期刊文献+
共找到45篇文章
< 1 2 3 >
每页显示 20 50 100
How the pollution stress acting on the phytoplankton populations ──an observation by the experimental enclosed ecosystem
1
作者 Tang Senming and Hou Shumin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1995年第4期563-568,共6页
A marine ended enclosed ecosystem expetiment was conducted by Chinese and Canadian scientists in Xiamen inApril 1985. Pollutants of heavy metals mixed with Cu, Hg, Pb, Zn and Cd and of suspended sediments were added t... A marine ended enclosed ecosystem expetiment was conducted by Chinese and Canadian scientists in Xiamen inApril 1985. Pollutants of heavy metals mixed with Cu, Hg, Pb, Zn and Cd and of suspended sediments were added tobags VOlumed about 10 m3. It was showed that dabing 21 days the effects on the plankton populations were evident in thebags due to the contamination, i. e. the growth of diatom population reduced to different levels characterized by the lagappearance of density peaks, low instant growth rate and delay of doulbling time with low biomass. A strong grazing fromthe pollutant affected zooplankton population resulted in heavy stress on the growth of algal population. As a result, thestress transferred to the phytoplankton population through the herbivores. 展开更多
关键词 PLANKTON enclosed experiment POLLUTION PREDATION
下载PDF
Fall detection system in enclosed environments based on single Gaussian model
2
作者 Adel Rhuma Jonathon A Chambers 《Journal of Measurement Science and Instrumentation》 CAS 2012年第2期123-128,共6页
In this paper,we propose an efficient fall detection system in enclosed environments based on single Gaussian model using the maximum likelihood method.Online video clips are used to extract the features from two came... In this paper,we propose an efficient fall detection system in enclosed environments based on single Gaussian model using the maximum likelihood method.Online video clips are used to extract the features from two cameras.After the model is constructed,a threshold is set,and the probability for an incoming sample under the single Gaussian model is compared with that threshold to make a decision.Experimental results show that if a proper threshold is set,a good recognition rate for fall activities can be achieved. 展开更多
关键词 humans fall detection enclosed environments one class support vector machine(OCSVM) imperfect training data shape analysis maximum likelihood(ML) background subtraction CODEBOOK voxel person
下载PDF
The effects of nutrients and heavy metals on the plankton in marine enclosed ecosystem
3
作者 Zhuang Dongfa, Lin YuThird Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1991年第4期637-640,共4页
Applying marine enclosed ecosystem extensively to study the nutrient variation and its relation to biochemical process by marine ecologists and biogeologists in North America, Europe, Japan and Australia has been last... Applying marine enclosed ecosystem extensively to study the nutrient variation and its relation to biochemical process by marine ecologists and biogeologists in North America, Europe, Japan and Australia has been lasting for many years. Santschi (1982) reviewed the geochemical recirculation of nutrients systematically. Kremling et al. (1978) described the changes in nutrient in marine enclosed e- 展开更多
关键词 The effects of nutrients and heavy metals on the plankton in marine enclosed ecosystem
下载PDF
Theory and Experiments on Enclosing Control of Multi-Agent Systems 被引量:4
4
作者 Yihui Wang Yanfei Liu Zhong Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第10期1677-1685,共9页
This paper proposes a control strategy called enclosing control.This strategy can be described as follows:the followers design their control inputs based on the state information of neighbor agents and move to specifi... This paper proposes a control strategy called enclosing control.This strategy can be described as follows:the followers design their control inputs based on the state information of neighbor agents and move to specified positions.The convex hull formed by these followers contains the leaders.We use the single-integrator model to describe the dynamics of the agents and proposes a continuous-time control protocol and a sampled-data based protocol for multi-agent systems with stationary leaders with fixed network topology.Then the state differential equations are analyzed to obtain the parameter requirements for the system to achieve convergence.Moreover,the conditions achieving enclosing control are established for both protocols.A special enclosing control with no leader located on the convex hull boundary under the protocols is studied,which can effectively prevent enclosing control failures caused by errors in the system.Moreover,several simulations are proposed to validate theoretical results and compare the differences between the three control protocols.Finally,experimental results on the multi-robot platform are provided to verify the feasibility of the protocol in the physical system. 展开更多
