Taihu Lake is one of the five biggest lakes in China. Surface water samples from 26 sampling sites of Taihu Lake were collected. Furthermore wet chemical analysis （CODCr and BOD5） and measurement of three dimensiona...Taihu Lake is one of the five biggest lakes in China. Surface water samples from 26 sampling sites of Taihu Lake were collected. Furthermore wet chemical analysis （CODCr and BOD5） and measurement of three dimensional excitation-emission matrix （3DEEM） spectra in the laboratory have been conducted. Using parallel factor analysis （PARAFAC） model, three components of colored dissolved organic matter （CDOM） have been identified successfully, based on the analysis of 3DEEM data. The characteristics of the three components also have been described by comparing them to some components of CDOM, identified in earlier researches. Meanwhile, spatial variations of concentration for the three components in Taihu Lake have been analyzed, and the result indicates that the concentration of component 1 depends more on the situation of wastewater pollution and can be used as the indicator of wastewater pollution. The relationship between the concentrations of the three components and results of the wet chemical analysis show that none of the three components can be used as indicators of gross organic matter in water. However, the concentrations of all the three components have obvious linear relationships with the BOD5 value, especially for component 1 （r = 0.72878）. Finally, the potential applications of the composition analysis based on 3DEEM and PARAFAC model in water quality monitoring have been illuminated.展开更多
The cDNA library of an ovary from Small Tail Han sheep before estrus was constructed by switching mechanism at 5＇ end of RNA transcript （SMART） approach. This library had a plaque titer of 1 x 109 pfu mL-1 and a 96...The cDNA library of an ovary from Small Tail Han sheep before estrus was constructed by switching mechanism at 5＇ end of RNA transcript （SMART） approach. This library had a plaque titer of 1 x 109 pfu mL-1 and a 96% recombinant ratio of which the fragment length of inserted average cDNA sequences was 1.0 kb. Based on bioinformatics analysis of the sequences, we obtained 338 expressed sequence tags （ESTs） from 380 cDNA clones which indicated 191 contigs. These contigs consist of 89 unmatched ESTs, 9 homologous known genes in sheep, and 93 homologous sequences in species of mouse, bovine, and human beings, including 19 sequences expressed in the ovary or follicle and 14 unknown sequences. Several candidate genes associated with sheep reproduction trait such as epidermal growth factor （EGF）, estrogen receptor （ESR）, Inhibin, follicle stimulating hormone receptor （FSHR）, prostaglandin （PG）, and transforming growth factor-β （TGF-β） were identified and the homologous were cloned from this library, which will contribute to compile expression profiles and find the major genes of prolificacy of Small Tail Han sheep.展开更多
Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β...Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β)-, to single β-phase with lithium content rising from 5 % to 22 % by wt. The main alloy studied was LA92 alloy with Mn addition. The results of the tensile tests show that the strength decreases with increasing lithium content, while the elongation increases sharply, and the UTS and YS rise by 26.8% and 22.7% respectively, when 0.5 % by wt. Mn is added. It is also known, by microstructure observation, SEM with EDS and X-ray analysis, that adding Mn can produce some new hard phases in the alloy, which may worsen the tensile properties.展开更多
利用国家环境保护部大气污染指标和常规气象观测资料,结合区域空气质量模式系统(Weather Research and Forecasting-Community M ultiscale Air Quality,WRF-CM AQ)的模拟结果,对2015年12月大连市大气污染过程的气象要素和气溶胶的时空...利用国家环境保护部大气污染指标和常规气象观测资料,结合区域空气质量模式系统(Weather Research and Forecasting-Community M ultiscale Air Quality,WRF-CM AQ)的模拟结果,对2015年12月大连市大气污染过程的气象要素和气溶胶的时空分布特征进行了分析,并对大气污染天气条件下有效开展人工增雨(雪)作业进行了初步探讨。结果表明:2015年12月大连市出现5次大气污染过程,累积污染日数为13 d,占12月总日数的41.94%,且日平均最低能见度为2.27 km。出现大气污染时,近地面温度均略有升高,大气层结稳定,因此,实施人工增雨(雪)作业时,宜选用增雨火箭和增雨飞机,从而保障催化剂可以播撒到高效核化层高度(-15℃^-10℃);同时,模拟结果表明,污染天气条件下一定量的细颗粒物在大气各种扰动下可以扩展至3.00 km以上,对具有增雨(雪)潜力的冷云实施作业时,应考虑催化剂量在常规作业剂量基础上适当减少。通过对2015年12月大连市的一次重度大气污染个例分析发现,大连市形成重污染的大气气溶胶物种主要为硝酸盐、铵盐和硫酸盐,其中硝酸盐占比最大,可以达到51.27%,说明除了相关工业源和燃煤排放,交通源排放也是大连市主要的大气污染源之一。展开更多
基金Project supported by the Knowledge Innovation Project of ChineseAcademy of Sciences (No. KGCX2-SW-111).
