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双针同步多点打结埋线法重睑成形术 被引量:3
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作者 胡维君 刘阳 +1 位作者 童芸 周国云 《组织工程与重建外科杂志》 2011年第3期162-164,共3页
目的探讨埋线法重睑成形术的一种新术式。方法双针同步、深浅交替、多点打结,行埋线法重睑成形术96例(186侧),观察重睑效果。结果随访观察6~48个月,重睑线流畅,并发症少,效果持久、恒定。结论本方法兼具了间断埋线法与连续埋线法的优点... 目的探讨埋线法重睑成形术的一种新术式。方法双针同步、深浅交替、多点打结,行埋线法重睑成形术96例(186侧),观察重睑效果。结果随访观察6~48个月,重睑线流畅,并发症少,效果持久、恒定。结论本方法兼具了间断埋线法与连续埋线法的优点,方法简便,效果肯定。 展开更多
关键词 埋线法 植结 重睑成形
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A multi-objective fuzzy optimization model for cropping structure and water resources and its method 被引量:3
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作者 马建琴 陈守煜 邱林 《Hunan Agricultural Science & Technology Newsletter》 2004年第1期5-10,共6页
Cropping structure has a close relationship with the optimal allocation of agricultural water resources. Based on the analysis of the relationship between agricultural water resources and sustainable development, this... Cropping structure has a close relationship with the optimal allocation of agricultural water resources. Based on the analysis of the relationship between agricultural water resources and sustainable development, this paper presents a multi objective fuzzy optimization model for cropping structure and water allocation, which overcomes the shortcoming of current models that only considered the economic objective,and ignored the social and environmental objectives. During the process, a new method named fuzzy deciding weight is developed to decide the objective weight. A case study shows that the model is reliable, the method is simple and objective, and the results are reasonable. This model is useful for agricultural management and sustainable development. 展开更多
关键词 cropping structure multi objective fuzzy optimization fuzzy deciding weight agricultural water resources
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Relationships between bird communities and vegetation structure in Honghuaerji, northern Inner Mongolia 被引量:2
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作者 王文 丸山直树 +2 位作者 刘伯文 森本英人 高中信 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第4期294-298,337,共5页
The survey on bird communities was conducted by the belt-style method in six different sample plots in the Honghua抏rji Forests area in the northern Inner Mongolia in June 2001 and totally 28 bird species were recorde... The survey on bird communities was conducted by the belt-style method in six different sample plots in the Honghua抏rji Forests area in the northern Inner Mongolia in June 2001 and totally 28 bird species were recorded. Vegetation investigation was carried out in five 10 m×10 m quadrats at each plot. The asymptotic regression function formulae were adopted to identify the relationships between the vegetation coverage and the numbers of bird species and individuals. The analytical results showed that the changes of species number and density of bird as well as the formation of bird communities follow the changes of forest type and the total foliage. Both the number of bird species and their density decreased with the de-crease of total foliage. The similarity of bird community was very low at the breeding time. In the same classification of cluster, no similarity was higher than 0.65, which indicated that the composition of species had a great difference between all the bird communities. The bird breeding density was closely related to forest growth stage. From the bare grassland ecosystem to cli-max ecosystem, the density of bird species showed a gradually increasing trend. 展开更多
关键词 Bird community Vegetation structure Honghua抏rji Northern Inner Mongolia
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Study on Soil Microbiotic Crust and Its Influences on Sand-fixing Vegetation in Arid Desert Region 被引量:132
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作者 李新荣 张景光 +2 位作者 王新平 刘立超 肖洪浪 《Acta Botanica Sinica》 CSCD 2000年第9期965-970,共6页
