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1.
1 Introduction Ultravioletradiationisahighlyactivecomponentofsolarspectrum .Ultravioletradiationhasdetrimentaleffectsonlivingthingsexposedtosunlight ,includingthedestructionofDNA ,proteinsandothermolecules(Harm ,1980 ) ,inhibitionofphotosynthesisandgrow… 相似文献
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This study showed that the combined effect of absorption of planktonic algae and water on water color shift can be simulated
approximately by the exponential function: Log(E
100cm
W
+E
100cm
Xch1
)=0.002λ−2.5 whereE
100 cm
W
,E
100cm
Xchl
are, respectively, extinction coefficients of seawater and chlorophyll—a (concentration is equal toX mg/m3), and λ (nm) is wavelength.
This empirical regression equation is very useful for forecasting the relation between water color and biomass in water not
affected by terrigenous material. The main factor affecting water color shift in the ocean should be the absorption of blue
light by planktonic algae. 相似文献
4.
1 INTRODUCTION The Yellow Sea and the East China Sea are typical coastal Case-II waters with high sediment load and complicate optical properties. The total absorption coefficient of sea water is one of the main parameters influencing the calculation of o… 相似文献
5.
Dual filtration effect of geochemical and biogeochemical processes in the Changjiang Estuary 总被引：2，自引：0，他引：2
Dissolved nutrients (NO
3
−
, PO4
3−, SiO3
2−) and oxygen, chlorophyll- a, pH, and Eh were measured on board during a cruise in August 1988 in the Changjiang Estuary region.
Heavy metals, organic matter and carbonate contents were analyzed in laboratory. The results show that geochemical processes
in the Changjiang Estuary have dual filtration effect: on the one hand geochemical filtration effect, reflected by ferromanganese
oxide flocculation and sedimentation, occurs near the turbidity maximum, and leads to enrichment of heavy metals in suspended
matter and sediments; on the other hand biogeochemical filtration, reflected by nutrients consumption, organic matter and
carbonate sedimentation and enrichment of trace elements in suspended matter, occurs outside the plume water front. The biogeochemical
filtration affects the environmental conditions; the dissolved oxygen and pH increase, in surface water and decrease in bottom
water. The biogeochemical filtration effect outside the plume front is more important than the geochemical filtration effect
near the turbidity maximum. 相似文献
6.
星载高光谱Hyperion数据在海滩涂调查应用中的分析 总被引：3，自引：0，他引：3
以江苏苏北地区为研究区,较系统地分析了目前世界上星载传感器中光谱分辨率最高的EO-1卫星Hyperion数据的基本特点和处理方法,研究了将图像的灰度值转变为辐射能量值和反射率的方法和步骤,并选取了15类典型地物,进行了样本采集、辐射亮度和反射率反演,最后对典型地物的光谱曲线进行综合分析研究,并概括了苏北沿海滩涂典型地物的基本光谱特征。 相似文献
7.
Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically 总被引：2，自引：1，他引：1
The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematococcus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba's method, alkali treatment destroys chlorophyll. However, we found that: 1) carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2) dimethyl sulfoxide (DMSO)-extracted chlorophyll of green Haematococcus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract. 相似文献
8.
QI Yanxia JI Hongwei XIN Huizhen LIU Li 《中国海洋大学学报(英文版)》2007,6(2):143-146
A new kinetic-spectrophotometric method is proposed for the determination of copper （ Ⅱ ）. The method is based on the catalytic effect of copper （ Ⅱ ） on the oxidation of weak acid brilliant blue dye （RAWL） by hydrogen peroxide. The copper （ Ⅱ ） can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The optimum reaction conditions are as follows： pH 7.20, buffer solution NaOH-KH2PO4, RAWL （200 mgL-1） 5.00 mL, H2O2 （30%） 0.50 mL, reaction temperature 80 ？？ and reaction time 20 min. The linear range of this method is between 0 μg L^-1 and 12 μg L^-1 and the limit of detection is 0.011 μg L-1, the relative standard deviation （RSD） in five replicate determinations for 2 and 8 μg L-1 copper （ Ⅱ ） are 3.2% and 2.3%, respectively. Twenty ions do not interfere in the determination of copper （ Ⅱ ）. The method has been applied satisfactorily to the determination of copper （ Ⅱ ） in freshwater samples （tap water and Yellow River water from Lijin, Shandong, China） and seawater samples （from the South China Sea）, the recovery rates are 98.0%, 102.5% and 96.0%, respectively. 相似文献
9.
Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Biosorption
of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal
of these pollutants from aqueous solution. The search of marine actinobacteria with potential heavy metal biosorption ability
resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species. The biosorption property of Streptomyces VITSVK5 spp. was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb). Physiochemical characteristics and trace
metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L−1, cadmium 3.1±0.3μg L−1, zinc 8.4±2.6μg L−1 and copper 0.3±0.1μg L−1, whereas mercury was well below the detection limit. The effect of pH and biomass dosage on removal efficiency of heavy metal
ions was also investigated. The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84%
biosorption respectively. The biosorbent dosage was optimized as 3 g L-1 for both the trace metals. Fourier transform infrared
absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (-COOH), hydroxyl (-CHOH) and
amine (-NH2) groups of biomass with the metal ions. This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp. The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments. 相似文献
10.
