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Thienothiophene-centered ladder-type π-systems that feature distinct quinoidal π-extension

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Chinese Chemical Letters 2024年第5期35卷 249-253页

作者： Jiaxiang Guo Zeyi Li Tianyu Zhang Xinyu Tian Yue Wang Chuandong dou State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials Soochow UniversitySuzhou 215123China

Quinoidalπ-conjugated structures,a kind of fundamental subunits for organicπ-systems,may produce some intriguing optical,electronic and magnetic properties of polycyclic hydrocarbons(PHs).Herein,we report two thienothiophene-centered ladder-type polycyclic molecules(1 and 2),which possess one quinoidal thienothiophene moiety and two para-quinodimethane(p-QDM)subunits,*** theoretically and experimentally studied,while 1 is a fully closed-shell molecule,2 owns an open-shell structure along with partial contribution of tetraradical state that is induced by the resonance of ***,although 2 has a largerπ-conjugated skeleton and open-shell electronic state,it exhibits larger bandgap and blue-shifted *** the other hand,the reversible oxidation activity of 1 enables the preparation of its dication 1^(2+),and the studies on its single-crystal and aromatic structures demonstrate that its two positive charges are delocalized onto the oxygen atoms,thus achieving fullyπ-extended structure and near-infrared *** study not only gains insight into quinoidalπ-subunits,but also provides an important basis for the development of antiaromatic and open-shellπ-electron materials.

关键词： Thienothiophene Quinoidal conjugation Open-shell structure Aromaticity Photophysical properties

Enhancing stability of diradical polycyclic hydrocarbons via P=O-attaching

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Chinese Chemical Letters 2024年第8期35卷 309-313页

作者： Jingyuan Yang Xinyu Tian Liuzhong Yuan Yu Liu Yue Wang Chuandong dou State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials Soochow UniversitySuzhou 215123China

Diradical polycyclic hydrocarbons(PHs)have unique open-shell structures and interesting physical ***,owing to high reactivity of unpaired electrons,such open-shell organic diradicaloids are usually less stable than closed-shell systems,limiting their practical *** this study,we report P=O-attaching of diradical PHs as a new strategy to enhance their stability while maintaining diradi-cal *** P=O-attached PHs containing the indeno[1,2-b]fluorene,fluoreno[3,2-b]fluorene and indeno[2,1-b]fluoreneπ-skeletons,respectively,were designed and *** theoretically and ex-perimentally proved,two of them have the relatively large diradical characters and open-shell singlet diradical *** comparison to their all-carbon analogues,the attached electron-withdrawing P=O groups endow them with much lower LUMO/HOMO energy levels but preserved magnetic activities and physical properties,such as thermally accessible triplet species and multi-redox ***,the P=O groups effectively decrease their oxidation activities and thereby lead to their remarkably excellent ambient ***,this P=O-attaching strategy will be applicable to other diradical PH systems and may promote the generation of stable organic diradicaloids for radical chemistry and materials.

关键词： Polycyclic hydrocarbons Open-shell structure Diradical character Stability Oxidation activity

基于Lognormal函数的脉搏波数学建模

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东北大学学报（自然科学版） 2016年第2期37卷 169-173页

作者：赵海窦圣昶李大舟陈星池东北大学计算机科学与工程学院辽宁沈阳110819

对健康的日常监测,时间长,数据量大.为了简化数据量,分析了现有的使用2~4个高斯函数拟合脉搏波的脉搏波数学建模方法,在此基础上,提出了Lognormal函数模型的数学建模方法.使用4个Lognormal函数对脉搏波的一个周期进行拟合建模,以脉搏波... 详细信息

对健康的日常监测,时间长,数据量大.为了简化数据量,分析了现有的使用2~4个高斯函数拟合脉搏波的脉搏波数学建模方法,在此基础上,提出了Lognormal函数模型的数学建模方法.使用4个Lognormal函数对脉搏波的一个周期进行拟合建模,以脉搏波的生理特性为基础调整4个Lognormal函数的起始时间点,并对其性能进行了分析对比.结果表明,与现有方法相比,Lognormal函数模型不仅有更高的拟合精确度,而且有更优的计算复杂度,更适合以日常健康监测为目的的体域网健康大数据应用.

