一类典型模糊阵及其在传递闭包化简中的应用

本文研究模糊矩阵传递闭包的化简问题。通过定义 1类典型阵 ,给出传递闭包能够进一步化简的充要条件 ,为网络最大流分析提供了 1种新的模式。     

烟单14号夏玉米产量三因素最佳取值范围的探讨

作者根据大量试验和调查数据的分析,提出烟单14号夏玉米在高产条件下,亩穗数、穗粒数、千粒重三因素的最佳取值范围。 亩穗数:3569～4980 穗/亩; 穗粒数:423～526 粒/穗; 千粒重:259～278 克/1000粒。     

伶仃洋L＿2和L＿（16）孔第四纪有孔虫群与孢粉化石带特征及其地质意义

本文所依据的分析样品是取自珠江最大的一个河口湾伶仃洋中部的水下钻孔岩芯，其底部到达花岗岩基底。通过对第四纪有孔虫群与孢粉化石带特征的分析，阐明在相同的钻孔岩芯中，有孔虫分布变化所反映的古沉积环境特征与孢粉分析的古气候特征较为吻合，并与相应的沉积相对应，结合￣（１４）Ｃ和￣（２３０）Ｔｈ／￣（２３２）Ｔｈ比值法测年数据，从而较好地重塑本区晚更新世中期以来的地质历史。     

中华绒螯蟹人工半咸水工厂化育苗试验研究报告

在盐度为14—19‰的人工海水中,温度20—25℃条件下,189只平均体重100g的抱卵亲蟹产蚤状幼体4025万只。布苗密度为50—100万只/m~3为宜。必须经常换水,保持水质良好。人工饵料以单胞藻和丰年虫无节幼体为主,可适当加喂蛋黄。     

深潜器操纵性自航模试验研究

深潜器的使命和一般的潜水艇不同,它在操纵性方面的特点与战斗潜艇相比有很大的差异,操纵要求和操纵手段均有不同.它不仅要求和普通潜艇一样在水平面和垂直面内有良好的操纵性,而且由于水下作业和潜艇救生等的需要,还要求艇能在水中完成停悬、横向平移、原地回转、纵摇、滚转以及水下对接等特殊的操作.     

普里兹湾陆缘水边界的变化

利用１９９８年１１月－１９９９年２月中国第１５次南极考察资料,讨论了普里兹湾附近陆缘水边界（ＣＷＢ）两侧的水团分布,以及ＣＷＢ的中心位置、锋面宽度、锋面强度、锋面的垂直深度和垂直厚度等物理特征的空间变化。并与１９９２年１２月－１９９３年２月中国第９次南极考察资料进行了比较,说明了ＣＷＢ的时间２变化。同时,还进一步分析了ＣＷＢ两侧海水运动的各向异性,以及动力高度场的形势,指出了动力高度槽,ＣＷＢ锋面     

Short-Term Benthic Recolonization after Dredging in the Harbour of Ceuta, North Africa

Abstract. The benthic recovery after dredging (area: 2625 m²) was studied in a polluted and enclosed area of the harbour of Ceuta, in which the recolonization through the water column (larvae and adult bedload transport) could be limited by the lack of renewal. The benthos was sampled at two sites (control and dredged) using a van Veen grab and adopting a BACI (Before, After, Control, Impacted) approach. Five samplings were conducted after dredging (3, 15, 30, 90, 180 days). The proportion of gravel in the sediment of the dredged site increased after dredging, while the organic matter decreased. The impact on the community was estimated at species level, using both univariate and multivariate analyses. The maximum negative effect on benthic macrofauna was a reduction by 65% for species richness (15 days after dredging) and by 75% for abundance (3 days after dredging). Between 15 and 30 days after dredging, the abundance of some species such as the molluscs Parvicardium exiguum and Retusa obtusa and the polychaete Pseudomalacoceros tridentata increased considerably in the dredged site, while typical ‘opportunistic’ species such as Capitella capitata were disfavoured by the disturbance. For this small‐scale dredging, about 6 months are required for the disturbed area to re‐establish a sediment structure and a macrobenthic community similar to the undisturbed area. Small‐patch dredging operations are proposed in harbour management whenever possible, since they allow a quick re‐adjustment of the initial sediment structure and benthic communities.     

Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties

Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge.     

黄海多毛类异毛虫科初步研究

本文对1987～1988年在山东省部分海岛底栖生物调查时发现的异毛虫科5个种进行了详细的描述并配有插图,其中一种为新亚种,另有3个种在我国为首次记录。     

关于胶莱盆地东南缘基性火山熔岩喷发时代上限的讨论

首次对采自青岛即墨WN部两个深钻孔中新鲜玄武岩样品进行Rb-Sr同位素测年,测定年龄值为65.77±13.6Ma。认为该年龄值代表了胶莱盆地东南缘基性火山熔岩喷发的时代上限,对于整个胶莱盆地中基性火山岩的划分和对比具重要的年代学意义。