In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a ...In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.展开更多
The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,pr...The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,promoting conventional intercropping strategies in modern agriculture can prove challenging.The innovative technology of soybean maize strip intercropping(SMSI)has been proposed as a solution.This system has produced remarkable results in improving domestic soybean and maize production for both food security and sustainable agriculture.In this article,we provide an overview of SMSI and explain how it differs from traditional intercropping.We also discuss the core principles that foster higher yields and the prospects for its future development.展开更多
Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflector...Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.展开更多
Electrical and electronic devices are becoming an increasingly important part of our society. In Africa, and in Senegal in particular, the handling and management of electronic and electrical equipment (EEE) that has ...Electrical and electronic devices are becoming an increasingly important part of our society. In Africa, and in Senegal in particular, the handling and management of electronic and electrical equipment (EEE) that has reached the end of its life is mainly informal. This professional environment is characterized by the disintegration of the sector and the social heterogeneity that can be found there. The objective of this study is to assess the standard of living of electrical and electronic equipment waste handlers in the Dakar region, as well as their perception of their health. A survey was used to obtain information on sociodemographic background, living arrangements, perception of health status, and good practices to be implemented in case of work-related health problems. Life style, perception of general health and health problems were ranged as excellent, very good, good, average and poor. Informal recyclers in the Dakar region lived mainly in rooms and buildings as tenants (49.1%), or in family homes (48.4%) before starting this activity, and 51.2% continue to live in rooms and buildings as tenants compared to 41.4% who still live in a family home. The perception of health status ranged from poor to excellent, and 4.9% believe that they are limited in work due to a disability or health problem. Informal work is a heterogeneous phenomenon that makes research and policymaking particularly complex. There are several external factors within informal WEEE re-cyclers that can cause health problems or functional disability. However, the living conditions and the perception they have of their state of health are contradictory to the working conditions and the social environment to which they belong. A biomedical approach would consolidate these achievements by confirming or invalidating them.展开更多
With a surge in the university’s student and staff population, parking problems and congestion have rapidly intensified. The recent inclusion of women drivers, particularly during official working hours, has exacerba...With a surge in the university’s student and staff population, parking problems and congestion have rapidly intensified. The recent inclusion of women drivers, particularly during official working hours, has exacerbated these challenges. This pressing issue underscores the critical necessity for a structured approach to managing university entries and overseeing parking at the gates. The proposed smart parking management system aims to address these concerns by introducing a design concept that restricts unauthorized access and provides exclusive parking privileges to authorized users. Through image processing, the system identifies available parking spaces, relaying real-time information to users via a mobile application. This comprehensive solution also generates detailed reports (daily, weekly, and monthly), aiding university safety authorities in future gate management decisions.展开更多
As of January 31,2024,China had concluded mutual visa exemption agreements covering different types of passports with 157 countries,reached agreements or arrangements on simplified visa procedures with 44 countries,an...As of January 31,2024,China had concluded mutual visa exemption agreements covering different types of passports with 157 countries,reached agreements or arrangements on simplified visa procedures with 44 countries,and enjoyed comprehensive mutual visa exemptions with 23 countries including Thailand,Singapore,Maldives,and the United Arab Emirates.展开更多
A multi-function protecting forest system was planed and arranged elaborately for im-provement of the local ecological conditions and high economical benefit. The system in-cludes level farmland shelter belt network, ...A multi-function protecting forest system was planed and arranged elaborately for im-provement of the local ecological conditions and high economical benefit. The system in-cludes level farmland shelter belt network, hillside farmland shelter belt network, stereoscop-ic sparse-wood pasture, erosion control fuel forest, fast growing commercial forest, eco-nomical forest, salt-soda controlling project and salt-soda protecting forest on salt-sodaland, ect..展开更多
It is a multifactor optimization problem to arrange examinations on a large scale for universities. In this paper, a kind of grouped optimization algorithm was proposed. A principle about related degree, which plays a...It is a multifactor optimization problem to arrange examinations on a large scale for universities. In this paper, a kind of grouped optimization algorithm was proposed. A principle about related degree, which plays a core role in realization, was introduced in the algorithm. According to the algorithm, we worked out a set of software correspondingly and applied it to a certain university in Shanghai to arrange examinations. It shows that the algorithm is very effective.展开更多
