bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Porous CeO2 Nanostructures Using Cotton Fibers as Biomaterial Template
Authors: Zou Yun Ling , Li Yan , Lian Xiao Xue
Published: August 2014

Porous CeO2 nanostructures were synthesized by a simple template method using cotton fibers as biomaterial template. The phase structure and morphology of the product were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM). The UV-blocking property was evaluated by UV-Vis spectrophotometry. Experimental results showed that the as-synthesized CeO2 was in a cubic fluorite structure and presented fiber-like structure. The fiber-like CeO2 nanostructures completely recorded the original morphology of cotton fibers, which consisted of large amounts of coalescent CeO2 nanoparticles with average particle size in the range of 6-10 nm. The UV test result showed that the UV transmittance of the product was closer to zero in the wavelength below 350 nm, indicating that the product exhibited excellent UV-blocking property.
The Study of Friction Materials in Brake Pad of Small Electric Car
Authors: Zhao Kun Yu , Jiang Wen , Li Zhe Kun , Zhu Xin Kun
Published: August 2014

Two kinds of friction materials in small electric car were studied by optical microscope(OM), X-ray diffraction(XRD) and scanning electron microscope(SEM). A sample was composed by Fe-based materials, SiO2, Al2O3 as hard phases, graphite and CaS as lubrications and carbonate and sulfate as fillers. MgO in B sample can increase its hardness, high temperature resistance and friction resistance. The lubrications of B sample consist of graphite and ZnS.
Failure Analysis and Welding Repair for Water Wall Tube Crack of Supercritical Boiler
Authors: Zheng Xiang Feng , Jiang Yun Jian , Xue Rong Gang , Wu Nan , Li Wen Bin , Hao Xiao Jun
Published: August 2014

Through methods, such as microscope analysis, mechanical analysis, chemical analysis, metallography examination etc, the causes resulting in water wall tube cracking of the supercritical boiler have been analyzed. The result indicates this water wall tube cracking is the high temperature creep fracture. The higher tensile stress, microstructure aging and high temperature strength degradation are the primarily inducement of cracking failure. In welding tube, the measures of reducing residual stress, such as lower welding heat input, reducing thickness of welding layer, assigning reasonably heat treatment power, lengthening holding time and so on, were taken. The welding repair succeeded greatly.
Exact Cram’er–Rao Lower Bound for Interferometric Phase Estimator
Authors: Mao Zhi Jie , Yan Zhi Jun , Li Hong Wei , Meng Jin
Published: August 2014

We are concerned with the problem of interferometric phase estimation using multiple baselines. Simple close-form efficient expressions for computing the Cramer-Rao lower bound (CRLB) for general phase estimation problems is derived. Performance analysis of the interferometric phase estimation is carried out based on Monte Carlo simulations and CRLB calculation. We show that by utilizing the Cramer-Rao lower bound we are able to determine the combination of baselines that will enable us to achieve the most accurate estimating performance.
Effect of Environment on Fatigue Crack Propagation Behavior of an Al-Cu-Mg Aluminum Alloy
Authors: Liu Ming , Zhang Kun , Dai Sheng Long , Li Guo Ai , Hao Min , Yi Lin Na
Published: August 2014

The fatigue crack propagation behaviors of an Al-Cu-Mg alloy are investigated in different environments and with varying stress ratios. Fatigue experiments are carried out via a fatigue crack growth rate test in laboratory air, a 3.5% (mass fraction) NaCl solution and a tank seeper. The results show that a corrosion environment has an obvious influence on the fatigue crack growth rate, and the degrees of influence of the two different corrosive environments are basically identical. When the stress ratio is R = 0.5 and 0.06 with a decrease of the stress intensity factor, the difference in the crack propagation rates for the corrosion and air environments gradually increases. However, the corrosion acceleration in each stage of crack propagation is obvious while R=−1.
Quality Evaluation for Automobile Seat Woven Fabric
Authors: Yao Gui Fen
Published: August 2014

Industrial textiles is designed with engineering structure textiles. Transportation textiles is one of the main types of industrial textiles. Automobile seat fabric is one of the decorative materials in automobile textile fabrics. The fabric should have soft handle, good air permeability, coordinate color, luxury and generous pattern, wear-resisting, anti-fouling, flame retardant, certain friction factor and antistatic property. In recent years, requirements for automobile textiles of safety, health, environmental protection is more and more high. In order to evaluate the automobile seat woven fabric quality, need to have a simple and effective standard. Quality indexes should be comprehensive. The test method of quality index should be operable. In the existing relevant standards, the test content is not consistent. The existing relevant standards are national standards, textile industry standards and automotive industry standards. Within textile industry standard FZ/T 24005-2010 wool textiles for chair, the technical requirements include safety specification, classification rules, physical quality rating, internal quality rating, appearance quality rating. For flame retardant performance, must meet the following requirements: damaged length ≤200mm, afterflame time ≤15s. Within national standard GB 8410-2006, flammability of automotive interior materials, for flame retardant performance, must meet the following requirements: burning rate ≤100mm/min. Within automotive industry standard QC/T 633-2009 the seats of passenger vehicles, for safety specification, seat fabric must meet the B grade in GB 18401. Based on some effective standard, established suitable standard for automobile seat woven fabric. The standard covers quality evaluation content, performance levels and the methods of test to be used to determine these performance levels.
Self-Compacting and Tiny Expanding Steel Tube Concrete Using in Large Span Bridges
Authors: Li Xiu , Su Ming Hui
Published: August 2014

