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Smoke Hazard Assessment Model Based on Fire Dynamics Simulator and FED Model 被引量:2
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作者 Nianfeng Li Shang Zhou +1 位作者 Zhiguo Xiao Yifei Zhao 《Journal of Computer and Communications》 2020年第9期81-93,共13页
Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the vi... Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable. 展开更多
关键词 smoke Hazard smoke Visualization Integrated smoke Assessment model FDS FED
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STUDY ON INFLAMMATORY CELLS IN BALF OF SMOKE-INDUCED CHRONIC BRONCHITIS RAT MODEL
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作者 李庆云 黄绍光 +3 位作者 吴华成 程齐俭 项轶 万欢英 《Journal of Shanghai Second Medical University(Foreign Language Edition)》 2004年第1期1-8,共8页
Objective To establish a smoke-induced chronic bronchitis rat model and evaluate the patho-logical change semi-quantitatively, and study the characteristics of the inflammatory cells in the bronchoalveolar lav-age flu... Objective To establish a smoke-induced chronic bronchitis rat model and evaluate the patho-logical change semi-quantitatively, and study the characteristics of the inflammatory cells in the bronchoalveolar lav-age fluid (BALF) in various stages. Methods Chronic bronchitis sequential rat model was established by passively inhaling smoke mixture. Experiments were performed in 30 young male Sprague-Dawley rats, which comprised 5 groups in random, i.e.,4 chronic bronchitis model groups and 1 control group. After stained with hematoxylin and eosin, the specimens were studied by semi-quantitative method to evaluate the morphologic changes in various stages. Meanwhile, the inflammatory cells of the BALF and the activity of myeloperoxidase (MPO) of lung tissue were analysed. Results During the process of the chronic bronchitis, the pathologic score was increasing as time went on, and the typical morphologic changes of chronic bronchitis emerged in the group 7 weeks. The total number of inflammatory cells in BALF was increasing as time went on, correlated with the pathologic scores (P <0.01). And the percentage of lymphocyte increased as well as positively correlated with pathologic scores (P < 0. 05) , whereas that of macrophage decreased and negatively correlated with pathologic scores (P <0. 05). The MPO lever of lung tissue was correlated with the pathologic scores (P < 0. 01). But the percentage of the neutrophil in the BALF was just in a high level during the first week, then it maintained relatively lower. Conclusion Smoke-induced chronic bronchitis is a slowly progressive inflammation process. The model we established is convenient and simple for the longitudinal study on the inflammatory process of chronic bronchitis and the therapy in the early stage. The semi-quantitative evaluation for the pathological change is with much more value. During the inflammatory sequential process of early stage of chronic bronchitis, the cellular characteristics are similar to that of the common chronic inflammation. 展开更多
