bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of asphaltene aggregation induced by supercritical CO2: insights from molecular dynamics simulation
Authors: Liu Bing , Li Jiawei , Qi Chao , Li Xiaoqi , Mai Tingyi , Zhang Jun
Published: November 2017

Asphaltene was found first separated and then associated in aggregation process due to the selective extraction.
Normal and abnormal dielectric relaxation behavior in KTaO3 ceramics
Authors: Tong Lei , Sun Jie , Wang Shuting , Guo Youmin , Li Qiuju , Wang Hong , Wang Chunchang
Published: November 2017

KTaO3 ceramic samples were prepared via a conventional solid state reaction route.
Chemical vapor deposition-assisted fabrication of a graphene-wrapped MnO/carbon nanofibers membrane as a high-rate and long-life anode for lithium ion batteries
Authors: Wang Juan , Li Chao , Yang Zhenyu , Chen Deliang
Published: November 2017

Novel MnO/CNFs@G membrane by electrospinning and APCVD; this anode with high specific capacity and longest cycling life is of great interest to high energy thin film or flexible Li-ion battery.
On-site separation of Cr(vi) and Cr(iii) in natural waters by parallel cartridge ion-exchange columns
Authors: Zhang Jia , Guo Wei , Guo Qinghai , Jin Lanlan , Liu Zhifu , Hu Shenghong
Published: November 2017

Development of a simple, fast, portable, and solvent-free method for on-site separation of Cr( = 6 \* ROMAN vi) and Cr( = 3 \* ROMAN iii) in natural waters.
Electroluminescence in a rectifying graphene/InGaN junction
Authors: Cho Hak Dong , Yoon Im Taek , Yuldashev Sh. U. , Kang Tae Won , Kim Deuk Young , Lee Jong-Kwon
Published: November 2017

A graphene-InGaN Schottky junction has been successfully fabricated by transferring graphene layers onto n-type In0.23Ga0.77N/GaN/Al2O3 substrates.
Selective lithium ion recognition in self-assembled columnar liquid crystals based on a lithium receptor
Authors: Luo Yuan , Marets Nicolas , Kato Takashi
Published: November 2017

The first examples of lithium ion-selective receptors that are capable of forming stable liquid-crystalline nanostructures have been developed.
Synthesis of mesostructured manganese phosphonate and its promising energy storage application
Authors: Mei Peng , Pramanik Malay , Young Christine , Huang Zhenguo , Hossain Md. Shahriar A. , Sugahara Yoshiyuki , Yamauchi Yusuke
Published: November 2017

Mesostructured manganese phosphonate (MnP) with a uniform nanorod morphology has been prepared through an easy surfactant-mediated procedure.
Zirconia-supported solid-state electrolytes for high-safety lithium secondary batteries in a wide temperature range
Authors: Chen Renjie , Qu Wenjie , Qian Ji , Chen Nan , Dai Yujuan , Guo Cui , Huang Yongxin , Li Li , Wu Feng
Published: November 2017

We fabricate a high-safety solid-state electrolyte by in situ immobilizing ionic liquids within a nanoporous zirconia-supported matrix.
SU-8 based pyrolytic carbon for the electrochemical detection of dopamine
Authors: Peltola Emilia , Heikkinen Joonas J. , Sovanto Katariina , Sainio Sami , Aarva Anja , Franssila Sami , Jokinen Ville , Laurila Tomi
Published: November 2017

Here we investigated the electrochemical properties and dopamine (DA) detection capability of SU-8 photoresist based pyrolytic carbon (PyC) as well as its biocompatibility with neural cells.
Increased serum lysyl oxidase-like 2 levels correlate with the degree of left atrial fibrosis in patients with atrial fibrillation
Authors: Zhao Yingming , Tang Kangting , Tianbao Xu , Wang Junhong , Yang Jin , Li Dianfu
Published: November 2017

Atrial fibrillation (AF) progression is generally accompanied by increased atrial fibrosis and atrial structural remodeling. Lysyl oxidase-like 2 (LOXL2) is known to play an important role in many fibrotic conditions, including cardiac fibrosis. The present study aimed to explore the relationship between serum LOXL2 levels and AF. Fifty-four AF patients and 32 control subjects were enrolled in the study. High-density three-dimensional electroanatomic mapping was performed, and mean bipolar voltage was assessed in AF patients. LOXL2 levels were measured by enzyme-linked immunosorbent assay. All patients underwent echocardiography to assess left atrium size and left ventricle function. Serum LOXL2 levels were significantly elevated in AF patients compared with the control group (526.81 ± 316.82 vs 240.94 ± 92.51 pg/ml, P<0.01). In addition, serum LOXL2 level was significantly correlated with the size of the left atrium (LAD) (r2 = 0.38, P<0.01). Furthermore, the serum LOXL2 levels were significantly higher in AF patients with LAD ≥ 40 mm compared with those with LAD < 40 mm (664.34 ± 346.50 vs 354.90 ± 156.23 pg/ml, P<0.01). And the Spearman’s correlation analysis further revealed that the mean bipolar left atrial voltage was inversely correlated with the LOXL2 (r2 = −0.49, P<0.01) in AF patients. Multivariate regression analysis further demonstrated that serum LOXL2 [odds ratio (OR) 1.013, 95% confidence interval (CI) 1.002–1.024, P<0.05] and LAD (OR 1.704, 95% CI 1.131–2.568, P<0.01) were independent predictors of AF. In conclusion, serum LOXL2 levels were significantly elevated and were correlated with the degree of left atrial fibrosis in AF patients.
Retransmission scheme for contention‐based data transmission systems
Authors: Li Lin , Long Hang , Zhao Long , Yang Haojun , Zheng Kan
Published: November 2017

