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Analysis of soil nematode feeding groups and functional guilds were used as a valuable tool to detect heavy metal pollution. Effects of cadmium (Cd) at 5 mg/kg, mercury (Hg) at 20mg/kg, combined Cd and Hg at 5+20mg/kg on the nematode communities were studied after three months application. Nematodes were collected from soil in rhizosphere of Morning glories (Pharhiris nil) which were applied as heavy metal accumulators and were grown in the experimental pots. Both single and combined heavy metals had marked effects on the nematode abundance, life-history strategies and feeding type composition. Bacteriovores and c-p 2 group were found to be the most abundant trophic group and functional guild, respectively. Acrobeloides and Pratylenchus were the most two abundant genera, decreasing number of them was responsible for the significant difference between control and polluted treatments. Cd-5 and Cd-Hg 5+20 presented lower values of nematode diversity index (H’) and evenness index (J’) than Hg-20. The combination of Cd and Hg showed lower nematode trophic diversity (TD), in comparison with single Cd or Hg. Conversely, heavy metals addition exhibited no pronounced effect on Maturity index (MI), structural index (SI) and enrichment index (EI). Our results demonstrate that genera composition is a better indicator to short-term heavy metal effects than some common indicator indices and emphasize that deeper assemblage analyses are needed for a correct interpretation of short-term disturbance on soil nematodes.

A consistently diamagnetic persistent current (PC) of period halving ( Φ 0 /2-current) observed in mesoscopic rings is in apparent contradiction with the theoretical prediction of barely exclusively paramagnetism . By developing a super-cell method, we analytically and numerically study the magnetic response mechanics of non-interacting mesoscopic rings in both the absence and presence of random disorder. A maximal paramagnetic and/or diamagnetic PC is obtained in primary Φ 0 - and/or Φ 0 /2-period, exhibiting a remarkable quantum size effect. It is shown that for lower free energy, an electron circling the ring accumulates an additional phase on each inter-channel transition induced by magnetic flux, leading to the period halving and the paramagnetic–diamagnetic transition. Our results can well mediate the disputes between the experiments and theory. [ABSTRACT FROM AUTHOR]

High-k dielectric stacks have been used in the 20 nm generation of floating gate (FG) flash memory cells. However, electron trapping in high-k materials remains a major concern for further development of FG technology. The hybrid FG (HFG) device with high-k inter-gate-dielectric (IGD) is a promising candidate with advantages of larger windows and less cell-to-cell interference, in which the poly floating gate is replaced by an n-poly/p-metal bi-layer structure. In this paper, to continue our previous work, the window instability in HFG with engineered IGD stacks during memory operations has been extensively studied. The results show that the HFG cell with the HAH (HaH) IGD structure provides not only the largest window but also the least instability, making it a suitable candidate beyond the 1× nm flash technology node. [ABSTRACT FROM AUTHOR]

To investigate the chemical constituents from Incarvillea delavayi Bureau et Franchet, a new sesquiterpene, named delavayol, together with three known ones, was isolated by column chromatography. Spectroscopic and chemical evidence revealed the structures to be 8β,9β-dihydroxy-1(10)-eremophiliene-11,12-diol (1), oleanolic acid (2), myrianthic acid (3), and sitoindoside I (4). Compounds 3 and 4 were isolated from the genus Incarvillea for the first time. [ABSTRACT FROM AUTHOR]

Abstract: SiO x N y /high-κ dielectric stack will soon replace the conventional SiO x N y -based dielectric stacks in the future generations of flash memory cells. Characterizing and reducing electron traps in the high-κ layer is an important task, as the large trap density may limit the memory retention via the trap-assisted tunneling. Since the Post-deposition Annealing (PDA) has great impact on the microstructure of high-κ dielectric, it is important to understand how PDA affects the properties of electron traps, such as the trap density, energy and spatial distributions. It is demonstrated in this paper that, by using a recently developed two-pulse C–V measurement technique, the energy and spatial distributions of electron traps throughout the SiO2/high-κ stack can be characterized, and PDA temperatures have different impacts on traps at different energy levels and spatial locations. [Copyright &y& Elsevier]

The mortality effects of crofton weed (Ageratina adenophora, (Asteraceae)) acetone extract and biogas fermentation residue on the cabbage aphid Brevicoryne brassicae, and the risk posed to its parasitoid Diaeretiella rapae, were studied. Laboratory trials demonstrated the insecticidal activity of both substances, and this was confirmed by field experiments in which reductions of 73 and 71% aphid populations were recorded 3 days after treatment for the acetone extract and the biogas fermentation residue, respectively. The results of a laboratory contact toxicity test on inert substrates for parasitoid adults, and calculation of the Hazard Quotient (HQ) ratio, indicate a low risk for D. rapae, with HQ being consistently below the trigger value of 2. [ABSTRACT FROM AUTHOR]

