Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of ma...Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in the natural stone-processing industry. An experimental study was carried out utilizing a fully instrumented block-cutter to investigate the sawing performances of five different types of travertine blocks during cutting with a circular diamond saw. The sawing tests were performed in the down-cutting mode. Performance measurements were determined by measuring the cutting speed and energy consumption. Then, specific energy was determined. The one main cutting parameter, cutting speed, was varied in the investigation of optimum cutting performance. Furthermore, some physico-mechanical properties of file travertine blocks were determined in the laboratory. As a result, it is found that the energy consumption （specific energy） of block cutting machines is highly affected by cutting speed. It is determined that specific energy value usually decreases when cutting speed increases. When the cutting speed is higher than the determined value, the diamond saw can become stuck in the travertine block; this situation can be a problem for the block-cutting machine. As a result, the optimum cutting speed obtained for the travertine mines examined is approximately 1.5-2.0 m/min.展开更多
Owing to overcoming the characteristics that there are many economic and technical indexes which are fuzzy and incompatibility to each other in evaluating investment project,a new method is proposed.The method is base...Owing to overcoming the characteristics that there are many economic and technical indexes which are fuzzy and incompatibility to each other in evaluating investment project,a new method is proposed.The method is based on the matter-element analysis and combined with the concepts of fuzzy mathematics,which is called the method of fuzzy matter-element analysis.It constructs the compound fuzzy matter element with the investment projects,evaluation factors and their fuzzy value.Through establishing the best subjection degree (fuzzy value),complex fuzzy matter element of relational coefficient and weight aggregation of fuzzy matter-element model,the writer achieves on optimum order of the investment projects according to the calculated relational degree and finds the best project.In this paper,the calculation of weight adopts the analytical hierarchy process method(AHP).Through the actual example,it shows that the model is simple and its calculation is reliable.It is very significant for the engineering evaluated bid and investment decision.展开更多
Through applying PPE model based on RAGA to evaluate the benefit of rice water saving,the author turns multi-dimension data into low dimension space.So the optimum projection direction can stand for the best influence...Through applying PPE model based on RAGA to evaluate the benefit of rice water saving,the author turns multi-dimension data into low dimension space.So the optimum projection direction can stand for the best influence on the collectivity.Thus,the value of projection function can evaluate each item good or not.The PPE model can avoid jamming of weight matrix in the method of fuzzy synthesize judgement,and obtain better result.The author wants to provide a new method and thought for readers who are engaged in investment decision-making of water saving irrigation and other relative study.展开更多
To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulate...To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulated discharge flow of steering pump to realize variable assist characteristic as well as uniquely transfer on-demand power from engine to steering pump. The model of ESC was established and the dynamic characteristics of ESC were presented by the way of simulation and experiment. Upon the layout of the assist characteristics, output torque of ESC was derived. Based on the ESC model, the output torque characteristics of ESC were simulated under steering situation and straight driving situation, respectively. The consistency of simulated ESC output torque and the one deduced from assist characteristics verifies the correctness of the ESC dynamic model. To illustrate energy saving characteristics of ESC-HPS, energy consumption comparison of ESC-HPS and conventional HPS was carried out qualitatively and quantitatively. It follows that the energy consumption of ESC-HPS decreases by 50% compared with that of HPS.展开更多
How to reduce the energy consumption powered mainly by battery to prolong the standby time is one of the crucial issues for IEEE 802.16e wireless MANs.By predicting the next downlink inter-packet arrival time,three tr...How to reduce the energy consumption powered mainly by battery to prolong the standby time is one of the crucial issues for IEEE 802.16e wireless MANs.By predicting the next downlink inter-packet arrival time,three traffic-prediction-assisted power saving mechanisms based on P-PSCI,i.e.,PSCI-PFD,PSCI-ED and PSCI-LD,were proposed.In addition,the corresponding adjustment strategies for P-PSCI were also presented when there were uplink packets to be transmitted during sleep mode.Simulation results reveal that compared with the sleep mode algorithm recommended by IEEE 802.16e,the proposed mechanism P-PSCI can improve both energy efficiency and packet delay for IEEE 802.16e due to the consideration of the traffic characteristics and rate changes.Moreover,the results also demonstrate that PSCI-PFD (a=-2) significantly outperforms PSCI-ED,PSCI-LD,and the standard sleep mode in IEEE 802.16e is in terms of energy efficiency and packet delay.展开更多