关键词 smoke chronic bronchitis inflammation cells animal model myeloperoxidase pathological evaluation
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Network Modeling of Inammatory Dynamics Induced by Biomass Smoke Leading to Chronic Obstructive Pulmonary Disease
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作者 Hai-shan Yu Zhi-chao Pan Jie-lou Liao 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第3期359-366,368,共9页
Chronic obstructive pulmonary disease(COPD) is a chronic inflammatory disorder characterized by airflow obstruction and progressive damage of lung tissues. As currently more than 3 billion people use biomass fuel for ... Chronic obstructive pulmonary disease(COPD) is a chronic inflammatory disorder characterized by airflow obstruction and progressive damage of lung tissues. As currently more than 3 billion people use biomass fuel for cooking and heating worldwide, exposure to biomass smoke(BS) is recognized as a significant risk factor for COPD. Recent clinical data have shown that BS-COPD patients have a Th2-type inflammatory profile significantly different from that in COPD induced by cigarette smoke. As COPD is essentially proinflammatory,however, the mechanism underlying this Th2-type anti-inflammatory profile remains elusive.In this work, a network model is applied to study BS-induced inflammatory dynamics. The network model involves several positive feedback loops, activations of which are responsible for different mechanisms by which clinical phenotypes of COPD are produced. Our modeling study in this work has identified a subset of BS-COPD patients with a mixed M1-and Th2-type inflammatory profile. The model’s prediction is in good agreement with clinical experiments and our in silico knockout simulations have demonstrated several important network components that play an important role in the disease. Our modeling study provides novel insight into BS-COPD progression, offering a rationale for targeted therapy and personalized medicine for treatment of the disease in future. 展开更多
关键词 Network model Inflammatory dynamics Positive feedback loops Biomass smoke Chronic obstructive pulmonary disease
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发烟剂的大气环境影响评价预测程序(smokeEIA)设计 被引量:1
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作者 张志生 张红雨 +1 位作者 王乃岩 商丹红 《华东船舶工业学院学报》 北大核心 2005年第3期87-90,共4页
以高斯模型为基础,用VisualBasic6.0程序编写了发烟剂的大气环境影响模型(smokeEIA),主要包括数值计算和烟幕的影响评价两方面内容。针对不同发烟剂,模型可适时添加污染物种类和质量标准。通过参数设置,根据所选择的污染物评价因子,可... 以高斯模型为基础,用VisualBasic6.0程序编写了发烟剂的大气环境影响模型(smokeEIA),主要包括数值计算和烟幕的影响评价两方面内容。针对不同发烟剂,模型可适时添加污染物种类和质量标准。通过参数设置,根据所选择的污染物评价因子,可计算在某一风速时不同大气稳定度下,下风向不同距离处污染物的地面浓度,并对计算结果进行大气环境影响评价。 展开更多
关键词 环境影响评价 发烟剂 预测模型 大气扩散模式
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A Structure Preserving Numerical Method for Solution of Stochastic Epidemic Model of Smoking Dynamics 被引量:4
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作者 Ali Raza Muhammad Rafiq +3 位作者 Nauman Ahmed Ilyas Khan Kottakkaran Sooppy Nisar Zafar Iqbal 《Computers, Materials & Continua》 SCIE EI 2020年第10期263-278,共16页
