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Highly selective and eco-friendly dihydroisoquinoline synthesis via Cu/Co synergistic catalysis in Cu NPs@MOFs catalyst under mild conditions

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Science China Chemistry 2024年第5期67卷 1561-1568页

作者： Peng-Fei Guo Ze-long Liang Yue-E Jiao Hang xu Bin Zhao Key Laboratory of Advanced Energy Material Chemistry Renewable Energy Conversion and Storage CenterDepartment of ChemistryNankai UniversityTianjin 300071China

3,4-Dihydroisoquinoline(DHIQ)is an important precursor used in the production of drugs for treating cancer,HIV,Alzheimer's disease,*** studies on DHIQ synthesis show low catalytic selectivity due to the susceptible over-oxidation feedstock of1,2,3,4-tetrahydroisoquinoline(THIQ),which often requires alkali ***,it is desirable yet challenging to explore a highly selective and efficient oxydehydrogenation capacity for DHIQ synthesis under eco-friendly reaction ***,a novel framework 1 was synthesized,exhibiting 1D channels with the size of 4.6 A×9.6 A and high solvent/p H/thermal stability.A stable framework allows it to encapsulate Cu nanoparticles(NPs)to form Cu NPs@1-x(x=1,2,3,and 4)with varying loading amounts of Cu NPs at 2.0 wt%,3.0 wt%,4.0 wt%,and 6.0 wt%,*** NPs@1-3 could selectively catalyze the reaction from THIQ to DHIQ with a high selectivity of 98%and a recorded turnover frequency(TOF)of 22.1 h-1under eco-friendly mild *** corresponding catalytic activity can maintain at least five recyclings and can be further applied to gram-scale ***,the efficient preparation of DHIQ catalyzed by Cu NPs@1-3 could be realized even under air ***,the anticancer molecule precursor synthesis of 6,7-dimethoxy-3,4-dihydroisoquinoline was also selectively catalyzed by Cu NPs@*** investigations revealed that high catalytic performance can be attributed to the stable framework and the synergistic catalytic effect of the loaded Cu NPs and Co metal *** importantly,this work represents the first example of MOF catalysts for selectively thermo-catalytic DHIQ synthesis and demonstrates a simple approach to obtain efficient catalysts for selective oxydehydrogenation in the production of unsaturated compounds.

关键词： metal-organic frameworks Cu NPs@MOFs 3 4-dihydroisoquinoline selective oxydehydrogenation synergistic catalysis

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A 26.5–29.5-GHz Doherty PA with enhanced linearity and efficiency based on adaptive bias circuit for 5G MIMO arrays

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Science China(Information Sciences) 2024年第7期67卷 341-342页

作者： long WANG Jixin CHEN Debin HOU Xiaojie xu Wei HONG State Key Laboratory of Millimeter Waves Southeast University Misic Microelectronics Co. Ltd.

Power amplifiers (PAs) play a crucial role in achieving key performance metrics such as efficiency, power, and ***, in the millimeter-wave frequency range, the performance of active devices rapidly deteriorates with increasing frequency. The typical Doherty architecture, through load modulation techniques, can achieve high back-off efficiency [1]. To enhance the linearity of the PA, adaptive bias circuits (ADBs) have been widely adopted [2, 3].

关键词： POWER-AMPLIFIER

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Analytical libration control law for electrodynamic tether system with current constraint

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Astrodynamics 2024年第2期8卷 237-246页

作者： Shidong xu Ti Chen Hao Wen Dongping jin State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

This study focuses on stabilizing the libration dynamics of an electrodynamic tether system(EDTS)using generalized torques induced by the Lorentz *** contrast to existing numerical optimization methods,a novel analytical feedback control law is developed to stabilize the in-plane and out-of-plane motions of a tether by modulating the electric current *** saturation constraint on the current is accounted for by adding an auxiliary dynamic system to the *** enhance the robustness of the proposed controller,multiple perturbations of the orbital dynamics,modeling uncertainties,and external disturbances are approximated using a neural network in which the weighting matrix and approximation error are estimated simultaneously,such that these perturbations are well compensated for during the control design of the ***,a dynamically scaled generalized inverse is utilized to address the singular matrix in the control *** closed-loop system is proven to be ultimately bounded based on Lyapunov stability ***,numerical simulations are performed to demonstrate the effectiveness of the proposed analytical control law.