The experimental studies on self-compacting and tiny expanding concrete filled in steel tube are introduced, which including the measurement of low ability of mixtures, the proportioning of the concrete filled in steel tube. The self-compacting and tiny expanding steel tube concrete has been applied in a large span bridge structure. The state of construction shows that the concrete have a good pump ability, a small loss of slump, a high strength early strength and a better self-compacting property.
The Quality Control on Shengmi Bridge Arch Rib Construction
Authors: Li Xiu
Published: August 2014

Introduced the essential construction craft of Nanchang Shengmi bridge (75+2×228+75m center bearing type steel tube concrete tie bar arched bridge). According to the construction craft and the quality specification request, discussed the steel arched bridge manufacture and the anticorrosion, the steel arched bridge rib erects, the steel arched bridge rib welding, the steel arched bridge in concrete configuration and the scene constructs, the steel tube protection coating construction, then proposed the construction quality control of large span steel tube concrete arch bridge. The conclusion of the article may be used at the similar steel tube concrete arched bridge construction.
Field Experiment Study of the Semi-Rigid Base on Port Reinforced with Glass Fiber Geogrid
Authors: Yuan Pu , Huang Jun Wen
Published: August 2014

The pavement and storage yard on port is located in depth soft soil foundation, the settlement is large, so that the approach of enhancing the bearing ability of the pavement and storage yard on port is advanced. Field Experiment of test section which satisfied with the field test methods was carried out. Resilient modulus was determined by the bearing plate method, the pavement base on port engineering reinforced with glass fiber geogrid was analyzed.The test result shows that the effect on the base on port engineering reinforced with glass fiber geogrid is satisfied, the ratio reaches 12% .In addition, the effect of the position reinforced with glass fiber geogrid is different, the better effect of reinforcement with glass fiber geogrid is the toper of the base on port. On this basis,the appoarch of the base on port reinforced with glass fiber geogrid is reference on design and contruction.
Flexural Behavior Finite Element Analysis of CFRP Reinforced Concrete Bridge Deck with Corrosion and Salt Resistance
Authors: Yang Ze Ying , Liu Jia You , Zhang Yi Dong , Qu Jian Bo
Published: August 2014

By numerical simulation and contrasting with experimental conclusions, mechanical models in every loading stage of CFRP reinforced concrete bridge deck were established. The results showed that, numerical simulation results of non-prestressed bridge decks fitted corresponding test results well. The stiffness of prestressed structures had been greatly improved than non-prestressed structures, so the high strength performance of CFRP had been used more effectively.
Micro-Macro Material Performance Tests of One Attacked Building Foundation
Authors: Gao Run Dong , Chen Hai Bin
Published: August 2014

One 6-stories brick-concrete structure was built in the late of 1990s. The uneven settlement of the foundation had occurred and the average concrete compressive strength of the foundation was close to C30 standard. Apparent observations indicated that some white powdery substance which was not adhesive was precipitated at the aggregate/mortar interface, pores and cracks. Micro observations by means of a Scanning Electron Microscope equipped with a Energy Dispersive Spectrometer showed the coexistence of ettringite and small amount of alkali–silica gel, which proved that the foundation had suffered from sulfate attack and alkali–silica reaction.
Research on Sliding Layer of Cross-Tensioned Prestressed Concrete Pavement
Authors: Chen De , Han Sen , Ling Cheng , Zhang Dong Sheng , Guan Fu Yang
Published: August 2014

A coefficient of friction tester (CFT) for the cross-tensioned prestressed concrete pavement (CTCP) sliding layer was designed and developed basing on the Amonton law. The CFT can obtain precise values of the CTCP sliding layer coefficient of friction. Meanwhile, the sand and polyethylene plastic film (SPPF) sliding layer which has already been used in CTCP experimental road was tested using the CFT. The best testing speed (1mm/min) for CFT was obtained with applying regression analysis method to the results. The optimum material parameters for the SPPF are the combination of 2.6 fineness modulus of sand, 10mm thickness of sliding layer, and 3 μm thickness of polyethylene plastic film (PPF). The optimum materials combination of the SPPF provides minimum coefficient of friction to the CTCP sliding layer which can reduce the stress and deformation of the CTCP slab.
Experimental Study of the Effect of Early Strength Admixture on Cement Stabilized Macadam Material
Authors: Song Yun Lian , Liu Kai , Lin Min , Liu Peng
Published: August 2014

5% cement was mixed into the cement stabilized macadam base material, then the cement was replaced by SES-I early strength admixture according to the amount of cement (mass ration) which was 0%, 8%, 10%, 12%, 14% and 16%. The unconfined compressive strength Rc of cement stabilized macadam material was tested during different curing periods 12h, 1d, 2d, 3d, 7d and 28d. Depending on the experimental date, the effect of early strength admixture on cement stabilized macadam material was investigated, and the logarithmic curve relationship can be fitted between the SES-I admixture and Rc. The experiment result shows that the 14% dosage of early strength agent is the best result for material early strength, and it also provides the foundation to increase early strength and shorten the construction period for meeting the project design demand.
Literature Review: Properties of Silica Fume Concrete
Authors: He Xi Xi , Wang Qing
Published: August 2014