关键词 Cooperative control directed network topology enclosing control leader-following multi-agent systems
下载PDF
Diagnostic model construction and example analysis of habitat degradation in enclosed bay: II. spatiotemporal variations in habitat degradation in Sansha Bay 被引量:2
5
作者 于格 孙芃 +3 位作者 刘光兴 徐东晖 丁光茂 黄东仁 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第3期636-644,共9页
The process of habitat degradation varies in habitat type and driving force which shows certain spatial and temporal heterogeneity on regional scales. In the present study, a new diagnostic model for enclosed bay habi... The process of habitat degradation varies in habitat type and driving force which shows certain spatial and temporal heterogeneity on regional scales. In the present study, a new diagnostic model for enclosed bay habitat degradation was established, with which the spatial and temporal variation patterns of habitat degradation during 1991–2012 in Sansha Bay, Fujian, China was investigated. The results show that anthropogenic disturbance is the major controlling factor for the habitat degradation in large temporal heterogeneity in the bay. On the other hand, the habitat degradation experienced signifi cant spatial variations among six sub-bays. Under the joint action of temporal and spatial heterogeneity, the degradation trend in growing scale shows a more signifi cant correlation with the distribution of local leading industries along shorelines. Therefore, we quantifi ed the main characters of habitat degradation in Sansha Bay, and have understood the relationship between the status of habitats spatio-temporal variation value and the main controlling factor leading to the changes. However, a defi ciency of this research is the lack of or inaccessible to the detailed data, which shall be better solved in the future study for accessing more data from more sources. 展开更多
关键词 enclosed bay habitat degradation diagnostic analysis Sansha Bay spatiotemporal variations
下载PDF
Acoustic characteristics of pulse detonation engine sound propagating in enclosed space 被引量:1
6
作者 Yang Kang Ning Li +1 位作者 Chun-Sheng Weng Xiao-Long Huang 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第1期378-386,共9页
Acoustic characteristics of pulse detonation engine(PDE)sound propagating in enclosed space are numerically and experimentally investigated.The finite element software LS-DYNA is utilized to numerically simulate the P... Acoustic characteristics of pulse detonation engine(PDE)sound propagating in enclosed space are numerically and experimentally investigated.The finite element software LS-DYNA is utilized to numerically simulate the PDE sound propagating in enclosed space.Acoustic measurement systems are established for testing the PDE sound in enclosed space,and the time-frequency characteristics of PDE sound in enclosed space are reported in detail.The experimental results show that the sound waveform of PDE sound in enclosed space are quite different from those in open space,and the reflection and superposition of PDE sound on the walls of enclosed space results in the sound pressure oscillating obviously.It is found that the peak sound pressure level(PSPL)and overall sound pressure level(OASPL)of PDE sound in enclosed space are higher than those in open space and their difference increases with the rise of propagation distance.The results of the duration of PDE sound indicate that the A duration of PDE sound in enclosed space is higher than that in open space except at measuring points located at 2-m and 5-m while the B duration is higher at each of all measuring points.Results show that the enclosed space has a great influence on the acoustic characteristic of PDE sound.This research is helpful in performing PDE experiments in enclosed laboratories to prevent the PDE sound from affecting the safety of laboratory environment,equipment,and staffs. 展开更多