In this manuscript,we consider a stochastic smoking epidemic model from behavioural sciences.Also,we develop a structure preserving numerical method to describe the dynamics of stochastic smoking epidemic model in a h... In this manuscript,we consider a stochastic smoking epidemic model from behavioural sciences.Also,we develop a structure preserving numerical method to describe the dynamics of stochastic smoking epidemic model in a human population.The structural properties of a physical system include positivity,boundedness and dynamical consistency.These properties play a vital role in non-linear dynamics.The solution for nonlinear stochastic models necessitates the conservation of these properties.Unfortunately,the aforementioned properties of the model have not been restored in the existing stochastic methods.Therefore,it is essential to construct a structure preserving numerical method for a reliable analysis of stochastic smoking model.The usual explicit stochastic numerical methods are time-dependent and violate most of the structural properties.In this work,we have developed the implicitly driven explicit method for the solution of stochastic smoking model.It is also proved that the newly developed method sustains all the aforementioned properties of the system.Finally,the convergence analysis of the newly developed method and graphical illustrations are presented. 展开更多
关键词 Smoking model stochastic numerical techniques CONVERGENCE
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基于WRF-SMOKE-CMAQ模型的济南市清洁取暖改造环境效益评估 被引量:1
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作者 张怀成 白浩强 +5 位作者 许宏宇 孙晓艳 夏志勇 陈妍君 王兆军 张桂芹 《环境污染与防治》 CAS CSCD 北大核心 2023年第8期1169-1175,共7页
为评估济南市清洁取暖改造后的环境效益,以2018年为基准年,采用WRF-SMOKE-CMAQ模型模拟计算了2019—2021年济南市冬季清洁取暖改造后各项污染物改善率,并分析了不同污染时段和不同气象条件下污染物的改善率。结果表明:济南市清洁取暖改... 为评估济南市清洁取暖改造后的环境效益,以2018年为基准年,采用WRF-SMOKE-CMAQ模型模拟计算了2019—2021年济南市冬季清洁取暖改造后各项污染物改善率,并分析了不同污染时段和不同气象条件下污染物的改善率。结果表明:济南市清洁取暖改造后各污染物浓度均有不同程度的改善,其中CO、SO_(2)和细颗粒物(PM_(2.5))基准年改善率(模拟的污染物浓度相对于基准年同时段的改善率)较大,主要与散煤燃烧CO、SO_(2)和PM_(2.5)的排放因子较大有关,2020年年均改善率(模拟的污染物浓度相对于去年同时段的改善率)最大,主要与污染物的减排量最多有关;各污染物改善呈现出明显的区域差异,清洁取暖改造户数较多的区县污染物年均改善率较高;各污染物在空气严重污染时段基准年改善率均最大,重度污染时段次之,并且在不利气象条件时基准年改善率也最大,说明清洁取暖改造对冬季不利气象条件造成的高污染物浓度起到明显的削峰作用,可为济南市空气质量持续改善提供有力保障。 展开更多
关键词 WRF-smoke-CMAQ模型 清洁取暖 环境效益评估 改善率
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A New Model of Erythrocyte Injury in Rats with Xueyu Syndrome and Its Application
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作者 陈琢 焦新福 +1 位作者 叶望云 舒沪英 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2000年第4期327-329,共3页
A new model of rats with Xueyu Syndrome which was characterized by erythrocyte injury was presented. Observation of morphology and functions of erythrocytes showed that this model could not only be used as a model i... A new model of rats with Xueyu Syndrome which was characterized by erythrocyte injury was presented. Observation of morphology and functions of erythrocytes showed that this model could not only be used as a model in Xueyu Syndrome and Huoxuequyu treatment study, but also be used for screening of drugs with the effect of preventing and treating damage of red blood cells. 展开更多