Abstract: A sol–gel method was employed to prepare Ni/CaO, Ni/Sm2O3 and a series of Ni/Sm2O3–CaO catalysts dispersed uniformly. The catalytic performance in CO2/CH4 reforming and the physicochemical properties were investigated by means of GC, BET, XRD, TG/DTA and HRTEM techniques, respectively. Under the condition of an atmospheric pressure at 700°C and a GHSV of 4.8×104 ml/h/gcat, the conversion of CH4 and CO2 over 10% Ni/Sm2O3–CaO (1:4) catalyst were 60% and 63%, respectively, the selectivity of H2 and CO were 85% and 95%, significantly higher than those over Ni/CaO and Ni/Sm2O3 due to high dispersion of Ni nanometer particles and interfacial effect of support in 10% Ni/Sm2O3–CaO. [Copyright &y& Elsevier]

Abstract: A La2NiO4/ZSM-5 catalyst was prepared by the sol–gel method, which ensured high dispersion of the metal and high activity in the CO2 reforming of methane. The catalytic performance, catalyst stability and coke deposition as well as the influence of the doped La species on the Ni/ZSM-5 catalyst were investigated. The results show that the conversion of CO2 and CH4 to syngas and the selectivity of CO and H2 observed over the La2NiO4/ZSM-5 catalyst were significantly higher than those over a Ni/ZSM-5 or La2NiO4/γ-Al2O3 catalyst. Such results suggest that the doping of the rare earth ion (La3+) in the ZSM-5 not only enhanced the stability of the catalyst, but also increased the catalytic activity. In addition, the catalysts were characterized by X-ray diffraction (XRD), BET and thermogravimetic and differential thermal analysis (TG/DTA). The X-ray diffraction (XRD) studies revealed that the prepared catalyst, La2NiO4, exhibited a typical spinel structure and was uniformly dispersed both on the surface and in the ZSM-5 zeolite channels. During the CO2/CH4 reforming, the La2O3 generated from the La2NiO4 decomposition was transformed into La2O2CO3 in an atmosphere of CO2, which promoted CO2 adsorption on the surface of the catalyst. The TG/DTA results indicate that the amount of carbon deposition on the La2NiO4/ZSM-5 catalyst was smaller than the amount on the Ni/ZSM-5 catalyst, and that there were at least two kinds of carbon deposition on the used La2NiO4/ZSM-5 catalyst. However, only one kind of carbon deposition existed on the used Ni/ZSM-5 catalyst. [Copyright &y& Elsevier]

Abstract: The recent development of silicon-based microreactors requires conventional catalyst carriers to be trimmed down to the sub-micrometer regime while keeping their complex geometrical shapes unchanged. In this work, we use a “top-down” etching approach to fabricate Al2O3 nano-trilobe carriers from the inter-channel parts of pseudo-hexagonally arranged one-dimensional channels of anodic alumina membranes. With a dilute NaOH (0.04M) etchant and prolonged etching time (1.5h), highly regulated Al2O3 nanocarriers have been prepared into two major forms: well-aligned (bundles) and freestanding trilobes. It has been found that the Al2O3 nano-trilobes are generated only on the upward facing of the membranes owing to the support provided by less etched membrane underneath and a less vibrant region in fluid exchange. The etching process can be described as a nucleophilic reaction that involves an attachment of hydroxyl ions to Lewis acid sites of aluminum cations. The amorphous as-prepared nano-trilobes can be further heat-treated to any crystallographic phases. For example, phase pure polycrystalline θ-Al2O3 nano-trilobes have been prepared at 1000°C in laboratory air. Future applications of these nanocarriers have also been discussed. [Copyright &y& Elsevier]

The paper extends a recently published Smith predictor scheme for controlling integrating and unstable processes with time delay, which results in a simpler control structure and improved tuning capacities for reference inputs and load disturbances. In the proposed scheme, a proportional controller is subtly employed to stabilise the setpoint response, and then an H2 optimal controller is analytically designed for setpoint tracking. To obtain the integral-squared-error (ISE) performance objective, a practically desired disturbance rejection transfer function is proposed to design the disturbance estimator in the inner closed loop of the proposed control structure. Essentially, the proposed control structure gives two-degrees-of-freedom (2DOF) control and correspondingly the setpoint and load disturbance responses can each be tuned conveniently by a single control parameter. Hence the setpoint response is decoupled from the load disturbance response, and both can be quantitatively estimated in terms of the proposed analytical tuning procedures. Simulation examples are included to show the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

