期刊文献+
共找到269篇文章
< 1 2 14 >
每页显示 20 50 100
Enhanced Ultraviolet-B Radiation Suppresses Magnaporthe oryzae Infection and Alleviates Its Damage to the Photosynthesis of Rice Leaves
1
作者 Qinghao Zhang Yijie Yang +4 位作者 Jiong Wu Hongru Li Yuan Li Zuran Li Yongmei He 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第10期2613-2628,共16页
In the present study,an indoor potting experiment was conducted to study the effects of enhanced UV-B radiation and Magnaporthe oryzae on the growth,stomatal structure,photosynthesis,and endogenous hormone contents of... In the present study,an indoor potting experiment was conducted to study the effects of enhanced UV-B radiation and Magnaporthe oryzae on the growth,stomatal structure,photosynthesis,and endogenous hormone contents of a traditional rice cultivar Baijiaolaojing in the Yuanyang terraces of Yunnan Province.In addition,the relationships between these parameters and disease indices were analyzed.We aimed to clarify the response of the photosynthetic physiology of rice under the combined stress of UV-B radiation and M.oryzae.Compared with the M.oryzae infection treatment,all the treatments,including M.oryzae infection before(MBR),simultaneously with(MSR),and after(MAR)UV-B radiation significantly increased the rice height and biomass by 4%–11%and 30%–111%,respectively,and the stomatal structure and carotenoids content of leaves,while decreasing the contents of chlorophyll a and b,by 21%–41%and 63%–73%,respectively.Both the MSR and MBR treatments significantly increased the photosynthetic rate and transpiration rate of rice leaves.The MAR treatment weakened chlorophyll fluorescence parameters,including the actual photosystem II(PS II)photochemical efficiency,electron transport rate,photochemical quenching,and nonphotochemical quenching by 40%,39%,43%,and 24%,respectively.Moreover,the treatments of MAR,MSR,and MBR decreased the phytohormones content and the M.oryzae disease index by 27%–62%in rice leaves.Thus,the enhanced UV-B radiation contributed to suppressing the M.oryzae infection and alleviating its damage to the photosynthesis of rice leaves.This study is valuable for the control of rice blast fungus and offers important insights into plant pathology. 展开更多
关键词 RICE uv-b radiation rice blast disease HORMONES plant responses
下载PDF
Influences of Different UV-B Radiation Treatments in Short Time on Some Physiological Characteristics of Winter Wheat Seedlings 被引量:14
2
作者 张文会 王明卓 +2 位作者 苗秀莲 张玉霞 李宝娟 《Agricultural Science & Technology》 CAS 2009年第5期18-21,共4页
[Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ... [Objective] studying the influences of different UV-B radiation treatments in short time on some physiological characteristics of winter wheat seedlings was to provide reference for the mechanism of plant response to ultraviolet irradiation in short time. [Method] The winter wheat taken as materials were treated with 15 and 30 pW/cm^2 UV-B radiation, then the physiological indexes such as pigment content and photosynthetic rate were determined. [ Results] The UV-B treatment caused the declines of chlorophyll content, soluble protein content and water content of leaves, besides, dose-effect was existed. The decline of 30 pW/cm^2 treatment was bigger than that of 15 μW/cm^2 treatment. The influences of UV-B radiation on carotenoid content and anthocyanidin content were similar; the change trends were declined firstly then increased. The UVB treatment with two doses restrained the electron transport of PSⅡ, particularly; the inhibitory effect was biggest after treated 2 h, and then this effect was declined in 4, 6 and 8 h, so the dose-effect was existed. The UV-B radiation with two doses restricted photosynthetic rate and the inhibitory effect increased with the increase of treatment time. The high dose treatment caused huge damage to membrane system, while the result of low dose treatment was not obvious. [ Conclusion] UV-B radiation treatment had dose-effect on winter wheat seedlings in short time and the influence of high dose was bigger than that of low dose. With the increase of treatment time, the damage was alleviated; besides, the result was not similar to that of UV-B radiation in long time. 展开更多
关键词 uv-b radiation Winter wheat seedling Physiological index
下载PDF
Responses of Membrane Lipid Peroxidation and Endogenous Hormones of Soybean Seedlings to UV-B Radiation and Rare Earth 被引量:7
3
作者 闫生荣 杨春和 +2 位作者 张跃群 花海蓉 蒋云霞 《Agricultural Science & Technology》 CAS 2009年第6期72-75,90,共5页
[ Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [ Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to U... [ Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [ Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth were studied through hydroponics in laboratory. [ Result] The results showed that under irradiation of UV-B( T1-0.15 W/m^2 and T2-0.45 W/m^2), chlorophyll and indole-3-acetic acid(IAA) contents firstly decreased during the stress phase (1 -5 d) and then increased during the restoration phase (6 -9 d) while contents of malonadialdehyde(MDA) and abscisic acid(ABA) gradually increased during the imposition of UV-B radiation (1 -5 d) and subsequently decreased during recovery from UV-B stress (6 -9 d) . With adding of La (III) with the concentration of 20 mg · L^-1 , the decline/dse trend of chlorophyll, IAA, MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accelerated during the recovery period. [ Conclusion] It suggests that the regulation of La ( III ) on membrane lipid peroxidation and endogenous hormones could increase chlorophyll and IAA contents, improve the metabolism of reactive oxygen species ( ROS), inhibit membrane lipid peroxidation, decrease the accumulation amount of ABA and alleviate injury of UV-B radiation to soybean seedlings. Further, the protective potential of La ( III ) was better under low UV-B radiation than under high one. 展开更多
关键词 La III uv-b radiation Soybean seedlings Membrane lipid peroxidation Endogenous hormones
下载PDF
Effect of Enhanced UV-B Radiation on Seed Setting Rate and 1 000-grain Weight of Indica Hybrid Rice Restorer Lines
4
作者 况浩池 曾祥瑞 +5 位作者 罗俊涛 曾正明 杨扬 陈光珍 何兴材 付均 《Agricultural Science & Technology》 CAS 2013年第2期226-229,共4页
[Objective] This study was to investigate the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight of hybrid rice combinations. [Method] The seed setting rate and 1 000-grain weight of 10 new ... [Objective] This study was to investigate the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight of hybrid rice combinations. [Method] The seed setting rate and 1 000-grain weight of 10 new sterile indica restorer lines planted in pots under enhanced UV-B radiation and fluorescent lamps (control) were respectively measured, and the differences were compared. [Result] The enhanced UV-B radiation significantly reduced the seed setting rate of indica restorer lines, and the differences between that UV-B radiation treatment and control all reached extremely significant level. In addition, the enhanced UV-B radiation reduced the 1 000-grain weight of most indica restorer lines, and compared with that of control the difference achieved significant or very significant level. However, the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight differed to different indica restorer lines, and the differences among restorer lines tested were significant or very significant, which indicated the possibility to screen antiUV-B radiation rice materials and combinations. Finally, the indica restorer lines 09R-14, Luhui 37 and 10R-7703 which were strongly resistant to UV-B radiation were screened out. [Conclusion] This study laid foundation for breeding hybrid rice varieties resistance to UV-B radiation. 展开更多
关键词 uv-b radiation Indica restorer lines Hybrid rice Seed setting rate Grain weight
下载PDF
Effects of UV-B radiation on the growth interaction of Ulva pertusa and Alexandrium tamarense 被引量:10
5
作者 CAIHeng-jiang TANGXue-xi ZHANGPei-yu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第4期605-610,共6页
Enhanced UV-B(280-320 nm) radiation resulting from ozone depletion is one of global environmental problems. Not only marine organisms but also marine ecosystems can be affected by enhanced UV-B radiation. The effects ... Enhanced UV-B(280-320 nm) radiation resulting from ozone depletion is one of global environmental problems. Not only marine organisms but also marine ecosystems can be affected by enhanced UV-B radiation. The effects of UV-B radiation on interaction of macro-algae and micro-algae were investigated using Ulva pertusa Kjellman and Alexandrium tamarense as the materials in this study. The results demonstrated that UV-B radiation could inhibit the growth of Ulva pertusa and Alexandrium tamarense when they were both mono-cultured, and the growth inhibition of algae was more significant with increasing doses of UV-B radiation. Alexandrium tamarense could inhibit the growth of Ulva pertusa in mixed culture, and the growth inhibition was more significant when increasing the initial cell density. However, Ulva pertusa could inhibit the growth of Alexandrium tamarense in early phase and stimulate the growth in latter phase when they were grown in mixed culture. Lower initial cell density(10~2 cell/ml) of Alexandrium tamarense could inhibit the growth of Ulva pertusa under UV-B radiation treatment,however, with the initial cell density increasing(10~3 and 10~4 cell/ml), the growth of Ulva pertusa was stimulated under lower dose of UV-B radiation and inhibited under higher dose of UV-B radiation by Alexandrium tamarense. Compared with that in mixed culture, Ulva pertusa showed more positive inhibition to the growth of Alexandrium tamarense under UV-B radiation treatment. 展开更多
