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The fossiliferous lower Cambrian (Series 2) successions along the north coast of Kangaroo Island, South Australia—known collectively as the Kangaroo Island Group—can be divided into two main areas: a western succession located between Snelling Beach and Smith Bay, which comprises the Mt McDonnell Formation (base), Stokes Bay Sandstone and Smith Bay Shale; and an eastern succession that extends from Emu Bay to Point Marsden, represented by exposures of the White Point Conglomerate (base), Marsden Sandstone, Emu Bay Shale and Boxing Bay Formation (top), with an overlap in the Cape d'Estaing/Emu Bay area. Some previous interpretations of the Kangaroo Island Group stratigraphy suggest that the western succession stratigraphically underlies the eastern succession. Most of the previously reported and described Cambrian fossils come from the eastern succession, especially the internationally significant Emu Bay Shale Konservat-Lagerstätte. Here we report the trilobites Redlichia takooensis and Balcoracania dailyi from the Smith Bay Shale near Freestone Creek, indicating that the eastern and western successions are at least partly contemporaneous. The present investigation indicates that the Smith Bay Shale of the western succession can be correlated with the stratigraphic interval represented by the Marsden Sandstone and the overlying Emu Bay Shale of the eastern succession. The Kangaroo Island Group was deposited as part of a fan delta system with the eastern succession representing the proximal part, and the western succession representing the distal part of the fan delta. The lack of substantial conglomerate units within the Kangaroo Island Group to the west of Cape d'Estaing suggests that the tectonic uplift that led to the deposition of the White Point Conglomerate was concentrated in the area immediately to the north of Emu Bay. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To analyze the correlation of serum placental growth factor (PLGF), pregnancy-associated plasma protein-A (PAPP-A) and disease severity in patients with hypertensive disorders in pregnancy (HDP). PATIENTS AND METHODS: Altogether 88 pregnant women with hypertensive disorder who underwent prenatal examination and delivery in our hospital from March 2017 to February 2019 were selected and included as the research group (n=88), and 62 healthy pregnant women who underwent prenatal examination during the same period were included as the normal control group (n=62). Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of PAPP-A and PLGF in the serum of the two groups. The correlation of the expression levels of PAPP-A and PLGF with the severity of HDP was analyzed. The occurrence of adverse pregnancy outcomes in the two groups was compared, and the relationship of the expression levels of PAPP-A and PLGF with adverse pregnancy outcomes was compared. RESULTS: PAPP-A expression level in serum of pregnant women in the research group was significantly higher than that in the control group, while PLGF expression level was significantly lower than that in the control group (p<0.001). PAPP-A expression level was positively correlated with HDF severity (r=0.753, p<0.001), while PLGF expression level was negatively correlated with HDP severity (r=-0.929, p<0.001). The incidence of adverse pregnancy outcomes in the research group was significantly higher than that in the control group (p<0.05). The serum PAPP-A level of patients in the group with adverse pregnancy outcomes was significantly higher than that in the group without adverse pregnancy outcomes, while PLGF level was significantly lower than that in the group without adverse pregnancy outcomes (p<0.001). CONCLUSIONS: In conclusion, the expression levels of PAPP-A and PLGF in serum were closely related to the severity of HDP and could be used as indicators for disease monitoring. [ABSTRACT FROM AUTHOR]

Elastic scattering of electrons in a plasma is studied for its pivotal role in relating transport properties to plasma composition. A unified effective potential model is developed to describe the interactions between electrons and atoms/ions in plasma. It not only contains the static Coulomb, polarization, and exchange interaction but also considers plasma environment effects with a Muffin-tin model based on the Roothaan–Hartree–Fock atomic wave functions. For electron–electron and electron–ion interactions, the dynamical screening effect is also considered by a velocity-dependent screening length. The validity of the potential model is demonstrated in the specific case of argon plasma. The calculated differential, total, and momentum transfer cross sections, as well as the electrical conductivities at varying plasma densities and temperatures, are compared to available experimental data and other calculations. These comparisons indicate that the proposed potential has correct low density limit behavior and works well for plasma in a wide range of densities and temperatures, including warm dense matter. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots are promising materials for near infrared light emitting diodes (NIR QLEDs) owing to the widely tunable wavelength of emitted light, high quantum efficiency, and full integration with solution processing techniques. However, the imbalance of charge carriers in NIR QLEDs greatly limits their performance, which in turn narrows the scope of their application. Here, we propose an approach for improving the brightness and stability of NIR PbS QLEDs through balancing the device current by an ultra-thin inorganic aluminum oxide (Al2O3) electron suppressing layer. This modification resulted in a 7.42 W/sr/m2 peak radiance at 1.3 μm wavelength. Moreover, the halide-capped PbS-based NIR QLEDs remained stable under constant current drive for over 144 h. [ABSTRACT FROM AUTHOR]

