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A biomass gasification-based combined cooling, heating, and power system integrated with an organic Rankine cycle is investigated. The energetic, economic, and environmental performances of the system in cooling mode and heating mode are analyzed. Based on the electrical and thermal demands of a large office building in Shanghai, the monthly and annual operation of the system is simulated and its performance is evaluated. Results show that the system has a better performance in its heating mode than in its cooling mode. Meanwhile, the advantage of this system over the system without the ORC module decreases with the increase of the thermal demand. The annual primary energy saving ratio, cost saving ratio, and CO 2 emission reduction ratio are 20.7%, 11.1%, and 43.7%, respectively. The increments of the above criteria owing to installation of the ORC module are 3.2%, 7.1%, and 1.4%, respectively. Sensitivity analysis shows that the equivalence ratio of biomass gasification has a relatively greater influence of the system on all aspects, which can increase the above criteria by up to 6.6%, 6.3%, and 3.6%, respectively. In addition, the parameters of the biomass feedstock and the public grid on different aspects affect the system performance on the corresponding aspect significantly. [ABSTRACT FROM AUTHOR]

Ordered mesoporous SiO 2 (KIT-6) was synthesized using triblock copolymer P123 as the structure template and tetraethyl orthosilicate (TEOS, C 8 H 20 O 4 Si) as silica source. Small-angle X-ray scattering and high resolution electron microscope measurements indicate the 3d cubic Ia3d symmetry of the pore structure of KIT-6 synthesized at 30–120  ° C. When the synthesis temperature increases to 180  ° C, the order of pores was deteriorated. The pore size was estimated by nitrogen adsorption/desorption measurements, which increases from 3.8 nm to 18.5 nm as the synthesis temperature increases from 30  ° C to 180  ° C. With the increase of mesopore size, the pore wall thickness shows continuous decrease. Positron annihilation lifetime spectra was measured for the synthesized KIT-6. The lifetime spectra can be resolved to two short and two long lifetime components. The two long lifetimes τ 3 and τ 4 correspond to o- Ps lifetime in micropore and mesopores, respectively. The size of mesopores was estimated from the o -Ps lifetime by using Goworeck’s model for cylindrical pores, which shows continuous increase with synthesis temperature, and is consistent with the N 2 adsorption/desorption measurements. The size of micropore has no change with increasing synthesis temperature. However due to the decrease in wall thickness, the number of micropores in the wall shows subsequent decrease. In addition, the second lifetime component τ 2 is also found to be a sensitive parameter for the pore size, which shows the same trend as lifetime τ 4 with increasing synthesis temperature. [ABSTRACT FROM AUTHOR]

• Two-phase microchannel heat sinks have great potential in electronic cooling. • Mass flow rate and heat flux are key parameters for microchannel heat sinks. • Dry-out caused by unreasonable parameters will reduce heat transfer performance. • The heat transfer coefficient in microchannels is more related to the heat flux. • The recommended value of mass flow rates is different under different heat fluxes. Two-phase microchannel heat sink has received extensive attention due to its small size, high heat transfer efficiency, good temperature uniformity, and low working fluid charge. Heat flux and mass flow rate are important parameters that affect the heat transfer performance of two-phase microchannel heat sink. For different heat fluxes, if the mass flow rate is not reasonable, dry-out may occur, which will significantly reduce the heat transfer performance. In order to further explore the influence of mass flow rate and heat flux on heat transfer characteristics, the flow boiling heat transfer performance and flow regimes under different mass flow rates and heat fluxes were studied for a two-phase microchannel heat sink using R245fa as the working fluid. The results showed that when the mass flow rate was 100 kg/(m2·s), the boiling heat transfer coefficient of R245fa showed a trend of increasing firstly and then decreasing with the increase of the heat flux. At a higher heat flux, the local dry-out in the microchannels began to appear, and the heat transfer performance decreased significantly. And the higher the heat flux was, the more serious the dry-out was. There was no obvious dry-out phenomenon when the mass flow rate was 150–300 kg/(m2·s) and the heat flux was below 500 kW/m2. The research provided a valuable reference for exploring the influence of the mass flow rate and the heat flux on the flow boiling heat transfer characteristics of the microchannel heat sink. [ABSTRACT FROM AUTHOR]

A combined cooling, heating, and power system based on biomass gasification is modeled via experiment and its performance is evaluated. The system operation is simulated using load data of small offices located in different climate zones in the U.S. The operation strategy comprises following the electric load (FEL) and following the thermal load (FTL). Based on the operation data, energetic, economic, environmental, and overall performances of the system are evaluated. Results show that the annual integrated performance ( S whole ) of the system ranges from 0.229 to 0.473 in FEL mode and from 0.067 to 0.457 in FTL mode, in different regions. The system has a better performance in FEL mode, and is more attractive to install in the regions with more thermal load. Furthermore, the match degree of heat to power ratio between load and output also has an effect on the system performance. Sensitivity analysis shows that the system performance is more sensitive to the cost of biomass, cost of grid electricity and CO 2 emission rate of the grid in both modes, and COP of thermally activated chiller in FTL mode. By changing the above-mentioned parameters, S whole can be improved by up to 13.7%, 8.2%, 11.0%, and 19.7% respectively. [ABSTRACT FROM AUTHOR]

