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An efficient Bi/NH_4I-mediated addition reaction for the highly diastereoselective synthesis of homoallylic alcohols in aqueous media

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Chinese Chemical Letters 2020年第2期31卷 391-395页

作者： Zhen wu Xue-Xin Feng Qing-Dong Wang Xuan-yu Liu Weidong Rao Jin-Ming Yang Zhi-Liang Shen School of Chemistry and Molecular Engineering Nanjing Tech UniversityNanjing 211816China School of Pharmacy Yancheng Teachers UniversityYancheng 224007China Jiangsu Key Laboratory of Biomass-based Green Fuels and Chemicals College of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China

An efficient water-based bismuth-mediated addition reaction of carbonyl compound with cyclic allylic halide was *** reactions proceeded smoothly in aqueous DMF in the presence of ammonium iodide to afford the corresponding syn-homoallylic alcohols in moderate to good yields with excellent diastereoselectivities(>99:1 syn:anti).Reversal of product diastereoselectivity was observed when heteroaryl aldehyde possessing an adjacent chelating nitrogen atom was employed as substrate.

关键词： Bismuth Ammonium iodide Water Homoallylic alcohol Diastereoselectivity

Optical monitoring and intra-day variabilities of BL Lac Objects OJ 287

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Research in Astronomy and Astrophysics 2021年第6期21卷 263-275页

作者： yu-Hai yuan Jun-Hui Fan Hong wu Jing-Meng Hao Wei-Rong Huang Xiao-Lan Liu Hong-Ren Huang Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006China Key Laboratory for Astronomical Observation and Technology of Guangzhou Guangzhou 510006China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Using the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NGT),we monitor one BL Lac object,OJ *** this source,we obtain 15094 gri observations(4900 at g band,5184 at r band and 5010 at i band)in 155 nights from 2014 December 13 to 2019 *** on the upper observations,we obtain the following results.(1)The total variation amplitude is~2.3 mag.(2)There are intra-day variabilities(IDVs).The IDV timescales(△T)are in the range from 7.69 min(Δm=0.06±0.02 mag)to 371.09 min(Δm=0.26±0.04 mag).(3)There are strong correlations betweenΔT andΔm,△m=(2.91±0.66)×10^(-4)ΔT+(0.08±0.009),with r=0.52,p=5.33×10^(-5).(4)There are intra-day periods in this source,with the period P≈94 min on 2017 December *** we supplement the observations from the literature,we can obtain that the long-term period is about 12.02±0.41 yr.(5)The spectral properties of OJ 287 show the bluer-when-brighter behavior,whatever state the source is at.

关键词： quasars:individual(OJ 287) photometry

兰卡斯特大学便携式电气设备维护管理分析及启示

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实验室研究与探索 2022年第7期41卷 153-156页

作者：于航北京交通大学(威海)实验中心山东威海264401

高校实验室便携式电气设备种类和数量繁多,为保证实验教学和科研有序安全地进行,加强对设备的维护管理至关重要。国内高校虽然特别重视实验室安全,但是对电气设备普遍存在重使用轻维护的现象,大部分高校没有切实可行的维护管理制度。在... 详细信息

高校实验室便携式电气设备种类和数量繁多,为保证实验教学和科研有序安全地进行,加强对设备的维护管理至关重要。国内高校虽然特别重视实验室安全,但是对电气设备普遍存在重使用轻维护的现象,大部分高校没有切实可行的维护管理制度。在电气设备的维护管理方面,通过分析英国兰卡斯特大学便携式电气设备维护管理办法,结合国内高校实际情况,采取风险评估、使用者检查、目视检查、综合检验和测试相结合的方法,将电气设备的维护管理落实到实处,以减少电气事故的发生。

关键词：高等学校便携式电气设备维护管理风险评估

Catalysis-based specific detection and inhibition of tyrosinase and their application

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Journal of Pharmaceutical Analysis 2020年第5期10卷 414-425页

作者： yunwei Qu Qing Zhan Shubo Du Yang Ding Bin Fang Wei Du Qiong wu Haidong yu Lin Li Wei Huang Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Nanjing Tech University(NanjingTech)NanjingPR China Department of Chemistry National University of SingaporeSingapore Frontiers Science Center for Flexible Electronics Xi’an Institute of Flexible Electronics(IFE)and Xi’an Institute of Biomedical Materials&EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’an710072China

