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An amorphous Ni-Fe-P alloy coated shielding fabric with dense uniform coating was prepared by conducting electrical deposition of amorphous Ni-Fe-P alloy on copper-coated polyethylene terephthalate (PET) fabric. This research investigated the preparation process by using orthogonal test with 8 factors and 3 levels. It analyzed the influences of components of the plating solution on the ohms per square, weight gain rate, and shielding effectiveness of coating. Besides, the morphology, composition, and structure of the coating were analyzed by using Scanning Electron Microscope (SEM), Energy Dispersive Spectrdmeter (EDS), and X-ray Diffraction (XRD). The shielding effectiveness of the alloy fabric was also tested. The results indicated that the processing conditions of the amorphous Ni-Fe-P alloy coated fabric using electrical deposition consisted of 135 g/L of NiSO4•6H2O, 105 g/L of FeSO4•7H2O, 8 g/L of NaH2PO2•H2O, 24 g/L of C6H8O6, 36 g/L of C6H8O7, 22 g/L of H3PO3, 65°C, pH=1.5, and current density =13 A/dm2. The fabric obtained in the paper presented compact, smooth, and uniform coating with fine crystal. The coating was the amorphous Ni-Fe-P alloy with 18.67% of P (mass fraction). The shielding effectiveness of this coated fabric reached to 60.82 dB-73.63 dB in a broad frequency range of 300 kHz-1.5 GHz.

This paper deals with maximum-likelihood (ML) detection of symbol sequence in the absence of synchronization information. A novel iterative scheme is proposed to obtain the ML estimates of the symbols without an estimation of synchronization parameters. Instead of the optimal sampling point recovery and explicit carrier phase compensation, the detection of symbols employs the direct calculation of the matched filter output, eliminating the need for a separate synchronizer. The detection problem is treated as ML estimation from incomplete data, which is solved by means of an iterative scheme based on the expectation-maximization algorithm. The proposed scheme is compared with conventional non-data-aided and iterative ML synchronizers. Accordingly, the simulation results indicate that the proposed detector enables improvements on both the bit error rate and convergence property.

In this paper, aiming at the poor performance of the existing symbol rate estimation methods when SNR is low, we proposed a method based on the timing square which can be simply calculated and applied to MASK/MPSK/MQAM modulated signal, improved the performance of signal symbol rate estimation compared with the existing method. Based on the principle of the timing square, the signal modules were squared to calculate the fourier coefficient modulus corresponding to different sampling ratios. Then the characteristic line was searched in the transform spectrum which contains symbol rate information and obtained an estimation of the symbol rate. The impact of the roll-off factor and the carrier wave was analyzed and solution was proposed in this paper. Simulation results show that the performance of symbol rate estimation of the improved method is better than the original method, the wavelet transform method and the cyclostationary method in low SNR and low roll-off factor environment.

The collision that between a car and a train is the main type of accidents in the case railway level-crossing, which is proved by the arrangement diagram analysing. The fault tree analysis and the event tree analysis are used to assess the level of the risk of the level-crossing quantificationally. Some conclusions can be drawn: the collision of the railway level-crossing that between a car and a train will happen 2.552 in a year, which can bring 0.061 equivalent fatalities. This paper puts forward some precautionary measures that based on the minimal cut set of the collision of the accident and the most probable or the highest risk event.

Nearly 40% of Chinese water pollution comes from agricultural sources of pollution, and the annual emissions are difference. If we want to control pollution emissions effectively, we need to accurately predict the amount of agricultural emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD). Due to the complex mechanism of the agricultural non-point source pollution, its emissions are very difficult to measure. Currently, the Bionics Research is in a stage of rapid development, and it continues to expand into many new areas of research. So the comprehensive study of Bionics and pollutant control study will be a good choice. This research used bionic BP（Back Propagation） neural network algorithm, and used pollution census data from 2002 to 2007 and established neural network model with neural network algorithm. And we predicted the agricultural sources of emissions of AN and COD with the data from 2008 to 2010. Finally we compared the predicted value and the actual value. Research results showed that, with using the bionic BP neural network, agricultural sources emissions of AN and COD are evaluated actually and the results indicate that the average error is under 5.0%. Research results proved that the model is effective. The neural network is a scientific predict method for the agricultural sources emissions of AN and COD. It can be widely used in the prediction of agricultural sources emissions of AN and COD.

This paper has introduced the principle and advantages of a new Permeability Plugging Apparatus(PPA) for drilling fluid working under high temperature and high pressure(HTHP). The domestic status and solution of PPA is also been analysed on properties of materials.

