An electrochemical method was developed for the determination of melamine (2,4,6 triamino- 1,3,5-triazine) on static mercury drop electrode (SMDE) and on gold nano particle modified carbon paste electrode. Interaction...An electrochemical method was developed for the determination of melamine (2,4,6 triamino- 1,3,5-triazine) on static mercury drop electrode (SMDE) and on gold nano particle modified carbon paste electrode. Interaction of melamine with Cu2﹢ ion was investigated and the decrease of Cu stripping peak was measured for the determination of melamine using SMDE. Oxidation property of melamine was improved using gold nano particle modified carbon paste electrode. Direct determination of melamine was proposed from the oxidation peak with three sigma detection limit of 0.43 μML﹣1. Recovery in milk powder sample has shown good recovery of melamine using the modified carbon paste electrode.展开更多
Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance ph...Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance phenolmenon. These two possibilities are explored here by solving the space and time dependent bio-heat equation under different conditions. The knowledge of temperature profiles in the tumor region helps to bypass the painful placement of sensors for monitoring tumor’s heating by the laser. Important properties which could be useful for developing an efficient tumor therapy are introduced for the first time. It is found that the effects of metabolism consist essentially in a redefinition of the blood temperature which increases proportional to the heat of metabolism. Blood perfusion in a given tissue leads to a new characteristic length of order one or two centimeters and a blood convection parameter typically of order 30 W·m-1·K-1. Effects of these parameters are scrutinized within the resolution of the bio-heat equation under a variety of conditions. In general, space modulations of the temperature throughout biological tissues are weak but front kinetics are quite fast. Specific examples show the way to monitor the temperature rise taking into account the tumor’s nature and size.展开更多
An effective procedure for constructing a DNA biosensor is developed based on covalent immobilization of NH2 labeled,single strand DNA（NH2-ssDNA） onto a self-assembled diazo-thiourea and gold nanoparticles modified ...An effective procedure for constructing a DNA biosensor is developed based on covalent immobilization of NH2 labeled,single strand DNA（NH2-ssDNA） onto a self-assembled diazo-thiourea and gold nanoparticles modified Au electrode（diazo-thiourea/GNM/Au）.Gold nano-particles expand the electrode surface area and increase the amount of immobilized thiourea and single stranded DNA（ssDNA） onto the electrode surface.Diazo-thiourea film provides a surface with high conductibility for electron transfer and a bed for the covalent coupling of NH2-ssDNA onto the electrode surface.The immobilization and hybridization of the probe DNA on the modified electrode is studied by differential pulse voltammetry（DPV） using methylene blue（MB） as a well-known electrochemical hybridization indicator.The linear range for the determination of complementary target ssDNA is from 9.5（±0.1） × 10^-13 mol/L to1.2（±0.2） x 10^-9 mol/L with a detection limit of 1.2（±0.1） 〉 10^-13 mol/L.展开更多
The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano...The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.展开更多
卡林型金矿中金的赋存状态一直是矿物学和矿床学的研究重点之一。我国右江盆地卡林型金矿中金的赋存状态长期存在纳米金颗粒(包裹体金)和晶格金之争(Feng Hongye et al.,2021)。黄铁矿在金矿床中通常作为主要载金矿物出现,其晶体内部结...卡林型金矿中金的赋存状态一直是矿物学和矿床学的研究重点之一。我国右江盆地卡林型金矿中金的赋存状态长期存在纳米金颗粒(包裹体金)和晶格金之争(Feng Hongye et al.,2021)。黄铁矿在金矿床中通常作为主要载金矿物出现,其晶体内部结构及微量元素组份特征可以用来限定成矿流体的性质、来源与演化规律、反映成矿过程、约束矿床成因等,离散不可见金的形成途径.展开更多
文摘An electrochemical method was developed for the determination of melamine (2,4,6 triamino- 1,3,5-triazine) on static mercury drop electrode (SMDE) and on gold nano particle modified carbon paste electrode. Interaction of melamine with Cu2﹢ ion was investigated and the decrease of Cu stripping peak was measured for the determination of melamine using SMDE. Oxidation property of melamine was improved using gold nano particle modified carbon paste electrode. Direct determination of melamine was proposed from the oxidation peak with three sigma detection limit of 0.43 μML﹣1. Recovery in milk powder sample has shown good recovery of melamine using the modified carbon paste electrode.
文摘Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance phenolmenon. These two possibilities are explored here by solving the space and time dependent bio-heat equation under different conditions. The knowledge of temperature profiles in the tumor region helps to bypass the painful placement of sensors for monitoring tumor’s heating by the laser. Important properties which could be useful for developing an efficient tumor therapy are introduced for the first time. It is found that the effects of metabolism consist essentially in a redefinition of the blood temperature which increases proportional to the heat of metabolism. Blood perfusion in a given tissue leads to a new characteristic length of order one or two centimeters and a blood convection parameter typically of order 30 W·m-1·K-1. Effects of these parameters are scrutinized within the resolution of the bio-heat equation under a variety of conditions. In general, space modulations of the temperature throughout biological tissues are weak but front kinetics are quite fast. Specific examples show the way to monitor the temperature rise taking into account the tumor’s nature and size.
文摘An effective procedure for constructing a DNA biosensor is developed based on covalent immobilization of NH2 labeled,single strand DNA（NH2-ssDNA） onto a self-assembled diazo-thiourea and gold nanoparticles modified Au electrode（diazo-thiourea/GNM/Au）.Gold nano-particles expand the electrode surface area and increase the amount of immobilized thiourea and single stranded DNA（ssDNA） onto the electrode surface.Diazo-thiourea film provides a surface with high conductibility for electron transfer and a bed for the covalent coupling of NH2-ssDNA onto the electrode surface.The immobilization and hybridization of the probe DNA on the modified electrode is studied by differential pulse voltammetry（DPV） using methylene blue（MB） as a well-known electrochemical hybridization indicator.The linear range for the determination of complementary target ssDNA is from 9.5（±0.1） × 10^-13 mol/L to1.2（±0.2） x 10^-9 mol/L with a detection limit of 1.2（±0.1） 〉 10^-13 mol/L.
文摘The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.
文摘卡林型金矿中金的赋存状态一直是矿物学和矿床学的研究重点之一。我国右江盆地卡林型金矿中金的赋存状态长期存在纳米金颗粒(包裹体金)和晶格金之争(Feng Hongye et al.,2021)。黄铁矿在金矿床中通常作为主要载金矿物出现,其晶体内部结构及微量元素组份特征可以用来限定成矿流体的性质、来源与演化规律、反映成矿过程、约束矿床成因等,离散不可见金的形成途径.
