Research and Application of Ecological Outdoor Ground Structure with Composite Water Storage and Drainage Function

In order to solve the problems of surface runoff increase,water accumulation in rainy days and urban heat island effect,an ecological outdoor ground structure with composite water storage and drainage functions was studied and applied in this paper:Through the comprehensive design of road ground,road inspection well,garden inspection well and drainage pipe network,it can quickly store and drain ground water,alleviate the urban heat island effect,realize plant infiltration irrigation,and achieve the purpose of saving water and energy.

Fabrication of Al_2O_3-NaCl Composite Heat Storage Materials by One-step Synthesis Method

Thermal energy storage is an attractive option for effectiveness since it gives flexibility and reduces energy consumption and costs. New composite materials for storage and transformation of heat of NaCl-Al2O3composite materials were synthesized by one-step synthesis method. The chemical composition, morphology, structure, and thermal properties were investigated by XRD, EDS, SEM, and DSC. The results show that NaCl can be absorbed by Al2O3particle from 800 to 900 ℃ for Al2O3particle surface is rich active structure. The results also indicate that the leakage of NaCl when the phase change can be prevented by Al2O3particles and the enthalpy of phase change of NaCl-Al2O3material is 362 J/g. The composites have an excellent heat storage capacity. Therefore, this study contributes to one new thought and method to prepare high temperature heat storage material and this material can be applied in future thermal engineering.

Phase Structure and Electrochemical Properties of RE-Mg Based Composite Hydrogen Storage Alloys

A new type of AB_5-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composite hydrogen storage alloys were prepared by sintering the powder mixtures of a commercial AB_5 alloy and LaMg_3 alloy. The phase structure and electrochemical characteristics of the composite hydrogen storage alloys were also studied. It is shown that AB_(5)-x%LaMg_3(x=2, 3, 4, 5, 6, 7, 8)composites have mult; phase structure. The matrix phase has CaCu_5 structure, the second phase is LaNi_3 phase. The maximum discharge capacity, discharge capacity at low temperature and HRD of AB_5 alloy electrodes are greatly improved after the composite. The maximum discharge capacity of the composite electrodes increases from 325 mAh·g^(-1) for x=0 to 358 mAh·g^(-1) for x=5, and the HRD of the composites for x=5 at the current density of 1200 mA·g^(-1)30% of that of the alloy at 60 mA·g^(-1). The discharge capacity of AB_5-x%LaMg_3 composite alloy electrode at 233 K is up to 174 mAh·g^(-1). The improvement of the electrochemical characteristics of the composite electrodes seems to be related with formation of the LaNi_3 second phase.

Phase Structure and Cycle Stabilities of Mg_2Ni/Mm_(0.3)Ml_(0.7)Ni_(3.55)Co_(0.75)Mn_(0.4)Al_(0.3) Composite Hydrogen Storage Alloys Prepared by Two-step re-melting

Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3 alloy has high chemical activity and favorable plateaus pressure. Mg2Ni is in favor of high hydrogen storage capacity and low weight, but it is difficult to be activated. In order to improve the capacity and cycle performances of hydrogen-storage alloy electrodes, Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3-x%Mg2Ni(x=0, 5, 10, 30) composite hydrogen storage alloys prepared by two-step re-melting were investigated in this work. The influences of Mg2Ni content on the cycle stabilities were analyzed by electrochemical methods. It was observed by XRD that the main phase of all the alloys is LaNi5 and the crystal lattice parameters of LaNi5 are changed with the increasing of x value, i.e, a-axis and unit cell volume decrease and c-axis decreases nonlinearly. The c-axis of alloy with x=5 is larger than the others. With the increasing of x value, capacity retentions of the composite hydrogen storage alloys rise from 66.21% while x=0 to 82.04% while x=10, but the capacity retention of the composite alloy with 30% Mg2Ni declines because of its decreasing axial ratio. More over, the composite alloy with 5% Mg2Ni shows the best cycle stability and higher discharge capacity, and it is an appropriate candidate for battery materials.

Microstructure and Characterization of Capric-stearic Acid/Modified Expanded Vermiculite Thermal Storage Composites

In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.

Li Storage Performance for the Composite Structure Of Graphene and Boron Fullerene

We study the stability and performance of Li absorption on the composite structure （B80 C72） of boron fullerene and graphene by first-principles calculations. Our results show that the Li storage capacity of the composite structure is estimated to be at least Li54B80C72, which is steady with improved dispersibility and electronic conductivity. The composite structure could have the potential application as the anode material of Li-ion batteries with high Li storage capacity and great mechanical property.

