Search

Abstract: The fish tissues from four species collected from Taihu Lake, China, were analyzed including dorsal, ventral, and tail muscles, heart, liver, and kidney. The highest and lowest concentrations of fatty acids were respectively observed in livers and muscles. There were significant intraspecies and interspecies differences in the compositions of most fatty acids among muscle, heart, liver, and kidney. All the tissues were generally beneficial for consumption considering fatty acids. People mainly consume the muscle. Hence, the benefits from two polyunsaturated fatty acids, i.e., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and risks from PCBs and PBDEs via fish consumption were evaluated by calculating the benefit-risk quotient (BFQ) for the intake of fish muscle containing EPA+DHA vs. PCBs or PBDEs. The BFQ values considering carcinogenic and noncarcinogenic effects for PCBs were ∼3000 and 10 times higher than those of PBDEs via fish consumption to achieve the recommended EPA+DHA intake of 250mgd−1, respectively. The results also suggested that the risk consuming the dorsal muscle was generally lower than the ventral and tail muscles. [Copyright &y& Elsevier]

Abstract: Exposure risks of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) via consumption of nine fish species from Taihu Lake in China and associated benefits, through ingestion of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) in fish, were evaluated. The concentrations of PBDEs, PCBs and ω-3 PUFAs in fish from Taihu Lake ranged from 98.2 to 269pg/g, from 279 to 1071pg/g and from 0.9 to 2.0mg/g, respectively. Omega-3 PUFAs accounted for 11.2–20.9% of the total fatty acid amounts. The PBDE/PCB contamination levels were moderate. To achieve the recommended intake of 250mg/d of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the associated PUFA and PBDE/PCB intakes from the species were estimated. Consumption of the species, to achieve the recommended EPA+DHA intake, did not exceed the allowable daily consumption of contaminated fish. Even though, consumers should make a sensible choice for fish species to maximise benefits and minimise risks. [Copyright &y& Elsevier]

Abstract: We aimed to develop a double-injection model of intracerebral hemorrhage (ICH) in rabbits and to evaluate it as a tool for investigating post-ICH brain injury. Rabbits were injected with 300μL fresh autologous whole blood into the right basal ganglia. Behavioral changes were rated, brain water content (BWC) was measured and brain tissue morphology was also examined. ICH was established in 93.5% of the blood injection group. At 1, 3 and 7 days after ICH, there were significant differences in the total neurological scores (p <0.01) and BWC (p <0.01) between a sham-operated group and the ICH group. These findings suggest that the model produces a persistent neurological deficit, hematoma volume and perihematomal edema and closely mimics human hypertensive basal ganglia ICH; it is a controllable and reproducible hematoma that lends itself to quantitative investigation. [Copyright &y& Elsevier]

Abstract: Optical filters composed of Ag, , and ZnSe films were prepared on BK7 substrates by evaporation. By employing spectrophotometer, microscope, scanning electron microscope (SEM), and energy dispersive spectrum (EDS) analysis, the moisture-dependent stability of the samples was tested. The experimental results revealed that filter failure often occurs initially at defect sites. Small sputtering particles and pinhole are found to be two types of defects that induced the optical coating filter failure. The mechanisms of the defect-induced failure of the filters also are discussed in the article. [Copyright &y& Elsevier]

Abstract Cuprous oxide has important applications from photovoltaic devices to photocatalysis and nitrogen-doping can improve the p-type conductivity of cuprous oxide. Here, phase-pure cuprous oxide thin films are prepared by sputtering a copper target in the atmosphere of Ar, O 2 and N 2 with the sputtering pressure varying from 0.6 Pa–3.0 Pa. The samples deposited at 0.6 Pa is also annealed in the flow of Ar or Ar plus N 2. The results show that sputtering pressure below 1.0 Pa results in higher deposition rate and more nitrogen incorporation into cuprous oxide while sputtering pressure of 3.0 Pa leads to lower deposition rate and no nitrogen doping though the gas flow rates are the same. In nitrogen-doped Cu 2 O, nitrogen exists as β-N (atomic nitrogen), α-N 2 (-N=N-) and γ-N 2 (N N). Annealing completely removes β-N and partially turns α-N 2 into γ-N 2. Nitrogen-doped cuprous oxide has smaller resistivity and larger hole density than undoped samples. The longest time for the absorbed nitrogen molecules to stay on the copper position is estimated to be 8.45 × 10−7 s. Annealing has little effect on the electrical and optical properties of nitrogen-doped cuprous oxide though it induces a weak decomposition. Highlights • The nitrogen content in Cu 2 O was controlled by varying the sputtering pressure. • Lower sputtering pressure results in higher deposition rate. • Lower sputtering pressure favors the incorporation of nitrogen into Cu 2 O. • Lowering sputtering pressure increases the hole density. • Annealing at 400 °C results in little electrical and optical change. [ABSTRACT FROM AUTHOR]

