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Micro-nano bubbles (MNBs) play important roles in the reduction of membrane fouling during membrane separation; however, such improvements are always attributed to the reduced concentration polarization on the surface of membranes and little attention has been paid on the variations of physicochemical properties of the feed caused by MNBs. In this study, the separation efficiencies of the feed containing humic acid (HA), bovine serum albumin (BSA), sodium alginate (SA) or dyes can be improved by MNBs during ultrafiltration, and the normalized fluxes can be maximally increased to 139% and 127% in the dead-end and cross-flow modes, respectively in the treatment of HA solution. We further reveal that the decreased apparent viscosity of the feed in the presence of MNBs is the key factor that enhances the normalized flux during ultrafiltration. This study gives new insight on the importance of MNBs in membrane separation and provides valuable clues for other chemical processes.

A flexible traction power system is proposed for AC-fed railway due to its benefits in power flow optimisation, online catenary anti-icing and power quality improvement. In this system, an energy optimisation controller in section post is adopted to provide reactive anti-icing current and control the energy flow in regenerative braking of the locomotives. The energy optimisation controller in traction substations is adopted to eliminate three-phase unbalance in power grid and perform reactive power compensation. The mathematic model of the proposed system is built based on a power transformation analysis and the validity of compensation algorithms is verified by case studies.

Quantitative assessment of urban thermal environment has become a focus for urban climate and environmental science since the concept of urban heat island has been proposed. With the continual development of space information and computer simulation technology, substantial progresses have been made on quantitative assessment techniques and methods of urban thermal environment. The quantitative assessment techniques have been developed to dynamics simulation and forecast of thermal environment at various scales based on statistical analysis of thermal environment on urban-scale using the historical data of weather stations. This study reviewed the development progress of ground meteorological observation, thermal infrared remote sensing and numerical simulation. Moreover, the potential advantages and disadvantages, applicability and the development trends of these techniques were also summarized, aiming to add fundamental knowledge of understanding the urban thermal environment assessment and optimization.自“城市热岛”概念提出以来,城市热环境定量评价一直是城市气候与环境研究领域的重要内容.随着空间信息技术与计算机模拟技术的不断发展,城市热环境定量评价的技术手段和方法也取得了长足进步.从最初单一利用气象站历史数据对城市宏观尺度热环境进行数理统计分析,逐步发展到综合利用地面气象观测、热红外遥感、数值模式模拟等多种技术对不同尺度热环境进行动态模拟与预测.本文系统回顾了地面气象观测、热红外遥感、数值模式模拟3类城市热环境定量评价技术的发展历程,并总结了各类技术的优缺点、适用性及发展趋势,以期为今后的城市热环境评价与优化研究提供参考.

According to the project interface risk classification including the physical interface risk, the contract interface risk, the tissue interface risk and the information interface risk, the integrated management model of project interface risk was put forward, which focused on the three dimensions: time dimension, relational dimension and information dimension. The project interface risk management system was developed, which consists of information subsystem, organizational subsystem, resources and support subsystem, and dynamic management subsystem. The system implements integration of project risk management from the perspective of the interface, and by using the system managers can foresee the exact location of the risk occurring or may occur.

The process of aluminothermic reduction of a mixture of calcined dolomite and calcined magnesite had been developed. The mechanism of the process was studied by SEM and EDS. The reduction process was divided into three stages: 0≤η t /η f ≤0.43±0.06, 0.43±0.06≤η t /η f ≤0.9±0.02 and 0.9±0.02≤η t /η f t and η f are the reduction ratio at time t and the final reduction ratio obtained in the experiment at temperature T , respectively. The first stage included the direct reaction between calcined dolomite or calcined magnesite and Al with 12CaO·7Al 2 O 3 and MgO·Al 2 O 3 as products. The reaction rate depended on the chemical reaction. The CA phase was mainly produced in the second stage and the overall reaction rate was determined by both the diffusion of Ca 2+ with molten Al and the chemical reaction. The CA 2 phase was mainly produced in the third stage and the reaction process was controlled by the diffusion of Ca 2+ .

Laboratory-scale carbon anodes were produced by a new method of high temperature mould pressing, and their physico-chemical properties were studied. The influence of mould pressing conditions and coal pitch addition on the bulk density, crushing strength, and oxidation resistance was analyzed. The microstructure of carbon anodes was investigated by scanning electron microscopy (SEM), and the mechanism of producing carbon anodes by high-temperature mould pressing was analyzed. The results show that when the anodes are produced by high-temperature mould pressing, coal pitch can expand into the coke particles and fill the pores inside the particles, which is beneficial for improving the quality of prebaked anodes. The bulk density of carbon anodes is 1.64–1.66 g/cm 3 , which is 0.08–0.12 g/cm 3 higher than that of industrial anodes, and the oxidation resistance of carbon anodes is also significantly improved.

