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Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19
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作者 Zhiding ZHANG Xu YUE +3 位作者 Hao ZHOU Jun ZHU Yadong LEI Chenguang TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期84-96,共13页
The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).Whil... The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming. 展开更多
关键词 diffuse radiation fertilization effects anthropogenic aerosols natural aerosols pan-Arctic net primary productivity
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Impact of digital economy development on carbon productivity:An empirical analysis based on threshold effect and spatial spillover effect
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作者 XING Huai-zhen YAO Jing 《Ecological Economy》 2024年第2期123-138,共16页
Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development an... Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation. 展开更多
关键词 digital economy carbon productivity threshold effect spatial spillover effect
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Research on the Impact of China’s Foreign Trade Technology Spillover on Green Total Factor Productivity of Countries Along the“Belt and Road”:Based on the Institutional Quality Threshold Effect
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作者 Li Chai Longnan Ma Lingwei Meng 《Proceedings of Business and Economic Studies》 2024年第2期120-125,共6页
China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model t... China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward. 展开更多
关键词 Technology spillover Green total factor productivity Institutional quality Threshold effect
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Transformation power or development pressure:economic growth targets and urban carbon productivity
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作者 Longtao Chen Yi Zheng +1 位作者 Xianfeng Han Juan Liu 《Chinese Journal of Population,Resources and Environment》 2024年第2期176-184,共9页
Maintaining moderate economic growth targets(EGTs)is the key for local governments to effectively implement the“carbon peak and carbon neutrality”goals under the refreshed development pattern.Utilizing panel data of... Maintaining moderate economic growth targets(EGTs)is the key for local governments to effectively implement the“carbon peak and carbon neutrality”goals under the refreshed development pattern.Utilizing panel data of 276 prefecture-level cities in China's Mainland from 2010 to 2020,and employing methods such as intermediary and threshold models,this study empirically analyzes the internal mechanism of EGT’s impact on urban carbon productivity(UCP).Our findings demonstrate that:①The overall EGT during the analyzed period is not conducive to improving UCP.This conclusion remains valid after a series of robustness tests.This effect is more pronounced in the central region and resource-based cities than in the east-west region and non resource-based cities.②EGT not only directly suppresses UCP but also exerts indirect negative impacts on UCP from three aspects:delaying the digital economy(DE),constraining financial expansion(FE),and hindering green technology innovation(GTI).This negative indirect effect is similar to or even surpasses the direct effect,suggesting that the internal relationship between EGT and“dual-carbon”goals should be re-evaluated from a new compound perspective.③EGT not only has a simple linear impact on UCP but also significantly exhibits a dynamic evolution pattern in inverted“U”shape.That is,as EGT continuously upgrades,a nonlinear impact on UCP emerges in the form of“promoting first,suppressing later”.This indicates that surpassing the“degree”limit for EGT will be detrimental to the improvement of UCP.This study broadens the scope of carbon productivity analysis by introducing a new perspective centered on EGT.The insights gleaned from this research offer valuable guidance for local governments to effectively manage economic growth expectations and promote the synchronized achievement of dual-carbon objectives. 展开更多
关键词 Economic growth target Urban carbon productivity Mediating effects Dynamic evolution
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Spatiotemporal changes of gross primary productivity and its response to drought in the Mongolian Plateau under climate change
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作者 ZHAO Xuqin LUO Min +3 位作者 MENG Fanhao SA Chula BAO Shanhu BAO Yuhai 《Journal of Arid Land》 SCIE CSCD 2024年第1期46-70,共25页
Gross primary productivity(GPP)of vegetation is an important constituent of the terrestrial carbon sinks and is significantly influenced by drought.Understanding the impact of droughts on different types of vegetation... Gross primary productivity(GPP)of vegetation is an important constituent of the terrestrial carbon sinks and is significantly influenced by drought.Understanding the impact of droughts on different types of vegetation GPP provides insight into the spatiotemporal variation of terrestrial carbon sinks,aiding efforts to mitigate the detrimental effects of climate change.In this study,we utilized the precipitation and temperature data from the Climatic Research Unit,the standardized precipitation evapotranspiration index(SPEI),the standardized precipitation index(SPI),and the simulated vegetation GPP