To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, th...To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, then presents a structure complexity measure for classdiagrams based on entropy distance.展开更多
The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reus...The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reuse, etc. The paper exploits some researches on measuring the structure complexity of Web application. Through a deep analysis of the configuration and objects＇ interactions of Web system, two conclusions have been drawn：① A generic Web application consists of static web page, dynamic page, component and database object; ② The main interactions have only three styles, that is static link, dynamic link and call/return relation. Based on analysis and modeling of the content of a Web page （static or dynamic）, complexity measure methods of both control logic of script and nesting of HTML code are further discussed. In addition, two methods for measuring the complexity of inte〉page navigation are also addressed by modeling the inte〉page navigation behaviors of Web application via WNG graph.展开更多
Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structura...Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.展开更多
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
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
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
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
In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in...In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different.We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields.For this purpose a complicated geologic structural model with rugged surfaces,near-surface low-velocity layers,and high-velocity outcropping layers was designed.Based on the instantaneous wave field distribution,we analyzed the mechanism forming complex wave fields.The influence of low velocity layers on the wave field is very strong.A strong waveguide occurs between the top and base of a low velocity layer,producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces.For verifying the correctness of the simulated wave fields,prestack depth migration was performed using different algorithms from the forward modeling.The structure revealed by the stacked migration profile is same as the known structure.展开更多
Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in ge...Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in general net theory(GNT), a quantitative method for structure description and analysis of information systems was introduced. Results The structural complexity index and two related factors, i.e. element complexity factor and connection complexity factor were defined, and the relations between them and the parameters of the Petri net based model of the system were derived. Application example was presented. Conclusion The proposed method provides a theoretical basis for quantitative analysis and evaluation of the structural complexity and can be applied in the general planning and design processes of the information systems.展开更多
Electromagnetic logging while drilling(LWD)is one of the key technologies of the geosteering and formation evaluation for high-angle and horizontal wells.In this paper,we solve the dipole source-generated magnetic/ele...Electromagnetic logging while drilling(LWD)is one of the key technologies of the geosteering and formation evaluation for high-angle and horizontal wells.In this paper,we solve the dipole source-generated magnetic/electric fields in 2D formations efficiently by the 2.5D finite diff erence method.Particularly,by leveraging the field’s rapid attenuation in spectral domain,we propose truncated Gauss–Hermite quadrature,which is several tens of times faster than traditional inverse fast Fourier transform.By applying the algorithm to the LWD modeling under complex formations,e.g.,folds,fault and sandstone pinch-outs,we analyze the feasibility of the dimension reduction from 2D to 1D.For the formations with smooth lateral changes,like folds,the simplified 1D model’s results agree well with the true responses,which indicate that the 1D simplification with sliding window is feasible.However,for the formation structures with drastic rock properties changes and sharp boundaries,for instance,faults and sandstone pinch-outs,the simplified 1D model will lead to large errors and,therefore,2.5D algorithms should be applied to ensure the accuracy.展开更多
