Northeast Asian cut-off lows are crucial cyclonic systems that can bring temperature and precipitation extremes over large areas.Skillful subseasonal forecasting of Northeast Asian cut-off lows is of great importance....Northeast Asian cut-off lows are crucial cyclonic systems that can bring temperature and precipitation extremes over large areas.Skillful subseasonal forecasting of Northeast Asian cut-off lows is of great importance.Using two dynamical forecasting systems,one from the Beijing Climate Center(BCC-CSM2-HR)and the other from the Met Office(GloSea5),this study assesses simulation ability and subseasonal prediction skill for early-summer Northeast Asian cut-off lows.Both models are shown to have good ability in representing the spatial structure of cut-off lows,but they underestimate the intensity.The skillful prediction time scales for cut-off low intensity are about 10.2 days for BCC-CSM2-HR and 11.4 days for GloSea5 in advance.Further examination shows that both models can essentially capture the initial Rossby wave train,rapid growth and decay processes responsible for the evolution of cut-off lows,but the models show weaker amplitudes for the three-stage processes.The underestimated simulated strength of both the Eurasian midlatitude and East Asian subtropical jets may lead to the weaker local eddy-mean flow interaction responsible for the cut-off low evolution.展开更多
The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic pe...The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic perspective,the seriousness of rural water quality,soil and atmospheric pollution in Xiangxiang,Xiangtan and the surrounding areas in Shaoshan irrigated area was revealed.The control measure which was 'four-dimensional pollution in the city and countryside'—— low-carbon-high-value agriculture and the technology innovation was proposed.The low-carbon-high-value technology innovation industrialization demonstration in three parts which included the pre-production,mid-production and post-production deep-processing of cultivation and breeding industry in the ecological cyclic agricultural garden in Shaoshan irrigated area was the driving force.We tried to propel the low-carbon ecological cultivation and breeding industry which included the paddy rice,grass,tree,medicinal herbs and pig,cow,chick,duck,fish.We wanted to relieve the structural unbalance of previous cultivation and breeding industry,'cheap grain hurting the farmers' and the short-leg problem of social-economic-ecological benefit.The results showed that the low-carbon-high-value agricultural system was a poly-generation technology system which promoted the multi-level and grading utilization,saved the energy,reduced the consumption and cleaned the production based on the ecology.展开更多
Development and application of ferrite materials for low temperature co-fired ceramic (LTCC) technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZ...Development and application of ferrite materials for low temperature co-fired ceramic (LTCC) technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZn ferrite, YIG ferrite, and lithium ferrite. In order to permit co-firing with a silver internal electrode in LTCC process, the sintering temperature of ferrite materials should be less than 950 ℃. These ferrite materials are research focuses and are applied in many ways in electronics.展开更多
The development theories of low-permeability oil and gas reservoirs are refined, the key development technologies are summarized, and the prospect and technical direction of sustainable development are discussed based...The development theories of low-permeability oil and gas reservoirs are refined, the key development technologies are summarized, and the prospect and technical direction of sustainable development are discussed based on the understanding and research on developed low-permeability oil and gas resources in China. The main achievements include:(1) the theories of low-permeability reservoir seepage, dual-medium seepage, relative homogeneity, etc.(2) the well location optimization technology combining favorable area of reservoir with gas-bearing prediction and combining pre-stack with post-stack;(3) oriented perforating multi-fracture, multistage sand adding, multistage temporary plugging, vertical well multilayer, horizontal and other fracturing techniques to improve productivity of single well;(4) the technology of increasing injection and keeping pressure, such as overall decreasing pressure, local pressurization, shaped charge stamping and plugging removal, fine separate injection, mild advanced water injection and so on;(5) enhanced recovery technology of optimization of injection-production well network in horizontal wells. To continue to develop low-permeability reserves economically and effectively, there are three aspects of work to be done well:(1) depending on technical improvement, continue to innovate new technologies and methods, establish a new mode of low quality reservoir development economically, determine the main technical boundaries and form replacement technology reserves of advanced development;(2) adhering to the management system of low cost technology & low cost, set up a complete set of low-cost dual integration innovation system through continuous innovation in technology and management;(3) striving for national preferential policies.展开更多