Abstract The deposition of ZnSnN 2 by co-sputtering was studied systematically. Different deposition parameters, including substrate temperatures, N 2 flow rates and different work pressure etc. were tried and the structural, optical and electrical properties were studied. The results show that the deposition parameters to fabricate ZnSnN 2 are relatively wide. The suitable substrate temperature to obtain polycrystalline ZnSnN 2 is around 350 °C when other parameters are kept constant. Relatively larger N 2 flow rate can suppress the formation of metallic phase such as Sn and favour the deposition of ZnSnN 2 with relatively pure phase, with other parameters to be constant. The addition of the substrate bias voltage or a relatively lower power of the Sn target is harmful to the film crystallization of ZnSnN 2. The samples are considered to be wurtzite due to the absence of the orthorhombic (110) and (011) peaks at 20°–22°. The hexagonal lattice constants a and c are about 3.36–3.40 Å and 5.49 Å, respectively. The sputtering pressure can affect the structural and electrical properties of ZnSnN 2. ZnSnN 2 prepared at larger work pressure such as 7.0 Pa has a lower electron density (6.72 × 1019 cm−3) and a higher mobility (24.3 cm2 V−1 s−1) as compared with those prepared at 1.0 and 3.0 Pa. Highlights • ZnSnN 2 of relatively pure phase was fabricated successfully by cosputtering • Relatively larger N 2 flow rate can prevent the formation of metallic phase • Applying bias voltage to substrate is harmful to the film crystallization • Increasing the sputtering pressure leads to ZnSnN 2 with lower electron density • Increasing the sputtering pressure leads to ZnSnN 2 with higher mobility [ABSTRACT FROM AUTHOR]

Abstract Nitrogen atoms exist as nitrogen molecules in cuprous oxide doped with nitrogen and the thermal stability of nitrogen doping has not been studied. Here phase-pure cuprous oxide doped with nitrogen was prepared with a direct current magnetron sputtering system. The samples were then annealed at 400 °C in Ar or Ar plus N 2 for 30, 60 and 90 min and the influence of annealing is studied. The results show that annealing results in the presence of metallic copper and the release of the tensile strain in the nitrogen-doped films. In nitrogen-doped cuprous oxide without annealing, nitrogen is found to exist as atomic nitrogen (β-N) and strongly chemisorbed π-bonded nitrogen molecules (α-N 2). After annealing, atomic nitrogen (β-N) is absent and the strongly chemisorbed π-bonded nitrogen molecules (α-N 2) partially turn into weakly chemisorbed nitrogen molecules (γ-N 2). Annealing can improve the transmittance of about 550–750 nm and widen the forbidden gap. Annealing can change the hole density by changing the density of donor defects, and the density and types of nitrogen molecules doped into cuprous oxide. Highlights • Phase-pure nitrogen-doped Cu 2 O was annealed at different time and atmosphere. • Annealing results in the presence of copper and the release of tensile strain. • After annealing, nitrogen molecules are still detected in the films. • Annealing improves the transmittance and widens the forbidden band gap • Annealing can change the hole density depending the on the annealing time and gas. [ABSTRACT FROM AUTHOR]

An easy method of preparing well-crystallized Sb 2 Se 3 films and nanorods through magnetron sputtering was proposed, and their growth mechanism was examined. The microstructure, morphology, composition, and optical and electrical properties of the Sb 2 Se 3 films depended strongly on the substrate temperature ( T sub ). Sb 2 Se 3 films prepared at > 250 °C contained the orthorhombic phase without Sb 2 O 3 phase owing to the high-purity vacuum environment. Well-crystallized Sb 2 Se 3 films deposited at T sub = 325 °C showed compact grains with a bandgap of 1.23 eV and a high absorption coefficient of 10 5 cm −1 in the visible region. Photoelectrochemical measurements showed that Sb 2 Se 3 films were p-type semiconductors with excellent photoresponse. A clear photovoltaic effect with a power conversion efficiency (PCE) of 3.35% was measured for the first time by using the sputtering Sb 2 Se 3 films as absorbers in a photovoltaic solar cell. At T sub = 375 °C, highly uniform films with monodispersed Sb 2 Se 3 nanorods were obtained. The preferential orientation of the Sb 2 Se 3 crystals by self-organization was promoted by increasing T sub . By using the Sb 2 Se 3 nanorods as absorbers in a solar cell, good photoresponse and a PCE of 2.15% were achieved. [ABSTRACT FROM AUTHOR]

