检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

硫自养反硝化技术优劣辨析

环境科学学报 2024年第4期44卷 1-10页

作者：郝晓地魏洪禹于文波朱洋墨北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室中-荷污水处理技术研发中心北京100044

硫自养反硝化因无需外加碳源、运行过程无CO_(2)直接碳排放,且硫或硫化物价格低廉而开始进入大众眼帘.硫自养反硝化概念始于20世纪70年代,但国际上对其研究与应用一直默默无闻,反而是近年来在我国方兴未艾,这一反差现象耐人寻味.通过对... 详细信息

硫自养反硝化因无需外加碳源、运行过程无CO_(2)直接碳排放,且硫或硫化物价格低廉而开始进入大众眼帘.硫自养反硝化概念始于20世纪70年代,但国际上对其研究与应用一直默默无闻,反而是近年来在我国方兴未艾,这一反差现象耐人寻味.通过对硫循环及硫资源概括总结发现,全球硫储量虽多,但硫资源开采主要来源于石油、天然气冶炼过程中对硫的回收,获得并不具有持久性.对硫自养反硝化过程原理、存在问题、直接碳排放等分析显示,自养反硝化速率较异养反硝化低61.5%~75.6%,反应过程会产生大量SO_(4)^(2-).此外,还存在硫填料滤床穿透逐渐降低处理负荷等问题.碳排放分析揭示,低pH(<6.5)会抑制反应进程,可能导致反硝化止步于氧化亚氮(N_(2)O)而产生相当释放量.相反,除外加碳源导致CO_(2)直接排放问题外,异养反硝化在同步脱氮除磷方面优势明显.况且,碳源缺乏问题存在多种解决方案,完全可以通过不外加碳源或选择废弃生源性碳源来解决碳排放问题.因此,在选择正确脱氮除磷技术路径时需要在深入了解反应机理的基础上,全面分析技术的优劣性,同时,横向、纵向观察国际相同领域对概念的发展以及相应的研发动态.

关键词：硫自养反硝化生物脱氮反应速率硫酸盐氧化亚氮(N_(2)O) 异养反硝化

Reductive immobilization and long-term remobilization of radioactive pertechnetate using bio-macromolecules stabilized zero valent iron nanoparticles

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第12期30卷 2163-2168页

作者： Haodong Ji yangmo zhu Jun Duan Wen Liu Dongye Zhao The Key Laboratory of Water and Sediment Science Ministry of EducationCollege of Environment Science and EngineeringPeking UniversityBeijing 100871China Environmental Engineering Program Department of Civil EngineeringAuburn UniversityAuburnAL 36849United States The Beijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT) Peking UniversityBeijing 100871China Institute of Environmental Science Taiyuan University of Science and TechnologyTaiyuan 030024China

Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic *** stabilized nZVI can effectively reduce soluble 99Tc(Ⅶ) to insoluble 99 Tc(Ⅳ),and they can be easily delivered into a contaminated groundwater zone and facilitate in situ *** this study,CMCstabilized nZVI showed higher reactivity than that using starch as the *** experiments indicated that more than 99% of 99 Tc(Ⅶ)(CO=12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%(w/w) at a broad pH of 5-8.X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS) analyses further confirmed that 99Tc(Ⅶ)O4^-transformed into 99Tc(Ⅳ)O2(s).The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid(HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA *** interesting,the immobilized Tc(Ⅳ) remained insoluble even after 120 d under anoxic condition,while only^21 % was remobilized when exposed to ***,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.

关键词： Reductive immobilization Radionuclide Stabilized nanoparticles Zero valent iron Groundwater Technetium

污水处理厂PFAS来源、迁移转化与去除方法

在线全文

学校读者我要写书评

暂无评论

环境科学学报 2023年第10期43卷 1-14页

作者：郝晓地邸文馨朱洋墨吴远远北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室中-荷污水处理技术研发中心北京100044

人工合成全氟/多氟烷基化合物(PFAS)因其结构中含有碳-氟键,使其具有疏水、疏油等特性而被广泛应用于人类生产、生活之中.使用后的PFAS大多都汇集于污水处理厂中,成为环境中一个重要的汇.加之,污水生物处理过程大多只能对PFAS前体物质... 详细信息

人工合成全氟/多氟烷基化合物(PFAS)因其结构中含有碳-氟键,使其具有疏水、疏油等特性而被广泛应用于人类生产、生活之中.使用后的PFAS大多都汇集于污水处理厂中,成为环境中一个重要的汇.加之,污水生物处理过程大多只能对PFAS前体物质进行转化而不是降解,以至于常常导致出水中PFAS浓度高于进水,甚至成为PFAS的源.因进入人体的PFAS的生物累积性和持久性会造成不同程度人体健康损害,所以,欧美等国家已开始限制PFAS的使用并致力于去除现存环境中的PFAS.在系统总结PFAS来源、浓度、转化和去除的基础上,对现存各种去除方法进行了效果分析,以便为后续污水处理厂污水、污泥中PFAS迁移转化及去除等进一步研究提供参考.最终得出,现有去除方法对PFAS去除降解效果十分有限;对出水吸附PFAS后原位同步降解、采用污泥焚烧处理似乎是最为有效的去除PFAS手段,也是未来该领域应重点研发的技术.

