[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved re...[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.展开更多
This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enh...This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enhance sustainable development. For small, portable applications that need long lifetime energy supply systems, size, width, finite energy lifetime, and the need for replacement are important drawbacks. New supply alternatives should be explored that are able to make recharging easier or to remove battery dependence altogether. A new trend in the energy sources for low power applications has emerged in recent years, involving the harvesting of the energy available in the environment to supply power for electronic applications instead of using battery technologies that provide only short, finite amounts of energy. In this paper, we describe an all-purpose module of energy harvesting from mechanical, thermal, solar and RF energy sources developed at the University of Barcelona. We provide proof of concept in order to incorporate this novel energy technology in a wide range of applications and environments.展开更多
Grapes are important sources of antioxidants compounds and one of the most used varieties to elaborate juices is ＂Isabel＂, or ＂Isabella＂, as it is called in North-America. This study aimed to evaluate the antioxid...Grapes are important sources of antioxidants compounds and one of the most used varieties to elaborate juices is ＂Isabel＂, or ＂Isabella＂, as it is called in North-America. This study aimed to evaluate the antioxidant activity of Isabella grape juices from the tropical semi-arid climate produced in Brazil on March and September, 2010. Total phenolics and anthocyanins were determined, as well as the antioxidant capacity by DPPH, FRAP and hydrophilic ORAC methods. Test T was used to compare statistical difference at 5% of significance level. As expected, the results showed that the season can play a significant role on phenolics content and antioxidant power. Polyphenols content in juices varied from 82.9 ± 0.92 to 102.2± 1.59 mg GAE 100 mL1- and anthocyanins content ranged from 44.3 ± 2.01 to 129.5 ± 2.82 mg cyanidin-3-glucoside 100 mL-1. Regression analyses showed a high correlation of antioxidant capacity and anthocyanins content. Grapes from Sao Francisco River Valley demonstrated to be a good source of antioxidant for human diet.展开更多
This work deals with a prey-predator model in an environment where the carrying capacities are assumed to be variable with time and one species feeds upon the other. Independent harvesting efforts are applied in eithe...This work deals with a prey-predator model in an environment where the carrying capacities are assumed to be variable with time and one species feeds upon the other. Independent harvesting efforts are applied in either species and asymmetrical intraguild predation occurs. A common resource is consumed by two competing species and at the same time predator also consumes the prey. At first we discuss the model under constant carrying capacity and make the conclusion that no limit cycle exists in this case. Then we discuss the model without intraspecific competition. Our main concern is to cover the above mentioned two cases together, i.e. the model with variable carrying capacity and intraspecific competition. We determine the steady states and examine the dynamical behavior. We also analyze the local and global stability of the interior equilibrium by Routh-Hurwitz criterion and a suitable Lyapunov function respectively. A Hopf bifur- cation occurs with respect to a parameter which is the ratio of predator＇s and prey＇s intrinsic growth rate. The possibility of bionomic equilibrium has been considered. The optimal harvest policy is formulated and solved with Pontryagin＇s maximum principle. Some numerical simulations are given to explain most of the analytical results.展开更多
We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafl...We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafluoroethylene film and an etched A1 film attached on two acrylic tubes, the fabricated triboelectric nanogenerator （TENG） can deliver an open-circuit voltage of about 90 V, a short-circuit current density of about 0.5 mA/m2, and a maximum power density of 16 mW/m2, which is capable of directly lighting up 20 blue light- emitting-diodes （LEDs）. By integrating a TENG, a solar cell, and an electrochemical cell, a hybrid energy cell has been fabricated to simultaneously scavenge three different types of energies. As compared with the individual energy units, the hybrid energy cell exhibited much better performance in charging a capacitor. Moreover, we also demonstrated that the hybrid energies generated can be stored in a Li-ion battery for powering a commercial wind speed sensor and a temperature sensor. This work represents significant progress toward practical applications of hybrid energy cells, providing potential solutions for simul- taneously scavenging wind, solar, and chemical energies.展开更多
The paper analyzes the influence of a susceptible-infectious-susceptible （SIS） infectious disease affecting both fish and broiler species. The paper also considers a joint SIS project of fish and broiler in which th...The paper analyzes the influence of a susceptible-infectious-susceptible （SIS） infectious disease affecting both fish and broiler species. The paper also considers a joint SIS project of fish and broiler in which the growth rates of both species vary with available nutrients and environmental carrying capacities of biomasses. The nutrients for both species are functions of the biomasses of the two species. The harvesting rates of fish and broiler depend linearly on common effort function. It is assumed that the diseases are trans- mitted to the susceptible populations by direct contact with the infected populations. Using the medicine, some portion of the infected populations are transmitted to the sus- ceptible populations. The existence of steady states and their stability are investigated analytically. The joint profit of the SIS model is maximized using Pontryagin＇s max- imum principle and corresponding optimum harvesting rates are also obtained. Using Mathematica software~ the models are illustrated and the optimum results are obtained and presented in tabular and graphical forms.展开更多
基金Supported by Sichuan Financial and Engineering Foundation for the Young(2007QNJJ-020)Sichuan Cultivation Foundation for Academy leaders+3 种基金Sichuan Key Project of Rice BreedingConstruction of Rice Industry System in SouthwestNational Crop-harvesting ProjectSichuan Financial Promotion~~
文摘[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.
