期刊文献+
共找到10,337篇文章
< 1 2 250 >
每页显示 20 50 100
Copper complexes of anthrahydrazone bearing pyridyl side chain:Synthesis,crystal structure,anticancer activity,and DNA binding 被引量:1
1
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
在线阅读 下载PDF
Synthesis,crystal structure,thermal decomposition mechanism,and fluorescence properties of benzoic acid and 4-hydroxy-2,2′:6′,2″-terpyridine lanthanide complexes
2
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
在线阅读 下载PDF
Parametric Dependence of Modified Yukawa Potential and Consequent Structure Changes of 2D Magnetized Complex Plasma
3
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
原文传递
In situ synthesis,crystal structure,and magnetic characterization of a trinuclear copper complex based on a multi-substituted imidazo[1,5-a]pyrazine scaffold
4
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
在线阅读 下载PDF
Crystal structure and antibacterial activity of two Gd_(2)complexes based on polydentate Schiff-base ligands
5
作者 ZHANG Yingyue KANG Liuqing +2 位作者 YANG Yating GUAN Xiaofen WANG Wenmin 《无机化学学报》 北大核心 2025年第9期1867-1877,共11页
Two Gd_(2)complexes,namely[Gd_(2)(dbm)_(2)(HL_(1))_(2)(CH_(3)OH)_(2)]·4CH_(3)OH(1)and[Gd_(2)(dbm)_(2)(L_(2))_(2)(CH_(3)OH)_(2)]·2CH_(3)OH(2),where H_(3)L_(1)=(Z)-N'-[4-(diethylamino)-2-hydroxybenzylidene... Two Gd_(2)complexes,namely[Gd_(2)(dbm)_(2)(HL_(1))_(2)(CH_(3)OH)_(2)]·4CH_(3)OH(1)and[Gd_(2)(dbm)_(2)(L_(2))_(2)(CH_(3)OH)_(2)]·2CH_(3)OH(2),where H_(3)L_(1)=(Z)-N'-[4-(diethylamino)-2-hydroxybenzylidene]-2-hydroxyacetohydrazide,H_(2)L_(2)=(E)-N'-(5-bromo-2-hydroxy-3-methoxybenzylidene)nicotinohydrazide,Hdbm=dibenzoylmethane,have been constructed by adopting the solvothermal method.Structural characterization unveils that both complexes 1 and 2 are constituted by two Gd^(3+)ions,two dbm-ions,two CH_(3)OH molecules,and two polydentate Schiff-base ligands(HL_(1)^(2-)or L_(2)^(2-)).In addition,complex 1 contains four free methanol molecules,whereas complex 2 harbors two free methanol molecules.By investigating the interactions between complexes 1 and 2 and four types of bacteria(Bacillus subtilis,Escherichia coli,Staphylococcus aureus,Candida albicans),it was found that both complexes 1 and 2 exhibited potent antibacte-rial activities.The interaction mechanisms between the ligands H_(3)L_(1),H_(2)L_(2),complexes 1 and 2,and calf thymus DNA(CT-DNA)were studied using ultraviolet-visible spectroscopy,fluorescence titration,and cyclic voltammetry.The results demonstrated that both complexes 1 and 2 can intercalate into CT-DNA molecules,thereby inhibiting bacterial proliferation to achieve the antibacterial effects.CCDC:2401116,1;2401117,2. 展开更多
关键词 Gd_(2)complex polydentate Schiff base crystal structure DNA INTERACTION antibacterial activity
在线阅读 下载PDF
Synthesis,structure,and magnetic property of a cobalt(Ⅱ)complex based on pyridyl⁃substituted imino nitroxide radical
6
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
在线阅读 下载PDF
Quantile-based optimization under uncertainties for complex engineering structures using an active learning basis-adaptive PC-Kriging model
7
作者 Yulian GONG Jianguo ZHANG +1 位作者 Dan XU Ying HUANG 《Chinese Journal of Aeronautics》 2025年第1期340-352,共13页
The Reliability-Based Design Optimization(RBDO)of complex engineering structures considering uncertainties has problems of being high-dimensional,highly nonlinear,and timeconsuming,which requires a significant amount ... The Reliability-Based Design Optimization(RBDO)of complex engineering structures considering uncertainties has problems of being high-dimensional,highly nonlinear,and timeconsuming,which requires a significant amount of sampling simulation computation.In this paper,a basis-adaptive Polynomial Chaos(PC)-Kriging surrogate model is proposed,in order to relieve the computational burden and enhance the predictive accuracy of a metamodel.The active learning basis-adaptive PC-Kriging model is combined with a quantile-based RBDO framework.Finally,five engineering cases have been implemented,including a benchmark RBDO problem,three high-dimensional explicit problems,and a high-dimensional implicit problem.Compared with Support Vector Regression(SVR),Kriging,and polynomial chaos expansion models,results show that the proposed basis-adaptive PC-Kriging model is more accurate and efficient for RBDO problems of complex engineering structures. 展开更多
