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Main observation and conclusion: With the rapid development of the wearable electronics, the flexible supercapacitor with high energy density has attracted more and more attentions. From the viewpoint of outdoor and underwater application, this research tried to impart the superhydrophobicity to the flexible supercapacitors. The polyvinyl alcohol/HNO3 hydrogel was utilized as the electrolyte, which could achieve self‐healing capability without the freezing/thawing process. Both microscale graphene and nanoscale carbon nanotubes were utilized as the electrode materials. After surface modification, the hydrophobic suspension composed of graphene and carbon nanotubes was sprayed onto the two sides of hydrogel electrolyte to construct superhydrophobic electrode. Hence, the superhydrophobicity endows the supercapacitor with outstanding self‐cleaning performance. The all‐in‐one structure endows the supercapacitor with improved capacitive ability, outstanding flexibility, good anti‐abrasion property, and reliable self‐healing capability. The combination of superhydrophobicity and flexible energy storage might have a broad application for the outdoor and underwater wearable electronics applications. [ABSTRACT FROM AUTHOR]

Karst topography is formed from the dissolution of soluble rocks, such as limestone and dolomite. In soils of such a landform, excessive contents of exchangeable calcium seriously limit the growth of vegetations. Researches have proved that rhizosphere microorganisms and endophytes help host plants to adapt to various adverse environments. The adaptive capacity of plants that grow in adverse environment with salt, drought, thermal and heavy metal stresses partially or completely comes from symbiotic microorganisms. By using the high-throughput amplicon sequencing, the bacterial community structures in soil with high calcium contents and roots and leaves of Cochlearia henryi that is commonly seen in karst area were analyzed. The bacteria community structures in these three compartments showed obvious differences. This indicates that C. henryi, which is adaptive to high calcium stress, selectively co-exists with specific bacteria. Although the bacteria community structures in these three compartments differed significantly, there were 73 operational taxonomic units (OTUs) shared by karst soils as well as roots and leaves of C. henryi. The phylogenetic diversity of these 73 OTUs differed significantly from that of overall OTUs detected. There were also obvious differences in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways and abundance values between the 73 OTUs and overall bacterial communities. A large number of OTUs shared by the karst soils, roots and leaves of C. henryi had close genetic relationship with known stress-resistant bacterial strains. Our results showed that the functional bacteria can be predicted by exploring core bacteria, bacteria shared by soils, adaptable plant roots and leaves. This information will potentially accelerate studies on natural microbial communities which can promote the adaptive capacity of host plants to high calcium stress, and will be valuable for finding microbial strains for field application in karst topography. [ABSTRACT FROM AUTHOR]

[Objective] To establish methods to determine the content of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine in Aconitun sungpanense Hand-Mazz. and provide scientific basis for its reasonable and safe application. [Methods] Aconitine, Yunaconitine, Crassicauline and Vilmorrianine were used as references. Phenomenex Gemini C18 110A (250 mm ×4.6 mm, 5 [μm); mobile phase; acetonitrile -0.2% acetic acid (pH was regulated to by triethylamine); gradient elute; flow rate; 1 mL/min; UV wavelength 235/254 nm; column temperature; 30 CC. [Results] The content of the 4 Ester-series alkaloids in Aconitun sungpanense Hand. -Mazz. could be determined at the same time. The average recovery rate (n = 6) of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine reached 99. 65% (RSD = 1. 46%), 99. 13% (RSD = 1.32%), 98.13% (RSD =0.98%) and 98.66% (RSD = 1.67%). [Conclusions] The method was simple, accurate and had good repeatability. It could determine the content of Aconitine, Yunaconitine, Crassicauline and Vilmorrianine in Aconitun sungpanense Hand.-Mazz. at the same time. It also provided scientific basis for standardizing the processing of Aconitun sungpanense Hand. -Mazz. and its reasonable and safe application. [ABSTRACT FROM AUTHOR]

Existing Siamese trackers usually do not update templates or adopt single‐updating strategies. However, historical information cannot be effectively utilized when using these strategies, and model drift from complex tracking challenges cannot be addressed. To address this issue, a novel tracking framework that learns the model update with local trusted templates is proposed in this paper. The authors propose a complementary confidence evaluation method to select local trusted templates in a sliding window. This provides high‐confidence historical information. The authors also propose a method including linear learning and deep learning to learn to model updates. Different from traditional update strategies, the authors' method combines non‐linear and linear updates to obtain reliable templates with the most abundant historical information, which solves the complex tracking challenges to a certain extent. Finally, the adaptive fusion response maps of the two strategies determine the final tracking based on the confidence evaluation. Experimental results on NFS, UAVDT, UAV123, UAV20L and VOT2016 show that our method performs favourably when compared with current state‐of‐the‐art methods. [ABSTRACT FROM AUTHOR]

Abstract: Color histogram is an important technique for color image database indexing and retrieving. However, the main problem with color histogram indexing is that it does not take the color spatial distribution into consideration. Previous researches have proved that the effectiveness of image retrieval increases when spatial feature of colors is included in image retrieval. In this paper, two new descriptors, color distribution entropy (CDE) and improved CDE (I-CDE), which introduce entropy to describe the spatial information of colors, are presented. In comparison with the spatial chromatic histogram (SCH) and geostat which also measure the global spatial relationship of colors, the experiment results show that CDE and I-CDE give better performance than SCH and geostat. [Copyright &y& Elsevier]

Floral development and senescence are a crucial determinant for economic and ornamental value. CircRNAs play an essential role in regulating plant growth and development; however, there is no systematic identification of circRNAs during the lifespan of flowers. This study aims to explore the expression profile and functional role of circRNAs in the full flowering stages of Rhododendron delavayi Franch. We carried out transcriptome sequencing of the six stages of Rhododendron delavayi Franch flowers to identify the circular RNA expression profile. In addition, using bioinformatics methods, we explored the functions of circRNAs, including analysis of the circRNA-miRNA-mRNA network, short time-series expression miner (STEM), and so on. We identified 146 circRNAs, of which 79 were differentially expressed from the budding to fading stages. Furthermore, using STEM analysis, one of the 42 circRNA expression model profiles was significantly upregulated during the senescence stage, including 16 circRNAs. Additionally, 7 circRNA-miRNA-mRNA networks were constructed with 10 differentially expressed circRNAs, in which some target mRNA may regulate the development and senescence of the Rhododendron flowers. Finally, by analyzing the correlation between circRNAs and mRNA, combined with existing reports, we proposed that circRNAs play a regulatory role during flower development and senescence by mediating the jasmonate signaling pathway. Overall, these results provide new clues to the potential mechanism of circRNAs acting as novel post-transcriptional regulators in the development and senescence process of flowers. [ABSTRACT FROM AUTHOR]

