摘要：ｗｈｅｎ的用法浅谈张继文，徐敬全ｗｈｅｎ在英语里是一个常用词，用法较多，而且有的不太容易掌握。有的词典先是介绍ｗｎｅｎ当“副词、连词……”用时，作“什么时候”、“当……时”、……解，接着就列举一些实例；而有的语法书只是介绍ｗｎｅｎ作“什么时候”、“引...

摘要：在英语中，ｂｅｆｏｒｅ是一种常见的从属连词。它可用来引导一个时间状语从句，其语法功能虽然简单，但由于英汉语言表达的习惯不同，当把它用在不同的语言情景或不同的句子中时，其汉译也可以是多种多样的。现将ｂｅｆｏｒｅ作从属连词的几种译法列举如下，仅供读者参考...

摘要：目的:研究TGFβ1、BMP-2、b FGF、IGF、BMP-7、ASA、Dex七种因素在滑膜间充质干细胞向透明软骨分化中起的作用。方法:酶消化法、有限稀释法获得滑膜间充质干细胞,并诱导其向脂肪细胞、软骨细胞和骨细胞分化。正交实验中纳入TGFβ1、BMP-2、b FGF、IGF、BMP-7、As A、Dex七种因素。通过SPSS22.0统计软件设计L8(27)正交实验及表头,定义2水平条件。结果:滑膜间充质干细胞在成骨、成脂、成软骨分化后分别进行油红染色、碱性磷酸酶染色、甲苯胺蓝染色,染色结果均呈现为阳性。正交实验中直观观察、主体间方差分析显示TGFβ1作用最强。结论:滑膜间充质干细胞能够成功诱导向各种组织细胞分化,TGFβ1是七种因素中作用最明显的一种。

摘要：In order to investigate characteristics of nitrogen use efficiency of CMS line Rong 18A, four hybrid rice combinations （Rong18 You188, Rong18 You198, Rong18 You662, Rong18 You908） derived from CMS line Rong 18A were used as experimental materials with Ⅱ You838 and Gangyou725 as controls. A split-plot experimental design was performed with four nitrogen fertilizer application rates to analyze the effects of different nitrogen fertilizer application rates on the yield and yield component factors of rice. The results showed that nitrogen fertilizer could significantly increase effective panicle number to improve rice yield. The increment in rice yield per unit nitrogen fertilizer application rate demonstrated a descending trend with the increase of nitrogen fertilizer application rate. Under low nitrogen levels, hybrid rice combinations derived from Rong 18A exhibited relatively high nitrogen use efficiency and showed remarkably high nitrogen use efficiency under low nitrogen levels.