检索结果-南通市图书馆

东江河口典型河段溶解氧时空动态及低氧成因解析

在线全文

学校读者我要写书评

暂无评论

湖泊科学 2025年第1期37卷 112-121页

作者：黄广灵黄本胜刘达邱静黄国如华南理工大学土木与交通学院广州510640 广东省水利水电科学研究院广州510635 广东省流域水环境治理与水生态修复重点实验室广州510635 华南理工大学亚热带建筑与城市科学全国重点实验室广州510640

为解析东江南支流低氧现象的成因,并为水环境治理提供科学依据,本研究分别于2019年春季和夏季对该河流的主要断面进行了水质监测。监测结果显示,东江南支流的溶解氧(DO)水平从中游道滘镇的6.93 mg/L降至出海口处的4.08 mg/L。DO与影响... 详细信息

为解析东江南支流低氧现象的成因,并为水环境治理提供科学依据,本研究分别于2019年春季和夏季对该河流的主要断面进行了水质监测。监测结果显示,东江南支流的溶解氧(DO)水平从中游道滘镇的6.93 mg/L降至出海口处的4.08 mg/L。DO与影响因子的相关性分析显示,DO与水温呈显著负相关,与盐度呈正相关,而与氨氮和总磷等营养物质呈显著负相关。这些营养物质的增加与DO的降低在空间上呈显著重叠,特别是在夏季。研究结果表明,东江南支流低氧现象受物理、化学和生物因素的共同影响,其中温度升高和营养物质浓度增加使得中下游水体的氧气消耗加快,河道汇流处的断面缩窄和下游水体的透光性差引起DO补给不足,从而导致下游沙田泗盛断面经常性出现氧亏(低氧)现象。

关键词：东江南支流溶解氧低氧营养物珠江

Microstructure Evolution and Mechanism of Strength Development of Fly Ash Paste

维普期刊数据库评论

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 Wuhan University of Technology(Materials Science) 2025年第1期40卷 152-163页

作者： MA Shuzhao WU Shunchuan huang Mingqing CHENG Haiyong JIANG Guanzhao NIU Yonghui LIU Zemin SUN Wei Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Zijin School of Ge-ology and Mining Fuzhou UniversityFuzhou 350108China

Three types of activators such as sodium hydroxide,calcium oxide and triethanolamine(TEA)are used to establish different activation environments to address the problems associated with the process of activating fly ash *** conducted mechanical tests and numerical simulations to understand the evolution of microstructure,and used environmental scanning electron microscopy(ESEM)and energy dispersive spectroscopy(EDS)techniques to analyze the microenvironments of the *** mechanical properties of fly ash paste under different activation conditions and the changes in the microstructure and composition were *** results revealed that under conditions of low NaOH content(1%-3%),the strength of the sample increased *** the content exceeded 4%,the rate of increase in strength *** on the results,the optimal NaOH content was identified,which was about 4%.A good activation effect,especially for short-term activation(3-7 d),was achieved using TEA under high doping *** activation effect was poor for long-term strength after 28 *** CaO content did not significantly affect the degree of activation *** maximum effect was exerted when the content of CaO was 2%.The virtual cement and concrete testing laboratory(VCCTL)was used to simulate the hydration process,and the results revealed that the use of the three types of activators accelerated the formation of Ca(OH)_(2) in the *** activators also corroded the surface of the fly ash particles,resulting in a pozzolanic *** active substances in fly ash were released efficiently,and hydration was *** pores were filled with hydration products,and the microstructure changed to form a new frame of paste filling that helped improve the strength of fly ash paste.

关键词： paste filling fly ash activator unconfined compressive strength microstructure hydration simulation

[Solid-phase extraction coupled with high performance liquid chromatography-triple quadrupole mass spectrometry for simultaneous determination of seven coumarins in water samples from drinking water treatment plants]

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Se pu = Chinese journal of chromatography 2025年第1期43卷 78-86页

作者： wen-Mei Jiao Jing-Ming Yang Ce Xu Fu-Kang Gao Lu-Yao Shen Yu-Bo Yuan Zhi-Fen Guo Guang huang School of Life Sciences and Chemical Engineering Jiangsu Second Normal University Nanjing 211200 China. School of Stomatology Nanjing Medical University Nanjing 210029 China. School of Public Health Nanjing Medical University Nanjing 211166 China. Key Laboratory of Modern Toxicology Ministry of Education School of Public Health Nanjing Medical University Nanjing 211166 China.

