bluuebunny/crossref_metadata_2025 huggingface dataset:
Dysregulated microRNA Expression in Serum of Non-Vaccinated Children with Varicella
Authors: Qi Yuhua , Zhu Zheng , Shi Zhiyang , Ge Yiyue , Zhao Kangchen , Zhou Minghao , Cui Lunbiao
Published: April 2014

Circulating microRNAs (miRNAs) may play an important role in pathogen-host interactions and can serve as molecular markers for the detection of infectious diseases. To date, the relationship between circulating miRNAs and varicella-zoster virus (VZV) caused varicella has not been reported. Using TaqMan Low-Density Array (TLDA) analysis, expression levels of miRNAs in serum samples from 29 patients with varicella and 60 patients with Bordetella pertussis (BP), measles virus (MEV) and enterovirus (EV) were analyzed. The array results showed that 247 miRNAs were differentially expressed in sera of the varicella patients compared with healthy controls (215 up-regulated and 32 down-regulated). Through the following qRT-PCR confirmation and receiver operational characteristic (ROC) curve analysis, five miRNAs (miR-197, miR-629, miR-363, miR-132 and miR-122) were shown to distinguish varicella patients from healthy controls and other microbial infections with moderate sensitivity and specificity. A number of significantly enriched pathways regulated by these circulating miRNAs were predicted, and some of them were involved in inflammatory response, nervous system and respiratory system development. Our results, for the first time, revealed that a number of miRNAs were differentially expressed during VZV infection, and these five serum miRNAs have great potential to serve as biomarkers for the diagnosis of VZV infection in varicella patients.
A Modified Gash Model for Estimating Rainfall Interception Loss of Forest Using Remote Sensing Observations at Regional Scale
Authors: Cui Yaokui , Jia Li
Published: April 2014

Rainfall interception loss of forest is an important component of water balance in a forested ecosystem. The Gash analytical model has been widely used to estimate the forest interception loss at field scale. In this study, we proposed a simple model to estimate rainfall interception loss of heterogeneous forest at regional scale with several reasonable assumptions using remote sensing observations. The model is a modified Gash analytical model using easily measured parameters of forest structure from satellite data and extends the original Gash model from point-scale to the regional scale. Preliminary results, using remote sensing data from Moderate Resolution Imaging Spectroradiometer (MODIS) products, field measured rainfall data, and meteorological data of the Automatic Weather Station (AWS) over a picea crassifolia forest in the upper reaches of the Heihe River Basin in northwestern China, showed reasonable accuracy in estimating rainfall interception loss at both the Dayekou experimental site (R2 = 0.91, RMSE = 0.34 mm∙d −1) and the Pailugou experimental site (R2 = 0.82, RMSE = 0.6 mm∙d −1), compared with ground measurements based on per unit area of forest. The interception loss map of the study area was shown to be strongly heterogeneous. The modified model has robust physics and is insensitive to the input parameters, according to the sensitivity analysis using numerical simulations. The modified model appears to be stable and easy to be applied for operational estimation of interception loss over large areas.
Contribution à la connaissance de la floraison et de la fructification chez l'Arachide
Authors: Martin Jean-Pierre , Bilquez André F.
Published: April 2014

A. l'occasion de l'étude de la dormance chez une variété précoce d'aracihide, les auteurs ont procédé au marquage des gousses, ce qui les a conduit à formuler ou proposer certaines réponses à diverses questions qui se sont trouvées soulevées au cours de ce travail. L'importance du début de la floraison et en particulier de la sixième semaine après le semis, se trouve mise en évidence ; cette observation intéresse une protection insecticide éventuelle et plus encore l'agronome chargé de réaliser les meilleures conditions culturales et le sélectionneur dont la tache essentielle est d'isoler des types à haut rendement. Il ressort, dans le cas de la variété étudiée que la non-dormance des graines peut cependant permettre d'envisager un arrachage relativement tardif des plantes — même en année pluvieuse — un phénomène d'inhibition se manifestant pour les graines demeurant attachées sur la plante.

Ce travail a été réalisé au C.R.A. de Bambey (Sénégal) par le Service de Génétique de l'Office de la Recherche Scientifique et Technique Outre-Mer.
Combined Inhibition of NF-κB and Bcl-2 Triggers Synergistic Reduction of Viability and Induces Apoptosis in Melanoma Cells
Authors: Watanabe Mariko , Umezawa Kazuo , Higashihara Masaaki , Horie Ryouichi
Published: April 2014

Constitutive activation of nuclear factor κB (NF-κB) characterizes melanoma cells. To explore the molecular mechanism of melanoma cell survival by constitutive NF-κB activation, we used the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ), which directly
binds to NF-κB. DHMEQ abrogated constitutive NF-κB activity, which included RelA (p65)/p50 in melanoma cell lines G361 and HMV-II; however, the reduction of the viability was marginal. Expression of c-FLIP was not observed in the melanoma cell lines tested, and DHMEQ could not
repress the expression of the Bcl-2 family proteins Bcl-2 and Bcl-xL. Concomitant treatment with DHMEQ and the inhibitor of antiapoptotic Bcl-2 family proteins, GX15-070, triggered synergistic reduction of the viability and induced apoptosis of G361 cells. These results indicate that abrogation
of the NF-κB pathway alone is not sufficient to suppress the survival of melanoma cells. The NF-κB and the antiapoptotic Bcl-2 pathways cooperatively support the survival, and the dual targeting triggers synergistic reduction of the viability and induces apoptosis of melanoma cells.
Cancer/Testis Antigen HCA587-Derived Long Peptide Vaccine Generates Potent Immunologic Responses and Antitumor Effects in Mouse Model
Authors: Zhang Lijie , Chen Juanjuan , Song Xiao , Wen Weigang , Li Yan , Zhang Yu , Yin Yanhui
Published: April 2014

