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High-volumetric-energy-density lithium-ion batteries require anode material with a suitable redox potential, a small surface area, and facile kinetics at both single-particle and electrode level. Here a family of coarse-grained molybdenum substituted titanium niobium oxides Mo[subscript x]Ti[subscript 1−x]Nb[subscript 2]O[subscript 7+y] (single crystals with 1~2 μm size) underwent hydrogen reduction treatment to improve electronic conduction was synthesized, which is able to stably deliver a capacity of 158.5 mAh g[superscript −1] at 6,000 mA g[superscript −1] (65.2 % retention with respect to its capacity at 100 mA g[superscript −1] ) and 175 mAh g[superscript −1] (73 % capacity retention over 500 cycles) at 2,000 mA g[superscript −1], respectively. Via careful in situ electrochemical characterizations, we identified the kinetic bottleneck that limits their high-rate applications to be mainly ohmic loss at the electrode level (which mostly concerns electron transport in the composite electrodes) rather than non-ohmic loss (which mostly concerns Li+ lattice diffusion within individual particles). Such a kinetic problem was efficiently relieved by simple treatments of Mo substitution and gas-phase reduction, which enable full cells with high electrode density, and high volumetric energy/power densities. Our work highlights the importance of diagnosis, so that modifications could be made specifically to improve full-cell performance.

Thermal decomposition of 1-hexene at temperatures 295-1410 K was conducted using a flash pyrolysis micro-reactor coupled to laser-based vacuum ultraviolet photoionization time-of-flight mass spectrometer (VUV-PI-TOFMS). The decomposition mechanism of 1-hexene was developed with the help of theoretical calculation performed at the MRCI/cc-pvtz//CASSCF/6–31+G(d,p) level. The γ-scission and diradical retro-ene reactions were determined as the main initial decomposition reactions in the temperature range 990-1240 K. Two diradical retro-ene reaction channels, 1,5-diradical and 1,6-diradical reactions, were proposed in order to interpret the appearance of the C4H8 species. The 1,5-diradical retro-ene reaction involved a 1,5-diradical intermediate that subsequently decomposed via C C β-scissions to the C2, C3 and C4 products. The 1,6-diradical retro-ene reaction proceeded via a 1,6-diradical intermediate and C C β-scissions to produce the C2 and C4 species. The proposed diradical retro-ene mechanism was evidenced indirectly by the early product distribution of 1-hexene pyrolysis in a flow reactor at 1173 K determined by synchrotron radiation VUV-PI-TOFMS. It was verified in the flash pyrolysis of 1-heptene as well.

International audience; Poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) diblock copolymers with different compositions were synthesized by ring-opening polymerization of D,L-lactide and glycolide, using monomethoxy PEG as macro-initiator. The resulting copolymers were characterized by nuclear magnetic resonance, gel permeation chromatography, and critical micelle concentration analyses. Self-assembly of the copolymers yielded aggregates of different architectures, including spherical micelles and a mixture of spherical and worm-like micelles with Y-junctions. The self-assembled architecture depends on both the hydrophilic/hydrophobic balance and the molar mass of copolymers. Valsartan, a widely used drug in the treatment of hypertension, was loaded in micelles using a co-solvent evaporation method. High drug-loading content was obtained for worm-like micelles. in vitro drug release was performed at 37°C in pH 7.4 phosphate-buffered saline. An initial burst release is detected in all cases, followed by slower release up to 9 days. The overall release rate is strongly dependent on the degradation of micelles. Copolymers with short PLGA blocks exhibit faster drug release due to faster degradation of micelles, and worm-like micelles present slower drug release as compared to spherical ones. Therefore, PLGA-PEG copolymer micelles with high drug-loading capacity, different architectures, and variable drug release rates could be most attractive for sustained delivery of valsartan.

This paper proposes a special capacitive wireless power transfer (CPT) system with the aluminum foil-based coupling coupler. The aluminum foil is much thinner and lighter than the general metal plates. What's more, it is flexible, cheap, and convenient. Compared with the general coupling capacitor, which is consisted of metal plates, the thickness of aluminum foil coupling capacitor is much thinner. The shape of aluminum foil could be easily built and changed according to the application requirements. This CPT system could be used for the flexible Organic Light-Emitting Diode (OLED) based electronic products. An experimental CPT system is built to demonstrate the theoretical analysis. The experimental results show that the proposed CPT system could work with the air dielectric. The stable load voltage could be achieved, and the 5 W LED lamp is lighted by the proposed CPT system. As a result, the power could be wirelessly transferred by the aluminum foil-based coupling coupler. The theory and design of proposed CPT system are verified by the experimental results. This paper provides opportunities on design and manufacture of CPT system that can solve challenging technological problems for future electronic device applications.

