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以酪蛋白和明胶为蛋白源 ,添加豆油、鱼油、糊精、纤维素以及适量的维生素和矿物质混合剂配制试验饲料 ,饲料配成5个蛋白质水平 ,每个蛋白水平分别包括5个能量级 ,以体质量增长倍数、蛋白质效率和饲料系数为评判依据 ,对体质量为8.73g±0.79g的中华鲟(Acipensersinensis)的适宜蛋白质含量及其蛋白能量比进行了研究。经过为期8周的试验 ,结果表明 :中华鲟幼鲟配合饲料中的适宜蛋白质含量范围为35.7%～41.8% ,饲料的最佳蛋白能量比范围为21.85～30.05ng/J。当试验饲料蛋白质含量为40.3% ,蛋白能量比为27.85ng/J时 ,试验鲟鱼获得最大体质量增长倍数为11.60±1.20,最低的饲料系数为1.68±0.23,以及最高的蛋白质效率为1.58%±0.14%。 相似文献
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金华地区位于金衢盆地东段,对其地下水同位素特征及更新能力研究对于整个盆地地下水资源研究具有重要意义,通过分析研究区内稳定同位素氘(D)和氧(~(18)O)以及放射性同位素氚(~3H)和碳(~(14)C)的空间分布特征,建立了金华地区降水线方程为:δD=8.29δ~(18)O+15.9,讨论了地表水、潜水、红层地下水的环境同位素的组成特征,对潜水及红层地下水的更新能力进行了评价。结果表明,金华地区降水线方程斜率及截距均大于全球大气降水;潜水、红层地下水及地表水三者联系密切;潜水、红层地下水在接受降水的补给后经历了不同程度的蒸发作用;红层地下水D和~(18)O同位素明显向下游富集;潜水~3H值介于6.6～19.0TU,~(14)C年龄显示为现代水,因此其可更新能力较强,红层地下水放射性~(14)C年龄为3020～5360BP,可更新能力较弱,红层地下水3H值介于4.4～12.3TU,表明红层地下水中有现代水的混入,δ~(18)O随着地下水的年龄的增加而偏负。 相似文献
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侧扫声呐是海洋调查常用的探测仪器,为保证测量数据的准确性,对其实际探测性能的评价就显得尤为迫切。文中从侧扫声呐的工作原理出发,梳理了检测力和分辨力在概念上的混淆,并提出了一种评价检测力的方法;通过在海底人工放置一些已知大小的目标物,精确测量各个目标物的位置信息,并使用EdgeTech 4200MP双频侧扫声呐系统对目标物进行扫测试验以检测其检测力。结果表明,目标物和航迹线方向平行时,能够清晰地分辨直径或边长为20 cm,30 cm的物体,不能分辨出直径为10 cm的圆形物体,但能较清晰的分辨出直径为0.9 cm的长绳;目标物在垂直航迹线方向时,能够清晰地分辨直径或边长为10 cm的目标物,但是不能分辨出直径为0.9 cm的长绳;综合评价得出其纵向检测力优于1 cm,横向检测力优于10 cm。对常用声呐探测仪器的标准化体系的建立有一定的帮助。 相似文献
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本文介绍了中国科学院青藏高原研究所在阿尔金断裂西段进行GPS观测的剖面布设和首期观测情况.利用GAMIT/GLOBK软件对首期观测数据进行了处理,并将结果归算到区域参考框架下.GAMIT计算得到的"准观测值"均满足所须精度,其中单天解标准化均方差小于0.3,基线的平均相对精度为1.8×10-9.GLOBK在区域参考框架... 相似文献
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选定遥感解译程度较好的贵州西部高原山区织金片作为研究对象,以美国Landsa t / TM数据为数据源,选择各波段之间相关系数最小的TM7、TM 4、TM1波段合成假彩色图像,采用人机交互的目视解译方法进行影像地层划分。研究区碳酸盐岩地层以其独特的溶蚀地貌而显示为斑状、块状影像,地表水系不发育; 碎屑岩地层因流水侵蚀地貌而表现为曲线状、网状纹理,从而使不同地层上下层位在空间结构信息上显示出差异。据此,通过界面、特殊纹理、代表性色调和典型水系等对地层影像进行比较、确认。在此基础上,将研究区主要出露的地层划分为14个影像地层单元。经野外验证,影像地层划分结果与传统的地层划分单元或单元组合吻合度较好。 相似文献
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A Simulating Study on Resolvable-Scale Microphysical Parameterization in a Mesoscale Model 总被引：3，自引：1，他引：2
The Penn State/ NCAR Mesoscale Model (MM5) is used to simulate the precipitation event that oc-curred during 1-2 May 1994 to the south of the Yangtze River. In five experiments the Kain-Fritsch scheme is made use of for the subgrid-scale convective precipitation, but five different resolvable-scale microphysical parameterization schemes are employed. They are the simple super-saturation removal scheme, the warm rain scheme of Hsie et al. (1984), the simple ice scheme of Dudhia (1989), the complex mixed-phase scheme developed by Reisner et al. (1993). and the GSFC microphysical scheme with graupel. Our interest is how the various resolvable-scale schemes affect the domain-averaged precipitation, the pre-cipitation