In conventional schedule‐based wireless transmission system, frequent interactions between devices and access networks lead to significant signalling overhead, and thus limit the development of low‐latency applications. Contention‐based data transmission (CBDT) is widely used as a promising solution to address the above issues. In this study, the authors propose a detection‐based retransmission scheme for CBDT to further reduce the delay‐outage probability which cannot be avoided due to collision. In this scheme, each device simultaneously monitors the occupied resource blocks during data transmission. When a collision event is detected, the retransmission for this packet is determined without waiting for the acknowledgment message from the receiver. The reliability performance is significantly improved for low‐latency applications, since the possible retransmission times for each packet is increased within the limited transmission period. In addition, the impacts of imperfect detection on extra transmission load and packet loss are analysed in detail. The simulation and analytical results demonstrate that the detection‐based scheme significantly improves the reliability of CBDT.
‐Fair resource allocation in non‐orthogonal multiple access systems
Authors: Pham Quoc‐Viet , Hwang Won‐Joo
Published: November 2017

A non‐orthogonal multiple access (NOMA) system is now considered as a promising radio access technique for next‐generation networks owing to its benefits, e.g. spectral efficiency improvement. Due to the successive interference cancellation order at receivers, fairness among users in NOMA may not be guaranteed. In this study, the authors focus on ‐fair resource allocation in NOMA. The complexity of the considered problem is then analysed. In particular, the problem is shown to be convex when and , non‐deterministic polynomial‐time (NP)‐hard when , and polynomial‐time solvable when . Finally, simulation results are provided to examine the effects of the fairness degree on the system performance and verify the effectiveness of the proposed algorithms.
Adaptive robust optimal reactive power dispatch in unbalanced distribution networks with high penetration of distributed generation
Authors: Li Peishuai , Wu Zaijun , Wang Yang , Dou Xiaobo , Hu Minqiang , Hu Jingyi
Published: November 2017

Due to the increasing penetration of the uncertain single‐phase distributed generations (DGs), the current distribution networks are becoming more uncertain, unbalanced, and complicated than ever before, which brings great challenges for distribution network operators. This study proposes an adaptive robust optimal reactive power dispatch approach for the unbalanced distribution networks (U‐DNs) considering uncertainty caused by DGs. Leveraging the reactive power compensation from inverters of DGs, the purpose of the proposed method is to minimise power losses and maintain the voltage within regulatory limits. The feasible region of DGs is estimated and considered as a new constraint, aiming to guarantee the reliable operation of U‐DNs. The optimal reactive power dispatch problem is then formulated as an adaptive robust optimisation problem based on semidefinite programming. The adaptive function, which derives the relationship between reactive power and active power outputs of DGs, is utilised to make the method more flexible and less conservative. The cutting plane algorithm is introduced to solve the proposed adaptive robust reactive power dispatch model efficiently. Moreover, case studies are separately conducted on the modified IEEE 13‐bus and 123‐bus test systems to demonstrate the effectiveness of the proposed method.
Adaptive CWT‐based overcurrent protection for smart distribution grids considering CT saturation and high‐impedance fault
Authors: AsghariGovar Saeed , Heidari Saeid , Seyedi Heresh , Ghasemzadeh Saeid , Pourghasem Pouya
Published: November 2017

In this study, an adaptive continuous wavelet transform (CWT)‐based overcurrent protection for smart grids is proposed to enhance the overcurrent protection performance encountering high‐impedance fault (HIF) and current transformer (CT) saturation, which are extremely complex phenomena and their impacts often cause mis‐coordination or mal‐operation. The proposed algorithm samples three phase current waveforms and imports them to CWT to extract high frequency coefficients. Afterwards, the sum of absolute values of the coefficients, Scoef, is calculated for each sample during the last cycle. Meanwhile, several simulations related to HIFs with different impedances and CT saturations with different severities are executed and the fault currents and the sum of absolute values of the coefficients are achieved and saved in the relay memory as (X, Y) coordinates of points (IL‐fault, SL‐coef), named ‘learning data’. Thereafter, each Scoef is imported to the X −Y plane and, consequently, the occurrence of HIF or CT saturation is detected and the real‐fault current is estimated by both non‐linear interpolation and extreme learning machine approaches. Subsequently, new time dial setting and Ipickup of the relays are computed and reloaded. Security, dependability, and sensitivity of the proposed adaptive protection method are confirmed by numerous simulation studies.
Acceleration of histogram‐based contrast enhancement via selective downsampling
Authors: Cao Gang , Tian Huawei , Yu Lifang , Huang Xianglin , Wang Yongbin
Published: November 2017

