期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
Spatial pattern recognition for near-surface high temperature increases in mountain areas using MODIS and SRTM DEM
1
作者 WANG Yanxia YANG Lisha +1 位作者 HUANG Xiaoyuan ZHOU Ruliang 《Journal of Mountain Science》 SCIE CSCD 2024年第6期2025-2042,共18页
Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are n... Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are necessary but highly difficult due to the complicated environmental conditions and instrumental issues.This paper develops a spatial pattern recognition method to measure the near-surface high temperature increase(NSHTI),one of the lesser-attended changes.First,raster window measurement was proposed to calculate the temperature lapse rate using MODIS land surface temperature and SRTM DEM data.It fully considers the terrain heights of two neighboring cells on opposite or adjacent slopes with a moving window of 3×3 cell size.Second,a threshold selection was performed to identify the NSHTI cells using a threshold of-0.65℃/100 m.Then,the NSHTI strips were parameterized through raster vectorization and spatial analysis.Taking Yunnan,a mountainous province in southwestern China,as the study area,the results indicate that the NSHTI cells concentrate in a strip-like pattern along the mountains and valleys,and the strips are almost parallel to the altitude contours with a slight northward uplift.Also,they are located mostly at a 3/5 height of high mountains or within 400 m from the valley floors,where the controlling topographic index is the altitude of the terrain trend surface but not the absolute elevation and the topographic uplift height and cutting depth.Additionally,the NSHTI intensity varies with the geographic locations and the proportions increase with an exponential trend,and the horizontal width has a mean of about 1000 m and a maximum of over 5000 m.The result demonstrates that the proposed method can effectively recognize NSHTI boundaries over mountains,providing support for the modeling of weather and climate systems and the development of mountain resources. 展开更多
关键词 High temperature increase Mountain areas MODIS Spatial pattern recognition Raster window measurement Threshold selection
下载PDF
Review on the Impact of Climate Change on Great Lakes Region’s Agriculture and Water Resources
2
作者 Zeyu Shen 《Journal of Geoscience and Environment Protection》 2024年第7期165-176,共12页
This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technol... This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technological advances since the 19th century. From 1900 to 2010, temperatures in the Midwest rose by an average of 1.5 degrees Fahrenheit, which would also lead to an increase in greenhouse gas emissions. Precipitation is also expected to increase due to increased storm activity and changes in regional weather patterns. This paper explores the impact of these changes on urban and agricultural areas. In urban areas such as the city of Chicago, runoff from the increasing impervious surface areas poses challenges to the drainage system, and agriculture areas are challenged by soil erosion, nutrient loss, and fewer planting days due to excessive rainfall. Sustainable solutions such as no-till agriculture and the creation of grassland zones are discussed. Using historical data, recent climate studies and projections, the paper Outlines ways to enhance the Midwest’s ecology and resilience to climate change. 展开更多
关键词 Climate Change Midwest USA Agricultural Impacts Urban Runoff Sustainable Practices Precipitation Patterns Temperature Increase Greenhouse Gas Emissions Soil Erosion Water Management
下载PDF
Microwave absorbing characteristics and temperature increasing behavior of basic cobalt carbonate in microwave field
3
作者 刘秉国 彭金辉 +4 位作者 张利波 SRINIVASAKANNAN C 黄铭 张泽彪 郭胜惠 《Journal of Central South University》 SCIE EI CAS 2010年第6期1211-1215,共5页
The microwave absorbing characteristics of basic cobalt carbonate,cobalt oxide(Co3O4),and the mixture of basic cobalt carbonate and cobalt oxide were investigated by means of microwave cavity perturbation,their temper... The microwave absorbing characteristics of basic cobalt carbonate,cobalt oxide(Co3O4),and the mixture of basic cobalt carbonate and cobalt oxide were investigated by means of microwave cavity perturbation,their temperature increasing curves were measured,and their ability to absorb microwave energy was also assessed based on the temperature increasing behavior of the material exposed to microwave field.Analyses of spectrum attenuation and relative frequency shift show that basic cobalt carbonate has weak capability to absorb microwave energy,while cobalt oxide has very strong capability to absorb microwave energy.It is feasible to thermally decompose basic cobalt carbonate though addition of small amount of cobalt oxide in microwave fields.The capability to absorb microwave energy of sample increases with an increase in mixing ratio of Co3O4. 展开更多
关键词 basic cobalt carbonate cobalt oxide (Co3O4) MICROWAVE temperature increasing behavior absorption
下载PDF
Effect of temperature on dielectric property and microwave heating behavior of low grade Panzhihua ilmenite ore 被引量:10
4