Structural energy storage composites based on modified carbon fiber electrode with metal-organic frame enhancing layered double hydroxide

Structural energy storage composites present advantages in simultaneously achieving structural strength and electrochemical properties.Adoption of carbon fiber electrodes and resin structural electrolytes in energy storage composite poses challenges in maintaining good mechanical and electrochemical properties at reasonable cost and effort.Here,we report a simple method to fabricate structural supercapacitor using carbon fiber electrodes(modified by Ni-layered double hydroxide(Ni-LDH)and in-situ growth of Co-metal-organic framework(Co-MOF)in a two-step process denoted as Co-MOF/Ni-LDH@CF)and bicontinuous-phase epoxy resin-based structural electrolyte.Co-MOF/Ni-LDH@CF as electrode material exhibits improved specific capacity(42.45 F·g^(-1))and cycle performance(93.3%capacity retention after 1000 cycles)in a three-electrode system.The bicontinuous-phase epoxy resin-based structural electrolyte exhibits an ionic conductivity of 3.27×10^(-4) S·cm^(-1).The fabricated Co-MOF/Ni-LDH@CF/SPE-50 structural supercapacitor has an energy density of 3.21 Wh·kg^(-1) at a power density of 42.25 W·kg^(-1),whilst maintaining tensile strength and modulus of 334.6 MPa and 25.2 GPa.These results show practical potential of employing modified commercial carbon fiber electrodes and epoxy resin-based structural electrolytes in structural energy storage applications.

Preparation and hydrogen sorption properties of Mg-Cu-Y-H systems

Mg-xwt.%CuY (x=15, 20, 25) composites were successfully prepared by reactive mechanical alloying (RMA). X-ray diffraction (XRD) measurement shows that main phases of the as milled composites are MgH2 and Mg2Cu, and they converted into Mg and MgCu2 after dehydrogenation, respectively. Pressure-Composition-Isotherm (PCI) test shows that the composites exhibit double pressure plateau at each isothermal desorption process. The hydrogen absorption and desorption kinetics of the composites become worse with increasing x content, indicating that Mg-Cu phase has a negative effect on the hydrogen sorption properties of the composites. It is supposed that the good hydrogen sorption properties of the composites attribute to the catalyst effect of yttrium hydride distributed in Mg substrate and the particles size reduction and crystal defects formed by RMA.

Hydrogen sorption properties of Mg-20wt.%Fe_(23)Y_8 composite prepared by reactive mechanical alloying

Mg-20wt.%Fe23Y8 composite was successfully prepared by reactive mechanical alloying (RMA). X-ray diffraction (XRD) measurement shows that the main phases of composite are MgH2 and Mg2FeH6. The composite exhibits excellent hydrogen abs/desorption properties and can absorb 4.36wt.% and 5.72wt.% hydrogen at 473 and 573 K in 10 min under 3.0 MPa hydrogen pressure, respectively. The composite can desorb 5.27wt.% hydrogen at 573 K in 30 min under 0.02 MPa hydrogen pressure. Compared with the pure MgH2, the hydrogen desorption temperature of Mg-20wt.% Fe23Y8 composite is decreased about 40 ℃. It is supposed that both the catalyst effect of Fe-Y distributed in Mg substrate and the crystal defects play the main role in improving hydrogen sorption properties of Mg-20wt.% Fe23Y8 composite.

Synthesis,Structural Characterization and Hydrogen Storage of Nickel-containing Mesoporous MCM-48 by Electroless Plating

Hydrogen is a promising fuel for it is clean,highly abundant and non-toxic,but on-board storage of hydrogen is still a challenge.So it is imperative to have an efficient method of hydrogen storage.The mesoporous MCM-48 especially the nickel-containing MCM-48 has great potential in hydrogen storage.MCM-48 was prepared by hydrothermal synthesis.Then electroless plating technology was used to deposit Ni on the surface of MCM-48 under ultrasonic environment.Powder X-ray diffraction（XRD）,transmission electron microscopy（TEM）,and N2 adsorption-desorption were employed to investigate the pore structure properties.The results showed that all the samples had Ia3 d cubic structure and pore channels were highly ordered.Hydrogen adsorption studies showed that the MCM-48 after nickel plating adsorbed nearly twice the amount of hydrogen than pure MCM-48 at 2.0 MPa,263 K.So we believe that a small amount of Ni can improve the capacity of hydrogen adsorption of MCM-48 efficiently.

Hydrogenation/Dehydrogenation Performances of the MgH_2-WS_2 Composites

The hydrogenation/dehydrogenation kinetics and thermodynamic behaviors of the MgH2- WS2 composites were investigated. The TPD （Temperature-Programmed-Desorption） curves showed that the onset dehydrogenation temperature of the MgH2 ＋ 20wt% WS2 composite was 615 K, 58 K lower than that of the pristine MgH2. The kinetic measurements showed that within 21 rain, the MgH2 ＋ 20wt% WS2 composite could absorb 2.818wt% at 423 K, and release 4.244 wt% of hydrogen at 623 K, while the hydriding/ dehydriding capacity of MgH2 reached only 0.979wt% and 2.319wt% respectively under identical conditions. The improvement of hydrogenation/dehydrogenation performances for the composite was attributed to the co- catalytic effect between the new phases W and MgS which formed durin~ the ball-milliw, ~rocess.

