bluuebunny/crossref_metadata_2025 huggingface dataset:
Hotspot Analysis of Spatial Environmental Pollutants Using Kernel Density Estimation and Geostatistical Techniques
Authors: Lin Yu-Pin , Chu Hone-Jay , Wu Chen-Fa , Chang Tsun-Kuo , Chen Chiu-Yang
Published: December 2010

Concentrations of four heavy metals (Cr, Cu, Ni, and Zn) were measured at 1,082 sampling sites in Changhua county of central Taiwan. A hazard zone is defined in the study as a place where the content of each heavy metal exceeds the corresponding control standard. This study examines the use of spatial analysis for identifying multiple soil pollution hotspots in the study area. In a preliminary investigation, kernel density estimation (KDE) was a technique used for hotspot analysis of soil pollution from a set of observed occurrences of hazards. In addition, the study estimates the hazardous probability of each heavy metal using geostatistical techniques such as the sequential indicator simulation (SIS) and indicator kriging (IK). Results show that there are multiple hotspots for these four heavy metals and they are strongly correlated to the locations of industrial plants and irrigation systems in the study area. Moreover, the pollution hotspots detected using the KDE are the almost same to those estimated using IK or SIS. Soil pollution hotspots and polluted sampling densities are clearly defined using the KDE approach based on contaminated point data. Furthermore, the risk of hazards is explored by these techniques such as KDE and geostatistical approaches and the hotspot areas are captured without requiring exhaustive sampling anywhere.
Casbane Diterpene as a Promising Natural Antimicrobial Agent against Biofilm-Associated Infections
Authors: Carneiro Victor Alves , Santos Hélcio Silva dos , Arruda Francisco Vassiliepe Sousa , Bandeira Paulo Nogueira , Albuquerque Maria Rose Jane Ribeiro , Pereira Maria Olívia , Henriques Mariana , Cavada Benildo Sousa , Teixeira Edson Holanda
Published: December 2010

Croton nepetaefolius is a native plant from northeastern Brazil that belongs to the Euphorbiaceae family. The biological action of this plant has been extensively explored, being the secondary metabolites responsible for its properties alkaloids, diterpenes, and triterpenes. This study aimed to evaluate the ability of casbane diterpene (CD), isolated from the ethanolic extract of C. nepetaefolius, to inhibit microbial growth and biofilm formation of several clinical relevant species (bacteria and yeasts). It was found that CD possessed biocidal and biostatic activity against the majority of the species screened, with minimal active concentrations ranging between 125 and 500 µg/mL. In addition, it was observed that biofilm formation was inhibited even when the planktonic growth was not significantly affected. In conclusion, CD showed potential to be a natural tool for the treatment of diseases caused by different infectious microorganisms.
Small Molecule Inhibitors as Countermeasures for Botulinum Neurotoxin Intoxication
Authors: Li Bing , Peet Norton P. , Butler Michelle M. , Burnett James C. , Moir Donald T. , Bowlin Terry L.
Published: December 2010

Botulinum neurotoxins (BoNTs) are the most potent of known toxins and are listed as category A biothreat agents by the U.S. CDC. The BoNT-mediated proteolysis of SNARE proteins inhibits the exocytosis of acetylcholine into neuromuscular junctions, leading to life-threatening flaccid paralysis. Currently, the only therapy for BoNT intoxication (which results in the disease state botulism) includes experimental preventative antibodies and long-term supportive care. Therefore, there is an urgent need to identify and develop inhibitors that will serve as both prophylactic agents and post-exposure ‘rescue’ therapeutics. This review focuses on recent progress to discover and develop small molecule inhibitors as therapeutic countermeasures for BoNT intoxication.
Phenolic Compounds in Brassica Vegetables
Authors: Cartea María Elena , Francisco Marta , Soengas Pilar , Velasco Pablo
Published: December 2010

Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.
Components of an Anticancer Diet: Dietary Recommendations, Restrictions and Supplements of the Bill Henderson Protocol
Authors: Mannion Cynthia , Page Stacey , Bell Laurie Heilman , Verhoef Marja
Published: December 2010

The use of complementary and alternative medicines including dietary supplements, herbals and special diets to prevent or treat disease continues to be popular. The following paper provides a description of an alternative dietary approach to the self-management and treatment of cancer, the Bill Henderson Protocol (BHP). This diet encourages daily intake of raw foods, a combination of cottage cheese and flaxseed oil and a number of supplements. Some foods and food groups are restricted (e.g., gluten, meat, dairy). Early background theory that contributed to the protocol’s development is presented as is a summary of relevant evidence concerning the anti-cancer fighting properties of the individual components. Supplement intake is considered in relation to daily recommended intakes. Challenges and risks to protocol adherence are discussed. As with many complementary and alternative interventions, clear evidence of this dietary protocol’s safety and efficacy is lacking. Consumers of this protocol may require guidance on the ability of this protocol to meet their individual nutritional needs.
Description and Performance of an L-Band Radiometer with Digital Beamforming
Authors: Bosch-Lluis Xavier , Ramos-Perez Isaac , Camps Adriano , Rodriguez-Alvarez Nereida , Valencia Enric , Marchan-Hernandez Juan F.
Published: December 2010