作者 刘晨辉 张利波 +4 位作者 彭金辉 刘秉国 夏洪应 顾晓春 史谊峰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3462-3469,共8页
The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The re... The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The results show that both the real (ε′) and imaginary (ε′) part of complex permittivity (ε′-jε′) of the ilmenite significantly increase with temperature. The loss tangent (tanδ) is a quadratic function of temperature, and the penetration depth of ilmenite decreases with temperature increase from 20 ℃to 100 ℃ The increase of the sample temperature under microwave radiation displays a nonlinear relationship between the temperature (T) and microwave heating time (t). The positive feedback interaction between complex permittivity and sample temperature amplifies the interaction between ilmenite and the microwave radiation. The optimum dimensions for uniform heat deposition vary from 10 cm to 5 cm (about two power penetration depths) in a sample being irradiated from both sides in a 2.45 GHz microwave field when temperature increases from room temperature to 100 ℃ 展开更多
关键词 dielectric properties Panzhihua ilmenite low grade microwave heating temperature increase
下载PDF
Dielectric properties and temperature increase characteristics of zinc oxide dust from fuming furnace 被引量:1
5
作者 张利波 马爱元 +4 位作者 刘晨辉 曲雯雯 彭金辉 罗永光 左勇刚 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期4004-4011,共8页
Cavity perturbation method was used to determine the dielectric properties (ε′,ε″, and tanδ) of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption prope... Cavity perturbation method was used to determine the dielectric properties (ε′,ε″, and tanδ) of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 &#176;C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability. 展开更多
关键词 zinc oxide dust apparent density dielectric properties microwave heating temperature increase characteristics
下载PDF
The effect of sea surface temperature increase on the potential habitat of Ommastrephes bartramii in the Northwest Pacific Ocean 被引量:10
6
作者 XU Jie CHEN Xinjun +2 位作者 CHEN Yong DING Qi TIAN Siquan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第2期109-116,共8页
In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid(Ommastrephes bartramii) from August to N... In the Northwest Pacific Ocean, the squid jigging fisheries from China, Japan and other countries and regions have targeted the west winter-spring cohort of neon flying squid(Ommastrephes bartramii) from August to November since the 1970 s. This squid is a short-lived ecological opportunist with a life-span of about one year,and its population is labile and recruitment variability is driven by the environment or climate change. This variability provides a challenge for ones to forecast the key habitats affected by climate change. The catch data of O. bartramii from Chinese squid jigging fishery and the satellite-derived sea surface temperature(SST) data are used in the Northwest Pacific Ocean from August to November of 1998 to 2004, the SST preferences of O.bartramii corresponding to high values of catch per fishing day(CPUE) are determined and monthly potential habitats are predicted using a histogram analysis of the SST data. The possible changes in the potential habitats of O. bartramii in the Northwest Pacific Ocean are estimated under four climate change scenarios based on the Fourth Assessment Report(AR4) of the Intergovernmental Panel on Climate Change, i.e., 0.5, 1, 2 and 4°C increases in the SST because of the climate change. The results reveal an obvious poleward shift of the potential habitats of O. bartramii in the Northwest Pacific Ocean. 展开更多
关键词 Ommastrephes bartramii sea surface temperature increase potential habitat Northwest Pacific Ocean
下载PDF
Fatty acids in microalgae and cyanobacteria in a changing world:Contrasting temperate and cold environments 被引量:1
7
作者 MARCELO P.HERNANDO IRENE R.SCHLOSS +1 位作者 FLORENCIA DE LA ROSA MARLEEN DE TROCH 《BIOCELL》 SCIE 2022年第3期607-621,共15页
Under the present changing climate conditions and the observed temperature increase,it is of high importance to understand its effects on aquatic microbial life,and organisms’adaptations at the biochemical level.To a... Under the present changing climate conditions and the observed temperature increase,it is of high importance to understand its effects on aquatic microbial life,and organisms’adaptations at the biochemical level.To adjust to temperature or salinity stress and avoid cell damage,organisms alter their degree of fatty acids(FAs)saturation.Thus,temperature is expected to have strong effects on both the quantity and quality of FAs in aquatic microorganisms.Here we review some recent findings about FAs sensitivity to climate change in contrasting environments.Overall,heat waves may induce changes in the relative abundance of polyunsaturated FAs(PUFA).However,the impact of the exposure to warming waters is different in temperate and polar environments.In cold marine waters,high concentration of omega-3(ω3)FAs such as eicosapentaenoic acid(EPA)is promoted due to the activation of the desaturase enzyme.In this way,cells have enough energy to produce or activate antioxidant protection mechanisms and avoid oxidative stress due to heat waves.Contrastingly,under high irradiance and heat wave conditions in temperate environments,photosystems’protection is achieved by decreasing EPA concentration due to desaturase sensitivity.Essential FAs are transferred in aquatic food webs.Therefore,any alteration in the production of essential FAs by phytoplankton(the main source ofω3)due to climate warming can be transferred to higher trophic levels,with cascading effects for the entire aquatic ecosystem. 展开更多