In the present work,the relevant components of the two basic system of measurement are defined through the analysis of existing systems of measurement for geometrical modeling.The major features of such systems relate...In the present work,the relevant components of the two basic system of measurement are defined through the analysis of existing systems of measurement for geometrical modeling.The major features of such systems related to the ways of formation of the two-dimensional complex drawing of a geometrical image on the basis of laws of projective connections are revealed.Interrelations of the elements of different systems of measurement with various projections of a geometrical image are defined.The relative location of projections of a geometrical image into the constructed two-dimensional complex drawings for various systems of measurement is discussed.The rationale behind a particular arrangement of views in the projective drawing of a product in the analyzed systems of measurement is explained.展开更多
As one of the National Major Scientific and Technological infrastructures proposed in the“12th Five-Year Plan”,the“China Initiative Accelerator Driven System(CiADS)”will be constructed to further promote the devel...As one of the National Major Scientific and Technological infrastructures proposed in the“12th Five-Year Plan”,the“China Initiative Accelerator Driven System(CiADS)”will be constructed to further promote the development of ADS technology.For ADS,structural materials with good performances on the resistances to intense particle irradiation are important to determine the system’s feasibility and safety.In this work,radiation damage of several structural materials,such as 316L,SIMP steel,and ZTA ceramics were analyzed by using MCNPx Monte Carlo software coupling with NJOY 2016 code.The CiADS target-reactor model was established by MCNPx 2.70 code,and the neutron spatial energy spectra and neutron flux were calculated under three different core arrangement schemes.展开更多
The combined use of silica fume(SF)and ceramic waste(CW)for the production of mortar is studied.Sand is replaced by 5%,10%,15%and 20%of CW while a fixed 5%percentage(%wt of cement)of SF is used.The results show that t...The combined use of silica fume(SF)and ceramic waste(CW)for the production of mortar is studied.Sand is replaced by 5%,10%,15%and 20%of CW while a fixed 5%percentage(%wt of cement)of SF is used.The results show that the best results are obtained by using silica fume and ceramic waste sand with 15%weight of sand and 5%wt of cement.With the addition of sand ceramic waste(SCW),the mortar compressive strength and density increase,while the porosity displays an opposite trend.The experimental analysis is complemented with theoretical considerations on the matrix strength and related improvements in mechanical behavior.It is shown that the agreement between the experimental values and the estimated values is good.展开更多
The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing th...The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing the conductor and phase sequence arrangement of multiple transmission lines is conducive to improving electromagnetic and electrostatic coupling caused by electromagnetic problems.This paper uses the ATP-EMTP simulation software to build a 500 kV multi-circuit transmission line on the same tower.It stimulates the induced voltage and current values of different line lengths,tower spacing,vertical and horizontal spacing between different circuits,phase sequence arrangement,and nominal tower height.Moreover,use the BP neural network optimized by a genetic algorithm to predict the induced voltage and current under the unknown conductor and phase sequence arrangement.Finally,based on multi-objective particle swarm algorithm to construct the optimization model of conductor arrangement scheme of overhead transmission line,combined with electromagnetic environment control index,determine the optimal conductor arrangement scheme by the size of particle fitness function,a significant reduction in induced voltages and currents between transmission lines and the four-circuit conductor layout scheme meeting the requirements of the electromagnetic environment is obtained,which provides a reference for the tower design of the transmission station project.展开更多
With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would ...With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.展开更多
Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,l...Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,low drilling efficiency,and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process,which affect the application effect of this technology.ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single,three,and five teeth arrangement drill bit respectively,to improve the application effect and solve the aforementioned technical problems.Based on the calculated parameters of tooth arrangement,we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.展开更多
The widespread usage of clean and sustainable energy sources is leading to a significant transformation of the world’s energy systems. Over-reliance on only the national grid energy system has made institutions fail ...The widespread usage of clean and sustainable energy sources is leading to a significant transformation of the world’s energy systems. Over-reliance on only the national grid energy system has made institutions fail to sustain energy systems. The council is only connected to the national grid electricity supply system, with diesel generators as the only alternative, which is unhealthy and unsafe. Surprisingly, even with such alternatives, power shortages have persisted despite government efforts to provide a solution to the shortages by installing numerous off-grid systems. Due to such a situation, the council would construct a sustainable energy system as a remedy. Thus, the purpose of this study was to establish critical success factors influencing the implementation of a sustainable energy system at the Inter-University Council of East Africa (IUCEA) Head Quarters, Kampala-Uganda. A cross-sectional survey design was used;a sample size of 84 participants was selected. Questionnaire survey and interview methods were utilized. The study found that the most significant (p < 0.05) critical factors in the implementation of sustainable energy in institutions are;the use of innovative technologies and infrastructure, the use of efficient zero emissions for heating and cooling, integration of renewable energy use in the existing buildings, building and renovating in an energy-efficient way, integrating regional energy systems, improving energy efficiency in the buildings, enhanced zero emission power technologies, energy efficient equipment in place and stakeholder empowerment in energy management. This study concludes that institutions like;the Inter-University Council of East Africa (IUCEA) need to clearly state policies and actions of energy management. The roles and responsibilities of each member have to be clearly stated while capturing the activities involved in energy conservation, energy security and energy efficiency.展开更多