In this work, a simple method for fabricating Cu 2 ZnSnSe 4 (CZTSe) thin film by ion-beam sputtering without post-selenization is proposed. The influence of annealing temperature on the composition, the micro-structure, the morphology, the electrical and optical properties of CZTSe thin films has been established. The relatively low annealing temperature of 400 °C is considered as very positive for obtaining the optimized Cu-poor and Zn-rich CZTSe films with pure CZTSe phase, high crystallinity, P-type conduction and ideal optical band-gap. These interesting features have been used in the prototype photovoltaic devices with a conversion efficiency of 4.67%. These are the first results concerning the use of ion-beam sputtering CZTSe films for photovoltaic application and further improvement of device performance is expected. [ABSTRACT FROM AUTHOR]

A comprehensive survey was conducted to Masson pine ( Pinus massoniana L.) needles widely distributed in Shanghai in order to investigate the levels and homologue group patterns of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs), to identify and quantitatively assess source contributions to the total CPs in pine needle samples. The concentration ranged from not detected (ND) to 13,600 ng g − 1 with a geometric mean (GM) value of 63.7 ng g − 1 for ΣSCCPs, from 12.4 to 33,500 ng g − 1 with a GM value of 677 ng g − 1 for ΣMCCPs, and from 14.0 to 45,700 ng g − 1 with a GM value of 768 ng g − 1 for total CPs. For different sampling units, the pollution levels both for SCCPs and MCCPs in pine needles were in the same orders: Pudong > suburbs > Puxi > Chongming. These significant differences in SCCPs and MCCPs among four sampling units could be associated with difference in industrial activities and to some extent also in population density. All pine needle samples ( n = 131) were divided into 2 groups by hierarchical cluster analysis (HCA) for SCCPs and MCCPs, the most abundant homologue groups in the bulk of pine needle samples were C 11 Cl 5 − 7 and C 13 Cl 5 − 7 for SCCPs, and C 14 Cl 7 − 8 and C 15 Cl 7 − 8 for MCCPs. Correlation analysis suggested that SCCPs and MCCPs in pine needles in the studied area may be derived from different sources. Four sources for pine needles were identified by the FA-MLR model; their relative contributions to the total CP burden in pine needles were 18.0% for F1 (attributed to commercial SCCP mixture), 42.2% for F2 (attributed to commercial MCCP mixture), 29.3% for F3 (attributed to LRAT), and 10.5% for F4 (unknown source). CP contamination of atmospheric air by point sources and long-range atmospheric transport in Shanghai should receive more attention by local government. [ABSTRACT FROM AUTHOR]

Zn-doped cuprous oxide thin films were deposited by direct current magnetron co-sputtering. Pure phase thin films can be obtained when the power of the Zn target is relatively lower than that of the copper target while increasing the power of the Zn target will lead to the presence of impurities such as Cu or ZnO. Zn-doped samples have smaller lattice constants, compared with undoped cuprous oxide. Zn-doped cuprous oxide thin films without impurities have larger optical band gaps and a relatively higher transmission in longer wavelength. All the cuprous oxide thin films, whether doped or undoped, are p-type, as revealed by Hall effect measurements and the positive Seebeck coefficients. Zn-doped cuprous oxide thin films have a lower conductivity due to compensation than undoped Cu 2 O thin films. The Seebeck coefficient of all samples was found to decrease with the increase in the measurement temperature. Zn-doping does not have an obvious effect on the Seebeck coefficient. At temperatures slightly higher than room temperature, Zn-doped cuprous oxide thin films have relatively smaller power factors than undoped samples. [ABSTRACT FROM AUTHOR]