Mechanism of the initial reactions of chlorine trifluoride oxide (ClF3O) and aluminum based composite fuel was investigated using density functional theory (DFT) at B3PW91/6–311++G (d,p) level and experimental methods. The composite fuel mainly contained isopropyl nitrate (IPN), hexogen (RDX), ammonium perchlorate (AP), n-decane, paraffin and aluminum powder. The results showed that ClF3O reacted exothermically with IPN, RDX, and hydrocarbons (n-decane and paraffin) via electrophilic substitution. The equatorial F atom was the reactive site of ClF3O. The reactive sites of IPN, RDX and hydrocarbon were different C H bonds according to the results of dual descriptor index. Reactivity of the composite fuel components was in the sequence of n-decane ≈ paraffin > RDX > IPN » AP according to the energy barriers. The value of released energy from the reaction of ClF3O with n-decane was greater than 400 kJ/mol, resulting in thermal decomposition of the composite fuel. The results from XPS indicated that the composite fuel was wrapped by hydrocarbons. ClF3O reacted with hydrocarbon first and then initialized the combustion of the composite fuel in the presence of oxygen. The emission spectrum of the composite fuel combustion was studied using an intensified CCD camera. Five characteristic radical intermediates (CH, C2, OH, NO and AlO) were determined.

Thermal decomposition of cyclohexane at temperatures up to 1310 K was performed using flash pyrolysis coupled with vacuum ultraviolet (118.2 nm) photoionization time-of-flight mass spectrometry. The experimental results revealed that the major initiation reaction of cyclohexane decomposition was C–C bond fission leading to the formation of 1,6-hexyl diradical. The 1,6-hexyl diradical could isomerize to 1-hexene and decompose into ˙C3H7 + ˙C3H5 and ˙C4H7 + ˙C2H5. The 1,6-hexyl diradical could also undergo direct dissociation; the C4H8 fragment via the 1,4-butyl diradical intermediate was observed, serving as evidence of the 1,6-hexyl diradical mechanism. Quantum chemistry calculations at UCCSD(T)/cc-pVDZ level of theory on the initial reaction pathways of cyclohexane were performed and found to be consistent with the experimental conclusions. Cyclohexyl radical was not observed as an initial intermediate in the pyrolysis. Benzene was produced from sequential H2 eliminations of cyclohexane at high temperatures.

High-resolution thermal and magnetic vector gradient imaging is demonstrated using diamond quantum sensors in a microstructured fiber probe platform. These sensors are capable of in situ magnetic field and temperature measurements with 160 pT / Hz and 25 mK / Hz sensitivities.

All-optical thermometry presents a promising avenue of investigation for sensitive biological and electronic systems, with methods free of radio-frequency interference of particular importance. In this work, an all-optical scanning fiber thermometer is tested and shown to possess $5\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{m}$ spatial and $20\phantom{\rule{0.2em}{0ex}}\mathrm{mK}/\sqrt{\mathrm{Hz}}$ temperature resolution. This probe is then used to generate noncontact scanning thermal images of active circuit elements with microscale thermal features.

Here, we report on the effect of different antisolvent dripping on film morphology and charge recombination of mixed formamidinium–methylammonium tin iodide (FA0.75MA0.25SnI3) as a light absorber in perovskite solar cells. N,N-dimethyl methanamide (DMF) and dimethyl sulfoxide (DMSO) were used as the mixed solvent in the perovskite precursors together with tin fluoride (SnF2) as an additive. Diethyl ether (DE), toluene (TL), and chlorobenzene (CB) were employed as antisolvents for comparison. Our results show that CB as an antisolvent leads to a dense and uniform Sn-based perovskite film. The maximum power conversion efficiency of our Sn-based perovskite solar cell achieves 9.06% (9.02%) under forward (reverse) voltage scan under AM 1.5G 100 mW/cm2 illumination. The encapsulated cells show good long-term stability with ∼75% of their initial efficiency retained over a period of 30 days of storage. Our work suggests the promising potential to further improve the performance of Pb-free Sn-based perovskite sol...