The framework of time and gifts and disabilities Time has several aspects that could be extremely enlightening that we will consider adopting.Those aspects or dimensions are Order,Onset,Duration,and Velocity.Order ref...The framework of time and gifts and disabilities Time has several aspects that could be extremely enlightening that we will consider adopting.Those aspects or dimensions are Order,Onset,Duration,and Velocity.Order refers to arrangement of things relative to one another.Onset relates to how and when something begins.Duration concerns how long something occurs.Velocity refers to the rate at which time is perceived to travel.Let us begin with the temporal aspect of order that characterizes the relation between gifts(g)and disabilities(d)as either one of“precedence”or“concurrence”.In other words,one and only one of the following situations may be the case:g before d,g after d,or g and d come to be simultaneously.展开更多
It is a great pleasure and privilege to be here among the distinguished delegates to the Conference on the Sironet Forum for International Cooperation.I sincerely thank the people and the Government of the People'...It is a great pleasure and privilege to be here among the distinguished delegates to the Conference on the Sironet Forum for International Cooperation.I sincerely thank the people and the Government of the People's Republic of China,BRI forum organiser team,and Sironet Forum for their warm and generous hospitality and for the excellent arrangements made for the conference.展开更多
[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other f...[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows: under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows: jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.展开更多
The parallel-inlet holes with one-row, two-row and three-row film hole arrangements and different di- ameters are proposed to experimentally study their cooling characteristics. Detailed experimental processes and res...The parallel-inlet holes with one-row, two-row and three-row film hole arrangements and different di- ameters are proposed to experimentally study their cooling characteristics. Detailed experimental processes and results are described and carried out. Results indicate that heat transfer coefficient (HTC) is increased with the increase of blowing ratio. When the blowing ratio is lower, the distribution of HTC along the heated wall can be divided into three regions. For larger blowing ratio or diameter, the cooling characteristics oi parallel-inlet film holes are similar to those of convective heat transfer around flat. Furthermore, when hole diameter is deter- mined, the arrangement patterns of film hole and the blowing ratio take a great influence on HTC.展开更多
A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterize...A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the riser.Rough risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference effect.The experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency responses.In addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser.展开更多
文摘In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.
基金supported by the National Natural Science Foundation of China(31971853)。
文摘The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,promoting conventional intercropping strategies in modern agriculture can prove challenging.The innovative technology of soybean maize strip intercropping(SMSI)has been proposed as a solution.This system has produced remarkable results in improving domestic soybean and maize production for both food security and sustainable agriculture.In this article,we provide an overview of SMSI and explain how it differs from traditional intercropping.We also discuss the core principles that foster higher yields and the prospects for its future development.
基金supported by the National Natural Science Foundation of China(Grant Nos.42120104008 and 42207198).
文摘Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters.
文摘Electrical and electronic devices are becoming an increasingly important part of our society. In Africa, and in Senegal in particular, the handling and management of electronic and electrical equipment (EEE) that has reached the end of its life is mainly informal. This professional environment is characterized by the disintegration of the sector and the social heterogeneity that can be found there. The objective of this study is to assess the standard of living of electrical and electronic equipment waste handlers in the Dakar region, as well as their perception of their health. A survey was used to obtain information on sociodemographic background, living arrangements, perception of health status, and good practices to be implemented in case of work-related health problems. Life style, perception of general health and health problems were ranged as excellent, very good, good, average and poor. Informal recyclers in the Dakar region lived mainly in rooms and buildings as tenants (49.1%), or in family homes (48.4%) before starting this activity, and 51.2% continue to live in rooms and buildings as tenants compared to 41.4% who still live in a family home. The perception of health status ranged from poor to excellent, and 4.9% believe that they are limited in work due to a disability or health problem. Informal work is a heterogeneous phenomenon that makes research and policymaking particularly complex. There are several external factors within informal WEEE re-cyclers that can cause health problems or functional disability. However, the living conditions and the perception they have of their state of health are contradictory to the working conditions and the social environment to which they belong. A biomedical approach would consolidate these achievements by confirming or invalidating them.
