lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-ti...lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction （qPCR） provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin （ACT）, α-tubulin （TUA）, β-tubulin （TUB）, ubiquitin （UBI）, 18S rRNA （18S） and one target gene, diacylglycerol acyltransferase （DGAT）, were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed 1. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experi- mental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expres- sion under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of/. zhangfiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.展开更多
In order to produce the high quality optical aspheric lens,the shrinkage of lens should be strictly controlled during the injection process.Serials of experiments are done to find the factors that affect the lens shri...In order to produce the high quality optical aspheric lens,the shrinkage of lens should be strictly controlled during the injection process.Serials of experiments are done to find the factors that affect the lens shrinkage during the injection molding process.The study is focused on the effect of gate size,packing time and pressure on the shrinkage.The gate size decides the effective packing time.Only when the effective packing time is enough,the shrinkage size will be decreased along with the packing pressure increased.However the packing time is determined by the gate size.But big gate size is not easily to be cut and the cutting difficulty will cause the part quality problems.The experiments show that packing pressure not only determines the part shrinkage size and also affects the part shrinkage uniformity.When the packing pressure is more than a critical one,the effect of packing pressure on the shrinkage size becomes smaller.And the shrinkage uniformity is guaranteed.展开更多
As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the ...As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,e.g.by reducing the diameter of the boiler,the thickness of its wall is also reduced.The attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler components.The basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.展开更多
基金supported by the Hundred Talent Program of the Chinese Academy of Sciences (No.A1097)National High Technology Research and Development Program ‘863’ (2012AA052101)+2 种基金Liaoning Provincial Natural Science Foundation (2012010263)Knowledge Innovation Programs of Dalian Institute of Chemical Physics,CAS (K2010A13)China Postdoctoral Science Foundation Funded Project (2014M551139)
文摘lsochrysis zhangfiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under ni- trogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction （qPCR） provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin （ACT）, α-tubulin （TUA）, β-tubulin （TUB）, ubiquitin （UBI）, 18S rRNA （18S） and one target gene, diacylglycerol acyltransferase （DGAT）, were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed 1. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experi- mental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expres- sion under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of/. zhangfiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.
文摘In order to produce the high quality optical aspheric lens,the shrinkage of lens should be strictly controlled during the injection process.Serials of experiments are done to find the factors that affect the lens shrinkage during the injection molding process.The study is focused on the effect of gate size,packing time and pressure on the shrinkage.The gate size decides the effective packing time.Only when the effective packing time is enough,the shrinkage size will be decreased along with the packing pressure increased.However the packing time is determined by the gate size.But big gate size is not easily to be cut and the cutting difficulty will cause the part quality problems.The experiments show that packing pressure not only determines the part shrinkage size and also affects the part shrinkage uniformity.When the packing pressure is more than a critical one,the effect of packing pressure on the shrinkage size becomes smaller.And the shrinkage uniformity is guaranteed.
文摘As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy system.To shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,e.g.by reducing the diameter of the boiler,the thickness of its wall is also reduced.The attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler components.The basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.