关键词： electrodynamic tether system(EDTS) libration dynamics analytical control current constraint

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New Vacuum Solar Telescope Achieves Narrowband Infrared Solar Imaging Observation at He I 10830 A

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Research in Astronomy and Astrophysics 2024年第5期24卷 76-84页

作者： Wei-Jie Meng Fang-Yu xu Zhen-Yu jin Yunnan Observatories Chinese Academy of SciencesKunming 650011China Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China University of Chinese Academy of Sciences Beijing 100049China

The near-infrared imaging channel constitutes a crucial component of the multichannel high-resolution imaging system of the New Vacuum Solar Telescope(NVST). We have successfully achieved high-resolution, narrowband imaging of the chromosphere using He I 10830 A triplet within this channel, which significantly enhances the imaging observation capabilities of NVST. This paper provides a concise overview of the optical system associated with the near-infrared imaging channel, detailing data processing procedures and presenting several observed images. Leveraging a high-resolution image reconstruction algorithm, we were able to generate a narrowband image near the diffraction limit at 10830 A with a temporal resolution of less than 10 s.

关键词： instrumentation detectors-instrumentation high angular resolution-Sun chromosphere-Sun infrared

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Regulation of interlayer channels of graphene oxide nanosheets in ultra-thin Pebax mixed-matrix membranes for CO_(2) capture

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Chinese Journal of Chemical Engineering 2024年第3期67卷 257-267页

作者： Feifan Yang Yuanhang jin Jiangying Liu Haipeng Zhu Rong xu Fenjuan Xiangli Gongping Liu Wanqin jin State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology School of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China Shandong Production and Research long Membrane Technology Development Co. Ltd.Yantai Economic Development ZoneYantai 265505China

For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective *** this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(MMMs)incorporated by graphene oxide(GO),in which the interlayer channels were regulated to optimize the CO_(2)/N_(2) separation *** membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance,including the lateral size of GO nanosheets,GO loading,thermal reduction temperature,and *** results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO_(2)-selective transport channels due to the synergetic effects of size sieving and preferential *** GO/Pebax ultra-thin MMMs exhibited CO_(2)/N_(2) selectivity of 72 and CO_(2) permeance of 400 GPU(1 GPU=106 cm^(3)(STP)·cm^(2)·s^(-1)·cmHg^(-1)),providing a promising candidate for CO_(2) capture.

关键词： Mixed-matrix membrane Ultra-thin membrane Pebax Graphene oxide CO_(2) capture

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Synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting

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Chinese Chemical Letters 2024年第2期35卷 44-56页

作者： Yan-long Ma Shi Yan Xiong-Jie xu Hua Cao Ruibing Wang School of Chemistry and Chemical Engineering and Guangdong Cosmetics Engineering & Technology Research Center Guangdong Pharmaceutical UniversityZhongshan 528458China State Key Laboratory of Quality Research in Chinese Medicine and the Institute of Chinese Medical ScienceUniversity of MacaoMacao 999078China

Due to its simplicity, high efficiency, and chemo-selectivity, bioorthogonal chemistry has shown a great application potential in ***, four bioorthogonal pairs as targeting tools, including (strept)avidin/biotin, antibody/antigen, oligonucleotide hybridization and IEDDA tools, have been developed and applied in targeted ***, all of these tools still suffer from some limitations, such as difficult modification, biochemical fragility and larger molecular weight for biological association tools, as well as chemical instability for IEDDA *** host-guest pairs with relatively small molecular sizes not only possess strong chemical stability, but also have the features of fast conjugation rate, tunable binding affinity , easy modification, and high ***, they can be used as a novel non-covalent bioorthogonal tool for *** order to further promote the development of host-guest pairs as novel bioorthogonal tools for pre-targeted delivery, we firstly calculate their conversion rate to make researcher aware of their unique advantages;next, we summarize the recent research progress in this *** future perspectives and limitations of these unique tools will be *** review will provide a systemic overview of the development of synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting, and may serve as a “go for” resort for researchers who are interested in searching for new synthetic tools to improve pre-targeting.

关键词： Bioorthogonal chemistry Synthetic host-guest pairs Pre-targeting Molecular recognition Biomedical applications

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Atomic-scale mechanism of effect of co-separation of elements at interface of ferrite and austenite on Cr-depleted zone of duplex stainless steel

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Journal of Iron and Steel Research(International) 2024年第3期31卷 710-718页

作者： Yan-hui Hou Ze-kun xu Shi-long Zhou Guang-qiang Li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Three-dimensional atom-probe tomography and first-principles calculation combined with density functional theory were used to study the effect of the co-segregation of different elements formed during the solidification process of S32205 duplex stainless steel on the Cr-depleted zone at the interface between ferrite and *** was found that the co-segregation of different elements formed during the solidification process of duplex stainless steel can also form Cr-depleted zone at the interface between ferrite and ***,Mo,Si,B,C and P atoms promote co-segregation with Cr atoms,which promotes the formation of Cr-depleted zone at the interface between ferrite and austenite in duplex stainless *** and Si strongly promote the segregation of Cr at the interface between ferrite and austenite,thereby promoting the formation of Cr-depleted zone.B,C and P elements also promote the segregation of Cr element at the interface between ferrite and austenite and the formation of Cr-depleted zone,but their effect is weaker than that of Mo and Si *** conclusions provide a new theoretical basis for improving the intergranular corrosion performance of duplex stainless steel.

