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The largest mass extinction event in the Phanerozoic, known as the end-Permian mass extinction (or EPME, ca. 252 Ma) is coincident with the main eruption phase of Siberian Traps volcanism (ca. 252 to 250 Ma), a large igneous province (LIP). This LIP is estimated to have a volume larger than 2 × 106 km3 and to have released both mantle carbon dioxide (CO2) through extrusions and thermogenic methane (CH4) and carbon dioxide (CO2) through intrusions. The climatic consequences of these greenhouse gases is detrimental to both marine and terrestrial life and may have delayed the recovery of ecosystems after the extinction. Quantitatively, the amount of CO2 released can be estimated using global carbon (C) cycle model or plant and soil-based proxies with varying time resolution. In light of the recent advances in geochemical proxies of ocean anoxia and acidification, we review the latest uranium isotopes (δ238U) and calcium isotope (δ44/40Ca) records and Earth system modeling results to summarize the environmental response to the forcing of increased atmospheric CO2 concentrations. The extent of increase in oceanic anoxic area can be estimated by δ238U, and the δ44/40Ca records may be used to evaluate ocean acidification. This evidence suggests that excessive nutrient load in the ocean (decreased strength of meridional overturning circulation) and ocean acidification in poorly buffered seawater (potentially triggered by the Siberian Traps LIP) worked together to create the most severe biological crisis and delayed recovery of life in the Earth’s history.

This paper investigates the characteristics of turbine wake which is the major factor determining the turbulence in wind farm and overall wind farm performance. Using the lattice Boltzmann method (LBM) and the large eddy simulation (LES) approach, dynamic simulations of detailed fluid flow and wake trajectory induced by the MEXICO wind turbine were carried out. Moreover, with the help of adaptive mesh refinement (AMR) method, the lattice units were allowed to be automatically refined to allocate more grid points on the solid walls and in the wake region. The simulation results were firstly compared with the experimental data for validation of the numerical model, as well as for investigation of the impact of sub‐grid scale (SGS) turbulence models. Within the present modeling framework, the characteristics of transient wake propagation, detailed flow field, and rotor‐tower interaction were investigated, and the effect of tip‐speed ratio was also analyzed. The present work indicates that, with a suitable SGS turbulence model, the LBM‐LES method is an effective way for dynamic simulations of wake structures induced by a wind turbine with a rotating rotor.

OBJECTIVE The expression of miR-338-5p has been reported to be upregulated in colorectal cancer (CRC) tissues. Clinicopathological features indicate that miR-338-5p overexpression correlates with the metastatic status of CRC. This study was aimed to investigate the diagnostic value of serum miR-338-5p for CRC. METHODS Peripheral blood samples were collected from 210 participants, including 80 patients with CRC, 50 with colorectal polyps and 80 healthy controls. Serum miR-338-5p was quantified by quantitative reverse-transcription polymerase chain reaction. The area under the receiver operating characteristic curve (AUROC) was used to estimate the diagnostic value of miR-338-5p, carcinoembryonic antigen (CEA) and the combination of these two biomarkers. RESULTS Serum miR-338-5p levels (fold change) in patients with CRC and colorectal polyps, and controls were 4.94 ± 1.13, 4.12 ± 0.75 and 3.07 ± 0.75, respectively. Significant differences were observed between the groups (P < 0.001). The AUROC of miR-338-5p was 0.923 (95% CI 0.882-0.964) and 0.845 (95% CI 0.792-0.898), respectively, for distinguishing CRC from healthy controls or from those without CRC. The AUROC of the combination of miR-338-5p and CEA was 0.932 (95% CI 0.882-0.964), with a sensitivity of 85%, a specificity of 88.8% at a cut-off value of 8.16. CONCLUSIONS Circulating miR-338-5p may serve as a potential noninvasive diagnostic biomarker for detecting CRC. The combination of miR-338-5p and CEA exhibits the highest diagnostic value in our study.