Based on secular fixed_site data in the artificial sand_fixing vegetation district at the southeast fringe of the Tengger Desert, the formative characteristics of soil microbiotic crusts and its influences on vegetati... Based on secular fixed_site data in the artificial sand_fixing vegetation district at the southeast fringe of the Tengger Desert, the formative characteristics of soil microbiotic crusts and its influences on vegetation dynamics were analyzed. Once sand barrier and artificial vegetation have stabilized the surface of the sifting sand, could form aeolian deposition crust and then evolve into algae_dominated crust. Such processes result from the interactions of physical effects of atmospheric dust and silt deposition on sand surface, sinking and raindrop impact, and soil microorganism activities. Under the condition of less than 200 mm precipitation, the presence of microbiotic crust changes the soil hydraulic conductivity, alters the temporal and spatial distribution of the limited precipitation in sand layer and leads to the decline of deep_rooted shrubs. The development of microbiotic crust and subsurface soil affects the plant growth and seed rain distribution, as a result, the diversity of plant species gradually tend to become saturated and finally affects the vegetation stability. 展开更多
关键词 arid desert region microbiotic crust sand_fixing vegetation
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Phytoplankton Community Structure and Its Spatial Distribution along Anhui-Jiangsu Reaches of the Yangtze River in Autumn 2009 被引量:2
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作者 孟顺龙 陈家长 +4 位作者 胡庚东 吴伟 瞿建宏 范立民 裘丽萍 《Agricultural Science & Technology》 CAS 2012年第1期220-226,共7页
[Objective] Surveys of phytoplankton were taken during the autumn of 2009 along Anhui-Jiangsu reaches of the Yangtze River to understand the species com- position and their spatial distributions. [Method] Phytoplankto... [Objective] Surveys of phytoplankton were taken during the autumn of 2009 along Anhui-Jiangsu reaches of the Yangtze River to understand the species com- position and their spatial distributions. [Method] Phytoplankton species, their quanti- ties, biomass and the Mcnaughton's dominance indices were all measured and their spatial distribution characteristics were determined using cluster analysis. [Result] There were 27 species, belonging to 5 phyla, namely Chlorophyta, Bacillariophyta, Cyanophyta, Euglenophyta and Cryptophyta, of phytoplankton collected and identified from the surveys. Results showed that Bacillariophyta was the predominant phyto- plankton with 16 species collected which accounted for 59.3% of the total species identified. The number of species collected belonging to Chlorophyta, Cyanophyta, Cryptophyta and Euglenophyta were 6, 2, 2, and 1, accounting for 22.2%, 7.4%, 7.4% and 3.7% of the total number identified, respectively. At the species level, the predominant species were Fragilaria crotonensis, Melosira italica, Navicula crypto- cephala, Cyclotella striata and Chroomonas acuta. Phytoplankton abundance was ranging from 5.68×10^4 to 7.08×10^4 cells/L with its average of 6.01×10^4 cells/L. Phyto- plankton biomass was ranging from 30.43 to 34.73 μg/L with its average of 32.46 μg/L. Compared with the previous reports, the number of phytoplankton species was decreased but its abundance and biomass was increased along the Jiangsu reach of the Yangtze River. However, Bacillariophyta species were still the predominant species and the phytoplankton community structure had not significantly changed from the previous studies. [Conclusion] These results might be explained as that the water quality in the Yangtze River was deteriorated but had not come to the worst. The results of similarity analysis gave two clusters of phytoplankton community as Nanjing, Wuhu and Jiangyin sampling sites were clustered into one group and Tongling and Anqing were clustered into another group. 展开更多
关键词 PHYTOPLANKTON Community structure Yangtze River Anhui-Jiangsu reaches Spatial characteristics
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Research Progress on Leaf Anatomical Structures of Plants Under Drought Stress 被引量:6
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作者 刘球 李志辉 吴际友 《Agricultural Science & Technology》 CAS 2016年第1期4-7,14,共4页
Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought... Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought resistance of higher plants, this study reviewed the adaptation response and damage performance of epidermal structure, palisade tissue and spongy tissue, thickness, veins and stomata of plant leaves under drought stress. 展开更多
关键词 Leaf anatomical structure Drought stress PLANT
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Characteristics of Phytoplankton and Its Correlation with Water Environment in SFTWs 被引量:1
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作者 张丹 吴小慧 +4 位作者 黄民生 何岩 张勇 童敏 潘震 《Agricultural Science & Technology》 CAS 2011年第3期439-442,共4页
[Objective] The aim was to carry out study on characteristics of phytoplankton and its correlation with water environment in SFTWs. [Method] Based on the pilot-scale SFTWs in Hongqiao transportation hub of Shanghai,ph... [Objective] The aim was to carry out study on characteristics of phytoplankton and its correlation with water environment in SFTWs. [Method] Based on the pilot-scale SFTWs in Hongqiao transportation hub of Shanghai,phytoplankton's community structure,diversity index and their correlation with water purification performance were investigated. [Result] 57 species of seven phylum of phytoplankton were detected in this tested river,including 12 species of Cyanophyta,2 of Cryptophyta,10 of Bacillariophyta,1 of Xanthophyta,7 of Euglenophyta,1 of Pyrrophyta and 24 of Chlorophyta,respectively. Additionally,it was found that Cyanophyta was the dominant phytoplankton,followed by Bacillariophyta and Cyanophyta. Biological density was far more than 10×105 ind./L,thus it could be considered that the river was eutrophic. The range of Shannon-Wiener index was 0.6-2.2,Pielou index was 0.5-2.5 and Margalef index's range was 0.35-0.85,which could further prove that the water was eutrophic. The biological density and species were significantly positively correlated with temperature and N content,indicating that the absorption of N by phytoplankton was the main N-removal pathway in SFTWs. [Conclusion] This study had provided basis for the river regulation and ecological restoration. 展开更多
关键词 SFTWs PHYTOPLANKTON Community structure Diversity index Physicochemical indexes
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Mechanism of Nutrient Silicon and Water Temperature Influences on Phytoplankton Growth 被引量:3
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作者 杨东方 高振会 +2 位作者 孙培艳 李梅 曲延峰 《Marine Science Bulletin》 CAS 2006年第2期49-59,共11页
This paper analyzed how nutrient silicon and water temperature influenced the variation of phytoplankton growth and the change of its assemblage structure, and probed the different characteristics of the variation of ... This paper analyzed how nutrient silicon and water temperature influenced the variation of phytoplankton growth and the change of its assemblage structure, and probed the different characteristics of the variation of phytoplankton growth and the different profiles of the change of its assemblage structure influenced by nutrient silicon and water temperature. Taking Jiaozhou Bay for example, this paper showed the process of both the variation of phytoplankton growth and the change of its assemblage structure, unveiled the mechanism of nutrient silicon and water temperature influencing the variation of phytoplankton growth and the change of its assemblage structure, and determined that nutrient silicon and water temperature were the motive power for the healthy running of the marine ecosystem. 展开更多
关键词 SILICON water temperature phytoplankton growth assemblage structure mechanism
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Ultrastructure of the Blepharoplast and the Multilayered Structure in Spermatogenesis in Osmunda cinnamomea var. asiatica 被引量:3
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作者 曹建国 包文美 戴绍军 《Acta Botanica Sinica》 CSCD 2003年第7期832-842,共11页
