低硼氢氧化镁的制备及热分解动力学参数

本文以水合氯化镁、工业氨水为原料制备出了低硼含量的纯度 >99%的氢氧化镁和氧化镁。利用差热 -热重 (DTA- TG)、X-射线衍射 (XRD)、透射电子显微镜 (TEM)等手段 ,对氢氧化镁的热稳定性、相结构、表观状态以及脱水动力学参数进行了分析。结果为 :氢氧化镁以束状纤维和片状粉末共存 ,在 6 2 3K基本完成脱水反应生成氧化镁 ,其脱水反应的表观活化能 E为135 .4 k J· mol-1,指前因子 A为 5 .15× 10 10 ,反应级数 n为 1.10     

利用牙鲆鳃细胞系分离和培养淋巴囊肿病毒

本文利用牙鲆鳃细胞系进行了养殖牙鲆淋巴囊肿病毒的分离及培养 ,并通过电镜对培养细胞中淋巴囊肿病毒的形态及感染循环进行了初步研究。将病鱼的淋巴囊肿组织无菌滤液接种牙鲆细胞系 ,细胞出现了明显的细胞病变 ( Cytopathic effect,CPE)。电镜观察在培养细胞的胞质中有病毒的包涵体 ,胞质中散在 6角形、5角形或圆形的病毒粒子 ,大小为 10 0～ 140 nm之间。在感染细胞的线粒体中也存在大量的病毒颗粒。     

基于GIS的无人机地面监控系统的设计与实现

在分析无人机领域飞行数据特征的基础上,设计实现了一套功能较为完善的无人机地面监控系统。该系统主要完成了无人机飞行状态实时显示、航线规划和航线回放等功能模块。系统借助于G IS技术,导入矢量形式的电子地图,利用丰富的地理信息来辅助实现无人机的地面监控,在V isual C 6.0开发环境下利用基于异步方式和事件驱动方式的串口通信实现了系统与地面控制站的通信,利用地图控制文件实现了地图数据的调度,利用显示缓存实现了视图实时刷新。经过实际联调,系统运行良好,实用性较好。     

冲绳海槽轴线地质特征

冲绳海槽位于东海大陆架与琉球岛弧之间，海槽中发育着一系列平行轴向延伸的地堑型正断层。穿越海槽的地震剖面证实了海槽扩张中心的存在，扩张轴沿海槽轴线方向延伸。由于地堑构造中心的扩张速率较大，由某引起的海槽中心下陷的速率大于沉积作用的补偿速率，使海槽中心海底出现明显的下陷。在轴线的大陆坡一侧，陆源沉积占绝对优势；轴线的岛坡一侧，以火山坡碎屑、浮岩、有孔虫软泥为沉积特征。     

赤道暖池区漂流浮标运动轨迹分析

TOGA—COARE强化观测期间,对赤道暖池区海流作了多种方法、多层次的观测;根据美国释放的漂流浮标不同时刻位置的资料,分别对赤道及其南、北海域的表层漂流状况作了计算分析,指出:从1°N向北存在单一的北向流;从1°N～1°S这个近赤道区域内为东向流;1°N～2°S区域为过渡区,以东向流为主,个别浮标出现涡旋状运动。2°S以南为一反时针运动的大涡旋。     

A proposed directional function and wind-wave directional spectrum

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海洋立管复模态动力特性分析

考虑阻尼的影响,研究海洋立管的动力特性。通过分析管内流体及管外海洋环境荷载的共同作用,建立海洋立管涡激振动偏微分方程,进而得到立管动力特性方程,用复模态分析法求解动力特性方程得到立管考虑阻尼的自振频率。算例计算表明:考虑阻尼的立管自振频率略小于不考虑阻尼的立管自振频率;立管的自振频率随着内流流速的增加而减小,但内流流速不大时,影响较小;管道长度对立管的自振频率影响较大。     

气候转型与早期人类迁徙

目前的旧石器考古证据表明，更新世早期可能发生了两次人类迁徙浪潮，时间分别在1.8-1.6MaBP和1.0MaBP左右，第一阶段，古人类演化为直立人并开始走出非洲、迁徙至其它中低纬度的热带－亚热带地区；第二阶段，直立人开始占据中高纬度的温带和干旱－半干旱地区。这两个阶段也是第四纪气候发生转型、环境产生重大调整的时期。二者在发生时间上的一致性揭示了它们之间的内在联系，推测气候转型时期环境转变是这两次人类迁徙浪潮的主要驱动力。     

Chronic sublethal effects of the water soluble fractions of no. 2 fuel oils on the marine isopod, Sphaeroma quadridentatum

Two series of experiments were carried out to assess the long-term effects of the water soluble fractions (WSF) of fuel oils on the marine isopod, Sphaeroma quadridentatum. In one experiment, juvenile isopods (one month old) were exposed to sublethal concentrations (0·1% to 15% WSF) of a fuel oil (Baytown, Exxon) at room temperatures of 24 ± 1–6°C for nine months. These isopods survived to maturity and reproduced. However, growth rate was adversely affected at concentration ≥ 3% WSF and fecundity was depressed at concentrations ≥ 1% WSF. Survival of offspring in clean seawater was dependent to a large extent on the history of the previous generation. Offspring from groups exposed to ≥ 1% WSF experienced high mortality (> 70% within five weeks) even in clean seawater. This may imply that a population of Sphaeroma exposed to WSF as low as 0·2 ppm may eventually disappear, although animals can grow to maturity and reproduce at concentrations < 3 ppm.In another experiment, adult Sphaeroma (three months old) were subjected to the WSFs of four fuel oils (Baton Rouge, Baytown, Montana and New Jersey) for one month. Fecundity was depressed at a concentration > 15% WSF, regardless of the kind of fuel oil. On the other hand, the number of young produced bythe surviving females varied with the type of fuel oil for the same level of WSF. This may be attributed to different relative amounts of toxic components present in the WSF.     

Improved form of wind wave frequency spectrum

The lower frequency part of the theoretical wind wave spectrum proposed by the authors (Wen et al. , 1988a, b,c) has been improved and the form of spectrum is appreciably simplified. In addition to the field data collected in the Bohai Sea region and used in the previous papers, those obtained in the Huanghai Sea, the East China Sea and the South China Sea have been employed so that the improved spectra can be verified on a more extensive observational basis. Computed results agree with the observations well. Further comparisons have been made between the proposed spectra and the JONSWAP spectrum. Though the two types of spectrum are close to each other in form, the former shows, as a whole, better agreement with the observation than the latter. By introducing an improved relation between the peak-ness factor and significant wave steepness, the spectrum contains only significant wave height and period as parameters. For spectra given in this form, the computed peak frequencies coincide approximately wit