Measurements of electronic structure, microstructure and thermoelectric properties of zinc antimonide thin films prepared by direct current magnetron co-sputtering were carried out. The as-deposited zinc antimonide thin film had a very high resistivity similar to insulating ceramics, which was due to a low binding energy of both zinc and antimony, with the electron scattering increases and impedes the current transport. With the increase in annealing temperature, the films became more crystalline and the thermoelectric properties were also improved. The resistivity of the film decreased rapidly with its crystallinity when the annealing temperature was above 350 °C. The Seebeck coefficients of the thin films were positive, indicating that the films were P-type. The Seebeck coefficient of those samples increased with increasing annealing temperature. The thin film annealed at 400 °C has an optimal power factor of 1.87 × 10 −3 Wm −1 K −2 with a Seebeck coefficient of 300 μVK −1 and a resistivity of 4.82 × 10 −5 Ωm at 573 K. [ABSTRACT FROM AUTHOR]

The self-catalytic growth of Al x Ga 1 − x N nanowires by chemical vapor deposition (CVD) with Ga, Al and NH 3 as the source materials and sapphire (0 0 0 1) as the substrates was studied. The Al mass, the distance between Al and Ga, and the growth temperatures have an influence on the morphologies of the samples. Without Ga, no nanowires are obtained. The Al content x in Al x Ga 1 − x N nanowires hardly changes with the starting mass of Al but slightly decreases with the increase in the growth temperature. We propose that it is Ga that acts as the catalyst during the self-catalytic growth of Al x Ga 1 − x N nanowires since the higher desorption rate of Ga and the N rich condition result in the island growth of GaN on sapphire and the island growth mode favors the formation of nanowires with the incorporation of Al. The Al content x in Al x Ga 1 − x N nanowires relies on the ratio of the saturation vapor pressure of Al to the sum of that of Ga and Al. [ABSTRACT FROM AUTHOR]

Antimonide cobalt thin films were deposited on BK7 glass substrates at various substrate temperatures by ion beam sputtering deposition with a fan-shape target. The influence of deposition temperature on the microstructure and thermoelectric properties of antimonide cobalt thin films were systematically investigated. It is found that the Seebeck coefficient of the thin film increases at first and then decreases with the increasing deposition temperature. The Seebeck coefficient of the sample deposited at 250 °C has maximum value and increases stably when the measuring temperature increased from room-temperature to 600 K. The electrical conductivity of the thin film increases significantly to 5.6 × 10 4 S cm −1 when the deposition temperature was 450 °C and then decreases greatly when the temperature increased to 500 °C and 550 °C. The behavior of electrical conductivity of the sample deposited at 250 °C changes from metallic to semiconducting after the measuring temperature exceeded 540 K. The power factor of antimonide cobalt thin film deposited at 250 °C has a maximum value of 0.93 × 10 −4 W m −1 K −2 at room-temperature and then increases to 3.5 × 10 −4 W m −1 K −2 when the measuring temperature was 540 K. [ABSTRACT FROM AUTHOR]

Highlights: [•] Zn-Sb thin film thermoelectric property enhanced via phase optimization. [•] The carrier concentration is suitable for obtaining high-quality sample. [•] Zn-Sb thin film with mixed ZnSb and Zn4Sb3 phase has highest power factor. [ABSTRACT FROM AUTHOR]

Abstract: Indium doped ZnO film was fabricated at room temperature by co-sputtering a zinc target and an indium plate under the flow of oxygen and argon. The film was then characterized and the field emission of the film was studied. The indium composition x in the film (Zn1−x In x O) is 5%. The film is hexagonal without any secondary phases or precipitates. The film has two major emission peaks, one related to the band edge emission and another possibly related to the electron acceptor transition. The possible acceptor is nitrogen occupying oxygen site in ZnO. The film is n-type and very resistive. The turn on field of the film at an emission current density of 10μA/cm2 is 17.5V/μm. The relatively weak field emission property is due to the unintentional incorporation of acceptors such as substitutional nitrogen and oxygen vacancies, which increase the work function of ZnO by reducing the electron density and lowering the Fermi level position of the ZnO:In film. [Copyright &y& Elsevier]

Abstract: CuInSe2 (CIS) thin films were prepared by ion beam sputtering deposition of copper layer, indium layer and selenium layer on BK7 glass substrates followed by annealing at different temperatures for 1h in the same vacuum chamber. The influence of annealing temperature (100–400°C) on the structural, optical and electrical properties of CIS thin films was investigated. X-ray diffraction (XRD) analysis revealed that CIS thin films exhibit chalcopyrite phase and preferential (112) orientation when the annealing temperature is over 300°C. Both XRD and Raman show that the crystalline quality of CIS thin film and the grain size increase with increasing annealing temperature. The reduction of the stoichiometry deviation during the deposition of CIS thin films is achieved and the elemental composition of Cu, In and Se in the sample annealed at 400°C is very near to the stoichiometric ratio of 1:1:2. This sample also has an optical energy band gap of about 1.05eV, a high absorption coefficient of 105 cm−1 and a resistivity of about 0.01Ωcm. [Copyright &y& Elsevier]

