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教育发展合生态性思想探源 被引量:5
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作者 罗玉莲 习萍 匡仁伟 《教育探索》 北大核心 2007年第7期11-12,共2页
利益多元的主体观、差异发展的本质观、和谐共生的结构观、价值平等的伦理观是教育发展合生态性思想的四个方面的内容。教育发展合生态性思想的理论是建立在整体有机论基础之上的生态哲学,其逻辑依据是通过主动控制形成的教育生态系统... 利益多元的主体观、差异发展的本质观、和谐共生的结构观、价值平等的伦理观是教育发展合生态性思想的四个方面的内容。教育发展合生态性思想的理论是建立在整体有机论基础之上的生态哲学,其逻辑依据是通过主动控制形成的教育生态系统智慧体的特殊性,其理想的实现形式是形成合理有序的生态位模型。 展开更多
关键词 教育发展 合生态性 教育生态
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人类生态意识与教育发展合生态性思想 被引量:2
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作者 尹观海 段秋平 朱德龙 《教育探索》 北大核心 2007年第5期23-24,共2页
人类生态意识的产生是对当前全球性危机和人类困境这一社会问题反思的结果,是对人类自我中心化倾向异化后的回归。教育是知识经济的基础,是信息社会应对未来变化的最有效的响应器,教育发展的合理性和合生态性关系到未来社会对变化的适... 人类生态意识的产生是对当前全球性危机和人类困境这一社会问题反思的结果,是对人类自我中心化倾向异化后的回归。教育是知识经济的基础,是信息社会应对未来变化的最有效的响应器,教育发展的合理性和合生态性关系到未来社会对变化的适应性。人类生态意识作为一种新的“应然性”价值判断,是指导教育合生态性发展的思想基础,要求确立利益多元、差异发展、和谐共生、价值平等的合生态性发展思想。 展开更多
关键词 生态意识 教育发展 合生态性 人类自我中心化倾向
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政治文明建设路径的生态化选择
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作者 顾玉兰 《广西梧州师范高等专科学校学报》 2004年第3期6-8,共3页
政治生态化的深层意蕴 ,在于以生态发展的理念指导人们的政治行为 ,以促使政治体系内各要素间及政治体系与其所处环境之间和谐、协调、稳定地发展。
关键词 政治生态 政治文明建设 合生态性选择
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Relationship Between Ecophysiological Features and Grain Yield in Different Soybean Varieties 被引量:14
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作者 朱桂杰 蒋高明 +4 位作者 郝乃斌 刘合芹 孔正红 杜维广 满为群 《Acta Botanica Sinica》 CSCD 2002年第6期725-730,共6页
Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( G... Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( Glycine max (L.) Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter_relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher P n , g s and Ψ than those with low yield potential. Their values of C i were remarkably lower. Such relationship was especially remarkable at the critical stage of pod_bearing. P n of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest P n was found in the pod_bearing stage and other values were higher, too. P n and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when P n values were remarkably higher in the pod_bearing stage. 展开更多
关键词 SOYBEAN ecophysiological characteristics photosynthetic rate stomatal conductance water potential
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Differences in Ecological Fitness Between Bt Transgenic Rice and Conventional Rice Under Insect-infestation Pressures 被引量:1
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作者 张富丽 雷绍荣 +7 位作者 刘勇 郭灵安 尹全 宋君 王东 常丽娟 刘文娟 周西全 《Agricultural Science & Technology》 CAS 2012年第12期2484-2488,2495,共6页
[Objective] This study aimed to improve density and practicality of the ge- netic map of sunflower (Helianthus annuus L.) by adding some SSR markers. [Method] A total of 123 F8 RILs populations derived from a cross ... [Objective] This study aimed to improve density and practicality of the ge- netic map of sunflower (Helianthus annuus L.) by adding some SSR markers. [Method] A total of 123 F8 RILs populations derived from a cross between PAC-2 and RHA-266 were selected as the materials, and a total of 300 pairs of SSR primers were used to screen polymorphic markers between the parents and some of their RILs, and finally 51 pairs of the primers producing polymorphic patterns were selected to construct the genetic map of the RILs populations. [Result] Nineteen pairs of SSR primers did not generate polymorphic patterns or any bands, and 32 SSR pairs showed polymorphism. Thirty-five alleles which distributed in the 15 link- age groups of the maps were detected. The new map covered a total length of 2 914.5 cM, 7.5 cM longer than that of the original map. The average marker interval is 8.1 cM replacing original 9.0 cM. [Conclusion] This study provided reference for genetic map integration and molecular marker assisted selection of sunflower. 展开更多
关键词 SUNFLOWER SSR markers Genetic linkage map
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Studies on Genetic Polymorphism of Different Biotypeswith RAPD Analysis1
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作者 吴玉萍 贾方钧 吴清江 《Developmental and Reproductive Biology》 1999年第2期25-31,共7页
In the present paper, RAPD was used to study the genetic polymorphism of fisheswith different genome combinations. Our results indicated that four of the 26 random primersproduced distinct and reproducible electrophor... In the present paper, RAPD was used to study the genetic polymorphism of fisheswith different genome combinations. Our results indicated that four of the 26 random primersproduced distinct and reproducible electrophoretic patterns which were genome-specific andcould distinguish different biotypes. This enabled us to derive a diagnostic profile, from whichwe constructed a molecular marker key for different biotypes. By the analysis of the data ofRAPD patterns, the genetic relationship was constructed with UPGMA (unweighted pair-groupmethod with arithmetical averages). Our experiments also concluded that RAPD was moresuccessful in variety identification than protein polymorphism analysis and serohematology for itstechnological simplicity and sensitivity. 展开更多