This paper presents the description and performance tests of an L-band microwave radiometer with Digital Beamforming (DBF), developed for the Passive Advanced Unit (PAU) for ocean monitoring project. PAU is an instrument that combines, in a single receiver and without time multiplexing, a microwave radiometer at L-band (PAU-RAD) and a GPS-reflectometer (PAU-GNSS-R). This paper focuses on the PAU‑RAD beamformer’s first results, analyzing the hardware and software required for the developed prototype. Finally, it discusses the first results measured in the Universitat Politècnica de Catalunya (UPC) anechoic chamber.
A Solar Energy Powered Autonomous Wireless Actuator Node for Irrigation Systems
Authors: Lajara Rafael , Alberola Jorge , Pelegrí-Sebastiá José
Published: December 2010

The design of a fully autonomous and wireless actuator node (“wEcoValve mote”) based on the IEEE 802.15.4 standard is presented. The system allows remote control (open/close) of a 3-lead magnetic latch solenoid, commonly used in drip irrigation systems in applications such as agricultural areas, greenhouses, gardens, etc. The very low power consumption of the system in conjunction with the low power consumption of the valve, only when switching positions, allows the system to be solar powered, thus eliminating the need of wires and facilitating its deployment. By using supercapacitors recharged from a specifically designed solar power module, the need to replace batteries is also eliminated and the system is completely autonomous and maintenance free. The “wEcoValve mote” firmware is based on a synchronous protocol that allows a bidirectional communication with a latency optimized for real-time work, with a synchronization time between nodes of 4 s, thus achieving a power consumption average of 2.9 mW.
Irredentism: Traditional and New Dimension of Threat for the Czech Republic
Authors: Mareš Miroslav
Published: December 2010

This article deals with the threat of irredentism for the Czech Republic, mostly from the comparative historical perspective. It analyses contemporary situation and possible future development of territorial claims in relation to the Czech Republic. It defines the term irredentism and its dimensions. The irredentist threats for the Czech Republic in the first half of the 20 century are described. Contemporary threats are conceptualized (new dimension of traditional threats with direct connection to the Czech territory, new dimension of traditional threats in regional security environment and new forms of irredentist threats). Author comes to conclusion that the substance of irredentist threat has been changed - from "hard security" threat to "weak security" threat, however, in the future can be the risk potential of some forms of irredentism again higher than today.
Shape Effects of Indenter on the Depth-Sensing Indentation
Authors: Shi Xin Yong , Liu Li Zhong , Bao Yi Wang
Published: December 2010

It is revealed that the conventional reduced modulus used in depth-sensing indentation tests is invalid for a flat-ended cylindrical indenter due to the fact that the contact area during the loading is a constant irrelative to load. The load-displacement curve of flat punch is related to the length of the punch and the ratio of the elastic modulus of the indenter to the specimen (the modulus ratio Ei/E). Furthermore, theoretic analysis and finite element simulation demonstrated that, for conical indenter, the measured hardness from depth-sensing indentation tests would increase with increasing modulus ratio because the load increased with the ratio for the same displacement.
Effect of Humidity on Delayed Propagation of Indentation Crack under Sustained Electric Field in Ferroelectric Ceramics
Authors: Li Li Wei , Li Jin Xu , Su Y.J. , Chu W.Y. , Qiao L.J.
Published: December 2010

The effect of humidity on delayed propagation of indentation crack in lead zirconate titanate ferroelectric ceramics under sustained electric field was investigated. The results indicated that delayed propagation of indentation crack could occur in humid air at 98%RH without electric field but it did not in air at RH  30%. The threshold electric field and incubation time for delayed propagation of indentation crack increased but the increment of propagation length decreased with decreasing the humidity. When the electric field is large of 0.14 times of the coercive field, the delayed propagation could also occur in vacuum.
Evaluation of Elastic Modulus and Strength of Glass and Brittle Ceramic Materials by Compressing a Notched Ring Specimen
Authors: Wan De Tian , Bao Yi Wang , Liu Xiao Gen , Zhao Hua , Tian Li
Published: December 2010

A simple and new method was introduced to measure the elastic modulus and strength of glass and brittle ceramic materials at different temperatures by compressing a notch ring specimen. For a notch ring specimen, the maximum tensile stress is generated in the outside of the testing sample at half of the height under an applied load. During the elastic deformation range, the elastic modulus can be calculated from the slope of loading curve and sample size. The fractured strength is derived by the critical load when the testing sample is failed. To verify the feasibility and reliability of this suggested method, typical brittle materials, including glass, coarse Al2O3 and fine ZrO2 ceramic, were used as the testing samples. The measured elastic modulus and strength obtained from this method at room temperature to 1300 oC agreed well with those from conventional testing methods.
Wear Behaviors of TiCN Cermet under Different Concentrations of Abrasive Slurries from Carborundum, Corundum and Silica Sands
Authors: Ren Xiao Yong , Peng Zhi Jian , Wang Zhi Yuan , Rong Hui Yong , Fu Zhi Qiang , Wang Cheng Biao , Qi Long Hao , Miao He Zhuo
Published: December 2010

Through a modified ASTM B611 wet sand rubber rimmed wheel test system (model: MLS-225), the wear resistance of commercially bought TiCN cermets FD22 was studied with water-based slurries of abrasive sands. The applied abrasives were angular sands of carborundum, corundum, and silica with particle size of about 350 μm. During experiments, the rotation speed of the rubber wheel was fixed at 498 rpm, and the load was 225 N. The results show that with increasing concentration of abrasive sands in the slurry, the wear loss of the cermet samples increased. Under the same conditions, when carborundum was used as abrasive, the cermet samples presented the heaviest wear loss and the highest wear rate, but when silica was used as abrasive, the cermet samples presented the slightest wear loss and the lowest wear rate. Under the abrasive concentrations of 5-20 wt% in slurry, the wear rate remained almost unchanged as the sliding distance increased. However, when the concentration was higher than 20 wt%, as the sliding distance increased, the wear rate increased at first and gradually decreased with the sliding distance over 30 km. Through the observations of 3D white-light interfering surface profiler, it was found that the wear mechanisms of TiCN cermet samples involved in extensive plastic deformation, grooves, binder removal and fracture.
Fracture Behavior of Silicon Carbide Measured by Different Test Methods
Authors: Jiang Liang , Chen Yu Hong , Han Fei , Jiang Liang
Published: December 2010

