海洋聚磷菌Halomonas YSR-3的除磷特性研究

本论文报道从海洋中分离到的一株聚磷菌的分离、鉴定、在系统发育中的地位、除磷特性、菌体内多磷酸盐颗粒的研究、D-海因酶和核苷二磷酸激酶基因的克隆及序列分析，为海水系统的生物除磷提供部分基础资料。 从黄海海域分离到聚磷菌Halomonas sp. YSR-3，菌体呈杆状，大小为3.5 μm×1 μm，革兰氏阴性，好氧生长，能运动。透射电镜观察发现，菌体内有致密颗粒。经DAPI染色确定该致密颗粒是多磷酸盐，亦可称为异染粒、迂回体。16S rDNA鉴定结果表明，YSR-3与Halomonas属中的marine bacterium B5-7有较高的同源性，相似值99%。YSR-3的生理生化特性：对氯霉素和卡那霉素敏感；淀粉水解呈阳性；反硝化和几丁质降解呈阴性；能将葡萄糖作为唯一碳源和能源。 对YSR-3的培养条件进行优化。以海水2216培养基、24 ℃、180 rpm、pH 6.5的条件培养，更利于菌体生长和菌体内多磷酸盐的形成。 对YSR-3的除磷特性进行研究。无磷培养时，菌体不能生长；用磷酸钾盐作为磷源时，菌体生长较好，形成多磷酸盐的菌体比例较高；较适合YSR-3菌体生长和多磷酸盐形成的磷源是KH2PO4，较适磷浓度为1.5 mmol/L。pH的变化影响菌株的生长、多磷酸盐形成和除磷效果。pH值为5时，菌体的数量几乎不增加，体内多磷酸盐和培养基中磷含量变化不大；pH值为6、7和8时，菌体生长良好，95%以上的菌体内形成多磷酸盐，培养基中磷含量明显下降。YSR-3在不同培养基中除磷量和除磷率不同。在高磷培养基中除磷量为0.7 mmol/L(磷含量由1.84 mmol/L降到1.14 mmol/L)，除磷率为37.5%；在低磷培养基中除磷量为0.02 mmol/L(磷含量由0.028 mmol/L降到0.008 mmol/L)，除磷率为72.2%。 以海洋聚磷菌Halomonas sp. YSR-3的总DNA为模板，用PCR法扩增D-海因酶基因和核苷二磷酸激酶基因，将扩增片段克隆到pGM-T载体，转化E.coli TOP10菌株，经蓝白斑筛选、菌落PCR得到阳性克隆，测序后对序列进行Blast比对分析。得到的D-海因酶基因序列长度为1510 bp，与Pseudomonas entomophila L48的海因酶基因序列的相似性为77%。翻译后的序列与Pseudomonas fluorescens Pf-5，Marinomonas sp. MED121，Burkholderia vietnamiensis G4的海因酶蛋白序列相似性分别为75%，73%，70%。得到的核苷二磷酸激酶基因序列长度为420bp，翻译后的序列与Loktanella vestfoldensis SKA53，Jannaschia sp. CCS1，Roseobacter sp. CCS2的核苷二磷酸激酶蛋白序列相似性分别为89%，86%，85%。 聚磷菌能将外界环境中的磷吸收到体内，并以多磷酸盐的形式储存。多磷酸盐对于细胞的生存和生长有很重要的作用，但目前对于多磷酸盐的形成过程以及过程调控还不是很清楚。在今后可以通过构建高效表达的重组菌，提高与除磷相关的酶的纯度及活性。同时可以将相关酶的基因进行突变，对基因表达的调控以及酶的代谢以及功能结构等多方面进行基础研究，使聚磷菌在生物除磷中得到广泛应用。

