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Science China Chemistry 2022年第10期65卷 1945-1952页

作者： Kun Yao Zheng Liu Hang Li Dan Xu Wen-Hua Zheng yi-Wu Quan yi-xiang cheng Jiangsu Key Laboratory of Advanced Organic Materials School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education Department of Polymer Science and EngineeringSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

We report the rational design of a dual stimulus-activated quaternary chiral emission nematic liquid crystals(Q-N*-LCs)containing light-driven chiral dopant R-S-R-1,a static chiral dopant S-2 and an achiral Nile Red(NR)in a nematic liquid crystal(SLC1717).The dopant R-S-R-1 acts as a dynamic chiral donor and an energy donor,and the achiral NR serves as a circularly polarized luminescence(CPL)emitter and energy ***,this kind of Q-N*-LCs appears reversal CPL emission direction(L-CPL)using 365 nm UV light irradiation compared with the initial state(R-CPL).Most importantly,the“On-Off”CPL switch behavior of Q-N*-LCs can be repeatedly driven by revoking or rearranging the applied direct current(DC)electric *** OR chiral information logic gate demonstrates that this dual driven Q-N*-LCs can be potentially used for chiral information storage and coding.

关键词： chiral supramolecular liquid crystals circularly polarized luminescence light and electricity dual stimuli-activated Förster resonance energy transfer

Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： yi-Cong Wang Hui Zhat Pei-yi cheng Shu Zhang xiang-Wei Liu yi-Xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu Wei Zhang Peng-yue Wang yi-xian Liu xiang-yi Jiao Ao-xiang Wan cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property

Astrometric Observations of NEA 1998 HH49 Using the Daocheng 50 cm Telescope

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Research in Astronomy and Astrophysics 2024年第7期24卷 74-81页

作者： Huan Xu xiang-Ming cheng yi-Gong Zhang Teng-Fei Song Zhen-Jun Zhang Qing-Yu Peng Yunnan Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Engineering Laboratory on Applied Astronomical Technology of Yunnan School of Information Engineering Kunming University School of Computer Science and Information Engineering Anyang Institute of Technology Department of Computer Science Jinan University Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan University

This study details an astrometric observation campaign of the Near-Earth Asteroid 1998 HH49, conducted with the aim of refining our understanding of its physical characteristics. Utilizing the 50 cm telescope located at the Wumingshan Mountain in Daocheng, Sichuan, images were obtained over four nights, from 2023 October 19 to October 22. These observations were processed using Astrometrica software, facilitating the precise determination of the asteroid's position. The observational results were compared with the ephemerides from three distinct sources to verify accuracy: the Jet Propulsion Laboratory(JPL) Horizons System, the Institut de Mécanique Céleste et de Calcul des éphémérides(IMCCE) Miriade, and the Near-Earth Objects Dynamic Site(NEODyS-2).When compared with the JPL ephemeris, a mean observed-minus-calculated(O-C) result of 0.''07 in the *** and-0.''35 in the decl. direction was yielded. Furthermore, the comparison with the IMCCE ephemeris yielded mean O-C results of 0.''08 in the R.A. direction and-0.''06 in the decl. direction. The comparison with the NEODyS-2 ephemeris yielded the mean O-C results of 0.''06 in R.A. and-0.''49 in decl. direction. The study's findings demonstrate a general consistency between the observed data and the ephemeris predictions, with minor discrepancies observed across the data sets. Notably, both the JPL and NEODyS-2 ephemerides show that the residuals in the decl. direction exceed those in the R.A. direction. The disparities may result from atmospheric differential color refraction, ephemeris discrepancies, observational errors, and other factors. Additionally, it is worth noting that further investigation is required due to the potential influence of additional factors. Overall, the Daocheng 50 cm Telescope exhibits the ability to conduct high-precision positional measurements.