• Clustering results of vFCM are more closer to the minimum of the k means objective. • vFCM provides reduced sensitivity to initialization. • vFCM improves the clustering performance in high dimensions. • vFCM does not need careful tuning as FCM. • Experimental results of vFCM are similar to or better than k means and FCM. Fuzzy c -means (FCM) is one of the most frequently used methods for clustering, where the fuzziness weighting exponent m is a key hyper-parameter that directly affects the clustering performance. However, FCM requires careful tuning the fuzziness parameter which results in significant time costs. In this research, an improved FCM clustering by v arying the fuzziness parameter, called vFCM, is proposed to overcome this issue, based on the facts that the FCM objective is easy to optimize when m is large, while more local valleys appear as m decreases, hence the optimization problem presents a search process from simple to complex when m varies from a large value to a small value approaching 1. Here, the nature of m is similar to the temperature parameter in the deterministic annealing, and moving along a sequence of the FCM objectives by a linear method that proposes to update m automatically provides a form of annealing. Extensive experiments on simulated and real-world data sets show that vFCM is not only more robust to initialization but also improves the clustering performance in high dimensions. Furthermore, the clustering results of vFCM have a low fluctuation according to different m , so it does not require careful tuning the fuzziness parameter. The time that vFCM takes is greatly reduced. [ABSTRACT FROM AUTHOR]

High-efficiency, large-area, non-destructive, and high-precision polishing of alumina ceramics was achieved by picosecond laser in an overlapping parallel line scanning mode. The ablation law and the ablation threshold during polishing were determined. The surface roughness (SR a) after polishing was decreased by 82% compared with that of the unpolished sample (1.80 μm) and the minimum SR a achieved was 0.32 μm, when the laser energy density was 5.09 J/cm2, scan rate was 800 mm/s, and scanning path gap was 10 μm. The polishing efficiency, which was described by the processing area per second, was 55 mm2/s. The mechanism of picosecond laser polishing was not direct removal of surface material, but entailed the recrystallization of nanoparticles excited by the ultrafast laser. The excited nanoparticles melted and recrystallized to form a layer of dense fine crystal structure on the ceramic surface, which resulted in the decreased SR a. • Large area and high efficiency ps laser polishing of Al 2 O 3 ceramics is realized. • The laser polished ceramic surface roughness is decreased to submicron level. • The polishing originates from recrystallization of ps pulse excited nanoparticles. • Melted layer consisting of the recrystallized nanoparticles forms polished surface. [ABSTRACT FROM AUTHOR]

Flower color is an important ornamental feature that is often modulated by the contents of flavonoids. Chalcone synthase is the first key enzyme in the biosynthesis of flavonoids, but little is known about the role of R. delavayi CHS in flavonoid biosynthesis. In this paper, three CHS genes (RdCHS1-3) were successfully cloned from R. delavayi flowers. According to multiple sequence alignment and a phylogenetic analysis, only RdCHS1 contained all the highly conserved and important residues, which was classified into the cluster of bona fide CHSs. RdCHS1 was then subjected to further functional analysis. Real-time PCR analysis revealed that the transcripts of RdCHS1 were the highest in the leaves and lowest in the roots; this did not match the anthocyanin accumulation patterns during flower development. Biochemical characterization displayed that RdCHS1 could catalyze p-coumaroyl-CoA and malonyl-CoA molecules to produce naringenin chalcone. The physiological function of RdCHS1 was checked in Arabidopsis mutants and tobacco, and the results showed that RdCHS1 transgenes could recover the color phenotypes of the tt4 mutant and caused the tobacco flower color to change from pink to dark pink through modulating the expressions of endogenous structural and regulatory genes in the tobacco. All these results demonstrate that RdCHS1 fulfills the function of a bona fide CHS and contributes to flavonoid biosynthesis in R. delavayi. [ABSTRACT FROM AUTHOR]

Nickel‐copper‐zinc (NiCuZn) spinel ferrites have attracted intensive research owing to their unique magnetic properties and low co‐fire temperature. Combustion synthesis has been viewed as a promising protocol for the large‐scale fabrication of NiCuZn spinel ferrites. However, the spinel ferrites prepared by this method usually suffer from limited saturation magnetization and high coercivity due to their large size, which will impose detrimental harmonics on electrical equipment (e. g. transformer, motor, etc.). To address these issues, highly porous NiCuZn spinel ferrite hierarchies were prepared within several hours through a modified solution combustion method, using glucose and ammonium nitrate as the fuel and combustion enhancer, respectively. The as‐obtained NiCuZn spinel ferrite hierarchies show excellent magnetic properties with a high saturation magnetization up to 62.61 emu/g and a low coercivity of 9.6 Oe thanks to the rational distribution of cations and grain size. More importantly, this method also allows various modifications (heteroatom doping) and large‐scale applications, which may be promising for the fabrication of high‐performance soft magnets for electrical equipment. [ABSTRACT FROM AUTHOR]

Bone mesenchymal stem cells (BMSCs) are the most commonly investigated progenitor cells in bone tissue engineering for treating severe bone defects. Strategies for regulating BMSC differentiation fate have received wide attention, in which redox homeostasis plays an important role due to the change in energy metabolism during stem cell differentiation. In the present study, it was observed that autophagic activity was induced along with BMSC osteogenic differentiation and subsequently regulated reactive oxygen species (ROS) generation and the level of osteogenesis. Furthermore, it was also observed that neuropeptide substance P (SP) administration could enhance the autophagic activity in rat BMSCs via the AMPK and mTOR pathways, as well as decreasing ROS generation and promoting osteogenic differentiation. Inhibition of autophagic activity by 3-MA reversed the effects of SP on ROS and osteogenic levels. The present results indicated that autophagic activity participated in the regulation of differentiation fate of BMSCs and SP could promote osteogenic differentiation by activating autophagy, providing a more precise biological mechanism for its application in bone tissue engineering. [ABSTRACT FROM AUTHOR]