The authors propose a general framework to accelerate the universal histogram‐based image contrast enhancement (CE) algorithms. Both spatial and grey‐level selective downsampling of digital images are adopted to decrease computational cost, while the visual quality of enhanced images is still preserved and without apparent degradation. Mapping function calibration is proposed to reconstruct the pixel mapping on the grey levels missed by downsampling. As two case studies, the accelerations of histogram equalisation (HE) and the state‐of‐the‐art global CE algorithm, i.e. spatial mutual information and PageRank (SMIRANK), are presented in detail. Both quantitative and qualitative assessment results have verified the effectiveness of their proposed CE acceleration framework. In typical tests, the computational efficiencies of HE and SMIRANK have been increased by about 3.9 and 13.5 times, respectively.
Co-evolution efficacy of project portfolio based on strategic orientation
Authors: Bai LiBiao , Du Qiang
Published: November 2017

Multi-project management has been a trend of many large organizations’ operations and a preferred organizational strategy in complex and dynamic environments. For an organization to achieve its strategy, it must integrate various projects into a project portfolio and implement coordinated management to make sure that these projects co-evolve in the direction of the overall strategy. As some elements in project portfolio (PP) cannot be quantified or determined accurately, a PP could be characterized as an uncertain and fuzzy problem where it is difficult to measure the co-evolution efficacy. To solve this difficulty, in this paper, we first propose a conceptual framework of Project Portfolio based on Strategic Orientation (PPSO) with quantitative indices and process of the co-evolution. A mathematical model based on Fuzzy Data Envelopment Analysis(FDEA) is built to measure the co-evolution efficacy of the PPSO, and provides a basis for optimal PPSO selection. The model is verified by a computational experiment based on actual data provided by a Chinese firm of HPM, a reputable Chinese project management consulting firm, which has also been officially certified by the International Project Management Association (IPMA). The results suggest that co-evolution efficacy is reasonably effective for selecting the optimal PPSO. To our knowledge, this study is the first time to apply the notion of co-evolution efficacy and fuzzy Data Envelopment Analysis to the PP domain, which enriches the theories of project management and strategic management. Also, this study makes an important contribution to integrating a group of projects into a PP under the strategic direction and helping an organization optimize its strategic management.
The support unit location problem to road traffic surveys with multi-stages
Authors: Camara Marcus Vinicius Oliveira , Ribeiro Glaydston Mattos
Published: November 2017

Large countries with extensive road networks, such as Brazil, require large volumes of financial resources to perform traffic surveys. In Brazil, the biggest road traffic survey was performed in 2011 with 120 counting survey stations. This survey was divided into three stages and 83 support units provided survey teams. A support unit is a place, such as a military organization, close to the survey stations. A stage indicates that only some survey stations must be considered at a time. In large scale traffic surveys with multi-stages, we must define which support unit will serve each survey station so that travel costs for the survey teams and the costs to use the support units are minimized. We present the Support Unit Location Problem to Assist Road Traffic Survey with Multi-Stages where, given a set of available support units, each one with a coverage area, and a set of multi-stage traffic survey stations, we must select units to serve stations so that the cost is minimized. Scenarios are evaluated for a real traffic survey with 300 counting stations and four stages in Brazil. Computational experiments show that large cost reductions can be found when a mathematical model is used.
Hydrodynamics experiments with soap films and soap bubbles: A short review of recent experiments
Authors: Kellay H.
Published: November 2017

In this short review, I focus on recent experiments that benefit from the advantages offered by the two-dimensionality of the flow in suspended thin liquid films to reconsider hydrodynamics problems which have resisted a full understanding. The first problem discussed here concerns friction drag in channel flows. The use of turbulent channel flows, using thin liquid films, allows measurements of friction drag as well as mean velocity profiles for flows with different spectral exponents. Is there a link between the spectral properties of the turbulence and the mean velocity profiles or the frictional drag? This is the first question considered. The second issue examined considers the long time dynamics of large scale vortices. These are obtained in half bubbles rendered “turbulent” through thermal convection. These vortices, which live in a quasi two-dimensional environment, have a long time dynamics where their vorticity goes through what seems to be a well-defined cycle with generic features.
True randomness from an incoherent source
Authors: Qi Bing
Published: November 2017

Quantum random number generators (QRNGs) harness the intrinsic randomness in measurement processes: the measurement outputs are truly random, given the input state is a superposition of the eigenstates of the measurement operators. In the case of trusted devices, true randomness could be generated from a mixed state ρ so long as the system entangled with ρ is well protected. We propose a random number generation scheme based on measuring the quadrature fluctuations of a single mode thermal state using an optical homodyne detector. By mixing the output of a broadband amplified spontaneous emission (ASE) source with a single mode local oscillator (LO) at a beam splitter and performing differential photo-detection, we can selectively detect the quadrature fluctuation of a single mode output of the ASE source, thanks to the filtering function of the LO. Experimentally, a quadrature variance about three orders of magnitude larger than the vacuum noise has been observed, suggesting this scheme can tolerate much higher detector noise in comparison with QRNGs based on measuring the vacuum noise. The high quality of this entropy source is evidenced by the small correlation coefficients of the acquired data. A Toeplitz-hashing extractor is applied to generate unbiased random bits from the Gaussian distributed raw data, achieving an efficiency of 5.12 bits per sample. The output of the Toeplitz extractor successfully passes all the NIST statistical tests for random numbers.
Charge-regularized swelling kinetics of polyelectrolyte gels: Elasticity and diffusion
Authors: Sen Swati , Kundagrami Arindam
Published: November 2017

