检索结果-南通市图书馆

Disinfection Byproducts and Their Precursors in Drinking Water Sources:Origins,Influencing Factors,and Environmental Insights

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第5期36卷 36-50页

作者： Rong Xiao Yang Deng Zuxin Xu Wenhai chu State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Ministry of Education Key Laboratory of the Yangtze River Water Environment Tongji UniversityShanghai 200092China Department of Earth and Environmental Studies Montclair State UniversityMontclairNJ 07043USA

Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public ***,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically *** byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection *** DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution *** providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water *** practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative *** jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.

关键词： Disinfection byproducts Disinfection byproduct precursors Drinking water sources Contamination indicator Natural factors Human factors

Multi-physics multi-scale simulation of unique equiaxed-to-columnar-to-equiaxed transition during the whole solidification process of Al-Li alloy laser welding

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 Materials Science & Technology 2024年第4期171卷 235-251页

作者： chu Han Ping Jiang Shaoning Geng Liangyuan Ren School of Mechanical Science and Engineering Huazhong University of Science&Technology(HUST)Wuhan430074China

In this study,a novel multi-physics multi-scale model with the dilute multicomponent phase-field method in three-dimensional(3D)space was developed to investigate the complex microstructure evolu-tion in the molten pool during laser welding of Al-Li *** accurately compute mass data within both two and three-dimensional computational domains,three efficient computing methods,including central processing unit parallel computing,adaptive mesh refinement,and moving-frame algorithm,were *** was placed on the distinctive equiaxed-to-columnar-to-equiaxed transition phenomenon that occurs during the entire solidification process of Al-Li alloy laser *** results indi-cated that the growth distance of columnar grains that epitaxially grew from the base metal(BM)de-creased as the nucleation rate *** the nucleation rate increased,the morphology of the newly formed grains near the fusion boundary(FB)changed from columnar to equiaxed,and newly formed equiaxed grains changed from having high-order dendrites to no obvious dendrite *** the nucleation rate was sufficiently high,non-dendritic equiaxed grains could directly form near the FB,and there was nearly no epitaxial growth from the ***,simulation results illustrated the com-petition among multiple grains with varying orientations that grow in 3D space near the ***,how equiaxed grain bands develop was *** equiaxed band not only hindered the growth of early columnar grains but also some of its grains could grow epitaxially to form new columnar *** predicted results were in good agreement with experimental measurements and observations.

关键词： Laser welding Al-Li alloy Equiaxed-to-columnar-to-equiaxed transition Multi-physics multi-scale model Multicomponent alloys 3D phase-field model

Demixing microwave signals using system-on-chip photonic processor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 399-401页

作者： Sheng Gao chu Wu Xing Lin Department of Electronic Engineering Tsinghua University100084 BeijingChina Beijing National Research Center for Information Science and Technology Tsinghua University100084 BeijingChina

The integrated photonic processor,co-packaged with electronic peripherals,is proposed for blind source separation of microwave signals,which separates signal-of-interest from dynamic interference with real-time adapta... 详细信息

关键词： processor microwave mixing

高功率微波窗材料及其透波性能测试方法的研究进展

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料导报 2022年第S2期36卷 95-102页

作者：蒋友福芦伟汪卫华储德林安徽大学物质科学与信息技术研究院合肥230601

基于磁约束聚变能氘氚等离子体辅助加热技术的发展需求,微波回旋管的研究朝着高功率、高频率方向发展,因此对微波窗透波性能的要求也逐步提高,这就需要更为精确的测试技术。本文综述了几种常用的微波窗材料和主要透波参数的测试原理、... 详细信息

基于磁约束聚变能氘氚等离子体辅助加热技术的发展需求,微波回旋管的研究朝着高功率、高频率方向发展,因此对微波窗透波性能的要求也逐步提高,这就需要更为精确的测试技术。本文综述了几种常用的微波窗材料和主要透波参数的测试原理、研究进展及应用现状,其中介电性能测试方法重点讨论了传输/反射法、自由空间法、高Q谐振腔法、准光学谐振腔法;驻波系数测试方法重点讨论了测量线法、功率衰减法和定向耦合器法。系统地比较了各方法的设备要求、适用条件、测试原理、可测波段、测量精度及优缺点,并对高功率微波窗材料及其透波性能测试方法的发展方向进行了展望。

