bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure Calculation of Die Carrier and Determination of Pre-Camber of Main Girder of Cable Stayed Bridge
Authors: Xu Hong Yu , Cui De Yong , He Cong
Published: April 2014

Based on the cable stayed bridge on Zhenshui Road in Xinmi City, structure calculation of die carrier and determination of construction pre-camber of its main girder were studied. Using the finite element method, the deformation of die carrier was calculated under the prepressing condition of supporting structure by ANSYS software. Considering the main influence factors, the calculated construction pre-camber was obtained and the construction pre-camber was determined. The comparison between the calculated camber and the actual measured camber of main girder was accomplished. It showed that the error was very small. This study shows that according to the calculated pre-camber, the determination of construction pre-camber is more reasonable. The linear control of main girder can attain excellent engineering effect. It has certain guiding significance for designing similar bridge to determinate the construction pre-camber of main girder.
The Key Technologies Research in Demolition Construction of Liuxi River Bridge
Authors: Wen Hai Qiang , Zhang Zhi Lin , Luo Wen Jin , Jia Bu Yu , He Zhen Zu , Chen De Yi
Published: April 2014

Because the flow of river bridge was not suitable for bearing existing vehicle load, it is needed to be dismantled, and a new bridge will build on the original site. The overall construction plan is using double bridge girder erection machines to remove box girder and the suspended beam of the main bridge. In order to guarantee the security of assembling the bridge girder erection machines and lifting the beam, we did some research in assembling technology, using the finite element software MIDAS to establish model of sling equipment, and analyses whether the sling equipment can bear the design load . With the purpose of ensuring the stability and safety of the suspended beam in the process of hoisting, the suitable order of hoisting suspended beam and risk control of slipping the suspended beam were analyzed. For purpose of guaranteeing the stability of the hoisting box girder, the construction team designed the stabilization system. Due to the complexity of the stress of the girder in the demolition process, we use the finite element software ANSYS to establish the model of e box girder in the process of hoisting, and analyze its stress and deformation. According to the practical engineering, we draw a conclusion: the box girder, suspended beam remained stable in the process of hoisting, and their internal forces conform to the requirements of the specification. The overall construction plan can provide a reference for other similar projects.
A Statistical Damage Constitutive Model for Brittle Rocks Based on the Lade-Duncan Failure Criterion
Authors: Tian Zhen Yuan , Wang Wei , Li Xue Hao , Xu Wei Ya
Published: April 2014

Micro-unit strength of rock is randomly distributed based on Lemaitres strain equivalence assumptions. The paper presents a method for measuring micro-unit strength taking into account the damage threshold. Assuming that the micro-unit strength obeys the Weibull distribution, combined with the Lade-Duncan failure criterion, a new statistical damage constitutive model for brittle rocks is established and the model parameters m and F0 are determined. The model can simulate the stress-strain relation of full process of rock failure well, especially reflects the influence of different stress on damage threshold and the linear elastic characteristic under low stress for rock. The good accord verifies the validity and feasibility of the new model.
Experimental Study of Meijiang Artificial Island Fill
Authors: Su Xiao Cheng , Wang Xiao Yun , Liu Zhi
Published: April 2014

The artificial island physical and mechanical property of fill index has a great influence on the island stability and the development of displacement. The fill is generally composed of a lot of construction rubbish, industrial waste or the living garbage .We discuss the relationship between shear strength and coarse particle,density relations under different compactness through the experimental study in this paper. The results show that cohesion increases with the content of coarse particles,and compression modulus increases along with the increase of the density. When the content of coarse changed from small to large, compression modulus increases with the increase of coarse grain content at the beginning. When the content of coarse reached 20%, compression modulus with compaction degree increases fastest.
Discussion on the Rationality Simplified Calculation Method of Reinforced Concrete Two-Way Slab
Authors: Liu Shu Zhi
Published: April 2014

We analyzed the rectangular slab with four sides supported, respectively elastic and plastic methods of calculation the slab. Generally considered l2/l1≤2 calculated as the two-way slab, 2< l2/l1<3 should be calculated as the two -way slab, however l2/l1≥3 calculated as one-way slab, consider these provisions is not reasonable, analysis shows, if using elastic or plasticity theory analysis, l2/l1 <3, or l2/l1 <4 as the two-way slab. Otherwise, it is one-way slab. Reasonable distinction between one-way slab and two-way slab are meaningful, not only simplifies the calculation, but also makes the design economical, safe and reliable.
Ground Response of Seasonal Frozen Site under Moderate Intensity Earthquake
Authors: Chen Zhuo Shi , Yuan Xiao Ming , Meng Shang Jiu
Published: April 2014

The seasonal permafrost is widely distributed in China. Seismic Design Code (GB50011-2010) assumes that the soil temperature is above 0°C, which lacks the analysis of seasonally frozen soil. This article considered various sources of shear wave velocity variability and the frozen depth variability and calculated the ground response spectrums of the sites with seasonal frozen soil. The results shows that when Class1 and Class2 venues with thinner overlying soil and higher shear wave velocities their peaks of response spectrum with frozen soil will higher than that without permafrost. In the design the spectrums with frozen soil need to be calculated independently. In Class 3 and Class4 venues the response spectrums are essentially coincident, so the design only need calculate the spectrums under normal condition.
Predicts Based on Multi Modality Support Vector of the Settlement of Composite Foundation
Authors: Zhang Li Hua , Liu Hai Bo , An Feng Ping
Published: April 2014