A motion parameter optimization method based on the objective of minimizing the total energy consumption in segment positioning was proposed for segment erector of shield tunneling machine. The segment positioning pro...A motion parameter optimization method based on the objective of minimizing the total energy consumption in segment positioning was proposed for segment erector of shield tunneling machine. The segment positioning process was decomposed into rotation, lifting and sliding actions in deriving the energy calculation model of segment erection. The work of gravity was taken into account in the mathematical modeling of energy consumed by each actuator. In order to investigate the relationship between the work done by the actuator and the path moved along by the segment, the upward and downward directions as well as the operating quadrant of the segment erector were defined. Piecewise nonlinear function of energy was presented, of which the result is determined by closely coupled components as working parameters and some intermediate variables. Finally, the effectiveness of the optimization method was proved by conducting a case study with a segment erector for the tunnel with a diameter of 3 m and drawing comparisons between different assembling paths. The results show that the energy required by assembling a ring of segments along the optimized moving path can be reduced up to 5%. The method proposed in this work definitely provides an effective energy saving solution for shield tunneling machine.展开更多
Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limeston...Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limestone were set up. With this model, numerical simulation is used to analyze the effects of operational parameters on the process of lime calcining and to optimize it. By using visual basic program to communicate and program, the centralized management and automatic control of the lime furnace are realized. The software is put into practical production, which makes the lime furnace operate steadily and efficiently, and causes the increase in output and decrease in energy consumption.展开更多
Exploiting the potentials of urban stock land and its intensive use have been widespread concerned, however the practical solutions are few,especially in the view of engineering.Basing on synthesizing and analysis of ...Exploiting the potentials of urban stock land and its intensive use have been widespread concerned, however the practical solutions are few,especially in the view of engineering.Basing on synthesizing and analysis of the traditional models,this paper introduces the concept of urban renewal pattern for land saving.A double-layer city model was proposed, following with calculation of land saving of展开更多
The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on si...The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on sinter pot test. The results show that the distance between cleavage planes is enlarged and the π electrons are re distributed because of the insertion of cations/molecules of ZC 1 into the cleavage planes of carbon , resulting in the weakening of C-C bond, improving the adsorption of oxygen and lowering the activation energy of gasification of carbon from 25.8 kJ/mol to 18.9 kJ/mol , and the burning rate being increased and combustion residual reduced, all of which can lead to lower solid fuel consumption . Compared with the sintering test without addition of additives , the solid fuel consumption is reduced by 16.0%, meanwhile, the rate of finished sinter, the output of finished sinter and the tumbling index are increased by 2.03%, 7.0% and 3.71% , respectively, with incorporating 0.2% of additive ZC 1 in the sintering mixture, which is in agreement with the catalyzing mechanism of ZC 1.展开更多
With the startup and execution of new socialistic countryside construction in Heilongjiang Province,the transition from castoff to resource is strengthened in the countryside,aiming at neat appearance of the countrysi...With the startup and execution of new socialistic countryside construction in Heilongjiang Province,the transition from castoff to resource is strengthened in the countryside,aiming at neat appearance of the countryside,clean production and saving energy.People produce biogas and provide the countryside with new energy by means of turning livestock＇s dejection into resources,composting of the plant and animal＇s leavings in the courtyard and even in the factory.It is helpful for the countryside to conserve the energy and reduce emission of the waste.And it also plays an important role in protecting the eco-environment,beautifying homestead and developing the ecological agriculture and so on.The liquid and solid residue in the biogas production can be reused as fertilizer for crops or food for animals after pretreatment,which is propitious to accelerate the development of the circular economy in Heilongjiang Province.展开更多
Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considere...Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considered a replacement for the current Indian production system.It is also suitable for mechanical harvesting,which reducing labour costs,increasing input use efficiency,timely harvesting timely,maintaining cotton quality,and offering the potential to increase productivity and profitability.This technology has become widespread in globally cotton growing regions.Water management is critical for the success of high density cotton planting.Due to the problem of freshwater availability,more crops should be produced per drop of water.In the high-density planting system,optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs.Deficit irrigation is a tool to save water without compromising yield.At the same time,it consumes less water than the normal evapotranspiration of crops.This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation.Based on the current research and combined with cotton production reality,this review discusses the application and future development of deficit irrigation,which may provide theoretical guidance for the sustainable advancement of cotton planting systems.展开更多
Shaanxi Electric Power（monthly issue）is a science and technology journal which is administrated by State Grid Corporation of China,sponsored by Shaanxi Electric Power Corporation.The journal mainly reflects the new ...Shaanxi Electric Power（monthly issue）is a science and technology journal which is administrated by State Grid Corporation of China,sponsored by Shaanxi Electric Power Corporation.The journal mainly reflects the new achievement,new technology,new trend in the fields ofdomestic＆international energy,electric technology.The scopeofShaanxi Electric Power covers new energy and distributed power generation,展开更多
Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recover...Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT （a computational fluid dynamics （CFD） program） with TRNSYS （a building energy simulation （BES） software）. The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air.展开更多
The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential...The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential buildings in Xi’an,China.A total of 2069 valid questionnaires,along with indoor environmental parameters were obtained.The results indicated occupants’thermal comfort requirements varied with seasons.The neutral temperatures were 17.9,26.1(highest),25.2,and 17.4℃(lowest),and preferred temperatures were 23.2,25.6(highest),24.8,and 22.4℃(lowest),respectively for spring,summer,autumn,and winter.The neutral temperature and preferred temperature in autumn are close to the neutral temperature in summer,while the neutral temperature and preferred temperature in spring are close to that in winter.Besides,the 80%and 90%acceptable temperature ranges,adaptive thermal comfort models,and thermal comfort zones for each season were established.Human’s adaptability is related to his/her thermal experience of the current season and the previous season.Therefore,compared with the traditional year-round adaptive thermal comfort model,seasonal models can better reflect seasonal variations of human adaptation.This study provides fundamental knowledge of the thermal comfort demand for people in this region.展开更多
Chaotic mixing is regarded as an effective method to improve the mixing effect in the laminar stirred tank.To generate chaos in flow field in stirred tank,many efforts including aperiodic movement,asystematic installa...Chaotic mixing is regarded as an effective method to improve the mixing effect in the laminar stirred tank.To generate chaos in flow field in stirred tank,many efforts including aperiodic movement,asystematic installation impeller,etc.,were made to save mixing time and energy consumption.The computational fluid dynamics of chaotic flow field and the hyperchaotic controlling method as well as macro-instability were reviewed.Multiple flow field coupling is important in the turbulent mixing region of stirred tank.The development trends of flow field coupling and hyperchaotic controlling in chaotic mixing were prospected in energy saving operation.展开更多
Accurate prediction of server load is important to cloud systems for improving the resource utilization, reducing the energy consumption and guaranteeing the quality of service(QoS).This paper analyzes the features of...Accurate prediction of server load is important to cloud systems for improving the resource utilization, reducing the energy consumption and guaranteeing the quality of service(QoS).This paper analyzes the features of cloud server load and the advantages and disadvantages of typical server load prediction algorithms, integrates the cloud model(CM) and the Markov chain(MC) together to realize a new CM-MC algorithm, and then proposes a new server load prediction algorithm based on CM-MC for cloud systems. The algorithm utilizes the historical data sample training method of the cloud model, and utilizes the Markov prediction theory to obtain the membership degree vector, based on which the weighted sum of the predicted values is used for the cloud model. The experiments show that the proposed prediction algorithm has higher prediction accuracy than other typical server load prediction algorithms, especially if the data has significant volatility. The proposed server load prediction algorithm based on CM-MC is suitable for cloud systems, and can help to reduce the energy consumption of cloud data centers.展开更多
