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估危副词“险些”的话语关联与语义情态 被引量:1
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作者 赵春利 阮秀娟 《汉语学习》 CSSCI 北大核心 2020年第6期3-16,共14页
本文以语义语法为理论指导,按照从话语、句法到语义的逻辑顺序,提取出估危副词“险些”的“危未暗庆义”。首先,前人的研究可分成比附解释和独立研究两个阶段,并取得了丰硕成果,但受制于理论方法,没有把话语关联、句法分布、语义类型结... 本文以语义语法为理论指导,按照从话语、句法到语义的逻辑顺序,提取出估危副词“险些”的“危未暗庆义”。首先,前人的研究可分成比附解释和独立研究两个阶段,并取得了丰硕成果,但受制于理论方法,没有把话语关联、句法分布、语义类型结合起来准确提取语法意义。其次,从话语的因果性来看,“险些”句的话语功能是“因情估危”,而所因之情主要有被动遭受类、应急行为类、意外事故类、主动对抗类四个语义类型。再次,从单句分布来看,副词“险些”在句法位置上遵循“已前将后”的排序规则,其谓语动词具有“结果性、非控性、违愿性、危急性”四个语义特征,整个“险些”后果句大致可分为:生命丧失类、能力失控类、事故引变类、关系失衡类。最后,提取估危副词“险些”的“危而未发”的认知义及其暗含“庆幸”的情态义。 展开更多
关键词 些” 估危副词 因情估危 已前将后 危未暗庆
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风险管理的CVaR法及其在银行信用风险度量中的运用 被引量:1
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作者 顾胥 蒲勇健 雍少宏 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2004年第11期125-127,133,共4页
作为银行主要风险的信用风险,在中国经济体制转轨时期表现得更加尖锐。鉴于现有测度体系对风险度量方法的研究和探索存在一定缺陷,笔者通过引入一种VaR的修正模型CVaR,率先将此方法运用于度量信用风险,建立了具体的数学模型,给出了求解... 作为银行主要风险的信用风险,在中国经济体制转轨时期表现得更加尖锐。鉴于现有测度体系对风险度量方法的研究和探索存在一定缺陷,笔者通过引入一种VaR的修正模型CVaR,率先将此方法运用于度量信用风险,建立了具体的数学模型,给出了求解方法及步骤,从而测算出银行贷款组合的CVaR值,得到了银行信用风险的预警值,并总结出目前CVaR风险测度法在我国运用的难度,最后提出建议。 展开更多
关键词 信用风 VALUE-AT-RISK CONDITIONAL VALUE-AT-RISK
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商业银行信贷风险的成因及控制对策 被引量:2
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作者 李飏 陈志芳 《特区经济》 2016年第11期65-66,共2页
信贷风险是银行业最突出、最集中的问题。一个良好的信贷体制对国民经济的发展以及银行的进步具有重大意义。本文分析了商业银行信贷风险产生的原因,针对重点行业进行行业风险分析,并提出了控制对策。
关键词 商业银行信贷 信贷风 控制
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论“险些”的词汇化——兼论同义词语词汇化过程中的交互影响 被引量:2
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作者 陈秀清 《新疆大学学报(哲学社会科学版)》 CSSCI 2018年第2期139-144,共6页
"险些"是现代汉语中比较常见的一个词语,它具有非常特殊的词汇化历程。"险"本身在不晚于宋朝就已经发展出和现代汉语中"险些"相当的语义和用法,但此后遭遇汉语双音化的大潮,需要和其它词语进行结合实现... "险些"是现代汉语中比较常见的一个词语,它具有非常特殊的词汇化历程。"险"本身在不晚于宋朝就已经发展出和现代汉语中"险些"相当的语义和用法,但此后遭遇汉语双音化的大潮,需要和其它词语进行结合实现双音化,而与之结合的词语只是起到填充音节的作用,在语义上并无贡献。"险"模仿了同义词语"争些"的构词方式,后加"些"形成了"险些"一词,后来又受同义词语"几乎"的影响出现"险乎"这一变体。除此之外,还出现过其它变体"险一点""险一些"。这些都反映了"险些"在词汇化过程中具有一定程度的不稳定性,一直在试图模仿其它词语,摇摆于多个形式之间。 展开更多
关键词 争些 几乎 词汇化 羡余否定
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“风险”探源与辨析
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作者 王世进 《山西高等学校社会科学学报》 2019年第8期98-102,共5页
文章通过溯源“风”字和“险”字的本义及其概念演变,着重考察先秦以来“风”观念中蕴含着的多种“险”之内涵,辨析“风险”一词的源起与变迁,并且还将其与英文“risk”一词进行比照,寻求二者含义上和翻译上的关联性。
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说“险”的形义与训诂问题
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作者 洪德荣 《励耘语言学刊》 CSSCI 2018年第1期303-312,共10页
“险”是古汉语的常用字,通过对文字构形的考察,“险”字不见于甲骨金文,而见于战国秦汉简牍中。在古文字中,《郭店楚简·老子甲》简5中的■可读为“深”,《上博(七)·凡物流形》中的“佥”字应读为“俭”,而楚文字的“■”应... “险”是古汉语的常用字,通过对文字构形的考察,“险”字不见于甲骨金文,而见于战国秦汉简牍中。在古文字中,《郭店楚简·老子甲》简5中的■可读为“深”,《上博(七)·凡物流形》中的“佥”字应读为“俭”,而楚文字的“■”应是“险”字较早的来源,已表危急之义。而“险”在训诂意义中,本义应为下陷较低之地,引申指艰难、危险,而不作为坡地等的专有名称。 展开更多
关键词 构形 本义 训诂
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内观认知疗法对医学生焦虑水平、自我效能感和应对方式的干预及机制 被引量:2
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作者 王宇暄 毛富强 +4 位作者 彭悦悦 郭子熊 江珊 王书哲 王新琦 《中国健康心理学杂志》 2024年第5期781-787,共7页
目的:探究内观认知疗法对医学生焦虑水平、自我效能感和应对方式的影响,并考察医学生内观认知疗法干预、自我效能感、应对方式和焦虑水平间的关系,以期为医学生心理健康教育工作和NCT疗法的作用机制研究提供理论支持。方法:采用随机数... 目的:探究内观认知疗法对医学生焦虑水平、自我效能感和应对方式的影响,并考察医学生内观认知疗法干预、自我效能感、应对方式和焦虑水平间的关系,以期为医学生心理健康教育工作和NCT疗法的作用机制研究提供理论支持。方法:采用随机数字表法将70名符合筛选标准的研究对象随机分配到内观认知疗法组和心理健康教育组,每组35人。内观认知疗法组接受为期7天的内观认知疗法干预,心理健康教育组接受相同时间的常规心理健康教育,最终共68人完成试验(内观认知疗法组34人,心理健康教育组34人)。干预前后使用SAS、GSES、SCSQ量表对两组研究对象进行测评。结果:①干预前,内观认知疗法组与心理健康教育组在焦虑,自我效能感,积极和消极应对方式得分上均不存在显著差异。②干预后,内观认知疗法组焦虑得分显著降低(t=5.835;P<0.01),自我效能感和积极应对方式得分均显著升高(t=2.289,4.668;P<0.05),消极应对方式得分不存在显著差异,干预前后心理健康教育组在上述所有量表得分中均不存在显著差异。③干预后,内观认知疗法组自我效能感和积极应对方式得分显著高于心理健康教育组(t=2.653,3.122;P<0.01),焦虑得分显著低于心理健康组(t=2.562;P<0.05)。④中介效应检验方面,内观认知疗法既可以直接影响医学生焦虑水平(β=-0.293,95%CI=-3.755~0.008),也可以通过自我效能感的中介作用(β=-0.307,95%CI=-0.612~-0.028)、积极应对方式的中介作用(β=0.140,95%CI=-0.293~-0.004)及自我效能感和积极应对方式的链式中介作用(β=0.222,95%CI=-0.553~-0.022)间接影响医学生焦虑水平。结论:内观认知疗法是一种能够有效降低医学生焦虑水平的干预手段,既能直接缓解焦虑,也能通过提高医学生自我效能感水平,改善积极应对方式间接降低医学生焦虑水平。 展开更多