文摘This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enhance sustainable development. For small, portable applications that need long lifetime energy supply systems, size, width, finite energy lifetime, and the need for replacement are important drawbacks. New supply alternatives should be explored that are able to make recharging easier or to remove battery dependence altogether. A new trend in the energy sources for low power applications has emerged in recent years, involving the harvesting of the energy available in the environment to supply power for electronic applications instead of using battery technologies that provide only short, finite amounts of energy. In this paper, we describe an all-purpose module of energy harvesting from mechanical, thermal, solar and RF energy sources developed at the University of Barcelona. We provide proof of concept in order to incorporate this novel energy technology in a wide range of applications and environments.
文摘Grapes are important sources of antioxidants compounds and one of the most used varieties to elaborate juices is ＂Isabel＂, or ＂Isabella＂, as it is called in North-America. This study aimed to evaluate the antioxidant activity of Isabella grape juices from the tropical semi-arid climate produced in Brazil on March and September, 2010. Total phenolics and anthocyanins were determined, as well as the antioxidant capacity by DPPH, FRAP and hydrophilic ORAC methods. Test T was used to compare statistical difference at 5% of significance level. As expected, the results showed that the season can play a significant role on phenolics content and antioxidant power. Polyphenols content in juices varied from 82.9 ± 0.92 to 102.2± 1.59 mg GAE 100 mL1- and anthocyanins content ranged from 44.3 ± 2.01 to 129.5 ± 2.82 mg cyanidin-3-glucoside 100 mL-1. Regression analyses showed a high correlation of antioxidant capacity and anthocyanins content. Grapes from Sao Francisco River Valley demonstrated to be a good source of antioxidant for human diet.
文摘This work deals with a prey-predator model in an environment where the carrying capacities are assumed to be variable with time and one species feeds upon the other. Independent harvesting efforts are applied in either species and asymmetrical intraguild predation occurs. A common resource is consumed by two competing species and at the same time predator also consumes the prey. At first we discuss the model under constant carrying capacity and make the conclusion that no limit cycle exists in this case. Then we discuss the model without intraspecific competition. Our main concern is to cover the above mentioned two cases together, i.e. the model with variable carrying capacity and intraspecific competition. We determine the steady states and examine the dynamical behavior. We also analyze the local and global stability of the interior equilibrium by Routh-Hurwitz criterion and a suitable Lyapunov function respectively. A Hopf bifur- cation occurs with respect to a parameter which is the ratio of predator＇s and prey＇s intrinsic growth rate. The possibility of bionomic equilibrium has been considered. The optimal harvest policy is formulated and solved with Pontryagin＇s maximum principle. Some numerical simulations are given to explain most of the analytical results.
文摘We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafluoroethylene film and an etched A1 film attached on two acrylic tubes, the fabricated triboelectric nanogenerator （TENG） can deliver an open-circuit voltage of about 90 V, a short-circuit current density of about 0.5 mA/m2, and a maximum power density of 16 mW/m2, which is capable of directly lighting up 20 blue light- emitting-diodes （LEDs）. By integrating a TENG, a solar cell, and an electrochemical cell, a hybrid energy cell has been fabricated to simultaneously scavenge three different types of energies. As compared with the individual energy units, the hybrid energy cell exhibited much better performance in charging a capacitor. Moreover, we also demonstrated that the hybrid energies generated can be stored in a Li-ion battery for powering a commercial wind speed sensor and a temperature sensor. This work represents significant progress toward practical applications of hybrid energy cells, providing potential solutions for simul- taneously scavenging wind, solar, and chemical energies.
文摘The paper analyzes the influence of a susceptible-infectious-susceptible （SIS） infectious disease affecting both fish and broiler species. The paper also considers a joint SIS project of fish and broiler in which the growth rates of both species vary with available nutrients and environmental carrying capacities of biomasses. The nutrients for both species are functions of the biomasses of the two species. The harvesting rates of fish and broiler depend linearly on common effort function. It is assumed that the diseases are trans- mitted to the susceptible populations by direct contact with the infected populations. Using the medicine, some portion of the infected populations are transmitted to the sus- ceptible populations. The existence of steady states and their stability are investigated analytically. The joint profit of the SIS model is maximized using Pontryagin＇s max- imum principle and corresponding optimum harvesting rates are also obtained. Using Mathematica software~ the models are illustrated and the optimum results are obtained and presented in tabular and graphical forms.