The ultrastructure of the blepharoplast and the multilayered structure (MLS) in the fern Osmunda cinnamomea var. asiatica Fernald have been studied by electron microscopy with respect to spermatogenesis. The blepharop... The ultrastructure of the blepharoplast and the multilayered structure (MLS) in the fern Osmunda cinnamomea var. asiatica Fernald have been studied by electron microscopy with respect to spermatogenesis. The blepharoplast appears in the young spermatid. The differentiating blepharoplast is approximately a spherical body, which is composed of densely stained granular material in the center and some cylinders outside of it. The differentiated blepharoplast is also a sphere, but without the densely stained material in the center, consisting of scattered or radially arranged cylinders. The MLS seen in the spermatid lies between the basal bodies and the giant mitochondrion. In the early developmental stage, the MLS only consists of lamellar layers, each of which runs parallel to one another and forms a strip. In the mid stage, the MLS is composed of the microtubular ribbon (MTr), the lamellar layers and a layer of plaque. In the late stage, the MLS forms accessory band, osmiophilic crest and a layer of osmiophilic material. The MTr grows out from the MLS and extends along the surface of the nucleus to unite with the nuclear envelope in a complex. The basal body coming from the cylinder produces the axoneme of the flagella in the distal end and the wedge-shaped structure in the proximal end, respectively. In the present study, the ultrastructural features of blepharoplast and the MLS of the protoleptosporangiopsida fern, O. cinnamomea var. asiatica, have been described and compared with those of other kinds of pteridophytes in detail. The lamellar layers appearing before the formation of the MTr was found and reported for the first time. 展开更多
关键词 Osmunda cinnamomea var. asiatica blepharoplast multilayered structure ULTRASTRUCTURE
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Genetic Structure of Reaumuria soongorica Population in Fukang Desert, Xinjiang and Its Relationship with Ecological Factors 被引量:13
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作者 徐莉 王祎玲 +5 位作者 王戌梅 张林静 岳明 顾峰雪 潘晓玲 赵桂仿 《Acta Botanica Sinica》 CSCD 2003年第7期787-794,共8页
Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diver... Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diversity and differentiation were revealed in the population of R soongorica by 15 random primers. One hundred and thirty-six individuals from seven subpopulations were sampled in the study. Seventy-one loci have been detected, and among them 69 were polymorphic. The mean proportion of polymorphic loci (PPB) was 97.18%. The analyses of Shannon information index (0.307 5), Nei's gene diversity (0.312 7) and G(ST)(0.312 0) indicated that there were more genetic variations within the subpopulations than those among the subpopulations. The results of AMOVA analysis showed that 61.58% of the genetic variations existed within subpopulations, and 38.02% among the subpopulations. The gene flow among the subpopulations of R soongorica (Nm = 1.102 8) was much less than that of the common anemophytes (Nm = 5.24), so genetic differentiation among the subpopulations occurred to some extent. Additionally, through the use of clustering and the correlation analyses, we found that the genetic structure of natural population of R soongorica was related to some ecological factors (soil factors mainly) of the oasis-desert transition zone. The genetic diversity level of R soongorica had negative correlation with the content of total soil P and Cl significantly (P < 0.05). On the contrary, it had significant positive correlation with CO32- (P < 0.05), showing that the distribution of the individuals of R soongorica in the sampled areas correlates with certain soluble salt. Furthermore, the genetic diversity of the natural population of R soongorica increased with the decreasing of the content of soil organic matters, water, total N and total P in soil. The paper concluded that the microenvironment ecological factors played an important role in the adaptive evolution of R soongorica population. 展开更多
关键词 Reaumuria soongorica genetic structure ecological factors desert plant
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Advancement of Structural Botany in the Past Fifty Years in China 被引量:1