We apply a recently developed method [S. Sen and A. Kundagrami, J. Chem. Phys. 143, 224904 (2015)], using a phenomenological expression of osmotic stress, as a function of polymer and charge densities, hydrophobicity, and network elasticity for the swelling of spherical polyelectrolyte (PE) gels with fixed and variable charges in a salt-free solvent. This expression of stress is used in the equation of motion of swelling kinetics of spherical PE gels to numerically calculate the spatial profiles for the polymer and free ion densities at different time steps and the time evolution of the size of the gel. We compare the profiles of the same variables obtained from the classical linear theory of elasticity and quantitatively estimate the bulk modulus of the PE gel. Further, we obtain an analytical expression of the elastic modulus from the linearized expression of stress (in the small deformation limit). We find that the estimated bulk modulus of the PE gel decreases with the increase of its effective charge for a fixed degree of deformation during swelling. Finally, we match the gel-front locations with the experimental data, taken from the measurements of charged reversible addition-fragmentation chain transfer gels to show an increase in gel-size with charge and also match the same for PNIPAM (uncharged) and imidazolium-based (charged) minigels, which specifically confirms the decrease of the gel modulus value with the increase of the charge. The agreement between experimental and theoretical results confirms general diffusive behaviour for swelling of PE gels with a decreasing bulk modulus with increasing degree of ionization (charge). The new formalism captures large deformations as well with a significant variation of charge content of the gel. It is found that PE gels with large deformation but same initial size swell faster with a higher charge.
On the EQE-bias characteristics of bottom-illuminated AlGaN-based metal-semiconductor-metal photodetectors with asymmetric electrode geometry
Authors: Brendel Moritz , Brunner Frank , Weyers Markus
Published: November 2017

The bias dependence of the external quantum efficiency (EQE) of bottom-illuminated Al0.5Ga0.5N/AlN metal-semiconductor-metal photodetectors shows certain features which are directly related to the device geometry, i.e., the electrode design and the absorber layer thickness. Asymmetric detectors of any absorber thickness between 0.5 μm and 0.1 μm show a reduced EQE in reverse saturation. Furthermore, an enhanced EQE appears below the threshold either in reverse polarity for thick (i.e., 0.5 μm, 0.3 μm) or in forward polarity for thin (0.1 μm) AlGaN absorber layers. In order to understand the underlying physics of these phenomena, measured and simulated data are compared in the framework of a recently developed model for symmetric devices, taking into account defect-related non-radiative recombination and electric polarization effects. The electron capture time for recombination in the AlGaN absorber and the (background) donor density in the AlN buffer layer are the only parameters to be adjusted to reproduce all experimental trends qualitatively.
Terahertz non-destructive imaging of cracks and cracking in structures of cement-based materials
Authors: Fan Shujie , Li Tongchun , Zhou Jun , Liu Xiaoqing , Liu Xiaoming , Qi Huijun , Mu Zhiyong
Published: November 2017

Cracks and crack propagation in cement-based materials are key factors leading to failure of structures, affecting safety in construction engineering. This work investigated the application of terahertz (THz) non-destructive imaging to inspections on structures of cement-based materials, so as to explore the potential of THz imaging in crack detection. Two kinds of disk specimens made of plain cement mortar and UHMWPE fiber concrete were prepared respectively. A mechanical expansion load device was deployed to generate cracks and control the whole process of cracking. Experimental tests were carried out on cracked specimens by using a commercial THz time domain spectroscopy (THz-TDS) during loading. The results show that crack opening and propagation could be examined by THz clearly and the material factors influence the ability of crack resistance significantly. It was found that the THz imaging of crack initiation and propagation agrees with the practical phenomenon and supplies more information about damage of samples. It is demonstrated that the damage behavior of structures of cement-based materials can be successfully detected by THz imaging.
Relativistic effects on the NMR parameters of Si, Ge, Sn, and Pb alkynyl compounds: Scalar versus spin-orbit effects
Authors: Demissie Taye B.
Published: November 2017

