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Green Energy & Environment 2024年第1期9卷 114-125页

作者： Yang Zhou Qiang Zeng Hongyan He kejia wu Fuqiao Liu Xuehui Li School of Chemistry and Chemical Engineering The Guangdong Provincial Key Laboratory of Green Chemical Product TechnologyState Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong510640China CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.

关键词： Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect

Theta Oscillations Support Prefrontal-hippocampal Interactions in Sequential Working Memory

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Neuroscience Bulletin 2024年第2期40卷 147-156页

作者： Minghong Su kejia Hu Wei Liu Yunhao wu Tao Wang Chunyan Cao Bomin Sun Shikun Zhan Zheng Ye Institute of Psychology Chinese Academy of SciencesBeijing 100101China Department of Psychology University of Chinese Academy of SciencesBeijing 100049China Department of Neurosurgery Center for Functional NeurosurgeryRuijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China Institute of Neuroscience Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China

The prefrontal cortex and hippocampus may support sequential working memory beyond episodic memory and spatial navigation.This stereoelectroencephalography(SEEG)study investigated how the dorsolateral prefrontal cortex(DLPFC)interacts with the hippocampus in the online processing of sequential information.Twenty patients with epilepsy(eight women,age 27.6±8.2 years)completed a line ordering task with SEEG recordings over the DLPFC and the hippocampus.Participants showed longer thinking times and more recall errors when asked to arrange random lines clockwise(random trials)than to maintain ordered lines(ordered trials)before recalling the orientation of a particular line.First,the ordering-related increase in thinking time and recall error was associated with a transient theta power increase in the hippocampus and a sustained theta power increase in the DLPFC(3–10 Hz).In particular,the hippocampal theta power increase correlated with the memory precision of line orientation.Second,theta phase coherences between the DLPFC and hippocampus were enhanced for ordering,especially for more precisely memorized lines.Third,the theta band DLPFC→hippocampus influence was selectively enhanced for ordering,especially for more precisely memorized lines.This study suggests that theta oscillations may support DLPFC-hippocampal interactions in the online processing of sequential information.

关键词： Sequential working memory Hippocampus Dorsolateral prefrontal cortex Theta oscillations Stereoelectroencephalography(SEEG) Phase coherence Granger causality

Level pinning of anti-PT-symmetric circuits for efficient wireless power transfer

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National Science Review 2024年第1期11卷 215-224页

作者： Zhiwei Guo Fengqing Yang Haiyan Zhang Xian wu Qiong wu kejia Zhu Jun Jiang Haitao Jiang Yaping Yang Yunhui Li Hong Chen MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Sciences and Engineering Tongji University Department of Electrical Engineering Tongji University School of Automotive Studies Tongji University

Wireless power transfer(WPT) technology based on magnetic resonance(a basic physical phenomenon)can directly transfer energy from the source to the load without wires and other physical contacts, and has been successfully applied to implantable medical devices, electric vehicles, robotic arms and other fields.However, due to the frequency splitting of near-field coupling, the resonant WPT system has some unique limitations, such as poor transmission stability and low efficiency. Here, we propose anti-resonance with level pinning for high-performance WPT. By introducing the anti-resonance mode into the basic WPT platform, we uncover the competition between dissipative coupling and coherent coupling to achieve novel level pinning, and construct an effective anti-parity-time(anti-PT)-symmetric non-Hermitian system that is superior to previous PT-symmetric WPT schemes. On the one hand, the eigenvalue of the anti-PT-symmetric system at resonance frequency is always pure real in both strong and weak coupling regions, and can be used to overcome the transmission efficiency decrease caused by weak coupling, as brought about by, for example, a large size ratio of the transmitter to receiver, or a long transmission distance.On the other hand, due to the level pinning effect of the two kinds of coupling mechanisms, the working frequency of the system is guaranteed to be locked, so frequency tracking is not required when the position and size of the receiver change. Even if the system deviates from the matching condition, an efficient WPT can be realized, thereby demonstrating the robustness of the level pinning. The experimental results show that when the size ratio of the transmitter coil to the receiver coil is 4.29(which is in the weak coupling region), the transfer efficiency of the anti-PT-symmetric system is nearly 4.3(3.2) times higher than that of the PT-symmetric system when the matching conditions are satisfied(deviated). With the miniaturization and integration of devices in mind, a synthetic anti-PT-symmetric sy

关键词： non-Hermitian system wireless power transfer anti-PT-symmetric circuits synthetic dimension metamaterials

Radical and(photo)electron transfer induced mechanisms for lignin photo-and electro-catalytic depolymerization

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Green Energy & Environment 2023年第2期8卷 383-405页

