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NHC-mediated photocatalytic para-selective C–H acylation of aryl alcohols: regioselectivity control via remote radical spiro cyclization

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Science China Chemistry 2025年

作者： Tinglei Zhang Lala Wang Xiaolin Peng Tianhui Liao dongmei Chen Ting Tu Donghan Liu Ziye Cheng Shiqing Huang Shi-Chao Ren Xinglong Zhang Yonggui Robin Chi State Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Qiannan Medical College for Nationalities School of Chemistry Chemical Engineering and Biotechnology Nanyang Technological University Department of Chemistry The Chinese University of Hong Kong Institute of High Performance Computing Agency for Science Technology and Research

Friedel-Crafts reaction and transition-metal catalysis represent primary methodologies for arene acylation; however, suffer from certain limitations, such as electronic effect-dependent reactivity, regioselectivity issues, the necessity of directing group, and relatively exceptionally limited exploration in meta-and para-acylations. N-heterocyclic carbene(NHC) catalysis has recently emerged as a promising alternative strategy for arene acylation, offering distinct regioselectivity profiles that are challenging to achieve through known methods. Herein, an NHC-mediated photo-catalytic para-selective C–H acylation of aryl alcohols is disclosed. The reaction employs a remote radical-induced temporary spiro cyclization strategy, proceeding via tandem radical dearomatization, radical acylation, rearomatization processes. Combined experimental and computational mechanistic studies support the proposed reaction pathway and observe an exclusive para-selectivity regardless of the nature of the substituents on the substrates. Despite the less satisfactory yields, the current method exhibits non-electronic nature-based reactivity and regioselectivity, enabling quick access to acylated arenes that are difficult or impossible for reported methods.

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婴儿肠道源长双歧杆菌B2-01的益生特性及其高密度培养

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食品科学 2025年第1期46卷 28-39页

作者：彭芸燕钟舒莹刘冬梅许喜林华南理工大学食品科学与工程学院广东广州510641

以广州市3月龄健康婴儿粪便中分离出的乳酸杆菌为研究对象,经分子生物学鉴定确认为长双歧杆菌(Bifidobacterium longum),命名为B2-01。对B2-01进行包括体外抗氧化活性和肝损伤保护活性在内的益生特性和高密度培养研究,结果表明:B2-01具... 详细信息

以广州市3月龄健康婴儿粪便中分离出的乳酸杆菌为研究对象,经分子生物学鉴定确认为长双歧杆菌(Bifidobacterium longum),命名为B2-01。对B2-01进行包括体外抗氧化活性和肝损伤保护活性在内的益生特性和高密度培养研究,结果表明:B2-01具有较强的1,1-二苯基-2-三硝基苯肼自由基、羟自由基、超氧阴离子自由基、2,2′-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力和抗脂质过氧化能力;在最高作用水平(DMEM完全培养基中发酵上清液体积分数10%)下,过氧化氢损伤和乙醇损伤L02细胞存活率可分别提高至89.10%和91.38%,同时能显著降低肝细胞中转氨酶的活力;高密度培养研究优化后的最佳培养条件确定为酵母浸提粉添加量3.45%、葡萄糖2.48%、乳糖2.79%、细菌学蛋白胨3.00%、低聚半乳糖2.50%。在此优化条件下,发酵液的活菌数最高可达4.20×10^(9) CFU/m L,比优化前(7.71×10^(8) CFU/mL)提高5.45倍。

关键词：长双歧杆菌婴儿肠道抗氧化活性酒精肝保护高密度培养

A Grobner Basis Algorithm for Ideals over Zero-Dimensional Valuation Rings

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Journal of Systems Science & Complexity 2021年第6期34卷 2470-2483页

作者： LI dongmei LIU Jinwang College of Mathematics and Computations Hunan University of Science and TechnologyXiangtan 411201China

Zero-dimensional valuation rings are one kind of non-Noetherian *** paper investigates properties of zero-dimensional valuation rings and prove that a finitely generated ideal over such a ring has a Grobner *** authors present an algorithm for computing a Gr?bner basis of a finitely generated ideal over ***,an interesting example is also provided to explain the algorithm.

