拟南芥中有一类含ARM结构域的蛋白质,研究表明它们中的一些在植物的生长发育和激素应答等方面发挥着重要的作用.在拟南芥突变体筛选中,获得了一个推测编码蛋白含ARM重复序列的新基因突变体lfr(leaf and flower relatedmutant),它在叶子...拟南芥中有一类含ARM结构域的蛋白质,研究表明它们中的一些在植物的生长发育和激素应答等方面发挥着重要的作用.在拟南芥突变体筛选中,获得了一个推测编码蛋白含ARM重复序列的新基因突变体lfr(leaf and flower relatedmutant),它在叶子和花的发育过程中表现出较明显的表型.为进一步研究该基因编码蛋白的生物学功能及其分子作用机制,构建了pGEX-2TGST∶LFR融合蛋白重组表达载体,将重组质粒转化到工程菌中诱导表达菌体蛋白,经SDS-聚丙烯酰胺凝胶电泳检测,结果表明,融合重组蛋白成功获得了高效表达,分子质量在77ku左右.重组蛋白经谷胱甘肽S-转移酶(GST)标签蛋白亲和层析法纯化,SDS-PAGE制备胶割胶富集,电洗脱法纯化后得到纯度较高的抗原.经对新西兰兔进行5次免疫,获得了多克隆抗血清.采用免疫吸附方法对抗血清进行了纯化,结果得到只识别LFR重组蛋白的抗血清.进一步提取拟南芥野生型及突变体的核蛋白,经蛋白质印迹检测,结果显示,在分子质量50ku左右处出现特异的蛋白质条带,证明所制备的抗血清可以与拟南芥LFR蛋白特异性结合.展开更多
土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响...土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响叶和花发育的重要功能基因。本文以lfr功能缺失突变体为实验材料,观察了不同浓度盐处理下的种子萌发、子叶转绿、主根生长及成苗生长表型,结果表明lfr突变体对盐胁迫敏感;定量RT-PCR检测表明在Na Cl处理下,盐胁迫SOS信号通路中的SOS1在lfr中的受诱导程度显著低于野生型,这与lfr突变体盐敏感表型相吻合,可能是导致lfr突变体对盐胁迫敏感的诱因之一。上述结果预示着LFR可能通过调控SOS1基因的转录表达,参与植物对盐胁迫的响应。展开更多
In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed...In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed by University of Science and Technology of China. The flow blockage shall cause a degradation of the heat transfer between the fuel assembly and the coolant potentially,which can eventually result in the clad fusion. An analysis of core blockage accidents in a single assembly is of great significance for LFR. Such scenarios are investigated by using the best estimation code RELAP5. Reactivity feedback and axial power profile are considered. The crosssectional fraction of blockage, axial position of blockage,and blockage-developing time are discussed. The cladding material failure shall be the biggest challenge and shall be a considerable threat for integrity of the fuel assembly if the cross-sectional fraction of blockage is over 94%. The blockage-developing time only affects the accident progress. The consequence will be more serious if the axial position of a sudden blockage is closer to the core outlet.The method of analysis procedure can also be applied to analyze similar transient behaviors of other fuel-type reactors.展开更多
EP-823 steel is one of the candidate materials for accelerator-driven systems/lead-cooled fast reactors （ADS/LFR）. Its weldability was investigated by mechanical property tests and microstructure analysis on the enl...EP-823 steel is one of the candidate materials for accelerator-driven systems/lead-cooled fast reactors （ADS/LFR）. Its weldability was investigated by mechanical property tests and microstructure analysis on the enlarged heat-affected zones （HAZs） made by numerical and physical simulation. The finite element numerical simulation could simulate the welding thermal cycle of the characteristic regions in HAZs with extremely high accuracy, The physical simulation performed on a Gleeble simulator could enlarge the characteristic regions to easily investigate the relationship between the microstructure evolution and the mechanical properties of the HAZs. The results showed that the simulated partially normalized zone comprising tempered martensite, newly formed martensite and more tiny carbides has the highest impact energy. The fully normalized zone exhibits the highest hardness because of the quenched martensite and large carbides. The ductile property of the overheated zone is poor for the residual delta- ferrite phases and the quenched martensite.展开更多
In the present review,parabolic trough collector(PTC)and linear Fresnel reflector(LFR)are comprehensively and comparatively reviewed in terms of historical background,technological features,recent advancement,economic...In the present review,parabolic trough collector(PTC)and linear Fresnel reflector(LFR)are comprehensively and comparatively reviewed in terms of historical background,technological features,recent advancement,economic analysis and application areas.It is found that although PTC and LFR are both classified as mainstream line-focus concentrating solar thermal(CST)technologies,they are now standing at different stages of development and