A new method for producing titanium and titanium alloys was studied at this paper. The experiment results indicate that Na2TiO3 could be synthesizing by heating at 450°C using NaOH and TiO2 powders.Metallic titanium was observed in XRD pattern of the electrolytes after experiment by means of constant-current electrolytic Na2TiO3 in a CaCl2-CaF2 melt at 850°C.Thendepending on the electrolytical residua,titanium aluminium alloy could be obtained by calcining with Al powders.

In China, with the accelerated urbanization and the rapid growth of urban population, potential urban emergency risk factors gradually increased. Therefore, how to forecast the urban emergency events seems to be important. This study elaborated the mechanism of catastrophe theory and grey forecast method, established the grey cusp catastrophe model according to further research. An empirical analysis on Chinese urban traffic accident forecast was made by this model through four indicators: the number of occurrences, the number of deaths, the number of people injured and direct economic losses. By operating the model with data from 2002 to 2006, the accuracy is verified. Based on data from 2002 to 2011, the model result shows that the next traffic accident occurrence catastrophe will occur in 2015-2016, the next death number catastrophe will occur in 2012-2013, the next injured number catastrophe will occur in 2018-2019, the next direct economic loss catastrophe will occur in 2014-2015.

Liquid co-precipitation method was applied to produce LiFePO4 cathode materials in which Ferrous carbonate was used as raw material. The morphology and electrochemical property of LiFePO4 were characterized by XRD, scanning electron microscopy (SEM) and charge/discharge test respectively. The results show when the precursor was synthesized at 80°C and then heat treated at 700°C for 5h, the particle size of LiFePO4 was 0.1-1μm and the obtained LiFePO4 shows impressive discharge specific capacity of 155mAh•g-1 at 1C rate.

The X-ray line broadening technique was used to calculate the grain size of MgO at 1023, 1123, 1223 K respectively either in or during the thermal decomposition of magnesites in air as well as in vacuum. By referring to the conventional grain growth equation, , the activation energy and pre-exponential factor for the process in air are gained as 125.8 kJ/mol and , respectively. Ranman spectroscopy was employed to study the surface structure of MgO obtained during calcination of magnesite, by which the mechanism of grain growth was analyzed and discussed. It is suggested that a kind of highly reactive MgO is produced during the thermal decomposition of magnesites, which is exactly the reason why the activation energy of the grain growth during the thermal decomposition of magnesite is lower than that of bulk diffusion or surface diffusion.

Anion exchange membranes based on poly(aryl ether oxadiazole)s (FPAEO) were prepared by quaternization of bromomethylated FPAEO with N-methyl imidazole. The structures of the obtained polymers were characterized and confirmed with 1H-NMR measurement. The physical and electrochemical properties of anion exchange membranes were also studied. The conductivity of FPAEO-xMIM membranes were almost higher than 10−2 S/cm at room temperature. In addition, TGA revealed that the AEMs based on imidazolium salts have excellent thermal stability. The experimental results suggested that the obtained AEMs may be potential membranes for anion exchange membrane fuel cells

A series of fluorinated poly(aryl ether oxadiazole)s (FPEO) were synthesized and brominated with N-bromosuccinmide (NBS) which were then functionalized with quaternary guanidinium to get fluorinated anion exchange membranes （AEM）with pendant quaternary guanidinium Groups. The structure of resulting polymers was characterized by FTIR spectroscopy. The properties of the obtained membranes were investigated in terms of ion exchange capacity (IEC), swelling ratio, area resistance and vanadium permeability. The results showed that the novel anion exchange membranes possess much higher selectivity in VRB system. The permeation rate of vanadium ions of GFPEO is 0.21×10-7 cm2min-1 which is much lower compared with that of Nafion.

The reduction ratio was compared between the Pidgeon process and the aluminothermic reduction process with CA2, CA, C12A7as the main production in the residue. The results of XRD show that the main phase in the reduction residue is CA2, CA, C12A7and Ca2SiO4, respectively. Consideration of the efficiency of extracting magnesium, the aluminothermic reduction process which is CA2as the main phase in the reduction residue, is the best one.