关键词 ANTARCTIC TEMPERATE Essential FAs Increased temperature MICROALGAE CYANOBACTERIA
下载PDF
ESTIMATION OF THE CRITICAL RATE OF TEMPERATURE INCREASE OF THERMAL EXPLOSION OF NITROCELLULOSE USING NON-ISOTHERMAL DSC 被引量:1
8
作者 胡荣祖 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2003年第3期285-290,共6页
A method of estimating the critical rate of temperature increase of thermal explosion for the first orderautocatalytic decomposition reaction system using non-isothermal DSC is presented. Information is obtained on th... A method of estimating the critical rate of temperature increase of thermal explosion for the first orderautocatalytic decomposition reaction system using non-isothermal DSC is presented. Information is obtained on theincreasing rate of temperature in nitrocellulose containing 13.54% of nitrogen when the first order autocatalytic decomposition converts into thermal explosion. 展开更多
关键词 DSC NITROCELLULOSE increasing rate of temperature NON-ISOTHERMAL
下载PDF
Key global climate governance problems and Chinese countermeasures 被引量:1
9
作者 Hailin Wang Xiaodan Huang +1 位作者 Xiaofan Zhao Jiankun He 《Chinese Journal of Population,Resources and Environment》 2021年第2期125-132,共8页
Presently,the full implementation of the negotiations and collaborations under the Paris Agreement faces new key problems and severe challenges.These problems and challenges include the following:how to honor the prin... Presently,the full implementation of the negotiations and collaborations under the Paris Agreement faces new key problems and severe challenges.These problems and challenges include the following:how to honor the principle of“common but differentiated responsibilities”to facilitate a comprehensive,balanced,and effective implementation of the key elements of the Paris Agreement,such as adaptation,mitigation,finance,technology,capacity building,and transparency;how to uphold and maintain the status of China and other emerging countries as developing countries in light of the requirements of the United Nations Framework Convention on Climate Change and the historical responsibilities of these countries;and how to assess the goal of limiting the global temperature increase to 1.5℃and what constitutes an equitable carbon mitigation pathway for different types of countries.Developed countries and developing countries have drastically diverging views on carbon border adjustment measures for trade with developing countries proposed by several developed countries such as the European Union.Developed countries have demonstrated obvious intentions and actions designed to weaken and neglect the principle of“common but differentiated responsibilities”,to impose mitigation pressure on developing countries,to shift the responsibilities for emissions onto others,and to pass on the costs of mitigation.The maneuvering among different types of countries and interest groups has become increasingly intense.In response,China must maintain its strategic focus,adhere to the goals and principles established by the Paris Agreement,stick to its strategic positioning as a developing country,solidify strategic support from the developing world,and safeguard the legitimate rights and interests of developing countries.China played a conducive role in facilitating the Paris Agreement and has become an active participant,contributor,and leader in global climate governance.China must continue to follow Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era and its conception of ecological civilization and the concept of building a community of common destiny,to actively lead the cooperation process in the construction of a global climate governance system characterized by equity,justice,and win-win collaborations,and to promote compliance with the Paris Agreement.At the same time,China should accelerate the green,low-carbon,circular transformation of its economy;accelerate the coordinated governance of the economy,environment,and climate change;and formulate and implement a long-term low-carbon development strategy.By the middle of the 21st century,while achieving the goal of building a great modern socialist country,China can also achieve a deep decarbonization development path that is in line with the goal of limiting the global temperature increase to well below 2°C and pursuing efforts to limit the increase to 1.5℃. 展开更多
关键词 Global climate governance Equity and responsibility Developing country positioning 1.5℃temperature increase Carbon border adjustment measures
下载PDF
Monitoring Day and Night-Time Situation of Urban Heat Island and Possible Adaptation Measures in Douala, Cameroon 被引量:1
10
作者 Mbia Ekolok Awuh 《Journal of Geoscience and Environment Protection》 2021年第8期163-176,共14页
