OALib Journal期刊

ISSN: 2333-9721




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匹配条件: “<br>赵巧华” ,找到相关结果约368923条。
The law of variation of light quantum yield of Algal in Meiliang Bay of Taihu Lake in spring

zhao qiaohua,<br>,秦伯强
生态学报 , 2009,
Abstract: The light quantum yield of algae particles is one of the important parameters characterizing the algae response to the environmental factors. Based on the water primary productivity and underwater irradiance at the head of the jetty as a station of the Taihu Ecological Network of the Academia Sinica the light quantum yields of algal were calculated for four observational times. Results suggest that the yields increased basically in a linear way from the just below surface down to 30 cm but further downward the yield increases were slowed down and between 60 and 80 cm the yields were level off, where the maxima were 0.12 mol (O2) /mol (photon), figures that were about 10 times those just below the surface. In spring above 60 cm in Meiliang Bay light was not a constraint of algal growing but under 60cm light was the limiting factor to photosynthesis due to light attenuation.
The variation features of the surface mixed layer depth in Erhai Lake and Taihu Lake in spring and autumn and their mechanism analyses

Zhao Qiao-Hua,Sun Ji-Hua,<br>,孙绩
物理学报 , 2013,
Abstract: The variation of the surface mixed layer depth may affect not only the evolution of aquatic ecosystem, but also the temporal-spatial distribution of precipitation and climate in the basin. Based on the meteorological data and water temperature profiles observed in Erhai Lake (located in the Tibetan Plateau) and Taihu Lake (located in the Taihu Plain), the variation features and the mechanisms of the surface mixed layer depths are investigated. The stratification in Erhai Lake can be established and sustained in summer; the diurnal stratification in Erhai Lake can also be established, However, in both summer and autumn, stratification may exist in Taihu Lake. The time length of stratification is longer in Erhai Lake than that in Lake Taihu in the autumn. And the surface mixed layer depths in Erhai Lake are shallower than those in Taihu Lake in summer and autumn. The transformation frequency between establishment and destruction of stratification in Taihu Lake is faster than that in Erhai Lake, which illustrated that the response of water body in Taihu Lake to atmospheric variation is quicker than that in Erhai Lake. The water depth is a key factor which prevents such shallow lakes as Taihu Lake from establishing and maintainaning stratifications and in a suitable radiation condition the stratification will exist. The net radiation is a key factor that determines the stratification and the length of the time when the stratification can be sustained in lakes whose depths are the same as that of Erhai Lake. The research result in this paper is helpful for exploring the coupling mechanism of the turbulence of water and air and the evolution law of aquatic ecosystem.
Numerical study on the effect of multiple scattering on upward scattering coefficients and diffuse absorption coefficients of medium in water

ZHAO Qiao-hua,SONG Yu-zhi,<br>,宋玉芝
遥感学报 , 2009,
Abstract: Upward scattering coefficients and diffuse absorption for the down- and up-welling streams are key factors for remote sensing of waters, and the interaction between biology and optics. They are also important parameters of underwater light fields. On the assumption that the radiance field has no internal light source, no inelastic scattering and the water surface was flat, we studied the effects of the zenith of incident, albedo and scattering coefficient on upward scattering coefficient, diffuse absorption coefficient for the downwelling and upwelling streams on condition that a scattering phase function was selected. The upward scattering coefficient showed an increase with the zenith of incident increasing, but the coefficient did not change along with the albedo and scattering coefficient just below water surface. With depth increasing, the profile of upward scattering coefficients gradually approached a constant, and the constant increased with albedo increasing. The profile of upward scattering coefficients strictly increased and then gradually approached a constant with depth increasing when the incidence was normal to the water surface. With further enhancement of zenith angle, the profile gradually increased, then decreased, hereafter kept invariable; while the invariant value increased with albedo increasing, but did not change with zenith angle of incident. The profiles of diffuse absorption coefficients for downwelling streams gradually shifted from strictly increase and followed stability to the new trend which took on first increase and next decrease, then to a constant state. Given that scattering coefficient and albedo was the same, the diffuse absorption coefficients for downwelling streams of different incident zenith converged to stability gradually. The less the albedo was, the more rapid convergent rate was, the shallower the depth of approaching to asymptotic state was. The characteristics of diffuse absorption coefficient for upwelling streams were very similar to that of diffuse absorption coefficient for downwelling streams, the former was merely bigger than the latter, and the diffuse absorption coefficients for upwelling streams were the maximum among them.
Char acter istics of Urban For est Landscape Pattern and Optimization of Urban For est Spatial Structur e: A Case Study of Nanjing City