Composite foundation settlement is affected by many factors, and settlement data is a non-linear changing process with complexity, suddenness and progressive nature and so on. So we must analyze and predict the stability of the foundation settlement. Because empirical mode decomposition (EMD) provides a new way for foundation settlement prediction, we can extract modal signals associated with the foundation settlement mechanisms by decomposing the monitoring data of settlement by EMD and use the support vector machine ( Support Vector Machine, SVM) modal to predict the obtained signal, Calculation results of the modal synthesis and accumulation of foundation settlement, get the evolution of Change with the time of foundation settlement. Combined with the engineering example for the application ,shows that the prediction model has good effect in multi modality support vector, a high degree of agreement with the monitoring values, indicating that this method has a promotional value.
Displacement Control Technology on High-Rise Steel Structure about Main Power House of Thermal Power Plant
Authors: Liu Huan Qin , Li Wei Bin , Ma Kang
Published: April 2014

With the background of optimal design study on main powerhouse of Power Plant, the finite element software ANSYS is adopted to control the overall structure's displacement. After the choice of structural form and loads bearing system, the static and dynamic characteristics of this boiler steel frame are analyzed in detail. And the structure's displacement response of this boiler steel frame will also be discussed under permanent load, wind load and seismic action. The structural displacement response causing by four wind load cases (front wind, back wind, left wind and right wind) is emphatically discussed and the dynamic characteristics and response spectrum analysis are also be studied. Results show that this main powerhouse owns good seismic performance and excellent lateral displacement resistance capacity because of the high structure stiffness. It shows that the horizontal displacement of the whole structure under all load cases can meet the requirements of the limit value, which demonstrates the feasibility of this structural program.
Research of Stratigraphic Classification Based on Difficult Degree of Construction
Authors: Duan Yuan Qing , Li Yong Quan
Published: April 2014

The principles about soil formation and the difference between rock and soil are introduced. The general knowledge about stratigraphic classification is interpreted in detail. Based on several hundred geological survey report about construction and renovation, one new classification method based on difficult degree of construction is put forward, by which rocks are divided into three levels on the base of Protodyakonov's coefficient f, and soils are divided into three levels on the base of geological age. The classification method put forward is helpful for estimating the difficulty of the construction, construction amount and Construction time.
Research on Application of Suction Bucket Foundation for Transmission Tower in River Network Area
Authors: Qin Li , Zhu Jin Xin , Zhao Si Wen
Published: April 2014

Because the suction bucket foundation is construction period and low cost advantages,application of suction bucket foundation is more and more widely. In this paper, whether the suction bucket foundation can be used as the basis of transmission tower in river area were studied.According to the working mechanism of bucket foundation in soft clay ground and characteristics, through ABAQUS finite element simulation, bearing capacity under the pressure and uplift ultimate draw suction bucket foundation, and compare with the experimental results, verify the feasibility and accuracy of simulation.According to the transmission requirements of bearing capacity of the foundations,design the basic size,and verify whether the requirements of bearing capacity of foundation, confirmed the suction bucket foundation can be applied to the area of river network transmission tower.
Stress-Strain State of Weightless Inhomogeneous Array with Cylindrical Hole
Authors: Andreev Vladimir I.
Published: April 2014

When creating underground pipelines, tunnels and other long cylindrical holes often used drilling-and-blasting method of penetration. Depending on the type of rock in the array may be local induration or sintering which results in increase in the deformation properties of the ground, or cracking resulting in a decrease in deformation properties. Thus the array becomes inhomogeneous. The article provides a calculation of the stress-strain state of array considering its local inhomogeneity.
Dynamic Analysis of Tapered Plates Based on Higher Order Beam Theory
Authors: Ibrahim S.M. , Al-Salloum Y.A. , Abbas H.
Published: April 2014

Modal solutions of plates with uniformly varying cross section using unified beam theory are presented. The results are given in the form of Euler-Bernoulli, Timoshenko and quasi 3D solutions. Numerical results for cantilever and CFCF supported rectangular planform plates are presented. Different types of modes, i.e. axial, bending and torsional modes are observed. The frequency values are in good agreement with 3D finite element results as well as published literature. Due to uniform taper in plate cross section, bending vibration modes become asymmetric along the longitudinal axis of the structure. Further, it can also be noticed that the vibration behavior of thick tapered plates is characterized by the appearance of significant number of axial and torsional modes at lower frequency values.
The Comparison of the Loess Mechanical Properties under Plane Strain and Conventional Triaxial Experiments
Authors: Ma Lin
Published: April 2014

Plane strain problem is currently prevalent in the loess engineering. However, this problem still using conventional triaxial test method for processing. So the paper conducted the plain strain test, analyze differences in plane strain experiments with conventional triaxial experiments under different moisture content and confining pressure. Research shows two points, the first one is the impact on the strength of the soil is more under moisture content than confining pressure, the other is that the soil strength under the plane strain condition is significantly greater than conventional triaxial conditions. It shows that the results were conservative under the plane strain problem at past. It played a certain role in guiding the engineering.
The Experiment on Soil Water Characteristic Curve Considering the Effect of Urea Concentration
Authors: Dai Gai Qing , Tian Dong Fang , Ruan Yao , Tian Lang , Wang You Le
Published: April 2014