Simulation for stochastic wind field is very important in analyzing dynamic responses of large complex structures due to strong wind.The typical simulation method is the spectrum representation method (SRM),but the SR...Simulation for stochastic wind field is very important in analyzing dynamic responses of large complex structures due to strong wind.The typical simulation method is the spectrum representation method (SRM),but the SRM has drawbacks of inferior precision in lower frequency and slow calculating speed.In view of this,the modified Fourier spectrum method (MFSM) is introduced into the simulation of stochastic wind field in this paper.In this method,phase information of wind velocity time history is determined by cross power spectral density (CPSD) between adjacent points,and the wind velocity time history with time and space correlation is generated by iterative modification for CPSD considering auto power spectral density (APSD).Simulation of the wind field for a long-span bridge is undertaken to verify the effectiveness of the MFSM.Simulation results of the SRM and the MFSM are compared.It can be concluded that the MFSM is more accurate and has higher calculation speed than the SRM.展开更多
Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, F...Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-vip.展开更多
In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image proc...In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.展开更多
The main purpose of this note is to construct almost complex or complex structures on certain isoparametric hypersurfaces in unit spheres.As a consequence,complex structures on S^(1)×S^(7)×S^(6),and on S^(10...The main purpose of this note is to construct almost complex or complex structures on certain isoparametric hypersurfaces in unit spheres.As a consequence,complex structures on S^(1)×S^(7)×S^(6),and on S^(10)×S^(3)×S(2)with vanishing first Chern class,are built.展开更多
One complex with a zwitterionic dicarboxylate ligand, [Mn（L）（N3）]n 1 （L = 1-car- boxymethylpyridinium-3-carboxylate）, was synthesized and structurally characterized. Complex 1 crystallizes in triclinic, space gr...One complex with a zwitterionic dicarboxylate ligand, [Mn（L）（N3）]n 1 （L = 1-car- boxymethylpyridinium-3-carboxylate）, was synthesized and structurally characterized. Complex 1 crystallizes in triclinic, space group P1 with a = 7.570（2）, b = 7.808（2）, c = 9.232（3） A, β= 94.450（19）°, V= 489.0（3） A3, Z = 2, Mr = 277.11, Dc = 1.882 g/cm3, F（000） = 278,μ = 1.359 mm-1, S = 1.021, the final R = 0.0509 and wR = 0.1149 for 2236 observed reflections with 1 〉 2σ（I）. Complex 1 consists of two-dimensional coordination layers in which the anionic uniform chains with mixed triple bridges （one end-on （EO） azide and two syn-syn carboxylates） are cross-linked by the flexible cationic N-methylpyridinium spacers. Magnetic studies demonstrated that the triple bridge in 1 transmits antiferromagnetic coupling between the Mn（Ⅱ） ions.展开更多
Accurately solving transient nonlinear inverse heat conduction problems in complex structures is of great importance to provide key parameters for modeling coupled heat transfer process and the structure’s optimizati...Accurately solving transient nonlinear inverse heat conduction problems in complex structures is of great importance to provide key parameters for modeling coupled heat transfer process and the structure’s optimization design.The finite element method in ABAQUS is employed to solve the direct transient nonlinear heat conduction problem.Improved particle swarm optimization(PSO)method is developed and used to solve the transient nonlinear inverse problem.To investigate the inverse performances,some numerical tests are provided.Boundary conditions at inaccessible surfaces of a scramjet combustor with the regenerative cooling system are inversely identified.The results show that the new methodology can accurately and efficiently determine the boundary conditions in the scramjet combustor with the regenerative cooling system.By solving the transient nonlinear inverse problem,the improved particle swarm optimization for solving the transient nonlinear inverse heat conduction problem in a complex structure is verified.展开更多
A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with ex...A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu(Ⅲ) and Nd(Ⅲ) is deduced to be M(DOGA)_3, and only La(Ⅲ) can form the complex HM(DOGA)_4 under condition of high consistency of the DOGA. The coordination number of Ln(Ⅲ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu(Ⅲ), Nd(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln-O are 0 240 nm, 0 244 nm respectively, while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln-O are 0 260 nm, 0 262 nm. For La(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La-O are 0 258 nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La-O is 0 28 nm. The results of IR and MS show that there is no water coordinating with Ln(Ⅲ) in the complexes.展开更多