Bi3+-Ln3+ (Ln = Dy, Er, Ho, Eu, and Sm) co-doped YVO4 phosphors are proposed as UV-absorbing luminescent converter candidate to enhance the power conversion efficiency and photochemical stability of dye-sensitized solar cells (DSSCs). The phosphors can efficiently convert UV photons in a broad range from 250 to 400 nm into visible emissions, which can be absorbed by DSSCs. Efficient broadband down-conversion UV light into near-infrared emission around 1000 nm was achieved in the YVO4:Bi3+,Yb3+ phosphors. The energy transfer from V5+-Bi3+ charge-transfer state to Yb3+ was shown to be a cooperative down-conversion type by the luminescence spectra, energy transfer efficiency, and luminescence decay curves. The YVO4:Bi3+,Yb3+ phosphors are promising for boosting the efficiency of crystalline silicon solar cells by down-converting the UV part of the solar spectrum to near-infrared photons with a twofold increase in the photon number. This research may open up promising new perspectives for designing novel luminescent materials for photovoltaic cells with high efficiency. [ABSTRACT FROM AUTHOR]

Using terahertz time-domain spectroscopy, we measured the frequency dependent complex dielectric response and conductivity of n-type single-crystal ZnO epilayers with different carrier concentrations over the frequency range from 0.1 to 3.0 THz. The measured complex dielectric response and conductivity are analyzed using Drude model. [ABSTRACT FROM AUTHOR]

We investigate the photoconductivity properties of ZnO thin films prepared by pulsed laser deposition with and without metals (Au or Pt) on the surface. The covering of nanostructured metals can largely enhance the photocurrent. Meanwhile, the dark currents have been increased significantly due to the increase in carrier concentration and mobility near the surface of ZnO thin film. Although plasmonic effect was observed by the photoluminescence enhancement, the main mechanism of the increase in the dark current and photoresponsivity for ZnO photoconductors has been interpreted by surface states, interface states, and persistent photoconductivity. [ABSTRACT FROM AUTHOR]

ZnO nanotubes were fabricated by vapor-phase transport using the mixture of ZnO and graphite powders in air. A self-catalyzed growth mechanism was proposed based on microstructure analysis by scanning electron microscopy, transmission electron microscopy, and x-ray diffraction. Raman scattering, integrated photoluminescence, and time-resolved photoluminescence were employed to explore the optical properties and the dynamic process. Combing with crystal structure and the spectral characteristics of the ZnO nanotubes, the charge carrier transport process was discussed. [ABSTRACT FROM AUTHOR]

Surface defect passivation for ZnO nanocombs (NCBs), random nanowires (RNWs), and aligned nanowires (ANWs) was performed through a metal plasma immersion ion implantation with low bias voltages ranging from 0 to 10 kV, where Ni was used as the modification ion. The depth of surface-originated green band (GB) emission is thus probed, revealing the surface origin of the GB. It is also found that the GB is closely related to oxygen gas content during growth of the nanostructures. The GB origin of NCBs and RNWs grown with higher oxygen content is shallower (∼0.5 nm), which can be completely quenched with no bias applied. However, the GB origin of ANWs grown at lower oxygen content is much deeper (∼7 nm) with a complete quenching bias of 10 kV. Quenching of the GB can be attributed to passivation of the surface hole or electron trapping sites (oxygen vacancies) by Ni ions. [ABSTRACT FROM AUTHOR]