A new soil water characteristic curve (SWCC) experiment contemplating urea concentration is presented in the paper. We focus on the impact of the SWCC considering urea concentration test method for materials selection and introduction, experimental results, and finally, we have conducted some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.
Effect of Loading Pattern on Performance of FRP-HSC-Steel Double Skin Tubular Columns
Authors: Louk Fanggi Butje Alfonsius , Ozbakkaloglu Togay
Published: April 2014

This paper reports on part of an ongoing experimental program at the University of Adelaide on FRP-concrete-steel double-skin tubular columns (DSTCs). The main emphasis of the study reported in this paper was to investigate the influence of loading pattern on the axial compressive behavior of DSTCs. To this end, 12 hollow and concrete-filled DSTCs were manufactured and tested under monotonic or cyclic axial compression. All of the specimens were manufactured using high-strength concrete (HSC). The results of the experimental study indicate that that concrete in cyclically loaded hollow DSTCs exhibits slightly larger strength and strain enhancement ratios than concrete in companion monotonically loaded DSTCs. The results also indicate that concrete in filled DSTCs exhibit slightly larger strength enhancement ratios than and similar strain enhancement ratios to concrete in monotonically loaded DSTCs.
A Scale Model Test on Hydraulic Resistance of Tunnel Elements during Floating Transportation
Authors: Ying Zong Quan , Su Lin Wang , Lin Mei Hong
Published: April 2014

The transportation of tunnel elements is one of the most important procedures of immersed tunnel construction. To investigate the hydraulic resistance of tunnel elements during transportation, hydrodynamic scale model tests of the were carried out in a towing tank for the tunnel element transportation under wave action. The test results show that the hydraulic resistance is linear to the square of towing speed basically. The drag coefficients of the element under different water depths and dragging angles are calculated. The dragging coefficient decreases with the increase of water depth, and increases with the increase of the dragging angle. Finally, the influence of the wave is also discussed for the tunnel dragged in the open sea.
Study of the Safety Evaluation of Urban Subway Operation Based on Extenics
Authors: Bai Shi Mei , Sun Hong Sheng , Zhao Yong Chun
Published: April 2014

In this context, firstly, the safety evaluation index system of subway operation is established on the basis of the recognition and analysis of risk factors. Then, the paper constructs the multi-level extensible evaluation model for subway operation safety with the extension method as the core. Finally, Beijing Changping subway is studied as an example. The risk degrees of the line and its subsystems are determined. A new method for comprehensive evaluation of subway operation safety in china is put forward.
Study on the Model Test of Tunnel Lining Deformation Characteristic under the Frost Heaving Force
Authors: Hu Yi , Li Zhao Yang , Qu Meng Fei
Published: April 2014

To study the lining deformation characteristic of the cold region tunnel under the frost heaving force, a model test was designed, and the low temperature environment in the tunnel of model was made by refrigeration equipment, the groundwater inside the model was frozen, the lining structure deformation characteristic under the frost heaving force was analyzed. The results show that the lining was distorted under the frost heaving force, the lining strain of the tunnel crown and side wall was greatly, the maximum strain is 122μ, the lining strains of inverted arch and foot of wall was less, the minimum strain is 25μ.
Experimental and Numerical Study of Enhancing the Seismic Behavior of Rammed Earth Buildings
Authors: Liu Kai , Wang Ya An , Wang Ming
Published: April 2014

Rammed earth structures are widely used as farmers dwellings in the southwest of China, however, they are extremely vulnerable to earthquake loadings. An economic, environmental-friendly and less-intervention seismic retrofitting technique is required to reinforce these dwellings so as to increase regional seismic capability. A preliminary laboratory testing was conducted to investigate the enhancement of the seismic behavior of the rammed earth wall with externally bonded fibers. Different retrofitting materials and adhesives were tested to characterize their mechanical properties and bonding performance when externally glued on rammed earth blocks. The most suitable and practical retrofitting material and adhesive were chosen based on the experimental results. Furthermore, a numerical analysis was performed to investigate the improvement of the shear capacity of the rammed earth wall with the proposed technique. It was verified that the proposed retrofitting technique is a promising option for seismic retrofitting of rammed earth walls.
Research on the Reparability of Structures Based on Post-Earthquake Residual Deformation
Authors: Hao Jian Bing , Wu Gang
Published: April 2014

The post-earthquake reparability of structures serves a crucial role in modern performance-based seismic design. However, due to intrinsic defects, traditional reinforced concrete structures continuously undergo significant residual deformation during earthquakes. As a result, the repair of these structures can be either technically challenging or economically inefficient. This paper contains a state-of-the-art review of post-earthquake residual deformation. Several technical methods to enhance the reparability of new and existing structures, which incorporate unbonded prestressed tendons or FRP (fiber reinforced polymer) materials, are introduced in this paper.
The Research Status of Wheel-Rail Interaction Study under the Seismic Load Condition
Authors: Wu Zuo Ju , Wang Zhi Jia , Bi Jun Wei
Published: April 2014

In the analysis of dynamic coupling interaction between wheel and rail, there are two kinds of models be widely applied, the Simplified dynamic model and the non-simplified dynamic model. And the calculation principles of these two models have been given in this thesis. At the same time, the calculation advantages and disadvantages also have been introduced. On the other hand, all the various factors which will affect the traffic safety have been summarized in this article, some measures also have been emphasized to avoid the derailment accident when the disaster is taking place.
Experiment Design of the Scale Model of the RC Frame Structure under Internal Blast Loading
Authors: Zhu Xiao Wei , Jia Bin , Liu Tong , Tao Jun Lin
Published: April 2014

