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An Empirical Study on the Reflective Feedback Model Based on Pedagogical Agents to Improve Students’ Problem-Solving Ability 被引量:1
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作者 Hui-Lin Zhang Jun-Jie Yan +4 位作者 Jing Liu Zhuo-Cen Zou Qun-Fang Zeng Yu-Lu Jin Jian-Nan Wu 《教育技术与创新》 2025年第1期66-75,共10页
This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with ... This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with 84 students from a middle school selected as the research subjects(44 in the experimental group and 40 in the control group).The experimental group used the reflective feedback model,while the control group used the factual feedback model.The results show that,compared with factual feedback,the reflective feedback model based on the pedagogical agent significantly improves students’problem-solving ability,especially at the action and thinking levels.In addition,this model effectively reduces students’cognitive load,especially in terms of internal and external load. 展开更多
关键词 pedagogical agent problem-solving ability reflective feedback
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Improving Complex Problem-Solving in Emergency Response:A Study of the Fire and Rescue Service in Sweden
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作者 Lotta Vylund Joel Jacobsson +1 位作者 Tove Frykmer Kerstin Eriksson 《International Journal of Disaster Risk Science》 CSCD 2024年第6期867-878,共12页
This study explored how the Swedish Fire and Rescue Service identifies problems and implements necessary actions during complex problem-solving in emergencies,aiming to increase our understanding of this process.Prima... This study explored how the Swedish Fire and Rescue Service identifies problems and implements necessary actions during complex problem-solving in emergencies,aiming to increase our understanding of this process.Primary and secondary data from large-scale fire events were analyzed,including semistructured interviews and incident reports.The concept of“possibility space”is applied to identify factors aff ecting complex problem-solving.This refers to the scope of action available at a specific point in time for a particular operation.The study identified eight factors,including problem identification,incident development,capability,collaboration,management,legal framework,logistics,and time available,that could either decrease or increase the scope of action.The findings contribute to an increased understanding of complex problem-solving in real-world environments and suggest that the possibility space could be a valuable tool for practitioners in enhancing problem-solving during emergency response. 展开更多
关键词 Emergency response Fire and Rescue Service Possibility space problem-solving Problem space Sweden
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Copper complexes of anthrahydrazone bearing pyridyl side chain:Synthesis,crystal structure,anticancer activity,and DNA binding 被引量:1
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作者 HUANG Yao WU Yingshu +5 位作者 BAO Zhichun HUANG Yue TANG Shangfeng LIU Ruixue LIU Yancheng LIANG Hong 《无机化学学报》 北大核心 2025年第1期213-224,共12页
To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bisp... To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects,the new anthraquinone derivatives,9‑pyridylanthrahydrazone(9‑PAH)and 9,10‑bispyridylanthrahydrazone(9,10‑PAH)were designed and synthesized.Utilizing 9‑PAH and 9,10‑PAH as promising anticancer ligands,their respective copper complexes,namely[Cu(L1)Cl_(2)]Cl(1)and{[Cu_(4)(μ_(2)‑Cl)_(3)Cl_(4)(9,10‑PAH)_(2)(DMSO)_(2)]Cl_(2)}_(n)(2),were subsequently synthesized,where the new ligand L1 is formed by coupling two 9‑PAH ligands in the coordination reaction.The chemical and crystal structures of 1 and 2 were elucidated by IR,MS,elemental analysis,and single‑crystal X‑ray diffraction.Complex 1 forms a mononuclear structure.L1 coordinates with Cu through its three N atoms,together with two Cl atoms,to form a five‑coordinated square pyramidal geometry.Complex 2 constitutes a polymeric structure,wherein each structural unit centrosymmetrically encompasses two five‑coordinated binuclear copper complexes(Cu1,Cu2)of 9,10‑PAH,with similar square pyramidal geometry.A chlorine atom(Cl_(2)),located at the symmetry center,bridges Cu1 and Cu1A to connect the two binuclear copper structures.Meanwhile,the two five‑coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom,respectively,thus forming a 1D chain‑like polymeric structure.In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin.Specifically,the IC_(50)values of 2 against HeLa‑229 and SK‑OV‑3 cancer cell lines were determined to be(5.92±0.32)μmol·L^(-1)and(6.48±0.39)μmol·L^(-1),respectively.2 could also block the proliferation of HeLa‑229 cells in S phase and significantly induce cell apoptosis.In addition,fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode,offering insights into its underlying anticancer mechanism.CCDC:2388918,1;2388919,2. 展开更多