The mechanism of the reactions of ClF3O and n-decane had two stages. The first stage was the initial reaction between ClF3O and n-decane. The initial reactions were investigated using a density functional theory (DFT) method. The results showed that the critical part of the mechanism of the initial reaction was the roaming of the HF intermediate. A H atom on n-decane was abstracted by a F atom on ClF3O to produce HF. The formed HF roamed around and then broke to give ClFO, fluorinated decane and a new HF molecule. The initial reactions were considered to be barrier-less reactions and extremely exothermic. The average released energy of the initial reactions was 412.9 kJ mol−1, which was great enough to cause thermal decomposition of n-decane. The second stage included the reaction between ClFO and n-decane and the thermal decomposition of n-decane. The secondary reactions involving ClFO were also studied using a DFT method. ClFO was less reactive than ClF3O. The average energy barrier of the reactions of ClFO and n-decane was 116.3 kJ mol−1 and the average released energy was 266.5 kJ mol−1. Thermal decomposition of n-decane was evidenced by the emission spectra of the characteristic radical intermediates CH and C2, which were observed using an intensified charge-coupled device (ICCD) system. The main gaseous products of the thermal decomposition of n-decane, as identified using gas chromatography, were hydrogen, ethylene and acetylene. The experimental results showed that the thermal decomposition of n-decane was an important secondary reaction following the initial reactions.

Steel strip winding reinforced composite pipe (SSRCP) is often used for oil and gas transportation in shallow sea. Its hysteresis characteristics under the action of low cycle load can effectively absorb external energy, which is beneficial to ensure the stability of marine structures such as ships and drilling platforms. In this paper, considering the nonlinear contact between layers, a finite element model is established to analyze the nonlinear hysteretic characteristics of SSRCP under cyclic bending load. Based on the Bouc-Wen (BW) model, an improved BW model was proposed to describe the hysteretic properties of SSRCP by introducing asymmetric factor and intensity enhancement factor. The hysteretic energy dissipation was regarded as the parameter to be identified, and the model was divided into 4 sections according to the loading law to reduce the difficulty of solving equations. Based on simulation data, PSO, GA and SA (Particle Swarm Optimization, Genetic Algorithm, and Simulated Annealing) stochastic intelligent optimization algorithm was used to identify the parameters of the improved BW model. The results show that the PSO algorithm has high calculation accuracy and efficiency, and the improved BW model can accurately describe the hysteresis characteristics of SSRCP under cyclic bending load.

The nozzle opening pressure of fuel injection systems affects the initial fuel atomization, the fuel injection quantity, the emission characteristics and the operation stability of diesel engines. This paper presents an investigation on the dynamic characteristics of the nozzle opening pressure for a double-solenoid-valve fuel injection system. A numerical model for the nozzle opening pressure based on the fluid–structure interaction theory is established, including the models for the physical properties of the fuel, the leakage rate of the piston pair and the elastic deformation of the piston chamber and the piston pair. Also, experiments were carried out to validate the proposed model. Good agreement was found between the simulated results and the measured results. Based on this model, the effects of some factors on the nozzle opening pressure are analysed. The results show that the rotational speed of the cam, the initial clearance of the piston pair and the sealing length of the piston pair have slight effects on the nozzle opening pressure but that the diameter of the piston, the initial fuel temperature and the residual volume greatly influence the nozzle opening pressure.

This paper presents an investigation combining both experiment and simulation on the sole impacts of the injection pressure p in on the inner cavitation process, and the effects of the cavitation on the flow capacity of the nozzle. An optical nozzle is designed based on the similarity principle of amplification in an equal proportion, and both the structure and the cavitation number are similar to the baseline nozzle. A numerical model is built to analyse the details of the inner flow. The results show that cavitation occurs as p in increases, and a bubble ring forms. The total flow process is divided into three periods: the no-cavitation, the cavitation developing and the stable cavitation periods. During the no-cavitation period, no bubbles occur, and the discharge coefficient C d is a constant and determined by the nozzle structure. During the cavitation developing period, when p in rises, the area of the bubble ring increases, but C d decreases and is governed by f the cavitation number CN and the cavitation area coefficient K A . During the stable cavitation period, at the inlet the bubble ring reaches the maximum then becomes stable; C d is determined only by CN , and infinitely close to a constant as p in increases.

Although titanium complex grease has captured wide attention, limited studies were carried out to develop an effective lubricant specifically for extreme operational applications. In this study, terephthalic acid-based titanium complex grease was synthesized. The effects of ceria oxide (CeO2) nanoparticles and sulfurized isobutene (SIB) on the tribological performance of titanium complex grease were investigated using a four-ball tribometer. It was found that because of a synergistic effect of SIB and CeO2 nanoparticles on titanium complex grease, the tribological properties were significantly improved. This study provides a promising lubricant for extreme pressure applications.