关键词 pulse detonation engine acoustics characteristics enclosed space
下载PDF
On Characteristics and Cultures of the Hakka's Enclosed Houses in South Jiangxi Province 被引量:1
7
作者 XIONG Jianxin LI Wenqin 《Journal of Landscape Research》 2012年第12期43-46,共4页
General situation and distribution of round houses of the Hakka in south Jiangxi were introduced, such architectural styles as enclosed house with a square yard (kouzi wei, in the shape of 口), enclosed house with a y... General situation and distribution of round houses of the Hakka in south Jiangxi were introduced, such architectural styles as enclosed house with a square yard (kouzi wei, in the shape of 口), enclosed house with a yard of three transverse and one longitudinal constructions (guozi wei, in the shape of 国), and enclosed house with a round house in its yard (tao wei) were taken to analyze features of the Hakka's enclosed houses. It was highlighted that the Hakka's enclosed houses in south Jiangxi has diversified architectural styles and outstanding defensive and living functions. Construction art and religious culture shown by the enclosed houses were interpreted, and the branch of Han people with unique dialects, cultures, folk customs and emotional attitudes was proposed as a miniature of the culture in south Jiangxi. Moreover, it was stressed that more attention of the public and more efforts for the protection should be given to the Hakka's cultures in south Jiangxi, carriers of the locals' history over the past thousands of years. 展开更多
关键词 SOUTH Jiangxi enclosed house Architectural CHARACTERISTICS the Hakka’s CULTURES
下载PDF
Was the enclosed Qaidam Basin of The Tibetan Plateau Accumulative or Erosive during the Late Quaternary? 被引量:1
8
作者 LAI Zhongping 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期14-14,共1页
A geological feature in the Qaidam Basin known as the"Shell Bar"contains millions of freshwater articulated clam shells buried in-situ.Since the 1980s this feature in the now hyper-arid basin has been interp... A geological feature in the Qaidam Basin known as the"Shell Bar"contains millions of freshwater articulated clam shells buried in-situ.Since the 1980s this feature in the now hyper-arid basin has been interpreted to be lake deposits that provide evidence for a warmer and more humid climate than present during late Marine Isotope Stage 3(MIS 3)(Bowler et al.,1986).However,the global climate during 展开更多
关键词 Was the enclosed Qaidam Basin of The Tibetan Plateau Accumulative or Erosive during the Late Quaternary OSL
下载PDF
Diagnostic model construction and example analysis of habitat degradation in enclosed bay: I. diagnostic model construction
9
作者 于格 孙芃 +3 位作者 刘光兴 徐东晖 丁光茂 黄东仁 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第3期626-635,共10页
Presently, research is lacking regarding the diagnosis and evaluation of habitat degradation in enclosed bay systems. We established a diagnostic model for enclosed bay habitat degradation(EBHD model) using a multi-ap... Presently, research is lacking regarding the diagnosis and evaluation of habitat degradation in enclosed bay systems. We established a diagnostic model for enclosed bay habitat degradation(EBHD model) using a multi-approach integrated diagnostic method in consideration of driving force-pressurestate-infl uence-response. The model optimizes the indicator standardization with annual average change rate of habitat degradation as the basic element, to refl ect accurately the impact of the change and speed of degradation on the diagnostic results, to quantify reasonably the contribution of individual diagnostic indicator to habitat degradation, and to solve the issue regarding the infl uence of subjective factors on the evaluation results during indicator scoring. We then applied the EBHD model for the Sansha Bay in Fujian Province, China, evaluated comprehensively the situation of habitat degradation in the bay, and screened out the major controlling factors in the study area. Results show that the diagnostic results are consistent in overall with the real situation of the study area. Therefore, the EBHD model is advantageous in terms of objectivity and accuracy, making a breakthrough in diagnosis and evaluation for habitat degradation in enclosed bay systems. 展开更多