关键词：高功率微波窗介电常数介电损耗驻波系数测试方法

p-n异质结BiVO_(4)/g-C_(3)N_(4)光阳极的制备及其光电化学水解性能

在线全文

学校读者我要写书评

暂无评论

无机材料学报 2023年第1期38卷 87-96,I0010-I0012页

作者：王如意徐国良杨蕾邓崇海储德林张苗孙兆奇合肥学院能源材料与化工学院合肥230601 合肥学院先进电池材料与技术重点实验室合肥230601 长鑫存储技术有限公司合肥230000 安徽大学物质科学与信息技术研究院合肥230039 安徽大学材料科学与工程学院合肥230039

钒酸铋(BVO)可用于光电化学(PEC)水解产氢,但受限于其缓慢的表面水氧化动力学,在电极表面修饰单一的析氧助催化剂达不到理想的性能。本工作在BVO电极表面修饰FeNiO_(x)助催化剂可以显著降低起始电压,增强光电化学性能。此外,沉积g-C_(3)... 详细信息

钒酸铋(BVO)可用于光电化学(PEC)水解产氢,但受限于其缓慢的表面水氧化动力学,在电极表面修饰单一的析氧助催化剂达不到理想的性能。本工作在BVO电极表面修饰FeNiO_(x)助催化剂可以显著降低起始电压,增强光电化学性能。此外,沉积g-C_(3)N_(4)后修饰FeNiO_(x)助催化剂得到的光电极具有更优异的性能。厚度适合的g-C_(3)N_(4)纳米片与BVO构成Ⅱ型p-n异质结,有效抑制了光生电子空穴的复合,促进了电极的电荷分离。电化学测试结果表明,沉积了g-C_(3)N_(4)后,电极的电荷分离效率达到88.2%,比BVO/FeNiO_(x)(60.6%)提升了近1.5倍。经过g-C_(3)N_(4)和FeNiO_(x)协同修饰的BVO/g-C_(3)N_(4)/FeNiO_(x)电极,表面电荷注入效率达到了90.2%,同时,在1.23 V(***)条件下光电流密度达到4.63 mA·cm^(–2),是纯BVO(1.86 mA·cm^(–2))的2.48倍。本工作为开发制备高性能光阳极提供了一种有效的策略。

关键词： g-C_(3)N_(4)纳米片 BiVO_(4) 光电化学水解 FeNiO_(x)助催化剂 p-n异质结

The Multi-parameter Test of Gravitational Wave Dispersion with Principal Component Analysis

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第5期24卷 140-150页

作者： Zhi-chu Ma Rui Niu Wen Zhao CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

In this work, we consider a conventional test of gravitational wave(GW) propagation which is based on the phenomenological parameterized dispersion relation to describe potential departures from General Relativity(GR)along the propagation of GWs. But different from tests conventionally performed previously, we vary multiple deformation coefficients simultaneously and employ the principal component analysis(PCA) method to remedy the strong degeneracy among deformation coefficients and obtain informative posteriors. The dominant PCA components can be better measured and constrained, and thus are expected to be more sensitive to potential departures from the waveform model. Using this method we analyze ten selected events and get the result that the combined posteriors of the dominant PCA parameters are consistent with GR within 99.7% credible intervals. The standard deviation of the first dominant PCA parameter is three times smaller than that of the original dispersion parameter of the leading order. However, the multi-parameter test with PCA is more sensitive to not only potential deviations from GR but also systematic errors of waveform models. The difference in results obtained by using different waveform templates hints that the demands of waveform accuracy are higher to perform the multiparameter test with PCA. Whereas, it cannot be strictly proven that the deviation is indeed and only induced by systematic errors. It requires more thorough research in the future to exclude other possible reasons in parameter estimation and data processing.