Heat shock proteins(Hsps)are a family of abundantly expressed ATP-dependent chaperone proteins.Hsp90 is an eminent member of Hsp family.Thus far,two primary functions have been described for Hsp90:first,as a regulator...Heat shock proteins(Hsps)are a family of abundantly expressed ATP-dependent chaperone proteins.Hsp90 is an eminent member of Hsp family.Thus far,two primary functions have been described for Hsp90:first,as a regulator of conformational change of some protein kinases and nuclear hormone receptors,and the other as an indispensable factor in cellular stress response.Hsp90 has an essential number of interaction proteins since it participates in almost every biological process and its importance is self-evident.Hsp90 has an inextricable relationship in the pathogenesis of cancer,especially in the proliferation and irradiation of cancer cells,thus being a notable cancer target.Since the discovery of geldanamycin,the first inhibitor of Hsp90,from the bacterial species Streptomyces hygroscopicus,even more attention has been focused toward Hsp90.Many structure-based inhibitors of Hsp90 have been designed to develop an innovative method to defeat cancer.However,already designed inhibitors have various deficiencies,such as hepatotoxicity,poor aqueous solubility,instability,and non-ideal oral bioavailability.Based on the aforementioned reasons and to achieve an optimal performance and fewer side effects,we designed a novel inhibitor of Hsp90,called FS5,and resolved the crystal structure of the Hsp90^N-FS5 complex(1.65 A°,PDB code 5XRB).Furthermore,we compared the complexes Hsp90^N,Hsp90^N-GDM,and Hsp90^N-ATP and suggest that the inhibitor FS5 may compete with ATP for binding to Hsp90,which can be regarded as a potential strategy for the development of novel cancer drugs in the future.展开更多
Using a tight binding transfer matrix method, we calculate the complex band structure of armchair graphene nanoribbons. The real part of the complex band structure calculated by the transfer matrix method fits well wi...Using a tight binding transfer matrix method, we calculate the complex band structure of armchair graphene nanoribbons. The real part of the complex band structure calculated by the transfer matrix method fits well with the bulk band structure calculated by a Hermitian matrix. The complex band structure gives extra information on carrier＇s decay behaviour. The imaginary loop connects the conduction and valence band, and can profoundly affect the characteristics of nanoscale electronic device made with graphene nanoribbons. In this work, the complex band structure calculation includes not only the first nearest neighbour interaction, but also the effects of edge bond relaxation and the third nearest neighbour interaction. The band gap is classified into three classes. Due to the edge bond relaxation and the third nearest neighbour interaction term, it opens a band gap for N = 3M- 1. The band gap is almost unchanged for N =3M ＋ 1, but decreased for N = 3M. The maximum imaginary wave vector length provides additional information about the electrical characteristics of graphene nanoribbons, and is also classified into three classes.展开更多
Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine （4,4′-bipy） has afforded a new Zn（Ⅱ） compound, [Zn（C12H9O3）2（C10H8N2）]n·nH2O1, which was structurally...Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine （4,4′-bipy） has afforded a new Zn（Ⅱ） compound, [Zn（C12H9O3）2（C10H8N2）]n·nH2O1, which was structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 7.7335（2）, b = 19.3834（4）, c = 20.1707（4） A, β = 104.9830（10）°, V = 2920.82（11） A^3, C34H28ZnN2O7, Mr = 641.95, Z = 4, Dc = 1.460 g/cm^3,μ = 0.895 mm^-1, F（000） = 1328, R = 0.0406 and wR = 0.0876 for 4417 observed reflections （I〉 2σ（I）） Complex 1 consists of one-dimensional zigzag chains deriving from Zn（C12H9O3）2 units linked by 4,4′-bipy ligands, and lattice water molecules decorate between the chains. Non-covalent interactions, such as hydrogen-bonding and aromatic π-π interactions, lead to the formation of a 3D network structure. The thermogravimetric analysis （TGA） and luminescent property for 1 have also been studied in this paper.展开更多
基金Supported in part by the National Natural Science Foundation of China(60073012),National Grand Fundamental Research 973 Program of China(G1999032701),Natural Research Foundation for the Doctoral Program of Higher Education of China,Natural Science Founda
文摘To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, then presents a structure complexity measure for classdiagrams based on entropy distance.
基金Supported by the Defense Pre-Research Project ofthe 10th Five-Year Plan of China (413150902) ,andthe Defense Pre-Research Project of the Navy Equipment Ministry (10104010201)
文摘The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reuse, etc. The paper exploits some researches on measuring the structure complexity of Web application. Through a deep analysis of the configuration and objects＇ interactions of Web system, two conclusions have been drawn：① A generic Web application consists of static web page, dynamic page, component and database object; ② The main interactions have only three styles, that is static link, dynamic link and call/return relation. Based on analysis and modeling of the content of a Web page （static or dynamic）, complexity measure methods of both control logic of script and nesting of HTML code are further discussed. In addition, two methods for measuring the complexity of inte〉page navigation are also addressed by modeling the inte〉page navigation behaviors of Web application via WNG graph.