Urban fringe is a dynamic development area and its development in a certain period and region makes greater damage on the environment;hence,it is important to select proper technologies for landscape reconstruction.Ba...Urban fringe is a dynamic development area and its development in a certain period and region makes greater damage on the environment;hence,it is important to select proper technologies for landscape reconstruction.Based on this theme,the paper has analyzed the development and functional orientation of watercourses and embankments landscapes in Wanjiang urban fringe.On this basis,from the perspective of the selection and application of materials for watercourse and embankment landscape reconstruction,the respect of specific environmental culture of Wanjiang urban fringe,and the adaptation to the integration of watercourse landscape reconstruction technologies of Wanjiang urban fringe,the paper has illustrated the application of low technologies in landscape reconstruction of watercourses and embankments in Wanjiang urban fringe,so as to improve the surrounding environment and even the built-up environment based on the eco-environment of watercourses and embankments.展开更多
The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the t...The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the total geological reserves of the oilfield.Therefore,they have considerable potential for future oil production.The current layered injection technologies fail to achieve effective control over the low single-layer injection rates since they can only produce low throttle differential pressure under low injection rates(5-20 m^(3)/d).In this study,a symmetrically-structured double-offset-hole injection allocator and a novel throttling component were developed.Their spatial layout was constructed and mechanical parameters were optimized using finite element analysis,which allows for expanding the flow rate range at low injection rates.According to experimental results,the throttle differential pressure increased from 0.2 MPa to 0.8 MPa at an injection rate of 5 m^(3)/d,and the range of the single-layer flow rates expanded from 20-70 m^(3)/d to 5-70 m3/d.The field test results show that the effective production of oil layers with medium and low permeability was achieved and that the ratio of producing oil layer thickness to the total reservoir thickness increased by 9.7%on average.Therefore,this study provides valuable technical support for the effective chemical-flooding-based development of Class-Ⅲ oil reservoirs.展开更多
The agricultural energy consumption per unit of GDP is selected as an indicator for measuring the development level of low-carbon agriculture. Using gray relational theory, I analyze the relationship between developme...The agricultural energy consumption per unit of GDP is selected as an indicator for measuring the development level of low-carbon agriculture. Using gray relational theory, I analyze the relationship between development level of agricultural science and technology and development level of low-carbon agriculture in China. The results show that the correlation between the two is prominent; the number of agricultural science and technology talents, the number of agricultural science and technology patents, and the number of agricultural science and technology input are three major factors influencing the development of low-carbon agriculture. On this basis, I propose to take further effective measures, and put forth corresponding recommendations, in order to improve the level of agricultural science and technology.展开更多
It is essential that China follows a low carbon pathway, in which technology plays a key role in the future economy and social development. Based on the Integrated Policy Assessment Model for China, this paper analyze...It is essential that China follows a low carbon pathway, in which technology plays a key role in the future economy and social development. Based on the Integrated Policy Assessment Model for China, this paper analyzes a technology development roadmap for China to achieve a low carbon scenario. The results show that there are plenty of potential and opportunities for China to move towards a low carbon society when given enhanced and accelerated applications and expansions of key low carbon technologies. Strong policy and measure supports from all sectors in China are needed to achieve this goal.展开更多
In economics,opportunity cost means the maximum value of choosing one behavior over others in the situation where resources are limited(Parkin,2016).In the process of making reproductive decision,opportunity cost reve...In economics,opportunity cost means the maximum value of choosing one behavior over others in the situation where resources are limited(Parkin,2016).In the process of making reproductive decision,opportunity cost reveals the trade-off between time,resources,and economic benefits that individuals face when choosing to have children or not.During this process,the technological changes make the paths of career development diverse and rapidly changing,remarkably increasing the opportunity cost of childbirth and parenting.This leads to individuals more inclined to postpone or reduce childbirth when balancing their careers and families,thereby resulting in low fertility rates in developed economies.展开更多
China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon ...China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon technology innovation responds to climate change should be tested. Based on the2004-2015 panel data of 30 provinces in China, we use the method of ESDA analyzing the spatial correlation of China's low-carbon innovation technology. Furthermore, we use the spatial Durbin model empirically analyzing the spatial spillover effects. The results obtained are as follows: first,supply and demand of Chinese low-carbon innovation has some deviation in the spatial distribution. The low-carbon technology innovation as the supply factor shows the characteristics of expanding from the east to the west. Innovation in eastern China has always been the most active, but innovative activities in the middle and western China are gradually decreased.However, carbon emissions have the characteristics of moving westward, implying the change of technology demand different from technology supply. Second, China's low-carbon innovation actively responds to the trend of climate change, indicating China's technological efforts have paid off. However, the spatial spillover effects are not significant, showing that the efforts in each region of China still work for himself. Third, environmental regulation and market pull are important factors for low-carbon technology innovation. Among them, both supporting policy and inhibitory policy have significant impact on the local low-carbon technology innovation, but no significant spatial spillover effects. It shows that environmental policies in different regions are competitive and lack of demonstration effects. Economic growth and export as market pull have higher level of effect on low-carbon technology innovation for both local and adjacent areas.Some policy implications are proposed based on these results finally.展开更多