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome,and plays a key role in the pigmentation of hair and *** abnormal expression or activation of tyrosinase is associated with several diseases such as albinism,vitiligo,melanoma and Parkinson *** deposition of melanin could cause diseases such as freckles and brown spots in the human body,and it is also closely related to browning of fruits and vegetables and insect *** and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these ***,many selective optical detection probes and small molecular inhibitors have been developed,and have made significant contributions to the basic and clinical research on these *** this paper,the detection and inhibition of tyrosinase and their application in whitening products are reviewed,with special emphasis on development of fluorescent probes and ***,this review will help design more efficient and sensitive tyrosinase probes and inhibitors,as well as shed light on novel treatment of diseases such as melanoma.

关键词： Tyrosinase Melanin Detection probe Inhibitors Melanoma

Nickel-catalyzed reductive coupling reaction of monofluoroalkyl triflates with alkyl carboxylic acids toward the synthesis of α-alkyl-α-fluoro-alkylketones

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Chinese Chemical Letters 2023年第10期34卷 163-167页

作者： Rui Wang Jie Xu Jin-Xiao Li Bing-Bing wu Ruo-Xing Jin yu-Xiang Bi Xi-Sheng Wang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China

The synthesis methods ofα-fluoro-arylketones were well-established through electrophilic/nucleophilic fluorination and transition metal catalyzed ***,due to the site selectivity and substrate restriction,only a few cases have been developed to affordα-alkyl-α-***,we report a general and efficient method of preparing diverseα-alkyl-α-fluoro-alkylketones via nickelcatalyzed reductive coupling reaction of monofluoroalkyl triflates with low-cost industrial raw material alkyl carboxylic *** transformations demonstrate high efficiency,mild conditions,and excellent functional group *** strategy provides a general and efficient method for the synthesis ofα-alkyl-α-fluoro-alkylketones。

关键词： Ni-catalyzed Reductive coupling α-Fluoroketones α-Alkyl-α-fluoro-alkylketones Monofluoroalkyl triflates

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1999年国内成品油市场简析

现代化工 2000年第3期20卷 45-47页

作者：吴俞中国石化集团公司北京100029

1999年我国成品油上半年供过于求 ,油价下滑 ;下半年资源趋紧 ,市场旺销 ,价格大幅升高。90 #和 0 #汽油的平均批发价分别为 2 3 71元 / t和 2 3 1 7元 / t,零售价分别为 2 83 1元 / t和 2 52 7元 / t。2 0 0 0年 ,由于我国将对成品油... 详细信息

1999年我国成品油上半年供过于求 ,油价下滑 ;下半年资源趋紧 ,市场旺销 ,价格大幅升高。90 #和 0 #汽油的平均批发价分别为 2 3 71元 / t和 2 3 1 7元 / t,零售价分别为 2 83 1元 / t和 2 52 7元 / t。2 0 0 0年 ,由于我国将对成品油进口加以限制 ,市场总体资源将逐渐趋于供需平衡。

关键词：成品油市场价格 1999年中国

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大蒜紫斑病及其防治方法的研究现状

中国植保导刊 2012年第9期32卷 14-17页

作者：余航四川农业大学农学院植物保护系四川雅安625014

大蒜紫斑病是真菌性病害,在大蒜叶部和颈部发病,严重时全株枯黄,病部组织失水死亡。虽然目前大蒜紫斑病的研究取得了一定的进展,但随着大蒜种植面积扩大,该病害发生、传播日趋严重,防治日趋困难。对国内、外大蒜紫斑病的发生、发展、防... 详细信息

大蒜紫斑病是真菌性病害,在大蒜叶部和颈部发病,严重时全株枯黄,病部组织失水死亡。虽然目前大蒜紫斑病的研究取得了一定的进展,但随着大蒜种植面积扩大,该病害发生、传播日趋严重,防治日趋困难。对国内、外大蒜紫斑病的发生、发展、防治方法以及现存的问题进行了综述,并对今后该病害的防治研究进行展望。

关键词：大蒜紫斑病防治进展

Distribution of chromophytic phytoplankton in the Western Subarctic Gyre of Pacific Ocean revealed by morphological observation and rbc L gene sequences

