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NHC-catalyzed Redox-Neutral Aza-Benzoin Reaction of Aldehydes with Tetrahydroisoquinolines

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Chinese Journal of Chemistry 2020年第2期38卷 135-138页

作者： Di Jiang zijun wu Jian Wang School of Pharmaceutical Sciences Key Laboratory of Bioorganic Phosphorous Chemistry&Chemical Biology(Ministry of Education)Tsinghua UniversityBeijing 100084China

Summary of main observation and conclusion Tetrahydroisoquinoline derivatives are useful synthetic intermediates,which play an important role in the preparation of natural products,pharmaceuticals and other ***,we report an unprecedented redox-neutral aza-benzoin protocol to construct such *** exposure of tetrahydroisoquinolines to aromatic aldehydes in the prese nee of an NHC catalyst,the C-l acylated tetra hydroisoquinolines were obtained in moderate to good yields.

关键词： materials. quinoline aldehydes

基于遥感影像的多方法评估氮元素对太湖水华影响

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南京师范大学学报（工程技术版） 2024年第1期24卷 72-79,92页

作者：吴梓隽孙亚辉南京师范大学地理科学学院江苏南京210023 南京师范大学能源与机械工程学院江苏南京210023

氮元素与太湖水华暴发有强相关性,是太湖水华暴发的重要因子.论文基于多源数据深入探讨了氮元素对太湖蓝藻水华暴发的影响机制.结果显示,氮元素通过营养盐释放和循环利用推动水华暴发,与蓝藻生长之间构成正反馈.高水温下,蓝藻生长与反... 详细信息

氮元素与太湖水华暴发有强相关性,是太湖水华暴发的重要因子.论文基于多源数据深入探讨了氮元素对太湖蓝藻水华暴发的影响机制.结果显示,氮元素通过营养盐释放和循环利用推动水华暴发,与蓝藻生长之间构成正反馈.高水温下,蓝藻生长与反硝化过程对硝态氮的竞争,削弱了反硝化微生物的脱氮效果,导致太湖水华持续化.相关性分析表明,不同形态氮与叶绿素a之间存在显著相关.论文从多层次、多角度解析氮元素与太湖水华暴发的关联机制,研究结果可为水体生态修复和水环境管理决策提供科学依据.

关键词：氮蓝藻水华太湖藻蓝素遥感影像机器学习模型水环境治理

Reusing the Evaluations of Basis Functions in the Integration for Isogeometric Analysis

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Computer Modeling in Engineering & Sciences 2020年第2期122卷 459-485页

作者： zijun wu Shuting Wang Wenjun Shao Lianqing Yu Hubei Key Laboratory of Digital Textile Equipment Wuhan Textile UniversityWuhan430200China. National CAD Support Software Engineering Research Center Huazhong University of Science and TechnologyWuhan430074China. School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China.

We propose a new approach to reuse the basis function evaluations in the numerical integration of isogeometric *** concept of reusability of the basis functions is introduced according to their symmetrical,translational and proportional features on both the coarse and refined *** on these features and the parametric domain regularity of each basis,we classify the bases on the original level and then reuse them on the refined level,which can reduce the time for basis calculations at integration *** using the sum factorization method and the mean value theorem for the integrals,a new integration method with high integral efficiency is *** validate the proposed method by some structural analysis problems in domains with different *** the numerical result accuracy and the time cost of the proposed integration method with the full Gauss integration quadrature,it turns out to be very promising.

关键词： Isogeometric analysis NURBS reusability integration.

Quantifying the sources of dissolved inorganic carbon within the sulfate-methane transition zone in nearshore sediments of Qi'ao Island, Pearl River Estuary, Southern China

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Science China Earth Sciences 2016年第10期59卷 1959-1970页

作者： wu zijun ZHOU HuaiYang REN DeZhang GAO Hang LI JiangTao State Key Laboratory of Marine Geology Tongji University

