The genesis and environmental significance of red and black sedimentary interlayers in coral reef of well Nanyong 2

The results of paleogeomagnetics and geochemistry of the coral reef in well Nanyong 2 of Nansha Islands showed that the bottom of the black sedimentary interlayer corresponds to the conversion boundary line between Brunhes Postive Polarity and Matuyama Reversed Polarity (B/M) and the cold/warm (19/20) climatic conversion bounds on δ¹⁸O curve, 0.78 Ma ago; and the red sedimentary interlayer corresponds to the ReunionⅠpolarity excursion (reversion) of the geomagnetic field, 2.01—2.04 Ma ago. Comparing with the normal light-coloured coral reef rock, the magnetic susceptibility (c), residual magnetization intensity (Mr) and the content of MnO and Fe₂O₃ of the black sedimentary layer appeared obviously positive abnormity. The magnetic susceptibility (c), residual magnetization intensity (Mr) and the content of Fe₂O₃ of the red sedimentary layer also appeared positive abnormity. Combining with the analyzing results of paleontology, we hold that this pair of special and typical sedimentary interlayers was relative to the sudden change of paleoclimate, i.e. the global climatic change and its incidental polarity reversal of the geomagnetic field directly affected the living environment of the paleontological species as well as the dispersion and enrichment of some chemical elements, especially the elements sensitive to redox such as Fe and Mn. For example, the elements Fe and Mn concentrated in the glacial period would be largely oxidized and diluted when the climate warmed up suddenly, and the originally oxidized high valence Fe would be condensed again when the climate cooled suddenly. This is possibly one of the important reasons of appearing and disappearing of the red and black sedimentary events of coral reef in well Nanyong 2.     

The ecological sequence of Hipparion fauna in the mid-dle reaches of the Yellow River during Neogene

The faunal ecological type and sequence in the Tertiary red clay indicate that Hipparion fauna during the period 7.4-6.1 Ma in the middle reaches of the Yellow River is composed mainly of dorcadoides and mixed types. This represents semiarid veld environment with small fluctuation. The fossil assemblages characterized by the abundance of gaudryi types and even the occurrence of some Hominoid and Chalicotherium indicate an obviously warm and humid period since 5.3 Ma. The fossil assemblages during 3.4 Ma show the typical steppe fauna representing dry climate. It is indicated by the changes of ecological sequence that the climatic conditions in Pliocene are drier than that in late Miocene. The clay-skin content of red clay, which has a synchronous change with faunal features, is a rather good replacing palaeoclimatic index.     

The ecological sequence of Hipparion fauna in the middle reaches of the Yellow River during Neogene

The faunal ecological type and sequence in the Tertiary red clay indicate that Hipparion fauna during the period 7.4–6.1 Ma in the middle reaches of the Yellow River is composed mainly of dorcadoides and mixed types. This represents semiarid veld environment with small fluctuation. The fossil assemblages characterized by the abundance of gaudryi types and even the occurrence of some Hominoid and Chalicotherium indicate an obviously warm and humi period since 5.3 Ma. The fossil assemblages during 3.4 Ma show the typical steppe fauna representing dry climate. It is indicated by the changes of ecological sequence that the climatic conditions in Pliocene are drier than that in late Miocene. The clay-skin content of red clay, which has a synchronous change with faunal features, is a rather good replacing palaeoclimatic index.     

中国南方红土的研究进展

中国南方的红土是晚新生代以来重要堆积物，为特定的气候环境下的产物，蕴藏着丰富的环境演化信息，为全球变化的 良好信息载体，作者对红土的成因、发育期次、年代学、古气候学、生物学、磁学性质等方面的不同观点作了较为详细的论述，从而提出了目前红土研究中存在的问题及解决的方法。     

海嘧啶抗肿瘤作用机制的研究

研究了海嘧啶抗肿瘤作用的机制,观察了海嘧啶对荷瘤小鼠红细胞免疫粘附肿瘤细胞的功能以及对红细胞膜及肿瘤细胞膜上唾液酸的含量的影响.结果表明海嘧啶可以提高荷瘤小鼠抗肿瘤免疫功能,提高红细胞膜上唾液酸的含量,而使肿瘤细胞上的唾液酸含量降低.这可能其抗肿瘤作用的机制之一.     

超细Co-γ-Fe_2O_3磁粉的研制

应用TEM、XPS、XRD等分析技术,研究了包钴过程中各种因素对钴改性γ-Fe_2O_3磁粉的微观结构以及磁性能的影响。结果表明,钴铁氧体的形成是Co-γ-Fe_2O_3磁粉磁性能提高的主要原因。包少量钴(钴含量<1%),可使原磁粉的矫顽力提高约6.37kA/m。     

室内外空气中氡子体浓度测量

报道了室内外空气中氡子体浓度的测量结果.红砖建筑物室内,RaA、RaB、RaC、ThB、ThC的浓度分别为7.80,5.86,5.69,0.37及1.11Bq/m~3;室外分别为5.28,4.44,5.37,0.27及0.46Bq/m~3.硅酸盐砖住宅室内分别为12.14,10.96,10.50,8.40及5.84Bq/m~3,室外分别为7.88,8.36,9.36,3.85及5.07Bq/m~3.     

两种赤潮藻对温度、氮、磷营养的反应及活体荧光特性的研究

在实验室分批培养条件下,研究了温度及氮磷营养元素对两种赤潮藻增殖的影响,发现海洋原甲藻(Prorocentrum micans)要求的温度较低,其生长最适温度为23℃,生长温度上限在33℃至34℃之间;微小角毛藻(Chaetoceras minutissmus)的生长最适温度约为30℃,生长温度上限在41℃与44℃之间。氮磷缺乏使两种藻的增殖受阻,生长周期缩短,且缺氮比缺磷的影响大,测定表明两种藻的荧光激发光谱的高峰位置都在580nm附近,而荧光发射光谱的峰位为675nm.DCMU能引起两种藻活体荧光的增益,海洋原甲藻的增益荧光比率(F_D/F_X)为2.5,角毛藻的荧光比率较低,通常小于2.0。     

表面包覆对TiO_2超微粒光学性质的影响

制备了一系列表面包覆油酸的TiO_2超微粒.结果表明,表面包覆油酸的TiO_2超微粒的表观光学带隙(E_s)随着超微粒粒径减小变小;相同粒径表面包覆油酸的TiO_2超微粒的表观光学带隙与表面包覆硬脂酸的TiO_2超微粒几乎相同,但比表面包覆十二烷基苯磺酸的TiO_2超微粒大.     

颗粒级配对水泥基材料有害孔隙率的影响

水泥基材料的硬化浆体中含有大量的孔隙 ,其中的有害孔隙直接影响到耐久性 .依据所建立的微粒级配模型 ,采用粉煤灰、硅灰等球形颗粒掺合料及纳米纤维红粉 (NR)掺合料 ,设计球形颗粒紧密堆积体系与纳米纤维增强紧密堆积体系 ,讨论 2种混合体系内部的总孔隙率与有害孔隙率之间的关系 ,确定活性NR粉在水泥基材料中的作用 .研究表明 ,NR粉能够增加体系密实度 ,水泥混合体系硬化后期的总孔隙率与有害孔隙率之间服从对数关系 ,通过微粒级配模型可预知体系有害孔隙率及颗粒级配的合理性 .