A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understandi...A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understanding of green roof in regions with cold winters and snow,an on-site experimental investigation was present with a focus on the assessment of green roof performance during the winter.This field experiment took place on a six small buildings during the winter of 2010-2011.The work monitored three buildings with green roofs,two buildings with reference roofs and one building with a bare soil coverage for the roof.These six buildings were identically constructed and instrumented with sensor networks to provide heat flux data through the roofs.The 15 min averaged data were statistically analyzed for a week under the two separate periods,first without a snow cover and second with a snow cover.The results show that the roof type is a significant factor in affecting the thermal performance of these buildings.Most importantly,green roofs reduce heat flow through the roof and thus reduce the heating energy demand during the winter.However,the energy savings for buildings with the green roofs are reduced under snow conditions because the snow diminishes thermal resistance of the roof and increases the heat transfer process through the roofs.展开更多
文摘Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in the natural stone-processing industry. An experimental study was carried out utilizing a fully instrumented block-cutter to investigate the sawing performances of five different types of travertine blocks during cutting with a circular diamond saw. The sawing tests were performed in the down-cutting mode. Performance measurements were determined by measuring the cutting speed and energy consumption. Then, specific energy was determined. The one main cutting parameter, cutting speed, was varied in the investigation of optimum cutting performance. Furthermore, some physico-mechanical properties of file travertine blocks were determined in the laboratory. As a result, it is found that the energy consumption （specific energy） of block cutting machines is highly affected by cutting speed. It is determined that specific energy value usually decreases when cutting speed increases. When the cutting speed is higher than the determined value, the diamond saw can become stuck in the travertine block; this situation can be a problem for the block-cutting machine. As a result, the optimum cutting speed obtained for the travertine mines examined is approximately 1.5-2.0 m/min.
基金Project supported by the National High-Tech Research and Development program of China (863 Program ) (No.2 0 0 2 AA2 Z42 5 1-2 10 0 41) Postdoctoral Scientific Foundation of Northeast Agricultural U niversity. (No. 2 40 0 0 9) and postdoctoral Scien
文摘Owing to overcoming the characteristics that there are many economic and technical indexes which are fuzzy and incompatibility to each other in evaluating investment project,a new method is proposed.The method is based on the matter-element analysis and combined with the concepts of fuzzy mathematics,which is called the method of fuzzy matter-element analysis.It constructs the compound fuzzy matter element with the investment projects,evaluation factors and their fuzzy value.Through establishing the best subjection degree (fuzzy value),complex fuzzy matter element of relational coefficient and weight aggregation of fuzzy matter-element model,the writer achieves on optimum order of the investment projects according to the calculated relational degree and finds the best project.In this paper,the calculation of weight adopts the analytical hierarchy process method(AHP).Through the actual example,it shows that the model is simple and its calculation is reliable.It is very significant for the engineering evaluated bid and investment decision.
基金National"863"High-Technique Programm e.(No.2 0 0 2 AA2 Z42 5 1-2 10 0 41) Postdoctoral Scientific Foundation of NEAU(No.2 3 0 0 0 9) and Postdoctoral Scientific Foundation of Heilongjiang Province.
文摘Through applying PPE model based on RAGA to evaluate the benefit of rice water saving,the author turns multi-dimension data into low dimension space.So the optimum projection direction can stand for the best influence on the collectivity.Thus,the value of projection function can evaluate each item good or not.The PPE model can avoid jamming of weight matrix in the method of fuzzy synthesize judgement,and obtain better result.The author wants to provide a new method and thought for readers who are engaged in investment decision-making of water saving irrigation and other relative study.