Objective Hepatocellular carcinoma (HCC) is a high-burden disease. Peroxiredoxin 1 (PRDX1) is a member of the peroxiredoxin family of antioxidant enzymes. The aim of this study was to assess the value of PRDX1 for predicting HCC recurrence after curative resection and to explore the role of PRDX1 in HCC cell migration and invasion. Methods Data of patients with HCC who had undergone complete resection between 2002 and 2006 were collected. Immunohistochemical detection of PRDX1 in HCC tissue and adjacent non-cancerous tissue was conducted. Kaplan-Meier survival estimate and log-rank test were used to assess the relationship between PRDX1 expression and prognostic significance. HCC cell migration and invasion together with the interaction between PRDX1 and ubiquitin C-terminal hydrolase 37 (UCH37) were studied in vitro. Results PRDX1 was expressed at lower levels in HCC tissues than in adjacent non-cancerous tissues, and PRDX1 was found to be an independent risk factor for disease-free survival and overall survival. PRDX1 restrained cell migration and invasion in vitro. PRDX1 was found to interact with UCH37 to affect HCC cell migration and invasion. Conclusion PRDX1 restrains cell migration and invasion in HCC cell lines and that may be involved in a UCH37-relevant pathway, suggesting that PRDX1 may be a new marker for HCC recurrence after surgery.

ATP-sensitive K+ (K-ATP) channels play significant roles in regulating the excitability of dopamine neurons in the substantia nigra zona compacta (SNC). We showed previously that K-ATP channel function is up-regulated by AMP-activated protein kinase (AMPK). This study extended these studies to the neurons adjacent to the SNC in the ventral tegmental area (VTA). Using patch pipettes to record whole-cell currents in slices of rat midbrain, we found that the AMPK activator A769662 increased the amplitude of currents evoked by the K-ATP channel opener diazoxide in presumed dopamine-containing VTA neurons. However, current evoked by diazoxide with A769662 was significantly smaller in VTA neurons compared to SNC neurons. Moreover, a significantly lower proportion of VTA neurons responded to diazoxide with outward current. However, A769662 was able to increase the incidence of diazoxide-responsive neurons in the VTA. In contrast, A769662 did not potentiate diazoxide-evoked currents in presumed non-dopamine VTA neurons. These results show that AMPK activation augments K-ATP currents in presumed dopamine neurons in the VTA and SNC, although diazoxide-evoked currents remain less robust in the VTA. We conclude that K-ATP channels may play important physiological roles in VTA and SNC dopamine neurons.

The blade element momentum (BEM) theory is widely used in aerodynamic performance calculations and optimization applications for wind turbines. The fixed point iterative method is the most commonly utilized technique to solve the BEM equations. However, this method sometimes does not converge to the physical solution, especially for the locations near the blade tip and root where the failure rate of the iterative method is high. The stability and accuracy of aerodynamic calculations and optimizations are greatly reduced due to this problem. The intrinsic mechanisms leading to convergence problems are addressed through both theoretical analysis and numerical tests. A term from the BEM equations equals to zero at a critical inflow angle is the source of the convergence problems. When the initial inflow angle is set larger than the critical inflow angle and the relaxation methodology is adopted, the convergence ability of the iterative method will be greatly enhanced. Numerical tests have been performed under different combinations of local tip speed ratio, local solidity, local twist and airfoil aerodynamic data. Results show that the simple iterative methods have a good convergence ability which will improve the aerodynamic or structural design of wind turbines. Copyright © 2017 John Wiley & Sons, Ltd.

A series of Mannich base monophenol ligands [2,4-tBu2-6-CH2NMe2-PhOH (), 2,4-tBu2-6-CH2NEt2-PhOH (), 2,4-tBu2-6-CH2Py-PhOH (), 2-tBu-4-Me-6-CH2Py-PhOH (), 4-tBu-2,6-(CH2Py)2-PhOH ()] were synthesized by Mannich reaction using phenol and formaldehyde reacting with secondary amine. A series of homoleptic lanthanide complexes [LaA3 (), GdA3 (), LaB3 (), GdB3 (), LaC3 (), GdC3 (), LaD3 (), GdD3 (), LaE3 (), GdE3 ()] were prepared by amine elimination reactions of the ligands with Ln[N(SiMe3)2]3 (Ln = La, Gd). Complexes , , , and were all characterized using NMR spectra, and the structures of complexes and were determined using single-crystal X-ray diffraction. Complexes and are isostructural, and the lanthanum center exhibits a distorted octahedral geometry, in which the O(1), O(2) and O(3) atoms occupy three positions and N(1), N(2) and N(3) atoms occupy the other three positions. All complexes were characterized using elemental analysis and infrared spectra. The catalytic properties of complexes for the ring-opening polymerization of e-caprolactone were studied, and the results show that all complexes are efficient initiators for this ring-opening polymerization reaction. Copyright © 2016 John Wiley & Sons, Ltd.

