Search

Background: In recent years, the computational memory and energy conservation have become a major problem in cloud computing environment due to the increase in data size and computing resources. Since, most of the different cloud providers offer different cloud services and resources use limited number of user’s applications. Objective: The main objective of this work is to design and implement a cloud resource allocation and resources scheduling model in the cloud environment. Methods: In the proposed model, a novel cloud server to resource management technique is proposed on real-time cloud environment to minimize the cost and time. In this model different types of cloud resources and its services are scheduled using multi-level objective constraint programming. Proposed cloud server-based resource allocation model is based on optimization functions to minimize the resource allocation time and cost. Results: Experimental results proved that the proposed model has high computational resource allocation time and cost compared to the existing resource allocation models. Conclusion: This cloud service and resource optimization model is efficiently implemented and tested in real-time cloud instances with different types of services and resource sets.

Resistive random access memories (RRAMs) have attracted tremendous attention due to their miniaturized size, low power consumption, high response speed, and simple fabrication requirements, which are regarded as a promising candidate for future nonvolatile memories. However, the traditional binary storage RRAMs fail to meet the high-density requirement in the area of big data. One of the ways to overcome this obstacle is to realize multilevel state transitions in a unit RRAM. Herein, we propose a facile spin-coating method to develop a multilevel RRAM based on Al/poly(methyl methacrylate) (PMMA)/ZnO quantum dots (QDs)/PMMA/ZnO QDs/PMMA/fluorine-doped tin oxide (FTO) structure, with the significant merits of typical forming-free bipolar resistive switching behavior, low-power operating voltage, stable endurance, and excellent retention. In specific, the ON/OFF ratio of the proposed ZnO QDs-based device can be adjusted by tuning the concentration of the ZnO QDs. Moreover, a multilevel RRAM performance with distinct four-level resistance states is obtained by varying the compliance current, which demonstrates that the proposed device has a specific application in multilevel data storage. The conductive filament model, combining the enhanced internal field and robust formation of the conductive filament, is introduced to explain the mechanism of the resistive switching behavior and multilevel performance. This work paves a new way for its prospect in constructing high-density data storage RRAMs.

Various sulfur host materials have been developed to improve the performance of lithium-sulfur (Li-S) battery. In this work, we used phosphorus-doped graphitic carbon nitride (xP-g-C3N4) as a sulfur host material for the first time. xP-g-C3N4 was prepared with dicyandiamide as the precursor and 1-butyl-3-methylimidazole hexafluorophosphate as a phosphorus source. The effect of phosphorus doping on the electrochemical properties of xP-g-C3N4/S as cathode material for the Li-S battery was studied. The results show that decreasing lattice spacing improves the conductivity by doping phosphorus, and the specific surface area of 0.1P-g-C3N4 reaches 19.66 m2 g−1, which is about two times higher than that of g-C3N4. 0.1P-g-C3N4/S has 1344 mAh g−1 for the initial discharge specific capacity and 882 mAh g−1 for reversible specific capacity after 100 cycles with a capacity decay of 0.34% per cycle, exhibiting outstanding cycling performance and rate performance. Phosphorus-doped materials have a high specific capacity due to their own stronger physical adsorption and chemisorption of polysulfides and higher conductivity. This doping strategy proposed a new and efficient pathway for the fabrication of high-performance sulfur electrodes for Li-S batteries.

A four-winding inductive filtering transformer (FW-IFT) that is of a special filtering winding is designed according to the equivalent zero impedance principle of multi-winding transformer. The inductive filtering method with the series connection of the passive filter and the filtering winding of a FW-IFT is proposed to deal with the problem of reactive power and harmonics in a high-voltage distribution network. The equivalent circuit model of the FW-IFT is analyzed in detail from the inductive filtering condition. Then, the voltage equations are established, and harmonic suppression factor is introduced to analyze its filtering characteristics. The simulation and experimental results are provided to verify the feasibility of implementing the inductive filtering for the FW-IFT.

