Simulation of the western North Pacific summer monsoon by regional ocean–atmosphere coupled model:impacts of oceanic components

A successful simulation of the western North Pacific summer monsoon needs a regional ocean–atmosphere coupled model(ROAM). How the performance of ROAM relies on the oceanic component model remains unknown. In this study, the authors investigated the effects of different oceanic components on the simulation of western North Pacific(WNP) summer monsoon in a ROAM. Three cases of simulations were performed, viz. the summer of 1998(El Nin o decaying phase), 2004(El Nin o developing phase), and 1993(the non-ENSO phase). Results show that the coupled simulations for different ENSO phases exhibit improvements in the simulation of location of Meiyu rainband and spatial distribution of monsoon low-level flow over WNP, whereas the systemic cold biases of sea surface air temperature are further increased. The coupled simulations with different oceanic components show similar performance, which is not ENSO phase dependent. For the case of the summer of 1998, a slightly stronger western Pacific subtropical high and colder sea surface air temperature are found in the simulation with colder sea surface temperature(SST) biases. The colder SST biases are partly contributed by the ocean dynamics processes because the sea surface net flux favors a warmer SST. This study suggests that the dependence of performance of ROAM over WNP on oceanic models is much weaker than that on atmospheric models.     

Investigation of the effects of MoO_3 buffer layer on charge carrier injection and extraction by capacitance–voltage measurement

The effects of MoO3thin buffer layer on charge carrier injection and extraction in inverted configuration ITO/ZnO/MEH-PPV(poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene))/MoO3(0,5 nm)/Ag hybrid solar cells are investigated by capacitance–voltage measurement under dark and light illumination conditions.The efficiency of charge carrier injection and extraction is enhanced by inserting 5 nm MoO3thin layer,resulting in better device performances.Charge carrier transport of the whole device is improved and the interface energy barrier is reduced by inserting 5 nm MoO3thin buffer layer.The device fill factor is increased from 54.1%to 57.5%after modifying 5 nm MoO3.Simulations and experimental results consistently show that in the forward voltage under dark,the device with the 5 nm MoO3thin layer modification generates larger value of capacitance than the device without MoO3layer.While under illumination,the device with the 5 nm MoO3layer generates smaller value of capacitance than the device without the 5 nm MoO3layer in the bias region of reverse and before the peak position of maximum capacitance(VCmax).The underlying mechanism of the MoO3anode buffer layer on device current density–voltage characteristics is discussed.     

Assessment of autonomic nervous system activity by heart rate recovery response

The assessment of autonomic nervous system (ANS) activity is a tool for diagnosing or predicting cardiovascular diseases,while heart rate recovery response (HRRR) after exercise has been promoted as a process under the regulation of ANS (sympathetic and parasympathetic nervous systems).Therefore,assessment of ANS activity was performed by HRRR in this study.Firstly,HRRR signal was extracted based on wavelet decomposition and difference curve of coarse component from heart rate signal.Then,HRRR was divided into quickly descending interval (QDI) and slowly descending interval (SDI).Finally,3 groups of indexes (Difference,Exponential and Quadratic Groups) from QDI and SDI were compared between 50 normotensive and 61 hypertensive subjects.The results showed that the indexes of Difference Group were better choices than others in analyzing the features of HRRR.Furthermore,parasympathetic activity is dominant in QDI,while sympathetic and parasympathetic activities affect SDI together.In conclusion,the proposed method was effective to assess ANS activity.     

Investigation on preparing boron nitride by nitriding pure boron at 1200–1550 1C

Boron nitride (BN) was prepared by nitriding pure boron (B) deposited on carbon substrates by chemical vapor deposition (CVD). Thermodynamic analysis of preparing BN by nitriding CVD B at 1200–1550 1C was firstly performed. And then, the effects of nitridation conditions, including temperature, nitridation atmosphere and CVD B microstructure, on the conversion of B to BN were analyzed by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Results show that the conversion degree of B to BN firstly increased and then slightly decreased with rising temperature. The nitridation degree was controlled by mutual actions between the nitridation of B and consumption of the effective nitrogen source (NH3). The morphology of products and the reaction mechanism between B and N were influenced by nitridation temperature. At high temperatures (1400–1500 1C), BN with highly ordered microstructure was produced. On using N2–H2 as nitridation atmosphere instead of NH3–H2– N2, no BN was obtained in the studied temperature range. The microstructure and component of BN obtained in nitridation process were little affected by the microstructure of CVD B.     

