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Floods:Dangers and responses
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作者 叶丹 《疯狂英语(新悦读)》 2025年第10期12-14,76,共4页
Being caught in a flood is incredibly dangerous.Like many other natural disasters,floods can occur with little or no warning.Flash floods move quickly and have strong currents.They are known to rip(扯)trees out of the... Being caught in a flood is incredibly dangerous.Like many other natural disasters,floods can occur with little or no warning.Flash floods move quickly and have strong currents.They are known to rip(扯)trees out of the ground,destroy buildings and cause bridges to collapse. 展开更多
关键词 floods RESPONSES DANGER flash floods
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The sweet trap
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作者 陈娟 《疯狂英语(新悦读)》 2025年第3期32-34,77,共4页
1 Most of us know that eating too much sugar isn't good for us.With its consumption being linked to health dangers like obesity,fatty liver disease,type 2 diabetes,heart disease and cancer,sugar is high on most of... 1 Most of us know that eating too much sugar isn't good for us.With its consumption being linked to health dangers like obesity,fatty liver disease,type 2 diabetes,heart disease and cancer,sugar is high on most of our lists of vices(恶行)worth giving up. 展开更多
关键词 cancer OBESITY type diabetes fatty liver disease heart disease SUGAR health dangers
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Stability deterioration and failure analysis of dangerous rock masses in cold regions under the influence of freeze-thaw cycles
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作者 SHU Jiajun LI Tao +2 位作者 WU Bingni DENG Zhengding HUANG Jingzhu 《Journal of Mountain Science》 2025年第11期4298-4315,共18页
Dangerous rock masses in cold regions subjected to repeated freeze–thaw cycles can cause progressive deterioration in structural planes and rock mechanical properties,which significantly reduces the overall stability... Dangerous rock masses in cold regions subjected to repeated freeze–thaw cycles can cause progressive deterioration in structural planes and rock mechanical properties,which significantly reduces the overall stability and often triggers collapses or landslides.Existing studies focus mostly on singlescale or single-factor analyses but cannot fully capture the coupled mechanisms driving instability under freeze-thaw conditions.This study aimed to establish a theoretical framework to quantitatively characterize the evolution of rock mass stability,thereby providing a sound basis for hazard prediction and prevention.By integrating limit equilibrium theory with rock frost heave and circular hole expansion theory,mechanical models for sliding-and toppling-type dangerous rock masses were established.Three key factors were incorporated:frost heave forces acting on throughgoing structural planes,rock property deterioration in nonpenetrative sections,and progressive freezing depth development.A theoretical relationship between the stability coefficient and the number of freeze-thaw cycles was derived.By considering the Zimei Peaks rock masses in Gansu Province as the case study and conducting parametric analyses,the results revealed that the stability coefficient rapidly decreases during the initial cycles,followed by a slower decrease and eventual stabilization.The coefficient decreased 4.5 times more during the first 15 cycles than during the subsequent 15 cycles.Moreover,stability degradation was strongly influenced by the freezing temperature,initial porosity,and rock debris loss ratio,with critical thresholds determined at a 3.8%porosity and a 0.83 debris loss ratio.The findings indicated that stability deterioration is governed by the coupled effects of frost heave loading,microstructural damage accumulation,and freezing depth development,with clear stagedependent and threshold-driven patterns.This work provides not only a quantitative explanation of instability mechanisms in cold-region rock masses but also practical guidance for engineering stability assessment and disaster mitigation. 展开更多
关键词 Dangerous rock masses Limit equilibrium Freeze-thaw cycles Frost heave force Freezing depth Stability deterioration
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Seismic pseudo-static stability analysis of bedding jointed rock slope stability under the interaction of the upper dangerous rock mass and lower stepped slope mass based on acceleration assessment
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作者 LI De-jian XIAO Yu +3 位作者 YANG Yan-song YU Peng-cheng ZHANG Ying-bin ZHAO Lian-heng 《Journal of Central South University》 2025年第7期2619-2637,共19页
