In vivo and in vitro biomineralization in the presence of the inner-shell film of pearl oyster

The inner shell surface is the biomineralization site in shell formation and an inner-shell film covers it.This surface is composed of two regions:an outer calcitic region and an inner aragonitic region.In this study,some amalgamated calcite crystals were found in the calcitic region and some aragonitic "imprints" were found in the central part of the aragonitic region.The "imprints" are probably the trace of mantle cells that adhered to the inner shell surface when the shell was produced.Furthermore,to build a novel in vitro biomineralization system,the inner-shell film was detached from the shell and introduced to the calcitic crystallization solution.Crystallization experiments showed that nacre proteins could induce aragonite crystals in the novel system but inhibited calcite growth in the absence of the inner-shell film.These data suggested that the inner-shell film may induce aragonite growth in vivo by combining nacre proteins.     

Drill holes and shell repair in brachiopods from a Late Cretaceous (Maastrichtian) oyster reef,North Canterbury,New Zealand

Several hundred brachiopods were separated from a bulk sample taken from a single locality of the Late Cretaceous Ostrea Bed at the top of the Broken River Formation in the Weka Pass area of North Canterbury, New Zealand. The specimens were divided among five different species and examined for drill holes and shell repair following failed predatory attacks. The results show that one or more unknown predators and/or parasites apparently selectively preyed on the rhynchonellide Wekarhynchia cataracta, with approximately 16.2% of complete shells showing evidence of attack. The larger, coarsely-ribbed terebratulide Ostreathyris allani was seemingly immune to drilling, while sample sizes for the three other brachiopod species were too small to allow even rudimentary estimates of predation/parasitism rates.     

马氏珠母贝黄壳色选系F1和养殖群体形态性状比较

马氏珠母贝（Pinctada martensii）是我国南方养殖的一种重要经济贝类，长期以来一直是我国主要的海水育珠的主要贝类，用马氏珠母贝育珠是广东、广西和海南沿海部分地区经济发展的支柱性产业。近年来，我国海水珍珠的质量出现明显滑坡，严重地削弱了在国际市场上的竞争力。为提高海水珍珠质量和在国际市场上的竞争力，国内科技工作者已经进行了大量的研究工作，这些工作主要包括对马氏珠母贝养殖群体性状的改良、育珠技术的优化和海水珍珠形成机理的研究。     

鲁北贝壳滩脊沉积特征及发育环境分析

渤海西南岸贝壳滩脊发育典型,贝壳含量高、规模大,不仅作为古岸线标志,还是抵御风暴潮的天然屏障。作者通过对鲁北贝壳滩脊的沉积结构,发育环境分析,将贝壳滩脊分为堤梗和堤内充填两个亚相。前者以贝壳和贝壳碎块为主,具有平行层理和高角度斜层理,后者以贝壳细碎屑为主,亦含细粉沙,具有向陆倾的平行层理。贝壳滩脊的形成和发育受多种因素的控制,其中贝壳物质的大量富集、较强的暴风浪、风的吹积作用及入海河流的改道效应等均与其有密切关系。当黄河从鲁北入海时,潮滩快速加积,贝壳贫乏,当黄河远离本区时,鲁北岸滩相对侵蚀,利于贝壳滩脊的发育。     

双层球面网壳动力失效分析及地震损失评估

双层球面网壳结构是一种缺陷敏感型结构,影响结构动力失效的初始缺陷主要有杆件的初弯曲、杆件的残余应力和结构节点的初始安装偏差3种。本文首先利用有限元软件ANSYS的二次开发功能开发了可以考虑初始弯曲和残余应力的杆单元,接着利用动力增量法(IDA)系统地研究了这3种缺陷对结构动力失效的影响,最后总结提出了考虑缺陷的双层球面网壳结构的抗震损失评估方法。     

渤海西南岸全新世最大海侵界线及其地貌特征

结合钻孔与探地雷达探测古海相层尖灭点的测量方法与图像处理原则,本研究在沿渤海西南岸分布的8个相关钻孔附近开展了探测,经图像处理、与钻孔对比分析以及在特征位置钻探浅钻的方式,获得了5处最大海侵尖灭点的位置、地层剖面形态以及高程等信息.结合6ka B.P.、2ka B.P. 左右和现代黄河流路变迁史及沿岸贝壳堤分布情况,揭示了最大海侵时期小清河向北至漳卫新河范围主要为古黄河形成的广阔三角洲潮滩地貌,海侵线远离海岸线深入内陆,其上的贝壳堤形成主要与黄河流路变迁相关; 而渤海湾西南岸黄骅、沧州附近及以北主要为沼泽-潟湖-沙坝海岸地貌特征,海侵线由潟湖的陆侧边缘向海逐渐推进,沿岸分布的6ka B.P. 左右贝壳堤的形成则是基于沿岸堤,并伴随风暴作用发育而来.莱州湾南岸依据埋藏古河道古湖泊的分布情况,推断该区全新世最大海侵前后具有与现代相似的海岸地貌特征,海侵时,海水直抵当时最大高潮线附近,使得海岸线与海侵线几乎相当.依据剖面地形校正结果可知,最大海侵时,海水侵入内陆至现代地表高程5.8~10.3m范围,后期新构造运动造成的隆起与下沉的区域差异,使得不同区域海侵层高程发生相应的变化,该结果为进一步估算海平面变化提供重要基础.     