文摘Taihu Lake is one of the five biggest lakes in China. Surface water samples from 26 sampling sites of Taihu Lake were collected. Furthermore wet chemical analysis （CODCr and BOD5） and measurement of three dimensional excitation-emission matrix （3DEEM） spectra in the laboratory have been conducted. Using parallel factor analysis （PARAFAC） model, three components of colored dissolved organic matter （CDOM） have been identified successfully, based on the analysis of 3DEEM data. The characteristics of the three components also have been described by comparing them to some components of CDOM, identified in earlier researches. Meanwhile, spatial variations of concentration for the three components in Taihu Lake have been analyzed, and the result indicates that the concentration of component 1 depends more on the situation of wastewater pollution and can be used as the indicator of wastewater pollution. The relationship between the concentrations of the three components and results of the wet chemical analysis show that none of the three components can be used as indicators of gross organic matter in water. However, the concentrations of all the three components have obvious linear relationships with the BOD5 value, especially for component 1 （r = 0.72878）. Finally, the potential applications of the composition analysis based on 3DEEM and PARAFAC model in water quality monitoring have been illuminated.
文摘The cDNA library of an ovary from Small Tail Han sheep before estrus was constructed by switching mechanism at 5＇ end of RNA transcript （SMART） approach. This library had a plaque titer of 1 x 109 pfu mL-1 and a 96% recombinant ratio of which the fragment length of inserted average cDNA sequences was 1.0 kb. Based on bioinformatics analysis of the sequences, we obtained 338 expressed sequence tags （ESTs） from 380 cDNA clones which indicated 191 contigs. These contigs consist of 89 unmatched ESTs, 9 homologous known genes in sheep, and 93 homologous sequences in species of mouse, bovine, and human beings, including 19 sequences expressed in the ovary or follicle and 14 unknown sequences. Several candidate genes associated with sheep reproduction trait such as epidermal growth factor （EGF）, estrogen receptor （ESR）, Inhibin, follicle stimulating hormone receptor （FSHR）, prostaglandin （PG）, and transforming growth factor-β （TGF-β） were identified and the homologous were cloned from this library, which will contribute to compile expression profiles and find the major genes of prolificacy of Small Tail Han sheep.
文摘Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β)-, to single β-phase with lithium content rising from 5 % to 22 % by wt. The main alloy studied was LA92 alloy with Mn addition. The results of the tensile tests show that the strength decreases with increasing lithium content, while the elongation increases sharply, and the UTS and YS rise by 26.8% and 22.7% respectively, when 0.5 % by wt. Mn is added. It is also known, by microstructure observation, SEM with EDS and X-ray analysis, that adding Mn can produce some new hard phases in the alloy, which may worsen the tensile properties.
文摘利用国家环境保护部大气污染指标和常规气象观测资料,结合区域空气质量模式系统(Weather Research and Forecasting-Community M ultiscale Air Quality,WRF-CM AQ)的模拟结果,对2015年12月大连市大气污染过程的气象要素和气溶胶的时空分布特征进行了分析,并对大气污染天气条件下有效开展人工增雨(雪)作业进行了初步探讨。结果表明:2015年12月大连市出现5次大气污染过程,累积污染日数为13 d,占12月总日数的41.94%,且日平均最低能见度为2.27 km。出现大气污染时,近地面温度均略有升高,大气层结稳定,因此,实施人工增雨(雪)作业时,宜选用增雨火箭和增雨飞机,从而保障催化剂可以播撒到高效核化层高度(-15℃^-10℃);同时,模拟结果表明,污染天气条件下一定量的细颗粒物在大气各种扰动下可以扩展至3.00 km以上,对具有增雨(雪)潜力的冷云实施作业时,应考虑催化剂量在常规作业剂量基础上适当减少。通过对2015年12月大连市的一次重度大气污染个例分析发现,大连市形成重污染的大气气溶胶物种主要为硝酸盐、铵盐和硫酸盐,其中硝酸盐占比最大,可以达到51.27%,说明除了相关工业源和燃煤排放,交通源排放也是大连市主要的大气污染源之一。
