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The use of biomass as fuel might solve several technological and environmental issues and overcome certain challenges of sinter production. In particular, as revealed by comprehensive analyses, biomass can be used as fuel for iron ore sintering. In this study, we investigate the use of some raw and pyrolysis-processed biomass pellet types, namely wood, sunflower husks (SFH), and straw, for iron ore sintering. In the experiments, the pyrolysis temperature was set to 673, 873, 1073, and 1273 K, and the proportion of biomass in the fuel composition was set to 25%. It was established that the addition of biofuels to the sintering blend leads to an increase in the gas permeability of the sintered layer. The analysis of the complex characteristics of the sintering process and the sinter strength showed the high potential of wood and sunflower husk pellets pyrolyzed at 1073 and 873 K, respectively, for iron ore sintering. The analysis of the macrostructure of the sinter samples obtained using biomaterials revealed that with higher pyrolysis temperatures; the materials tend to have greater sizes and higher amounts of pores and cracks. The composition analyses of the resultant sinters revealed that with higher temperature, the FeO content of the sinters tends to increase.

Fe3O4 nanoparticles (NPs) have previously been employed in various fields owing to their unique physical and chemical properties. In this paper, Fe3O4 NPs are prepared by co-precipitation method in a helical microreactor under different reaction conditions which affect the size of Fe3O4 NPs. The product is characterized by FT-IR and XPS. Also, VSM characterization shows that Fe3O4 exhibits typical superparamagnetic behavior and the saturation magnetization of NPs is 53 emu/g.

A novel geopolymer supported nanobimetallic catalyst for isopropanol dehydrogenation was prepared by modified wet impregnation and reduction method. XRD, SEM, EDX and TEM analysis confirmed formation of amorphous geopolymer from the polymerization of metakaolin and deposition of nanometals over the geopolymer support. The bimetallic catalyst containing 5wt. % Cu and 10wt. % Ni loading over geopolymer shows an excellent performance with 23.18% conversion of isopropanol and 88.24% selectivity to acetone under reaction conditions of 90 °C, 3 hours, and catalyst amount of 0.15g/5.0g of isopropanol. Moreover, the catalyst maintains its catalytic stability without noticeable loss of activity after five cycles.

Based on bridges routine examination, special detection is in-depth and meticulous testing that according to the disease characteristics, using some expertise technology and testing equipment for steel corrosion, concrete carbonization, the thickness of the protective layer and component quality to some key parts or typical bridge opening. Bridge condition of technology can be controlled more fully and accurately through a special bridge inspection, combined with conventional test results on the status of a comprehensive assessment of structures. This may provide technical data for the next bridge inspection count and load test, moreover, according to the variation of the data in the field test, it may dedicate variation characteristic and influencing factors for damage of structural durability from these special detections.

Mortarless interlocking blocks have the advantage of convenient construction and low cost, but establishing the geometry interlocking mechanism between horizontal blocks has been overlooked. Optimizing the shape of mortarless interlocking block. The connection of vertical direction in the form of a frustum of a cone, and the connection of horizontal direction in the form of trapezoid shape. This design proposal builds geometry interlocking mechanism between the block and its all adjacent ones. Setting cone and rectangular holes on block body, accordingly, block laying could forming taper vertical channel and rectangular vertical channel. The concrete of interlocking mortarless block has particularity, which is not suitable for “Mix Proportion Design of Ordinary Concrete Regulation” (JGJ55-2010) of China. This paper presents a platter idea to establish the concrete mix proportion design method of mortarless interlocking block, moreover, an example calculation and confirmatory experiment is dispensable.

In situ chemical oxidation with persulfate (PS) anion (S2O82-) is a viable technique for remediation of groundwater contaminants such as trichloroethylene (TCE). This laboratory study investigated the use of the oxidant sodium PS for the chemical oxidation of TCE at different conditions to determine the influence of temperature, pH, and the PS/TCE molar ratio. Experiments revealed that higher temperatures, lower pH, and higher PS/TCE molar ratios were to the benefit of TCE oxidation by PS. By investigating the reaction kinetics, the degradations of contaminant can be described by use of pseudo-first-order reaction. At the temperatures ranging from 25°C to 40°C, the activation energy for the degradation of TCE was determined to be 85.04 KJ/mol.