关键词 内观认知疗法 医学生 焦虑水平 应对方式 自我效能感
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Pricing Catastrophe Options with Credit Risk in a Regime-Switching Model
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作者 XU Yajuan WANG Guojing 《应用概率统计》 CSCD 北大核心 2024年第4期572-587,共16页
In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space... In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space.By using the measure change technique,we derive the price expressions of catastrophe put options.Moreover,we conduct some numerical analysis to demonstrate how the parameters of the model affect the price of the catastrophe put option. 展开更多
关键词 PRICING catastrophe option credit risk REGIME-SWITCHING measure change
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DYNAMIC ANALYSIS OF A TYPE OF FINANCIAL RISK CONTAGION MODEL INVOLVING IMMUNITY PERIOD AND SELF-RESCUE
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作者 ZHANG Shuang-hui WANG Hai-xia XU Hui-ling 《数学杂志》 2024年第5期413-425,共13页
In this paper,we study the dynamics of a Susceptible-Exposed-Infectious-Recovered(SEIR)nancial risk contagion model with time delay.Using stability theory and Hopf bifurcation theory,equilibria stability and Hopf bifu... In this paper,we study the dynamics of a Susceptible-Exposed-Infectious-Recovered(SEIR)nancial risk contagion model with time delay.Using stability theory and Hopf bifurcation theory,equilibria stability and Hopf bifurcation are analyzed in detail.Based on the epidemic model,we improve it by taking prior prevention and self-rescue into consideration,conclude pre-ventive intensity and self-rescue capabilities e ect the number of infections.At the same time,the analytical conditions for Hopf bifurcation are obtained,and the relevant results are veri ed by numerical simulations. 展开更多
关键词 nancial risk contagion SELF-RESCUE time delay Hopf bifurcation
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Re-searching nasopharyngeal carcinoma
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作者 Ingemar Ernberg ZHENG Shixing ZHOU Xiaoying 《广西医科大学学报》 CAS 2024年第9期1227-1236,共10页
Nasopharyngeal carcinoma(NPC)has been a focus of medical research for more than 100 years,with significant interest emerging over the last 58 years following the identification of the link between the disease and Epst... Nasopharyngeal carcinoma(NPC)has been a focus of medical research for more than 100 years,with significant interest emerging over the last 58 years following the identification of the link between the disease and Epstein-Barr virus(EBV)infection.NPC possesses several distinctive characteristics among human cancers,notably its well-documented global epidemiology,which reveals localized high-incidence regions primarily in Southeast Asia,particularly in the Southern provinces of China near the Pearl river,as well as in Greenland and North Africa.Epidemiological data indicate a marked male predominance,early disease onset,and a nearly 100%prevalence of latent EBV infection in the tumors.Due to lack of consistent pattern of cancer-related mutations in NPC genomes and excessive DNA-methylation in the tumor cells,NPC can be considered"an epigenetic cancer".Despite extensive researches,convincing biological explanations for these unique characteristics remain elusive.Recently,suggestive evidence has been published that specific local variants of EBV may represent major high risk factors.In spite of tumor and virus specific immunity,it has not been possible to use this for improved treatment.Ongoing studies on the role of the local microflora and tumor microenvironment are essential for a comprehensive understanding of host-EBV-tumor interactions.Ultimately,this knowledge aims to enhance diagnosis,disease fractionation,treatment strategies,and potentially prevention of NPC. 展开更多
