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Ligand-controlled NiH-catalyzed regiodivergent hydroalkylation of 2-alkenylazaarenes

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Science China Chemistry 2024年第6期67卷 1935-1940页

作者： ya-Ping Shao Zhuo-min Chi Yong-min Liang State Key Laboratory of Applied Organic Chemistry School of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou730000China

A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor *** method enables the synthesis of diverseβ-orγ-branched aromatic *** mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable ***,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.

关键词： NiH regiodivergent hydroalkylation azaarenes interrupted chain-walking

Sex-biased adaptation shapes uniparental gene pools in Tibetans

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Science China(Life Sciences) 2024年第3期67卷 611-613页

作者： min-Sheng Peng ya-Ping Zhang State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunming 650201China KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases Kunming Institute of ZoologyChinese Academy of SciencesKunming 650201China Kunming College of Life Science University of Chinese Academy of SciencesKunming 650204China State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan School of Life SciencesYunnan UniversityKunming 650091China

During the past two decades, a series of archaeological and genetic investigations substantially improve our perception of the hominin settlement of the Tibetan Plateau(Zhang et al., 2022). In addition to the identifi... 详细信息

关键词： Tibetan Plateau altitude

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Ka波段滤波器加载三间隙耦合输出腔的设计

红外与毫米波学报 2010年第2期29卷 105-108,131页

作者：王树忠马菁王勇全亚民中国科学院电子学研究所中国科学院高功率微波源与技术重点实验室北京100190

扩展相互作用速调管(EIK)由多个重入式多间隙耦合腔构成,毫米波段高功率微波源的需求推动了Ka波段EIK的研制.分别利用等效电路理论和场分析方法推导了由三个同样间隙构成的三间隙耦合输出腔间隙阻抗实部的计算公式,然后应用等效电路方... 详细信息

扩展相互作用速调管(EIK)由多个重入式多间隙耦合腔构成,毫米波段高功率微波源的需求推动了Ka波段EIK的研制.分别利用等效电路理论和场分析方法推导了由三个同样间隙构成的三间隙耦合输出腔间隙阻抗实部的计算公式,然后应用等效电路方法获得了滤波器加载宽频带输出回路的基本参数,应用场分析方法设计了冷测带宽达4.6%的滤波器加载三间隙耦合输出腔结构,为宽频带EIK的研制打下坚实的基础.

关键词：宽频带扩展相互作用速调管场分析法

Experimental and numerical study on protective effect of RC blast wall against air shock wave

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Defence Technology（防务技术） 2024年第1期31卷 567-579页

作者： Xin-zhe Nian quan-min Xie Xin-li Kong Ying-kang yao Kui Huang State Key Laboratory of Precision Blasting Jianghan UniversityWuhan430056China Hubei Key Laboratory of Blasting Engineering Jianghan UniversityWuhan430056China Hubei(Wuhan)Institute of Explosion and Blasting Technology Jianghan UniversityWuhan430056China College of Defense Engineering Army Engineering University of PLANanjing210007China Institute of Defense Engineering AMSPLALuoyang471023China

Prototype experiments were carried out on the explosion-proof performance of the RC blast *** mass of TNT detonated in the experiments is 5 kg and 20 kg *** shock wave overpressure was tested in different *** above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP *** results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP *** dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was *** to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are *** above results can provide a reference for the design and construction of the reinforced concrete blast wall.

关键词： Blast wall Shock wave Diffraction Overpressure Protection

双轨道Hubbard模型的动力学平均场理论研究

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物理学报 2022年第14期71卷 235-245页

作者：倪煜孙健全亚民罗东奇宋筠北京师范大学物理系北京100875 上海科技大学物质科学与技术学院上海201210 中国科学院合肥物质科学研究院固体物理研究所材料物理重点实验室合肥230031

基于以Lanczos方法为杂质求解器的动力学平均场理论,研究了非局域轨道间跃迁对于双轨道强关联体系中轨道选择Mott相变的影响.计算了轨道间跃迁系数不同的双轨道Hubbard模型的准粒子权重和态密度,并构建了它们在相互作用强度U和轨道带宽... 详细信息

基于以Lanczos方法为杂质求解器的动力学平均场理论,研究了非局域轨道间跃迁对于双轨道强关联体系中轨道选择Mott相变的影响.计算了轨道间跃迁系数不同的双轨道Hubbard模型的准粒子权重和态密度,并构建了它们在相互作用强度U和轨道带宽比t_(2)/t_(1)影响下的相图.通过正则变换引入两个有效的退耦和轨道,在一定条件下轨道间跃迁会有利于轨道选择Mott相变的发生.还比较了Bethe晶格和正方晶格的相图,虽然基于两种不同晶格能带结构得到的轨道选择Mott相变的相变点存在一定的差异,但其中关于轨道选择Mott相变的基本物理图像具有一致性.并将方法拓展到半满的Ba_(2)CuO_(4-d)材料的研究中,与根据密度泛函理论得到的能带对比,我们发现各向同性的轨道间跃迁对能带结构影响较大,进一步采用动量空间各向异性的非局域轨道间跃迁项,得到了材料的相图,在半满条件下Ba_(2)CuO_(4-d)应为轨道选择Mott材料.

