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Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-Bo Li Qi Zhang Jun-zhao xiao Yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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Ko⁃LLaMA:基于LLaMA的朝鲜语大语言模型

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外语学刊 2025年第1期 1-8页

作者：庞杰闫晓东赵小兵中央民族大学北京100081 国家语言资源监测与研究民族语言中心北京100081 民族语言智能与安全治理教育部重点实验室北京100081

在本文中,我们通过扩展LLaMA现有的词表,增加额外的20,000个朝鲜语Token,从而提高其对朝鲜语的编码和语义理解的能力;并且进一步使用朝鲜语数据进行继续预训练,使用朝鲜语指令微调数据集对模型进行SFT(Supervised Fine⁃Tuning),并分析... 详细信息

在本文中,我们通过扩展LLaMA现有的词表,增加额外的20,000个朝鲜语Token,从而提高其对朝鲜语的编码和语义理解的能力;并且进一步使用朝鲜语数据进行继续预训练,使用朝鲜语指令微调数据集对模型进行SFT(Supervised Fine⁃Tuning),并分析不同数据量对指令精调效果的影响,经过继续预训练和指令微调后的模型显著提高了理解和遵循朝鲜语指令的能力。实验结果表明,新提出的模型Ko⁃LLaMA显著提高了原版LLaMA在理解和生成朝鲜语内容方面的能力。此外,在朝鲜语文本分类数据集YNAT上对Ko⁃LLaMA与擅长少数民族语言的CINO模型及CINO的多种模型组合以及原版LLaMA和GPT⁃3.5进行了效果对比。结果表明,Ko⁃LLaMA的朝鲜语文本分类能力远超CINO和CINO的组合模型以及LLaMA和GPT⁃3.5等未经过朝鲜语语料进行词表扩充和继续预训练的大语言模型。

关键词：朝鲜语大语言模型词表扩充继续预训练指令微调

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习近平文化思想研究的现状、热点与趋势——基于CiteSpace的知识图谱分析

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长江师范学院学报 2025年第1期41卷 14-24页

作者：赵颖彬赵晓营华南师范大学马克思主义学院广东广州510631 中国人民警察大学公安政治学院河北廊坊065000

习近平文化思想是当前学术界研究的热点议题。借助CiteSpace软件,对中国知网2014年1月—2024年4月收录的465篇相关核心期刊文献进行可视化计量分析。结果显示:习近平文化思想研究的相关文献整体呈上升态势,伴随间断性波动与爆发式增长;... 详细信息

习近平文化思想是当前学术界研究的热点议题。借助CiteSpace软件,对中国知网2014年1月—2024年4月收录的465篇相关核心期刊文献进行可视化计量分析。结果显示:习近平文化思想研究的相关文献整体呈上升态势,伴随间断性波动与爆发式增长;研究力量初具规模,研究成果较为丰硕,相关合作呈内部性与近邻性、大分散与小聚集的特点;现有研究较为全面地阐述了习近平文化思想的理论意涵与理论特色、实践意义与实践路径,初步形成以马克思主义为主导、多学科共建的研究格局,但相关研究的理论系统性有待深化、内容创新性有待提升、现实应用性有待强化。未来,要把握理论整体,深化理论体系研究;创新研究内容,推动话语体系研究;聚焦现实应用,强化实践路向研究。

关键词：习近平文化思想热点与趋势 CiteSpace

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Progress in understanding hormonal regulation during the postembryonic development of Helicoverpa armigera

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Journal of Integrative Agriculture 2020年第6期19卷 1417-1428页

作者： zhao xiao-fan Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology School of Life SciencesShandong UniversityQingdao 266237P.R.China

Lepidoptera,with 0.16 million species,is the second largest order of *** order includes silk worms,butterflies,and many agricultural *** cotton bollworm,Helicoverpa armigera(Hubner)is one of the pests in Lepidoptera that seriously harms cotton plant and other crops in China and other *** pest develops resistance to chemical insecticides *** thuringiensis(Bt)transgenic cotton plants are developed to control *** population in the ***,duri ng the past years,the rapid evoluti on of Bt toxi n resista nee is observed in *** in tran sge nic cott on *** approaches for the development of new envir on mentally friendly insecticides to control *** have become necessary,and the molecular mechanisms underlying the development and physiological processes of this species need to be further *** progress in the study of *** development and physiology has been achieved in the last *** mini-review summarizes the main fin dings on the molecular mechanisms of horm onal regulation of the development of *** to present new target genes for developing new approaches to control the pest.

