检索结果-南通市图书馆

Nationwide distribution of polycyclic aromatic hydrocarbons in soil of China and the association with bacterial community

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第6期128卷 1-11页

作者： Qiuyue Zhang Meng Gao Xinhui Sun Yu Wang Chaolei Yuan Hongwen Sun MOE Key Laboratory of Pollution Processes and Environmental Criteria College of Environmental Science and EngineeringNankai UniversityTianjin 300350China School of Agriculture Sun Yat-sen UniversityShenzhen 518107China

Soil contamination by polycyclic aromatic hydrocarbons(PAHs)has raised great environmental concerns.However,the information on national wide distribution of PAHs in soil as well as their effect on soil bacterial community are limited.In this study,16 PAHs weremeasured in 94 soil samples collected across China.The total concentration of 16 PAHs(PAHs)in soil ranged from 74.0 to 17,657 ng/g(dry weight basis),with a median value of 200 ng/g.Pyrene was themajor soil PAH,with amedian concentration of 71.3 ng/g.Soil samples from Northeast China had a higher median concentration ofPAHs(1,961 ng/g)than those from other regions.Petroleum emission and wood/grass/coal combustion were potential sources for soil PAHs based on diagnostic ratios and positive matrix factors analysis.A nonnegligible ecological risk(hazard quotients>1)was found in over 20%of soil samples analyzed and the highestmedian total HQs value(8.53)was found in soils from Northeast China.The effect of PAHs on bacterial abundance,α-diversity,andβ-diversity was limited in the soils surveyed.Nevertheless,the relative abundance of some members in genera Gaiella,Nocardioides,and Clostridium was significantly correlated with the concentrations of some PAHs.Especially,the bacterium Gaiella Occulta showed potential in indicating soil contamination by PAH,which is worth further exploration.

关键词： PAHs Soil Source analysis Bacterial community

Chemical oxidation of arsenic in the environment and its application in remediation: A mini review

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2023年第1期33卷 185-193页

作者： Chaolei Yuan Qi LI Zhaoyang SUN Wenjun ZHANG Jiangrong CHEN Zheng CHEN Shuo NA Hongwen SUN Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityTianjin 300350China The Institute of Seawater Desalination and Multipurpose Utilization Ministry of Natural ResourcesTianjin 300192China Department of Health and Environmental Sciences Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China

Arsenic(As)contamination in soil and water poses a serious threat to the ecosystem health and human beings,and is of widespread concern.The main As species found in soil and water are arsenite As(Ⅲ)and arsenate As(V).Because As(Ⅲ)is more toxic and often more mobile than As(Ⅴ),many remediation strategies aim to oxidize As(Ⅲ)to As(Ⅴ).In the environment,the reduction of As(Ⅴ)under anaerobic conditions is mainly mediated by microorganisms,but the oxidation of As(Ⅲ)under aerobic conditions can be mediated primarily by chemical processes.This article first reviews the existing knowledge on chemical oxidation of As(Ⅲ)in the environment,with an emphasis on the roles of iron(Fe)and manganese(Mn)oxides.The application of Fe and Mn oxides for the remediation of As-contaminated soil and water is then summarized.The oxidation of As(Ⅲ)by oxygen is very slow in the absence of catalysts.Many Mn oxides,on the other hand,can efficiently oxidize As(Ⅲ).Although the oxidation of As(Ⅲ)by Fe(Ⅲ)is also slow,this process can be accelerated by light or Fe(Ⅱ).Iron and Mn oxides are widely used for the remediation of As-contaminated soil and water,with Fe oxides generally acting as absorbents while Mn oxides as oxidants.To better understand and regulate As transformation and transport in the environment,further study is needed on the mechanisms and influencing factors of As(Ⅲ)oxidation by Fe and Mn oxides,and the development of innovative methods and materials based on Fe and Mn oxides are desired.

