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Real-time in-situ monitoring of chiral changes during a reaction at single-molecule level

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Science China Chemistry 2024年第2期67卷 422-423页

作者： Min Tan dong Xiang Institute of Modern Optics and Center of Single-Molecule Science Tianjin Key Laboratory of Micro-scale Optical Information Science and TechnologyNankai UniversityTianjin300350China School of Materials Science and Engineering Smart Sensing Interdisciplinary Science CenterNankai UniversityTianjin300350China TongLu FeiRan Garment–Nankai University Joint Laboratory Nankai UniversityTianjin300350China

Molecular chirality is a widespread phenomenon in nature,playing a critical role in various fields such as chemistry [1],life sciences [2], and materials science [3], and has therefore attracted significant attention and research by scholars [4–6].However, the chirality in chemical reactions is often dynamic, making real-time monitoring of chiral changes during chemical reactions at the single-molecule level extremely challenging.

关键词： chiral chirality critical

Could π-aromaticity cross an unsaturated system to a fully saturated one?

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Chinese Chemical Letters 2024年第6期35卷 298-302页

作者： Shicheng dong Jun Zhu State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChem)Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China

The classification of π-/σ-aromaticity depends on the electrons with the dominating ***,π-andσ-aromaticity are used to describe the unsaturated and saturated systems,***,it is rarely reported that π-aromaticity is dominated in a saturated *** we demonstrate that π-aromaticity could be dominating in several fully saturated four-membered rings(4MRs),supported by various aromaticity indices including ΔBL,NICS,EDDB,MCI,and Ad *** origin of suchπ-aromaticity in saturated rings could be attributed to an introduction of two additional electrons into the π-type LUMO of the parent neutral *** findings represent a novel approach to achieve π-aromaticity into a fully saturated system which has traditionally been dominated by σ-aromaticity.

关键词： π-Aromaticity Saturated rings Silicon

经济分析视角下“唯分数”的逻辑成因与治理思路

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教育与考试 2022年第6期 54-59页

作者：董思成沈彦彬上海市晋元高级中学上海200333 上海市闵行区教育测评与研究中心上海201199

已有研究深化了对“唯分数”现象产生机制的认识,但较多受制于学科视角,未能对“唯分数”背后的逻辑成因做出统一解释。本文运用经济分析的方法,分析学生、家长、学校、校外培训机构及教育行政部门“唯分数”的逻辑成因,发现他们在教育... 详细信息

已有研究深化了对“唯分数”现象产生机制的认识,但较多受制于学科视角,未能对“唯分数”背后的逻辑成因做出统一解释。本文运用经济分析的方法,分析学生、家长、学校、校外培训机构及教育行政部门“唯分数”的逻辑成因,发现他们在教育市场中作为消费者或生产者,采用理性策略实现自身效用或利润的最大化,在互动中形成了“唯分数”的市场均衡。基于此,本文提出的治理思路是深化招生主体的信号投放机制,创生新的市场均衡。

关键词： “唯分数” 经济分析教育评价

Metal-based inorganic nanocrystals for biological sonodynamic therapy applications:recent progress and perspectives

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Rare Metals 2024年第2期43卷 413-430页

作者： dong Wang Jia-Tao Zhang Institute of Medical-Industrial Integration Beijing Key Laboratory of Structurally Controllable Advanced Functional Materials and Green ApplicationsSchool of Materials Science and EngineeringBeijing Institute of TechnologyBeijing100081China Key Laboratory of Medical Molecule Science and Pharmaceutics Engineering Ministry of Industry and Information TechnologySchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing100081China

With the fast development of technology for the treatment of tumor and bacteria,photo-therapeutic strate-gies emerge as a kind of highly effective and common treatment,but the low tissue penetration depth of light limits their *** therapy(SDT),as an efficient and non-invasive treatment,attracts more people's attention due to the inherent property of high tissue *** soft tissue penetration depth of ultrasound(US)can even reach more than 10 cm,which has great advantage over that of ***,many sonosensitizers are studied and applied to SDT-based ***-based inorganic nanocrystals are able to generate more reactive oxygen species(ROS)due to the special composition and band *** representative achievements and the specific functions of the nanocrystals sonosensitizers are summarized in this work,and the relationship of structure/composition-SDT performance and the internally regulated composite is ***-gistic effects of SDT in combination with other therapeutic modalities are mainly *** the same time,the critical and potential issues and future perspectives are addressed.