关键词： Non-Noetherian ring Grobner basis Gr?bner ring conjecture valuation ring

无人机边缘计算系统任务卸载的URLLC安全设计

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计算机应用研究 2025年第1期42卷 250-256页

作者：钟冬梅崔苗张广驰广东工业大学信息工程学院广州510006

旨在解决无人机移动边缘计算(MEC)系统中任务卸载的物理层安全问题。在该系统中,多个地面用户将计算任务卸载给一架配备MEC服务器的无人机,一个地面窃听者尝试窃取用户向无人机卸载的任务信息。为保证任务卸载的可靠性和低时延,卸载通... 详细信息

旨在解决无人机移动边缘计算(MEC)系统中任务卸载的物理层安全问题。在该系统中,多个地面用户将计算任务卸载给一架配备MEC服务器的无人机,一个地面窃听者尝试窃取用户向无人机卸载的任务信息。为保证任务卸载的可靠性和低时延,卸载通信使用超可靠低时延通信(URLLC)技术。通过联合优化无人机的部署位置、用户的卸载链路带宽、用户本地计算和无人机计算的中央处理器(central processing unit,CPU)频率来最大化用户的最小安全计算量。为了解决该问题,首先采用块坐标下降法将问题分解为仅优化无人机的位置和计算时延,以及仅优化无人机和用户的CPU频率和用户卸载带宽两个子问题;然后利用对数函数近似的方法对卸载带宽的速率表达式进行化简,利用连续凸逼近法将非凸的子问题变成可解的凸优化问题;最后交替求解这两个子问题直至目标函数值收敛。仿真结果表明,与现有基准方案相比,所提算法能够有效提高系统的安全计算量。这证明了所提方法的必要性,为实现安全通信和计算平衡提供了解决方案。

关键词：无人机移动边缘计算超可靠低时延通信

基于液相色谱-质谱代谢组学技术的硒化黑木耳代谢产物及通路分析

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食品科学 2025年第3期46卷 162-168页

作者：岳诗博崔航沈琴曹冬梅黑龙江八一农垦大学食品学院黑龙江大庆163319 黑龙江八一农垦大学牡丹江食品与生物技术创新研究院黑龙江牡丹江157000 国家杂粮工程技术研究中心黑龙江大庆163319 潍坊食品科技职业学院山东潍坊262123 黑龙江省农产品加工与质量安全重点实验室黑龙江大庆163319 黑龙江省杂粮加工及质量安全工程技术研究中心黑龙江大庆163319

本研究通过在黑木耳菌包中添加外源硒,结合液相色谱-质谱联用代谢组学技术,运用主成分分析、偏最小二乘判别分析、层次聚类分析等多元统计学分析,探究硒化对黑木耳代谢通路及代谢物的动态变化影响。结果表明,从黑木耳(HME)、亚硒酸钠无... 详细信息

本研究通过在黑木耳菌包中添加外源硒,结合液相色谱-质谱联用代谢组学技术,运用主成分分析、偏最小二乘判别分析、层次聚类分析等多元统计学分析,探究硒化对黑木耳代谢通路及代谢物的动态变化影响。结果表明,从黑木耳(HME)、亚硒酸钠无机硒化黑木耳(HMEa)和富硒玉米秸秆有机硒化黑木耳(HMEb)组共定性出669个代谢物,通过对差异代谢物进行筛选,无机硒化组(HME vs HMEa)共得到228个差异代谢物;有机硒化组(HME vs HMEb)共得到267个差异代谢物,硒化对黑木耳中有机酸及其衍生物、脂类及类脂质分子含量影响较大,且有机硒化富硒效果更显著。综合两组的京都基因与基因组百科全书代谢通路分析,发现硒化对脂类代谢、氨基酸类代谢影响显著。综上所述,黑木耳受到硒化后,脂类代谢、氨基酸代谢以及其他次生代谢产物的生物合成过程发生显著变化,对黑木耳中脂类和氨基酸等代谢产物产生显著影响,说明硒化会对黑木耳的营养成分和风味品质产生一定影响。