关键词：动力学平均场理论 Mott 相变双轨道 Hubbard 模型

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双间隙耦合腔中自激振荡问题的分析和模拟

强激光与粒子束 2008年第10期20卷 1699-1703页

作者：全亚民丁耀根王树忠中国科学院电子学研究所北京100190 中国科学院研究生院北京100039

建立了双间隙耦合腔中高次模式小信号电子电导计算模型,使用该模型和ISFIEL3D电磁场软件模拟的高次模式电场分布图分析了双间隙耦合腔中高次模式的自激性质。由3维粒子模拟软件对双间隙耦合腔自激模拟显示实际结构中存在高次模式3.17 GH... 详细信息

建立了双间隙耦合腔中高次模式小信号电子电导计算模型,使用该模型和ISFIEL3D电磁场软件模拟的高次模式电场分布图分析了双间隙耦合腔中高次模式的自激性质。由3维粒子模拟软件对双间隙耦合腔自激模拟显示实际结构中存在高次模式3.17 GHz和3.99 GHz自激,验证了使用该方法分析双间隙耦合腔中高次模式自激性质的合理性。并通过对热测数据的分析说明实际结构中确实存在相应的模式自激并伴随吸收腔和耦合环发热现象。

关键词：多注速调管双间隙耦合腔自激振荡高次模式电子电导

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外加载谐振腔的理论计算与分析

强激光与粒子束 2008年第5期20卷 802-806页

作者：全亚民丁耀根王树忠中国科学院电子学研究所

通过建立外加载谐振腔的等效电路模型,给出了加载以后外加载谐振腔的频率、品质因数和间隙阻抗的解析计算公式,并使用电磁场模拟软件证明了计算结果的正确性。由计算和模拟结果显示,在使用谐振腔加载的方法降低品质因数的同时,还可以利... 详细信息

通过建立外加载谐振腔的等效电路模型,给出了加载以后外加载谐振腔的频率、品质因数和间隙阻抗的解析计算公式,并使用电磁场模拟软件证明了计算结果的正确性。由计算和模拟结果显示,在使用谐振腔加载的方法降低品质因数的同时,还可以利用模式重叠进一步展宽频带。由等效电路模型分析了主腔和负载腔的品质因数、主腔和负载腔之间的频率差以及耦合口的大小对加载后谐振腔的品质因数和间隙阻抗的影响。

关键词：速凋管外加载谐振腔品质因数间隙阻抗

Constructing energetic covalent organic frameworks with high stability and low sensitivity

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Chinese Chemical Letters 2024年第3期35卷 544-548页

作者： Hui-min Guo Xiao-Yu Dong Shan Wang Qian-You Wang Shuang-quan Zang Henan Key Laboratory of Crystalline Molecular Functional Materials Green Catalysis Centerand College of ChemistryZhengzhou UniversityZhengzhou 450001China

Developing new functional explosives that display high stability,good energy performance,and low sensitivity are one of the key directions of energetic materials *** this work,two-dimensional(2D)Schiff-based energetic covalent organic frameworks(COFs)are prepared based on triaminoguanidine salts with different anions as building *** from the robust covalent bond in 2D extended polygons and strongπ-πinteractions in the eclipsed interlayers,the synthesized energetic COFs showed higher thermal stability and lower mechanical sensitivity than their precursor *** importantly,incorporating triaminoguanidine salts into COFs effectively increase the corrosion resistance to metal under high humidity conditions,which is due to the imine moieties in COFs functioning asπacceptors and offering strong bonding with metallic *** work provides a new pathway for the development of high-performance energetic materials.

关键词： Covalent organic frameworks Energetic materials High thermal stability Low sensitivity Corrosion resistance

In Situ Atomic Reconstruction Engineering Modulating Graphene-Like MXene-Based Multifunctional Electromagnetic Devices Covering Multi-Spectrum

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Nano-Micro Letters 2024年第9期16卷 247-261页

作者： Ting‑Ting Liu Qi Zheng Wen‑Qiang Cao Yu‑Ze Wang min Zhang quan‑Liang Zhao Mao‑Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China Department of Physics Beijing Technology and Business UniversityBeijing 100048People’s Republic of China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144People’s Republic of China

With the diversified development of big data,detection and precision guidance technologies,electromagnetic(EM)functional materials and devices serving multiple spectrums have become a hot *** the multispectral response of materials is a challenging and meaningful scientific *** this study,MXene/TiO_(2)hybrids with tunable conduction loss and polarization relaxation are fabricated by in situ atomic reconstruction *** importantly,MXene/TiO_(2)hybrids exhibit adjustable spectral responses in the GHz,infrared and visible spectrums,and several EM devices are constructed based on *** antenna array provides excellent EM energy harvesting in multiple microwave bands,with|S11|up to−63.2 dB,and can be tuned by the degree of *** ultra-wideband bandpass filter realizes a passband of about 5.4 GHz and effectively suppresses the transmission of EM signals in the *** infrared stealth device has an emissivity of less than 0.2 in the infrared spectrum at wavelengths of 6-14μ*** work can provide new inspiration for the design and development of multifunctional,multi-spectrum EM devices.

关键词： Graphene-like MXene hybrids Multi-spectral response Multi-function antenna Ultra-wideband bandpass filter Electromagnetic device