The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma trea...The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma treatment technology for the environmental contaminantswas synthetically studied, and the reaction processing and mechanism between the low-pressureplasma and the environmental contaminants were theoretically analyzed. At last, the prospectsand existing problems on the application of low-pressure plasma in the field of environmentalprotection were discussed.展开更多
With the coordinated development of social economy and technology today,various advanced construction techniques and well-established management measures have begun to be widely used in coal-tunnel construction.Howeve...With the coordinated development of social economy and technology today,various advanced construction techniques and well-established management measures have begun to be widely used in coal-tunnel construction.However,in the construction process of low-gas tunnels,it will also cause a certain degree of adverse impact on the construction quality and safety due to the lack of technical experience and management experience to a certain extent.Based on this,this paper takes the actual tunnel project of a coal mine as an example to analyze the main construction technology and safety management measures of low-gas tunnels,so as to provide guarantee for the quality and safety of such tunnel construction.展开更多
The paper introduced low-carbon economy and low-carbon technology, and proposed the de-tailed technical measures of low-carbon build-ing technology. Moreover, it has quantitatively calculated the “implicit” CO2 emis...The paper introduced low-carbon economy and low-carbon technology, and proposed the de-tailed technical measures of low-carbon build-ing technology. Moreover, it has quantitatively calculated the “implicit” CO2 emission of C40 and C50 concrete columns, aluminium curtain wall, wall paintings and common floor decora-tion materials. The calculation results show that it is preferable to use high strength concrete, reduce the usage of aluminium materials and use wooden floor according to location. The paper can be a reference for quantitative meas-urement to the low-carbon technology and en-ergy efficiency.展开更多
Introduction: Infertilityaffects one in six couples, and it is an important public health issue largely due to thepervasive effects on the emotional and psychological wellbeing of affected couples. In many developing ...Introduction: Infertilityaffects one in six couples, and it is an important public health issue largely due to thepervasive effects on the emotional and psychological wellbeing of affected couples. In many developing nations emphasis is placed on childbirth and inability to fulfill this role can be very distressing. There is an unmet need for assisted reproductive technology (ART) in many developing countries and where facilities exist, they are mostly privately owned, expensive and concentrated in urban areas. To bridge this gap, public fertility clinics have been established to provide subsidized care. Evaluating the characteristics and peculiarities of clientele presenting at these public facilities will aid planning and prioritization of care. Methodology: A descriptive retrospective study of 116 infertile patients presenting to the fertility clinic of the University College Hospital, Ibadan, Nigeria from inception on the 14<sup>th</sup> of February 2019 and 31<sup>st</sup> of December 2022.Data was analyzed using the Statical Package for Social Sciences (IBM, SPSS, New York) version 23. Descriptive statistics were used to summarize the results which were presented with the aid of bar charts and frequency tables. Result: The mean age of the patients was 40.70 ± 6.62 years. Post-menopausal patients accounted for about one-fifth of the study population while 80.2% (93 women) were older than 35 years. The mean duration of infertility was 9.39 ± 6.11years and nine patients (7.8%) had a duration greater than 2 decades. Secondary infertility occurred in 67.2% of the women. Twenty-nine women (25%) had undergone myomectomy prior to presentation. Hypertension (11.2%) was the most prevalent comorbidity. Nineteen patients (16.4%) had used contraceptives in the past with the male condom (36.8%)being the most preponderant. Sixty-seven patients had experienced pregnancy losses before 28 weeks of gestation while just 16 patients (13.8%) had undergone ART, and none was successful. Conclusion: Secondary infertility was the prevalent type of infertility and may not be unconnected with the low contraceptive usage and high risk of sexually transmitted infection. Late presentation coupled with a large proportion of post-menopausal clientele suggests delayed health-seeking behavior most probably due to the prohibitive cost of ART. The need to streamline services offered in public fertility clinics is paramount in low-income countries grappling with scarce resources. A pragmatic approach will involve the provision of low-cost ART, while enhancing gamete donation programs through the implementation of gamete sharing policies. This will invariably bridge the unmet need and skewed access to ART in developing countries.展开更多