关键词 Reliability-based design optimization Quantile-based Basis-adaptive PC-Kriging complex engineering structures Active learning Uncertainty
原文传递
Tailoring microstructures and mechanical properties of Zr_(45)Ti_(15)Nb_(30)Ta_(10) refractory complex concentrated alloy using warm-rolling 被引量:1
8
作者 Yongkang Zhou Shuai Zeng +4 位作者 Hongwei Zhang Haifeng Zhang Hongquan Gao Hongwei Zhao Zhengwang Zhu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第20期101-112,共12页
Compared with cold rolling,warm rolling can significantly reduce or completely eliminate microstruc-ture damage to regulate the microstructure of the material,which is an effective method to improve the mechanical pro... Compared with cold rolling,warm rolling can significantly reduce or completely eliminate microstruc-ture damage to regulate the microstructure of the material,which is an effective method to improve the mechanical properties of the material.However,the effect of warm rolling on refractory complex concen-trated alloys(RCCAs)has rarely been reported.This research examines how warm rolling influences the microstructure,texture,and mechanical properties of the Zr_(45)Ti_(15)Nb_(30)Ta_(10)RCCA.The RCCA was warm-rolled to a 75%reduction in thickness at 650℃(two-phase zone)and then annealed at 1000°C for 1 h.To highlight the advantages of warm rolling,a comparison was conducted with similarly deformed and annealed cold-rolled RCCA.The warm-rolled RCCA exhibits a layered heterogeneous structure and induces the precipitation of the(Nb,Ta)-enriched bcc2 phase.The deformation texture of warm-rolled RCCA is weaker than that of cold-rolled RCCA,which is attributed to localized deformation inhomogene-ity.After annealing,warm rolling resulted in a remarkable increase in the yield strength of the RCCA,i.e.,from 861 MPa to 1071 MPa;meanwhile,moreover,the tensile plasticity was almost identical.Warm rolling leads to a change in plastic deformation of the RCCA from dislocation cross-slip to one dominated by the interaction of dislocations with subgrain boundaries as well as the bcc2 phase.The back tress gen-erated by the heterogeneous structure induced by warm rolling is also effective in increasing the yield strength of the RCCA.The remarkably layered heterogeneous structure,subgrain boundaries and textures result in warm-rolled RCCA with optimal strength-ductility combination.Our results provide an effective processing approach for tailoring the microstructure and mechanical properties of RCCAs. 展开更多
关键词 Refractory complex concentrated alloy Warm rolling Heterogeneous structure Mechanical properties
原文传递
Syntheses,crystal structures,and characterizations of two cadmium(Ⅱ)coordination polymers
9
作者 LI Xiumei LI Linlin +1 位作者 LIU Bo PAN Yaru 《无机化学学报》 北大核心 2025年第3期613-623,共11页
Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfull... Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2. 展开更多
关键词 coordination polymer cadmium(Ⅱ)complex crystal structure quantum⁃chemical calculations
在线阅读 下载PDF
Electrical structure identification of deep shale gas reservoir in complex structural area using wide field electromagnetic method 被引量:1
10
作者 Gu Zhi-Wen Li Yue-Gang +6 位作者 Yu Chang-Heng Zou Zhong-Ping Hu Ai-Guo Yin Xue-Bo Wang Qinag Ye Heng Tan Zhang-Kun 《Applied Geophysics》 SCIE CSCD 2024年第3期564-578,619,620,共17页
To fully exploit the technical advantages of the large-depth and high-precision artificial source electromagnetic method in the complex structure area of southern Sichuan and compensate for the shortcomings of the con... To fully exploit the technical advantages of the large-depth and high-precision artificial source electromagnetic method in the complex structure area of southern Sichuan and compensate for the shortcomings of the conventional electromagnetic method in exploration depth,precision,and accuracy,the large-depth and high-precision wide field electromagnetic method is applied to the complex structure test area of the