High-resolution imaging of molecules intrinsically involved in malignancy and metastasis would be of great value for clinical detection and staging of tumors. Based on the selective cell-penetrating ability in the tumor sites of the activatable cell-penetrating peptide (ACPP), the superparamagnetic Fe3O4–silica composite nanoparticles (SSCNs) coated with Au nanoshells (AuNSs) were prepared and subsequently surface-modified with polyethylene glycol (PEG) conjugated an ACPP to form SSCNs@AuNSs-PEG-ACPP nanoparticles for realizing tumor site-specific multimode bioimaging and photothermal therapy. SSCNs@AuNSs-PEG-ACPP nanoparticles showed high photothermal efficiency, X-ray attenuation property and T2 relaxation rate, which were confirmed by a series of characterizations in vitro and in vivo. The enhanced accumulation of SSCNs@AuNSs-PEG-ACPP nanoparticles in the tumor was investigated by the in vivo X-ray computed tomography (CT) imaging and magnetic resonance (MR) imaging. SSCNs@AuNSs-PEG-ACPP nanoparticles will be likely to realize simultaneous CT/MR bioimaging and photothermal therapy on the tumor by the combination of superparamagnetization, X-ray attenuation property, near-infrared (NIR) absorption and tumor-selected accumulation.

Although lubricating greases with zinc dialkyl-dithiophates (ZDDP) have been used widely, the influence of ZDDP on the rheological properties of lithium–calcium-based greases (LCBG) has not been reported. This work investigated the effects of ZDDP on the rheology and mechanical stability of lithium–calcium-based greases (LCBG) by means of scanning electron microscopic (SEM) analysis, rheology characterization and roll stability test. It was found that the thickener's base grease fiber containing ZDDP becomes looser, and the effects of ZDDP on low-alkali LCBG are greater than that on low-acid LCBG. Thereby, the values of the viscoelastic functions in the linear viscoelastic region, the shear stress and mechanical stability of LCBG decrease with the increase in ZDDP concentration. Due to the fibrous instability of the thickener above 60 °C, considerable shortening of the thickener's fibers and increasing penetration values after shearing of the grease in a roll stability tester at 75 °C, as well as transformation from shear thinning to shear thickening at the shear rate of 1800 s−1 and 80 °C, were observed. The maximum recommended ZDDP concentrations related to mechanical stability and resistance under working conditions are below 4 wt% for low-alkali grease and 5 wt% for low-acid grease. Additionally, the saturated adsorption of 3 wt% ZDDP on the soap fibers can lead to sufficient ZDDP migration to the polar metallic surface, which indicates the optimized tribological effect of ZDDP on LCBG. This study provides a promising formulation range of around 3% to 5 wt% ZDDP in low-acid grease.

Tin oxide (SnO2) with high specific capacity and excellent safety performance has become potential candidate for next generation lithium-ion batteries (LIBs). However, the practical application of SnO2 is hindered by large volume change and particle aggregation. Herein, a type of three-dimensional (3D) hierarchical porous titanium-based microclews composed of one-dimensional (1D) titanium dioxide (TiO2) nanoribbons and SnO2 nanoparicles, is synthesized for the first time with the assistance of cationic surfactant, cetyltrimethylammonium bromidewere (CTAB). SnO2 nanoparticles distribute uniformly on the nanoribbons, and CTAB as growth controller plays a key role in the formation of the uniform and stable hierarchical-structure. The as-synthesized CTAB assisted hierarchical-structure TiO2@SnO2 microclews (CA–TiO2@SnO2 MCs) elelctrode demonstrates outstanding ionic conductivity due to the structure assisting efficient contact between electrode and electrolyte, with a remarkable discharge capacity of 448.3 mAh g−1 after cycling for 500 times at a current density of 500 mA g−1, and a capacity retention of 558.8 mAh g−1 at 200 mA g−1 after 400 cycles in LIBs.

The thermal decomposition of tetramethylsilane (TMS) was studied over the temperature range of 298-1450 K by combining flash pyrolysis vacuum ultraviolet photoionization time-of-flight mass spectrometry (VUV-PI-TOFMS) and density functional theory (DFT). The initial step in TMS pyrolysis produced a methyl radical (Me˙) and Me3Si˙. Me3Si˙ underwent subsequent loss of a hydrogen atom to form Me2Si[double bond, length as m-dash]CH2 and loss of a methyl radical to form Me2Si:. Isomerizations via 1,2-shift and H2 eliminations were major secondary decomposition reactions of Me2Si[double bond, length as m-dash]CH2 and Me2Si:. Among the various isomers, silylene species containing Si-H bonds, such as :Si(H)CH2CH2CH3, :Si(H)CH2CH[double bond, length as m-dash]CH2, :Si(H)CH2CH3, and :Si(H)CH[double bond, length as m-dash]CH2, played an important role in H2 elimination reactions. On the other hand, silene species were insignificant in H2 eliminations. Unlike the silylene species, H2 elimination of :Si[double bond, length as m-dash]CH2 was energetically unfavorable.