The cancer/testis antigen HCA587 (also known as MAGE-C2), one of the most immunogenic tumor antigens, is overexpressed in a wide spectrum of malignant tumors and can serve as a target for immunotherapy. In this study, we synthesized 14 overlapping (25‐35 amino acids) long peptides representing the sequence of the most immunogenic part of the HCA587 protein and evaluated the antigen-specific immune responses and antitumor effects generated by immunization with the synthetic long peptide (SLP) vaccine in a mouse model. HCA587 SLPs in combination with adjuvants CFA and CpG ODN induced potent T-cell responses, which were dominated by type 1 cytokine IFN-γ-producing CD4+T cells as measured by ELISPOT and intracellular cytokine staining assay. Moreover, HCA587 SLP vaccination conferred protection against challenge with HCA587-expressing B16 melanoma in a therapeutic setting. Our findings may provide a scientific basis for the use of HCA587-derived long overlapping peptide vaccine for the treatment of patients with cancer in future clinical trials.
Stromal Cell-Derived Factor-1 (SDF-1)/CXCR4 Axis Enhances Cellular Invasion in Ovarian Carcinoma Cells Via Integrin β1 and β3 Expressions
Authors: Yu Yuecheng , Shi Xiaoyan , Shu Zhen , Xie Tingting , Huang Kan , Wei Li , Song Hui , Zhang Wei , Xue Xiaochang
Published: April 2014

Accumulating evidence has showed that stromal cell-derived factor-1 (SDF-1/CXCR4 axis played important roles in cancer metastases, but the detailed function in ovarian cancer is still largely unknown. In the present study, we determined the location of CXCR4 and lipid rafts, a specialized
structure on cell membrane, in ovarian cancer tissues and ovarian cancer cell line SKOV3 cells by immunofluorescence. To analyze the role of SDF-1/CXCR4 and lipid rafts in tumor cell migration and invasion, Transwell assay and wound healing assay were also performed. Cytoflowmetry was carried
out to determine the participation of integrins. Our data showed that CXCR4 and GM1 (marker of lipid rafts) were expressed in both ovarian cancer tissue and SKOV3 cells, and SDF-1 promoted the invasion and migration of SKOV3 cells, which was mediated by complete lipid rafts. Further studies
uncovered that SDF-1 upregulated the expression of integrin β1 and β3, two molecules closely related with cancer metastasis. These results indicated that SDF-1 might promote the invasion and metastasis of ovarian cancer by regulating these two integrin molecules.
Branching morphology of decapitated arborescent monocotyledons with secondary growth
Authors: Haushahn Tobias , Speck Thomas , Masselter Tom
Published: April 2014

• Premise of the study: Dragon trees (Dracaenaceae) are arborescent monocotyledons with anomalous secondary growth and are able to branch, exhibiting a treelike habit. Studies of the morphology and anatomy of ramifications allow for a better understanding of the complex course and arrangement of the vascular bundles in the stem–branch attachment region for Dracaena and other arborescent monocots with anomalous secondary growth.

• Methods: Morphological and anatomical analyses of ramifications induced in decapitated specimens of D. marginata and D. reflexa included serial sectioning, maceration, staining, and bleaching techniques as well as high and low resolution optical microscopy and three‐dimensional (3D)‐visualization techniques.

• Key results: The use of innovative 3D reconstruction and high‐resolution imaging revealed the extent of connections between branch and stem on various hierarchical levels in Dracaena. A stem‐clasping attachment of the side shoot was observed, which in more detail shows a strong regional dependence of course and connectivity of individual vascular bundles to the main stem. Consequently, the attachment of branch tissue is strongly limited to the outer periphery of the main stem.

• Conclusions: Our results indicate that the observed course of vascular bundles with fiber caps cannot only be a result of physiological need for water and nutrient supply but are interpreted in terms of mechanical constraints acting on the branching region. In addition, the used 3D cine technique and coupled 3D reconstruction provide a valuable tool for botanists working in the field of anatomy.
Dihaploidy yields diploid apomicts and parthenogens in Erigeron (Asteraceae)
Authors: Noyes Richard D. , Wagner Jennifer D.
Published: April 2014

• Premise of the study: Dihaploids result when tetraploids produce reduced eggs that develop without fertilization into diploid progeny. This process is useful for reducing genome complexity and studying trait expression at different ploidal levels. In this study we evaluated genetic inheritance and expression of diplospory (D) and parthenogenesis (P) in a population of dihaploids produced by tetraploid apomictic Erigeron.

• Methods: From 400 mostly maternal (tetraploid) progeny, we identified 64 (16%) dihaploids with 2n = 18 (53 plants) or 2n = 19 (11 plants). Differential interference contrast (DIC) imaging of ovules was used to evaluate megasporogenesis (meiosis vs. diplospory) and capacity for parthenogenetic embryo development. Seed production was estimated as the proportion of filled seeds.