A spectral method to investigate the effect of Fe3+, Fe2+ on the thermostability of phycocyanin (PC) ofSpirulina maxima showed that iron ions provent decrease of visible light absorbance and fluorescence intensity of PC. Increase in denaturation temperature caused by Fe3+ was observed by the micro-differential scanning calorimetric method. All results showed iron ions maintain the aggregation stability of the PC. The absorption spectrum of phycocyanobilin (PCB, a prosthetic group of PC) with Fe3+ in chloroform was quite different from that of free PCB.
相似文献11.
Chitosan derived from crab shells,was used to prepare the graft polymer in aqueous solution with acrylamide (AM) and methacrylatoethyl trimethyl ammonium chloride (DMC) as raw materials and ceric ammonium nitrate (CAN) as initiator.The floc-culation ability of the resulting polymer (PCAD) was studied in waste water treatment experiments.Its properties were determined on the basis of the transmittance of waste water after flocculation.The effects of chitosan and DMC content on PCAD’s flocculation ability wer... 相似文献
12.
1 IntroductionHydrophobically modified water-soluble polymers,also known as hydrophobized polymers, are thosemodified by hydrophobic groups such as alkyl,arolkyl, and deoxycholic acid. In water, they canself-aggregate due to their intro- and/or intermolecularhydrophobic interaction. By this process, unique hy-drogel nanoparticles with hydrophobic core and hy-drophilic shell can be prepared, which is a new ap-proach to preparing the monodispersed hydrogelnanoparticles (Whitesides et al., 1991; … 相似文献
13.
Phytoplankton Community Dynamics in West Lake After Drawing Water from the Qiantang River 总被引：2，自引：0，他引：2
1INTRODUCTIONTheWestLake ( 30°1 5′N ,1 2 0°1 6′E)isasmallshallowlakeinthewesternpartofHangzhouCityinthesoutheasterncoastalareaofChina.Thelakeissur roundedonthreesidesbyhills ;andisfamousforitspicturesquesceneryandinterfusionofhillsandwaterbodies.Thesurfaceareaisabout 5 .66km2 andmeandepthis 1 .8m .Beforethe 1 95 0s ,thelakewaterwascleanandmacrophytesgrewveryluxuriantlyinthelit toralareasofthelake .In 1 95 2 ,WestLakewasdredgedand 70 0× 1 0 4m3 mudwasremovedfromthebottomofthelake … 相似文献
14.
Distribution, variation and impact factors of biomass of bacterioplankton from April to May 1999 in Bohai Sea were studied in DAPI method with epifluorescence microscopy. The biomass in surface waters showed a small day-night variation, varying from 0.13 to 2.51μg/dm^3 with an average of 0.84μg/dm^3. The biomass in bottom waters showed, however, a large variation, changing from 0.15 to 4.18μg/dm^3 with an average of 1.36μg/dm^3. The peak values occurred at 5 and 11 a.m. The bottom water biomass showed a significant correlation with particulate organic carbon （r=0.639, P〈0.05）. Heterotrophic bacterioplankton biomass was high in nearshore waters and low in offshore areas with a high biomass zone around Huanghe （Yellow） River mouth, showing the same distribution of nutrients. In vertical distribution, heterotrophic bacteria biomass in bottom waters was higher than that in surface water. 相似文献
15.
The distribution and chemical properties of colored dissolved organic matter(CDOM) in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated. The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a_(355)) in the study area. The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37 m~(-1)) to the open sea(0.18 m~(-1)). The spectral slope ratio(the slope ratio S_R defined as S_(275-295):S_(350-400)) during the cruise was correlated with salinity, and exhibited a large variation from inshore(average of 2.515) to offshore sites(average of 5.327) compared with the distribution of a_(355). The values of S_R were related to CDOM molecular weight(MW). The a_(355), S_R, and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples, implying a strong exchange action between the microlayer and bulk water. The a_(355) and S_R of CDOM exhibited significant microlayer enrichment, with mean enrichment factors(EFs) of 1.72 and 1.62, respectively. 相似文献
16.
