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21.
Induction of EROD activity in Paralichthys olivaceus by polychlorinated biphenyl CB-28 总被引:2,自引:0,他引:2
Abstract-The test organisms (Paralichthys olivaceus) were exposed to CB-28 with differentspiked concentrations. After 72 h, EROD activities in livers of the test organisms were measured. It wasfound that EROD activities significantly mounted up with the increase of spiked quantity. Therefore,there existed a dose-response relationship between EROD activities and specific pollutant concentrations.In the meantime, the optimal conditions for the analysis of EROD activity were discussed. The limita-tion of EROD activities as a monitoring parameter was also analyzed. 相似文献
22.
ATMOSPHERIC WAVE AND ITS PHYSICAL ESSENCE AS REVEALED BY CHANGED CORRELATION COEFFICIENTS AND CORRELATION FIELD*
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Formal change is made of the correlation coefficient(COCOEF) expression,leading to a new formula consisting of Fourier spectral coefficients that indicates a direct connection between the new form and atmospheric dynamic equations,thus resulting in a dynamic equation represented by COCOEF,which is meaningful in exploring a large-scale dynamic process in terms of the correlation field because the connection revealed by the field can have dynamic explanation with the aid of the new formula. 相似文献
23.
I.Intr0ducti0nAwnerresource-environmentalsystem,withmanyquantitativeandqualitativefactors,consistsofwaterresourcesdevelopmentandenvironment.Itisveryddriculttocarryoutoverallassessmentsanddecision-maldngstudiesofthesystemusingapurelyquantitativen1athematical-l11odel.However,AnalyticalHicerarcl1yProcess(AHP,anewmethodfOrtheplanninganddecisioll-making,combiningqualitativefactorswithquantitativefactors,cansolvethedecision-mdengpr0blemsOfmultiplehierarchiesandgOalsforacomplexsystem.Thismeth0d,t… 相似文献
24.
Interannual and Interdecadal Variations in Heat Content of the Upper Ocean of the South China Sea 总被引:2,自引:0,他引:2
The vertically averaged temperature (TAV) from surface to 100 m depth of the South China Sea for the period 1959-1988 is analyzed. The results indicate that there is a significant long-term variability from interannual to interdecadal scales in the heat content in the upper ocean. The heat content of the upper ocean of the South China Sea increases evidently in the El Nino year. TAV anomaly in the ocean was negative from the end of 1950’s to early l970’s, and then changed to positive. The changes of TAV of the ocean are closely related to ENSO events, the Asian winter monsoon and the tropical atmospheric circulation anomalies. 相似文献
25.
SHI Zejin LI Wenjie ZHANG Jin TIAN Yaming WANG Yong YIN Guan LUO Qichao 《《地质学报》英文版》2020,94(6):2053-2076
The in situ zircon U-Pb-Lu-Hf isotope records from end-Permian volcanic interlayers in southwest China, integrated with previous studies, restructure the evolutionary history of the Yangtze Craton from Precambrian to Late Paleozoic. This includes early continental crust formation before ~3.0 Ga and massive juvenile crustal growth at 2.6–2.4 Ga; large-scale crustal reworking at ~2.1–1.7 Ga; Neoproterozoic crust addition at ~1.1 to 0.7 Ga; collision and subduction along the craton margin between ~700–541 Ma; Early Ordovician to Late Silurian magmatism; and large tectono-thermal events in the Middle Carboniferous to end-Permian. Some zircons with TMD2 ages from 4.40 to 4.01 Ga and lower initial 176Hf/177Hf values of 0.280592 to 0.280726 may imply the existence of Hadean crust relics beneath the Yangtze Craton and their provenances could be associated with Hadean crustal remelting. This study further clarifies that the Precambrian-age zircons between the end-Permian volcanic interlayers, the complexes in the western margin of the Yangtze Craton, and the sedimentary Kangdian Basin, may share an affinity based on similar U-Pb age spectra and Hf isotope features. It also shows that the Neoproterozoic tectono-thermal event may be associated with large-scale tectono-rifting activity, which is different from the Grenville-age continental collision between Yangtze and Cathaysia blocks in South China. The above findings support the inference of a widespread Archean basement extending to the western Yangtze Craton and a provenance in the Kangdian Basin that is derived from the weathering and erosion of Paleoproterozoic continental crust. 相似文献
26.
INTRODUCTIONForavarietyofapplications,includingcoastalandoceanengineering,shiproutingandtheinterpretationofremotelysensedata,informationonthedirectionalwavespectrumisdesirable.Knowledegeoftheintegratedorone-dimensionalspectrumisconsiderable,duelargelytofieldmeasurementssuchasJONSWAP.Asimilarsituation,however,doesnotexistinthecaseofdirectionalsprectra.Thisislargelyduetotheaddedcomplexityandthecostofdirectionalmeasure1.InstituteofPhysicalOceanography,OceanUniversityofQingdao,Qingdao266… 相似文献
27.
<正>China,the world’s leading producer and consumer of mineral resources,faces significant ecological and environmental challenges resulting from the extensive and intensive exploitation of these resources.These challenges include the degradation of the geological environment in mining areas,depletion of land resources,and the decline in ecosystem functions.In 2018,remote sensing monitoring of the mining environment revealed that mining-damaged land (excluding salt lakes) in China accounted... 相似文献
28.
DDT, PAH and PCB in sediments from the intertidal zone of the Bohai Sea and the Yellow Sea 总被引:18,自引:0,他引:18
Current contents of persistent organic contaminants, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and the congeners (naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(a)pyrene and benzo(e)pyrene), DDTs and metabolites in the intertidal sediments of the Bohai Sea and the Yellow Sea were studied. The mean levels of DDTs, PAHs and PCBs were 177.52, 877.2 and 3.4 ng g-1 dry weight, respectively. The spatial trends of the contaminant residue levels were analysed too. 相似文献
29.
Dioxin-like compounds in sediments from the Daliao River Estuary of Bohai Sea: distribution and their influencing factors 总被引:1,自引:0,他引:1
The concentrations, compositional profiles, and potential ecological risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in sediments of the Daliao River Estuary were investigated. Total concentrations of PCDD/Fs, PCBs, and PCNs were in the range of 11.3-133.2 ng/kg dry weight (dw), 1 971-37 632 ng/kg dw and 33.1-284.4 ng/kg dw, respectively. The total TEQ values varied from 0.37 to 4.08 ng/kg dw, with the dominant contributions by PCDD/Fs, then by PCBs and PCNs. The spatial distributions of PCDD/Fs, PCBs and PCNs in the river estuary were much related to hydrodynamic conditions. The risk of contamination to the deeper sea was increased in the flood seasons. Moreover, our data confirmed that both organic matter in sediments and molecular properties of dioxin-like compounds were the factors which strongly influenced the partition behavior of these dioxin-like compounds between sediments and water phase in the estuarine zone. 相似文献
30.
Xiaoguo Guan Hongzhou Chai Guorui Xiao Zhenqiang Du Wenlong Qi Xueping Wang 《海洋学报(英文版)》2022,41(2):166-179
This study analyzes the signal quality and the accuracy of BeiDou 3 rd generation Satellite Navigation System(BDS3) Precise Point Positioning(PPP) in the Arctic Ocean. Assessment of signal quality of BDS3 includes signal to noise ratio(SNR), multipath(MP), dilution of precision(DOP), and code-minus-carrier combination(CC). The results show that, 5 to 13 satellites are visible at any time in the Arctic Ocean area as of September 2018, which are sufficient for positioning. In the mid-latitude ocea... 相似文献