Novel records and observations of the barnacle Stephanolepas muricata (Cirripedia: Balanomorpha: Coronuloidea); including a case for chemical mediation in turtle and whale barnacles

We report new distribution and host records of the turtle barnacle Stephanolepas muricata Fischer. Ours is the first study to document this species' occurrence in Mexico and in the Atlantic Ocean (North Carolina, Georgia and Florida: USA). We also present the first record of S. muricata from olive ridley sea turtles, Lepidochelys olivacea (Eschscholtz). We discuss the physical and ecological characteristics associated with the specimens collected and present evidence suggesting the likelihood of chemical mediation between embedding coronuloid barnacles like S. muricata and host turtles. We provide the first data on the diet and fecundity of S. muricata.     

Spatial and temporal distributions of juvenile horseshoe crabs (Arthropoda: Chelicerata) approaching extirpation along the northwestern shoreline of the New Territories of Hong Kong SAR,China

Juvenile horseshoe crabs, Tachypleus tridentatus and Carcinoscorpius rotundicauda, with prosomal widths of between 11.5 and 102.5 mm, occur along Hong Kong's northwestern shoreline abutting Deep Bay where dissolved oxygen (DO) has been identified as the principal factor determining distribution and survival. Unreported upon hitherto, however, Tachypleus tridentatus occurred consistently in association with sea-grass (Halophila beccarii) beds, with DO concentrations of 8–14 mg·L^?1, a median grain size of >180 μm, interstitial water contents of <36% (sediment wet weight) and organic contents of <3.2% (sediment dry weight). Most individuals occurred between 60 and 120 m down from the shoreline although there appeared to be a trend of down-shore migration in summer, possibly to alleviate thermal stress. No individuals were found at sediment temperatures ≤20°C, i.e. in sub-tropical Hong Kong's winter, when they adopt buried repose. Abundances of emerged T. tridentatus, peaking in November, were synchronized with interstitial salinities of 22–26‰ and averaged 1–2 individuals per 100 m². Mean population density of T. tridentatus was 4–9 individuals per 100 m². Only four individuals of C. rotundicauda were found in August and September, suggesting a recent dramatic decline in numbers. The natal crèche environment for juvenile horseshoe crabs in Hong Kong is deteriorating and threatening their survival.     

Sipunculans and echiurans from the deep Angola Basin

Sipunculans and echiurans collected by the “DIVA 1” expedition by RV Meteor (Cruise M48/1) to the deep‐sea bottom of the Angola Basin are recorded. Seven species from five genera and two separate phyla are recognized; only the echiuran Pseudoikedella achaeta has not been recorded hitherto in the southern sector of the Atlantic Ocean. A gradient analysis using redundancy analysis (RDA) under the CANOCO package indicates the existence of a neat latitudinal gradient of sipunculans along the Angola Basin from the southernmost stations towards the northern ones. The local abundance of abandoned horny tubes of polychaetes at some of the sampling sites of the northernmost stations explains the dense aggregations of Nephasoma diaphanes. This species exhibits an opportunistic lifestyle inside empty polychaete tubes on the abyssal plains of the Angola Basin.     

The deep‐sea chiton Nierstraszella (Mollusca: Polyplacophora: Lepidopleurida) in the Indo‐West Pacific: taxonomy,morphology and a bizarre ectosymbiont

Three hundred and three individuals representing 14 species of lizards (Scincidae), collected in Papua New Guinea, were examined for metazoan endoparasites. Two species of Digenea, four species of Cestoda, 21 species of Nematoda (adults and larvae in cysts), two species of Acanthocephala and one species of Pentastomida were found. Forty-two new host records and two new locality records are reported. Skinks from Papua New Guinea are infected by “generalist” endoparasites, which parasitize a variety of reptile or amphibian hosts. Mean endoparasite species diversity per skink species was 5.0 ± 3.3 SD, range: 1–11.     