关键词 anthrahydrazone metal complex crystal structure anticancer activity cell apoptosis
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Data-Driven Prediction in Complex Systems of Virus Evolution and Global Warming 被引量:1
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作者 LUO Liaofu LÜJun 《内蒙古大学学报(自然科学版)》 2025年第1期1-7,共7页
A complex system is inherently high-dimensional.Recent studies indicate that,even without complete knowledge of its evolutionary dynamics,the future behavior of such a system can be predicted using time-series data(da... A complex system is inherently high-dimensional.Recent studies indicate that,even without complete knowledge of its evolutionary dynamics,the future behavior of such a system can be predicted using time-series data(data-driven prediction).This suggests that the essential dynamics of a complex system can be captured through a low-dimensional representation.Virus evolution and climate change are two examples of complex,time-varying systems.In this article,we show that mutations in the spike protein provide valuable data for predicting SARS-CoV-2 variants,forecasting the possible emergence of the new macro-lineage Q in the near future.Our analysis also demonstrates that carbon dioxide concentration is a reliable indicator for predicting the evolution of the climate system,extending global surface air temperature(GSAT)forecasts through 2500. 展开更多
关键词 data-drivenprediction complex system virus evolution global warming
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Exploring the Effects of Background Image Complexity and Map Symbol Load on the Usability of Image-maps 被引量:1
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作者 PENG Qian XIA Yuxin QIU Zeren 《Journal of Geodesy and Geoinformation Science》 2025年第2期5-20,共16页
Image-maps,a hybrid design with satellite images as background and map symbols uploaded,aim to combine the advantages of maps’high interpretation efficiency and satellite images’realism.The usability of image-maps i... Image-maps,a hybrid design with satellite images as background and map symbols uploaded,aim to combine the advantages of maps’high interpretation efficiency and satellite images’realism.The usability of image-maps is influenced by the representations of background images and map symbols.Many researchers explored the optimizations for background images and symbolization techniques for symbols to reduce the complexity of image-maps and improve the usability.However,little literature was found for the optimum amount of symbol loading.This study focuses on the effects of background image complexity and map symbol load on the usability(i.e.,effectiveness and efficiency)of image-maps.Experiments were conducted by user studies via eye-tracking equipment and an online questionnaire survey.Experimental data sets included image-maps with ten levels of map symbol load in ten areas.Forty volunteers took part in the target searching experiments.It has been found that the usability,i.e.,average time viewed(efficiency)and average revisits(effectiveness)of targets recorded,is influenced by the complexity of background images,a peak exists for optimum symbol load for an image-map.The optimum levels for symbol load for different image-maps also have a peak when the complexity of the background image/image map increases.The complexity of background images serves as a guideline for optimum map symbol load in image-map design.This study enhanced user experience by optimizing visual clarity and managing cognitive load.Understanding how these factors interact can help create adaptive maps that maintain clarity and usability,guiding AI algorithms to adjust symbol density based on user context.This research establishes the practices for map design,making cartographic tools more innovative and more user-centric. 展开更多
关键词 remote sensing image map point label complexity
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Zircon U-Pb-Hf and Trace Element Signatures Reveal the Petrogenesis of the Jiuyishan Granitic Complex,South China:Implications for W-Sn and Rare Metal Mineralization 被引量:1