基金Project(51275211)supported by the National Natural Science Foundation of ChinaProject(11KJA580001)supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,ChinaProject(CXZZ12_0665)supported by the Postgraduate Innovation Natural Science Foundation of Jiangsu Province,China
文摘To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulated discharge flow of steering pump to realize variable assist characteristic as well as uniquely transfer on-demand power from engine to steering pump. The model of ESC was established and the dynamic characteristics of ESC were presented by the way of simulation and experiment. Upon the layout of the assist characteristics, output torque of ESC was derived. Based on the ESC model, the output torque characteristics of ESC were simulated under steering situation and straight driving situation, respectively. The consistency of simulated ESC output torque and the one deduced from assist characteristics verifies the correctness of the ESC dynamic model. To illustrate energy saving characteristics of ESC-HPS, energy consumption comparison of ESC-HPS and conventional HPS was carried out qualitatively and quantitatively. It follows that the energy consumption of ESC-HPS decreases by 50% compared with that of HPS.
基金Projects(60873265,61070194)supported by the National Natural Science Foundation of ChinaProject(2009AA112205)supported by the National High Technology Research and Development Program of China+1 种基金Project(2011FJ2003)supported by Science and Technology Key Projects of Hunan Province,ChinaProject(531107040201)supported by Chinese Universities Scientific Fund
文摘How to reduce the energy consumption powered mainly by battery to prolong the standby time is one of the crucial issues for IEEE 802.16e wireless MANs.By predicting the next downlink inter-packet arrival time,three traffic-prediction-assisted power saving mechanisms based on P-PSCI,i.e.,PSCI-PFD,PSCI-ED and PSCI-LD,were proposed.In addition,the corresponding adjustment strategies for P-PSCI were also presented when there were uplink packets to be transmitted during sleep mode.Simulation results reveal that compared with the sleep mode algorithm recommended by IEEE 802.16e,the proposed mechanism P-PSCI can improve both energy efficiency and packet delay for IEEE 802.16e due to the consideration of the traffic characteristics and rate changes.Moreover,the results also demonstrate that PSCI-PFD (a=-2) significantly outperforms PSCI-ED,PSCI-LD,and the standard sleep mode in IEEE 802.16e is in terms of energy efficiency and packet delay.
基金Project(51305328)supported by the National Natural Science Foundation of ChinaProject(2012AA041803)supported by the NationalHigh Technology R&D Program of China+1 种基金Project(GZKF-201210)supported by the Open Fund of State Key Laboratory of Fluid Power Transmission and Control of Zhejiang University,ChinaProject(2013M532031)supported by the China Postdoctoral Science Foundation
文摘A motion parameter optimization method based on the objective of minimizing the total energy consumption in segment positioning was proposed for segment erector of shield tunneling machine. The segment positioning process was decomposed into rotation, lifting and sliding actions in deriving the energy calculation model of segment erection. The work of gravity was taken into account in the mathematical modeling of energy consumed by each actuator. In order to investigate the relationship between the work done by the actuator and the path moved along by the segment, the upward and downward directions as well as the operating quadrant of the segment erector were defined. Piecewise nonlinear function of energy was presented, of which the result is determined by closely coupled components as working parameters and some intermediate variables. Finally, the effectiveness of the optimization method was proved by conducting a case study with a segment erector for the tunnel with a diameter of 3 m and drawing comparisons between different assembling paths. The results show that the energy required by assembling a ring of segments along the optimized moving path can be reduced up to 5%. The method proposed in this work definitely provides an effective energy saving solution for shield tunneling machine.
文摘Based on the principle of thermal balance and material balance of lime furnace, the reaction and heat transfer process mathematical-physical model and the on-line monitoring model of the decomposition rate of limestone were set up. With this model, numerical simulation is used to analyze the effects of operational parameters on the process of lime calcining and to optimize it. By using visual basic program to communicate and program, the centralized management and automatic control of the lime furnace are realized. The software is put into practical production, which makes the lime furnace operate steadily and efficiently, and causes the increase in output and decrease in energy consumption.