The micro-arc oxidation (MAO) process of 2A70 aluminum alloy in different electrolytes containing silicate or phosphate by two-step oxidation was investigated. The growth rate, surface roughness and element distributions of the micro-arc oxidation coatings were characterized. The results show that the coating growth patterns are different in Si and P electrolytes although they both grow inward. The discharge channels formed in Si-electrolyte and P-electrolyte are trumpet-shaped and dumbbell-shaped, respectively. The trumpet-shaped channel is conducive to gather heat and extend the reaction area inward, which leads to a layer growth pattern in P-electrolyte. The dumbbell-shaped channel limits the reactive area but introduces more electrolytes during the cooling process, which results in an island growth pattern in Si-electrolyte. Therefore, a newly formed P-rich layer can be observed between substrate and initially formed Si-rich layer after the second-step oxidation in P-electrolyte, but only localized Si-rich areas could be found when the second-step oxidation was performed in Si-electrolyte.

The electrochemical oxidation of p-nitrophenol (p-Np) has been studied on glassy carbon electrode modified with the single-walled carbon nanotubes/silver nanowires hybrids (SWNTs-Ag) by using cyclic and differential pulse voltammetry. p-Np is irreversibly oxidized at +0.88 V (vs. the Ag/AgCl) in PBS solutions of pH 7.4. The modified electrodes display the detection sensitivity of 0.0212 µA/µM with an unusually wide linear response of 5-1700 µM (R2 = 0.998) and the detection limit of 1 µM. The current response of SWNTs-Ag modified electrode to p-Np is better than that of SWNTs or Ag nanowires modified electrode under the same concentration. Combining the adsorption ability of SWNTs and the conductivity of SWNTs and Ag nanowires, the detection performance of SWNTs-Ag modified electrode to p-Np was greatly improved.

The fabrication of superhydrophobic surfaces and the studies on water flow characteristics therein are of great significance to many industrial areas as well as to science and technology development. Experiments were carried out to investigate slip characteristics of water flowing in circular superhydrophobic microtubes within laminar flow region. The superhydrophobic microtubes of stainless steel were fabricated with chemical etching–fluorination treatment. An experimental setup was designed to measure the pressure drop as function of water flow rate. For comparison, superhydrophilic tubes were also tested. Poiseuille number Po was found to be smaller for the superhydrophobic microtubes than that for superhydrophilic ones. The pressure drop reduction ranges from 8% to 31%. It decreases with increasing Reynolds number when Re Re after Re > 900. The slip length in superhydrophobic microtubes also exhibits a Reynolds number dependence similarly to the pressure drop reduction. The relation between slip length and Darcy friction factor is theoretically analyzed with consideration of surface roughness effect, which was testified with the experimental results.

A two-step oxidation method was explored to study the growth mechanism of micro-arc oxidation (MAO) coating. 2A70 aluminum alloy specimens were oxidized in silicious electrolyte in the first step; then the specimens with the as-oxidized MAO coating were transferred into the phosphatic electrolyte for further oxidation in the second step. Distributions of elements in MAO coatings were investigated by energy dispersion X-ray spectrometry (EDS). The results showed that P and Si were layered in the MAO coating. The newly formed coating, P-rich layer, formed in the second step was located under the layer formed in the first step, which increased the coating's thickness. Discharge channels can be found in MAO coating by the distribution of P, which connect substrate and the outside of coating. The inner newly formed P-rich layer increased its thickness as the oxidation time increased. These results give some direct experimental evidences for the inward growth mechanism of MAO coatings and indicate that discharge channels are the main ways to form the new coating which lead to the inward growth of MAO coating.

More and more ultra-high voltage (UHV) transmission linewillbe builtin China, and the design of external insulation is critical for the safe operation of UHV transmission line. Air relative humidity (RH) and temperature can affect its permittivity and electric field around the transmission line, hence in the paper the numerical relationship between the electric field, air permittivity and air temperature, RH is investigated by field measurement test and numerical analysis. Firstly the measurement tests are setup to measure electric field strength and atmospheric parameters, in which the electric field, air temperature and RH at same measuring point are measured repeatedly on different days. Then scatter plots are used to reflect the relationship between field strength and temperature along with relative humidity intuitively, and correlation analysis is conducted on the measurement data. Finally the numerical model for the electric field and air RH & temperature, numerical model for the air permittivity and air RH & temperature are obtained. The results provide reference for UHV external insulation design to improve their operation stability and performance.

