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Asbestos Exposure during Gasket Removal from Aircraft Engine

Occupational Diseases and Environmental Medicine 2024年第2期12卷 59-67页

作者： Charles L. Blake Kevin M. Guth Raymond D. Harbison Apex Companies Marietta USA center for Environmental and Occupational risk Analysis and management College of Public Health University of South Florida Tampa USA

We have previously evaluated asbestos exposure associated with various maintenance procedures on light aircraft. The purpose of this study was to evaluate asbestos exposure during engine maintenance on light aircraft. This test was designed to evaluate the potential for asbestos exposure to mechanics and others who remove asbestos-containing engine gaskets from reciprocating style aircraft engines. Utilized in this test was an air cooled, horizontally opposed, aviation gasoline burning engine, assembled during 1986 and operated intermittently up into 2015, having accumulated 1680 hours run time. Nearly 75% of the asbestos-containing gaskets installed during 1986 were still in place at the time of testing. Chrysotile asbestos contents of such gaskets ranged from 55% to 60% by area, for those of sheet style and 5% by area, for the spiral wound metal/asbestos style. Despite the levels of effort required to effect gasket removals, the professional aircraft mechanic was not exposed to airborne asbestos fibers at the lower limits of sampling and analytical detection achieved;all of which were substantially less than the current Occupational Safety and Health Administration Permissible Exposure Limits for asbestos. The results of this testing indicate an absence of gasket related asbestos exposure risk to mechanics who work with light aircraft engines, including those having asbestos-containing gaskets. These results are consistent with the findings of Mlyarek and Van Orden who studied the asbestos exposure risk occasioned during overhaul of larger radial style reciprocating aircraft engines [1].

关键词： Asbestos Exposure Gaskets Aircraft Engine Friction Materials

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Evaluation and Influencing Factors on Particle Agglomeration in RAP

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 60-68页

作者：唐伟李宁 ZHUANG Yuan ZHAN He YU Xin WU Wenxiu DING Gongying College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China Jiangsu Expressway Engineering Maintenance Technology center Nanjing 211106China Jinhua Highway and Transportation management center Jinhua 321000China

Asphalt extraction test and scanning electron microscopy(SEM) were used for analysis of agglomerations of reclaimed asphalt pavement(RAP) particles. In order to quantify the agglomeration degree of RAP, the fineness modulus ratio(FMR) and the percentage loss index(PLI) were proposed. In addition, grey correlation analysis was conducted to discuss the relationship between particle agglomerations and RAP size,asphalt content(AC), and surface area. Two indexes indicate that the agglomeration degree increases in general as the RAP size reduces. This can be attributed to that particles are prone to agglomeration in the case of higher AC. Based on the SEM images and the material composition of RAP, the particle agglomeration in RAP can be classified into weak agglomeration and strong agglomeration. Grey correlation analysis shows that AC is the crucial factor affecting the agglomeration degree and RAP variability. In order to produce consistent and stable reclaimed mixtures, disposal measures of RAP are suggested to lower the AC of RAP.

关键词： RAP particle agglomeration grey correlation analysis asphalt content

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Reducing Social Media Attention Inequality in Disasters: The Role of Official Media During Rainstorm Disasters in China

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International Journal of Disaster risk Science 2024年第3期15卷 388-403页

作者： Longfei Zheng Lei Chen Fenjie Long Jianing Liu Lei Li School of Geography Faculty of Geographical Science Beijing Normal University Hang Lung center for Real Estate and Department of Construction management Tsinghua University