Single edge notched beam (SENB) and indentation methods (IM) were used to test the fracture toughness (KIC) of SiC ceramic in present work. Both of testing results were compared. The applicative computational equation of indentation crack was determined through studying indentation morphology formed by IM. The results showed that the indentation crack in SiC could be Babcock crack, and the KIC value calculated by Niihara (P) indentation equation approximated to real value mostly with minimum relative deviation.
Ultra-High-Hardness (Ti, W)C Matrix Metal Ceramics Prepared through Combustion Synthesis under High Gravity
Authors: Pan Chuan Zeng , Zhang Long , Zhao Zhong Min , Zhang Jing , Su Guan Ling
Published: December 2010

(Ti, W)C matrix metal ceramics were prepared through combustion synthesis under high gravity, structure formation mechanism of the ceramics was discussed and the properties of the ceramics were also measured. XRD and FESEM images show the matrix of metal ceramics was mainly composed of TiC and (Ti, W)C1-x. The formation mechanism mainly involves two stages: firstly, combustion reaction is advanced rapidly under high gravity, and the layered melt consisting of Ti-W-Fe-C-B liquid at the bottom and oxide liquid at the top is formed due to rapid liquid-liquid separation under high gravity, subsequently, TiC solids as the primary phase precipitates from Ti-W-Fe-C-B liquid due to the higher concentration and faster diffusion of C relative to B in the alloy liquid, whereas (Ti, W)C1-x solid nucleates and grows on the surface of TiC solids. The Vickers hardness, flexural strength and fracture toughness of the (Ti, W)C matrix Metal ceramics measured 25.6 GPa, 1060 MPa and 8.5 MPa•m1/2, respectively.
Influence of Substrate Hardness on Coating-Substrate Adhesion
Authors: Zhang Cheng , Hu Tuo , Zhang Na
Published: December 2010

Good coating-substrate adhesion is an essential requirement for almost all kinds of coated devices to perform normally and stay usable for a long period. Researchers have been developing many reliable means to characterize coating adhesion and have been exploring factors that might affect the adhesion status. In this paper, the influence of substrate hardness on coating-substrate adhesion was investigated. Zr and ZrN were coated onto steel substrates with different hardness. Critical loads of coated samples were determined by scratch test combined with microscopic observation. It is found that, for either Zr or ZrN coatings, adhesion between coating and substrate increases linearly with the increasing of substrate hardness.
Fracture Toughness of CNTs/AlN Ceramics Tested by Indentation
Authors: Kuang Jia Cai , Wang Hong Lei , Zhou Xin Gui , Deng Ying Jun
Published: December 2010

CNTs/AlN ceramics were fabricated by hot-pressing sintering process. The fracture toughness was measured by indentation method. The morphologies of indentation cracks were analyzed by SEM. The results show that the facture toughness of AlN was slightly improved because appreciate toughening mechanisms such as CNTs pull-out, crack bridging and deflect operate in CNTs/AlN. In addition, the facture toughness of CNTs/AlN increased with increasing CNTs content up to 3wt%. Then, the fracture toughness decrease when the CNTs content is 4wt%.
High Temperature Creep Behavior of In Situ TiC/Ni Composites
Authors: Li Bin , Liu Zong De , Wang Song , Chen Yong
Published: December 2010

A 70 wt% TiC particulate reinforced Ni matrix composite was in-situ synthesized using self-propagating high-temperature synthesis and combined with pseudo heat isostatic pressing technique. The nearly spherical TiC particle reinforcements were uniformly distributed in the Ni matrix and most of the carbide grains were of 3-4 μm in diameter. Creep behavior of the TiC/Ni composites had been investigated in ambient atmosphere under constant load tensile tests. The stress exponent values of 7.69 and 6.62 were obtained at 923 K and 1023 K, respectively. The creep fracture should be initiated by a mixture of particle cracking, interface debonding and void nucleating, while interface debonding was dominant fracture at high temperature.
Finite-Element Simulations of Residual Stresses Developed in Ti3AlC2 Diffusion Bonds with a Si Interlayer
Authors: Yin X.H. , Wang H.D.
Published: December 2010

The distributions of the residual stress in Ti3AlC2/Si/Ti3AlC2 diffusion bonded joints were studied using finite element method (FEM) considering the properties of reaction product. The effect of thickness of reaction layer on the residual stress was also investigated. The results indicate that the gradients of the residual stress are great near the joint edge. The maximal residual stress produces at the reaction layer adjacent to the interface of the Ti3Al(Si)C2 solid solution and Ti3AlC2, which can have a great effect on joint strength. With the increase of reaction layer thickness, the magnitudes of the residual stress decrease.
Two Dynamic Fracture Problems Concerning Bridging Fiber Pull-Out of Composite Materials
Authors: Lü Nian Chun , Cheng Yun Hong , Wang Yun Tao
Published: December 2010