Aiming at the business requirements of the urban metro transport operational asset management, this paper explored urban metro transport operational asset management system; by means of analyzing information cost of urban metro transport, smart urban metro transport operational asset management system were put forward, and the characteristics and relationship: “Asset Instrumentation, Resource Virtualization, Capacity Servitization, Business Collaboration and Decision-making Intelligentialize” in full life-cycle operational asset management process were discussed in details. Finally, system construction suggestions were given.

With improvement of the level of modernization and mechanization of railway infrastructure maintenance, Railway large maintenance machinery (RLMM) is considered to be one of the main equipment. We have accumulated large amounts of RLMM construction data. How to mine valuable information from these data has become an important research subject. The C4.5 algorithm of decision tree is a useful method of data mining and classification. The paper solves evaluation of RLMM construction problem based on the C4.5 algorithm. By means of extracting the attribute with maximum gain ratio as the root node of the decision tree from training sample data, the evaluation decision tree was constructed. The decision tree modeling of evaluation of RLMM construction was gained by the post-pruning approach. The experimental results and analysis show that this model has high precision and credibility.

For the scene where there is a toxic gas leak, in order to detect the gas quickly and safely and make the effective solutions, the project of monitoring toxic gases in a remote wireless way and the process of the development is proposed in this paper. The device developed in this paper includes several wireless sensor network (WSN) nodes and one hand-held terminal, and the sensor module of WSN node is composed of several chemical gas sensors. The nodes will be sent to the scene by ground robots or unmanned aerial vehicles and make up the WSN monitoring system automatically, to achieve an aim of monitoring the toxic gas in real time. The experiment results show that the device can deal with the emergencies about the leak of toxic gas efficiently. And it has the advantages of low power consumption, high cost performance, self-forming network, anti-interference. Its suitable to monitor the toxic gas in various environments of industrial production and chemical scene of accident and unexpected occasions where there is a leak of toxic gas.

For layout space in the limited land resources and improving the utilization efficiency of urban transportation bridge and traffic conditions, in this paper, according to the request of four lanes of roof, two-way urban light rail traffic in the box, considering the requirements of pipeline layout, water supply and drainage, and fire escape, lighting, ventilated at the same time, based on the existing related specification, give full play to the characteristics of the concrete box girder, preliminarily design out of the single box three rooms inclined web box girder for double-deck traffic of urban bridge, in order to provide the reference design.

A full rang of external prestressing CFRP concrete box girder flexural performance have been tested. Crack distribution, deflection,strain distribution, stress increment of external CFRP have been measured. The results demonstrate that that as the load increase, the shear lag phenomenon on the upper and bottom plate of the box girder is more significantly; There is a certain friction Loss on the interface between CFRP and two steering block which arrange in the mid-span. If suitable element models and material constitutive laws are chose, the ANSYS program may simulate the fully flexural experimental process of the box girder, the result is well agree with the experimental result.

The engine is the power source of the vehicle, it is the main and the most directly reason which causey the vehicle vibration. If you cannot control and attenuation of the vibration generated by it will make other parts of the body associated with strong vibration and noise, and also seriously affect vehicle handling stability and ride comfort, the occupant generated feel discomfort , even when serious damage to the body parts, shorten the car's life. Therefore, the role of the engine mounting system for attenuation and control of vehicle vibration is very important, the shock absorber is an important part of the engine mounting system; engine shock absorbers assembly performance will directly determine them can or cannot work to achieve the desired damping effect. In this paper, the authors propose a new, reliable assembly process; the assembly of the damper can achieve the production process requirements.