Effect of Zinc additive on dielectric properties of Cd–Se glassy system

Cd5Se95–xZnx(x=0, 2, 4, 6) glassy alloy has been prepared by a melt-quenching technique. Thin films were deposited by thermal coating unit on ultraclean glass substrate under a vacuum of 10–6Torr. The absence of any sharp peaks in the X-ray diffraction confirms the amorphous nature of thin films. The frequency and temperature dependence of dielectric constant and dielectric loss in the frequency range of 1 kHz to 1 MHz and in the temperature range of 290–370 K were studied. Dielectric dispersion was observed when Zinc(Zn) was incorporated into the Cd–Se system.The increase in dielectric parameter with Zn concentration may be due to increase in defect states. The DC conductivity has been reported to investigate the effect of Zn concentration on DC conduction loss. The results are interpreted in term of dipolar theory for Cd5Se95 and Cd5Se93Zn2samples, while the remaining samples have been explained on the basis of DC conduction loss. It was also observed that the DC conductivity increased with the increase of Zinc concentration, which may be due to the decrease in the band gap near Fermi level.     

Spheroidization of silica powders by radio frequency inductively coupled plasma with Ar–H_2 and Ar–N_2 as the sheath gases at atmospheric pressure

Amorphous spherical silica powders were prepared by inductively coupled thermal plasma treatment at a radio frequency of 36.2 MHz. The effects of the added content of hydrogen and nitrogen into argon(serving as the sheath gas), as well as the carrier gas flow rate, on the spheroidization rate of silica powders, were investigated. The prepared silica powders before and after plasma treatment were examined by scanning electron microscopy, X-ray diffraction, and laser granulometric analysis. Results indicated that the average size of the silica particles increased, and the transformation of crystals into the amorphous state occurred after plasma treatment. Discharge image processing was employed to analyze the effect of the plasma temperature field on the spheroidization rate. The spheroidization rate of the silica powder increased with the increase of the hydrogen content in the sheath gas. On the other hand, the spheroidization rate of the silica power first increased and then decreased with the increase of the nitrogen content in the sheath gas. Moreover, the amorphous content increased with the increase of the spheroidization rate of the silica powder.     

Investigation of electron transfer across the ice/liquid interface by scanning electro- chemical microscopy

Charge transfer across a liquid/liquid (L/L) interface is not only related to chemical sensors, drug delivery and phase transfer catalysis, but also significant for mimicking biological membranes[1—3]. The thermodynamics, kinetics and mechanism regarding of this type of heterogeneous transfer process have been intensively investigated in the past three decades. An external potential is usually applied to polarizing the interface in the case of conventional electrochemistry at L/L interfaces.…     

Investigation on chain structure of LLDPE obtained by ethylene in-situ copolymerization with DSC and XRD

Thermal segregations of LLDPE were treated with successive self-nucleation/annealing (SSA) on dif-ferential scanning calorimetry (DSC). Information on molecular heterogeneity of LLDPE was obtained. After SSA was treated, the multiple endothermic peaks were observed in the DSC thermograms during heating experiment. It is obtained that the thickness of different lamellas formed by segments of vari-ous lengths was 4―10 nm. X-ray diffraction (XRD) results showed that the crystallites dimensions of various reflections were about several dozens of nanometers. The ethylene/α-olefin copolymers and the copolymer via in-situ copolymerization were similar to each other for molecular heterogeneity and XRD characteristics, which revealed that it was possible to use the ethylene/α-olefin copolymers to simulate the copolymer via in-situ copolymerization of ethylene to simplify the complexity of the structure of the ethylene in-situ copolymer.     

