海洋单细胞藻对紫外吸收的比较研究   总被引：4，自引：0，他引：4  

杨震  童家明  唐学玺  李永祺  贺君 《海洋通报》1999,18(5):93-96

用日本岛津UV-260分光光度计,对9种海洋单细胞藻的紫外吸收变化进行了研究.结果表明:(1)9种海洋单细胞藻的吸收峰的波长均在280nm以下,它们相应的波长范围在252.8～266.4nm之间,高低相差仅为13.6nm;(2)按吸收峰值从大到小排列依次为:盐藻＞扁藻＞小球藻＞塔胞藻＞角毛藻＞三角褐指藻＞新月菱形藻＞金藻3011＞金藻8701,呈现明显的规律性变化,即:绿藻门＞硅藻门＞金藻门;(3)在UV-B(280～320nm)波段,9种海洋单细胞藻的吸收度均随波长的增加呈现逐渐下降的趋势,而吸收度的大小排列次序同吸收峰值完全一致,同样表现出绿藻＞硅藻＞金藻的规律.  相似文献   

Effects of UV-B radiation and different light repair conditions on the early development of the tetraspores of Chondrus ocellatus Holm     

JU Qing  TANG Xuexi  ZHAO Xiaowei  REN Xiuquan  LI Yunfei 《海洋学报(英文版)》2011,30(3):100-111

The effects of exposure to UV-B radiation,280-315 nm,and dark or dark repair conditions on the early development of Chondrus ocellatus Holm collected from Qingdao coast were studied under the laboratory condition.After being exposed to different doses [0,36,72,108,144 and 180 J/(m 2 · d)] of UV-B radiation,one treatment of tetraspores were put back to normal culture condition (PAR),the other treatment were put into dark condition to repair for 2 h.During the cultivation,the diameter of the tetraspores were recorded every 4 d till the 50th day when vertical branches formed in all treatments.Then at the 50th day,CPDs,phycoerythrin,chlorophyll a and MAAs (Palythine and asterina-330) were measured.The results showed that low doses UV-B radiation could significantly accelerate the growth rate of the tetraspores of C.ocellatus and the growth rate reduced gradually with UV-B radiation keep on increasing.The variation trend of both the phycoerythrin and chlorophyll a concentration reduced significantly ( P < 0.05) once given the UV-B radiation. Under UV-B stress,the CPDs were induced,and the concentrations of CPDs were significant low in dark repair groups.The data of MAAs analyzed by LC/MS in the tetraspores of C. ocellatus suggested that there were two MAAs formed (palythine and asterina-330) after UV-B radiation induced, and low dose of UV-B irradiation could significantly induced the concentration of MAAs.From the growth and development state of the tetraspores,negative effects of UV-B radiation on the dark repair groups were more serious than PAR.  相似文献   

Global NOx Production by Lightning     

Xuexi Tie  Renyi Zhang  Guy Brasseur  Wenfang Lei 《Journal of Atmospheric Chemistry》2002,43(1):61-74

Lightning is thought to represent an important source of tropospheric reactive nitrogen species NO_x (NO + NO₂),but estimates of global production of NO_x by lightning varyconsiderably. We evaluate the production of NO_x by lightning using a global chemical/transport model, satellite lightning observations, and airborne NO_x measurements. Various model calculations are conducted toassess the global NO_x production rate of lightning by comparing the model calculations with airborne measurements. The results show that the simulated NO_x in the tropical middle and upper troposphere are very sensitiveto the amount and altitude of the lightning NO_x used in the model. A global lightning NO_x production of 7 Tg N yr^–1uniformly distributed in convective clouds or 3.5 Tg N yr^–1 distributedin the upper cloud regions produces good agreement between calculated and measured NO_x concentrations in the tropics.  相似文献   

褐藻酸降解菌在海带绿烂病发生中的作用   总被引：1，自引：1，他引：1  

王丽丽  唐学玺  王蒙  张培玉 《中国海洋大学学报(自然科学版)》2003,33(2):245-248

从海带幼苗上病烂明显处分离得到 2 3株褐藻酸降解菌 ,并对其菌落形态、细胞形态及革兰氏染色反应等进行了观察。通过对褐藻酸钠的降解实验 ,筛选出 4株具较高降解能力的菌株。感染实验表明 ,分离到的褐藻酸降解菌为海带幼苗病烂的主要病原菌。  相似文献   