Unequal social media attention can lead to potentially uneven distribution of disaster-relief funds, resulting in long-term inequality among regions after disasters. This study aimed to measure inequalities in social media attention to regions during disasters and explore the role of official media in reducing such inequality. This is performed by employing social media,official media, and official aggregated statistics regarding China's rainstorm disasters. Through a set of panel-data regressions and robustness tests, three main conclusions were drawn:(1) There were inequalities among regions regarding social media attention they received during rainstorm disasters. For disasters of the same magnitude, regions with low economic outcome per capita received less attention on social media.(2) Official media can reduce inequality in social media attention during disasters. Official media statements can encourage netizens to pay attention to disaster-stricken areas, and especially the overlooked underdeveloped areas.(3) Of all the measures taken by official media, timely, accurate, and open disclosure of disaster occurrences proved to be the most potent means of leveling the playing field in terms of social media attention;contrarily, promotional or booster-type messages proved futile in this regard. These findings revealed the vulnerabilities within social media landscapes that aff ect disaster relief response, shedding light on the role of official guidance in mitigating inequalities in social media attention during such crises. Our study advises social media stakeholders and policymakers on formulating more equitable crisis communication strategies to bridge the gap in social media attention and foster a more balanced and just relief process.

关键词： China, inequality of attention Official media Rainstorm disasters Situational crisis communication theory Social media

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Polypore funga and species diversity in tropical forest ecosystems of Africa,America and Asia,and a comparison with temperate and boreal regions of the Northern Hemisphere

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Forest Ecosystems 2024年第4期11卷 391-400页

作者： Heng Zhao Yingda Wu Zhirong Yang Honggao Liu Fang Wu Yucheng Dai Yuan Yuan State Key Laboratory of Efficient Production of Forest Resources School of Ecology and Nature ConservationBeijing Forestry UniversityBeijing 100083China Key Laboratory of Forest and Grassland Fire risk Prevention Ministry of Emergency ManagementChina Fire and Rescue InstituteBeijing 102202China Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic Biology Zhaotong UniversityZhaotong 657000China Yunnan Engineering Research center of Green Planting and Processing of Gastrodia Zhaotong UniversityZhaotong 657000China

Polypores play a cru cial role in energy recycling and forest regeneration in forest *** majority of them are wood degraders;some are forest pathogens and others are ectomycorrhizal *** basidiocarps provide food and shelter for many organisms,mostly invertebrates,but also some vertebrates,as well as food and medicine for *** extensive research on the species diversity and phylogenetic relationships of polypores in recent years,there remains a lack of comprehensive understanding of their distribution patterns and species composition at the large *** of polypores from the tropical zone,including tropical Africa,tropical America,and tropical Asia,were analyzed for species diversity,distribution patterns,major taxa,and nutritional modes.A total of 1,902 polypore species was found in the three regions,representing 8 orders,46families,and 250 genera of *** orders Polyporales(especially the family Polyporaceae)and Hymenochaetales(especially the family Hymenochaetaceae)had the most prolific taxa,with their species accounting for 93.4%of the total polypores *** of 1,565(or 82.3%)of the total 1,902 species were found in only one of the three regions studied,and we treat them temporarily as"regional endemic species".Only 141species were shared among all three regions,accounting for a mere 7.4%.Tropical Africa and tropical America had the greatest number of shared species and the highest S?rensen similarity index(SC)*** forests had a higher species richness compared with temperate to boreal forests of the Northern Hemisphere,and in addition,also a higher proportion of white rot polypores compared to brown rot and ectomycorrhizal *** study outlines the distribution patterns and species diversity of polypores in the world,shedding light on their ecological significance in diverse ecosystems.

关键词： Agaricomycetes Macrofungi Species composition Wood-decay fungi

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Ecological Network Resilience of Shiyang River Basin: An Arid Inland Watershed of Northwest China

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Chinese Geographical Science 2024年第5期34卷 951-966页

作者： HE Yangxi LIU Chunfang NI Bowen LIAN Hugang School of management Northwest Normal UniversityLanzhou 730070China Research center of Land Use and Comprehensive Improvement Engineering of Gansu Province Lanzhou 730070China

Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem *** assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid *** River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)*** results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial ***,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river ***,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.