Hierarchical alveolate structures of micro-nano scale were prepared on stainless steel substrates with chemical etching. Fine papillae stand on protuberances are found. After fluorination treatments, the surfaces exhibit super-hydrophobic properties, with water contact angles of 163°. Stainless-steel micro-tubes with super-hydrophilic and super-hydrophobic surface were fabricated with chemical etching and chemical etching-fluorination treatment respectively. The effect of surface wettability on the fluid flow in micro-tubes was investigated with water as the working fluid. The experimental setup was designed in such a way that the investigation of the pressure drop and friction factor was possible. It is found that friction factor in super-hydrophilic micro-tube is in good agreement with Hagen-Poiseuille theory at low Reynolds number (Re

In recent years, considerable efforts have been made for the development of multifunctional nanoparticles with diagnosis and therapy functions. To achieve enhanced CT imaging and photothermal therapy on the tumor, we employed iodinated nanoparticles as template to construct Au nanoshell structure and demonstrated a facile but effective approach to synthesize biocompatible and well-dispersed multifunctional nanoparticles by coating iodinated nanoparticles with Au nanoshell and subsequent surface modification by hyaluronic acid. The resultant poly(2-methacryl(3-amide-2,4,6-triiodobenzoic acid))/polyethylenimine/Au nanoshell/hyaluronic acid (PMATIB/PEI/Au nanoshell/HA) nanoparticles had relatively high X-ray attenuation coefficient and photothermal efficiency. After intravenous injection into MCF-7 tumor-bearing mice, PMATIB/PEI/Au nanoshell/HA nanoparticles were efficiently accumulated in the tumor, remarkably enhanced the tumor CT imaging, and selectively ablated the tumor through the thermal treatment of lesions under the NIR irradiation. Thus, PMATIB/PEI/Au nanoshell/HA nanoparticles displayed a great potential for CT diagnosis and CT-guided, focused photothermal tumor therapy.

Guano-caused surface flashover of insulators seriously threatens safety and stability of power system. Antiguano surface flashover plays an important role in antipollution flashover of insulators. In this paper, a super-hydrophobic surface(SHPs) is prepared by a simple method. The wettability and morphology are respectively investigated by a contact angle meter(CAM) and a field emission scanning electron microscope(FE-SEM). Sliding performances of guano on glass surface(Gs), silicone rubber surface(SRs) and SHPs are compared, reasons of guano-sliding differences on the three kinds of surfaces are analysed. The results show that: the as-prepared surface achieved excellent super-hydrophobic performance. The amount of guano residue on these surfaces decreases gradually, and sliding velocity of guano droplet increases gradually as the angle between tested surface and horizontal plane increases. Greatly reduced guano residue are found on SHPs compared with Gs and SRs, and sliding velocity of guano droplet increases a lot. When the angle between tested surface and horizontal plane is 70°, the amount of guano residue on SHPs accounts for 0.35%, and 1.1% of that on the Gs and SRs respectively. Sliding velocity of guano droplet on SHPs is respectively 6 and 2.17 times faster than that on the Gs and SRs. The as-prepared SHPs plays good anti-guano performance.

Among the many possible device configurations for organic memory devices, organic field-effect transistor (OFET) memory is an emerging technology with the potential to realize lightweight, low-cost, flexible charge storage media. In this feature article, the recent progress in the classes of OFET-based memory, including floating gate OFET memory, polymer electret OFET memory, ferroelectric OFET memory and several other kinds of OFET memories with unique configurations, are introduced. Finally, the prospects and problems of OFETs memory are discussed.

Organic field-effect transistors (OFETs) have received significant research interest because of their promising applications in low cast, lager area, plastic circuits, and tremendous progress has been made in materials, device performance, OFETs based circuits in recent years. In this article we introduce the advances in organic semiconductor materials, OFETs based integrating techniques, and in particular highlight the recent progress. Finally, the prospects and problems of OFETs are discussed.

In this paper, the reproducible nonpolar resistive switching is demonstrated in devices with the sandwiched structure of Au/poly(3,4-ethylene-dioxythiophene): polystyrenesulfonate/Au for nonvolatile memory application. The switching between high resistance state (OFF-state) and low resistance state (ON-state) does not depend on the polarity of the applied voltage bias, which is different from both the WORM characteristics and the bipolar switching characteristics reported before. The resistive ratio between the ON- and OFF-state is on the order of 103 and increases with the device area decreasing. Both the ON- and OFF-state of the memory devices are stable, showing no significant degradation over 104 s under continuous readout testing. It is proposed that the reduction and oxidation of PEDOT: PSS film might be the switching mechanism.