亚心形扁藻超氧化物歧化酶活性对镉和铜的应答   总被引：3，自引：0，他引：3  

李信书  唐学玺 《海洋湖沼通报》2007,(3):75-80

以亚心形扁藻为实验材料,对不同浓度重金属镉(Cd2 )和铜(Cu2 )作用下亚心形扁藻的超氧化物歧化酶(SOD)活性的变化和膜脂过氧化作用进行了探讨,以期了解藻类抗重金属的机制。结果表明:随着Cd2 和Cu2 浓度的增加亚心形扁藻的SOD的活性逐渐升高,但高浓度Cd2 可导致SOD活性活性下降。膜脂过氧化实验结果显示,半抑制浓度的重金属处理72hr后,膜脂过氧化产物丙二醛(MDA)显著提高。用72h半抑制浓度的重金属处理亚心形扁藻随时间的变化关系表明,在最初的12hr内SOD活性被两种重金属离子诱导迅速升高,然后逐渐趋于平稳。总之,SOD活性的变化与重金属的种类、浓度和处理时间有关。  相似文献   

The effect of UV-B radiation enhancement on the interspecific competition between Skeletonema costatum and Heterosigma akashiwo   总被引：4，自引：1，他引：4  

XIAO Hui  TANG Xuexi  ZHANG Peiyu  CAI Hengjiang 《海洋学报(英文版)》2005,24(2):77-84

1 Introduction R ed tide is a global m arine ecological calam ity.In recentyears, there has been an increase in frequen-cy, affected area and extentof injury of red tide out-breaks in the coastalw aters ofour country.A ccordingto China M arine D isaster B ulletin issued by the StateO ceanic A dm inistration of C hina, harm ful red tideshad occurred up to 119 tim es in 2003, w hich w as 40tim es m ore than thatin 2002. O w ing to the w orsenedcultural environm ent and increased nutrient en…  相似文献   

The effects of enriched CO₂ and enhanced UV-B radiation on ultra-structure of Dunaliella salina, singly and in combination     

YU Juan  XIAO Hui  TIAN Jiyuan  ZHANG Peiyu  DONG Shuanglin  TANG Xuexi 《海洋学报(英文版)》2006,25(1):137-146

1 Introduction The amount of stratospheric ozone was being re duced due to anthropogenic emission of chlorofluoro carbons (CFCs) and nitrogen orides (Molina and Row land, 1974; Rowland, 1989; Yang et al., 1998; Xiao e al., 2005). This reduction of ozone r…  相似文献   

A wind tunnel study of sand-cemented bodies on wind erosion intensity and sand transport   总被引：1，自引：0，他引：1  

Jie Zhou  Jiaqiang Lei  Shengyu Li  Haifeng Wang  Na Sun  Xuexi Ma 《Natural Hazards》2016,82(1):25-38

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Analysis of Air Quality in Eastern China and its Interaction with Other Regions of the World     

Chunsheng Zhao  Xuexi Tie  Geli Wang  Yu Qin  Peicai Wang 《Journal of Atmospheric Chemistry》2006,55(3):189-204

In this study, we used satellite data (GOME and MOPITT) together with a global chemical-transport-model of atmosphere (MOZART-2) to characterize the chemical/aerosol composition over eastern China. We then estimated the effects of local emissions in China on the chemical budgets in other regions of the world. Likewise, we also investigated the effects of air pollution from other regions on the chemical budget over eastern China. The study shows that the column CO and NO _x concentrations are also high in eastern China. The high CO and NO _x concentrations produce modest levels of O₃ concentrations during summer (about 40 to 50 ppbv) and very low O₃ during winter (about 10 to 20 ppbv) in eastern China. The calculated NO₂ column is fairly consistent from the GOME measurement. The calculated CO column is underestimated from the MOPITT measurement. One of the reasons of the underestimation of the predicted CO is due to a fact that the CO emissions were taken without considering the rapid increase of emissions from 1990 to 2000. The calculated surface O₃ is consistent with the measured values, with strong seasonal variations. However, the measurement is very limited, and more measurements in eastern China will be needed. The column NO₂ has a very strong seasonal variation in eastern China, with the highest concentrations during winter and the lowest concentrations during summer. The cause of this seasonal variability is mainly due to the seasonal changes in the chemical loss of NO _x , which is very high in summer and very low during winter. The effects of the local emissions in China and long-range transport from other regions on the chemical distributions in eastern China are studied. The results show that NO _x concentrations in eastern China are mostly caused by the local emissions in China, especially during the winter. The CO concentration over eastern China is from both the local emissions (30% to 40%) and the transport from other regions. Likewise, the CO emissions in China have an important effect on the other regions of the world, but the effect is limited in the northern hemisphere. The local emissions in China also have an important effect on surface O₃ concentrations. During winter, the local emissions reduce the surface O₃ concentrations by 30 to 50%. During summer, the local emissions produce about 50 to 70% of the O₃ concentration in eastern China.  相似文献   

Diversity and Bioactivity of Actinomycetes from Marine Sediments of the Yellow Sea     

ZHANG Shumin  YE Liang  TANG Xuexi 《青岛海洋大学学报(英文版)》2012,(1):59-64

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