关键词：人工合成全氟/多氟烷基化合物(PFAS) 污水处理前体物质生物转化原位吸附降解污泥焚烧

在线全文

学校读者我要写书评

暂无评论

厌氧氨氧化技术研究与应用反差现象归因

环境科学学报 2023年第9期43卷 1-13页

作者：郝晓地杨万邦李季朱洋墨北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室中-荷污水处理技术研发中心北京100044

厌氧氨氧化(ANAMMOX)因无需氧气和有机物而被视为可持续污水处理技术,以致学界对其研究趋之若鹜并愈演愈烈.然而,20多年过去了,过热的研究与少有的工程应用形成了巨大反差,这一现象耐人寻味.因此,有必要对产生这种反差现象的原因进行理... 详细信息

厌氧氨氧化(ANAMMOX)因无需氧气和有机物而被视为可持续污水处理技术,以致学界对其研究趋之若鹜并愈演愈烈.然而,20多年过去了,过热的研究与少有的工程应用形成了巨大反差,这一现象耐人寻味.因此,有必要对产生这种反差现象的原因进行理性分析,以期获得对ANAMMOX技术工程应用场景以及运行瓶颈的清晰信息.分析表明,ANAMMOX工程化步履蹒跚的主要原因为应用场景误区与运行控制难度.ANAMMOX技术定位于高氨氮(NH_(4)^(+))、低有机物(COD)浓度厌氧消化液或类似工业废水,即属于应用场景较小的小众技术.再者,实现ANAMMOX的关键是前端与之匹配的亚硝酸氮(NO_(2)^(-))积累,而这恰恰成为其运行成败的关键.尽管存在着多种让NO_(2)^(-)积累的方法,但实现其稳定运行最后均归结为精准的控制技术,因为ANAMMOX本身以及NO_(2)^(-)积累所需要的环境窗口均十分狭窄.另一方面,ANAMMOX过程本身并不产生强温室气体-氧化亚氮(N_(2)O,温室效应为CO_(2)的265倍),但无论是短程硝化(PN)还是短程反硝化(PD)均涉及N_(2)O释放且量并不低,这就让原本可持续的ANAMMOX工艺蒙上了应用阴影.因此,对ANAMMOX的研究应适当降温,即使是针对性的应用场景也应重新评估其碳排放问题.

关键词：厌氧氨氧化(ANAMMOX) 短程硝化(PN) 短程反硝化(PD) 控制技术氧化亚氮(N_(2)O) AOB同步亚硝化及其反硝化

Few-shot incremental radar target recognition framework based on scattering-topology properties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 246-260页

作者： Chenxuan LI Weigang zhu Bakun zhu Yonggang LI Graduate School Space Engineering UniversityBeijing 101400China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101400China

The continuous emergence of new targets in open scenarios leads to a substantial decrease in the performance of Inverse Synthetic Aperture Radar(ISAR)recognition ***,data scarcity further exacerbates the challenge of identifying new classes of ISAR *** this paper,a few-shot incremental target recognition framework based on Scattering-Topology Properties(STPIL)is ***,STPIL extracts scattering-topology properties of ISAR targets as recognition ***,the pseudo-incremental training strategy effectively alleviates the algorithm’s forgetting of old knowledge,and improves compatibility with new ***,a feature embedding network,with few parameters,is designed based on the graph neural *** embedding network is highly adaptable to changes in data ***,STPIL fully considers the joint distribution and marginal distribution in scattering features,and uses the Brownian distance metric module to make the scattering-topology features more *** results on both the simulation dataset and the public measured data indicate that STPIL can effectively balance new classes with old classes,and has superior performance to other advanced methods in the incremental recognition of targets.