关键词 genome addition RAPD genetic polymorphism
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Photocatalytic degradation of dyes by AgBr/Ag_3PO_4 and the ecotoxicities of their degraded products 被引量:8
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作者 Pongsaton Amornpitoksuk Sumetha Suwanboon 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第5期711-719,共9页
Ag3PO4 powders were prepared through a precipitation reaction between AgNO3 and precipitating agent solutions that were prepared by adjusting the amount of H3PO4 in the Na3PO4 solutions. The Ag3PO4 powders prepared fr... Ag3PO4 powders were prepared through a precipitation reaction between AgNO3 and precipitating agent solutions that were prepared by adjusting the amount of H3PO4 in the Na3PO4 solutions. The Ag3PO4 powders prepared from the precipitation solution with a pH of 6 showed the highest photocatalytic activity for decolorizing the methylene blue and rhodamine B dyes. These Ag3PO4 powders were further modified by the addition of KBr solutions to obtain AgBr/Ag3PO4 powders and these photocatalysts can decolorize the anionic dyes as reactive orange and methyl orange. The reactive species involved in the photocatalytic degradation process were evaluated for their inhibitory activity using the appropriate scavengers. After photocatalysis, mass spectrometry confirmed that the dyes were degraded to smaller molecules. The ecotoxicities of the dye solutions before and after treatment were evaluated by studying their ability to inhibit the growth of the bioindicator Chlorella vulgaris. 展开更多
关键词 Silver phosphate Silver bromide Photocatalytic degradation One-pot synthesis ECOTOXICITY
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Natural Heritage Value of Xinjiang Tianshan and Global Comparative Analysis 被引量:5
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作者 XU Xiaoliang YANG Zhaoping +2 位作者 Adayi Saiken Shao Rui LIU Xinyu 《Journal of Mountain Science》 SCIE CSCD 2012年第2期262-273,共12页
Xinjiang Tianshan is a serial natural property that has been nominated for World Heritage status.This paper presents a systematically comprehensive and comparative analysis of the heritage resources of Xinjiang Tiansh... Xinjiang Tianshan is a serial natural property that has been nominated for World Heritage status.This paper presents a systematically comprehensive and comparative analysis of the heritage resources of Xinjiang Tianshan according to the World Heritage criteria.Its biological,ecological and aesthetic values,which are of global importance, are documented.It is concluded that Xinjiang Tianshan meets the world heritage criteria(vii)and (ix).Xinjiang Tianshan is compared with other mountain world heritage sites,mountains in Central Asia,the Tianshan Mountains outside China,and with the protected areas of the Tianshan Mountains on the Tentative List for World Heritage Sites,so as to provide objective data for the world heritage application. 展开更多
关键词 Xinjiang Tianshan Natural Heritage Heritage characteristics Heritage values Comparative analysis
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Molecular mechanisms of "off-on switch" of activities of human IDH1 by tumor-associated mutation R132H 被引量:12
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作者 Bei Yang Chen Zhong +2 位作者 Yingjie Peng Zheng Lai Jianping Ding 《Cell Research》 SCIE CAS CSCD 2010年第11期1188-1200,共13页
Human cytosolic NADP-1DH (IDH1) has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent on... Human cytosolic NADP-1DH (IDH1) has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent one. This mutation impairs the oxidative IDH activity of the enzyme, but renders a new reduction function of converting a-ketoglutarate (aKG) to 2-hydroxyglutarate. Here, we report the structures of the R132H mutant IDH1 with and without isocitrate OCT) bound. The structural data together with mutagenesis and biochemical data reveal a previ- ously undefined initial ICT-binding state and demonstrate that IDH activity requires a conformational change to a closed pre-transition state. Arg132 plays multiple functional roles in the catalytic reaction; in particular, the R132H mutation hinders the conformational changes from the initial ICT-binding state to the pre-transition state, leading to the impairment of the IDH activity. Our results describe for the first time that there is an intermediate conformation that corresponds to an initial ICT-binding state and that the R132H mutation can trap the enzyme in this conforma- tion, therefore shedding fight on the molecular mechanism of the "off switch" of the potentially tumor-suppressive IDH activity. Furthermore, we proved the necessity of Tyr139 for the gained aKG reduction activity and propose that Tyr139 may play a vital role by compensating the increased negative charge on the C2 atom of aKG during the trans- fer of a hydride anion from NADPH to aKG, which provides new insights into the mechanism of the "on switch" of the hypothetically oncogenic reduction activity of IDH1 by this mutation. 展开更多