Urba<span>n Heat Island (UHI) has the potential to directly influence the health and welfare of urban residents. The study employed a traditional method called “</span>pair<span>ed measurement prog... Urba<span>n Heat Island (UHI) has the potential to directly influence the health and welfare of urban residents. The study employed a traditional method called “</span>pair<span>ed measurement program” to analyze the effects of four land use/land- cover patterns on intra-urban air temperature variations in the Doual</span>a Metropolis, Cameroon under different atmospheric conditions. This study also investigated the possible adaptation measures employed by the inhabitants to combat the urban heat island effects. The result revealed a variation in the temperature of the selected transects. There was a mix of cool and heat islands by day, especially during rainy seasons. The daytime variations were strongly correlated to the amount of tree shading. It was also observed that the temperature gradient was formed at the Central Business District (CBD) and progressively lowered to the suburbs. The thermal comfort classification for the area ranges between 25.4<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C and 27<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C, which is a class where over 50% of the population feels stressed;and the range of 32<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C and above, where most of the population suffers discomfort. In order to investigate the possible adaptation measures employed by the inhabitants of Douala, two hundred and fifty questionnaires were distributed and analyzed using descriptive statistics. The result revealed that the inhabitants use various coping strategies in order to adapt to UHI effects. The strategies identified include;stay indoors, drink plenty of water, wear light clothing, go to an A/C location, take a cool shower, avoid outdoors, and wear a hat or cover head. The widely used coping strategy identified is drinking plenty of water. The expensive nature of A/C makes it the least used coping strategy. 展开更多
关键词 Surface Modifications Increase Temperature Coping Strategy
下载PDF
Effect of elevated CO_(2) concentration on growth course of tree seedlings in Changbai Mountain
11
作者 韩士杰 周玉梅 +2 位作者 张军辉 王琛瑞 邹春静 《Journal of Forestry Research》 CAS CSCD 2000年第4期223-227,共5页
One-year-old seedlings of Pinus koraiensis, Pinus sylvestriformis, Phellodendron amurense were grown in open-top chambers (OTCs) with 700 and 500 (mol/mol CO2 concentrations, control chamber and on open site (ambient ... One-year-old seedlings of Pinus koraiensis, Pinus sylvestriformis, Phellodendron amurense were grown in open-top chambers (OTCs) with 700 and 500 (mol/mol CO2 concentrations, control chamber and on open site (ambient CO2, about 350 (mol/mol CO2) respectively at the Open Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, and the growth course responses of three species to elevated CO2 and temperature during one growing season was studied from May to Oct. 1999. The results showed that increase in CO2 concentration enhanced the growth of seedlings and the effect of 700 (mol/mol CO2 was more remarkable than 500 (mol/mol CO2 on seedling growth. Under the condition of doubly elevated CO2 concentration, the biomass increased by 38% in average for coniferous seedlings and 60% for broad-leaved seedlings. With continuous treatment of high CO2 concentration, the monthly-accumulated biomass of shade-tolerant Pinus koraiensis seedlings was bigger in July than in August and September, while those of Pinus sylvestriformis and Phellodendron amurense seedlings showed an increase in July and August, or did not decrese until September. During the hot August, high CO2 concentration enhanced the growth of Pinus koraiensis seedlings by increasing temperature, but it did not show dominance in other two species. 展开更多
关键词 elevated CO2 growth course tree seedling increased temperature?
下载PDF
Offshore Wind-Parks and Northern Europe's Mild Winters: Contribution from Ships, Fishery, et cetera?
12
作者 Arnd BERNAERTS 《Journal of Shipping and Ocean Engineering》 2016年第1期46-56,共11页
The marine environment of North Sea and Baltic is one of the most heavily strained by numerous human activities. Simultaneously water and air temperatures increase more than elsewhere in Europe and globally, which can... The marine environment of North Sea and Baltic is one of the most heavily strained by numerous human activities. Simultaneously water and air temperatures increase more than elsewhere in Europe and globally, which cannot be explained with "global warming". The climatic change issue would be better understood if this extraordinary regional warming is sufficiently explained. The regional features are unique for in-depth studies due to different summer-winter conditions, shallowness of the seas, geographical structure, and main pathway for maritime weather patterns moving eastwards. The impact of sea activities on the seasonal sea water profile structure is contributing to stronger regional warming, change in growing season, and less severe sea ice conditions. The impact of the man, whether small or large, should be understood very soon and very thoroughly. 展开更多
关键词 Human maritime activities sea temperature increase North Sea and Baltic warming change in seasonality sea icedecrease.