The brachiopods from the upper part of the Mobarak Formation at the Kiyasar section in the eastern Alborz Mountains, northern Iran, have been studied in detail. Fifteen species assigned to 13 genera of Strophomenida, Orthotetida, Orthida, Productida, Athyridida and Spiriferida are described. The fauna is determined as early Visean in age based on the presence of Eomarginifera paucispinosa, Grandispirifer mylkensis and Unispirifer sp., and their associated foraminifers Uralodiscus, Paraarchaediscus, Glomodiscus and Endothyra, though taxa ranging through the Tournaisian–Visean are also present. A comparison of its palaeogeographical affinities with other faunas show that the Alborz brachiopod fauna maintains strong Palaeotethyan affinities based on its general similarities with those of Eurasia, North America and Australia. This is suggestive of a prevailing oceanic current that circulated between the northern and southern shelf sea of the Palaeotethys Ocean, with which the warm-water brachiopod taxa were widespread in the Palaeotethyan Realm through the early Visean. Copyright © 2016 John Wiley & Sons, Ltd.

The first attempt of constructing supramolecular prodrug micelles based on the host-guest interaction between water-soluble pillar(6)arene (WP6) and a novel doxorubicin (DOX)-based drug-drug conjugate (G) is reported, in which the drug-drug conjugate is synthesized by conjugating anticancer drug DOX with another drug isoniazide via the acid-cleavable hydrazone bond. The obtained WP6⊃G micelles are stable under physiological conditions, whereas the cumulative release of DOX is approximate to 100% within 30 min at pH 5.5 by simulating the endo-lysosomal environment at 37 ℃. Therefore, this WP6-based prodrug micelles can achieve efficient DOX ac- cumulation in the acidic tumor cells within a short period of time, which is very important and valuable; meanwhile it can also reduce the unexpected premature burst release under physiological condition. Furthermore, cellular in- ternalization and localization experiments demonstrated that these prodrug micelles enter cancer cells mainly via endocytosis and can lead to significant drug accumulation in SKOV3 cancer cells, implying its promising future for cancer therapy.

In this paper, a computational model for predicting the aerodynamic behavior of wind turbine wakes and blades subjected to unsteady motions and viscous effects is presented. The model is based on a three-dimensional panel method using a surface distribution of quadrilateral sources and doublets, which is coupled to a viscous boundary layer solver. Unlike Navier-Stokes codes that need to solve the entire flow domain, the panel method solves the flow around a complex geometry by distributing singularity elements on the body surface, obtaining a faster solution and making this type of codes suitable for the design of wind turbines. A free-wake model has been employed to simulate the wake behind a wind turbine by using vortex filaments that carry the vorticity shed by the trailing edge of the blades. Viscous and rotational effects inside the boundary layer are taken into account via the transpiration velocity concept, applied using strip theory with the cross sectional angle of attack as coupling parameter. The transpiration velocity is obtained from the solution of the integral boundary layer equations with extension for rotational effects. It is found that viscosity plays a very important role in the predictions of blade aerodynamics and wake dynamics, especially at high angles of attack just before and after boundary layer separation takes place. The present code is validated in detail against the well-known MEXICO experiment and a set of non-rotating cases. Copyright © 2014 John Wiley & Sons, Ltd.