Postgrowth annealing was carried out on ZnO thin films grown by metal-organic chemical-vapor deposition. It was found from the scanning electron microscopy and atomic force microscopy measurements that the morphology of the thin films changed drastically after annealing. The as-grown thin films consist of fine nanoscale-sized sheets with random orientation. Upon annealing at 800 °C, the ZnO nanosheets changed to three-dimensional nanoneedles. The different types of the mass transport mechanisms are discussed and correlated with the experimental results. A coarsening kinetics developed by Lifshitz and Slyozov [J. Phys. Chem. Solids 19, 35 (1961)] and Wagner [Z. Elektrochem. 65, 581 (1961)] was used to estimate the activation energy of the coarsening process. The activation energy of the Ostwald ripening in ZnO films was estimated in the first attempt, and the value is at around 1.33 eV. Hall effect and photoluminescence measurements were carried out to investigate the effect of coarsening on electrical and optical properties of the ZnO thin films. [ABSTRACT FROM AUTHOR]

The band structures of wurtzite ZnO are calculated by the empirical pseudopotential method (EPM). The eight parameters of the Zn and O atomic pseudopotential form factors are obtained with the formula of Schluter et al.[Phys. Rev. B 12, 4200 (1975)]. The band parameters are extracted by using a k·p Hamiltonian to fit the EPM results. The calculated band-edge energies (Eg, EA, EB, and EC) at the Γ point are in good agreement with the experimental results. Based on the band parameters obtained, valence subbands of wurtzite ZnO/MgxZn1-xO tensile-strained quantum wells with different well widths and Mg compositions are calculated by the six-band k·p method. [ABSTRACT FROM AUTHOR]

Based on vapor-phase transport method, manganese-doped zinc oxide (ZnO:Mn) tetropod whiskers were fabricated. The pods of the ZnO:Mn whiskers show hexagonal hollow shape with multitips at the front. X-ray diffraction and high-resolution transmission electron microscopy demonstrate that the tube pods and the tips are composed of wurtzite ZnO growing along [0001] direction. The generation of the luminescent center in ZnO whiskers and electron transport between the ground state and the excitation states of Mn2+ are analyzed by Raman-scattering, photoluminescence, and photoluminescent excitation measurements. [ABSTRACT FROM AUTHOR]

The optical band gap of ZnO thin films deposited on fused quartz by metal-organic chemical-vapor deposition was studied. The optical band gap of as-grown ZnO blueshifted from 3.13 to 4.06 eV as the growth temperature decreased from 500 to 200 °C. After annealing, the optical band gap shifted back to the single-crystal value. All the ZnO thin films studied show strong band-edge photoluminescence. X-ray diffraction measurements showed that samples deposited at low temperatures (<450 °C) consisted of amorphous and crystalline phases. The redshift of the optical band gap back to the original position after annealing was strong evidence that the blueshift was due to an amorphous phase. The unshifted photoluminescence spectra indicated that the luminescence was due to the crystalline phase of ZnO, which was in the form of nanocrystals embedded in the amorphous phase. [ABSTRACT FROM AUTHOR]

The electro-optical and response properties of a nematic liquid crystal cell driven by double-side fringe-field switching [ C. Y. Xiang, X. W. Sun, and X. J. Yin, Appl. Phys. Lett. 83, 5154 (2003) ] have been studied. The transmission-voltage curve of the double-side fringe-field cell can be modeled by the change of the maximum twist angle. It is shown that the liquid crystal layer is linearly twisted before the transmission reaches the maximum. The threshold voltage of double-side fringe-field switching is the same as that of single-side fringe-field switching. The turn-on and turn-off response times, showing four time improvement over the single-side fringe-field switching, have been derived. The experimental turn-off times of the double-sides fringe-field switching and single-side fringe-field switching cell match with the theoretical prediction. The experimental turn-on time of the double-side fringe-field switching cell shows four times improvement over the single-side fringe-field one as predicted by the theoretical analysis. [ABSTRACT FROM AUTHOR]