To establish the evaluation index system on relationship between urban mass rail transit and its surrounding land use based on transit oriented development (TOD) mode, the suitable methods and principles of evaluation index system were analyzed. An evaluation procedure frame was proposed based on data envelopment analysis (DEA) model. Then the evaluation indexes from urban mass rail transit system and land use system selected based on interactive relations between urban mass rail transit and land use under TOD mode.

The rapid urbanization in China has caused significant urban land use changes and extensive urban growth these years. That has led to a dramatic decrease in arable land and would challenge the national food security. To understand the anthropogenic driving forces of urban growth and find out effective control methods, this study established the Hierarchical Liner Model (HLM) to explore the influence of such factors including society and economy, population, and industry development. On the base of factor analysis and HLM, the decomposition of the affecting factors for urban growth was performed, it visually shows that the social retail goods, public transit passengers, and nonagricultural populations significantly drove the urban growth in China; the tertiary industry development has weak effects on urban growth. By weighting the role of the anthropogenic factors on urban growth, some advices were given at last, and it could provide possible management options for the government to mitigate the excessive urban growth in the near future.

Laboratory-scale carbon anodes were produced by a new method of high-temperature mould pressing, and their physico-chemical properties were studied in laboratory. The results showed that the bulk density of carbon anodes produced by high-temperature mould pressing are 1.61-1.63g/cm3, they are higher than industrial carbon anode by 0.06 g/cm3, but the specific electrical resistance is higher and crushing strength is lower.

Graft modification is a common means to improve performance of natural polymers. Graft modification of collagen with acrylonitrile in zinc chloride aqueous solution was developed to apply in improvement moisture absorption of synthetic fiber. Polymerization yield, graft ratio and graft efficiency increase at first and then decline following monomer concentration, they reach the top when monomer concentration is 7.0 wt%. Graft ratio and graft efficiency increase at first and then decline following initiator concentration, they reach the top when initiator concentration is 0.2 wt%. Polymerization yield consistently rises with the increasing initiator concentration. Polymerization yield, graft ratio and graft efficiency drop with the increasing collagen concentration. The optimal reaction conditions are: reaction time , 90min; reaction temperature, 60°C; monomer concentration, 7.0 wt%; initiator concentration, 0.2 wt%.

To study interactive relations between urban arterial transit route and land-use under TOD mode, the features of urban arterial transit route and its surrounding land-use were analyzed. An interactive relation model between urban arterial transit route and land-use was established with nonlinear differential equations. Dynamic evolvement and trends of urban arterial transit route and land-use were analyzed, and stability and conditions on equilibrium states were shown by differential equation stability theory. A simulation was done to show that the development of arterial transit route in urban had a trend to surpass traffic capacity of equilibrium state.

PTFE suspension latex and PVA solution are blended at different ratio, and the rotary rheometer is used to test the rheological properties of these solutions. The result shows that both PTFE suspension latex and PTFE/PVA blended solution are all shear thinning fluid; with increasing shear rate, apparent viscosity decreases; with increase of PVA content in blended solution, apparent viscosity and Non-Newtonian index increase, and spinnability of blended solution can be improved; with increase of temperature, the apparent viscosity decreases.

According to the principle of muscular hydrostats, a flexible biomimetic octopus arm is put forward firstly. The method of vector control for the flexible biomimetic octopus arm is presented and analysed in detail. Based on the combination of ARM (advanced RISC microprocessor) and FPGA (Field Programmable Gate Arry), a control system for the flexibie biomiometic octopus arm is discussed, and the functions of every components is analysed. To verify the feasibility and reliability of the method of vector control, experimets are carried out. The experimemtal results demonstrate that this method applied in the control of the biomimetic octopus arm has a good performance.

Based on characteristics of environmental impact of railway construction projects, the paper drew on experience of environmental impact assessment (EIA) projects, carried out preliminary EIA on China's mid-long term railway network plan from macro perspective according to planning requirements, and discussed the key points of EIA on guiding special planning.

Effects of various reaction parameters such as atmospheric pressure, treating temperature, sintering time and bituminite content on the preparation of primary Al-Si alloy by carbothermal reduction of bauxite tailings were investigated by XRD, XRF, infrared absorption carbon-sulfur analysis unit and SEM coupled with EDS. Meanwhile, the mechanism of carbothermal reduction of Al 2 O 3 and SiO 2 was discussed. It is found that pressure and temperature are major factors that influence the carbothermal reduction of bauxite tailings. The appropriate conditions for preparation of primary Al-Si alloy are as follows: atmospheric pressure of 0.1 MPa, heating temperature of 1 900 °C, bituminite content of 95% (mass fraction) of theoretic bituminite content and sintering time of 1 h. Among four mechanisms of carbothermal reduction of Al 2 O 3 and SiO 2 , the theory of the formation and decomposition of carbides might be the best one to interpret the reaction process.