关键词：硒化黑木耳液相色谱-质谱法非靶向代谢组学

Observer-based H_∞ control over packet dropping networks

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1215-1225页

作者： Zhang dongmei Wang Xingang Dept. of Applied Mathematics Zhejiang Univ. of Technology Hangzhou 310032 P. R. China Coll. of Information Engineering Zhejiang Univ. of Technology Hangzhou 310032 P. R. China

A new controller design problem of networked control systems with packet dropping is proposed. Depending on the place that the observer is put in the system, the network control systems with packet dropping are modeled as stochastic systems with the random variables satisfying the Bernoulli random binary distribution. The observer-based controller is designed to stabilize the networked system in the sense of mean square, and the prescribed H∞ disturbance attenuation level is achieved. The controller design problem is formulated as the feasibility of the convex optimization problem, which can be solved by a linear matrix inequality （LMI） approach. Numerical examples illustrate the effectiveness of the proposed methods.

关键词： networked control systems packet dropping linear matrix inequality

Adsorption of 2-naphthalenesulfonic acid/sulfuric acid/sulfurous acid from aqueous solution by iron-impregnated weakly basic resin：Equilibrium and model

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Chinese Journal of Chemical Engineering 2016年第11期24卷 1522-1526页

作者： Changhai Li dongmei Jia Department of Chemical Engineering Binzhou University Binzhou 256603 China Research Center of Chemical Engineering and Technology Binzhou University Binzhou 256603 China

Commercial grade weakly basic resin D301 was impregnated with iron through a simple method using ferric chloride. Experiments for single, bisolute and trinary competitive adsorption were carried out to investigate the adsorption behavior of 2-naphthalenesulfonic acid(NSA), sulfuric acid and sulfurous acid from their solution at 298 K onto the novel hybrid iron impregnated D301(Fe-D301). Adsorption affinity of NSA on Fe-D301 was found to be much higher than that of sulfuric acid, while adsorption affinity of sulfuric acid was slightly higher than that of sulfurous acid. The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model. The non-ideal competitive adsorbed model coupled with the single-solute adsorption models were used to predict the bisolute and trinary-solute competitive adsorption equilibria. The NICM coupled with the Langmuir model yields the favorable representation of the bisolute and trinary-solute competitive adsorption behavior.

关键词： 2-naphthalenesulfonic acid Hybrid iron impregnated D301 Adsorption Non-ideal competitive adsorbed model Model Equilibrium

The Generalized Serre Problem over K-Hermite Rings

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Journal of Systems Science & Complexity 2017年第2期30卷 510-518页

作者： LIU Jinwang LI dongmei College of Mathematics and Computations Hunan University of Science and TechnologyXiangtan 411201China State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing 100093China

This paper investigates the completion and the zero prime factorization for matrices over a K-Hermite ring. The authors have generalized Kaplansky's related results, solved similar Lin-Bose problem and generalized Ser... 详细信息

关键词： Completion of matrix factorization of matrix K-Hermite ring.

Restoration potential of pioneer plants growing on lead-zinc mine tailings in Lanping, southwest China

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Journal of Environmental Sciences 2008年第10期20卷 1202-1209页

作者： Lei dongmei Duan Changqun Yunnan Univ Lab Conservat & Utilizat Bioresource Kunming 650091 Peoples R China Yunnan Univ Inst Environm Sci & Ecol Restorat Kunming 650091 Peoples R China Yunnan Univ Finance & Econ Inst Land & Resources & Sustainable Dev Kunming 650221 Peoples R China

This study focused on the restoration potential of ten pioneer plants (Artemisia roxburghiana, Artemisia tangutica, Carex inanis, Cyperaceae hebecarpus, Plantago depresa, Cynoglossum lanceolatum, Potentilla saundesiana, Coriaria sinica, Oxyria sinensis, and Miscanthus nepalensis) during the early phase of Pb-Zn mine tailings phytostabilization, in Lanping, China. The concentrations of heavy metals (Pb, Zn, and Cu) and soil fertility (the available N, P, K, and organic matter) in the rhizosphere of these spe...

关键词： pioneer plant mine tailings phytostabilization rhizosphere soil