关键词 enclosed bay habitat degradation diagnostic model Sansha Bay
下载PDF
Enclosed Extent of the Saline Water and its Constraints on the Sedimentary and Salt Forming Characteristics:A Case Study of the Paleogene Playas in Hoh Xil Basin
10
作者 GONG Daxing YI Haisheng +2 位作者 ZHOU Jiayun WU Chi Hua Xia Guoqing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期320-322,共3页
1 Introduction There is a long period of hot,arid climates in the Jurassic-Neogene,in the eastern of the Neo-Tethys where is been called Western Yunnan—Qiangtang tectonic belt(Zheng et al.,2010).Especially in the Pal... 1 Introduction There is a long period of hot,arid climates in the Jurassic-Neogene,in the eastern of the Neo-Tethys where is been called Western Yunnan—Qiangtang tectonic belt(Zheng et al.,2010).Especially in the Paleogene,under the control of the planetary winds and the north subtropical high pressure belts,a ribbon arid,semi-arid 展开更多
关键词 enclosed extent Paleogene playas sedimentary and salt forming characteristics Hoh Xil Basin
下载PDF
Relic Oceanic Crust at Sub-arc Depth: an Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan Mountains, China
11
作者 SHEN T.T. ZHANG L.F. +1 位作者 LIU F.L HERMANN J. 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期238-,共1页
Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhumation
关键词 UHP an Example from UHP Eclogites enclosed in Serpentinites from the Southwestern Tianshan Mountains China Relic Oceanic Crust at Sub-arc Depth
下载PDF
Relic Oceanic Crust at Sub-Arc Depth: An Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan, China
12
作者 SHEN Tingting ZHANG Lifei +1 位作者 Joerg HERMANN LIU Fenglin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期35-,共1页
Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhum... Ultra-high pressure(UHP)eclogites that derive from subducted oceanic crust are rarely found at the Earth’s surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhumation(Hermann et al.,2000;Guillot et al.,2001).Under normal subduction geotherms,serpentinites break down just before UHP conditions are reached and therefore most of the exhumed eclogites representing subducted oceanic crust formed under fore-arc conditions.We investigated eclogite blocks enclosed into serpentinites that occur in the southwestern Tianshan oceanic subduction,China.A previous study proved that the serpentinites derive from altered oceanic crust and experienced UHP metamorphism at low temperatures of 510-530°C(Shen et al.,2015).Three relatively fresh eclogite samples were studied in detail.Sample 129-7 shows the retrograde mineral assemblage of amphibole+biotite+albite+chlorite+minor titanite and peak metamorphic relics of omphacite+garnet±chlorite.Sample C107-23 is mainly composed of amphibole+albite+chlorite+zoisite+muscovite+minor titanite as a retrograde assemblage and garnet+phengite as the peak metamorphic relics with omphacite only found as inclusions in garnet.Similar to sample C107-23,sample C11066 preserves large-grained euhedral to subhedral garnet relics with omphacite inclusions,and epidote,diopside,amphibole,muscovite,chlorite,albite and biotite are in the matrix belong to the retrograde assemblage.These three retrograde eclogite samples were modelled using thermodynamic calculations in the Mn NCKFMSHO(Mn O-Na;O-Ca O-K;O-FeO-Mg O-Al;O;-SiO;-H;O-Fe;O;)system.Based on the peak assemblage of omphacite+garnet and the crossing of the grossular and pyrope isopleths in garnet,peak P-T conditions of;60-470oC,28-29 kbar(129-7),450-500oC,28-35 kbar(C107-23),;75-505oC,26-29 kbar(C11066)were calculated.The retrograde assemblages indicate near isothermal decompression resulting in a clockwise P-T evolution of these eclogites.The peak metamorphic pressures at 500°C are well within UHP conditions(coesite stability field)and are within error the same as peak conditions of the host serpentinites(Shen et al.,2015).This provides evidence that eclogites and serpentinites shared the same evolution.We infer that the subducted low-density serpentinites were assembled with the high-density eclogites during subdution and helped the latter to exhume back to the surface.The studied eclogites thus represent rare examples of relics of oceanic crust that was subducted to sub-arc depth. 展开更多
关键词 UHP An Example from UHP Eclogites enclosed in Serpentinites from the Southwestern Tianshan China Relic Oceanic Crust at Sub-Arc Depth
下载PDF