关键词： Duplex stainless steel Cr-depleted zone Intergranular corrosion Co-segregation First-principles calculation

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Real-time Abnormal Detection of GWAC Light Curve based on Wavelet Transform Combined with GRU-Attention

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Research in Astronomy and Astrophysics 2024年第5期24卷 151-168页

作者： Hao Li Qing Zhao long Shao Tao Liu Chenzhou Cui Yunfei xu College of Artifcial Intelligence Tianjin University of Science and TechnologyTianjin 300457China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

Nowadays, astronomy has entered the era of Time-Domain Astronomy, and the study of the time-varying light curves of various types of objects is of great significance in revealing the physical properties and evolutionary history of celestial bodies. The Ground-based Wide Angle Cameras telescope, on which this paper is based, has observed more than 10 million light curves, and the detection of anomalies in the light curves can be used to rapidly detect transient rare phenomena such as microgravity lensing events from the massive data. However, the traditional statistically based anomaly detection methods cannot realize the fast processing of massive data. In this paper, we propose a Discrete Wavelet(DW)-Gate Recurrent Unit-Attention(GRU-Attention) light curve warning model. Wavelet transform has good effect on data noise reduction processing and feature extraction, which can provide richer and more stable input features for a neural network, and the neural network can provide more flexible and powerful output model for wavelet transform. Comparison experiments show an average improvement of 61% compared to the previous pure long-short-term memory unit(LSTM) model, and an average improvement of 53.5% compared to the previous GRU model. The efficiency and accuracy of anomaly detection in previous paper work are not good enough, the method proposed in this paper possesses higher efficiency and accuracy,which incorporates the Attention mechanism to find out the key parts of the light curve that determine the anomalies. These parts are assigned higher weights, and in the actual anomaly detection, the star is detected with83.35% anomalies on average, and the DW-GRU-Attention model is compared with the DW-LSTM model, and the detection result f1 is improved by 5.75% on average, while having less training time, thus providing valuable information and guidance for astronomical observation and research.

关键词： methods data analysis-stars variables general-techniques photometric

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Phase separation of GRP7 facilitated by FERONIAmediated phosphorylation inhibits mRNA translation to modulate plant temperature resilience

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Molecular Plant 2024年第3期17卷 460-477页

作者： Fan xu long Wang Yingbin Li Junfeng Shi Dorothee Staiger Feng Yu state Key Laboratory of Chemo/Biosensing and Chemometrics College of Biologyand Hunan Key Laboratory of Plant Functional Genomics and Developmental RegulationHunanUniversityChangsha 410082P.R.China State Key Laboratory of Hybrid Rice Hunan Agricultural Biotechnology Research InstituteHunan Academy of Agricultural SciencesChangsha 410125P.R.China RNA Biology and Molecular Physiology Faculty of BiologyBielefeld University33615 BielefeldGermany

Changes in ambient temperature profoundly affect plant growth and ***,the molecu-larbasis of plant acclimation to temperature fluctuation is of great *** this study,we discovered that GLYCINE-RICH RNA-BINDING PROTEIN 7(GRP7)contributes to cold and heat tolerance in Arabidopsis *** found that exposure to a warm temperature rapidly induces GRP7 condensates in planta,which can be reversed by transfer to a lower *** biology and biochemical assays revealed that GRP7 undergoes liquid-liquid phase separation(LLPS)in vivo and in *** of GRP7 in the cyto-plasm contributes to the formation of stress granules that recruit RNA,along with the translation machinery component eukaryotic initiation factor 4E1(elF4E1)and the mRNA chaperones COLD SHOCK PROTEIN 1(CSP1)and CSP3,to inhibit ***,natural variations in GRP7 affecting the residue phos-phorylated by the receptorkinase FERONIA alter its capacity to undergo LLPS and correlate with the adap-tation of some Arabidopsis accessions to a widertemperature *** together,ourfindings illustrate the role of translational control mediated by GRP7 LLPS to confer plants with temperature resilience.

关键词： fluctuating temperature glycine-rich RNA-binding protein phase separation cold shock proteins translation

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Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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Nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao jin-Hui Chen xu-Guang Huang Yu-Gang Ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

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