Compatibility and specific interactions in poly(beta-hydroxybutyrate) and poly(p-vinylphenol) blends

The miscibility and specific interactions in poly (beta-hydroxybutyrate) (PHB)/poly(p-vinylphenol) (PVPh) blends were studied by differential scanning calorimetry(DSC) , fourier transform infrared(FTIR) spectrometer and high resolution solid state C-13 NMR, A single composition-dependent glass transition temperatures were obtained by DSC which indicate the blends of PHB/PVPh were miscible in the melt state, The experimental glass transition temperatures were fitted quite well with those obtained from Couchman-Karasz equation. The FTIR study shows that the strong intermolecular hydrogen bonding exists in blends of PHB with strong proton acceptor and PVPh with strong proton donor and is the origin of its compatibility. The CPMAS C-13 NMR spectra also show that the strong hydrogen bonding exists in PHB/PVPh blends. From the T-1 rho(H) relaxation time it follows that the blends of PHB/PVPh(40/60, 20/80) studied are completely homogeneous on the scale of about 3.2 nm.

PHB／PVPh共混体系的相容性及分子间的特殊相互作用

ＰＨＢ／ＰＶＰｈ共混体系的相容性及分子间的特殊相互作用邢佩祥，董丽松，冯汉桥，安玉贤，庄宇钢，冯之榴（中国科学院长春应用化学研究所高分子物理开放实验室，长春，１３００２２；中国科学院武汉物理研究所波谱与原子分子实验室）关键词氢键，相容性，聚（β－羟基...

Bioorganic/inorganic hybrid composition of sponge spicules: Matrix of the giant spicules and of the comitalia of the deep sea hexactinellid Monorhaphis

The giant basal spicules of the siliceous sponges Monorhaphis chuni and Monorhaphis intermedia (Hexactinellida) represent the largest biosilica structures on earth (up to 3 m long). Here we describe the construction (lamellar organization) of these spicules and of the comitalia and highlight their organic matrix in order to understand their mechanical properties. The spicules display three distinct regions built of biosilica: (i) the outer lamellar zone (radius: >300 mu m), (ii) the bulky axial cylinder (radius: <75 mu m), and (iii) the central axial canal (diameter: <2 mu m) with its organic axial filament. The spicules are loosely covered with a collagen net which is regularly perforated by 7-10 mu m large holes; the net can be silicified. The silica layers forming the lamellar zone are approximate to 5 mu m thick; the central axial cylinder appears to be composed of almost solid silica which becomes porous after etching with hydrofluoric acid (HF). Dissolution of a complete spicule discloses its complex structure with distinct lamellae in the outer zone (lamellar coating) and a more resistant central part (axial barrel). Rapidly after the release of the organic coating from the lamellar zone the protein layers disintegrate to form irregular clumps/aggregates. In contrast, the proteinaceous axial barrel, hidden in the siliceous axial cylinder, is set up by rope-like filaments. Biochemical analysis revealed that the (dominant) molecule of the lamellar coating is a 27-kDa protein which displays catalytic, proteolytic activity. High resolution electron microscopic analysis showed that this protein is arranged within the lamellae and stabilizes these surfaces by palisade-like pillars. The mechanical behavior of the spicules was analyzed by a 3-point bending assay, coupled with scanning electron microscopy. The load-extension curve of the spicule shows a biphasic breakage/cracking pattern. The outer lamellar zone cracks in several distinct steps showing high resistance in concert with comparably low elasticity, while the axial cylinder breaks with high elasticity and lower stiffness. The complex bioorganic/inorganic hybrid composition and structure of the Monorhaphis spicules might provide the blueprint for the synthesis of bio-inspired material, with unusual mechanical properties (strength, stiffness) without losing the exceptional properties of optical transmission. (C) 2007 Elsevier Inc. All rights reserved.

Growth, survival and immune activity of scallops, Chlamys farreri Jones et Preston, compared between suspended and bottom culture in Haizhou Bay, China

We examined the growth, survival and immune response of the scallop, Chlamys farreri, during a 1-year period in deep water of Haizhou Bay. Scallops were cultured using two methods: (1) in lantern nets at a 5 m depth and (2) in a bottom culture system (sleeves) on the seabed at about a 25 m depth. Shell heights, meat dry weight and immune activities in the haemolymph (superoxide dismutase and myeloperoxidase) were measured bimonthly or quarterly from July 2007 to June 2008. Survival was measured at the end of the study and environmental parameters in the experimental layers were monitored during the experiment. The growth and immune activities of scallops were lower when the water temperature was high, which was consistent with the main mortality occurring in summer. The growth and immunity of scallops were higher in the suspended culture than in the bottom culture during the experiment, with the exception of shell growth during the last study period. Survival of scallops in the suspended culture (54.6 +/- 12.3%) was significantly lower than that in the bottom culture (86.8 +/- 3.5%) at the end of this study. We conclude from our results that the high mortality of C. farreri can be prevented by culturing them in a bottom culture system before November of the first year, and then transferring them to a suspended culture to improve scallop production.

