bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suggestions on Efficiency Droop of GaN-based LEDs
Authors: Ding Jixiang 
Published: February 2020

Abstract
InGaN/GaN-based light-emitting diodes (LEDs) are widely used in modern society and industry among different areas. However, InGaN/GaN LEDs suffer from an efficiency droop issue: The internal efficiency decreases during high current injection. The efficiency droop significantly affects the development of GaN-based LEDs devices in efficiency and light-output areas. Therefore, the improvement of the droop phenomenon has become a significant topic. This paper introduces several possible mechanisms of droop phenomenon based on different hypotheses including Auger Recombination, Carrier Delocalization and Electron Leakage. Furthermore, some proposals to mitigate efficiency droop, including semipolar LEDs, electron blocking layer(EBL), quaternary alloy and chip design will be discussed and analyzed. Also, it will provide some suggestions for the further optimization of droop phenomenon in each proposal.
Improve dielectric properties of Lamellar Calcium Niobate ceramics by spark plasma sintering
Authors: Liu Xinxin , Xie Xiong , Zhai Yunling , Wang Liang 
Published: February 2020

Abstract
The structure and dielectric properties of HCa2Nb3O10·1.5H2O (HCNO) and its exfoliated products (e-HCNO) ceramics were investigated. Where two-dimensional e-HCNO sheets were obtained by ion-exchange and exfoliating consequently. Spark plasma sintering (SPS) was introduced for products processing. After which, the dielectric constant of e-HCNO is 1300 and the loss is 0.002 at 2 M Hz. Compared to ordinary solid phase sintering, the dielectric constant of ceramics was found to be directly improved by the SPS processing.
Density functional theory study on bond dissociation energy of polystyrene trimer model compound
Authors: Huang Jinbao , Meng Hanxian , Cheng Xiaocai , Pan Guiying , Cai Xunming , Liu Jiangtao 
Published: February 2020

Abstract
The bond dissociation energy (BDE) of syndiotactic polystyrene(s-PS) was calculated by using four density functional theory methods, which were M062X, B3LYP, B3P86, BH and HLYP with different LANL2DZ, 6-31G(d), 6-31G(d, p), and 6-311++G(d, p) basis sets. The influence of these computational methods on the accuracy of the BDE of s-PS was analyzed. It was found that the BDE had a higher accuracy at B3P86/6-31G (d, p) level than other methods, and B3P86/6-31G (d, p) spent more less time to calculate the bond dissociation energy of s-PS, and the average of the C-C bonds’ BDE values calculated by B3P86/6-31G (d, p) is about 8.3 kJ/mol lower than the experimental value (310.0 kJ/mol), which is derived from the i-bond database. Besides, the bond dissociation energy values of the C-C bonds computed by M062X/LANL2DZ, B3LYP/6-31G(d), M062X/6-31G(d), B3LYP/LANL2DZ and BH and HLYP/6-311++G(d, p) methods were as follows: 330.8 kJ/mol, 345.3 kJ/mol, 283.2 kJ/mol, 267.6 kJ/mol, 267.4 kJ/mol. The calculation conclusion is drawn that different calculation methods with the same basis set have an obvious influence on the result of BDE values’ calculation. Finally, based on the calculation of bond dissociation energy of polystyrene, three possible reaction paths of polystyrene pyrolysis are designed to analyze the influence of bond dissociation energy on polystyrene pyrolysis.
Application of VSP well drive data in the prediction of complex carbonate reservoirs
Authors: Qin Li , Luo Kun , Cheng Lili 
Published: February 2020

Abstract
The qixia formation carbonate rocks in the northwest of sichuan are of great buried depth, thin reservoir thickness and strong heterogeneity. Therefore, VSP data are used to control the seismic data on the surface, VSP well drive data lay a good foundation for interpretation. Then, through waveform clustering analysis, favorable facies zones were developed. Secondly, natural faults are predicted based on maximum likelihood attribute technique. Finally, the reservoir quantitative prediction is carried out by using phase control inversion technique. The drilling well location is optimized based on reservoir and fracture prediction information, and the drilling effect is good, which provides strong technical support for subsequent exploration and development in this area.
Study on Thermal Storage Performance of Industrial Paraffin and Fatty Acid Binary Mixture
Authors: Yan Quanying , Fan Qingzhu , Jing Zhang 
Published: February 2020