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作者 崔克明 胡正海 《Acta Botanica Sinica》 CSCD 2002年第9期1043-1067,共25页
Structural botany, being derived from plant anatomy, has been considered as an important branch of botany, both in concept and practice. In this paper, a review concerning the evolutionary trends of development from p... Structural botany, being derived from plant anatomy, has been considered as an important branch of botany, both in concept and practice. In this paper, a review concerning the evolutionary trends of development from plant developmental anatomy to plant developmental biology, plant comparative anatomy to plant systematic biology and plant ecological anatomy to plant environmental biology during the past 50 years in China is addressed and their potential development and usefulness in the near future were largely discussed. 展开更多
关键词 plant anatomy structural botany developmental anatomy comparative anatomy ecological anatomy
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Investigation on the Pointed Cocoon of Wild Silkworm Descendant
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作者 陈义安 张友洪 +5 位作者 王晓芬 刘彬斌 杜周和 刘俊凤 韩兵 胡春梅 《Agricultural Science & Technology》 CAS 2012年第1期217-219,226,共4页
[Objective] To study the cocoon traits of wild silkworm descendants. [Method] In the selective breeding of domesticated raising wild silkworm and wild silkworm descendants, investigation on the traits of the built coc... [Objective] To study the cocoon traits of wild silkworm descendants. [Method] In the selective breeding of domesticated raising wild silkworm and wild silkworm descendants, investigation on the traits of the built cocoons was carried out. [Result] The pointed traits of cocoons displayed obviously in the wild silkworm descendants, its pointed parts were consistent with the rear part of silkworm chrysalis, and the female silkworm has slight difference, indicating the silkworm co- coon pointed trait was hereditary. [Conclusion] This study provided references for the study of silkworm cocoon traits of wild silkworm descendant and guides the selective breeding of silkworm variety. 展开更多
关键词 Silkworm cocoon Pointed Wild silkworm
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Ultrastructure of Oogenesis in Osmunda cinnamomea var. asiatica 被引量:3
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作者 包文美 曹建国 戴绍军 《Acta Botanica Sinica》 CSCD 2003年第7期843-851,共9页
The ultrastructure of oogenesis in the fern Osmunda cinnamomea L. var. asiatica Fernald has been studied by electron microscopy. During oogenesis, numerous vesicles not only moved towards the periphery, but also were ... The ultrastructure of oogenesis in the fern Osmunda cinnamomea L. var. asiatica Fernald has been studied by electron microscopy. During oogenesis, numerous vesicles not only moved towards the periphery, but also were arranged in line along the inside of plasmalemma, and in addition aggregated outside the plasmalemma by exocytosis. They released or excreted osmiophilic material. It was observed that a few vesicles containing lamellar osmiophilic material situated closely along the plasmalemma, seemed to break open. Simultaneously, a separation cavity between egg cell and archegonium wall formed. Its width was broader than the other advanced ferns reported previously, and an extra egg membrane occurred outside around the plasmalemma of the egg, its thickness being greater than in Pteridium and Dryopteris. Amyloplasts around the nucleus were filled with large triangular semicircular or subelliptical starch grains, but as the egg matured they progressively decreased. Nucleus was large and flattened, and paired membrane in two to three couples laid within the nucleus, close and parallel to the nuclear membrane. No nuclear evagination was observed. Mitochondria seemed to have been undeveloped, but finally recovered normally. 展开更多
关键词 ULTRASTRUCTURE OOGENESIS Osmunda cinnamomea var. asiatica FERN
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Research Overview on Urban Plant Community
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作者 廉丽华 申曙光 《Journal of Landscape Research》 2010年第2期43-46,共4页
The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.