The oxidation of cyclohexane in the microchannels not only improves the safety of the reaction, but also the performance of the oxidation reaction. Different gas-liquid micro mixers were used for the mixing of gas and liquid before entering into microchannels, and SIMM-V2 performed best of all. Excellent slug/plug flow can be formed in the microchannels after mixing in the gas-liquid micro mixer when the molar ratio of oxygen to cyclohexane is less than 0.5:1. The conversion of cyclohexane increased as the residence time increased, but the selectivity of cyclohexanol and cyclohexanone increased first and then decreased. At the reaction temperature of 200 °C, with the flow rate of the solvent isopropanol being 1 mL/min and the molar ratio of oxygen to cyclohexane being 0.15:1, both the conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone increased with the increase of pressure. The conversion of cyclohexane and selectivity of cyclohexanol and cyclohexanone reached 10.10% and 66.93% respectively at the pressure of 8 MPa. It is indicated that the new process by use of uncatalyzed cyclohexane oxidation in the microchannels will have very attractive prospects in the improvement of the safety, intensification of the gas-liquid mass transfer and obtaining good reactive performance. Therefore, the technology shows good potential in industrial applications.

A new route to substitute for the traditional two-step method for adipic acid production has been investigated. Supported nano metal catalysts Au/C and Co/C were prepared and used for liquid phase oxidation of cyclohexane to adipic acid with oxygen as an oxidant. These catalysts were characterized by XRD, TEM and ICP-AES. The reactions were carried out in an autoclave with solvent and radical initiator at 373~423K and 1.5 MPa. Au/C (1.25%) was found to be a highly efficient catalyst for the oxidation of cyclohexane with a high conversion (44.93%) of cyclohexane and more than 54.85% selectivity to adipic acid. It is indicated that there was a potential application prospect for the nano-catalysts in one-step oxidation of cyclohexane to adipic acid.

To solve the problem that is the poor demagnetizing effect and stability issues by the way of demagnetization in the one-dimensional space, a new degaussing method was studied in this paper, based on the analysis of magnetic moment angle distribution during the degaussing deal to iron material. Through the magnetization process analysis to iron material in the rotating magnetic field, the theory has some merits such as good degaussing effect and stability to the iron material after degaussing deal in two-dimensional space. The rotation degaussing enhancing the stability of material magnetic field is tested effectively, comparing to degaussing at one-dimensional space.

In this article, simulation tests of chloride binding were made under the condition of sodium chloride as an internal admixture while loaded with stray current externally. Through the potential titration method, free chloride ion concentration Cf 、 total chloride ion concentration Ct and chloride binding rate RCl were determined. The results show that: With the increase of the strength and action time of the stray current, the number of internal free chloride ions in the cement paste increases while that of the corresponding bound chloride ions reduces significantly, leading to the decrease of chloride binding rate. The relationship between chloride binding rate and the two can be shown as follows respectively:RCl=50.754e(-I/28.258)+42.532、RCl=63.427 e(-T/8.238)+27.325.

A Large-scale underground interchange tunnels will be applied in the Chongqing Two Rivers Tunnel project with six crossings and four interchanges adopting NATM. The paper analyzes and discusses the whole-process construction mechanical behavior of the underground interchange by the numerical analysis method, at the same time considering the similar project established, and then suggests some important design parameters about crossings and close overlap interchanges between NATM tunnels, such as proper space of crossings and interchanges. Through the analyses, the paper suggests the design and construction method and construction organization project, especially for the crossings and close overlap interchanges between the NATM tunnels. The paper discusses the key problems of an underground interchange tunnels, and first suggests a mode how to construct an underground interchange tunnels. So, it is important in theory and practical engineering.

The Rayleigh wave testing method is one of the in-situ nondestructive tests, which the theory is quite mature, and it characterized by portable equipment, well operability and fast detection speed. So it can greatly improve the efficiency of the compaction detection of the highway embankment, and it especially has incomparable advantage for the compaction quality detection and monitoring of earth-rock filled or rock filled embankment. In the paper, by the analysis of the field wave testing result of the rock-filled embankment, obtained the velocity of the rock-filled embankment, and researched the relationship of the field wave velocity and the dry density, the relationship of the field wave velocity and the porosity. The fitted formulas between the wave velocity and the dry density and porosity were established, and the results indicate there are well correspondences between the wave velocity and the dry density and porosity. The relationship of between porosity and the shear velocity of the rock-filled is a good linear correlation, and the relationship of between dry density and shear wave velocity of the rock-filled is a good power function relation.