Identification of a silicatein(-related) protease in the giant spicules of the deep-sea hexactinellid Monorhaphis chuni

Silicateins, members of the cathepsin L family, are enzymes that have been shown to be involved in the biosynthesis/condensation of biosilica in spicules from Demospongiae (phylum Porifera), e. g. Tethya aurantium and Suberites domuncula. The class Hexactinellida also forms spicules from this inorganic material. This class of sponges includes species that form the largest biogenic silica structures on earth. The giant basal spicules from the hexactinellids Monorhaphis chuni and Monorhaphis intermedia can reach lengths of up to 3 m and diameters of 10 mm. The giant spicules as well as the tauactines consist of a biosilica shell that surrounds the axial canal, which harbours the axial filament, in regular concentric, lamellar layers, suggesting an appositional growth of the spicules. The lamellae contain 27 kDa proteins, which undergo post-translational modification (phosphorylation), while total spicule extracts contain additional 70 kDa proteins. The 27 kDa proteins cross-reacted with anti-silicatein antibodies. The extracts of spicules from the hexactinellid Monorhaphis displayed proteolytic activity like the silicateins from the demosponge S. domuncula. Since the proteolytic activity in spicule extracts from both classes of sponge could be sensitively inhibited by E-64 (a specific cysteine proteinase inhibitor), we used a labelled E-64 sample as a probe to identify the protein that bound to this inhibitor on a blot. The experiments revealed that the labelled E-64 selectively recognized the 27 kDa protein. Our data strongly suggest that silicatein(-related) molecules are also present in Hexactinellida. These new results are considered to also be of impact for applied biotechnological studies.

CAD/CAM一体化的应用与开发

文章概要地介绍了CAD/CAM系统的结构、CAD/CAM一体化的工作流程,提出实现CAD/CAM一体化的几种可行方案,并以具体零件机床为例,给出从设计到数控编程和机床加工的全过程。

CIMS环境下CAPP系统的设计

本文结合国家CIMS重点应用工厂——沈阳鼓风机厂实施 CIMS 的实际,对 CIMS 环境下的CAPP 系统的结构、采用的设计方法、涉及的关键技术,以及所需的基础工作进行了讨论.

岩溶生态系统脆弱性剖析

生态系统的脆弱性评价对于生态系统管理具有重要作用。在分析岩溶生态系统脆弱性特征和影响因素的基础上,构建了针对岩溶自然系统的脆弱性评价指标体系,涵盖了岩溶生态系统的结构脆弱性、生态过程脆弱性、生态功能脆弱性和人为胁迫脆弱性4个方面,评价指标分别是结构稳定性、多样性生境、能量利用和积累、直接使用价值、石漠化程度和速率等。以不同类型的原生岩溶生态系统的生态基准值作为比较基础,评价系统将现有的退化岩溶生态系统的脆弱性划分为轻微脆弱、中度脆弱、重度脆弱以及系统崩溃4级

中国典型泥炭区现代植物的碳、氧同位素组成及在古环境研究中的意义

本文测定了中国3个典型泥炭沼泽四川红原、吉林金川和哈尼的现代沼泽植物中的碳、氧同位素组成。吉林金川和哈尼的沼泽在相似的气候和环境条件下发育演化，而四川红原的泥炭发育在截然不同的气候条件下。结果表明，每个泥炭沼泽现代植物中的碳、氧同位素均有较大的离散度，表现为不同营养状况下的成沼植物之间的同位素差异；从δ13C值来看，三个沼泽中的植物均属C3植物；红原与金川、哈尼有着明显不同的现代植物稳定氧同位素组成，前者更富集18O。同一泥炭植物碳、氧同位素的不均一性要求在利用泥炭沉积物恢复过去气候变化方面一定要谨慎。非常有意义的是贫营养泥炭(高位泥炭)的成沼植物有着非常接近的同位素组成，揭示贫营养型泥炭可能是更为理想的过去全球变化信息档案。

Growth of Motor Coordination in Early Robot Learning

M. H. Lee and Q. Meng, Growth of Motor Coordination in Early Robot Learning, IJCAI-05, 2005.

Volcanoes as agents of past environmental change

Sadler, J. Grattan, J. Volcanoes as agents of past environmental change. Global and Planetary Change. 1999. 21 pp 181-196

Komparatystyka na rozdrożu?

The author of the article attempts to present the situation of comparative studies as a field of research and a way of thinking about the contemporary world on the basis of the analyses presented in Comparative Literature at a Crossroads? in the monographic issue of “Comparative Studies” 2006. Much attention is paid to the phenomenon of the crisis of comparative studies connected with a noticeable reluctance towards great theoretical models shared by many researchers, the extensiveness of the topic area and resulting methodological problems but also the fact that comparatists abandon the studies of other languages. This results in a need of searching for a satisfactory definition of this field of study, its scope of research and applicable research methods. Among the specific issues raised in the article there is, e.g. the case of world literature seen in the context of the classical contradiction between cultural hegemony and cultural pluralism. Moreover, an interesting review of the picture of the Polish culture from the perspective of postcolonial theories and intracultural differences is presented.

Metafora transcendentalna jako zgłębienie rzeczywistości

The article concerns the crucial role of language in the creation of the character’s identity. This issue is analysed by the author on the basis of the Russian writer Tatiana Tolstoj’s short stories. In the works of T. Tolstoj the idiosyncratic language of the character, full of surprising metaphors, repetitions and syntactic innovations creates the prose style named ornamental prose by H. Goscilo. According to the author of the article, the metaphor plays a special role in Tolstoj’s short stories. The short story becomes subordinate to one superior metaphor accompanied by a number of subsidiary metaphors. By means of applying the metaphor that transcendents the reality, Tolstoj’s realistic prose becomes deeply emotional and presents unexpected and unknown aspects of Russian reality.