Ma Yanyan Li Guangxue Ye Siyuan Zhang Zhiheng Zhao Guangming Li Jingyang Zhou Chunyan Ding Wenjie Yang Xin 《中国海洋湖沼学报》2010,28(6):1362-1370
The water and sediment discharge regulation (WSDR) project, which has been performed since 2002 before flood season every
year, is of great significance to the river management in China. Until 2007, six experiments have been fulfilled to evaluate
the effect of the project on the natural environment. To fill the gap of investigations, a study on flood and suspended sediment
transportation and channel changing along the distributary channel of the Huanghe (Yellow) River was conducted during the
WSDR project period in 2007. The lower channel was scoured rapidly and the channel became unobstructed gradually several days
after the flood peak water was discharged from the Xiaolangdi Reservoir. Within four days after the flood peak at 3 000 m3/s entered the distributary, the channel in the river mouth area was eroded quickly. Both the mean values of area and depth
of the main channel were tripled, and the maximum flood carrying capacity increased to 5 500 m3/s or more. Then, the river channel was silted anew in a very short time after completion of the WSDR. Favored by the WSDR
project, the river status in April 2008 became better than that of the year before. The adjustment ranges of main channel
parameters were about 30%, 10%, and 10% at sections C2, Q4, and Q7, respectively. The process of rapid erosion-deposition
was more active 15 km away in the channel from the river mouth due to the marine influence. It is reasonable for discharging
sediment at concentration peak from Xiaolangdi Reservoir at the end of the flood peak. As a result, the sediment peak reached
the river mouth about two days later than that of the water current. In addition, the WSDR project has improved the development
of the estuarine wetland. Wetland vegetation planted along the river banks restrained the water flow as a strainer and improved
the main channel stability. It is suggested to draw water at mean rate of 150 m3/s from the Huanghe River during flood periods, because at the rate the water in the wetland would be stored and replenished
in balance. Moreover, we believe that cropland on the river shoal of the lower Huanghe River should be replaced by wetland.
These activities should achieve the Huanghe River management strategy of “To concentrate flow to scour sediment, stabilize
the main channel, and regulate water and sediment”. 相似文献
17.
A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports
through the four main straits in the South China Sea. The results show that the annual transports through the four straits
Luzon Strait, Taiwan Strait, Sunda Shelf and Mindoro Strait are −4.5, 2.3, 0.5 and 1.7 Sv (1 Sv=106 m3s−1), respectively. The Mindoro Strait has an important outflow that accounts for over one third of the total inflow through
the Luzon Strait. Furthermore, it indicates that there are strong seasonal variations of water transport in the four straits.
The water transport through the Luzon Strait (Taiwan Strait, Sunda Shelf, Mindoro Strait) has a maximum value of −7.6 Sv in
December (3.1 Sv in July, 2.1S v in January, 4.5Sv in November), a minimum value of −2.1 Sv in June (1.5 Sv in October, −1.0
Sv in June, −0.2 Sv in May), respectively.
Supported by National Natural Science Foundation of China (No. 40806012, 40876013), Open Fund of the Key Laboratory of Ocean
Circulation and Waves, Chinese Academy of Sciences (No. KLOCAW0803) and Scientific Research Foundation for talent, Guangdong
Ocean University (No. E06118) 相似文献
18.
1 INTRODUCTION Bioavailability to the biota and the biogeo-chemistry of trace metals in marine environment areaffected by their chemical speciation in the naturalsystem (Bruland et al., 1991; Van den Berg andDonat, 1992; Wells et al., 1998). Therefore, thesetwo parameters, the ligands concentrations andconditional stability constants, are important todetermine the complexing capacity. Sea surface microlayer (SML), the thin interfa-cial boundary between ocean and atmosphere, playsan imp… 相似文献
19.
Based on the optical data for transmitted radiation through sea ice in the Arctic during the late autumn and early winter of 2007,the authors studied the arriving solar radiation,reflected radiation and transmitted radiation under very low solar altitude.Through the atmosphere,the light of the arriving solar radiation at short wavelength was weakened,with the spectral distribution of double peaks centered at 490 nm and 683 nm.The magnitude of the peak at 683 nm even exceeded that at 490 nm under the very low solar radiation condition.The reflection was lower than that in summertime because of the thin thicknesses of ice and snow,allowing higher ratio of heat to enter the sea ice and snow.When higher ratio of solar radiation entered sea ice in late autumn,the new ice freezing would be affected.The spectral reflectivity from snow surface was almost a constant,but the reflection without snow decreased at longer wavelengths.In the transmission spectrum,the light of 490nm was dominant.It indicates that the radiation at longer wavelength was weakened by sea ice.Therefore,under the condition of low solar altitude,the radiation at shorter wavelength was weakened by the atmosphere while the radiation at longer wavelength was weakened by the sea ice.The combined effect of atmosphere and sea ice made the solar radiation under sea ice much weaker.The absorption of sea ice for the longer-wavelength radiation allowed the sea ice to gain more heat to slow down the freezing process. 相似文献
20.
Study on the organic compounds and stable isotope composition of a sediment section in Dabusu Lake revealed that the organic materials in the sediments came mainly from terrestrial plants brought into the lake by rtmoff.The δ^13 C of the organic materials had high values during warm-dry climatic stages and decreased in cold-wet stages.Analysis of data on carbonate content and ^14C age showed that the lake basin had experienced several wet-cold and warm-dry climatic cycles since 15000 a BP. Since 6700 a BP, the climate reached a relatively stable warm-dry stage,so that the lake water was gradually condensed and finally a saline lake was formed. 相似文献