关键词： Helicoverpa armigera Lepidoptera hormonal regulation development pest control

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Nanomaterial-based delivery vehicles for therapeutic cancer vaccine development

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Cancer Biology & Medicine 2021年第2期18卷 352-371页

作者： Jie Liang xiao zhao CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety&CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology of ChinaBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Nanomaterial-based delivery vehicles such as lipid-based,polymer-based,inorganics-based,and bio-inspired vehicles often carry distinct and attractive advantages in the development of therapeutic cancer *** on various delivery vehicles,specifically designed nanomaterials-based vaccines are highly advantageous in boosting therapeutic and prophylactic antitumor ***,therapeutic vaccines featuring unique properties have made major contributions to the enhancement of antigen immunogenicity,encapsulation efficiency,biocompatibility,and stability,as well as promoting antigen cross-presentation and specific CD8^(+)T cell ***,for clinical applications,tumor-associated antigen-derived vaccines could be an obstacle,involving immune tolerance and deficiency of tumor specificities,in achieving maximum therapeutic ***,when using bioinformatics predictions with emerging innovations of in silico tools,neoantigen-based therapeutic vaccines might become potent personalized vaccines for tumor *** this review,we summarize the development of preclinical therapeutic cancer vaccines and the advancements of nanomaterial-based delivery vehicles for cancer immunotherapies,which provide the basis for a personalized vaccine delivery ***,we review the existing challenges and future perspectives of nanomaterial-based personalized vaccines for novel tumor immunotherapies.

关键词： Nanomaterial-based delivery vehicles bioinformatic prediction neoantigen personalized vaccines tumor immunotherapy

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Joint optimization of inspection, maintenance, and spare ordering policy considering defective products loss

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Journal of Systems Engineering and Electronics 2021年第5期32卷 1167-1179页

作者： HAN Mengying YANG Jianhua zhao xiao School of Economics and Management University of Science and Technology BeijingBeijing 100083China Beijing Enter-prise Low-Carbon Operation Strategy Research Base University of Science and Technology BeijingBeijing 100083China School of Business Hebei University of Economics and BusinessShijiazhuang 050061China

This paper proposes a joint inspection-based maintenance and spare ordering optimization policy that considers the problem of integrated inspection,preventive maintenance,spare ordering,and quality control for a four-state single-unit manufacturing *** an inspection detects a minor defect,a second phase inspection is initiated and a regular order is *** quality begins to deteriorate when the system undergoes a severe *** counter this,an advanced replacement of the minor defective system is carried out at the Jth second phase *** a severe defect is recognized prior to the Jth inspection,or if system failure occurs,preventive or corrective replacement is *** timeliness of replacement depends on the availability of *** adopt two modes of ordering:a regular order and an emergency ***,a threshold level is introduced to determine whether an emergency order is preferred even when the regular order is already ordered but has not yet *** optimal joint inspection-based maintenance and spare ordering policy is formulated by minimizing the expected cost per unit time.A simulation algorithm is proposed to obtain the optimal two-phase inspection interval,threshold level and advanced replacement *** from several numerical examples demonstrate that,in terms of the expected cost per unit time,our proposed model is superior to some existing models.

关键词： maintenance two-phase inspection spare ordering three-stage failure process delay-time model

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On-chip boost regulator with projected off- and on-time control

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第8期10卷 1223-1230页

作者： xiao-ru XU Meng-lian zhao xiao-bo WU Institute of VLSI Design Zhejiang University Hangzhou 310027 China

The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) *** these applications,a regulator with small volume,fewer external components and high efficiency is highly *** paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as *** projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is *** projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control *** results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.