关键词： As contamination iron oxide manganese oxide soil water

Effects of Cd on reductive transformation of lepidocrocite by Shewanella oneidensis MR-1

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2017年第3期36卷 479-481页

作者： Chaolei Yuan Fangbai Li Rui Han Tongxu Liu Weimin Sun Weilin Huang Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management Guangdong Institute of Eco-environmental Science and Technology Guangzhou 510650 China Department of Environmental Sciences Rutgers UniversityNew Brunswick NJ 08901 USA

We investigated the reduction of lepidocrocite(γ-FeOOH) by Shewanella oneidensis MR-1 in the presence and absence of Cd. The results showed that Cd^(2+) retarded microbial reduction of γ-Fe OOH and avoided formation of magnetite. The inhibitory effect on γ-Fe OOH transformation may not result from Cd^(2+) toxicity to the bacterium; it rather was probably due to competitive adsorption between Cd^(2+) and Fe^(2+) on γ-Fe OOH as its surface reduction catalyzed by adsorbed Fe^(2+) was eliminated by adsorption of Cd^(2+).

关键词：微生物还原纤铁矿无镉转化 FeOOH 毒害作用抑制作用 cd

Microstructure Control of Non-quenched and Tempered CT80Grade Coiled Tubing Steel

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 464-468页

作者： Leyu Zhou Bo Jiang Mingyang Li Fuchun yuan chaolei Zhang Yazheng Liu School of Materials Science and Engineering University of Science and Technology Beijing

Complex working condition of coiled tube （CT） steel demands high strength and low ratio of yield strength （YS） to tensile strength （TS）. Reasonable microstructure control is a key problem of CT steel. Controlled rolling and controlled cooling experiments were carded out by two kinds of tested steels with different chemical compositions to develop the non-quenched and tempered CT80 steel. Mechanical properties of the tested steels at different processes are all in good agreement with the properties requirement of CT80. Increasing of Mo and Nb contents improves transformation of acicular ferrite and martensite-austenite （M-A） islands. 4 vol% of fine M/A islands increase TS and decreases ratio of YS/ TS, Cooling rate increasing also improves acicular ferrite transformation and enhances TS, but has little effect on ratio of YS/TS. To meet the requirement of high strength and low ratio of YS/TS, optimized complex microstructure of the CT80 steel is composed of acicular ferrite, about 30 vol% of bainite and 4 vol% of M-A islands.

关键词： Coiled tube M-A islands Acicular ferrite Mechanical properties

氨基酸序列分析揭示苯丙氨酸/酪氨酸解氨酶在陆生植物中的演化

在线全文

学校读者我要写书评

暂无评论

复旦学报:自然科学版 2023年第5期62卷 553-564页

作者：盛超雷原野庞力豪卢宝荣复旦大学生命科学学院生物多样性与生态工程教育部重点实验室上海200438

苯丙烷途径在陆生植物木质素和黄酮类等次生代谢产物的生物合成中至关重要,其中一步必需的反应为苯丙氨酸解氨酶(PAL)将底物苯丙氨酸脱氨催化为下游产物。最新研究发现了能够同时催化苯丙氨酸和酪氨酸脱氨的双功能酶—苯丙氨酸/酪氨酸... 详细信息

苯丙烷途径在陆生植物木质素和黄酮类等次生代谢产物的生物合成中至关重要,其中一步必需的反应为苯丙氨酸解氨酶(PAL)将底物苯丙氨酸脱氨催化为下游产物。最新研究发现了能够同时催化苯丙氨酸和酪氨酸脱氨的双功能酶—苯丙氨酸/酪氨酸解氨酶(PTAL),但是对诸多问题,例如怎样精准鉴定PAL和PTAL、植物PAL演化为PTAL其氨基酸序列发生了什么变异、哪些植物类群包含PTAL等,仍属未知。为了探索PAL基因家族在陆生植物中的演化及关键变异,本研究利用PAL氨基酸全长序列构建了陆生植物不同类群系统发育树,比较和分析了PAL和PTAL氨基酸序列并模拟了其蛋白质三维构象。结果表明,以PAL氨基酸序列构建的系统发育树,能够反映已知陆生植物的系统关系,PAL和PTAL的氨基酸序列中存在着8个差异位点,其中121和123这两个关键位点非常稳定,可以联合用于准确鉴定包含PAL和PTAL的植物,并且I121L和F123H的关键变异,导致只能与苯丙氨酸结合的PAL演化为也能同时结合酪氨酸的PTAL。