关键词：脉搏波健康大数据 Lognormal模型函数拟合健康监测

CO_(2) corrosion of X80 steel welded joints under micro-turbulence induced by welding reinforcement height

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Journal of Iron and Steel Research International 2024年第4期31卷 1015-1032页

作者： Xiao-hui dou Bin Li Zong-hao He Xin-wei Zhang Da-lei Zhang Yan Li School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

Corrosion failure accidents owing to flow erosion and pipeline corrosion frequently occur during *** welding reinforcement height(WRH)can induce locally micro-turbulent flow field,which aggravates local corrosion of welded joints.A high wall shear stress(WsS)experimental setup was established to conduct the online electrochemical corrosion *** influence of WRH sizes on local corrosion of welded joints was studied at different flow *** electrochemical signals of the local corrosion of X80 welded joints at different flow rates were monitored in real time using electrochemical impedance spectroscopy and wire beam *** addition,the corrosion products composition and properties were *** results show that the micro-turbulent flow fields induced by the WRHs can enhance ion mass transfer near the welded *** corrosion products on the WRH surface also present different microscopic morphologies at different flow *** strong flow fields,the locally enhanced wsS can peel off the dense corrosion product partially,leading to the electrochemical distribution of large cathode and small anode,which accelerates the occurrence and development processes of the local corrosion of welded *** scientific guidelines for the corrosion protection of long-distance oil and gas pipelines can be potentially provided.

关键词： X80 steel welded joint Welding reinforcement height Micro-turbulence CO_(2)corrosion-Ion mass transfer

Wave Attenuation and Turbulence Driven by Submerged Vegetation Under Current-Wave Flow

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China Ocean Engineering 2024年第4期38卷 602-611页

作者： HUANG Yu-ming Ding Lei WANG Yi-fei CHEN Ben YANG Xiao-yu dou Xi-ping School of Water Resources and Hydropower Engineering Wuhan UniversityWuhan430072China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China

A set of laboratory experiments are carried out to investigate the effect of following/opposing currents on wave *** vegetation canopies with aligned and staggered configurations were tested under the condition of various regular wave heights and current velocities,with the constant water depth being 0.60 m to create the desired submerged *** show that the vegetation-induced wave dissipation is enhanced with the increasing incident wave height.A larger velocity magnititude leads to a greater wave height attenuation for both following and opposing current ***,there is a strong positive linear correlation between the damping coefficientβand the relative wave height H_(0)/h,especially for pure wave *** the velocity profile,the distributions of U_(min)and U_(max)show different patterns under combined wave and *** time-averaged turbulent kinetic energy(TKE)vary little under pure wave and U_(c)=±0.05 m/s *** the increase of flow velocity amplitude,the time-averaged TKE shows a particularly pronounced increase trend at the top of the *** vegetation drag coefficients are obtained by a calibration *** empirical relations of drag coefficient with Reynolds and Keulegane-Carpenter numbers are proposed to further understand the wave-current-vegetation interaction mechanism.

关键词： wave attenuation rigid vegetation following and opposing currents turbulent kinetic energy

Responses of nitrogen cycling and related microorganisms to brackish wetlands formed by evapotranspiration

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Pedosphere 2024年第1期34卷 252-266页

作者： Jiaohui FANG Tianshu LU Jian LIU Shangbin HE Xiufeng YANG Huashan dou Honghai ZHANG School of Life Sciences Qufu Normal UniversityQufu 273100China Environment Research Institute Shandong UniversityQingdao 266237China Hulunbuir Academy of Inland Lakes in Northern Cold&Arid Areas Hulunbuir 021000China

Elevated evapotranspiration due to warmer air temperature could raise salinity and nutrient levels of some inland wetlands, potentially impacting nitrogen cycling. To characterize the impact of high evapotranspiration on soil microbial nitrogen cycling in inland wetlands, we compared freshwater and brackish marsh(or non-marsh) wetlands in terms of sediment ammonia-oxidizing rate(AOR), denitrifying rate(DR), and related microbial communities in a typical inland basin, the Hulun Lake basin, in China. Results showed that marsh ecosystems(ME) exhibited 31% higher AOR and 65% higher DR than non-marsh ecosystems(NE). For NE, freshwater non-marsh wetland exhibited 12% higher AOR than brackish non-marsh wetland. This was probably due to the inhibitory effects of high NH_4~+ and salinity levels on ammonia-oxidizing archaea in brackish non-marsh wetland. Conversely, DR in brackish non-marsh wetland was 23% higher than that in freshwater non-marsh wetland, with total organic carbon(TOC) significantly influencing this difference,suggesting that the higher DR in brackish non-marsh wetland was mainly due to its higher TOC level. For ME, due to the direct and indirect interference of salinity, brackish marsh wetland displayed 26% lower AOR and 19% lower DR than freshwater marsh wetland. Besides, brackish wetlands harbored distinct ammonia-oxidizing and denitrifying microbial communities compared to freshwater wetlands. The assembly of these communities was dominated by stochastic processes, while brackish wetlands exhibited more prominent deterministic processes than freshwater wetlands. Overall, high evapotranspiration altered activities and community characteristics of ammonia oxidizers and denitrifiers in inland brackish wetlands by enhancing salinity and nutrient levels,while emergent plants occurring in ME could mitigate the adverse effects of salt stress of inland brackish wetlands on nitrogen cycling.