The significance of the various biogeochemical pathways that drive carbon cycling and the relative fractions of dissolved inorganic carbon(DIC) produced by these reactions within the sulfate-methane transition zone(SMTZ) are still being debated. Unraveling these processes is important to our understanding of the benthic DIC sources and their contributions to the global carbon cycle. Here, we measure pore water geochemistry(chlorine, sulfate, methane, Ca^(2+), Mg^(2+), DIC and δ^(13)C-DIC) as well as solid geochemistry(sedimentary organic carbon(SOC) and δ^(13)C of SOC) in nearshore sediments from Qi'ao Island in the Pearl River Estuary of the Southern China Sea. Our analysis indicates that SOC originates from the mixing of carbon from terrestrial and marine sources, and that terrestrial materials dominate the net loss of SOC during the degradation of organic matter, especially at sites located near the river outlets. Sulfate reduction via SOC degradation is not appreciable in the upper sediment layer due to conservative mixing-dilution by freshwater. However, below this layer, the anaerobic oxidation of methane(AOM) and methanogenesis occur. Within the SMTZ, the δ^(13)C mass balance shows that the proportions of DIC derived from organoclastic SO_4^(2-) reduction(OSR) and AOM are 50.3% to 66.7% and 0.1% to 17.9%, respectively, whereas methanogenesis contributes 17.0% to 43.9%. This study reveals that the upward diffusion of DIC from ongoing methanogenesis significantly influences carbon cycling within the SMTZ in these estuarine sediments. As a result, we suggest that the plots of the ratio of change in sulfate to change in DIC in pore water should be used with caution when discriminating between sulfate reduction pathways in methane-rich sediments.

关键词： Dissolved inorganic carbon Sulfate reduction Methane Carbon isotopes Estuaries

New Benchmark for Household Garbage Image Recognition

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Tsinghua Science and Technology 2022年第5期27卷 793-803页

作者： Zhize wu Huanyi Li Xiaofeng Wang zijun wu Le Zou Lixiang Xu Ming Tan School of Artificial Intelligence and Big Data Hefei UniversityHefei 230601China School of Energy Materials and Chemical Engineering Hefei UniversityHefei 230601China

Household garbage images are usually faced with complex backgrounds,variable illuminations,diverse angles,and changeable shapes,which bring a great difficulty in garbage image *** to the ability to discover problem-specific features,deep learning and especially convolutional neural networks(CNNs) have been successfully and widely used for image representation ***,available and stable household garbage datasets are insufficient,which seriously limits the development of research and ***,the state-of-the-art in the field of garbage image classification is not entirely *** solve this problem,in this study,we built a new open benchmark dataset for household garbage image classification by simulating different lightings,backgrounds,angles,and *** dataset is named 30 classes of household garbage images(HGI-30),which contains 18 000 images of 30 household garbage *** publicly available HGI-30 dataset allows researchers to develop accurate and robust methods for household garbage *** also conducted experiments and performance analyses of the state-of-the-art deep CNN methods on HGI-30,which serves as baseline results on this benchmark.

关键词： benchmark household garbage image classification deep convolutional neural networks

海南文昌清澜湾红树林潮沟地下水溶解碳通量的潮汐动态

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海洋地质前沿 2024年第5期40卷 27-39页

作者：张越朱虹霓王一清 ALYAA Zidan 崔振昂吴自军同济大学海洋地质国家重点实验室上海200092 中国地质调查局广州海洋地质调查局广州510760

海底地下水排泄(SGD)是陆地溶解碳向海洋输送的一个重要途径。以清澜湾潮沟为研究对象,以盐度为保守参数计算淡水SGD的占比为2.5%~22.7%,平均为13.0%;SGD净流量为0.86×10^(5) m^(3)/d。基于地下水溶解碳浓度,计算出该潮沟输出的溶解无... 详细信息

海底地下水排泄(SGD)是陆地溶解碳向海洋输送的一个重要途径。以清澜湾潮沟为研究对象,以盐度为保守参数计算淡水SGD的占比为2.5%~22.7%,平均为13.0%;SGD净流量为0.86×10^(5) m^(3)/d。基于地下水溶解碳浓度,计算出该潮沟输出的溶解无机碳(DIC)和溶解有机碳(DOC)通量分别为5.78×10^(5)和0.10×10^(5) mol/d。其中,DIC是潮沟溶解碳输送的主要形式,占总溶解碳的98.3%。低潮时,DOC的49%来源于红树林植物碎屑,51%来源于SGD;DIC的78%来源于SGD,22%来源于红树林沉积物有机质。高潮时,DOC的44%来源于被污染的海水,56%来源于红树林植物碎屑;DIC的65%来源于海水,35%来源于孔隙水交换。红树林潮沟SGD向清澜湾输送了大量的溶解碳,其对近海水体碳酸盐平衡体系的影响需要进一步研究。

关键词：红树林潮沟淡水SGD 溶解碳稳定碳同位素潮汐作用

Anaerobic oxidation of methane: Geochemical evidence from pore-water in coastal sediments of Qi’ao Island (Pearl River Estuary), southern China

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Chinese Science Bulletin 2006年第16期51卷 2006-2015页

作者： wu zijun ZHOU Huaiyang PENG Xiaotong CHEN Guangqian Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