文摘With a surge in the university’s student and staff population, parking problems and congestion have rapidly intensified. The recent inclusion of women drivers, particularly during official working hours, has exacerbated these challenges. This pressing issue underscores the critical necessity for a structured approach to managing university entries and overseeing parking at the gates. The proposed smart parking management system aims to address these concerns by introducing a design concept that restricts unauthorized access and provides exclusive parking privileges to authorized users. Through image processing, the system identifies available parking spaces, relaying real-time information to users via a mobile application. This comprehensive solution also generates detailed reports (daily, weekly, and monthly), aiding university safety authorities in future gate management decisions.
文摘As of January 31,2024,China had concluded mutual visa exemption agreements covering different types of passports with 157 countries,reached agreements or arrangements on simplified visa procedures with 44 countries,and enjoyed comprehensive mutual visa exemptions with 23 countries including Thailand,Singapore,Maldives,and the United Arab Emirates.
文摘A multi-function protecting forest system was planed and arranged elaborately for im-provement of the local ecological conditions and high economical benefit. The system in-cludes level farmland shelter belt network, hillside farmland shelter belt network, stereoscop-ic sparse-wood pasture, erosion control fuel forest, fast growing commercial forest, eco-nomical forest, salt-soda controlling project and salt-soda protecting forest on salt-sodaland, ect..
文摘It is a multifactor optimization problem to arrange examinations on a large scale for universities. In this paper, a kind of grouped optimization algorithm was proposed. A principle about related degree, which plays a core role in realization, was introduced in the algorithm. According to the algorithm, we worked out a set of software correspondingly and applied it to a certain university in Shanghai to arrange examinations. It shows that the algorithm is very effective.
文摘In the present work,the relevant components of the two basic system of measurement are defined through the analysis of existing systems of measurement for geometrical modeling.The major features of such systems related to the ways of formation of the two-dimensional complex drawing of a geometrical image on the basis of laws of projective connections are revealed.Interrelations of the elements of different systems of measurement with various projections of a geometrical image are defined.The relative location of projections of a geometrical image into the constructed two-dimensional complex drawings for various systems of measurement is discussed.The rationale behind a particular arrangement of views in the projective drawing of a product in the analyzed systems of measurement is explained.
文摘As one of the National Major Scientific and Technological infrastructures proposed in the“12th Five-Year Plan”,the“China Initiative Accelerator Driven System(CiADS)”will be constructed to further promote the development of ADS technology.For ADS,structural materials with good performances on the resistances to intense particle irradiation are important to determine the system’s feasibility and safety.In this work,radiation damage of several structural materials,such as 316L,SIMP steel,and ZTA ceramics were analyzed by using MCNPx Monte Carlo software coupling with NJOY 2016 code.The CiADS target-reactor model was established by MCNPx 2.70 code,and the neutron spatial energy spectra and neutron flux were calculated under three different core arrangement schemes.
文摘The combined use of silica fume(SF)and ceramic waste(CW)for the production of mortar is studied.Sand is replaced by 5%,10%,15%and 20%of CW while a fixed 5%percentage(%wt of cement)of SF is used.The results show that the best results are obtained by using silica fume and ceramic waste sand with 15%weight of sand and 5%wt of cement.With the addition of sand ceramic waste(SCW),the mortar compressive strength and density increase,while the porosity displays an opposite trend.The experimental analysis is complemented with theoretical considerations on the matrix strength and related improvements in mechanical behavior.It is shown that the agreement between the experimental values and the estimated values is good.
文摘The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing the conductor and phase sequence arrangement of multiple transmission lines is conducive to improving electromagnetic and electrostatic coupling caused by electromagnetic problems.This paper uses the ATP-EMTP simulation software to build a 500 kV multi-circuit transmission line on the same tower.It stimulates the induced voltage and current values of different line lengths,tower spacing,vertical and horizontal spacing between different circuits,phase sequence arrangement,and nominal tower height.Moreover,use the BP neural network optimized by a genetic algorithm to predict the induced voltage and current under the unknown conductor and phase sequence arrangement.Finally,based on multi-objective particle swarm algorithm to construct the optimization model of conductor arrangement scheme of overhead transmission line,combined with electromagnetic environment control index,determine the optimal conductor arrangement scheme by the size of particle fitness function,a significant reduction in induced voltages and currents between transmission lines and the four-circuit conductor layout scheme meeting the requirements of the electromagnetic environment is obtained,which provides a reference for the tower design of the transmission station project.