The interface microzone characteristics determine the thermophysical properties of diamond/Cu composites, while the mechanisms of interface formation and heat transport still need to be revealed. Here, diamond/Cu-B composites with different boron content were prepared by vacuum pressure infiltration. Diamond/Cu-B composites up to 694 W/(mK) were obtained. The interfacial carbides formation process and the enhancement mechanisms of interfacial heat conduction in diamond/Cu-B composites were studied by HRTEM and first-principles calculations. It is demonstrated that boron can diffuse toward the interface region with an energy barrier of 0.87 eV, and these elements are energetically favorable to form the B4C phase. The calculation of the phonon spectrum proves that the B4C phonon spectrum is distributed in the range of the copper and diamond phonon spectrum. The overlapping of phonon spectra and the dentate structure together enhance the interface phononic transport efficiency, thereby improving the interface thermal conductance. [ABSTRACT FROM AUTHOR]

Numerical simulation of free surface multi-fluid flow is a challenging problem owning to the interaction between deformed interface and free surface. In this paper, a multiphase particle solver (free surface multiphase moving particle semi-implicit method, FS-MMPS) is developed to predict the early spreading flow of spilled oil where exist the oil–water interface and air–oil/air–water free surface. First, a multiphase virtual particle model is proposed to substitute the inaccurate free surface boundary condition for multiphase flow in conventional MPS methods. Specifically, virtual particles of different liquid phases are compensated outside free surface so that the pressure of free surface particles can be solved from pressure Poisson equation, thereby improving the accuracy of multi-fluid interaction at free surface. Meanwhile, a pressure gradient model based on the coupling of Taylor series expansion and dynamic specification of particle stabilizing term (PST) is proposed to simultaneously enhance accuracy and depress instability caused by multiphase virtual particles. Experiments of early spreading of thick oil slicks and continuous oil spill from a damaged tank are conducted for validation and demonstration of the accuracy and stability enhancements in 2D. Finally, the effects of traveling wave and continuous spilling on oil spreading are investigated to show the capability of the proposed method. The spreading of thick oil slicks is accelerated when wave height increases or wave length decreases, and the largest increase of spreading rate accelerated by traveling wave is 14%. [ABSTRACT FROM AUTHOR]

Spinel ferrites have been widely used in various fields, among which nickel‐zinc (NiZn) ferrites have drawn much attention due to their high electrical resistivity as well as low eddy current loss. To accommodate highly‐integrated modern electronic devices, the preparation methods for nano/micro‐sized NiZn ferrites have been widely discussed. Nevertheless, these current synthesis routes are usually cost/time‐consuming, which hinders their large‐scale production for practical applications. Herein, we present a facile, low‐cost synthesis strategy for NiZn ferrites (NixZn1−xFe2O4, x=0, 0.25, 0.5, 0.75 and 1) through a blowing‐combustion method. The effect of Ni/Zn molar concentration on the structure, morphology as well as magnetic properties has been thoroughly investigated through X‐ray diffraction, Raman spectroscopy, scanning electron microscopy and vibrating sample magnetometer. Thanks to the synergetic effect of the pure phase and moderate Ni molar concentration, the Ni0.75Zn0.25Fe2O4 shows an enhanced saturation magnetization of 44.98 emu/g. More importantly, this blowing‐combustion method may also be commonly applied to other spinel ferrites with different stoichiometric ratios and heteroatom doping. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen production by biomass gasification using solar energy is a promising approach for overcoming the drawbacks of fossil fuel utilization, but the storage of discontinuous solar flux is a critical issue for continuous solar hydrogen production. A continuous hydrogen production system by biomass gasification in supercritical water using molten-salts-stored solar energy was proposed and constructed. A novel double tube helical heat exchanger was designed to be molten salts reactor for hydrogen production. Model compounds (glycerol/glucose) and real biomass (corn cob) were successfully gasified in this molten salts reactor for producing hydrogen-rich gas. The unique temperature profiles of biomass slurry in the reactor were observed and compared with that of conventional electrical heating and direct solar heating approaches. Product gases yield, gasification efficiency and exergy conversion efficiency of the reactor were analyzed. The results showed that the performances of reactor were determined by feedstock style, biomass concentration, residence time and biomass slurry temperature profiles. [Copyright &y& Elsevier]

Abstract: Supercritical water gasification (SCWG) is a promising technology for wet biomass utilization. In this paper, orthogonal experimental design method, which can minimize the number of experiments compared with the full factorial experiments, was used to optimize the operation parameters of SCWG with a tubular reactor system. Using this method, the influences of the main parameters including pressure, temperature, residence time and solution concentration on biomass gasification were also investigated. Simultaneously, in order to further improve the gasification efficiency of biomass, acid hydrolysis pretreatment of feedstock, oxidizers addition and increasing reaction temperature were employed. Results from the experiments show that in the range of experimental parameters, the order of the effects of the factors on H2 yield of corn cob gasification in SCW is temperature>pressure>feedstock concentration>residence time. Temperature and pressure have a significant and complicated effect on biomass gasification. Hydrogen yield increases by the acid hydrolysis pretreatment of feedstock, and oxidizer addition reduces the hydrogen yield but it promotes the increase in carbon gasification efficiency. Biomass feedstock with high concentration was gasified successfully at high reaction temperature. [Copyright &y& Elsevier]

Abstract: The technology of supercritical water gasification can convert coal to hydrogen-rich gaseous product efficiently and cleanly. A novel continuous-flow system for coal gasification in supercritical water was developed successfully in State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF). The experimental device was designed for the temperature up to 800°C and the pressure up to 30MPa. The gasification characteristics of coal were investigated within the experimental condition range of temperature at 650–800°C, pressure at 23–27MPa and flow rate from 3kgh−1 to 7kgh−1. K2CO3 and Raney-Ni were used as catalyst and H2O2 as oxidant. The effects of main operation parameters (temperature, pressure, flow rate, catalyst, oxidant, concentration of coal slurry) upon gasification were carried out. The slurry of 16wt% coal+1.5wt% CMC was successfully transported into the reactor and continuously gasified in supercritical water in the system. The hydrogen fraction reached up to 72.85%. The experimental results demonstrate the bright future of efficient and clean conversion of coal. [Copyright &y& Elsevier]