In the practical slope engineering,the stability of lower sliding mass(region A)with back tensile cracks of the jointed rock slope attracts more attentions,but the upper rock mass(region B)may also be unstable.Therefo... In the practical slope engineering,the stability of lower sliding mass(region A)with back tensile cracks of the jointed rock slope attracts more attentions,but the upper rock mass(region B)may also be unstable.Therefore,in this study,based on the stepped failure mode of bedding jointed rock slopes,considering the influence of the upper rock mass on the lower stepped sliding mass,the improved failure model for analyzing the interaction force(F_(AB))between two regions is constructed,and the safety factors(F_(S))of two regions and whole region are derived.In addition,this paper proposes a method to determine the existence of F_(AB) using their respective acceleration values(a_(A) and a_(B))when regions A and B are unstable.The influences of key parameters on two regions and the whole region are analyzed.The results show that the variation of the F_(AB) and F_(S) of two regions can be obtained accurately based on the improved failure model.The accuracy of the improved failure model is verified by comparative analysis.The research results can explain the interaction mechanism of two regions and the natural phenomenon of slope failure caused by the development of cracks. 展开更多
关键词 bedding jointed rock slope upper dangerous rock mass stepped sliding interaction mechanism stability analysis
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Application of Unmanned Aerial Vehicle Remote Sensing on Dangerous Rock Mass Identification and Deformation Analysis:Case Study of a High-Steep Slope in an Open Pit Mine
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作者 Wenjie Du Qian Sheng +5 位作者 Xiaodong Fu Jian Chen Jingyu Kang Xin Pang Daochun Wan Wei Yuan 《Journal of Earth Science》 2025年第2期750-763,共14页
Source identification and deformation analysis of disaster bodies are the main contents of high-steep slope risk assessment,the establishment of high-precision model and the quantification of the fine geometric featur... Source identification and deformation analysis of disaster bodies are the main contents of high-steep slope risk assessment,the establishment of high-precision model and the quantification of the fine geometric features of the slope are the prerequisites for the above work.In this study,based on the UAV remote sensing technology in acquiring refined model and quantitative parameters,a semi-automatic dangerous rock identification method based on multi-source data is proposed.In terms of the periodicity UAV-based deformation monitoring,the monitoring accuracy is defined according to the relative accuracy of multi-temporal point cloud.Taking a high-steep slope as research object,the UAV equipped with special sensors was used to obtain multi-source and multitemporal data,including high-precision DOM and multi-temporal 3D point clouds.The geometric features of the outcrop were extracted and superimposed with DOM images to carry out semi-automatic identification of dangerous rock mass,realizes the closed-loop of identification and accuracy verification;changing detection of multi-temporal 3D point clouds was conducted to capture deformation of slope with centimeter accuracy.The results show that the multi-source data-based semiautomatic dangerous rock identification method can complement each other to improve the efficiency and accuracy of identification,and the UAV-based multi-temporal monitoring can reveal the near real-time deformation state of slopes. 展开更多
关键词 high-steep slope UAV remote sensing dangerous rock identification multi-temporal monitoring multi-source data fusion engineering geology
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Automatic identification of concealed dangerous rock blocks on highsteep slopes considering finite-sized discontinuity intersections
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作者 Xiaohan Zhao Wen Zhang +6 位作者 Junqi Chen Zhengxuan Xu Yingxu Zhang Han Yin Jia Wang Tengyue Li Bo Han 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第11期7093-7106,共14页
The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to ca... The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to capture high-resolution discontinuity data and develops a fully automated rock block extraction method consisting of three steps:(1)determination of free face and non-free fracture intersections,(2)surface search for rock blocks on free face.and(3)extraction and analysis of rock blocks.This approach simplifies the determination of discontinuity intersections while maintaining high accuracy.By incorporating all types of discontinuities contributing to rock block formation,the method enables precise in-situ rock block identification and extraction.Application to a rock slope in China,produced results consistent with the rock blocks observed in the 3D model,highlighting its accuracy and practical value. 展开更多
关键词 Concealed dangerous rock block High-steep rock slope Rock block identification In-situ block characterization
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Psychiatric Expertise in Benin Penal Justice Context: What Do They Reveal?