By means of the built dynamic fracture model of bridging fiber pull-out of composite materials, the problems considered will be transformed into Riemann-Hilbert problem in terms of the theory of complex functions. Analytical solutions of the stresses displacements, dynamic stress intensity factors, strain energy release rate and bridging fibrous fracture speeds under the conditions of an moving increasing loads, Pt/x, Px2/t, respectively, can be facilely obtained by the approaches of self-similar functions. After those solutions were utilized by superposition theorem, the solutions of arbitrary complex problems can be attained.
Particle Shape Characterization of Inorganic Powders by SEM and Image Analysis
Authors: Li Zheng Min , Tan Min , Jiang Bing , Chen Zhi Wei , Si Wei Jiang
Published: December 2010

The shape of inorganic powder particles, prepared by spray-drying process, is close to sphere, and the dry conditions have greater effect on the sphericity. The particle shape is normally described by words or shown by micrographs — these are qualitative and imprecise. In order to characterize the particle shape quantitatively, three shape factors, i.e. aspect ratio (M), roundness (R) and concavity (C), are proposed to describe the particle shape of the inorganic powders in different aspects. An image process method, that “holes” were filled and then particle clusters were separated, was developed and applied in scanning electron microscope (SEM) image in which some particles with “shadow” contact with each other. Mean shape factors, based on about 500 particles in 10 micrographs, are proposed to characterize the particle shape of the inorganic powders. The determination results of four inorganic powders show that cracking catalyst powders without silicon additive and produced after rebuilding of the spray-drying device are closer to spheres.
Effective Elastic Constants of Fiber-Eutectics and Transformation Particles Composite Ceramic
Authors: Li Bao Feng , Zheng Jian , Ni Xin Hua , Ma Ying Chen , Zhang Jing
Published: December 2010

The composite ceramics is composed of fiber-eutectics, transformation particles and matrix particles. First, the recessive expression between the effective stress in fiber-eutectic and the flexibility increment tensor is obtained according to the four-phase model. Second, the analytical formula which contains elastic constant of the fiber-eutectic is obtained applying Taylor’s formula. The eutectic is transverse isotropy, so there are five elastic constants. Third, the effective elastic constants of composite ceramics are predicted. The result shows that the elastic modulus of composite ceramic is reduced with the increase of fibers fraction and fibers diameter.
Preparation and Properties of Niobate Thin Films from Nanosheets
Authors: Chu Jing , Li Yu Lin , Xu Bing , Zhang Na , Li Qiang
Published: December 2010

Niobium oxide thin films were successfully synthesized starting from niobate nanosheets. The microstructure of as-prepared nanosheets was observed by TEM. The morphology of niobate thin films was investigated by SEM. The phase structure was determined by XRD. The transmittance spectra of as-obtained niobium oxide thin films were measured, and the optical properties were studied. The influences of different thickness on optical properties were also analyzed. As-prepared niobium thin films were treated by being heated at different temperature. The effects of soaking temperature on the structure and optical properties of niobium oxide thin films were discussed in detail.
High Discharge Rate Lithium Ion Batteries with the Composite Cathode of LiFePO4/Mesocarbon Nanobead
Authors: Gu Yi Jie , Zeng Cui Song , Chen Yu Bo , Wu Hui Kang , Liu Hong Quan , Chen Lin , Wang Meng , Zuo Lin Li , Huang Xiao Wen , Liu Xiu Bo , Zhang Jun , Lu Cheng , Hu Yong , Guo Zhen , Hu Zu Wang
Published: December 2010

Olivine compounds LiFePO4 were prepared by the solid state reaction, and the electrochemical properties were studied with the composite cathode of LiFePO4/mesocarbon nanobead. High discharge rate performance can be achieved with the designed composite cathode of LiFePO4/mesocarbon nanobead. According to the experiment results, batteries with the composite cathode deliver discharge capacity of 1087mAh for 18650 type cell at 20C discharge rate at room temperature. The analysis shows that the uniformity of mesocarbon nanobead around LiFePO4 can supply enough change for electron transporting, which can enhance the rate capability for LiFePO4 cathode lithium ion batteries. It is confirmed that lithium ion batteries with LiFePO4 as cathode are suitable to electric vehicle application.
Ferroelectric Properties and Microstructures of Pr6O11-Doped Bi4Ti3O12 Thin Films
Authors: Chen Min , Mei X.A. , Su K.L. , Cai A.H. , Liu J. , An Wei Ke , Zhou Yong
Published: December 2010

Pr6O11-doped bismuth titanate (BixPryTi3O12 BPT) thin films were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the microstructures and ferroelectric properties of the films were investigated. Microstructure studies indicate that all of BPT films with well-developed rod-like grains consist of single phase of a bismuth-layered structure without preferred orientation. Pr doping into Bi4Ti3O12 (BIT) causes a large shift of the Curie temperature (TC) of paraelectric-ferroelectric phase transition of BIT from 675°C to lower temperature and improvement in dielectric properties. The experimental results indicate that Pr doping into Bi4Ti3O12 results in a remarkable improvement in ferroelectric properties. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT film with y=0.9 were 35 μC/cm2 and 80 kV/cm, respectively. After 3  1010 switching cycles, 20% degradation of Pr is observed in the film.
Depolarization Behavior of Lead-Free (Bi1/2Na1/2)TiO3-Based Ferroelectrics with Different Li+ Introduction Sources
Authors: Lei Na , Zhu Man Kang , Wang Long Fei , Yang Peng , Hou Yu Dong , Yan Hui
Published: December 2010