Bimetal nickel–cobalt phosphide directly grown on commercial graphite substrate by the one-step electrodeposition as efficient electrocatalytic electrode

It is challenging to find a method to obtain a catalyst with low cost and efficient multifunctional performances. Herein, in order to obtain the electrode with high-performance water splitting and non-enzymatic glucose detection, the commercial graphite sheet (GS) with excellent durability and electroconductivity was used as substrate material, and the non-noble ternary component Ni–Co–P catalyst with hierarchical architecture was fabricated on GS via a co-electrodeposition. The catalyst only required low overpotentials of 44.6, 76.5 and 49 mV to drive the current density of 10 mA cm⁻² alongside with the smaller Tafel slopes of 39.2, 44.8 and 112 mV dec⁻¹ for hydrogen evolution reaction (HER) in 1.0 M KOH, 0.5 M H₂SO₄ and 1.0 M PBS solution, respectively. For oxygen evolution reaction (OER), the catalyst demonstrated a low overpotential of 304 mV to achieve the current density of 20 mA cm⁻² with excellent Tafel slope of 89.8 mV dec⁻¹ in alkaline solution. Furthermore, the Ni–Co–P/GS electrode serving as non-enzymatic glucose sensor exhibited the superior electrocatalytic activity with an ultrahigh sensitivity of 7400 μA mM⁻¹ cm⁻², low detection limit of 0.425 μM (S/N = 3), and wide linear range (1–1200 μM).     

Investigation of Performances and Mechanism of Fluoride Removal by Fe（Ⅲ）-Loaded Ligand Exchange Cotton Cellulose Adsorbent

0Introduction Highconcentrationoffluorideoccurrednaturallyingroundwaterthroughoutmanypartsoftheworldduetoitsnaturalpresenceintheearthcrustordischargebyagri cultureorindustryactivities.Long termingestionofhighflu oridedrinkingwatercausedserioustoxiceffectsandaffectedmanypeoplearoundworld.In1993,25millionpeoplein15ofIndia’s32stateswereidentifiedasendemicforfluorosis[1].InMexico,5millionpeople(about6%ofthepopulation)wereaffectedbyfluorideingroundwater[2].Fluorosiswas alsothreateningsomepartsof…     

Morphology characterization of periclase–hercynite refractories by reaction sintering

A periclase?hercynite brick was prepared via reaction sintering at 1600°C for 6 h in air using magnesia and reaction-sintered hercynite as raw materials. The microstructure development of the periclase?hercynite brick during sintering was investigated using X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. The results show that during sintering, Fe2+, Fe3+ and Al3+ ions in hercynite crystals migrate and react with periclase to form(Mg1-xFex)(Fe2-yAly)O4 spinel with a high Fe/Al ratio. Meanwhile, Mg2+ in periclase crystals migrates into hercynite crystals and occupies the oxygen tetrahedron vacancies. This Mg2+ migration leads to the formation of(Mg1-uFeu)(Fe2-vAlv)O4 spinel with a lower Fe/Al ratio and results in Al3+ remaining in hercynite crystals. Cation diffusion between periclase and hercynite crystals promotes the sintering process and results in the formation of a microporous structure.     

Investigation of the kinetic mechanism of the demanganization reaction between carbon-saturated liquid iron and CaF_2–CaO–SiO_2-based slags

The demanganization reaction kinetics of carbon-saturated liquid iron with an eight-component slag consisting of CaO–SiO_2–MgO–FeO–MnO–Al_2O_3–TiO_2–CaF_2 was investigated at 1553, 1623, and 1673 K in this study. The rate-controlling step(RCS) for the demanganization reaction with regard to the hot metal pretreatment conditions was studied via kinetics analysis based on the fundamental equation of heterogeneous reaction kinetics. From the temperature dependence of the mass transfer coefficient of a transition-metal oxide(Mn O), the apparent activation energy of the demanganization reaction was estimated to be 189.46 k J·mol~(–1) in the current study, which indicated that the mass transfer of Mn O in the molten slag controlled the overall rate of the demanganization reaction. The calculated apparent activation energy was slightly lower than the values reported in the literature for mass transfer in a slag phase. This difference was attributed to an increase in the specific reaction interface(SRI) value, either as a result of turbulence at the reaction interface or a decrease of the absolute amount of slag phase during sampling, and to the addition of calcium fluoride to the slag.     