关键词： astrometry ephemerides time

Root-derived long-distance signals trigger ABA synthesis and enhance drought resistance in Arabidopsis

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Journal of Genetics and Genomics 2024年第7期51卷 749-761页

作者： Qian-Qian Liu Jin-Qiu Xia Jie Wu yi Han Gui-Quan Zhang Ping-Xia Zhao cheng-Bin xiang Division of Life Sciences and Medicine Division of Molecular&Cell BiophysicsHefei National Science Center for Interdisciplinary Sciences at the MicroscaleUniversity of Science and Technology of ChinaThe Innovation Academy of Seed DesignChinese Academy of SciencesHefeiAnhui 230027China College of Life Sciences Anhui Agricultural UniversityHefeiAnhui 230036China College of Agronomy South China Agricultural UniversityGuangzhouGuangdong 510642China School of Biology and Basic Medical Sciences Soochow UniversitySuzhouJiangsu 215123China

Vascular plants have evolved intricate long-distance signaling mechanisms to cope with environmental stress,with reactive oxygen species(ROS)emerging as pivotal systemic signals in plant stress ***,the exact role of ROS as root-to-shoot signals in the drought response has not been *** this study,we reveal that compared with wild-type plants,ferric reductase defective 3(frd3)mutants exhibit enhanced drought resistance concomitant with elevated NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3(NCED3)transcript levels and abscisic acid(ABA)contents in leaves as well as increased hydrogen peroxide(H_(2)O_(2))levels in roots and *** experiments distinctly illustrate that drought resistance can be conferred by the frd3 rootstock regardless of the scion genotype,indicating that long-distance signals originating from frd3 roots promote an increase in ABA levels in ***,the drought resistance conferred by the frd3 mutant rootstock is weakened by the CAT2-overexpressing scion,suggesting that H_(2)O_(2)may be involved in long-distance ***,the results of comparative transcriptome and proteome analyses support the drought resistance phenotype of the frd3 *** together,our findings substantiate the notion that frd3 root-derived long-distance signals trigger ABA synthesis in leaves and enhance drought resistance,providing new evidence for root-to-shoot long-distance signaling in the drought response of plants.

关键词： frd3 Drought resistance Root-to-shoot long-distance signals Reactive oxygen species(ROS) H_(2)O_(2) Iron ABA

PDCD2 as a prognostic biomarker in glioma correlates with malignant phenotype

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Genes & Diseases 2024年第5期11卷 390-406页

作者： Fengsheng Dai yixiao Yuan Jiaqi Hao Xing cheng xiangyi Zhou Li Zhou Rui Tian yi Zhao Tingxiu xiang Department of Oncology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400010China Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment Chongqing University Cancer HospitalChongqing 400030China Department of Neurosurgery Xiangya HospitalCentral South UniversityChangshaHunan 410008China Hunan International Scientific and Technological Cooperation Base of Brain Tumor Research Xiangya HospitalCentral South UniversityChangshaHunan 410008China Department of Neuro-Oncology Chongqing University Cancer HospitalChongqing 400030China

Programmed cell death 2(PDCD2)is related to cancer progression and chemotherapy *** role of PDCD2 in solid cancers(excluding hematopoietic malignancies)and their diagnosis and prognosis remains *** TCGA,CGGA,GEPIA,cBioPortal,and GTEx databases were analyzed for expression,prognostic value,and genetic modifications of PDCD2 in cancer *** enrichment analysis,CCK8,colony formation assay,transwell assay,and xenograft tumor model were undertaken to study the PDCD2’s biological function in glioma(GBMLGG).The PDCD2 gene was associated with solid cancer *** the functional enrichment analysis results,PDCD2 was shown to participate in several important GBMLGG biological *** cells may be inhibited in their proliferation,migration,invasion,and xenograft tumor growth by knocking down *** research can provide new insights into solid cancer prognostic biomarkers of PDCD2.