舟山沿岸四种藤壶类壳板的亚显微结构

本文研究了舟山沿岸四种藤壶（三角藤壶Ｂａｌａｎｕｓｔｒｉｇｏｎｕｓ，纹藤壶Ｂ．ａｍｐｈｉｔｒｉｔｅａｍｇｈｉｔｒｉｔｅ，白脊藤壶Ｂ．ａｌｂｉｃｏｓｔａｔｕｓ及日本笠藤壶Ｔｅｔｒａｃｌｉｔａｊａｐｏｎｉｃａ）壳板的亚显微结构。结果表明，壳板表面的亚显微结构主要有生长脊（包括毛脊、大脊、微脊）和放射脊。其中，大脊和放射脊系本文首次报道。大脊于蔡壶蜕皮后毛脊（刚毛）形成的同时或其后形成，与蜕度周期有关。放射脊的形成可增加壳板的坚固度。各种生长脊的数量及强弱变化反映了藤壶的生理代谢状况及环境对藤壶成长的影响。本文比较了四种藤壶之间壳板表面的亚显微结构，发现它们有很大的差异。通过比较四种藤壶成体和幼体之间壳板表面的亚显微结构，发现藤壶壳板表面结构与年龄有密切关系，尤以生活于潮间带中上区的白脊藤壶和日本笠藤壶为显著。环境，尤其是潮区，对藤壶壳板的生长有很大影响。日本笠藤壶、白脊藤壶、纹藤壶壳板结构明显受其生活的潮区影响。     

长牡蛎壳黑选育系F7代的生长规律和模型

为研究长牡蛎壳黑选育系F7的生长规律,分别采用了线性回归方程和Von Bertalanffy、Gompertz和Logistic 3种非线性模型对长牡蛎(Crassostrea gigas)壳黑选育系F7幼虫期和养成期的生长参数进行生长模型构建,并对长牡蛎壳黑选育系F7养成期的壳高、壳长、壳宽分别与总重进行曲线拟合,以研究长牡蛎壳黑选育系F7的生长规律。研究表明,幼虫期壳高、壳长对日龄的回归方程分别为y=39.723 8+11.697 2x,R^2=0.991;y=31.346 2+9.802 8x,R^2=0.986。壳高与壳长成线性相关,回归方程为y=4.867 0+1.175 0x,R^2=0.989。养成期长牡蛎壳黑选育系F7的总重增长与Von Bertalanffy生长模型最符,R^2=0.955;长牡蛎壳黑选育系F7的总重与壳高、总重与壳长、总重与壳宽分别遵循复合曲线y=0.706×1.055~x,R^2=0.991、y=1.336×1.075~x,R^2=0.983、y=1.287×1.154~x,R^2=0.944。     

Kinematics of the Gum nebula region

To investigate the kinematics of the neutral material around the Gum nebula, emission from hydroxyl at 1667 MHz was observed at many positions over the region. Fitting models of expanding shells to these data together with previously published molecular line data shows that the diffuse molecular clouds and cometary globules form a single expanding shell centred on G261−2.5. The mean angular radius is 10.5° and its maximum radius is 14°. The models show that the distance range to the expansion centre is from 200 pc to 500 pc.
The path of the runaway O-star ζ Puppis passed within <0.5° of the expansion centre of the neutral shell ∼1.5 Myr ago. The supernova of the erstwhile binary companion of ζ Puppis is the probable origin of the Gum nebula and the swept up expanding neutral shell. The 500-pc distance to the supernova is adopted as the distance to the expansion centre of the neutral shell. At this distance the energy required to produce the observed expansion could have been met with a single supernova. The radii of the front and back faces of the shell are 130 and 70 pc respectively. The front face is expanding faster than the back face, at 14 and 8.5 km s⁻¹ respectively.
The extent of the neutral shell matches the radio continuum and H α emission of the Gum nebula well. The photoionized gas in the nebula is probably primarily ionized by ζ Puppis, which is still within the neutral shell. No evidence was found for the IRAS -Vela shell as a separate expanding shell.