关键词 Plant community Community classfication Community structure Community ecology
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Phylogenetic Analysis of Chirality of Twining Plants
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作者 林恭华 慈海鑫 +1 位作者 刘永安 苏建平 《Agricultural Science & Technology》 CAS 2010年第2期34-38,共5页
Phylogenetic relations of twining chirality of Dioscorea sp.in China were analyzed based on the genes matK,rbcL and trnL;phylogenetic character of higher-level phylogeny of twining plants was analyzed at a high taxon ... Phylogenetic relations of twining chirality of Dioscorea sp.in China were analyzed based on the genes matK,rbcL and trnL;phylogenetic character of higher-level phylogeny of twining plants was analyzed at a high taxon level based on matK gene.A significant phylogenetic framework of chirality was found:(i)based on matK analysis,right-handed Dioscorea species in China congregate completely to form a monophyly;(ii)rbcL and trnL data sets also supported Chinese right-handed Dioscorea a monophyly,although with ex... 展开更多
关键词 Twining plant CHIRALITY Phylogenetic structure ORIGIN
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Effects of Three-dimensional Structure of Vegetation on Particle Size Distribution and Nutrient Content of Water-eroded Red Soil
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作者 顾祝军 罗昊 《Agricultural Science & Technology》 CAS 2016年第2期453-459,466,共8页
Based on the vertical stratification type of vegetation in the 48 plots (15m×15 m) in Hetian Town, Changting County, Fujian Province, this study was conduct ed to determine the overall vegetation fractional cov... Based on the vertical stratification type of vegetation in the 48 plots (15m×15 m) in Hetian Town, Changting County, Fujian Province, this study was conduct ed to determine the overall vegetation fractional coverage (VFC), litter thickness, soi particle size distribution and nutrient content at different vertical level, analyze the correlations between vegetation characters and soil properties, and compare the dif ferences in the VFC, litter thickness, soil particle size distribution and nutrient con- tent among different erosion degrees and vertical structure types. The result., showed that the VFC and litter thickness were all negatively related to erosion de gree; they were positively related to soil organic matter content, total nitrogen con- tent and total phosphorus content, but not significantly correlated with soil tota potassium content. When the VFC was higher than 50% and litter thickness wa.' higher than 20 ram, the water and soil could be effectively conserved; and the plan litter showed better water and soil conservation effect than the upper vegetation o~ canopy layer. In the vertical structure types of different vegetations, the forest-shrub grass, forest-shrub, shrub-grass and pure grass all could promote vegetation growth improve soil structure and maintain soil fertility. 展开更多
关键词 VEGETATION Soil nutrient 3-D structure Soil erosion
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Structure and Function of ε-Subunit of ATP Synthase in Higher Plant Chloroplast
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作者 倪张林 石晓冰 +1 位作者 沈允钢 魏家绵 《Acta Botanica Sinica》 CSCD 2003年第8期896-900,共5页
The ε-subunit is the smallest subunit of chloroplast ATP synthase, and is known to inhibit ATPase activity in isolated CF1-ATPase. As a result ε is sometimes called an inhibitory subunit. In addition, and perhaps mo... The ε-subunit is the smallest subunit of chloroplast ATP synthase, and is known to inhibit ATPase activity in isolated CF1-ATPase. As a result ε is sometimes called an inhibitory subunit. In addition, and perhaps more importantly, the ε -subunit is essential for the coupling of proton translocation to ATP synthesis (as proton gate). The relation between the structure and function of ε -subunit of ATP synthase in higher plant chloroplast has been studied by molecular biological methods such as site-directed mu-tagenesis and truncations for C- or N-terminus of ε -subunit. The results showed that: (1) Thr42 of ε-subunit is important for its structure and function; (2) compared with the ε-subunit in E.coli, the ε-subunit of chloroplast ATP synthase is more sensitive to C- or N-terminus truncations. 展开更多
关键词 CHLOROPLAST ATP synthase ε-subunit PHOTOPHOSPHORYLATION site-directed mutagenesis yeast two-hybrid system
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Impacts of the Rising Opportunity Cost of Farm Labor on Agricultural Land Use Structure: Theory and Empirical Evidences 被引量:2
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作者 Tian Yujun Li Xiubin +1 位作者 Ma Guoxia Hao Haiguang 《Chinese Journal of Population,Resources and Environment》 2011年第1期85-90,共6页
Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics ... Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low's model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure. 展开更多
关键词 opporttmity cost of farm labor agricultural land use structure theoretical analysis empirical study
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Floristic and structural analysis of the woodland vegetation around Dello Menna,Southeast Ethiopia 被引量:3