Luochang syncline and Yuhe nose anticline in the southern Sichuan.The advantages of the wide field electromagnetic method in detecting deep,low-resistivity thin layers are demonstrated.First,on the basis of the analysis of physical property data,a geological–geoelectric model is established in the test area,and the wide field electromagnetic method is numerically simulated to analyze and evaluate the response characteristics of deep thin shale gas layers on wide field electromagnetic curves.Second,a wide field electromagnetic test is conducted in the complex structure area of southern Sichuan.After data processing and inversion imaging,apparent resistivity logging data are used for calibration to develop an apparent resistivity interpretation model suitable for the test area.On the basis of the results,the characteristics of the electrical structure change in the shallow longitudinal formation of 6 km are implemented,and the transverse electrical distribution characteristics of the deep shale gas layer are delineated.In the prediction area near the well,the subsequent data verification shows that the apparent resistivity obtained using the inversion of the wide field electromagnetic method is consistent with the trend of apparent resistivity revealed by logging,which proves that this method can effectively identify the weak response characteristics of deep shale gas formations in complex structural areas.This experiment,it is shown shows that the wide field electromagnetic method with a large depth and high precision can effectively characterize the electrical characteristics of deep,low-resistivity thin layers in complex structural areas,and a new set of low-cost evaluation technologies for shale gas target layers based on the wide field electromagnetic method is explored. 展开更多
关键词 complex tectonic area in southern Sichuan wide field electromagnetic method deep exploration shale gas reservoir electrical structure
在线阅读 下载PDF
Multiscale structural complexity analysis of neuronal activity in suprachiasmatic nucleus:Insights from tetrodotoxin-induced disruptions
11
作者 Ping Wang Changgui Gu Huijie Yang 《Chinese Physics B》 2025年第4期605-613,共9页
The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals,coordinating physiological processes with the 24-hour day–night cycle.Comprising various cell types,the suprachiasmatic nucleus... The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals,coordinating physiological processes with the 24-hour day–night cycle.Comprising various cell types,the suprachiasmatic nucleus(SCN)integrates environmental signals to maintain complex and robust circadian rhythms.Understanding the complexity and synchrony within SCN neurons is essential for effective circadian clock function.Synchrony involves coordinated neuronal firing for robust rhythms,while complexity reflects diverse activity patterns and interactions,indicating adaptability.Interestingly,the SCN retains circadian rhythms in vitro,demonstrating intrinsic rhythmicity.This study introduces the multiscale structural complexity method to analyze changes in SCN neuronal activity and complexity at macro and micro levels,based on Bagrov et al.’s approach.By examining structural complexity and local complexities across scales,we aim to understand how tetrodotoxin,a neurotoxin that inhibits action potentials,affects SCN neurons.Our method captures critical scales in neuronal interactions that traditional methods may overlook.Validation with the Goodwin model confirms the reliability of our observations.By integrating experimental data with theoretical models,this study provides new insights into the effects of tetrodotoxin(TTX)on neuronal complexities,contributing to the understanding of circadian rhythms. 展开更多
关键词 suprachiasmatic nucleus circadian rhythm complexITY synchrony multiscale structural complexity
原文传递
Exploring the proper statistical proxy to distinguish random structures
12
作者 Mei Xie Fei Xie +2 位作者 Baoyu Song Qiaoyu Guo Xuechen Jiao 《Chinese Physics B》 2025年第5期646-655,共10页