using the eddy covariance-light use efficiency(EC-LUE)model to analyze the spatiotemporal change of GPP and its response to different drought indices in the Mongolian Plateau during 1982-2018.The main findings indicated that vegetation GPP decreased in 50.53% of the plateau,mainly in its northern and northeastern parts,while it increased in the remaining 49.47%area.Specifically,meadow steppe(78.92%)and deciduous forest(79.46%)witnessed a significant decrease in vegetation GPP,while alpine steppe(75.08%),cropland(76.27%),and sandy vegetation(87.88%)recovered well.Warming aridification areas accounted for 71.39% of the affected areas,while 28.53% of the areas underwent severe aridification,mainly located in the south and central regions.Notably,the warming aridification areas of desert steppe(92.68%)and sandy vegetation(90.24%)were significant.Climate warming was found to amplify the sensitivity of coniferous forest,deciduous forest,meadow steppe,and alpine steppe GPP to drought.Additionally,the drought sensitivity of vegetation GPP in the Mongolian Plateau gradually decreased as altitude increased.The cumulative effect of drought on vegetation GPP persisted for 3.00-8.00 months.The findings of this study will improve the understanding of how drought influences vegetation in arid and semi-arid areas. 展开更多
关键词 gross primary productivity(GPP) climate change warming aridification areas drought sensitivity cumulative effect duration(CED) Mongolian Plateau
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Effects of grazing on net primary productivity,evapotranspiration and water use efficiency in the grasslands of Xinjiang,China 被引量:10
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作者 HUANG Xiaotao LUO Geping +1 位作者 YE Feipeng HAN Qifei 《Journal of Arid Land》 SCIE CSCD 2018年第4期588-600,共13页
Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary ... Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary productivity (NPP), evapotranspiration (ET) and water use efficiency (WUE) in this region remain unclear. Using the spatial Biome-BGC grazing model, we explored the effects of grazing on NPP, ET and WUE across the different regions and grassland types in Xinjiang during 1979-2012. NPP, ET and WUE under the grazed scenario were generally lower than those under the ungrazed scenario, and the differences showed increasing trends over time. The decreases in NPP, ET and WUE varied significantly among the regions and grassland types. NPP decreased as follows: among the regions, Northern Xinjiang (16.60 g C/(m2·a)), Tianshan Mountains (15.94 g C/(m2·a)) and Southern Xinjiang (-3.54 g C/(m2·a)); and among the grassland types, typical grasslands (25.70 g C/(m2·a)), swamp meadows (25.26 g C/(m2·a)), mid-mountain meadows (23.39 g C/(m2·a)), alpine meadows (6.33 g C/(m2·a)), desert grasslands (5.82 g C/(m2·a)) and saline meadows (2.90 g C/(me.a)). ET decreased as follows: among the regions, Tianshan Mountains (28.95 mm/a), Northern Xinjiang (8.11 mm/a) and Southern Xinjiang (7.57 mm/a); and among the grassland types, mid-mountain meadows (29.30 mm/a), swamp meadows (25.07 mm·a), typical grasslands (24.56 mm/a), alpine meadows (20.69 mm/a), desert grasslands (11.06 mm/a) and saline meadows (3.44 mm/a). WUE decreased as follows: among the regions, Northern Xinjiang (0.053 g C/kg H2O), Tianshan Mountains (0.034 g C/kg H2O) and Southern Xinjiang (0.012 g C/kg H2O); and among the grassland types, typical grasslands (0.0609 g C/kg H2O), swamp meadows (0.0548 g C/kg H2O), mid-mountain meadows (0.0501 g C/kg H2O), desert grasslands (0.0172 g C/kg H2O), alpine meadows (0.0121 g C/kg H2O) and saline meadows (0.0067 g C/kg H2O). In general, the decreases in NPP and WUE were more significant in the regions with relatively high levels of vegetation growth because of the high grazing intensity in these regions. The decreases in ET were significant in mountainous areas due to the terrain and high grazing intensity. 展开更多
关键词 grazing effect grassland type net primary productivity EVAPOTRANSPIRATION water use efficiency BiomeBGC grazing model
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Immediate effects of scalp acupuncture with twirling reinforcing manipulation on hemiplegia following acute ischemic stroke: a hidden association study 被引量:28
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作者 Xiao-zheng Du Chun-ling Bao +1 位作者 Gui-rong Dong Xu-ming Yang 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第5期758-764,共7页
Data mining has the potential to provide information for improving clinical acupuncture strategies by uncovering hidden rules between acupuncture manipulation and therapeutic effects in a data set. In this study, we p... Data mining has the potential to provide information for improving clinical acupuncture strategies by uncovering hidden rules between acupuncture manipulation and therapeutic effects in a data set. In this study, we performed acupuncture on 30 patients with hemiplegia due to acute ischemic stroke. All participants were pre-screened to ensure that they exhibited immediate responses to acupuncture. We used a twirling reinforcing acupuncture manipulation at the specific lines between the bilateral Baihui(GV20) and Taiyang(EX-HN5). We collected neurologic deficit score, simplified Fugl-Meyer assessment score, muscle strength of the proximal and distal hemiplegic limbs, ratio of the maximal