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作者 Wenzhou Xiao Chaoyun Liu +6 位作者 Kaixuan Tan Xianzhe Duan Qinglin Sui Kaituo Shi Peng Feng Mabrouk Sami Quan Ou 《Journal of Earth Science》 2025年第3期1069-1089,共21页
The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,... The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex. 展开更多
关键词 Jiuyishan granitic complex ZIRCON fractionation geochemistry rare metal mineralization
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A phenylphenthiazide anchored Tb(Ⅲ)-cyclen complex for fluorescent turn-on sensing of ClO^(-) 被引量:1
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作者 Ya-Ping Liu Zhi-Rong Gui +4 位作者 Zhen-Wen Zhang Sai-Kang Wang Wei Lang Yanzhu Liu Qian-Yong Cao 《Chinese Chemical Letters》 2025年第2期269-273,共5页
A phenylphenothiazine anchored Tb(Ⅲ)-cyclen complex PTP-Cy-Tb for hypochlorite ion(ClO^(-))detection has been designed and prepared.PTP-Cy-Tb shows a weak Tb-based emission with AIE-characteristics in aqueous solutio... A phenylphenothiazine anchored Tb(Ⅲ)-cyclen complex PTP-Cy-Tb for hypochlorite ion(ClO^(-))detection has been designed and prepared.PTP-Cy-Tb shows a weak Tb-based emission with AIE-characteristics in aqueous solutions.After addition of ClO^(-),the fluorescence of PTP-Cy-Tb gives a large enhancement for oxidization the thioether to sulfoxide group.The detection limit of PTP-Cy-Tb toward ClO^(-)is as low as 8.85 nmol/L.The sensing mechanism was detailedly investigated by time of flight mass spectrometer(TOF-MS),Fourier transform infrared spectroscopy(FT-IR)and density functional theory(DFT)calculation.In addition,PTP-Cy-Tb has been successfully used for on-site and real-time detection of ClO^(-)in real water samples by using the smartphone-based visualization method and test strips. 展开更多
关键词 Phenylphenothiazine Tb(III)complex AIE Hypochlorite ion SENSING
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A mitochondria targeting Ir(Ⅲ)complex triggers ferroptosis and autophagy for cancer therapy:A case of aggregation enhanced PDT strategy for metal complexes 被引量:1
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作者 Panpan Wang Hongbao Fang +5 位作者 Mengmeng Wang Guandong Zhang Na Xu Yan Su Hongke Liu Zhi Su 《Chinese Chemical Letters》 2025年第1期374-380,共7页
Metal complexes hold significant promise in tumor diagnosis and treatment.However,their potential applications in photodynamic therapy(PDT)are hindered by issues such as poor photostability,low yield of reactive oxyge... Metal complexes hold significant promise in tumor diagnosis and treatment.However,their potential applications in photodynamic therapy(PDT)are hindered by issues such as poor photostability,low yield of reactive oxygen species(ROS),and aggregation-induced ROS quenching.To address these challenges,we present a molecular self-assembly strategy utilizing aggregation-induced emission(AIE)conjugates for metal complexes.As a proof of concept,we synthesized a mitochondrial-targeting cyclometalated Ir(Ⅲ)photosensitizer Ir-TPE.This approach significantly enhances the photodynamic effect while mitigating the dark toxicity associated with AIE groups.Ir-TPE readily self-assembles into nanoaggregates in aqueous solution,leading to a significant production of ROS upon light irradiation.Photoirradiated Ir-TPE triggers multiple modes of death by excessively accumulating ROS in the mitochondria,resulting in mitochondrial DNA damage.This damage can lead to ferroptosis and autophagy,two forms of cell death that are highly cytotoxic to cancer cells.The aggregation-enhanced photodynamic effect of Ir-TPE significantly enhances the production of ROS,leading to a more pronounced cytotoxic effect.In vitro and in vivo experiments demonstrate this aggregation-enhanced PDT approach achieves effective in situ tumor eradication.This study not only addresses the limitations of metal complexes in terms of low ROS production due to aggregation but also highlights the potential of this strategy for enhancing ROS production in PDT. 展开更多
关键词 Metal complex AIEgens Mitochondria targeting Enhanced photodynamic therapy Anticancer agent
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Method and Apparatus for Creating Problem-Solving Complexes from Individual Elements
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作者 Bernhard Mitterauer 《Advances in Bioscience and Biotechnology》 2014年第4期311-315,共5页
