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排序方式: 共有207条查询结果,搜索用时 15 毫秒
151.
Costaria costata(C.Agardh) Saunders is one of common kelps distributed in many coastal areas worldwide;however,in China,no reports have been made on cultivation of the genus.To investigate potential cultivation of the species in the northern part of China,trials on isolation and preservation of the gametophytes were conducted using C.costata from Korea;growth and development of the gametophytes were observed.We showed that at 10±1°C,60 μmol m-2s-1 and 12:12 h(L:D),freshly released zoospores settled down wit... 相似文献
152.
Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamysfarreri 总被引:2,自引:0,他引:2
Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentr... 相似文献
153.
An open reading frame (lcn61) of iymphocystis disease virus China (LCDV-cn), probably responsible for encoding putative zinc-finger proteins was amplified and inserted into pET24a (+) vector.Then it expressed in E. coli BL21 (DE3), and His-tag fusion protein of high yield was obtained. It was found that the fusion protein existed in E. coli mainly as inclusion bodies. The bioinformatics analysis indicates that LCN61 is C2H2 type zinc-finger protein containing four C2H2 zinc-finger motifs. This work provides a theory for functional research of lcn61 gene. 相似文献
154.
Flatfish or flounder moves one eye to change body proportion into vertebral asymmetry during metamorphosis, during which some become sinistral while others dextral. However, the mechanism behinds the eye-position has not been well understood. In this research, hybrids between Japanese flounder(♀) and stone flounder (♂) show mixed eye-location in both dextral type and sinistral type, and thus become good samples for studying the eye-migration. mRNAs from pro-metamorphosis sinistral and dextral hybrids larvae... 相似文献
155.
In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well. 相似文献
156.
Fractional energy losses of waves due to wave breaking when passing over a submerged bar are studied systematically using a modified numerical code that is based on the high-order Boussinesq-type equations.The model is first tested by the additional experimental data,and the model's capability of simulating the wave transformation over both gentle slope and steep slope is demonstrated.Then,the model's breaking index is replaced and tested.The new breaking index,which is optimized from the several breaking i... 相似文献
157.
莱阳盆地莱阳群恐龙足迹化石的新发现 总被引:9,自引:1,他引:9
在山东莱阳盆地早白垩世莱阳群龙旺庄组发现15个足迹化石。化石产在灰绿色细砾粗砂岩(转石)的下层面,呈层底凸形(Convex hyporelief)保存。研究表明,足迹为二足行走、趾行式、三趾型,趾端具尖、长爪。足长约13 cm,长大于宽,近中趾对称。趾间角较大:平均值Ⅱ27°Ⅲ27.2°Ⅳ,Ⅱ、Ⅳ趾夹角平均54.2°。趾垫不清晰,无尾迹印痕。经研究,笔者认为这是一新的足迹类型,命名为Paragrallator ichnogen. nov.,并将其归入Coelurosauria Huene 1914次亚目,Anchisauripodidae(Lull 1904)足迹科。即该足迹系由小型兽脚类恐龙——虚骨龙类所形成。恐龙足迹形成于滨湖相—河流相环境中。 相似文献
158.
REN Jianguo WANG Xianbin OUYANG Ziyuan College of Marine Geosciences Ocean University of Chin Qingdao Shandong Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou Gansu Institute of Geochemistry Chinese Academy of Sciences Guiyang Guizhou 《《地质学报》英文版》2005,79(3):426-431
Gas concentrations and isotopic compositions of He and CO2 were determined on free gas samples from ten hot springs of the Rehai geothermal field, Tengchong, China. The results showed that hot-spring CO2 gas, together with He,was derived mainly from the mantle, indicating the accumulation of mantle-derived volatiles beneath the survey area. The δ^13C values of CO2, higher than those of the typical mantle-derived carbon and the isotopic composition of hot-spring-free CO2 in unequilibrium with dissolved CO2, are recognized only in the Rehai geothermal field, suggesting that there seems to be a still-degassing magmatic intrusion at depths, which provides mantle-derived volatiles to the hydrothermal system above. The accumulation of those volatiles has probably played an important role in triggering earthquakes in this region.In addition, the isotopic characteristics of He and C also indicate that the magmatic intrusion seems to have been derived from the MORB source, and could be contaminated by crustal materials during its upwelling through the continental crust. 相似文献
159.
东、黄海大气湿沉降中常量阴离子组分的研究 总被引:2,自引:0,他引:2
用离子色谱法分析了嵊泗群岛和千里岩岛两个观测站湿沉降样品中的F^-、NO3^-、Cl^-和SO4^2-等4种阴离子。结果表明,它们的月均浓度之间差别较大,季节性变化明显;与近岸城市相比,具有显的海洋性特征;对全年中酸雨的统计表明,两个观测站都受到了酸雨的影响,而嵊泗群岛更严重一些。 相似文献
160.
This study deals with the nonlinear dynamic response of deep-sea risers subjected to parametric excitation at the top of a platform.As offshore oil and gas exploration is pushed into deep waters,difficulties encountered in deep-sea riser design may be attributed to the existence of parametric instability regarding platform heave motions.Parametric resonance in risers can cause serious damage which might bring disastrous accidents such as environment pollution,property losses and even fatalities.Therefore,th... 相似文献