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Recyclable adsorbent of BiFeO_3/Carbon for purifying industrial dye wastewater via photocatalytic reproducible 被引量:9
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作者 Shuang Jiao Yiming Zhao +2 位作者 Chensha Li Binsong Wang Yang Qu 《Green Energy & Environment》 SCIE CSCD 2019年第1期66-74,共9页
It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic r... It is essential to prepare highly-efficiency reproducible adsorbent for purifying industrial dye wastewater. In this work, biscuit with a layered porous structure as a template is applied to prepare a photocatalytic recyclable adsorbent of BiFeO3/Carbon nanocomposites for purifying simulative industrial dye wastewater. It is found that the structure of the prepared BiFeO3/Carbon nanocomposite is related to the natural structure of the biscuit, annealing temperatures and immersing times, demonstrated by XRD, TEM, UV-Vis and adsorptive activities. Kinetics data shows that the adsorption rate of the adsorbent to the dye is rapid and fitted well with the pseudo-second-order model, that more than 80% of dyes can be removed in the beginning 30 min. The adsorption isotherm can be perfectly described by the Langmuir model as well. It can be seen from the adsorption data that the adsorption performance can reach over 90% at pH ? 2–12, which can imply its universal utilization. The prepared BiFeO_3/Carbon nanocomposites have also displayed excellent capacities(over 90% within 30 min) for adsorption of seven different dyes and their mixed one. According to the five times photocatalytic reproducible experiments, it is proved that BiFeO_3/Carbon nanocomposites show the excellent stability and reproduction for purifying simulative industrial dyes, even the sample have been placed for one year. These research results indicate that the adsorbent BiFeO_3/Carbon can be a suitable material used in treating industrial dye wastewater potentially. 展开更多
关键词 Reproducible ADSORBENT BiFeO3/Carbon nanocomposites Photocatalysis purifying INDUSTRIAL dye wastewater Pseudo-second-order model
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Mechanical Properties,Purifying Techniques and Processing Methods of Metal Yttrium 被引量:2
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作者 金红 孙国强 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期362-366,共5页
The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced . The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium... The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced . The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium including extruding, forging, rolling, wiredrawing and welding were also introduced. Finally, the potential use of yttrium and its alloys were prospected. 展开更多
关键词 metal yttrium mechanical properties purifying PROCESSING rare earths
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STUDIES OF PURIFYING OF CLAYEY DIATOMITE
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作者 郑水林 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1994年第1期125-133,共9页
This article discusses the purifying method of the clayey diatomite or clay ——bearing diatotnite minerals found in China. And the processes of acidizing, beneficiation and gravitational fluidized dry sepa-ration are... This article discusses the purifying method of the clayey diatomite or clay ——bearing diatotnite minerals found in China. And the processes of acidizing, beneficiation and gravitational fluidized dry sepa-ration are reviewed. 展开更多
关键词 DIATOMITE BENEFICIATION purifying
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Scheme for purifying a general mixed entangled state and its linear optical implementation
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作者 董冬 张延磊 +2 位作者 邹长铃 邹旭波 郭光灿 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期67-70,共4页
We propose a scheme for purification of a general mixed entangled state. In this scheme, we start from a large number of general mixed entangled states and end up, after local operation and classical communication, wi... We propose a scheme for purification of a general mixed entangled state. In this scheme, we start from a large number of general mixed entangled states and end up, after local operation and classical communication, with a smaller number of Bell diagonal states with higher entanglement. In particular, the scheme can purify one maximally entangled state from two entangled pairs prepared in a class of mixed entangled state. Furthermore we propose a linear optical implementation of the present scheme with polarization beam splitters and photon detectors. 展开更多
关键词 ENTANGLEMENT purifying optical implementation
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Genomic Mutations Within the Host Microbiome: Adaptive Evolution or Purifying Selection