A Markov Model for Subway Composite Energy Prediction

Electric vehicles such as trains must match their electric power supply and demand,such as by using a composite energy storage system composed of lithium batteries and supercapacitors.In this paper,a predictive control strategy based on a Markov model is proposed for a composite energy storage system in an urban rail train.The model predicts the state of the train and a dynamic programming algorithm is employed to solve the optimization problem in a forecast time domain.Real-time online control of power allocation in the composite energy storage system can be achieved.Using standard train operating conditions for simulation,we found that the proposed control strategy achieves a suitable match between power supply and demand when the train is running.Compared with traditional predictive control systems,energy efficiency 10.5%higher.This system provides good stability and robustness,satisfactory speed tracking performance and control comfort,and significant suppression of disturbances,making it feasible for practical applications.

Microstructure and Hydrogen Absorption Pro-perties of Mg/MmNi_(5-x) (CoAlMn)_x Composite Prepared by Mechanical Alloying

The microstructure ofthe Mg/MmNi5-x (CoAlMn )x composite hydrogen storage material preparedby the method of mechanical alloyingwas characterized by X-ray diffraction, SEM and particle size distribution analysis. By measuring PCTcurves, the hydrogen absorption properties of the composite was evaluated.The results show that nanocrystallinecomposite structure can be obtainedunder adequate ball milling condition. The reactive activation and hydrogen absorption capacity are improved compared with the sole MmNi5-x(CoAlMn)x alloy. The effect ofmagnesium on the microstructure andhydrogen absorption properties of thecomposite were also evaluated.

Carbonate-salt-based composite materials for medium- and high-temperature thermal energy storage

This paper discusses composite materials based on inorganic salts for medium- and high-temperature thermal energy storage application. The composites consist of a phase change material （PCM）, a ceramic material, and a high thermal conductivity material. The ceramic material forms a microstructural skeleton for encapsulation of the PCM and structural stability of the composites; the high thermal conductivity material enhances the overall thermal conductivity of the composites. Using a eutectic salt of lithium and sodium carbonates as the PCM, magnesium oxide as the ceramic skeleton, and either graphite flakes or carbon nanotubes as the thermal conductivity enhancer, we produced composites with good physical and chemical stability and high thermal conductivity. We found that the wettability of the molten salt on the ceramic and carbon materials significantly affects the microstructure of the composites.

Preparation and photochromic properties of pyrazolones/polyvinyl alcohol composite films

Novel photochromic composite films have been successfully fabricated by dispersing pyrazolone derivative：1,3-Diphenyl-4-（3-chlorobenzal）-5-hydroxypyrazole 4-phenylsemicarbazone（la） into hydrosol of polyvinyl alcohol（PVA）.The microstructure,photochromic behaviors and thermal bleaching properties were investigated by Raman spectroscopy,X-ray powder diffraction（XRD）,field emission scanning electron microscopy（FE-SEM） and ultraviolet-visible absorption spectroscopy（UV-vis）.The results showed that la was not only blended but also well dispersed in the PVA polymer films with a suitable content of chromophore.Upon UV light irradiation,the composite films gradually changed from colorless to yellow and recovered fully to the initial state upon thermal bleaching.The time constants of photochromic reactions were almost the same as those of la observed in their crystalline state,indicating that the photochromic phenomenon is barely disturbed by the polymer matrix.

Effect of LaFeO_3 on hydrogenation/dehydrogenation properties of MgH_2

LaFeO3 was used to improve the hydrogen storage properties of Mg H2. The Mg H2＋20 wt.%La Fe O3 composite was prepared by ball milling method. The composite could absorb 3.417 wt.% of hydrogen within 21 min at 423 K while Mg H2 only uptaked 0.977 wt.% hydrogen under the same conditions. The composite also released 3.894 wt.% of hydrogen at 623 K, which was almost twice more than Mg H2. The TPD measurement showed that the onset dissociation temperature of the composite was 570 K, 80 K lower than the Mg H2. Based on the Kissinger plot analysis of the composite, the activation energy E des was estimated to be 86.69 k J/mol, which was 36 k J/mol lower than Mg H2. The XRD and SEM results demonstrated that highly dispersed La Fe O3 could be presented in Mg H2, benefiting the reduction of particle size and also acting as an inhibitor to keep the particles from clustering during the ball-milled process.