关键词 nasopharyngeal carcinoma Epstein-Barr virus risk factors EPIGENOME tumor microenvironment
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Earthquake disaster chain model based on complex networks for urban engineering systems
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作者 Lu Zheng Yan Deyu Jiang Huanjun 《Journal of Southeast University(English Edition)》 EI CAS 2024年第3期230-237,共8页
According to news reports on severe earthquakes since 2008,a total of 51 cases with magnitudes of 6.0 or above were analyzed,and 14 frequently occurring secondary disasters were identified.A disaster chain model was d... According to news reports on severe earthquakes since 2008,a total of 51 cases with magnitudes of 6.0 or above were analyzed,and 14 frequently occurring secondary disasters were identified.A disaster chain model was developed using principles from complex network theory.The vulnerability and risk level of each edge in this model were calculated,and high-risk edges and disaster chains were identified.The analysis reveals that the edge“floods→building collapses”has the highest vulnerability.Implementing measures to mitigate this edge is crucial for delaying the spread of secondary disasters.The highest risk is associated with the edge“building collapses→casualties,”and increased risks are also identified for chains such as“earthquake→building collapses→casualties,”“earthquake→landslides and debris flows→dammed lakes,”and“dammed lakes→floods→building collapses.”Following an earthquake,the prompt implementation of measures is crucial to effectively disrupt these chains and minimize the damage from secondary disasters. 展开更多
关键词 EARTHQUAKE disaster chain seismic resilience secondary disaster complex network VULNERABILITY risk level
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Rapid detection and risk assessment of soil contamination at lead smelting site based on machine learning
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作者 Sheng-guo XUE Jing-pei FENG +5 位作者 Wen-shun KE Mu LI Kun-yan QIU Chu-xuan LI Chuan WU Lin GUO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期3054-3068,共15页
A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model cor... A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model correction coefficients.The eXtreme Gradient Boosting(XGBoost)model was used to fit the relationship between the content of heavy metals and environment characteristics to evaluate the soil ecological risk of the smelting site.The results demonstrated that the generalized prediction model developed for Pb,Cd,and As was highly accurate with fitted coefficients(R^(2))values of 0.911,0.950,and 0.835,respectively.Topsoil presented the highest ecological risk,and there existed high potential ecological risk at some positions with different depths due to high mobility of Cd.Generally,the application of machine learning significantly increased the accuracy of pXRF measurements,and identified key environmental factors.The adapted potential ecological risk assessment emphasized the need to focus on Pb,Cd,and As in future site remediation efforts. 展开更多
关键词 smelting site potentially toxic elements X-ray fluorescence potential ecological risk machine learning
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Impact of correlated private signals on continuous-time insider trading
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作者 ZHOU Yonghui XIAO Kai 《运筹学学报(中英文)》 CSCD 北大核心 2024年第3期97-107,共11页
A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establ... A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed. 展开更多
关键词 continuous-time insider trading risk neutral private correlated signals linear bayesian equilibrium market depth residual information
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Assessing the Hazard Grade of Birdstrike in Spring at Baita Airport, Hohhot 被引量:13
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作者 李新 杨贵生 +4 位作者 姜春扬 张世峰 王晓东 范作杰 邢莲莲 《Zoological Research》 CAS CSCD 北大核心 2007年第2期161-166,共6页