The propagation characteristics of swell energy are important for applications such as swell wave power generation, ocean wave forecasting, disaster prevention and reduction, etc. However, the study on the propagation of swell energy is still relatively rare. This study proposed a new method to exhibit the exact propagation route and speed and intraseasonal oscillation of swell energy. The Indian Ocean is selected as a case study, using the 45-year (1957.09–2002.08) European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA-40) wave reanalysis dataset. The main results are as follows. (1) empirical orthogonal function (EOF) analysis and 6-hourly zonal averages of swell wave power density (WPD) show that the Indian Ocean swell energy has an obvious but fluctuating northeastward propagation. (2) The swell energy of the southwest Indian Ocean generally spreads to two regions: the main body propagates in a NE–NNE direction to Sri Lankan waters, while a small branch propagates to Christmas Island waters. (3) Swell energy in the west of the southern Indian Ocean westerly (SIOW), in Sri Lankan waters, and in Christmas Island waters share a common period of quasi-weekly oscillation. Swell energy takes ∼6 days to propagate from the west of the SIOW to Sri Lankan and Christmas Island waters. Swell energy propagates faster during June–September than in other months. [ABSTRACT FROM AUTHOR]

Adsorption of small gas molecules (O 2 , NO, NO 2 and NH 3 ) on transition-metal Cu atom embedded monolayer MoS 2 was investigated by first-principles calculations based on the density-functional theory (DFT). The embedded Cu atom is strongly constrained on the sulfur vacancy of monolayer MoS 2 with a high diffusion barrier. The stable adsorption geometry, charge transfer and electronic structures of these gas molecules on monolayer MoS 2 embedded with transition-metal Cu atom are discussed in detail. It is found that the monolayer MoS 2 with embedded Cu atom can effectively capture these gas molecules with high adsorption energy. The NH 3 molecule acts as electron donor after adsorption, which is different from the other gas molecules (O 2 , NO, and NO 2 ). The results suggest that MoS 2 -Cu system may be promising for future applications in gas molecules sensing and catalysis, which is similar to those of the transition-metal embedded graphene. [ABSTRACT FROM AUTHOR]

Background Actinic keratosis ( AK) is one of the most common conditions treated by dermatologists in western countries. Studies have shown that AK prevalence in Europe, the U.S.A. and Australia is 4·5-60%. No data of AK prevalence in China has been reported. Objectives This study aimed to explore the prevalence of AK in patients visiting dermatologists in two hospitals in China. Methods This study was conducted in the dermatology departments of two teaching hospitals (Peking University First Hospital, Beijing, and Fourth Military Medical University, Xi'an). All records for 5 years between 2008 and 2012 with clinically or pathologically diagnosed AKs were collected from the pathological databases of both hospitals. Data from these records were used to calculate the prevalence of AKs among patients who were seen by dermatologists in these hospitals. To estimate the reliability of data from the previous database, a cross-sectional study was conducted simultaneously in the two hospitals from 15 October to 8 December in 2012 after all dermatologists in the two departments were retrained through intensive courses on recognizing AK clinically. Results The prevalence of total clinical AKs through 2008-2012 was 0·52% in 1 590 817 patient visits in the two hospitals. The yearly prevalence of clinical AKs was 0·30-1·20%. In the cross-sectional study, 72 437 clinical patients were screened and 76 patients (1·05%) were identified to have clinically recognized AK. Conclusions The overall prevalence of AKs in patients visiting dermatologists in the two hospitals in China was 0·52%, which is much lower than the prevalence in western countries. [ABSTRACT FROM AUTHOR]

Mesoporous silica with ordered pore structure was synthesized at various temperatures using TEOS as the silica source and P123 as the template. Both small angle X-ray scattering (SAXS) and high resolution transition electron microscopy (HRTEM) measurements verify the ordered pore structure of the synthesized SiO 2 . With synthesis temperature increasing, the pore structure has slight damage at 130 °C, while it shows ordered structure again at 150 °C. When the synthesis temperature increases to 180 °C, the ordered pore structure is severely destructed. The change of pore structure is further confirmed by scanning electron microscopy (SEM) measurements. Positron lifetime measurements reveal four lifetime components in the synthesized mesoporous SiO 2 , and the two long lifetimes τ 3 and τ 4 correspond to the annihilation of o-Ps in the micropores and large pores of the material, respectively. The longest lifetime τ 4 tends to increase slightly with increasing synthesis temperature. However, its intensity I 4 shows an overall decrease with exception at 150 °C. At the synthesis temperature of 180 °C, the intensity I 4 decreases drastically to about 17.5%. This indicates variation of the size and fraction of pores with increasing synthesis temperature, and the pore structure is seriously destructed at 180 °C. By comparing with the N 2 adsorption–desorption measurements, it was found that the Goworek's model is more suitable for the size estimation of cylindrical pores from the o-Ps lifetime, while Dull's and Ito's model is appropriate for the rectangular and spherical pores, respectively. [ABSTRACT FROM AUTHOR]