Lead-free 0.85(Bi1/2Na1/2)TiO3- 0.10(Bi1/2K1/2)TiO3- 0.05BaTiO3 (BNKB) ceramics with Li2CO3 or (Bi1/2Li1/2)TiO3 (BLT) added were fabricated by a conventional solid oxide route. The XRD analysis indicates that Li2CO3 introduction leads to the increasing of fraction of tetragonal phase while the BLT introduction does in a reverse tendency. Meanwhile, the depolarization temperature Td of Li2CO3-added BNKB ceramics was enhanced obviously while that of BLT-added BNKB ceramics went down as the addition amount increased. The similarity in variation of the phase structure and the Td of BNKB ceramics reveals the nature of Li+ introduction source on phase structure in BNKB ceramics.
Determination of Particle Size Distribution of Nano-TiO2 Coating Film by AFM and Image Analysis
Authors: Li Zheng Min , Chen Zhi Wei , Tan Min , Xu Ke Jing , Jiang Bing
Published: December 2010

Nano-TiO2 coating film is one of the efficient photocatalysts. The particle size distribution of TiO2 has important influence on photocatalytic activity. A new method to determine the particle size distribution of TiO2 nano-film coated on ceramic was developed, by which the images of film acquired by Atom force microscope (AFM) were processed, and TiO2 particles contacted with others were separated and detected. The particle size distributions of two TiO2 nano-films were determined.
Effect of Sample Shape and Size on the Thermal Shock Resistance for Ultra-High Temperature Ceramics
Authors: Zeng Tao , Yan Shi , Gu Yu , Jiang Li Li , Fang Dai Ning , Gao Yu
Published: December 2010

The ceramic thermal shock resistance is usually determined by a strip or a disk sample. However, sample shape and size have greatly effect on determining the strength of Ultra-high temperature ceramics (UHTCs). Study on the thermal shock resistance of UHTCs with different shape and size is very important. Combining mechanics with oxidation dynamic theory, the present work studied the mechanical behavior of UHTCs under high temperature condition, which is different from the traditional thermal shock theory. The parameters, such as thermal expansion coefficient and Young's modulus, are considered as a function of temperature and incorporated into ANSYS code to calculate the stress field of UHTCs under high temperature condition. The effects of sample shape and size on UHTCs stress are discussed. It is found that the thermal shock resistance of UHTCs is strongly affected by the sample shape and size and this is useful for the characterization of UHTCs on mechanical properties.
Accuracy Research on the Measured Values of the Ceramic Material’s Normal Temperature Infrared Emissivity
Authors: Gu Xing Yong , Luo Ting , Wu Shao Ling , Wu Jun Ming
Published: December 2010

The IR-2 Dual-Band Emissivity Measuring Instrument is widely used in the domestic normal temperature infrared technology research field at present. However, the problem is that the measured data has a greatly dispersion when using the IR-2 doing multiple measuring for the one same sample and the same group samples. The different flatness and the surface state of the samples might lead to the above phenomenon. The article discussed how the ceramic massive sample’s flatness and surface affect the measured values of the IR-2, and proposed the way to make the testing result more accurate and more stable. The research showed that the great deformation degree of the sample influences the accuracy; the ‘eight-divided equal angles’ test method and the treatment method what refers to take square root for the average value of the sum of the data’s square could realize less disperse among the measured values and more accurate in the case of the same group samples have different flatness state; the samples polished or not affect the value deeply.
Preparation and Properties of Porous Barium Ferrite
Authors: Zheng Shu Fang , Xiong Guo Xuan , Huang Hai Qing , Luo Liu Jun
Published: December 2010

Nano-porous Barium ferrite (BaFe12O19) nanoparticles were synthesized by sol-gel technique using CTAB as template. The structure, morphology, and magnetic properties of samples were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results show that particles size are about 45 nm to 65 nm. And the nanoparticles show a saturation magnetization (Ms) of 62.831 emu/g, a coercivity (Hc) of 5481.0 Oe and a remament magnetization (Mr) of 33.083 emu/g.
Comparative Study on Mn-Zn Ferrites by One-Step Synthesis and Conventional Two-Step Synthesis
Authors: Xing Qing Kai , Peng Zhi Jian , Fu Xiu Li , Fu Zhi Qiang , Wang Cheng Biao , Qi Long Hao , Miao He Zhuo
Published: December 2010

Mn-Zn ferrites doped with Cr3+ were prepared by “one-step synthesis” and conventional two-step synthesis methods, respectively. Their phase compositions and microstructures were characterized by X-ray diffraction and scanning electron microscopy, respectively. And their magnetic magnetic performance, such as saturation magnetization (Ms), magnetic hysteresis, initial permeability μi and power loss were comparatively investigated by vibrating sample magnetometer. It was observed that the difference of magnetic performance of the samples prepared by both methods is little. The similar performance of both methods makes the “one-step synthesis” especially attractive for application when considering energy economization.
Microstructure and Luminance Properties of Integrated Translucent Alumina Tube Used in Metal Halide Lamps
Authors: Feng Liu , Chen Zhi Wei , Niu Jin Ye
Published: December 2010

The integrated translucent alumina tube used in metal halide lamps have been fabricated by gelcasting process. The influence of sintering process, various sintering fluxes on the micro- structure was discussed. Furthermore, the relation between the luminance and the microstructure was also investigated. The results reveal that when the sintering temperature is 1750°C, the holding time is 6h, the compact product whose average grain size is about 20μm could be obtained; the triple dopant combinations of MgO, Y2O3, La2O3 can promote sintering and improve the microstructure more than double, single dopants and the contents of sintering flux are 99.6wt%Al2O3, 0.2wt%MgO, 0.1wt.%Y2O3 and 0.1wt.%La2O3 respectively; The transmittance increases with the pore decreaseing, the grain size enlarging and the degree of the surface finish improving, the average in line transmittance is about 40%.
Photocatalytic Activity of F-/ SiO2/TiO2 Nanowires
Authors: Zhang Shao Hua , Wang Jian Jun , Xie Bing , Wei Yu
Published: December 2010

