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21.
耳石锶标记在识别鳙(Aristichthys nobilis)放流个体的可行性 总被引:1,自引:0,他引:1
为探讨耳石微化学分析的相关方法和技术在鳙(Aristichthys nobilis)放流群体识别中的应用,以鳙的1龄幼鱼为研究对象,设置1、2、4、8、16 mg/L 5个浓度梯度的Sr Cl2溶液标记,利用元素电子显微探针技术(EPMA)检测获得了良好的标记图谱.面分布分析结果显示,暂养28 d后外源Sr在耳石的边缘形成明显的标记环,与对照组的蓝色边缘相比,高锶环带从黄绿色过渡到橘红色,随着标记浓度增大有加深的趋势.定量线分析表明对照组的Sr/Ca比值处于稳定的2.14±0.39,而不同浓度Sr的实验组Sr/Ca比值均出现一个较为明显的峰值范围(5.04~32.32),且外源Sr浓度与耳石边缘的Sr/Ca比值之间存在明显的线性关系,标记过程中对照组和标记浓度间的死亡率并没有显著差异.结果表明锶标记原理和方法在鳙的大规模放流群体标记是可靠和安全的,验证了耳石锶标记在识别鳙放流个体上的可行性.建议选择鳙放流前仔稚鱼和幼鱼,以4 mg/L设为外源Sr的最适标记浓度,标记持续时间为28 d以上为宜. 相似文献
22.
叙述了我校WWW信息系统主页的设计思想和制作方法。该系统运用自顶向下的方法,设计了以主叶为根的多级树结构WWW资源信息库,并通过使用超文本标记语言(HTML)以及GIF动画等技术编制了我校WWW主页及其它页面。 相似文献
23.
用非线性方法分析了1989年3月13日大磁暴发生时地磁场的各分量,研究了非线性物理过程,讨论了非线性特征及其与纬度和K指数变化的关系,并指出地磁场是一个具有低昆沌的非线性系统。 相似文献
24.
热带气旋过程中海-气界面热量交换 总被引:3,自引:1,他引:3
为探索热带气旋与海洋相互作用,采用国家海洋局南海分局Marex(马瑞克斯)数据浮标实测资料,计算了1986年南海的7个热带气旋海气界面热量交换值.结果表明:热带气旋海气界面热量交换强烈,主要贡献来自潜热通量;热带气旋环流内水温、气温均是下降趋势,气温下降更为明显;夏季热带气旋环流内,感热通量会出现负值,海面有效反射辐射通量出现减弱现象;秋季热带气旋环流内,感热通量和海面有效反射辐射通量显著加强;在热带气旋环流内,海面吸收的短波辐射通量均出现减弱现象;热带气旋环流内受到冷空气影响时,感热变得相当重要,热带气旋表现为对海洋的响应为主. 相似文献
25.
地磁方法在地震预报中的应用 总被引:1,自引:5,他引:1
1989 年以来, 我们陆续提出转换函数法, 空间相关和加权差分法, 以及加卸载响应比法等3 种地磁方法, 将其用于200 多个震例分析, 其中有106 个地震作了正式的年度预报, 在97个次危险区预报中, 有15 个地震的时间、地点和震级三要素的预报较为成功。 相似文献
26.
Characterizing spatial patterns of precipitation based on corrected TRMM 3B43 data over the mid Tianshan Mountains of China 总被引:1,自引:1,他引:1
The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were characterized based on the TRMM 3B43 monthly precipitation data. By comparing satellite estimates with observed data, it shows that TRMM 3B43 data underestimate the precipitation in mountain region. Regression models were developed to improve the TRMM 3B43 data, using geographic location and topographic variables extracted from DEM using GIS technology. The explained variance in observed precipitation was improved from 64% (from TRMM 3B43 products alone) to over 82% and the bias reduced by over 30% when location and topographic variables were added. We recalculated all the TRMM 3B43 monthly precipitation grids for the period 1998 to 2009 using the best regression models, and then studied the variation patterns of precipitation over the mid Tianshan Mountains. The results are well explained by a general understanding of the patterns of precipitation and orographic effects. This indicated that the Tianshan Mountains strongly influences the amount and distribution of precipitation in the region. This is highlighted by the confinement of the precipitation maxima to the windward (northern slope). And complex vertical changes in the provenance and distribution of precipitation, like that a negative increasing rate of precipitation in the vertical direction exists in the north but does not in south. The results have also revealed large gradients and different patterns in seasonal precipitation that are not simply related to elevation, the distribution of precipitation may also be affected by other seasonal factors such as the sources of moist air, wind direction and temperature. 相似文献
27.