H-reflex to the maximal M-wave(Hmax/Mmax), muscle tension at baseline and immediately after treatment, and the syndromes of traditional Chinese medicine at baseline. We then conducted data mining using an association algorithm and an artificial neural network backpropagation algorithm. We found that the twirling reinforcing manipulation had no obvious therapeutic difference in traditional Chinese medicine syndromes of "Deficiency and Excess". The change in the muscle strength of the upper distal and lower proximal limbs was one of the main factors affecting the immediate change in Fugl-Meyer scores. Additionally, we found a positive correlation between the muscle tension change of the upper limb and Hmax/Mmax immediate change, and both positive and negative correlations existed between the muscle tension change of the lower limb and immediate Hmax/Mmax change. Additionally, when the difference value of muscle tension for the upper and lower limbs was 〉 0 or 〈 0, the difference value of Hmax/Mmax was correspondingly positive or negative, indicating the scalp acupuncture has a bidirectional effect on muscle tension in hemiplegic limbs. Therefore, acupuncture with twirling reinforcing manipulation has distinct effects on acute ischemic stroke patients with different symptoms or stages of disease. Improved muscle tension in the upper and lower limbs, reflected by the variation in the Hmax/Mmax ratio, is crucial for recovery of motor function from hemiplegia. 展开更多
关键词 nerve regeneration traditional Chinese medicine needling reinforcing manipulation hemiplegia due to acute ischemic stroke im- mediate effect association algorithm artificial neural network algorithm neurological deficit score simplified Fugl-Meyer assessment Hmax/Mmax traditional Chinese medicine syndromes scalp acupoints neural regeneration
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Warming effect of desert and its impact on oasis heat resources and agricultural productivity in arid land,China
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作者 FengHua Zhang Qiang Zhao Munir A. Hanjra 《Research in Cold and Arid Regions》 2012年第3期229-235,共7页
This paper provides a positive view of the desert, in terms of the warming effect of deserts on oases and the impact of heat re- sources and agricultural production. We use data from experimental sites in the Manas Ri... This paper provides a positive view of the desert, in terms of the warming effect of deserts on oases and the impact of heat re- sources and agricultural production. We use data from experimental sites in the Manas River Basin in China to characterize these relationships. We note that the warming effect of the desert was found to be significant but gradually reduced with in- creased distance of the oasis from the desert. The range of wanning effect is about 100 km, and the improvement in tempera- ture is about 1.8 ℃. Due to this warming effect, the desert serves as the second heat source for the oasis, which represents one important aspect of the ecologic value of the desert. Our results also show the warming effect has a strong spatial impact on agricultural productivity. Crop productivity fell by about 49 kg/ha with every 10 km increase in distance away from the desert. Our results imply that crop suitability must correspond to the warming effect of the desert. More efficient use of heat resources can contribute towards achieving potential productivity. 展开更多
关键词 warm effect DESERT crop productivity arid land
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Tree diversity effects on forest productivity increase through time because of spatial partitioning
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作者 Shinichi Tatsumi 《Forest Ecosystems》 SCIE CSCD 2020年第3期327-333,共7页
Background: Experimental manipulations of tree diversity have often found overyielding in mixed-species plantations. While most experiments are still in the early stages of stand development, the impacts of tree diver... Background: Experimental manipulations of tree diversity have often found overyielding in mixed-species plantations. While most experiments are still in the early stages of stand development, the impacts of tree diversity are expected to accumulate over time. Here, I present findings from a 31-year-old tree diversity experiment(as of2018) in Japan.Results: I find that the net diversity effect on stand biomass increased linearly through time. The species mixture achieved 64% greater biomass than the average monoculture biomass 31 years after planting. The complementarity effect was positive and increased exponentially with time. The selection effect was negative and decreased exponentially with time. In the early stages(≤ 3 years), the positive complementarity effect was explained by enhanced growths of early-and mid-successional species in the mixture. Later on(≥ 15 years), it was explained by their increased survival rates owing to vertical spatial partitioning — i.e. alleviation of self-thinning via canopy stratification. The negative selection effect resulted from suppressed growths of late-successional species in the bottom layer.Conclusions: The experiment provides pioneering evidence that the positive impacts of diversity-driven spatial partitioning on forest biomass can accumulate over multiple decades. The results indicate that forest biomass production and carbon sequestration can be enhanced by multispecies afforestation strategies. 展开更多
