Effect of Heat Treatment on Microstructure and Mechanical Properties of Multiscale SiC_p Hybrid Reinforced 6061 Aluminum Matrix Composites

The performance of solid solution aging treatment on aluminum matrix composites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silicon carbide particles(nm Si Cp), submicron silicon carbide particles(1 μm Si Cp) and Ti particles were studied. The Al/Si Cp composite powder was prepared by high-energy ball milling, and then cold-pressed, sintered, hotextruded, and then heat-treated with different solution temperatures and aging times for the extruded composites. Optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy(EDS), X-ray diffractometer(XRD) and extrusion testing were used to analyze and test the microstructure and mechanical properties of aluminum matrix composites. The results show that after the multi-stage solid solution at 530 ℃×2 h+535 ℃×2 h+540 ℃×2 h, the particles are mainly equiaxed grains and uniformly distributed. There is no reinforcement agglomeration, and the surface is dense and the insoluble phase is basically dissolved. In the matrix, the strengthening effect is good, and the hardness and compressive strength are 179.43 HV and 680.42 MPa, respectively. Under this solution process, when the aluminum matrix composites are aged at 170 ℃ for 10 h, the hardness and compressive strength can reach their peaks and increase to 195.82 HV and 721.48 MPa, respectively.

MHD(SWCNTS+MWCNTS)/H_(2)O-Based Williamson Hybrid Nanofluids Flow Past Exponential Shrinking Sheet in Porous Medium

The present study numerically investigates the flow and heat transfer of porous Williamson hybrid nanofluid on an exponentially shrinking sheet with magnetohydrodynamic(MHD)effects.The nonlinear partial differential equations which governed the model are first reduced to a set of ordinary differential equations by using the similarity transformation.Next,the BVP4C solver is applied to solve the equations by considering the pertinent fluid parameters such as the permeability parameter,the magnetic parameter,the Williamson parameter,the nanoparticle volume fractions and the wall mass transfer parameter.The single(SWCNTs)and multi-walled carbon nanotubes(MWCNTs)nanoparticles are taken as the hybrid nanoparticles.It is found that the increase in magnetic parameter in SWCNT+MCWNT hybrid nanofluid results in an increase of 72.2%on skin friction compared to SWCNT nanofluid while maintaining reducing a small number of Nusselt number.This shows the potential of the Williamson hybrid nanofluid for friction application purposes especially in transportation like braking system,flushing fluid and mechanical engineering.

基于二阶混联灵敏度矩阵的ECT图像重建

电容层析成像技术求解图像重建问题属于非线性问题。在灵敏度矩阵的推导过程中,通常只保留灵敏度系数的线性部分,但是被忽略的非线性部分同样包含重要的成像信息。为了提高图像重建精度,基于二阶灵敏度系数的数学定义,结合模糊C-均值聚类算法和电场中心线理论,建立了二阶混联灵敏度矩阵,并将矩阵引入到Landweber算法中,提出了二阶Landweber算法;最后,进行仿真和静态实验,并与传统的Tikhonov算法和一阶Landweber算法进行对比,结果表明,二阶混联灵敏度矩阵可以提高图像重建精度。

基于C-NCAP中MPDB试验对HybridⅢ5百分位假人的伤害分析

正面50%重叠移动渐进变形壁障(MPDB)工况是源于不同类型车辆碰撞相容性的研究,本文针对MPDB试验中的HybridⅢ5百分位假人在碰撞试验中受到的损伤进行研究。通过对比汽车副驾位置的HybridⅢ5百分位假人和驾驶员后排位置的HybridⅢ5百分位假人的头颈,胸腹部,大腿、骨盆等身体部位的伤害值,分析HybridⅢ5假人在车辆不同位置的损伤情况。结果表明,HybridⅢ5假人在副驾位置时比在主驾后排位置时受到的损伤较小,尤其是其头部HIC值和头部合成加速度方面。