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作者 Francis Tognon Cedric Bigot +1 位作者 Yves Amonles Feldia Adéossi 《Open Journal of Psychiatry》 2020年第1期1-8,共8页
In this study, the authors describe the profile of people seen in criminal psychiatric expertise in northern Benin and their results. It covered the 138 psychiatric assessments carried out as part of criminal proceedi... In this study, the authors describe the profile of people seen in criminal psychiatric expertise in northern Benin and their results. It covered the 138 psychiatric assessments carried out as part of criminal proceedings in the years 2017 and 2018. Expertises were on men in 94.9% of the cases. They were over 30 years old in 66.2% of cases. They were prosecuted for blood crimes in 89.5% of cases. The defendants were in detention at the time of the expert in 87.5% of cases. Psychiatric experts diagnosed a psychiatric disorder in 22.8% of cases. There was a relationship between the identified psychiatric disorder and the offense that motivated the charge in 25.8% of the mental disorder cases. It was exclusively cases of psychotic disorders. There was an abolition of discernment in 3.8% of the accused. 展开更多
关键词 PSYCHIATRIC EXPERTISE CRIMINAL Responsibility PSYCHOSES Forensic PSYCHIATRY dangerousness
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汉译英训练(34)
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作者 李运兴 《大学英语》 2017年第4期62-64,共3页
暗途许地山"我的朋友,且等一等,待我为你点着灯,才走。"*吾威~1听见他的朋友这样说,便笑道:"哈哈,均哥,你以我为女人么?女人在夜间走路才要用火;男子,又何必呢?不用张罗,我空手回去罢——省得以后还要给你送灯回来。"吾威的村... 暗途许地山"我的朋友,且等一等,待我为你点着灯,才走。"*吾威~1听见他的朋友这样说,便笑道:"哈哈,均哥,你以我为女人么?女人在夜间走路才要用火;男子,又何必呢?不用张罗,我空手回去罢——省得以后还要给你送灯回来。"吾威的村庄和均哥所住的地方隔着几重山,*路途崎岖得很厉害~2。*若是夜间要走那条路~3,无论是谁,都得带灯。 展开更多
关键词 许地山 给你 FRIEND mountains EVERYWHERE NIGHT weather DANGER walking VILLAGE
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高一(上)词语辨析练习(英文)
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作者 郝昌明 《中学生英语(高中版)》 2008年第34期19-21,共3页
Unit 7 1.include/contain (1)I can’t go home now,because my task _______cleaning the windows. (2)As we all know,sea water______ much salt. 2.give in/give up (1)You must______smoking,because it is dangerous for us. (2)... Unit 7 1.include/contain (1)I can’t go home now,because my task _______cleaning the windows. (2)As we all know,sea water______ much salt. 2.give in/give up (1)You must______smoking,because it is dangerous for us. (2)The young man won’t_____before any difficulty. 3. 展开更多
关键词 DANGEROUS DIFFICULTY young SMOKING cleaning HAVEN AGAIN never holds suddenly
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Future impacts of climate change on forest fire danger in northeastern China 被引量:16
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作者 TIAN Xiao-rui SHU Li-fu +2 位作者 ZHAO Feng-jun WANG Ming-yu Douglas J. McRae 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第3期437-446,共10页
Climate warming has a rapid and far-reaching impact on forest fire management in the boreal forests of China. Regional climate model outputs and the Canadian Forest Fire Weather Index (FWI) Sys- tem were used to ana... Climate warming has a rapid and far-reaching impact on forest fire management in the boreal forests of China. Regional climate model outputs and the Canadian Forest Fire Weather Index (FWI) Sys- tem were used to analyze changes to fire danger and the fire season for future periods under IPCC Special Report on Emission Scenarios (SRES) A2 and B2, and the data will guide future fire management planning. We used regional climate in China (1961 1990) as our validation data, and the period (1991–2100) was modeled under SRES A2 and B2 through the weather simulated by the regional climate model system (PRECIS). Meteorological data and fire danger were interpolated to 1 km 2 by using ANUSPLIN software. The average FWI value for future spring fire sea- sons under Scenarios A2 and B2 shows an increase over most of the region. Compared with the baseline, FWI averages of spring fire season will increase by 0.40, 0.26 and 1.32 under Scenario A2, and increase by 0.60, 1.54 and 2.56 under Scenario B2 in 2020s, 2050s and 2080s, respectively. FWI averages of autumn fire season also show an increase over most of the region. FWI values increase more for Scenario B2 than for Scenario A2 in the same periods, particularly during the 2050s and 2080s. Average future FWI values will increase under both scenarios for autumn fire season. The potential burned areas are expected to increase by 10% and 18% in spring for 2080s under Scenario A2 and B2, respectively. Fire season will be prolonged by 21 and 26 days under ScenariosA2 and B2 in 2080s respectively. 展开更多
关键词 climate change fire season forest fire danger northeastern China
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当住院变得不再顺畅患者康复之路在何方?(英文) 被引量:9
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作者 谢斌 《上海精神医学》 2012年第01X期38-40,共3页
