物质跨膜转运机制及最新研究进展

质膜对物质的通透性由膜和物质本身的属性来决定,脂溶性和分子直径不同的物质通过不同方式实现跨膜转运。本文综述了特跨膜转运的几种机制及春最新研究进展情况。     

Removal of Organic Acids from Indoor Air in Museum Storage Rooms by Active and Passive Sorption Techniques

ABSTRACT

Adsorbent materials can be used for the removal of organic acids from air in storage rooms with heritage collections. The organic acid removal efficiency of two commercially available activated carbon air-filters were tested in situ in two unoccupied stores with densely packed collections. One filter was designed for outdoor type pollutants (Filter A), while the other was designed for organic acids in indoor air (Filter B). Furthermore, the acetic acid removal efficiency of a desiccant silica gel rotor used for dehumidification was measured in a laboratory at different relative humidity levels. Finally, passive removal of acetic acid by silica gel and unfired clay brick were tested in a chamber, and for clay brick at room level as well. Filter B had the highest removal efficiency. The removal efficiency of both filter types depended on the airflow and the filter performance varied considerably in situ from the values reported from standard laboratory tests. Increasing the filter airflow reduced the removal efficiency from 77% and down to 7% for Filter A, and from 92% to 24% for Filter B. There was almost no effect of active air filtration on the concentration of organic acids when this was measured in the middle and in the corner of the storage rooms away from the ventilation inlets. The desiccant dehumidifier removed 98–100% of the acetic acid from the air, independently of the relative humidity. The desiccant rotor will, however, only be running when there is a need for dehumidification and as a result will only periodically remove pollutants. The high acid removal efficiency by dry silica gel was furthermore demonstrated in a chamber test. A clay brick wall in a test room established a concentration gradient across the room and reduced the concentration of organic acids by 56% compared to close to the emission source.     

与预设有关的歧义

与预设有关的歧义是句子中某个成分能同时引发两个相同性质的预设而使句子及其某些成分的意义有分歧的现象，能引发分歧性预设的成分主要是一些有[ 重复／界限]意义特征的副词，方位词，数量词等。前一种成分形成歧义的条件是句子重复性动作行为涉及的人或事物在事件中可以同几个其他人或事物构成相对地位，相对状态，后一种成分形成歧义的条件是范围或界限涉及的人或事物在事件中有特指与例指两种可能。     

英语词汇教学探讨

词汇教学是英语教学中的一个重要环节,但往往被教师所忽略。如何有效地进行词汇教学是教师面临的一个课题。方法得当,则事半功倍。     

英汉语被动式的比较与翻译

英语被动式在使用场合和主题意义上有一定的相似性 ,但在表达意义、应用范围及表达形式三个方面存在较大的差异。在翻译英语被动句时 ,不能一一对应地硬译为汉语被动句 ;而应根据具体情况 ,充分考虑英汉语特点 ,适当转换形式 ,使译文通顺达意 ,避免翻译腔     

中专学生的消极心理及其防治

归纳列举了中专学生消极心理的几种表现,提出了防治的措施。     

试论英语被动态与汉语被动句之差异

英汉两种语言中表示主语和谓语之间的关系都要借助主动或被动这组语法形式和手段。但同一语法术语在这两种语言中所代表的内容不会完全相同。在英语中 ,有语态语法范畴 ,故有主动和被动语态之分 ,其被动语态的标记为be + -en ;而在汉语中因缺乏语态范畴 ,也就无所谓被动语态和主动语态之分。在动词谓语句中 ,如果主语是动作或行为的受事者 ,句子就是被动句。本文主要分析两种被动句的不同之处 ,以求从这一侧面来进行英汉对比。     

工程结构振动控制技术与发展

随着社会的发展,人们对建筑结构的性能提出了更高的要求,如发射塔的抗震要求、高层建筑中居住者的舒适感和抗震安全性的要求等。这些实际需求促进了对建筑结构控制的研究,其中,结构振动控制已成为目前结构工程学科中的一个十分活跃的研究领域。     

结果补语的语义指向分析

汉语动结式的语法结构复杂多样,结果补语的语义指向也有多种情况：既可以指向主语,谓语、宾语等核心成分,也可以指向动作发生的处所,凭借的材料,工具等非核心成分。由于动结式自身的性质,它与其后成分间的关系不同,还会出现语义指向的歧义现象。     

The South China Sea is not a mini-Atlantic: plate-edge rifting vs intra-plate rifting

The South China Sea, as ‘a non-volcanic passive margin basin’ in the Pacific, has often been considered as a small-scale analogue of the Atlantic. The recent ocean drilling in the northern South China Sea margin found, however, that the Iberian model of non-volcanic rifted margin from the Atlantic does not apply to the South China Sea. In this paper, we review a variety of rifted basins and propose to discriminate two types of rifting basins: plate-edge type such as the South China Sea and intra-plate type like the Atlantic. They not only differ from each other in structure, formation process, lifespan and geographic size, but also occur at different stages of the Wilson cycle. The intra-plate rifting occurred in the Mesozoic and gave rise to large oceans, whereas the plate-edge rifting took place mainly in the mid-Cenozoic, with three-quarters of the basins concentrated in the Western Pacific. As a member of the Western Pacific system of marginal seas, the South China Sea should be studied not in isolation on its origin and evolution, but in a systematic context to include also its neighboring counterparts.