3-7岁儿童对情景化习俗道义情境中社会行为的认知发展

Children’s understanding of deontic rules and theory of mind (ToM) were the two research domains for children’s social cognition. It was significant for understanding children’s social cognition to combine the researches in the two domains. Children at 3, 5 and 7years were required to answer three questions according to the stories which happened in children’s familiar context. The three questions were designed to address the three problems:⑴Development of 3-7-Year-old children’s understanding about how the deontic rules were enacted or changed.⑵ Development of 3-7-Year-old children’s understanding about that the deontic rules and the actor’s mental states could impact on his behaviors.⑶ Development of 3-7-Year-old children’s capacity to integrate the deontic rules and mental state to evaluate the actor’s behavior. The results showed that: ① The 3-7-Year-old children had known that deontic rules were established by the authority’s speech act. But there were still some irrelevant factors which influenced the children’s judgments, such as the authority’s desire. ② The children gradually recognized the relationship between actors should do something and they will do the same thing. 3-year-old children could recognize such relationship in a way, but their predictions were usually influenced by some irrelevant factors. The children at 5 and 7 years old understood this relationship more steady. ③ In deontic context, more and more children predicted the actors’ behaviors according to the actors’ mental states as they grown up. The ratio that the 3-7-Year-old children predicted the actors’ behavior according to their false belief about the deontic rules was smaller in deontic context compared with the children’s performance in traditional false belief task. This maybe indicated that the deontic context influenced the children’s inference stronger than the physical context. ④ When they could get the actors’ desires and the deontic rules, all the children could predict the actors’ behaviors according to their desires, but not the deontic rules. It meant that all the children could understand that the actors’ desire mediated between the deontic rules and their behaviors. But when the actors wanted to transgress the deontic rules, all the children’s predications became less accurate. ⑤ When they assigned criticism, more and more children could discriminate different behaviors as a result of diverse mental states although they all transgressed the deontic rules. But the most part of children overweighed the deontic rules but overlooked the actors’ mental state about the deontic rules; their criticism to behaviors which transgressed the deontic rules just differ in quantity according to diverse mental states, that is: if the actors known the rules or want to transgress the rules, then punished more, and if the actors didn’t know the rules or transgress the rules accidentally, then punished a little.

5-9岁儿童对常见病病因及其致病不确定性的认知发展

Research on children's naive concepts has previously tended to focus on the domains of physics and psychology, but more recently attention has turned to conceptual development in biology as a core domain of knowledge. Because of its familiarity, illness has been a popular topic for researchers in this domain. However, they have only studied the children’s understanding of its causes. Other aspects of illness, such as treatment and prognosis, have received little attention. This research addresses the development of 5- to 9-year-old children’s understanding of the causes of illness and their probabilities via open-ended and forced choice interviews. The results of this research are: 1) Most of the 5- to 7-year-old children used behavioral causes to explain illness, and the 9-year-old children primarily used biological causes to interpret illness. With age, more and more children selected psychological causes to explain illness. 2) Pre-school children did not over-generalize contagions to non-contagious illnesses. They used behavioral and biological causes to explain contagious illnesses. For non-contagious illnesses, they chose only behavioral causes. 3) Most of the children used only one kind of cause to explain illness. 4) Some preschool-aged children viewed outcomes of familiar causes of illness as probabilistic. With age, more and more could make uncertain predictions of illness. 5) The children’s understanding of the causes’ probabilities appeared to be based on naïve biology. 5- to 9-year-old children often made probabilistic predictions by analyzing a single cause of illness. 6) Children coming from higher educational backgrounds outperformed their counterparts coming from lower educational backgrounds with respect to understanding illness. 7) Specific knowledge acquired could generally improved the preschoolers’ understanding of causes of illness and their probabilities.

Butene catalytic cracking to propene and ethene over potassium modified ZSM-5 catalysts

Catalytic cracking of butene over potassium modified ZSM-5 catalysts was carried out in a fixed-bed microreactor. By increasing the K loading on the ZSM-5, butene conversion and ethene selectivity decreased almost linearly, while propene selectivity increased first, then passed through a maximum (about 50% selectivity) with the addition of ca. 0.7-1.0% K, and then decreased slowly with further increasing of the K loading. The reaction conditions were 620 degrees C, WHSV 3.5 h(-1), 0.1 MPa 1-butene partial pressure and 1 h of time on stream. Both by potassium modification of the ZSM-5 zeolite and by N(2) addition in the butene feed could enhance the selectivity towards propene effectively, but the catalyst stability did not show any improvement. On the other hand, addition of water to the butene feed could not only increase the butene conversion, but also improve the stability of the 0.7%K/ZSM-5 catalyst due to the effective removal of the coke formed, as demonstrated by the TPO spectra. XRD results indicated that the ZSM-5 structure of the 0.07% K/ZSM-5 catalyst was not destroyed even under this serious condition of adding water at 620 degrees C.