Silica fume (SF) modifies interfacial transition zone between cement paste and aggregate at the micro level. Properties of both fresh and hardened silica fume concrete are affected significantly compared to normal concrete. Experiments indicate that concretes become more cohesive and less prone to segregation in the presence of silica fume, moreover, performance of water demand, setting of time, plastic shrinkage varies respectively from concretes without silica fume. Obvious mechanical enhancement of concrete is observed in the aspects of compressive strength tensile strength, elastic modulus as well as fracture toughness.
Mineralogical Aspects of Durable Geocement Matrix Formation - Role of Alkali
Authors: Kryvenko Pavlo V. , Cao Hai Lin , Weng Lu Qian , Kаvalerova Еlena
Published: August 2014

Less than half a century ago just an idea of presence of free alkalis in a ceramic matrix was considered by ordinary Portland cement people as an absurd one and this was a basic postulate accepted in chemistry of cements. In 1957 a scientist from Ukraine (USSR) Viktor Glukhovsky put forward an assumption which was taken as a base for development and bringing into practice of construction a principally new class of cementitious materials which first appeared in the field under a name of alkaline (now also known under a general name of alkali-activated) cementitious materials. A validity of these ideas was confirmed by more than 50 years of evolutional development and vast experience collected on practical use of new materials in different applications. The paper covers theoretical views on role played by alkali in the formation of an alkali-activated cement matrix with high durability. Examples of compositional build-up of the alkali-activated cementitious materials vs. quantity of added alkali and type of aluminosilicate component are reported together with results of 50-year experience obtained from observation of concrete structures made from these cements.
The Comparative Analysis of Chinese Green Building Assessment System and Foreign Evaluation System
Authors: Liu Ping , Lei Jun Hong
Published: August 2014

At present, China's economy is developing rapidly, urbanization level enhances increasingly, the energy consumption and environmental pollution problems are getting serious increasingly, and it is deviating from the concept of sustainable development. Green building is an important way to achieve the concept of sustainable development and green building assessment system is the important basis and key to its development. Through the comparative study on evaluation methods and objects of the main evaluation system in China and abroad, this article find out the deficiency of the evaluation system in our country, draw lessons from foreign assessment system, and make our country green building assessment system more perfect.
The Energy-Saving Design and Construction Study on Exterior Windows in the Building
Authors: Su Xiao Ping , Sun Wei Dong
Published: August 2014

Doors and windows,especially the exterior windows, are the weak parts to preserve or insulate heat in the exterior protected construction of a building, and the main contents in energy-saving architectural designs. The energy-saving design of exterior windows should start from such aspects as size, shape, frame form, glass type, gap sealing, etc. The size of the exterior window holes should be determined according to the window-wall area ratio specified in the relevant rules. It is priority to choose side-hung window in energy-saving design, to choose the low heat transferring window frame, to take measures to break the “thermal bridge”, and to select the energy-saving glass such as decalescence glass, coated glass, hollow glass and vacuum glass. The gaps should be sealed tightly between wall and window frame, window frame and sash, glass and window sash to reduce the air permeable.
The Influence and Suppression Effect of Limestone Powder on Concrete Shrinkage
Authors: Wang Pi Ming , Gao Min Jie , Xiao Shuz Hong , Li Ru Feng
Published: August 2014

In order to study the suppression effect of increasing concrete shrinkage induced by limestone powder, the aliphatic water reducer and polycarboxylate superplasticizer was used in experiments about effect of limestone powder content on concrete shrinkage. The results showed that the concrete shrinkage increased as the limestone powder content increasing. Comparing to the aliphatic water reducer, the polycarboxylate superplasticizer showed obviously effect on concrete shrinkage suppression. Besides, the polycarboxylate superplasticizer can reduce the sensitivity of concrete cracking. The polycarboxylate superplasticizer using in concrete can effectively reduce the emission amount and environmental pollution in the production process of artificial sand, simultaneously, this is helpful to improve the volume stability of concrete.
Analysis of Anshan Existing Residential Building Exterior Wall Energy Saving Reconstruction
Authors: Tian Yu Ze , Yu Yang
Published: August 2014

This paper introduces the present situation of existing residential building energy saving reconstruction of Anshan area, the result of the analysis is that the renovation of retaining structure is the key of the reconstruction of existing residential buildings of Anshan. Exterior wall area ratio of the total area of the building envelope accounts for quite large, so transformation of exterior wall is the key. Energy saving wall approach divided into external wall insulation and exterior insulation. Analysis of energy-saving measures by the external wall insulation, and the external wall of a residential district in Anshan city and analysis of thermal insulation and energy saving renovation case, better energy-saving effect, energy saving measures of external economy more external insulation, the region has provided the reference and basis transformation of external wall energy-saving residence building.
Influences of Polypropylene Fiber on Properties of Foam Concrete with Iron Tailings
Authors: Xiao Li Guang , Liu Chang , Zhang Shi Ting
Published: August 2014

Iron tailings are mineral wastes obtained from industrial processing and magnetic separation of iron ore. Foam concrete with iron tailings can be made with iron tailings, cement, fly ash, silica fume, polypropylene fiber, superplasticizer, early strength agent, accelerating agent and foaming agent. The influences of polypropylene fiber on the crack resistance and frost resistance of foam concrete have been investigated in this study. Further, the microstructure of foam concrete was observed. This result demonstrates that polypropylene fiber has greatly increased the crack resistance and frost resistance of foam concrete. The pore structure of foam concrete is improved obviously by polypropylene fiber. Due to the uniformly distributed pores, high porosity and rather complete pore wall, the mechanical properties and thermal properties of foam concrete are excellent. The foam concrete with high-strength and excellent thermal insulation property develops a new route for the comprehensive utilization of iron tailings.
Effects of Specimen Diameter on Microstructure and Microhardness of Hot Extruded AZ31B Magnesium Alloy
Authors: Hong Xiang Ting , Chen Fu , Chen Fei , Yu Wang , Sang Bo Rong , Zhang Xin Ping
Published: August 2014