• Key results: For 60 analyzed dihaploids, diplospory vs. meiosis segregated approximately 1: 1 (P = 0.44) while all exhibited parthenogenetic embryo development. Parthenogenesis for meiotic progeny (n = 27) was observed in approximately 50% of ovules. Apomictic dihaploids (combining D and P; n = 33) produced seeds with mean 24.8% (range 1.3–74.4%) of total flowers.

• Conclusions: The dihaploid population consisted of half apomicts (D + P) and half parthenogens (P only). We infer that formation of dihaploid seeds requires the parthenogenesis locus. The highest seed values obtained for diploid apomicts are comparable to those recorded for wild type polyploid apomicts. This is one of the first reports of diploid apomixis in the Asteraceae and it demonstrates that both diplospory and parthenogenesis can be transmitted and expressed at a high level in the diploid condition.
Is gene flow the most important evolutionary force in plants?
Authors: Ellstrand Norman C.
Published: April 2014

Although theory has demonstrated rather low levels of gene flow are sufficient to counteract opposing mutation, drift, and selection, widespread recognition of the evolutionary importance of gene flow has come slowly. The perceived role of gene flow as an evolutionary force has vacillated over the last century. In the last few decades, new methods and analyses have demonstrated that plant gene flow rates vary tremendously—from nil to very high—depending on the species and specific populations involved, and sometimes over time for individual populations. In many cases, the measured gene flow rates are evolutionarily significant at distances of hundreds and sometimes thousands of meters, occurring at levels sufficient to counteract drift, spread advantageous alleles, or thwart moderate levels of opposing local selection. Gene flow in plants is likely to often act as a cohesive force, uniting individual plant species into real evolutionary units. Also, gene flow can evolve under natural selection, decreasing or increasing. The fact of frequent, but variable, plant gene flow has important consequences for applied issues in which the presence or absence of gene flow might influence the outcome of a policy, regulatory, or management decision. Examples include the unintended spread of engineered genes, the evolution of invasiveness, and conservation. New data‐rich genomic techniques allow closer scrutiny of the role of gene flow in plant evolution. Most plant evolutionists now recognize the importance of gene flow, and it is receiving increased recognition from other areas of plant biology as well.
J.G.C. Lehmann's 'Botanical Observations' of 1818 on Coldenia, Colsmannia, Cynoglossum, and Omphalodes (commented translation)
Authors: Hilger Hartmut , Cole Theodor , Selvi Federico
Published: April 2014

An annotated English translation of a German early 19th century text including Latin diagnoses is presented with a high-quality scan of the original publication and direct links to the cited pages with taxon and literature citations (including TL-2 entries).
Study on the Extraction of Phenolic Compounds from Model Oil by Using Ionic Liquid
Authors: Zhuang Xu Lei , Li Zhen Qiu , Wang Er Qiang
Published: April 2014

This study proposed green ionic liquids (ILs) as solvent to extract phenolic compounds from model oil. The effects of reaction time (0-80 min), reaction temperature (10-60 °C), and phase volume ratio of BmimBF4 / phenol were investigated. The phenolic compounds existed in the lower layer were separated from the oil products, and analyzed by Liquid Chromatography; the oleic layer was analyzed by gas chromatography. The selectivity of two kinds of cresols was studied. A variety of ILs (BmimBF4, EmimBF4, BmimPF6, EmimNTf2) were used in this study and the effect of concentration difference between the o-cresol and m-cresol and the reaction temperature (10-60 °C) were explored.
Recent Development of Biomass Fast Pyrolysis Technology and Bio-Oil Upgrading: An Overview
Authors: Ab Rasid Nurul Suhada , Asadullah M.
Published: April 2014

The increasing demand of energy has led to the development of renewable energy in order to mitigate the dependency of fossil fuels. Fast pyrolysis of biomass is one of the most anticipated renewable energy technologies since it has a huge potential to become the efficient, environmentally sustainable, and cost effective technology for energy. Fast pyrolysis process produces liquid bio-oil as a main product, along with solid char and combustible gas. Bio-oil can be utilized for heat and power generation as well as it can be used as a feedstock for pure chemicals production. Over the last decades, numerous researches have been conducted in order to develop the process in terms of reactor design and process optimization in order to achieve the high yield of liquid with high organics and less water content. The aim of this review is to provide the state of the art on fast pyrolysis of biomass with some suggestions presented on upgrading the bio-oil. Based on the recent reactor configurations, current status of biomass fast pyrolysis in commercial scale around the world, the fuel and chemical characteristic of bio-oil compared to the conventional fossil fuels, and the potential application of bio-oil in the future, some recommendations are proposed.
Gasification of Oil Palm Biomass to Produce Syngas for Electricity Generation – Cost Benefit Analysis
Authors: Hanina N. , Asadullah M.
Published: April 2014

Fossil fuel burning for energy production creates two major issues: the global warming effect and the weak energy security. These problems can be minimized by utilizing renewable energy sources such as biomass. In order to assess the potential contribution of these technologies to the future energy security and sustainable development, a thorough evaluation of gasification technology towards economic aspects is required. This study aims to determine whether the syngas production from EFB gasification for electricity generation is viable in terms of cost-benefit analysis by evaluating the economic aspects of these technologies.
Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics
Authors: Zhang Bao Lin , Zhang Bin Bin , Wang Ning Ning , Fei Jing Ming
Published: April 2014