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作者 Jiachao Zhang Rob Knight 《Engineering》 SCIE EI CAS CSCD 2023年第1期96-102,共7页
Next-generation sequencing technology has transformed our ability to assess the taxonomic composition functions of host-associated microbiota and microbiomes. More human microbiome research projects—particularly thos... Next-generation sequencing technology has transformed our ability to assess the taxonomic composition functions of host-associated microbiota and microbiomes. More human microbiome research projects—particularly those that explore genomic mutations within the microbiome—will be launched in the next decade. This review focuses on the coevolution of microbes within a microbiome, which shapes strain-level diversity both within and between host species. We also explore the correlation between microbial genomic mutations and common metabolic diseases, and the adaptive evolution of pathogens and probiotics during invasion and colonization. Finally, we discuss advances in methods and algorithms for annotating and analyzing microbial genomic mutations. 展开更多
关键词 Gut microbiota Genomic mutations Adaptive evolution purifying selection Single-nucleoti de variants
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Effect of Distribution of Magnetic Flux Density on Purifying Liquid Metal by Travelling Magnetic Field
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作者 Zhong Yunbo Ren Zhongming Deng Kang Jiang Guochang Xu Kuangdi (School of Material Science and Engineering, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第2期73-77,共5页
The distribution of the magnetic flux density in the magnetic field generator which provided travelling magnetic field was determined. The experiments using liquid gallium and aluminum silicon alloy to observe the ... The distribution of the magnetic flux density in the magnetic field generator which provided travelling magnetic field was determined. The experiments using liquid gallium and aluminum silicon alloy to observe the turbulent flow or remove inclusions were performed to obtain the basic principles how the distribution of the magnetic flux density took effect on removing inclusions from molten metal by electromagnetic field. The suitable area in the field for purifying metal was suggested. 展开更多
关键词 purifying metal by electromagnetic field distribution of the magnetic flux density turbulent flow
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Research of the Purifying of Welding Fume on the Spot with Corona Plasma
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作者 Yansheng Du ChunduWu Jinyu Chu 《Journal of Environmental Science and Engineering》 2010年第1期61-64,共4页
The welding fume has significant effects on the weld workers' health. In order to overwhelm the shortcomings of the control measures of the welding fume, the research of the purifying of welding fume on the spot was ... The welding fume has significant effects on the weld workers' health. In order to overwhelm the shortcomings of the control measures of the welding fume, the research of the purifying of welding fume on the spot was carried out. The purifying device was designed. The relationship between the corona discharge voltage and the purifying efficiency was investigated through experiments with different needle electrode numbers, different ring electrode numbers and different needle-plate distances. The results show that 5-needle double-ring electrode has the best efficiency; the purifying efficiency is increase with the lessening of the needle-plate distance and the increase of the discharge voltage. Using 5-needle double-ring electrode, the purifying efficiency reaches its maximum value 97.9% while the needle-plate distance is 6 cm, the discharge voltage is -35 kV. The purifying device has an excellent purifying effect on the welding fume. 展开更多
关键词 Corona plasma welding fume purifying on the spot.
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Inbreeding and genetic load in a pair of sibling grouse species:Tetrastes sewersowi and T.bonasia
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作者 Kai Song Tom van der Valk +7 位作者 Bin Gao Peter Halvarsson Yun Fang Wendong Xie Siegfried Klaus Zhiming Han Yue-Hua Sun Jacob Hoglund 《Avian Research》 SCIE CSCD 2024年第2期265-270,共6页