Abstract
Taking the industrial paraffin and fatty acid binary mixture as the research object, the phase change temperature, latent heat of phase change and supercooling degree were studied by differential scanning calorimeter, aiming at reducing the application cost of simple fatty acid as phase change material, broadening the range of phase transition and increasing the amount of latent heat value of phase change. The results show that the paraffin-tannic acid and paraffin-lauric acid binary mixture reduces the phase transition temperature and increases the latent heat of phase change compared with the single fatty acid, which is suitable for the energy storage of the envelope structure. The phase transition temperature of paraffin-myristic acid, paraffin-stearic acid, paraffin-palmitic acid mixture is lower than 40 °C. Although it is lower than the phase transition temperature of single fatty acid under certain mixing ratio conditions, which is not suitable for application. In the energy storage of the structure, it can be used in other energy-saving systems such as phase change heat exchangers for waste heat recovery. Paraffin-tannic acid and paraffin-lauric acid binary mixtures are less subcooled and are ideal for energy storage in envelope structures.
Experimental and theoretical research on the thermal properties of carbonate mixtures
Authors: Yan Quanying , Wang Chenyu , Liu Chao , Zhang Jing 
Published: February 2020

Abstract
In this paper, Na2CO3, Li2CO3 and K2CO3 were selected to prepare carbonate mixtures according to different proportions. The thermal property and stability of the samples were tested by differential scanning calorimeter (DSC). The phase change temperature and latent heat of carbonate mixtures were calculated by theoretical formula, and compared with the experimental data to verify whether the theoretical formula are applicable in the field of high temperature molten salt. The results show that the melting point of carbonates which melted together is about 400°C. And the melting point of ternary carbonates is lower than the single component. The initial crystallization points of some samples are higher than the melting points. The differences between the melting point and the primary crystallization temperature are 5∼20°C. The phase change latent heat of the carbonate mixtures is lower than the single component’s. The latent heat of melting is more than the latent heat of solidifying. The DSC testing curves of the carbonate mixtures are almost coincident. The stability of mixed carbonate is very good. This experiment will provide reference and basis for its application in solar thermal power generation.
Research on the change rule of microbial community in the microbial flooding process of Baolige oilfield
Authors: Wang Guan , Duan Lisha , Han Feng , Wang Rui , Liu Shasha , Lei Xiaoyang , Jing Jizhe , Gu Yi , Lei Yuchao 
Published: February 2020

Abstract
In Baolige oilfield, through the research and field implementation of microbial flooding technology, some application effects had been achieved. In order to further improve the implementation effect, the microbial community in the produced liquid during microflooding was tracked, monitored and analyzed by high-throughput sequencing (NGS). The results showed that the microflora diversity was plentiful. The species diversity after micro-flooding was higher than that during micro-flooding. In microbial flooding stage, due to replenish nutrients and exogenous bacteria to reservoir, the advantage bacteria group was mainly Pseudomonas, Acinetobacter, Thauera and Wallingella. After the microbial flooding, due to stop supplying nutrients, the bacteria community changed. The relative abundance of hydrocarbon-degrading bacteria declined and that of anaerobic aerogen increased.
Adsorption Properties of Sulfonylcalix[4] arenetetrasulfonate-loaded Resin towards Strontium(II) from Aqueous Solutions
Authors: Liu Cong , Su Guofeng 
Published: February 2020

Abstract
Sulfonylcalix[4]arenetetrasulfonate-loaded D201 composite (SCAS-D201) was prepared by a simple method and used as an adsorbent for removal of Sr(II) from aqueous solutions. The adsorption of the Sr(II) onto SCAS-D201 composite as a function of contact time, pH, Sr(II), temperature concentration was investigated. Results show that the adsorption capacities of SCAS-D201 composite towards Sr(II) reached a maximum at pH values of ∼7. The adsorption has reached equilibrium within 120 min and the kinetics can be well fitted by a pseudo-second-model. The adsorption isotherm was well fitted by the Langmuir model, and the maximum value of adsorption capacity of the adsorbent was 76.43 mg·g−1. Possible adsorption mechanisms are also analysed.
Application of F− modified Fe-SAPO-34 as a New Photo-catalyst in Printing and Dyeing Wastewater Treatment
Authors: Cao Ying , Shen Taoyi , Guo Weilin , Song Xianzhen , Kong Lingxue , Wang Lijun 
Published: February 2020

