The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variatio...The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms?1, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.展开更多
The paper focuses on the optimal control of natural resources in mining industry. The purpose is to pro- pose an optimal extraction series of these resources during the lifetime of the Mine＇s maintenance. Fol- lowing...The paper focuses on the optimal control of natural resources in mining industry. The purpose is to pro- pose an optimal extraction series of these resources during the lifetime of the Mine＇s maintenance. Fol- lowing the proposed optimal control model, a sensitivity analysis has been performed that includes the interest rate impact on the optimal solution. This study shows that the increasing of the interest rate sti- mulates faster extraction of the resources. The discounting factor induces that the resource has to be extracted faster hut this effect is counterbalanced by the diminishing returns of the annual cash flow. At higher parameters of ＂alpha＂ close to one of the power function about 80% from the whole resource will be extracted during the first 4 years of object/mine maintenance. An existence of unique positive root with respect to return of investment has been proposed and proved by two ways： by the ＂method of chords＂ and by using specialized software.展开更多
Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola...Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.展开更多
Some sociologists of the 20th century--Popper, Nisbet, Tilly, Wallerstein--doubted the applicability of the concept ＂evolution＂ to the process of social changes. It was stated that processes happening in a society c...Some sociologists of the 20th century--Popper, Nisbet, Tilly, Wallerstein--doubted the applicability of the concept ＂evolution＂ to the process of social changes. It was stated that processes happening in a society cannot be described using the approach of strict causality. However, dignifying life of the mankind is doubtful without elaborated scheme of social evolution and universal guiding line for the control over the further aociety evolution. General logica of social evolution can be traced by the change of human position in a society. Describing this change with the help of the activity-value approach one can construct ideal types of such evolutionary stages as wilderness, barbarism, civilization. The study of features and properties of ideal types of social evolution stages shows the regularity of two natural civilizations appearance： home-service civilization and market one. Countries of home-service civilization are ancient Egypt, China, and Russia （since Moscow Kingdom arose）. Athens, Novgorod Republic and Western countries are examples of the market civilization. The study of the market civilization properties shows that its long existence is doubtful. Authors propose an ideal type of spirit-game civilization as a long-term guiding line for the controlled social evolution. Control over evolution could save mankind and solve their main problems.展开更多
The introduction of daylight can improve buildings’energy efficiency and bring benefit to occupant satisfaction.However,the introduction of daylight may accompany with excessive heat.Properly counterbalancing the ene...The introduction of daylight can improve buildings’energy efficiency and bring benefit to occupant satisfaction.However,the introduction of daylight may accompany with excessive heat.Properly counterbalancing the energy consumption of air conditioning and lighting systems owing to the entry of daylight is a critical control target of dynamic shading adjustment in cooling season.Most dynamic shading control strategies in use only consider one single system.Additionally,for advanced control mode like performance-based control,the predictive model usually only examines the instantaneous effect of energy performance to determine the shading adjustment state,unable to quantify the overall influence of shading adjustment state on building energy consumption.In order to address this issue,special consideration is given to calculating the cumulative contribution of heat gains to cooling load in this study.An overall energy-efficient shading control metric is proposed and used as basis to develop optimized dynamic shading control strategy.An application example demonstrates that the SGR-Optimal control strategy can further save energy by 21.8%~38.8%when compared to the Rule-based control strategy,thus allowing a better exploration of the energy efficiency potential of daylight measure.展开更多
