system in a critical state. 展开更多
关键词 MULTIBEAM power law distribution submarine geomorphology self-organizing criticality East China Sea
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Approach in High Precision Topic-Specific Resource Discovery on the Web
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作者 YeWei-guo LuZheng-ding 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第1期41-45,共5页
The Internet presents numerous sources of useful information nowadays. However, these resources are drowning under the dynamic Web, so accurate finding user-specific information is very difficult. In this paper we dis... The Internet presents numerous sources of useful information nowadays. However, these resources are drowning under the dynamic Web, so accurate finding user-specific information is very difficult. In this paper we discuss a Semantic Graph Web Search (SGWS) algorithm in topic-specific resource discovery on the Web. This method combines the use of hyperlinks, characteristics of Web graph and semantic term weights. We implement the algorithm to find Chinese medical information from the Internet. Our study showed that it has better precision than traditional IR (Information Retrieval) methods and traditional search engines. Key words HITS - evolution web graph - power law distribution - context analysis CLC number TP 391 - TP 393 Foundation item: Supported by the National High-Performance Computation Fund (00303)Biography: Ye Wei-guo (1970-), male, Ph. D candidate, research direction: Web information mining, network security, artificial intelligence. 展开更多
关键词 HITS evolution web graph power law distribution context analysis
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Influence of Oscillation Frequency of a Sieve on the Screening Process for a Conical Sieve with Oscillatory Circular Motion
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作者 Gh. Voicu D. Stoica N. Ungureanu 《Journal of Agricultural Science and Technology(B)》 2011年第8期1224-1231,共8页
Removal of foreign bodies from seed mixtures, or their calibration for use as planting material, as well as fraction classification of granular materials requires screening surfaces with vibratory motion. This paper p... Removal of foreign bodies from seed mixtures, or their calibration for use as planting material, as well as fraction classification of granular materials requires screening surfaces with vibratory motion. This paper presents some aspects on the working process of a sieve, made of perforated sheet and having an outer conical surface with oscillatory circular motion (alternative) on the horizontal. Results are presented for some experimental researches on the movement of material on the sieve, for various kinematical parameters of the sieve (amplitude and oscillation frequency). A conical sieve, suspended at the upper and lower in three points, was tested for screening of rapeseeds in order to estimate the influence of oscillation frequency on the screening process. Curves were drawn for separation intensity on the sieve generating line, and by regression analysis with normal distribution law were determined the equation coefficients and the correlation with experimental data. Movement of material on the sieve and its working process, in general, was appreciated by means of the peak position of distribution curve depending on the oscillation frequency of the sieve, considering that the normal distribution law correlates very well the data obtained by experiments. 展开更多
关键词 Grain sieving conical sieve oscillatory circular motion oscillation frequency normal distribution law.
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Discussion on the relationship between longitudinal cracks and alignment of subgrade in permafrost regions
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作者 AnHua Xu 《Research in Cold and Arid Regions》 2011年第2期132-136,共5页
At present, embankment longitudinal cracks are a major problem in highways through permafrost regions, and seriously affect traffic safety and the normal operations of the highway. In the past, roadbed height in perma... At present, embankment longitudinal cracks are a major problem in highways through permafrost regions, and seriously affect traffic safety and the normal operations of the highway. In the past, roadbed height in permafrost regions was relatively low, and embankment cracks were rare and did not affect traffic safety. Thus, highway designers and researchers paid little attention to this problem, and they knew very little about distribution laws and mechanism of embankment longitudinal cracks. Due to this lack of knowledge, there is no uniform opinion on this problem, making it difficult to find measures that will mediate the impact of longi- tudinal crocks. Temperature is a major factor that affects and controls embankment stability in permafrost regions, especially in ice-rich and high-temperature regions, and solar radiation is the principal factor that determines surface temperatures. Under higher embankment, the difference of temperature will be larger between a sunny slope and a shady slope. Hence, the probability for longitudinal cracks generation is higher. In this paper, a survey and analysis of longitudinal cracks along the Qinghai-Tibet Highway were carried out. The longitudinal cracks are found to be related to the road strikes. Solar radiation is considered to play an important role in the generation of longitudinal cracks. 展开更多
关键词 permafrost regions embankment longitudinal cracks road alignment distribution laws
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The Proof of Riemann Hypothesis, the Key to the Door Is the Periodicity
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作者 Jinliang Wang 《Applied Mathematics》 2021年第8期723-765,共43页
The Riemann hypothesis is a well-known mathematical problem that has been in suspense for 162 years. Its difficulty lies in the fact that it is involved in an infinite integral which includes infinite series with comp... The Riemann hypothesis is a well-known mathematical problem that has been in suspense for 162 years. Its difficulty lies in the fact that it is involved in an infinite integral which includes infinite series with complex variables. To detour this is in vain, since all the messages are hid in it. To unscramble them, there is a totally new idea, that is, the “periodicity”! By investigating the numerical approximate values of zero points, an explicit distribution law on the critical line was found. To accord with this, a periodic form for the real part of Xi function was constructed and rigidly proved. The Riemann hypothesis can be divided into three progressive propositions. The first proposition (the number of zero points in the critical strip satisfies a certain estimation) had been proved in 1905. The second proposition (the number of zero points on the critical line satisfies the same estimation as in the critical strip) is ever in suspense. It can be solved perfectly with the newly found “periodicity”. The third proposition (all the nontrivial zero points are on the critical line), that is, the Riemann hypothesis, is also true. The proof is a combination of the symmetry, monotonicity, periodicity of the Xi function and the extremum principle of the harmonic functions. It is the moment to draw full stop for this suspending problem. 展开更多
关键词 Riemann Hypothesis Riemann Zeta Function Distribution law of Zero Point PERIODICITY MONOTONICITY Extremum Principle
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