基于对分易的线上线下混合式教学模式探索——以C语言程序设计为例

为解决编程类教学中学生线下课学习效率不高,教师无法及时掌握学情以及成绩评价体系单一等问题,设计并实施了线上线下混合式教学方案。该方案以“C语言程序设计”为例,借助“对分易”教学平台,通过上传课件、视频等方式搭建线上教学资源,用签到,在线练习,讨论区等模块管理教学过程,实现全过程跟踪考核。该教学方法能提高学生的学习主动性,从整体上提高课程的教学质量。

基于模块化的C语言课程线上线下混合式教学探讨

C语言课程是计算机及其相关专业的专业基础课,旨在培养学生的程序设计能力和计算思维能力。针对该课程的教学现状,基于内容的模块化,开展线上线下混合式教学模式探讨。整个教学过程线上线下相结合、理论与实训相结合,前后内容融会贯通,有效激发学生对C语言课程的学习兴趣,提高教学效果。

Infiltration of A6063 aluminium alloy into SiC-B_4C hybrid preforms using vacuum assisted block mould investment casting technique

Production of A6063/SiC-B4C hybrid composite using vacuum assisted block mould investment casting was investigated. Firstly,SiC-B4C hybrid preforms were fabricated in cylindrical shape.The preferred mean particle size of the SiC and B4C powders were 60μm and 55μm respectively.In early experiments,single powder ratio of 85%SiC and 15%B4C was selected to produce the tough preforms.Subsequently,the preforms were placed into the cylindrical shape gypsum bonded block investment moulds and A6063 alloy was infiltrated into the preforms using vacuum assisted（-10 5 Pa）casting machine.Porosity fraction of preforms was determined using Archimedes’test.The fabricated cast specimens were characterized using hardness tests,image analysis and SEM observations and EDX analysis.The result indicates that,by the vacuum assisted block mould investment casting technique,the infiltration of the preforms by molten metal was successfully realized.

CYP2C19 polymorphism has no influence on rabeprazole-based hybrid therapy for Helicobacter pylori eradication

AIM To evaluate the impact of cytochrome P450 2C19(CYP2C19) and interleukin-1β(IL-1β) polymorphisms on the efficacy of Helicobacter pylori(H. pylori) eradication by using rabeprazole-based hybrid therapy.METHODS A total of 88 H. pylori-infected patients were recruited to receive 14-d of hybrid therapy from March 2013 to May 2014. Three patients were excluded from analysis because of incomplete compliance. Either a follow-up endoscopy or 13 C-urea test was performed to determine the results of H. pylori eradication therapy. The genotypes of CYP2C19 and IL-1β were analyzed to investigate the impact on treatment effect. RESULTS The total eradication rate of H. pylori was 92.94%(79/85). According to the CYP2C19 genotypes, the rates of H. pylori eradication were 89.19% in extensive metabolizers(EM) and 95.83% in non-EM. The H.pylori eradication rates regarding the IL-1β genotypes were 92.59% in the normal acid secretion group and 93.10% in the low acid secretion group. After multivariable logistic regression analysis, both the genotypes of CYP2C19 and IL-1β had no significant influences on the eradication rates of H. pylori.CONCLUSION The CYP2C19 and IL-1β polymorphisms are not significantly independent factors of H.pylori eradication using rabeprazole-based hybrid therapy.

Screening of hepatocyte proteins binding to NS5ABP37 protein by yeast-two hybrid system

Objective To investigate the biological function of NS5ABP37 and to look for proteins interacting with NS5ABP37 protein in hepatocytes.Methods We constructed bait plasmid expressing NS5ABP37 protein of hepatitis C virus(HCV)by cloning the gene of NS5ABP37 protein into pGBKT7,then the recombinant plasmid DNA was transformed into yeast AH109(α type).The transformed yeast AH109 was mated with yeast Y187(α type)containing liver cDNA library plasmid in 2×YPDA medium.Diploid yeast was plated on synthetic dropout nutrient medium(SD/-Trp-Leu-His-Ade)containing X-α-gal for selection and screening.After extracting and sequencing of plasmids from positive(blue)colonies,we made a sequence analysis by bioinformatics.Results We screened twenty-five proteins binding to NS5ABP37,including Homo sapiens cyclin I(CCNI)gene,Homo sapiens matrix metallopeptidase 25(MMP25)and Homo sapiens talin 1.Conclusion The yeast-two hybrid system is an effective method for identifying hepatocyte proteins interacting with NS5ABP37 of HCV.And the biological function of NS5ABP37 may be associated with glycometabolism,lipid metabolism and apoptosis.