To investigate the image quality and radiation dose of combined coronary and carotid/cerebrovascular angiography with ECG gating and iterative reconstruction using 256-slice CT compared with the findings with the two examinations performed separately.One hundred sixty-five consecutive patients underwent a single-injection single-pass combination of coronary and carotid/cerebrovascular CT angiography (group A), coronary CT angiography alone (group B), or carotid/cerebrovascular CT angiography alone (group C). We assessed the image quality of the combined and separate examinations and calculated the respective effective radiation doses. We evaluated the differences in the proportions of image quality grade between the combination and single-examination groups. Diagnostic performance of the combined scanning for detecting significant vascular stenosis has been compared with reference digital subtraction angiography (DSA) in the patient subgroup of group A.There was no significant difference in age, body mass index (BMI), or gender distribution among the 3 groups (all P 0.05). But there was significant difference in scan length, DLP, and effective dose among the 3 groups (all P 0.05). There were no significant differences in the effective radiation dose of coronary scanning between groups A and B (P 0.05), while the effective radiation dose of carotid/cerebrovascular scanning in group A was significantly lower than that in group C (P 0.05), and the total effective radiation dose in group A were relatively low (2.21 ± 1.38 mSv). The differences of the proportion of carotid/cerebrovascular image quality grades between groups A and C were not significant (P 0.05). In a subgroup of group A of 30 patients with DSA, combined computed tomographic angiography successfully detected 56 coronary stenosis on per-segment basis, and 62 stenosis on carotid and cerebral artery. The sensitivity, specificity, positive and negative predictive value (NPV) of coronary stenosis were 91.80%, 95.60%, 87.50% and 97.21%, respectively. The sensitivity, specificity, positive and NPV of carotid/cerebrovascular stenosis were 93.55%, 94.68%, 92.06% and 95.70%, respectively.Combination of coronary and carotid/cerebrovascular angiography with 256-slice CT scanner with prospective ECG gating and iterative reconstruction produces diagnostic-quality images of the coronary, carotid, and cerebrovascular systems in a single examination, using less contrast medium and a lower radiation dose than when the two examinations are performed separately. This novel technique has high accuracy in detecting significant stenosis in one image setting.

Aerodynamic and structural dynamic performance analysis of modern wind turbines are routinely estimated in the wind energy field using computational tools known as aeroelastic codes. Most aeroelastic codes use the blade element momentum (BEM) technique to model the rotor aerodynamics and a modal, multi-body or the finite-element approach to model the turbine structural dynamics. The present work describes the development of a novel aeroelastic code that combines a three-dimensional viscous–inviscid interactive method, method for interactive rotor aerodynamic simulations (MIRAS), with the structural dynamics model used in the aeroelastic code FLEX5. The new code, called MIRAS-FLEX, is an improvement on standard aeroelastic codes because it uses a more advanced aerodynamic model than BEM. With the new aeroelastic code, more physical aerodynamic predictions than BEM can be obtained as BEM uses empirical relations, such as tip loss corrections, to determine the flow around a rotor. Although more costly than BEM, a small cluster is sufficient to run MIRAS-FLEX in a fast and easy way. MIRAS-FLEX is compared against the widely used FLEX5 and FAST, as well as the participant codes from the Offshore Code Comparison Collaboration Project. Simulation tests consist of steady wind inflow conditions with different combinations of yaw error, wind shear, tower shadow and turbine-elastic modeling. Turbulent inflow created by using a Mann box is also considered. MIRAS-FLEX results, such as blade tip deflections and root-bending moments, are generally in good agreement with the other codes. Copyright © 2017 John Wiley & Sons, Ltd.

A Kubergandian (Kungurian) fusuline fauna from the lower part of the Lugu Formation in the Cuozheqiangma area, central Qiangtang Block is described. This fusuline fauna belongs to the Southern Transitional Zone in palaeobiogeography, and is characterised by the presence of the distinctive bi-temperate genus Monodiexodina and many genera common in lower latitude Tethyan areas such as Parafusulina and Pseudodoliolina. The occurrence of Monodiexodina in the fauna confirms that the seamount-type carbonates of the Lugu Formation did not originate from the Palaeotethys Ocean, but rather from a branch of the Neotethys Ocean after the rifting of the Qiangtang Block from the Tethys Himalaya area in the Artinskian. © 2014 Geological Society of China.

The purpose of the present work is to validate the capability of the actuator line method to compute vortex structures in the near wake behind the MEXICO experimental wind turbine rotor. In the MEX ...