关键词 Biomass productivity Complementarity effect Biodiversity and ecosystem functioning Forest dynamics Mixed plantation Plant succession Selection effect Shade tolerance Stand structure Tree diversity experiment
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Experimental and Numerical Assessment of the Influence of Bottomhole Pressure Drawdown on Terrigenous Reservoir Permeability and Well Productivity
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作者 Sergey Popov Sergey Chernyshov Evgeniy Gladkikh 《Fluid Dynamics & Materials Processing》 EI 2023年第3期619-634,共16页
During oil and gas fields development,a decrease in reservoir and bottomhole pressure has often a detrimental effect on reservoir properties,especially permeability.This study presents the results of laboratory tests ... During oil and gas fields development,a decrease in reservoir and bottomhole pressure has often a detrimental effect on reservoir properties,especially permeability.This study presents the results of laboratory tests conducted to determine the response of terrigenous reservoir core-sample permeability to changes in the effective stresses and a decrease in the reservoir pressure.The considered samples were exposed for a long time to a constant high effective stress for a more reliable assessment of the viscoplastic deformations.According to these experiments,the decrease of the core samples permeability may reach 21%with a decrease in pressure by 9.5 MPa from the initial reservoir conditions.Numerical simulations have been also conducted.These have been based on the finite element modeling of the near-wellbore zone of the terrigenous reservoir using poroelasticity relations.The simulation results show a limited decrease in reservoir permeability in the near-wellbore zone(by 17%,which can lead to a decrease in the well productivity by 13%). 展开更多
关键词 Terrigenous reservoir PERMEABILITY core sample reservoir pressure bottomhole pressure drawdown effective stress well productivity
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An effective technique to improve photosynthetic productivity and adaptability of rice
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作者 TU Zengping CAI Weijuan LIU Bin Rice Re Inst,Guangdong Acad of Agr Sci,Guangzhou 510640,China 《Chinese Rice Research Newsletter》 1994年第2期3-4,共2页
High photosynthetic productivity and widephotosynthetic adaptability are two importantphysiological characteristics for the sustained highyield and wider growing range of rice.Preliminaryexperiments indicated that the... High photosynthetic productivity and widephotosynthetic adaptability are two importantphysiological characteristics for the sustained highyield and wider growing range of rice.Preliminaryexperiments indicated that the utilization ofbeterosis between two different ecotype rices,US 展开更多
关键词 An effective technique to improve photosynthetic productivity and adaptability of rice high
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The Productivity Model of Horizontal Well Considering Acidification Effect in Anisotropic Reservoirs
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作者 Enhui Sun Wei Yang +2 位作者 Qin Peng Peng Meng Songru Mu 《World Journal of Engineering and Technology》 2020年第1期19-32,共14页
When the horizontal well was acidized, in order to predict the productivity, through coordinate transformation method, based on the formation seepage model of horizontal well after acidification,?wededuced the formula... When the horizontal well was acidized, in order to predict the productivity, through coordinate transformation method, based on the formation seepage model of horizontal well after acidification,?wededuced the formula of horizontal well local skin factor,?established the coupling model of reservoir and horizontal wellbore flow,?and?deduced the semi-analytical productivity model of horizontal well considering the change of local skin factor. Based on the example, the effect of horizontal well length, reservoir anisotropy coefficient, mud damage depth and damage degree on the production-increasing ratio after acidification were studied. The results showed reservoir with greater anisotropy, serious wellbore pollution and deeper mud invasion near wellbore,?and?that the stimulation effect of horizontal well after acidification was better. 展开更多
关键词 ANISOTROPY ACIDIFICATION effect COORDINATE Transformation SKIN Factor productivity of Horizontal Well
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Learning Effect and Productivity Convergence of Chinese Industrial Enterprises
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作者 Tinghua Liu Jingru Wang Xiao Liu 《Journal of Finance Research》 2020年第2期92-105,共14页