Lithium–sulfur (Li–S) batteries have attracted increasing attention due to their high theoretical capacity, being a promising candidate for portable electronics, electric vehicles and large-scale energy storage. The interactions of bilayer structured graphitic C3N4 (bi-C3N4) with S8, lithium polysulfides (LiPSs), 1,3-dioxolane, 1,2-dimethoxyethane and tetrahydrofuran ether-based solvents have been studied using first-principles calculations. It has been found that the (micropore-scale) interlayer of bi-C3N4 shows intimate contact and strong binding with S8 and LiPSs due to the formation of chemical Li–N bonds. The incorporation of soluble LiPSs by the wrinkled layers of bi-C3N4 with 5.5–7.2 A interlayer pores can suppress the shuttling effect. The interlayer ultramicropores with interlayer distances of

This paper solves the problem of reactive power and harmonics compensation in a high-voltage (HV) distribution network supplying nonlinear loads. An inductive filtering (IF) approach where passive filters connect to the filtering winding of a four-winding inductive filtering transformer (FW-IFT) is presented to enhance the power quality of the public grid. This method can not only greatly suppress harmonic currents of the medium and/or low-voltage (LV) side, but also prevent them from flowing into the public grid. The new main circuit topology, where the FW-IFT has specific filtering winding by adopting the ampere-turn balance of the transformer, is presented. On the basis of the structure of the FW-IFT, the magnetic potential balanced equation and inductive filtering technology, its equivalent circuit and mathematical model are established, and the filtering performances are analyzed in detail. Simulation and experimental results rated at SN-10/0.38 of the FW-IFT are presented to prove the efficacy of the comprehensive enhancement of power quality on the grid side.

The economy of distribution networks largely depends on the utilization rate of distribution network equipment. Most of the emerging intelligent power consumption technologies have a positive effect on equipment utilization and their use can save investment of distribution networks. In this paper, the influence of intelligent power consumption technologies on the utilization rate of distribution network equipment is reviewed. The evaluation methods and indexes are assessed first and then intelligent power consumption equipment with energy storage function, vehicle-to-grid (V2G) technology and time-of-use (TOU) tariff are reviewed respectively. It is concluded that these intelligent power consumption technologies and measures have great potential to improve utilization rate of distribution network equipment because of their effective improvement to power load. Meanwhile, recommendations on how to utilize these intelligent power consumption technologies to improve utilization rate of distribution network equipment are proposed.

In this work, the protein coronas of activated sludge proteins on TiO2 nanoparticles (TNPs) and ZnO nanoparticles (ZNPs) were characterized. The proteins with high affinity to TNPs and ZNPs were identified by shotgun proteomics, and their effects of on the distributions of TNPs and ZNPs in activated sludge were concluded. In addition, the effects of protein coronas on the aggregations of TNPs and ZNPs were evaluated. Thirty and nine proteins with high affinities to TNPs and ZNPs were identified, respectively. The proteomics and adsorption isotherms demonstrated that activated sludge had a higher affinity to TNPs than to ZNPs. The aggregation percentages of ZNPs at 35, 53, and 106 mg/L of proteins were 13%, 14%, and 18%, respectively, whereas those of TNPs were 21%, 30%, 41%, respectively. The proteins contributed to ZNPs aggregation by dissolved Zn ion-bridging, whereas the increasing protein concentrations enhanced the TNPs aggregation through macromolecule bridging flocculation.

Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata.

Hyper-branched 4A zeolite (HB-4A zeolite) was prepared by condensation reaction between 4A zeolite and the monomer we prepared. It was then characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). This HB-4A zeolite was then used in the preparation of natural rubber (NR)/HB-4A zeolite composite. Different types of NR/HB-4A zeolite composites were prepared with different amounts of HB-4A zeolite and compared with the composites directly incorporated with 4A zeolite. The cure characteristics of different 4A zeolite filled NR composites were studied. Then, the tensile and thermal properties were compared. Results revealed that the mechanical properties of NR/HB-4A zeolite, especially elongation at break, showed a remarkable enhancement compared with that of NR/4A zeolite and NR systems. SEM studies showed that hyper-branching modification might increase the compatibility between 4A zeolite and NR matrix. A reinforcing mechanism was proposed, assuming that the ‘anchor’ effect caused by the hyper-branched polymer may reduce the amount and size of voids and increase the length of the crack spread path during tensile drawing.