Effect of carbon on microstructure of CrAlC_xN_(1-x) coatings by hybrid coating system

A systematic investigation of the microstructure of CrA1CxN1-x coatings as a function of carbon contents was conducted. Quaternary CrA1CxN1-x coatings were deposited on Si wafers by a hybrid coating system combining an arc-ion plating technique and a DC reactive magnetron sputtering technique using Cr and AI targets in the Ar/N2/CH4 gaseous mixture. The effect of carbon content on microstructure of CrA1C^N~ x coatings was investigated with instrumental analyses of X-ray diffraction, X-ray photoelectron, and high-resolution transmission electron microscopy. The results show that the carbon content of CrA1CxN1-x coatings linearly increases with increasing CH4/（CH4/N2） gas flow rate ratio. The surface roughness of the CrA1CxN1-x coating layer decreases with the increase of carbon content.

Intermediate sp-hybridization for chemical bonds in nonplanar covalent molecules of carbon

General representations for symmetrical and asymmetrical intermediate sp-hybridization are provided, with which the development of electronic structure in C3v-symmetrical C2H6 and the bonding configuration in C60 have been analyzed as an example. The spherical structure of C60 does not necessarily require the fourth hybrid, h4, to lie along the radial direction. Rather, h4 runs at an angle of 3.83° from the radius, in the plane bisecting a pentagon, to achieve maximum overlap with adjacent h4-hybrids. By virtue of these representations, a number of properties of covalent molecules and solids can be conveniently calculated. This work might be particularly helpful for the study of C-C bonding in curved structures of carbon, such as fullerenes, carbon nanotubes, and buckled graphene.

Numerical Simulation of Root Growth Dynamics of CO_2-Enriched Hybrid Rice Cultivar Shanyou 63 Under Fully Open-Air Field Conditions

Hybrid indica rice （Oryza sativa L.） cultivars play an important role in rice production system due to its heterosis, resistance to environmental stress, large panicle, and high yield potential. However, no attention has been given to its root growth dynamic responses to rising atmospheric CO2 concentration （[CO2]） in conjunction with nitrogen （N） availability. Free air COz enrichment （FACE） and N have significant effects on rice root growth. In this experiment, a hybrid cultivar Shanyou 63 （Oryza sativa L.） was used to study the effects of FACE and N levels on roots growth of rice. The results showed a significant increase in both adventitious root volume （ARV） and adventitious root dry weight （ARD） under the FACE treatment. The application of nitrogen also increased ARV and ARD, but the increase was smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root volume and dry weight were built with the time as the driving factor. The models illustrated the dynamic development of rice adventitious root volume and dry weight after transplanting, regulated either by the influence factor of atmospheric [CO2] or by N application. The models were successfully used to predict ARV and ARD under FACE treatment in a different year with the predicted data being closely related to the actual experimental data. The model had guiding significance to growth regulation of rice root under the condition of atmospheric [CO2] rising in the future.

Regulation of hydrogen evolution performance of titanium oxide-carbon composites at high current density with a Ti-O hybrid orbital

Rational design and controllable synthesis of practical electrodes with high sta bility and activity at high current density for a hydrogen evolution reaction(HER)are critical for renewable and sustainable energy conversion.However,high-performance TiO_(2)-based electrocatalysts for HER are quite limited,and the cat alytic active centers still remain elusive.Herein,a simple strategy is demonstrated for the synthesis of TiO_(2)-carbon composite(TiO_(2)/C)with high HER performance and stability.The remarkable HER performance of TiO_(2)/C can be ascribed to the doping of carbon atoms,which leads to stronger hybridization of Ti 3d and O 2p orbitals,thus substantially improving the electrocatalytic efficiency.This study elucidates that the hydrogen evolution activity of oxide electrocatalysts can be largely improved by regulating their electronic structures by doping carbon atoms and also provides an effective strategy for designing heterostructured electro catalysts with high catalytic activity and stability at high current density for HER.