ZHAO Qing,ZHENG Guoqiang,HUANG Qiaohua,<br>,郑国强,
地理学报 , 2007,
Abstract: Urban forest research is a rising research area. One of the trends of urban forest research is researching urban forest by using landscape ecological methods. Landscape pattern analysis is the basis of urban forest landscape ecological researches. By utilizing RS and GIS technologies and theories and methods of landscape ecology and vegetation ecology, we analyzed the characteristics of the urban forest landscape pattern of Nanjing city, and discussed the ways and methods for urban forest landscape ecological researches. The main content and results of this paper are as follows: (1) Based on the landscape ecological classification principles, two urban forest landscape types and four subtypes were identified; (2) urban forest classification survey was carried out, and urban forest landscape distribution maps and spatial attribution data were obtained by using RS and GIS technologies; and (3) choosing a set of indices of landscape spatial pattern, the characteristics of the urban forest landscape pattern of the study area were quantitatively and qualitatively analyzed. On the basis of these characteristics, we put forward some measures and suggestions for the urban forest landscape planning and construction. We think that the Nanjing urban forest has the following characteristics: proper coverage, higher naturality, higher fragmentation, and intensive disturbance by human activities. We also think that the large landscape patches of high naturality should be strictly protected and the design of landscape corridors of different scales is a key measure for the urban forest to effectively perform its landscape ecological functions.
Analysis on the Spatial Characteristics of the Light Quantum Yields in Lake Taihu in Spring

ZHAO Qiao-hua,QIU Hui,<br>,邱辉
环境科学 , 2010,
Abstract: Based on the primary productions and underwater irradiance in the head of the jetty in a station of the Lake Taihu ecology network of the Chinese academia, Zhihugang estuary area, the center of Lake Taihu and Xukou Bay at April 28, May 4,May 5, May 6 in 2009, the light quantum yields of algae and P-I curve were calculated. Then the spatial characteristics were analyzed. There was significant photoinhibition in the head of the jetty in a station of the Lake Taihu ecology network of the Chinese academia; there was not appreciable photoinhibition in Zhihugang estuary area and the center of Xukou Bay; and there was only light-saturation phenomena in the center of Lake Taihu. The order of the light quantum yield per Chl-a was the center of Lake Taihu, the head of the jetty, Zhihugang estuary area and the center of Xukou Bay.
Effect of Inherent Optical Parameters on Average Penetration Depth of Photon Flux and the Integral Average Cosine of Underwater Light Field in Lake Taihu During Summer

ZHAO Qiao-hua,ZHANG Yun-lin,<br>,张运林
环境科学 , 2010,
Abstract: Based on the inherent optical parameters of the water and water quality data in lake Taihu from 2006-07-29 to 2006-08-01, the effect of scattering on the penetration path along the original direction of the flux and the Integral average cosine of underwater light field were study by the radiative transfer theory, and the possible mechanism was analyzed. There were increasing trend from northwest to southeast of them. There were a nonlinear relation between them and concentration of Chl-a, suspended matter, inorganism matter, organism matter. The relation was described by logarithmic function. The study was helpful for bio-optical model and the environmental effects of photosynthetic active radiation in waters.
Variation of Spectrum of Photosynthesis Available Radiation Absorbed by Underwater Optical Medium with Depth in Lake Taihu in Summer