The NMR chemical shifts and indirect spin-spin coupling constants of 12 molecules containing 29Si, 73Ge, 119Sn, and 207Pb [X(CCMe)4, Me2X(CCMe)2, and Me3XCCH] are presented. The results are obtained from non-relativistic as well as two- and four-component relativistic density functional theory (DFT) calculations. The scalar and spin–orbit relativistic contributions as well as the total relativistic corrections are determined. The main relativistic effect in these molecules is not due to spin–orbit coupling but rather to the scalar relativistic contraction of the s-shells. The correlation between the calculated and experimental indirect spin–spin coupling constants showed that the four-component relativistic density functional theory (DFT) approach using the Perdew’s hybrid scheme exchange-correlation functional (PBE0; using the Perdew-Burke-Ernzerhof exchange and correlation functionals) gives results in good agreement with experimental values. The indirect spin-spin coupling constants calculated using the spin-orbit zeroth order regular approximation together with the hybrid PBE0 functional and the specially designed J-coupling (JCPL) basis sets are in good agreement with the results obtained from the four-component relativistic calculations. For the coupling constants involving the heavy atoms, the relativistic corrections are of the same order of magnitude compared to the non-relativistically calculated results. Based on the comparisons of the calculated results with available experimental values, the best results for all the chemical shifts and non-existing indirect spin–spin coupling constants for all the molecules are reported, hoping that these accurate results will be used to benchmark future DFT calculations. The present study also demonstrates that the four-component relativistic DFT method has reached a level of maturity that makes it a convenient and accurate tool to calculate indirect spin–spin coupling constants of “large” molecular systems involving heavy atoms.
Exact-solution for cone-plate viscometry
Authors: Giacomin A. J. , Gilbert P. H.
Published: November 2017

The viscosity of a Newtonian fluid is often measured by confining the fluid to the gap between a rotating cone that is perpendicular to a fixed disk. We call this experiment cone-plate viscometry. When the cone angle approaches π/2, the viscometer gap is called narrow. The shear stress in the fluid, throughout a narrow gap, hardly departs from the shear stress exerted on the plate, and we thus call cone-plate flow nearly homogeneous. In this paper, we derive an exact solution for this slight heterogeneity, and from this, we derive the correction factors for the shear rate on the cone and plate, for the torque, and thus, for the measured Newtonian viscosity. These factors thus allow the cone-plate viscometer to be used more accurately, and with cone-angles well below π/2. We find cone-plate flow field heterogeneity to be far slighter than previously thought. We next use our exact solution for the velocity to arrive at the exact solution for the temperature rise, due to viscous dissipation, in cone-plate flow subject to isothermal boundaries. Since Newtonian viscosity is a strong function of temperature, we expect our new exact solution for the temperature rise be useful to those measuring Newtonian viscosity, and especially so, to those using wide gaps. We include two worked examples to teach practitioners how to use our main results.
Diffusion Monte Carlo simulations of gas phase and adsorbed D2-(H2)n clusters
Authors: Curotto E. , Mella M.
Published: November 2017

We have computed ground state energies and analyzed radial distributions for several gas phase and adsorbed D2(H2)n and HD(H2)n clusters. An external model potential designed to mimic ionic adsorption sites inside porous materials is used [M. Mella and E. Curotto, J. Phys. Chem. A 121, 5005 (2017)]. The isotopic substitution lowers the ground state energies by the expected amount based on the mass differences when these are compared with the energies of the pure clusters in the gas phase. A similar impact is found for adsorbed aggregates. The dissociation energy of D2 from the adsorbed clusters is always much higher than that of H2 from both pure and doped aggregates. Radial distributions of D2 and H2 are compared for both the gas phase and adsorbed species. For the gas phase clusters, two types of hydrogen–hydrogen interactions are considered: one based on the assumption that rotations and translations are adiabatically decoupled and the other based on nonisotropic four-dimensional potential. In the gas phase clusters of sufficiently large size, we find the heavier isotopomer more likely to be near the center of mass. However, there is a considerable overlap among the radial distributions of the two species. For the adsorbed clusters, we invariably find the heavy isotope located closer to the attractive interaction source than H2, and at the periphery of the aggregate, H2 molecules being substantially excluded from the interaction with the source. This finding rationalizes the dissociation energy results. For D2-(H2)n clusters with n≥12, such preference leads to the desorption of D2 from the aggregate, a phenomenon driven by the minimization of the total energy that can be obtained by reducing the confinement of (H2)12. The same happens for (H2)13, indicating that such an effect may be quite general and impact on the absorption of quantum species inside porous materials.
Rayleigh-Taylor instability and internal waves in strongly coupled quantum plasma
Authors: Dolai Bivash , Prajapati R. P.
Published: November 2017

The Rayleigh–Taylor instability (RTI) and internal waves in both the incompressible and compressible dense degenerate strongly coupled quantum plasma have been investigated considering isothermal ion fluid compressibility. The quantum hydrodynamic model is formulated considering weakly coupled degenerate electrons and strongly coupled non-degenerate ions using smooth quantum potential for mixed quantum states. The modified dispersion relations of the internal waves and RTI are analytically derived using Fourier analysis and discussed in both the incompressible and compressible limits. In the incompressible limit, it is observed that the unstable RT modes grow below the critical wavenumber modified by the quantum corrections and strong coupling effects. The influence of compressibility, quantum corrections, and compressional wave velocity is observed in the condition of RTI in the compressible limit. The growth rates of unstable RT modes are solved numerically and plotted which shows suppression due to the quantum Froude number (quantum corrections), strong coupling effects, and isothermal compressibility of the medium. The results are analyzed for understanding the suppression of the RTI in dense white dwarfs which consist of degenerate electrons and strongly coupled ions.
Effects of temperature on Rb and 129Xe spin polarization in a nuclear magnetic resonance gyroscope with low pump power
Authors: Chen Linlin , Zhou Binquan , Lei Guanqun , Wu Wenfeng , Zhai Yueyang , Wang Zhuo , Fang Jiancheng
Published: November 2017