Abstract: Cu–In–O composite thin films were deposited by reactive DC magnetron sputtering at room temperature. The samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV/vis spectrophotometer, four-probe measurement and Seebeck effect measurement, etc. The samples contain Cu, In and O. The ratios of Cu to In and O to In increase with increase in O2 flow rates. The ratio of Cu to In is over 1 and this suggests that Cu is in excess. The obtained Cu–In–O thin films are very possibly made of rhombohedral In2O3 and monoclinic CuO. Transmittance of the films decreases with increase in O2 flow rate. The decrease in transmittance results from increase in Cu content in the films. The optical band gap of all the samples is estimated to be 4.1–4.4eV, which is larger than those of In2O3 and CuO. The sheet resistance of the films decreases with increase in O2 flow rate. Conductivity of the films is a little low, due to the addition of Cu and the poor crystalline quality of the film. The conduction behavior of the films is similar to that of In2O3 and the conduction mechanism of Cu–In–O thin films is through O vacancy. [ABSTRACT FROM AUTHOR]

Abstract: Ion beam sputtering process was used to deposit n-type fine-grained Bi2Te3 thin films on BK7 glass substrates at room temperature. In order to enhance the thermoelectric properties, thin films are annealed at the temperatures ranging from 100 to 400°C. X-ray diffraction (XRD) shows that the films have preferred orientations in the c-axis direction. It is confirmed that grain growth and crystallization along the c-axis are enhanced as the annealing temperature increased. However, broad impurity peaks related to some oxygen traces increase when the annealing temperature reached 400°C. Thermoelectric properties of Bi2Te3 thin films were investigated at room temperature. The Bi2Te3 thin films, including as-deposited, exhibit the Seebeck coefficients of −90 to −168μVK−1 and the electrical conductivities of 3.92×102–7.20×102 Scm−1 after annealing. The Bi2Te3 film with a maximum power factor of 1.10×10−3 Wm−1 K−2 is achieved when annealed at 300°C. As a result, both structural and transport properties have been found to be strongly affected by annealing treatment. It was considered that the annealing conditions reduce the number of potential scattering sites at grain boundaries and defects, thus improving the thermoelectric properties. [ABSTRACT FROM AUTHOR]

Abstract: A novel system for image guidance in totally endoscopic coronary artery bypass (TECAB) is presented. Key requirement is the availability of 2D–3D registration techniques that can deal with non-rigid motion and deformation. Image guidance for TECAB is mainly required before the mechanical stabilisation of the heart, when the most dominant source of misregistration is the deformation and non-rigid motion of the heart. To augment the images in the endoscope of the da Vinci robot, we have to find the transformation from the coordinate system of the preoperative imaging modality to the system of the endoscopic cameras. In a first step we build a 4D motion model of the beating heart. Intraoperatively we can use the ECG or video processing to determine the phase of the cardiac cycle, as well as the heart and respiratory frequencies. We then take the heart surface from the motion model and register it to the stereo endoscopic images of the da Vinci robot resp. of a validation system using photo-consistency. To take advantage of the fact that there is a whole image sequence available for registration, we use the different phases together to get the registration. We found the similarity function to be much smoother when using more phases. This also showed promising behaviour in convergence tests. Images of the vessels available in the preoperative coordinate system can then be transformed to the camera system and projected into the calibrated endoscope view using two video mixers with chroma keying. It is hoped that the augmented view can improve the efficiency of TECAB surgery and reduce the conversion rate to more conventional procedures. [Copyright &y& Elsevier]

Abstract: HfN x O y thin films were deposited on Si substrates by direct current sputtering at room temperature. The samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). SEM indicates that the film is composed of nanoparticles. AFM indicates that there are no sharp protrusions on the surface of the film. XRD pattern shows that the films are amorphous. The field electron emission properties of the film were also characterized. The turn-on electric field is about 14V/μm at the current density of 10μA/cm2, and at the electric field of 24V/μm, the current density is up to 1mA/cm2. The field electron emission mechanism of the HfN x O y thin film is also discussed. [Copyright &y& Elsevier]