Abstract
The development of new photocatalysts with a wide range of applications is one of the important challenges in the field of photocatalysis research. In this thesis, ferric phosphate was used as a transition metal salt, and HF was used as a mineralizer to prepare Fe-SAPO-34 photocatalyst, which was applied to the degradation of organic dye wastewater. The materials were characterized by XRD, SEM and other characterization methods. After the photocatalyst is supported on the molecular sieve, it usually exhibits excellent performance in catalyzing the degradation of different dyes, and generally higher than the catalytic efficiency of the unmodified catalyst under the same conditions.
Fabrication of Ag-incorporated TiO2 film on TiNb substrate and evaluation on its antibacterial activity against E. coli
Authors: Xiaogang Liao , Gang Li , Xiaoqian Xiang , Tao Fu , Guo Tang 
Published: February 2020

Abstract
For the purpose of endowing TiNb alloy with antibacterial function, a two-step strategy was proposed to fabricate Ag-incorporated TiO2 film on TiNb substrate in this study. X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM) and X-ray photoelectron microscopy (XPS) were used to characterize the crystal phases, morphologies and chemical compositions of the samples. The results showed that a layer of anatase TiO2 film with two kinds of morphologies was formed by hydrothermal treatment of TiNb alloy in NH4F-H2O2 solution. When the as-obtained TiNb-based TiO2 film was subjected to a further ultraviolet light irradiation in AgNO3 solution, metallic Ag granules with size range from 60 nm to 1.3 μm were uniformly deposited on the surface of TiO2 particles. Escherichia coli (E. coli) was selected as a model to estimate the bacteriostatic effect of the Ag-TiO2 film. The experimental result indicated that Ag-incorporated TiO2 exhibited excellent antibacterial activity against E. coli. It suggests that this two-step method for preparation of Ag-TiO2 composite film may provide an alternative strategy to reduce bacterial infection for Ti-implants in clinical application.
Micellar and Interfacial Behavior of Mixed Systems Containing Anionic-nonionic Gemini Surfactant
Authors: Chen Hong , Zhu Baowei , Liu Haiyan 
Published: February 2020

Abstract
The Anionic-nonionic Gemini Surfactant oxalamide polyoxyethylene lauryl ether(9)succinate sodium sulfonate(OPLES-9) was synthesized. It was mixed with the anionic surfactant sodium lauryl sulfate(SDS) and the nonionic surfactant dodecanol polyoxyethylene(9) ether (AEO9) respectively in different ratios to enhance application performance. The experimental results showed that the surface performance of the mixed systems was more superior to the relevant single surfactants. The mixed critical micelle concentration (CMC) of the binary surfactant systems was determined by surface tension measurement. Critical micelle concentration of mixed system reached the minimum 0.146mmol·L−1 when the molar fraction of OPLES-9 to SDS was 1:1. Critical micelle concentration of OPLES-9/AEO9 mixed system reached the minimum 0.259mmol·L−1 when the molar fraction of OPLES-9 to AEO9 was 0.9:1.
Electrochemical Decontamination of Platinum Nanocrystals and its Applications for Methanol Electrooxidation
Authors: Lu Leilei , Zhu Mi , Zheng Yaoping , Yang Rong 
Published: February 2020

Abstract
Polyvinylpyrrolidone (PVP) is an effective surface-capping agent for engineering metal surface structure but is hardly to be thoroughly removed. In this study, the electrochemical treatment was applied for the decontamination of polyvinylpyrrolidone (PVP) on platinum (Pt) nanocrystals. Spherical, cubic, octahedral and cuboctahedral Pt nanocrystals were prepared by the colloidal method with PVP K30 as the capping agent. Electrochemical decontamination of Pt nanocrystals was performed by using square-wave potential steps and methanol electrooxidation was used as a probe reaction. High-frequency potential steps were set up between a high voltage and a low voltage to avoid surface distortion. Cyclic voltammetry (CV) and chronoamperometry measurements were used to evaluate the catalytic activity of the cleaned Pt nanocrystals for methanol. The results showed that electrochemical decontamination was an effective way to clean Pt nanocrystals and the cuboctahedral Pt nanocrystals displayed the best electrocatalytic activity for methanol electrooxidation.
Welding performance of the dissimilar joints of Fe-Mn-Si alloy and 304 stainless steel
Authors: Liu Linlin , Du Jinqiao , Zhou Chaoyu 
Published: February 2020

