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混凝土结构碳化深度影响因素研究
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作者 文青瑶 《技术与市场》 2024年第11期73-77,共5页
混凝土的碳化作用对其耐久性有较大影响。为探明影响混凝土碳化深度的主要因素,先对混凝土碳化机理进行了分析,发现影响混凝土碳化深度的主要因素有材料因素、环境因素以及施工因素等;并在此基础上开展了混凝土的碳化试验,试验结果表明... 混凝土的碳化作用对其耐久性有较大影响。为探明影响混凝土碳化深度的主要因素,先对混凝土碳化机理进行了分析,发现影响混凝土碳化深度的主要因素有材料因素、环境因素以及施工因素等;并在此基础上开展了混凝土的碳化试验,试验结果表明:影响混凝土碳化深度的主要因素有碳化周期、水灰比以及混凝土强度等。 展开更多
关键词 深度 水灰比 混凝土强度 碳化周期
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双碳背景下智慧零碳园区建设路径与实践
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作者 李渤 马韵鸿 +1 位作者 吴平 张浩 《江苏通信》 2024年第4期67-71,共5页
随着“双碳”行动持续深入推进,智慧园区零碳转型已成为必然趋势。智慧零碳园区需要历经由智慧低碳园区、智慧近零碳园区向智慧零碳园区逐步转型的三个阶段。本文对智慧零碳园区全生命周期进行了总体架构设计、支撑平台设计及解决方案设... 随着“双碳”行动持续深入推进,智慧园区零碳转型已成为必然趋势。智慧零碳园区需要历经由智慧低碳园区、智慧近零碳园区向智慧零碳园区逐步转型的三个阶段。本文对智慧零碳园区全生命周期进行了总体架构设计、支撑平台设计及解决方案设计,并规划了智慧零碳园区在策划筹备、规划设计、投资建设、运维迭代时期的一体化实施路径,为整体建设和未来低碳城市提供借鉴。 展开更多
关键词 达峰、中和” 智慧零园区 全生命周期设计
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轻集料混凝土抗渗及抗碳化性能研究 被引量:2
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作者 张等 《湖南交通科技》 2015年第2期136-138,共3页
为了研究轻集料混凝土的抗渗性能和抗碳化性能,通过试验研究了水灰比对轻集料混凝土抗渗性能、抗碳化性能,以及碳化龄期和瞬时荷载对抗碳化性能的影响,并与同等强度等级的普通混凝土作对比。结果表明,水灰比越大轻集料混凝土的抗渗性能... 为了研究轻集料混凝土的抗渗性能和抗碳化性能,通过试验研究了水灰比对轻集料混凝土抗渗性能、抗碳化性能,以及碳化龄期和瞬时荷载对抗碳化性能的影响,并与同等强度等级的普通混凝土作对比。结果表明,水灰比越大轻集料混凝土的抗渗性能和抗碳化性能越差,当水灰比超过0.38时,轻集料混凝土的抗渗性能和抗碳化性能比普通混凝土差;碳化初期,碳化深度随碳化龄期的延长急速增长,14 d结束时碳化深度达到整个碳化周期的70%左右;当瞬时荷载比小于60%时,碳化深度随着瞬时荷载比的变化趋势较缓慢,而当瞬时荷载比大于60%时,再增大瞬时荷载比会使碳化深度急剧增大,抗碳化性能急剧降低。 展开更多
关键词 轻集料混凝土 抗渗性能 性能 水灰比 碳化周期 瞬时荷载
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“双碳”背景下零碳园区建设研究 被引量:10
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作者 马欣 《合作经济与科技》 2023年第8期4-7,共4页
“2030年前碳达峰”和“2060年前碳中和”目标是我国应对气候变化和全面推进经济社会绿色转型而提出的重大战略决策。园区作为先进要素高度集聚、创新活动蓬勃发展的产业活动主要载体,既是地区社会经济发展水平的衡量标志,也是能源消费... “2030年前碳达峰”和“2060年前碳中和”目标是我国应对气候变化和全面推进经济社会绿色转型而提出的重大战略决策。园区作为先进要素高度集聚、创新活动蓬勃发展的产业活动主要载体,既是地区社会经济发展水平的衡量标志,也是能源消费碳排放的主要源头。对此,零碳园区的建设是实现我国“双碳”目标的重要切入点和着力点,是园区智慧转型的必由之路,有助于促进工业企业高质量发展,重塑城市发展新格局。本文通过分析当前零碳园区建设所遇的障碍,结合我国“双碳”目标的实现,提出推进零碳园区建设的可实现路径。 展开更多
关键词 园区 达峰、中和” 全生命周期设计
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Effect of surface roughness on femtosecond laser ablation of 4H-SiC substrates 被引量:2
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作者 CHEN Jian-qiang XIE Xiao-zhu +4 位作者 PENG Qing-fa HE Zi-yu HU Wei REN Qing-lei LONG Jiang-you 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第10期3294-3303,共10页
Ablation threshold is an important concept in the study of femtosecond laser micro-and nano-machining.In this paper,the ablation experiments of three kinds of surface roughness 4H-Si C substrates irradiated by femtose... Ablation threshold is an important concept in the study of femtosecond laser micro-and nano-machining.In this paper,the ablation experiments of three kinds of surface roughness 4H-Si C substrates irradiated by femtosecond laser were carried out.The feature thresholds were systematically measured for three surface roughness Si C substrates and found in the modification and annealing regions ranging from coincidence(R_(a)=0.5 nm)to a clear demarcation(R_(a)=5.5 nm),eventually being difficult to identify the presence of the former(R_(a)=89 nm).Under multi-pulse laser irradiation,oriented ripple structures were generated in the annealing region,where deep subwavelength ripples(about 110 nm,Λ≈0.2λ)can be generated above substrates with surface roughness higher than 5.5 nm.We investigated the effect of surface roughness on the ablation morphology,ablation threshold,and periodic structures of femtosecond laser ablation of 4H-Si C substrates,while the ablation threshold was tended to decrease and stabilize with the increase of pulse number N≥500. 展开更多
关键词 4H-SIC surface roughness ablation threshold periodic structure femtosecond laser
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Environmental life cycle assessment of Indian coal-fired power plants 被引量:6