Synthesis and Characterization of W-doped TiO_2 Supported by Hybrid Carbon Nanomaterials of Multi-walled Carbon Nanotubes and C_(60) Fullerene by a Hydrothermal Method

W-doped TiO2 supported by hybrid carbon nanomaterials of multi-walled carbon nanotubes and C60 fullerene was synthesized by a simple hydrothermal method. The material displayed high visible light photocatalytic activity. X-ray diffraction, field emission transmission electron microscopy, ultra violet/visible light absorption and photoluminescence spectroscopy were used to characterize the material as photoeatalyst. Photocatalytic activity on the degradation of Rhodamine B dye in an aqueous solution under ultraviolet light and visible light irradiation was also studied. The experimental results indicated that the photocatalytic activity of the material was much higher than that of pure TiO2 or Degussa P25 TiO2.

Hybrid External Fixation for Open Severe Comminuted Fractures of the Distal Femur

Background: The treatment of distal femoral open comminuted fractures is a major problem for orthopedic surgeon. The basic and important aim in treatment of these fractures is to assemble the condylar fragments and then fix the condyles to the femoral shaft by minimum handling of the bone and soft tissues. Objectives: To evaluate the treatment of distal femoral open comminuted fractures (type C2 and C3) with hybrid external fixator. Methods: Thirty-four patients with distal femur open comminuted fracture (type C2 and C3) were treated by hybrid external fixator between January 2005 and December 2008. All of the fractures were opened with extension to joint surface. 30 patients were male and 4 were female. Their average age was 30.5 years (17 to 72 years). Average follow up period was 36 months. 12 patients had isolated fracture and 22 patients had multiple fractures. The bony and functional results were evaluated by the association for the study and application of the method of Ilizarov (ASAMI) protocol and knee society score. Results: 29 out of 34 fractures (85%) had union without bone grafts. Average time of union was 6.1 months (4 - 19 ms). The average knee range of motion was 87.5 degrees (30 - 115 degrees). The bony results were excellent in 24 patients (70.5%), good in 6 (17.7%), fair in 2 (5.9%), and poor in 2 (5.9%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%) according to ASAMI protocol. According to the knee society score the functional results were excellent in 9 (26.44%) patients, good in 13 (38.26%), fair in 7 (20.6%), and poor in 5 (14.7%). Conclusion: Hybrid external fixator is an effective method for treatment of distal femoral open comminuted fractures (type C2 and C3) and may be considered as an alternative surgical methods in the management of these fractures.

Cytological Analyses on Development of Male and Female Gametophytes in an Interspecific Hybrid F_1 from Cucumis hystrix Chakr. × Cucumis sativus L.

An interspecific hybrid F1 of Cucumis hystrix Chakr. x Cucumis sativus L. （NC4406） was used to establish the developmental sequence and to characterize the male and female gametophytes at cytological level for further understanding of the phylogenic relationship and the mechanism of fertility or sterility in the interspecific hybrid F1 The development of male and female gametophytes was studied through meiotic analysis and paraffin section observation technique, respectively. Meanwhile, the fertility level was assessed through hybrid F1 backcrossing to cultivated cucumber 4406. Variable chromosome configurations were observed in the pollen mother cells （PMCs） of hybrid F1 at metaphase Ⅰ , e.g., univalents, bivalents, trivalents, quadravalents, etc. At anaphase Ⅰ and Ⅱ, chromosome lagging and bridges were frequently observed as well, which led to the formation of polyads and only a partial number of microspores could develop into fertile pollen grains （about 23.3%）. Observations of the paraffin sections showed numerous degenerated and abnormal embryo sacs during the development of female gametophytes, and only 40% of the female gametophytes could develop into normal eight-nuclear megaspore. On an average, 22.8 and 6.3 seeds per fruit could be obtained from the reciprocal backcross. The interspecific hybrid F1 of C. hystrix x NC4406 was partially fertile; however, the meiotic behaviors of hybrid F1 showed a high level of intergenomic recombination between C. hystrix and C. sativus chromosomes, which indicated that it plays an important role for introgression of useful traits from C. hystrix into C. sativus.