关键词 erythroeyte injury Xueyu Syndrome lipid peroxidation RAT smoking model
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Application of causal model to maternal smoking cessation intervention in pregnancy
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作者 Rashid M. Ansari John B. Dixon +1 位作者 Colette Browning Saiqaa Y. Ansari 《Open Journal of Preventive Medicine》 2013年第4期347-354,共8页
The adverse effects of maternal smoking during pregnancy on both the offspring and women are well known. The main objective of this research article is to provide health professional causal modelling approach to make ... The adverse effects of maternal smoking during pregnancy on both the offspring and women are well known. The main objective of this research article is to provide health professional causal modelling approach to make a more comprehensive assessment of major determinants of smoking behaviour during and after pregnancy and consequently the outcomes of pregnant women smoking which are adversely affecting both the offspring and pregnant women. The causal model based on theory and evidence was modified and applied to material smoking cessation intervention to control the adverse effects of smoking on offspring obesity and neurodevelopment. In this approach a generic model links behavioural determinants, causally through behaviour, to physiological and biochemical variables, and health outcomes. It is tailored to context, target population, behaviours and health outcomes. The model provides a rational guide to appropriate measures, intervention points and intervention techniques, and can be tested quantitatively. The causal modelling approach showed promising results which can be used to help maternal smoking women to understand the risk of smoking and help them to quit smoking. The regression analysis of maternal smoking women BMI (n = 1000) on offspring BMI was statistically significant, p 0.05). This supported the hypothesis that maternal smoking women BMI during pregnancy is an important determinant of offspring obesity and consequently the risk factors of cardiovascular development. The causal modelling approach is unique as it provides an incentive to health professional to use these models to target any important and modifiable determinants of the maternal smoking behaviour and decrease the risk of adverse pregnancy outcomes for the offspring and the mother. 展开更多
关键词 INTERVENTION PREGNANT Women MATERNAL SMOKING CAUSAL modelling OFFSPRING
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Stability Analysis of Chain, Mild and Passive Smoking Model
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作者 Abeer A. Alshareef H. A. Batarfi 《American Journal of Computational Mathematics》 2020年第1期31-42,共12页