This paper standardizes the operation of rapeseed production including variety choosing,field preparation,mechanical seeding,field management,mechanical harvesting etc.,to realize full mechanization of rapeseed produc...This paper standardizes the operation of rapeseed production including variety choosing,field preparation,mechanical seeding,field management,mechanical harvesting etc.,to realize full mechanization of rapeseed production. The key technologies: the optimum sowing date was from mid-September to mid-October in rapeseed-rice(corn) double cropping system region,and from mid-October to late October in rapeseed-rice-rice triple-cropping region; seeding rate was 4. 5 kg/ha-6. 0 kg/ha; the optimum density was 450000-750000 plants per ha;150-240 kg N fertilizer,60-90 kg P2O5 fertilizer,90-135 kg K2O fertilizer and 7. 5-15 kg B fertilizer were used per ha,50% of N fertilizer and the rest of fertilizer were used as basal fertilizer; segmented harvesting was done when 70%-80% of siliques per plant was yellow and combined harvesting was done when more than 90% of siliques per plant was yellow or brown.展开更多
In order to avoid the loss of ammonia during solar drying of stored urine, low-tech stripping is suggested as a pretreatment process for ammonia recovery. The mass transfer of ammonia from stored urine with an initial...In order to avoid the loss of ammonia during solar drying of stored urine, low-tech stripping is suggested as a pretreatment process for ammonia recovery. The mass transfer of ammonia from stored urine with an initial pH of about 9 was tested in a simple closed vessel operated at 72°C, 74°C and 85°C. The specific urine/gas interface was 16.97 m-1. For ammonia absorption, a beaker with sulfuric acid was positioned in the gas phase of the container. After keeping the stored urine for 73 h at 85°C, the concentration of free ammonia (NH3) was reduced by more than 99%, and the pH of the stored urine decreased to 6.4 due to ammonia volatilization. Total ammonia (NH3+ NH4+) concentration was reduced by only 83% in the same period. At lower temperatures, the process was slower. Required treatment time can be reduced when specific gas/liquid interface is increased. Because it is known that water can be heated in solar boxes to temperatures above 90°C, this simple stripping apparatus is feasible to be operated with solar energy in remote areas with suitable climatic conditions where no electric power is available. As the area demand for solar “low-tech stripping” is less than 1 m2 per capita, this process can be looked at as a suitable pretreatment of stored urine prior to solar evaporation.展开更多
Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this...Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this area. How would this process to inherit the quintessence of traditional local-style dwelling as well as integrate with low energy consumption technology is also an important problem due to the valuable Chinese traditional architectural culture in this area. Taking SI system as breaking point,this paper analyzes the green ecological characteristics of traditional residence in the south of the lower reaches of the Yangze River,discusses the current residential technology of low energy consumption, and proposes the low energy consumption residential technology integration system in the south of the lower reaches of the Yangze River.Based on this,this paper takes the SDC 2013 entry "solark"as a practical application case study and further expounds the prospects of this technology system.展开更多
It is an important and unique approach of achieving sustainable urban development to save and use energy intensively, reduce carbon emission, and take the low-carbon development road. Taking Gaochun Zijin Science and ...It is an important and unique approach of achieving sustainable urban development to save and use energy intensively, reduce carbon emission, and take the low-carbon development road. Taking Gaochun Zijin Science and Technology Special Community for example, this paper introduced planning measures for building a low-carbon city, including building a green network, compound utilization of urban spaces, establishing green transportation, using renewable resources, development of green architecture, so as to provide references for the future researches on the low-carbon urban development.展开更多
基金supported by the National Key Research and Development Program of China(2021YFA0718000)NSF of China under Grant No.42175075the UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘Northeast Asian cut-off lows are crucial cyclonic systems that can bring temperature and precipitation extremes over large areas.Skillful subseasonal forecasting of Northeast Asian cut-off lows is of great importance.Using two dynamical forecasting systems,one from the Beijing Climate Center(BCC-CSM2-HR)and the other from the Met Office(GloSea5),this study assesses simulation ability and subseasonal prediction skill for early-summer Northeast Asian cut-off lows.Both models are shown to have good ability in representing the spatial structure of cut-off lows,but they underestimate the intensity.The skillful prediction time scales for cut-off low intensity are about 10.2 days for BCC-CSM2-HR and 11.4 days for GloSea5 in advance.Further examination shows that both models can essentially capture the initial Rossby wave train,rapid growth and decay processes responsible for the evolution of cut-off lows,but the models show weaker amplitudes for the three-stage processes.The underestimated simulated strength of both the Eurasian midlatitude and East Asian subtropical jets may lead to the weaker local eddy-mean flow interaction responsible for the cut-off low evolution.
