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181.
利用短边GPS点阵、短基线标石阵和精密激光测距 ,在与鲜水河断裂带的断层破裂带垂直的剖面上和构造盆地内进行构造大地测量 ,获得了断层软弱带和断层蠕变带上的最佳形变分布。综合利用相关地学成果和理论 ,揭示了构造形变所隐含的动力学信息 ,识别了断层应变带、塑性流变带和主断面在地面的分布范围。用外围GPS远场联测成果探讨了该断裂带的驱动力机制 ,匡正了其“左旋”运动和现今活动速度的含义。最后 ,评估了该断裂的地震活动趋势 相似文献
182.
183.
A three-dimensional baroclinic shelf sea model was employed to simulate the seasonal characteristics of the South China Sea (SCS) upper circulation. The results showed that: in summer, an anticyclonic eddy, after its formation between the Bashi Channel and Dongsha Islands in the northeastern SCS, moves southwestward until it disperses slowly. There exists a northward western boundary current along the east shore of the Indo-China Peninsula in the western SCS and an anticyclonic gyre in the southern SCS. But at the end of summer and beginning of autumn, a weak local cyclonic eddy forms in the Nansha Trough, then grows slowly and moves westward till it becomes a cyclonic gyre in the southern SCS in autumn. At the beginning of winter, there exists a cyclonic gyre in the northern and southern SCS, and there is a southward western boundary current along the east shore of the Indo-China Peninsula. But at the end of winter, an anticyclonic eddy grows and moves toward the western boundary after forming in the Nansha Trough. The eddy‘s movement induces a new opposite sign eddy on its eastern side, while the strength of the southward western boundary current gets weakened. This phenomenon continues till spring and causes eddies in the southern SCS. 相似文献
184.
With the increasing effects of global climate change and fishing activities,the spatial distribution of the neon flying squid(Ommastrephes bartramii) is changing in the traditional fishing ground of 150°-160°E and 38°-45°N in the northwest Pacific Ocean.This research aims to identify the spatial hot and cold spots(i.e.spatial clusters) of O.bartramii to reveal its spatial structure using commercial fishery data from2007 to 2010 collected by Chinese mainland squid-j igging fleets.A relatively strongly-clustered distribution for O.bartramii was observed using an exploratory spatial data analysis(ESDA) method.The results show two hot spots and one cold spot in 2007 while only one hot and one cold spots were identified each year from2008 to 2010.The hot and cold spots in 2007 occupied 8.2%and 5.6%of the study area,respectively;these percentages for hot and cold spot areas were 5.8%and 3.1%in 2008,10.2%and 2.9%in 2009,and 16.4%and 11.9%in 2010,respectively.Nearly half(45%) of the squid from 2007 to 2009 reported by Chinese fleets were caught in hot spot areas while this percentage reached its peak at 68.8%in 2010,indicating that the hot spot areas are central fishing grounds.A further change analysis shows the area centered at156°E/43.5°N was persistent as a hot spot over the whole period from 2007 to 2010.Furthermore,the hot spots were mainly identified in areas with sea surface temperature(SST) in the range of 15-20℃ around warm Kuroshio Currents as well as with the chlorophyll-a(chl-a) concentration above 0.3 mg/m~3.The outcome of this research improves our understanding of spatiotemporal hotspots and its variation for O.bartramii and is useful for sustainable exploitation,assessment,and management of this squid. 相似文献
185.
Remote sensing technique has played an important role in land use dynamic monitoring, but as for the land use dynamic monitoring
at county level, traditional remote sensing methods such as satellite imagery visual interpretation and computer classification
can not meet its demand for accuracy. The result of 1: 10 000 land use investigation map has high accuracy, but this method
can not be used to dynamically monitor the land use because of its big expenses, long period and difficulty in updating data.
In this paper, the characteristics of physiognomy, climate and the status of land use in Dehui County are taken into consideration
and a set of method, which takes use of 3S techniques and applies to Northeast China Plain, is come up with. When the land
use type of a land parcel changed as a whole, the date updating can be make by changing its land type ID in the attribute
table in a GIS. When the land use type of an irregular area changed, GPS receivers are used to position its border. This set
of method is characteristic of high accuracy and low expenses. It gets the information of land use change timely and can be
used to dynamically monitor the land use.
Foundation item: Under the auspices of the key project of the National Ninth Five-year Plan (96-B02-01-07).
Biography: LI Lin-yi (1968 —), female, a native of Jilin, Ph. D. candidate of Changchun Institute of Geography, the Chinese
Academy of Sciences. Her research interest includes land use change monitoring and crop yield estimation using “3S” techniques. 相似文献
186.