facing their individual opportunities and challenges.For PTC,the development is commercially mature with steady and reliable performance;therefore,extension of application is the main future demand.For LFR,the development is still in rapid progress to commercial maturity,yet indicating very promising potentials with high flexibility in novel designs and remarkable reduction in capital and operational costs.The question,which has to be answered in order to estimate the future perspectives of these two line-focus CST technologies,becomes which of these characteristics carries more weight or how to reach an optimal trade-off between them.展开更多
The fractal property and low frequency Raman scattering of Eu(DBM)3 nanosized microcrystals were investigated. The influence of the fractal structure of Eu(DBM)3 non-crystalline solids on low frequency scattering was ...The fractal property and low frequency Raman scattering of Eu(DBM)3 nanosized microcrystals were investigated. The influence of the fractal structure of Eu(DBM)3 non-crystalline solids on low frequency scattering was studied. It was found that vibrational excitations ou the fractal are localized and can be described in terms of fraction8. It was sliown that reduced Raman scattering intensity is of a power law dependence of the vibrational frequencies for all samples.The fractal and spectraJ dimensiou were also determined, we found that our experimental value was in fair agreement with the theoretical one.展开更多
染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征...染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征尚有待进一步探究.酵母单杂交实验表明,酵母转录因子GAL4的DNA结合域与全长LFR的融合蛋白(GBD-LFR)具有转录辅激活活性,LFR的C端至少有2个犰狳蛋白(ARM)重复结构域及完整N端对于其转录辅激活活性是必需的.但在野生型拟南芥原生质体中,与典型的转录激活因子相比,GBD-LFR的转录辅激活活性并不明显.缺失或突变LFR与黄色荧光蛋白(YFP)的原生质体亚细胞定位的荧光显微观察表明,N端的1～25位氨基酸,特别是其中第22位的赖氨酸和第4、23以及25位精氨酸影响其核定位.利用激光共聚焦显微镜观察共表达黄色或青色荧光(CFP)融合蛋白的细胞核内分布,结果表明LFR与染色质结构蛋白组蛋白H4及染色质结合蛋白HMGA有一定的核内共定位.这些结果表明LFR可能作为一个染色质相关的蛋白质,在拟南芥的生长发育中发挥重要作用.展开更多
文摘拟南芥中有一类含ARM结构域的蛋白质,研究表明它们中的一些在植物的生长发育和激素应答等方面发挥着重要的作用.在拟南芥突变体筛选中,获得了一个推测编码蛋白含ARM重复序列的新基因突变体lfr(leaf and flower relatedmutant),它在叶子和花的发育过程中表现出较明显的表型.为进一步研究该基因编码蛋白的生物学功能及其分子作用机制,构建了pGEX-2TGST∶LFR融合蛋白重组表达载体,将重组质粒转化到工程菌中诱导表达菌体蛋白,经SDS-聚丙烯酰胺凝胶电泳检测,结果表明,融合重组蛋白成功获得了高效表达,分子质量在77ku左右.重组蛋白经谷胱甘肽S-转移酶(GST)标签蛋白亲和层析法纯化,SDS-PAGE制备胶割胶富集,电洗脱法纯化后得到纯度较高的抗原.经对新西兰兔进行5次免疫,获得了多克隆抗血清.采用免疫吸附方法对抗血清进行了纯化,结果得到只识别LFR重组蛋白的抗血清.进一步提取拟南芥野生型及突变体的核蛋白,经蛋白质印迹检测,结果显示,在分子质量50ku左右处出现特异的蛋白质条带,证明所制备的抗血清可以与拟南芥LFR蛋白特异性结合.
文摘土壤盐渍化是影响农作物生长、发育及产量的非生物胁迫之一,对参与盐胁迫响应的功能基因的研究将有助于揭示植物胁迫响应的分子机制。本实验室前期报道的拟南芥LFR(Leaf and Flower Related)是一个表达广泛、编码细胞核定位蛋白、影响叶和花发育的重要功能基因。本文以lfr功能缺失突变体为实验材料,观察了不同浓度盐处理下的种子萌发、子叶转绿、主根生长及成苗生长表型,结果表明lfr突变体对盐胁迫敏感;定量RT-PCR检测表明在Na Cl处理下,盐胁迫SOS信号通路中的SOS1在lfr中的受诱导程度显著低于野生型,这与lfr突变体盐敏感表型相吻合,可能是导致lfr突变体对盐胁迫敏感的诱因之一。上述结果预示着LFR可能通过调控SOS1基因的转录表达,参与植物对盐胁迫的响应。
文摘In this paper, we perform an unprotected partial flow blockage analysis of the hottest fuel assembly in the core of the SNCLFR-100 reactor, a 100 MW_(th) modular natural circulation lead-cooled fast reactor, developed by University of Science and Technology of China. The flow blockage shall cause a degradation of the heat transfer between the fuel assembly and the coolant potentially,which can eventually result in the clad fusion. An analysis of core blockage accidents in a single assembly is of great significance for LFR. Such scenarios are investigated by using the best estimation code RELAP5. Reactivity feedback and axial power profile are considered. The crosssectional fraction of blockage, axial position of blockage,and blockage-developing time are discussed. The cladding material failure shall be the biggest challenge and shall be a considerable threat for integrity of the fuel assembly if the cross-sectional fraction of blockage is over 94%. The blockage-developing time only affects the accident progress. The consequence will be more serious if the axial position of a sudden blockage is closer to the core outlet.The method of analysis procedure can also be applied to analyze similar transient behaviors of other fuel-type reactors.