We propose an average Rb polarization model to analyze the influence of temperature on the spin polarization of Rb and 129Xe in a Nuclear Magnetic Resonance Gyroscope (NMRG) with low pump power. This model is essentially based on summing the Rb spin polarization along the direction of the pump beam and dividing the result by the cell length. We experimentally study the spin polarization of Rb and 129Xe atoms as a function of the cell temperature at low values of the pump power. The experimental results and the values calculated with the average Rb polarization model are in good agreement for both Rb and 129Xe. The spin polarization of Rb atoms decreases with increasing cell temperature, with a decreasing trend which is rapid at temperatures below 110 °C, and slower at temperatures above 110 °C. The experimental values of the 129Xe polarization, obtained with a pump power of 1 mW, first increase to a maximum P  129Xe−ave = 0.66 % at 118 °C, and then decreases as the temperature increases. Increasing the power of the pump beam shifts the temperature maximum to a higher value. Our model is suitable for the analysis of Rb and 129Xe polarization at high temperature and low pump power, i.e. when the power of the pump beam is completely absorbed within a few millimeters of the front window of the cell. Therefore, the present model can provide theoretical support for the improvement of the Signal-to-Noise-Ratio (SNR) of the NMRG, and to determine its optimal working temperature.
Magnetic sensor based on serial magnetic tunnel junctions for highly sensitive detection of surface cracks
Authors: Jin Zhenhu , Oogane Mikihiko , Fujiwara Kosuke , Ando Yasuo
Published: November 2017

Magnetic tunnel junctions (MTJs) that consist of two ferromagnets separated by a thin insulator are among the core devices used in spintronic applications such as magnetic sensors. Since magnetic sensors require high sensitivity for nondestructive eddy current testing, we developed and demonstrated magnetic sensors based on various configurations of serial MTJs. We fabricated sensors with 4, 16, 28, 40, and 52 serial MTJs in various numbers of rows (1, 4, 7, 10, and 13) to detect surface cracks via eddy current testing. All of the sensors could detect and discriminate between surface cracks 0.1 mm in width and 0.1 to 1.0 mm in depth on an aluminum specimen. Systematic studies on the effect of the number of MTJs showed a signal to noise ratio as high as 115 dB when detecting 0.1 mm deep cracks with 28 serial MTJs in 7 rows. This suggests that suitably configured serial MTJ sensors can offer an excellent performance in the detection of tiny surface defects via eddy current testing.
Performing SELEX experiments in silico
Authors: Wondergem J. A. J. , Schiessel H. , Tompitak M.
Published: November 2017

Due to the sequence-dependent nature of the elasticity of DNA, many protein-DNA complexes and other systems in which DNA molecules must be deformed have preferences for the type of DNA sequence they interact with. SELEX (Systematic Evolution of Ligands by EXponential enrichment) experiments and similar sequence selection experiments have been used extensively to examine the (indirect readout) sequence preferences of, e.g., nucleosomes (protein spools around which DNA is wound for compactification) and DNA rings. We show how recently developed computational and theoretical tools can be used to emulate such experiments in silico. Opening up this possibility comes with several benefits. First, it allows us a better understanding of our models and systems, specifically about the roles played by the simulation temperature and the selection pressure on the sequences. Second, it allows us to compare the predictions made by the model of choice with experimental results. We find agreement on important features between predictions of the rigid base-pair model and experimental results for DNA rings and interesting differences that point out open questions in the field. Finally, our simulations allow application of the SELEX methodology to systems that are experimentally difficult to realize because they come with high energetic costs and are therefore unlikely to form spontaneously, such as very short or overwound DNA rings.
Insights into antiferroelectrics from first-order reversal curves
Authors: Hoffmann Michael , Schenk Tony , Pešić Milan , Schroeder Uwe , Mikolajick Thomas
Published: November 2017

Antiferroelectric (AFE) HfO2 and ZrO2 based thin films are promising for energy and low power computing related applications. Here, we investigate 10 nm thin AFE Si:HfO2 films by means of first-order reversal curves (FORCs). Polarization-voltage, capacitance-voltage, and X-ray diffraction measurements confirm typical AFE behavior originating from the tetragonal phase. FORC analysis reveals two oppositely biased switching density peaks with a narrow distribution of coercive fields around 0.23 MV/cm, which is at least 4 times lower than that in typical ferroelectric HfO2 and ZrO2 films. The distributions along the internal bias field axis are much broader compared to the distribution of coercive fields. The exceptional stability of the switching density magnitude and coercive fields for up to 108 electric field cycles is demonstrated. Only small reductions of the internal bias fields are observed with cycling. These results highlight pathways towards improved cycling stability and variability of ferroelectric HfO2 and ZrO2 based devices as well as AFE supercapacitors with enhanced efficiency and energy storage density.
Atomic scale study of surface orientations and energies of Ti2O3 crystals
Authors: Gu Meng , Wang Zhiguo , Wang Chongmin , Zheng Jianming
Published: November 2017