The ultimate solution to anthropogenic air pollution depends on an adjustment and upgrade of industrial and energy structures. Before this process can be completed, reducing the anthropogenic pollutant emissions is an...The ultimate solution to anthropogenic air pollution depends on an adjustment and upgrade of industrial and energy structures. Before this process can be completed, reducing the anthropogenic pollutant emissions is an effective measure. This is a problem belonging to "Natural Cybernetics", i.e., the problem of air pollution control should be solved together with the weather prediction; however, this is very complicated. Considering that heavy air pollution usually occurs in stable weather conditions and that the feedbacks between air pollutants and meteorological changes are insufficient, we propose a simplified natural cybernetics method. Here, an off-line air pollution evolution equation is first solved with data from a given anthropogenic emission inventory under the predicted weather conditions, and then, a related "incomplete adjoint problem" is solved to obtain the optimal reduction of anthropogenic emissions. Usually, such solution is sufficient for satisfying the air quality and economical/social requirements. However, a better solution can be obtained by iteration after updating the emission inventory with the reduced anthropogenic emissions. Then, this paper discusses the retrieval of the pollutant emission source with a known spatio-temporal distribution of the pollutant concentrations, and a feasible mathematical method to achieve this is proposed. The retrieval of emission source would also help control air pollution.展开更多
Evaluating cloud seeding effects is one of the most critical issues in artificial precipitation enhancement experiments. However, the evaluation is not straightforward because there is natural rainfall variability, wh...Evaluating cloud seeding effects is one of the most critical issues in artificial precipitation enhancement experiments. However, the evaluation is not straightforward because there is natural rainfall variability, which subjects the atmosphere to spatiotemporal instabilities. The aim of this study is to analyze natural rainfall variability using the modern statistical simulation method, "bootstrap", to analyze its influence on the evaluation of seeding activities and to take proper measures to control the influence. The study is based on the 1997?2007 airborne seeding macro records and the daily precipitation data in Jilin Province. The influence of natural rainfall variability can be reduced through three approaches: the increase of the supposed "seeded" sample size N, the rejection of outliers, and the selection of similar control units. A larger N leads to smaller calculated precipitation variability and detectable lower limits of seeding effects. When N is near 470 and the seeding effect is between 20% and 30%, the confidence level reaches 90%. For a single seeding operation, the case deletion model that rejects strong influence points and selects similar control units is established to control the influence of natural precipitation variability, which obviously improves the evaluation of artificial precipitation enhancement. The results demonstrate that the relative seeding effect in Jilin Province is concentrated mainly in the range of 0 to 30%, with an average of 11.95%, and has no significant linear relationship with the actual precipitation amount. However, the fluctuation amplitude of the relative effect decreases as the precipitation amount rises.展开更多
基金Project (No. 50175101) supported by the National Natural ScienceFoundation of China
文摘The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms?1, wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.
文摘The paper focuses on the optimal control of natural resources in mining industry. The purpose is to pro- pose an optimal extraction series of these resources during the lifetime of the Mine＇s maintenance. Fol- lowing the proposed optimal control model, a sensitivity analysis has been performed that includes the interest rate impact on the optimal solution. This study shows that the increasing of the interest rate sti- mulates faster extraction of the resources. The discounting factor induces that the resource has to be extracted faster hut this effect is counterbalanced by the diminishing returns of the annual cash flow. At higher parameters of ＂alpha＂ close to one of the power function about 80% from the whole resource will be extracted during the first 4 years of object/mine maintenance. An existence of unique positive root with respect to return of investment has been proposed and proved by two ways： by the ＂method of chords＂ and by using specialized software.
文摘Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.
文摘Some sociologists of the 20th century--Popper, Nisbet, Tilly, Wallerstein--doubted the applicability of the concept ＂evolution＂ to the process of social changes. It was stated that processes happening in a society cannot be described using the approach of strict causality. However, dignifying life of the mankind is doubtful without elaborated scheme of social evolution and universal guiding line for the control over the further aociety evolution. General logica of social evolution can be traced by the change of human position in a society. Describing this change with the help of the activity-value approach one can construct ideal types of such evolutionary stages as wilderness, barbarism, civilization. The study of features and properties of ideal types of social evolution stages shows the regularity of two natural civilizations appearance： home-service civilization and market one. Countries of home-service civilization are ancient Egypt, China, and Russia （since Moscow Kingdom arose）. Athens, Novgorod Republic and Western countries are examples of the market civilization. The study of the market civilization properties shows that its long existence is doubtful. Authors propose an ideal type of spirit-game civilization as a long-term guiding line for the controlled social evolution. Control over evolution could save mankind and solve their main problems.