Abstract: Biomass gasification in supercritical water is a promising technology for hydrogen production by utilizing wet biomass. A new experimental system of biomass gasification in supercritical water was built in SKLMF. In this paper, a comprehensive thermodynamic analysis, including chemical equilibrium in the reactor, gas–liquid equilibrium in the high-pressure separator, exergy and energy analysis of the whole system, was conducted. Chemical equilibrium model is based on minimizing Gibbs free energy. By chemical equilibrium analysis in the reactor, rules of the main parametric effects on biomass gasification in supercritical water are obtained. Simultaneously, a high-pressure gas–liquid equilibrium model was proposed based on modified universal functional activity coefficient (UNIFAC) model, Soave–Redlich–Kwong (SRK) equation of state and modified Huron–Vidal second-order (MHV2) mixing rule. Effects of pressure, temperature and water recycled ratio on gas–liquid equilibrium in high-pressure separation were discussed. Finally, results from energy and exergy analysis show that energy and exergy efficiencies of the whole system are in excess of 40% and increase with increasing heat transfer efficiencies. Energy loss of the system is caused mainly by heat transfer and exergy loss is mainly caused by heat transfer and chemical reaction. Our research provided a thermodynamic tool for improvement of design and operation optimization of biomass gasification system in SKLMF, which may be also applicable to other biomass gasification system. [Copyright &y& Elsevier]

Abstract: Experiments were performed in a horizontal test loop with inner diameter 50mm to study the gas–liquid slug flow. The translational velocities of elongated bubbles, lengths of liquid slugs and elongated bubbles, and slug frequencies were measured using two pairs of conductivity probes. Correlations are presented for elongated bubble translational velocity, length of elongated bubble and slug frequency, respectively. It was found that the translational velocity of elongated bubble is not only dependent on Froude number, but also is significantly affected by the distance from the entrance of pipeline in the higher mixture velocity range. Mean liquid slug length is relatively insensitive to the gas and liquid flow rates in the higher mixture velocity range, however in the lower mixture velocity range, the mean liquid slug length is affected by the mixture velocity. Mean slug frequency clearly increases as the liquid superficial velocity increases but it weakly depends on the gas superficial velocity. [Copyright &y& Elsevier]

Abstract: Interests in large-scale use of biomass for energy and in hydrogen are motivated largely by global environmental issues. Cellulose and sawdust were gasified in supercritical water to produce hydrogen-rich gas in this paper, and Ru/C, Pd/C, CeO2 paticles, nano-CeO2 and nano-(CeZr) x O2 were selected as catalysts. The experimental results showed that the catalytic activities were Ru/C>Pd/C>nano-(CeZr) x O2 >nano-CeO2 >CeO2 particle in turn. Low-concentration sodium carboxymethylcellulose (CMC) (2–3wt.%) was mixed with particulate biomass and water to form a uniform and stable viscous paste which can be efficiently gasified. The 10wt.% cellulose or sawdust with CMC can be gasified near completely with Ru/C catalyst to produce 2–4g hydrogen yield and 11–15g potential hydrogen yield per 100g feedstock at the condition of 500°C, 27MPa, 20min residence time in supercritical water. [Copyright &y& Elsevier]

This paper presents a new numerical model, called the CAS model, for boiling heat transfer. The CAS model is based on the cellular automata (CA) technique that is integrated into the popular SIMPLER algorithm for CFD problems. In the model, the CA technique deals with the microscopic nonlinear dynamic interactions of bubbles while the traditional CFD algorithm is used to determine macroscopic system parameters such as pressure and temperature. The popular SIMPLER algorithm is employed for the CFD treatment. The model is then employed to simulate a pool boiling process. The computational results show that the CAS model can reproduce most of the basic features of boiling and capture the fundamental characteristics of boiling phenomena. The heat transfer coefficient predicted by the CAS model is in excellent agreement with the experimental data and existing empirical correlations. [Copyright &y& Elsevier]

The present study is to contribute some knowledge of phase separation phenomena of liquid–solid two-phase turbulent flow in curved pipes and provide a basis for the invention and development of a new type of curved pipe separator. Firstly, the solid–liquid two-phase flows in two-dimensional (2D) curved channels were numerically simulated using a two-way coupling Euler–Lagrangian scheme. Phase distribution characteristics of 2D curved channel two-phase flow were examined under conditions of different particle size, liquid flowrate and coil curvature. Based on the numerical results, the dynamic effects and contributions to phase separation of particle-subjected forces, including centrifugal force, drag force, pressure gradient force, gravity force, buoyancy force, virtual mass force and lift force, were exposed by kinematic and dynamic analysis along particle trajectories. Secondly, measurement of particle size and concentration profiles in helically coiled tube two-phase flow was conducted using a nonintrusive Malvern 2600 particle sizer based on laser diffraction. Particle size and concentration distribution characteristics of helically coiled tube two-phase flow and the effect of secondary flow on phase separation were analyzed based on experimental data. [Copyright &y& Elsevier]

Copper matrix composites reinforced with 60 vol% diamond particles were prepared by pressure infiltration using Cu-Cr alloy with 0.3–1.0 wt% Cr. The x-ray diffraction, scanning electron microscopy, and transmission electron microscopy were conducted to characterize the Diamond/Cu composites interface. The interface structure evolves from the discontinuous point contact to continuous strip carbides depending on the availability of Cr source. With Cr content increasing, the thermal conductivity of the Diamond/Cu-Cr composites increases first and then decreases. The highest thermal conductivity of 696 W/mK was achieved at 0.5 wt% Cr addition, while the highest tensile strength and bending strength of 252 MPa and 523 MPa were achieved at 0.7 wt% Cr addition. By optimizing the interface thermal resistance and interface bonding strength, Diamond/Cu composites with excellent comprehensive properties can be obtained. [Display omitted] • An interface with low thermal resistance and high strength of Diamond/Cu composites is optimized. • The maximum thermal conductivity of 696 W/mK and the maximum bending strength of 523 MPa were achieved. • The Cr 3 C 2 -Cu interface is in atomic-level contact and chemically bonded. [ABSTRACT FROM AUTHOR]

Diamond particle-reinforced copper matrix composites (Diamond/Cu) are recognized as promising electronic packaging materials due to their excellent thermophysical properties. It is necessary to investigate the reliability of Diamond/Cu composites under extreme environmental conditions. The corrosion behavior of Diamond/Cu composites was studied in a 5 wt% NaCl neutral salt spray. Surface morphology, thermal conductivity, bending strength, corrosion rate, and corrosion depth resulting from corrosion were researched in this paper. The results showed that the corrosion phenomenon mainly occurs on the copper matrix, and the diamond and interface products do not corrode. The corrosion mechanism of Diamond/Cu composites was micro-galvanic corrosion. The corrosion product formed was Cu2Cl(OH)3. The salt spray environment had a great influence on the composite surface, but the composite properties were not significantly degenerated. After a 168-h test, the bending strength was unaltered and the thermal conductivity of gold-plated composites showed a slight decrease of 1–2%. Surface gold plating can effectively improve the surface state and thermal conductivity of Diamond/Cu composites in a salt spray environment. [ABSTRACT FROM AUTHOR]