关键词： Brownian distance metric Graph neural networks Incremental learning Inverse Synthetic Aperture Radar(ISAR) Scattering

Stress-strain relationship for reactive powder concrete with recycled powder under uniaxial compression

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第7期18卷 1015-1027页

作者： Peng zhu Yunming zhu Wenjun QU Liyu XIE College of Civil Engineering Tongji UniversityShanghai 200092China Key Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education Tongji UniversityShanghai 200092China

The recycled powder(RP)from construction wastes can be used to partially replace cement in the preparation of reactive powder *** this paper,reactive powder concrete mixtures with RP partially replacing cement,and natural sand instead of quartz,are *** curing is used,instead of steam curing that is normally requested by standard for reactive powder *** influences of RP replacement ratio(0%,10%,20%,30%),silica fume proportion(10%,15%,20%),and steel fiber proportion(0%,1%,2%)are *** effects of RP,silica fume,and steel fiber proportion on compressive strength,elastic modulus,and relative absorption energy are analyzed,and theoretical models for compressive strength,elastic modulus,and relative absorption energy are established.A constitutive model for the uniaxial compressive stress-strain relationship of reactive powder concrete with RP is *** the increase of RP replacement ratio from 0% to 30%,the compressive strength decreases by 42% and elastic modulus decreases by 24%.

关键词： recycled powder reactive powder concrete elastic modulus relative absorbed energy stress-strain relationship

Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Geographical Science 2024年第1期34卷 181-194页

作者： zhu Yuanyuan ZHANG Yan zhu Xiaohua Key Laboratory of Geographic Process Analysis&Simulation Hubei Province Central China Normal UniversityWuhan430079China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing100101China

Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important *** study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary *** results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption *** dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality *** the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing *** per capita food carbon emissions of residents in urban and rural showed an overall upward *** total food carbon emissions in urban increased significantly,while that in rural increased first and then *** influence of beef and mutton on carbon emissions is the highest in dietary *** with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.

关键词： dietary structure structural evolution carbon emission effects carbon neutrality China

Designing hierarchical structures for innovative cooling textile

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第10期17卷 9202-9224页

作者： Xiran Du Jinlei Li Bin zhu Jia zhu National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210023China School of Sustainable Energy and Resources Nanjing UniversitySuzhou 215163China

The potential of personal cooling technologies in reducing air conditioning energy consumption and enhancing human thermal comfort is *** review focuses on recent advancements in hierarchical structure design for innovative cooling *** with insights into fundamental heat transfer processes between the human body,textile,and the surroundings,we uncover key control *** the advanced hierarchical structure designs enabling effective radiation,sweat evaporation,conduction management,and integration of cold energy sources for realizing effective human body cooling are systematically ***,we explore multifunctional designs beyond cooling,including switchable cooling-heating and ***,we engage in discussions on unifying cooling performance tests and additional multiple requirements to make strides toward practical *** review is anticipated to be a valuable resource,providing the scientific and industrial communities with a quick grasp of past advancements,current challenges,and future directions in achieving effective human body cooling.

关键词： thermal comfort personal cooling textile hierarchical structures

Old Pinus massoniana forests benefit more from recent rapid warming in humid subtropical areas of central-southern China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第5期35卷 155-170页

作者： Wenxin Li Liangjun zhu Lianhua zhu Mengdan Jing Censhi Qian Yu zhu Paolo Cherubini College of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004People’s Republic of China Swiss Federal Institute for Forest Snow and Landscape Research WSL8903 BirmensdorfSwitzerland Department of Forest and Conservation Sciences Faculty of ForestryUniversity of British Columbia2004-2424 Main MallVancouverBC V6T 1Z4Canada

Trees progress through various growth stages,each marked by specific responses and adaptation strate-gies to environmental *** the importance of age-related growth responses on overall forest health and management policies,limited knowledge exists regarding age-related effects on dendroclimatic relationships in key subtropical tree *** this study,we employed a den-drochronological method to examine the impact of rapid warming on growth dynamics and climatic sensitivity of young(40–60 years)and old(100–180 years)Pinus mas-soniana forests across six sites in central-southern *** normalized log basal area increment of trees in both age groups increased significantly following rapid warming in *** in young forests further showed a distinct growth decline during a prolonged severe drought(2004–2013),whereas those in old forests maintained growth *** growth was more strongly influenced by temperature than by moisture,particularly in old *** tem-peratures strongly and positively impacted the growth of old trees but had a weaker effect on young *** forests had a significantly lower resistance to extreme drought but faster recovery compared to young ***“divergence problem”was more pronounced in younger forests due to their heightened sensitivity to warming-induced drought and heat *** ongoing warming,young forests also may initially experience a growth decline due to their heightened sensitivity to winter *** findings underscore the importance of considering age-dependent changes in forest/tree growth response to warming in subtropical forest man-agement,particularly in the context of achieving“Carbon Peak&Carbon Neutrality”goals in China.

关键词： Tree rings Pinus massoniana Age effects Drought resilience Subtropical forests Rapid warming