Nanostructural zinc oxide fibers have been fabricated by a simple vapor transport method of heating the mixture of zinc oxide, gallium oxide, and carbon powders in air. The zinc oxide nanofibers showed cauliflower-like, disordered, vertically and horizontally aligned morphologies in different temperature regions. The aligned nanofibers were composed of hexagonal zinc oxide with good crystallinity. Gallium was doped into zinc oxide with a concentration of 0.73 at. %. The growth process and the characteristics can be interpreted by a vapor-liquid-solid mechanism. The field emission of the vertically aligned zinc oxide fiber array showed a low field emission threshold, high current density, rapid surge, and high field enhancement factor. The threshold electric field is about 2.4 V/μm at a current density of 0.1 μA/cm[sup -2]. The field enhancement factor was 2991. The emission current density and the electric field followed the Fowler–Nordheim relationship. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

An approach improving diamond–metal adhesion has been developed based on modeling predictions and experimental verifications on the interfacial stresses modified by catalytic reaction. It is found that N-plasma irradiating onto Ti and tungsten-carbide substrates generates tensile surface stresses while C-plasma irradiation creates strongly compressive stress at the surfaces, both of which deteriorate the diamond–metal adhesion. It is also found that surface oxidation prevents diamond nucleation. Therefore, we applied a graded TiCN interlayer with carefully adjusting the ratio of C and N in the gas mixture to neutralize the interfacial stress and, hence, we have improved the diamond–metal adhesion substantially. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The electro-optical and response properties of a nematic liquid crystal cell driven by double-size fringe-field switching are studied. The findings show that turn-on and turn-off response times, showing four time improvement over the single-side fringe-field switching have been derived.

Focuses on a study which focused on the epitaxial growth of gallium nitride thin films deposited on sapphire(0001) substrates with a thin zinc oxide buffer layer by a liquid target pulsed laser deposition technique. Experimental details; Crystal structures; Photoluminescence measurement of the thin film; Conclusions.

Transparent conductive films (TCFs) based on rectangularly shaped silver nanowires (AgNWs) with different width-to-height ratios were theoretically studied. We show that tall AgNWs (height > width) possess higher transmittance and lower sheet resistance compared to other configurations of AgNWs. Moreover, tall AgNWs possesses significantly higher optical haze, which makes them a transparent conductor of choice for thin solar cell applications. For applications requiring low haze such as displays and touch screens, we propose an updated figure of merit embodying transmittance, sheet resistance and haze, allowing tuning width-to-height ratio to achieve a reasonable AgNW TCF performance trade-off. Obtained results offer a means for deeper analysis of AgNW properties for many optoelectronic applications. [ABSTRACT FROM AUTHOR]

Temperature dependent lasing was demonstrated in a dye-doped two-dimensional hexagonal photonic crystal made of holographic polymer-dispersed liquid crystals (LCs) along ΓM direction in TE polarization. A redshift in lasing peaks was observed as the temperature increased from 25 to 45 °C. The downward movement of photonic band of TE polarization, majorly caused by the decrease in the anisotropy of LC droplets with the increase in temperature, is responsible for the redshift in lasing peaks. [ABSTRACT FROM AUTHOR]

Single-crystalline, transparent conducting ZnO nanowires were obtained simply by Ti plasma immersion ion implantation (PIII). Electrical transport characterizations demonstrate that the n-type conduction of ZnO nanowire could be tuned by appropriate Ti-PIII. When the energy of PIII is increased, the resistivity of ZnO decreases from 4×102 to 3.3×10-3 Ω cm, indicating a semiconductor-metal transition. The failure-current densities of the metallic ZnO could be up to 2.75×107 A/cm2. Therefore, this facile method may provide an inexpensive alternative to tin doped indium oxide as transparent conducting oxide materials. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We aimed at analyzing the efficacy of low molecular heparin in the prevention of venous thromboembolism (VTE) after resection of primary liver cancer and at exploring the correlation of VTE with P-selectin (CD62P), lysosomal granule glycoprotein (CD63), platelet activating factor (PAF) and plasma D-dimer (D-D). PATIENTS AND METHODS: A total of 233 patients treated with primary liver cancer resection in our hospital from February 2014 to October 2016 were enrolled in this study. The patients were randomly divided into the observation group (n=117) and the control group (n=116). The observation group received a subcutaneous injection of low molecular weight heparin at 2-7 days after surgery, and the control group was not treated with anticoagulation. The prevalence of VTE and the changes of CD62P, CD63, PAF, and D-D before and after treatment were compared between the two groups. The VTE prevalence after surgery, the changes of CD62P, CD63, PAF, D-D before and after surgery and the correlation of the above indexes with VTE were analyzed. RESULTS: The prevalence of VTE in the observation group was 0.85% (1/117), which was lower than that of the control group (13.79%) (16/116); the difference was statistically significant (p<0.05). There was no significant difference in blood coagulation function between the two groups before and after operation (p>0.05). The CD62P, CD63, PAF, and D-D of the two groups were continuously decreased after the operation, and the serum CD62P, CD63 and plasma D-D of the observation group 6 d and 10 d after operation were lower than that of the control group; the difference was statistically significant (p<0.05). The serum CD62P, CD63 and plasma D-D in the VTE group 6 d and 10 d after operation were lower than those in the non-VTE group; the differences were statistically significant (p<0.05). CONCLUSIONS: Low molecular weight heparin can effectively prevent VTE after primary liver cancer resection. Regularly monitoring CD62P, CD63, PAF, and D-D in patients after the operation is pivotal for early diagnosis, evaluation and treatment of VTE. [ABSTRACT FROM AUTHOR]