Titania nanowire arrays were synthesized in highly ordered porous anodic alumina template by sol-gel method. The samples were characterized by means of SEM, XRD. The photocatalytic property of TiO2, SiO2/ TiO2, F-/SiO2/TiO2 nanowire arrays were studied by methyl orange degradation. The results show that F-/ SiO2/ TiO2 nanowire arrays have higher photocatalytic activities than those of TiO2 and SiO2 /TiO2. Under the condition of 1 h irradiation, the degradation ratio of methyl orange exceeds 90%. At the same time, the higher photocatalytic activity and the smaller crystal size of F-/ SiO2/ TiO2 are related to the incorporation of F-.
Mechanochemical Synthesis and Characteristics of Pb(Mg1/3Nb2/3)O3
Authors: Wu Hao , Chen Cheng , Jiang Dan Yu , Feng Tao , Li Qiang
Published: December 2010

This paper presents a novel mechanochemical synthesis technique for making nano-structured Pb(Mg1/3Nb2/3)O3 (PMN) ferroelectric material without annealing treatment in a much shorter time and at much lower temperature than those reported in the literature, by using the starting precursors MgO, PbO, and Nb2O5. Specimens of various milling time (3-6h) are characterized from XRD patterns to track and analyze the synthesizing procedure of this mechanochemical processing route. The time used to make the desired PMN powders varies with different milling power. When the constituent oxides were mechanically activated at 1.8KW milling power for 6h, the perovskite phase PMN powder was obtained; while it was formed when milling at 3KW for only 3h. Typical SEM images of the as-received PMN powders show that the powders are aggregated of nano-particles of about 100nm in size.
Test of Relative Translucency for Three Veneered All-Ceramic Systems Core Material
Authors: Ma Ting Ting , Yi Yuan Fu , Shao Long Quan , Tian Jie Mo , Hou Kang Lin , Deng Bin , Lu Rong Jian , Wen Ning
Published: December 2010

Objective: To study the relative translucency of 3 veneered and glazed all-ceramic systems core material, including Vita In-Ceram Alumina, Vita In-Ceram Zirconium and Ivoclar Vivodent Empress. Methods: Under standard black and write background, the surface light reflectivity of 3 veneered all-ceramic systems core material was determined with contact color difference meter, and the ratio of Yb /Yw was calculated. Results: After veneered, the relative translucency of 3 core materials all declined, and ranged from 0.8880 of Empress II to 1.00 of In-Ceram zirconia, among of that Empress II was most transparent. Conclusion: The relative translucency of 3 veneered all-ceramic systems core material had significant statistical difference. There was a decreasing range as Vitadur Alpha dentin (standard) > Empress II (0.8 mm) > In-Ceram Alumina > In-Ceram Zirconia.
Density of Li2TiO3 Solid Tritium Breeding Ceramic Pebbles
Authors: Zhang Ying Chun , Wu Ze Shuang , Wang Shu Ming , Wan Xiu Juan , Liu Yan Hong
Published: December 2010

As an important solid tritium breeding ceramic material, Li2TiO3 pebbles with the diameter of 1mm are used in the breeding pebble bed for ITER test blanket module (TBM). Therefore, it is very important to evaluate the densities of Li2TiO3 ceramic pebbles accurately. In this paper, Li2TiO3 ceramic pebbles with the diameter of about 1mm were prepared by wet method using Li2CO3 and TiO2 as the main raw materials. The shape and microstructure are characterized by SEM technique. Densities of the ceramic pebbles were analyzed by both Archimedes principle and Mercury porosimetry methods. The results show that the density measured by Archimedes principle is higher than reality density, while the density measured by mercury porosimetry is accurate.
Evaluation of Glass Infiltration Speed within Dental CAD/CAM Alumina at Different Temperatures
Authors: Liu Jie , Lu Huai Xiu , Shao Long Quan , Deng Bin , Yi Yuan Fu , Tian Jie Mo , Zhang Wei Wei , Wen Ning
Published: December 2010

Objective: to investigate glass infiltrating rates (depth/time) within dental CAD/CAM alumina at different temperatures. Methods: micron α-alumina powder was prepared with cold isostastic pressure at 250 MPa and sintered at 1450°C. The presintered alumina specimens were then infiltrated with special glass at 1150°C, 1200°C and 1250 °C. The infiltrating depths and time to form the infiltrate at the different temperatures were evaluated. Results: As the infiltrating temperature increased, the viscosity of the infiltrating glass decreased, and the infiltrating depth increased. A 1 mm infiltration depth into the presintered alumina at 1150°C, 1200°C and 1250°C required 95 min, 22 min and 8 min, respectively. Conclusion: An optimal infiltrating time required to reach a suitable infiltration depth into the presintered alumina was observed at 1200°C, an important finding for clinical applications at this commonly used furnace temperature.
ZnFe2O4 Modified by Fe(NO3)3 for the Synthesis of Ionic Ferrofluids
Authors: Wang An Rong , Li Jian , Zhang Qing Mei , Miao Hua
Published: December 2010