Microwave dielectric ceramics based on ixiolite-structure ZnTiNb 2 O 8 were prepared by an aqueous sol–gel process. Highly reactive nanosized ZnTiNb 2 O 8 powders with particle sizes of 30–50 nm were successfully obtained at 700 °C as precursors. Sintering characteristics and microwave dielectric properties of ZnTiNb 2 O 8 ceramics were studied depending on sintering temperatures ranging from 950 °C to 1100 °C. The dielectric properties were strongly dependent on the compositions, the densifications and the microstructures of the specimens. With the increase of sintering temperature, density, ε r and Q ⋅ f values were increased and saturated at 1050 °C with excellent microwave properties with an ε r of 35.3, an high Q ⋅ f of 66,700 GHz, and a τ f of −55.4 ppm/°C. The correlations of microstructure and dielectric properties for ZnTiNb 2 O 8 ceramics were also investigated. The relatively low sintering temperature and high dielectric properties in microwave range would make these ceramics promising for application in electronics. [ABSTRACT FROM AUTHOR]

Microwave dielectric ceramics based on fergusonite-type NdNbO 4 were prepared by an aqueous sol–gel process. The precursor powders and dielectric ceramics were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and microwave methods. Highly reactive nano-sized magnesium titanate powders with particle sizes of 20–40 nm were successfully obtained at 900 °C as precursors. The sintering characteristics and microwave dielectric properties of NdNbO 4 ceramics were studied depending on sintering temperatures ranging from 950 °C to 1300 °C. With the increase of sintering temperature, density, ε r and Q ƒ values increased and saturated at 1150 °C with excellent microwave properties of ε r =29.8, Q ƒ=49,010 GHz and τ ƒ =53 ppm/°C. The correlations of microstructure and dielectric properties for NdNbO 4 ceramics were also investigated. [ABSTRACT FROM AUTHOR]

Quasi-static and dynamic compressive tests with a series loading rates were conducted on (Zr 0.6336 Cu 0.1452 Ni 0.1012 Al 0.12) 97 Tm 3 bulk amorphous alloy at cryogenic temperature. It is found that mechanical properties of the alloy such as yield strength and plasticity are obviously dependent on temperature and strain rate. The plastic strain of the specimens at 298 K and 77 K is 8.4% and 13.7% respectively under quasi-static load with strain rate of 1 × 10−4 s−1. Additionally, the dynamic mechanical properties of amorphous alloys at different strain rates were tested by split Hopkinson pressure bar(SHPB) to unveil the dynamic deformation behaviors at cryogenic temperature of 177 K and 77 K. Compared with the results of quasi-static compression, strain rate softening phenomenon can be observed under dynamic loading, but the compressive strength of specimens increases significantly with the decrease of temperature. Moreover, the specimens have no obvious plastic deformation under dynamic loading. Compared with room temperature, the improvement of quasi-static and dynamic compressive strength of the alloy at cryogenic temperature can be attributed to the strong interatomic binding force between the alloy elements. • Quasi-static and dynamic deformation behavior of a Zr-based amorphous alloys at cryogenic temperature was compared. • Relationships between fracture mechanism and temperature under different stress states were discussed. • The effect of stress state on the dynamic fracture behavior of Zr-based metallic glass was analyzed. [ABSTRACT FROM AUTHOR]

Microwave dielectric properties of corundum-structured Mg4Ta2O9 ceramics were investigated as a function of sintering temperatures by an aqueous sol–gel process. Crystal structure and microstructure were examined by X-ray diffraction (XRD) technique and field emission scanning electron microscopy (FE-SEM). Sintering characteristics and microwave dielectric properties of Mg4Ta2O9 ceramics were studied as a function of sintering temperature from 1250°C to 1450°C. With increasing sintering temperature, the density, ε r and Qf values increased, saturating at 1300°C with excellent microwave properties of ε r =11.9, Qf=195,000GHz and τ f =−47ppm/°C. Evaluation of dielectric properties of Mg4Ta2O9 ceramics were also analyzed by means of first principle calculation method and ionic polarizability theory. [ABSTRACT FROM AUTHOR]

Abstract: In situ synchrotron X-ray powder diffraction experiment on TiSi2 has been performed using a diamond anvil cell at ambient temperature. The present experimental results showed that the structure of C54-type TiSi2 is stable in the experimental pressure range up to around 52GPa. The compressibility of C54-type TiSi2 under high pressure presents anisotropic behavior. The compressibility along the a-, b- and c-axes has an approximate ratio of 6:5:4. And the anisotropic compressibility of the studied crystal is discussed in terms of the crystallography stacking. The c/a and b/a axial ratios both increase as the pressure increases. With pressure increasing, the c/a shows a tendency of approaching the ideal value, but the b/a deviates from the ideal value. The pressure–volume data of C54-type TiSi2 were fitted to a Birch–Murnaghan equation of state, which yielded a bulk modulus of B 0=155 (2)GPa. [Copyright &y& Elsevier]

Abstract: The structural stability in TaSi2 was investigated by in situ angle dispersive X-ray diffraction (AD-XRD), which shows that the structure is stable even up to about 50.0GPa at room temperature. However, under high pressure and high temperature (HPHT) conditions it was revealed that TaSi2 could undergo a structural phase transition from a C40-type hexagonal phase to a metastable phase after a temperature quench from 573K at 10.6GPa. [Copyright &y& Elsevier]

Abstract: The effect of anisotropic strain induced by SrTiO3 (STO) substrate with different orientations on charge ordering (CO) behavior in epitaxial Sm0.5Ca0.5MnO3 (SCMO) films was investigated using cross-sectional transmission electron microscopy at 103K. Incommensurate modulated structure caused by CO transition was observed in the SCMO film grown on a [101]-oriented STO substrate while none were found for SCMO film grown on a [100]-oriented STO substrate. This distinctive orientation-dependent CO transition is correlated with anisotropic strain in the films induced by lattice mismatch, confirming the previous results for growth on different substrates. [Copyright &y& Elsevier]