基金Supported by " Research on The Control Technology of Subtropical Agriculture Pollution System" Special Project of National Environment Protection Public Welfare Industry Science Research "Research on The Construction Strategy of Ecological Civilization" Development Plan Research Project of State Development and Reform Commission+1 种基金Xiangxiang " High-output and Efficient Cultivation of High Quality Rice and Processing Technology Industrialization Demonstration " in The Plan Test Site of National Science and Technology Enriching People and Developing County Special Project Action" Xiangxiang Middle and Long-term Development Plan of Modern Agriculture" of Subtropical Agriculture Ecology Institute in Chinese Academy of Science
文摘The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic perspective,the seriousness of rural water quality,soil and atmospheric pollution in Xiangxiang,Xiangtan and the surrounding areas in Shaoshan irrigated area was revealed.The control measure which was 'four-dimensional pollution in the city and countryside'—— low-carbon-high-value agriculture and the technology innovation was proposed.The low-carbon-high-value technology innovation industrialization demonstration in three parts which included the pre-production,mid-production and post-production deep-processing of cultivation and breeding industry in the ecological cyclic agricultural garden in Shaoshan irrigated area was the driving force.We tried to propel the low-carbon ecological cultivation and breeding industry which included the paddy rice,grass,tree,medicinal herbs and pig,cow,chick,duck,fish.We wanted to relieve the structural unbalance of previous cultivation and breeding industry,'cheap grain hurting the farmers' and the short-leg problem of social-economic-ecological benefit.The results showed that the low-carbon-high-value agricultural system was a poly-generation technology system which promoted the multi-level and grading utilization,saved the energy,reduced the consumption and cleaned the production based on the ecology.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB933100)the National Natural Science Foundation of China(Grant Nos.51132003,61021061,and 61171047)the Second Item of Strongpoint Industry of Guangdong Province,China(Grant No.2012A090100001)
文摘Development and application of ferrite materials for low temperature co-fired ceramic (LTCC) technology are dis- cussed, specifically addressing several typical ferrite materials such as M-type barium ferrite, NiCuZn ferrite, YIG ferrite, and lithium ferrite. In order to permit co-firing with a silver internal electrode in LTCC process, the sintering temperature of ferrite materials should be less than 950 ℃. These ferrite materials are research focuses and are applied in many ways in electronics.
文摘The development theories of low-permeability oil and gas reservoirs are refined, the key development technologies are summarized, and the prospect and technical direction of sustainable development are discussed based on the understanding and research on developed low-permeability oil and gas resources in China. The main achievements include:(1) the theories of low-permeability reservoir seepage, dual-medium seepage, relative homogeneity, etc.(2) the well location optimization technology combining favorable area of reservoir with gas-bearing prediction and combining pre-stack with post-stack;(3) oriented perforating multi-fracture, multistage sand adding, multistage temporary plugging, vertical well multilayer, horizontal and other fracturing techniques to improve productivity of single well;(4) the technology of increasing injection and keeping pressure, such as overall decreasing pressure, local pressurization, shaped charge stamping and plugging removal, fine separate injection, mild advanced water injection and so on;(5) enhanced recovery technology of optimization of injection-production well network in horizontal wells. To continue to develop low-permeability reserves economically and effectively, there are three aspects of work to be done well:(1) depending on technical improvement, continue to innovate new technologies and methods, establish a new mode of low quality reservoir development economically, determine the main technical boundaries and form replacement technology reserves of advanced development;(2) adhering to the management system of low cost technology & low cost, set up a complete set of low-cost dual integration innovation system through continuous innovation in technology and management;(3) striving for national preferential policies.
