学习动机是指直接推动学生进行学习的一种内部动力,是激励和指引学生进行学习的一种需要。特殊儿童由于自身的某些特殊性给学习造成了不利的影响,因而,激发特殊儿童的学习动机就具有了特殊的意义。美国佛罗里达州立大学John M Keller教...学习动机是指直接推动学生进行学习的一种内部动力,是激励和指引学生进行学习的一种需要。特殊儿童由于自身的某些特殊性给学习造成了不利的影响,因而,激发特殊儿童的学习动机就具有了特殊的意义。美国佛罗里达州立大学John M Keller教授创立的ARCS(Attention,Relevence,Confidence,Satisfaction)动机模式,简单实用,引起世人好感。本文就ARCS动机模式在特殊教育中的应用作些探讨。展开更多
The peel color of fruit is an important commercial trait in cucumber, but the underlying molecular basis is largely unknown. A mutant showing light green exocarp was discovered from ethyl methane sulfonate （EMS） mut...The peel color of fruit is an important commercial trait in cucumber, but the underlying molecular basis is largely unknown. A mutant showing light green exocarp was discovered from ethyl methane sulfonate （EMS） mutagenized cucumber line 406 with dark green exocarp. Genetic analysis showed the mutant phenotype is conferred by a single recessive gene, here designated as lgp （light green peel）. By re-sequencing of bulked segregants, we identified the candidate gene Csa7Go51430 encoding ACCUMULATION AND REPLICATION OF CHLOROPLASTS 5 （ARCS） that plays a vital role in chloroplast division in Arabidopsis. A single nucleotide polymorphism （SNP） causing amino acid alteration in the conserved GTPase domain of Csa7Go5143o showed co-segregation with the altered phenotype. Furthermore, the transient RNA interference of this gene resulted in reduced number and enlarged size of chloroplasts, which were also observed in the Igp mutant. This evidence supports that the non-synonymous SNP in Csa7G051430 is the causative mutation for the light green peel. This study provides a new allele for cucumber breeding for light green fruits and additional resource for the study of chloroplast development.展开更多
The Einstein ring is usually explained in the framework of the gravitational lens. Conversely here we apply the framework of the expansion of a superbubble (SB) in order to explain the spherical appearance of the ring...The Einstein ring is usually explained in the framework of the gravitational lens. Conversely here we apply the framework of the expansion of a superbubble (SB) in order to explain the spherical appearance of the ring. Two classical equations of motion for SBs are derived in the presence of a linear and a trigonometric decrease for density. A relativistic equation of motion with an inverse square dependence for the density is derived. The angular distance, adopting the minimax approximation, is derived for three relativistic cosmologies: the standard, the flat and the wCDM. We derive the relation between redshift and Euclidean distance, which allows fixing the radius of the Einstein ring. The details of the ring are explained by a simple version of the theory of images.展开更多
文摘学习动机是指直接推动学生进行学习的一种内部动力,是激励和指引学生进行学习的一种需要。特殊儿童由于自身的某些特殊性给学习造成了不利的影响,因而,激发特殊儿童的学习动机就具有了特殊的意义。美国佛罗里达州立大学John M Keller教授创立的ARCS(Attention,Relevence,Confidence,Satisfaction)动机模式,简单实用,引起世人好感。本文就ARCS动机模式在特殊教育中的应用作些探讨。
基金supported by funding from the National Natural Science Foundation of China(NSFC:31225025)the National Program on Key Basic Research Projects in China(The 973 Program:2012CB113900)+2 种基金the National High Tech Research Development Program in China(The 863 Program:2010AA10A108,2012AA100101)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)the Chinese Ministry of Finance(1251610601001)
文摘The peel color of fruit is an important commercial trait in cucumber, but the underlying molecular basis is largely unknown. A mutant showing light green exocarp was discovered from ethyl methane sulfonate （EMS） mutagenized cucumber line 406 with dark green exocarp. Genetic analysis showed the mutant phenotype is conferred by a single recessive gene, here designated as lgp （light green peel）. By re-sequencing of bulked segregants, we identified the candidate gene Csa7Go51430 encoding ACCUMULATION AND REPLICATION OF CHLOROPLASTS 5 （ARCS） that plays a vital role in chloroplast division in Arabidopsis. A single nucleotide polymorphism （SNP） causing amino acid alteration in the conserved GTPase domain of Csa7Go5143o showed co-segregation with the altered phenotype. Furthermore, the transient RNA interference of this gene resulted in reduced number and enlarged size of chloroplasts, which were also observed in the Igp mutant. This evidence supports that the non-synonymous SNP in Csa7G051430 is the causative mutation for the light green peel. This study provides a new allele for cucumber breeding for light green fruits and additional resource for the study of chloroplast development.
文摘The Einstein ring is usually explained in the framework of the gravitational lens. Conversely here we apply the framework of the expansion of a superbubble (SB) in order to explain the spherical appearance of the ring. Two classical equations of motion for SBs are derived in the presence of a linear and a trigonometric decrease for density. A relativistic equation of motion with an inverse square dependence for the density is derived. The angular distance, adopting the minimax approximation, is derived for three relativistic cosmologies: the standard, the flat and the wCDM. We derive the relation between redshift and Euclidean distance, which allows fixing the radius of the Einstein ring. The details of the ring are explained by a simple version of the theory of images.