关键词： ammonia-oxidizing archaea ammonia-oxidizing bacteria aquatic plants denitrifying bacteria nitrogen transformation inland wetlands

Evaluation of erastin synergized cisplatin anti-nasopharyngeal carcinoma effect with a glutathione-activated near-infrared fluorescent probe

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Chinese Chemical Letters 2024年第2期35卷 311-316页

作者： Rong He Dandan Tang Ningge Xu Heng Liu Kun dou Xuejun Zhou Fabiao Yu Department of Otolaryngology Head and Neck SurgeryThe First Affiliated Hospital of Hainan Medical UniversityHaikou 570102China Key Laboratory of Hainan Trauma and Disaster Rescue Key Laboratory of Emergency and TraumaMinistry of EducationEngineering Research Center for Hainan Bio-Smart Materials and Bio-Medical DevicesCollege of Emergency and TraumaHainan Medical UniversityHaikou 571199China Sichuan Provincial General Hospital of Judicial Police Chengdu 610225China

Nasopharyngeal carcinoma(NPC),a malignant tumor originating from the nasopharynx,is one of the common malignant tumors of the head and *** are significant geographical differences in the incidence of nasopharyngeal carcinoma,with a high incidence in China and Southeast Asian ***,we designed and synthesized a novel near-infrared fluorescent(NIRF)probe to detect glutathione(GSH)in cellular and tumor environments using semi-naphthofluorescein(SNAFL)as the fluorescent molecular backbone and 2-fluoro-4-nitrobenzenesulfonate as the recognition *** reaction with GSH,SNAFL-GSH emitted a fluorescence signal,and its emission wavelength at 650 nm was remarkably *** results of selectivity experiments indicated that SNAFL-GSH was able to discriminate GSH from Cys,Hcy,and H_(2) ***,SNAFL-GSH could image both endogenous and exogenous GSH and distinguish normal and cancer cells by fluorescence signal *** the cellular level,cisplatin(DDP)-induced ferroptosis and inhibition of proliferation of various NPC cell lines(CNE2,CNE1,5-8F cells)by erastin combined with DDP were visualized with the help of *** a mouse tumor xenograft model,we successfully employed SNAFL-GSH for the evaluation of the efficacy of erastin combined with DDP in the treatment of *** importantly,the probe could image cancerous tissue sections from NPC patients with an imaging depth of approximately 80µ*** was foreseen that SNAFL-GSH offered great potential for application in the diagnosis and evaluation of the therapeutic efficacy of NPC,and these results would also provide new ideas for the clinical treatment of NPC.

关键词： Glutathione NIRF probe Ferroptosis Anti-tumor therapy evaluation Bioimaging

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

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Journal of Integrative Agriculture 2024年第3期23卷 836-848页

作者： Yingxia dou Hubing Zhao Huimin Yang Tao Wang Guanfei Liu Zhaohui Wang Sukhdev Malhi Coliege of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China Ministry of Agriculture and Rural AffairsYangling 712100China Department of Renewable Resources University of AlbertaEdmonton T6G 2H1Canada

Water is the key factor limiting dryland wheat grain *** affects crop yield and yield components by affecting soil *** research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance *** results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,*** average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) *** were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically *** water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,*** relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in *** terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three *** on the three analysis methods,we found that spike number and ET were positively correlated with grain ***,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in *** SWSSF could indirectly increase spike number and ET in the three treatments.B

关键词： dryland winter wheat plastic mulch spike number straw mulch

Effect of temperature and reaction path interaction on fluidization reduction kinetics of iron ore powder

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Journal of Iron and Steel Research International 2024年第8期31卷 1840-1849页

作者： Guo-min Zhu Ming-wei Hu An-nan dou Jin-yu Huang Jing Ding Qi-yan Xu School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina

Due to the instability of FeO at temperatures below 843 K,the fuidization reduction pathway of iron ore powder changes with the reduction ***,the effect of temperature and reaction pathway interaction on the kinetics of fuidization reduction of iron ore powder under low-temperature conditions ranging from 783 to 903 K was investigated to describe the fluidization reduction rate of iron ore powder from three aspects:microstructure change,reaction limiting link,and apparent activation energy of the reaction,exploring their internal *** experimental results revealed that in a temperature range of 783-813 K,the formation of a dense iron layer hindered the internal diffusion of reducing gas,resulting in relatively high gas diffusion *** addition,due to the differences in limiting links and reaction pathways in the intermediate stage of reduction,the apparent activation energy of the reaction *** apparent activation energy of the reaction ranged from 23.36 to 89.13 kJ/mol at temperature ranging from 783 to 813 K,while it ranged from 14.30 to 68.34 kJ/mol at temperature ranging from 873 to 903 K.

关键词： Reaction limiting link Gas internal diffusion Interface reaction Apparent activation energy Iron ore powder Reaction pathway Fluidization reduction