Between March and May 2005, bird communities in four sample plots at Baita Airport were studied using strips methods in Hohhot, Inner Mongolia. A total of 59 species belonging to 10 orders and 26 families were recorde... Between March and May 2005, bird communities in four sample plots at Baita Airport were studied using strips methods in Hohhot, Inner Mongolia. A total of 59 species belonging to 10 orders and 26 families were recorded. Based on the principles of avian community ecology, the community parameters were discussed, including the comparative importance value, distribution coefficient, density and probability of interactive encounter. By analyzing these indices, combined with their flight behaviors at the airport and its neighbourhood, we identified bird species that have the potential to threaten flight security at Baita Airport; The results showed that the 23 bird species including magpie and red falcon are the most hazard to flight security and the eight bird species including sparrow Hawk and Greenfinch are the hazard. Furthermore, we assessed the bird species' different hazard grades to flight security. 展开更多
关键词 Birdstrike Hazard grade Hohhot Baita airport
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Ecological risk assessment of heavy metals in sediments of Xiawan Port based on modified potential ecological risk index 被引量:40
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作者 祝慧娜 袁兴中 +7 位作者 曾光明 蒋敏 梁婕 张长 尹娟 黄华军 刘智峰 江洪炜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第6期1470-1477,共8页
Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical... Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical speciation of heavy metals. Xiawan Port, a typical region contaminated by industrial production, was selected as a case study area. The total concentrations and chemical speciation of heavy metals in sediments of Xiawan Port were analyzed. The experimental data indicate that Xiawan Port is seriously polluted by heavy metals, especially by Cd. The risks of heavy metals are evaluated by RI, RAC and MRI, respectively. The resluts of MRI show that the risks of heavy metals are in the decreasing order of Cd〉Pb〉Cu〉Zn. Comparison of results by different methods reveals that MRI integrates the characters of RI and RAC. MRI is recognized to be useful for risk managemnt of heavy metals in sediments. 展开更多
关键词 heavy metals chemical speciation modified potential ecological risk index SEDIMENTS Xiawan Port
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Migration and transfer of chromium in soil-vegetable system and associated health risks in vicinity of ferro-alloy manufactory 被引量:6
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作者 廖映平 王振兴 +3 位作者 杨志辉 柴立元 陈建群 袁平夫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第11期2520-2527,共8页
Study was carried out to analyze the distribution and migration patterns,soil-to-plant transfer and potential health risks of chromium in soil-vegetable system in areas near a ferro-alloy manufactory in Hunan province... Study was carried out to analyze the distribution and migration patterns,soil-to-plant transfer and potential health risks of chromium in soil-vegetable system in areas near a ferro-alloy manufactory in Hunan province.The results show that soils near sewer outlet,sewer channel and in control area are averaged 2 239.5,995.33 and 104.9 mg/kg,respectively.The total Cr has a relative accumulation in soil depth of 200-400 mm near the sewer outlet,mainly enriches in the surface layer(0-200 mm) near the sewer channel and decreases gradually in unpolluted soils.The differential concentration level of enrichment between layers is little.The results also indicate that the three vegetables of celery,lettuce and Chinese cabbage are able to convert the potentially toxic Cr(Ⅵ) species into the non-toxic Cr(Ⅲ) species,and the chromium contents in the edible parts of the vegetables are averaged 11.95 mg/kg.The transfer factors of the three vegetables follow the order:Chinese cabbage lettuce celery.The estimated total daily intake of chromium substantially exceeds the dietary allowable value,which may pose health risks to local population. 展开更多