Based on the biological key-lock-principle common in various biological systems such as the human brain, this paper relates to a method and device for creating problem-solving complexes from individual elements that c... Based on the biological key-lock-principle common in various biological systems such as the human brain, this paper relates to a method and device for creating problem-solving complexes from individual elements that can be coupled with one another and that have different properties to solve problems. The problem solution can be carried out either serially with a large computer, or with several independent, hierarchically joined computers. In this system, an independent control unit that assumes a multitude of tasks and also acts as an interface with access to all participating computers, is assigned to each problem or object class according to the amount of potential problem-oriented solutions. Such a unit prepares the partial solutions found in its computer for the totality of the solutions computed in the associated computers, finally leading to a total problem solution. 展开更多
关键词 Key-Lock-Principle GEOMETRICAL ELEMENTS Computer System Composition problem-solving
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Synthesis and fluorescent properties of a one-dimensional Tb-calixarene complex as a luminescent thermometer material
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作者 PENG Dan WANG Hao +2 位作者 WANG Yanyan YOU Hongpeng LIAO Wuping 《无机化学学报》 北大核心 2025年第9期1859-1866,共8页
Luminescence thermometry has attracted more and more attention due to its non-contact and noninvasive operation,fast response,high spatial resolution,and so on,for which the luminescent thermometers are the key.Here,a... Luminescence thermometry has attracted more and more attention due to its non-contact and noninvasive operation,fast response,high spatial resolution,and so on,for which the luminescent thermometers are the key.Here,a 1D complex[Tb_(4)(HTC4A)(TC4A)(OBBA)_(2)(CH_(3)OH)_(4)(μ4-OH)]n(1)was obtained by solvothermal synthesis,where H 4TC4A=p-tert-butylthiacalix[4]arene,and H_(2)OBBA=4,4'-oxybisbenzoic acid.This complex is featured with a chain-like polymer constructed by bridging some sandwich-like Tb_(4)-(TC4A)_(2)entities through OBBA2-ligands.It exhibited the characteristic emission of the Tb^(3+)ion.Both fluorescence intensity and lifetime decreased with increasing temperature.The relative sensitivity was up to 8.743%·K^(-1)at 473 K,indicating it is a good ratiometric luminescent thermometer.This complex had good stability under different pH values and in common solvents.CCDC:2392643. 展开更多
关键词 TERBIUM CALIXARENES complexes luminescent thermometer
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Diversity,Complexity,and Challenges of Viral Infectious Disease Data in the Big Data Era:A Comprehensive Review 被引量:1
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作者 Yun Ma Lu-Yao Qin +1 位作者 Xiao Ding Ai-Ping Wu 《Chinese Medical Sciences Journal》 2025年第1期29-44,I0005,共17页
Viral infectious diseases,characterized by their intricate nature and wide-ranging diversity,pose substantial challenges in the domain of data management.The vast volume of data generated by these diseases,spanning fr... Viral infectious diseases,characterized by their intricate nature and wide-ranging diversity,pose substantial challenges in the domain of data management.The vast volume of data generated by these diseases,spanning from the molecular mechanisms within cells to large-scale epidemiological patterns,has surpassed the capabilities of traditional analytical methods.In the era of artificial intelligence(AI)and big data,there is an urgent necessity for the optimization of these analytical methods to more effectively handle and utilize the information.Despite the rapid accumulation of data associated with viral infections,the lack of a comprehensive framework for integrating,selecting,and analyzing these datasets has left numerous researchers uncertain about which data to select,how to access it,and how to utilize it most effectively in their research.This review endeavors to fill these gaps by exploring the multifaceted nature of viral infectious diseases and summarizing relevant data across multiple levels,from the molecular details of pathogens to broad epidemiological trends.The scope extends from the micro-scale to the macro-scale,encompassing pathogens,hosts,and vectors.In addition to data summarization,this review thoroughly investigates various dataset sources.It also traces the historical evolution of data collection in the field of viral infectious diseases,highlighting the progress achieved over time.Simultaneously,it evaluates the current limitations that impede data utilization.Furthermore,we propose strategies to surmount these challenges,focusing on the development and application of advanced computational techniques,AI-driven models,and enhanced data integration practices.By providing a comprehensive synthesis of existing knowledge,this review is designed to guide future research and contribute to more informed approaches in the surveillance,prevention,and control of viral infectious diseases,particularly within the context of the expanding big-data landscape. 展开更多
