Project cost can control the input in construction project and improve economic benefits of construction enterprises,so it is an important section of construction engineering.Reasonable control and management of proje...Project cost can control the input in construction project and improve economic benefits of construction enterprises,so it is an important section of construction engineering.Reasonable control and management of project cost is the principle that building units must obey in the whole process of project,particularly in the construction stage,so it is extremely important to control and manage the project cost.This paper first analyzed possible causes for the unreasonable cost of construction projects,and put forward pertinent strategies for the control and management of construction project cost.展开更多
This article proposes a method of management and control of a continuous bus powered by renewable energies for autonomous applications. The DC bus is obtained from two systems of renewable sources (the solar system an...This article proposes a method of management and control of a continuous bus powered by renewable energies for autonomous applications. The DC bus is obtained from two systems of renewable sources (the solar system and the wind system) and storage battery (Lithium Ion). The continuous bus control and management procedure require efficiency in the control of the charge and discharge of the battery according to the load energy demand (DC Motor). The battery charging process is non-linear, varying over time with considerable delay, so it is difficult to achieve the best performance on control with energy management using traditional control approaches. A fuzzy control strategy is used in this article for battery control. To improve battery life, fuzzy control manages the desired state of charge (SOC). The entire system designed is modeled and simulated on MATLAB/Simulink Environment.展开更多
In recent years,China’s society and economy has been developing very rapidly,and various industries are showing a trend of vigorous development.The importance of control and management of project cost in highway proj...In recent years,China’s society and economy has been developing very rapidly,and various industries are showing a trend of vigorous development.The importance of control and management of project cost in highway project management is becoming more and more prominent.PPP model has been widely used in the control and management of highway project cost with its own unique advantages.The author analyzes the important advantages of the PPP model and the existing problems in the cost control and management of highway projects,and puts forward effective measures for the cost control and management of highway projects using the PPP model,in hope of helping with the smooth implementation of the work.展开更多
Chemical ecology of the spruce bark beetle lps typographus （L.） was reviewed. The outbreak of 1.typographus in central Europe triggered extensive research on chemical ecology, Males initiate host location and produc...Chemical ecology of the spruce bark beetle lps typographus （L.） was reviewed. The outbreak of 1.typographus in central Europe triggered extensive research on chemical ecology, Males initiate host location and produce semiochemicals which attract both males and females, A successful mass attack must first overcome the resistance of the host tree. Pioneer I. typographus evolved to use the resin flow of host trees as kairomones in host location, and synthesized semiochemicals initially to detoxify the resin. If small bark beetle populations infest healthy trees, mass attack is prevented by host resistance, Nine monoterpene alcohols were found in male hind-guts, including cis-verbenol （cV） and 2-methyl-3-buten-2-ol （MB） which are regarded as primary aggregation pheromones, and a low proportion of lpsdienol （ld） which increases attractiveness of cV and MB, Verbenone （Vn） and Ipsenol （le） are anti-aggregation pheromones, that play important roles in adjusting attack density and insect density under the bark. Non-host volatiles are repellent to L typographus, so that beetles do not waste energy boring into non-host trees. The relationship between host resistance, pheromone compounds and behavior, non-host volatiles, bioassays and mass trapping are reviewed, Results of field bioassays stressed that traps baited with specific pheromones could be used as a reasonable protection measure.展开更多
文摘Project cost can control the input in construction project and improve economic benefits of construction enterprises,so it is an important section of construction engineering.Reasonable control and management of project cost is the principle that building units must obey in the whole process of project,particularly in the construction stage,so it is extremely important to control and manage the project cost.This paper first analyzed possible causes for the unreasonable cost of construction projects,and put forward pertinent strategies for the control and management of construction project cost.
文摘This article proposes a method of management and control of a continuous bus powered by renewable energies for autonomous applications. The DC bus is obtained from two systems of renewable sources (the solar system and the wind system) and storage battery (Lithium Ion). The continuous bus control and management procedure require efficiency in the control of the charge and discharge of the battery according to the load energy demand (DC Motor). The battery charging process is non-linear, varying over time with considerable delay, so it is difficult to achieve the best performance on control with energy management using traditional control approaches. A fuzzy control strategy is used in this article for battery control. To improve battery life, fuzzy control manages the desired state of charge (SOC). The entire system designed is modeled and simulated on MATLAB/Simulink Environment.
文摘In recent years,China’s society and economy has been developing very rapidly,and various industries are showing a trend of vigorous development.The importance of control and management of project cost in highway project management is becoming more and more prominent.PPP model has been widely used in the control and management of highway project cost with its own unique advantages.The author analyzes the important advantages of the PPP model and the existing problems in the cost control and management of highway projects,and puts forward effective measures for the cost control and management of highway projects using the PPP model,in hope of helping with the smooth implementation of the work.
文摘Chemical ecology of the spruce bark beetle lps typographus （L.） was reviewed. The outbreak of 1.typographus in central Europe triggered extensive research on chemical ecology, Males initiate host location and produce semiochemicals which attract both males and females, A successful mass attack must first overcome the resistance of the host tree. Pioneer I. typographus evolved to use the resin flow of host trees as kairomones in host location, and synthesized semiochemicals initially to detoxify the resin. If small bark beetle populations infest healthy trees, mass attack is prevented by host resistance, Nine monoterpene alcohols were found in male hind-guts, including cis-verbenol （cV） and 2-methyl-3-buten-2-ol （MB） which are regarded as primary aggregation pheromones, and a low proportion of lpsdienol （ld） which increases attractiveness of cV and MB, Verbenone （Vn） and Ipsenol （le） are anti-aggregation pheromones, that play important roles in adjusting attack density and insect density under the bark. Non-host volatiles are repellent to L typographus, so that beetles do not waste energy boring into non-host trees. The relationship between host resistance, pheromone compounds and behavior, non-host volatiles, bioassays and mass trapping are reviewed, Results of field bioassays stressed that traps baited with specific pheromones could be used as a reasonable protection measure.