In this paper, the global stability of free smoking equilibrium point was evaluated and presented graphically. The linear stability of a developed mathematical model illustrates the effect on the population of chain, ... In this paper, the global stability of free smoking equilibrium point was evaluated and presented graphically. The linear stability of a developed mathematical model illustrates the effect on the population of chain, mild and passive smokers. MATLAB programming was used to simulate the solutions, the reproduction number R0 and the nature of the equilibria. 展开更多
关键词 SMOKING model STABILITY Analysis Global STABILITY and LYAPUNOV Method Qualitative Behavior Passive smokeRS
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Peer Pressure and Family Smoking Habits Influence Smoking Uptake in Teenage Boys Attending School: Multilevel Modeling of Survey Data
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作者 Shafquat Rozi Sadia Mahmud +1 位作者 Gillian Lancaster Nida Zahid 《Open Journal of Epidemiology》 2016年第3期167-172,共6页
Introduction: Among young teens, about one in five smokes worldwide. Adolescents spend a considerable amount of their time in school, and the school environment is therefore important for child health practices and ou... Introduction: Among young teens, about one in five smokes worldwide. Adolescents spend a considerable amount of their time in school, and the school environment is therefore important for child health practices and outcomes. Objectives: We aimed to investigate the impact on smoking behavior of the school environment and the personal characteristics of male teenage students attending schools in Pakistan, taking into account the survey sampling structure. Methods: A two-stage cluster sampling with stratification was employed, and we interviewed 772 male secondary school students. We adopted random effect and generalizing estimating equation models. Results: Peer pressure in particular had a strong influence on adolescents smoking;those whose friends smoked were up to 6 times more likely to smoke. Family smoking was also significantly associated with adolescents smoking, but those students whose mother was educated were 50% less likely to smoke. The fitted random effect model indicated that the between school variability was significant (p-value < 0.01), indicating differences in smoking habits between schools. A random coefficient model showed that variability among schools was not significantly different for public and private schools. Conclusion: Public health campaigns for smoking cessation should target not only the individual but also the families of adolescents attending schools. 展开更多
关键词 Teenage Smoking Multilevel model Binary Outcome Public & Private Schools
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Factors Related to Smoking Initiation by Adolescents and a Causal Model for Early Smoking Initiation
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作者 Tomoko Kawabata Yuko Tomari Junko Takemura 《Health》 2017年第8期1128-1144,共17页