关键词 uv-b radiation mono-culture mixed culture Ulva pertusa Alexandrium tamarense GROWTH
下载PDF
Effects of lanthanum(Ⅲ) on nitrogen metabolism of soybean seedlings under elevated UV-B radiation 被引量:9
6
作者 CAO Rui HUANG Xiao-hua +1 位作者 ZHOU Qing CHENG Xiao-ying 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第11期1361-1366,共6页
The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm... The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m^2 and high level 0.45 W/m^2 significantly affected the whole nitrogen metabolism in soybean seedlings (p 〈 0.05). It restricted uptake and transport of NO3^-, inhibited activity of some key nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one. 展开更多
关键词 lanthanum(Ⅲ) uv-b radiation soybean seedlings nitrogen metabolism alleviating effect
下载PDF
The effect of UV-B radiation enhancement on the interspecific competition between Skeletonema costatum and Heterosigma akashiwo 被引量:7
7
作者 XIAOHui TANGXuexi +1 位作者 ZHANGPeiyu CAIHengjiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2005年第2期77-84,共8页
The responses of the interspecific competition between Skeletonema costatum and Heterosigma akashiwo to UV-B radiation enhancement were studied by the co-culture method. The results showed that Heterosigma akashiwo ex... The responses of the interspecific competition between Skeletonema costatum and Heterosigma akashiwo to UV-B radiation enhancement were studied by the co-culture method. The results showed that Heterosigma akashiwo exhibited inhibition on the growth of Skeletonema costatum, and with the increase of initial inoculation density of Heterosigma akashiwo, heavier inhibition on Skeletonema costatum appeared. Under different inoculation proportions, Heterosigma akashiwo could always be in predominance in competition with Skeletonema costatum. The UV-B radiation treatment could change the competition relationship between Skeletonema costatum and Heterosigma akashiwo, which could increase the competitive dominance of Skeletonema costatum and decrease the competitive dominance of Heterosigma akashiwo. When the inoculation proportions of Heterosigma akashiwo and Skeletonema costatum were H∶S=1∶4 and H∶S=1∶1,Skeletonema costatum was in predominance in this competition; however, Heterosigma akashiwo was in predominance when the inoculation proportion was H∶S=4∶1. 展开更多
关键词 uv-b radiation interspecific competition INHIBITION Skeletonema costatum Heterosigma akashiwo
下载PDF
Effects of UV-B radiation on tetraspores of Chondrus ocellatus Holm(Rhodophyta),and effects of red and blue light on repair of UV-B-induced damage 被引量:5
8
作者 鞠青 肖慧 +1 位作者 王悠 唐学玺 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第3期650-663,共14页
We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,... We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,36,72,108,144 and 180 J/m2),and thereafter subjected to PAR,darkness,or red or blue light during a 2-h repair stage,each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers(CPDs),chlorophyll a(Chl a),phycoerythrin,and UV-B-absorbing mycosporinelike amino acids(MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation(36 and 72 J/m 2) promoted the growth of C. ocellatus; however,increased UV-B radiation gradually reduced the C. ocellatus growth(greater than 72 J/m2). The MAAs(palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition,photorepair was inhibited by red light,so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase,greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore,PAR,red light,and blue light play different roles during the repair processes for damage induced by UV-B radiation. 展开更多
关键词 Chondrus ocellatus Holm tetraspores uv-b radiation red light blue light REPAIR
下载PDF
Effect of UV-B Radiation on Ingesting and Nutritional Selecting Behavior of Rotifer Brachionus urceus 被引量:4
9
作者 FENG Lei TANG Xuexi +3 位作者 WANG You XIAO Hiu MENG Xianghong CHEN Xiguang 《Wuhan University Journal of Natural Sciences》 CAS 2007年第2期361-366,共6页