Polymeric materials used in memory devices have attracted significant scientific interest due to their several advantages, such as low cost, solution processability, and possible development of three-dimensional stacking devices. Polythiophenes, including tethered alkyl substituted polythiophenes and block copolymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and composites, are one of the most attractive polymeric systems for memory applications because of their commercial availability, high conductivity, and mechanical strength. In this article, recent studies of functional polythiophene for memory applications are reviewed, mostly focusing on the role of the materials in the memory functionality, optimizing the chemical structure of the polythiophene and the component of each layer in memory device. A critical summary of the proposed mechanisms, including filament formation, electric field-induced charge transfer and reduction-oxidation (redox) driven, is given to explain the resistive switching phenomena in the polythiophene system. In addition, the challenges facing the research and development in the field of polythiophene electronic memories are summarized. POLYM. ENG. SCI., 54:2470–2488, 2014. © 2013 Society of Plastics Engineers

A novel control approach is proposed to optimize the fatigue distribution of wind turbines in a large-scale offshore wind farm on the basis of an intelligent agent theory. In this approach, each wind turbine is considered to be an intelligent agent. The turbine at the farm boundary communicates with its neighbouring downwind turbines and organizes them adaptively into a wind delivery group along the wind direction. The agent attributes and the event structure are designed on the basis of the intelligent agent theory by using the unified modelling language. The control strategy of the intelligent agent is studied using topology models. The reference power of an individual wind turbine from the wind farm controller is re-dispatched to balance the turbine fatigue in the power dispatch intervals. In the fatigue optimization, the goal function is to minimize the standard deviation of the fatigue coefficient for every wind turbine. The optimization is constrained such that the average fatigue for every turbine is smaller than what would be achieved by conventional dispatch and such that the total power loss of the wind farm is restricted to a few percent of the total power. This intelligent agent control approach is verified through the simulation of wind data from the Horns Rev offshore wind farm. The results illustrate that intelligent agent control is a feasible way to optimize fatigue distribution in wind farms, which may reduce the maintenance frequency and extend the service life of large-scale wind farms. Copyright © 2012 John Wiley & Sons, Ltd.

New N-silver(I) acetylbenzamide complexes of type Ln⋅AgNC9H8O2 (L = PPh3; n = 1, 2a; n = 2, 2b; n = 3, 2c; L = P(OEt)3; n = 1, 2d; n = 2, 2e; n = 3, 2f) were prepared. These complexes were obtained in high yields and characterized by elemental analysis, 1H NMR, 13C{H} NMR, 31P{H} NMR and IR spectroscopy, respectively. The molecular structure of 2b has been determined by X-ray single-crystal analysis in which the silver atom is in a distorted tetrahedral geometry and crystallizes as cis–trans. New N-silver(I) acetylbenzamide complexes have a four-membered ring, which could influence their chemical and physical properties and modulate volatility. Metal organic chemical vapor deposition experiments were carried out successfully at 400°C and 450°C using 2e as precursor for the deposition of silver films, respectively. The high-purity silver film obtained at 400°C is dense and homogeneous. Copyright © 2012 John Wiley & Sons, Ltd.

In this paper, we propose a novel task scheduling algorithm Divisible Task scheduling Algorithm for Wireless sensor networks DTAW based on divisible load theory in heterogeneous wireless sensor networks to complete the tasks within the shortest possible time and reduce the sensors' energy-consuming. In DTAW, the tasks are distributed to the wireless sensor network by the SINK on the basis of the processing and communication capacity of each sensor. After receiving the subtasks, the intracluster sensors carry out its tasks simultaneously and send the results to cluster head sequentially. By removing communication interference between each sensor, reduced task completion time and improved network resource utilization are achieved. Each cluster head simultaneously finishes sending fused data to the SINK after fusing the data obtained from intracluster sensors. In this way, the overlap between the task performing and communication phase would be much better. Simulation results are presented to demonstrate the impacts of different network parameters on the makespan and energy consumption. The results show that the algorithm enables to reasonably distribute tasks to each sensor and then effectively reduces the time-consuming and energy-consuming. Copyright © 2012 John Wiley & Sons, Ltd.