The primary goal of this study was to assess the effect of varying densities on serum reproductive parameters of immature rainbow trout Oncorhynchus mykiss. Experimental trout were maintained in intensive, pen-reared farms for 300 days in fresh water reservoirs. Initial densities were 4.6, 6.6, and 8.6 kg/m3 (40, 60, 80 ind./m3), indicated as SD1, SD2, SD3, and final densities were 31.1, 40.6, 49.3 kg/m3, respectively. A summary of the ovarian stages were observed by histological examination. Serum E2 (estradiol), T (testosterone) were evaluated by radioimmunoassay and FSH (follicle-stimulating-hormone), LH (luteinizing-hormone), vitellogenin, 17α,20β-P (17α,20βdihydroxy4-pregnen-3-one) were measured by enzyme-linked immunosorbent assay. Our findings demonstrated that ovarian development were retarded (from stage III to stage IV) at highest rearing density (SD3) after 180 days of intensive culture (over 40.6 kg/m3). In addition, we observed an inverse relationship between serum reproductive parameters and rearing density. Furthermore, compared to serum reproductive parameters of SD1, E2, T, FSH, vitellogenin, 17α,20β-P, GSI and LH of two higher density groups decreased firstly and significantly at 60 (over 15.9 kg/m 3 ), 180 (over 31.7 kg/m 3 ), 180 (over 40.6 kg/m3), 240 (over 36 kg/m3), 240 (over 36 kg/m3), 240 (over 45 kg/m3) and 300 (over 49.3 kg/m3) days, respectively. Comparing serum reproductive parameters within the same ovarian development stage of rainbow trout from varying densities revealed that higher population density also led to significantly lower overall serum reproductive parameters. Overall, this study presents the reproductive, endocrinological parameters of juvenile female rainbow trout at high rearing densities and indicates the need for rainbow trout (114.44±5.21 g, 19.69±0.31 cm) that are initially stocked at 6.6 or 8.6 kg/m3 should be classified and subdivided into lower density after 180 days of farming (not over 31.7 kg/m3). 相似文献
187.
Summarized results of studies on the physical and interfacial chemistry of the Huanghe estuary are presented as follows: 1.
The relationship between the exchange ratio (%) and pH for the Cu (II)-Sedi.ments of the Huanghe Estuary and that of the Cu
(II)-illite system were observed to be very similar. 2. A stepwise ion/coordination particle exchange isotherm of trace metal
in Huanghe estuary sediment was derived. 3. The ion/coordination particle exchange between trace metal and Huanghe Estuary
sediment is analogous to the interfacial chemical characteristic of illite. 相似文献
188.
本文介绍在IBM-PC微机(或兼容机)上利用DBASEⅡ、BASIC和FOR-TRAN语言设计和研制的一套大气边界层气象资料数据库软件系统,给出它的主要结构和功能。该系统实现了大气边界层气象资料共享和信息化处理,不但操作简便、快速、准确、稳定性好,而且具有较强的通用性和较大的实用价值。 相似文献
189.
The results obtained from the Cu(II)%-pH curve of the system in the presence of added amino acid indicated that the added
amino acids of higher concentration can inhibit the Cu(II)-σ-MnO2 ion exchange and that their inhibiting effects decrease in the following sequence when the initial amino acid concentrations
are 20.00 ppm: histidine > cystine > glutamic acid > proline > alanine > glycine. The determination of amino acid in solution
performed with an amino acid analyser showed that added amino acids react chemically on the surface of the σ-MnO2 According to thermodynamic equilibria relations in the system, amino acids can be changed to amines because of their decarboxylation
on the surface of the σ-MnO2. Considering (1) the effect-inhibiting factor of amine FA(β, Ka, pH) representing the complex potential of amine with Cu(II) in solution and (2) the acidic constant of −NH
3
+
group in the amine molecule representing the ability of cation exchange of the amine with σ-MnO2, the inhibiting seqence of added amino acid of 20.00 ppm (Eq.(1)) is reasonable. Thus added amino acids do inhibit Cu(II)-σ-MnO2 ion exchange because (1) the amino acid and/ or amine, which is the decarboxylate of the corresponding amino acid, complex
with Cu(II) in solution and compete with σ-MnO2 for Cu(II); (2) the cation exchange of the amino acid and/or amine reduce the exchange site on the surface of the σ-MnO2. The results obtained from the isotherms indicated that the theory of interfacial stepwise ion exchange can be extended to
the Cu(II) σ-MnO2 ion exchange system in the presence of added amino acid. 相似文献
190.
Regional Differences of China′s Urban Expansion from Late 20th to Early 21st Century Based on Remote Sensing Information 总被引:1,自引:3,他引:1
This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors. 相似文献