ZHAO Qiao-hua,QIN Bo-qiang,<br>,秦伯强
环境科学 , 2009,
Abstract: Normalized spectrum of photosynthesis available radiation(PAR),which was absorbed by all kinds of medium per unit volume of water at different depths,was calculated by the data from downward and upward irradiance and absorption coefficients of phytoplankton,non-algae particles and chromophoric dissolved organic matter(CDOM) in 41 locations in Lake Taihu from July 29 to August 1,2006.The results showed that there were two peaks at about 450 nm and 675 nm in the normalized spectrum of PAR absorbed by phytopla...
Spectral absorption characteristics of algae and discrimination of the absorption spectrum of mixed algae

ZHAO Qiaohua,QIN Boqiang,<br>,秦伯强
环境科学学报 , 2008,
Abstract: The absorption spectra of Microcystis aeruginosa, Scenedesmus obliquus, Chlorella pyrenoidosa, Selenostrum capricornutum and Melosira granulate var angustissima were taken and compared to the counts obtained by the quantitative filter technique. The normalized absorption spectra were then compared. The normalized absorption spectra were seldom variational in different growth period. The species differences of pigment and the ratio among different pigment species account for the variance of absorption spectra and are also the primary reason for species succession of phytoplankton in waters. Cyanobacteria have a peak at 620 nm, which is propitious to compete for light. The short-wave advantage of Melosira granulate var angustissima was waken by the colored dissolved organic matter (CDOM) and non-algae particles and the absorption peak at 630 nm is not strong, which is why Melosira granulate var angustissim is less able to compete for light. For green algae, the absorption shoulder at 655 nm helps them compete for light. The spectral absorption of mixed algae was successfully partitioned from the normalized absorption spectrum. This research is relevant to research on the mechanisms of cyanobacteria blooms, species succession of phytoplankton in natural waters, and remote sensing for case 2 waters.
Spectral characteristics and seasonal variation of photosynthetically active radiation absorbed by the medium in the water of Taihu lake

ZHAO Qiaohua,QIN Boqiang,<br>,秦伯强
环境科学学报 , 2008,
Abstract: 针对2005年8月、11月及2006年2月,5月太湖31个采样点的水样,测定了其中黄质(chromophoric dissolved organic matier)和颗粒物的吸收系数.通过次氯酸钠漂白法及数值分离法,将颗粒物吸收系数分离为藻类颗粒物及非藻类颗粒物的吸收系数,并对2种结果进行了比较.同时分析了太湖水体介质吸收有效光合辐射能量的谱特征及其季节变化.结果表明,水体中的绝大部份光合有效辐射能量主要由黄质和非藻类颗粒物所获取,对夏季的400~473nm、秋季的400-461nm、冬季的400~476nm、春季的400~569nm的能量而言,黄质的吸收贡献大于非藻类颗粒物;而在其余波段中,非藻类颗粒物的吸收贡献相对较大.藻类颗粒物的吸收贡献谱在490nm、676nm左右处存在2个主峰区,620nm左右处存在一次峰区,且该次峰在夏、秋季尤为明显,春季次之,冬季最小.藻类的吸收贡献也呈现出较为明显的季节特征,夏季吸收贡献最大达到22.1%,平均为16.4%;秋季最大为18.4%,平均为13.1%;春季最大为15.1%,平均为9.7%;冬季最大为10.1%,平均为6.8%.由于太湖颗粒物的吸收系数主要由非藻类颗粒物决定,因而用次氯酸钠漂白法从中提取藻类颗粒物的吸收系数会造成较大的误差,而改进的数值分离法在此基础上有了一定的提高.
Retrieving for Chlorophyll-a Concentration and Suspended Substance Concentration Based on HJ-1A HIS Image

YANG Ting,ZHANG Hui,WANG Qiao,ZHAO Qiao-hua,<br>杨婷,张慧,王桥,
环境科学 , 2011,
Abstract: Based on geometry correction using ERDAS software and radiation correction using 6S model for HJ-1A hyper-spectrum image(HSI) on May 2 in 2010 and the analysis of spectrum for water data and spectral data of hyper-spectrum image,this paper processes original spectrum data of 28 sample points using method of normalization and method of first-order derivation.Single-band and band combination are selected to establish inversion models of the concentration of chlorophyll-a and solid suspensions.Choosing the mod...

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