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Journal of Oceanology and Limnology 2023年第6期41卷 2166-2179页

作者： Tao JIANG Xiaohan QIN Guannan wu Huaxian ZHAO Xiaotao yu Xueyan XIAO Wenjing LIU Qingjing HU Jufa CHEN Nan LI School of Ocean Yantai UniversityYantai 264005China Key Laboratory of Sustainable Development of Marine Fisheries Ministry of AgricultureYellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdao 266071China Key Laboratory of Ministry of Education for Environment Change and Resources Use in Beibu Gulf Guangxi Key Laboratory of Earth Surface Processes and Intelligent SimulationNanning Normal UniversityNanning 530001China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China School of Medicine Yunnan UniversityKunming 650091China College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiang 524088China

Western Subarctic Gyre(WSG),which possesses distinctive differences in oceanographic and biogeochemical processes,is situated in the northwest subarctic *** WSG is characterized by high nutrient and low *** carried out a field investigation in this area in summer 2020 and performed microscopic observation,cytometric counting,and RuBisCO large subunit(rbc L)gene analysis to understand the community structure and spatial distribution of chromophytic phytoplankton *** method revealed that total phytoplankton(>10μm,including Bacillariophyta,Dinoflagellata,Ochrophyta,and Chlorophyta)abundances ranged(0.6×10^(3))-(167.4×10^(3))cells/L with an increasing trend from south to *** and Pennatae diatoms dominated the phytoplankton assemblages in the southern and northern stations,*** chromophytic phytoplankton groups derived from rbc L genes included Haptophyta,Ochrophyta,Bacillariophyta,as well as rarely occurring groups,such as Xanthophyta,Cyanobacteria,Dinoflagellata,Rhodophyta,and *** the phylum level,Haptophyta was the most abundant phylum,accounting for approximately 30.80%of the total obtained operational taxonomic units in all *** and Bacillariophyta were the second and third most abundant phylum,and their relative abundance was 20.26% and 19.60%,***,redundancy analysis showed that high proportion of diatoms(e.g.,microscopic and rbc L methods)was positively correlated with nutrients(e.g.,dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous,and dissolved silicate(DSi))and negatively correlated with temperature and *** proportion of Ochrophyta,Rhodophyta,and Cyanobateria identified by rbc L genes was positively correlated with salinity and temperature and showed negative correlation to *** work is the first molecular study of phytoplankton accomplished in the WSG,and our results show some discrepancies between morphological observa

关键词： flow cytometry microscopic counting phytoplankton rbc L Western Subarctic Gyre

Inclusion of methylviologen dication in a cadmium tetracyanoplatinate host clathrate showing photochromism and photoluminescence modulation

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Chinese Chemical Letters 2023年第3期34卷 498-501页

作者： Jiang-Zhen Qiu Ye yu Zhuo-Fan Chen Min Zhu Yongxia Lu Qinwu wu Long-Fei Wang Jiang Liu College of Chemistry and Chemical Engineering Zhongkai University of Agriculture and EngineeringGuangzhou 510225China Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of ChemistrySun Yat-sen UniversityGuangzhou 510006China c School of Chemistry South China Normal UniversityGuangzhou 510006China

A cadmium tetracyanoplatinate host clathrate,(MV)[Cd_(2){Pt(CN)_(4)}_(3)]·2(H_(2)O)(1),including a methylviologen dication (MV^(2+)) was synthesized,and the crystal structures,photochromic and photoluminescence properties were *** 1,the alternatively parallel stacking between the MV^(2+)dications as electron acceptors in the channels and the electron donors[Pt1(CN)_(4)]^(2-) units in the host frameworks give a unique donor-acceptor (DA) *** UV irradiation,the electron transfer between MV^(2+) and[Pt(CN)_(4)]^(2-) ions generates MV^(·+)radicals with a photochromic behavior from pale-yellow to *** process occurs through single-crystal-to-single-crystal (SCSC) transformation and obvious structure variation of viologen cations is successfully ***,the spectral overlap between the emission bands of 1 and the absorption around 623 nm for the MV^(·+) radicals leads to a modulation of the photoluminescence.

关键词： Methylviologen dication Cadmium Polycyanidometallate clathrate Photochromism Photoluminescence