In this article, we try to find out the reasons of urban water logging . We will pay attention to the generation process, the affecting factors, and then seek the end solutions to solve the embarrassing situation.

Electrorheological fluid (ERF) is a new kind of smart materials, which has a great deal of market value and broad application prospects. To meet the needs of the ERFs performance testing, design and produce of the ERF's performance test system are based on the relationship of the apparent viscosity, shear stress and electric field strength. Select the NDJ-8S digital viscometer, high voltage DC power supply, liquid container, and other parts to constitute the ERFs performance test system after considering the relationship of the apparent viscosity, shear stress, shear rate and electric field strength. The system has potentials to control voltage, change velocity, change the distance between the parallel panels, and test the yield stress of the ERF, shear stress, viscosity and other parameters. The study introduces the hardware and software device, the related experiments, and obtains the relationship of the viscosity, rotational speed, voltage, and plate gap.

As a typical man-machine interface, vehicle driver seat directly affects driver seating and riding comfort. Lumbar support of driver seat plays a particularly important role in improving driver seating and riding comfort and is usually realized by installing adjustable lumbar support, which provides stable, comfortable support for drivers with different body sizes. Traditional lumbar support has several shortcomings, such as complex structure, high cost, insufficient adjustments ranges, etc. In this work, forward design method of lumbar support with adequate design confidence level was developed, with four-way electric adjustments system. Firstly, lumbar support adjustments ranges was analyzed according to ergonomic principles. Then the concept of lumbar support adjustments mechanism was designed and the parameters of adjustments mechanism were determined including the length and angle ranges of parts, motor and spring parameters, etc. Finally, with consideration of product processing technology and manufacturing cost requirements, detailed lumbar support adjustments system structure was determined. The validated system structure parts were produced and assembled into a prototype. The prototype was tested and accepted, which showed that not only the lumbar support system met the design requirements well, but also the forward design method presented was scientific and reasonable.

To improve energy harvesting performance, a resonance frequency tunable piezoelectric (PZT) energy harvester for vibrating applications was presented and investigated experimentally. A piezoelectric vibrational energy harvester (PVEH) consisted of a piezo-cantilever with a permanent magnet at its free-end and another excitation magnet fixed on vibration structure. The two magnets are placed with the same magnetic poles facing each other to produce repulsive force. The cantilever has dimensions of 70x10x0.6mm3, clamped 10mm, and two magnets sized ø10x4mm3. The testing results show that the magnetic force, denoted by the initial separated distance between the magnetic dipoles (SDMD), exerts great influence on the generated performance. With the SDMD increasing from 15mm to 40mm, the generated voltage rises from 24.4V to 40V, and the resonant frequency increases from 33.75Hz to 38.75Hz.

Due to the concrete self-shrinkage, frequent load application and temperature fluctuation, and so on，the gap formed between the inner tube wall and the core concrete surfaces would decrease the performance of concrete-filled steel tube (CFST). To prevent this cavity problem, various types of expansive agents and aggregates were used in this study to improve the volume stability of core concrete. Comparative experiments with mortars and concrete were carried out respectively under standard curing condition and under enclosed curing condition which simulated the environment in steel tube. The results could be summarized as follows: ● Two types of expansive agents, ZY type expansive agent mainly containing sulfates and aluminates and M type expansive agent mainly containing magnesium oxide, presented different expansive behaviors with curing ages in mortar and concrete. Two types of expansive agents combined with each other could produce complementary and superimposition effects to improve continuously the volume stability of mortar and concrete. ● Sufficient water supply is the key factor for the formation and maintenance of expansion. The volume change caused by the self-shrinkage effect of core concrete could not be effectively off-set with whether two types expansive agents or their compounds under enclosed environment in which water was scarce and could not be supplied from outside. ● When some water-saturated ceramsite were used to partially replace aggregates in core concrete,the volume expansion performance of core concrete improved dramatically with the water storage and supply effects of water-saturated ceramsite.

Early cracks of box girder are widespread during the construction stage of PC box girder bridges. The cracking resistance of a prestressed concrete continuous beam bridge was conducted from the point of construction technique. Experimental study on hydration heat and mechanical properties of box girder concrete at early age were carried out. The results shown that the casting temperature of the concrete, the peak temperature and the maximum temperature difference between inside and outside of the hydration heat were very low, which were 15.7°C, 8°C and 10.2°C, respectively. The strength development of the concrete was stable, and the mixture ratio was optimal. The concrete appearance quality was fairly good without visible cracks in the construction stage. The study reveals that the crack of girder bridges during the construction stage can be avoided by taking effective measures in the construction.