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作者 Udayan Singh Naushita Sharma Siba Sankar Mahapatra 《International Journal of Coal Science & Technology》 EI 2016年第2期215-225,共11页
Coal is the backbone of the Indian power sector. The coal-fired power plants remain the largest emitters of carbon dioxide, sulfur dioxide and substantial amounts of nitrogen oxides, which are associated with climate ... Coal is the backbone of the Indian power sector. The coal-fired power plants remain the largest emitters of carbon dioxide, sulfur dioxide and substantial amounts of nitrogen oxides, which are associated with climate and health impacts. Various CO2 mitigation technologies (carbon capture and storage--CCS) and SO2/NOx mitigation technologies (flue gas desulfurization and selective catalytic reduction) have been employed to reduce the environmental impacts of the coal-fired power plants. Therefore, it is imperative to understand the feasibility of various mitigation technologies employed. This paper attempts to perform environmental life cycle assessment (LCA) of Indian coal-fired power plant with and without CO2, SO2 and NOx mitigation controls. The study develops new normalization factors for India in various damage categories, using the Indian emissions and energy consumption data, coupled with the emissions and particulate emission to come up with a final environmental impact of coal-fired electricity. The results show a large degree of dependence on the perspective of assessment used. The impact of sensitivities of individual substances and the effect of plant efficiency on the final LCA results is also studied. 展开更多
关键词 Lifeinventory Fluecycle assessment Coal-fired power plants - Carbon capture and storage Environmental impact Plantgas desulfurization
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Effects of carbohydrate supplements on exercise-induced menstrual dysfunction and ovarian subcellular structural changes in rats
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作者 Can Zhao Xiao-Li Liu +3 位作者 Run-Xiao Hong He Li Rena Li Ren-Wei Wang 《Journal of Sport and Health Science》 SCIE 2014年第3期189-195,共7页
Background: Exercise-associated menstrual dysfunction (EAMD) is a common health problem in female athletes as a part of female athlete triad (FAT), a condition related to low energy availability. In this study, w... Background: Exercise-associated menstrual dysfunction (EAMD) is a common health problem in female athletes as a part of female athlete triad (FAT), a condition related to low energy availability. In this study, we explored the possibility that carbohydrate supplements can improve the status of EAMD and prevent exercise-induced ovarian injury in a FAT rat model. This research aimed to provide experimental evidence with regard to the relationship of energy intervention and EAMD. Methods: Forty-five female Sprague-Dawley rats (2 months old) were randomly divided into five experimental groups: control group (C), 9-week exercise as model for EAMD (E), post-EAMD recovery group (R), oligosaccharide intervention group (O), and glucose intervention group (G). All rats were sacrificed at the end of 9 weeks. Serum samples were collected for measuring gonadotropin releasing hormone, follicle stimulating hormone, luteinizing hormone, 1713-estradiol and progesterone levels. The ovaries were taken for investigation of exercise- and carbohydrate-induced follicular subcellular structure changes. Results: Exercise induced irregular menstrual cycles and ovary subcellular structural damages, such as swollenness of mitochondria in rats from groups E and R. Both glucose and oligosaccharide supplements restored well-differentiated mitochondria in the ovarian follicular cells, and a significant improvement of endoplasmic reticulum and Golgi in swollenness in theca cells in groups O and G compared to groups C, E, and R. There was no difference in mitochondria subcellular structural changes between groups O and G. Group E showed attenuation