A two-dimensional linear spring model is established to study the microbuckling of a plane monomolecular layer adhering to a substrate. The model is for the layer subjected to a compressive load having an arbitrary an...A two-dimensional linear spring model is established to study the microbuckling of a plane monomolecular layer adhering to a substrate. The model is for the layer subjected to a compressive load having an arbitrary angle with the chemical bond of the layer. The effects of the load angle, the strength of adhesion and the bending stiffness and shearing stiffness (the capability of resisting transverse bending and in-plane shearing) of the layer on the minimal buckling force and the critical buckling mode are discussed. It is found that the minimal buckling force increases with increasing load angle and, for a given bending stiffness, increases with increasing strength of adhesion and decreasing shearing stiffness. Furthermore, a critical condition under which the buckling of the layer can just occur is obtained, which is helpful to avoid buckling in an engineering application.展开更多
It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcit...It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcity of water is compounded by high evaporation loss from the open water surfaces of lakes and reservoirs. The use of surface covering by a monomolecular film to reduce evaporation loss from large open water surfaces offers the greatest promise among all currently available techniques. This is the only system that retains the water surface in a state that does not interfere with other uses of the body of water such as boating, navigation recreation, fish, and wildlife propagation. Various experiments and field trials worldwide have proven conclusively that the fatty alcohols and their emulsions effectively retard water evaporation and result in saving to the tune of about 20% to 50%. An experiment was carried out at the Aji Reservoir (India) using a mixture of Cetyl and Stearyl alcohol that confirmed 19.26% saving in evaporation loss. During this six-month trial, about 0.18 mcum of water was saved which otherwise might have evaporated.展开更多
A comparison was made of adsorption characteristics and adsorption thermodynamics about benzene in aqueous solution onto new adsorption resins ZH-00 and ZH-03 prepared in this laboratory.The static equilibrium adsorpt...A comparison was made of adsorption characteristics and adsorption thermodynamics about benzene in aqueous solution onto new adsorption resins ZH-00 and ZH-03 prepared in this laboratory.The static equilibrium adsorption isotherms in the temperature range of 283-293K were measured.The results show that Langmuir equation can give a better fitting for the data from the above adsorption isotherms and the process of adsorption for benzene in aqueous solution with the two new adsorbents is an exothermic,monomolecular layer,physical one,and the temperature has an important effect on the adsorption process.The static efficiency of removal of benzene reaches 90 percent at the low concentration and the breakthrough capacities of benzene on ZH-00 and ZH-03 are 40.1 and (45.6 mg)/(ml dry resin),respectively.展开更多
The modification of electrode involves the attachment of chemical substances to the surfaces by physical adsorption, chemical bonding or polymer coating. The modified electrodes can thereby exhibit properties related ...The modification of electrode involves the attachment of chemical substances to the surfaces by physical adsorption, chemical bonding or polymer coating. The modified electrodes can thereby exhibit properties related to those of the modifying substances. It is quite clear that in order to perform increasingly complicated and demanded tasks using chemically modified electrodes, complex molecular structure must be constructed with a high degree of Control over the design and structure of the systems. The merits of展开更多
基金The project supported by the National Distinguished Young Scientist Fund Cheung Kong Scholars Programme+1 种基金the National Natural Science Foundation of China (10272082, 10172068)Shanghai Post-doctoral Science Foundation
文摘A two-dimensional linear spring model is established to study the microbuckling of a plane monomolecular layer adhering to a substrate. The model is for the layer subjected to a compressive load having an arbitrary angle with the chemical bond of the layer. The effects of the load angle, the strength of adhesion and the bending stiffness and shearing stiffness (the capability of resisting transverse bending and in-plane shearing) of the layer on the minimal buckling force and the critical buckling mode are discussed. It is found that the minimal buckling force increases with increasing load angle and, for a given bending stiffness, increases with increasing strength of adhesion and decreasing shearing stiffness. Furthermore, a critical condition under which the buckling of the layer can just occur is obtained, which is helpful to avoid buckling in an engineering application.
文摘It is an established fact that huge quantities of water are lost from lakes, reservoirs and soils by evaporation. This assumes greater significance in arid and semi-arid regions around the globe when a general scarcity of water is compounded by high evaporation loss from the open water surfaces of lakes and reservoirs. The use of surface covering by a monomolecular film to reduce evaporation loss from large open water surfaces offers the greatest promise among all currently available techniques. This is the only system that retains the water surface in a state that does not interfere with other uses of the body of water such as boating, navigation recreation, fish, and wildlife propagation. Various experiments and field trials worldwide have proven conclusively that the fatty alcohols and their emulsions effectively retard water evaporation and result in saving to the tune of about 20% to 50%. An experiment was carried out at the Aji Reservoir (India) using a mixture of Cetyl and Stearyl alcohol that confirmed 19.26% saving in evaporation loss. During this six-month trial, about 0.18 mcum of water was saved which otherwise might have evaporated.
文摘A comparison was made of adsorption characteristics and adsorption thermodynamics about benzene in aqueous solution onto new adsorption resins ZH-00 and ZH-03 prepared in this laboratory.The static equilibrium adsorption isotherms in the temperature range of 283-293K were measured.The results show that Langmuir equation can give a better fitting for the data from the above adsorption isotherms and the process of adsorption for benzene in aqueous solution with the two new adsorbents is an exothermic,monomolecular layer,physical one,and the temperature has an important effect on the adsorption process.The static efficiency of removal of benzene reaches 90 percent at the low concentration and the breakthrough capacities of benzene on ZH-00 and ZH-03 are 40.1 and (45.6 mg)/(ml dry resin),respectively.
基金the National Natural Science Foundation of China.
文摘The modification of electrode involves the attachment of chemical substances to the surfaces by physical adsorption, chemical bonding or polymer coating. The modified electrodes can thereby exhibit properties related to those of the modifying substances. It is quite clear that in order to perform increasingly complicated and demanded tasks using chemically modified electrodes, complex molecular structure must be constructed with a high degree of Control over the design and structure of the systems. The merits of