The fact that adolescents are starting to smoke at a younger age is an issue in Japan, but no studies have identified the causal relationship between factors affecting this early smoking initiation. The aim of this st... The fact that adolescents are starting to smoke at a younger age is an issue in Japan, but no studies have identified the causal relationship between factors affecting this early smoking initiation. The aim of this study was to produce a causal model of factors related to smoking initiation by adolescents and early smoking initiation. A specially prepared questionnaire containing 72 items extracted from previous studies as constituting factors in smoking by minors was administered to 215 students aged ≥ 20 years. All items were rated on a 5-point Likert scale according to how closely they were connected to smoking initiation. Exploratory factor analysis of factors related to smoking initiation by adolescents was performed, after which the data were analyzed by structural equation modeling. The following five factors were found to affect early smoking initiation: self-disgust, growing up in an inappropriate home environment, reduction of norms consciousness for adolescents’ smoking, perception of smoking as stress relief, and inadequate knowledge of the dangers of smoking. The findings suggest that antismoking education for adolescents should provide more information on smoking, and that assessing the home environment and mediating in the parent-child relationship, increasing self- control of stress, emotions, and the capacity for self-regulation, and incorporating parents into antismoking education may also be important. 展开更多
关键词 ADOLESCENCE SMOKING INITIATION Factor EARLY SMOKING INITIATION Structural EQUATION modeling
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城市浅埋隧道自然排烟竖井临界间距研究
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作者 王洁 王璐 姜学鹏 《消防科学与技术》 CAS 北大核心 2024年第1期65-69,共5页
竖井间距会改变竖井内外压差,当竖井内外压差为0时,隧道火灾烟气将无法排出,此时竖井对应位置为竖井临界间距。由竖井内外口压差理论分析,给出竖井临界间距理论模型,再采用FDS模拟进行仿真验证。结果表明:设置竖井可明显降低隧道温度,... 竖井间距会改变竖井内外压差,当竖井内外压差为0时,隧道火灾烟气将无法排出,此时竖井对应位置为竖井临界间距。由竖井内外口压差理论分析,给出竖井临界间距理论模型,再采用FDS模拟进行仿真验证。结果表明:设置竖井可明显降低隧道温度,竖井间距为临界间距时,温度下降幅度接近150℃,人员疏散路径温度低于60℃,竖井排烟效率在55%~80%,可有效进行竖井排烟;当竖井间距大于竖井临界间距时,隧道内烟气压强小于竖井出口处风压,竖井排烟效率低于50%。 展开更多
关键词 城市浅埋隧道 竖井排烟 竖井临界间距模型 自然排烟
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烟草烟雾与机动车尾气暴露建立的大鼠慢性阻塞性肺疾病模型比较
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作者 李德富 叶园园 +5 位作者 章洪萍 侯润华 何耀军 张春云 胡杰英 陈蕊 《解放军医学杂志》 CAS CSCD 北大核心 2024年第9期1038-1044,共7页
目的对比烟草烟雾(CS)暴露和机动车尾气(MVE)暴露两种方法构建的大鼠慢性阻塞性肺疾病(COPD)模型的模拟程度。方法将24只雄性SD大鼠按随机数字表分为对照组、CS组与MVE组,每组8只。CS组与MVE组大鼠分别采用CS或MVE暴露建立COPD模型。建... 目的对比烟草烟雾(CS)暴露和机动车尾气(MVE)暴露两种方法构建的大鼠慢性阻塞性肺疾病(COPD)模型的模拟程度。方法将24只雄性SD大鼠按随机数字表分为对照组、CS组与MVE组,每组8只。CS组与MVE组大鼠分别采用CS或MVE暴露建立COPD模型。建模结束后,检测各组大鼠的肺功能;收集大鼠支气管肺泡灌洗液(BALF),检测其中炎性细胞数、炎性因子白细胞介素(IL)-6和肿瘤坏死因子(TNF)-α及黏蛋白5AC(MUC5AC)含量;HE染色观察肺组织和气道病理变化;PAS染色检测气道杯状细胞增生情况。结果与对照组比较,CS组和MVE组大鼠的肺功能参数吸气阻力(RI)、肺总量(TLC)、肺静态顺应性(Cchord)均明显增高(P<0.05),而呼气流速参数FEV50/FVC明显降低(P<0.05);与MVE组相比,CS组大鼠的RI、TLC、Cchord均明显增高(P<0.05),FEV50/FVC降低(P<0.05)。肺组织HE染色结果显示,CS组和MVE组大鼠平均肺泡截距(MLI)均高于对照组(P<0.05),CS组MLI高于MVE组(P<0.05)。CS组和MVE组大鼠BALF中白细胞、中性粒细胞、巨噬细胞和淋巴细胞数,以及IL-6、TNF-α含量均高于对照组(P<0.05);且CS组中炎性细胞数、IL-6及TNF-α含量均高于MVE组(P<0.05)。肺组织PAS染色结果显示,CS组和MVE组大鼠大气道杯状细胞较对照组均明显增多(P<0.05),且CS组杯状细胞数高于MVE组(P<0.05);CS组和MVE组BALF中MUC5AC含量均高于对照组(P<0.05),且CS组大鼠BALF中MUC5AC含量高于MVE组(P<0.05)。结论应用CS或MVE暴露均可建立大鼠COPD模型,但CS暴露比MVE暴露能更好地模拟COPD急性加重期特征。 展开更多