distribution, the sea level pressure, the cloud water and the cloud ice.Through a series of experiments about a warm sector rainfall case, results show that although the dif-ferent resolvable-scale scheme is used, the differences of the precipitation characteristics among all five runs are not very obvious. However, the precipitation is over-predicted and the strong mesoscale low is produced by the simple super-saturation removal scheme. The warm rain scheme with the inclusion of condensation and evaporation under-predicts the precipitation and allows the cloud water to reach the 300 hPa level The scheme of the addition of graupel increases the resolvable-scale precipitation by about 20%–30%. The inclusion of supercooled liquid water in the grid-scale scheme does not affect significantly the results. 相似文献
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江西永豐縣南,古縣至瑤田間之梁坊橋附近,有一變形礫岩層,恰位於走向北10度東及北80度东兩逆斷層啣接處。該礫岩層中之礫石,多為扁平橢圓形,其長軸兩端逐漸尖化,外附絲澤、臘狀、光滑表皮,並有新生之雲母片及長纖維狀物質,於此光滑面上,常具深刻水平擦痕。這些變形礫石,受外力變形後,共長軸近於東西,扁平面平行於北80度東之斷層面舆附近岩層之片理。垂直變形礫石a,b,c三軸及膠結物質延長方向,分製薄片,在顯微鏡下觀察,其膠結物為灰白色雲母及許多無光性之黑色物質,呈顯著之流紋構造,內含大小不一之眼球狀石英粒等;石英礫石內之石英晶體,均具極强之波浪消光,於晶體四周,圍繞密擠再結晶之小型石英粒,而示標準磨碎構造。晶體本身含有無數極小之氣孔或包體,並作一定方向排列,而成變形紋理,平行於扭應面;在石英岩礫石內,石英粒均沿一定方向延長,並按其大小作帶狀排列。礫石內部,擁有極複雜之節理舆顯明之断層,這些事實象微着强烈的外力作用。根據弗氏旋轉台再結晶石英粒。軸及雲母底面等之統計舆分析,得知其晶體排列恆受扭應力支配。 相似文献
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By using 40-year NCEP reanalysis daily data (1958-1997), we have analyzed the climatic
characteristics of summer monsoon onset in the South China Sea (105°E ~ 120°E, 5°N ~ 20°N, to be simplified
as SCS in the text followed) pentad by pentad (5 days). According to our new definition, in the monsoon area of
the SCS two of the following conditions should be satisfied: 1) At 850hPa, the southwest winds should be greater
than 2m/s. 2) At 850 hPa, θse should be greater than 335°K. The new definition means that the summer
monsoon is the southwest winds with high temperature and high moisture. The onset of the SCS summer monsoon
is defined to start when one half of the SCS area (105°E ~ 120°E,5°N ~ 20°N) is controlled by the summer
monsoon. The analyzed results revealed the following: 1) The summer monsoon in the SCS starts to build up abruptly
in the 4th pentad in May. 2) The summer monsoon onset in the SCS is resulted from the development and
intensification of southwesterly monsoon in the Bay of Bengal. 3) The onset of the summer monsoon and
establishment of the summer monsoon rainfall season in the SCS occur simultaneously. 4) During the summer
monsoon onset in the SCS, troughs deepen and widen quickly in the lower troposphere of the India; the
subtropical high in the Western Pacific moves eastward off the SCS in the middle troposphere; the easterly
advances northward over the SCS in the upper troposphere. 相似文献