Abstract
The dissimilar joints of Fe-17Mn-5Si-10Cr-5Ni memory alloy and 304 stainless steel were welded by 5 kw transverse flow CO2 laser. The microstructure, morphology and composition of the welding of the dissimilar joints were analyzed by metallographic microscope, field emission scanning electron microscopy. The results showed that the crystals of dissimilar joints of Fe-17Mn-5Si-10Cr-5Ni memory alloy and 304 stainless steel were symmetrically distributed on both sides of the joint weld center. At Fe-17Mn-5Si-10Cr-5Ni memory alloy close to the side of the weld, ε martensite phase was also found, which was caused by the γ→ε martensite transformation induced by the residual stress. The distribution of dissimilar joint weld elements was in zones obviously, the distribution mode was related to the unique keyhole effect of laser welding, and the weld center metal was still Fe-Mn-Si memory alloy, which had the characteristic of the inverse phase transition of the stress induced martensite.
Unique hierarchical Sn3O4 nanoflowers decorated with ZnO nanoparticles and their formaldehyde gas sensing properties
Authors: Wang Lei , Li Yang , Gao Song , Yue Wenjing 
Published: February 2020

Abstract
Gas sensors with high response are highly desirable for the detection of harmful gases in real-time. Herein, the ZnO nanoparticles decorated hierarchical Sn3O4 nanoflowers are synthesized by a hydrothermal method. The gas sensor based on the ZnO/Sn3O4 composites exhibits excellent sensing properties to formaldehyde with a low operating temperature of 180°C. Specifically, the sensor has a response value of 44 for 100 ppm formaldehyde and a fast response time of 5 s. Moreover, it is noteworthy that the proposed gas sensor shows a wide detection range and a low detection limit of 1 ppm. Besides, the ZnO/Sn3O4 sensor exhibits good selectivity for formaldehyde and perfect reproducibility. The sensing mechanism of the gas sensor is discussed, and the heterojunction between ZnO and Sn3O4 enhances the sensing performance of the proposed gas sensor.
Preparation of nanofluids and their applications in enhanced CO2 absorption
Authors: Han Huiyu , Ma Xiaoxun , Xu Long 
Published: February 2020

Abstract
Nanofluids opened up research in the field of thermal energy and mass transfer engineering when it was first proposed by American scientist Choi. In this paper, a two-step method was used to prepare stable nanofluids. Enhancement factor was introduced to study the enhancement of CO2 absorption by nanofluids under different experimental conditions. The results show that the enhancement of the three nanoparticles in the same solid content is TiO2 > Al2O3 > SiO2; The optimum solid content of SiO2 and Al2O3 is 0.8 g/L, and the optimum solid content of TiO2 is 0.6 g/L; Within the scope of this study, the larger the particle size, the better the absorption effect. As the organic amine concentration increases, absorption of solution improves.
Formation technology of effective electrode materials based porous silicon with platinum metal nanoparticles for autonomous energy systems
Authors: Ragutkin A V , Antropov A P , Lebedeva M V , Sigov A S , Yashtulov N A 
Published: February 2020

Abstract
In this work the effective electrode materials for autonomous energy sources based on porous silicon modified by platinum nanoparticles have been obtained. The functional characteristics of the electrodes have been studied by transmission electron microscopy and voltammetry methods. The electrode materials based on porous silicon had demonstrated high catalytic activity in fuel cells with hydrogen oxidation.
Automatic Lab scale equipment for continuous HMF production in biphasic systems
Authors: Klushin V A , Chizhikova A A , Gorchakov V V , Smirnova N V 
Published: February 2020

Abstract
An automatic lab scale equipment for continuous HMF production by the dehydration of fructose with homogeneous catalysis in biphasic systems (water solution - MIBK) was designed, manufactured and tested. The dependencies of the HMF yield on the process parameters were studied. The feed rate of fructose varied from 50 to 100 g·h−1, the extractant (MIBK) flow rate from 0.5 to 1.4 L·h−1 and the process temperature was maintained in the range from 50 to 87 °C. The maximum productivity of the automatic lab scale equipment 33.6 g·h−1 with a high HMF yield 48 % is achieved with the following process parameters - 87 °C, the fructose feed rate 100 g·h−1 and the extractant flow rate 1 L·h−1. This automatic lab scale equipment may be prospectively used for the kilogram scale HMF synthesis.
Nafion-carbon containing nanocomposite materials with high catalytic activity for portable energy sources
Authors: Lebedeva M V , Ragutkin A V , Antropov A P , Yashtulov N A 
Published: February 2020