下载PDF
Implications of 1.5 K climate warming on warm-season ozone exposure and atmospheric oxidation capacity in China
13
作者 Zhihao Shi Lin Huang +5 位作者 Xiaodong Xie Momei Qin Jingyi Li Bingye Xu Lingling Jin Jianlin Hu 《Atmospheric and Oceanic Science Letters》 2024年第6期53-61,共9页
Surface ozone(O_(3))poses significant threats to public health,agricultural crops,and plants in natural ecosystems.Global warming is likely to increase future O_(3)mainly by altering atmospheric photochemical reaction... Surface ozone(O_(3))poses significant threats to public health,agricultural crops,and plants in natural ecosystems.Global warming is likely to increase future O_(3)mainly by altering atmospheric photochemical reactions and enhancing biogenic volatile organic compound(BVOC)emissions.To assess the impacts of the future 1.5 K climate target on O_(3)concentrations and ecological O_(3)exposure in China,numerical simulations were conducted using the CMAQ(Community Multiscale Air Quality)model during April-October 2018.Ecological O_(3)exposure was estimated using six indices(i.e.,M7,M24,N100,SUM60,W126,and AOT40f).The results show that the temperature rise increases the MDA8 O_(3)(maximum daily eight-hour average O_(3))concentrations by∼3 ppb and the number of O_(3)exceedance days by 10-20 days in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan Basin(SCB)regions.All O_(3)exposure indices show substantial increases.M24 and M7 in eastern and southern China will rise by 1-3 ppb and 2-4 ppb,respectively.N100 increases by more than 120 h in the surrounding regions of Beijing.SUM60 increases by greater than 9 ppm h^(−1),W126 increases by greater than 15 ppm h^(−1)in Shaanxi and SCB,and AOT40f increases by 6 ppm h^(−1)in NCP and SCB.The temperature increase also promotes atmospheric oxidation capacity(AOC)levels,with the higher AOC contributed by OH radicals in southern China but by NO_(3)radicals in northern China.The change in the reaction rate caused by the temperature increase has a greater influence on O_(3)exposure and AOC than the change in BVOC emissions. 展开更多
关键词 Temperature increase Ozone exposure Biogenic emissions Atmospheric oxidation capacity
下载PDF
Enhancing crop yield by using Rubisco activase to improve photosynthesis under elevated temperatures
14
作者 Inosha Wijewardene Guoxin Shen Hong Zhang 《Stress Biology》 CAS 2021年第1期3-22,共20页
With the rapid growth of world population,it is essential to increase agricultural productivity to feed the growing population.Over the past decades,many methods have been used to increase crop yields.Despite the succ... With the rapid growth of world population,it is essential to increase agricultural productivity to feed the growing population.Over the past decades,many methods have been used to increase crop yields.Despite the success in boosting the crop yield through these methods,global food production still needs to be increased to be on par with the increasing population and its dynamic consumption patterns.Additionally,given the prevailing environmental conditions pertaining to the global temperature increase,heat stress will likely be a critical factor that negatively affects plant biomass and crop yield.One of the key elements hindering photosynthesis and plant productivity under heat stress is the thermo-sensitivity of the Rubisco activase(RCA),a molecular chaperone that converts Rubisco back to active form after it becomes inactive.It would be an attractive and practical strategy to maintain photosynthetic activity under elevated temperatures by enhancing the thermo-stability of RCA.In this context,this review discusses the need to improve the thermo-tolerance of RCA under current climatic conditions and to further study RCA structure and regulation,and its limitations at elevated temperatures.This review summarizes successful results and provides a perspective on RCA research and its implication in improving crop yield under elevated temperature conditions in the future. 展开更多
关键词 Climate change DROUGHT Heat stress Temperature increase Rubisco activase
原文传递
A Meta-analysis of the Effects of Warming and Elevated CO_2 on Soil Microbes 被引量:7
15
作者 FU Gang ZHANG Haorui +1 位作者 LI Shaowei SUN Wei 《Journal of Resources and Ecology》 CSCD 2019年第1期69-76,共8页