Abstract: NiO/γ-Al2O3 catalysts with NiO content of 9wt% and 24wt% were prepared by solid state reaction method. They are annealed in air at temperatures from 100°C to 1000°C. Positron lifetime spectra were measured to study the microstructure variation during annealing process. Four positron lifetime components were resolved with two long lifetime τ 3 and τ 4, which can be attributed to the ortho-positronium lifetime in microvoids and large pores, respectively. It was found that the longest lifetime τ 4 is rather sensitive to the chemical environment of the large pores. The NiO active centers in the catalysts cause decrease of both τ 4 and its intensity I 4, which is due to the spin-conversion of positronium induced by NiO. However, after heating the catalysts above 600°C, abnormal increase of the lifetime τ 4 is observed. This is due to the formation of NiAl2O4 spinel from the reaction of NiO and γ-Al2O3. The generated NiAl2O4 weakens the spin-conversion effect of positronium, thus leads to the increase of o-Ps lifetime τ 4. Formation of NiAl2O4 is further confirmed by both X-ray diffraction and X-ray photoelectron spectroscopy measurements. [Copyright &y& Elsevier]

The structural behaviour of Cu5Si under high-pressure (HP) has been studied by angular dispersive X-ray diffraction up to 49.9 GPa. The experimental results suggest that a pressure-induced isostructural phase transition occurs around 13.5 GPa as revealed by a discontinuity in volume as a function of pressure. The lattice parameter decreases with the pressure increasing for both low-pressure (LP) and HP phases of Cu5Si. However, a plot of the lattice parameter vs. pressure shows the existence of a plateau between 11.7 and 15.3 GPa. The bulk moduli, derived from the fitting of Birch–Murnaghan equation of state, are 150(2) GPa and 210(3) GPa for the LP phase and the HP phase of Cu5Si, respectively. A change in the electronic state of the copper is assumed to govern the observed structural phase transition. [ABSTRACT FROM PUBLISHER]

Abstract: An in vitro experiment was conducted to elucidate the role of polyamines and phospholipase D (PLD) in maize (Zea mays L.) response to drought stress simulated by PEG-6000. During the early stage of drought stress, an increase of PLD activity played a major role in stomatal closure as an adaptive response to drought stress and this process was independent of polyamine synthesis. Under prolonged drought stress, the total content of polyamines including putrescine (Put), spermidine (Spd) and spermine (Spm) increased at 120min after drought stress treatment while the ratio of Spd+Spm/Put decreased, which caused an increase in PLD activity, relative membrane permeability and malondialdehyde content (MDA). Exogenous polyamines enhanced PLD activity, and the greatest effect was induced by Put. Therefore, we concluded that PLD played an important role in mitigation of drought stress damage in the early stage of drought stress which was independent of polyamine accumulation. However, in the later stage of drought stress, the obvious elevation of PLD activity led to serious membrane damage regulated by the ratio of Spd+Spm/Put. [Copyright &y& Elsevier]

Abstract: The low-lying collective states in Sn isotopes are studied by a five-dimensional collective Hamiltonian with parameters determined from the triaxial relativistic mean-field calculations using the PC-PK1 energy density functional. The systematics for both the excitation energies of states and values are reproduced rather well, in particular, the enhanced E2 transitions in the neutron-deficient Sn isotopes with . We show that the gradual degeneracy of neutron levels and around the Fermi surface leads to the increase of level density and consequently the enhanced paring correlations from to 58. It provokes a large quadrupole shape fluctuation around the spherical shape, and leads to an enhanced collectivity in the isotopes around . [Copyright &y& Elsevier]

Abstract: We report on a LD-end-pumped passively Q-switched Nd:YAG ceramic laser by using a novel single wall carbon nanotube saturable absorber (SWCNT-SA). The SWCNT wafer was fabricated by electric Arc discharge method on quartz substrate with absorption wavelength of 1064nm. We firstly investigated the continuous wave (CW) laser performance and scattering properties of Nd:YAG ceramic sample. For the case of passively Q-switched operation, a maximum output power of 376mW was obtained at an incident pump power of 8.68W at 808nm, corresponding to an optical–optical conversion efficiency of 4.3%. The repetition rate as the increase of pump power varied from 14 to 95kHz. The minimum pulse duration of 1.2μs and maximum pulse energy of 4.5μJ was generated at a repetition rate of 31.8kHz. [Copyright &y& Elsevier]

Abstract: The n-, (n,l)- and fine-structure level state-selective radiative recombinations (RR) cross sections of argon ions Ar18+,Ar13+,Ar7+ and Ar+ are obtained with the semi-classical Kramer formula, the relativistic self-consistent field (RSCF) method and the relativistic configuration interaction (RCI) method. It is found that for the highly charged ions with few electrons, the cross sections calculated with these three methods are in good agreement with each other. But as the number of electrons increases, the Kramer formula deviates from the RSCF and RCI results. For instance, when the energy of the incident electron is larger than 100eV, the n-state selective cross sections of Ar7+ calculated from the Kramer formula are underestimated for more than 50%. The RSCF results are in general agreement with the RCI results. However, for the low charged ions, a clear distinction appears due to the strong configuration interaction, especially near the Cooper minimum. The n-resolved (n≤10) and total Maxwellian averaged rate coefficients are calculated, and the analytic fitting parameters are also provided. [Copyright &y& Elsevier]