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).
The Microwave Synthesis and Photocatalytic Activity of InVO4 Nanocrystalline
Authors: Lei Jian , Zhu Quan Xin , Xiong Wan Qing , Ye Wen Xiang , Liao Xue Hong
Published: April 2014

Indium vanadate nanocrystalline was prepared by Indium chloride, vanadium (V) oxide as raw materials and sodium dodecyl sulfate as surfactant under microwave irradiation. The sample was characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM). We studied the photocatalytic activity of the as-prepared samples using degradation of methyl orange in visible light. It shows that the photocatalytic activity of Indium vanadate nanocrystalline was very well. It found that when the catalyst calcined at 773 K was 0.10 g, and 0.3 mL hydrogen peroxide joined as well as pH was 2.0, the degradation ratio of InVO4 for methylene orange of 100 mL 2 mg/L reached 75% in 50 min.
Photo-Thermal Conversion and Stability of Gold and Silver Nanostructures
Authors: Ni Yuan , Kan Cai Xia , Cong Bo , Liu Jin Sheng , Xu Hai Ying
Published: April 2014

Gold and silver nanostructures (such as Au nanorods and Ag nanoplates) exhibit strong and tunable surface plasmon resonance in the near-infrared region (NIR). Under a certain NIR laser irradiation, noble metal nanostructrues achieve a high photo-thermal effect, which would be useful in the therapy. In this work, Au nanorods with longitude surface plasmon resonance (SPRL) shifting in the region of 650 ~1100 nm were synthesized by a seed method. Ag nanoplates and nanocubes with SPR located in the region of 650~850 nm were produced by a hydrothermal method. Through adjusting laser power and irradiating time, the photo-thermal conversions of these nanostructures were studied under NIR laser irradiation. Under low power laser (808 nm, <1W) irradiation, the shape of the Au nanorods are stable and the temperature of colloid increase from room temperature to ~57°C. However, Au nanorods undergo deformation from rod to spherical particle under irradiation of high power (808 nm laser; 6W; 1064nm laser, 7W), resulting in the disappearance of SPRL. Morphology evolutions and photo-thermal conversion of Ag nanostructures were also studied. Ag nanostructures have a lower photo-thermal conversion compared with that of Au nanorods colloid. Snipping and dendrite can be observed for Ag nanoplates after irradiating, while Ag nanocubes have no obvious shape change.
Structural and Mechanical Properties of Poly(ε-Caprolactone) Biocomposites Reinforced with Different Silk-Fibroin Fabric Structures
Authors: Wu Yong Min , Liu Xin , Sun Jun Cheng , Wang Le Zhi , Yao Zhong Shan , Dong Jian Jian , Sui Kun Yan
Published: April 2014

To develop novel biocomposites, three different silk-fibroin fabrics (plain woven fabric, plain weft-knit fabric and non-woven fabric) were, respectively, blended with poly (ε-caprolactone) (PCL) by a solution blending method. The effects of various fabric structures on the mechanical and microstructure properties of silk-fibroin fabric reinforced (SF-fabric-reinforced) PCL biocomposites were investigated. It was obvious that the breaking strength and elongation of SF-fabric-reinforced PCL biocomposites decreased while the Youngs modulus increased. Scanning Electron Microscopy (SEM) photographs showed that silk-fibroin fabrics were well bonded with PCL matrix. From Wide-Angle X-ray Diffraction (WXRD) analysis, plain woven and plain weft-knit fabrics showed higher ability to increase the crystallinity of PCL matrix compared with non-woven fabric.
Electrospun Absorbable Polycaprolactone (PCL) Scaffolds for Medical Applications
Authors: Wang Ying Chu , Zhang Pei Hua
Published: April 2014

The electrospun scaffold plays a crucial role in tissue engineering for its unique structure which can mimic the structure and biological functions of the natural extracellurlar matrix (ECM). This study discuss the effects of electrospinning parameters, such as applied voltage, tip-collector distance, DMF content percentage and polymer concentration, on the porosity and the surface area of electrospun fibrous scaffolds. The results show that the fiber diameter of electrospun scaffold can be increased with the lower applied voltage, the shorter the tip-collector distance, the smaller DMF content percentage or the higher the polymer concentration. The PCL electrospun scaffolds have high porosity ranging from 85.5 to 92.4%. Furthermore, the surface area to volume ratio exhibits a clear relationship with the fiber diameter. The surface area can be improved through decreasing the diameter of nanofibers.
Effect of Calcium Titanate and/or Titanium-Phosphides in the Properties of Titanium Composites for Implant Materials
Authors: Gemelli Enori , da Silva Maia Patrícia Borges , Nery Fabio , Camargo Nelson Heriberto Almeida , Henriques Vinícius André Rodrigues , de Jesus Jailson , Franczak Priscila Ferraz
Published: April 2014