Soil microbes play important roles in terrestrial ecosystem carbon and nitrogen cycling. Climatic warming and elevated CO2 are two aspects of climatic change. In this study, we used a meta-analysis approach to synthes... Soil microbes play important roles in terrestrial ecosystem carbon and nitrogen cycling. Climatic warming and elevated CO2 are two aspects of climatic change. In this study, we used a meta-analysis approach to synthesise observations related to the effects of warming and elevated CO2 on soil microbial biomass and community structure. Ecosystem types were mainly grouped into forests and grasslands. Warming methods included open top chambers and infrared radiators. Experimental settings included all-day warming, daytime warming and nighttime warming. Warming increased soil actinomycetes and saprotrophic fungi, while elevated CO2 decreased soil gram-positive bacteria(G+). Mean annual temperature and mean annual precipitation were negatively correlated with warming effects on gram-negative bacteria(G–) and total phospholipid fatty acid(PLFA), respectively. Elevation was positively correlated with the warming effect on total PLFA, bacteria, G+ and G–. Grassland exhibited a positive response of total PLFA and actinomycetes to warming, while forest exhibited a positive response in the ratio of soil fungi to bacteria(F/B ratio) to warming. The open top chamber method increased G–, while the infrared radiator method decreased the F/B ratio. Daytime warming rather than all-day warming increased G–. Our findings indicated that the effects of warming on soil microbes differed with ecosystem types, warming methods, warming times, elevation and local climate conditions. 展开更多
关键词 ecosystem types elevated CO2 increased temperature response ratio warming methods
原文传递
Fluidization behavior of graphitized glassy particles in a fluidized carbon bed cooling process for investment casting
16
作者 Paul Git Matthias Hofmeister +1 位作者 Robert F.Singer Carolin Körner 《Particuology》 SCIE EI CAS CSCD 2022年第6期32-38,共7页
Fluidized Carbon Bed Cooling(FCBC)is an innovative investment casting process for directional solidification of superalloy components.It takes advantage of a fluidized bed with a base of small glassy carbon beads for ... Fluidized Carbon Bed Cooling(FCBC)is an innovative investment casting process for directional solidification of superalloy components.It takes advantage of a fluidized bed with a base of small glassy carbon beads for cooling and other low-density particles that form an insulating layer by floating to the bed surface.This so-called“Dynamic Baffle”protects the fluidized bed from the direct heat input from the high-temperature heating zone and provides the basis for an improved bed microstructure.The prerequisites for a stable casting process are stable fluidization conditions where neither collapse of the bed nor particle blow out at excessive bubble formation occur.This work aimed to investigate the fluidization behavior of spherical carbon bed material in argon and air at temperatures between 20 to 350℃.Systematic studies at reduced pressures using the FCBC prototype device were performed to understand the stable fluidization conditions at all stages of the investment casting process.The particle shape factor and size distribution characterization and the measurement of the powder’s minimum fluidization velocity and bed voidage show that this material can be fully utilized as a cooling and buoyancy medium during the FCBC process. 展开更多
关键词 Gas-solid fluidization Glassy carbon Reduced pressure Increased temperature Fluidized carbon bed
原文传递
Effect of shipping activity on warming trends in the Canadian Arctic
17
作者 Mian Sabir HUSSAIN Inhye HEO +1 位作者 Sujeong IM Seungho LEE 《Journal of Geographical Sciences》 SCIE CSCD 2021年第3期369-388,共20页
This paper presents a detailed account of the effect of shipping activity on the increasing trends of air temperatures in the Canadian Arctic region for the period of 1980–2018.Increasing trend of temperature has gai... This paper presents a detailed account of the effect of shipping activity on the increasing trends of air temperatures in the Canadian Arctic region for the period of 1980–2018.Increasing trend of temperature has gained significant attention with respect to shipping activities and sea ice area in the Canadian Arctic.Temperature,sea ice area and shipping traffic datasets were investigated,and simple linear regression analyses were conducted to predict the rate of change(per decade)of the average temperature,considering winter(January)and summer(July)seasons.The results indicate that temperature generally increased over the studied region.Significant warming trend was observed during July,with an increase of up to 1℃,for the Canadian Arctic region.Such increasing trend of temperature was observed during July from the lower to higher latitudes.The increase in temperature during July is speculated to increase the melting of ice.Results also show a decline in sea ice area has a significant positive effect on the shipping traffic,and the numbers of marine vessel continue to increase in the region.The increase in temperature causes the breaking of sea ice due to shipping activities over northern Arctic Canada. 展开更多
关键词 shipping activity increasing trend of temperature sea ice area Canadian Arctic
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部