关键词：苯丙氨酸酪氨酸解氨酶氨基酸序列分析苯丙烷途径分子对接蛋白质结构

在线全文

学校读者我要写书评

暂无评论

2022年国外军用无人机装备技术发展综述

战术导弹技术 2023年第3期 11-25,31页

作者：朱超磊金钰王靖娴袁成中国航空工业发展研究中心北京100029 中国科学院文献情报中心北京100190 中国航空研究院北京100029

2022年,俄乌冲突爆发,无人机大量投入战场,发挥低价高效、灵活机动、冗余抗损等作战优势,迅速成为左右战局的关键力量,进一步推动无人化战争到来。为跟踪研究国外军用无人机装备技术最新动态,系统梳理了美、俄、英、澳、印等国战略规划... 详细信息

2022年,俄乌冲突爆发,无人机大量投入战场,发挥低价高效、灵活机动、冗余抗损等作战优势,迅速成为左右战局的关键力量,进一步推动无人化战争到来。为跟踪研究国外军用无人机装备技术最新动态,系统梳理了美、俄、英、澳、印等国战略规划、经费预算、科研项目、型号产品信息;归纳了国外无人机系统簇、无人作战飞机、中空长航时无人机、太阳能无人机、高超声速无人机、无人运输机等最新进展;分析了无人蜂群、无人自主、无人协同等前沿技术成果;总结了国外无人机装备技术未来趋势。2022年,世界军事强国不断加大无人机领域研发投入,发展无人机新技术、新概念、新产品,拓展军用无人机任务域、空间域和能力域,重塑未来空中战场攻防形态。

关键词：无人机自主战略蜂群无人僚机智能空战有人/无人协同

在线全文

学校读者我要写书评

暂无评论

2021年国外军用无人机装备技术发展综述

战术导弹技术 2022年第1期 38-45页

作者：朱超磊袁成杨佳会康国卫航空工业发展研究中心北京100029 航空研究院北京100029

2021年以来,国外先进军用无人机装备在多个领域及技术方面取得重大突破。从无人僚机、空射无人机、垂直起降无人机、无人加油机、太阳能无人机等方面针对2021年度军用无人机装备技术最新进展情况进行梳理归纳,总结分析美国等军事强国在... 详细信息

2021年以来,国外先进军用无人机装备在多个领域及技术方面取得重大突破。从无人僚机、空射无人机、垂直起降无人机、无人加油机、太阳能无人机等方面针对2021年度军用无人机装备技术最新进展情况进行梳理归纳,总结分析美国等军事强国在无人机领域重要发展方向。外军聚焦新质无人作战力量开展大量技术攻关、能力验证和型号研制工作,以无人化、智能化为发展核心,以期在短期内发展出谱系完整的无人装备体系,持续塑造新型战场优势,极大拓展未来空中战场复杂性。

关键词：无人机蜂群忠诚僚机空中加油垂直起降有人-无人协同

在线全文

学校读者我要写书评

暂无评论

土壤宏基因组学研究方法与进展

土壤学报 2012年第1期49卷 155-164页

作者：贺纪正袁超磊沈菊培张丽梅中国科学院生态环境研究中心北京100085 中国科学院研究生院北京100049

土壤微生物驱动着土壤中的物质循环和养分转化。在土壤学的研究中,长期将土壤作为一个黑箱系统来对待,对其中的生物组成及其参与的生化过程知之甚少。土壤中绝大部分微生物目前尚难以分离培养,因此基于传统的培养方法对于认识土壤微生... 详细信息