For nanostructured particles, the faceting planes and their terminating chemical species are two critical factors that govern their chemical behavior. The surface atomistic structure and termination of Ti2O3 crystals were analyzed using atomic-scale aberration-corrected scanning transmission electron microscopy (STEM) combined with density functional theory (DFT) calculations. STEM imaging reveals that the Ti2O3 crystals are most often faceted along (001), (012), (−114), and (1–20) planes. The DFT calculation indicates that the (012) surface with TiO-termination has the lowest cleavage energy and correspondingly the lowest surface energy, indicating that (012) will be the most stable and prevalent surfaces in Ti2O3 nanocrystals. These observations provide insights for exploring the interfacial process involving Ti2O3 nanoparticles.
An embeddable optical strain gauge based on a buckled beam
Authors: Du Yang , Chen Yizheng , Zhu Chen , Zhuang Yiyang , Huang Jie
Published: November 2017

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6–17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.
Valence band splitting in bulk dilute bismides
Authors: Bannow Lars C. , Badescu Stefan C. , Hader Jörg , Moloney Jerome V. , Koch Stephan W.
Published: November 2017

The electronic structure of bulk GaAs1−xBix systems for different atomic configurations and Bi concentrations is calculated using density functional theory. The results show a Bi-induced splitting between the light-hole and heavy-hole bands at the Γ-point. We find a good agreement between our calculated splittings and experimental data. The magnitude of the splitting strongly depends on the local arrangement of the Bi atoms but not on the uni-directional lattice constant of the supercell. The additional influence of external strain due to epitaxial growth on GaAs substrates is studied by fixing the in-plane lattice constants.
A dish-type high-concentration photovoltaic system with spectral beam-splitting for crop growth
Authors: Huang Wenjuan , Lv Hui , Liao Jun , Shang Yiyuan , Liu Wen , Lv Qinghua , Cheng Chunfu , Su Yuehong , Riffat Saffa
Published: November 2017

Photovoltaic (PV) systems are playing a more and more important role as a renewable energy supplier. However, their large-scale applications is still limited by low conversion efficiency and high land-use requirement, especially for those areas where land and solar energy resources are more important for agriculture. In this paper, we suggest a dish-type high-concentration photovoltaic system, with which the competition between sunlight for crops' growth and PV application is solved by beam-splitting techniques. A purposely-designed beam filter acts as a solar spectrum splitter, and the most effective bands of solar spectrum for plant growth are transmitted down to plants while the other parts are all directed to the solar cell receiver. The spectral and spatial distribution of radiant intensity is investigated by ray tracing method, and the quantitative evaluation of the beam splitting effect on crop growth and PV power generation is provided in detail. The results show that, on one hand, the proposed system is superior to other natural and artificial light sources at driving the photosynthetic process (thus promoting crop growth); on the other hand, it generates PV power with high efficiency. Furthermore, the design can be optimized for certain kinds of plants and PV generation, both or independently. This spectral splitting scheme opens a promising future for PV applications in cooperation with precision farming.
Shifts in nitrogen and phosphorus uptake and allocation in response to selection for yield in Chinese winter wheat
Authors: Wang Zheng , Sadras Victor O. , Hoogmoed Marianne , Yang Xueyun , Huang Fang , Han Xiaoyu , Zhang Shulan
Published: November 2017

This study assessed changes in nitrogen (N) and phosphorus (P) uptake and partitioning in response to selection for yield in milestone varieties of Chinese winter wheat (Triticum aestivum L.). We established a factorial trial combining 11 nutrient–water regimes with three (2013–14) and five (2014–15) varieties released from 1970 to 2005. Grain yield increased at a rate of 0.46% year–1, with no apparent increase in the uptake of nutrients. Nitrogen harvest index did not change, and P harvest index increased at a rate of 0.15% year–1. Consequently, yield per unit N uptake and yield per unit P uptake increased at similar rates (0.4% year–1) at the expense of nutrient concentration in grain, which declined at a rate of 0.47% year–1 for N and 0.31% year–1 for P. No trends in N nutrition index were found. Selection for yield in wheat increased the yield per unit nutrient uptake at the expense of grain nutrient concentration. Further gains in yield need to be matched by increasing N uptake to maintain grain protein. Dilution of P in grain needs to be considered in terms of the putatively undesirable role of phytate for human nutrition, and the need for P reserves in seed for crop establishment.
OzFoodNet into the future: the rapid evolution of foodborne disease surveillance in Australia
Authors: Polkinghorne Ben , Draper Anthony , Harlock Michelle , Leader Robyn
Published: November 2017