Experimental Study on Seismic Behavior ofSeismic-damaged Lateral Joints in CompositeFrame Consisting of CFSST Columns and SteelBeams Strengthened with Enclosed ReinforcedConcrete
13
《建筑工程(中英文版)》 2015年第2期22-29,共8页
A new composite strengthening method of seismic-damaged lateral joints in composite frame consisting of Concrete-Filled SquareSteel Tubes (CFSST) columns and steel beams strengthened with enclosed Reinforced Concre... A new composite strengthening method of seismic-damaged lateral joints in composite frame consisting of Concrete-Filled SquareSteel Tubes (CFSST) columns and steel beams strengthened with enclosed Reinforced Concrete (RC) at the ends of columns andwelding steel plates at the ends of beams was presented. Based on the current design specifications, one half scaled models of 4lateral joints in composite frame consisting of CFSST columns and steel beams were designed and manufactured. One model wasoriginal control specimen, one was strengthened by enclosed RC, and the others were strengthened after pre-damage. The destructiontests under lateral cyclic load on the models were carried. The effectiveness of seismic-damaged joints strengthened with enclosedRC and the reinforcement effect on different levels of seismic damage were studied. The test results show that seismic- damagedjoints in composite frame consisting of CFSST columns and steel beams strengthened with enclosed RC meets the strongcolumn-weak beam joints requirement of seismic design, and the failure modes are of all joints are the bending failure of steel beam.The reinforcement with enclosed RC has a significant on increasing the ultimate capacity and the seismic behaviors of joints. Thestudy indicated the rehabilitated joints recover the level of their original seismic performances before seismic damage in a certainextent damage level. Based on the test data, namely the ultimate capacity, limit displacement, ductility, the energy consumptioncoefficient, limit displacementthe strengthening method of seismic-damaged joints by strengthened with enclosed RC is an effectivemethod for seismic strengthening. 展开更多
关键词 Frame Joint with Concrete-Filled Square STEEL Tube (CFSST)-Steel Beam Strengthening with enclosed ReinforcedConcrete (RC) QUASI-STATIC Test SEISMIC Damage SEISMIC Behavior
下载PDF
直流GIL中自由线形金属微粒的运动与放电特性 被引量:31
14
作者 王健 李庆民 +2 位作者 李伯涛 刘思华 王志远 《中国电机工程学报》 EI CSCD 北大核心 2016年第17期4793-4800,共8页
针对直流GIL中较常见且具有严重影响的自由线形金属微粒,搭建了贴合实际工况的封闭式同轴圆柱电极平台,同时使用高速相机和局放监测手段观测线形金属微粒的运动、局放与击穿行为。定量获得了微粒长度对站立与跳跃两种不同运动模式发生... 针对直流GIL中较常见且具有严重影响的自由线形金属微粒,搭建了贴合实际工况的封闭式同轴圆柱电极平台,同时使用高速相机和局放监测手段观测线形金属微粒的运动、局放与击穿行为。定量获得了微粒长度对站立与跳跃两种不同运动模式发生概率的影响;拍摄了站立线形微粒引起的电晕图像,同时监测、提取并统计微粒引起的局部放电情况;记录金属微粒引起的击穿图像,并基于流注理论分析了自由线形金属微粒引起的气隙击穿特性。研究表明:线形微粒的起动场强与微粒的长度基本无关,而与微粒的半径开方成正比,微粒越短,起动后越易达到跳跃运动状态,而微粒越长,越易保持站立状态;微粒引起的局部放电随着微粒长度的增大而更加剧烈;对于跳跃的自由线形微粒,其引起的微放电击穿间距随着微粒长度的增加而增加,击穿电压随着微粒长度的增加而降低。 展开更多
关键词 直流气体绝缘金属封闭输电线路(gas insulated metal enclosed transmission line GIL) 自由线形金属微粒 运动模式 局部放电特征 微放电间距
下载PDF
主动脉隔离技术应用于非体外冠脉手术中期疗效评估 被引量:1
15
作者 孔烨 隋亮 +3 位作者 章剑锋 朱良纲 杭钧彪 沈振亚 《中国临床医学》 北大核心 2008年第3期290-292,共3页
目的:总结主动脉隔离技术用于非体外循环冠状动脉旁路移植手术的经验,探讨其可行性与安全性,评估中期临床疗效。方法:在180例非体外循环下冠状动脉旁路移植手术中,应用Enclose装置,以主动脉隔离技术完成桥血管与升主动脉近端吻合。术前... 目的:总结主动脉隔离技术用于非体外循环冠状动脉旁路移植手术的经验,探讨其可行性与安全性,评估中期临床疗效。方法:在180例非体外循环下冠状动脉旁路移植手术中,应用Enclose装置,以主动脉隔离技术完成桥血管与升主动脉近端吻合。术前用薄层CT平扫评价升主动脉粥样硬化及钙化程度,术中用超声检查升主动脉结合手指扪查升主动脉。23例(12.8%)存在明显升主动脉粥样硬化斑块或钙化灶。术中再血管化的顺序为:(1)应用主动脉隔离技术,完成所有静脉或桡动脉桥血管与主动脉近端吻合;(2)左乳内动脉与左前降支远端吻合;(3)顺次完成所有桥血管与冠状动脉远端吻合。术后常规应用肠溶阿司匹林及硫酸氢氯吡格雷抗血小板治疗。结果:共完成桥血管536根,平均2.98±0.8根.例-1。用主动脉隔离技术成功完成近端吻合口408个;其中,桡动脉桥近端吻合口7个,静脉桥近端吻合口401个,平均2.27±0.7个.例-1。术中无技术故障和相关意外情况发生。围手术期死亡4例(2.2%)。176例存活患者无心肌梗死、脑梗死、主动脉夹层动脉瘤、二次开胸止血及心功能衰竭等严重围术期并发症和心脏相关事件发生。术后147例(83.5%)存活患者接受门诊或电话随访,随访时间27.7±9.4(6~39)个月。1例(0.7%)患者术后15个月死于肠道肿瘤;胸痛发生率2.7%、房颤发生率2.0%、脑梗发生率3.4%、下肢栓塞发生率1.4%。全组患者无其它心血管不良事件发生。术后心功能NYHA分级较手术前明显改善(P<0.05)。术后30个月以上的25例患者行冠状动脉CTA检查,结果58个桥血管近端吻合口中53个(91.4%)近端吻合口均通畅。结论:用Enclose装置的主动动脉隔离技术可安全地用于非体外冠脉旁路移植术的近端吻合,尤其可用于升主动脉明显钙化和粥样硬化的患者,术后中期疗效满意。 展开更多
关键词 主动脉隔离技术 Enclos装置 非体外循环下冠状动脉旁路移植
下载PDF
Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels——Elasto-plastic analysis of stress field of enclosing rock mass 被引量:10
16
作者 WU Hao FANG Qin ZHANG Ya-dong GONG Zi-ming 《Mining Science and Technology》 EI CAS 2009年第1期84-90,共7页
The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constit... The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plastic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass. 展开更多