OBJECTIVE: To determine the function of Smad ubiquitin regulatory factor 2 (Smurf2) on the development of liver fibrosis and cirrhosis. METHODS: In vivo Smurf2 expression in fibrotic and cirrhotic rat and human liver tissues were measured using reverse transcription-polymerase chain reaction, Western blot (WB) and immunohistochemistry. In vitro Smurf2 levels were determined in LX-2 cell line with or without transforming growth factor (TGF)-β1 treatment; I, III, IV collagen and laminin levels were determined by ELISA. The recombinant plasmid pcDNA3.1-Smurf2 was transfected into LX-2 cells, and WB and ELISA were utilized to analyze the expression of TGF-β receptor type I (TβRI), Smad7, collagens and laminin with or without proteasome inhibitor MG-132. Coimmunoprecipitation was utilized to characterize the interactions among these factors and the ubiquitination levels. pcDNA3.1-Smad7 vector was transfected and subsequent examinations were conducted just as Smurf2. RESULTS: Smurf2 levels were elevated in the early period of fibrotic rat liver and TGF-β1-treated LX-2 cells but were reduced in the cirrhotic livers. Smurf2 overexpression in LX-2 cells reduced TβRI and Smad7 levels, which was accompanied by decreased collagen and laminin levels. Coimmunoprecipitation demonstrated that Smurf2 interacted with TβRI and Smad7, which increased TβRI and Smad7 ubiquitin levels. Smad7 overexpression reduced the TβRI level and was accompanied by decreased collagen and laminin levels. MG-132 could antagonize these effects. CONCLUSION: Smurf2 interacts with Smad7 to suppress TGF-β-mediated liver fibrosis through the ubiquitin-dependent degradation of TβRI during the early period of liver fibrosis.

OBJECTIVE: The aim of this study was to summarize the clinical features of autoimmune pancreatitis (AIP) and review the advances in the differential diagnosis with pancreatic carcinoma, thus help to make a correct diagnosis and avoid unnecessary surgery in clinical practice. METHODS: Five patients diagnosed as AIP in accordance with the HISORt criteria in Zhongshan Hospital, Fudan University from 2008 to 2010 were enrolled in the study. Clinical features were analyzed and related literature was reviewed. RESULTS: Progressive jaundice and abdominal pain were the most frequent symptoms, as well as weight loss, together with serological changes such as elevation of alkaline phosphatase, γ-glutamyl-transpeptidase and serum bilirubin. Two of them showed high serum immunoglobulin G4 (IgG4) levels. Both focal and diffuse changes were found on computed tomography and magnetic resonance imaging. Two of our patients underwent operation because of a high suspicion of malignant tumor, and steroid therapy was administered to the other three patients diagnosed as AIP. No relapse was observed during the follow-up duration of all the patients. CONCLUSIONS: Although some recent advances have been made to help the diagnosis of AIP, the differentiation between AIP and pancreatic carcinoma is still a challenge. Clinicians must remember to exclude AIP before making a diagnosis of pancreatic carcinoma.

Six organophosphine/phosphite-stabilized silver(I) N-hydroxysuccinimide complexes of type [C4H4NO3Ag⋅Ln] (L = PPh3; n = 1, 2a; n = 2, 2b; L = P(OEt)3; n = 1, 2c; n = 2, 2 d; L = P(OMe)3; n = 1, 2e; n = 2, 2f) were prepared. These complexes were obtained in high yields and characterized by elemental analysis, 1H NMR, 13 C{1H} NMR and IR spectroscopy, respectively. The molecular structure of 2b has been determined by X-ray single-crystal analysis in which the silver atom is in a distorted tetrahedral geometry. An interstitial methanol solvent molecule is hydrogen bonded to the oxygen atom of N-hydroxysuccinimide molecule. Complex 2f was used to deposit silver films by metal-organic chemical vapor deposition (MOCVD) for the first time. The silver film obtained at 480 °C is dense and homogeneous, which is composed of many well-isolated, granular particulates spreading all over the substrate surface. Copyright © 2012 John Wiley & Sons, Ltd.

This paper describes an extensive assessment and a step by step validation of different turbulent boundary-layer trailingedge noise prediction schemes developed within the European Union funded wind energy project UpWind. To validate prediction models, measurements of turbulent boundary-layer properties such as two-point turbulent velocity correlations, the spectra of the associated wall pressure fluctuations and the emitted trailing-edge far-field noise were performed in the laminar wind tunnel of the Institute of Aerodynamics and Gas Dynamics, University of Stuttgart. The measurements were carried out for a NACA 643-418 airfoil, at Re D 2:5 106, angle of attack of 6i to 6i. Numerical results of different prediction schemes are extensively validated and discussed elaborately. The investigations on the TNO-Blake noise prediction model show that the numerical wall pressure fluctuation and far-field radiated noise models capture well the measured peak amplitude level as well as the peak position if the turbulence noise source parameters are estimated properly including turbulence anisotropy effects. Large eddy simulation based computational aeroacoustic computations show good agreements with measurements in the frequency region higher than 1 kHz, whereas they over-predict the sound pressure level in the low-frequency region. Copyright © 2011 John Wiley & Sons, Ltd.

