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81.
福建省地壳形变观测网络建设   总被引:1,自引:5,他引:1  
介绍了福建省地壳形变观测网络的建设。福建省地壳形变观测网络,以GPS观测技术为主,结合精密水准、精密重力和流动地磁测量,将3者重合到GPS观测基准站上获取观测信息,初步构成一个时空相结合,点线面与长中短兼顾的高精度、高时空分辨率的地壳形变观测网络。该网络可动态监测福建省东南沿海地区地壳运动变化,为地震预测预报提供背景信息,将取得显著的社会效益和经济效益。  相似文献   
82.
研究了外源性蜕皮激素对凡纳滨对虾生长和表观消化率的影响 ,实验时在基础饲料中分别添加 0 .1%、0 .2 %、0 .4 %的两种市售蜕壳素产品 ,制成 6种外源性脱壳素配合饲料 ,不添加的基础饲料作为对照组 ,试验在 2 6 0L玻璃钢循环水养殖系统中 ,每个剂量组设 3个重复 ,8周生长试验结果表明 :市售蜕壳素产品能有效地促进对虾生长 ,试验结束时 ,试验组虾体增重分别较对照组增加 16 .8%、7.5 2 %、5 .9%、11.4 %、2 9.0 7%、16 .5 3% ,但是凡纳滨对虾对饲料粗蛋白的表观消化率没有明显地提高 ,凡纳滨对虾对脂肪的表观消化率较低。推算凡纳滨对虾饲料中最佳蜕皮酮添加量为 6 0mg/kg。  相似文献   
83.
大姚6级双震前的地震前兆特征   总被引:6,自引:2,他引:6  
在连续形变观测资料中除了存在于整个时间域的短周期潮汐信息(固体潮)外,还有出现在某个时间段的长周期非潮汐信息.如何从时间或空间上认识和提取这些信息.成为认识地震过程和进行地震预报关键和迫切的问题之一。利用小波分析的时一频特性和奇异性检测特性,对大姚6级双震前的连续形变观测资料进行了处理,提取潮汐资料中的非潮汐信息。发现在地震前震中附近的形变台站都接收到了相同频段的异常信号.周期为几天到十几天,出现在各个台站的时间也大致相同。这些在震前具有一定时、空分布的信息有可能是地震前兆。  相似文献   
84.
85.
Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer(MODIS) Normalized Difference Vegetation Index(NDVI) data and meteorological data(temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase(especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass.  相似文献   
86.
The feasibility of using fluorescence excitation-emission matrix (EEM) along with parallel factor analysis (PARAFAC) and nonnegative least squares (NNLS) method for the differentiation of phytoplankton taxonomic groups was investigated. Forty-one phytoplankton species belonging to 28 genera of five divisions were studied. First, the PARAFAC model was applied to EEMs, and 15 fluorescence components were generated. Second, 15 fluorescence components were found to have a strong discriminating capability based on Bayesian discriminant analysis (BDA). Third, all spectra of the fluorescence component compositions for the 41 phytoplankton species were spectrographically sorted into 61 reference spectra using hierarchical cluster analysis (HCA), and then, the reference spectra were used to establish a database. Finally, the phytoplankton taxonomic groups was differentiated by the reference spectra database using the NNLS method. The five phytoplankton groups were differentiated with the correct discrimination ratios (CDRs) of 100% for single-species samples at the division level. The CDRs for the mixtures were above 91% for the dominant phytoplankton species and above 73% for the subdominant phytoplankton species. Sixteen of the 85 field samples collected from the Changjiang River estuary were analyzed by both HPLC-CHEMTAX and the fluorometric technique developed. The results of both methods reveal that Bacillariophyta was the dominant algal group in these 16 samples and that the subdominant algal groups comprised Dinophyta, Chlorophyta and Cryptophyta. The differentiation results by the fluorometric technique were in good agreement with those from HPLC-CHEMTAX. The results indicate that the fluorometric technique could differentiate algal taxonomic groups accurately at the division level.  相似文献   
87.