砗磲人工繁育、资源恢复与南海岛礁生态牧场建设

南海珊瑚岛礁是海洋生态系统的重要组成部分,是区域特色海洋和渔业生物资源及其多样性的保障。砗磲是珊瑚岛礁的构成物种,具有优良的造礁、固礁护礁功能,并为其它岛礁生物提供栖息地、繁育和庇护场所；近二十多年来,在人类活动和全球环境变化影响下,砗磲及珊瑚等岛礁生物资源受到比较严重的破坏,其岛礁生态牧场天然参与者和构建者的功能受损明显。我们突破砗磲幼虫虫黄藻植入难点和变态率极低的瓶颈问题,率先在海南成功研发了砗磲规模化人工繁育和中培技术,并进行了放流增殖试验,取得了良好的效果。但目前和今后砗磲及珊瑚等生物资源情况依然严峻,期望今后开展更系统、科学、更大规模的基于砗磲、珊瑚及其它重要礁栖生物的放流增殖与生态牧场构建,全面恢复南海珊瑚岛礁的生态环境和生物资源,推动南海的可持续发展。     

双体及三体船船舶尾浪的数值计算

采用近、远域结合的方法对深水条件下的双、三体船的尾浪进行了数值计算.近域兴波计算采用基于NURBS的高阶面元法,远域尾浪计算采用波谱函数法.以最大波高作为衡量标准,分析了片体间距对双体船尾浪的影响,及侧体排水量、主侧体纵横向间距等对三体船尾浪的影响.计算结果与部分试验结果的对比验证了该方法的可行性.该研究可为船舶尾浪对环境影响的评估及低尾浪船舶的设计提供一定的理论依据.     

影响物理学发展的8个问题

本文论述影响物理学发展的8个问题：①在波粒二象性理论中，何处是“波有粒子性”的频率（波长）分界；②如何看Newton力学与相对论力学的分歧；③非相对论性量子波方程与相对论性量子波方程是否对立；④狭义相对论与量子力学究竟有无矛盾；⑤因果性是不是“自然科学家的底线”；⑥负速度是什么；⑦超前波、引力波是否存在；⑧基本物理常数会不会变化。本文认为对这些基本问题作梳理和澄清是很重要的．有助于找到物理学界再次陷入迷茫的原因。     

黄海粮仓绿色生态高效现代农业的建设

 黄海沿岸是中国沿海滩涂面积最大的区域，后备耕地和海洋资源开发潜力巨大。目前中国正在实施海洋"蓝色粮仓"战略，但黄海陆地"绿色粮仓"尚未开发。建议重点支持黄海粮仓绿色生态高效现代农业建设，加强沿海滩涂地区耐盐水稻品种选育和示范推广，加强稻麦两茬区的抗逆品种和减灾栽培配套技术体系创建；创建不同的现代农业、水产养殖、工业建设、生态建设、休闲养生、观光旅游等模式，实现工农业、生态环境的绿色协同发展。     

水平管外海水降膜蒸发传热特殊现象分析

以低温多效蒸发海水淡化装置中的水平管降膜蒸发过程为研究对象,对海水水平管降膜蒸发的传热系数在不同蒸发温度、雷诺数(Re)等条件下沿圆周角方向的分布特征进行了实验研究.研究结果表明:海水作为实验流体时,传热系数随蒸发温度的升高而降低,随Re的增大而呈现先升高,达到最大值后略微降低的趋势,随圆周角的增大而先减小后增大.     

等离子体中离子声波的色散关系

以含有满足玻耳兹曼分布的低温电子、远离平衡态的高温电子和离子组成的等离子体为研究对象,推导得到在该等离子体中传播的离子声波的色散关系.利用数值模拟方法讨论系统参数如快电子数、两种电子温度之比和数密度比值对离子声波的色散关系的影响.结果表明:系统参数的变化均会影响和改变着系统的色散关系,其中ω2随快电子数α的增大而增大.