The canonical description of structures comprises two aspects:(1)basic structural elements and(2)arrangement pattern between those elements.This tidy description has been very successful and facilitates the developmen... The canonical description of structures comprises two aspects:(1)basic structural elements and(2)arrangement pattern between those elements.This tidy description has been very successful and facilitates the development of structural physics tremendously,enabling the classification,comparison and analysis of an extremely wide range of structures,including crystals,quasi-crystals,liquid crystals,semi-crystalline materials and so on.However,it has been gradually realized that many novel materials and devices exhibit random structures in which either basic elements or arrangement patterns may not exist.With the rapid development of modern advanced materials,this type of apparently random structure pops up frequently,leaving researchers struggling with how to describe,classify and quantitatively compare them.This paper proposes the utilization of statistical characteristics as the major indicators for the description of apparently random structures.Specifically,we have explored many statistical properties,including power spectral density,histograms,structural complexity,entropic complexity,autocorrelation,etc.,and found that autocorrelation may serve as a promising statistical proxy to distinguish similar-looking random structures.We discuss eight atomic force microscope images of random structures,demonstrating that autocorrelation can be used to distinguish them.In addition,14 more diverse datasets are used to support this conclusion,including atomic force microscopy images of polymers and non-polymers,transmission electron microscopy images of nanocomposite layers and scanning electron microscopy images of non-polymers. 展开更多
关键词 complexITY complex structure AUTOCORRELATION
原文传递
An improved model for predicting thermal contact resistance at multi-layered rock interface
13
作者 WEN Min-jie XIE Jia-hao +4 位作者 LI Li-chen TIAN Yi EL NAGGAR M.Hesham MEI Guo-xiong WU Wen-bing 《Journal of Central South University》 2025年第1期229-243,共15页
This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi... This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient. 展开更多
关键词 multi-layered structures general thermal contact model thermal contact resistance GL thermoelastic theory Laplace transform
在线阅读 下载PDF
Electronic Structure Computations and Optical Spectroscopy Studies of ScNiBi and YNiBi Compounds
14
作者 Yury V.Knyazev Semyon T.Baidak +1 位作者 Yury I.Kuz’min Alexey V.Lukoyanov 《Computers, Materials & Continua》 2025年第6期4085-4095,共11页
Thework presents the electronic structure computations and optical spectroscopy studies of half-Heusler ScNiBi and YNiBi compounds.Our first-principles computations of the electronic structures were based on density f... Thework presents the electronic structure computations and optical spectroscopy studies of half-Heusler ScNiBi and YNiBi compounds.Our first-principles computations of the electronic structures were based on density functional theory accounting for spin-orbit coupling.These compounds are computed to be semiconductors.The calculated gap values make ScNiBi and YNiBi valid for thermoelectric and optoelectronic applications and as selective filters.In ScNiBi and YNiBi,an intense peak at the energy of−2 eV is composed of theNi 3d states in the conduction band,and the valence band mostly contains these states with some contributions from the Bi 6p and Sc 3d or Y 4d electronic states.These states participate in the formation of the indirect gap of 0.16 eV(ScNiBi)and 0.18 eV(YNiBi).Within the spectral ellipsometry technique in the interval 0.22–15μm of wavelength,the optical functions of materials are studied,and their dispersion features are revealed.A good matching of the experimental and modeled optical conductivity spectra allowed us to analyze orbital contributions.The abnormally low optical absorption observed in the low-energy region of the spectrum is referred to as the results of band calculations indicating a small density of electronic states near the Fermi energy of these complex materials. 展开更多