Non-structural cracking of concrete is a serious problem and the underlying phenomena, namely, shrinkage and creep, need to be better understood. Much research has been devoted to this complex problem. However, despite major successes, the phenomenon of autogenous shrinkage is still far from being fully understood. The paper discusses the main aspects of concrete shrinkage, with a focus on autogenous shrinkage, which are especially important in low water/binder ratio concrete. These aspects include the theories of physical mechanism, prediction models and future research trends. Shrinkage of concrete due to moisture changes, which result in surface and capillary tension, was reviewed. The mechanisms often cannot be directly linked to the macroscopically observed dilatation/contraction. An overview of recent model developments is also presented.

A series of supported catalysts Co3O4/SiO2 were prepared by deposition precipitation method. ICP-AES, XRD and TEM data revealed that the Co3O4 active site was highly dispersed on the surface of SiO2. The catalysts were evaluated for selective epoxidation of styrene with molecular oxygen. The results showed that the catalysts were of good catalytic activity for styrene epoxidation and many factors had an evident effect on the catalytic epoxidation activity. The best catalyst was 3% Co3O4/SiO2 on which 96.3% conversion of styrene and 52.7% selectivity of styrene oxide were obtained under the flow rate of O2 20mL/min, 100°C, 10h with solvent.

Through a lot of investigations and studies ,and refering to the current related technical specifications and relevant reference, and combining with the characteristics of the ordinary concrete box section component , single box double room concrete huge section box girder which can realize city bridges double traffic is devised creatively,considering of the need of structure and function. By choosing proper element type and material modle, the designed box grider is modeled by the nonlinear analysis software ANSYS. The shear lag effect of the concrete huge section box girder is studied by applying four load conditions including prestressed load, the upper and lower live load and double load. Parameter analysis are done, which include the load type and width-span ratio.And corresponding conclusions are drawn.

Beizhangdian watershed is a typical semi-dry and semi-humid region, where human activities have little effect on the hydrological cycle. Based on a 30-year hydrological observation data, the precipitation, runoff, and rainfall-runoff relationship were researched by the hydrology statistics analysis methods. The results indicated that the inter-annual change of rainfall-runoff of the watershed is remarkable, the annual distribution of rainfall-runoff is extremely uneven, and rainfall-runoff mainly occurred in flood season (June ~ September). There is a good uniformity between the variation tendency of annual rainfall and annual runoff in time and amount, the correlation coefficient of rainfall and runoff is 0.74, the value of the F-test is 4.23.

In this article, some empirical and theoretical models accounting the relationship between the strength and pore structure of cement-based materials is reviewed and analyzed. From the literature review and analysis, it can be found that the total porosity can be singly used to characterize the relationship between compressive strength and pore structure, but can not be applied into describe the relationship between pore structure and tensile strength. Another major parameter of pore structure - pore size distribution, will have a major impact on strength; the relationship between pore structure and tensile strength is for most models of cement paste, without the consideration of aggregate, and the application of the model must comply with the relevant assumptions. The research on the relationship between the tensile strength of concrete is still at a preliminary stage, requiring more theoretical and experimental study.

Au/Co3O4catalysts were prepared by a co-precipitation method and characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), transmission electron microscope (TEM) and X-ray diffraction (XRD). The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol was investigated over Au/Co3O4catalysts using molecular oxygen as oxidant. These catalysts showed higher activities as compared to the pure Co3O4under the same reaction conditions.

Alumina was modified by doping with metal oxide and then used as the support for depositing gold by an impregnation-ammonia washing method to obtain Au/MxOy/Al2O3(M=Co, Zr and Ce) catalysts. These samples were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), transmission electron microscope (TEM) and X-ray diffraction (XRD). The effects of Co3O4content, metal oxide and mixed metal oxides on the catalytic activity for the selective oxidation of cyclohexane to cyclohexanone and cyclohexanol using molecular oxygen as oxidant were studied. The results showed that better catalytic performance was obtained over Au/MxOy/Al2O3catalysts compared with over Au/Al2O3catalysts. 9.69% conversion of cyclohexane and 93.31% selectivity to cyclohexanone, cyclohexanol and cyclohexyl hydroperoxide, with 1.02 ratio of cyclohexanone to cyclohexanol were obtained over the Au/MxOy/Al2O3catalyst at 150 , 1.5 MPa for 3 h. Moreover, according to the recycling test, the catalyst could be reused four times without remarkable loss of activity.

