Nickel ferrite nano-powders were prepared by microwave radiating low-temperature solid-state reaction method, and then modified with Ag by dipping method. The crystal structure and morphology of the samples were chara...Nickel ferrite nano-powders were prepared by microwave radiating low-temperature solid-state reaction method, and then modified with Ag by dipping method. The crystal structure and morphology of the samples were characterized by means of X-ray diffraction（XRD）, scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）. The gas sensing properties of the samples were also investigated. The results reveal that the Ag, as amorphous structure, can efficiently prevent the reuniting and growing-up of nanosized NiFe2O4 grains, and 1.5% Ag modified NiFe2O4 sensor has a better sensitivity, up to 43, for acetone gas than 1.5%Ag mixed NiFe2O4 sensor prepared by low-temperature solid-state reaction, at an optimal working voltage of 4.5 V. The quick response time （1 s） and fast recovery time （～10 s） are the main characteristics of this sensor.展开更多
The complex coating on the MgO CaO clinker was prepared by dipping method and adding the second mineral to restrain the formation and expansion of the cracks. Meanwhile, the microstructure and the morphology of the c...The complex coating on the MgO CaO clinker was prepared by dipping method and adding the second mineral to restrain the formation and expansion of the cracks. Meanwhile, the microstructure and the morphology of the coating and hydration resistance of the MgO CaO clinker were also investigated. The result shows that the coating consists mainly of Ca 2P 2O 7, MgO and CaCO 3, its thickness ranges from 5μm to 20μm, and the coating is dense and even, no micro cracks are observed. Also, the coating adheres closely to the matrix. The hydration resistance of the MgO CaO clinker after treatment is improved greatly, and the castables prepared with the treated MgO CaO clinker have better physical properties than MgO castable.展开更多
[Objectives] The aim was to study the contact activity of combination use of garlic,onion and stone calamus extracts on Helicoverpa armigera and their co-toxicity coefficient( CTC) and mixture ratio. [Methods] Leaf di...[Objectives] The aim was to study the contact activity of combination use of garlic,onion and stone calamus extracts on Helicoverpa armigera and their co-toxicity coefficient( CTC) and mixture ratio. [Methods] Leaf dipping method was used to study the contact activity of the three kinds of plant extracts against H. armigera. Based on this,the co-toxicity coefficient of the compound of the three kinds of extracts was determined. Orthogonal test was used to explore the optimal mixture ratio of the three kinds of extract for combination use. [Results]The extracts of garlic,onion and stone calamus had good inhibition and contract activity on H. armigera larvae. The LC50 values of the three kinds of plant extracts against H. armigera were 175. 0,217. 0 and 79. 2 mg/L,respectively. When the mixture ratios of stone calamus to garlic,and stone calamus to onion were both 2:1,the extract showed a synergistic effect( CTC > 120); when the mixture ratios of stone calamus to garlic,and stone calamus to onion were 1:1 and 1:2,respectively,the extracts showed an additive effect( 80 < CTC < 120); and then garlic extract and onion extract were mixed according to the ratio of 1:1,the additive effect was slight( CTC < 90). Among the three kinds of extracts,the extract of stone calamus showed the strongest contact activity,followed by that of garlic. The results of co-toxicity coefficient determination and orthogonal test showed that the contact activity of combination use of the three kinds of extracts was stronger than that of the single extract overall. When the extracts of garlic,onion and stone calamus were mixed according to the ratio of 2:3:1( mass concentration ratio),the contact activity of the compound against H. armigera reached 95. 3%. [Conclusions]The study results provide a scientific basis and theoretical reference for the development of new plant-derived pesticides based on the pharmacodynamics of garlic,onion and stone calamus.展开更多
基金Project (2006BS04035) supported by the Youth Scientific Research Foundation of Shandong Province, China
文摘Nickel ferrite nano-powders were prepared by microwave radiating low-temperature solid-state reaction method, and then modified with Ag by dipping method. The crystal structure and morphology of the samples were characterized by means of X-ray diffraction（XRD）, scanning electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）. The gas sensing properties of the samples were also investigated. The results reveal that the Ag, as amorphous structure, can efficiently prevent the reuniting and growing-up of nanosized NiFe2O4 grains, and 1.5% Ag modified NiFe2O4 sensor has a better sensitivity, up to 43, for acetone gas than 1.5%Ag mixed NiFe2O4 sensor prepared by low-temperature solid-state reaction, at an optimal working voltage of 4.5 V. The quick response time （1 s） and fast recovery time （～10 s） are the main characteristics of this sensor.
文摘The complex coating on the MgO CaO clinker was prepared by dipping method and adding the second mineral to restrain the formation and expansion of the cracks. Meanwhile, the microstructure and the morphology of the coating and hydration resistance of the MgO CaO clinker were also investigated. The result shows that the coating consists mainly of Ca 2P 2O 7, MgO and CaCO 3, its thickness ranges from 5μm to 20μm, and the coating is dense and even, no micro cracks are observed. Also, the coating adheres closely to the matrix. The hydration resistance of the MgO CaO clinker after treatment is improved greatly, and the castables prepared with the treated MgO CaO clinker have better physical properties than MgO castable.
文摘[Objectives] The aim was to study the contact activity of combination use of garlic,onion and stone calamus extracts on Helicoverpa armigera and their co-toxicity coefficient( CTC) and mixture ratio. [Methods] Leaf dipping method was used to study the contact activity of the three kinds of plant extracts against H. armigera. Based on this,the co-toxicity coefficient of the compound of the three kinds of extracts was determined. Orthogonal test was used to explore the optimal mixture ratio of the three kinds of extract for combination use. [Results]The extracts of garlic,onion and stone calamus had good inhibition and contract activity on H. armigera larvae. The LC50 values of the three kinds of plant extracts against H. armigera were 175. 0,217. 0 and 79. 2 mg/L,respectively. When the mixture ratios of stone calamus to garlic,and stone calamus to onion were both 2:1,the extract showed a synergistic effect( CTC > 120); when the mixture ratios of stone calamus to garlic,and stone calamus to onion were 1:1 and 1:2,respectively,the extracts showed an additive effect( 80 < CTC < 120); and then garlic extract and onion extract were mixed according to the ratio of 1:1,the additive effect was slight( CTC < 90). Among the three kinds of extracts,the extract of stone calamus showed the strongest contact activity,followed by that of garlic. The results of co-toxicity coefficient determination and orthogonal test showed that the contact activity of combination use of the three kinds of extracts was stronger than that of the single extract overall. When the extracts of garlic,onion and stone calamus were mixed according to the ratio of 2:3:1( mass concentration ratio),the contact activity of the compound against H. armigera reached 95. 3%. [Conclusions]The study results provide a scientific basis and theoretical reference for the development of new plant-derived pesticides based on the pharmacodynamics of garlic,onion and stone calamus.