of serum levels of 17β-estradiol and progesterone compared to C. There were no differences of 17β-estradiol serum levels among groups O, G, and R, while group G showed a lower level of progesterone than C. Conclusion: Female adult rats with 9-week continuous exercise can cause menstrual dysregulation as a model for EAMD. Post-EAMD intervention with glucose and oligosaccharide intake can normalize the menstrual cycle, restore the follicular subcellular structure, and reverse the exercise-induced reduction of ovary sex hormones. It suggests a positive feedback of hypothalamus-pituitary-ovary axis might be involved in the molecular mechanisms of energy intake in treating EAMD. 展开更多
关键词 Carbohydrate supplement ESTRADIOL Estrous cycle restrain Follicular subcellular injury Ovary PROGESTERONE RATS
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Carbon Footprint Analysis for Baby Strollers
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作者 Yu Ang Luo Yifan 《Chinese Journal of Population,Resources and Environment》 2012年第4期16-21,共6页
The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas(GHG) emissions linked to their products or services.The publicly available spec... The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas(GHG) emissions linked to their products or services.The publicly available specification PAS 2050 has been developed in response to broad community and industry desire for a consistent method-carbon footprint for assessing the life cycle GHG emissions of goods and services.Specifically,this paper illustrates the implementation of carbon footprint for a baby stroller in accordance with PAS 2050.A fial value of 321 kg per one stroller including package was calculated.Moreover,the study led to identify raw materials production of the stroller as the main source of GHS emissions where efforts need to focus for emission reduction opportunities.This case study is hoped to be a starting point for organizations to benefit from the increasing application of carbon footprint assessment. 展开更多
关键词 baby stroller carbon footprint greenhouse gas emis- sions life cycle PAS 2050
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Life Cycle Input-Output Analysis Extended to Use, Disposal, and Recycling Stages Applied to Embodied CO2 Emissions of a Refrigerator
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作者 Yuki Mizumoto Yohji Uchiyama Keiichi Okajima 《Journal of Energy and Power Engineering》 2013年第4期695-704,共10页
Input-output analysis is widely employed to analyze inventories of a product's embodied energy and environmental burdens. However, input-output analysis focuses only on the production stage and ignores other life cyc... Input-output analysis is widely employed to analyze inventories of a product's embodied energy and environmental burdens. However, input-output analysis focuses only on the production stage and ignores other life cycle phases. Input-output analysis is not exactly a LCA (life cycle assessment) method in the strict sense of ISO 14040 standards, which must cover all stages of a product's life cycle, "from the cradle to the grave", so to speak. A tiered hybrid LCA is a useful tool that covers all life cycle stages by combining a process analysis with the input-output analysis method. This study aims to extend input-output analysis to the use, disposal, and recycling stages by using matrix-based method. The new method is applied to the analysis of the embodied CO2 emissions of a refrigerator as a case study. The entire life cycle C02 emissions are estimated to be 2.9 tons, including indirect emissions, and the reduction in CO2 emissions due to recycling steel scrap is calculated as 48.5 kg. The authors conclude that the new method enables a consistent inventory analysis for all life cycle stages by combining process and input-output methods. 展开更多
关键词 Input-output analysis matrix-based method hybrid lifecycle analysis RECYCLING REFRIGERATOR CO2 emission.