关键词 慢性阻塞性肺疾病 烟草烟雾 机动车尾气 动物模型
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Experimental Simulation Study of Smoke Flowing Properties in Running Train
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作者 杜红兵 戚宜欣 马国超 《International Journal of Mining Science and Technology》 SCIE EI 1999年第2期183-186,共4页
Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a w... Tbe experimental simulation has been performed to investigate the smoke flowing properties within the 1/5 reduced-scale model of a sleeping carriage. The velocity field of the running train on fire is simulated in a wind tunnel of the State Key Lab of Fire Science, USTC (University of Science & Technology of China). In this paper, the fire-smoking properties and the variation of the temperature field in the sleeping carriage are analyzed. This paper introduces the simulation method of reducedscale experiment about the running train and the analysis or the experimental data. It provides the basis of experiment for the running train’s fire-safety and full-scale experiment in the future study. 展开更多
关键词 reduce-scale model of running CARRIAGE fire-smoke flowing temperature field simulative experiment
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隧道单向大间距点式排烟设计方法研究
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作者 姜学鹏 张子迪 陈玉远 《安全与环境学报》 CAS CSCD 北大核心 2024年第6期2220-2229,共10页
排烟口间距≤60 m、开启数量不少于3处的重点排烟模式已在隧道中广泛应用。针对其存在因间距小而排烟口数量多、漏风量大问题,提出了火源上游侧纵向通风+下游侧精准开启1处排烟口(含多个排烟阀)的新型单向大间距点式排烟模式。考虑参数... 排烟口间距≤60 m、开启数量不少于3处的重点排烟模式已在隧道中广泛应用。针对其存在因间距小而排烟口数量多、漏风量大问题,提出了火源上游侧纵向通风+下游侧精准开启1处排烟口(含多个排烟阀)的新型单向大间距点式排烟模式。考虑参数间相互关联性,基于特殊消防设计思路,构建了单向大间距点式排烟模式有效性评估模型,并提出了优化设计方法。依托实际隧道工程,通过数值模拟对新型点式排烟模式进行了研究,探讨了不同排烟阀个数、纵向风速、排烟口间距及坡度对烟控效果的影响,结果表明:考虑隧道火灾最不利情况火源功率50 MW下,推荐纵向风速3.67 m/s、1处排烟口(含12个排烟阀)、排烟口间距300 m的通风排烟方案。并采用缩尺寸模型试验,验证了新型点式排烟设计的合理性。 展开更多
关键词 安全工程 隧道火灾 单向大间距 点式排烟 设计方法 评估模型
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1990-2019年中国归因于吸烟因素的食管癌疾病负担分析 被引量:1
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作者 马一楷 王耿 刘彩霞 《中山大学学报(医学科学版)》 CAS CSCD 北大核心 2024年第4期593-601,共9页
【目的】分析1990-2019年中国归因于吸烟因素的食管癌疾病负担变化趋势。【方法】利用Joinpoint4.9.1.0软件基于GBD2019在1990-2019年归因于吸烟因素的中国食管癌死亡人数、死亡率、伤残寿命调整年(DALY)数据和国家人口数据,描述疾病负... 【目的】分析1990-2019年中国归因于吸烟因素的食管癌疾病负担变化趋势。【方法】利用Joinpoint4.9.1.0软件基于GBD2019在1990-2019年归因于吸烟因素的中国食管癌死亡人数、死亡率、伤残寿命调整年(DALY)数据和国家人口数据,描述疾病负担变化趋势,利用年龄-时期-队列模型分析年龄、时期、队列对归因于吸烟的食管癌疾病负担变化趋势的影响。【结果】Joinpoint分析结果显示,归因于吸烟因素的食管癌标化死亡率和DALY率的平均年变化百分比(AAPC)值分别为-1.42%和-1.72%,女性的标化死亡率和DALY率AAPC值分别为-3.26%和-3.70%,男性的标化死亡率和DALY率AAPC值分别为-1.28%和-1.54%。归因于吸烟因素的年龄别疾病负担变化趋势显示,各年龄段死亡率和DALY率随时间变化整体呈下降趋势。40~45岁段下降速度最快,死亡率和DALY率AAPC值分别为-3.05%和-3.04%,其次为45-49岁年龄段,AAPC值分别为-2.73%和-2.72%。年龄-时期-队列模型分析表明,年龄效应归因于吸烟因素的食管癌死亡率和DALY率随年龄的增大呈先上升后下降。时期效应显示归因于吸烟因素的中国食管癌死亡率随时期发展总体呈上升趋势,除2005到2010时间组下降外其他时间段均随时期推进而上升;归因于吸烟因素的中国食管癌DALY率随时期增加则呈波动变化。队列效应显示归因于吸烟因素的中国食管癌死亡率和DALY率随出生队列的发展均呈下降趋势。【结论】1990-2019年,归因于吸烟因素的食管癌疾病负担存在性别差异,随时间变化整体呈下降趋势。应加强对男性的相应健康教育,尤其是35~39岁等年龄段吸烟者的控烟教育,提高食管癌一级预防的整体水平。 展开更多