OzFoodNet is Australia's national enhanced foodborne disease surveillance network. OzFoodNet is currently evolving in order to meet the most significant challenges faced since it commenced in 2000: the transition to culture independent diagnostic tests and the introduction of whole genome sequencing for typing of enteric pathogens. This has changed the nature of foodborne disease surveillance and outbreak investigation in Australia.
Over-expression of ΔNp63α facilitates rat corneal wound healingin vivo
Authors: Yao Jeng-Yuan , Chen Jan-Kan
Published: November 2017

To investigate the roles of ΔNp63α during corneal wound healing and the genes regulated by ΔNp63α in limbal epithelial cells. Adenovirus or shRNA targeting ΔNp63α were pre-injected into the anterior chamber of rat eyeballs and the central corneal epithelium was then wounded with NaOH. The effects of ΔNp63α expression during wound healing were observed by propidium iodide staining. In addition, limbal epithelial cells were cultured and ectopically expressed ΔNp63α by transfecting Ad-ΔNp63α. Total RNA was extracted from transfected epithelial cells and subjected to a gene expression microarray assay. The results showed that over-expression of ΔNp63α accelerated the process of corneal wound healing while knockdown of ΔNp63α impaired the process. ΔNp63α positively up-regulated several cell growth promoter genes and could be referred as a positive regulator of limbal epithelial cell proliferation. It might also inhibit cell differentiation and cell death by differential target gene regulation.
Structure and function of polyketide biosynthetic enzymes: various strategies for production of structurally diverse polyketides
Authors: Miyanaga Akimasa
Published: November 2017

Polyketides constitute a large family of natural products that display various biological activities. Polyketides exhibit a high degree of structural diversity, although they are synthesized from simple acyl building blocks. Recent biochemical and structural studies provide a better understanding of the biosynthetic logic of polyketide diversity. This review highlights the biosynthetic mechanisms of structurally unique polyketides, β-amino acid-containing macrolactams, enterocin, and phenolic lipids. Functional and structural studies of macrolactam biosynthetic enzymes have revealed the unique biosynthetic machinery used for selective incorporation of a rare β-amino acid starter unit into the polyketide skeleton. Biochemical and structural studies of cyclization enzymes involved in the biosynthesis of enterocin and phenolic lipids provide mechanistic insights into how these enzymes diversify the carbon skeletons of their products.
Biomass Briquette Investigation from Pterocarpus Indicus Leaves Waste as an Alternative Renewable Energy
Authors: Anggono Willyanto , Sutrisno  , Suprianto Fandi D. , Evander Jovian
Published: November 2017

Indonesia is a tropical country located in Southeast Asia. Indonesia has a lot of variety of plant species which are very useful for life. Pterocarpus indicus are commonly used as greening and easily found everywhere in Surabaya city because of its characteristics that they have dense leaves and rapid growth. Pterocarpus indicus leaves waste would be a problem for residents of Surabaya and disturbing the cleanliness of the Surabaya city. Therefore, the Pterocarpus indicus leaves waste would be used as biomass briquettes. This research investigated the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the effect of tapioca as an adhesive material to the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the optimum composition for Pterocarpus indicus leaves waste biomass briquette as an alternative renewable fuel and the property of the optimum resulted biomass briquette using ultimate analysis and proximate analysis based on the ASTM standard. The calorific value biomass briquettes from the Pterocarpus indicus leaves waste were performed using an oxygen bomb calorimeter at various composition of Pterocarpus indicus from 50% to 90% rising by 10% for each experiment. The experimental results showed that the 90% raw materials (Pterocarpus indicus leaves waste)-10% adhesive materials (tapioca) mixtures is the optimum composition for biomass briquette Pterocarpus indicus leaves waste. The lower the percentage of the mass of tapioca in the biomass briquettes, the higher calorific value generated.
Phosphorylation of multiple sites within an acidic region of Alcadein α is required for kinesin-1 association and Golgi exit of Alcadein α cargo
Authors: Sobu Yuriko , Furukori Keiko , Chiba Kyoko , Nairn Angus C. , Kinjo Masataka , Hata Saori , Suzuki Toshiharu
Published: November 2017

Alcadein α (Alcα) is a major cargo of kinesin-1 that is subjected to anterograde transport in neuronal axons. Two tryptophan- and aspartic acid-containing (WD) motifs located in its cytoplasmic domain directly bind the tetratricopeptide repeat (TPR) motifs of the kinesin light chain (KLC), which activate kinesin-1 and recruit kinesin-1 to Alcα cargo. We found that phosphorylation of three serine residues in the acidic region located between the two WD motifs is required for interaction with KLC. Phosphorylation of these serine residues may alter the disordered structure of the acidic region to induce direct association with KLC. Replacement of these serines with Ala results in a mutant that is unable to bind kinesin-1, which impairs exit of Alcα cargo from the Golgi. Despite this deficiency, the compromised Alcα mutant was still transported, albeit improperly by vesicles following missorting of the Alcα mutant with amyloid β-protein precursor (APP) cargo. This suggests that APP partially compensates for defective Alcα in anterograde transport by providing an alternative cargo receptor for kinesin-1.