关键词： Boost regulator Integrated circuits Pulse frequency modulation Projected off-time Projected on-time

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Synthesis and Crystal Structure of a New Complex [CuL(Phen)]·NO_3

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1343-1346页

作者： QIU xiao-Hang zhao Jun TONG xiao-Lan Department of Chemistry Nankai University Tianjin 300071 China

A new mononuclear copper（Ⅱ） complex [CuL（Phen）]-NO3 （L - 2-{2-[（3,5-dibro- mosalicylidene）amino]ethyl }- 1 H- 1,3-benzimidazole, Phen = 1,10-phenanthroline） has been synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in monoclinic, space group C2/c with a = 24.966（7）, b = 15.673（4）, c = 16.600（5） A,β = 123.981（4）°, C28H20Br2CuN604, Mr = 727.86, V = 5386（2） A^3, Z = 8, Dc = 1.795 g/cm^3,μ（MoKα = 3.826 mm^-1, F（000） = 2888, the final R = 0.0508 and wR = 0.1024 for 5440 independent reflections with Rint = 0.1134. The title compound is composed of [CuL（Phen）]＋ cation and NO3^- anion. The coordination geometry around copper atom is a highly distorted trigonal bipyramid consisting of one benzimidazole nitrogen atom, one phenolato oxygen atom and one phenanthroline nitrogen atom on the equatorial plane together with one imine nitrogen atom and one phenanthroline nitrogen atom occupying the axial positions. The hydrogen bonding and π-π stacking interactions link the copper complex molecules into a 3-D supramolecular structure.

关键词： crystal structure copper complex 1,10-phenanthroline hydrogen bonds

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Damping properties of fly ash/epoxy composites

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Journal of University of Science and Technology Beijing 2008年第4期15卷 509-513页

作者： Jian Gu Gaohui Wu xiao zhao School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

An inexpensive fly ash （FA）, which is from a waste product, was employed to prepare fly ash/epoxy composites. The purpose of this study is to characterize the contributions of matrix viscoelasticity, hollow structure characteristic （porosity）, and filler/matrix interface friction to the high vibration damping capacity of such composites. The damping properties of the composites were investigated in the temperature range of-40 to 150℃ and in the frequency range of 10 to 800 Hz by using a tension-compression mode. The results indicate that the peak value of damping loss factor （tan3） for the fly ash/epoxy composites can reach 0.70-0.90 in test specification, and the attenuation of damping loss factor is inconspicuous with increasing frequency. In addition, scanning electron microscope （SEM） was used to observe the morphology of the fly ash as well as its distribution in the matrix, which will help to analyze the effect of fly ash on the damping properties of the fly ash/epoxy composites.

关键词： composites epoxy fly ash damping property loss factor

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Masses and Widths of Light Scalar Mesons in Chiral Perturbation Theory

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Communications in Theoretical Physics 2008年第2期49卷 451-455页

作者： CHEN xiao-zhao LI xiao-Ya LU xiao-Fu Department of Physics Sichuan University Chengdu 610064 China Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China China Center of Advanced Science and Technology （World Laboratory） Beijing 100080 China

Based on the diquark model, we assume that the light scalar mesons are q^2q^-2 states rather than qq^-. The chiral effective Lagrangian for the light scalar meson is constructed, and the mass relations are obtained： the isotriplet （a0） and the isosinglet （f0） are the heaviest and are degenerate, the isodoublets （κ） are heavier and the other isosinglet （σ） is the lightest; and 2Mκ^2 = Mα0^2＋ Mσ^2. Using experimental value for a0 and σ mass, we obtain Mκ=794 MeV, which is consistent with the experimental value. Then taking Г（a0^0 →ηπ^0） = 90 MeV and Г（f0→π^0π^0） = 20 MeV, we get the width of σ is： Г（σ0→π^＋π^-）= 150 MeV.

关键词： scalar meson honer diquark model chiral perturbation theory

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