Having a burnt pot is bothersome in the kitchen, and the carbonized food on it is difficult to clean. Here, burnt starch, which has the advantage of being mechanically robust, was utilized as the carbon material for energy storage applications. Interestingly, 2D amorphous carbon nanosheets (CNs) could be synthesized by simply burning corn starch above a Ni foam. By further coating a CoO/CoF 2 composite film onto the CNs, the hybrid electrode exhibited significant improvement in terms of electron collection efficiency. Benefiting from the synergistic effect of the Co compounds and CNs, the synthesized electrode demonstrated high specific capacitance (12.00 F cm−2 at a current density of 5 mA cm−2), excellent rate capability, and superior cycling stability. Furthermore, three connected symmetric supercapacitors were able to power LED lights for more than 10 min. Therefore, this work provides a new strategy for the fabrication of 2D CN and further applications in supercapacitors. • 2D amorphous carbon nanosheets were introduced by burning starch above Ni foam. • The CoO/CoF 2 compounds were further coated onto carbon nanosheets. • The sample shows a high capacitance of 12.00 F cm−2 and a long cyclic stability. • Three connected symmetric supercapacitor could power the LED lights for more than 10 min. [ABSTRACT FROM AUTHOR]

Copper matrix composites reinforced with bimodal diamond particles were prepared via pressure infiltration. The effects of diamond particles mixing mode on the microstructure and thermal conductivity of the composites were analyzed. The heat flux vector distributions of the composites with or without the secondary diamond were simulated using finite element models based on the experimental microstructure images. The results show that the thermal conductivity of Diamond/Cu composites under different diamond particle mixing schemes all exceeded 700 W/mK. The obtained maximum thermal conductivity of Diamond/Cu composite is 853 W/mK when 25 vol% of secondary diamond particles with a particle size ratio of 10 were introduced. Such a result is explained by the optimization effect of secondary diamond particles on heat conduction channel and interfacial thermal resistance. Furthermore, the simulation results also prove that the introduction of secondary diamond can effectively improve the heat flux conduction along the diamond reinforced phase. Unlabelled Image • Diamond/Cu composites with bimodal diamond particles were fabricated via vacuum pressure infiltration. • The maximum thermal conductivity value of 853 W/mK in Diamond/Cu composites was obtained. • A uniform and continuous strip Cr 3 C 2 about 0.5 μm thick were formed at the interface between the diamond and copper matrix. [ABSTRACT FROM AUTHOR]

The Diamond/Cu composites with bimodal diamond particles reinforced were fabricated by vacuum pressure infiltration. The influence of diamond volume fractions on the microstructure, thermal expansion behaviour, residual Stress and dimensional stability of the composites were investigated by using scanning electron microscopy, X-ray diffraction, Raman spectroscopy and thermal cycling tests. The CTEs of 3.8–5.8 ppm/K at 50 °C were achieved for the Diamond/Cu composites, owing to the high diamond content (63–81.8 vol%) and the strong interfacial bonding strength. The CTEs of Diamond/Cu composites vary by less than 2 ppm/K in the range of 50–300 °C.Thermal cycling tests show that the residual strain of Diamond/Cu composites ranges from 1.6 × 10−4 to 1.0 × 10−4 as the diamond content increases from 63 vol% to 81.8 vol%. Increasing the diamond content introduces higher residual tensile stress, so the total residual strain drops slowly when the diamond content exceeds 72.5 vol%. The results show that an appropriate amount of diamond addition can obtain a coefficient of thermal expansion matching the semiconductor material and a high dimensional stability of Diamond/Cu composites. • Diamond/Cu composites with bimodal diamond were fabricated via vacuum pressure infiltration. • The average CTE of Diamond/Cu composites is 3.8–5.8 ppm/K (50 °C). • The residual strain is lower than 1.6 × 10−4 under different diamond content. [ABSTRACT FROM AUTHOR]

Highlights • A dataset with 13,526 records of nitrogen (N) content of plant organs was built. • N content significantly differed among plant organs, with higher N in active organs. • Plant N content was significantly different among different regions. • N content in plant organs increased with increasing latitude. • N content references were established for N storage assessments. Abstract Nitrogen (N) is an essential nutrient that is important for plant growth and productivity. How plants distribute N in different plant organs is aligned to the N use strategy of plants, and, in turn, provides an accurate way of assessing N storage in vegetation at the regional scale. Here, we analyzed variation in N concentrations across different organs and at different spatial scales. Specifically, we obtained 13,526 observations of plant N in China from consistent field measurements and from the published literature. The results showed that N concentration was significantly different across different plant organs (leaf, branch, trunk, and root), with more active organs having higher N. For forests, N concentration was ordered as: leaf (17.35 g kg−1) > root (6.66 g kg–1) > branch (6.47 g kg–1) > trunk (2.79 g kg–1). Similar trends were observed in grasslands, deserts, and wetlands. The N concentration of different plant organs significantly differed among different vegetation types [e.g., leaf N was ordered as: grassland (19.20 g kg–1) > desert (17.91 g kg–1) > forest (17.35 g kg–1) > wetland (14.58 g kg–1)]. Furthermore, N concentration in different plant organs significantly differed across various regions. With increasing latitude and decreasing mean annual temperature, the N concentration of different plant organs increased, to some extent. Our findings provide new insights about the differences in the N use strategy of plants across plant organs and at different spatial scales. In conclusion, the data assimilated here provide a systematic reference point for estimating vegetation N storage at different scales. [ABSTRACT FROM AUTHOR]

Abstract The microstructure of the oxide dispersion strengthened (ODS) Fe-15Cr ferritic steel with Ti and Zr additions was characterized using transmission electron microscopy (TEM), elemental mapping, synchrotron small angle X-ray scattering (SAXS) and electron backscatter diffraction (EBSD) techniques. The results showed that bimodal grain size distribution in the matrix was observed, which is attributed to the heterogeneous recrystallization process during the Spark Plasma Sintering (SPS). TEM and SAXS results showed that very high density nanoscale oxides are formed in 15Cr-ODS steel. Large concentration of nm-scale trigonal-phase Y 4 Zr 3 O 12 oxides and some large oxides of monoclinic CrTi 2 O 5 are observed in specimen by high resolution TEM (HRTEM) and Energy-dispersive X-ray spectroscopy (EDS) mapping. Finally, the yield stress was experimentally measured and quantitatively estimated. The findings indicated that theoretical calculation was in accordance with the experimental results, and strengthening contributions from solute atoms, grains boundaries, dislocations and oxides was presented. [ABSTRACT FROM AUTHOR]