Due to the constraints of the cost, the space and other factors, scale model of the building structure is commonly used in the study of blast effect on building structure experiment. However, in order to make the experimental results reflect the real prototype structure characteristics, the accuracy of the similarities between the prototype structure and the scale model must be ensured. Therefore, its important to study the way to solve the existing problems in the design of the experiment of RC model of frame structure under the influence of the loads of the internal explosion, which is designed to provide some references for the similar experiments in the future.
Verification of the Applicability of Seismic Safety Evaluation Program LSSRLI-1 in Stiff and Half-Stiff Sites Using Exact Solution
Authors: Li Rui Shan , Yuan Xiao Ming
Published: April 2014

The equivalent linearization program LSSRLI-1, proposed by Xiaojun Li in 1989, is the important content in seismic zoning work and seismic safety evaluation of engineering sites. It is necessary to check the applicability of LSSRLI-1 to all kinds of sites. The mainly elaboration of this paper is verifying the applicability of seismic safety evaluation program LSSRLI-1 in stiff and half-stiff sites by exact solution. The results show that, it is well for both of them in most of the case, which is useful for the engineering practice.
Assessment Tool for Refurbishments reSBToolCZ Emphasising Cultural-Historical Buildings
Authors: Mancik Stepan , Růžička Jan
Published: April 2014

This paper presents reSBToolCZ, the first multicriterion assessment tool for existing buildings and their refurbishments which takes into account their cultural-historical value. The assessment scheme comes from a general platform of SBToolCZ and adjusts selected criteria in a way that the assessment reflects cultural-historical value of buildings and recognizes it as a quality that is an inseparable part of sustainable development..
Observation of Biological Pests on Building Facades by Thermocamera
Authors: Peřina Zdeněk , Solař Jaroslav , Maršálek Blahoslav , Maršálková Eliška , Fabian Radek , Čmiel Filip
Published: April 2014

Microorganisms on the facades of buildings (eg, algae and cyanobacteria) are the harmful factors that cause destruction of the surface of building materials in exterior (facade paints, plasters, masonry, stone, concrete, etc.). One of the properties of listed biological factors is the production of thermal energy, which can vary in different species. Mentioned energy can be recorded using infrared thermography. The paper contains the results of the examined expressions of the biological pests on the insulated facades of the buildings using infrared thermography.
The Elimination of Reflected Radiation in an Infrared Thermographic Measurement in the Exterior
Authors: Peřina Zdeněk , Solař Jaroslav , Čmiel Filip , Fabian Radek
Published: April 2014

The reflected radiation significantly negatively influences the results of the quantitative infrared thermographic measurement in the exterior. The paper deals the method of elimination of reflected radiation using appropriate equipment including examples of practical results of measurements.
Durability Evaluation of Wood Based Board Materials against Brown-Rot Fungi Effect
Authors: Vanerek Jan , Palovcikova Dagmar , Helanová Ester
Published: April 2014

The aim of the experiment was to determine the durability of wood based board materials against wood-rot fungi (Serpula lacrymans) effect. The particle boards, oriented strands boards and plywood as the testing materials were chosen. The spruce solid wood as the reference testing material was selected due to the fact that is most common timber species in the Central European region. The testing samples were exposed to wood-rot fungi and in the individual time periods the weight loss (declaring the deterioration process) and mechanical properties (static bending strength and tensile strength perpendicular to the plane of the board) was investigated. It was found that the deterioration of board materials in a very small weight decreases (up to 1.0%) leads to a significant decrease of their strength properties.
Investigation of Glass Fibre Reinforced Cement (GFRC) Material Exposed to High Temperatures
Authors: Kostelecká Michaela , Vokáč Miroslav , Dobiáš Daniel
Published: April 2014

In this paper we present the tests of high temperatures resistances of glass fibre cement plates. The aim of the research was to determine the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 °C in endurance at the highest temperature level for 24 hours. The bending strength was performed according to the norm EN 1170-4. The thermal dilatometric analysis was performed in the temperatures till 540 °C.
Modified Plasters for Restoration and Finishing Works
Authors: Sanytsky Myroslav , Kropyvnytska Tetiana , Kotiv Roman
Published: April 2014

The paper is devoted to the research and development of modified plasters for restoration and finishing works based on decorative multicomponent cements containing white Portland cement and supplementary cementitious materials (silica fume, metakaolin and fine ground limestone). This cements are similar to Roman cement by their chemical composition. The use of optimal granulometry of decorative multicomponent cements provide directed formation of microstructure of the cement matrix with the formation of stable hydration products. Compositions of modified plasters by the criterions of workability and compressive strength were designed. Physico-chemical modification of plaster by complex air-entraining admixture allows to obtain high-quality modified plasters with improved quality parameters.
Stabilization, Conversation and Strenghthening of Historic Plaster Using Nanofibres
Authors: Kroftová Klára , Šmidtová Markéta
Published: April 2014

