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Double [5]carbohelicene: facile synthesis, chiroptical properties,isomerization study, and lasing application

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Science China Chemistry 2025年第1期68卷 233-240页

作者： Peipei Liu yantong Li Meng-Xiang Wu Hao Kang Xiao-Li Zhao Lin Xu Linlin Liu Xiaodong Li Junfeng fang Zhiwei fang ya Cheng Hai-Bo yang Huakang Yu Xueliang Shi State Key Laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University School of Physics and Optoelectronics South China University of Technology Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology School of Physics and Electronic Science Engineering Research Center of Nanophotonics & Advanced Instrument Ministry of EducationEast China Normal University State Key Laboratory of Precision Spectroscopy School of Physics and Electronic Science East China Normal University

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double[5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by Xray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase highperformance liquid chromatography（HPLC）, and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 m J cm-2. We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

关键词： double carbohelicene optical resolution organic laser isomerization X-ray diffraction

A versatile synthetic strategy towards rare earth based metal-organic frameworks

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Science China Chemistry 2025年

作者： quan Shi Yun-Hao Xu Ming-Hui Chen Peng Zhao Wen-Bo Deng Ji Xiong Kai Guo ya-Qing Feng Bao Zhang School of Chemical Engineering and Technology Tianjin University Tianjin Collaborative Innovation Center of Chemical Science and Engineering Guangdong Laboratory Chemistry & Fine Chemical Industry Jieyang Center

Rare earth metal-organic frameworks (RE-MOFs) have drawn wide attention owing to diverse network structures and various application ***,due to the unpredictable formation of the nodes,it is still challenging to design novel RE-MOFs.A novel versatile strategy was developed employing a RE-acetate complex (RE2(CH3COO)6·4H2O) as a precursor to construct RE-MOFs.2D RE-MOFs (RE-DBP) and 3D RE-MOFs (RE-TCPP) could be obtained by using dicarboxylic porphyrin ligands H2DBP and tetracarboxylic porphyrin ligands H2TCPP,*** RE-MOFs were further synthesized to verify the universality of the *** crystalline RE-MOFs could also be prepared at room temperature via the developed strategy,which could significantly promote large-scale preparation and practical application of *** proof of the concept,the performance of porphyrin-based RE-MOFs was investigated in the photocatalytic cycloaddition of CO2with *** the RE-DBP(Co) MOFs,Tb-DBP(Co) exhibited the best photocatalytic performance,which was also greater than that of the corresponding 3D MOF Tb-TCPP(Co) due to the optimal 2D structure and thus the accelerated photogenerated charge separation and transfer *** work not only provides a novel versatile strategy to design and develop RE-MOFs,but also proposes a promising approach for the potential bulk production of RE-MOFs at room temperature.

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Positive effect of Mo on mechanical properties of a Ni-42W-10Co-x Mo medium heavy alloy

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China Foundry 2025年

作者： Guo-xin Cao Jian-xin Dong Yong-sheng He He Jiang fang Hao Zhi-hua Nie Teng-fei Ma Bao-quan Fu School of Materials Science and Engineering University of Science and Technology Beijing Xi'an Superalloy Technology Co. Ltd. School of Materials Science and Engineering Beijing Institute of Technology Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou University

In this study,a novel Ni-W-Co-Mo medium heavy alloy (MHA) was designed to improve its mechanical strength via Mo *** the Ni-42W-10Co-xM o alloy series,where x represents the weight percent of Mo and varies between 0,1,2,5,and 10,the microstructure transitions from a dendritic structure to a hypoeutectic structure as the Mo content increases from 0 to 5wt.%.Moreover,as the Mo content increases from 0to 10wt.%,the distribution of theμ-phase shifts from being individually dispersed to forming aggregates,and its volume fraction rises from 0.5%to 7.9%.Notably,theμ-phase evolves into an eutectic microstructure,which helps in minimizing the segregation of *** change is accompanied by a substantial enhancement in mechanical properties;specifically,the compressive yield strength at room temperature increases from 350 MPa to 646 MPa,indicating a significant 85%***,the microhardness increases from 230 HV to 304 *** dynamics simulations further reveal that the strengthening mechanism of Ni-42W-10Co-xM o alloys is Mo-induced solid solution strengthening and precipitation strengthening.

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主体结构荷载可控的新型组合式防护结构(Ⅱ):影响因素及设计理念

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爆炸与冲击 2025年第1期45卷 16-27页

作者：方秦高矗孔祥振杨亚陆军工程大学爆炸冲击防灾减灾国家重点实验室江苏南京210007 内蒙古财经大学财政税务学院内蒙古呼和浩特010070

为明确泡沫混凝土厚度和强度对组合式防护结构抗爆性能的影响,充分发挥和合理利用泡沫混凝土良好的消波特性,首先通过试验及数值模拟探讨不同泡沫混凝土厚度和强度对组合式防护结构抗爆性能的影响,并分析分层梯度泡沫混凝土在爆炸波作... 详细信息

为明确泡沫混凝土厚度和强度对组合式防护结构抗爆性能的影响,充分发挥和合理利用泡沫混凝土良好的消波特性,首先通过试验及数值模拟探讨不同泡沫混凝土厚度和强度对组合式防护结构抗爆性能的影响,并分析分层梯度泡沫混凝土在爆炸波作用下的消波特性。然后将组合式防护结构与采用中粗砂为分配层的传统成层式结构进行对比分析验证其优越性,在此基础上,总结凝练出组合式防护结构的主体结构荷载可控的设计理念。结果表明,利用泡沫混凝土材料较长的屈服平台和较低的波阻抗,以泡沫混凝土作为能量调控层,通过设计泡沫混凝土强度等级(密度等级)和厚度以及采用多层梯度泡沫混凝土,可使得作用于主体结构上的爆炸荷载峰值恰为泡沫混凝土屈服强度,实现对主体结构上荷载的可控设计,有效解决了中粗砂为分配层的传统成层式结构不易控制作用于主体结构上荷载的问题。研究结果可为抗新型钻地弹的防护设计提供重要参考。

