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CuCl-based ionic liquid ([HMim]Cl/CuCl) was synthesized by mixing 1-hydracid-3-methylimidazolium chloride ([HMim]Cl) with CuCl. Ionic liquid ([HMim]Cl/CuCl) was employed as an extractant remove sulfur from gasoline. It was found that [HMim]Cl/CuCl can remove sulfur-containing compounds from gasoline at room temperature. The extractive desulfurization mechanism of ionic liquid was proposed. The effects of extractive conditions on desulfurization of gasoline was investigated. The used ionic liquids can be regenerated by re-extraction using tetrachloromethane and reused five times. [ABSTRACT FROM PUBLISHER]

One-step oxidative desulfurization of dibenzothiophene (DBT) using cyclohexanone peroxide (CYHPO) was performed in the presence of N-alkyl-imidazolium-based ionic liquids (ILs). CYHPO is an oil-soluble oxidant and ILs are employed as extractants. The effect of the ILs, the molar ratio of CYHPO/S (O/S), volume ratio (VIL/Vmodel oil), reaction time (T), and reaction temperature (t) were investigated in detail. The results showed that the desulfurization ability of the ILs followed the order [OMim]BF4 > [HMim]BF4 > [BMim]BF4, reversing the length of the alkyl group to the imidazolium ring. When IL [OMim]BF4 was used, O/S was 2 and VIL/Vmodel oil was 1:1, and 93.5% of DBT in the model oil was removed at 40°C for 30 min. The desulfurization rate of gasoline was 70.8% under optimal conditions. IL ([OMim]BF4) could be recycled for five times without a significant decrease in activity. [ABSTRACT FROM PUBLISHER]

Photochemical oxidative desulfurization of thiophene with tetrabutylammonium bromide (TBAB) as phase transfer catalyst was studied. The effects of the TBAB addition and pH on the desulfurization yield of thiophene were investigated. The cycle model of desulfurization of thiophene with TBAB was proposed. The results show that the desulfurization yield of thiophene in n-octane is 80.6% for a 2-hr photoirradiation under the conditions of air flow at 150 mL/min, V (n-octane):V (water) = 1:1, pH = 12, and 0.1 g of TBAB as catalyst. The photooxidation kinetics of thiophene is first-order with rate constant of 0.5702 hr-1 and half-life of 1.22 hr. [ABSTRACT FROM AUTHOR]

Vacuum hot roll bonding of titanium alloy and stainless steel using a nickel interlayer was investigated. No obvious reaction or diffusion layer occurs at the interface between stainless steel and nickel. The interface between titanium alloy and nickel consists of an occludent layer and diffusion layers, and there are the intermetallic compounds (TiNi3, TiNi, Ti2Ni and their mixtures) in the layers. The total thickness of intermetallic layers at the interface between titanium alloy and nickel increases with the bonding temperature, and the tensile strength of roll bonded joints decreases with the bonding temperature. The maximum tensile strength of 440.1 MPa was obtained at the bonding temperature of 760°C, the reduction of 20% and the rolling speed of 38 mm s-1. [ABSTRACT FROM AUTHOR]

The hot roll bonding was carried out in vacuum condition between titanium alloy and stainless steel using copper interlayer. The stainless steel/Cu can not be bonded if the bonding temperature is lower than or equal to 730°C, and the Cu–Ti alloy can not be bonded if the bonding temperature is higher than or equal to 880°C. The testing results show that the total thickness of intermetallic layers at the interface between copper and titanium alloy increases with the bonding temperature, and the tensile strength of bonded joints decreases with increasing bonding temperature. The maximum strength of 343 MPa was obtained at the bonding temperature of 780°C, the reduction of 20% and the rolling speed of 38 mm s–1. [ABSTRACT FROM AUTHOR]

In our study, an effective phosphomolybdic acid/hexadecyltrimethyl-ammonium bromide catalyst for oxidative desulfurization of thiophene in a model compound was formed. The oxidation activities of thiophene for a series of heteropoly acids were estimated. The results show that the oxidation activity of thiophene increased with increasing oxidation time, oxidation temperature, and the volume of 30% H2 O2 oxidant. The optimal values are 150 min, 40°C, and 3 mL, and sulfur removal attained 96.3% when phosphotungstic acid/hexadecyltrimethylammonium bromide was used as a catalyst. [ABSTRACT FROM AUTHOR]