The paper deals with the stabilization, conservation and strengthening of historic plaster fabrics based on nanofibers. As a result of degradation processes, especially of a chemical nature, accompanied by increased humidity of historic masonry, there is a loss of cohesion and a disturbance of the surface finish and plaster. Traditional remediation techniques and methods normally lead to a reduction of diffuse permeability in the multiphase structure and create different expansion properties under the plaster. The undesirable feature of this method is its irreversible character. Currently there are a number of primarily preferred procedures that stabilize the structure of the external finish, yet at the same time preserve the original features of the historical plasters. This paper will list the partial results of the ongoing in-situ and laboratory research applications of fabric based on nanofibers formed by the supporting layer and spinning polymer.
Experimental Comparison of Moisture Characteristics of Two Types of Sandstone
Authors: Burgetová Eva , Kulhánek František , Raicic Vesna
Published: April 2014

The paper presents the results of an experimental comparison of essential moisture characteristics of two types of sandstone, intended for the outdoor use. In addition to traditional physical properties, dynamics of absorption of both materials in its original condition as well as after the hydrophobization were investigated. The aim of the experiment is to determine the most suitable material variations for the reconstruction.
Effect of Pozzolanic Additive on Pore Structure of Cement Mortar
Authors: Pernicová Radka , Dobiáš Daniel
Published: April 2014

In this paper are explored the changes of pore structures of mortar with pozzolanic admixture exposed to aggressive environments, namely 5% wt. sodium sulphate solution. Influence of non-flowing sulphate solution on the test specimens were determined in dependence on the different type of cement and used minced clay brick as pozzolanic admixture. Attention is also paid to the properties of the individual components of the mortar. From the results obtained follows that the additive of minced clay bricks has positive impact on the sulphate resistance.
Stabilization and Strengthening of Historic Buildings' Stone Masonry Columns
Authors: Witzany Jiří , Zigler Radek
Published: April 2014

The experimental research of failure mechanism of stone columns made of coursed masonry of regular sandstone blocks and coursed masonry of irregular (freestone) blocks under concentric compression and the research of the performance of non-reinforced as well as CFRP-reinforced stone columns completed to-date pointed out the necessity of a different approach to the assessment of the load-bearing capacity, or residual load-bearing capacity, of masonry composed of stone blocks.
Preparation and Properties of Brij97-Based Curcumin-Encapsulated O/W Microemulsions
Authors: Wang Zhong Ni , Guo Fu Min , Lu Juan , Wei Ling , Liu Xin , Zhou Wu
Published: April 2014

Oxidative damage is a public health issue in the modern world and promoting dietary anti-oxidants, such as curcumin, is a promising strategy. However, curcumin is unstable and poorly water-soluble and of poor bioavailability. This study constructed new curcumin-loaded O/W microemulsions using a pharmaceutically accepted Brij97 nonionic surfactant and evaluated several properties of curcumin encapsulated in the microemulsions. The pseudo-ternary phase diagram of Brij97/isopropyl alcohol/ethyl acetate/water system was determined and three microregions of the microemulsionsW/O, bicontinuous, and O/Ware identified by conductivity measurements, according to percolation theory. The properties investigation of a series of curcumin-loaded O/W microemulsions indicates: (1) The curcumin in such a situation performs sustained release following the first-order kinetics; (2) Better stability of curcumin to the sun light is observed over a time scale; (3) The curcumin presents relatively high anti-oxidant activity, with the IC50in between 31.5 and 17.2 μg/ml on scavenging the superoxide radicals. In addition, the structure difference in the homologues acetate seems having no effect on the stability and release behavior of curcumin, while the investigated properties clearly depend on the ME/acetate ratio in the microemulsions. This study might be a potential help to the protection and the delivery of curcumin.
The Preparation and Properties of AP-Based Nano-Limit Growth Energetic Materials
Authors: Li Guo Ping , Shen Lian Hua , Zheng Bao Ming , Xia Min , Luo Yun Jun
Published: April 2014

AP-based nanolimit growth energetic materials (NLGEM) were prepared by using SiO2 gel as nanolimit growth skeleton materials and using sol-gel method combining solution crystallization to make AP recrystallized in the nanopores of SiO2 gel skeleton to form AP/SiO2 NLGEM. The chemical and physical structure and properties of AP/SiO2 NLGEM were studied in detail. AP with nanoscale particles size range from 69nm to108nm was recrystallized in the pore of SiO2 gel skeleton and the particle size of AP increased with the amount of AP in NLGEM increasing. Moreover, the preparation method didnt change the crystal form of AP and bring impurities to NLGEM. The decomposition of AP/SiO2 NLGEM was a one-step process, which was indicated its decomposition was more concentrate than pure AP and AP/SiO2 simple physical mixture (AP/SiO2 SPM), whose decomposition was a two-step process. At the time, the decomposition heat of AP/SiO2 NLGEM was higher than that of pure AP and AP/SiO2 SPM. The sensitivity of AP/SiO2 NLGEM was lower than those of the pure energetic components and physical mixtures according to the impact sensitivity test.
Character and Preparation of Nano-SiO2/PI Composites by Sol-Gel Method
Authors: Chen Zhuo , Guo Jun , Qin Hao Li , Xie Hui , Liu Ke Jia , Zhao Wei , Liu Ji Ping
Published: April 2014

Polyimide/nano-SiO2 (PI/SiO2) composites with different contents of SiO2 were prepared by in situ polymerization. The transmittance, solubility, thermal property, flame retardant properties and mechanics properties of PI/nano-SiO2 composites were investigated. The results showed that with the increased addition of SiO2 content, the transmittance of PI/SiO2 compositions reduced; tensile strength changed with the amount of nanometer powder, when the addition content was 10 wt%, it achieve the maximum value. Thermal resistance of the composite was improved obviously while with the amount of nanometer powder increased, volume resistivity coefficient of volume resistance would have decreased.
Preparation and Study of 0.7(Mg0.8Zn0.2)TiO3·0.3{Ba4Nd28/3Ti18O54·zBi2O3} Microwave Dielectric Ceramics
Authors: Ji Xiao Li , Zhai Cheng C. , Zhang Song
Published: April 2014