Nano-BaSO4 was treated with surface modification agents and was mixed with different contents into the matrix of polybutadiene styrene rubber (SBR) to obtain composites. The cure characteristics, tensile and wear resistance properties of different nano-BaSO4 filled SBR composites were studied using scanning electron microscopy (SEM) and the mechanism was analyzed. Experimental results demonstrated that the incorporation of 2 phr 2%-SA modified nano-BaSO4 powder into neat SBR system can decrease the abrasion loss from 0.160 cm3 to 0.115 cm3, a decrease of about 28%.

This investigation focuses on the synthesis and characterization of an intumescent flame-retardant (IFR) agent. Three steps are used in the synthesis process. Meanwhile, the structure is characterized by Fourier transform infrared spectroscopy (FTIR), magic-angle spinning nuclear magnetic resonance (MAS-NMR) 13C spectroscopy, and elemental analysis. The addition of this IFR agent in a natural rubber (NR) system leads to an improvement in its flame-retardant (FR) properties. The second part focuses on the evaluation of some characteristics such as FR property, thermal stability, cure characteristics, and tensile properties of IFR/NR systems.

A stepwise pretreatment of combination of bacterial treatment with NaOH/Urea (NU) treatment was conducted to enhance enzymatic hydrolysis of rice straw (RS). The results showed that the composition of RS changed significantly, the lignin and hemicellulose decreased while cellulose increased. The biological treatment with a bacterium Sphingobacterium sp. LD-1 achieved mild conditions for the sequential NU treatment, reducing the concentration of the NU solution from 7%/12% to 4%/6% and increasing the temperature from -20°C to -10°C. The saccharification of rice straw co-treated with bacterium Sphingobacterium sp. LD-1 and 4%/6% NU at -10°C resulted in 1.396-fold and 1.372-fold increase of reducing sugar and glucose yield respectively than that of sole NU treatment.

This paper presents a proprietary process developed to manufacture organic montmorillonite (OMMT)- reinforced and isocyanate (-NCO) -blocked pouring-type polyurethane (BPPU) nanocomposites. The BPPU polymer was prepared from phenol- blocked blends of toluene diisocyanate (TDI), polyethylene glycol and 3,3'-dichloro-4,4'-diamido diphenyl methane (MOCA). The physical and mechanical properties of OMMT reinforced BPPU composites have been studied. BPPU samples containing 4 phr OMMT exhibited excellent mechanical properties because of the exfoliation and intercalation of the organic silicate layers.

The properties of nano-zinc oxide master batch filled butadiene styrene rubber (SBR) systems were researched in comparison with those of common zinc oxide and nano-zinc oxide filled systems. First, the nano-zinc oxide master batch was prepared and the cure characteristics of three different kinds of zinc oxide filled SBR composites were studied; second, the mechanical properties and wear resistance were compared; then, the improved mechanical properties were confirmed by dynamic mechanical properties and transmission electron microscopy. Finally, the zinc oxide amount reducing mechanism was analyzed. Results show that nano-zinc oxide master batch filled SBR system has better mechanical properties than those of nano-zinc oxide and common zinc oxide filled systems, which is due to the improved dispersion by master batch mixing technology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 922–930, 2006

The adhesion between polyethylene terephthalate (PET) cord and nitrile-butadiene rubber (NBR) has been compared. The PET cord treated by hydrated silica-resorcinol-hexamethoxymethylmelamine (HRH) shows 300% T-test strength and 40% H-test strength adhesion to NBR higher than that of rescorcinolformaldehyde-latex (RFL) treated system. The adhesion mechanisms and models are analyzed and put up by Fourier transform infrared spectra (FTIR) and scanning electron microscopy (SEM). Results show that the rubber of HRH system has deeper penetration into the cord compared with that of RFL treated system, which leads to different adhesion behaviors of the two systems.

This paper presents a new model of multistage and coordinated planning of transmission systems. Reliability constraints are considered in this model. Particle swarm algorithm is improved and applied to the multistage planning, which is available to handle multi-dimension discrete variables. And double mutation operators are described to enhance the search efficiency of particles and escape the local optima. The test results show the feasibility of the improved PSO in multistage and coordinated planning of transmission systems

A method based on a finite state machine (FSM) that assesses the correctness of a protocol implementation with respect to its specification is proposed. A value is calculated based on the errors in the implementation model.