关键词 isocitrate dehydrogenase NADP catalytic mechanism crystal structure cancer metabolism
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Soil Attributes and Production of Eucalyptus in Monoculture and Silvopastoral Systems in the North of Minas Gerais, Brazil
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作者 Pedro Henrique Lopes Santana Leidivan Almeida Frazao +2 位作者 Leonardo David Tuffi Santos Luiz Amaldo Femandes Regynaldo Arruda Sampaio 《Journal of Agricultural Science and Technology(B)》 2016年第6期361-370,共10页
The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and eval... The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and evaluated the following four systems: native vegetation system (Cerrado), a degraded pasture, a Eucalyptus urograndis monoculture (E. urophylla x E. grandis) and a silvopastoral system (E. urograndis combined with Brachiaria brizantha cv. "Marandu"). The experimental design used was completely randomized. In each system, four soil samples were collected from the 0-20 cm depth layer, and the chemical and physical attributes of the soil were evaluated. The diameters of all Eucalyptus trees at 1.30 m above the ground as well as the total height were measured. Subsequently, the trees dimensions were measured and their individual volumes obtained by applying the Smalian formula. The correlation between the parameters for Eucalyptus production and soil attributes was established using the Pearson's correlation coefficient method. The planting of Eucalyptus in monoculture and silvopastoral systems contributed to the improvement of the soil's chemical and physical attributes, which indicates the potential of these systems for recovery of degraded pastures. The silvopastoral system yielded the highest average volume of wood per tree (0.2228 m^3), with a productivity of 111.4 m^3/ha. The Eucalyptus monoculture yielded 0.1895 m^3 per tree and 315.71 m^3/ha due to the higher density of the crop. The growth and productivity of Eucalyptus showed highly correlation with the soil attributes, thus suggesting that well-managed crops are an indicator of the soil quality recovery. 展开更多
关键词 Diameter at breast weight forest-livestock integration system forest production soil quality.
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Depth distribution and ecological preferences of periphytic algae in Kenyir Lake,the largest tropical reservoir of Malaysia 被引量:1
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作者 ROUF A.J.M.Abdur PHANG Siew-Moi AMBAK M.Azmi 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第4期856-867,共12页
We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of sp... We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of species richness,abundance,diversity and cell density.In regression analysis,all these algal attributes were negatively correlated with the depth gradients at P<0.05.In terms of species richness,the bacillariophytes showed dominance over the cyanophytes and chlorophytes;whereas with respect to standing crop,the cyanophytes showed dominance over the bacillariophytes and chlorophytes.The chlorophyll a was higher at the mid and bottom-depths than the surface-depth in both the downstream and upstream sites,which showed that vertical productivity or biomass accumulation was greater in low light irradiance.The product-moment correlation analysis showed that conductivity,turbidity,dissolved oxygen,reactive phosphate and ammonium-nitrogen were highly correlated with the algal assemblage data.However,photosynthetic active radiation(PAR) showed poor correlation with the community data.These observations have cast some light on the autoecological characteristics,habitat preferences and environmental responses of tropical periphytic communities. 展开更多
关键词 depth periphytic algae TROPICAL large reservoir Kenyir Lake community structure biomass
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Diversity of plant species in arecanut agroforests of south Meghalaya,north-east India
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作者 H.Tynsong B.K.Tiwari 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第3期281-286,396,共7页
In south Meghalaya, farmers maintain a variety of economically important plant species in arecanut agroforestry systems. We investigated plant species composition of arecanut agroforests of south Meghalaya and encount... In south Meghalaya, farmers maintain a variety of economically important plant species in arecanut agroforestry systems. We investigated plant species composition of arecanut agroforests of south Meghalaya and encountered 160 plants, which included 83 tree species, 22 shrub species, 41 herb species and 14 climber species. The study reveals that arecanut agroforests provide cash income, medicine, timber, fuelwood and edibles for household consumption as well as for sale. We conclude that these agroforestry systems serve as home for many economically important plant species, harbour rich biodiversity and mimic the natural forests both in structural composition as well as ecological and economic functions. 展开更多