基金Supported by the Project of Humanities and Social Sciences Research of Department of Education of Anhui Province in 2011 (2011-sk455)
文摘Urban fringe is a dynamic development area and its development in a certain period and region makes greater damage on the environment;hence,it is important to select proper technologies for landscape reconstruction.Based on this theme,the paper has analyzed the development and functional orientation of watercourses and embankments landscapes in Wanjiang urban fringe.On this basis,from the perspective of the selection and application of materials for watercourse and embankment landscape reconstruction,the respect of specific environmental culture of Wanjiang urban fringe,and the adaptation to the integration of watercourse landscape reconstruction technologies of Wanjiang urban fringe,the paper has illustrated the application of low technologies in landscape reconstruction of watercourses and embankments in Wanjiang urban fringe,so as to improve the surrounding environment and even the built-up environment based on the eco-environment of watercourses and embankments.
基金sponsored by the key consulting project of the Chinese Academy of Engineering entitled Research on the Sustainable Development Strategy of China's High Water-cut Old Oilfields(No.2019-XZ-15)the National major project entitled Large Oil and Gas Field and Coalbed Methane Development(No.:2016ZX05010006).
文摘The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the total geological reserves of the oilfield.Therefore,they have considerable potential for future oil production.The current layered injection technologies fail to achieve effective control over the low single-layer injection rates since they can only produce low throttle differential pressure under low injection rates(5-20 m^(3)/d).In this study,a symmetrically-structured double-offset-hole injection allocator and a novel throttling component were developed.Their spatial layout was constructed and mechanical parameters were optimized using finite element analysis,which allows for expanding the flow rate range at low injection rates.According to experimental results,the throttle differential pressure increased from 0.2 MPa to 0.8 MPa at an injection rate of 5 m^(3)/d,and the range of the single-layer flow rates expanded from 20-70 m^(3)/d to 5-70 m3/d.The field test results show that the effective production of oil layers with medium and low permeability was achieved and that the ratio of producing oil layer thickness to the total reservoir thickness increased by 9.7%on average.Therefore,this study provides valuable technical support for the effective chemical-flooding-based development of Class-Ⅲ oil reservoirs.
基金Supported by the Project of Jiangsu Provincial Department of Education (2011SJD630046)the Project of Huai'an Federation of Social Sciences (C-11-15)
文摘The agricultural energy consumption per unit of GDP is selected as an indicator for measuring the development level of low-carbon agriculture. Using gray relational theory, I analyze the relationship between development level of agricultural science and technology and development level of low-carbon agriculture in China. The results show that the correlation between the two is prominent; the number of agricultural science and technology talents, the number of agricultural science and technology patents, and the number of agricultural science and technology input are three major factors influencing the development of low-carbon agriculture. On this basis, I propose to take further effective measures, and put forth corresponding recommendations, in order to improve the level of agricultural science and technology.
文摘It is essential that China follows a low carbon pathway, in which technology plays a key role in the future economy and social development. Based on the Integrated Policy Assessment Model for China, this paper analyzes a technology development roadmap for China to achieve a low carbon scenario. The results show that there are plenty of potential and opportunities for China to move towards a low carbon society when given enhanced and accelerated applications and expansions of key low carbon technologies. Strong policy and measure supports from all sectors in China are needed to achieve this goal.
文摘In economics,opportunity cost means the maximum value of choosing one behavior over others in the situation where resources are limited(Parkin,2016).In the process of making reproductive decision,opportunity cost reveals the trade-off between time,resources,and economic benefits that individuals face when choosing to have children or not.During this process,the technological changes make the paths of career development diverse and rapidly changing,remarkably increasing the opportunity cost of childbirth and parenting.This leads to individuals more inclined to postpone or reduce childbirth when balancing their careers and families,thereby resulting in low fertility rates in developed economies.
