Stickies problems in recycling were introduced in this paper which were divided in six parts at all. They are potential sources ofstickies and their chemical nature; classification and deposits mechanism of stickies a...Stickies problems in recycling were introduced in this paper which were divided in six parts at all. They are potential sources ofstickies and their chemical nature; classification and deposits mechanism of stickies as well as harmfullness from stickies; methods forquantiative characterization and qualitative analysis of stickies; mechanical control methods for stickies; chemical methods for stickiescontrol; stickies control programme in paper mills and future trends in stickies research studies.展开更多
Luffing mechanism is a key component of the construction machinery.This paper proposes a two degree of freedom(2-DOF)luffing mechanism,which has one more pair of driving cylinders than the single DOF luffing mechanism...Luffing mechanism is a key component of the construction machinery.This paper proposes a two degree of freedom(2-DOF)luffing mechanism,which has one more pair of driving cylinders than the single DOF luffing mechanism,to improve the performance of the machinery.To establish the dynamic model of the 2-DOF luffing mechanism,firstly,we develop a hierarchical method to deduce the Jacobian matrix and Hessian matrix for obtaining the kinematics equations.Subsequently,we divide the luffing mechanism into six bodies considering actuators,and deduce the kinetic equations of each body by the Newton-Euler method.Based on the dynamic model,we simulate the luffing process.Finally,a prototype is built on a pile driver to validate the model.Simulations and experiments show that the dynamic model can reflect the dynamic properties of the proposed luffing mechanism.And the control strategy that the front cylinders retract first shows better mechanical behavior than the other two control strategies.This research provides a reference for the design and application of 2-DOF luffing mechanism on construction machinery.The modeling approach can also be applied to similar mechanism with serial closed kinematic chains,which allows to calculate the dynamic parameters easily and exactly.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
Silver nanoparticles （Ag-NPs） were prepared using an electrochemical technique. The optical properties were measured by absorption spectroscopy. The dimension of the prepared nanoparticles as estimated by the Atomic...Silver nanoparticles （Ag-NPs） were prepared using an electrochemical technique. The optical properties were measured by absorption spectroscopy. The dimension of the prepared nanoparticles as estimated by the Atomic Force Microscope （AFM）, was 91.57 nm. This reaserch effort proposes a mechanism for reducing the size of silver nanoparticles by adding the hydrogen peroxide （H202）, and protecting the silver nanoparticle to inhibit agglomeration by adding PVP polymer.展开更多
Effects of an electric field on CO oxidation of Au-embedded graphene are investigated using first-principles method. Results of our calculations show that the initial step of the reaction is more likely to proceed via...Effects of an electric field on CO oxidation of Au-embedded graphene are investigated using first-principles method. Results of our calculations show that the initial step of the reaction is more likely to proceed via the Langmuir-Hinshelwood mechanism in the presence of the field, and the reaction barrier can be tuned continuously by the electric field. However, the applied electric field makes it more difficult for the product of the reaction, CO2, to desorb from the reaction site. These two competing effects make an electric field not entirely advantageous in controlling the activity of Au-embedded graphene for CO oxidation reaction. Nevertheless, the findings of our study provide a basis for further investigation on control of chemical reactions by electric fields.展开更多
文摘Stickies problems in recycling were introduced in this paper which were divided in six parts at all. They are potential sources ofstickies and their chemical nature; classification and deposits mechanism of stickies as well as harmfullness from stickies; methods forquantiative characterization and qualitative analysis of stickies; mechanical control methods for stickies; chemical methods for stickiescontrol; stickies control programme in paper mills and future trends in stickies research studies.
基金Project(2015B020238014)supported by the Science and Technology Program of Guangdong Province,China。
文摘Luffing mechanism is a key component of the construction machinery.This paper proposes a two degree of freedom(2-DOF)luffing mechanism,which has one more pair of driving cylinders than the single DOF luffing mechanism,to improve the performance of the machinery.To establish the dynamic model of the 2-DOF luffing mechanism,firstly,we develop a hierarchical method to deduce the Jacobian matrix and Hessian matrix for obtaining the kinematics equations.Subsequently,we divide the luffing mechanism into six bodies considering actuators,and deduce the kinetic equations of each body by the Newton-Euler method.Based on the dynamic model,we simulate the luffing process.Finally,a prototype is built on a pile driver to validate the model.Simulations and experiments show that the dynamic model can reflect the dynamic properties of the proposed luffing mechanism.And the control strategy that the front cylinders retract first shows better mechanical behavior than the other two control strategies.This research provides a reference for the design and application of 2-DOF luffing mechanism on construction machinery.The modeling approach can also be applied to similar mechanism with serial closed kinematic chains,which allows to calculate the dynamic parameters easily and exactly.
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Silver nanoparticles （Ag-NPs） were prepared using an electrochemical technique. The optical properties were measured by absorption spectroscopy. The dimension of the prepared nanoparticles as estimated by the Atomic Force Microscope （AFM）, was 91.57 nm. This reaserch effort proposes a mechanism for reducing the size of silver nanoparticles by adding the hydrogen peroxide （H202）, and protecting the silver nanoparticle to inhibit agglomeration by adding PVP polymer.
基金supported by the National Research Foundation (Singapore) Competitive Research Program (Grant No. NRF-G-CRP 2007-05)
文摘Effects of an electric field on CO oxidation of Au-embedded graphene are investigated using first-principles method. Results of our calculations show that the initial step of the reaction is more likely to proceed via the Langmuir-Hinshelwood mechanism in the presence of the field, and the reaction barrier can be tuned continuously by the electric field. However, the applied electric field makes it more difficult for the product of the reaction, CO2, to desorb from the reaction site. These two competing effects make an electric field not entirely advantageous in controlling the activity of Au-embedded graphene for CO oxidation reaction. Nevertheless, the findings of our study provide a basis for further investigation on control of chemical reactions by electric fields.