• A phase field model on MPB with local compositional heterogeneity is developed. • Three-phase mixture forms due to the local compositional heterogeneity. • Polarization rotation under electric fields contribute to the piezoelectricity. • d 33 coefficient decreases due to the on-average more difficult polarization rotation. In this work, the effect of local compositional heterogeneity on the domain structure and piezoelectricity at ferroelectric morphotropic phase boundary (MPB) is studied by phase field simulations. It is found that the local compositional heterogeneity leads to a unique domain structure at MPB, i.e., a mixture of tetragonal, monoclinic and rhombohedral domains. Although polarization rotation occurs for both MPB samples with and without local compositional heterogeneity, the piezoelectric d 33 coefficient becomes reduced for the sample with local compositional heterogeneity because polarization rotation becomes more difficult on average. This work unravels the effect of local compositional heterogeneity on the piezoelectric property of ferroelectric MPB. [ABSTRACT FROM AUTHOR]

Chinese liquor is one of the world’s oldest distilled alcoholic beverages and an important commercial fermented product in China. The Chinese liquor fermentation process has three stages: making Daqu (the starter), stacking fermentation on the ground, and liquor fermentation in pits. We investigated the bacterial diversity of Maotai and Guotai Daqu and liquor fermentation using high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. A total of 70,297 sequences were obtained from the Daqu samples and clustered into 17 phyla. The composition of the bacterial communities in the Daqu from these two soy sauce aroma-style Chinese liquors was the same, although some bacterial species changed in abundance. Between the Daqu and liquor fermentation samples, 12 bacterial phyla increased. The abundance of Lactobacillus and Pseudomonas increased in the liquor fermentation. This study has used high-throughput sequencing to provide new insights into the bacterial composition of the Chinese liquor Daqu and fermentation. Similarities in the distribution of bacteria in the soy sauce aroma-style Chinese liquors Daqu suggest that the abundance of bacteria might be generally concerned to other liquor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nickel-copper-zinc (NiCuZn) ferrites were prepared by a facile blowing-combustion method. • Variation of zinc content with temperature was investigated through inductive coupled plasma (ICP). • The effect of sintering temperatures on structural and magnetic properties of NiCuZn ferrites were investigated. We report the fabrication of nickel-copper-zinc (NiCuZn) ferrites via a facile blowing-combustion method, where the grain size and morphology can be readily controlled by adjusting the sintering temperature. The effect of sintering temperatures on the structural evolution as well as the magnetic properties of the NiCuZn ferrites was systematically studied. It's found that the Zn elemental content is highly dependent on the sintering temperature and would undergo evaporation when annealing at 800 °C, which consequently greatly affects the magnetic properties of NiCuZn ferrites. [ABSTRACT FROM AUTHOR]

Abstract: Direct contact condensation is widely used in industrial applications due to its highly efficient heat and mass transfer. Many experimental and theoretical works have been performed on steam jet condensation in stagnant water in pool. However, the condensation of steam jet in water flow in pipes is not yet fully understood. Here, experiments are performed to study the direct contact condensation of stable steam jet in water flow in a vertical pipe. By using high speed camera and mobile thermocouple probe, we investigate condensation characteristics including the plume shape, plume length, temperature distribution, average heat transfer coefficient, and average Nusselt number. Five different plume shapes (hemispherical, conical, ellipsoidal, cylinder, and divergent) are identified visually, and their distribution is described in a three-dimensional condensation regime diagram based on steam mass flux, water temperature, and Reynolds number of water flow. The dimensionless plume length and average heat transfer coefficient are found to be within the range of 0.29–4.64 and 0.34–11.36MW/m2 K, respectively. Besides, empirical correlations are obtained for the dimensionless plume length, average heat transfer coefficient, and average Nusselt number as a function of three dimensionless parameters, i.e., dimensionless steam mass flux, condensation driving potential, and Reynolds number of water flow. The dimensionless radial temperature decreases exponentially from the center to the pipe wall and shows good self-similarity. [Copyright &y& Elsevier]

Abstract: The inorganic substances precipitate in the reactor for its low solubility in supercritical water, which may influence the performance of supercritical water gasification (SCWG). In the present study, we studied the influence of alkali precipitation on the gasification of glucose with NaOH as catalyst at 500 °C, 25 MPa in a fluidized-bed reactor. The presence of NaOH increased H2 fraction by accelerating water–gas shift reaction and also increased the gas yield. The catalytic effect was further improved with longer reaction time due to the alkali accumulation in the reactor. The precipitated alkali in the reactor still showed high catalytic effect on the subsequent gasification of glucose without further addition of alkali. The catalytic activity was slightly reduced for the transformation of NaOH to Na2CO3 and NaHCO3. The precipitated alkali flowed out of the reactor with water when the temperature in the reactor decreased to near the critical temperature because of the increasing solubility. Most of the sodium fed into the system (81.07%) was recovered in this process. [Copyright &y& Elsevier]

Abstract: A novel receiver/reactor driven by concentrating solar energy for hydrogen production by supercritical water gasification (SCWG) of biomass was designed, constructed and tested. Model compound (glucose) and real biomass (corncob) were successfully gasified under SCW conditions to generate hydrogen-rich fuel gas in the apparatus. It is found that the receiver/reactor temperature increased with the increment of the direct normal solar irradiation (DNI). Effects of the DNI, the flow rates and concentration of the feedstocks as well as alkali catalysts addition were investigated. The results showed that DNI and flow rates of reactants have prominent effects on the temperature of reactor wall and gasification results. Higher DNI and lower feed concentrations favor the biomass gasification for hydrogen production. The encouraging results indicate a promising approach for hydrogen production with biomass gasification in supercritical water using concentrated solar energy. [Copyright &y& Elsevier]