Titanium-based composites containing TixPy phase (s) or CaTiO3 and TixPy phase (s) were produced by a non conventional method using suitable mixtures of TiH2 powder and phosphoric acid (TiH2/P), or TiH2 and 10 vol.% of calcium phosphate (TiH2/CP), respectively. The composites were produced with the same phosphor molar concentration. The mixtures were prepared by ultrasound in water, dried in a rotary evaporator, pressed at 600 MPa and vacuum-sintered at 1200 °C for 2 hours. The mixtures were well dispersed by ultrasound and agglomerate-free. The analyses show that titanium particles were coated with TixPy phase (s) for the TiH2/P composite or with an intermediary layer of TixPy phase (s) and an external deposit of calcium titanate for the TiH2/CP composite. The TiH2/P composite presented higher compressive strength and about the same contact angle compared to the TiH2/CP composite. However, both materials displayed lower contact angle than that of pure titanium.
Rheological Behaviors of Carbonaceous Materials Suspended in Sodium Alginate Solutions
Authors: Liu Hai Xiang , Tan Ye Qiang , Zhang Qing Xu , Qin Xue , Zheng Ran Ran , Sui Kun Yan , Xia Yan Zhi
Published: April 2014

Three kinds of carbonaceous materials with different structural and chemical properties, Carbon Black (CB), Multi-walled Carbon Nanotubes (MWNTs), and Graphene Oxide (GO), were well suspended in sodium alginate (SA) solutions, and the suspension rheological behaviors were investigated in details. Steady rheological results showed that the suspensions exhibited same shear-thinning behaviors as SA solution. Dynamic rheological results showed that the complex viscosity (η*) was similar to that of steady rheological measurement, and both SA solution and SA/carbonaceous materials suspensions exhibited liquid-like behaviors, confirmed by the loss modulus larger than the storage modulus. The loss factor tanδremarkably decreased for SA/GO solution compared with SA/CB and SA/MWNTs suspension at the same concentration, indicating the increase of elasticity via interactions between the GO and SA.
Improvement in the Low-Fire Dielectric Compositions with Middle Permittivity for LTCC Applications
Authors: Zhang Yong Gang , Wu Xiao Gang
Published: April 2014

Low temperature co-fired ceramics (LTCC) technology becomes crucial in the development of various modules and substrates in electronic packaging, especially in wireless and microwave applications [. self-integrated component has laid basis on flexibility of design, wiring density and dependability for multilayer structures due to LTCC technology. Recently, with the rapid progress in wireless communications,to realize more highly integrated passive components in multilayer LTCC structure, however, it is important to control the matching behavior between component and substrate. The dielectric compositions the permittivity range of which is 20100 are most appropriate for realizing strip or microstrip resonator structures in LTCC multilayer structures due to the RF frequency range which is used in current telecommunication systems (130GHz) and the desirable chip sizes in the current technologies (210 mm)[.
Statistical Analysis of Pit Dimensions for Pre-Corroded AA 7075-T6
Authors: Huang Yong Fang , Chen Li Jie , Ye Xu Bin
Published: April 2014

Aluminum alloy 7075-T6 specimens were corroded in 3.5% NaCl solution for 120 hours and 240 hours, respectively. Morphology and dimensions of corrosion pits on specimen surface were inspected with white light confocal profiler. Statistical analysis shows that pit dimensions can be fitted well with log-normal and Gumbel distribution. After surface inspections, we performed high-cycle fatigue tests for the specimens. Fracture analysis shows that fatigue cracks initiate from single pit or two adjacent pits, and the crack-initiation pit shape and dimensions were examined with SEM. It is found that initiation pit dimensions can be well described with the log-normal distribution. Additionally, initiation pit dimensions are significantly larger than those measured on specimen surface before fatigue tests.
The Extrusion Behavior of AZ31 Mg Alloys by Finite Element Simulation
Authors: Li Ping , Wang Shou Ren , Wang Yong , Xue Guang Ji
Published: April 2014

The three-dimensional finite element (FE) numerical simulation of extrusion forming of AZ31 matrix magnesium alloy was analyzed in four extrusion velocities. The flow pattern and the influence of extrusion velocity for the temperature, the distribution of effective stress and strain of composites were analyzed. The results showed that, when the extrusion velocity increased from 1.5 mm/s to 4.5 mm/s, the heat flux under steady extrusion state would change from-2.77e+004 (Wm2) to 1.14e+005 (Wm2), meanwhile the effective stress and strain increased at first and then decreased, and the average effective strain and stress value were smallest when v = 4.5 mm/s. It showed that along with the increase of the extrusion velocity, the rise degree of the temperature increased and the distribution of the effective stress and strain tended to be more evenly. Finally, the best extrusion technical parameters of AZ31 magnesium alloy were determined, that was the extrusion velocity was equal to 4.5 mm/s when extrusion ratio was 25 and extrusion temperature was 350 °C.
Evolution of Wear on the Abrasive Tool during the Polishing of Porcelain Tile Using Morphological Space
Authors: Pinheiro Sousa Fabio Jose , Seewig Jörg , Chiamulera Catia , Alarcon Orestes Estevam , Weingärtner Walter Lindwolf
Published: April 2014

Costs with the polishing process represent nearly a third of what costumers pay for polished floor tiles. This is in part due to the high consumption of cemented-matrix abrasive tools, whose demand is about half kilogram per square meter final product. The present study addresses the wear of such abrasive tools, colloquially known as fickerts in the industrial polishing process of ceramic tiles. The focus was set on the evolution of the fickert ́s surface during polishing. The fickert ́s topography was periodically measured by both optical and confocal microscopy. The abrasive tool was submitted to a sequence of ten polishing steps of one second each. All variations were quantitatively characterized and were successfully represented by means of the morphological space. Such space is in turn composed by two statistical parameters: the skewness and kurtosis, both based on the distribution of heights collected from roughness profiles taken along the fickert ́s active surface. The experimental points showed a linear relationship between skewness and kurtosis, in a very good accordance with the behavior expected for typical abrasive wear.
Synthesis of Hierarchy-Structural BaTiO3 Powder Used for X8R Multilayer Ceramic Capacitors by Two-Step Soft Chemical Method
Authors: Wang Jing , Rong Gui Juan , Ding Yu , Wang Ting Wei , Yao Hao
Published: April 2014