关键词 heavy metal CHROMIUM MIGRATION transfer factor health risk soil VEGETABLE
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Product reliability assessment based on proportional hazard degradation model 被引量:4
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作者 苏春 张烨 张恒 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期480-483,共4页
In order to evaluate the reliability of long-lifetime products with degradation data, a new proportional hazard degradation model is proposed. By the similarity between time-degradation data and stress-accelerated lif... In order to evaluate the reliability of long-lifetime products with degradation data, a new proportional hazard degradation model is proposed. By the similarity between time-degradation data and stress-accelerated lifetime, and the failure rate function of degradation data which is assumed to be proportional to the time covariate, the reliability assessment based on a proportional hazard degradation model is realized. The least squares method is used to estimate the model's parameters. Based on the failure rate of the degradation data and the proportion function of the known time, the failure rate and the reliability function under the given time and the predetermined failure threshold can be extrapolated. A long life GaAs laser is selected as a case study and its reliability is evaluated. The results show that the proposed method can accurately describe the degradation process and it is effective for the reliability assessment of long lifetime products. 展开更多
关键词 degradation data hazard function proportional hazard model reliability assessment
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Bayes discriminant analysis method to identify risky of complicated goaf in mines and its application 被引量:25
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作者 胡玉玺 李夕兵 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期425-431,共7页
A Bayes discriminant analysis method to identify the risky of complicated goaf in mines was presented. Nine factors influencing the stability of goaf risky, including uniaxial compressive strength of rock, elastic mod... A Bayes discriminant analysis method to identify the risky of complicated goaf in mines was presented. Nine factors influencing the stability of goaf risky, including uniaxial compressive strength of rock, elastic modulus of rock, rock quality designation (RQD), area ratio of pillar, ratio of width to height of pillar, depth of ore body, volume of goaf, dip of ore body and area of goal, were selected as discriminant indexes in the stability analysis of goal. The actual data of 40 goals were used as training samples to establish a discriminant analysis model to identify the stability of goaf. The results show that this discriminant analysis model has high precision and misdiscriminant ratio is 0.025 in re-substitution process. The instability identification of a metal mine was distinguished by using this model and the identification result is identical with that of practical situation. 展开更多
关键词 GOAF risky identification Bayes discriminant analysis metal mines
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Survey of damaging pests and preliminary assessment of forest health risks to the long term success of Pinus radiata introduction in Sichuan, southwest China 被引量:3
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作者 李荣伟 肖育贵 +4 位作者 周建华 吴宗兴 阎红 黄泉 刘千里 《Journal of Forestry Research》 CAS CSCD 2008年第2期85-100,共16页
Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area... Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area of Aba Prefecture. Within this region a total area of 26 000 ha have been identified through climate matching as suitable and a further 63 000 ha potentially suitable for environmental plantings of P. radiata. The plantations are being established in widely separated small patches on steep and degraded slopes along the dry river valley The newly introduced P. radiata are exposed to two kinds of forest health risks: they may be attacked by (a) indigenous pathogens and pests against which they may not possess any resistance or (b) by inadvertently introduced foreign pests or pathogens. This paper presents a survey of the potential damaging pests and a preliminary assessment of forest health risks facing the P. radiata plantations over a much longer timeframe than the initial phase of introduction and early plantation establishment. An empirical appmach was adopted to evaluate forest health risks by a combination of literature review, examination of historical records of pest and disease outbreaks in the surrounding conifemus forests, field surveys and inspections, specimen collection and identification, and most importantly, expert analysis of the likelihood of attack by specific pests and pathogens and the subsequent impact of such attacks. The assessment identified some specific forest health risks to the long-term success of P. radiata introduction in this area. These risks are closely associated with the indigenous pests and pathogens of the two native pine species, P. tabulaeformis and P. armondii since these pests and pathogens are considered more likely to establish on P. radiata over time. Exotic pests and pathogens are of a quarantine concern at present. Based on the results of assessment, recommendations are pmvided to improve forest vigour and to reduce the forest health risks posed by indigenous as well as exotic pests and pathogens to the introduced P. radiata. Ways to increase the ability to manage the forest health risks once a particular pest infestation and disease eventuates are also recommended. Although detrimental to the survival and growth of the introduced P. radiata, the impact of identified forest health risks are not considered to be fatal to the long term success ofP. radiata in this area. 展开更多
关键词 Pinus radiata species introduction dry river valley forest health risks
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Comprehensive ecological risk assessment for heavy metal pollutions in three phases in rivers 被引量:5
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作者 张颖 周军 +3 位作者 高凤杰 张宝杰 马彪 李立清 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3436-3441,共6页
Literature lacked in providing a comprehensive research on heavy metal detection in aquatic, biological and sedimentary states of rivers. The present study was imparted with all these three components of the river. He... Literature lacked in providing a comprehensive research on heavy metal detection in aquatic, biological and sedimentary states of rivers. The present study was imparted with all these three components of the river. Heavy metal toxicity or pollution index was used as a tool for ecological risk assessment by considering the single state studies conducted by many researchers. An intensive ecological risk assessment model was constructed and heavy metals were indicated as a serious threat to the environment. The model was applied to determining five toxic heavy metals in three states of the Songhua River. According to the ecological risk index, heavy metal pollution in three phases was categorized as aquatic〉biological〉sedimentary, while the overall descending order of heavy metal ecological risk index was as Cd〉Hg〉As〉Pb〉Cr. Cd and Hg were selected as the priority pollutants of Songhua River. 展开更多
关键词 comprehensive ecological risk assessment priority pollutants selection heavy metal Songhua River
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