Abstract: High pressure effect on the structural polymorphy of YCu was studied based on the first principle density functional theory. The calculated values of lattice parameters are in good agreement with the available experimental results. The geometry optimization results indicate the anisotropy of the compressibility of FeB-type YCu under high pressure. It is remarkable that the compressibilities along the b- and c-axes experience an abnormality at about 3.3GPa. Energy calculation results demonstrate that YCu is stable in the FeB-type structure at low temperature and ambient pressure, which is in good agreement with the experimental results. And there exists a structural phase transition from FeB-type structure to CsCl-type structure at the transition pressure of approximate 6.7GPa. This is the quantitative theoretical prediction of structural phase transition, and it still awaits the experimental confirmation. [Copyright &y& Elsevier]

Abstract: Nb3Al, which is widely used in high field magnets, was studied under a range of pressures up to 39.5GPa using diamond anvil cell. The Nb3Al superconductor is structurally stable up to the highest pressure of the present investigation from previous reports. However, an anomaly of the compressibility beyond 19.2GPa was detected in the pressure versus volume plot. The curve of volume versus pressure shows the existence of a plateau around 18.0GPa as seen in several other highly correlated electrons systems, The observed pressure-induced isostructural phase transition was accomplished with a volume inclination without any symmetrical change (space group, Wyckoff position). The physical mechanism behind this isostructural phase transition is the interesting issue for further studies. [Copyright &y& Elsevier]

Abstract: Cr2As, which is an intermetallic compound of Cu2Sb-type with Strukturbericht designation C38 was studied under a pressure of up to 32.5 GPa at room temperature using in situ synchrotron X-ray powder diffraction with a diamond anvil cell. From the X-ray diffraction analysis, our results showed that the Cu2Sb (C38)-type phase of Cr2As undergoes a pressure-induced structural phase transition near 15.4 GPa. The high-pressure (HP) phase of Cr2As is suggested as an orthorhombic structure. No additional structural phase transition was observed up to 32.5 GPa, and the initial low-pressure (LP) Cu2Sb (C38)-type structure was recovered as the pressure was released, implying that the observed pressure-induced structural phase transformation was reversible. The pressure–volume data of Cr2As was fitted to a second-order Birch–Murnaghan equation of state, which yielded a bulk modulus of and 340 (12) GPa for the LP and the HP phases, respectively. Furthermore, the axis is more compressible than the axis for the LP phase of Cr2As. The anisotropic compressibility of the studied crystal is discussed in terms of the crystallography stacking. [Copyright &y& Elsevier]

Abstract: In this paper, we propose an extended car-following model which takes into account the honk effect. The analytical and numerical results show that the honk effect improves the stability of traffic flow. The dependence of the stability on the properties of the honk effect is investigated in this paper. [Copyright &y& Elsevier]

Abstract: A facile method to immobilize the initiators onto the substrate is desirable for surface initiated atom transfer radical polymerization (ATRP). In this work, a two-step process was first developed for covalent immobilization of ATRP initiators on the outside and inside surfaces of the porous nylon membrane. The nylon membrane was functionalized with poly(dopamine), and the bromoalkyl initiators were then immobilized on the poly(dopamine) functionalized nylon membrane surfaces in a two-step solid-phase reaction, followed by ATRP of acrylic acid (AAc), which was deprotonated by the addition of NaOH in an aqueous solution. The resulting nylon membranes with grafted poly(acrylic acid) (PAAc) side chains were characterized by X-ray photoelectron spectroscopy (XPS). The morphology of the nylon membranes was studied by scanning electron microscopy (SEM). The results indicated that the grafted PAAc polymers formed uniformly inside the pores throughout the entire membrane. With the increase of the polymerizing time, the average diameter of the pores became smaller. A kinetics study revealed that the chain growth from the membranes was consistent with a “controlled” process. The nylon-g-PAAc membranes exhibit rapid and reversible responses of the flux to the environmental pH varied from 3 to 8. Between pH 3.5 and 5.5, the membranes demonstrated a pH-valve function as the carboxyl group changed from neutral to charged states with a corresponding variation of chain configuration. [ABSTRACT FROM AUTHOR]

Abstract: We demonstrate a kilowatt level Quasi-continuous-wave (QCW) diode-side-pumped Nd:YAG ceramic laser at 1064nm. The laser system adopts a master oscillator power amplifier scheme (MOPA). The master oscillator contains two diode-pumped laser modules. Under the pump power of 2000W, an output power of 686W was obtained. After amplified by an identical ceramic laser module, a maximum output power of 1020W was obtained under a total incident pump power of 3433W, corresponding to an optical–optical conversion efficiency of 29.7%. At the maximal output power, the repetition frequency was measured to be 1kHz and the pulse width was 114μs. To the best of our knowledge, this is the first time to realize QCW side-pumped Nd:YAG ceramic laser system with output power above 1kW. [Copyright &y& Elsevier]

Abstract: In this Letter, we develop a new car-following model with the consideration of the driver''s forecast effect (DFE). The analytical and numerical results show that the stability of traffic flow will gradually be enhanced with the increase of the forecast effect coefficient and the forecast time. [Copyright &y& Elsevier]