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作者 Motuma Didita Sileshi Nemomissa Tadesse Woldemariam Gole 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第4期395-408,521,共15页
Floristic composition and vegetation structure were described for the woodland vegetation around Dello Menna, Bale zone, southeast Ethiopia. A total 50 (20 m ×20 m) quadrats were sampled to identify and describ... Floristic composition and vegetation structure were described for the woodland vegetation around Dello Menna, Bale zone, southeast Ethiopia. A total 50 (20 m ×20 m) quadrats were sampled to identify and describe plant community types, species diversity, richness and evenness and to relate the identified plant community types with some environ- mental factors and describe the population structure of woody plant species. In each quadrrat, data on species identity, abundance, height and Diameter at Breast Height (DBH) of woody plant species, altitude and slope were recorded. Vegetation classification was performed using PC - ORD software package. Sorensen's similarity coefficient was used to detect dissimilarities among communities. Shannon - Wiener diversity index, species richness and Shannon's evenness were computed to de- scribe species diversity of the plant community types. Results show that a total of 171 vascular plant species representing 53 families were re- corded. Fabaceae is the dominant family represented by 13 genera and 26 species (15%) followed by Asteraceae, Lamiaceae and Anacardiaceae with eight species each (4.6%). Based on the results of vegetation classi- fication, three plant communities (Dalbergia microphylla community, Grewia bicolar- Acacia brevispica community, and Combretum molle- Combretum collinum community) are recognized and described. Species richness, diversity and evenness varied among the plant communities.Species richness and diversity exhibit a bell - shaped pattern along alti- tude. Species turn over among communities more or less follow altitud- inal gradients. Tukey's pairwise comparison of means among the plant community types shows significant variations in altitude, implying that altitude is one of the most important factors determining the distribution of plant communities. The community Dalbergia microphylla type exhibits the highest species richness and diversity. Analysis of population structure of the dominant species reveals various patterns. Future research directions and recommendations are suggested for the sustainable utilization. 展开更多
关键词 vegetation structure ty species diversity species richness
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Determination of the spatial and temporal variability of phytoplankton community structure in Daya Bay via HPLC-CHEMTAX pigment analysis 被引量:4
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作者 WANG Longhua OU Linjian +4 位作者 HUANG Kaixuan CHAI Chao WANG Zhaohui WANG Xiaomin JIANG Tao 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第3期750-760,共11页
The spatial and temporal variability of the phytoplankton community structure in Daya Bay, South China Sea, were identified by using HPLC-CHEMTAX analytical techniques. The highest chlorophyll a(Chl a) concentrations ... The spatial and temporal variability of the phytoplankton community structure in Daya Bay, South China Sea, were identified by using HPLC-CHEMTAX analytical techniques. The highest chlorophyll a(Chl a) concentrations were observed during summer(with an average value of 0.84 μg/L) and lowest ones during winter(with an average value of 0.33 μg/L). CHEMTAX processing revealed the seasonal succession of phytoplankton species in Daya Bay. During winter, diatoms were the dominant phytoplankton species and contributed 41.5% to total Chl a. Based on Chl a concentration, the average ratio of dinofl agellates to total phytoplankton biomass substantially increased with increasing temperature and nitrogen to phosphorus(N/P) ratio, reaching 52.2% in spring. Nutrient limitation shifted from phosphorus to nitrogen during summer. Moreover, this period was associated with the predominance of diatoms, which accounted for 71.1% of Chl a. Prasinophytes and cryptophytes were the other two dominant groups and particularly dominated during winter. Cyanobacteria became an important group during summer and autumn. Canonical correspondence analysis suggested that chrysophytes, dinofl agellates, and cryptophytes were strongly associated with high nitrate concentration, ammonium, dissolved inorganic nitrogen(DIN), and N/P ratio, and were negatively associated with temperature and phosphate. Diatoms and cyanobacteria were strongly associated with temperature, phosphate, and salinity, and are negatively influenced by nitrate, ammonium, DIN, and N/P ratio. Microscopic observations and pigment HPLC information were in good agreement for diatoms and dinofl agellates in the bay. This study demonstrated the usefulness of pigment analysis in investigating the distribution of phytoplankton groups in a complex physical environment, such as Daya Bay. 展开更多
关键词 phytoplankton pigments environmental factor HPLC-CHEMTAX Daya Bay
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