The modern history of mental health services in China dates back to the founding of the first psychiatric hospital in Guangzhou by the missionary physician John Kerr in 1898.By the time of liberation in 1949 China’s ... The modern history of mental health services in China dates back to the founding of the first psychiatric hospital in Guangzhou by the missionary physician John Kerr in 1898.By the time of liberation in 1949 China’s population was already 500 million but there were only 10 mental health institutions,1 100 psychiatric beds and 50-60 psychiatrists in the country.Health services developed rapidly in the 1950s but by 1957 there were still only 70 psychiatric hospitals with 11 000 beds 展开更多
关键词 PSYCHIATRIC institutions FOUNDING PHYSICIAN mentally DATES GUANGZHOU DANGEROUS legal currently
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Extreme meteorological disaster effects on grain production in Jilin Province, China 被引量:12
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作者 XU Lei ZHANG Qiao +3 位作者 ZHANG Jing ZHAO Liang SUN Wei JIN Yun-xiang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第2期486-496,共11页
Extreme meteorological disaster effects on grain production is mainly determined by the interaction between danger degree of hazard-induced factors and vulnerability degree of hazard-affected bodies. This paper treats... Extreme meteorological disaster effects on grain production is mainly determined by the interaction between danger degree of hazard-induced factors and vulnerability degree of hazard-affected bodies. This paper treats physical exposure, sensitivity of the response to the impact, and capabilities of disaster prevention and mitigation as a complex system for vulnerability degree of hazard-affected bodies, which included the external shocks and internal stability mechanism. Hazard-induced factors generate external shocks on grain production systems though exposure and sensitivity of hazard-affected body, and the result can be represented as affected area of grain. By quantile regression model, this paper depicts the quantitative relationship between hazard-induced factors of extreme meteorological disaster and the affected area in the tail of the distri- bution. Moreover, the model of production function have also been utilized to expound and prove the quantitative relationship between the affected area and final grain output under the internal stability mechanism of the agricultural natural resources endowment, the input factors of agricultural production, and the capacity of defending disaster. The empirical study of this paper finds that impact effects of drought disaster to grain production system presents the basic law of "diminishing marginal loss", namely, with the constant improvement of the grade of drought, marginal affected area produced by hazard-induced factors will be diminishing. Scenario simulation of extreme drought impact shows that by every 1% reduction in summer average rainfall, grain production of Jilin Province will fell 0.2549% and cut production of grain 14.69% eventually. In re- sponse to ensure China's grain security, the construction of the long-term mechanism of agricultural disaster prevention and mitigation, and the innovation of agricultural risk management tools should be also included in the agricultural policy agenda. 展开更多
关键词 extreme meteorological disaster grain production danger degree of hazard-induced factors vulnerability degreeof hazard-affected bodies Jilin Province in China
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Determining areas in an inclined coal seam floor prone to water-inrush by micro-seismic monitoring 被引量:11
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作者 Sun Jian Wang Lianguo +2 位作者 Wang Zhansheng Hou Huaqiang Shen Yifeng 《Mining Science and Technology》 EI CAS 2011年第2期165-168,共4页
The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer.Determining the floor failure depth is the essential precondition f... The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer.Determining the floor failure depth is the essential precondition for predicting the water-resisting ability of the floor.We have used a high-precision microseismic monitoring technique to overcome the limited amount of data available from field measurements. The failure depth of a coal seam floor,especially an inclined coal seam floor,may be more accurately estimated by monitoring the continuous,dynamic failure of the floor.The monitoring results indicate the failure depth of the coal seam floor near the workface conveyance roadway(the lower crossheading) is deeper and that the failure range is wider here compared to the coal seam floor near the return airway(the upper crossheading).The results of micro-seismic monitoring show that the dangerous area for water-inrush from the coal seam floor may be identified.This provides an important field measurement that helps ensure safe and highly efficient mining of the inclined coal seam above the confined aquifer at the Taoyuan Coal Mine. 展开更多
关键词 Inclined coal seam Water-inrush from floor Dangerous area Micro-seismic monitoring
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Immune multi-agent model using vaccine for cooperative air-defense system of systems for surface warship formation based on danger theory 被引量:9
