排序方式： 共有35条查询结果，搜索用时 15 毫秒
31.
L. Terray O. Thual S. Belamari M. Déqué P. Dandin P. Delecluse C. Levy 《Climate Dynamics》1995,11(8):487-505
A 10-year simulation with a coupled ocean-atmosphere general circulation model (CGCM) is presented. The model consists of the climate version of the Météo-France global forecasting model, ARPEGE, coupled to the LODYC oceanic model, OPA, by the CERFACS coupling package OASIS. The oceanic component is dynamically active over the tropical Pacific, while climatological time-dependent sea surface temperatures (SSTs) are prescribed outside of the Pacific domain. The coupled model shows little drift and exhibits a very regular seasonal cycle. The climatological mean state and seasonal cycle are well simulated by the coupled model. In particular, the oceanic surface current pattern is accurately depicted and the location and intensity of the Equatorial Undercurrent (EUC) are in good agreement with available data. The seasonal cycle of equatorial SSTs captures quite realistically the annual harmonic. Some deficiencies remain including a weak zonal equatorial SST gradient, underestimated wind stress over the Pacific equatorial band and an additional inter-tropical convergence zone (ITCZ) south of the equator in northern winter and spring. Weak interannual variability is present in the equatorial SST signal with a maximum amplitude of 0.5°C. 相似文献
32.
文蛤(Meretrix meretrix Linnaeus)外套膜的组织学与组织化学研究 总被引：2，自引：0，他引：2
利用组织学和组织化学染色方法对文蛤外套膜进行了研究。结果表明 ,文蛤外套膜具有双壳贝类外套膜的典型结构特征 ,即由中央膜与边缘膜组成 ,边缘膜具有 3个突起。组织结构包括内外上皮层、结缔组织与肌纤维。不同部位的外套膜 ,其上皮细胞的形态结构、结缔组织与肌纤维含量等有差异。上皮细胞与结缔组织中分布有几种不同类型的粘液分泌细胞。组织化学研究结果显示 ,缘膜突起上皮细胞内含有丰富的糖类。分泌细胞内含物中含有丰富的糖类和少量的 RNA,同时在分泌细胞检测到较强的 ACP酶活性 相似文献
33.
通过扫描电镜观察,太平洋牡蛎精子由头部、中段和尾段组成.精子全长约21.6μm,尾段长约18.2μm,末端观察到"针眼"样结构;头部最大处的直径约2.6μm;中段直径约1.1μm;未成熟精子尾段中部出现膨大,该处直径约0.3μm.卵呈梨形;卵的直径约为41.9μm.卵表面有微绒毛组成的皱折结构,可见卵黄膜孔.卵质收回时,在卵表面卵柄处可见明显的树枝状结构.受精后,受精卵表面的卵黄膜剥离处可见较多数量的皮质小泡.在水温21.2～23.5℃,精卵混合34min时,释时出第1极体;1h22min时,放出第2极体;21h55min时,胚胎发育至初期D形幼虫. 相似文献
34.
Structure and function of the digestive system of a bivalve mollusc, Solen grandis, were studied using light microscopy and histochemical methods. The wall of digestive tube consists of four layers: the mucosal
epithelium, connective tissue, muscular and fibrosa or serosa (only in the portion of rectum) from the inner to the outer.
The ciliated columnar epithelial cells, dispersed by cup-shaped mucous cells, rest on a thin base membrane. There are abundant
blood spaces in connective tissue layer. The digestive diverticula are composed of multi-branched duct and digestive tubules.
The digestive tubules are lined with digestive and basophilic secretory cells, and surrounded by a layer of smooth muscle
fibers and connective tissues. Activities of acid and alkaline phosphatases, esterase and lipase are detected in the digestive
cells, and the epithelia of stomach and intestine, suggesting that these cells are capable of intracellular digesting of food
materials and absorbing. Besides, acid phosphatase and esterase activities are present in the posterior portion of esophagus.
Phagocytes are abundant in blood spaces and the lumens of stomach and intestine, containing brown granules derived from the
engulfed food materials. The present work indicates that phagocytes play important roles in ingestion and digestion of food
materials, which is supported as well by the activities of acid phosphatase, esterase and lipase detected in blood spaces. 相似文献
35.
河北省冬麦区干热风成因分析 总被引：11，自引：0，他引：11
利用河北省冬麦区1971--2005年5月10日至6月10日逐日降水、气温、湿度、风向风速及同期500hPa高度场等资料,采用小波分析、滑动-t检验等统计方法,对冬麦区近35年来干热风时空分布、周期、突变等特征进行了分析,同时对河北省冬麦区干热风成因进行了分析。分析表明：轻度和重度干热风年平均发生日数分布具有一致性;而轻度和重度干热风的周期、年代际变化等均具有不同特征;干热风偏多、偏少除与同期气温、降水有关外,还与同期500hPa环流形势场关系密切。 相似文献