Effect of UV-B radiation on ingesting and nutritional selecting behavior of the roifer Brachionus urceus on 5 species of microlgae were studied under controlled laboratory conditions. Restdts showed that enhanced UV-B... Effect of UV-B radiation on ingesting and nutritional selecting behavior of the roifer Brachionus urceus on 5 species of microlgae were studied under controlled laboratory conditions. Restdts showed that enhanced UV-B radiation significantly inhibited ingesting of the rotifer B. urceus when it was fed with 5 species of micro-algae (p〈0.05). The ingesting selectivity rate varied with the UV-B radiation enhancement when it was fed with 5 species micro-algal mixture. Results indicated that the enhanced UV-B radiation could affect ingesting and nutritional selectivity of B. urceus. 展开更多
关键词 uv-b radiation Brachionus urceus ingesting nutritional selecting behavior MICROALGAE
下载PDF
Effects of UV-B Radiation and Water Stress on Soybean Yield 被引量:2
10
作者 REN Hongyu XU Haiming LI Dongming HUANG Rui WANG Licheng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2009年第3期1-6,共6页
Soybean Dongnong 47 was subjected to the experiments of increasing UV-B radiation and water stress on soybean yield components in different growth periods. The results showed that 100-seed weight greatly increased dur... Soybean Dongnong 47 was subjected to the experiments of increasing UV-B radiation and water stress on soybean yield components in different growth periods. The results showed that 100-seed weight greatly increased during the early stage of pod filling in the treatment of weak UV-B radiation, seed number per plant as well as seed weight per plant and Dongnong47 yield also increased, while the yield and yield components of Dongnong47 during the blossom to mature period were negatively affected in the treatment of intensive UV-B radiation. 100-seed weight of Dongnong47 all increased in the double factor treatments of UV-B radiation and water stress, with the drought intensified, seed number per plant, seed weight per plant and yield of Dongnong47 decreased, the change of 100-seed weight were various and the antagonistic action of UV-B radiation and water stress were related with their intensity. 展开更多
关键词 uv-b radiation water stress SOYBEAN YIELD yield components
下载PDF
Effects of UV-B radiation intensity and timing on epidemiological components of wheat stripe rust 被引量:2
11
作者 WANG Hui QIN Feng +2 位作者 CHENG Pei MA Zhan-hong WANG Hai-guang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第12期2704-2713,共10页
Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental fa... Stripe rust caused by Puccinia striiformis f. sp. tritici is an important wheat disease worldwide that is greatly influenced by environmental conditions. Ultraviolet B(UV-B) radiation is one important environmental factor affecting the occurrence and epidemiology of wheat stripe rust. Investigating UV-B radiation effects on the epidemiology of stripe rust may be conducive to monitoring and predicting this disease. In this study, wheat seedlings were exposed to UV-B radiation during different periods under laboratory conditions and radiation effects on epidemiological components of wheat stripe rust were investigated. Results showed that incubation period was shortened, and the infection efficiency, sporulation quantity and disease index increased when UV-B radiation was performed only pre-inoculation. When the UV-B radiation was performed only postinoculation or both pre-and post-inoculation, the incubation period was prolonged, and the infection efficiency, sporulation quantity and disease index were reduced. When healthy wheat seedlings were inoculated using urediospores collected from wheat leaves irradiated by UV-B only post-inoculation or both pre-and post-inoculation, infection efficiency, sporulation quantity and disease index were also reduced. However, in the latter, the disease incubation period did not differ under varying UV-B radiation intensities compared to that when wheat leaves were not treated with UV-B radiation. Overall, the effects of direct exposure of wheat plants to UV-B radiation with different intensities in different periods on epidemiological components of wheat stripe rust were systematically explored, and the results suggest that the effects of UV-B radiation increased gradually with the increase of UV-B radiation intensity. This information provides a basis for monitoring and predicting this disease as well as for conducting further studies on pathogen virulence variation. 展开更多
关键词 wheat stripe rust uv-b radiation epidemiological component Puccinia striiformis f.sp.tritici
下载PDF
UV-B irradiation and allelopathy by Sargassum thunbergii affects the activities of antioxidant enzymes and their isoenzymes in Corallina pilulifera 被引量:1
12
作者 Ming LIU Jiqiang ZHAO +3 位作者 Yujuan PANG Lipei ZHANG Fuhua BIAN Lixia LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第5期1950-1962,共13页