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作者 Jun Wang Xiaozhe Zhao +2 位作者 Beiping Xu Wei Wang Zhiyong Niu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第6期946-953,共8页
Aiming at the problem on cooperative air-defense of surface warship formation, this paper maps the cooperative airdefense system of systems (SoS) for surface warship formation (CASoSSWF) to the biological immune s... Aiming at the problem on cooperative air-defense of surface warship formation, this paper maps the cooperative airdefense system of systems (SoS) for surface warship formation (CASoSSWF) to the biological immune system (BIS) according to the similarity of the defense mechanism and characteristics between the CASoSSWF and the BIS, and then designs the models of components and the architecture for a monitoring agent, a regulating agent, a killer agent, a pre-warning agent and a communicating agent by making use of the theories and methods of the artificial immune system, the multi-agent system (MAS), the vaccine and the danger theory (DT). Moreover a new immune multi-agent model using vaccine based on DT (IMMUVBDT) for the cooperative air-defense SoS is advanced. The immune response and immune mechanism of the CASoSSWF are analyzed. The model has a capability of memory, evolution, commendable dynamic environment adaptability and self-learning, and embodies adequately the cooperative air-defense mechanism for the CASoSSWF. Therefore it shows a novel idea for the CASoSSWF which can provide conception models for a surface warship formation operation simulation system. 展开更多
关键词 immune multi-agent model (IMM) VACCINE surface warship formation cooperative air-defense system of systems (CASoS) danger theory (DT)
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Approach to Mountain Hazards in Tibet, China 被引量:4
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作者 MADongtao TUJianjun +1 位作者 CUIPeng LURuren 《Journal of Mountain Science》 SCIE CSCD 2004年第2期143-154,共12页
Tibet is located at the southwest boundary of China. It is the main body of the Qinghai-Tibet Plateau, the highest and the youngest plateau in the world. Owing to complicated geology, Neo-tectonic movements, geomorpho... Tibet is located at the southwest boundary of China. It is the main body of the Qinghai-Tibet Plateau, the highest and the youngest plateau in the world. Owing to complicated geology, Neo-tectonic movements, geomorphology, climate and plateau environment, various mountain hazards, such as debris flow, flash flood, landslide, collapse, snow avalanche and snow drifts, are widely distributed along the Jinsha River (the upper reaches of the Yangtze River), the Nu River and the Lancang River in the east, and the Yarlungzangbo River, the Pumqu River and the Poiqu River in the south and southeast of Tibet. The distribution area of mountain hazards in Tibet is about 589,000 km2, 49.3% of its total territory. In comparison to other mountain regions in China, mountain hazards in Tibet break out unexpectedly with tremendously large scale and endanger the traffic lines, cities and towns, farmland, grassland, mountain environment, and make more dangers to the neighboring countries, such as Nepal, India, Myanmar and Bhutan. To mitigate mountain hazards, some suggestions are proposed in this paper, such as strengthening scientific research, enhancing joint studies, hazards mitigation planning, hazards warning and forecasting, controlling the most disastrous hazards and forbidding unreasonable human exploring activities in mountain areas. 展开更多
关键词 TIBET mountain hazard formation cause DANGER mitigation countermeasure
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STUDY ON FOREST FIRE DANGER MODEL WITH REMOTE SENSING BASED ON GIS 被引量:2
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作者 Fang Huang Xiang-nan Liu Jin-guo Yuan 《Chinese Geographical Science》 SCIE CSCD 2000年第1期62-68,共7页
Forest fire is one of the main natural hazards because of its fierce destructiveness. Various researches on fire real time monitoring, behavior simulation and loss assessment have been carried out in many countries. A... Forest fire is one of the main natural hazards because of its fierce destructiveness. Various researches on fire real time monitoring, behavior simulation and loss assessment have been carried out in many countries. As fire prevention is probably the most efficient means for protecting forests, suitable methods should be developed for estimating the fire danger. Fire danger is composed of ecological, human and climatic factors. Therefore, the systematic analysis of the factors including forest characteristics, meteorological status, topographic condition causing forest fire is made in this paper at first. The relationships between biophysical factors and fire danger are paid more attention to. Then the parameters derived from remote sensing data are used to estimate the fire danger variables, According to the analysis, not only PVI (Perpendicular Vegetation Index) can classify different vegetation but also crown density is captured with PVI. Vegetation moisture content has high correlation with the ratio of actual evapotranspiration (LE) to potential ecapotranspiration (LEp). SI (Structural Index), which is the combination of TM band 4 and 5 data, is a good indicator of forest age. Finally, a fire danger prediction model, in which relative importance of each fire factor is taken into account, is built based on GIS. 展开更多
