Greenhouse Effects in Global Warming based on Analogical Reasoning

Using an analogy in science and everyday life is a double-edged sword because they are accompanied by alternative ideas, in addition to scientific concepts. Schools and public education explain global warming by making a common analogy between this phenomenon and greenhouse effects (Chen in Philos Cogn Sci 105–114, 2012). Unfortunately, this analogy sometimes produces various incorrect explanatory mental models. To construct a correct understanding of global warming, it is necessary: first, to investigate the attributes of analogical reasoning; second, to understand these features by restructuring the greenhouse analogy; and third, to explore the problems and benefits of the greenhouse analogy. The characteristics of relations, rather than objects, must be mapped according to the principle of systematicity, but the public tends to preserve the attributes of the base domain, which is mapped relatively easily. In conclusion, certain facets of the prevailing greenhouse analogy cause a distorted public view of climate change. We must use the greenhouse analogy and yet simultaneously emphasize the relations and attributes highlighted and hidden in the analogy during evaluation.     

Germline-specific dgcr8 knockout in zebrafish using a BACK approach

Zebrafish is an important model to study developmental biology and human diseases. However, an effective approach to achieve spatial and temporal gene knockout in zebrafish has not been well established. In this study, we have developed a new approach, namely bacterial artificial chromosome-rescue-based knockout (BACK), to achieve conditional gene knockout in zebrafish using the Cre/loxP system. We have successfully deleted the DiGeorge syndrome critical region gene 8 (dgcr8) in zebrafish germ line and demonstrated that the maternal-zygotic dgcr8 (MZdgcr8) embryos exhibit MZdicer-like phenotypes with morphological defects which could be rescued by miR-430, indicating that canonical microRNAs play critical role in early development. Our findings establish that Cre/loxP-mediated tissue-specific gene knockout could be achieved using this BACK strategy and that canonical microRNAs play important roles in early embryonic development in zebrafish.     

Mouse ooplasm confers context-specific reprogramming capacity

Enucleated oocytes have the distinctive ability to reprogram somatic nuclei back to totipotency. Here, we investigate genome-scale DNA methylation patterns after nuclear transfer and compare them to the dynamics at fertilization. We identify specific targets for DNA demethylation after nuclear transfer, such as germline-associated promoters, as well as unique limitations that include certain repetitive element classes.     

多酸衍生物非线性光学性质的理论研究新进展

近年来,分子基非线性光学材料因其优异的非线性光学特性受到了人们集中的关注,多金属氧酸盐具有多样的结构和良好的电子性质,作为优良的无机构筑模块参与到分子设计中,可以获得有较好应用前景的非线性光学材料.本文在微结构非线性光学材料方面综合概述了Keggin型和Lindqvist型多酸衍生物类非线性光学材料的理论研究及分子设计进展.     

几种植物分生组织细胞高尔基体的超微结构

应用电镜观察石刁柏胚芽、水仙幼叶、根尖和甜菊愈伤组织等分生细胞高尔基体、液泡以及内质网和细胞壁之间的联系,在高尔基体的形成面,由内质网芽生的运输小泡,分布于高尔基潴泡周围,高尔基潴泡末端扩大发展形成高尔基液泡,在分生细胞的大小液泡,是由高尔基潴泡末端扩大形成的,这些液泡合并形成中央液泡.在细胞壁的形成过程中,高尔基小泡沿着细胞壁边缘转移,并且与质膜融合。     

马来眼子菜抑制藻类增长及其抑制系数的计算

不同处理的马来眼子菜种植术培养藻类所得的结果证明抑藻物质及其效应的存在，并且各处理的藻类最大数量与马来眼子菜生物量及其种植时间有显著的负的幂函数关系．按照Ｌｏｔｋａ－Ｖｏｌｔｅｒｒａ模型求得水草对藻类的抑制系数ａ．去根水草与留根水草的试验有相似的结果．     

铁铬铝合金晶粒长大及合金中稀土元素

研究了不同稀土含量铁铬铝合金,在高温下晶粒长大及界面结构。结果表明:在1200℃以上高温,稀土组元(以La为主)对抑制合金的晶界长大有一定效果,La_2O_3可作为TiN相析出的形核中心,细小TiN质点可在晶界上出现,阻碍晶界迁移;在变温过程中,La向界而扩散,在晶界以La_2O_3形式出现,同时稀土加速氧穿过氧化膜向基体中渗透,导致Al_2O_3及La_2O_3在基体中形成。     

机械设计中的模糊规划模型及其解法

本文应用 Fuzzy 集理论,描述了机械设计中的模糊现象。提出了机械设计的 Fuzzy 最优化方法。并进一步论证了 Fuzzy 最优化可转化为普通规划问题。通过实例计算,证明了本文提出的方法是有效的。     

Edaphic factors determining variation of two ecotypes of Leymus chinensis in North China

Leymus chinensis(Trin.) Tzvel .is a type ofperennial ,rhizome grass with biological andecologicalproperties of resisting drought , poor-nutrient andsalt-alkaline stress .L. chiensiscan adapt to manycomplicated habitats due toits highecological plastici-ty.L. chinensisis always distributed as scatteredpatches with either grey-green or yellow-greenleaves. Steppe dominated by this species is widelydistributed at the eastern end of the Eurasian steppezone. Its main locations in China are the Son…