Intertidal macroalgae can cope with the dual effects of UV-B irradiation and allelopathy.To study the impacts of the two stressors,we co-cultured Corallina pilulifera with Sargassum thunbergii in 1:1 and 1:10 ratios u... Intertidal macroalgae can cope with the dual effects of UV-B irradiation and allelopathy.To study the impacts of the two stressors,we co-cultured Corallina pilulifera with Sargassum thunbergii in 1:1 and 1:10 ratios under different doses of UV-B radiation.The response of the antioxidant defense system,focusing on activities of superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POX)and glutathione reductase(GR),was monitored.In addition,isoenzyme patterns were analyzed using nondenaturing poly acry lamide gel electrophoresis.The results show that the activities of SOD,APX,and GR were all significantly affected by both UV-B radiation and allelopathy,and the effect of their interaction was significant.However,POX activity was only influenced by UV-B radiation.The enzymatic assay revealed four distinct bands of SOD.The SODⅢband weakened significantly when the co-cultures were exposed to extremely high dosage of UV-B irradiation under both co-culturing ratios of 1:1 and 1:10.When the coculturing ratio was 1:10,both POXⅡand APXⅡenzy me activities increased with different UV-B doses.GR activity was at its greatest when the co-culture ratio was 1:10 and exposure was to the higher UV-B doses.The activities of GRⅢand GRⅣwere elevated under all UV treatments whereas the activities of GRI and GRII were reduced under the lower UV-B treatments but were elevated under the higher UV-B treatments.However,lipid peroxidation,as indicated by the thiobarbituric acid-reacting substance(TBARS)assay,increased significantly under the dual stressors.Our data sugge st that allelopathy and UV-B radiation stre ss can each affect the antioxidant enzyme activities of C.pilulifera.Critically,the adverse effects of UV-B on C.pilulifera were intensified by the compounding effects of allelopathy. 展开更多
关键词 Corallina pilulifera antioxidant system ISOENZYMES uv-b radiation ALLELOPATHY
下载PDF
Effect of atmospheric aerosols on UV-B radiation reaching the ground 被引量:1
13
作者 Wang Shaobin Su WeihanResearch Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1993年第2期224-229,共6页
Solar ultraviolet radiation reaching the ground can be reduced due to light scattering of atmospheric aerosols. Aerosol pollution has led to the decrease in biological active UV-B radiation by about 45% and 10% in cit... Solar ultraviolet radiation reaching the ground can be reduced due to light scattering of atmospheric aerosols. Aerosol pollution has led to the decrease in biological active UV-B radiation by about 45% and 10% in city and rural areas, respectively. In populated areas, effect of aerosol scattering on UV-B radiation may offset the increased amount of UV-B caused by ozone depletion, but in clean areas such as two poles, ozone depletion may have great damage effects on ecosystems. 展开更多
关键词 atmospheric aerosol uv-b radiation ozone reduction.
下载PDF
Effects of UV-B radiation and different light repair conditions on the early development of the tetraspores of Chondrus ocellatus Holm 被引量:1
14
作者 JU Qing TANG Xuexi +2 位作者 ZHAO Xiaowei REN Xiuqun LI Yunfei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第3期100-111,共12页
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. A... 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/(m2.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 rate reduced gradually with UV-B radiation keep on tetraspores of C. ocellatus and the growth 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. 展开更多
关键词 C. ocellatus uv-b radiation enhancement PAR dark repair condition MAAS
下载PDF
The effects of enriched C0_(2) and enhanced UV-B radiation on ultrastructure of Dunaliella salina, singly and in combination 被引量:1
15
作者 YU Juan XIAO Hui +3 位作者 TIAN Jiyuan ZHANG Peiyu DONG Shuanglin TANG Xuexi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期137-146,共10页
The effects of ambient CO2/ambient UV-B, enriched CO2/ambient UV-B, ambient CO2/enhanced UV-B, and enriched CO2/enhanced UV-B on the ultrastructure of Dunaliella salina were investigated. (1) The ultrastructure of D... The effects of ambient CO2/ambient UV-B, enriched CO2/ambient UV-B, ambient CO2/enhanced UV-B, and enriched CO2/enhanced UV-B on the ultrastructure of Dunaliella salina were investigated. (1) The ultrastructure of D..salina cell in the control experiment showed that the arrangement of thylakoid lamellae was regular, and there were many large starch grains among the thylakoid lamellae. A prominent well-developed pyrenoid was found in the middle of the chloroplast. Nucleus envelope and nucleolus were