Abstract: In this work, gasification of sewage sludge in supercritical water was investigated in a fluidized bed reactor. Effect of operating parameters such as temperature, concentration of the feedstock, alkali catalysts and catalyst loading on gaseous products and carbon distribution were systematically studied. The results showed that the increase of temperature and the decrease of feedstock concentration were both favorable for gasification, and the addition of catalyst enhanced the formation of hydrogen better. The K2CO3 catalyst could better enhance gasification efficiency and the catalytic activity of different catalysts for hydrogen production was in the following order: KOH > K2CO3 > NaOH > Na2CO3. The maximum molar fraction and yield of hydrogen reached to 55.96% and 15.49 mol/kg respectively with KOH at 540 °C. Most carbon in feedstock existed in gaseous and liquid products, and alkali catalysts mainly promoted the water-gas shift reaction rather than steam reforming. [Copyright &y& Elsevier]

Abstract: The gasification of sewage sludge in near and super-critical water was investigated in a batch reactor. Results showed that the formation of gaseous products could be intensively affected by temperature. In order to understand the effect of temperature on the development of reaction process and the formation of gaseous products better, the detailed characteristics of solid and liquid products were analyzed by SEM, N2 adsorption–desorption technique, FTIR, TOC, Ammonia–nitrogen analysis and SPE-GC/MS. The changes in the yield distribution of products and the characteristics of solid and liquid products indicated that organic matters in sewage sludge were almost completely dissolved and hydrolyzed in water at 425 °C. The dissolution and hydrolysis products were gasified by reforming and other reactions. The polymerization and dehydrogenation also occurred in dissolution and hydrolysis products, and the Diels–Alder reaction mechanism could be used to explain the phenomenon. [Copyright &y& Elsevier]

Abstract: Supercritical water fluidized bed is a new reactor concept for biomass gasification. In this paper, an experimental study on the hydrodynamics of a supercritical water fluidized bed was conducted. The frictional pressure drops of a fixed bed and a fluidized bed were measured for a temperature ranging from 633 to 693K and pressure ranging from 23 to 27MPa. The results show that the Ergun formula for calculating the frictional pressure drop of a fixed bed can still be applied in supercritical water conditions. The average deviation between Ergun formula and experiment results is 13.3%. A predicting correlation for the minimum fluidization velocity in a supercritical water fluidized bed was obtained based on the experimental results of a fixed bed and the fluidized bed pressure drop. The average error between the correlation and experiment results was about 3.1%. The results in this paper are useful for the design of SCW fluidized bed. [Copyright &y& Elsevier]

Abstract: In this work, glycerol was used for hydrogen production by supercritical water gasification. Experiments were conducted in a continuous flow tubular reactor at 445∼600 °C, 25 MPa, with a short residence time of 3.9∼9.0 s. The effects of reaction temperature, residence time, glycerol concentration and alkali catalysts on gasification were systematically studied. The results showed that the gasification efficiency increased sharply with increasing temperature above 487 °C. A short residence time of 7.0 s was enough for 10 wt% glycerol gasification at 567 °C. With the increase of glycerol concentration from 10 to 50 wt%, the gasification efficiency decreased from 88% to 71% at 567 °C. The alkali catalysts greatly enhanced water-gas shift reaction and the hydrogen yield in relation to catalysts was in the following order: NaOH > Na2CO3>KOH > K2CO3. The hydrogen yield of 4.93 mol/mol was achieved at 526 °C with 0.1 wt% NaOH. No char or tar was observed in all experiments. The apparent activation energy and apparent pre-exponential factor for glycerol carbon gasification were obtained by assuming pseudo first-order kinetics. [Copyright &y& Elsevier]

Abstract: Supercritical water gasification (SCWG) of wet biomass is a very promising technology for hydrogen energy and the utilization of biomass resources. Ni-based catalysts are effective in catalyzing SCWG of original biomass and organic compounds for hydrogen production. In this paper, hydrogen production by SCWG of glucose over alumina-supported nickel catalysts modified with Cu, Co and Sn was studied. The bimetallic Ni–M (M = Cu, Co and Sn) catalysts were prepared by a co-impregnation method and tested in an autoclave reactor at 673 K with a feedstock concentration of 9.09 wt.%. XRD, XRF, N2 adsorption/desorption, SEM and TGA were adopted to investigate the changes of chemical properties between Ni and Ni–M catalysts and the deactivation mechanism of catalysts. According to the experimental results, the hydrogen yield followed this order: Ni–Cu/γAl2O3 > Ni/γAl2O3 > Ni–Co/γAl2O3 > Ni–Sn/γAl2O3. The results show that Cu could improve the catalytic activity of Ni catalyst in reforming reaction of methane to produce hydrogen in SCWG. In addition, Cu can mitigate the sintering of alumina detected by SEM. Co was found to be an excellent promoter of Ni-based catalyst in relation to hydrogen selectivity. [Copyright &y& Elsevier]

Abstract: A novel system of hydrogen production by biomass gasification in supercritical water using concentrated solar energy has been constructed, installed and tested at the State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF). The “proof of concept” tests for solar-thermal gasification of biomass in supercritical water (SCW) were successfully carried out. Biomass model compounds (glucose) and real biomass (corn meal, wheat stalk) were gasified continuously with the novel system to produce hydrogen-rich gas. The effect of direct normal solar irradiation (DNI) and catalyst on gasification of biomass was also investigated. The results showed that the maximal gasification efficiency (the mass of product gas/the mass of feedstock) in excess of 110% were reached, hydrogen fraction in the gas product also approached to 50%. The experimental results confirmed the feasibility of the system and the advantage of the process, which supports future work to address the technical issues and develop the technology of solar-thermal hydrogen production by gasification of biomass in supercritical water. [Copyright &y& Elsevier]

Abstract: Hydrogen production by supercritical water gasification (SCWG) is a promising technology for wet biomass utilization. Ni catalyst can realize the high gasification efficiency of biomass near the critical temperature of water. In this paper, Ni/γAl2O3 and Ni/CeO2-γAl2O3 catalysts were prepared by an impregnation method. The catalyst performance for glucose gasification in supercritical water was tested in autoclave reactor. All experiments were carried out in the autoclave at 673 K, 24.5 MPa, and the concentration of glucose was 9.09 wt.%. The catalysts before and after reaction were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET specific surface area measurements, X-ray fluorescence spectrum (XRF) and Thermo-gravimetric analyses (TGA) in order to investigate on the chemical property and catalytic mechanism. The experimental results showed that hydrogen yield and hydrogen selectivity increased sharply with addition of Ni/γAl2O3 and Ni/CeO2-γAl2O3 catalysts. The catalytic activity and H2 selectivity of Ni/CeO2-γAl2O3 was higher than that of Ni/γ-Al2O3 catalyst. The results revealed that carbon deposition and coking led to the deactivation of the catalysts. Ce in the Ni/CeO2-γAl2O3 catalyst had a certain role in the inhibition of carbon deposition and coking. [Copyright &y& Elsevier]