关键词： Metal-based inorganic nanocrystals Sonodynamic therapy(SDT) Tumor treatment Antibacteria

Recent Advances in Pd-Catalyzed Reactions Involving the “On-Water” Mechanism

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Chinese Journal of Chemistry 2024年第5期42卷 533-542页

作者： dong Wei Guo-Qiang Lin State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteShanghai Key Laboratory of Systems Regulation and Clinical Translation for CancerRen Ji HospitalShanghai Jiao Tong University School of MedicineShanghai200127 China State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032 China

As the chemical industry grapples with the need for more eco-friendly practices,the use of water as a reaction medium is gaining attraction in organic *** mini-review delves into Pd-catalyzed reactions that utilize the "on-water" mechanism,spanning from 2019 to late *** reactions are neatly categorized into several types: (A) Catalytic C—H activations,(B) Mizoroki- Heck-type reactions,(C) Suzuki-Miyaura reactions,and (D) Cyclization *** showcasing the potential of water as a sustainable reaction medium for organic transformations,these reactions leave no doubt about the importance of embracing eco-friendly practices in the chemical *** Scientists In 1980,a seminal work by Breslow et *** an acceleration of reaction rate in the Diels-Alder *** and co-workers noted a significant increase in the rate of the [2σ+2σ+2π] cycloaddition of quadricyclane and dimethyl azodicarboxylate (DMAD) when the reaction was conducted in water,as opposed to when it was carried out in organic *** term "on-water" was then coined to describe this *** strategy was further expanded to transition-metal catalyzed transformations by Ackermann in ***,Varma and Leazer disclosed a Pd-catalyzed Mizoroki-Heck type arylation of alkenes with diaryliodonium salts “on-water”.The enantioselective version of "on-water" process was not realized until 2014 by the Zhou *** on,the Schaub group described a Pd-catalyzed Suzuki–Miyaura coupling reaction of electron-poor aryl chlorides with water,using only 50 ppm of catalyst *** recently,Liu and Lin extended the "on-water" strategy to Pd-catalyzed double Mizoroki-Heck *** mini-review has focused on Pd-catalyzed reactions involving the “on-water” mechanism.

关键词： Pd-catalyzed “On-water” Green chemistry Aqueous reactions Mechanism Methodology and reactions Mizoroki-Heck reaction Cross-coupling

Local search yields a PTAS for fixed-dimensional k-means problem with penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 351-362页

作者： Fan Yuan Da-Chuan Xu dong-Lei Du dong-Mei Zhang Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFrederictonNB E3B 9Y2Canada School of Computer Science and Technology Shandong Jianzhu UniversityJinan 250101ShandongChina

We study a problem called the k-means problem with penalties(k-MPWP),which is a natural generalization of the typical k-means *** this problem,we have a set D of client points in R^(d),a set F of possible centers in R^(d),and a penalty cost Pj>O for each point j∈*** are also given an integer k which is the size of the center point *** want to find a center point set S■F with size k,choose a penalized subset of clients P■D,and assign every client in D\P to its open *** goal is to minimize the sum of the squared distances between every point in D\P to its assigned centre point and the sum of the penalty costs for all clients in *** using the multi-swap local search technique and under the fixed-dimensional Euclidean space setting,we present a polynomial-time approximation scheme(PTAS)for the k-MPWP.

关键词： Approximation algorithm k-means Local search Penalty

Sensitivity analysis of modeling parameters to soot and PAHs prediction in ethylene inverse diffusion flame

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Science China(Technological Sciences) 2024年第2期67卷 486-498页

作者： WU BingKun LI TianJiao LIU dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and Technology Nanjing 210094China