关键词 agroforests ARECANUT DIVERSITY South Meghalaya War Khasi
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Integrity of Local Ecosystems and Storm Water Management in Residential Areas
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作者 WANG Lin WANG Weida GONG Zhaoguo 《Journal of Ocean University of China》 SCIE CAS 2006年第4期363-367,共5页
The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. Th... The authors designed an ecological storm water system in a residential area to replace the conventional underground channels for the collection of storm water so as to reduce the nutrients and sediments discharged. This system contains natural sub-creeks as drainage channels discharging overflow to nearby creeks, an open green trench, a storage pond, and natural sub-creeks. The sub -creeks were designed to be integrated into community landscape, which not only increases the efficiency of water usage, but also improves the aesthetic qualities of the community residence area as required by Agenda 21. This research proved the feasibility of an open storm water collection and utilization system for the design of a community water system. 展开更多
关键词 storm water management ecological community water management open trench GREENWAY pond system
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Redox physiology in animal function:The struggle of living in an oxidant environment
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作者 David COSTANTINI 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期687-702,共16页
A strong focus of ecological research for several decades has been to understand the factors underlying the variation in animal life-histories. In recent times, ecological studies have begun to show that oxidative str... A strong focus of ecological research for several decades has been to understand the factors underlying the variation in animal life-histories. In recent times, ecological studies have begun to show that oxidative stress may represent another important modulator of competitive trade-offs among fitness traits or of positively integrated patterns of traits. Therefore, incorporating mechanisms underlying oxidative physiology into evolutionary ecology has the potential to help understand variation in life-history strategies. In this review, I provide a general overview of oxidative stress physiology, and subsequently focus on topics that have been neglected in previous ecological reviews on oxidative stress. Specifically, I introduce and discuss the adaptations that animals have evolved to cope with oxidative stress; the environmental stressors that can generate changes in oxidative balance; the role of reactive species in transduction of environmental stimuli and cell signaling; and the range of hormetic responses to oxidative stress [Current Zoology 56 (6): 687-702, 2010]. 展开更多
关键词 ANTIOXIDANTS Free radicals LIFE-HISTORY Oxidative stress Stress response Vertebrates
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Variants of the Mitochondrial Displacement Loop in Patients with Myelodysplastic Syndromes
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作者 Xiaojing Hu Yaqin Cong +3 位作者 Conggao Xu Jinbo Feng Yujie Jiang Hong Jin 《Chinese Journal of Clinical Oncology》 CSCD 2008年第5期343-348,共6页
OBJECTIVE Some mtDNA mutations have been detected in patients with myelodysplastic syndromes(MDSs).As the non-coding region of mitochondria,the displacement loop(D-loop) region of mtDNA contains important elements for... OBJECTIVE Some mtDNA mutations have been detected in patients with myelodysplastic syndromes(MDSs).As the non-coding region of mitochondria,the displacement loop(D-loop) region of mtDNA contains important elements for mtDNA replication and transcription.Variants of the D-loop region were found to be related to the cause of many diseases.The aim of our study was to investigate mutations and single nucleotide polymorphisms in the D-loop region of MDS patients.METHODS The mutations and SNPs in the hypervariable regions of the D-loop were detected by direct sequencing in MDS patients and normal controls.RESULTS Sixty-four SNPs were found in the D-loop region in MDS cases and control group.Among the SNPs,the 16,189 variant(T > C transition) was found to have an increased frequency in the MDS group(P = 0.044).However,no mutations were detected in neither group.CONCLUSION Our data provide evidence for a highly polymorphic D-loop region in patients with MDS,but do not support the presence of mutations in the mitochondrial D-loop region in MDS cases.The mtDNA T16,189C variant,which may be a functional variant,is associated with increased susceptibility to a MDS. 展开更多
关键词 myelodysplastic syndrome mitochondrial DNA single nucleotide polymorphism mutation.