A simple and reliable method has been developed for the controlled growth of well-aligned carbon nanotubes patterns with different sizes and shapes on a silicon substrate. A patterned film of sputtered cobalt on the silicon was prepared by a lift-off process, and the carbon nanotubes were grown via chemical vapor deposition using ethylenediamine as a precursor. The carbon nanotubes are vertically aligned with high density within the micro patterns. The diameter of carbon nanotubes is determined by the thickness of cobalt film while the length of the nanotubes can be controlled by varying the reaction time. The bamboo-like multi-walled carbon nanotubes have been observed by high-resolution transmission electron microscopy. The micro-Raman spectrum further confirmed the graphitic structure of the nanotubes. The potential application of the carbon nanotubes to flat-panel displays is demonstrated by the ability to provide stable high field-emission current densities. [Copyright &y& Elsevier]

Abstract: To improve the knowledge of nematode communities in the Liaohe estuary, the spatiotemporal variations of free-living nematode communities (density, diversity and trophic structure) in the protected zone (PZ) and the development zone (DZ) were seasonally studied. Soil nematode communities were analysed at the depths of 0–10 and 10–20 cm. The results showed that bacterial feeder nematodes were the most abundant trophic groups in both depths and at both sites. Nematode abundance and plant-parasitic nematodes maturity index/maturity index in the DZ were higher than that in the PZ (p < 0.05); trophic diversity, Shannon index, fungivore/bacterivore ratio and Wasilewska index in the PZ were higher than those in the DZ (p < 0.05). No significant differences were found in nematode indices between soil layers. Structural equation modelling (SEM) revealed that season, plant biomass and soil properties explained 78% of the variation in soil nematode, and plant biomass controlled nematodes indirectly through affecting soil properties. In general, anthropogenic activities could affect nematode communities, but the degree of influence varied with seasonal change. [Copyright &y& Elsevier]

A probing technique to obtain the energy distribution of positive charges in high-k gate stack dielectrics, both within and beyond the substrate bandgap, has been proposed. The energy distribution of different high-k devices has been investigated and attention has been paid to their differences from the single-layered SiON devices. The results obtained from the technique demonstrate the existence of different types of positive charges with each type of them dominating a different energy region. It is observed that the positive charges in high-k stacks are dominated by the as-grown hole traps below the valence band and the cyclic positive charges within the bandgap. The increase in the cyclic positive charges in thinner high-k devices suggests higher NBTI for future CMOS technologies. It is also observed from the energy profile that the metal gate can impact the NBTI substantially. The energy profile obtained from this technique clearly indicates that process optimization is essential for minimizing NBTI in the high-k gate stacks. [ABSTRACT FROM AUTHOR]

Abstract: The ternary oxide Li6Gd(BO3)3:Ce crystals with dimensions up to Ø14×100mm3 were prepared by the modified Bridgman method. The crystallinity of crystal was measured using X-ray rocking curve analysis. The composition of the inclusions existing in the crystal was measured by electronic microprobe. The optical properties at room temperature were investigated by transmittance spectra and X-ray stimulated luminescence spectra (XSL). [Copyright &y& Elsevier]

Double-C60-end-capped poly(ethylene oxide) (FPEOF) was reinforced with acid-treated multi-walled carbon nanotubes (MWNTs). The storage modulus of FPEOF was significantly enhanced, whereas the crystallization behavior was not significantly affected upon the incorporation of MWNTs. Fourier transform infrared spectroscopy showed the existence of hydrogen-bonding interactions between the ether oxygen atoms on FPEOF and proton-donating functionalities on the MWNTs, leading to a strong matrix-filler interfacial adhesion. The low-temperature storage modulus of a FPEOF/MWNT composite (6.0 GPa) is more than twice that of a poly(ethylene oxide)/fluorinated single-walled carbon nanotube composite (2.5 GPa) with the same nanotube loading of 4 wt%. The thermal stability of FPEOF is also improved by the addition of MWNTs. [Copyright &y& Elsevier]

In situ functionalized multi-walled carbon nanotube (MWNT)/Phenoxy composites were prepared by melt mixing Phenoxy with MWNT and 1-(aminopropyl)imidazole (NIm). Composites with 4.8 wt% or more of in situ functionalized MWNT show higher storage modulus than Phenoxy, provided a sufficient amount of NIm was used to aid in the dispersion of the hydrophobic MWNTs in the hydrophilic Phenoxy matrix. [Copyright &y& Elsevier]