Abstract: The technology of supercritical water gasification of coal can converse coal to hydrogen-rich gaseous products effectively and cleanly. However, the slugging problem in the tubular reactor is the bottleneck of the development of continuous large-scale hydrogen production from coal. The reaction of coal gasification in supercritical water was analyzed from the point of view of thermodynamics. A chemical equilibrium model based on Gibbs free energy minimization was adopted to predict the yield of gaseous products and their fractions. The gasification reaction was calculated to be complete. A supercritical water gasification system with a fluidized bed reactor was applied to investigate the gasification of coal in supercritical water. 24 wt% coal-water-slurry was continuously transported and stably gasified without plugging problems; a hydrogen yield of 32.26  mol/kg was obtained and the hydrogen fraction was 69.78%. The effects of operational parameters upon the gasification characteristics were investigated. The recycle of the liquid residual from the gasification system was also studied. [Copyright &y& Elsevier]

Abstract: Photocatalytic water splitting with solar light is one of the most promising technologies for solar hydrogen production. From a systematic point of view, whether it is photocatalyst and reaction system development or the reactor-related design, the essentials could be summarized as: photon transfer limitations and mass transfer limitations (in the case of liquid phase reactions). Optimization of these two issues are therefore given special attention throughout our study. In this review, the state of the art for the research of photocatalytic hydrogen production, both outcomes and challenges in this field, were briefly reviewed. Research progress of our lab, from fundamental study of photocatalyst preparation to reactor configuration and pilot level demonstration, were introduced, showing the complete process of our effort for this technology to be economic viable in the near future. Our systematic and continuous study in this field lead to the development of a Compound Parabolic Concentrator (CPC) based photocatalytic hydrogen production solar rector for the first time. We have demonstrated the feasibility for efficient photocatalytic hydrogen production under direct solar light. The exiting challenges and difficulties for this technology to proceed from successful laboratory photocatalysis set-up up to an industrially relevant scale are also proposed. These issues have been the object of our research and would also be the direction of our study in future. [Copyright &y& Elsevier]

Abstract: Partial oxidative gasification in supercritical water is a new technology for hydrogen production from biomass. Firstly in this paper, supercritical water partial oxidative gasification process was analyzed from the perspective of theory and chemical equilibrium gaseous product was calculated using the thermodynamic model. Secondly, the influence of oxidant equivalent ratio on partial oxidative gasification of model compounds (glucose, lignin) and real biomass (corn cob) in supercritical water was investigated in a fluidized bed system. Experimental results show that oxidant can improve the gasification efficiency, and an appropriate addition of oxidant can improve the yield of hydrogen in certain reaction condition. When ER equaled 0.4, the gasification efficiency of lignin was 3.1 times of that without oxidant. When ER equaled 0.1, the yield of hydrogen from lignin increased by 25.8% compared with that without oxidant. Thirdly, the effects of operation parameters including temperature, pressure, concentration, and flow rate of feedstock on the gasification were investigated. The optimal operation parameters for supercritical water partial oxidative gasification were obtained. [Copyright &y& Elsevier]

Abstract: The local flow characteristics of oil–water dispersed flow in a vertical upward pipe were studied experimentally. The inner diameter and length of the test section are 40mm and 3800mm, respectively. A double-sensor conductivity probe was used to measure the local interfacial parameters, including interfacial area concentration, oil phase fraction, interfacial velocity, and oil drops Sauter mean diameter. The water flow rates varied from 0.12m/s to 0.89m/s, while the oil flow rates ranged from 0.024m/s to 0.198m/s. Typical radial profiles of interfacial area concentration, oil phase fraction, interfacial velocity, and oil drops Sauter mean diameter are presented. An interesting phenomenon is that the local and cross-section-averaged interfacial area concentrations display concave change with water flow rate under constant oil flow rate. The physical mechanism of such a variation is discussed in details. [Copyright &y& Elsevier]

Abstract: Interfacial area concentration is an important parameter in modeling the interfacial transfer terms in the two-fluid model. In this paper, the interfacial area concentration, void fraction, and bubble Sauter mean diameter for air–water bubbly flow through a vertical transparent pipe with 40mm internal diameter was investigated experimentally using both digital high-speed camera system and a double-sensor conductivity probe. Based on the experimental data of digital high-speed camera system, the statistical models derived by different researchers for local interfacial area concentration measurement using double-sensor conductivity probe were evaluated. The results show that there are obvious differences among the values of local interfacial area concentration calculated by different statistical models even from the same probe signals. The section-averaged values of the local interfacial area concentration calculated using the statistical model by Kataoka et al. agree best with experimental data of digital high-speed camera system. Therefore, the statistical model developed by Kataoka et al. is recommended for the local measurement of interfacial area concentration using a double-sensor conductivity probe in bubbly two-phase flow. Using the verified double-sensor probe method, we carry out experiment to study the local distribution characteristic of the interfacial area concentration and void fraction in air–water bubbly flow through a vertical pipe. [Copyright &y& Elsevier]

The pressure drop and boiling heat transfer characteristics of steam-water two-phase flow were studied in a small horizontal helically coiled tubing once-through steam generator. The generator was constructed of a 9-mm ID 1Cr18Ni9Ti stainless steel tube with 292-mm coil diameter and 30-mm pitch. Experiments were performed in a range of steam qualities up to 0.95, system pressure 0.5–3.5 MPa, mass flux 236–943 kg/m2s and heat flux 0–900 kW/m2. A new two-phase frictional pressure drop correlation was obtained from the experimental data using Chisholm’s B-coefficient method. The boiling heat transfer was found to be dependent on both of mass flux and heat flux. This implies that both the nucleation mechanism and the convection mechanism have the same importance to forced convective boiling heat transfer in a small horizontal helically coiled tube over the full range of steam qualities (pre-critical heat flux qualities of 0.1–0.9), which is different from the situations in larger helically coiled tube where the convection mechanism dominates at qualities typically >0.1. Traditional single parameter Lockhart–Martinelli type correlations failed to satisfactorily correlate present experimental data, and in this paper a new flow boiling heat transfer correlation was proposed to better correlate the experimental data. [Copyright &y& Elsevier]