关键词 enclosing rock mass around deep tunnels zonal disintegration equivalent material Hoek-Brown strength criterion
下载PDF
Zonal disintegration phenomenon in rock mass surrounding deep tunnels 被引量:9
17
作者 WU Hao FANG Qin GUO Zhi-kun 《Journal of China University of Mining and Technology》 EI 2008年第2期187-193,共7页
Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope duri... Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope during excavation of a deep tunnel. Zonal disintegration phenomenon was successfully demonstrated in the laboratory with 3D tests on analogous gypsum models, two circular cracked zones were observed in the test. The linear Mohr-Coulomb yield criterion was used with a constitutive model that showed linear softening and ideal residual plastic to analyze the elasto-plastic field of the enclosing rock mass around a deep tunnel. The results show that tunneling causes a maximum stress zone to appear between an elastic and plastic zone in the surrounding rock. The zonal disintegration phenomenon is analyzed by considering the stress-strain state of the rock mass in the vicinity of the maximum stress zone. Creep instability failure of the rock due to the development of the plastic zone, and transfer of the maximum stress zone into the rock mass, are the cause of zonal disintegration. An analytical criterion for the critical depth at which zonal disintegration can occur is derived. This depth depends mainly on the character and stress concentration coefficient of the rock mass. 展开更多
关键词 block-hierarchical structure zonal disintegration phenomenon enclosing rock mass around deep tunnel equivalent material stress concentration coefficient
下载PDF
Airport automatic detection in large space-borne SAR imagery 被引量:5
18
作者 Shaoming Zhang Yi Lin Xiaohu Zhang Yingying Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第3期390-396,共7页
A method to detect airports in large space-borne synthetic aperture radar(SAR) imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP) est... A method to detect airports in large space-borne synthetic aperture radar(SAR) imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP) estimator based on the heavytailed Rayleigh model.The attention is then paid on the object of interest(OOI) extracted from the large images.The minimumarea enclosing rectangle(MER) of OOI is created via a rotating calipers algorithm.The projection histogram(PH) of MER for OOI is then computed and the scale and rotation invariant feature for OOI are extracted from the statistical characteristics of PH.A support vector machine(SVM) classifier is trained using those feature parameters and the airport is detected by the SVM classifier and Hough transform.The application in space-borne SAR images demonstrates the effectiveness of the proposed method. 展开更多
关键词 synthetic aperture radar(SAR) imagery airport detection image segmentation minimum-area enclosing rectangle support vector machine(SVM).
下载PDF
New Campus Design of Institute of Technology, Jiangxi Normal University 被引量:1
19
作者 LENG Haoran LUO Qi CHEN Xiaogang 《Journal of Landscape Research》 2013年第10期7-10,12,共5页
The construction of new campus of Institute of Technology,Jiangxi Normal University was based on "returning to teaching",natural ecological conditions of the local area and enclosed house characterized by &q... The construction of new campus of Institute of Technology,Jiangxi Normal University was based on "returning to teaching",natural ecological conditions of the local area and enclosed house characterized by "Gan-Po culture"(culture of Jiangxi and Lake Poyang) were integrated into the design,and innovative auxiliary pedestrian roads introduced,so as to build an ecological,natural and humanistic campus with regional characteristics,multiple-level and three-dimensional development. A novel mode was given to the campus construction from a brand-new perspective. 展开更多
关键词 RETURNING to teaching Three-dimensional Axis AUXILIARY PEDESTRIAN ROADS ECOLOGY enclosed space Gan-Po culture
下载PDF
Please Subscribe for the Supplements to the Video Teaching Materials for Chinese Acupuncture and Moxibustion (Only in Chinese)
20
《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 1994年第4期311-311,共1页
关键词 中国针灸学 考试复习 PLEASE letter 特别注明 PAYMENT enclosed
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部