The main purpose of this paper is to test the production efficiency of different Chinese property industrial enterprises.Based on the large sample panel data of industrial enterprises of the National Bureau of Statist... The main purpose of this paper is to test the production efficiency of different Chinese property industrial enterprises.Based on the large sample panel data of industrial enterprises of the National Bureau of Statistics,we found that although the production efficiency of China-funded enterprises is generally weaker than foreign-funded enterprises,some China-funded enterprises have better learning ability.On the one hand,dynamic analysis found that private enterprises have significant learning ability.On the other hand,the results of convergence analysis show that China’s private enterprises have the potential to gradually catch up with the frontier level of world production efficiency and have better learning ability to catch up potential.And state-owned enterprises tend to be more efficient at the beginning of their establishment,but their productivity is fairly slow to improve,especially for state-owned enterprises with high efficiency sub-samples,so that it’s hard for them to continue improving their efficiency.Institutional analysis found that the marketization process helped the China enterprises to improve their learning ability and China should continue to strengthen the reform of property rights and promote the marketization process. 展开更多
关键词 Production efficiency Learning effect Efficiency catch-up βconvergence analysis
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Investigation of Pile Construction and Productivity Loss: An Analysis of Macro Impact Factor
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作者 Minhaz Ahmed Wang Xu 《World Journal of Engineering and Technology》 2023年第4期932-964,共33页
Pile foundations are challenging to build due to subsurface obstacles, contractor ignorance, and difficulties with site planning. Given the unpredictable environment of the construction site, productivity losses durin... Pile foundations are challenging to build due to subsurface obstacles, contractor ignorance, and difficulties with site planning. Given the unpredictable environment of the construction site, productivity losses during pile work are to be thought possible. Prior to finishing a site pre-investigation, a foundation’s area is usually sampled for statistical reasons. There are studies on pile construction outside of Bangladesh that are supported by relevant empirical data in the literature. Since Bangladesh, which is regarded as a third-world country, is ignored in this regard, the literature currently available about pile building and the associated productivity loss is unable to provide adequate information or appropriate empirical data. Due to this pile-building sector in Bangladesh has been experiencing a decline in production for quite some time now. Before attempting to increase productivity in pile construction, it is essential to investigate the potential losses and the variables that might have an influence. This study aims to accomplish the following objectives: 1) identify the primary factors that have an impact on pile construction;2) develop an SVR model that accurately predicts productivity loss;and 3) figure out the projected loss by basing it on the historical scenario that is the most comparable to the current one. A Support Vector Regression (SVR) model was developed after a study of the relevant literature. This model enabled the collection of 110 pile building projects from five significant locations in Bangladesh. The model was constructed using a list of eight inputs in addition to a list of five macro elements (labor, management, environment, material, and equipment) (soil condition, pile type, pile material, project size, project location, pile depth, pile quantity, and equipment quantity). Using 10-way cross validation, the SVR achieves an accuracy of 87.2% in its predictions. On the basis of what has occurred in the past, we are able to estimate that there will be a loss of around 18.55 percent of the total output. A new perspective for engineers studying the delay factors with productivity loss is provided by the outcome of important tasks as it relates to loss in productivity and overall factors faced. In the building construction industry, effective management should place more emphasis on the correlation between productivity loss and the factors that cause it. Therefore, to represent the effect on productivity loss, real factors can be summed up as a decline in productivity loss. The findings of the study would urge specialists to concentrate on waste as a means of increasing overall production. 展开更多
关键词 productivity Loss Macro-effect Factor Pile Construction Regression Model SVR Model
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Dominating factors on well productivity and development strategies optimization in Weiyuan shale gas play, Sichuan Basin, SW China 被引量:4
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作者 MA Xinhua LI Xizhe +7 位作者 LIANG Feng WAN Yujin SHI Qiang WANG Yonghui ZHANG Xiaowei CHE Mingguang GUO Wei GUO Wei 《Petroleum Exploration and Development》 2020年第3期594-602,共9页