基金supported by the UGent GOA project“Forest biodiversity and multifunctionality drive chronic stress-mediated dynamics in pathogen reservoirs(FORESTER)”(No.BOF20/GOA/009).
文摘Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275179,11875042,and 12150410309)the Natural Science Foundation of Shanghai(Grant No.21ZR1443900).
文摘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.
基金supported by the School Important Direction Project Cultivation Fund and Key Fund Project for Youth Innovation(Grant Nos.WK2310000101,YD2310002006,and BJ2310000055).
文摘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.
基金supported by the National Key R&D Program of China(No.2021YFB1715000)the National Natural Science Foundation of China(No.52375073)。
文摘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.
基金National Natural Science Foundation of China (50635040)National High-tech Research and Development Program (2009AA04Z302)Jiangsu Provincial Natural Science Foundation (BK2008043)
文摘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.
基金supported in part by the National Natural Science Foundation of China(Grant No.40974069)PetroChina Innovation Foundation(Grant No.2009D-5006-03-01)+1 种基金National Key Basic Research Development Program(GrantNo.2007CB209601)National Major Science and Technology Program(Grant Nos.2008ZX05010-002 and 2008ZX05024-001)
文摘In western China seismic wave fields are very complicated and have low signal to noise ratio.In this paper,we focus on complex wave field research by forward modeling and indicate that density should not be ignored in wave field simulation if the subsurface physical properties are quite different.We use the acoustic wave equation with density in the staggered finite-difference method to simulate the wave fields.For this purpose a complicated geologic structural model with rugged surfaces,near-surface low-velocity layers,and high-velocity outcropping layers was designed.Based on the instantaneous wave field distribution,we analyzed the mechanism forming complex wave fields.The influence of low velocity layers on the wave field is very strong.A strong waveguide occurs between the top and base of a low velocity layer,producing multiples which penetrate into the earth and form strong complex wave fields in addition to reflections from subsurface interfaces.For verifying the correctness of the simulated wave fields,prestack depth migration was performed using different algorithms from the forward modeling.The structure revealed by the stacked migration profile is same as the known structure.
文摘Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in general net theory(GNT), a quantitative method for structure description and analysis of information systems was introduced. Results The structural complexity index and two related factors, i.e. element complexity factor and connection complexity factor were defined, and the relations between them and the parameters of the Petri net based model of the system were derived. Application example was presented. Conclusion The proposed method provides a theoretical basis for quantitative analysis and evaluation of the structural complexity and can be applied in the general planning and design processes of the information systems.
基金the National Natural Science Foundation of China (41674131,41574118,41974146,41904109)the Fundamental Research Funds for the Central Universities (17CX06041,17CX06044)the China National Science and Technology Major Project (2016ZX05007-004,2017ZX05072-002)
文摘Electromagnetic logging while drilling(LWD)is one of the key technologies of the geosteering and formation evaluation for high-angle and horizontal wells.In this paper,we solve the dipole source-generated magnetic/electric fields in 2D formations efficiently by the 2.5D finite diff erence method.Particularly,by leveraging the field’s rapid attenuation in spectral domain,we propose truncated Gauss–Hermite quadrature,which is several tens of times faster than traditional inverse fast Fourier transform.By applying the algorithm to the LWD modeling under complex formations,e.g.,folds,fault and sandstone pinch-outs,we analyze the feasibility of the dimension reduction from 2D to 1D.For the formations with smooth lateral changes,like folds,the simplified 1D model’s results agree well with the true responses,which indicate that the 1D simplification with sliding window is feasible.However,for the formation structures with drastic rock properties changes and sharp boundaries,for instance,faults and sandstone pinch-outs,the simplified 1D model will lead to large errors and,therefore,2.5D algorithms should be applied to ensure the accuracy.