• A biomass gasification-based CCHP system with an ORC module is optimized. • The ORC module is driven by the excess waste heat of the power generation unit. • System improvement by ORC integration and multi-criteria optimization is compared. • The annual PESR , TCSR , and CERR can be improved by up to 8.4%, 3.5%, and 12.0%. • The parameters of the biomass feedstock and grid electricity have decisive effect. In this work, a multi-criteria optimization on a biomass gasification-based combined cooling, heating, and power system integrated with an organic Rankine cycle (ORC) is conducted. The ORC module is driven by the waste heat of the power generation unit. The criteria for the optimization comprise primary energy saving ratio (PESR), total cost saving ratio (TCSR), and CO 2 reduction saving ratio (CERR). A criterion based on Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is employed as the evaluation basis of the multi-criteria optimization. The improvement caused by ORC integration and multi-criteria optimization is investigated by comparing with the systems without the former and/or the latter one. Through case studies of a hypothetical hotel building located in six different climate zones in China, it is found that after the integration of an ORC module and multi-criteria optimization, the annual PESR , TCSR , and CERR are varied from 4.8%/−2.2%/7.0% to 8.4%/ 3.5%/12.0%, respectively, in different climate zones. The parameters of biomass and grid electricity, which are both location-related, have decisive effect on the system performance and the optimization results. Comparing with integration of an ORC module, the multi-criteria optimization has larger improvement of PESR when cooling demand is low, of TCSR when thermal demand is low, and of CERR in all the studied load conditions. [ABSTRACT FROM AUTHOR]

Abstract: Diamond nanowhiskers were fabricated by etching as-grown and aluminum coated diamond films in radio frequency (RF) Ar/O2 plasma. It was found that diamond nanowhiskers could be obtained by anisotropic etching of both kinds of films. For the as-grown diamond film, the whiskers randomly formed on the diamond surface with higher etching rate. However, for the Al-coated diamond film, an energy dispersive X-ray spectroscopy measurement revealed that the distribution of the whiskers was the same as that of the coated Al particles. During the etching process, Al particles served as masks contributing to restraining the etching of the film underneath. It was found that the distribution of the whiskers was significantly influenced by the Al coating. The whiskers (1 μm in height and 50 nm in diameter) could be obtained under the optimum etching condition. In addition, the dependence of the distribution of the whiskers on Al coating time was demonstrated. [Copyright &y& Elsevier]

Abstract: This work is aimed at evaluating the in vivo histological performance of HA coated NiTi through chemical treatments and the untreated NiTi after two years implantation by animal model. A complete implant–bone interfacial osseointegration was observed after HA coated and untreated NiTi was implanted into the animal model for two years. However, the osseous lamella structure on HA coated NiTi was more mature and the osseous tissue was more compact as compared with that of untreated NiTi, which was ascribed to the differences resulted from nickel ion release from the alloy, cell adhesion ability and osteogenesis mechanism during the early stage of implantation. The bioactivity and biocompatibility of NiTi alloy are significantly improved by coating the alloy with HA through chemical treatment, though the untreated NiTi shows good biocompatibility after long time implantation. [Copyright &y& Elsevier]

Abstract: Calcium lanthanide oxyborate doped with rare-earth ions LnCa4O(BO3)3:RE3+ (LnCOB:RE, Ln=Y, La, Gd, RE=Eu, Tb, Dy, Ce) was synthesized by the method of solid-state reaction at high temperature. Their fluorescent spectra were measured from vacuum ultraviolet (VUV) to visible region at room temperature. Their excitation spectra all have a broadband center at about 188nm, which is ascribed to host absorption. Using Dorenbos’ and Jφrgensen''s work [P. Dorenbos, J. Lumin. 91 (2000) 91, R. Resfeld, C.K. Jφrgensen, Lasers and Excite States of Rare Earth [M], Springer, Berlin, 1977, p. 45], the position of the lowest 5d levels E(Ln,A) and charge transfer band E ct were calculated and compared with their excitation spectra. Eu3+ and Tb3+ ions doped into LnCOB show efficient luminescence under VUV and UV irradiation. In this system, Ce3+ ions do not show efficient luminescence and quench the luminescence of Tb3+ ions when Tb3+ and Ce3+ ions are co-doped into LnCOB. GdCOB doped with Dy3+ shows yellowish white light under irradiation of 254nm light for the reason that Gd3+ ions transfer the energy from itself to Dy3+. Because of the existence of Gd3+, the samples of GdCOB:RE3+ show higher excitation efficiency than LaCOB:RE3+ and YCOB:RE3+, around 188nm, which indicates that the Gd3+ ions have an effect on the host absorption and can transfer the excitation energy to the luminescent center such as Tb3+, Dy3+ and Eu3+. [Copyright &y& Elsevier]

Abstract: Diamond nanowhiskers could be obtained by anisotropic etching of as-grown and aluminum coated diamond films in a radio frequency (RF) Ar/O2 plasma. The distributions of diamond nanowhiskers were on the presence of Al coatings. For the Al-coated diamond film, the distribution of the whiskers was almost same as that of the coated Al particles. However, for the as-grown diamond film, the whiskers randomly formed on the diamond surface with higher etching rate. Comparing these two situations, we found that Al coating was a critical factor in the etching process which served as mask contributing to restraining etching the film underneath. The whiskers (1 μm in height and 50 nm in diameter) could be obtained under optimum etching conditions. In addition, the dependence of the distribution of the whiskers on Al coating time was demonstrated. [Copyright &y& Elsevier]