关键词 Computational physics first-principles calculations electronic structure band gap excited states optical properties semiconductors complex materials optoelectronic applications
在线阅读 下载PDF
Synthesis,crystal structure,and DNA‑binding of binuclear lanthanide complexes based on a multidentate Schiff base ligand
15
作者 GUAN Xiaofen LIU Yating +5 位作者 LI Jia HU Yiwen DING Haiyuan SHI Yuanjing WANG Zhiqiang WANG Wenmin 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第12期2486-2496,共11页
Two new dinuclear lanthanidecomplexes,namely[Ln_(2)(dbm)_(2)(HL)_(2)(CH_(3)OH)_(2)]·4CH_(3)OH[Ln=Tb(1)and Dy(2),Hdbm=dibenzoylmethane]have been synthesized using prepared multidentate Schiff base ligand H_(3)L(hy... Two new dinuclear lanthanidecomplexes,namely[Ln_(2)(dbm)_(2)(HL)_(2)(CH_(3)OH)_(2)]·4CH_(3)OH[Ln=Tb(1)and Dy(2),Hdbm=dibenzoylmethane]have been synthesized using prepared multidentate Schiff base ligand H_(3)L(hydroxy‑acetic acid(4‑diethylamino‑2‑hydroxy‑benzylidene)‑hydrazide)with good biological activity.Structure characterizations show that the complex comprises two Ln3+ions,two dbm-ions,two HL^(2-)ligands,two CH_(3)OH molecules,and four free methanol molecules.Each Ln^(3+)ion is eight‑coordinated.The two central Lnions are bridged by twoμ_(2)‑O atoms leading to a parallelogram[Ln2O2]core.The interaction between the compounds(H_(3)L,1,and 2)and the calf thymus DNA(CT‑DNA)has been further confirmed by UV‑Vis spectrometry,fluorescence titration,and cyclic voltammetry.The results showed that both 1 and 2 could undergo insertion with CT‑DNA.CCDC:2343005,1;2343006,2. 展开更多
关键词 binuclear lanthanide complexes crystal structures multidentate Schiff base DNA INSERTION
在线阅读 下载PDF
Generalizable data driven full waveform inversion for complex structures and severe topographies
16
作者 Mahdi Saadat Hosein Hashemi Majid Nabi-Bidhendi 《Petroleum Science》 CSCD 2024年第6期4025-4033,共9页
Traditionally, simplification has been used in scientific modeling practices. However, recent advancements in deep learning techniques have provided a means to represent complex models. As a result, deep neural networ... Traditionally, simplification has been used in scientific modeling practices. However, recent advancements in deep learning techniques have provided a means to represent complex models. As a result, deep neural networks should be able to approximate the complex models, with a high degree of generalization. To achieve generalization, it is necessary to have a diverse range of examples in the training of the neural network, for example in data-driven FWI, training data should cover the expected subsurface models. To meet this requirement, we porposed a method to create geologically meaningful velocity models with complex structures and severe topography. However, it is important to note that generalization comes with its own set of challenges.Because of significant variation in topography of the generated velocity models, we need to include this information as an additional input data in training of the network. Therefore, we have transformed the seismic data to a fixed datum to incorporate geometric information. Additionally, we have enhanced the network's performance by introducing a term in the network loss function. Multiple metrics have been employed to evaluate the performance of the network. The results indicate that by providing the necessary information to the network and employing computational techniques to refine the model's accuracy, deep neural networks are capable of accurately estimating velocity models in complex environments characterized by extreme topography. 展开更多
关键词 Deep learning GENERALIZATION Full waveform inversion Data-driven inversion complex structure
原文传递
Discussion on the Complex Structure of Nilpotent Lie Groups Gk
17
作者 Caiyu Du Yu Wang 《Open Journal of Applied Sciences》 2024年第6期1401-1411,共11页