关键词： Biomarker Glioma Programmed cell death 2 Progression Solid cancer

Reinforcing oxygen electrocatalytic activity via selective dualphase heterointerface engineering for rechargeable Zn-air batteries

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Rare Metals 2024年第4期43卷 1524-1536页

作者： Chao cheng Chuang Zhi Zhong-Ti Sun Yong-Qiang Ming Ting-Ting xiang Qing-Chao Zhu Zi-Rui Wu Bing Li yi Li cheng Jin Yong Cao Juan Yang School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming650093China

Dual-phase heterointerface electrocatalysts(DPHE)constructed by oxygen reduction reaction(ORR)-and oxygen evolution reaction(OER)-active elements exhibit excellent bifunctional activity and long-term durability due to the abundant interface exposure and synergistic catalytic ***,low-dimensional N-doped graphene nanoribbons(N-GNRs)coupling with ultrathin CoO nanocomposites(N-GNRs/CoO)were controllably fabricated through a facile two-step approach using synthesized Co(OH)_2 nanosheet as CoO *** functional theory(DFT)calculations and experimental characterizations prove that the formation of interface between N-GNRs and CoO can induce local charge redistribution,contributing to the improvement of catalytic activity and *** optimal N-GNRs/CoO DPHE possesses hierarchically porous architectures and presents outstanding bifunctional activities with a small potential gap of 0.729 V between the potential at 10 mA·cm^(-2)for OER and the halfwave potential for ORR,which outperforms Pt/C+IrO_(2)and the majority of noble-metal-free bifunctional ***-and solid-state rechargeable Zn-air batteries assembled with N-GNRs/CoO as the cathode also display high peak power density and fantastic cycle stability,superior to that of benchmark Pt/C+IrO_(2)*** is anticipated to offer significant benefits toward high activity,stability and mechanical flexibility bifunctional oxygen electrocatalysts for rechargeable Zn-air batteries.

关键词： Interface engineering Graphene nanoribbons CoO Bifunctional electrocatalyst Zn-air batteries

Ytterbium modified birnessite MnO_(2) for improving deep oxidation of toluene

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Journal of Rare Earths 2024年第4期42卷 668-675页

作者： Linjiang Sun Yan cheng Yujie Liu Can yi Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu611756China

A series of rare earth metals modified birnessite manganese dioxides(RE-Mn)was synthesized by hydrothermal method and their catalytic degradation of toluene was ***-Mn shows the best toluene oxidation activity with the conversion of T50%and T99%at 196 and 226℃,*** physiochemical characterizations identified that the high catalytic performance and excellent stability of Yb-Mn are mainly associated with its higher molar ratios of Mn^(4+)/Mn^(3+),more lattice oxygen(Olatt),and better mobility of surface adsorbed oxygen(O_(ads)).Moreover,it is confirmed that introduction of Yb into birnessite MnO_(2) facilitates the production of acetic acid at lower *** results can aid the design of high-efficiency manganese oxide catalysts for the catalytic combustion of VOCs.

关键词： Manganese oxide Rare earth metal doping Toluene Catalytic combustion

Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

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Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua cheng yi He Xiaohe Liu Chi He Department of Environmental Engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

Coarse-fine joint target parameter estimation method based on AN-RSC in OFDM passive radar

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Journal of Systems Engineering and Electronics 2024年第2期35卷 339-349页

作者： WANG Chujun WAN Xianrong yi Jianxin cheng Feng School of Electronic Information Wuhan UniversityWuhan 430072China

In this paper,we study the accuracy of delay-Doppler parameter estimation of targets in a passive radar using orthogonal frequency division multiplexing(OFDM)signal.A coarse-fine joint estimation method is proposed to achieve better estimation accuracy of target parameters without excessive computational ***,the modulation symbol domain(MSD)method is used to roughly estimate the delay and Doppler of ***,to obtain high-precision Doppler estimation,the atomic norm(AN)based on the multiple measurement vectors(MMV)model(MMV-AN)is used to manifest the signal sparsity in the continuous Doppler *** the same time,a reference signal compensation(RSC)method is presented to obtain highprecision delay *** results based on the OFDM signal show that the coarse-fine joint estimation method based on AN-RSC can obtain a more accurate estimation of target parameters compared with other *** addition,the proposed method also possesses computational advantages compared with the joint parameter estimation.

关键词： passive radar orthogonal frequency division multiplexing(OFDM)signal atomic norm(AN) parameter estimation