基金financial support from the National Natural Science Foundation of China(NSFC)under grant No.91226204the Chinese Academy of Science Strategic Pilot Project(The Future of Advanced Nuclear Energy,ADS Evolution System)under grant No.XDA03010304
文摘EP-823 steel is one of the candidate materials for accelerator-driven systems/lead-cooled fast reactors （ADS/LFR）. Its weldability was investigated by mechanical property tests and microstructure analysis on the enlarged heat-affected zones （HAZs） made by numerical and physical simulation. The finite element numerical simulation could simulate the welding thermal cycle of the characteristic regions in HAZs with extremely high accuracy, The physical simulation performed on a Gleeble simulator could enlarge the characteristic regions to easily investigate the relationship between the microstructure evolution and the mechanical properties of the HAZs. The results showed that the simulated partially normalized zone comprising tempered martensite, newly formed martensite and more tiny carbides has the highest impact energy. The fully normalized zone exhibits the highest hardness because of the quenched martensite and large carbides. The ductile property of the overheated zone is poor for the residual delta- ferrite phases and the quenched martensite.
基金The present work is financially supported by National Natural Science Foundation of China(51776196)the Natural Science Foundation of Shaanxi Province(2020JM-048)+2 种基金the Shaanxi Creative Talents Promotion Plan-Technological Innovation Team(2019TD-039)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHD2020-001)Fundamental Research Funds for the Central Universities.
文摘In the present review,parabolic trough collector(PTC)and linear Fresnel reflector(LFR)are comprehensively and comparatively reviewed in terms of historical background,technological features,recent advancement,economic analysis and application areas.It is found that although PTC and LFR are both classified as mainstream line-focus concentrating solar thermal(CST)technologies,they are now standing at different stages of development and facing their individual opportunities and challenges.For PTC,the development is commercially mature with steady and reliable performance;therefore,extension of application is the main future demand.For LFR,the development is still in rapid progress to commercial maturity,yet indicating very promising potentials with high flexibility in novel designs and remarkable reduction in capital and operational costs.The question,which has to be answered in order to estimate the future perspectives of these two line-focus CST technologies,becomes which of these characteristics carries more weight or how to reach an optimal trade-off between them.
文摘The fractal property and low frequency Raman scattering of Eu(DBM)3 nanosized microcrystals were investigated. The influence of the fractal structure of Eu(DBM)3 non-crystalline solids on low frequency scattering was studied. It was found that vibrational excitations ou the fractal are localized and can be described in terms of fraction8. It was sliown that reduced Raman scattering intensity is of a power law dependence of the vibrational frequencies for all samples.The fractal and spectraJ dimensiou were also determined, we found that our experimental value was in fair agreement with the theoretical one.
文摘染色质相关蛋白在真核生物DNA复制、基因转录调控等过程中起着非常重要的作用.前期报道拟南芥叶花相关蛋白(leaf and flower related,LFR)蛋白定位于细胞核中,其缺失突变体在叶、花发育及育性等方面存在着许多表型,但LFR蛋白的自身特征尚有待进一步探究.酵母单杂交实验表明,酵母转录因子GAL4的DNA结合域与全长LFR的融合蛋白(GBD-LFR)具有转录辅激活活性,LFR的C端至少有2个犰狳蛋白(ARM)重复结构域及完整N端对于其转录辅激活活性是必需的.但在野生型拟南芥原生质体中,与典型的转录激活因子相比,GBD-LFR的转录辅激活活性并不明显.缺失或突变LFR与黄色荧光蛋白(YFP)的原生质体亚细胞定位的荧光显微观察表明,N端的1～25位氨基酸,特别是其中第22位的赖氨酸和第4、23以及25位精氨酸影响其核定位.利用激光共聚焦显微镜观察共表达黄色或青色荧光(CFP)融合蛋白的细胞核内分布,结果表明LFR与染色质结构蛋白组蛋白H4及染色质结合蛋白HMGA有一定的核内共定位.这些结果表明LFR可能作为一个染色质相关的蛋白质,在拟南芥的生长发育中发挥重要作用.