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Impacts of Seasonal Fossil and Ocean Emissions on the Seasonal Cycle of Atmospheric CO_2
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作者 CHEN Zhao-Hui 《Atmospheric and Oceanic Science Letters》 2011年第2期70-74,共5页
The seasonal cycle of atmospheric CO2 at surface observation stations in the northern hemisphere is driven primarily by net ecosystem production (NEP) fluxes from terrestrial ecosystems. In addition to NEP from terres... The seasonal cycle of atmospheric CO2 at surface observation stations in the northern hemisphere is driven primarily by net ecosystem production (NEP) fluxes from terrestrial ecosystems. In addition to NEP from terrestrial ecosystems, surface fluxes from fossil fuel combustion and ocean exchange also contribute to the seasonal cycle of atmospheric CO2. Here the authors use the Goddard Earth Observing System-Chemistry (GEOS-Chem) model (version 8-02-01), with modifications, to assess the impact of these fluxes on the seasonal cycle of atmospheric CO2 in 2005. Modifications include monthly fossil and ocean emission inventories. CO2 simulations with monthly varying and annual emission inventories were carried out separately. The sources and sinks of monthly averaged net surface flux are different from those of annual emission inventories for every month. Results indicate that changes in monthly averaged net surface flux have a greater impact on the average concentration of atmospheric CO2 in the northern hemisphere than on the average concentration for latitudes 30-90°S in July. The concentration values differ little between both emission inventories over the latitudinal range from the equator to 30°S in January and July. The accumulated impacts of the monthly averaged fossil and ocean emissions contribute to an increase of the total global monthly average of CO2 from May to December.An apparent discrepancy for global average CO2 concentration between model results and observation was because the observation stations were not sufficiently representative. More accurate values for monthly varying net surface flux will be necessary in future to run the CO2 simulation. 展开更多
关键词 CO2 GEOS-CHEM seasonal cycle
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Energy Crisis in Nigerian University System: Implications of Self Auto-generation for Human Capital Development
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作者 Stephen Chijioke Nwanya 《Journal of Energy and Power Engineering》 2014年第12期2017-2026,共10页
Energy requirements for tertiary educational purpose is burgeoning, a reflection of its criticality to human asset formation and to use self auto-generation by petrol or diesel generators as the energy supply source i... Energy requirements for tertiary educational purpose is burgeoning, a reflection of its criticality to human asset formation and to use self auto-generation by petrol or diesel generators as the energy supply source is an unsustainable practice. The situation is worrisome in view of the noise pollution and nuisance that constitutes to the learning environment. This paper, therefore, determines the quantity of self generated energy supply, its intensity, the associated CO2 emissions and their possible implications for human capital development. A survey of generating sets was conducted using the University of Nigeria Nsukka as a representative of Nigerian universities. A walk-through-approach was adopted in gathering data and two metrics-life cycle cost and cost of electricity from auto-generation were used to determine the economic implications of the self generation. The results show that self auto-generation contributed installed energy capacity of amount 19 MVA, 20 MVA, 34 MVA, 11 MVA and 22 MVA to run human capital development activities, respectively for academic sessions from July 2006 to November 2010. The study helps us understand that reforms in educational sector are not effective as long as energy insecurity is a dominant factor. 展开更多
关键词 Self-generation energy impact human asset university.