Chlorinated coumarins, which are as cytotoxic as highly toxic halobenzoquinones toward CHO-K1 cells, have recently been identified as disinfection byproducts in drinking water disinfection processes. Therefore, detecting coumarins in water samples collected at various stages from drinking water treatment plants helps assess the formation of chlorinated coumarins in drinking water. Hence, a simple, rapid, accurate, and sensitive method for quantifying coumarins in water samples is required. In this study, a method was developed based on solid-phase extraction coupled with high performance liquid chromatography-triple-quadrupole mass spectrometry for analyzing seven coumarins in water samples from drinking water treatment plants, including 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, 8-chloro-7-hydroxycoumarin, coumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin. Sample pretreatment involved solid-phase extraction using HLB columns, followed by elution with water and methanol, each containing 0.25% formic acid. The extracted solution was separated via gradient elution using a Phenomenex Luna C18 column (100 mm×2.0 mm, 3 mm) with 0.1% formic acid aqueous solution and methanol as the mobile phases, with analytes detected by triple-quadrupole mass spectrometry equipped with electrospray ionization source in multiple reaction monitoring mode. The matrix effect, precision, and accuracy of the developed method were investigated using raw and treated water as matrices. Matrix effects of 0.84-1.12 were recorded for the detection of 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, and coumarin in raw water, while values of 0.67-0.70 were recorded for 8-chloro-7-hydroxycoumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin in finished water. The three chlorinated coumarins exhibited matrix effects above 0.80 after the finished water matrix had been diluted four times. These re

关键词： coumarins disinfection byproducts drinking water high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) solid-phase extraction (SPE)

Laser assisted phase transformation of carbon-based transition metal oxide electrode for high-performance supercapacitor application

维普期刊数据库评论

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 Chemistry 2025年

作者： Mingzhen Xiu Jianghong Zhang Yu Lu Xun Cao Kang huang Siyu Zhu Bowei Zhang Yu Liang Chunwang Zhao Junsheng Wu Yizhong huang School of Materials Science and Engineering Nanyang Technological University Energy Research Institute Interdisciplinary Graduate Programme Nanyang Technological University Institute of Sustainability for Chemicals Energy and Environment Agency for Science Technology and ResearchSingapore Institute of Advanced Materials and Technology University of Science and Technology Beijing School of Materials Science and Technology Shenyang University of Chemical Technology School of Materials Science and Hydrogen Energy Foshan University

Transitional metal oxides have a wide range of applications due to their superior *** enhanced performance of metal oxide relies on their desirable oxidation states,which is challenging to achieve and requires complex *** study demonstrates a facile strategy enabling rapid phase transformation of transition metal *** approach involves synthesis of a tetragonal Mn3O4/carbon cloth composite using the liquid plasma discharge deposition （LPDD） technique,followed by laser irradiation with the presence of ethylene glycol under an N2gas *** resulting face-centered cubic MnO/carbon cloth electrode exhibits an excellent capacitance of 1,125 F g-1at 2 A g-1,with remarkable capacitance retention of 95%after10,000 *** approach can be extended to other transition metals including Co,Cu,Cr,Fe,Ni,and *** simulations reveal the significance of ethylene glycol and the underlying mechanism associated with the phase transformation of transition metal *** present study offers a powerful technique for the phase transformation of transition metal oxide which can guide the development of new electrode materials with enhanced electrochemical properties for high-performance energy storage applications.

关键词：

Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 123-138页

作者： Chentong GAO Huiyu SUN Jianping GU W.M.huang College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics School of Mechanical and Aerospace Engineering Nanyang Technological University Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates with large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate with fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

关键词： three-dimensional (3D) braided composite braiding direction composite thin plate large overall motion dynamic model O313.7

Infrared Photodetectors and Image Arrays Made with Organic Semiconductors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第10期41卷 1629-1637页

作者： Zhi-Ming Zhong feng Peng Lei Ying Zhen-Qiang huang wen-Kai Zhong Gang Yu Yong Cao Fei huang Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou510640China

Combining the strategies of introducing larger heteroatom,regio-regular backbone and extended branching position of side-chain,we developed polymer semiconductors(PPCPD)with narrow band-gap to construct the photosensing layer of thin-film photodiodes and image *** spectral response of the resulting organic photodiodes spans from the near ultra-violet to short-wavelength infrared *** performance of these short-wavelength infrared photodiodes in 900–1200 nm range achieved a level competitive with that of indium gallium arsenide-based inorganic crystalline detectors,exhibiting a specific detectivity of 5.55×1012 Jones at 1.15µ*** photodetectivity and quantum efficiency in photodiode with amorphous/nanocrystalline thin-films of 100–200 nm thickness enabled high pixel-density image arrays without pixel-level-patterning in the sensing layer.1×256 linear diode arrays with 25µm×25µm pixel pitch were achieved,enabling high pixel-density short-wavelength infrared imaging at room temperature.