关键词： gravitational waves-gravitation-black hole physics

Properties of the phase diagram from the Nambu-Jona-Lasino model with a scalar-vector interaction

在线全文

学校读者我要写书评

暂无评论

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-12页

作者： Yang, Yong-Hang Liu, He chu, Peng-Cheng Qingdao Univ Technol Sch Sci Qingdao 266520 Peoples R China Qingdao Univ Technol Res Ctr Theoret Phys Qingdao 266033 Peoples R China

We investigated the properties of the phase diagram of high-order susceptibilities, speed of sound, and polytropic index based on an extended Nambu-Jona-Lasinio model with an eight-quark scalar-vector interaction. Non-monotonic behavior was observed in all these quantities around the phase transition boundary, which also revealed the properties of the critical point. Further, this study indicated that the chiral phase transition boundary and critical point could vary depending on the scalar-vector coupling constant GSV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$G_\text {SV}$$\end{document}. At finite densities and temperatures, the negative GSV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$G_\text {SV}$$\end{document} term exhibited attractive interactions, which enhanced the critical point temperature and reduced the chemical potential. The GSV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$G_\text {SV}$$\end{document} term also affected the properties of the high-order susceptibilities, speed of sound, and polytropic index near the critical point. The non-monotonic (peak or dip) structures of these quantities shifted to a low baryon chemical potential (and high temperature) with a negative GSV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$G_\te

关键词： QCD phase diagram High-order susceptibilities Speed of sound Polytropic index NJL model QUANTUM CHROMODYNAMICS TRANSITION STATE

Characteristics and geological significance of the stress state of the lithosphere in the Qinghai-Tibetan Plateau and its neighboring areas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 1836-1855页

作者： Qianwen ZHANG Ya XU Wei chu Shupeng LU Key Lab of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The present-day lithospheric stress state of the Qinghai-Tibetan Plateau and neighboring areas is controlled by both the lithosphere itself and the underlying *** other words,the stress is affected by the gravitational potential energy(GPE)difference caused by the change in the density distribution within the lithosphere and the drag force on the base of the lithosphere caused by mantle *** study of the lithospheric stress state plays an important role in further understanding the dynamic background and mechanism for the evolution of the Qinghai-Tibetan *** this study,the Crust1.0 crustal density model combined with the S40RTS mantle shear wave velocity variation model was used to calculate the *** EGM2008gravity field model was used to calculate the drag force from mantle convection at the base of the *** lithospheric and joint stress fields of the two sources were obtained by solving the force balance under the thin sheet *** way,we could comprehensively analyze the characteristics of the stress state within the *** regions were classified according to the GPE stress field,mantle drag force stress field,the relative magnitude of the two stress fields,and correlation between the two stress fields and surface *** lithospheric stress fields of the Tarim Basin and other stable blocks are mainly controlled by the GPE *** lithospheric stress field in the collision zone between the Indian Plate and the QinghaiTibetan Plateau is predominantly controlled by the deep mantle drag *** lithospheric stress field in the interior of the Plateau is controlled by both GPE and mantle *** correlation between the lithospheric stress field and surface deformation at the southeast margin of the Qinghai-Tibetan Plateau is *** is hypothesized that the presence of lower crustal flow with lower effective viscosity leads to crust-mantle decoupling,and the mantle drag force has a weaker influe

关键词： Qinghai-Tibetan Plateau Gravitational potential energy Mantle convection Lithospheric deviatoric stress field GPS strain rate field

A Study on the Impact of Chemical Structure on the Evolution of Aggregate Structure in Fiber-shaped High Density Polyethylene Vitrimer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第10期42卷 1557-1565,I0013页

作者： Bing Wang Yuan-chu Gao Hai Wang Hui Niu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian116024China

Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene(M-g-HDPE)as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction extrusion and post-drawing *** chemical structure characterization,morphology observation,thermal and mechanical properties investigation,as well as aggregate structure analysis,this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing.A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing,resulting in a lower orientation of the PE ***,lamellar growth and fibril formation during post-drawing at high temperature are enhanced to some extent due to the competition between dynamic bond and chain *** uneven morphology of fibershaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding,which plays a more dominant role in determining the mechanical properties of fiber-shaped vitrimers compared to aggregate *** Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene(M-g-HDPE)as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shap

关键词： High density polyethylene vitrimer Fiber-shaped Aggregate structures Transesterification reaction