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Soil Organic Carbon Mineralization as Affected by Cyclical Temperature Fluctuations in a Karst Region of Southwestern China 被引量:12
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作者 CI En Mahdi M.AL-KAISI +2 位作者 WANG Liange DING Changhuan XIE Deti 《Pedosphere》 SCIE CAS CSCD 2015年第4期512-523,共12页
The diurnal fluctuation in soil temperature may influence soil organic carbon (SOC) mineralization, but there is no consensus on SOC mineralization response to the cyclical fluctuation in soil temperature. A 56-d in... The diurnal fluctuation in soil temperature may influence soil organic carbon (SOC) mineralization, but there is no consensus on SOC mineralization response to the cyclical fluctuation in soil temperature. A 56-d incubation experiment was conducted to investigate the effects of constant and variable temperatures on SOC mineralization. Three soils were collected from the karst region in western Guizhou Province, southwestern China, including a limestone soil under forest, a limestone soil under crops and a yellow soil under crops. According to the World Reference Base (WRB) classification, the two limestone soils were classified as Haplic Luvisols and the yellow soil as a Dystric Luvisol. These soils were incubated at three constant temperatures (15, 20 and 25 ℃) and cyclically fluctuating temperatures (diurnal cycle between 15 and 25 ℃). The results showed that the 56-d cumulative SOC mineralized (C56) at the fluctuating temperatures was between those at constant 15 and 25 ℃, suggesting that the cumulative SOC mineralization was restricted by temperature range. The SOC mineralization responses to the fluctuating temperatures were different among the three soils, especially in contrast to those at constant 20 ~C. Compared with constant 20 ℃, significant (P 〈 0.05) decreases and increases in C56 value were found in the limestone soil under forest and yellow soil under crops at the fluctuating temperatures, respectively. At the fluctuating temperatures, the forest soil with lower temperature coefficient Q10 (the relative change in SOC mineralization rate as a result of increasing the temperature by 10 ℃) had a significantly (P 〈 0.05) lower SOC mineralization intensity than the two cropland soils. These indicated that differences in temperature pattern (constant or fluctuating) could significantly influence SOC mineralization, and SOC mineralization responses to the fluctuating temperatures might be affected by soil characteristics. Moreover, the warmer temperatures might improve the ability of soil microbes to decompose the recalcitrant SOC fraction, and cyclical fluctuations in temperature could influence SOC mineralization through changing the labile SOC pool size and the mineralization rate of the recalcitrant SOC in soils. 展开更多
关键词 labile C limestone soil recalcitrant C temperature coefficient (Q10) yellow soil
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Power generation and heat sink improvement characteristics of recooling cycle for thermal cracked hydrocarbon fueled scramjet 被引量:7
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作者 BAO Wen QIN Jiang +2 位作者 ZHOU WeiXing ZHANG Duo YU DaRen 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第4期955-963,共9页
In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat ... In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle. 展开更多
关键词 recooling cycle SCRAMJET heat sink power generation thermal cracking
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Performance analysis for power generating system by using matrix method 被引量:2
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作者 Kanji OSHIMA Yohji UCHIYAMA 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第7期1689-1696,共8页
We verified that the matrix method, a process analysis method used mainly for life cycle inventory analysis, has several advantages in the analysis of power systems, which have recently become more complex to enhance ... We verified that the matrix method, a process analysis method used mainly for life cycle inventory analysis, has several advantages in the analysis of power systems, which have recently become more complex to enhance efficiency and to reduce C02 emissions. While designing a conceptual thermodynamic model of a complex power system, the matrix method provides a definite procedure and facilitates calculations, even if there is a recttrsive loop between the upstream and downstream processes. Similarly, in the case of partial modification to the constructed model, the matrix method can potentially reduce the time and effort required to calculate the thermodynamic balances, even if the constructed model is designed by others. In this study, we obtained mass flow and energy balances of example model power systems by the matrix method from the common thermodynamic conditions including temperatures and pressures which are set on the basis of an existing industrial steam power system. While analyzing the environmental impact of complex multiproduct power systems, such as carbon emissions, the matrix method can be used to easily derive the environmental impact of each final product. We could verify the efficacy of the matrix method in accurately deriving that of an example model power system. 展开更多
关键词 power system matrix method EFFICIENCY environmental impact hybrid power generation conceptual design
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