基金supported by the Major Tender Projects of National Social Science Foundation of China "Study on Optimization and Operation Mechanism of Industrial Eco Economic System in China"[grant number 12&ZD207]National Natural Science Foundation of China "Research on Value Chain Structure and Firm Embeddedness of Emerging Industries Driven by Technology Convergence"[grant number 71704069]+2 种基金MOE(Ministry of Education in China)Liberal Arts and Social Sciences Foundation "Research on the Formation Mechanism of Dynamic Capability of China's Manufacturing Clusters for Sustainable Eco-innovation"[grant number 16YJC630125]Social Science Foundation of Jiangsu Province "Research on Eco-innovation and New Competitive Advantages of Jiangsu Manufacturing Industrial Clusters"[grant number17GLB020]Natural Science Foundation of the Jiangsu Higher Education Institutions "Spatial Pattern Evolution and Influencing Factors of Carbon Emissions Efficiency of Construction Industry in China"[grant number17KJB170004]
文摘China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon technology innovation responds to climate change should be tested. Based on the2004-2015 panel data of 30 provinces in China, we use the method of ESDA analyzing the spatial correlation of China's low-carbon innovation technology. Furthermore, we use the spatial Durbin model empirically analyzing the spatial spillover effects. The results obtained are as follows: first,supply and demand of Chinese low-carbon innovation has some deviation in the spatial distribution. The low-carbon technology innovation as the supply factor shows the characteristics of expanding from the east to the west. Innovation in eastern China has always been the most active, but innovative activities in the middle and western China are gradually decreased.However, carbon emissions have the characteristics of moving westward, implying the change of technology demand different from technology supply. Second, China's low-carbon innovation actively responds to the trend of climate change, indicating China's technological efforts have paid off. However, the spatial spillover effects are not significant, showing that the efforts in each region of China still work for himself. Third, environmental regulation and market pull are important factors for low-carbon technology innovation. Among them, both supporting policy and inhibitory policy have significant impact on the local low-carbon technology innovation, but no significant spatial spillover effects. It shows that environmental policies in different regions are competitive and lack of demonstration effects. Economic growth and export as market pull have higher level of effect on low-carbon technology innovation for both local and adjacent areas.Some policy implications are proposed based on these results finally.
文摘The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma treatment technology for the environmental contaminantswas synthetically studied, and the reaction processing and mechanism between the low-pressureplasma and the environmental contaminants were theoretically analyzed. At last, the prospectsand existing problems on the application of low-pressure plasma in the field of environmentalprotection were discussed.
文摘With the coordinated development of social economy and technology today,various advanced construction techniques and well-established management measures have begun to be widely used in coal-tunnel construction.However,in the construction process of low-gas tunnels,it will also cause a certain degree of adverse impact on the construction quality and safety due to the lack of technical experience and management experience to a certain extent.Based on this,this paper takes the actual tunnel project of a coal mine as an example to analyze the main construction technology and safety management measures of low-gas tunnels,so as to provide guarantee for the quality and safety of such tunnel construction.
文摘The paper introduced low-carbon economy and low-carbon technology, and proposed the de-tailed technical measures of low-carbon build-ing technology. Moreover, it has quantitatively calculated the “implicit” CO2 emission of C40 and C50 concrete columns, aluminium curtain wall, wall paintings and common floor decora-tion materials. The calculation results show that it is preferable to use high strength concrete, reduce the usage of aluminium materials and use wooden floor according to location. The paper can be a reference for quantitative meas-urement to the low-carbon technology and en-ergy efficiency.
文摘Introduction: Infertilityaffects one in six couples, and it is an important public health issue largely due to thepervasive effects on the emotional and psychological wellbeing of affected couples. In many developing nations emphasis is placed on childbirth and inability to fulfill this role can be very distressing. There is an unmet need for assisted reproductive technology (ART) in many developing countries and where facilities exist, they are mostly privately owned, expensive and concentrated in urban areas. To bridge this gap, public fertility clinics have been established to provide subsidized care. Evaluating the characteristics and peculiarities of clientele presenting at these public facilities will aid planning and prioritization of care. Methodology: A descriptive retrospective study of 116 infertile patients presenting to the fertility clinic of the University College Hospital, Ibadan, Nigeria from inception on the 14<sup>th</sup> of February 2019 and 31<sup>st</sup> of December 2022.Data was analyzed using the Statical Package for Social Sciences (IBM, SPSS, New York) version 23. Descriptive statistics were used to summarize the results which were presented with the aid of bar charts and frequency tables. Result: The mean age of the patients was 40.70 ± 6.62 years. Post-menopausal patients accounted for about one-fifth of the study population while 80.2% (93 women) were older than 35 years. The mean duration of infertility was 9.39 ± 6.11years and nine patients (7.8%) had a duration greater than 2 decades. Secondary infertility occurred in 67.2% of the women. Twenty-nine women (25%) had undergone myomectomy prior to presentation. Hypertension (11.2%) was the most prevalent comorbidity. Nineteen patients (16.4%) had used contraceptives in the past with the male condom (36.8%)being the most preponderant. Sixty-seven patients had experienced pregnancy losses before 28 weeks of gestation while just 16 patients (13.8%) had undergone ART, and none was successful. Conclusion: Secondary infertility was the prevalent type of infertility and may not be unconnected with the low contraceptive usage and high risk of sexually transmitted infection. Late presentation coupled with a large proportion of post-menopausal clientele suggests delayed health-seeking behavior most probably due to the prohibitive cost of ART. The need to streamline services offered in public fertility clinics is paramount in low-income countries grappling with scarce resources. A pragmatic approach will involve the provision of low-cost ART, while enhancing gamete donation programs through the implementation of gamete sharing policies. This will invariably bridge the unmet need and skewed access to ART in developing countries.