Ba0.985Bi0.01TiO3-BaTi1-xZrxO3 powders have been synthesized by two-step soft chemical method to satisfy EIA-X8R specification. Microstructural evaluation conducted by X-ray diffraction and scanning electron microscopy confirms the hierarchical structure of the ceramic grain. The shape of the ε-T curves near the dielectric peak becomes broad with the increase of Zr content. The permittivity of Ba0.985Bi0.01TiO3-BaTi0.9Zr0.1O3 ceramic is ~3000, C/C20 °C is-14.67%, 6.23% and-14.50% at-55°C, 130°C and 160°C, respectively, and the dielectric loss is less than 0.020. This work shows that the two-step soft chemical method is a promising approach for high performance temperature-stable capacitor materials.
Study of the Effect of Cement Asphalt Mortar Disease on Mechanical Properties of CRTS II Slab Ballastless Track
Authors: Liu Fu Shan , Zeng Zhi Ping , Wu Bin , Zhang Zhi Chao , Peng Kui
Published: April 2014

This paper built the three dimension mechanics model of CRTSII slab ballastless track structure on subgrade with ANSYS software. Analysis the influence of deformation and stress characteristics caused by different temperature gradients and the coupling action of temperature gradients and train loads under different work conditions, including no-separated, separated, and multiple-slabs separated with the cement asphalt mortar layer. The results show that, temperature gradients on track slab is one of the main reasons which caused the gap appearing between the bottom of slab track and cement asphalt mortar elastic cushion. And the joint main cause the deterioration of vibration of track slab, accelerating the deterioration of the cement asphalt mortar layer.
High Efficient Photoreduction CO2 with H2O on Metal Cu-Modified Graphitic Ordered Mesoporous Carbon Supported TiO2 Catalysts under Simulated Solar
Authors: Zhang Cheng Li , Kang Shi Fei , Zhang Qian Yu , Li Xi
Published: April 2014

Cu-modified graphitic ordered mesoporous carbon supported TiO2 catalyst was synthesized based on a hard template method. X-ray diffraction, nitrogen adsorption-desorption, scanning electron microscopy and transmission electron microscopy analysis techinques were used to characterize the sample. It was observed that copper and anatase TiO2 nanoparticles were well dispersed in the Cu-modified mesoporous graphitic carbon, and the resulting composite with ordered mesostructure and high specific surface area exhibited an exceptionally high activity in the photocatalytic reduction of CO2 with H2O under simulated solar irradiation.
Effect of H3BO3 Coating on the Microwave Dielectric Properties of BZN Ceramics
Authors: Yang Liu Shuan , Jin Biao , Wang Xiao
Published: April 2014

(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7(BZN) ceramic samples were prepared by solid state reaction. B2O3 was introduced by liquid coating technology with H3BO3 solution in the BZN ceramic specimen to reduce its sintering temperature. The sintering behavior, phase composition and dielectric properties of ceramics were investigated by X-ray diffraction, scanning electron microscopy and vector network analyzer. The (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramic composite could be sintered well at 900°C for 3h when 0.9M/l H3BO3 was added and showed good dielectric properties of εr=150,Q×f=228,τf=-362ppm/°C.
Calculations of Absorbed Dose in Heavy-Ion Irradiated Phase-Change Memory Cells
Authors: Zdjelarević Nevena , Timotijević Ljubinko , Marić Radeta , Stanković Koviljka , Vujisić Miloš
Published: April 2014

Heavy ion irradiation on phase change memory cell was conducted using Monte Carlo simulations. Absorbed dose in the whole memory cell, as well as in its active layer was assessed. Phase change memory cell was modeled as a sandwiched structure of two TiW electrodes and ZnS-SiO2films as insulators surrounding the active region. The most commonly used phase change material, Ge2Sb2Te5, was used as active layer of the cell. Ionization effects of heavy ion irradiation were investigated for various thicknesses of phase change layer and different ion energies.
A Fluorescence Quenching Study for the Interaction of 2,6-bis(5-(p-methylphenyl)-1-H-pyrazol-3-yl)pridine with Zn2+ Ion
Authors: Pi Yan , Liu Hua , Wang Dun Jia
Published: April 2014

The synthesis of a novel bispyrazole derivative 2,6-bis (5-(p-methylphenyl)-1-H-pyrazol-3-yl) pridine (BMPP) was described and its structure was conforrmed by1H NMR, FTIR, MS techniques and elemental analysis. The interactions of Zn2+ion with BMPP were assessed by fluorescence quenching techniques. The results revealed that the quenching effect is resulting from the formation of Zn2+-BMPP nonfluorescent complex. The SternVolmer curves suggested that the quenching effect was the static quenching. The main action forces of these reactions was spontaneous, mainly hydrogen bonds and ΔS-driven obtained by using thermodynamic equations.
Life Cycle Assessment of Steel Production
Authors: Hu Jiang Yuan , Gao Feng , Wang Zhi Hong , Gong Xian Zheng
Published: April 2014