Abstract: As-grown and metal-coated CVD diamond films were etched in an O2 radio-frequency plasma. In this study, Molybdenum (oxidizable) and Nickel (non-oxidizable) were used as coating materials. The distribution of the whiskers was investigated and compared. In the case of as-grown diamond film, the whiskers were found preferentially formed at the diamond grain boundaries. The metal-coated diamond films were distinctly influenced by the oxidizability of the coating metal. Under the same etching condition, lower density whiskers (10 μm−2) were obtained from the Mo-coated diamond film, and in this case the whiskers were about 50 nm in diameter and 200 nm in height. However, the peak intensities of the whiskers measured by cathodoluminescence remained the same as those of the non-etched diamond films. Compared to the Mo-coated film, whiskers obtained from the Ni-coated film were more densely distributed (40 μm−2); also, their quality deteriorated with the etching, as did their cathodoluminescence peak intensities. In both cases, the properties of bonding structures were compared before and after etching. It was found that the whiskers kept the sp3 diamond bonding structure even after etching. [Copyright &y& Elsevier]

Abstract: Radio frequency (RF) plasma etching of chemical vapor deposition (CVD) diamond film has been investigated in Ar/O2 plasmas, with an emphasis to elucidate the effects of reacting gas on the fabrication of diamond whiskers. Diamond whiskers were formed on diamond films pre-coated with Al. It was found that diamond whiskers preferentially formed at the diamond grain boundaries. The densities of diamond whiskers increased with O2 /Ar ratio. Whiskers obtained in pure O2 plasma etching were 50 nm in diameter and 1 μm in height. The etching rate was increased by mixing Ar with appropriate volume of O2. Al coated on the diamond surface reacted with O2 to form Al2O3, serving as mask to restrain the etching underneath. Raman spectroscopy measurement confirmed that the whiskers kept sp3 diamond bonding structure after RF plasma etching. The field emission characteristics of the whiskers were also inspected. [Copyright &y& Elsevier]

Integration of Cu with low k dielectrics provided solution to reduce both resistance–capacitance time delay and parasitic capacitance of BEOL interconnections for 130nm and beyond technology node. The motivation of this work is to study and improve electrical and reliability performance of two-level Cu/CVD low k SiOCH metallization from the results of diffusion barrier deposition schemes. Barrier deposition schemes are (a) high-density-plasma 250Å Ta; (b) surface treatment of forming gas followed by high-density-plasma 250Å Ta and (c) bi-layer of 100Å Ta(N)/150Å Ta. In this work, we demonstrated the superior and competency of high-density-plasma Ta deposition for Cu/CVD low k metallization and achieved excellent electrical and reliability results. Wafers fabricated with high-density-plasma Ta barrier scheme resulted in the best electrical yields, >90% for testing vehicles of dense via chains (via size=200nm) and interspersed comb structures (width/space=200nm/200nm). Dielectric breakdown strength of the interspersed comb structures obtained at electric field of 0.3MV/cm was ∼4MV/cm. [Copyright &y& Elsevier]

The impact of barrier metal on electrical performance of Cu/low K (Black Diamond™) in 0.13-μm dual damascene (DD) interconnection has been investigated. The via resistance and its distribution were reduced by using high-density plasma barrier metal (Ta) deposition technique. The average breakdown electrical field for samples with high-density plasma barrier metal (Ta) was increased to 2.4 MV/cm as compared to samples with conventional Ta deposition. Transmission electron microscope (TEM) images reveal that nonuniformity of barrier metal on the sidewall and bottom of the DD structure were significantly improved by applying high-density plasma barrier metal (Ta) deposition technique. Burn-in test at 200 °C for 1000 h was carried out, and it was found that there was no significant change of via resistance and line–line leakage behavior. The thickness of barrier metal was also optimized. Electrical results show that high-density plasma barrier metal deposition of 200 Å Ta improved electrical performance and enhanced the reliability of 0.13-μm dual damascene interconnection. [Copyright &y& Elsevier]

Effect of Ar and He/H2 (5%) plasma treatments on the electrical properties of the Cu/SiLK damascene structures for multilevel interconnect technology have been investigated. It was found that the Kelvin via resistances of the samples treated using the two kinds of plasma have no significant difference when the vias in the structures is more than 0.24 μm in diameter. However, the via resistance of He/H2-treated samples is much lower than that of Ar-plasma-treated samples when the vias is reduced to 0.22 μm and below. It was also found that the line–line leakage current has no obvious difference for both the Ar- and He/H2-plasma-treated samples. By increasing the applied voltage to the comb structures, the leakage current undergoes an abrupt rise at 3 MV/cm for the Ar-plasma-treated samples, but at 2 MV/cm for the He/H2-treated samples. After annealing at 350 °C for 1 h under N2 ambient, the line–line leakage current increases significantly from 3×10-12 to 5×10-9 A for the samples with He/H2 plasma treatment, but no obvious change was observed for the samples with Ar plasma treatment. The Fourier transform infrared spectroscopy results indicated that a new Si–H peak appears in the samples treated using the He/H2 (5%) plasma, which is likely related to the differences observed in the breakdown voltages and the leakage current after annealing. [Copyright &y& Elsevier]

Examines the vertical vibration of a vehicle traveling on an imperfect track system. Model of the car body and sleepers; Imperfection of the track system; Limitation of deflection to the rail.