关键词： Ecological Network Resilience(ENR) Complex Adaptive System(CAS) element-structure-function Shiyang River Basin Northwest China

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Predictive factors and model validation of post-colon polyp surgery Helicobacter pylori infection

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 173-185页

作者： Zheng-Sen Zhang Health management center Affiliated Hospital of Shaoxing University(Shaoxing Municipal Hospital)Shaoxing 312000Zhejiang ProvinceChina

BACKGROUND Recently,research has linked Helicobacter pylori(***)stomach infection to colonic inflammation,mediated by toxin production,potentially impacting colorectal cancer *** To investigate the risk factors for post-colon polyp surgery,*** infection,and its correlation with pathologic *** Eighty patients who underwent colon polypectomy in our hospital between January 2019 and January 2023 were retrospectively *** were then randomly split into modeling(n=56)and model validation(n=24)sets using *** modeling cohort was divided into an ***-infected group(n=37)and an ***-uninfected group(n=19).Binary logistic regression analysis was used to analyze the factors influencing the occurrence of *** infection after colon polyp surgery.A roadmap prediction model was established and ***,the correlation between the different pathological types of colon polyps and the occurrence of *** infection was analyzed after colon polyp *** Univariate results showed that age,body mass index(BMI),literacy,alcohol consumption,polyp pathology type,high-risk adenomas,and heavy diet were all influential factors in the development of *** infection after intestinal *** multifactorial logistic regression analysis showed that age,BMI,and type of polyp pathology were independent predictors of the occurrence of *** infection after intestinal *** area under the receiver operating characteristic curve was 0.969[95%confidence interval(95%CI):0.928–1.000]and 0.898(95%CI:0.773–1.000)in the modeling and validation sets,*** slope of the calibration curve of the graph was close to 1,and the goodness-of-fit test was P>0.05 in the two *** decision analysis curve showed a high rate of return in both *** results of the correlation analysis between different pathological types and the occurrence of *** infection after colon polyp surgery showed that hyperplastic

关键词： Colon polyps Helicobacter pylori risk factors Pathologic type Columnar graphic modeling

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Could the EU carbon border adjustment mechanism promote climate mitigation?An economy-wide analysis

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Advances in Climate Change Research 2024年第3期15卷 557-571页

作者： Kun ZHANG Yun-Fei YAO Xiang-Yan QIAN Yu-Fei ZHANG Qiao-Mei LIANG Yi-Ming WEI College of Economics and management Beijing University of TechnologyBeijing 100124China center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing 100081China School of management and Economics Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Energy Economics and Environmental management Beijing 100081China Sinopec Research Institute of Petroleum Engineering SinopecBeijing 100101China College of Economics and management Nanjing Agricultural UniversityNanjing 210095China

Due to concerns about carbon leakage and sectoral competitiveness,the European Union(EU)proposed implementing the carbon border adjustment mechanism(CBAM).The effectiveness and potential negative consequences of CBAM have aroused extensive *** the perspective of the economy-wide analysis,this study uses a global computable general equilibrium model to explore the rationality of CBAM from the aspects of socioeconomic impact and the effects of promoting climate ***,the potential alternative mechanism of CBAM is *** results show that CBAM can reduce the EU's gross domestic product(GDP)loss;however,the GDP loss in all other regions ***,CBAM raises household welfare losses in most regions,including the ***,although CBAM can reduce the marginal abatement cost in eight regions,it comes at the cost of greater economic ***,the economic and household welfare cost of raising emissions reduction targets in regions like the USA and Japan is substantially higher than the impact of passively accepting the CBAM;therefore,CBAM's ability to drive ambitious emission reduction initiatives may be ***,for the potential alternative mechanism,from the perspective of reducing economic cost and household welfare losses,the EU could implement domestic tax cuts in the short-term and promote global unified carbon pricing in the long-term.

关键词： Border adjustment mechanism Computable general equilibrium model Carbon price Climate policy Global carbon pricing

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Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions

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Earth and Planetary Physics 2024年第3期8卷 445-458页

作者： Jie Wang YanYan Yang ZhiMa Zeren Jian Wang Xin Wang YuXin Luo XuHui Shen National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China School of Emergency management Science and Engineering University of Chinese Academy of SciencesBeijing 100049China National Space Science center Chinese Academy of SciencesBeijing 100190China

