TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and th...TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.展开更多
Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active in...Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.展开更多
Grinding requires high specific energy which develops high temperatures at wheel work piece interface. High temperatures impair work piece quality by inducing tensile residual stress, burn, and micro cracks. Control o...Grinding requires high specific energy which develops high temperatures at wheel work piece interface. High temperatures impair work piece quality by inducing tensile residual stress, burn, and micro cracks. Control of grinding temperature is achieved by providing effective cooling and lubrication. Conventional flood cooling is often ineffective due to enormous heat generation and improper heat dissipation. This paper deals with an investigation on using TRIM E709 emulsifier with Al_2O_3 nanoparticles to reduce the heat generated at grinding zone. An experimental setup has been developed for this and detailed comparison has been done with dry, TRIM E709 emulsifier and TRIM E709 emulsifier with Al_2O_3 nanoparticles in grinding EN-31 steel in terms of temperature distribution and surface finish. Results shows that surface roughness and heat penetration were decreased with addition of Al_2O_3 nanoparticles.展开更多
The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow...The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow of sewer block, the drainage networks routing block and the waterlogged areas calculating block. This model can be used for simulating sewer surcharge and calculating area and water depth of waterlogged areas under storm conditions. The best design of rebuilding storm sewer system or combined sewer system can be provided by simulating existing state of built drainage pipeline. The model was used for rebuilding Shenyang drainage works last year, and the good results were obtained.展开更多
基金Supported by the National Key R&D Program of China(2018YFB0605700).
文摘TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.
文摘Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.
文摘Grinding requires high specific energy which develops high temperatures at wheel work piece interface. High temperatures impair work piece quality by inducing tensile residual stress, burn, and micro cracks. Control of grinding temperature is achieved by providing effective cooling and lubrication. Conventional flood cooling is often ineffective due to enormous heat generation and improper heat dissipation. This paper deals with an investigation on using TRIM E709 emulsifier with Al_2O_3 nanoparticles to reduce the heat generated at grinding zone. An experimental setup has been developed for this and detailed comparison has been done with dry, TRIM E709 emulsifier and TRIM E709 emulsifier with Al_2O_3 nanoparticles in grinding EN-31 steel in terms of temperature distribution and surface finish. Results shows that surface roughness and heat penetration were decreased with addition of Al_2O_3 nanoparticles.
文摘The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow of sewer block, the drainage networks routing block and the waterlogged areas calculating block. This model can be used for simulating sewer surcharge and calculating area and water depth of waterlogged areas under storm conditions. The best design of rebuilding storm sewer system or combined sewer system can be provided by simulating existing state of built drainage pipeline. The model was used for rebuilding Shenyang drainage works last year, and the good results were obtained.