Pentacene organic field effect transistors with a series of sub-micrometer channel have been fabricated and characterized. Source and drain metal electrodes was made by electron-beam lithography and lift-off process. Image reversal photo resist was used to make integrated mask to pattern the organic semiconductor film to reduce the off-state current. And thiol treatment was applied on gold electrodes to modify their surface energy and improve the charge carrier injection. All the devices can behavior as typical p-type transistor, and have obvious saturation. Using electrode and dielectric surface treatment, device performances have significant improvement. All of the performances, including mobility, threshold voltage and on/off current ratio will change with the channel length decreasing because of the low quality interface between the OSC and dielectrics.

We fabricated high performance organic field-effect transistors with novel hybrid electrode-semiconductor contact geometry. The HC OFETs contain both the top electrodes and the bottom electrodes in a single transistor simultaneously. The bottom electrodes induce an ordering CuPc film during the active layer depositing. Due to a high order CuPc layers and low total device resistance, as well as little charge effect below the top electrodes, OFETs with the hybrid contact geometry exhibit a higher performance. With convenience of the new structure, the contact resistance between the two traditional contact geometries was studied in one single transistor.

This paper reports on the application of a bilayer polymethylmethacrylate (PMMA)/ZrO2 dielectric in copper ph-thalocyanine (CuPc) organic field-effect transistors (OFETs). By depositing a PMMA layer on ZrO2, the leakage of the dielectric is reduced by one order of magnitude compared to single- layer ZrO2. A high-quality interface is obtained between the organic semiconductor and the combined insulators. By integrating the advantages of polymer and high-fe dielectrics, the device achieves both high mobility and low threshold voltage. The typical field-effect mobility, threshold voltage, on/off current ratio, and subthreshold slope of OFETs with bilayer dielectric are 5.6 times 10-2 cm2/V ldr s, 0.8 V, 1.2 times 103, and 2.1 V/dec, respectively. By using the bilayer dielectrics, the hysteresis observed in the devices with single-layer ZrO2 is no longer present.

Polytetrafluoroethylene-polyphenylene sulfide composite coating mesh film was successfully prepared by a simple layered transitional spray-plasticizing method on a stainless steel mesh. It shows super-hydrophobic and super-oleophilic properties. The contact angle of this mesh film is 156.3° for water, and close to 0° for diesel oil and kerosene. The contact angle hysteresis of water on the mesh film is 4.3°. The adhesive force between the film and substrate is grade 0, the flexibility is 1 mm and the pencil hardness is 4H. An oil-water separation test was carried out for oil-contaminated water in a six-stage superhydrophobic film separator. The oil removal rate can reach about 99%.

The compatibility, stability and the pyrolysis behavior of aluminum based solid-liquid compound fuel were systematically investigated by thermogravimetric analysis (TGA). The compound fuel lost its 30% weight before the temperature rose to 150°C. AP decomposed at 210°C and lead to 50% weight loss. The reaction between aluminum and oxygen was accelerated at 660°C since the melting of solid combustible agent. The total weight loss after 1000°C pyrolysis is about 80% for nitrogen atmosphere. On the contrary, the total weight loss for oxygen atmosphere is approximate 70% because of the generation of aluminum oxide. The microscopic structures and the elementary composition of the pyrolysis products were analyzed using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The structures of the products after 200°C pyrolysis are spherical and flaky. All these structures are destroyed after 1000°C pyrolysis. Instead, massive structures were found in the products. Aluminum is the main element in the final pyrolysis products for all conditions. The second-most element in the product for nitrogen atmosphere is carbon. Carbon deposited accompany with the decomposition of paraffin or other organic components. The second-most element in the product for oxygen atmosphere is oxygen. This conclusion is attributed to the formation of aluminum oxide.

In this letter, the effect of the interface on the electrical characteristics of a rectifier based on an organic diode with pentacene as the electroactive layer is studied. It was found that the on/off ratio had a strong correlation with the interface effect (i.e., the bottom electrode material). The rectification ratio was improved to 2 × 106 at 5 V by modifying the bottom electrode with copper tetracyanoquinodimethane. The ac rectification frequency exceeded 13.56 MHz, which is a main requirement for an organic radio-frequency identification application.