Weiyuan shale gas play is characterized by thin high-quality reservoir thickness,big horizontal stress difference,and big productivity differences between wells.Based on integrated evaluation of shale gas reservoir ge... Weiyuan shale gas play is characterized by thin high-quality reservoir thickness,big horizontal stress difference,and big productivity differences between wells.Based on integrated evaluation of shale gas reservoir geology and well logging interpretation of more than 20 appraisal wells,a correlation was built between the single well test production rate and the high-quality reservoir length drilled in the horizontal wells,high-quality reservoir thickness and the stimulation treatment parameters in over 100 horizontal wells,the dominating factors on horizontal well productivity were found out,and optimized development strategies were proposed.The results show that the deployed reserves of high-quality reservoir are the dominating factors on horizontal well productivity.In other words,the shale gas well productivity is controlled by the thickness of the high-quality reservoir,the high-quality reservoir drilling length and the effectiveness of stimulation.Based on the above understanding,the development strategies in Weiyuan shale gas play are optimized as follows:(1)The target of horizontal wells is located in the middle and lower parts of Longyi 11(Wei202 area)and Longyi 11(Wei204 area).(2)Producing wells are drilled in priority in the surrounding areas of Weiyuan county with thick high-quality reservoir.(3)A medium to high intensity stimulation is adopted.After the implementation of these strategies,both the production rate and the estimated ultimate recovery(EUR)of individual shale gas wells have increased substantially. 展开更多
关键词 Weiyuan shale gas play dominating factors of well productivity deployed reserves of high-quality reservoir thickness of high-quality reservoir high-quality reservoir drilling length effectiveness of stimulation development strategies optimization
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The Growth of Sub-Saharan Africa in the 2000s:Estimation of the Contributions of Factor Accumulation and Factor Productivity
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作者 Robert Dauda Korsu Mohamed Ben Omar Ndiaye 《Economics World》 2021年第2期43-59,共17页
Sustained economic growth is a key source of poverty alleviation and growth that is driven more by productivity than the quantity of factors of production is useful for long-term inclusive growth and poverty reduction... Sustained economic growth is a key source of poverty alleviation and growth that is driven more by productivity than the quantity of factors of production is useful for long-term inclusive growth and poverty reduction,which is needed in Sub-Saharan Africa.The paper sought to investigate the relative roles of capital and labour as factors of production and their productivity in the growth process of Sub-Saharan Africa using annual data from 2000 to 2018.A production function was estimated,following the construction of data for capital stock using the perpetual inventory method.The production function was estimated by applying the instrumental variables(IV)to the two-way fixed effects model,using clustered standard errors.The results show that the share of capital and labour in production were 0.14 and 0.86 respectively.Capital,labour and their productivity contributed 24.7%,51.1%and 24.2%respectively to real GDP growth during the period 2001 to 2018.Further efforts in building the productivity of capital and labour are therefore required in Sub-Saharan Africa.Building good governance,the legal framework,political stability,expanded access to quality education and affordable quality healthcare,greater openness towards technological progress are therefore imperative. 展开更多
关键词 GROWTH factor productivity Sub-Saharan Africa two-way fixed effects
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Biodiversity, productivity, and temporal stability in a natural grassland ecosystem of China 被引量:3
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作者 Bing Liu WenZhi Zhao +1 位作者 YangYang Meng Chan Liu 《Research in Cold and Arid Regions》 CSCD 2018年第4期293-304,共12页
Understanding the effect of biodiversity on ecosystem function is critical to promoting the sustainability of ecosystems and species conservation in natural ecosystems. We observed species composition, species richnes... Understanding the effect of biodiversity on ecosystem function is critical to promoting the sustainability of ecosystems and species conservation in natural ecosystems. We observed species composition, species richness and aboveground biomass,and simulated the competitive assemblages in a natural grassland ecosystem of China, aiming to test some assumptions and predictions about biodiversity–stability relationships. Our results show that aboveground productivity and temporal stability increased significantly with increasing species richness, and via a combination of overyielding, species asynchrony, and portfolio effects. Species interactions resulted in overyielding caused by trait-independent complementarity, and were not offset by a negative dominance effect and trait-dependent complementarity effect. Therefore, the mechanisms underlying the biodiversity effect shifted from the selection effect to the complementarity effect as diversity increased, and both effects were coexisted but the complementarity effect represent a mechanism that facilitates long term species coexistence in a natural grassland ecosystem of China. 展开更多
关键词 BIODIVERSITY productivity TEMPORAL stability OVERYIELDING effect SPECIES interactions complementarity effect selection effect
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Technical Components of Total Factor Productivity Growth in Malaysian Manufacturing Industry 被引量:2
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作者 Nik Hashim Nik Mustapha Nik Mohd Hazrul Hashim Ridzuan Yacob 《Applied Mathematics》 2013年第9期1251-1259,共9页