clearly observed. The Golgi apparatus accompanied by numerous vesicles with a compact arrangement of cisternae and the peripheral tips of the cisternae were swollen to a size comparable to that of some of the associated vesicles. (2) The ultrastructure of D. salina cell in enriched CO2 showed that the arrangement of thylakoid was regular and the lamellae were vivid. Developed pyrenoids were found in the low-CO2-grown cells, but not in the high-CO2-grown cells. The mitochondria cristae were vivid. The arrangement of Golgi apparatus was compact. (3) The ultrastructure of D. salina cell in enhanced UV-B showed that the thylakoid was dissolved and the cells had a less developed pyrenoid or no detectable pyrenoid. Part of the nucleus envelope was dissolved. The number ofmitochondria was increased and some mitochondria cristae were disintegrated. The starch grains were broken apart into many small starch grains. The Golgi apparatus with a loose arrangement ofcistemae and the peripheral tips of the Golgi cistemae were not especially swollen, with several large associated vesicles. (4) The ultrastructure of D. salina cell in the enriched CO2/enhanced UV-B showed that part of the thylakoid and nucleus envelopes of some cells were dissolved. The pyrenoid was larger than that of the enhanced UV-B. There were many mitochondria between stroma and chloroplast membrane, but mitochondria cristae were partly dissolved. Many small starch grains were accumulated in cells. The starch sheath was broken into several discontinuous starch grains with different sizes. The arrangement of Golgi apparatus was loose. Above all, although the enriched CO2 can alleviate the damage induced by the UV-B radiation, the effects of experimental UV-B radiation were larger than the effects of actual UV-B radiation, the damage induced by the UV-B radiation was so severe, therefore, CO2 enrichment could not restore the ultrastructure to the control level. 展开更多
关键词 enriched CO2 enhanced uv-b radiation ULTRASTRUCTURE Dunaliella salina
下载PDF
Changes of proteins in the Antarctic ice microalga Chlamydomonas sp. cultured under UV-B radiation stress 被引量:1
16
作者 KAN Guangfeng MIAO Jinlai +1 位作者 SHI Cuijuan LI Guangyou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第2期135-141,共7页
Antarctic ice microalga Chlamydomonas sp. can thrive undisturbed under high UV radiation in the Antarctic ice layer. However, it is unknown that the initial adaptation mechanisms in protein level occurring in response... Antarctic ice microalga Chlamydomonas sp. can thrive undisturbed under high UV radiation in the Antarctic ice layer. However, it is unknown that the initial adaptation mechanisms in protein level occurring in response to high UV radiation. Global-expression profiling of proteins in response to stress was analyzed by two-dimensional electrophoresis (2-DE) and image analysis. In the 2-DE analysis, protein preparation is the key step. Three different protein extract methods were compared, and the results showed that the trichloroacetic acid (TCA)-acetone fractional precipitation method was the fittest one. At the same time, the proteins in Chlamydomonas sp. were compared in 2-DE way, and the synthesis of seven protein spots was found disappeared and 18 decreased after exposed to UV-B radiation. In addition, 14 protein spots were enhanced or induced, among which two new peptides (20 and 21 kDa) appeared whose isoelectric point (pI) was 7.05 and 4.60 respectively. These changed proteins might act as key role in the acclimation of Antarctic ice microalga to UV-B radiation 展开更多
关键词 Antarctic ice alga Chlamydomouas sp. uv-b radiation 2-DE adaptation mechanisms
下载PDF
Radiation-induced attenuation self-compensating effect in super-fluorescent fiber source 被引量:2
17
作者 杨远洪 索鑫鑫 杨巍 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期266-270,共5页
The compact super-fluorescent fiber source (SFS) output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced at... The compact super-fluorescent fiber source (SFS) output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation (RIA) self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation (RIBA) at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward (DPB) configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad (Si) gamma-ray irradiation. 展开更多
关键词 super-fluorescent fiber source Er-doped fiber radiation-induced attenuation mean wavelength stability
下载PDF
Response of Marine Microalgae,Heterotrophic Bacteria and Their Relationship to Enhanced UV-B Radiation
18
作者 ZHOU Wenli TANG Xuexi +2 位作者 XIAO Hui WANG You WANG Renjun 《Journal of Ocean University of China》 SCIE CAS 2009年第1期35-38,共4页