Mesoporous aluminum oxide with high specific surface area is synthesized using aluminum alkoxide and tartaric acid. It was found that the average pore size increases with increasing amount of tartaric acid. Moreover, the mesoporous structure is thermally stable up to 1273 K, indicating potential application as catalyst supports.

The authors have investigated the effect of a metal coating--copper--on the tetragonal structure of fine barium titanate (BaTiO{sub 3}) particles. The BaTiO{sub 3} particles were synthesized by a sol-gel method and heat treated at temperatures >900 C for various amounts of time before coating. The copper coating was achieved by an electroless coating technique. The transmission electron microscopy micrographs revealed that the coated powder contained fine BaTiO{sub 3} particles that were embedded in copper patches. The X-ray diffractometry patterns showed that the copper coating increased the c/a ratio of the fine BaTiO{sub 3} particles. For powders that were heat treated at 900 C for 10 h and were initially cubic, the copper coating changed the c/a ratio, from 1 to 1.0034. For powders that were calcined at 900 C for 20 h and were initially tetragonal, the copper coating further enhanced the c/a ratio, from 1.0028 to 1.0043. When the copper-coated BaTiO{sub 3} particles were oxidized, the c/a ratio was reduced to a value that was approximately equal to or below that of the uncoated powders. A conductive coating can eliminate the depolarization energy of an insulating polar particle. The fact that the copper coating promoted the polar tetragonal phasemore » but the nonconductive copper-oxide coating did not was consistent with the interpretation that the presence of the cubic phase (nonpolar) in small BaTiO{sub 3} particles was caused by the depolarization effect.« less

UVC upconversion emission is observed in a LiYFsub4/sub:Prsup3+/supmicrocrystal under sunlight excitation. The dependence of UVC UC emission intensity on the excitation density of a 488 nm laser and sunlight is investigated. The obtained data indicates that two-photon processes play an important role in UVC UC emission. The UVC UC mechanisms of Prsup3+/supunder the excitation of a laser and sunlight are presented and discussed. The UVC emission under sunlight excitation has broad prospects for application.

This paper presents an improved self-consistent, multi-component and two-dimensional plasma hybrid model for the simulation of DC positive corona discharge under atmospheric environment. The model is based on the plasma hydrodynamics and the chemical modles, it includes 12 species and 27 reactions. Besides, the photoionization effect is also considered in the proposed model. Based on this model, the volume of dynamics charged species generation, the discharge current waveform, electron temperature, and electric field variations are investigated in details. The results indicate that the model provides valuable insights to the physics of air corona discharge.

An electric controlled ignition system was developed for CNG engine, which was successfully applied in the bench test. The charge time of primary circuit is one of the most important parameters for the ignition system, which control the secondary voltage and current signal of the ignition coil, has a significant influences on the spark energy. Though a measurement system was developed to study the relationship between the charge time and output signal of the ignition coil. The tests results show that: the effective secondary voltage and current signal are mainly include 3 periods: charge period, spark duration period and oscillation period. The charge period is equivalent to the charge time of primary circuit; when the charge time is less than 6ms, the spark duration period increases with the increasing of charge time, but does not change significantly after more than 6ms; the oscillation period is not changed with the charge time changing.

Low dimensional molecular crystals of Ni[TCNQ] 2 (H 2 O) 2 was controlled synthesized by water in large area. Based on the accurate control of the reaction, the nanorods assembled in bundle clusters The nanorods have an average radius at ∼450 nm, with the length at 5 micrometers.

By depositing a PMMA (poly(methyl methacrylate)) layer on top of an evaporated layer of ZrO2, the leakage has 4 orders of magnitude reducing compared with bare ZrO2 layer. Low roughness of PMMA/ZrO2 surface produces a high quality interface between the organic semiconductor and the combined insulator, thus the device has a significant improvement in performance. The typical field effect mobility, on/off current ratio, and sub-threshold slope of OFETs with bilayer dielectric are 5.6×10-2 cm2/Vs, 1.2×103, and 0.3 V/decade respectively. It is noticeable that the threshold voltage is only 0.1 V.

This work studied systemically the device characteristics when the OFETs' channels turn into hundreds of nm. Standard planar OFETs have been fabricated using electronic beam lithography. Copper phthalocyanine is used as the semiconductor materials. When reduce the L to about 300 nm will lead an abrupt degradation of device performance. The ratio of Ion/Ioff turns from several hundreds into couple of tens. And when change the L to about 100 nm, the mobility turns from 10−2 cm2/Vs into 10m5 cm2/Vs, and the threshold voltage turns from about 12 V into 36 V. These abrupt changes are due to the changes of interface between active layer and insulator layer caused by the reducing the L to close to the grain size.