文摘The introduction of daylight can improve buildings’energy efficiency and bring benefit to occupant satisfaction.However,the introduction of daylight may accompany with excessive heat.Properly counterbalancing the energy consumption of air conditioning and lighting systems owing to the entry of daylight is a critical control target of dynamic shading adjustment in cooling season.Most dynamic shading control strategies in use only consider one single system.Additionally,for advanced control mode like performance-based control,the predictive model usually only examines the instantaneous effect of energy performance to determine the shading adjustment state,unable to quantify the overall influence of shading adjustment state on building energy consumption.In order to address this issue,special consideration is given to calculating the cumulative contribution of heat gains to cooling load in this study.An overall energy-efficient shading control metric is proposed and used as basis to develop optimized dynamic shading control strategy.An application example demonstrates that the SGR-Optimal control strategy can further save energy by 21.8%~38.8%when compared to the Rule-based control strategy,thus allowing a better exploration of the energy efficiency potential of daylight measure.
基金supported by the National Natural Science Foundation of China (Grant No. 41630530the National Key Research and Development Program of China (Grant No. 2016YFC0209000)
文摘The ultimate solution to anthropogenic air pollution depends on an adjustment and upgrade of industrial and energy structures. Before this process can be completed, reducing the anthropogenic pollutant emissions is an effective measure. This is a problem belonging to "Natural Cybernetics", i.e., the problem of air pollution control should be solved together with the weather prediction; however, this is very complicated. Considering that heavy air pollution usually occurs in stable weather conditions and that the feedbacks between air pollutants and meteorological changes are insufficient, we propose a simplified natural cybernetics method. Here, an off-line air pollution evolution equation is first solved with data from a given anthropogenic emission inventory under the predicted weather conditions, and then, a related "incomplete adjoint problem" is solved to obtain the optimal reduction of anthropogenic emissions. Usually, such solution is sufficient for satisfying the air quality and economical/social requirements. However, a better solution can be obtained by iteration after updating the emission inventory with the reduced anthropogenic emissions. Then, this paper discusses the retrieval of the pollutant emission source with a known spatio-temporal distribution of the pollutant concentrations, and a feasible mathematical method to achieve this is proposed. The retrieval of emission source would also help control air pollution.
基金supported by the National Meteorological Public Benefit Research Foundation(Grant No.GYHY201006031)the China Meteorological Administration Soft Science Project(Grant No.2012-053)+1 种基金the Jiangsu Province Science Department Grant(Grant No.CB10X_295Z)the Jiangsu Province Qinglan Project for Cloud Fog Precipitation and Aerosol Research Group
文摘Evaluating cloud seeding effects is one of the most critical issues in artificial precipitation enhancement experiments. However, the evaluation is not straightforward because there is natural rainfall variability, which subjects the atmosphere to spatiotemporal instabilities. The aim of this study is to analyze natural rainfall variability using the modern statistical simulation method, "bootstrap", to analyze its influence on the evaluation of seeding activities and to take proper measures to control the influence. The study is based on the 1997?2007 airborne seeding macro records and the daily precipitation data in Jilin Province. The influence of natural rainfall variability can be reduced through three approaches: the increase of the supposed "seeded" sample size N, the rejection of outliers, and the selection of similar control units. A larger N leads to smaller calculated precipitation variability and detectable lower limits of seeding effects. When N is near 470 and the seeding effect is between 20% and 30%, the confidence level reaches 90%. For a single seeding operation, the case deletion model that rejects strong influence points and selects similar control units is established to control the influence of natural precipitation variability, which obviously improves the evaluation of artificial precipitation enhancement. The results demonstrate that the relative seeding effect in Jilin Province is concentrated mainly in the range of 0 to 30%, with an average of 11.95%, and has no significant linear relationship with the actual precipitation amount. However, the fluctuation amplitude of the relative effect decreases as the precipitation amount rises.