Long-wavelength(>500 km)magnetic anomalies originating in the lithosphere were first found in satellite magnetic *** to the striking magnetic anomalies around the world,the long-wavelength magnetic anomalies in China and surrounding regions are relatively *** research on each of these anomalies has been quite inadequate;their geological origins remain unclear,in particular their connection to tectonic activity in the Chinese and surrounding *** focus on six magnetic high anomalies over the(1)Tarim Basin,(2)Sichuan Basin(3)Great Xing’an Range,(4)Barmer Basin,(5)Central Myanmar Basin,and(6)Sunda and Banda Arcs,and a striking magnetic low anomaly along the southern part of the Himalayan-Tibetan *** have analyzed their geological origins by reviewing related research and by detailed comparison with geological *** tectonic backgrounds for these anomalies belong to two cases:either ancient basin basement,or subduction-collision ***,the geological origins of large-scale regional magnetic anomalies are always subject to dispute,mainly because of limited surface exposure of sources,later tectonic destruction,and superposition of multi-phase events.

关键词： long-wavelength magnetic anomaly lithospheric magnetic anomaly lithospheric magnetic field model satellite magnetic survey CSES

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Global Value Chain Participation and Firms'Responses to Exchange Rate Fluctuations

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China & World Economy 2024年第5期32卷 53-86页

作者： Chun Jiang Fuwei Sun Zhida Zhang center for Economic Development Research Wuhan UniversityChina Economics and management School Wuhan UniversityChina

Greater participation in global value chains(GVCs)has highlighted the impact of exchange rate shocks on international *** paper examines how such participation influences firms'responses to exchange rate movements,focusing on the relationship between firms'pricing and value-added in *** study,using detailed Chinese firm-level data,demonstrates that firms with a high degree of GVC participation reacted to currency appreciation by lowering their export prices more substantially and reducing their export volumes *** is mainly attributable to the"cost-hedging effect"within the marginal cost channel and the"pricing inhibition effect"within the markup *** categorizing export firms by trade models and product types,this study further demonstrates that processing trade firms at the low end of the value chain and those with low product differentiation were more inclined to absorb exchange rate *** study adds to the existing theoretical framework and provides strong evidence for China in deepening GVC integration and supporting the development of high-quality export firms.

关键词： exchange rate elasticity exchange rate fluctuations exchange rate pass through firm response global value chain participation

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Deformation and stability of the seawall,considering the strength uncertainty of cement mixing piles

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 483-501页

作者： Yuansheng YU Lingling LI Xiangmiao KONG Chengyuan LI Zhen GUO Key Laboratory of Offshore Geotechnics and Material of Zhejiang Province College of Civil Engineering and ArchitectureZhejiang UniversityHangzhou310058China Hainan Institute Zhejiang UniversitySanya572000China Ninghai Highway and Transportation management center Ningbo315600China Ninghai Traffic Engineering Construction management Institute Ningbo315600China

The cement mixing (CM) pile is a common method of improving soft offshore ground. The strength growth of CM piles under complex conditions is affected by many factors, especially the cement and moisture contents, and shows significant uncertainty. To investigate the stochasticity of the early strength of CM piles and its impact on the displacement and stability of a seawall, a series of laboratory tests and numerical analyses were carried out in this study. Vane shear tests were conducted on the cement-solidified soil to determine the relationships between the undrained shear strength s_(u) of the cement soil curing in the seawater and the cement content a_(c), as well as the in situ soil moisture content w. It can be inferred that the 24 h undrained shear strength follows a normal distribution. A numerical model considering the random CM pile strength was established to investigate the deformation of the seawall. Due to the uncertainty of CM pile strength, the displacement of the seawall demonstrates a certain discreteness. The decrease of the mean undrained shear strength of CM piles causes a corresponding increase in the average displacement of the seawall. When the mean strength of CM piles is lower than a certain threshold, there is a risk of instability. Furthermore, the heterogeneity of the strength within an individual CM pile also has an impact on seawall displacement. Attention should be paid to the uncertainty of CM pile strength to control displacement and stability.

关键词： Construction uncertainty Cement mixing(CM)pile Strength of cement soil Seawall stability Random finite element method(RFEM) Monte Carlo simulation(MCS)

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