In order to utilize the waste steel slag effectively, three kinds of alkaline activator such as Na2SO4, Na2SiO3, Na2CO­3 were used to prepare steel slag cementitious material and measure its strength of 28 days and 60 days in the standard wet conditions. Microcosmic structure form of hydration products of cementitious material was analyzed by the test of SEM. The results indicate that: three activators on the strength of steel slag all have certain stimulation effect, and Na2SO4 has the apparent stimulation effect on the strength of steel slag, the analysis and test of SEM also shows that hydration products structure form of steel slag cementitious material added with Na2SO4 is much more than other two activators and is more helpful to improve steel slag strength.

Carbon-supported gold catalysts Au/C were prepared by an impregnation-reduction method and modified by AgNO3to obtain bi-metallic catalysts Au-Ag/C, which were characterized by X-ray-diffraction (XRD) and Transmission Electron Microscope (TEM). Their catalytic performance was tested in the oxidation of cyclohexene in an autoclave without any solvent. The results showed that Ag doping can significantly enhance the catalytic performance of carbon-supported gold catalyst. Au(1.0 wt.%)-Ag(1.0 wt.%)/C has been found to be an efficient catalyst for the cyclohexene oxidation with a conversion of 27.6% at 80 °C and 0.4 MPa for 12 h while selectivity for ∑C6products (including cyclohexene oxide, 2-cyclohexene-1-ol, 2-cyclohexene-1-one and cyclohexane-1,2-diol) exceeding 88.9%, especially the selectivity of cyclohexane-1,2-diol up to 47.6%. Moreover, the effects of Au, Ag content on catalytic performance were also reported.

With wide applications of FRP in civil engineering, it is necessary to study the durability of FRP reinforced concrete structure. Based on the related research both at home and abroad, the factors affecting durability of FRP reinforced concrete structures and the corresponding improvements have been put forward by analyzing the durability of concrete, FRP materials and reinforced structures, respectively.

The major industrial by-product largely generated in southern China is ceramic polishing powder (PP) produced from ceramic industries. In this paper, gross of silicon and aluminum dissolved from polishing powder and fly ash were studied by alkali dissolve experiments, pozzolanic activity of PP and fly ash were studied as well by determining chemical combined water and fast strength experiments. Results show that the cement mortar strength active index of PP is up to 82%. The average size of PP is 6.31 um; the fine granule of PP fills in the pore of mortars and improves the compressive strength of mortars. Microstructure of mortars added PP demonstrates that hydration gel is close-grained, dense and reticular. It reveals that “the granule domino effect” enhance the density of mortars added PP and conduce to the high compressive strength. Polishing powder can be used as cementitious material, especially the quality of early stage is higher than that of fly ash. Gross of vitreous phase is not the single factor to determine pozzolanic quality of polishing powder, ability of alive silicon and aluminum responding to Ca(OH)2 is one of the most important impact.

A full test on the flexible behaviors of the long flanges and trapezoidal section high-strength concrete thin-walled box girder has been performed. The deflection horizontal distribution, strain and strain distribution of concrete and reinforced bars in the compressive flanges, strain distribution along rib height have been studied. The results demonstrate that reinforced concrete thin-walled box girder has fine flexible behavior and ductility, strain distribution along rib height agrees with the basic assume, i.e. Plane section before deforming remain plane, and the destructive experimental results disclosed the full process law of shear lag effect and equivalent calculated coefficient of compressed flange width at middle span section, which can be served as a reference for that applying elementary reinforced concrete beam theory settles the ultimate flexural capacity calculation of concrete thin-walled box girder.