基金Project supported by the National Natural Science Foundation of China (No.90915004)the Six Talents Peak in Jiangsu Province(No.2008178)the 333 High-Level Talent Training Project of Jiangsu Province,China
文摘Simulation for stochastic wind field is very important in analyzing dynamic responses of large complex structures due to strong wind.The typical simulation method is the spectrum representation method (SRM),but the SRM has drawbacks of inferior precision in lower frequency and slow calculating speed.In view of this,the modified Fourier spectrum method (MFSM) is introduced into the simulation of stochastic wind field in this paper.In this method,phase information of wind velocity time history is determined by cross power spectral density (CPSD) between adjacent points,and the wind velocity time history with time and space correlation is generated by iterative modification for CPSD considering auto power spectral density (APSD).Simulation of the wind field for a long-span bridge is undertaken to verify the effectiveness of the MFSM.Simulation results of the SRM and the MFSM are compared.It can be concluded that the MFSM is more accurate and has higher calculation speed than the SRM.
文摘Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-vip.
文摘In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.
基金The project is partially supported by the NSFC(11871282,11931007)BNSF(Z190003)Nankai Zhide Foundation.
文摘The main purpose of this note is to construct almost complex or complex structures on certain isoparametric hypersurfaces in unit spheres.As a consequence,complex structures on S^(1)×S^(7)×S^(6),and on S^(10)×S^(3)×S(2)with vanishing first Chern class,are built.
基金Supported by the NNSFC(21301087)Programs of Higher-level talents of Inner Mongolia University(SPH-IMU-30105-125135)Inner Mongolia autonomous region natural science fund project(2013MS0206)
文摘One complex with a zwitterionic dicarboxylate ligand, [Mn（L）（N3）]n 1 （L = 1-car- boxymethylpyridinium-3-carboxylate）, was synthesized and structurally characterized. Complex 1 crystallizes in triclinic, space group P1 with a = 7.570（2）, b = 7.808（2）, c = 9.232（3） A, β= 94.450（19）°, V= 489.0（3） A3, Z = 2, Mr = 277.11, Dc = 1.882 g/cm3, F（000） = 278,μ = 1.359 mm-1, S = 1.021, the final R = 0.0509 and wR = 0.1149 for 2236 observed reflections with 1 〉 2σ（I）. Complex 1 consists of two-dimensional coordination layers in which the anionic uniform chains with mixed triple bridges （one end-on （EO） azide and two syn-syn carboxylates） are cross-linked by the flexible cationic N-methylpyridinium spacers. Magnetic studies demonstrated that the triple bridge in 1 transmits antiferromagnetic coupling between the Mn（Ⅱ） ions.
基金supported by the National Natural Science Foundation of China(Nos.12172078,51576026)Fundamental Research Funds for the Central Universities in China(No.DUT21LK04)。
文摘Accurately solving transient nonlinear inverse heat conduction problems in complex structures is of great importance to provide key parameters for modeling coupled heat transfer process and the structure’s optimization design.The finite element method in ABAQUS is employed to solve the direct transient nonlinear heat conduction problem.Improved particle swarm optimization(PSO)method is developed and used to solve the transient nonlinear inverse problem.To investigate the inverse performances,some numerical tests are provided.Boundary conditions at inaccessible surfaces of a scramjet combustor with the regenerative cooling system are inversely identified.The results show that the new methodology can accurately and efficiently determine the boundary conditions in the scramjet combustor with the regenerative cooling system.By solving the transient nonlinear inverse problem,the improved particle swarm optimization for solving the transient nonlinear inverse heat conduction problem in a complex structure is verified.
基金Project supported by the China National"863"Program
文摘A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu(Ⅲ) and Nd(Ⅲ) is deduced to be M(DOGA)_3, and only La(Ⅲ) can form the complex HM(DOGA)_4 under condition of high consistency of the DOGA. The coordination number of Ln(Ⅲ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu(Ⅲ), Nd(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln-O are 0 240 nm, 0 244 nm respectively, while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln-O are 0 260 nm, 0 262 nm. For La(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La-O are 0 258 nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La-O is 0 28 nm. The results of IR and MS show that there is no water coordinating with Ln(Ⅲ) in the complexes.