The foundations of some ocean engineering structures are built to withstand not only the vertical gravity load V, but also the horizontal load H induced by sea waves and current. The horizontal load includes the concentrated force load, the moment load M, and the torque load T termed also as combined loading. It is of academic and engineering significance to study the deformation law of submarine seabed due to combined loading. On the basis of the three-dimensional elastic mechanics solution of circular foundation, numerical methods are used to analyze the deformation law of submarine soil under circular foundation with six degrees of freedom. The finite element analysis results give the elastic deformation law of soil in three dimensional spaces, modify the theoretical elasticity solution, and presents nonlinear soil deformation mechanism under the circular foundation with six degrees of freedom.  相似文献   
88.
Due to their particular physiology and life history traits, bryophytes are critical in regulating biogeochemical cycles and functions in alpine ecosystem. Hence, it is crucial to investigate their nutrient utilization strategies in comparison with vascular plants and understand their responses to the variation of growing season caused by climate change. Firstly, this study testified whether or not bryophytes can absorb nitrogen(N) directly from soil through spiking three chemical forms of 15N stable isotope tracer. Secondly, with stronger ability of carbohydrates assimilation and photosynthesis, it is supposed that N utilization efficiency of vascular plants is significantly higher than that of bryophytes. However, the recovery of soil N by bryophytes can still compete with vascular plants due to their greater phytomass. Thirdly, resource acquisition may be varied from the change of growing season, during which N pulse can be manipulated with 15N tracer addition at different time. Both of bryophytes and vascular plants contain more N in a longer growing season, and prefer inorganic over organic N. Bryophytes assimilate more NH4+ than NO3– and amino acid, which can be indicated from the greater shoot excess 15N of bryophytes. However, vascular plants prefer to absorb NO3– for their developed root systems and vascular tissue. Concerning the uptake of three forms N by bryophytes, there is significant difference between two manipulated lengths of growing season. Furthermore, the capacity of bryophytes to tolerate N-pollution may be lower than currently appreciated, which indicates the effect of climate change on asynchronous variation of soil N pools with plant requirements.  相似文献   
89.
In order to make use of ocean clay reasonably and excavate its potential applications the properties of ocean clay in Chinese investigating area of the East Pacific have been tested with the chemical analysis, XRFS, ICP/MAS, granulometry and SSA, etc. The results show that the clay sediments of this area are rich in clay minerals, fine granularity, bigger SSA, bigger water absorbability and lower ion changing ability etc. To improve the adaptability of ocean clay and macromolecule materials, using the dry milling method with silane, aluminate, stearic acid coupling agents etc the properties of ocean clay are improved. The effect has been evaluated by testing the water absorbing of the modified ocean clay and their dispersing in paraffin liquid. The result is that KH550 is better than any other active reagents, and the best activation technics is that 1.5% (volume) of KH550 quantity, 20min of milling time. The DTA, XRD, SEM and IR analyses and SSA testing show that the organic activation can not change the mineral structure but can densify the structure of clay, and activation mechanism is chemical covered mainly and chemical combined secondly.  相似文献   
90.
Reserves of some kinds of the crisis mines will be lack now or from now on, because of lacking seriously reserves of mineral resources and the crisis of exploring bases in support. So that it is urgent to predict, appraise, development and utilize the replaceable resources of the crisis mines. The mineral resources prediction software system of synthetic information is intelligent GIS which is used to quantitative prediction of large-scale synthetic information mineral target. It takes the geological body and the mineral resource body as a unit. And it analyzes the ore deposit genesis and metallotect, knows the spatial distribution laws of the ore deposit and ore body, and establish the prospecting model based on the concept of establishing the three-dimensional space of a mine. This paper will primarily discuss some important problems as follows: the secondary development of various kinds of data(including geology, geophysical prospecting, geochemical prospecting and remote sensing, etc); process synthetically and establish the synthetic information interpretative map base; correspond prospecting model with synthetic information of ore deposit; divided into statistical units of metallogenic information synthetic anomalies based on the synthetic information anomalies of ore control, then research the metallogenic information variable of unit synthetically and make quantitative prediction according to choose the quantitative prediction math model which is suitable to the demands of large-scale precision; at last, finish the target area optimization of ore deposit (body).  相似文献   
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