Based on life cycle assessment, analysis of energy consumption and other environment load by steel production in Chinese typical iron and steel industry was carried out. The process accounted for the most environment load was found by studying the different processes in steel production route. The results indicate that the most important process is blast furnace (BF) which is the major factor of CO2 and CO emissions, and contributes most to globe warming potential (GWP) and photochemical ozone creation potential (POCP).
Electrochromic Property of Cured Epoxy Resins Containing Triphenylamine Moiety
Authors: Li Hong Ling , Bai Xu Duo , Zhu Yu , Wang Yan Qiu , Liang Yu , Niu Hai Jun
Published: April 2014

4-Phenoxy-4', 4''-diaminotriphenylamine was synthesized from N, N-diarylation of 4-amino diphenyl ether and 4-fluoro nitrobenzene, and subsequent reduction of the resultant dinitro compound. The prepared triphenylamine and 4-methoxy-4', 4''-diaminotriphenylamine were dissolved in acetone respectively as the curing agents with epoxy resins to obtain a homogeneous mixture of the reactants. The cross-linked polymer film, which was well adhered to the ITO glass were cured by gradually increasing the temperature under N2 atmosphere. The cured epoxy resins films exhibited good thermal stability and electroactive properties. CV of the films revealed two pairs of reversible redox peaks, with coloration change from the colorless neutral state to the blue oxidized state.
Study on the Recovery and Recycling Standard System of Abandoned Fluorescent Lamps in China
Authors: Wu Yu Feng , Gu Yi Fan , Li Yan Mei
Published: April 2014

Compared to incandescent bulbs, the advantages of the fluorescent lamps (such as less energy consumed and longer life expectancy) have greatly contributed to their rising use all around China, which leads to an increase in the number of the abandoned fluorescent lamps when they reach their end of life. However, their recovery and recycling (R&R) rate is still at a low level because it is lacking a complete standard system. In order to raise the R&R rate of abandoned fluorescent lamps in China. In this investigation the characteristics of the R&R standard system of abandoned fluorescent lamps in the developed countries has been analyzed, the deficiencies of the existing R&R standards studied, and a framework of the system suitable for China built.
Correlation Analysis between Emission and Impact Factors of Greenhouse Gases Caused by Production of Primary Aluminum
Authors: Guo Jie , Gao Feng , Wang Zhi Hong , Liu Yu , Hu Jiang Yuan , Li Zhu
Published: April 2014

Aluminum is an essential material for the construction and development of national economy, however the GHG (greenhouse gas) emissions caused by its production have been noticed by China’s government gradually. In this study, the life cycle energy consumption and GHG emissions caused by the production of primary aluminum in different years in China were calculated, and the correlation between GHG emissions and some important factors i.e. resource consumption and procedure energy consumption was analyzed. The final results show that for GHG emissions, electricity is the major contributor that accounts for 68.5% of the total, followed by the emissions of anode effect and calcination of limestone, which accounts for 7.9% and 6.8% respectively, and the percentages other factors account for less than 6%. The results also show that the calcination of limestone, combustion of coal gas and consumption of electricity are the three main factors which have the largest correlation degree with GHG emissions, and their correlation degrees are 0.96, 0.94 and 0.90 respectively. Therefore, decreasing the consumption of coal gas and improving the efficiency of the calcination of limestone are effective ways to decrease the GHG emissions of primary aluminum production.
Analysis on the Energy-Saving Property of Solar Heat Reflective Coatings on Building in Beijing
Authors: Mao Qian Jin , Lv Qiu Rui , Wang Ya Li , Ma Xiao Yu , Wang Rui , Cui Su Ping , Wang Zi Ming
Published: April 2014

To discuss the effect of energy saving of heat-reflective coating on building, the heat gain of exterior building envelope in summer and winter in Beijing has been calculated. The results indicated that the higher the reflectivity of coating, the better the energy saving effect. The energy consumption of roof and different direction walls were analyzed. The energy saving effect on roof is the best, however the effect is not obvious on the east and west walls. The heat reflective coating has no effect on north wall but exhibits effect on south wall. The energy saving effect of brick red heat-reflective coating is not obvious compared with the common brick red coating.
A Life Cycle Inventory Case Study for Marble Mining in China
Authors: Meng Xian Ce , Li Chen , Wang Zhi Hong , Gong Xian Zheng , Liu Yu , Sun Bo Xue
Published: April 2014

The goal of this paper is to conduct a life cycle inventory (LCI) case study for marble mining in China. The scope focuses on the whole life of marble mining. The functional unit is “per cubic meter of marble block”. The LCI data, including the input of energy and natural resources and the output of pollutant emissions, were collected on-site. The LCI results show that if the waste quarries could be recovered after the exploration, the environmental damages from the marble decorative materials would be much less. The environmental impacts of fresh water consumptions are also discussed. Some suggestions and recommendations on how to improve the environmental performance, at the same time the marble materials can be produced to support the increasing sales, are made. In the future, the land use and the mine recovery should be discussed.
Comparative Study on Life Cycle Assessment for Typical Building Thermal Insulation Materials in China
Authors: Ma Li Ping , Jiang Quan , Zhao Ping , Zhao Chun Zhi
Published: April 2014