Weak magnetic ZnFe2O4 nanoparticles were prepared by coprecipitation and treated with different concentrations of Fe(NO3)3 solution. Untreated and treated particles were studied using a vibrating sample magnetometer, transmission electron microscope, by X-ray diffraction, X-ray energy dispersive spectroscopy and X photoelectron spectroscopy. The results showed that, after treatment, the ZnFe2O4/γ-Fe2O3 forms disphase nanoparticles, with enlarged size, enhanced magnetic properties and with a surface parceled with Fe(NO3)3. The size of the particles and their magnetic properties are related to the concentration of the treatment solution. The particle size and magnetic properties could be controlled by controlling the concentration of treating solution, therefore nanoparticles can be more widely used.
Effect of Heat Treatment Temperature on Properties of SiO2-ZrO2-Al2O3-Cr2O3 Coatings on Stainless Steel Substrate
Authors: Liu Shu Xian , Wang Qian Ping , Nie Yi Miao
Published: December 2010

The SiO2-ZrO2-Al2O3-Cr2O3 film is coated on the surface of stainless steel using analytical reagent TEOS, ZrOCl2•8H2O, Al(NO3)3•9H2O and Cr(NO3)3•9H2O as precursor and basing on mole ratio to calculate through Sol-gel method. The phase transformation behavior, erosion resistance, thermal shock resistance and abrasion resistance of ceramic coating by different heat treatment are studied. The results show that: 1) The SiO2-ZrO2-Al2O3-Cr2O3 gel coatings has non-crystalline structure after the treatment at 700°C and 800°C. New substance is not created below 700°C. 2) The stainless steel substrate with ceramic coating has a higher erosion resistance at high temperature (700°C and 800°C)than that without coating.3) Thermal shock resistance of the samples treated in 700°C is the best which has reached within 17-21cycles (900°C, air cooling). 4) The stainless steel substrate with ceramic coating has a higher abrasion resistance than that without coating. The samples treated at 700°C and 800°C have the best abrasion resistance.
Oxidation-Resistance of (Ti,Al,Cr,Y)N Coatings Prepared by Arc Ion Plating
Authors: Li Ming Sheng , Fan Yong Zhong , Zhang Shu Juan
Published: December 2010

In this study, composite metastable (Ti0.49Al0.49Y0.02)N, (Ti0.44Al0.44Cr0.1Y0.02)N and (Ti0.34Al0.34Cr0.3Y0.02)N coatings were respectively deposited on a wrought martensite steel 1Cr11Ni2W2MoV for aero-engine compressor blades by arc ion plating technique with a pulse substrate bias. All the coatings have B1NaCl phase structure with a (220) preferred orientation and dense structures. The introduction of chromium into the coatings gave rise to a minute shrinkage of crystal lattice and a decrease of crystal size. Annealed at 800°C, Oxidation-resistance of the coatings improved with increased Cr content. But heat-treated at 900°C, the incorporation of Cr gave rise to obvious decrease of oxidation-resistance.
Dissolution of Fused Magnesia in Alkaline Solution
Authors: Chen Yin Juan , Song Jie , Li Qiang , Jiang Dan Yu
Published: December 2010

This work mainly studied the corrosion and dissolution performance of fused magnesia in alkaline solution . The influences of temperature, time and the concentration of alkaline solution on the weight change and particle morphology of magnesia powder were investigated. The corrosion mechanism and dynamics of the magnesia in alkaline solution were discussed by measuring the weight change and XRD analysis. Above results of dissolution studied of fused magnesia powders in alkaline solution would offer important corrosion information for ceramic bulks.
Microstructure and Properties of Al2O3-ZrO2(n) Composite Ceramics Prepared by Microwave Sintering
Authors: He Wen , Ai Yun Long , Liu Chang Hong , Zhang Jian Ping , Ding Jia Yuan
Published: December 2010

Al2O3-ZrO2(n) composite ceramics were prepared by microwave sintering. The properties and microstructure were investigated, including vickers hardness, fracture toughness, bending strength, wear resistance and heat-shocking resistance. The results show that the properties and microstructure of alumina matrix ceramics are affected by the addition of nano-ZrO2 particles. When the content of ZrO2 is 15vol%, the hardness, fracture toughness and bending strength of the Al2O3-ZrO2 composites reach maximum values 13350MPa, 6.41MPa•m1/2 and 502MPa, respectively. The wear resistance of alumina matrix ceramics are improved only on the condition of adding an appropriate amount of nano-ZrO2. The wear mechanism of the composites are abrasive particle wear and adhesion wear co-existing. The crack propagation rate of Al2O3 matrix ceramics decreases remarkably with the addition of nano-ZrO2 particles. The mechanisms of ZrO2 improving the heat-shocking resistance of alumina matrix ceramics are mainly phase transfer toughening. Nano-ZrO2 particles exist in the intragranular and grain boundary of alumina matrix ceramics, and exist intragranular structures.
Properties of Pressureless Sintered SiC-TiB2 Composites
Authors: Chen Yu Hong , Jiang Liang , Jia Xue Hong
Published: December 2010

Silicon carbide( SiC) – titanium diboride (TiB2) composite was prepared with boron (B) and carbon (C) as sintering additive via pressureless sintering at 2180°C. The density of sintered samples achieved 96% of full densification. The mechanical properties and electrical conductivity of composite ceramics with different SiC content were researched. The results showed that with the increasing of SiC content the hardness and electrical resistivity of composites decreased, while the strength increased. Although the XRD patterns of sintered samples showed that non new phase was produced, SEM images showed that SiC particle enlarged and surrounded by TiB2 grain during sintering. In this case the fracture mode was intergranular fracture.
XRD Study on D-Values of Modified PbTiO3 Ceramics during Poling Process
Authors: Zhang Yuan Wei , Tang X.G. , Kuang A.X. , Chan H.L.W.
Published: December 2010