作者： kejia wu Minglong Cao Qiang Zeng Xuehui Li School of Chemistry and Chemical Engineering State Key Laboratory of Pulp&Paper EngineeringSouth China University of TechnologyGuangzhou510640China

As one of the three major components of woody biomass,lignin is a kind of natural organic polymer and the only abundant natural renewable resource with aromatic nucleus.Chemical catalysis induced depolymerization is an important and effective approach for lignin utilization.In particular,photocatalysis and electrocatalysis show great potential in accurately activating C-O/C-C bonds,which is a critical point of selective cleavage of lignin.In this contribution,we focus on radical and(photo)electron transfer induced reaction mechanisms of the photo(electro)catalytic depolymerization of lignin.Primarily,the general situation of Carbon-centered radicals and active oxygen species mediated lignin conversion has been discussed.Then the mechanisms for(photo)electron transfer mediated lignin depolymerization have been summarized.At the end of this review,the challenges and opportunities of photo(electro)catalysis in the applications of lignin valorization have been forecasted.

关键词： Lignin Photocatalysis Electrocatalysis Depolymerization Reaction mechanism

Selective photocatalytic aerobic oxidative cleavage of lignin C–O bonds over sodium lignosulfonate modified Fe_(3)O_(4)/TiO_(2)

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Journal of Energy Chemistry 2023年第9期84卷 89-100页

作者： kejia wu Jinrong Liang Sijie Liu Yimin Huang Minglong Cao Qiang Zeng Xuehui Li School of Chemistry and Chemical Engineering State Key Laboratory of Pulp&Paper EngineeringGuangdong Provincial Key Lab of Green Chemical Product TechnologySouth China University of TechnologyGuangzhou 510640GuangdongChina

Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.

关键词： Lignin Photocatalytic oxidation Selective cleavage Titanium dioxide

Determination of perchlorate and its distribution in unhusked rice in China

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Food Quality and Safety 2022年第2期6卷 252-256页

作者： Changxin Shen Lian Liu Xiaoyao Yin Fengqin Tu kejia wu Qian wu Lingfeng Peng Min Fang Yongning wu Zhiyong Gong Key Laboratory for Deep Processing of Major Grain and 0il of Ministry of Educ ation Wuhan Polytechnic UniversityWuhanChina wuhan Institute for Food and Cosmetic Control WuhanChina China National Center for Food Safety Risk Assessment NHC Key Laboratory of Food Safety Risk AssessmentFood Safety Research Unit(2019RU014)of Chinese Academy of Medical ScienceBeiingChina

Perchlorate concentrations in 387 unhusked rice samples from 15 main producing provinces/municipality in China were investigated by high-performance liquid chromatography-tanden mass spectrometry.The results indicated that perchlorate displays a mean level of 17.17μg/kg in un-husked rice samples.Intriguingly,we also found that perchlorate is mainly observed in rice husk among these collected unhusked rice samples,while less observed in rice bran and milled rice.Specifically,the perchlorate levels in rice were found in the husks(73.61%),bran(10.09%),and milled rice(19.52%),respectively.Our results indicated that there is no significantly perchlorate exposure risk in edible milled rice.

关键词： Perchlorate unhusked rice distribution China

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中断离港航班恢复的改进NSGA2算法

北京航空航天大学学报 2024年第6期50卷 1784-1793页

作者：陈可嘉吴钧涛福州大学经济与管理学院福州350108

为解决因突发事件产生的航空公司航班中断问题,对中断的离港航班进行恢复,构建最小化航空公司总延误成本和最小化乘客总延误时间的双目标优化模型,设计基于支配强度的自适应非支配排序遗传算法(ANSGA2-DS)。提出3种改进操作:快速支配排... 详细信息

为解决因突发事件产生的航空公司航班中断问题,对中断的离港航班进行恢复,构建最小化航空公司总延误成本和最小化乘客总延误时间的双目标优化模型,设计基于支配强度的自适应非支配排序遗传算法(ANSGA2-DS)。提出3种改进操作:快速支配排序方法、新的拥挤距离和自适应精英保留策略。通过福州长乐国际机场某航空公司的运行数据对所提算法进行验证,实验结果表明:与传统的先规划先服务方法相比,所提算法得到的解有大幅优化;与ε约束法相比,所提算法的求解时间总体上低于ε约束法,且求解结果接近ε约束法所得最优结果;与NSGA2、MOEAD等多目标优化算法相比,所提算法表现出更优的性能,能够有效且高效地解决问题,为航空公司达成优化的解决方案提供基础。

关键词：航空运输中断航班恢复多目标遗传算法离港航班双目标优化

Combination Mechanism and Enhanced Visible-Light Photocatalytic Activity and Stability of CdS/g-C3N4 Heterojunctions