文摘This paper standardizes the operation of rapeseed production including variety choosing,field preparation,mechanical seeding,field management,mechanical harvesting etc.,to realize full mechanization of rapeseed production. The key technologies: the optimum sowing date was from mid-September to mid-October in rapeseed-rice(corn) double cropping system region,and from mid-October to late October in rapeseed-rice-rice triple-cropping region; seeding rate was 4. 5 kg/ha-6. 0 kg/ha; the optimum density was 450000-750000 plants per ha;150-240 kg N fertilizer,60-90 kg P2O5 fertilizer,90-135 kg K2O fertilizer and 7. 5-15 kg B fertilizer were used per ha,50% of N fertilizer and the rest of fertilizer were used as basal fertilizer; segmented harvesting was done when 70%-80% of siliques per plant was yellow and combined harvesting was done when more than 90% of siliques per plant was yellow or brown.
文摘In order to avoid the loss of ammonia during solar drying of stored urine, low-tech stripping is suggested as a pretreatment process for ammonia recovery. The mass transfer of ammonia from stored urine with an initial pH of about 9 was tested in a simple closed vessel operated at 72°C, 74°C and 85°C. The specific urine/gas interface was 16.97 m-1. For ammonia absorption, a beaker with sulfuric acid was positioned in the gas phase of the container. After keeping the stored urine for 73 h at 85°C, the concentration of free ammonia (NH3) was reduced by more than 99%, and the pH of the stored urine decreased to 6.4 due to ammonia volatilization. Total ammonia (NH3+ NH4+) concentration was reduced by only 83% in the same period. At lower temperatures, the process was slower. Required treatment time can be reduced when specific gas/liquid interface is increased. Because it is known that water can be heated in solar boxes to temperatures above 90°C, this simple stripping apparatus is feasible to be operated with solar energy in remote areas with suitable climatic conditions where no electric power is available. As the area demand for solar “low-tech stripping” is less than 1 m2 per capita, this process can be looked at as a suitable pretreatment of stored urine prior to solar evaporation.
基金Sponsored by the Chinese Nature Science Foundation(Grant No.51278110)the Fundamental Research Funds for the Central Universities+1 种基金the Research Funds of Graduate Student Innovation Planning Program for Jiangsu Province's University(Grant No.KYLX-0143)the Fundamental Research Fundsof Southeast University
文摘Development of new vernacular dwelling of water town in the southern bank of the Yangze River is an important approach to improve rural appearance,infrastructure,quality of life,and to realize new urbanization of this area. How would this process to inherit the quintessence of traditional local-style dwelling as well as integrate with low energy consumption technology is also an important problem due to the valuable Chinese traditional architectural culture in this area. Taking SI system as breaking point,this paper analyzes the green ecological characteristics of traditional residence in the south of the lower reaches of the Yangze River,discusses the current residential technology of low energy consumption, and proposes the low energy consumption residential technology integration system in the south of the lower reaches of the Yangze River.Based on this,this paper takes the SDC 2013 entry "solark"as a practical application case study and further expounds the prospects of this technology system.
文摘It is an important and unique approach of achieving sustainable urban development to save and use energy intensively, reduce carbon emission, and take the low-carbon development road. Taking Gaochun Zijin Science and Technology Special Community for example, this paper introduced planning measures for building a low-carbon city, including building a green network, compound utilization of urban spaces, establishing green transportation, using renewable resources, development of green architecture, so as to provide references for the future researches on the low-carbon urban development.