Studies on life cycle assessment of three typical building thermal insulation materials including polystyrene board, rock wool board, and rigid foam polyurethane board related to building energy-saving were carried out. Based on the method of life cycle assessment, "1 kg of thermal insulation material" is first selected as one of the functional units in this study based on the production field data statistics and general market transaction rules of the thermal insulation materials, and life cycle resource consumption, energy consumption and exhaust emission of the three products in China are deeply surveyed and analyzed. The abiotic depletion potential (ADP), primary energy demand (PED), and global warming potential (GWP) for production of 1 kg of the three thermal insulation materials are calculated and analyzed. Furthermore, the functional unit is extended to be "1 m2 of thermal insulation material meeting the same energy-saving requirements" so as to compare the difference of environmental friendliness among the three building thermal insulation materials, and the corresponding life cycle environmental impact is also calculated and analyzed. As shown by the results, where calculated in unit mass, the order of production life cycle environmental impact significances of the thermal insulation materials is as follows: rock wool board < polyurethane board < polystyrene board. However, where calculated in unit area (m2) meeting the 65% energy-saving requirements, the production life cycle environmental impact significances of the three kinds of insulation materials are sorted as polystyrene board < polyurethane board < rock wool board, whatever the region is, which is opposite with that of the results for the insulation materials in unit mass (kg). The reason for such difference is that they have different volume weights and heat conductivity coefficients. The polystyrene board has a smaller volume weight and the smallest heat conductivity coefficient, whereas the rock wool board has the highest volume weight and heat conductivity coefficient.
Source of the project fund. Subject "the Research and Application of Life Cycle Assessment Technology to the Building Materials for Building Engineering in Typical Regions" of the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (No.: 2011BAJ04B06)
Structural and Optical Properties of ZnO1-xSx Thin Films Grown by Pulse Laser Deposition on Glass Substrates
Authors: Zhang Lei , Wang Liang Heng , Li Ming Kai , Shang Xun Zhong , He Yun Bin
Published: April 2014

With a wide band gap of 3.4 eV and a large exciton binding energy of 60 meV at room temperature, ZnO is attractive for blue and ultra-violet optoelectronic devices, and transparent conducting oxide films for photovoltaic applications. For a semiconductor to be useful, particularly in reference to optoelectronic devices, band gap engineering is of great importance in device development. Alloying of MgO and CdO with ZnO has been studied extensively in comparison to other ZnO alloys incorporating equivalent anions like ZnO1-xSx (ZnOS). In this work, high-quality ZnOS thin films were grown on glass substrates by pulsed laser deposition using a ZnS ceramic target with varying O2 partial pressures between 0 and 6 Pa. ZnOS alloys with a wurtzite structure were achieved and no evident phase separation was observed in the whole composition range as determined by X-ray diffraction. The optical transmission measurements show that the average transmittance in the visible range of the films is about 80%. The absorption edges of the films first shift towards low-energy side with increasing the oxygen partial pressure and then blueshift when the oxygen partial pressure is over 2 Pa. The bandgap energies of the ZnOS films were calculated to change from 3.06 to 3.72 eV, showing a nonlinear variation with a bowing behavior that was previously reported.
High Quality AlN Thin Films Deposited by Middle-Frequency Magnetron Sputtering at Room Temperature
Authors: Li Chuan , Shu Lin , He Li Jun , Liu Xing Zhao
Published: April 2014

A study of depositing high quality c-axis oriented polycrystalline aluminum nitride thin film at room temperature was presented. Aluminum nitride films were grown by mid-frequency (MF) reactive sputtering. Metallic aluminum target was used to deposit AlN films in Ar/N2 gas mixture. A 50nm thick of N-rich AlN buffer layer was deposited at the initial stage of sputtering process to improve the film quality. The composition, preferred orientation and residual stress of the films were analyzed by EDS, XRD and Raman microscope, respectively. The results showed that the N-rich AlN buffer layer improved the textured degree and reduced the residual stress significantly of the AlN thin films. The near stoichiometric AlN thin film with highly textured degree was obtained. The FWHM value of the rocking curve for (0002) diffraction peak was about 1.6°, and the residual tensile stress was about 500MPa. The piezoelectric d33 coefficient increased with the decreasing of FWHM value, and the highest d33 coefficient of 3.6 pF/C was obtained.
Effects of (Li, Ce) Co-Doping on Microstructure, Dielectric and Ferroelectric Properties of Strontium Niobate Ceramics
Authors: Chen Gang , Wei Jie Hao , Peng Xiao Dong , Fu Chun Lin , Cai Wei
Published: April 2014

Sr2-x(Li2/3, Ce1/3)xNb2O7(x = 0, 0.05, 0.1, 0.2, 0.3, 0.5) (SLCN) ceramics were prepared by solid-state reaction method. The microstructure, dielectric and ferroelectric properties were investigated. The results show that all ceramics have high relative densities. Li+and Ce4+co-doping can promote the grains growing, and improve the dielectric and ferroelectric properties of strontium niobate ceramics. The dielectric constant decreases firstly, and then increases with the increasing of x in Sr2-x(Li2/3, Ce1/3)xNb2O7, and the sample with x = 0.5 exhibits enhanced dielectric properties (εr≈ 250, tanδ ≈ 0.02). The remnant polarization (Pr) and coercive electric field (Ec) of SLCN ceramics increase firstly, and then decrease with the increasing of Li+and Ce4+content, finally reach the maximum value of remnant polarization (Pr≈ 0.058μC/cm2, Ec ≈ 6.87 kV/cm ) for x = 0.2.