文摘With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.
基金Project of National Key Research and Development of China(No.2018YFC1505303).
文摘Down-the-hole(DTH)hammer with casing while drilling(CWD)is a technology that has been proven to be able to alleviate many of the problems faced by complex formations.However,the drill bit is suffered from rapid wear,low drilling efficiency,and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process,which affect the application effect of this technology.ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single,three,and five teeth arrangement drill bit respectively,to improve the application effect and solve the aforementioned technical problems.Based on the calculated parameters of tooth arrangement,we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.
文摘The widespread usage of clean and sustainable energy sources is leading to a significant transformation of the world’s energy systems. Over-reliance on only the national grid energy system has made institutions fail to sustain energy systems. The council is only connected to the national grid electricity supply system, with diesel generators as the only alternative, which is unhealthy and unsafe. Surprisingly, even with such alternatives, power shortages have persisted despite government efforts to provide a solution to the shortages by installing numerous off-grid systems. Due to such a situation, the council would construct a sustainable energy system as a remedy. Thus, the purpose of this study was to establish critical success factors influencing the implementation of a sustainable energy system at the Inter-University Council of East Africa (IUCEA) Head Quarters, Kampala-Uganda. A cross-sectional survey design was used;a sample size of 84 participants was selected. Questionnaire survey and interview methods were utilized. The study found that the most significant (p < 0.05) critical factors in the implementation of sustainable energy in institutions are;the use of innovative technologies and infrastructure, the use of efficient zero emissions for heating and cooling, integration of renewable energy use in the existing buildings, building and renovating in an energy-efficient way, integrating regional energy systems, improving energy efficiency in the buildings, enhanced zero emission power technologies, energy efficient equipment in place and stakeholder empowerment in energy management. This study concludes that institutions like;the Inter-University Council of East Africa (IUCEA) need to clearly state policies and actions of energy management. The roles and responsibilities of each member have to be clearly stated while capturing the activities involved in energy conservation, energy security and energy efficiency.
文摘The framework of time and gifts and disabilities Time has several aspects that could be extremely enlightening that we will consider adopting.Those aspects or dimensions are Order,Onset,Duration,and Velocity.Order refers to arrangement of things relative to one another.Onset relates to how and when something begins.Duration concerns how long something occurs.Velocity refers to the rate at which time is perceived to travel.Let us begin with the temporal aspect of order that characterizes the relation between gifts(g)and disabilities(d)as either one of“precedence”or“concurrence”.In other words,one and only one of the following situations may be the case:g before d,g after d,or g and d come to be simultaneously.
文摘It is a great pleasure and privilege to be here among the distinguished delegates to the Conference on the Sironet Forum for International Cooperation.I sincerely thank the people and the Government of the People's Republic of China,BRI forum organiser team,and Sironet Forum for their warm and generous hospitality and for the excellent arrangements made for the conference.
基金Supported by Special Foundation for Young Scientific and Technological Talents,Xinjiang Academy of Agricultural Sciences(xjnky-2012-009)Special Fund for Agroscientific Research in the Public Interest(201003043-07)+1 种基金Scientific Research Programof the Higher Education Institution of XinJiang(XJEDU2012S14)National-level College Students’Innovative Entrepreneurial Training Plan Program(201210758002)~~
文摘[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows: under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows: jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality.
文摘The parallel-inlet holes with one-row, two-row and three-row film hole arrangements and different di- ameters are proposed to experimentally study their cooling characteristics. Detailed experimental processes and results are described and carried out. Results indicate that heat transfer coefficient (HTC) is increased with the increase of blowing ratio. When the blowing ratio is lower, the distribution of HTC along the heated wall can be divided into three regions. For larger blowing ratio or diameter, the cooling characteristics oi parallel-inlet film holes are similar to those of convective heat transfer around flat. Furthermore, when hole diameter is deter- mined, the arrangement patterns of film hole and the blowing ratio take a great influence on HTC.
基金financially supported by the Natural Science Foundation of Shandong Province(Grant Nos.ZR2023ME040 and ZR2022QE118)the Key Technology Research and Development Program of Shandong Province(Grant No.2023CXGC010316)+1 种基金the Natural Science Foundation of Qingdao(Grant No.23-2-1-207-zyyd-jch)the Introduction and Education Plan for Young Innovative talents in Colleges and Universities of Shandong Province(Marine Civil Engineering Materials and Structure Innovation Research Team).
文摘A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the riser.Rough risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference effect.The experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency responses.In addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser.