Synthesis and Characterization of Radiate MgO Whiskers

In this paper,radiate MgO whiskers were fabricated in the system of Mg-B-NaCl-Ar at relatively low temperature. The Mg vapor reacted with trace O_2 contained in the reaction system and formed MgO vapor.On appropriate conditions,the MgO vapor could reach supersaturation and grow into highly radiate structure.They were characterized by means of field emission scanning electronic microscopy (FE-SEM),transmission electronic microscopy (TEM) and energy dispersive spectrometer (EDS).The mechanism of the morphologies of MgO was discussed.

Research on the Influencing Factors of Personal Credit Based on a Risk Management Model in the Background of Big Data

Between states, between enterprises and enterprises, between people, it can be stated that credit is full of every corner of our lives. But the current lack of social credit is fundamental. Credit risk is particularly prominent. In the extensive data generation today, the information on personal credit statistics is very large, but still lack the data system processing and screening. Through the information retrieval of 200 credit information reports, this paper constructs the evaluation system of personal credit by using the basic information of the individual. The basic information of these individuals has great convenience in information collection and information statistics, and this basic information covers all aspects that are likely to result in the breach of contract. Through the use of single factor analysis and logistic model to solve the index system, you can not only find the impact of individual indicators on the degree of personal credit, but also see the overall impact of indicators on the degree of credit, that is, the weight of the indicators. Finally, four different credit ratings are divided by assigning the indicators to the scores. Credit rating can clearly measure the respective credit situation. Through the classification of these levels, measuring the credit line when a person in the individual credit operation, at the same time, it can provide reference and proval to administrative departments, which is benefit for managing credit risks. It has a substantial meaning and value in use. The solution to the rating system cannot only be applied to individuals, but also to the enterprises, with a wide range of versatility.

Residential Community Open-Up Strategy Based on Prim’s Algorithm and Neural Network Algorithm

“Open community” has aroused widespread concern and research. This paper focuses on the system analysis research of the problem that based on statistics including the regression equation fitting function and mathematical theory, combined with the actual effect of camera measurement method, Prim’s algorithm and neural network to “Open community” and the applicable conditions. Research results show that with the increasing number of roads within the district, the benefit time gradually increased, but each type of district capacity is different.

Research on Smart Growth of Sustainable Cities Based on Information Entropy and Super-Efficiency DEA Model

Since the “smart growth” was put forward in the late 90s, it has become an accepted design idea and concept in the field of urban design in the world, and has been deeply studied and applied. In order to better promote “smart grown”, we set up an evaluation system, which consists of eleven indicators. In this paper, Oxford City and Fengzhen City are used as the objects of the study. Then smart growth evaluation model is established. The weight of the index is calculated by the entropy method. We use the model to evaluate the development plans of the two cities, from which to calculate the contribution of the indicators on the level of smart growth. Finally, we use the super-efficient data envelopment analysis model (DEA) to rank the importance of the indicators to the smart growth. The results show that the level of smart growth in Oxford is higher than that in Fengzhen. And “Multifunctional Building Density in Central City”, “The Density of Public Area in Central City” two indicators account for more than 36% weight. The contribution of the two indicators is also located in the top two indicators. Two cities focus on the direction of smart growth is also different. In summary, the differences between China and Western countries in urban planning are mainly focused on housing and public resources.

Biomimetic Preparation of Alumina Hierarchical Papillary Microrough Structure for Hydrophobic Improvement and Its Abrasion Resistance Finite Element Analysis

The surface of lotus leaves has a hierarchical micro–nano-rough structure.We determined that the papillary structure also possesses hierarchical features on the microscale.We used alumina particles as rough structure building units to construct a Hierarchical Papillary microrough Structure(HPS)on a ceramic surface.The effects of the spatial distribution of HPS on the abrasion resistance and mechanical stability of hydrophobic coatings were investigated.Furthermore,for each HPS,the falling sand abrasion process was analyzed using finite element fluid mechanics analysis.A denser or more two-dimensional HPS implied that more area was impacted by the falling sand and that the abrasion amount and rate were higher.This is contrary to the common belief that when there are more wear-resistant substances on the surface,the abrasion resistance is better;thus,abrasion resistance does not necessarily depend entirely on the concentration of wear-resistant substances on the surface,but it is also influenced by the abrasion mode and the spatial distribution structure of the wear-resistant substances.The 3D stacked HPS(3D-HPS)with excellent abrasion resistance and rich pore structure considerably enhanced the mechanical stability of the hydrophobic coatings.These findings provide novel insights and a theoretical basis for designing spatial structures on high abrasion-resistant superhydrophobic ceramic surfaces.