In the European collaborative MEXICO (Model Experiments in Controlled Conditions) project, a series of experiments was carried out on a 4.5 m diameter wind turbine rotor to validate numerical diagnostics tools. Here, some of the measured data are compared with computations of the combined actuator line/Navier–Stokes (AL/NS) model developed at the Technical University of Denmark. The AL/NS model was combined with a large eddy simulation technique and used to compute the flow past the MEXICO rotor in free air and in the DNW German-Dutch wind tunnel for three commonly defined test cases at wind speeds of 10, 15 and 24 m s −1. Two sets of airfoil data were used. Comparisons of blade loadings showed that the AL/NS technique with the modified airfoil data is in better agreement with the measurements than with the original 2D airfoil data. Comparisons of detailed near-wake velocities showed good agreement with the measurements. Computations including the influence of the geometry of the wind tunnel showed that tunnel effects are not significant and the effect of the geometry of the wind tunnel only results in a speedup of 3% at a thrust coefficient of CT = 1.Copyright © 2011 John Wiley & Sons, Ltd.

As part of a strategy to explore highly functionalized macromolecular semiconductors, two novel polyimides consisting of electron-donating carbazole and triphenylamine side groups are synthesized and characterized. Polyimide films sandwiched between an indium-tin oxide (ITO) bottom electrode and Al top electrode exhibit two accessible conductivity states and can be switched from the low-conductivity state to the high-conductivity state. Memory devices with the configuration of Al/PI(CzBD-DPBPDA)/ITO exhibit bipolar flash-type memory characteristics while that of Al/PI(TPABD-DPBPDA)/ITO demonstrate excellent unipolar ON and OFF switching behavior. Both devices show high ON/OFF current ratios up to 104 and long retention times of 104 s in ambient atmosphere.

For a wireless ad hoc network to achieve fault-tolerance, it is desired that the network is bi-connected. This means that each pair of nodes in the network have at least two node-disjoint paths between them, and thus, failure at any single node does not partition the network. In other words, in a bi-connected network, there is no cut-node (defined as a node such that the removal of it partitions the network). To make a connected but not bi-connected network become bi-connected, actions should be taken such that all cut-nodes become non-cut-nodes. In this research, we propose to deal with cut-nodes from a new perspective. Specifically, we first introduce a new concept of removable node, defined as a non-cut-node such that the removal of it does not generate any new cut-node in the network. Then, we propose to move a removable node to a new location around a cut-node. In this way, the cut-node becomes a non-cut-node, that is, the failure of it does not partition the network anymore. Algorithms are provided (i) to identify removable nodes; (ii) to match cut-nodes with a feasible set of removable nodes, in which all nodes can be simultaneously removed from the network without generating any new cut-node in the network; and (iii) to derive the final location of a removable node such that its movement distance is the shortest and the associated cut-node becomes a non-cut-node. The proposed algorithms do not guarantee the final bi-connectivity but have the merits of a large success rate (almost 100% in the simulation), a small number of moved nodes, and a short total movement distance. In addition, the proposed algorithms are shown to be effective even when there are a large portion of fixed nodes in the network. Copyright © 2011 John Wiley & Sons, Ltd.

2,2′-Position aryl-substituted tetracarboxylic dianhydrides including 2,2′-bis(biphenyl)-4,4′,5,5′-biphenyl tetracarboxylic dianhydride and 2,2′-bis[4-(naphthalen-1-yl)phenyl)]-4,4′,5,5′-biphenyl tetracarboxylic dianhydride were synthesized. A new series of aromatic polyimides (PIs) were synthesized via a two-step procedure from 3,3′,4,4′-biphenyl tetracarboxylic dianhydride and the newly synthesized tetracarboxylic dianhydrides monomers reacting with 2,2′-bis[4′-(3″,4″,5″-trifluorophenyl)phenyl]-4,4′-biphenyl diamine. The resulting polymers exhibited excellent organosolubility and thermal properties associated with Tg at 264 °C and high initial thermal decomposition temperatures (T5%) exceeding 500 °C in argon. Moreover, the fabricated sandwich structured memory devices of Al/PI-a/ITO was determined to present a flash-type memory behaviour, while Al/PI-b/ITO and Al/PI-c/ITO exhibited write-once read-many-times memory capability with different threshold voltages. In addition, Al/polymer/ITO devices showed high stability under a constant stress or continuous read pulse voltage of − 1.0 V. Copyright © 2011 Society of Chemical Industry