Genetic load and inbreeding are recognized as important factors to be considered in conservation programs.Elevated levels of both can increase the risk of population extinction by negatively impacting fitness-related ... Genetic load and inbreeding are recognized as important factors to be considered in conservation programs.Elevated levels of both can increase the risk of population extinction by negatively impacting fitness-related characters in many species of plants and animals,including humans(inbreeding depression).Genomic tech-niques are increasingly used in measuring and understanding genetic load and inbreeding and their importance in evolution and conservation.We used whole genome resequencing data from two sibling grouse species in subarctic Eurasia to quantify both.We found a large range of inbreeding measured as FROH(fraction of runs of homozygosity)in individuals from different populations of Chinese Grouse(Tetrastes sewerzowi)and Hazel Grouse(T.bonasia).FROH estimated from genome-wide runs of homozygosity(ROH)ranged from 0.02 to 0.24 among Chinese Grouse populations and from 0.01 to 0.44 in Hazel Grouse.Individuals from a population of Chinese Grouse residing in the Qilian mountains and from the European populations of Hazel Grouse(including samples from Sweden,Germany and Northeast Poland)were the most inbred(FROH ranged from 0.10 to 0.23 and 0.11 to 0.44,respectively).These levels are comparable to other highly inbred populations of birds.Hazel Grouse from northern China and Chinese Grouse residing in the Qinghai-Tibetan Plateau showed relatively lower inbreeding levels.Comparisons of the ratio between deleterious missense mutations and synonymous mutations revealed higher levels in Chinese Grouse as compared to Hazel Grouse.These results are possibly explained by higher fixation rates,mutational melt down,in the range-restricted Chinese Grouse compared to the wide-ranging Hazel Grouse.However,when we compared the relatively more severe class of loss-of-function muta-tions,Hazel Grouse had slightly higher levels than Chinese Grouse,a result which may indicate that purifying selection(purging)has been more efficient in Chinese Grouse on this class of mutations. 展开更多
关键词 Genetic load INBREEDING purifying selection Qinghai-Tibetan Plateau ROH Tetrastes
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Molecular Evolutionary Analysis of DFR Gene in Lamiidae Plants 被引量:1
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作者 陈大志 叶春 李萍 《Agricultural Science & Technology》 CAS 2011年第8期1129-1132,共4页
[Objective]The aim of this study was to reveal the molecular evolutionary characteristics of dihydroflavonol 4-Reductase(DFR)—a key enzyme in anthocyanin synthesis pathway in Lamiidae plants.[Method]Based on DFR am... [Objective]The aim of this study was to reveal the molecular evolutionary characteristics of dihydroflavonol 4-Reductase(DFR)—a key enzyme in anthocyanin synthesis pathway in Lamiidae plants.[Method]Based on DFR amino acid and cDNA sequences released by NCBI,molecular evolution of DFR gene was analyzed with bioinformatic software.[Result]Seventeen plants fell into two major branches,Lamiidae and Liliidae.Most of the plants within a same family cluster assembled together,which basically accords with the morphological development of species.Prediction results based on selection pressure using MEGA,DNAsp and PAML software showed that DFR gene in Lamiidae plants underwent strong purifying selection pressure.[Conclusion]Our results laid basis for analyzing the molecular mechanism of enzymatic characteristics of DFR and of the anthocyanin synthesis pathway. 展开更多
关键词 Lamiidae DFR purifying selection pressure
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亚里士多德的施授美学思想 被引量:1
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作者 刘大先 《楚雄师范学院学报》 2004年第1期81-84,共4页
亚里士多德的文艺“模仿”说与效果“净化 /陶冶”说 ,体现出对接受主体的高度重视 ,这是源于其哲学伦理学的“施授美学”观念 ,表明创作主体控制话语权力的企图。
关键词 模仿 净化/陶冶 话语霸权 受众
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Preparation of 5N high purified indium by the method of chemical purification-electrolysis 被引量:5
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作者 ZENG Dongming, ZHOU Zhihua, SHU Wangen, LIU Younian, and HU AipingCollege of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第2期137-141,共5页
The application of indium requires high purity indium as material.5N high purity indium had been prepared by the method of acombination of chemically smelting and electrolysis. Smelting timewas 10 min, the abstraction... The application of indium requires high purity indium as material.5N high purity indium had been prepared by the method of acombination of chemically smelting and electrolysis. Smelting timewas 10 min, the abstraction rate of cadmium was 80/100-90/100 whenused solution of I_2-KI and glycerine to smelt indium. 4N metalindium was used as anode, high purity indium as cathode, In-2(SO_4)_3-H_2SO_4 system as electrolyte, and In content is 100 g/L, pH2-3 and current density 80-100 a/m^2. 展开更多
关键词 high-purify INDIUM PREPARATION chemical purifying
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Regulation of water quality and growth characteristics of indoor raceway culture of Litopenaeus vannamei 被引量:4
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作者 臧维玲 杨明 +3 位作者 戴习林 侯文杰 刘永士 丁福江 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第4期740-747,共8页
Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone... Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone, composite microbe preparation, and Ceratophyllum demersum were placed in the experimental ponds and the culture water was circulated along the raceway inside the pond using a paddle wheel aerator. In addition, the water quality in the experimental pond was improved by draining effluent from the pipeline at the bottom of ponds 7 and 8 (mode I) and exchanging the circulating water in pond 10 (mode Ⅱ) with the reservoir water in pond 9 using a pump and pipeline. The water quality in the experimental ponds was similar in response to regulation using mode Ⅰ or mode Ⅱ. Water quality parameters in the experimental ponds were controlled within a suitable range by simple facilities during culture period without using any chemical treatments. The rich content of dissolved oxygen was maintained by the circular flow and continuous aeration of the pond water. The respective average values of the main water parameters in experimental ponds 7 and 10 in response to regulation of the water quality using modes Ⅰ and Ⅱwere as follows: pH 8.17 and 7.99; DO 5.16 mg/L and 5.97 mg/L; CODMn18.45 and 12.61 mg/L; TAN (NH3-N) 0.854 mg/L (0.087 mg/L) and 0.427 mg/L (0.012 mg/L); NO2-N 0.489 mg/L and 0.337 mg/L. Moreover, the average body length and body weight of harvested shrimp of pond 7 and pond l0 were 7.56 cm and 8.99 cm, 5.10 g and 8.33 g, respectively. Furthermore, the survival rate, average biomass yield and average condition factor of the shrimp harvested were 70% and 60%, 2.54 kg/m2 and 2.14 kg/m2, and 0.675 g/cm and 0.927 g/cm, respectively. Linear equations describing the relationship between body length and culture time and cubic or power functions describing the relationship between body weight and body length were obtained based on evaluation of the growth data of shrimps throughout the culture period. 展开更多
关键词 Litopenaeus vannamei RACEWAY water purifying net body length body weight regressiveequation
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Application of Rare Earths in Oil Country Tubular Goods 被引量:1
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作者 林勤 姚庭杰 +4 位作者 刘爱生 陈宁 叶文 余宗森 卢先利 《Journal of Rare Earths》 SCIE EI CAS CSCD 1996年第3期189-194,共6页
The effect of rare earths(RE) on purifying molten steels, modifying inclusion and micro-alloying are studied in J55 steel. The results show that RE improves the transverse impact energy and increases the resistance of... The effect of rare earths(RE) on purifying molten steels, modifying inclusion and micro-alloying are studied in J55 steel. The results show that RE improves the transverse impact energy and increases the resistance of perforation cracking. The extent on modifying MnS and Al2O3 inclusions is dependent on the activity ratios of RE to Mn and RE to Al. The(a(RE). a(s))/(a(o) . a(Al)) value determines the relative amount of REAlO(3) and RE(2)O(2)S and the properties of steel. RE segregation on grain boundary reduces the segregation of phosphorus and sulfur there. 展开更多
关键词 RE purifying molten steel modifying inclusion micro-alloying J55 steel
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Molecular Cloning,Genomic Organization and Functional Analysis of the Ribosomal Protein S30(RPS30) Gene from Arachis hypogaea 被引量:1
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作者 WU Qi WANG Xiuzhen +2 位作者 TANG Yueyi WANG Zhiwei WANG Chuantang 《Journal of Donghua University(English Edition)》 EI CAS 2019年第3期267-276,共10页
The ribosomal proteins are crucial for the maintenance of ribosomal translational efficiency and fidelity.In the study,we characterized the ribosomal protein S30(RPS30)gene from Arachis hypogaea that has been isolated... The ribosomal proteins are crucial for the maintenance of ribosomal translational efficiency and fidelity.In the study,we characterized the ribosomal protein S30(RPS30)gene from Arachis hypogaea that has been isolated through Genefishing analysis during defense responses to Ralstonia solanacearum.The cDNA of RPS 30 contained a 189 base pair(bp)open-reading frame encoding 62 amino acids.The genomic DNA consists of 272 bp containing two exons and one 83 bp intron.The RPS 30 mRNA transcript was mainly expressed in roots and leaves.The expression level of the RPS 30 mRNA transcripts was up-regulated sharply 6 h after bacterial challenge and was 12 times greater than that of the control group.The phylogenetic analysis for genes encoding proteins showed that RPS30 were conserved within dicotyledonous and monocotyledonous plants.d S extremely exceeded d N in all branches of the tree(d N/d S<1.0),indicating that functional constraint have acted on RPS 30 throughout evolution. 展开更多
关键词 RIBOSOMAL protein S30(RPS30) ARACHIS HYPOGAEA Ri Hua 1 purifying selection