Prediction of Cancer-Associated piRNA–mRNA and piRNA–lncRNA Interactions by Integrated Analysis of Expression and Sequence Data

piwi-interactingRNAs(piRNAs) are valuable biomarkers, but functional studies are still very limited.Recent research shows that piRNA-mediated cleavage acts on Transposable Elements(TEs), messengerRNAs(mRNAs), and long non-codingRNAs(lncRNAs). This study aimed to predict cancer-associated piRNA-mRNA and piRNA-lncRNA interactions as well as piRNA regulatory functions. Four cancer types(BRCA, HNSC, KIRC,and LUAD) were investigated. Interactions were identified by integrated analysis of the expression and sequence data. For the expression analysis, only piRNA–mRNA and piRNA–lncRNA pairs with expression profiles that were significantly inversely correlated were retained to reduce false-positive rates during the prediction. For the sequence analysis, miRanda was used for the target prediction. We identified 198 piRNA–mRNA and 10 piRNA–lncRNA pairs. Unlike mRNA and lncRNA expressions, the piRNA expression was relatively consistent across the cancer types. Furthermore, the identified piRNAs were consistent with previously published cancer biomarkers, such as piRNA-36741, piR-21032, and piRNA-57125. More importantly, predicted piRNA functions were determined by constructing an interaction network, and piRNA targets were placed in gene ontology categories related to the cancer hallmarks activating invasion and metastasis and sustained angiogenesis.     

Observation of Pt-{100}-p(2×2)-O reconstruction by an environmental TEM

The surface structure of noble metal nanoparticles usually plays a crucial role during the catalytic process in the fields of energy and environment. It has been studied extensively by surface analytic methods, such as scanning tunneling microscopy. However, it is still challenging to secure a direct observation of the structural evolution of surfaces of nanocatalysts in reaction(gas and heating) conditions at the atomic scale. Here we report an in-situ observation of atomic reconstruction on Pt {100} surfaces exposed to oxygen in an environmental transmission electron microscope(TEM). Our high-resolution TEM images revealed that Pt-{100}-p(2×2)-O reconstruction occurs during the reaction between oxygen atoms and{100} facets. A reconstruction model was proposed, and TEM images simulated according to this model with different defocus values match the experimental results well.     

Synthesis of a NiTi_2–AlNi–Al_2O_3 nanocomposite by mechanical alloying and heat treatment of Al–TiO_2–NiO

The aim of the present study was to investigate the phases formed during ball milling of Al–TiO_2–NiO. For this purpose, a mixture of Al–TiO_2–NiO with a molar ratio of 6:1:1 was used. Characterization of the milled powders by X-ray diffraction, differential thermal analysis, field-emission scanning electron microscopy, and transmission electron microscopy showed the formation of nanocrystalline NiTi_2 along with AlNi. A thermodynamical investigation confirmed that NiO was reduced by Al during ball milling, which consequently promoted TiO_2 reduction and the formation of NiTi_2. Al is capable of reducing NiO either during ball milling or at temperatures above the melting point of Al; by contrast, TiO_2 can be reduced by Al only by milling.     

Extraction of penicillin G by aqueous two-phase system of [Bmim]BF4/NaH2PO4

A novel approach for the extraction of penicillin G by aqueous two-phase system comprised of hydrophilic ionic liquid [Bmim]BF4 （1-butyl-3-methylimidazolium tetrafluoroborate） and NaH2PO4 is reported. The effects of some important parameters involving the concentration of NaH2PO4, the concentration of penicillin G, the amount of [Bmim]BF4 on the formation of aqueous two-phase system and the extraction yield of penicillin were investigated. The primary result shows that the ATPS can take advantage of penicillin concentrated in upper phase at higher pH value for penicillin extraction from its aqueous solution without emulsification.