关键词： Conjugated polymer Organic semiconductor Infrared Photodetector Image array

Provenance Study of Fe–Ti Oxide Minerals in the Quaternary Sediments in Yichang Area and Its Implication of Formation Time of the Yangtze Three Gorges, China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2018年第4期92卷 1598-1608页

作者： XIANG Fang DU wen huang Henxu KANG Dongya ZHU Hongbo feng Qin State Key Laboratory of Oil and Gas reservoir Geology and exploitation Chengdu University of Technology Shangdong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral Shangdong University of Science and Technology Institute of sedimentary geology Chengdu University of Technology

The Three Gorges are considered to be critical to understand the formation of Yangtze River. Recent research results suggest that the Yangtze Three Gorges was created during the Quaternary but the exact time is debatable. Fe-Ti oxide minerals are seldom used to study sediment provenance, expecially using scanning electron microscopy （SEM）, and energy dispersive spectrometer （EDS）. In this study, the provenance of Quaternary sediments in Yichang area, which is located to the east of the Yangtze Three Gorges, was investigated by using SEM and EDS to research Fe-Ti oxides. The Panzhihua vanadium titanomagnetite and Emeishan basalt outcrop are located to the west of the Three Gorges. Further, the materials from them are observed in the Quaternary sediments of Yichang area. Fe-Ti oxide minerals from the huangling granite are observed in the Yunchi and Shanxiyao Formations, which were formed before 0.75 Ma B.P., whereas Fe-Ti oxide minerals from the huangling granite, Panzhihua vanadium titanomagnetite, and Emeishan basalt are observed in the riverbed and fifth-terrace sediments of the Yangtze River, which were formed after 0.73 Ma B.P.. Thus, we can infer that the Three Gorges formed after the deposition of the Shanxi Formation and before the fifth-terrace; i.e., 0.75-0.73 Ma B.P..

关键词： Yangtze Three Gorges Yichang area Quaternary sediments Fe-Ti oxide minerals China

Discrimination of rice panicles by hyperspectral reflectance data based on principal component analysis and support vector classification

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第1期11卷 71-78页

作者： Zhan-yu LIU Jing-jing SHI Li-wen ZHANG Jing-feng huang Institute of Agricultural Remote Sensing and Information System Application Zhejiang University Hangzhou 310029 China Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health Zhejiang University Hangzhon 310029 China Key Laboratory of Agricultural Remote Sensing and lnformation System in Zhejiang Province Hangzhou 310029 China

Detection of crop health conditions plays an important role in making control strategies of crop disease and insect damage and gaining high-quality production at late growth stages. In this study, hyperspectral reflectance of rice panicles was measured at the visible and near-infrared regions. The panicles were divided into three groups according to health conditions： healthy panicles, empty panicles caused by Nilaparvata lugens St^l, and panicles infected with Ustilaginoidea virens. Low order derivative spectra, namely, the first and second orders, were obtained using different techniques. Principal component analysis （PCA） was performed to obtain the principal component spectra （PCS） of the foregoing derivative and raw spectra to reduce the reflectance spectral dimension. Support vector classification （SVC） was employed to discriminate the healthy, empty, and infected panicles, with the front three PCS as the in- dependent variables. The overall accuracy and kappa coefficient were used to assess the classification accuracy of SVC. The overall accuracies of SVC with PCS derived from the raw, first, and second reflectance spectra for the testing dataset were 96.55%, 99.14%, and 96.55%, and the kappa coefficients were 94.81%, 98.71%, and 94.82%, respectively. Our results demonstrated that it is feasible to use visible and near-infrared spectroscopy to discriminate health conditions of rice panicles.

关键词： Rice panicle Principal component analysis (PCA) Support vector classification (SVC) Hyperspectra reflectance Derivative spectra

Efficient photocatalytic H2 evolution over tubular mesoporous carbon nitride with N-vacancy by microwave-assisted synthesis

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Yuanlong Pan Qiang Zhang Guangzheng huang Yannan Luo Honglin Gao School of Materials and Energy National Center for International Research on Photoelectric and Energy MaterialsYunnan University

Modifying the microstructure of photocatalysts while simultaneously introducing vacancies has shown significant potential in enhancing their performance for hydrogen production. Herein, a novel tubular mesoporous carbon nitride（TMCN） with nitrogen vacancies was fabricated using a microwave-assisted synthesis strategy, employing melamine-cyanuric acid supramolecular（MC-S） as the precursor. The optimized TMCN exhibited an outstanding H2production rate, approximately 29 times higher than that of pristine g-C3N4. The N-vacancies serve as sites for reactant adsorption and activation, leading to enhanced delocalization of HOMO-LUMO. Furthermore, the porous structures of TMCN facilitate the reactant diffusion, while its tubular architectures promote the oriented transfer of charge carriers. Crucially, the markedly improved photocatalytic performance of TMCN can be predominantly attributed to the synergistic effects arising from its superior structure and N-vacancy defects. This work opens new possibilities for the simultaneous formation of surface defect states as photocatalytic reaction sites and distinctive structures conducive to charge carrier transport.

关键词：