文摘Exploiting the potentials of urban stock land and its intensive use have been widespread concerned, however the practical solutions are few,especially in the view of engineering.Basing on synthesizing and analysis of the traditional models,this paper introduces the concept of urban renewal pattern for land saving.A double-layer city model was proposed, following with calculation of land saving of
基金TheFoundationfortheTeachingandResearchProgramforOutstandingYoungTeachersinHigherEducationInstitu tionsofMOE P .R .C .
文摘The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on sinter pot test. The results show that the distance between cleavage planes is enlarged and the π electrons are re distributed because of the insertion of cations/molecules of ZC 1 into the cleavage planes of carbon , resulting in the weakening of C-C bond, improving the adsorption of oxygen and lowering the activation energy of gasification of carbon from 25.8 kJ/mol to 18.9 kJ/mol , and the burning rate being increased and combustion residual reduced, all of which can lead to lower solid fuel consumption . Compared with the sintering test without addition of additives , the solid fuel consumption is reduced by 16.0%, meanwhile, the rate of finished sinter, the output of finished sinter and the tumbling index are increased by 2.03%, 7.0% and 3.71% , respectively, with incorporating 0.2% of additive ZC 1 in the sintering mixture, which is in agreement with the catalyzing mechanism of ZC 1.
基金Supported by Foundation of Heilongjiang Province Educational Committee (11551056)Scientific Fund of Heilongjiang Province for Youth (QC2009C40)+1 种基金Fund of Harbin City Innovative Talent (2009RFQXN096)Heilongjiang Province Postdoctoral Science Foundation
文摘With the startup and execution of new socialistic countryside construction in Heilongjiang Province,the transition from castoff to resource is strengthened in the countryside,aiming at neat appearance of the countryside,clean production and saving energy.People produce biogas and provide the countryside with new energy by means of turning livestock＇s dejection into resources,composting of the plant and animal＇s leavings in the courtyard and even in the factory.It is helpful for the countryside to conserve the energy and reduce emission of the waste.And it also plays an important role in protecting the eco-environment,beautifying homestead and developing the ecological agriculture and so on.The liquid and solid residue in the biogas production can be reused as fertilizer for crops or food for animals after pretreatment,which is propitious to accelerate the development of the circular economy in Heilongjiang Province.
文摘Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considered a replacement for the current Indian production system.It is also suitable for mechanical harvesting,which reducing labour costs,increasing input use efficiency,timely harvesting timely,maintaining cotton quality,and offering the potential to increase productivity and profitability.This technology has become widespread in globally cotton growing regions.Water management is critical for the success of high density cotton planting.Due to the problem of freshwater availability,more crops should be produced per drop of water.In the high-density planting system,optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs.Deficit irrigation is a tool to save water without compromising yield.At the same time,it consumes less water than the normal evapotranspiration of crops.This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation.Based on the current research and combined with cotton production reality,this review discusses the application and future development of deficit irrigation,which may provide theoretical guidance for the sustainable advancement of cotton planting systems.
文摘Shaanxi Electric Power（monthly issue）is a science and technology journal which is administrated by State Grid Corporation of China,sponsored by Shaanxi Electric Power Corporation.The journal mainly reflects the new achievement,new technology,new trend in the fields ofdomestic＆international energy,electric technology.The scopeofShaanxi Electric Power covers new energy and distributed power generation,
基金Project supported by Grant-in-Aid for Scientific Research (JSPS KAKENHI for Young Scientists (S), 21676005)
文摘Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT （a computational fluid dynamics （CFD） program） with TRNSYS （a building energy simulation （BES） software）. The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air.