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洛南县森林生态系统净化大气效益价值评估 被引量:1
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作者 宋书堂 李雪晴 陈永卫 《农业科学》 2018年第8期888-893,共6页
通过森林资源二类调查数据,依据国家林业局2008年发布实施的《森林生态系统服务功能评估规范》(LY/T1721-2008),对洛南县森林生态系统固碳、释氧、净化SO2和滞尘4项净化大气效益进行初步评估。结果表明:研究区森林生态系统净化大气总效... 通过森林资源二类调查数据,依据国家林业局2008年发布实施的《森林生态系统服务功能评估规范》(LY/T1721-2008),对洛南县森林生态系统固碳、释氧、净化SO2和滞尘4项净化大气效益进行初步评估。结果表明:研究区森林生态系统净化大气总效益为21.65亿元/a,其中年固碳30.76万t,效益3.69亿元。年释氧82.349万t,效益8.23亿元。年净化SO22.63万t,效益0.316亿元。年滞尘627.391万t,效益9.41亿元。森林生态系统净化大气效益非常显著。 展开更多
关键词 森林生态系统 净化大气 价值 FOREST ECOSYSTEMS purifying the ATMOSPHERE VALUE
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Microstructure Features with Ultrafined and Purified Grains for Si-Mn Hot-rolling TRIP Steel
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作者 Yu CHEN Guoyi TANG +5 位作者 Feipeng LI Yu ZHANG Xiao CHE Pinghe LI Wei LIU Qing LI 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第6期799-802,共4页
The advanced hot-rolled transformation induced plasticity (TRIP) steel with high tensile strength of 775 MPa, high elongation of 29% and low ductile-brittle transmission temperature less than -80℃ has been develope... The advanced hot-rolled transformation induced plasticity (TRIP) steel with high tensile strength of 775 MPa, high elongation of 29% and low ductile-brittle transmission temperature less than -80℃ has been developed in laboratory based on the common silicon and manganese chemical composition. The experimental results showed that the microstructures were featured with ultra fine grain size less than 5μm, appropriate retained austenite volume fraction around 11.8% and purified ferrite grain, which may result in well balanced mechanical properties for the steel. 展开更多
关键词 Ultra fine grain purifying grain Retained austenite Silicon ELONGATION
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A preliminary study on air microorganism in a wood mill
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作者 ZOULi XUJi-fei +1 位作者 WANGXiang-li ZHENGHong 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第2期161-162,共2页
The air microbial species and quantities in a wood mill in Harbin, China weremeasured using sedimentation plate method. Results showed that the microbial quantity in the air atthe workshop without depurator (54939 cfu... The air microbial species and quantities in a wood mill in Harbin, China weremeasured using sedimentation plate method. Results showed that the microbial quantity in the air atthe workshop without depurator (54939 cfu·m^(-3)) was 2.1 times that of the workshop withdepu-rator (25768 cfu·m^(-3)). The depurator could purify air microorganisms at the workshop, witha purifying rate of 53.1%, but it did not reach the standards of clean air. Comparatively thedepurator is effective in reducing the quantity of air actinomyces, and some kinds of airactinomyces, such as Scabies, Cinereas and Hygroscopicas, can be clean out, but it is not veryeffective to bacteria and fungi. It is suggested that more effective and feasible methods should bedeveloped for purifying air microorganisms at the workshop in the future. 展开更多
关键词 air microorganism method of sedimentation plate purifying rate depurator
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Complete Mitochondrial Genome of the Steppe Ribbon Racer(Psammophis lineolatus):The First Representative from the Snake Family Psammophiidae and its Phylogenetic Implications
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作者 Minli CHEN Jinlong LIU +2 位作者 Jun LI Na WU Xianguang GUO 《Asian Herpetological Research》 SCIE CSCD 2021年第3期295-307,共13页
Comparisons of vertebrate mitochondrial genomes(mitogenomes)may yield significant insights into the evolution of organisms and genomes.However,no complete mitogenome from the snake family Psammophiidae has been report... Comparisons of vertebrate mitochondrial genomes(mitogenomes)may yield significant insights into the evolution of organisms and genomes.However,no complete mitogenome from the snake family Psammophiidae has been reported.In this study,we sequenced and annotated the complete mitogenome of Psammophis lineolatus,representing the first mitogenome of Psammophiidae.The total length is 17166 bp,consisting of 13 protein-coding genes(PCGs),22 transfer RNAs(tRNAs),two ribosomal RNAs(12 S rRNA and16 S rRNA),and duplicate control regions(CRs).This gene arrangement belongs to the TypeⅢpattern,which is a widely shared gene order in Alethinophidian snakes.All tRNAs exhibit cloverleaf structures with the exception of tRNA-Ser^(AGY) and tRNA-Pro,which lack a dihydrouridine(DHU)arm/stem and TΨC loop,respectively.The 13 PCGs include five start codons(ATG,GTG,ATA,ATT,and ATC),two complete stop codons(TAA and AGG),and two incomplete stop codon(T--and TA-).In addition,the Ka/Ks ratios indicate that all PCGs had undergone a strong purifying selection.Four types of CR domains rearrangement occurred among eight species of Elapoidea.The phylogenetic reconstructions with both Bayesian inference and maximum likelihood methods support the placement of Psammophiidae in the Elapoidea superfamily,with Homalopsidae being the sister taxon to Elapoidea and Colubroidea.However,the sister taxon of Psammophiidae is unclear due to the availability of Elapoidea mitogenomes being limited to the family Elapidae.More mitogenomes from different taxonomic groups in Elapoidea are needed to better understand the phylogenetic relationships within Elapoidea. 展开更多
