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The application of the DeNitrification-DeComposition (DNDC) model in soil respiration of winter wheat at the Ecological Experimental Station of Fuping County, China is researched for the year 2013-2014. The applied results indicate that DNDC is available to research soil respiration in cropland agroecosystems of Guanzhong Plain, China. Also the cumulative and seasonal variation emissions of soil respiration and components (root respiration, soil heterotrophic respiration) are estimated. Based on the simulated results, it can be seen that a significant variation appears in winter wheat growing season, where a downward trend starts from planting season to wintering season, and a steady low level at about 8.3 kg C·hm-2·d-1 keeps until the overwintering, then a significant upward to harvest, where the top point is almost 101.84 kg C·hm-2·d-1, with the total amount is 8342.35 kg C·hm-2. The seasonal amount of root respiration is 5345.47 kg C·hm-2, occupies 61.1% of soil respiration emissions.

The two-dimensional braid heterogeneous-reinforced (BHR) polyvinylidene fluoride (PVDF) hollow fiber membranes which include PVDF polymer solutions (coating layer) and the two-dimensional braid as a reinforcement were prepared through the dry-wet spinning process. The influence of PVDF concentration in polymer solutions on performance of BHR hollow fiber membranes were investigated by terms of pure water flux, protein rejection, a mechanical strength test, and morphology observations by a scanning electron microscope (SEM). The results of this study indicated that the tensile strength of the BHR PVDF hollow fiber membranes was nearly 75 MPa and the hollow fiber membranes were endowed with better flexibility performance. The BHR PVDF hollow fiber membranes had a favorable interfacial bonding between the coating layer and the two-dimensional braid. The pure water flux decreased, while the rejection ratio increased with the increase of polymer concentration.

Increasing impermeable surface area has become a serious burden for drainage of urban stormwater. It is thus important to know how much surface runoff may be generated by storms of varying intensity and duration, especially on a continual daily basis. In this paper, the field hydrology model-DRAINMOD was used to simulate daily surface runoff under different surface condition in Xi’an, China. As a major hydrological components in DRAINMOD, daily evapotranspirations were calculated with the FAO Penman-Monteith method and read into the model. Infiltration parameters were considered as calibration factors in the modeling process. Available data from a local rainfall-runoff experiment were used for model calibration by matching the model predicted surface runoff with the measured values on an event basis. The calibrated model was then used for long term simulations in order to examine the impact of varying climatic conditions and land cover on urban runoff. The modeling results may provide a practical guidance for city storm water management.

With the increasingly wide use of screw components in industry, technologies for efficiently fabricating the complex helical surfaces on these components play an important role in modern metal-working. In this paper, the helical surface of a screw shaft is mathematically modeled based on the profile of its end section, and the whirlwind milling process and its requirements for machining the screw using standard cutter blades are overviewed. Then a theoretical approach to calculating the tool path and the corresponding movements of the machine axes for producing such a helical surface are presented. Finally a case study is provided with an example screw whose end section is described using sampled points.

The improvement effect of the external concrete to stability of the core steel-tube was demonstrated by the steel-tube replacement ratio through experimental study. The test results show that, with the steel-tube replacement ratio increasing, the ultimate bearing capacity of composite columns increased correspondingly, and the ductility of composite columns was improved obviously also. Therefore, the steel-tube replacement ratio should be involved in the formula for calculating the ultimate bearing capacity of composite columns. By finite element method and regression analysis, the slenderness ratio is amended by the steel-tube replacement ratio and the calculation results of the eccentric compression bearing capacity agreed well with the test results．

How to determine a representative and economical soil sampling method that combines soil properties with advanced technologies has been an unsolved issue in soil related studies. This paper proposes a new method for soil sampling based on some measured salinity data and remote sensing images, as well as analysis of spatial distributions of soil properties in Lubotan land reclamation area in Shaanxi, China. The results showed that with the available data sets of 33 points, up to 101 unknown points can be estimated, and further interpolation of 343 points displayed spatial distribution of soil salinity in the study area, the coefficients of determination (R2) for the predicted soil salinity were 0.817, respectively. A further Kriging analysis for top soil salinity distribution in the study area showed that soil salinity has a medium degree of autocorrelation and low variability. The study in this paper may help understand the effect of soil reclamation efforts and local water management practice.

The paper presents a platform architecture of digital design and manufacture for Printing and Die-Cutting Machinery of Corrugated Board (PDMCB) based on Multi-Agent System (MAS) to improve the design and manufacture efficiency of PDMCB. In the first, the framework of digital design and manufacture platform for PDMCB has been developed based on the technology of MAS and Product Lifecycle Management (PLM) after analyzing the characteristic of digital design and manufacture system for PDMCB. Secondly, the agents’ functions of the MAS developed for PDMCB are defined and the communication ways between agents are illustrated by Unified Modeling Language (UML). Finally, the prototype system for PDMCB digital design is developed with JADE. The framework brought out in the paper will provide some references to develop the platform of digital design and manufacture for PDMCB.

Structural signal is taken self-adaptive decomposition by Hilbert-Huang Transform mainly composed of the EMD(empirical mode decomposition) and HT(Hilbert Transform), which is especially suitable for structural projects in the non-linear, non-stationary signal analysis through local characteristic. However, some weak signal may be ignored by EMD resulting in modal missing. Butterworth filter is an electronic filter designed to have flat frequency response. Considering the influence of noise , Hilbert-Huang Transform and Butterworth band pass filter are applied together to process the structural signal in order to obtain the frequency, damping ratio and mode shapes of the structure more precisely in this paper. Numerical Simulation results show that the proposed method in this paper could identify the modal parameters effectively and accurately.

Eccentric loading experiment of 13 steel tube-reinforced concrete columns and a reinforced concrete column is implemented. The whole process from the start load on the steel tube-reinforced concrete column until damage has been researched. Change of ultimate bearing capacity with eccentricity, longitudinal reinforcement ratio, position coefficient has been studied, and deflection curve and load-vertical displacement curve under eccentric compressive load were obtained. Failure characteristics of steel tube-reinforced concrete were divided into two different type, small eccentric damage and big eccentric damage. With the same conditions, when steel tube ratio of steel tube-reinforced concrete was 2%, its ultimate bearing capacity was nearly double of reinforced concrete columns.

Nonlinear constitutive law was used in this paper. On the basis of plain section assumption, through isoparametric element theory, nonlinear secant and tangent stiffness matrices of section were derived. Nonlinear equation was solved by Newton-Raphson method. The bearing mechanism under the eccentric compression was revealed by changing eccentricity and position coefficient. The result is found to be in good agreement with the experimental data, and it shows that large and minor eccentricity failure mode, which are similar to reinforced concrete, are existed in steel tube-reinforced concrete column. In addition, force-moment correlation curve is derived. By calculation and comparison. The ultimate capacity is found to be greatly underestimated in the current technical specification.