The concentrations of CH4 and SO42? in pore-water and the carbon isotope compositions of total dissolved inorganic (ΣCO2) and CH4 were de- termined for three coastal sedimentary cores col- lected from Qi’ao Island (Pearl River Estuary), southern China. Results show that methane concen- tration changes dramatically at the base of the sul- fate-reducing zone and sulfate concentration gradi- ents are linear for all stations. In addition, the carbon isotope of methane becomes heavier at the sul- fate-methane transition (SMT), which causes ΣCO2-δ 13C to become the minimum. The geo- chemical profiles of pore-water render indirect evi- dence for anaerobic oxidation of methane (AOM). Based on numerical modeling of AOM and sul- fate-reducing rates, the portion of total sulfate reduc- tion occurring via AOM is 9.0%, 84% and 45.5%, re- spectively, and the percentage of ΣCO2 added to the pore-water is 4.7%, 72.4% and 29.45% correspond- ingly for three sites. Furthermore, it is found that the methane concentration, methane diffusive flux and the depth of SMT are controlled by the quantity and quality of sedimentary organic matter incorporated into the sediments. The great amount of organic material is favorable for rapid depletion of sulfate via sedimentary organic matter degradation, and on the other hand, causes the increase of the methane flux in the SMT, which results in a portion of sulfate re-duction supported by AOM. Accordingly, the SMT was shifted towards the sediment surface.

关键词：缺氧氧化甲烷硫酸盐沉积珠江河口地球化学

Biomineralization process occurring in iron mud of coastal seepage area of Zhoushan Island, Zhejiang Province

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Chinese Science Bulletin 2008年第12期53卷 1894-1904页

作者： wu zijun JIA Nan YUAN LinXi SUN LiGuang School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China

The biomineralization process of iron oxidizing bacteria and its influence on accumulation of metals were investigated by modern biological observation techniques (i.e., SEM and TEM) and geochemical methods, in coastal area of Zhoushan Island, Zhejiang province where a thick ancient wood layers were buried, Results show that the iron mud samples mainly contain Leptothrix-like sheaths and Gal-lionella-like stalks, which are known as neutrophilic iron-oxidizing bacteria. These two bacteria are present as obviously different abundance in two sampling sites, which may be regulated by the geo-chemistry of seepage water. The biomineralization product of iron oxidizing bacteria is ferrihydrite, a poorly ordered iron oxide, and formation of amorphous mineral is affected by the factors of bacteria, minor Si and temperature preventing any further transformation into more crystalline phases. Organic functional groups, extracellular polymers and surface charges can provide favorable nucleation sites or template for formation of iron precipitates on the bacterial surface. The mineralization process of the iron oxidizing bacteria is divided into different stages, i.e., extracellular mineralization, intracellular mineralization and the whole cell mineralization. Furthermore, due to BIOS containing the bacterial organic matter, the accumulation capacity of metals specially Fe and Co is highly increased, suggest-ing that BIOS exert a degree of controlling in the cycling of metal elements in seepage area.

关键词：生物矿化过程铁矿浙江省渗流水

Rates of bacterial sulfate reduction and their response to experimental temperature changes in coastal sediments of Qi'ao Island, Zhujiang River Estuary in China

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Acta Oceanologica Sinica 2014年第8期33卷 10-17页

作者： wu zijun ZHOU Huaiyang PENG Xiaotong LI Jiangtao CHEN Guangqian State Key Laboratory of Marine Geology Tongji University Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Subtropical sediment cores （QA09-1 and QA12-9） from the coastal zone of Qi’ao Island in the Zhujiang River Estuary were used to determine the rates of sulfate reduction and their response to experimental tempera-ture changes. The depth distribution of the sulfate reduction rates was measured from whole-core incu-bations with radioactive tracer35SO42-, and peaks of 181.19 nmol/（cm3·d） and 107.49 nmol/（cm3·d） were exhibited at stations QA09-1 and QA12-9, respectively. The profiles of the pore water methane and sulfate concentrations demonstrated that anaerobic oxidation of methane occurred in the study area, which result-ed in an increase in the sulfate reduction rate at the base of the sulfate-reducing zone. Meanwhile, the sulfate concentration was not a major limiting factor for controlling the rates of sulfate reduction. In addition, the incubation of the sediment slurries in a block with a temperature gradient showed that the optimum tem-perature for the sulfate reduction reaction was 36°C. The Arrhenius plot was linear from the lowest tempera-ture to the optimum temperature, and the activation energy was at the lower end of the range of previously reported values. The results suggested that the ambient temperature regime of marine environments prob-ably selected for the microbial population with the best-suited physiology for the respective environment.

关键词： sulfate reduction rate temperature-gradient incubations 35SO42- tracer Qi’ao Island