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Journal of Materials Science & Technology 2017年第1期33卷 30-38页

作者： Huanyan Xu Licheng wu Liguo Jin kejia wu School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150040 China

In this study, CdS/g-C3N4 （CSCN） heterojunctions were in situ fabricated with a large amount of CdS nanoparticles anchored on g-C3N4 nanosheets, A wet chemical method was developed for the first time to determine the actual content of CdS in CSCN composites. X-ray diffraction （XRD）, Fourier transform infrared spectra （FFIR）, high-resolution transmission electron microscopy （HRTEM） and UV-vis diffuse reflectance spectra （DRS） were employed to characterize the composition, structure and optical prop- erty of CSCN composites. Based on the is0electric point （liP） analysis of g-C3N4, a conclusion was obtained on the combination mechanism between CdS nanoparticles and g-C3N4 nanosheets. The photocatalytic activity of CSCN composites was much better than those of individual CdS and g-C3N4 for the degrada- tion of azo dye Methyl Orange （MO） by 40 min adsorption in the dark followed by 15 min photocatalysis under visible light irradiation. After 5 cycles, CSCN composites still maintained high reactive activity with the MO degradation efficiency of 93.8%, exhibiting good photocatalytic stability. The Cd2~ concentration dissolved in the supernatant detected by atomic absorption spectroscopy （AAS） of CSCN composites was lower than that of pure CdS, implying that the photocorrosion of CdS could be suppressed via the combination with g-C3N4. Photoluminescence emission spectra （PL） results clearly revealed that the recombination of photogenerated electron-hole pairs in CSCN composites was effectively inhibited due to the formation of heterojunctions. Based on the band alignments of g-C3N4 and CdS, the possible photocatalvtic mechnism was discussed.

关键词： CdS/g-C3N4 Heterojunctions Photocatalytic stability Photocatalytic mechanism

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离心式血泵优化设计研究进展

医用生物力学 2024年第3期39卷 552-558页

作者：张珂嘉吴鹏苏州大学机电工程学院人工器官研究所江苏苏州215131 东南大学机械工程学院江苏省微纳生物医疗器械设计与制造重点实验室南京211189

人工心脏(血泵)应兼具优良的水力学性能和血液相容性,血泵性能的提升依赖于良好的优化设计方法。本文对近年离心式血泵优化设计相关的工作进行总结,首先回顾数值模拟方法的进展,高保真度的流场数值模拟是进行血泵优化设计的先决条件;接... 详细信息

人工心脏(血泵)应兼具优良的水力学性能和血液相容性,血泵性能的提升依赖于良好的优化设计方法。本文对近年离心式血泵优化设计相关的工作进行总结,首先回顾数值模拟方法的进展,高保真度的流场数值模拟是进行血泵优化设计的先决条件;接着主要从叶轮、蜗壳、间隙等方面概括优化设计的参数敏感性研究;总结优化设计常用的几种方法,包括参数敏感性研究、正交优化、机器学习/遗传算法、拓扑优化;最后提出血泵优化设计的展望及存在的挑战。研究结果可为未来的血泵优化设计工作提供有益的借鉴和参考。

关键词：血泵叶轮蜗壳优化设计数值模拟

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街道公务员政策执行创新行为的特征与优化研究

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中共宁波市委党校学报 2024年第4期46卷 55-65页

作者：吴芸侯可嘉首都师范大学管理学院北京100089 北京市通州区不动产登记中心北京101100

街道公务员的政策执行过程也是运用自由裁量权进行决策的过程,具有创新的空间和可能。问卷调查和访谈发现:街道公务员创新行为水平普遍较高且波动幅度较小;做出改变原有秩序创新行为的可能性较小,而使用自由裁量权进行创新的可能性较大... 详细信息

街道公务员的政策执行过程也是运用自由裁量权进行决策的过程,具有创新的空间和可能。问卷调查和访谈发现:街道公务员创新行为水平普遍较高且波动幅度较小;做出改变原有秩序创新行为的可能性较小,而使用自由裁量权进行创新的可能性较大;不经常改变其他人想法去强调创新行为的重要性,而倾向于多角度分析问题。硕士研究生及以上学历的街道公务员比本科学历街道公务员的创新行为更多;新入职街道公务员的创新行为更多。部分街道公务员创新意愿强但创新行为少,主要集中在26岁—35岁、担任现任职务3年以下且非领导职务的街道公务员。建议完善创新过程的责任性控制机制,减负放权、提供资源支持,培训赋能、构建创新型队伍,以促进街道公务员创新。

关键词：街道公务员自由裁量权创新行为创新意愿