土壤微生物驱动着土壤中的物质循环和养分转化。在土壤学的研究中,长期将土壤作为一个黑箱系统来对待,对其中的生物组成及其参与的生化过程知之甚少。土壤中绝大部分微生物目前尚难以分离培养,因此基于传统的培养方法对于认识土壤微生物群落组成和功能有其局限性。宏基因组学直接从环境样品中提取全部微生物的DNA,或通过测序探究环境中微生物的群落结构和功能(序列驱动),或构建宏基因组文库,筛选新的基因或生物活性物质(功能驱动),克服了传统培养方法的缺陷,极大地丰富了对土壤微生物多样性及其功能的认知。本文在综述土壤宏基因组学研究基本流程的基础上,重点介绍了日益重要的第二代测序平台在土壤宏基因组学研究中的应用及其产生的海量数据的分析处理方法,并简要探讨了宏基因组学在土壤微生物生态学中的应用。最后,作者建议在国家层面上展开相关土壤宏基因组学研究,调查微生物群落及其变化,为生物资源开发、农业生产和环境保护作出应有的贡献。

关键词：宏基因组学研究方法第二代测序平台微生物生态学土壤环境

在线全文

学校读者我要写书评

暂无评论

一个红壤剖面微生物群落的焦磷酸测序法研究

土壤学报 2013年第1期50卷 138-149页

作者：袁超磊贺纪正沈菊培戴宇张丽梅中国科学院生态环境研究中心北京100085 中国科学院大学北京100049

利用定量PCR和454焦磷酸测序法,研究了湖南湘阴县一典型红壤剖面微生物相关基因的多度及微生物(古菌、细菌、真菌)群落结构。结果显示,随剖面深度增加,土壤黏粒含量增多,有机质和全氮含量、碳氮比则下降。每克干土微生物基因拷贝数也趋... 详细信息

利用定量PCR和454焦磷酸测序法,研究了湖南湘阴县一典型红壤剖面微生物相关基因的多度及微生物(古菌、细菌、真菌)群落结构。结果显示,随剖面深度增加,土壤黏粒含量增多,有机质和全氮含量、碳氮比则下降。每克干土微生物基因拷贝数也趋于下降,其值为:107.09～109.30(古菌16S rDNA),108.10～109.70(细菌16S rDNA),106.54～107.95(真菌18S rDNA),107.24～108.61(古菌amoA基因),104.76～106.25(细菌amoA基因),105.94～107.88(nirK基因),106.81～109.21(nirS基因),107.03～109.46(nosZ基因)。焦磷酸测序得到了6 459条古菌16S rRNA基因序列,平均长度为496 bp;28 626条细菌16S rRNA基因序列,平均长度为448 bp;4 683条真菌18S rRNA基因序列,平均长度为534 bp。OTU(97%相似度)分析表明,微生物群落α-多样性与所测土壤理化性质均无显著相关。Jaccard差异度分析表明同一剖面各土壤层次间微生物群落结构更为相似,而不同位点的三个表层土之间的差异较大;Mantel检验发现,与微生物群落变化相关的主要土壤因子是黏粒含量。在所有土样中,古菌以泉古菌门中的热变形菌纲(89%)为主,其分布与土壤黏粒含量相关。细菌的主要类群为酸杆菌门(33%)、变形菌门(17%)、绿弯菌门(12%)、厚壁菌门(10%)和放线菌门(7%),分类地位不明确的细菌约占11%。其中,酸杆菌门和变形菌门的相对多度在表层土中高于非表层土;而绿弯菌门和厚壁菌门的相对多度则在非表层土中更高,与土壤深度呈显著正相关。所有真菌序列分属于三个门,即子囊菌门(87%)、担子菌门(9%)和球囊菌门(4%),在纲一级的分类水平上,各样品间群落结构无明显差异。

关键词：红壤焦磷酸测序微生物多样性古菌细菌真菌