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Effects of curing age on compressive and tensile stress-strain behaviors of ecological high ductility cementitious composites 被引量:1
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作者 Chai Lijuan Guo Liping +1 位作者 Chen Bo Cao Yuanzhang 《Journal of Southeast University(English Edition)》 EI CAS 2020年第1期73-80,共8页
To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.Th... To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.The reaction degree of fly ash,non-evaporable water content and the pH value in pore solution were calculated to reveal the mechanical property.The results indicate that as the curing age increases,the peak compressive strength,peak compressive strain and ultimate tensile strength of Eco-HDCC increase.However,the ultimate compressive strain and ultimate tensile strain of Eco-HDCC decrease with the increase in curing age.Besides,as the curing age increases,the reaction degree of fly ash and non-evaporable water content in Eco-HDCC increase,while the pH value in the pore solution of Eco-HDCC decreases.Finally,the simplified compressive and tensile stress-strain constitutive relationship models of Eco-HDCC with a curing age of 28 d were suggested for the structure design safety. 展开更多
关键词 ecological high ductility cementitious composites(Eco-HDCC) compressive stress-strain behavior tensile stress-strain behavior curing age reaction degree non-evaporable water content pH value in pore solution
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Analysis of the Economical, Ecological and Quality Advantages Consequent Resulting from Initiation of Technology Integrated in Metallurgy
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作者 Ewa Kubinska-Jabcon Wiktor Kubinski Mariusz Niekurzak 《Journal of Mechanics Engineering and Automation》 2015年第10期549-553,共5页
Metallurgical sector plays an important role in the economy of each country because steel products present essential raw material for basic industries. Changes in the sectors of iron, steel and non-ferrous metals and ... Metallurgical sector plays an important role in the economy of each country because steel products present essential raw material for basic industries. Changes in the sectors of iron, steel and non-ferrous metals and the current development of technology forces the steel mills increased productivity, reduce production costs while ensuring to obtain a product with the required properties and to improve the competitiveness of enterprises in the global market. Currently, the most popular in meeting these requirements, enjoys a method of integration which combines individual operations into one integrated whole. The use of modem, perfectly designed, fully automated design of mechanical, hydraulic and measurement allowed us to achieve an innovative line of production. This article presents the general characteristics of the steel industry and a description of the latest integrated technology currently used in foundries and rolling mills. It also presents examples of the use of integrated technologies in metallurgy and the effects of economic, environmental and quality resulting from their use on an industrial scale. 展开更多
关键词 Metallurgical sector integrated technology
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Tensile behaviors of ecological high ductility cementitious composites exposed to interactive freeze-thaw-carbonation and single carbonation
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作者 Chai Lijuan Guo Liping +2 位作者 Chen Bo Tang Yongjian Fei Xiangpeng 《Journal of Southeast University(English Edition)》 EI CAS 2019年第3期367-373,共7页
To explore the tensile property parameters in the structural design of bridge deck link slabs made by ecological high ductility cementitious composites (Eco-HDCC), the tensile properties of Eco-HDCC exposed to interac... To explore the tensile property parameters in the structural design of bridge deck link slabs made by ecological high ductility cementitious composites (Eco-HDCC), the tensile properties of Eco-HDCC exposed to interactive freeze-thaw-carbonation cycles and single carbonation cycles were studied. The carbonation front of Eco-HDCC was determined by X-ray diffraction and differential scanning calorimetry-thermal gravimetric methods. Results indicate that the carbonation front of Eco-HDCC after interaction tests is deeper than that of Eco-HDCC after single carbonation tests. In addition, the ultimate tensile strength for Eco-HDCC shows an increasing trend after the interaction of 1 to 5 cycles compared with that of virgin specimens, while the ultimate tensile strength decreases after the interaction of 10 to 15 cycles. For single carbonation tests, the ultimate tensile strength of Eco-HDCC increases as cycles increase. After being subjected to interaction and single carbonation environments, both the ultimate tensile strain and tensile strain energy of Eco-HDCC decrease as cycles increase, and the decrease degrees of Eco-HDCC after interaction cycles are larger than those of Eco-HDCC after single carbonation. For general consideration, the tensile stress-strain relationship of Eco-HDCC after the interaction of 15 cycles can be adopted in the design of bridge deck link slabs for the purpose of safety. 展开更多