This article attempts to disaggregate and explore the components of TFP growth that contribute to changes in output, scale of production, and allocative efficiency and technical efficiency of the Malaysian manufacturi... This article attempts to disaggregate and explore the components of TFP growth that contribute to changes in output, scale of production, and allocative efficiency and technical efficiency of the Malaysian manufacturing sector. The total factor productivity (TFP) concept defined as total output per unit of all inputs used in the production of an industry has gained a prominent place in academia. The investigation on TFP growth is obviously useful for identifying sources of output growth in the development of an industry. The TFP growth is often interchangeably understood as the technical progress or changes in technology as the sole contributor to economic development. Nonetheless there are other factors contributing to its substance. Knowledge on these technical changes would help decision makers to realize the strengths and weaknesses that contribute to the growth and development of an industry. Alternatively this research would be more beneficial in the case of cross-industry or cross-country comparative studies in order to plan for developmental goal. In such a case a model industry or country can be chosen that exhibits special growth features. 展开更多
关键词 TOTAL Factor productivity Growth TECHNICAL Efficiency Scale effect Stochastic Production FRONTIER
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A NEW METHOD FOR INCREASING THE PRODUCTIVITY OF LARCH PLANTATION
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作者 陈祥伟 丁宝永 赵春梅 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1994年第2期9-12,共4页
A new method for increasing the productivity of larch plantation was pointed out by applying the edge effect in production in this paper. For the radiation of sunlight is identical in the same unit area of the same la... A new method for increasing the productivity of larch plantation was pointed out by applying the edge effect in production in this paper. For the radiation of sunlight is identical in the same unit area of the same latitude, we could not increase the productivity by changing the total radiation, but we can change the property of the floor by setting up effect be1ts and develop the structure of community and the photosynthetic system. In the end, significant benefits on productivity and biological, ecological effects were showed by 30 years experiments. 展开更多
关键词 Edge effect Community structure Property of the floor productivity
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Resilience provides mediating effect of resilience between fear of progression and sleep quality in patients with hematological malignancies
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作者 Yuan Tian Ying-Li Wang 《World Journal of Psychiatry》 SCIE 2024年第4期541-552,共12页
BACKGROUND Hematological tumors are common malignant tumors,with high morbidity and mortality rates.Most patients with hematological malignancies develop sleep disorders that seriously affect their life and health bec... BACKGROUND Hematological tumors are common malignant tumors,with high morbidity and mortality rates.Most patients with hematological malignancies develop sleep disorders that seriously affect their life and health because of acute onset of disease,rapid progression,high recurrence rates,complex treatment methods,and treatment costs.AIM To explore the mediating effect of resilience on fear of disease progression and sleep quality in patients with hematological malignancies.METHODS A cross-sectional analysis of 100 patients with hematological malignancies,treated in the First Affiliated Hospital of Jinzhou Medical University between August 2022 and August 2023,was conducted.Patients were assessed using a general data survey,a simplified scale for the fear of progression(FoP)of disease,a resilience scale,and the Pittsburgh Sleep Quality Index.Statistical analysis was conducted to determine the relationship between various patient characteristics and FoP,resilience,and sleep quality.Spearman’s correlation analysis was used to examine the correlations between mental resilience,FoP,and sleep quality.RESULTS The total FoP score mean value in patients with hematological malignancies was 38.09±5.16;the total resilience score mean value was 40.73±7.04;and the Pittsburgh Sleep Quality Index score mean value was 10.72±1.90.FoP,resilience,and sleep quality of the patients were associated with family per capita monthly income and patient education level(P<0.05).Spearman correlation analysis revealed that FoP was negatively correlated with resilience and sleep quality scores(r=-0.560,-0.537,P<0.01),respectively,and resilience was significantly associated with sleep quality scores(r=0.688,P<0.01).Mediation analysis showed that the mediating effect of resilience between FoP and sleep quality in patients with hematological malignancies was-0.100 and accounted for 50.51%of the total effect.This indicated that FoP directly and indirectly affected sleep quality through the mesomeric effect of resilience.CONCLUSION Resilience is an intermediary variable between FoP and sleep quality in patients with hematological malignancies.Medical staff should evaluate and follow-up FoP and resilience to implement measures to improve sleep quality. 展开更多
关键词 RESILIENCE Blood tumor Fear of progression Sleep quality Mediating effect
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