The (Mg0.8Zn0.2)TiO3(MZT) as the foundation is mainly studied to join high dielectric material Ba4Nd28/3Ti18O54·zBi2O3(BNT) to preparation microwave dielectric ceramic 0.7(Mg0.8Zn0.2)TiO3·0.3{Ba4Nd28/3Ti18O54·zBi2O3}(z=0.15, 0.18, 0.2) to improve dielectric properties of MZT. While Bi3+could reduce the sintering temperature to make MZT and BNT composite in a lower sintering temperature (1200~1230 °C). According to the results of the dielectric properties, density, XRD and SEM tests of the obtained ceramics, we can find out that the amount of doped Bi3+ and the sintering temperature affected the structure and properties of the ceramics. The results show that when z=0.18, 0.7(Mg0.8Zn0.2)TiO3·0.3{Ba4Nd28/3Ti18O54·zBi2O3}
Experimental Study on the Adsorption of MB on Novel Photocatalyst Yeast/ZnS Hybrid Microspheres
Authors: Gou Hai Gang , Guan Wei Sheng , Yang Li , Wang Zhao Qi , Zhu Yang Zhi
Published: April 2014

Employing yeast cells as carriers,a novel cell-loaded photocatalyst yeast/ZnS (YC/ZnS) was successfully synthesized. The adsorption performance of methylene blue on the YC/ZnS microspheres was studied. Experimental results showed that the optimized adsorption conditions were 23°C,pH7 and the YC/ZnS dosage 4.5g/L. Under these conditions,the adsorption capacity of YC/ZnS could reach 471.2μg/g. Isotherm modeling revealed that Freundlich equations described well the adsorption of methylene blue onto YC/ZnS.
Study on the Surface Morphologies of Nickel-Phosphorus Ultra-Black Films
Authors: Yue Pan Pan , Jin Yong Zhong , Hu Xu Dong , Yan Hong Yang , Zeng Guo Qing
Published: April 2014

Ni-P ultra-black films having conical pores with the diameter of ~ 10-30 μm and the depth of ~ 15-30 μm were prepared by chemical etching of electroless plated Ni-P films using 8 mol/L nitric acid at 40 °C for 60 s. The phase composition and microstructure of the film samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results show that the diameter and depth of the etching pores become larger and the flat top regions bounded by etching pores become smaller by the coalescence of adjacent pores with the increase of etching time. The surface morphologies of the etched Ni-P films are characterized by the distribution of conical pores.
Super-Hydrophobic Properties of Unitary Structure
Authors: Li Jing , Xu Cheng Yu , Du Feng , Liu Xian Li , Yu Hua Dong
Published: April 2014

In this paper, the unitary structure characteristics and the super-hydrophobic properties of the lower surface of the lotus leaf and artificial biomimetic surfaces were investigated through scanning electron microscopy, field emission scanning electron microscopy, x-ray photoelectron spectroscopy and contact angle measurement. The measurement of wettability showed that artificial unitary structure surfaces modified with the lower surface energy material exhibit a super-hydrophobic property with a water contact angle of about 150°. The artificial structure characteristics and the super-hydrophobic properties are similar to those on the lower surface of the lotus leaf. The contribution mechanism of the unitary structure on the hydrophobic property was discussed for the surfaces of the lotus leaf and artificial biomimetic surfaces based on the Cassis-Baxter model.
Catalytic Properties of Ni/CNTs and Ca-Promoted Ni/CNTs for Methanation Reaction of Carbon Dioxide
Authors: Hu Xiang Feng , Yang Wen , Wang Ning , Luo Shi Zhong , Chu Wei
Published: April 2014

Nickel/carbon nanotubes (Ni/CNTs), Nickel/alumina (Ni/Al2O3), calcium-promoted Ni/CNTs and calcium-promoted Ni/Al2O3 were synthesized by impregnation method. Methanation of carbon dioxide was used as a probe to evaluate their catalytic performance. The features of these Ni-based catalysts were investigated via XRD, H2-TPR, H2-TPD and the N2 adsorptiondesorption isotherms. H2-TPR showed that nickel species on Ni/CNTs was reduced more easily with respect to that on Ni/Al2O3, and addition of Ca can increase the content of easily reducible Ni species for Ni/CNTs. XRD and H2-TPD indicated that addition of Ca promoted dispersion for CNTs-supported catalyst. These finding ultimately enhanced catalytic activity and stability for Ni/CNTs catalyst modified with Ca.
The Growth and Optical Properties of Al-Doped ZnO Nanofibers Using PVP Nanofibers as Templates by Atom Layer Deposition
Authors: Fang Dan , Fang Xuan , Zhao Hai Feng , Li Shuang , Wei Zhi Peng , Wang Xiao Hua
Published: April 2014