利用东亚及邻区49个地磁台1970-1979年、H、Z的实测年均值,逐年计算、缓制了蒙古异常的地磁非偶极场等值图,给出了蒙古异常非偶极场Zn分量的焦点位置和强度变化及其对中国东北地区地磁场的影响量级,计算表明蒙古异常的年变化是该区地磁场年变化的主要成份。 相似文献
28.
将日本从北至南划分为5个区, 分析1900—2011年3月共110 a期间发生的67个Ms=6.9~9.0大震事件, 与其后4 a在中国及邻区发生的Ms≥6.0(极个别为Ms=5.5~5.8)共569个中强地震的对应比较.得出结论: (1)日本大震和中国及邻区中强震二者有很好的遥相关关系; (2)分析了日本各区与中国及邻区地震相对应的特点; (3)中国地区地震的滞后时间多为0.5~2.0 a, 最长4 a; (4)用"遥相关法"预测2011—2013年期间, 中国及邻区的中强地震危险区.年度预测与实际发生地震检验结果显示: 预测的34个次地震危险区中, "报对"28个次, 约占总预测个次的82%, "虚报"6个次, 约占18%, 显示"遥相关法"对年度地震预测有一定效果; (5)提出"蜘蛛网"逆反应模型解释中国及邻区对日本大震的响应现象. 相似文献
29.
依据地磁台观测数据和地磁研究的方法,在 VAX-11/750计算机上应用 FORTRAN 语言,编制了14个用于数据处理和地磁方法研究的程序,共计4800条 FORTRAN 语句行.处理了100多个台15个月的观测资料,总计26万个数据。为地震预报和地震科研工作提供了可靠的数据,为管理部门考核台站的观测质量提供了定量依据。 相似文献
30.
Automated image classification and visual interpretation of Landsat imagery were used to extract the glacier boundary in the Nujiang-Salween River Basin (NSRB) around the years 1975, 2000, and 2020. The spatiotemporal characteristics of glacier area changes in the NSRB were determined and the reasons for the spatial heterogeneity in glacier area changes were discussed, based on comparative analyses of temperature and precipitation data from meteorological stations around the NSRB. The results indicate that 1) the total glacier area in the NSRB decreased by 477.78 km² (28.17%) at a rate of -0.62%/a in 1975-2020. Most shrinkage occurred at low and mid altitudes, with the most severe occurring at 5290-5540 m, accounting for 40% of the total shrinkage. Considering other river basins in China, the relative glacier area change rate in the NSRB was similar to that for typical inland river basins in northwest China but lower than that for other transboundary river basins in the southeastern Tibetan Plateau. 2) These areal changes in the NSRB presented obvious regional differences. The glaciers in the Hengduan Mountains retreated significantly, followed by those in the Nyainqentanglha Mountains, with relatively low shrinkage observed in the Tanggula Mountains. The number of cold and hot spots indicating areal changes increased after 2000, along with their spatial heterogeneity. 3) The glacier shrinkage rate over different time intervals was positively correlated with temperature. Thus, spatial heterogeneity of climate change effects could elucidate differences in the glacier area change rate in different regions of the NSRB. The temperature rise was determined as the primary reason for the significant glacial retreat over the past 45 years. As the significant warming trend continues, the glacier area in the NSRB is likely to shrink further. 相似文献