The coarse Al-Si alloy produced by carbothermal reduction of aluminous ore contains 55% Al, 25% Si and some impurities. The main impurities are slag and iron. The process of manufacturing casting Al-Si alloy ZL101 with the coarse Al-Si alloy was studied. The phase constitution and microstructure of the coarse Al-Si alloy, slag and ZL101 were examined by X-ray diffractometry and scanning electron microscopy. The results show that the content of silicon and iron in the casting alloy reduces with the increase of the dosage of purificant and manganese, but increases with the rise of filtering temperature. It is found that casting Al-Si alloy conforming to industrial standard can be produced after refining by using purificant, and removing iron by using manganese and added magnesium.

The outstanding power quality problems including three-phase voltage unbalance and large reactive power have drawn more and more attention of railway company and power system. Moreover, the neutral section insulators at exits of substations affect the safety and efficiency of the electric trains, especially in high speed railway and heavy haul railway. A new traction power supply system adopting Vx connection traction transformer and active power flow controller (PFC) is proposed. The mathematic model of the new system is built and the compensation currents of PFC are calculated for comprehensive compensation. Moreover, the optimized topology and control method of PFC are studied. The simulation and performance of the different operation modes verify the validity of the proposed system, which can be used in high speed and heave haul railways.

Partial substitution of certain cations for manganese is an attractive route to improve the electrochemical property of LiMn2O4. In this paper, we focus on the effect of chromium substitution. LiCryMn2−yO4 (y=0.00, 0.03, 0.05, 0.08, 0.12, 0.16, 0.20) has been prepared and their structure and electrochemical characteristics have been investigated. Rietveld refinements of the XRD patterns indicated that with increasing Cr content, the occupation of Mn3+ (or Cr3+) in octahedral 16d sites increased and the crystal structure improved. At the same time, in the 32e (z, z, z) sites, which are occupied by oxygen, the value of z also increases and result in decreasing the bond lengths of O–M (Mn, Cr) and Mn–Mn and increasing the bond length of O–Li. The optimal composition was LiCryMn2−yO4 (y=0.05), whose initial discharge capacity was 121.6 mAh g−1.

A solvothermal route has been adopted to prepare γ-LiV2O5 nanorods via the reaction of vanadium pentoxide (V2O5) and lithium hydrate (LiOH) in ethanol at 160–200 °C. The as-obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The electrochemical performance of products as cathode active materials was investigated, which indicates that the nanorods of γ-LiV2O5 with smaller size showed better electrochemical properties.

A novel method which is based on the hydrothermal reaction was employed to synthesize LiV3O8. First, the mixture solution of LiOH, V2O5, and NH4OH was subjected to the hydrothermal reaction. The hydrothermal treatment yielded a clear, homogeneous solution. The evaporation of this solution led to the formation of a precursor gel. The gel was then heated at different temperatures in the range of 300–600 °C. The characterization by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) indicated that LiV3O8 nanorods have been obtained by this novel synthesis method. The electrochemical performance of the LiV3O8 nanorods have been investigated, which indicates that the highest discharge specific capacity of 302 mAh/g in the range of 1.8–4.0 V was obtained for the sample heated at 300 °C, and its capacity remained 278 mAh/g after 30 cycles.

Credit sale acts a very important role in the operation of one company. Nowadays, in order to reduce the credit risks, ensure the benefits of companies, and communicate effectively with the customers, analysis of customerspsila credit has become a very popular research question. In this paper, the author develops a credit evaluation model for medicament enterprise based on data mining methods clustering and neural network. By using this model, a company can predict that if the customer will default of contract.

γ-LiV2O5 nanorods with diameters of 30–40 nm and lengths of 0.4–2 μm have been synthesized by a simple solvothermal method at 160 °C using ethanol as a solvent, which also serves as a reducing agen...

γ-LiV2O5 nanorods with diameters of 30–40 nm and lengths of 0.4–2 μm have been synthesized by a simple solvothermal method at 160 °C using ethanol as a solvent, which also serves as a reducing agen...