太阳反射镜(Optical Solar Reflector,OSR)是应用较为广泛的航天器热控器件,通常粘贴在舱板外侧,若胶粘过程排气不畅,玻璃型OSR在热真空环境下可能发生碎裂。文章建立了胶层含气泡的OSR片分析模型并进行力学理论推导,揭示了温度、压强...太阳反射镜(Optical Solar Reflector,OSR)是应用较为广泛的航天器热控器件,通常粘贴在舱板外侧,若胶粘过程排气不畅,玻璃型OSR在热真空环境下可能发生碎裂。文章建立了胶层含气泡的OSR片分析模型并进行力学理论推导,揭示了温度、压强、结构尺寸及材料强度等因素对OSR片碎裂现象的耦合作用机理。基于OSR片的弯曲强度试验,绘制了适用于工程应用的OSR片碎裂相图,对不同OSR片厚度对碎裂现象的影响进行比较。基于OSR片真空碎裂试验,提出了OSR碎片脱离速度的理论上限。根据航天器全寿命期任务剖面,定量分析了OSR片的环境适应性。研究表明,胶层厚度减薄有利于降低碎片率,OSR片厚度减薄提升了其对气泡缺陷的敏感性,经历地面热试验筛选的OSR片在后续任务环境不会发生新的碎裂。本研究工作有望为航天器胶粘薄膜脆性器件的真空碎裂问题提供解决思路。展开更多
Osr1(odd-skipped related 1)基因编码一个锌指转录因子,在小鼠及人类的早期胚胎中随着发育在胚胎中呈动态模式表达,是间介中胚层最早发现的标记基因。研究表明,Osr1在胃癌细胞系中优先甲基化而表达减少或被沉默,发挥肿瘤抑制因子作用,...Osr1(odd-skipped related 1)基因编码一个锌指转录因子,在小鼠及人类的早期胚胎中随着发育在胚胎中呈动态模式表达,是间介中胚层最早发现的标记基因。研究表明,Osr1在胃癌细胞系中优先甲基化而表达减少或被沉默,发挥肿瘤抑制因子作用,并与胃癌的不良预后相关,有可能为作为早期胃癌的筛查指标和预后评估依据。Osr1在其他肿瘤中的作用机制尚未完全明了。展开更多
The promoter region of a drought and abscisic acid （ABA） inducible gene, osr40c1, was isolated from a salt-tolerant indica rice variety Pokkali, which is 670 bp upstream of the putative translation start codon. In ...The promoter region of a drought and abscisic acid （ABA） inducible gene, osr40c1, was isolated from a salt-tolerant indica rice variety Pokkali, which is 670 bp upstream of the putative translation start codon. In silico promoter analysis of resulted sequence showed that at least 15 types of putative motifs were distributed within the sequence, including two types of common promoter elements, TATA and CAAT boxes. Additionally, several putative cis-acing regulatory elements which may be involved in regulation of osr40c1 expression under different conditions were found in the 5′-upstream region of osr40c1. These are ABA-responsive element, light-responsive elements （ATCT-motif, Box I, G-box, GT1-motif, Gap-box and Sp1）, myeloblastosis oncogene response element （CCAAT-box）, auxin responsive element （TGA-element）, gibberellin-responsive element （GARE-motif） and fungal-elicitor responsive elements （Box E and Box-W1）. A putative regulatory element, required for endosperm-specific pattern of gene expression designated as Skn-1 motif, was also detected in the Pokkali osr40c1 promoter region. In conclusion, the bioinformatic analysis of osr40c1 promoter region isolated from indica rice variety Pokkali led to the identification of several important stress-responsive cis-acting regulatory elements, and therefore, the isolated promoter sequence could be employed in rice genetic transformation to mediate expression of abiotic stress induced genes.展开更多
采用激光切割方法对OSR(Optical Solar Reflector)片的制造工艺进行了试验研究,分析了激光切割OSR片的可行性及切割参数对加工质量的影响因素,通过试验数据的理论分析,建立了OSR片激光切割的数学模型,得到了切割宽度与切割功率及切割速...采用激光切割方法对OSR(Optical Solar Reflector)片的制造工艺进行了试验研究,分析了激光切割OSR片的可行性及切割参数对加工质量的影响因素,通过试验数据的理论分析,建立了OSR片激光切割的数学模型,得到了切割宽度与切割功率及切割速度之间的关系,为实际应用提供了理论依据.展开更多
A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the...A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.展开更多
文摘太阳反射镜(Optical Solar Reflector,OSR)是应用较为广泛的航天器热控器件,通常粘贴在舱板外侧,若胶粘过程排气不畅,玻璃型OSR在热真空环境下可能发生碎裂。文章建立了胶层含气泡的OSR片分析模型并进行力学理论推导,揭示了温度、压强、结构尺寸及材料强度等因素对OSR片碎裂现象的耦合作用机理。基于OSR片的弯曲强度试验,绘制了适用于工程应用的OSR片碎裂相图,对不同OSR片厚度对碎裂现象的影响进行比较。基于OSR片真空碎裂试验,提出了OSR碎片脱离速度的理论上限。根据航天器全寿命期任务剖面,定量分析了OSR片的环境适应性。研究表明,胶层厚度减薄有利于降低碎片率,OSR片厚度减薄提升了其对气泡缺陷的敏感性,经历地面热试验筛选的OSR片在后续任务环境不会发生新的碎裂。本研究工作有望为航天器胶粘薄膜脆性器件的真空碎裂问题提供解决思路。
文摘Osr1(odd-skipped related 1)基因编码一个锌指转录因子,在小鼠及人类的早期胚胎中随着发育在胚胎中呈动态模式表达,是间介中胚层最早发现的标记基因。研究表明,Osr1在胃癌细胞系中优先甲基化而表达减少或被沉默,发挥肿瘤抑制因子作用,并与胃癌的不良预后相关,有可能为作为早期胃癌的筛查指标和预后评估依据。Osr1在其他肿瘤中的作用机制尚未完全明了。
文摘The promoter region of a drought and abscisic acid （ABA） inducible gene, osr40c1, was isolated from a salt-tolerant indica rice variety Pokkali, which is 670 bp upstream of the putative translation start codon. In silico promoter analysis of resulted sequence showed that at least 15 types of putative motifs were distributed within the sequence, including two types of common promoter elements, TATA and CAAT boxes. Additionally, several putative cis-acing regulatory elements which may be involved in regulation of osr40c1 expression under different conditions were found in the 5′-upstream region of osr40c1. These are ABA-responsive element, light-responsive elements （ATCT-motif, Box I, G-box, GT1-motif, Gap-box and Sp1）, myeloblastosis oncogene response element （CCAAT-box）, auxin responsive element （TGA-element）, gibberellin-responsive element （GARE-motif） and fungal-elicitor responsive elements （Box E and Box-W1）. A putative regulatory element, required for endosperm-specific pattern of gene expression designated as Skn-1 motif, was also detected in the Pokkali osr40c1 promoter region. In conclusion, the bioinformatic analysis of osr40c1 promoter region isolated from indica rice variety Pokkali led to the identification of several important stress-responsive cis-acting regulatory elements, and therefore, the isolated promoter sequence could be employed in rice genetic transformation to mediate expression of abiotic stress induced genes.
基金supported by National and Fujian Provincial Natural Science Foundation(No.31371557 and K55NI921A)Fujian Provincial Department of Education Project(K58MLV03A)a startup fund from Fujian Agriculture and Forestry University(http://www.fafu.edu.cn/)to X.S
文摘A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.