Microstructures of metal micro parts after microforming at elevated temperatures must be evaluated due to mechanical properties depend on average grain size. In this work, the effects of specimen diameter on the microstructure and microhardness of a hot-extruded AZ31B magnesium alloy were studied. Obvious size effect on microstructure and microhardness of the alloy could be observed. The size effects could be explained by strain distribution and dislocation density differences between the two kinds of specimens.
The Preparation and Research of Drilling Bitten Pile in Kunming Metro Engineering
Authors: Hu Ya Nan , Xu Qing , Wu Guo Qiang
Published: August 2014

In consider of construction characteristics of drilling bitten pile in Kunming metro engineering, this paper study on preparation and performance of super retarded concrete. Meanwhile, this paper find appropriate raw materials and mixing amount, which can meet construction requirement of high flowability and long setting time for this engineering. Combined theory with experiments, it lay the foundation of popularization and application of super retarded concrete to find the influence law of performance of super retarded concrete by mixing amount of all materials.
The Theoretical Study of the Cinnabar-to-Rocksalt Phase Transitions of HgTe and CdTe under High Pressure
Authors: Hu Xi Duo , Zhu De Hai , Zeng Zhi Feng , Sun Shao Rui
Published: August 2014

We performed the first-principle calculation to study the structures of cinnabar phase and the Cinnabar-to-rocksalt Phase transitions of HgTe and CdTe under high pressure. The calculated results show that for HgTe, the zincblende-to-cinnabar phase transition is under 2.2GPa, and the cinnabar-to-rocksalt phase transition is under 5.5 GPa; For CdTe, the two phase transitions occur under 4.0 GPa and 4.9 GPa, respectively, which well agree with the experimental results. The cinnabar-to-rocksalt phase transitions of most compounds, including HgTe and CdTe, except HgS are of first-order, and it is due to that their cinnabar phases are not chain structure as HgS and there are no relaxation process before the phase transition.
Load Shedding Scheme Optimization Design of the Dump Slope
Authors: Feng Shao Jie , Zhao Xue Fang , Sun Shi Guo , Cui Meng Meng
Published: August 2014

In this paper, xingshan iron mine as an engineering example. Based on slip field theory, numerical simulation method and limit equilibrium method for the mine slope stability research and evaluation. Meanwhile, a variety of load shedding scheme was designed and optimized design. The results showed that the final dump slope angle is 19.2, considering the most unfavorable conditions in saturated with earthquake. And ultimate load shedding scheme can guarantee the slope stability, and saves the load shedding costs is about 20 million yuan. The economic effect is remarkable.
Numerical Simulation of Stress Intensity Factor under Multiaxial Loading
Authors: Liu Zhi Yun , Wu Zhi Kai , Xia Yu Feng , He Jun Ru , Jiang Wu Gui
Published: August 2014

Based on the theory of fracture mechanics and finite element method, this paper presents a numerical calculation of typical experimental models, with emphasis on calculation of the stress intensity factor of I-type crack. A two-dimensional finite element analysis of a plate sample including an initial crack was carried out to study the propagation of a fatigue crack under multiaxial loadings. The effects of crack length and the multiaxial condition on the stress intensity factor were especially investigated. Our present approach provides an effective method for edge crack fracture criterion under complex loading calculation.
Performance of Cu-Based Catalysts in Low-Temperature Methanol Synthesis
Authors: Yang Rui Qin , Gai Xi Kun , Xing Chuang , Mao Jian Wei , Lv Cheng Xue
Published: August 2014

The reactions of the methanol synthesis were conducted from the CO/CO2/H2 on the Cu-based catalysts using different solvent at 443 K and 3.0 MPa. The alcohol solvent had the activity in the low-temperature methanol synthesis reaction. The activity of the Cu-based catalyst with ZnO as carrier was higher than that of the catalyst with CeO2, Al2O3, or TiO2 as carrier separately in the reaction. The addition of the CeO2 to the Cu/ZnO catalysts improved the copper species dispersion, so that it was easier for the reduction of the Cu/CeO2-ZnO catalyst than that of the Cu/ZnO catalyst according to the TPR analysis. The variation trend of the BET surface area and the copper surface area was consistent with those of the activity for the Cu/ZnO and the Cu/CeO2-ZnO catalysts in the reaction. The activity of the Cu/CeO2-ZnO catalyst was higher than that of the Cu/ZnO catalyst in the reaction.
Influence of Pre-Deformation Temperature on Mechanics Performance of NiTiNb Shape Memory Alloy: First-Principles Calculation
Authors: Zhu Hong Chang , Yanguan Fu Sheng , Li Gui Fa , Peng Ping
Published: August 2014

Based on first-principles calculation, the mechanism of optimal pre-deformation temperature (Ms+30) for NiTiNb alloy was characterized and analyzed by several parameters, such as crystal constant, cohesive energy and the elastic constants. Simulation results showed that the shear modulus c′ and c44 of matrix NiTi phase was softened at 208K. At the same time, its cohesive energy obtained its local maximum value, which was originated from the easy transition ability of valence electrons in d orbital. In other words, the matrix NiTi phase was instable only when the pre-deformed temperature was not only for Ms but also to 208K (Ms+30K).
Microstructure Characteristic of AZ31/7005 Joints by GTAW with Filler Wire of Mg-Al Alloy
Authors: Du Hong Yan , Li Yaj Jang , Wang Juan
Published: August 2014