Different doping concentration Al-doped ZnO nanofibers were synthesized by Atom Layer Deposition (ALD) using PVP fibers as template. The influence of Al doping concentration on the structure and optical properties of nanofibers was investigated. The samples were characterized by means of X-ray diffraction spectra, field emission scanning electron microscopy (FESEM). After doping, the morphologies were not changed, only the diameters of Al-doped ZnO nanofibers became larger. Compared with undoped ZnO, the intensity of diffractive peaks of Al-doped ZnO nanofibers became weak with the increasing of the doping concentration due to stress generation in the crystallization process. In raman spectra, Al2O3peak related peaks were also observed. In addition, the intensity of UV emission decreased with increasing Al doping concentration and had a red shift.
Characterizations of Novel Binuclear Transition Metal Polynitrogen Compounds: M2(N5)4 (M=Co, Rh and Ir)
Authors: Tang Li Hong , Guo Hui Bin , Li Qian Shu , Peng Jin Hui , Gu Jun Jie , Xiao Li Bai
Published: April 2014

Theoretical studies on a series of binuclear transition metal pentazolides M2(N5)4(M=Co, Rh and Ir) predict Paddlewheel-type structures with very short metal-metal distances suggesting high-order metal-metal multiple bonds. Natural Bonding Orbital (NBO) analysis have indicated that the bonding between the metal atom and the five-membered ring is predominantly ionic for each M2(N5)4species, and a high-order metal-metal multiple bonding exists between the two metal atoms, in addition, the presence of the delocalized π orbital plays an important role in the stabilization of this metal-polynitrogen species. Nucleus independent chemical shift (NICS) values confirm that the planar N5exhibits aromaticity in these M2(N5)4species. The values of NICS(0.0), NICS(0.5) and NICS(1.0) for Co2(N5)4are larger than those of the other two M2(N5)4species (M=Rh and Ir), with the order of Co2(N5)4>Rh2(N5)4>Ir2(N5)4. The dissociation energies into Mononuclear Fragments for M2(N5)4(M=Co, Rh and Ir) are predicted to be 82.9 (85.7), 139.9 (113.2), and 155.1 (149.7) kcal/mol, respectively. However, the dissociation energies for the loss of one pentazolato group from the M2(N5)4analysis have indicated that the Co2(N5)4is relatively higher at ~40 kcal/mol. Thermochemistry suggests Co2(N5)4to be a viable species.
Thermal and Flame Retardant Properties of MWNT Reinforced Conductive PAN Film
Authors: Chen Zhuo , Dong Xian , Zhao Wei , Liu Ke Jia , Liu Ji Ping
Published: April 2014

Conductive polyacrylonitrile film reinforced by multiwall carbon nanotubes was prepared via ultrasonic dispersion and vacuum casting. The structure of MWNT/PAN composite film was characterized by WAXD and FT-IR. The LOI of the blend was enhanced from 18.1 % to 24.5 % and TGA show better thermal stability. MWNT composite at 10 wt% MWNT loading showed an electrical conductivity of 10-2S/cm.
The Synthesis of High Yield PbS Nanocrystalline and its Photovoltaic Applications
Authors: Gao Yu Ping , Qin Dong Huan
Published: April 2014

High quality PbS nanorcrystallines (NCs) have been fabricated in high yield by a simple hydrothermal method using unique ligands. We find that the experiment conditions such as different ligands,the reaction temperature greatly influence the morphology and the size of PbS NCs. Specifically, the complex ligands OPA and butylamine have great effects on the final products compared with no ligand. We can obtain PbS nanocrystalline with more homogeneous size and higher optical properties. On the other hand, higher external quantum efficiency (EQE) of the solar cell will be achieved with Schottky device structure of ITO/PbS/Al.
Functionalized Gold Nanoparticles Coated Polymer Spheres as SERS Substrate for the Detection of TNT Explosives
Authors: Gu Hai Xin , Xue Lin , Zhang Ya Heng , Zhang Yong Feng , Cao Li Ying
Published: April 2014

In this paper, we fabricated the 4-aminobenzenethiol modified gold nanoparticles onto polymer spheres as SERS substrate to selectively detect 2,4,6-trinitrotoluene (TNT) explosives. The gold nanoseeds were fixed on polymer surface by reduction of HAuCl4·3H2O with sodium citrate. About 60~100nm nanoparticles were formed from the previous seeds and self-assembled by 4-aminobenzenethiol. The functionalized gold nanopartilces aggregation coated on large polymer sphere surface not only absorbed more TNT molecules via conjugation system, but also generated numerous "hot spots". It was demonstrated that this substrate displayed high SERS activity for TNT detection. It could also be anticipated that the aforementioned material would be used for fast and sensitive SERS detection of TNT in real-world situation. Keywords: gold nanopartilces, SERS, TNT, functionalization
Research on Eliminating Cumulative Errors for Stitching Algorithm of Large Aperture Aspheric Optical Elements
Authors: Zhang Yan Ting , Yang Xu , Li Xin , Guo Yin Biao
Published: April 2014

The sptitching measuring method applied in large-aperture aspheric surface optical elements can expand the range of precision measuring instrument. And the key point is developing the technique for high precision measuring data processing. To deal with the problem of cumulative errors which existed in the process of multi-section stitching, datum-transformation method was proposed, according to the characteristic of stitching measurement. The stitching measuring experiments were carried out based on Talysurf PGI 1240 profilometer of Taylor Hobson Company to verify the purpose for eliminating cumulative errors. The results show that datum-transformation method is feasible with the characteristic such as fast speed, high precision, and good operability.
One-Step Synthesis of Aqueous Graphene Dispersion Stabilized by Sodium Dodecylbenzene Sulfonate
Authors: Luo Kun , Li Xiao Gang , Wang Hai Ming , Wang Peng , Wei Chun
Published: April 2014