关键词 FOREST fire DANGER index models for DANGER prediction INVERSION of remote sensing data OVERLAY analysis GEOGRAPHICAL information system(GIS)
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Food Safety and Health—Past Problems and Future Solutions 被引量:4
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作者 Christopher J.Smith 《Engineering》 SCIE EI 2020年第4期384-388,共5页
The dictum of Hippocrates“Let thy food be thy medicine and medicine be thy food”is potentially both more accurate and more dangerous than ever before.This dictum can only be realistically applied if all foods are kn... The dictum of Hippocrates“Let thy food be thy medicine and medicine be thy food”is potentially both more accurate and more dangerous than ever before.This dictum can only be realistically applied if all foods are known to be safe.Nowadays foods are being produced,which are processed in a variety of ways with ingredients sourced from many different countries and processed in a variety of ways.This processing may include the addition of supplements which are intended to improve health and of adulterants which are potentially harmful.Additionally,foods may be contaminated with pesticides and other materials encountered during production and processing.Thus there is a need to identify“unsafe”foods.The question may be better put as:Which foods are safe? 展开更多
关键词 PESTICIDES intended DANGEROUS
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Fuel classification and mapping from satellite imagines 被引量:3
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作者 TIAN Xiao-rui Douglas J.McRae +1 位作者 SHU Li-fu WANG Ming-yu 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第4期311-316,共6页
This paper summarizes the fuel type systems currently adopted by the fire danger rating systems or fire behavior prediction systems of some countries, such as Canada, the United States, Australia, Greece, and Switzerl... This paper summarizes the fuel type systems currently adopted by the fire danger rating systems or fire behavior prediction systems of some countries, such as Canada, the United States, Australia, Greece, and Switzerland. As an example, the Canadian Forest Fire Danger Rating System organizes fuel types into five major groups, with a total of 16 discrete fuel types recognized. In the United States National Fire Danger Rating System, fuel models are divided into four vegetation groups and twenty fire behavior fuel models. The Promethus System (Greece) divides fuels into 7 types, and Australia has adopted only three distinct fuel types: open grasslands, dry eucalyptus forests, and heath/shrublands. Four approaches to mapping fuels are acceptable: field reconnaissance, direct mapping methods, indirect mapping methods, and gradient modeling. Satellite remote-sensing techniques provide an alternative source of obtaining fuel data quickly, since they provide comprehensive spatial coverage and enough temporal resolution to update fuel maps in a more efficient and timely manner than traditional aerial photography or fieldwork. Satellite sensors can also provide digital information that can be easily tied into other spatial databases using Geographic Information System (GIS) analysis, which can be used as input in fire behavior and growth models. Various fuel-mapping methods from satellite remote sensing are discussed in the paper. According to the analysis of the fuel mapping techniques worldwide, this paper suggests that China should first create appropriate fuel types for its fire agencies before embarking on developing a national fire danger rating system to improve the current data situation for it's fire management programs. 展开更多
关键词 Fire behavior Fire danger Fuel type classification Fuel mapping Fuel model.
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Why is the Danger Cylinder Dangerous in the P3P Problem? 被引量:5
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作者 ZHANG Cai-Xia HU Zhan-Yi 《自动化学报》 EI CSCD 北大核心 2006年第4期504-511,共8页
The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution a... The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution analysis,which is also a key research issue of the problem.In this paper,we prove that given 3 control points,if the camera's optical center lies on the so-called“danger cylinder”and is enough far from the supporting plane of control points,the corresponding P3P problem must have 3 positive solutions.This result can bring some new insights into a better understanding of the multi-solution problem.For example,it is shown in the literature that the solution of the P3P problem is instable if the optical center lies on this danger cylinder,we think such occurrence of triple-solution is the primary source of this instability. 展开更多
关键词 The P3P problem the danger cylinder instability of solution
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