Mg/Al dissimilar materials were welded successfully by GTAW with SAlMg-1 and SAlMg-2 welding wire of Mg-Al system. The nice weld shape and free defects of joints are obtained. The test results indicated that continuous lamellar intermetallic compounds is not found The structure of Mg side in the fusion zone is composed of α-Mg solid solution+ β-Al12Mg17 eutectic structure and precipitates β-A112lMg17 on the grain boundary. The structure in the weld zone is mainly α-Mg solid solution + β-A112lMg17 solid solutions. Mg and Al content are stable in the fusion zone of Mg side. However, in the weld zone of Mg side the Mg content is decreased gradually, and the Al content is increased that reaches a stable level in the weld zone of Al side. As a result, when Mg content in the wire can hold a proper level, the intermetallic compounds will be controlled effectively, and the performance of AZ31/7005 welding joint can be improved.
Research of Microstructure and Mechanical Properties of the Cold Rolled Hot-Dip Galvanizing DP450 Steel with Low Carbon and High Chromium
Authors: Han Yun , Kuang Shuang , Liu Hua Sai , Jiang Ying Hua , Liu Guang Hui
Published: August 2014

A new cold rolled hot-dip galvanizing DP450 steel with low carbon and high chromium was designed and effect of the galvanizing processes on the microstructure and mechanical properties was also investigated. At last, it was compared with the referenced DP450 steel which was already produced in industry. The results show that microstructure of the experimental steel consists of regular polygonal ferrite, almost 1% MA island and little bainite. The industrial experimental cold-rolled galvanizing DP steel has excellent combined mechanical properties as follow: yield strength is 306 MPa, tensile strength is 467 MPa and elongation (A80) is 33%. Compared to the referenced steel, the experimental DP450 steel has lower yield strength, better elongation and better forming performance, accordingly.
Effect of Feeding Rate on Properties of Cu-Ag Alloy Nanopowders
Authors: Zou Min Ming , Wu Hong , Zhu Li Jun , Jia Wan Ming , Zhang Zhong Ya , Ye Xiang Hai , Tian Kai Wen , Shi Hong Gang
Published: August 2014

The relations between specific surface area, morphologies and collection rate, feeding rate of Cu-Ag alloy nanopowders prepared by plasma induction system were studied by specific surface area tester and SEM. The results show that with the increase of powder feeding rate from 300g/h to 500g/h and to 800g/h, the collection rate decreases from 59.1% to 47.2% and to 46.1%, respectively, and the specific surface area accordingly decreases from 9.25m2/g to 7.17m2/g and to 5.45m2/g.
Enhanced Mechanical Properties of a 0.22C-Mn-Si-Cr Low Alloyed Steel Treated by ART and Q&P Processes
Authors: An Bai Feng , Gao Gu Hui , Gui Xiao Lu , Tan Zhun Li , Bai Bing Zhe
Published: August 2014

There is a currently desirable demand for high strength steels with good ductility reduce the weight of steel parts for automobile and train applications. Retained austenite in steels can improve the toughness and plasticity. The austenite reverse transformation + quenching and partitioning (ART + Q&P) process was treated on a 0.2C-Mn-Si-Cr low alloyed steel, a multiphase microstructure composed of intercritical ferrite (IF), martensite, bainite and retained austenite (RA) can be obtained in the low carbon steel. Microstructures of the steel treated by different heat treatments were characterized by SEM and XRD. Results show that the formation of RA in low alloy steel depends on the following: (1) the enrichment of the carbon and manganese in the reversed austenite during the ART step; (2) the secondary enrichment of carbon in retained austenite during the following Q&P step. High fraction of RA (14 vol.%) was obtained through the two-step element enrichment treatment (ART + Q&P). Due to continuous TRIP effect of RA during the deformation, a good combination of strength and plasticity was achieved in our works: the product of strength and elongation is greater than 35 GPa•%, the tensile strength is more than 1230 MPa, the yield strength greater than 890 MPa, the total elongation is about 28.6%.
Investigation on the Austenitic Reverse Transformation of 0.2C-3Mn-1.7Si Steel with an Ultra-Slow Heating Rate
Authors: Zhang Bao Xiang , Gui Xiao Lu , Gao Gu Hui , Tan Zhun Li , Bai Bing Zhe
Published: August 2014

In order to clarify the austenite reverse transformation of a 0.2C-3Mn-1.7Si steel during intercritical region with an ultra-slow heating rate of 0.05°C/s, DIL (dilatometer), SEM, XRD and EPMA were carried out. The experimental results indicated that the dilatometric cures exhibited the shape of two “valleys” and the growth of austenite from quenched martensite was composed of three consecutive sub-stages. This phenomenon is associated with Mn-rich and Mn-poor regions in martensite matrix. During the heat treatment,the austenite forms firstly in region enriched in Mn. However, with increasing temperature, the growth of γ is restrained owing to the concentration of Si. Upon the further process of heating, the free energy for the reverse transformation increases, and the residual Mn-depleted regions start to transform at a higher temperature.
Analysis of Orange Peel Defects on Hot-Dip Galvanized High Strength Low Alloy Steel
Authors: Wang Li Hui , Tang Di , Liu Xiang Dong , Zhang Yan Wen , Zhou Shi Zheng
Published: August 2014