关键词 viral infectious diseases big data data diversity and complexity data standardization artificial intelligence data analysis
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Synthesis,crystal structure,thermal decomposition mechanism,and fluorescence properties of benzoic acid and 4-hydroxy-2,2′:6′,2″-terpyridine lanthanide complexes
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作者 HAN Yahui ZHAO Jinjin +1 位作者 REN Ning ZHANG Jianjun 《无机化学学报》 北大核心 2025年第5期969-982,共14页
Two novel lanthanide complexes,[Sm_(2)(BA)_(6)(4-OH-terpy)_(2)]·2H_(2)O·2EtOH(1)and[Pr_(2)(BA)_(6)(4-OH-terpy)_(2)(H_(2)O)_(2)]·HBA·H_(2)O(2),where HBA=benzoic acid,4-OH-terpy=4-hydroxy-2,2'∶6... Two novel lanthanide complexes,[Sm_(2)(BA)_(6)(4-OH-terpy)_(2)]·2H_(2)O·2EtOH(1)and[Pr_(2)(BA)_(6)(4-OH-terpy)_(2)(H_(2)O)_(2)]·HBA·H_(2)O(2),where HBA=benzoic acid,4-OH-terpy=4-hydroxy-2,2'∶6',2″-terpyridine,were successfully synthesized using ultrasonic dissolution and the conventional solution method with two mixed ligands HBA and 4-OH-terpy.During the synthesis,4-OH-terpy was involved in the reaction as a neutral ligand,while HBA,in its deprotonated form(BA-),coordinated with the lanthanide ions as an acidic ligand.The crystal structures of these two complexes were precisely determined by single-crystal X-ray diffraction.Elemental analysis,infrared and Raman spectroscopy,and powder X-ray diffraction techniques were also employed to further explore the physicochemical properties of the two complexes.The single-crystal X-ray diffraction data indicate that,despite their structural differences,both complexes belong to the triclinic crystal system P1 space group.The central lanthanide ions have the same coordination number but exhibit different coordination environments.To comprehensively evaluate the thermal stability of these two complexes,comprehensive tests including thermogravimetric analysis,differential thermogravimetric analysis,differential scanning calorimetry,Fourier transform infrared spectroscopy,and mass spectrometry were conducted.Meanwhile,an in-depth investigation was conducted into the 3D infrared stacked images and mass spectra of the gases emitted from the complexes.In addition,studies of the fluorescence properties of complex1 showed that it exhibited fluorescence emission matching the Sm^(3+)characteristic transition. 展开更多
关键词 lanthanide complexes crystal structure THERMOCHEMISTRY fluorescence spectrum
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Parametric Dependence of Modified Yukawa Potential and Consequent Structure Changes of 2D Magnetized Complex Plasma
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作者 Li Xingyang Li Fei +2 位作者 Ma Jinghan Li Xinru Kong Wei 《南开大学学报(自然科学版)》 北大核心 2025年第2期78-86,共9页
For the magnetized complex plasma,dependences of modified Yukawa potential on the gov-erning parameters,viz.,mass ratio md/mi,number ratio nd/ne0,charge magnitude Q/e,and temperature ratio Te/Ti are investigated.It is... For the magnetized complex plasma,dependences of modified Yukawa potential on the gov-erning parameters,viz.,mass ratio md/mi,number ratio nd/ne0,charge magnitude Q/e,and temperature ratio Te/Ti are investigated.It is found that md/mi,nd/ne0 and Q/e contribute to the coupling strength of the system,and Te/Ti contributes to the shielding cloud surrounding the charged dust particles.Further analysis shows that the modified Yukawa potential depends on Te/Ti.The consequent structure changes of the system are discussed based on the Langevin dynamics simulation.It is found that the variation of Ham-iltonian contributes to the equilibrium structure of the system. 展开更多
关键词 complex plasma magnetic field modified Yukawa potential STRUCTURE
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Intramolecular Charge Transfer Complex Enabled Trifluoromethylation of Heteroarenes with Trifluoromethyl Phosphonium Salt
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作者 Liu Shuai Chen Kunquan +2 位作者 Sun Dequn Liu Qiang Chen Xiangyu 《有机化学》 北大核心 2025年第7期2545-2551,共7页