Abstract
In this work the electrode materials on combined polymer-carbon matrix-supports modified by bimetal platinum-ruthenium nanoparticles have been formed. The functional characteristics of the electrodes have been studied by atomic force microscopy, scanning electron microscopy and voltammetry methods. The catalytic activity of the synthesized composites in the methanol oxidation reaction had been studied.
Modeling of atomic interactions in carbon nanotubes
Authors: Chwał M , Muc A 
Published: February 2020

Abstract
This work concerns atomic potentials applied in the description of carbon nanotubes mechanical behavior. The explicit relations of interatomic forces for different interatomic potentials have been derived. The fluctuations in the values of interatomic potential, interatomic force, elastic constant and Young’s modulus have been put forward to elucidate the similarities and differences between potentials. The present analysis may be helpful in the equivalent continuum modelling of carbon nanotubes and nanocomposites.
Numerical Simulation of Hydraulic Fracturing Effect Based on Abaqus
Authors: Li Xinyong , Qu Ximo , Sun Ting , Wang Jie , Fang Haoqing , Liu Zhiyuan , Luo Pandeng , Zhao Bing , Zhang Wenzhe 
Published: February 2020

Abstract
This study simulates the hydraulic fracturing process based on ABAQUS, and obtains the results of hydraulic fracturing fracture propagation under the influence of multi-parameters. Our research shows that:The effect of reservoir modification increases with the increase of injection rate of fracturing fluid. Under the condition of 8m3/min or above, the fracture can communicate with the fault zone 100m away from the bottom of the well. Under the condition of 10cP, the effect of fracture propagation in formation is good. Under the condition of 50cP, the effect of fracture propagation in fracture zone is good. Under the condition of 200cP, the effect of crack propagation is poor. When the injection volume of fracturing fluid is between 0 and 1440m3, the effect of fracture propagation increases gradually. When the injection volume of fracturing fluid is larger than 1440m3, the contribution of continuous injection become weak. The maximum vertical crustal stress results in the fracture extending to the depth. The maximum horizontal crustal stress results in the horizontal propagation of fractured fractures. This study analyzed the influence of formation parameters and hydraulic fracturing parameters on fracture propagation. It also plays an active role in predicting the effect of hydraulic fracturing.
Review of the Surface Treatment s of Plant Fibers as Reinforcements in Polymer Composites
Authors: Zhu Z H , Zhang Y , Zhang N , Wang T , Hao M Y 
Published: February 2020

Abstract
The poor compatibility between plant fiber and polymer matrix leads to many defects and deficiencies in plant fiber reinforced polymer composites. Various common physical or chemical treatments of plant fibers are listed in this paper. Surface treatments can improve the interface bonding of fibers and matrix, whereas the mechanical properties of plant fibers will be greatly reduced after treatments. How to retain the properties of plant fibers to the greatest extent and improve the comprehensive properties of plant fibers reinforced polymer composites is a problem that needs attention and urgent solution when treating plant fibers by various treatments.
Magnetised photocatalyst TiO2/Fe3O4 nanocomposite capable to photodegrade organic dye
Authors: Tan Thian Khoon , Khiew PoiSim , Chiu WeeSiong , Chia ChinHua 
Published: February 2020

Abstract
In this study, methylene blue (MB) is used as a measure of the photocatalytic capabilities of the prepared TiO2/Fe3O4 photocatalyst nanocomposite. The nanocomposite was suspended in the dye aqueous solutions placed in a UV chamber under UV-C (254 nm) light irradiation. The TiO2/Fe3O4 nanocomposite was characterised by XRD, FESEM, TEM and EDX analysis. The TiO2/Fe3O4 nanocomposite crystal structure retained TiO2 pure anatase of tetragonal crystal structure (SG: I4/
a

md) and Fe3O4 cubic spinel crystal structure with average crystalline size of (62.1 ± 5.7) nm. The optimum performance of the magnetic nanocomposite was monitored through few categories, such as concentration of photocatalyst, doping amount of Fe3O4 nanoparticle into the nanocomposite and sintering temperature. The TiO2/Fe3O4 nanocomposite optimum loading was detected at 3.0 wt%. The nanocomposite performed well at 1 wt% of Fe3O4 doping and 350 °C of sintering temperature. The reliability of the TiO2/Fe3O4 nanocomposite was also conducted where it was successfully repeated for at least 3 times with no obvious changes observed in the degradation efficiency.