The surface of hot-dip galvanized high strength low alloy (HSLA) steel easily occurs orange peel in the deformation process. On the other hand, the defects possess a specific directivity and sits at approximately a 45-degree angle to the sheet steel rolling direction. The microstructures and properties of steel specimens with the orange peel defects and the normal were analyzed, which results showed that their microstructures consist of ferrite and few granular pearlite. The yield point elongation of the HSLA steel resulted in the orange peel defects on the surface of sheet stamping and it is associated with skin rolling and stretch rolling process. Further studied on the fine microstructures by means of SEM and electron back scatter diffraction (EBSD) techniques, which was apparent for the defect steel that the orange peel defects were resulted from weak favorable {111} texture might be the key factors aggravating the formation of orange peel defects. It can be concluded that the formation of Cottrell atmospheres caused the yield point elongation by the interaction between dislocation and diffusive solute atoms as basic reason and the directivity of the orange peel defects was related with the LUDERS slip forming. The yield point elongation can be eliminated to avoid the orange peel defects beyond to 1.8% skin-rolling and stretch rolling method with an appropriate annealing technology.
Deep Denitrogenization Technology of 23Co-Ni Steel in Vacuum Induction Melting Furnace
Authors: Wang Rui , Zhang Hui Shu , Tang Lei , Zhan Dong Ping , Jiang Zhou Hua , Zhang Yang Peng , Zhou Wei Ji
Published: August 2014

23Co-Ni is an ultra-high strength steel and it needs ultra low nitrogen content in the steel. The removal of nitrogen for 23Co-Ni steel in a 6t/12t Vacuum Induction Melting Furnace (VIM) with different melting processes was studied. The results show that, the longer of the melting time and the higher of the vacuum level, the lower of the final nitrogen contents is. The denitrogenization rate can reach 70% when the melting time is more than 8 hours. The electromagnetic stirring can increase the denitrogenization speed. When the VIM is vacuumed to 1-3 Pa, it can make the nitrogen content reaches 0.0005%-0.0008%.
Effect of Mn Addition on Mechanical Property and Corrosion Behavior in Hot Rolled 19 % Cr Duplex Stainless Steel
Authors: Yang Yin Hui , Gu Yang
Published: August 2014

The effect of Mn addition on mechanical property and corrosion behavior of hot rolled 19 % Cr duplex stainless steel was investigated. The ultimate tensile strength of specimen decreased from 950 to 840 MPa with increasing Mn content from 3.6 to 5.5 wt.%, and further decreased to 768MPa with Mn content addition up to 8.1 wt.%. The sample with the addition of 5.5 wt.% Mn exhibited the highest elongation up to 43%. The polarization result revealed that higher value of breakdown potentials Eb was obtained with increasing Mn content from 3.6 to 5.5 wt. %, but which decreased with increasing Mn content to 8.1 wt.%. The electrochemical impedance spectroscopy (EIS) spectra showed higher corrosion prevention capability was obtained due to enhancement of polarization resistance with increasing Mn content from 3.6 to 5.5 wt.%.
Simulation of Martensitic Transformation of High Strength and Elongation Steel by Cellular Automaton
Authors: Zhi Ying , Liu Wei Jie , Liu Xianghua
Published: August 2014

The model of cellular automaton (CA) for simulating the martensitic transformation of the high strength and elongation steel during quenching was established. The microstructure evolution of martensitic transformation of high strength and elongation steel during continuous cooling was simulated dynamically, in terms of parameters such as the volume fraction and morphology of the martensite and retained austenite were quantitatively, accurately and visually described. The simulation results could provide a theoretical reference for the control of the microstructure and property of high strength and elongation steel.
Morphological Characteristics of W-Nanowires after Selective Etching
Authors: Wang Wen Jia , Zhao Zhi Long , Tang Ming , Gao Jian Jun
Published: August 2014

An eutectic NiAl–1.5 at.% W alloy prepared by using directionally solidified (DS)was employed as a source for producing W-nanowires. Several growth rate of 8,15,25/s was respectively used at a temperature gradient of ~240 K/cm in a Bridgman-type directional solidification furnace. A combined stability diagram was applied to predict proper conditions for the selective dissolution of NiAl matrix to get W-wires. Etching in a mixture of HCl:H2O2 released parallel aligned W-nanowires with a wire diameter of ~500 nm. Different morphologies, such as nanobelts, lotus-shaped, conical of W-nanowires are obtained at the different conditions.
Application of a Novel DOPO-Based Polymeric Phosphate Flame Retardant for Polycarbonate/Acrylonitrile-butadiene-styrene Alloy
Authors: Yan Li , Sang Ji Meng
Published: August 2014

A novel flame retardant additive, DOPO-based polymeric phosphate (PFR-D), which simultaneously contained phosphorus and sulfur, was synthesized from 9,10-dihyro-9-oxa-10-phosphaphnanthrene-10-oxide (DOPO), POCl3 and bisphenol S. And the structure of PFR-D has been characterized by 1H-NMR, 31P-NMR and FT-IR. PFR-D was used as additive in polycarbonate/acrylonitrile-butadiene-styrene alloy (PC/ABS). The UL94 V-0 rating was achieved by addition of 5-7% PFR-D in PC/ABS, the LOI reached 27.5%. The thermal degradation of PFR-D and polymers with it was investigated by TGA, and the results showed that addition of PFR-D apparently changed the pyrolysis pathways of PC/ABS. The TGA curves indicated that the flame retardant effect was attributed to promoting the char yield by involving the polymer in charring.
Nanoscience: The Scale of Latvia
Authors: Staube Tatjana , Ciemleja Guna , Geipele Ineta
Published: August 2014

