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It is quite inadequate in providing formula retrieval function by traditional retrieval techniques used in full-text information retrieval system. The main reason is that there are many difficulties to extract the keywords of the mathematical formulas. In this paper, a detailed analysis of the structural characteristics of mathematical formulas and existing index mechanism of mathematical formula searching engine is fulfilled. Then a full-text index (named SLIndex) of mathematical formulas with B+ tree structure is designed and implemented which extracts the structured logic sub-tree feature as keywords of formulas and employs inverted index. Finally, a formula search engine model based on SLIndex is implemented in Apache 2.0 web server.

Radio astronomy telescope can get information from invisible universe by receiving electromagnetic waves. Difference from optical telescopes, there exists many difficulties for making the public understanding the radio astronomy phenomenon. In this paper, we will introduce a new platform for radio astronomy science popularization education in order to help public know radio telescope and radio astronomy. The platform consists of a 0.8meter parabolic antenna, a wide bandwidth low noise amplifier (LNA) and a Software Defined Radio (SDR) terminal. Based on SDR terminal which covers the band from 70MHz to 6GHz, we can get some strong emissions such as the Neutral hydrogen, solar radio bursts and so on in this band. People can carry out many radio astronomy experiments focusing on science popularization by this platform. This new science education tool can interest high school students in science and technology, also students can understand how radio telescopes works.

Based on the classical Mayer-arc model, this paper establishes the equivalent circuit of traction network for AC25kV electric railway from the essence of contact loss discharge. The voltage waves of contact loss arc at different moments are obtained by MATLAB/simulink. Through the analysis, it can be confirmed that the EMI (electromagnetic interference) with broad band and high amplitude will appear at the moment the contact loss between pantograph and catenary happens. Finally, relevant measures are given to avoid the probability event of contact loss.

On the basis of the second-order upwind scheme, combined with the flux splitting method, we derive a uniform multi-conductor transmission line time-domain calculations. This method is a direct time-domain discrete numerical method with second order accuracy. It does not have any special requirements for circuit and the application process and complex transformations which lead to facilitate the preparation of the program. Numerical experiments show that this method of preparation of general purpose computing program has roughly the same computational efficiency with the traditional leapfrog scheme and at the discontinuous solutions, there are no non-physical oscillations. It can easily be used to calculate a uniform multi-conductor transmission line coupling.

This paper, based on STM32 and nRF905 wireless module, introduces a wireless temperature gathering and transmitting system. From RF modules and master control module, the hardware platform has been designed, beyond that, the paper introduces the temperature sensor network software design. The test show that the system is stable, and datas are reliable.

Biomass is renewable and carbon neutral. Biochar, derived from the carbonization of biomass, is a kind of solid fuel with excellent properties. Utilization of biomass in ironmaking process as heating agent and reducing agent contributes to energy conservation and emission reduction, and can partially replace for coal and coke. Research status of the utilization of biomass in ironmaking process is discussed. Application prospects of biomass energy in ironmaking process are analyzed, and a novel bioenergy auxiliary ironmaking system is suggested, which is meaningful for the effective use of biomass and for decreasing the consumption of fossil fuels, namely metallurgical coal and coke.

This paper introduce the relationship between fracture energy of refractories and its thermal shock resistance, and research status about fracture energy of refractories. It shows that investigation on fracture energy of refractories at high temperature is positive significance for evaluation of thermal shock resistance, and wedge splitting method for fracture energy of refractories is an effective method.

The binary polymer AA/SAS was synthesized by acrylic acid (AA) and sodium allylsulfonate (SAS), named as AS and its structure was characterized. Its scale inhibition performance was also investigated for single CaCO₃, CaSO₄ scales, and composite scales in simulated formation water containing Ca²⁺, Mg²⁺, Ba²⁺ and Sr²⁺. The results indicate that when adding 50mg/L of the inhibitor, it is 85.05% efficient for CaCO₃ inhibition and 98.85% for CaSO₄, but only 49.05% and 51.58% for BaSO₄ and SrSO₄ separately. The scale inhibition performance is obvious in the simulated formation water with high concentration of calcium (1300mg/L) and low barium ion (100mg/L ), the inhibition efficiency are both above 85% at a dosage of 80mg/L. And it can fairly satisfy the demand of inhibiting composite scales (CaCO₃ scale, CaSO₄ scale, BaSO₄ scale and SrSO₄ scale), when AS and CT was combined at a mass ratio of 2:1 in high calcium , barium and strontium ions contained formation water, being 95.3% efficient at the dosage of 100mg/L.

In order to improve the coke residue of phenolic resins (PF), different solvents were used in the present work. The research indicates that in comparison with other solvents, such as ethylene glycol (EG) and ethyl silicate (ES), furfural (FF) can enhance crosslinking density and increase residual coke yield of phenolic resins (PF). The results demonstrate that the residual coke yield of PF with furfural is 68 % higher than that with other solvents. In addition, pyrolysis peak temperature of PF with furfural is relatively high and pyrolysis process is more smoothly. FTIR results show that new bonds formed in PF when take furfural as solvent, and furfural changed the structure of phenolic resins. Raman spectra analysis results show that the order degree of the carbonized products (treated at 800 °C) is higher than that in other solvents, and stability of the carbonized products is improved. The research concludes that the type of solvent has great influence on the structure and coke residue.

Electrocatalytic oxidation of polyacrylamide (PAM) at Ti/PbO2 anode was studied in a three-electrode cell without any diaphragm but with a sandwich bath by galvanostatic electrolysis. Turbidimetry was used to determine the concentration of PAM. The change of degradation ratio with current density and reaction temperature was studied through single factor experiment in order to determine the optimal conditions. The optimal conditions of PAM degradation by electrocatalytic oxidation were: current density was 200 mA•cm-2, and reaction temperature was 60 °C. Under these conditions, the degradation ratio of PAM reached 88% after 3.0 h electrolysis. The total dissolved salts (TDS) and different ions affected on the degradation ratio of PAM by changing the size of PAM molecule and the viscosity of solution. The results of experiments showed that the degradation ratio increased firstly then decreased with the increasing of ion concentration. When TDS was 3000 mg•L-1, the degradation ratio reached the highest level. The high valence cation promoted the degradation of PAM. Cl- and HCO3- promoted the degradation of PAM because of the direct and indirect electrocatalytic oxidation and hydrolysis in alkaline solution respectively.