The Calcium modified PbTiO3 ceramics with large piezoelectric anisotropy was poled in consecutive steps. X-ray diffraction (XRD) found that the values of inter-planar spacing, d002 and d200, increased with poling field at initial poling stages. A noticeable drop of the d¬002 and d200 at the coercive field was observed. The residual stresses measured by the  angle tilt method were introduced. The relations of d002-sin2ψ and d¬¬200-sin2ψ at different poling stages were simulated by a mathematic model. The linear terms in the model are related to the macro-stress which may cause an elastic deformation; the exponential term in the model is related to the micro-stress which may cause a plastic deformation by the 90o domain switch. The results show that macro-stress and micro-stress decreased and the decay speed along  angle increased as to the d002 lattice spacing. The residual stresses related to the d200 lattice spacing were almost not changed.
Effect of Molybdenum on the Microstructure and Mechanical Properties of TiC/Ni Cermet Cladding Layers
Authors: Liu Miao , Liu Zong De
Published: December 2010

TiC/Ni cermet cladding layer on the surface of 16Mn steel was fabricated with plasma cladding process. Different additions of Mo were 0%, 5%, 10% and 15% in mass percent. The cladding layer was composed of ceramic particles and Ni alloy binder. And the gradient distribution of ceramic particles was observed. And Mo was found in TiC ceramic particles in solid solution. The mechanical properties of the cladding layers with different Mo additions were all better than the cladding layer without Mo. However, the cladding layer with 10% Mo had more defective microstructure and worse mechanical properties.
TiB2-(Ti,W)C Eutectic Composite Ceramics Prepared by Combustion Synthesis under High Gravity
Authors: Huang Xue Gang , Zhang Long , Zhao Zhong Min , Pan Chuan Zeng , Su Guan Ling
Published: December 2010

Large bulk solidified TiC-TiB2 eutectic composite ceramics were prepared by combustion synthesis under high gravity, and the WO3 was introduced into the combustion synthesis as one of oxidants in thermit to obtain the Ti-W-Cr-C-B liquid, so near-full-density TiB2-(Ti,W)C eutectic composite ceramics without the macrocracks were achieved. The ceramic matrix was mainly composed of TiB2-(Ti,W)C eutectic microstructures, and a few of Al2O3 and Al2O3-ZrO2 eutectic structures were also detected in between Ti-W carbides. Due to the introduction of the high gravity field, Stocks immigration of the immiscible liquids took place due to their density differences, resulting in float-up of oxide liquid and settle-down of Ti-W-Cr-C-B liquid, and the layered melt consisting of oxide liquid and Ti-W-Cr-C-B liquid was formed, finally, TiB2-(Ti,W)C eutectic composite grown from the melt. Due to the mutual solubility of W-Ti, the W atom diffused into the TiC, leading to the formation of (Ti,W)C solid solution as same as crystal lattice structure of TiC. The relative density, Vickers hardness and fracture toughness of the composite ceramics measured 98.4%, 26.4 GPa and 7.6±0.5 MPa•m1/2, respectively.
Al2O3-Reinforced Feldspar Ceramic Composite Material
Authors: Zhang Guang Lei , Qin Guo Qiang , Gao Hui , Shao Chang Tao
Published: December 2010

This paper focused on the properties of Al2O3-rainforced feldspar dental ceramic. The results indicated that the introduced Al2O3 could elevate the density of the sintered feldspar ceramic, where the relative density reached 97.9% under the conditions of 20 wt% Al2O3 additive and 1200°C. On the other hand, Al2O3 additive could remarkably promote the machinability and the ultimate bending strength of the modified feldspar ceramic. The grinding efficiency increased by 260.1% if the content of Al2O3 additive was 5 wt%, while the ultimate bending strength enhanced under increasing Al2O3 additive content. The microstructure analysis revealed a composition of α-Al2O3 as the dominant phase and crystalline calcium aluminum silicate hydrate as the minor phase in the Al2O3-rainforced feldspar ceramic. The feldspar represented totally as glass phase, wherein the Al2O3 grains showed a homogenized dispersion.
Large-Bulk Solidified Al2O3-ZrO2(Y2O3) Prepared by Self-Pressure Assisting Combustion Synthesis under High Gravity
Authors: Su Guan Ling , Zhao Zhong Min , Zhang Long , Huang Xue Gang , Pan Chuan Zeng
Published: December 2010

By introducing self-pressure processing into combustion synthesis under high gravity, Al2O3-ZrO2(4Y) eutectic composite ceramics without shrinkage cavities and holes were achieved, and the self-pressure processing also made the macro-crack be controlled and the ceramic densification be promoted evidently. XRD results showed the eutectic ceramics were composed of α-Al2O3, t-ZrO2 and a few m-ZrO2 phases, and the volume fraction of the transformable t-ZrO2 increased with self-pressure force increasing. SEM images showed that with increasing self-pressure force, the rod-shaped eutectic colonies were refined and the volume fraction of the colonies increased. Meanwhile, the irregular ZrO2 crystals around eutectic colonies transformed to be fine t-ZrO2 spherical crystals gradually, and thickness of eutectic colonies decreased. With the changes in microstructures of the ceramics, the mechanical properties of the ceramics were improved greatly.