The Paper provides preliminary results with the aim to determine a range of the local scientific activity in the development of advanced technologies on a global scale. Analysis on ranking is made in the Baltic Sea Region accepted as the main limitation of the Paper. The applied methods are logical approach, analysis of the literary sources, assessment of the indicators (including financing, scientific and innovative activities ratios), its dynamics in the scientific field and business arena. The enclosed analytical data ensure the value of the Paper. Among the main findings are: available data for the economic assessment of the nanotechnologies in Latvia are of a general character, limited or controversial. Recently, Latvia has had both the lowest and the highest rankings.
Preparation and Study of P(Styrene-Divinylbenzene)/Polyacrylamide Particles
Authors: Wang Jian Li , Wang Zhong Hua
Published: August 2014

The micro-sized p(styrene-1,4-divinylbenzene)/polyacrylamide(p(St-DVB)/pAM) particles were prepared by a two-step method. P(St-DVB) cores were firstly obtained via concentrated emulsion polymerization, and then the cores were swelled sufficiently and reacted with acrylamide until p(St-DVB)/pAM particles were obtain. The morphologies and compositions of p(St-DVB)/pAM particles were characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR) individually. It was proved that the micro-morphologies of p(St-DVB)/pAM particles were nearly spherical or even peanut shape. It was also found that the diameter distribution of p(St-DVB)/pAM particles became narrower with the increasing of DVB amounts, and the same trade was also observed on emulsifier amounts.
Study on the Cell Structure and Mechanical Properties of Methyl Vinyl Silicone Rubber Foam Materials
Authors: Luo Shi Kai , Ding Guo Fang , Dai Bin , Yang Meng , Liu Fang
Published: August 2014

The mechanical properties of methyl vinyl silicone rubber foam materials with different cell diameters of the spherical cell structure were investigated. The results showed that the cell diameter had significant effects on the mechanical properties,the foam materials with cell diameter range 300~450μm had the best compression stress property and stress-relaxation property. The changing of cell shape of the spherical cell foam materials in the process of dynamic compression were analyzed by using micro focus uCT technology, with obtaining the parameters of cell volume, porosity and so on.
Study on Synthesis of Starch Based Polymer Microspheres and Adsorption Behavior for Lead Ions
Authors: Zhao Yang , Ren Jian Wei
Published: August 2014

The starch based polymer microspheres were synthesized in the system of the inverse emulsion polymerization. These polymer microspheres were characterized by Scanning Electron Microscope and Grain Size Analyzer. Adsorption behavior of starch based polymer microspheres for Pb2+ was investigated by atomic absorption spectrophotometry. The results showed that the average particle diameter of starch based polymer microspheres was about 43.9 μm, and surface of starch microsphere was rough and porous which could be beneficial to form adsorption layer. And the starch based polymer microsphere exhibited good adsorption of lead ions.
Preparation of Conductive Ink with Silver Nanoparticles and Application in Transparent Conductive Films
Authors: Liu Wei , Xu Yan Fang , Li Lu Hai
Published: August 2014

The silver nanoparticles (Ag NPs) with average diameter of 84nm are synthesized via a simple liquid phase reduction method in the mixture of water and ice. The conductive ink with good performance is formulated using the synthesized Ag NPs and its average sheet resistance reaches to 0.62Ω/□. Furthermore, the grid transparent conductive films (TCFs) with three different geometries are fabricated using the formulated conductive ink through flexographic printing, and the transparent and conductive properties are analyzed and compared, resulting in the comprehensive quality Q of 20um/ 400um hexagon grid (3.79) is relatively the highest.
Small Angle Neutron Scattering Study of Ferritic ODS Alloys
Authors: Zhang Li , Luo Ji , Li Tian Fu , Wang Wei , Liu Rong Deng , Wang Zi Jun , Wang Hong Li , Liu Yun Tao , Chen Dong Feng
Published: August 2014

Small Angle Neutron Scattering (SANS) technique allows characterizing the nanomicrostructure of the ferritic Oxide Dispersion Strengthened (ODS) steels which are candidates for the structure material of fusion reactor and fast reactor. A SANS study of domestic ferritic ODS alloys are presented. The main objective is to study the evolution of the oxide dispersion nanoparticle during the different stages of the fabrication and different content.
Synthesis and Luminescent Properties of Blue-Emitting Hydrotalcite-Like Compound for NUV Light-Emitting Diodes
Authors: Hong Chen , Gao Hui , Xuan Zhao , Jiang Li Hong , Ling Qi Dan
Published: August 2014

Layered organic-inorganic hybrid nanocomposite material with the hydrotalcite-like structure, containing Mg (II),Zn (II) and Al (III) in the layers, and salicylate ions in the interlayer, have been prepared by a simple coprecipitation method (MgAlZn-sal-HTlc). Fluorescence spectrum, XRD and TG were used to characterize the properties of the sample. Additionally, A LED device was fabricated by coating MgAlZn-sal-HTlc onto InGaN-based LED chip. The device emits bright blue light. All the results indicate that blue-emitting fluorescent hydrotalcite-like compound can act as blue components in the fabrication of white LED.
The Synthesis of the Novel Vacuum Ultraviolet Double Frequency Crystal KBe2BO3F2 (KBBF)
Authors: Ban Yao Wen , Wang Wen Li , Zhang Wei , Han Jian
Published: August 2014