The growing demand for flexible low-power reflective photonics and display devices has fueled research into high quality flexible materials with super-reflectivity and high stability to environmental influences including broad working temperature ranges and excellent mechanical stress insensitivity. Although tremendous effort has been dedicated towards developing cholesteric film materials with super-reflectivity or high stability, challenges still remain in achieving both due to the existence of liquid crystals that are susceptible and sensitive to external stimuli, such as temperature or mechanical stress. Herein, we fabricate a novel flexible film having super-reflectivity (＞80%), a broad working temperature range (−70 °C to 70 °C) and excellent mechanical stress insensitivity (up to 7.88 × 105 Pa) via a “washout–refill–assemble” approach by refilling a polymer (optical adhesive) into a cholesteric film assembled using two cholesteric templates with opposite handedness based on a liquid crystal/reactive mesogen mixture, where no liquid crystals exist in the final fabricated multi-layer film. The all-polymer structure of the film selectively reflects color due to the helical structure of the cholesteric liquid crystals applied in the fabrication procedure of the cholesteric templates with both super-reflectivity and high stability to temperature and mechanical stress. Flexible displays with vivid colors based on proposed films have been demonstrated using the direct printing method on glass and flexible substrates. These materials show great potential for applications such as low-power flexible reflective displays, and other photonic flexible devices including lasers, smart windows, color pixels in digital photographs, and colored cladding of a variety of objects. [ABSTRACT FROM AUTHOR]

The characteristics of organic light-emitting devices based on tris-(8-hydroxyqunoline) aluminum with an ultrathin tetrahedral amorphous carbon (ta-C) film on indium tin oxide have been investigated. The device with a 1.0-nm ta-C layer has the highest current and power efficiency. The current efficiency of a device with a ta-C layer thickness of 1.0 nm is 3.7 cd/A at 20 mA/cm2, however, the current efficiency of a standard device without a ta-C layer is 2.56 cd/A at the same current density. The current efficiency is improved by 46% compared to the standard device. Although there is a 1.2-V increase in driving voltage for 100-cd/m2 luminance, the power efficiency is still improved by 22% compared to that of the standard device. The improvement of the efficiency is due to smoothing indium tin oxide surface, blocking hole injection from anode and balancing hole and electron currents. The optimal thickness of ta-C layer for hole injection mechanics can be understood by tunneling. [ABSTRACT FROM AUTHOR]

The significance of trilobites described from six cores from the Kalladeina 1 drillhole from the Warburton Basin, northeastern South Australia is discussed. The oldest are from a dark grey shale of Core 16 from a depth of 3453.7–3455.8 m; they are of possible early Drumian (Cambrian Series 3, middle Cambrian) age. The youngest come from a dark grey shale of Core 4 at a depth of 2017.2–2022.04 m. This fauna contains the trilobitesAsaphellus? sp.,Yosimuraspissp.,Conophryssp. andProtopliomerops? sp. thus indicating a Tremadoc (earliest Ordovician) age. These are the youngest known trilobites from the Warburton Basin and the youngest known in South Australia. [ABSTRACT FROM AUTHOR]