关键词：泡沫混凝土组合式防护结构可控设计爆炸波消波

Fully enclosed hybrid electromagnetic-triboelectric nanogenerator to scavenge vibrational energy

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Nano Research 2016年第8期9卷 2226-2233页

作者： Ting quan ya yang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology Beijing 100083 China

We propose a fully enclosed hybrid nanogenerator consisting of five elec- tromagnetic generators （EMGs） and four triboelectric nanogenerators （TENGs）. Under a vibration frequency of 15.5 Hz, one TENG can deliver a high output voltage of approximately 24 V and a low output current of approximately 24 μA, whereas one EMG can deliver a low output voltage of approximately 0.8 V and a high output current of approximately 0.5 mA. By integrating five rectified EMGs in series and four rectified TENGs in parallel, the hybrid nanogenerator can be used to charge a home-made Li-ion battery from 1 to 1.9 V in 6.3 h. By using the hybrid nanogenerator to scavenge the vibrational energy produced by human hands, a temperature-humidity sensor can be sustainably powered by the nanogenerator, which is capable of charging the 200 ~F system power capacitor from 0 to 2 V in 15 s, and sustainably power the sensor in 29 s.

关键词： hybrid nanogenerator electromagnetic triboelectric vibration energy Li-ion battery

双轴应变对NbSe_(2)/MoSi_(2)N_(4)肖特基势垒的调控

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原子与分子物理学报 2025年第5期42卷 182-188页

作者：张宇哲安梦雅谢泉贵州大学大数据与信息工程学院新型光电子材料与技术研究所贵阳550025

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中... 详细信息

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中,构建了金属-半导体NbSe_(2)/MSN肖特基结并使用第一性原理密度泛函理论计算研究了该肖特基结的材料特性.发现NbSe_(2)/MSN接触具有超低肖特基势垒高度(Schottky barrier height,SBH),这有利于纳米电子学应用.SBH可以通过施加双轴应变的方式进行有效的调控.当施加拉伸应变时能实现NbSe_(2)/MSN肖特基结由p型肖特基接触转变为p型欧姆接触,而当施加较大的压缩应变时能实现p型肖特基接触和n型肖特基接触之间的转换.我们的研究结果为MSN的2D电触点的物理特性提供了见解,并将为设计基于MSN的2D纳米器件的高性能电触点提供关键的一步.

关键词： MoSi_(2)N_(4) NbSe_(2) 肖特基结欧姆接触

Relativistic Calculation of Dielectronic Recombination on the C4^(+) Ground State

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Chinese Physics Letters 2001年第6期18卷 761-763页

作者： LIU Yong ZOU Yu fang quan-Yu XU ya-Qiong Institute of Applied Physics and Computational Mathematics P.O.Box 8009Beijing 100088 Center of Atomic and Molecular Science Tsinghua UniversityBeijing 100084 Institute of Physics Chinese Academy of SciencesBeijing 100080

The relativistic multichannel theory has been applied and a nonperturbative formula adopted to calculate the dielectronic recombination cross section due toΔN=1 resonances for the ground state C4^(+).The first-order approximation is adopted for the radiative process and a correction based on the isolated resonance approximation is used for the very narrow resonances to include the radiation *** convoluted cross section is in agreement within 5%with that of observation for resonances with n≤*** n=6 and 7,the integral cross section is overestimated by a factor of 6 and 4,*** to our calculation,the Rydberg cut-off due to field ionization should be at a principal quantum number higher than that given by Mannervik et al.A Small relativistic effect is noticed at intrashell resonance.

关键词： relativistic approximation correction

Chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin

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Journal of Environmental Sciences 2009年第12期21卷 1710-1715页

作者： WANG Cui CHEN fang ZHANG quan fang Zhuo College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China College of Environmental Science and Engineering Zhejiang Gongshang University Hangzhou 310035 China

With the increasing use of synthetic pyrethroids （SPs）, the significance of ecological safety and health risk is an emerging concern, In this study, we evaluated the chronic aquatic toxicity of eis-bifenthrin （cis-BF） in Daphnia magna and its cytotoxicity in Chinese hamster ovary （CHO） cells as well as human cervical carcinoma （Hela） ceils. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 μg/L, respectively, and the chronic value was 0.014 μg/L. The intrinsic rate of natural increase was significantly decreased （p 〈 0.05） to 0.02 μg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration- and time-dependent manner. The IC50 values for Hela and CHO cells were 4.0 × 10^-5 and 3.2 × 10^-5 mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.

关键词： cis-bifenthrin Daphnia magna chronic toxicity cytotoxicity

The Global Well-posedness of Strong Solutions to 2D MHD Equations in Lei-Lin Space

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Acta Mathematicae Applicatae Sinica 2023年第3期39卷 647-655页

作者： Bao-quan YUAN ya-min XIAO School of Mathematics and Information Science Henan Polytechnic UniversityJiaozuo 454000China

In this paper, we study the Cauchy problem of the 2D incompressible magnetohydrodynamic equations in Lei-Lin space. The global well-posedness of a strong solution in the Lei-Lin space χ^(-1)(R^(2)) with any initial data in χ^(-1)(R^(2)) ∩ L^(2)(R^(2)) is established. Furthermore, the uniqueness of the strong solution in χ^(-1)(R^(2)) and the Leray-Hopf weak solution in L^(2)(R^(2)) is proved.

关键词： 2D MHD equations strong solutions Lei-Lin space weak-strong uniqueness