Ozone depletion in the stratosphere has enhanced solar UV-B radiation reaching the Earth surface and has brought about significant effects to marine ecosystems. The effects of enhanced UV-B radiation on marine microal... Ozone depletion in the stratosphere has enhanced solar UV-B radiation reaching the Earth surface and has brought about significant effects to marine ecosystems. The effects of enhanced UV-B radiation on marine microalgae, heterotrophic bacteria and the interaction between them are discussed. The effects on marine microalgae have been proved to occur at molecular, cellular and population levels. Enhanced UV-B radiation increases microalgal flavonoid content but decreases their chlorophyll content and pho- tosynthesis rate; this radiation induces genetic change and results in DNA damage and change of protein content. There have been fewer studies on the effects of UV-B radiation on marine heterotrophic bacteria. Establishment of a microalgal ecological dynamic model at population and commuity levels under UV-B radiation has gradually become a hotspot. The effects of enhanced UV-B radiation on microalgae commtmities, heterotrophic bacterial populations and interaction between them will become a focus in the near future. This paper will make an overview on the studies concerning the effects of enhanced UV-B radiation on marine microalgae and heterotrophic bacteria and the interaction between them. 展开更多
关键词 uv-b radiation EFFECT MICROALGAE heterotrophic bacteria
下载PDF
Effect of UV-B radiation on the population dynamics of the rotifer Brachionus urceus
19
作者 WANG Jinhe FENG Lei TANG Xuexi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第2期113-119,共7页
The effect of UV-B radiation enhancement at experimental doses of 0.00,0.24,0.48,0.72,0.96,and 1.20 kJ/m 2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp.was studied under... The effect of UV-B radiation enhancement at experimental doses of 0.00,0.24,0.48,0.72,0.96,and 1.20 kJ/m 2 on the population dynamics of the rotifer Brachionus urceus feeding on the alga Chlorella sp.was studied under controlled laboratory conditions using clonal culture and life-table techniques.The results show that UV-B radiation treatment significantly shortened the survival time of the rotifer (P 0.05): The longest survival time (336 h) occurred in the control (0.00 kJ/m 2 ) while the shortest (222 h) occurred when exposed to the highest UV-B radiation treatment (1.20 kJ/m 2 ).The fecundity of the rotifer B.urceus was enhanced by the lower UV-B radiation treatment (0.24 and 0.48 kJ/m 2 ) but inhibited by the higher treatments (0.96 and 1.20 kJ/m 2 ).Life expectancy also was obviously affected by UV-B radiation (P 0.05).The highest life expectancy occurred in the control (0.00 kJ/m 2 ),and it became shorter with increasing doses of UV-B radiation.The resutls in the present study indicate that the life expectancy of the rotifer B.urceus can be used as an indicator for UV-B radiation enhancement. 展开更多
关键词 uv-b radiation marine rotifer Brachionus urceus population dynamics
下载PDF
Calculations of Radiations Attenuation and Dose Assessments of Tunnels Passing under Water Canals
20
作者 Mohamed Farahat Moustafa Aziz 《Journal of Environmental Science and Engineering(A)》 2015年第11期607-613,共7页
Most of the developed countries have used their tunnels as protective structures (public nuclear shelters) in case of nuclear emergencies to protect their citizens from the dangerous effects of nuclear weapons. The ... Most of the developed countries have used their tunnels as protective structures (public nuclear shelters) in case of nuclear emergencies to protect their citizens from the dangerous effects of nuclear weapons. The research aims to explain how to use tunnels to protect some people from neutrons and gamma rays and account the required safe depth. The computer code (MCNP5) is used at this model for such tunnel to account attenuation of both neutrons and gamma rays passing through the canal water, sand, soil and reinforced concrete wall layers. The last one (thickness 105 cm) constructed the tunnel construction. Also, the computer code is used to account the dose inside the tunnel, and account (neutron) dose, (neutron, gamma) dose, prompt (gamma) dose, total (gamma) dose and total (neutron + gamma) dose estimated by μsv/h, at different depths from the water surface level (depths 200 cm, 500 cm, 1,000 cm, 1,600 cm, 2,200 cm, 2,600 cm, 2,800 cm, 3,400 cm, 3,700 cm, 4,000 cm and 4,600 cm). Then, account these doses for three bombs (its intensity 20 KT, 100 KT and 1,000 KT). 展开更多
关键词 Calculations of radiations radiations attenuation dose assessments TUNNELS water canals.
下载PDF
上一页 1 2 14 下一页 到第
使用帮助 返回顶部