关键词 食管癌 吸烟 疾病负担 Joinpoint回归模型 年龄-时期-队列模型
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免疫粒子群算法在修正高斯模型下的源强反演
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作者 万邦银 蒯念生 +2 位作者 何雄元 彭敏君 邓利民 《中国安全科学学报》 CAS CSCD 北大核心 2024年第7期132-138,共7页
为提高危险气体泄漏溯源定位的科学性和实效性,确定危险气体泄漏位置和强度是事故应急响应的关键。首先,根据质量守恒定律,分析、改进近似高斯分布的气体羽流扩散幅度,修正高斯烟羽模型;然后,基于免疫浓度筛选机制作为主策略的免疫算法(... 为提高危险气体泄漏溯源定位的科学性和实效性,确定危险气体泄漏位置和强度是事故应急响应的关键。首先,根据质量守恒定律,分析、改进近似高斯分布的气体羽流扩散幅度,修正高斯烟羽模型;然后,基于免疫浓度筛选机制作为主策略的免疫算法(IA),通过与粒子群算法(PSO)耦合,将混合免疫粒子群(PSO-IA)算法应用到源强反演中;最后,验证PSO-IA算法溯源定位效果。结果表明:与模式搜索法(PS)、遗传算法(GA)、PSO相比,修正高斯烟羽模型预测值误差均下降2%左右;混合PSO-IA算法相较PSO算法反演源强效果有明显提升,其算法定位误差为1.3 m,求解源强误差为0.8%,单次计算时间小于1 s,能实现快速、准确定位并估算源强度。 展开更多
关键词 免疫粒子群(PSO-IA)算法 修正高斯烟羽模型 源强反演 危险气体泄漏 求解精度
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海洋作战场景下烟幕仿真的空间优化方法
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作者 王英 樊鹏远 +3 位作者 明德烈 徐海林 杨建伟 柯龙 《舰船电子工程》 2024年第7期97-102,共6页
在海洋军事领域,基于物理模型的烟幕仿真一直是各国学者研究的重点对象。针对物理模型中网格划分效率过慢的问题,提出了基于BVH树的空间组织方式,并采用遮挡剔除优化渲染速度。此外为了解决环境对烟幕仿真的影响,建立了海面舰船红外辐... 在海洋军事领域,基于物理模型的烟幕仿真一直是各国学者研究的重点对象。针对物理模型中网格划分效率过慢的问题,提出了基于BVH树的空间组织方式,并采用遮挡剔除优化渲染速度。此外为了解决环境对烟幕仿真的影响,建立了海面舰船红外辐射的传输模型,实现了舰船与海面穿过大气与烟幕到达探测器并成像的全链路建模。最终经过实验,空间优化后的烟幕仿真效率得到了大幅提升,并针对烟幕干扰的效果提出了评价指标,分别对烟幕仿真的图像与红外辐射计算做出了定量分析。 展开更多
关键词 红外烟幕 物理模型 辐射计算 空间优化
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近地场景下爆炸型烟雾弹结构仿真方法
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作者 闫鹏 温荣臻 +2 位作者 盛庆红 王博 李俊 《兵工学报》 EI CAS CSCD 北大核心 2024年第9期3125-3134,共10页
爆炸型烟雾弹在反制红外武器、保护高价值军事目标方面具有重要意义。目前绝大多数的烟雾仿真模型未考虑到爆炸的矢量信息和近地粒子扩散效果,在壁面效应与空气湍流现象显著的近地场景下对爆炸型烟雾仿真的真实性较低。针对现有方法,在... 爆炸型烟雾弹在反制红外武器、保护高价值军事目标方面具有重要意义。目前绝大多数的烟雾仿真模型未考虑到爆炸的矢量信息和近地粒子扩散效果,在壁面效应与空气湍流现象显著的近地场景下对爆炸型烟雾仿真的真实性较低。针对现有方法,在近地场景下对爆炸型烟雾弹仿真精度差的问题,提出一种近地场景下的爆炸型烟雾弹结构模型仿真方法。该方法利用粒子位置信息代替粒子模型的生命周期,以高斯烟团模型为基础,构建了基于爆弹方向和壁面效应的近地烟雾爆炸模型,以提高对近地烟雾弹爆炸场景仿真的精确性。在仿真的图像上采用结构相似度(Structural Similarity,SSIM)分析,经过最佳参数选取实验后,SSIM值达到0.9443,标准差为±0.0005。对比粒子系统-高斯烟团模型、椭球爆炸模型和爆炸型烟雾弹模型,分别高出0.0112、0.1329和0.0063。实验结果对比表明,新模型在烟雾仿真中具有明确的方向信息,对烟雾湍流和壁面效应的细节表达能力更强,对近地烟雾弹爆炸场景的仿真具有更高的精确性。 展开更多
关键词 爆炸型烟雾弹 烟雾仿真 粒子系统 高斯烟团模型 向量法
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聚氯乙烯火灾烟气环境中无铅焊料腐蚀动力学预测模型
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作者 李倩 林锦 +2 位作者 赵梦珂 黎昌海 陆守香 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第7期2304-2312,共9页
采用质量损失法研究聚氯乙烯火灾烟气环境中283.15~323.15 K温度范围内无铅Sn-3.0Ag焊料的腐蚀动力学、表面微观结构和腐蚀机理。结果表明,随着温度从283.15 K升高到323.15 K,Sn-3.0Ag焊料的质量损失从(22.09±2.01)g/m^(2)增加到(4... 采用质量损失法研究聚氯乙烯火灾烟气环境中283.15~323.15 K温度范围内无铅Sn-3.0Ag焊料的腐蚀动力学、表面微观结构和腐蚀机理。结果表明,随着温度从283.15 K升高到323.15 K,Sn-3.0Ag焊料的质量损失从(22.09±2.01)g/m^(2)增加到(44.66±1.20)g/m^(2)。此外,腐蚀动力学符合阿伦尼乌斯定律。Sn-3.0Ag焊料表面腐蚀产物呈叠加生长趋势。在283.15 K,Sn-3.0Ag焊料的表面出现大量的腐蚀产物。Sn-3.0Ag无铅焊料的腐蚀过程为电化学腐蚀,阴极发生析氢和吸氧反应,阳极发生富锡相的溶解。腐蚀产物为Sn_(21)Cl_(16)(OH)_(14)O_(6)、SnO_(2)和SnO。 展开更多
关键词 腐蚀 预测模型 Sn-3.0Ag焊料 火灾烟气 温度
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