基金supported by the Open Project of Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases,Ministry of Education(No.XN201904)Gannan Medical University(No.QD201910)+1 种基金the National Natural Science Foundation of China(Nos.31770795 and 31971043)the Jiangxi Province Natural Science Foundation(No.20181ACB20014)
文摘Heat shock proteins(Hsps)are a family of abundantly expressed ATP-dependent chaperone proteins.Hsp90 is an eminent member of Hsp family.Thus far,two primary functions have been described for Hsp90:first,as a regulator of conformational change of some protein kinases and nuclear hormone receptors,and the other as an indispensable factor in cellular stress response.Hsp90 has an essential number of interaction proteins since it participates in almost every biological process and its importance is self-evident.Hsp90 has an inextricable relationship in the pathogenesis of cancer,especially in the proliferation and irradiation of cancer cells,thus being a notable cancer target.Since the discovery of geldanamycin,the first inhibitor of Hsp90,from the bacterial species Streptomyces hygroscopicus,even more attention has been focused toward Hsp90.Many structure-based inhibitors of Hsp90 have been designed to develop an innovative method to defeat cancer.However,already designed inhibitors have various deficiencies,such as hepatotoxicity,poor aqueous solubility,instability,and non-ideal oral bioavailability.Based on the aforementioned reasons and to achieve an optimal performance and fewer side effects,we designed a novel inhibitor of Hsp90,called FS5,and resolved the crystal structure of the Hsp90^N-FS5 complex(1.65 A°,PDB code 5XRB).Furthermore,we compared the complexes Hsp90^N,Hsp90^N-GDM,and Hsp90^N-ATP and suggest that the inhibitor FS5 may compete with ATP for binding to Hsp90,which can be regarded as a potential strategy for the development of novel cancer drugs in the future.
基金Project supported by the Fundamental Research Funds for the Central Universities (Grant No. YWF-10-02-040)
文摘Using a tight binding transfer matrix method, we calculate the complex band structure of armchair graphene nanoribbons. The real part of the complex band structure calculated by the transfer matrix method fits well with the bulk band structure calculated by a Hermitian matrix. The complex band structure gives extra information on carrier＇s decay behaviour. The imaginary loop connects the conduction and valence band, and can profoundly affect the characteristics of nanoscale electronic device made with graphene nanoribbons. In this work, the complex band structure calculation includes not only the first nearest neighbour interaction, but also the effects of edge bond relaxation and the third nearest neighbour interaction. The band gap is classified into three classes. Due to the edge bond relaxation and the third nearest neighbour interaction term, it opens a band gap for N = 3M- 1. The band gap is almost unchanged for N =3M ＋ 1, but decreased for N = 3M. The maximum imaginary wave vector length provides additional information about the electrical characteristics of graphene nanoribbons, and is also classified into three classes.
基金Supported by the Foundation of Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces (No. 0506)Department of Education of Zhejiang Province (No. 20071374)
文摘Under hydrothermal condition, the reaction of 2-naphthoxyacetic acid with ZnCl2 and 4,4′-bipyridine （4,4′-bipy） has afforded a new Zn（Ⅱ） compound, [Zn（C12H9O3）2（C10H8N2）]n·nH2O1, which was structurally characterized by single-crystal X-ray diffraction analysis. The crystal is of monoclinic, space group P21/c with a = 7.7335（2）, b = 19.3834（4）, c = 20.1707（4） A, β = 104.9830（10）°, V = 2920.82（11） A^3, C34H28ZnN2O7, Mr = 641.95, Z = 4, Dc = 1.460 g/cm^3,μ = 0.895 mm^-1, F（000） = 1328, R = 0.0406 and wR = 0.0876 for 4417 observed reflections （I〉 2σ（I）） Complex 1 consists of one-dimensional zigzag chains deriving from Zn（C12H9O3）2 units linked by 4,4′-bipy ligands, and lattice water molecules decorate between the chains. Non-covalent interactions, such as hydrogen-bonding and aromatic π-π interactions, lead to the formation of a 3D network structure. The thermogravimetric analysis （TGA） and luminescent property for 1 have also been studied in this paper.