Consider the real, simply-connected, connected, s-step nilpotent Lie group G endowed with a left-invariant, integrable almost complex structure J, which is nilpotent. Consider the simply-connected, connected nilpotent... Consider the real, simply-connected, connected, s-step nilpotent Lie group G endowed with a left-invariant, integrable almost complex structure J, which is nilpotent. Consider the simply-connected, connected nilpotent Lie group Gk, defined by the nilpotent Lie algebra g/ak, where g is the Lie algebra of G, and ak is an ideal of g. Then, J gives rise to an almost complex structure Jk on Gk. The main conclusion obtained is as follows: if the almost complex structure J of a nilpotent Lie group G is nilpotent, then J can give rise to a left-invariant integrable almost complex structure Jk on the nilpotent Lie group Gk, and Jk is also nilpotent. 展开更多
关键词 Almost complex structure Nilpotent Lie Group Nilpotent Lie Algebra
在线阅读 下载PDF
Experimental Investigation on Complex Structures Machining by Electrochemical Micromachining Technology 被引量:10
18
作者 刘勇 朱荻 +2 位作者 曾永彬 黄绍服 余宏兵 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2010年第5期578-584,共7页
Electrochemical micromachining (EMM) technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to... Electrochemical micromachining (EMM) technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to the electrode. First, an EMM system for meeting the requirements of the EMM process is established. Second, sets of experiments is carried out to investigate the influence of some of the predominant electrochemical process parameters such as electrical parameters, feed rate, electrode geometry features and electrolyte composition on machining quality, especially the influences of pulse on time on shape precision and working end shape of electrode on machined surface quality. Finally, after the preliminary experiments, a complex microstructure with good shape precision and surface quality is successfully obtained. 展开更多
关键词 ELECTROCHEMICAL MICROMACHINING ultra short pulse working end shape surface quality complex structure
原文传递
Synthesis and Crystal Structure of t he Complex of Antimony Trichloride and Dioxane 被引量:1
19
作者 臧祥生 陈娅如 +2 位作者 栾绍嵘 钟国清 郭应臣 《无机化学学报》 SCIE CAS CSCD 北大核心 2001年第6期901-904,共4页
New solid complex of the antimony trichloride and dioxane was obtained th rough a reaction of the dioxane and the absolute methanol solution of the antimony trichloride.The formula of the complex is[SbCl_(3)·{(CH... New solid complex of the antimony trichloride and dioxane was obtained th rough a reaction of the dioxane and the absolute methanol solution of the antimony trichloride.The formula of the complex is[SbCl_(3)·{(CH_(2))_(4)O_(2)}_(1.5)].The crystal structure of the comple x belongs to cubic system,space group I-43d,a=17.1417(5)?,Z=16.The trivalent antimony ion not only bonds directly to three chlorine anions,but also is co ordinated by three oxygen atoms of th e dioxane molecules.Two oxygen atoms in a dioxane molecule wi ll coordinate to different antimony ions,respectively. 展开更多
关键词 dioxane complex of antimony trichloride synthesis crystal structure
在线阅读 下载PDF
Theoretical Studies on Structures and Spectroscopic Properties of Highly Efficient Phosphorescent [Ru(terpy)(phen)X]+ Complexes
20
作者 金丽 张建坡 +1 位作者 张红星 白福全 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第4期391-398,I0003,共9页
The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2',6',2″-terpyridine... The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2',6',2″-terpyridine, phen=l,10-phenanthroline, and X=-C-=CH (1), X=Cl (2), X-CN (3)) were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the com- plexes in CHaCN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru-C, Ru-N, and Ru-Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for a, while the lowest unoccupied molecular orbital were π*(terpy) type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nln are attributed to a dyz (Ru)+Tr/p(X)--π* (terpy) transition with MLCT/XLCT (metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer) character, whereas that of 3 at 529 nm is related to a dyz (Ru)+π(terpy)-π* (terpy) transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm (1), 913 nm (2), and 838 nm (3) have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru(II) complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand. 展开更多
关键词 Mixed-ligand Ru(II) complexes Electronic structure Spectroscopic property DFT calculation UB3LYP method
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部