A photoinduced intramolecular charge transfer complex(ICTC)-enabled photoreduction of trifluoromethyl phosphonium salt for the trifluoromethylation of heteroarenes was developed.It offers a convenient approach to intr... A photoinduced intramolecular charge transfer complex(ICTC)-enabled photoreduction of trifluoromethyl phosphonium salt for the trifluoromethylation of heteroarenes was developed.It offers a convenient approach to introduce trifluoromethyl group to a wide range of aromatic heterocycles,such as indoles,pyrrole,substituted benzene,coumarin,and chromone.This strategy provides operational simplicity,photocatalyst-,transition metal-,and oxidant-free conditions,making it highly advantageous. 展开更多
关键词 trifluoromethyl phosphonium salt charge transfer complex TRIFLUOROMETHYLATION PHOTOINDUCED
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Photoinduced Decarboxylative Amination Driven by Electron Donor-Acceptor Complex
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作者 Gao Ang Yan Luyu +1 位作者 Wang Guangzu Fu Mingchen 《有机化学》 北大核心 2025年第5期1747-1754,共8页
A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cy... A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale. 展开更多
关键词 PHOTOREDOX decarboxylative amination iodine anion electron donor-acceptor complex
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In situ synthesis,crystal structure,and magnetic characterization of a trinuclear copper complex based on a multi-substituted imidazo[1,5-a]pyrazine scaffold
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作者 WANG Zhaodong 《无机化学学报》 北大核心 2025年第3期597-604,共8页
A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]py... A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713. 展开更多
关键词 amide ligand copper complex single crystal structure C-N coupling magnetic characterization
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Coordination equilibrium between cyclometalated Pt(Ⅱ)complexs[Pt(κ^(3)-N^C^N′)(CNXyl)]Cl and[Pt(κ^(2)-N^C^N′)(CNXyl)Cl]
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作者 ZHANG Huahong ZHAO Yang +2 位作者 NING Rui WU Shuixing ZHANG Xiaopeng 《无机化学学报》 北大核心 2025年第9期1840-1850,共11页
Reaction of the non-substituted/substituted unsymmetric pinene-derived complex[Pt(N^C^N')Cl]with the aryl isocyanide 2,6-dimethylphenyl isocyanide(CNXyl)afforded a mixture of two isomeric species:the ionic complex... Reaction of the non-substituted/substituted unsymmetric pinene-derived complex[Pt(N^C^N')Cl]with the aryl isocyanide 2,6-dimethylphenyl isocyanide(CNXyl)afforded a mixture of two isomeric species:the ionic complex[Pt(κ^(3)-N^C^N')(CNXyl)]Cl([A]Cl)and the molecular complex[Pt(κ^(2)-N^C^N')(CNXyl)Cl](B).Isomer B was almost the dominating product.The structures of the isomer B derivatives bearing-CF_(3)and-Cl substituents on the pyridine ring of the pinene moiety(5B and 7B,respectively)have been confirmed by single-crystal X-ray diffraction,revealing a slightly distorted square planar geometry with trans-N_(N^C^N'),CNR configuration(The terminal N atom of theκ^(2)-N^C^N'ligand is trans to the isocyanide ligand CNXyl.).Isomer B is thermodynamically more stable,as confirmed by theoretical calculations.CCDC:2416415,5B;2416414,7B. 展开更多
关键词 coordination equilibrium cyclometalated Pt(Ⅱ)complex isocyanide pinene group
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Ligand substitution of diiron hexacarbonyl complex with aminodiphosphine to prepare diiron aminophosphine complexes relevant to[FeFe]-hydrogenases
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作者 LIU Xufeng WANG Shaojie ZHAO Peihua 《无机化学学报》 北大核心 2025年第9期1851-1858,共8页
To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(... To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2. 展开更多
关键词 [FeFe]-hydrogenases diiron model complexes aminophosphine ligand STRUCTURE electrochemical performance
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Synthesis,structure,and magnetic property of a cobalt(Ⅱ)complex based on pyridyl⁃substituted imino nitroxide radical
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作者 WANG Xiaoling ZHANG Hongwu LIU Daofu 《无机化学学报》 北大核心 2025年第2期407-412,共6页
A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,el... A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,elemental analysis,IR,and magnetic properties.X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB-ligands.The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ)and im4-py radical.The magnetic property is explained by the magnetic and structure exchange mechanism.CCDC:976028. 展开更多
关键词 Co(Ⅱ)complex imino nitroxide radical crystal structure magnetic property
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