Graphite oxide (GO), prepared by modified Hummer’s method from graphite, was reduced by hydrazine hydrate in the presence of sodium dodecylbenzene sulfonate (SDBS), leading to a concentrated aqueous graphene dispersion which was stable for more than one month. The analyses of XRD, UV-vis and Raman spectroscopy indicate that the reduced graphene oxide (RGO) was formed after chemical reaction, where single or multiple graphene sheets were observed by TEM and AFM, indicating that the RGO is well-dispersed in water through the operation.
Influence of the Reaction Temperature on Cd1-xZnxS Thin Films with Chemical Bath Deposited
Authors: Zhou Li Mei , Dong Yue Jie
Published: April 2014

Cd1-xZnxS thin films were deposited on soda-lime glass substrates with chemical-bath deposition (CBD) using cadmium acetate, zinc sulfate, thiourea, ammonia and ammonium acetate aqueous solution at different with stirring. All the samples were annealed at 200 °C for 60 min in the air. The crystal structure, surface morphology, thickness and optical properties of Cd1-xZnxS thin films with increasing ammonia concentration were studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), step height measurement instrument and spectrophotometer respectively. The results revealed that Cd1-xZnxS thin films had cubic crystal structure and the intensity of the diffraction peak decreased gradually as reaction temperature rose and the average crystal size was from 7.0 nm to 8.9 nm. All of Cd1-xZnxS thin films had a granular surface with some smaller pores. The Cd1-xZnxS thin films band gap was from 2.68 eV to 2.83 eV. The transmission of film deposited at 80 °C was highest. The suitable reaction temperature was from 70 °C to 80 °C.
Electrospun Cellulose Triacetate Fibers Using DMSO/Chloroform Co-Solvent System
Authors: Lan Tian , Shao Zi Qiang , Wang Wen Jun , Wang Fei Jun , Zhang Da Lun , Wang Jian Quan , Liu Yan Hua , Kong Lin Lin
Published: April 2014

Nonwoven fibers of cellulose triacetate (CTA) were continuously electrospun by using DMSO/chloroform co-solvent system and the size and morphology of fibers were investigated. It was found that the concentration of 8wt% CTA fibers were obtained from DMSO/chloroform with volume ratio of 1:1, 3:2, 2:1, 3:1. The average diameters of CTA fiber was decreased with decreasing chloroform content in the mixed solvent. The minimum diameter of the continuous electrospun cellulose triacetate fibers obtained in this work ranged between 210 and 880 nm.
Hydrothermal Synthesis of α-Fe2O3 Nanocrystals as Anode Electrode Materials for Rechargeable Li-Ion Batteries
Authors: Lou Xiao Ming , Huang Jia Li , Li Tan Ping , Hu Han Xiang , Hu Bo Nian
Published: April 2014

In this paper, α-Fe2O3 nanocrystals have been synthesized, using FeCl3, oleic acid, ethanol and NaOH as raw materials by a hydrothermal method at 180°C for 10h. The samples were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) for the information of crystal category, form and size. The results showed the materials are nanocubes and side-length about 20 nm. Moreover, the properties of α-Fe2O3 nanocrystals as anode materials for Li-ion batteries had been studied. The first-discharge capacity is 1280 mAh g-1, which made this material maybe one of the candidates for the negative materials.
Preparation of TiO2/Six-Ring Rock Composite with Highly Photocatalytic Efficiency
Authors: Zhou Jing , Li Qing Shan , Wang Xiao , Lv Wen Feng , Wei Hong
Published: April 2014

Using six-ring rock (a natural mineral with good adsorption ability) as carrier, the TiO2/six-ring rock composite was successfully synthesized by sol-gel process. The sintering temperatures and condensate return times exhibit a strong effect on the catalytic performance of the photocatalyst. X-ray diffractometer (XRD) showed that obvious diffraction peaks of anatase TiO2appeared when the calcination temperature is 550°C. The SEM images revealed that nanoTiO2has been widely loaded on the surface and pores of six-ring rock particles. Photodegradation for methyl orange (MO) exhibited that the TiO2/six-ring rock photocatalyst is of higher photocatalytic activity than pure six-ring rock, and the maximum degradation rate can reach 75% under the optimized conditions.
Effect of Post-Deposition Annealing Process on the Resistive Switching Behaviour of TiO2 Thin Films by Sol-Gel Method
Authors: Kamarozaman Nur Syahirah , Mohamed Soder Mohd Firdaus , Musa Mohamed Zahidi , Bakar Raudah A. , Abdullah Wan Fazlida Hanim , Herman Sukreen Hana , Mahmood Mohamad Rusop
Published: April 2014

The paper presents the memristive behaviour of spin-coated titania thin films on ITO substrate. The sample was annealed in air ambient at different annealing temperature and duration of 250 and 450 °C for 20 and 60 min. The effect of post-annealing process to the physical thickness and crystallinity of the films towards switching behaviour was studied. It was found that the thickness and crystallinity of the films increases as the post annealing process increases. Sample annealed at 250 °C for 20 min with thinner film showed better switching behaviour even though the sample is still in amorphous form. Thus, in our work, we believed that the crystallinity of the films does not affect the switching behaviour of the sample. The reliability of device performance was studied by repeating the measurement for three times.