关键词 ecological high ductility cementitious composites (Eco-HDCC) interaction cycle single carbonation carbona-tion front tensile stress-strain curve tensile strain energy
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Fluorescence Properties of Submerged Macrophytes in Nanjishan Wetland,Southern Poyang Lake 被引量:1
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作者 简敏菲 汪斯琛 +3 位作者 余厚平 李玲玉 简美锋 余冠军 《Journal of Resources and Ecology》 CSCD 2015年第1期52-59,共8页
We used a FluorCam portable chlorophyll fluorescence imaging system to measure QY-max (the maximum light quantum yield, Fv/Fm, the largest light quantum efficiency of PS Ⅱ) of submerged plants in wetlands of Baisha... We used a FluorCam portable chlorophyll fluorescence imaging system to measure QY-max (the maximum light quantum yield, Fv/Fm, the largest light quantum efficiency of PS Ⅱ) of submerged plants in wetlands of Baisha Lake and Changhu Lake, Jiangxi Nanjishan Wetland National Nature Reserve, in winter 2013. Specifically, we measuredΦPS Ⅱ (PS Ⅱ actual quantum efficiency), qP (photochemical quenching) and corresponding fluorescence images. Using the visual method and sampling sites method to obtain coverage, richness and abundance of submerged plants, and determined nutrient levels in water. The results show that the QY-max ofHydrilla verticillata andVallisneria natans in Baisha Lake ranged from 0.48 to 0.68 and 0.52 to 0.71, respectively; theΦPS Ⅱ of these two species ranged from 0.32 to 0.58 and 0.20 to 0.46, respectively. The two plants had similar photosynthetic efifciency. The QY-max ofNymphoides peltatum andV. natans in Changhu Lake ranged from 0.66 to 0.77 and 0.19 to 0.68, respectively; theΦPS Ⅱ of these two species ranged from 0.26 to 0.48 and 0.22 to 0.43, respectively. The observed higher photosynthetic efifciency of N peltatum suggests it is more likely to become the dominant species. In Baisha Lake, the frequency of occurrence of plants was:H. verticilata, 90%;V. natans, 93.3%;Najas minor26.7%, andPotamogeton francheti10%. In Changhu Lake, the frequency of N. pel-tatum was 86.7%,V. natans was 16.7%, andN. minor was 56.7%. The overal frequency of submerged plants living in Baisha Lake was much higher than that of submerged plants living in Changhu Lake, with different species dominating the two lakes. According to comprehensive analysis and comparison of trophic levels, biodiversity and photosynthetic fluorescence characteristics in the two lakes, eutrophication of Baisha Lake was higher than for Changhu Lake; andH. verticillata andV. natans were the dominant species, with similar photosynthetic activity. Conversely, in Changhu Lake,N. peltatum andV. natans were the dominant species, but the photosynthetic activity of N. peltatum was higher thanV. natans. Differences in eutrophication levels in different water bodies in the Nanjishan Wetland and differing ecological niches of submerged plant species are characteristic of this system. 展开更多
关键词 wetland ecology submerged macrophytes photosynthetic characteristics chlorophyll fluorescence
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A generalized model of island biogeography 被引量:2
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作者 CHEN XiaoYong JIAO Jing TONG Xin 《Science China(Life Sciences)》 SCIE CAS 2011年第11期1055-1061,共7页
MacArthur and Wilson's equilibrium theory is one of the most influential theories in ecology.Although evolution on islands is to be important to island biodiversity,speciation has not been well integrated into isl... MacArthur and Wilson's equilibrium theory is one of the most influential theories in ecology.Although evolution on islands is to be important to island biodiversity,speciation has not been well integrated into island biogeography models.By incorporating speciation and factors influencing it into the MacArthur-Wilson model,we propose a generalized model unifying ecological and evolutionary processes and island features.Intra-island speciation may play an important role in both island species richness and endemism,and the contribution of speciation to local species diversity may eventually be greater than that of immigration under certain conditions.Those conditions are related to the per species speciation rate,per species extinction rate,and island features,and they are independent of immigration rate.The model predicts that large islands will have a high,though not the highest,proportional endemism when other parameters are fixed.Based on the generalized model,changes in species richness and endemism on an oceanic island over time were predicted to be similar to empirical observations.Our model provides an ideal starting point for re-evaluating the role of speciation and re-analyzing available data on island species diversity,especially those biased by the MacArthur-Wilson model. 展开更多
关键词 island biogeography SPECIATION IMMIGRATION EXTINCTION area ISOLATION species richness island development
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