Four Lewis-base stabilized N-silver(I) succinimide complexes of type [Ln·Rm·AgNC4H4O2] (L = N,N,N′,N′-tetramethylethylenediamine (TMEDA), n = 1, m = 0, 2a; L = P(OEt)3, n = 2, m = 0, 2b; L = PPh3, m = 0, n = 2, 2c; L = P(OMe)3, R = TMEDA, n = 1, m = 1, 2d) were prepared by a “one-pot” synthesis methodology and characterized. The molecular structures of 2a and 2c have been determined by using X-ray single crystal analysis. Complex 2a exists as ion pair {[Ag(TMEDA)2]+[Ag(NC4H4O2)2]–} in the solid state and complex 2c is a monomer with the three-coordinate silver atom. Complex 2b was used as precursor in the deposition of silver for the first time by using MOCVD technique. The silver films obtained were characterized using scanning electron microscopy (SEM) and energy-dispersion X-ray analysis (EDX). SEM and EDX studies show that the dense and homogeneous silver films could be obtained.

The Kungurian Stage is one of the three remaining stages of the Permian that is not yet defined at the base by a Global Stratotype Section and Point (GSSP). The candidate section at the Yuryuzan' River in the Urals yields few conodonts, and contains non-marine sediments near the boundary. The search for a suitable, continuous marine succession is a principal task for the Subcommission on Permian Stratigraphy. The Leonardian, with its type area in the southwest United States, and in objective stratigraphic succession directly beneath the basal Guadalupian Roadian Stage, has priority to serve as a subseries of the Lower Permian. However, distinct provincialism limits the correlation of Leonardian fossil zones with the fusuline-based Tethyan timescale. Conodonts can be correlated in many important regions on opposite sides of Pangea, yet contradictions arise when relating conodont zones with fusuline and ammonoid zones. The different taxonomic philosophies are highly suspected for the cause of the conflicts, but also there are different conodonts from the type Roadian in West Texas. Given that the Pamir and Darvaz in central Asia are difficult to access, further investigations should focus on South China, where abundant fusulines and ammonoids facilitate correlation throughout the Tethyan region, and where conodonts permit correlation with North America.

A newly developed technique for determining the angle of attack (AOA) on a rotating blade is used to extract AOAs and airfoil data from measurements obtained during the MEXICO (Model rotor EXperiments in COntrolled conditions) rotor experiment. Detailed surface pressure and Particle Image Velocimetry (PIV) flow fields at different rotor azimuth positions are examined for determining sectional airfoil data. The AOA is derived locally by determining the local circulation on the blade from pressure data and subtracting the induction of the bound circulation from the local velocity. The derived airfoil data are compared to 2D data from wind tunnel experiments and XFOIL computations. The comparison suggests that the rotor is subject to severe 3D effects originating from the geometry of the rotor, and explains why the Blade Element Momentum technique with 2D airfoil data over-predicts the loading of the rotor. The extraction technique is verified by employing the derived airfoil characteristics as input to computations using the BEM technique and comparing the calculated axial and tangential forces to the measured data. The comparison also demonstrates that the used technique of determining the AOA is a reliable tool to extract airfoil data from experimental data. Copyright © 2010 John Wiley & Sons, Ltd.

Theoretical consideration was proposed for the frequency response of a series piezoelectric sensor to the properties of liquid and verified experimentally. This kind of sensor has sensitive and selective frequency response to the permittivity and specific conductivity of solution with excellent stability, and was applied to the determination of micro-content of water in organic solvents. The detection limit is 0.01 g/L in dioxane.

The geometries of molecules H3AXAH3 (X=O, S, Se and A=C, Si) have been optimized using STO-3G ab initio calculations and gradient method and the results are in good agreement with reported experimental values. From the STO-3G optimized geometries, we have also calculated the electronic structures of these molecules using 4–31G and 6–31G basis sets to obtain the MO energies, atomic net charges and dipole moments. The ionization potentials calculated by 6–31G basis set are in good agreement with experimental values.