The soot formation model based on inverse ethylene diffusion flames was performed to study the sensitivity of the soot formation process to the prediction *** effects of efficiency parameters such as soot inception,surface growth and coagulation on the simulation results were studied by using the adjustable efficiency *** addition,the reversible soot model and conjugate heat transfer(CHT)model were also introduced to explore their *** indicated that,among adjustable efficiency parameters,the nucleation efficiency had the greatest influence on the predicted soot and PAHs distributions,while the Habstraction-C2H2-addition(HACA)process and PAH adsorption surface growth efficiencies impacted *** adjustable efficiency parameters had a significant effect on the concentration of soot gaseous precursors and soot particles,but their effects on temperature,gas phase molecules,and intermediate species were not *** the nucleation efficiency increased from 2×10^(-6)to 1×10^(-4),the predicted value of the integrated soot was increased by nearly 50%,and the maximum primary particle number density and the number of aggregates were increased by an order of *** maximum concentration of BAPYR was ***,the peak temperature along the axial direction increased by only 3.5 *** the reversible soot model,the approximation results of the adjustable efficiency parameters could be modified,which showed the feasibility of the *** use of the CHT model promoted pyrolysis of the fuel below the outlet of the fuel tube,with high-temperature zones,soot zones,and PAHs zones moving towards higher flame ***,when using the reversible model and the CHT model,the maximum soot volume fraction decreased by 39%compared with the basic efficiency parameters,while the concentration of BAPYR increased by 162%,and the concentrations of gas phase species were decreased.

关键词： inverse diffusion flames soot formation soot model ethylene

Projections of summer light rain frequency in typical terrain over eastern China under wind speed constraint

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Science China Earth Sciences 2024年第6期67卷 1885-1894页

作者： Xuechen dong Daoyi GONG Cuicui SHI Institute of Disaster Risk Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster MOEFaculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China School of Systems Science Beijing Normal UniversityBeijing 100875China

The variation in near-surface wind speed is a key dynamic parameter in the orographic effect of precipitation over eastern *** this study,we used the latest high-resolution outputs from six GCMs in CMIP6-HighResMIP to evaluate the performance of high-resolution models in simulating the orographic precipitation characteristics of typical mountainous areas in summer over eastern *** orographic precipitation under warming scenarios was projected and constrained according to observational *** results indicated that during the contemporary climate reference period(1979-2009),although the relationship between model-simulated near-surface wind speed and orographic light rain frequency was consistently stable,the sensitivity of the orographic light rain frequency to surface wind variability was generally underestimated,with a deviation approximately 24.1% lower than the observational *** estimated orographic light rain frequency corrected based on the observed near-surface wind speed under a 1.5℃ warming scenario,was 36.1% lower than that of the contemporary period;this reduction was 8.6 times that without the wind speed constraint(4.2%).The MRI-AGCM3-2-S model,with a longer dataset,demonstrated relatively stable reductions in orographic light rain frequency under different warming scenarios(1.5℃,2℃,3℃,and 4℃)after the application of wind speed *** all cases,the reductions exceeded those for the predictions made without the wind speed constraint.

关键词： Frequency of orographic light rain HighResMIP High-resolution projection Observational constraint Eastern China

Rapid and chemoselective imidation of sulfides in aqueous buffer enabled by a novel guanidine-derived N-O reagent

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Science China Chemistry 2024年第6期67卷 1929-1934页

作者： Hanzheng Li Long Xu Jiajia dong Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032China Institute of Translational Medicine National Facility for Translational Medicine(Shanghai)Shanghai Jiao Tong UniversityShanghai200240China School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced StudyShanghai Jiao Tong UniversityShanghai200240China Shanghai Artificial Intelligence Laboratory Shanghai200232China

Herein we report the facile synthesis of a series of novel N-O reagents and identify N′-di-Boc-N′′-[(mesitylsulfonyl)oxy]-guanidine as an efficient imidating *** reagent is synthetically scalable and bench-stable,yet it shows unprecedented reactivity and chemoselectivity towards S(II)in buffer/hexafluoroisopropanol(HFIP)system,to generate a new class of Nguanyl *** transformation of N-guanyl sulfilimines to N-guanyl sulfoximines provides us a chance to investigate these rarely reached compounds,which are shown to be versatile precursors to a variety of N-heterocyclic and *** work provides an addition to the tool box of both sulfur imidation and guanidine synthesis,especially for the need of rapid and selective modifications of sulfur(II)center under biocompatible conditions.

关键词： sulfur imidation N-O reagent