Although microstrip bends in high-speed digital MMICs have been widely investigated for the past two decades, their local radiation characteristics rather than their reflection characteristics have not been completely explored yet. In this paper, the generalized non-uniform transmission-line equations are used in analysing the microstrip bends including their local radiations. In our new models, the whole structure of a bend is regarded as a non-uniform transmission line that is totally governed by the generalized non-uniform transmission-line equations. Except for analytical simplification and broad bandwidth performance, the new analysis could indicate where the strongly local radiations along a bend structure come from. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A general equation for surface stress is established based on a thermodynamic consideration of the size dependence of solid-liquid interface energy under an assumption that the solid-liquid interface of a particle immersed in surrounding liquid disappears when almost all atoms of the particle are located on its surface. The predicted surface stresses of semiconductors in terms of the model are in agreement with the first principles calculations and calculations based on forces associated with the elastic distortion of the covalent bonds. [ABSTRACT FROM AUTHOR]

Based on the theoretical consideration on the size-dependence of solid-liquid interface energy, a model for the intrinsic interface stress of metallic, ionic and semiconductor nanosolid has been developed, free from adjustable parameters. Modeling predictions agree well with experimental observations and other theoretical results. [ABSTRACT FROM AUTHOR]

Reports that the enzyme telomerase plays a crucial role in cellular proliferation and tumorigenesis. Addition of hexameric repeats to chromosome ends to prevent telomeric loss and thus entry into senescence; Composition of the RNA-directed DNA polymerase; Determination of enzyme activity through catalytic protein component telomerase reverse transcriptase.

Objectives: To determine the relationship between diurnal temperature range (DTR) and outpatient visits for childhood acute bronchitis (AB) in Hefei, China, to analyze whether DTR effect was delayed, and to explore the susceptible populations. Study design: An ecological study. Methods: A Poisson generalized linear regression model combined with a distributed lag non-linear model was used to analyze the relationship between DTR and childhood AB from Hefei, China during 2010e2013, after adjusting for long-term trend and seasonality, mean temperature and relative humidity. Results: An adverse effect of DTR on childhood AB was observed, and the impact of DTR was greatest at three days lag, with a 1.0% (95% confidence interval = 0.5e1.6%) increase of AB cases per 1 °C increment of DTR. Female children and children aged 0e4 years appeared to be more vulnerable to DTR effect than other children. Conclusions: Our study suggests that large DTR may increase the incidence of childhood AB in Hefei, particularly for those who are female and young. Caregivers and health practitioners should be made aware of the potential threat posed by large DTR. [ABSTRACT FROM AUTHOR]

A model to determine the stress on the (100) surface of NaCl-type alkali halides is developed. The model predictions correspond to those of other theoretical calculations. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive field investigation of the ground response of a gateroad subjected to high stress induced by extracting a 17 m-thick coal seam. The test site is located at Datong City, Shanxi Province, China. The measurement results of the entry convergence and fracture development indicated that the gateroad with a 30 m-wide coal pillar maintained a good performance during the development period but suffered a strong response, including roof sag, floor heave, support unit failure and internal fractures sharply developed during the current panel-retreating period. During panel retreating, the impact range of the mining disturbance was about 110 m ahead of the active panel, and the mining disturbance accelerated dramatically at 50–60 m ahead of the mining panel. The results of the borehole stress measurement showed that the maximum stress induced in the virgin coal pillar and the coal pillar reached 15.3 MPa and 23.9 MPa, which are about 1.5 and 2.3 times the initial ground stress, respectively. This high stress contributed significantly to the instability of the gateroad. The average stress within the coal pillar was greater than that in the virgin coal pillar, and a high-stress zone was found at the coal pillar depth of 11–20 m. This stress distribution characteristics implies that the 30 m-wide coal pillar has a relatively sufficient bearing capacity to withstand the majority of mining-induced loads and that the coal pillar size could be reduced from 30 to 15–20 m wide to decrease the range of high stress in the coal pillar. Furthermore, taking into consideration of intense mining disturbance and abundant time interval for gateroad development as well as a high-strength support scheme, a small-width coal pillar of 8 m was recommended and tentatively applied in the field. The field application demonstrated that the newly designed pillar size and support pattern could ensure gateroad stability at some level. The study finding can help to better understand the stability control of entry driven along gob-side and its correlation with coal pillar size as well as the mining disturbance in specially thick coal seam (ETCS). In addition, the design principle and support strategy for the coal pillar in ETCS presented in this study can potentially be applied to other similar projects. [ABSTRACT FROM AUTHOR]

Wurtzite stalactite-like quasi-one-dimensional ZnS nanoarrays with ZnO protuberances were synthesized through a thermal evaporation route. The structure and morphology of the samples are studied and the growth mechanism is discussed. X-ray diffraction (XRD) results show both the ZnS stem and the ZnO protuberances have wurtzite structure and show preferred [001] oriented growth. The photoluminescence and field emission properties have also been investigated. Room temperature photoluminescence result shows it has a strong green light emission, which has potential application for green light emitter. Experimental results also show that the stalactite arrays have a good field emission property, with turn-on field of 11.4 V/μm, and threshold field of 16 V/μm. The ZnO protuberances on the ZnS stem might enhance the field emission notably. [ABSTRACT FROM AUTHOR]