KBe2BO3F2 (KBBF) crystal is a sole important and practical ultraviolet nonlinear optical material. It can realize the output of vacuum ultraviolet laser below 200nm with the method of phase-matching. However, it is difficult to grow a practical crystal size with the general growth methods such as fluxed melts, hydrothermal or prism-coupling technique because of the layering growth habit. A reduced-pressure melts growth method was presented to grow bulk KBBF crystal and how to achieve the high quality raw material for growth is a critical factor. In this paper, the influences of syntheses methods of raw material and experiment conditions were discussed, and the best syntheses method was selected.
Doping Strategies of Bi (Ti0.5Ni0.5)O3 for Increased Performance in BiFeO3
Authors: Ma Zheng Zheng , Li Jian Qing , Chen Zi Peng , Hu Xiao Jun
Published: August 2014

Investigation of crystal structure, dielectric, magnetic and local ferroelectric properties of the diamagnetically substituted (1-x)BiFeO3-xBi (Ti0.5Ni0.5)O3 solid solutions samples have been carried out. The solid solutions have been found to possess a rhombohedrally distorted perovskite structure described by the space group R3c. Compared with pure BiFeO3 compound, both ferroelectric and magnetic properties are much improved by solid solution with Bi (Ti0.5Ni0.5)O3 with saturation hysteresis loops observed. Among all the samples, the x=0.1 samples shows the optimal ferromagnetism with Mr~0.56531emμ/g and the optimal ferroelectricity with Pr~5.767μC/cm2 at room temperature.
Synthesis, Structure and Photocatalytic Property of [Ni(en)2]{[Ni(en)2]2[Mo8V8O40(VO4)]}[(NH2)2(C2H4)2NH]2·2H2O
Authors: Liu Ya Bing , Xiao Li Guang
Published: August 2014

A 1-D chain-like POM - based organic-inorganic hybrid compound with the chemical formula of [Ni (en)2]{[Ni (en)2]2[Mo8V8O40(VO4)]}[(NH2)2(C2H4)2NH]2·2H2O (en = ethylenediamine) (1) has been hydrothermally synthesized and structurally characterized by the elemental analysis, and single crystal X-ray diffraction. Compound 1 consists of the bi-supported tetra-capped Keggin-type {[Ni (en)2]2[Mo8V8O40(VO4)]}2- building blocks and [Ni (en)2]2+ metal organic cationic moieties are connected together to form 1-D chain through covelent-bonding interactions, which is further linked into 3-D supramolecular networks . The degradation of methylene blue (MB) under UV irradiation with 1 as the heterogeneous photocatalyst has been investigated, showing a good photocatalytic property of 1 for MB degradation.
The Effect of Different Meshes on the AC Loss Calculation of HTS Conductors
Authors: Song Meng , Zhang Yi , Deng Xu Zhi , Liu Hao , Hu Nan Nan , Ren Li , Shen Shi Feng
Published: August 2014

The AC loss calculation is crucial for the thermal analysis of the High Temperature Superconducting (HTS) magnet. Generally, the critical state model is used to calculate the AC loss value of the HTS conductor with Finite Element Method (FEM). The mesh of the model have a large impact both on the convergence and the accuracy in calculation processes. In this paper, we investigate the effect of different meshes on the AC loss calculation of HTS conductors using a second generation tape model. Both triangular and quadrangle element with fix number of elements and predefined distribution type meshes have been used. The results illustrates that quadrangle with geometric sequence is the best choice when calculating the AC loss in HTS tape.
Influences of Different Calcining Method on the Characteristics of 0.65(K0.5Bi0.5TiO3)–0.35BaTiO3 Ceramics
Authors: Hsieh Yuan Tai , Diao Chien Chen , Yang Cheng Fu , Lin Ying Hsun
Published: August 2014

0.65(K0.5Bi0.5)TiO3–0.35BaTiO3 (0.65 KBT-0.35 BT3) ceramic was synthesized using a conventional calcination process (CC-process), and using a two-step calcination process that combined hydrothermal and CC processes (HT-CC-process). The effects of these two different calcination processes on the physical and dielectric properties of 0.65 KBT-0.35 BT3 ceramics were recorded and analyzed. When the CC-process was used, secondary phases—namely, BaBi4Ti4O15, K2TiO3, and K4Ti3O8—were observed in the XRD patterns of 0.65 KBT-0.35 BT3 ceramics. When the HT-CC-process was used, only the (K0.5Bi0.5)TiO3 (or (K0.5Bi0.5, Ba)TiO3) phase was observed in the XRD patterns, with no secondary phases. Due to the secondary phases, the CC-process 0.65 KBT-0.35 BT3 ceramic had lower dielectric peaks and broader temperature-dielectric constant curve than the 0.65 KBT-0.35 BT3 ceramic synthesized using the HT-CC-process.
Error Analysis of Ceramic Materials Fracture Toughness Measured by the Single Edge Notched Beam Method
Authors: Wang Jia Liang , Shen Xian Feng , Bai Meng Liang , Zhou Gang , Jiang Mian
Published: August 2014

In this study, the fracture toughness of ceramic materials such as Al2O3, SiC, Si3N4, ZrO2 were measured by the SENB method and IF method respectively. The results shown that the value of fracture toughness obtained from the SENB method is significantly higher than the IF method. When the notch width is fixed, with the flexural strength of ceramic materials increasing, the error of fracture toughness from the SENB method compared to the IF method is increased. For example, the flexural strength of ZrO2 is about 847MPa and the error of fracture toughness from the SENB method compared to the IF method is 50.14%, the flexural strength of Al2O3 is about 338MPa and the error of fracture toughness from the SENB method compared to the IF method is only 4.52%.