Fabrication and morphology of NbC_x-C composite three-dimensinal netted fibers

The raw materials were commercial powders of Nb2O5 (99.95%), reactive carbon (99.99%), NaCI (99.95%) and sucrose (99.94%). By the carbothermal method, the NbCx (x= 0.98)-C composite three-dimensional netted fibers were prepared in graphite resistance furnace in 0.1 MPa/N2 ambient atmosphere at temperature from 970 to 1 120℃. The diameters of composite three-dimensional netted fibers are 12-38 μm, the hole circumferences of netted fibers are 0.22-2.2 mm, and the hole diameters are 70-701 μm. The process conditions for fabricating NbCx-C composite three-dimensional netted fibers and related morphology, composition and crystal structure of NbCx-C composite netted fibers were investigated in detail.

Strengthening the Mechanical Performance of Sea Urchin Skeleton by Tube Feet Pore

In this paper,the effects of tube feet pores on the mechanical properties of Sea Urchin Skeleton (SUS) have been studied.The pore structure of drop-like Tripnenstes gratilla (a sea urchin) skeleton is characterized by Scanning Electron Microscopy (SEM).Based upon the data,the finite element method has been employed to analyze the Maximum Tensile Stress (MTS) of SUS models with different pore positions,accompanied by compressive tests on SUS-like ceramics.Results indicate that for a drop-like SUS,the MTS keeps a linear relationship with the maximum load applied on the SUS.More importantly,the mechanical performances of some perforated SUSs are better than their non-perforated counterparts due to their lower MTS values,e.g.the maximum load can thus be increased by 35% when the pore is perforated at-10°.The strengthening is attributed to the introduced pore that causes the redistribution of stress and partly reduces the stress intensity on the original MTS position.By contrast,the pore only increases the MTS value of a spherical shell under isostatic pressure or unidirectional pressing.This is a strong hint that the drop-like shape of SUS has evolved to work with the tube feet pores to better protect their bodies.

Fabrication of flexible α-MnO_2 nanowire membranes with superior mechanical strength

The Assembly of one-dimensional(1D)nanostructures such as nanowires/nanorods/nanotubes into twodimensional(2D)macrostructured films is attracting considerable research interest because of their unique properties and wide applications.In this study,flexible membranes were successfully fabricated using a-MnO2nanowires synthesized through a hydrothermal method.The effects of thickness and post-annealing temperature on the mechanical properties of the membranes were investigated in detail.Nano-indentation measurements showed that the modulus of the as-prepared 11.75 lm-thick membrane reached5.765 GPa,and the modulus increased with the increasing post-annealing temperature.Thus,the fabricated membranes with superior mechanical strength can have potential applications such as in photocatalysis,filtering,and supporting substrates.

Effect of cationic groups in organic sulfide electrolyte on the performance of CdS quantum dot sensitized solar cells

Two organic sulfide redox couples derived from2-mercapto-5-methyl-1,3,4-thiadiazole(McMT):tetrabutylammonium thiolate(McMT-TBA?)/disulfide dimer(BMT)and tetramethylammonium thiolate(McMTTMA?)/BMT were incorporated into quantum dots sensitized solar cells(QDSCs)as alternatives to the inorganic polysulfide electrolyte(Na2S/S).It was found in symmetrical cells test that the interfaces of the organic sulfide electrolytes/platinum counter-electrode have much lower charge transfer resistances as well as higher interface reaction rates compared with that for the inorganic one.Besides,QDSCs based on organic sulfide electrolytes exhibited obviouslyhigher fill factors,open circuit photovoltages,and therefore higher conversion efficiency,thanks to the prohibited recombination and lower redox potential.In addition,by comparing and analyzing the performance of devices based on organic sulfide electrolytes with different cationic groups,it is found that cationic group TMA?with smaller size was favorable for the mass transport in the electrolyte,which explains the better photovoltaic performance of McMT-TMA?/BMT based solar cell than that of McMT-TBA?/BMT based one.Eventually,a power conversion efficiency(PCE)of 0.63%was achieved for QDSCs using McMT-(TMA?)/BMT redox couple as electrolyte,which was till now the highest for CdS QDSC based on organic sulfide electrolyte.

Investigation on the Effect of the Multilayered Porous Structure of Sea Urchin Skeleton on Its Mechanical Behavior

In this paper,the effect of stereom structure on the mechanical behavior of the Sea Urchin Inorganic Skeleton(SUIS)has been studied.The stereom microstructure of both Anthocidaris crassispina and Tripnenstes gratilla was characterized by Scanning Electron Microscopy(SEM).Results indicate that a three-layer porous structure consisting of a growth,a support,and a resorption(GSR)layer is a common denominator for both species.The effect of GSR layer order on the mechanical behavior of the SUIS was studied by a finite element method.The results show that the GSR model could effectively reduce the maximum tensile stress on its meridional sutures under unidirectional pressure,hydrostatic pressure,and self-weight situation.For a fabricated three-layered ceramic test strips with different layer orders,the mechanical properties have a completely opposite performance compared with the compressive properties of the calculated SUIS-Iike models.This indicates that the GSR structure can effectively improve the mechanical properties of the SUIS,but it cannot be applied to bionics without considering its synergistic effect with the macro-structure of the SUIS.This is a typical example of bionic invalidation by single structure,where multi-level structure bionics may be an effective solution.