PRODUCTS OF RESOLVENTS AND MULTIVALUED HYBRID MAPPINGS IN C AT(0) SPACES

In this article, we introduce and investigate the concept of multivalued hybrid mappings in C AT（0） spaces by using the concept of quasilinearization. Also, we present a new iterative algorithm involving products of Moreau-Yosida resolvents for finding a common element of the set of minimizers of a finite family of convex functions and a common fixed point of two multivalued hybrid mappings in C AT（0） spaces.

A Hybrid Multifarious Clustering Algorithm for the Analysis of Memmogram Images

A number of clustering algorithms were used to analyze many databases in the field of image clustering. The main objective of this research work was to perform a comparative analysis of the two of the existing partitions based clustering algorithms and a hybrid clustering algorithm. The results verification done by using classification algorithms via its accuracy. The perfor-mance of clustering and classification algorithms were carried out in this work based on the tumor identification, cluster quality and other parameters like run time and volume complexity. Some of the well known classification algorithms were used to find the accuracy of produced results of the clustering algorithms. The performance of the clustering algorithms proved mean-ingful in many domains, particularly k-Means, FCM. In addition, the proposed multifarious clustering technique has revealed their efficiency in terms of performance in predicting tumor affected regions in mammogram images. The color images are converted in to gray scale images and then it is processed. Finally, it is identified the best method for the analysis of finding tumor in breast images. This research would be immensely useful to physicians and radiologist to identify cancer affected area in the breast.

Efficient separation of C_(4) olefins using tantalum pentafluor oxide anion-pillared hybrid microporous material

With the increasing demand for synthetic rubber,the purification of 1,3-butadiene(C_(4)H_(6))is of great industrial significance.Herein,the successful removal of n-butene(n-C_(4)H_(8))and iso-butene(iso-C_(4)H_(8))from 1,3-butadiene(C_(4)H_(6))was realized by synthesizing a novel TaOF_(5)^(2-) anion-pillared ultramicroporous material TaOFFIVE-3-Ni(also referred to as ZU-96,TaOFFIVE=TaOF_(5)^(2-),3=pyrazine).Single-component adsorption isotherms show that TaOFFIVE-3-Ni can achieve the exclusion of n-C_(4)H_(8) and iso-C_(4)H_(8) in the low pressure region(0–30 kPa),and uptake C_(4)H_(6) with a high capacity of 92.78 cm^(3)·cm^(-3)(298 K and 100 kPa).The uptake ratio of C_(4)H_(6)/iso-C_(4)H_(8) on TaOFFIVE-3-Ni was 20.83(298 K and 100 kPa),which was the highest among the state-of-the-art adsorbents reported so far.With the rotation of anion and pyrazine ring,the pore size changes continuously,which makes smaller-size C_(4)H_(6) enter the channel while larger-size n-C_(4)H_(8) and iso-C_(4)H_(8) are completely blocked.The excellent breakthrough performance of TaOFFIVE-3-Ni shows great potential in industrial separation of C4 olefins.The specific adsorption binding sites within ZU-96 was further revealed through the modeling calculation.

Thinking on the Successful Promotion of Twoline Hybrid Rice C Liangyou 34

C Liangyou 343 is a two-line hybrid rice combination with multiple spikes, which has high yield and wide adaptability, and with superior rice quality to other combination. Analysis showed that innovation was the key to the successful promotion of C Uangyou 343, and if it could be applied to the dry-cultivation successfully, a new market could be opened up.