关键词 mitochondrial genome phylogenetic relationships Psammophis lineolatus Psammophiidae purifying selection
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Thermal performance of sputtered Cu films containing insoluble Zr and Cr for advanced barrierless Cu metallization
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作者 王新建 董显平 姜传海 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第2期217-222,共6页
Pure Cu films and Cu alloy films containing insoluble substances(Zr and Cr)were deposited on Si(100)substrates,in the presence of interfacial native suboxide(SiOx),by magnetron sputtering.Samples were vacuum annealed ... Pure Cu films and Cu alloy films containing insoluble substances(Zr and Cr)were deposited on Si(100)substrates,in the presence of interfacial native suboxide(SiOx),by magnetron sputtering.Samples were vacuum annealed between 300℃and 500 ℃to investigate effects of Zr and Cr additions on the thermal performance of Cu films.After annealing,copper silicides were found in the Cu(Zr)films,while no detectable silicides were observed in Cu and Cu(Cr)films.Upon annealing,Zr accelerated the diffusion and reaction between the film and the substrate,and lowered the thermal stability of Cu(Zr)alloy films on Si substrates,which was ascribed to the‘purifying effect’of Zr on the Si substrates.Whereas,Cr prohibited the agglomeration of Cu films at 500℃and decreased the surface roughness.As a result,the diffusion of Cu in Si substrates for Cu(Cr)films was effectively inhibited.In contrast to the high resistivity of Cu(Zr)films,the final resistivity of about 2.76μΩ·cm was achieved for the Cu(Cr)film.These results indicate that Cu(Cr)films have higher thermal stability than Cu(Zr)films on Si substrates and are preferable in the advanced barrierless Cu metallization. 展开更多
关键词 copper film barrierless metallization magnetron sputtering thermal stability purifying effect
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MHC Class I Exon 4 in the Multiocellated Racerunners(Eremias multiocellata): Polymorphism, Duplication and Selection
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作者 Xiuyun YUAN Xiaomao ZENG Xianguang GUO 《Asian Herpetological Research》 SCIE 2014年第2期91-103,共13页
The major histocompatibility complex (MHC) is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- deat... The major histocompatibility complex (MHC) is a dynamic genetic region with an essential role in the adaptive immunity of jawed vertebrates. The MHC polymorphism is affected by many processes such as birth-and- death evolution, gene conversion, and concerted evolution. Studies investigating the evolution of MHC class I genes have been biased toward a few particular taxa and model species. However, the investigation of this region in nonavian reptiles is still in its infancy. We present the first characterization of MHC class I genes in a species from the family Lacertidae. We assessed genetic diversity and a role of selection in shaping the diversity of MHC class I exon 4 among 37 individuals of Eremias multiocellata from a population in Lanzhou, China. We generated 67 distinct DNA sequences using cloning and sequencing methods, and identified 36 putative functional variants as well as two putative pseudogene-variants. We found the number of variants within an individual varying between two and seven, indicating that there are at least four MHC class I loci in this species. Gene duplication plays a role in increasing copy numbers of MHC genes and allelic diversity in this species. The class I exon 4 sequences are characteristic of low nucleotide diversity. No signal of recombination is detected, but purifying selection is detected in β2-microglobulin interaction sites and some other silent sites outside of the function-constraint regions. Certain identical alleles are shared by Eremias multiocellata and E. przewalskii and E. brenchleyi, suggesting trans-species polymorphism. The data are compatible with a birth-and-death model of evolution. 展开更多
关键词 MHC class I Eremias multiocellata trans-species polymorphism balancing selection purifying selection birth-and-death evolution
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