氢气氛下电子辐照对氧化铝特性的影响

处在H2 气氛围下的氧化铝陶瓷受电子辐照时表面电导率会发生变化 ,这在某些应用中是非常重要的。本文采用X射线光电子谱仪对阳极氧化法制备的氧化铝薄膜 (厚度 6 0nm)作了模拟研究。结果表明 ,原制备的样品存在有氧化铝和氢氧化铝 2种化学状态 ,然而 ,经H2 气氛围下荷能电子 (5keV)辐照后 ,部分氢氧化铝态转变为氧化铝态。同时 ,样品表面的C污染将降低约 1个数量级。经上述处理后 。

Hamatophyton from the Late Devonian of Anhui Province,South China and Evolution of Sphenophyllales

Well-preserved specimens of Hamatophyton verticillatum collected from the Upper Devonian （Famennian） Wutong Formation of Chaohu district, Anhui Province, South China, display more complete fertile axes in three orders and multiple divisions. Comparisons indicate that Hamatophyton possibly does not have palmate planate sterile leaves but hook-like linear ones with rare divisions. We propose seven definitive characters of Sphenophyllales： （1） completely whorled lateral organs; （2） sterile leaves; （3） strobili; （4） ＂sporangiophores＂ or stalks with reflexed tips bearing sporangia; （5） three- or four-ribbed primary xylem; （6） exarch maturation of primary xylem; and （7） secondary xylem. The Sphenophyllales probably originated from the Iridopteridales based on similarities in whorled lateral organs, ribbed primary xylem and peripheral protoxylem strands. In transition from Iridopteridales to Sphenophyllales, morphological changes involve partially whorled to completely whorled lateral organs, sterile ultimate appendages to leaves, and fertile ultimate appendages to ＂sporangiophores＂/stalks with bracts; anatomical modifications include configuration and maturation of primary xylem, and presence of secondary xylem.

Changes of smooth muscle contractile filaments in small bowel atresia

AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients(n = 12) were divided into three sections(proximal,atretic and distal).Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers-smooth muscle actin(SMA) and desmin using conventional paraffin sections of the proximal and distal bowel.Small bowel from agematched patients(n = 2) undergoing Meckel's diverticulum resection served as controls.RESULTS:The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue,but the distal bowel was unchanged.Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue.There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel.The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.CONCLUSION:Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.

Chemical Variation in Essential Oils of Salvia Officmalis L, Ecotypes Cultivated in Albania

Salvia officinalis L. was cultivated in different geographic locations of Albania. Sage plants originated from imported seeds and wild Albanian plants. Around 30 chemical compounds were identified in the essential oils of all cultivated sage plants; the latter were found to be very rich in camphen, fl-thujone, a-pinene, eucaliptol, rich to moderate in β-pinene and camphor, and less rich in a-thujone and limonene. Sharp differences in chemical composition patterns and content of individual chemical compounds were noticed between and within cultivation sites. Cultivated sage was poorer in α-thujone versus wild plants. Cultivated sage, of Albanian wild plants origin, was the richest in α-thujone （18.45%） versus imported seeds sage. β-thujone over-dominated α-thujone in all cultivated sage plants. Volatile characters of cultivated sage were indicative of the species but not of the geographic origin of plant material. Variation in essential oils composition and chemical compounds＇ content （biosynthetic pathways） in cultivated sage is related more to the genetic background than the environmental factors. If cultivating sage in Albania, then wild local ecotypes would be best to use as α-thujone is maintained at satisfactory levels, local natural base is preserved, unnecessary hybridization with imported seeds sage is prevented, and are more resistant and cost effective.

A Contrastive Study on Mark Phenomena of English and Chinese Languages

Linguistic marker is a common phenomenon, and there are different levels of markers in various languages. Mark theory was first proposed by the Prague School in 1930s, which is an important principle of language analysis system. The function and meaning of markup languages are mainly pragmatic, which have procedural meaning and no conceptual meaning. Markedness phenomenon is not only the inherent characteristics of language symbols, but also the product of social life and different cultures. Due to the great difference between cultural background and social environment of Chinese and English speaker, thus there are many similarities and differences in the language, society and culture mark. The mark phenomena of English nouns are mainly related to the category of nouns and the opposite nouns. However, Chinese nouns have no strict morphological changes. In this paper, we discuss the theory of mark phenomenon and analyze a contrastive study on mark phenomena of English and Chinese Languages.

Impacts of climate change on the ecotoxicology of chemical contaminants in estuarine organisms

Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuafine species. Estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has hig- hlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on es- tuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and manage- ment capabilities under changing climate conditions [Current Zoology 61 （4）： 641-652, 2015].