Online pulse-reaction chromatography, MS transient response technique and fixed bed reaction apparatus were used to investigate the cracking of thiophene and alkyl-thiophene species. Thiophene cracks over the USY zeolite to propylene, butane, butene and H2S. Furthermore, 2-methyl-thiophene, 3-methyl-thiophene, di-methyl-thiophene, tri-methyl-thiophene and benzothiophene are formed, but cracking desulfurization is the dominant reaction. Compared to thiophene, alkyl-thiophene species in gasoline are easier to desulfurize via cracking over the specially prepared sulfur removal catalyst with the USY zeolite as the cracking component, and the conversion increases with the alkyl carbon number of alkyl-thiophene. Cracking and hydrogen transfer are two important elementary reaction steps for thiophene and alkyl-thiophene species desulfurization via cracking. Higher temperature favors the former, while lower does the latter. The contradiction leads to about 400 °C to be the optimal temperature for thiophene and alkyl-thiophene species to desulfurize via cracking. [Copyright &y& Elsevier]

Focuses on the use of capnograph to confirm appropriate nasogastric positioning (NS). Confirmation of NS positioning by palpation; Documentation of the intra-operative positioning of NG; Limitation of the palpation technique.

Abstract: Using the first principle method based on density functional theory, the structural and elastic properties calculations of RbAu have been performed. The results demonstrate that RbAu is stable in the CsCl structure (B2) at ambient pressure, which is in well agreement with the experimental results. And there exists a structural phase transition from CsCl-type structure (B2) to NaTi-type structure (B32) at the transition pressure of approximate 6GPa. The pressure effects on the elastic properties are discussed and the elastic property calculation indicates elastic instability maybe provide phase transition driving force according to the variations relation of the elastic constant versus pressure. [Copyright &y& Elsevier]

Abstract: We report on to our knowledge the first time a diode-side-pumped simultaneous dual-wavelength Nd:YAG laser at 1116 and 1123nm. By inserting an etalon to balance the gain and loss, a stable dual-wavelength oscillation is acquired. The numerical simulations for wavelength tuning are discussed by principles of laser threshold and Fabry–Perot etalon. Under the pump power of 250W, a total output power of 23W is obtained. Meanwhile, the two components have approximately equal intensities. The beam quality of M2 factor was measured to be 7.52. [Copyright &y& Elsevier]

Abstract: We demonstrate a high power continuous wave (CW) diode-side-pumped Nd:YAG laser operating at 1123nm with a plano–plano configuration. By means of precise coating, a single 1123nm wavelength is achieved. Under the pump power of 1080W, an output power of 219.3W is obtained, which corresponds to an optical–optical conversion efficiency of 20.3%. To the best of our knowledge, this is the highest output power for CW 1123nm laser based on Nd:YAG crystal. [Copyright &y& Elsevier]

• A gasifier–engine–generator system was studied by experiments and modeling. • The instant interaction between the engine and the gasifier was considered. • The comparison between experimental and modelling results has been made. • The performance of the entire system was analyzed through energy distribution. This paper presents a combined experimental and modeling investigation on an integrated gasifier–engine–generator system. Both power and waste heat output of the system are studied. Other than the similar investigations in the existed literatures, the instant interaction between the internal combustion engine and the gasifier is considered. Meanwhile, waste heat from both syngas and exhaust gas is recovered to heat biomass feedstock. Two types of commercialized woody biomass, redwood pellets and woodchips, are used as the feedstock, respectively. An integrated model is established and experiments are performed to acquire parameters and relations for modeling, as well as to validate the model. Experiment results show that in most cases, the deviations of major elements, C and O, between input and output of the system are below 15%. The deviations of total mass are lower than 10%. For all experimental conditions, the highest cold gas efficiency (η cg)/power generation efficiency is 75.0%/16.4% and 80.8%/19.0%, respectively, for redwood pellets and woodchips. Results of model validation show that the accuracy of the developed model is acceptable. Standard deviations (SD s) of syngas compositions and η cg are all below 10%. The maximum SD of waste heat is 12.81%. According to the evaluation results based on the developed model, energy loss during the gasification process takes up the largest proportion among all energy loss items. For all evaluated conditions, the combined energy of electricity and waste heat account for 43.0–54.6% and 40.0–60.4% of the total energy input when using redwood pellets and woodchips, respectively. The methods and findings can serve as basis and reference for combined cooling, heating, and power systems based on biomass gasification. [ABSTRACT FROM AUTHOR]

We report on the successful implementation of interconnects with metal–organic chemical vapor-deposited copper using dual damascene technology. The average resistances of the Kelvin vias and via chains (with a via diameter of 0.28 μm) are 0.62 and 0.72 Ω, respectively. The average line–line leakage current measured at a field of 4500 V/cm at room temperature is about 10-10 A. It does not increase significantly with the applied electrical field up to about 2.5 MV/cm. These data meet the industrial standards for copper interconnects in the deep submicron integrated circuits and can be improved further by optimizing the ionized metal plasma flash copper. [Copyright &y& Elsevier]

Abstract. The pulsed laser-light-induced band radiation of molecular potassium generated by the energy-pooling effect is reported for the first time. The producing mechanism of the diffuse-band radiation and the appearance of the atomic trapping effect are discussed. [ABSTRACT FROM AUTHOR]