基金Project(51325803)supported by the National Science Foundation for Distinguished Young Scholars of ChinaProject(2020M673489)supported by China Postdoctoral Science FoundationProject(2020-K-196)supported by the Science and Technology Project of Ministry of Housing and Urban-Rural Development,China。
文摘The study aims to investigate the thermal comfort requirements in residential buildings and to establish an adaptive thermal comfort model in the cold zone of China.A year-long field study was conducted in residential buildings in Xi’an,China.A total of 2069 valid questionnaires,along with indoor environmental parameters were obtained.The results indicated occupants’thermal comfort requirements varied with seasons.The neutral temperatures were 17.9,26.1(highest),25.2,and 17.4℃(lowest),and preferred temperatures were 23.2,25.6(highest),24.8,and 22.4℃(lowest),respectively for spring,summer,autumn,and winter.The neutral temperature and preferred temperature in autumn are close to the neutral temperature in summer,while the neutral temperature and preferred temperature in spring are close to that in winter.Besides,the 80%and 90%acceptable temperature ranges,adaptive thermal comfort models,and thermal comfort zones for each season were established.Human’s adaptability is related to his/her thermal experience of the current season and the previous season.Therefore,compared with the traditional year-round adaptive thermal comfort model,seasonal models can better reflect seasonal variations of human adaptation.This study provides fundamental knowledge of the thermal comfort demand for people in this region.
基金supported by Natural Science Foundation of China(20806095)ScientificResearch Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(教外司留20091341-2)+1 种基金China Postdoctoral Science Foundation(20080430747)National High Technology Research and Development Program of China(2008AA0312)
文摘Chaotic mixing is regarded as an effective method to improve the mixing effect in the laminar stirred tank.To generate chaos in flow field in stirred tank,many efforts including aperiodic movement,asystematic installation impeller,etc.,were made to save mixing time and energy consumption.The computational fluid dynamics of chaotic flow field and the hyperchaotic controlling method as well as macro-instability were reviewed.Multiple flow field coupling is important in the turbulent mixing region of stirred tank.The development trends of flow field coupling and hyperchaotic controlling in chaotic mixing were prospected in energy saving operation.
基金supported by the National Natural Science Foundation of China(61472192 61772286)+3 种基金the National Key Research and Development Program of China(2018YFB1003700)the Scientific and Technological Support Project(Society)of Jiangsu Province(BE2016776)the "333" Project of Jiangsu Province(BRA2017228 BRA2017401)
文摘Accurate prediction of server load is important to cloud systems for improving the resource utilization, reducing the energy consumption and guaranteeing the quality of service(QoS).This paper analyzes the features of cloud server load and the advantages and disadvantages of typical server load prediction algorithms, integrates the cloud model(CM) and the Markov chain(MC) together to realize a new CM-MC algorithm, and then proposes a new server load prediction algorithm based on CM-MC for cloud systems. The algorithm utilizes the historical data sample training method of the cloud model, and utilizes the Markov prediction theory to obtain the membership degree vector, based on which the weighted sum of the predicted values is used for the cloud model. The experiments show that the proposed prediction algorithm has higher prediction accuracy than other typical server load prediction algorithms, especially if the data has significant volatility. The proposed server load prediction algorithm based on CM-MC is suitable for cloud systems, and can help to reduce the energy consumption of cloud data centers.
基金Project(CMMI-0900486) supported by the National Science Foundation (NSF) in the Division of Civil, Mechanical, and Manufacturing Innovation, USA
文摘A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understanding of green roof in regions with cold winters and snow,an on-site experimental investigation was present with a focus on the assessment of green roof performance during the winter.This field experiment took place on a six small buildings during the winter of 2010-2011.The work monitored three buildings with green roofs,two buildings with reference roofs and one building with a bare soil coverage for the roof.These six buildings were identically constructed and instrumented with sensor networks to provide heat flux data through the roofs.The 15 min averaged data were statistically analyzed for a week under the two separate periods,first without a snow cover and second with a snow cover.The results show that the roof type is a significant factor in affecting the thermal performance of these buildings.Most importantly,green roofs reduce heat flow through the roof and thus reduce the heating energy demand during the winter.However,the energy savings for buildings with the green roofs are reduced under snow conditions because the snow diminishes thermal resistance of the roof and increases the heat transfer process through the roofs.
