bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced stability of smoothly electrodeposited amorphous Fe2O3@electrospun carbon nanofibers as self-standing anodes for lithium ion batteries
Authors: Kobayashi Yuta , Abe Jyunichiro , Kawase Koki , Takahashi Keisuke , Vogt Bryan D. , Shiratori Seimei
Published: December 2017

Fe2O3 and carbon nanofiber (Fe2O3@CNFs) composite anodes for lithium ion batteries (LIBs) were fabricated by electrospinning and electrodeposition to provide a simple route for modulating the morphology of the anodes and their performance.
Iodine mediated oxidative cross-coupling of unprotected anilines and heteroarylation of benzothiazoles with 2-methylquinoline
Authors: Rahim Abdul , Shaik Siddiq Pasha , Baig Mirza Feroz , Alarifi Abdullah , Kamal Ahmed
Published: December 2017

Iodine mediated dual C–H activation of Csp3–H of 2-methylquinoline and Csp2–H of anilines for the construction of C–C and C–O bonds and the oxidative insertion of 2-methylquinoline to the benzothiazole under metal and peroxide free condition.
Asymmetric total synthesis of talienbisflavan A
Authors: Huang Deng-Ming , Li Hui-Jing , Wang Jun-Hu , Wu Yan-Chao
Published: December 2017

The first asymmetric total syntheses of talienbisflavan A and bis-8,8′-epicatechinylmethane as well as a facile synthesis of bis-8,8′-catechinylmethane has been accomplished from readily available starting materials by using a newly developed direct regioselective methylenation of catechin derivatives as one of the key steps.
Surface-attached poly(phosphoester)-hydrogels with benzophenone groups
Authors: Becker Greta , Deng Zhuoling , Zober Maria , Wagner Manfred , Lienkamp Karen , Wurm Frederik R.
Published: December 2017

Photo-reactive poly(phosphoester)s (PPEs) forming surface-attached PPE-networks and hydrogels are presented.
Stimuli-responsive dendronized polymeric hydrogels through Schiff-base chemistry showing remarkable topological effects
Authors: Liu Jie , Zhang Xiacong , Chen Xiao , Qu Liangliang , Zhang Liyuan , Li Wen , Zhang Afang
Published: December 2017

Crowded and thick dendronized polymers enhance the formation of a Schiff-base through thermally-induced collapse or freezing, resulting in hydrogels with different performances.
Direct growth of Ni–Mn–O nanosheets on flexible electrospun carbon nanofibers for high performance supercapacitor applications
Authors: Tian Di , Lu Xiaofeng , Nie Guangdi , Gao Mu , Wang Ce
Published: December 2017

Ni–Mn–O nanosheets on flexible electrospun carbon nanofibers have been fabricated as binder-free supercapacitor electrodes, showing good performance for supercapacitor applications.
Fabrication of a TiO2 trapped meso/macroporous g-C3N4 heterojunction photocatalyst and understanding its enhanced photocatalytic activity based on optical simulation analysis
Authors: Wu Wanbao , Li Xu , Ruan Zhaohui , Li Yudong , Xu Xianzhu , Yuan Yuan , Lin Kaifeng
Published: December 2017

The enhanced photocatalytic performance of a TiO2 nanoparticle trapped meso/macroporous g-C3N4 heterojunction photocatalyst is strongly related to its enhanced light absorption as revealed by optical simulation.
Palladium-catalyzed CO-free cyclizative carbonylation of 2-benzylpyridines leading to pyridoisoquinolinones
Authors: Yang Rui , Yu Jin-Tao , Sun Song , Cheng Jiang
Published: December 2017

A CO-free palladium-catalyzed cyclizative carbonylation of 2-benzylpyridines was developed, leading to pyridoisoquinolinones in moderate to good yields.
Effect of R-site element on crystalline phase and thermal stability of Fe substituted Mn mullite-type oxides: R2(Mn1−xFex)4O10−δ (R = Y, Sm or Bi; x = 0, 0.5, 1)
Authors: Thampy Sampreetha , Ashburn Nickolas , Martin Thomas J. , Li Chenzhe , Zheng Yongping , Chan Julia Y. , Cho Kyeongjae , Hsu Julia W. P.
Published: December 2017

R-site dependent phase formation and thermal stability of Mn-Fe mullite-type oxides are experimentally and theoretically investigated.
Synthesis, characterization and assessment of hydrophilic oxidized carbon nanodiscs in bio-related applications
Authors: Zygouri Panagiota , Tsoufis Theodoros , Kouloumpis Antonios , Patila Michaela , Potsi Georgia , Sevastos Apostolos A. , Sideratou Zili , Katsaros Fotios , Charalambopoulou Georgia , Stamatis Haralambos , Rudolf Petra , Steriotis Theodore A. , Gournis Dimitrios
Published: December 2017

Hydrophilic oxidized carbon nanodiscs able to be used as drug delivery system and as support in nanobiocatalytic applications.
Designing and looking for novel cage compounds based on bicyclo-HMX as high energy density compounds
Authors: Pan Yong , Zhu Weihua
Published: December 2017

We designed four cage compounds by introducing intramolecular linkages into the bicyclo-HMX framework. Their molecular and electronic structures, energetic properties, thermal stability, and impact sensitivity were evaluated using DFT.
Ultrastable, cationic three-dimensional lead bromide frameworks that intrinsically emit broadband white-light
Authors: Peng Chengdong , Zhuang Zewen , Yang Huimin , Zhang Guiyang , Fei Honghan
Published: December 2017

We have discovered the first two lead halide materials adopting a purely cationic inorganic 3D topology. The highly distorted PbII centers afford strong electron–phonon coupling in a deformable lattice and unusual broadband white-light emission as an intrinsic property.
Understanding light-driven H2 evolution through the electronic tuning of aminopyridine cobalt complexes
Authors: Call Arnau , Franco Federico , Kandoth Noufal , Fernández Sergio , González-Béjar María , Pérez-Prieto Julia , Luis Josep M. , Lloret-Fillol Julio
Published: December 2017

Electronic effects provide a general mechanistic scenario for rationalizing photocatalytic water reduction activity with aminopyridine cobalt complexes.
Probing the origin of the giant magnetic anisotropy in trigonal bipyramidal Ni(ii) under high pressure
Authors: Craig Gavin A. , Sarkar Arup , Woodall Christopher H. , Hay Moya A. , Marriott Katie E. R. , Kamenev Konstantin V. , Moggach Stephen A. , Brechin Euan K. , Parsons Simon , Rajaraman Gopalan , Murrie Mark
Published: December 2017

The synergistic combination of high pressure techniques withab initiomethods creates a powerful tool to understand giant magnetic anisotropy.
Combining battery-like and pseudocapacitive charge storage in 3D MnOx@carbon electrode architectures for zinc-ion cells
Authors: Ko Jesse S. , Sassin Megan B. , Parker Joseph F. , Rolison Debra R. , Long Jeffrey W.
Published: December 2017

Nanoscale MnOx expressed in 3D carbon nanofoam electrodes exhibits both pseudocapacitive and battery-like charge-storage using a mixed Na+ : Zn2+ aqueous electrolyte.
Nematic line defects in microfluidic channels: wedge, twist and zigzag disclinations
Authors: Agha Hakam , Bahr Christian
Published: December 2017

Using the interplay between anchoring, flow and electric field, structural transformations of nematic disclination lines in microfluidic channels are induced.
Mitochondrial toxicity of organic arsenicals: membrane permeability transition pore opening and respiratory dysfunction
Authors: Fan Xiao-Yang , Yuan Lian , Wu Can , Liu Yu-Jiao , Jiang Feng-Lei , Hu Yan-Jun , Liu Yi
Published: December 2017

Organic arsenicalMOPIMPinduced mitochondrial membrane permeability transition pore opening, respiration suppression and metabolic thermogenesis dysfunction in isolated mitochondria.
Miniaturised CP aperture antenna with tri‐mode operation for broadening bandwidth
Authors: Zhang Yi‐Xuan , Jiao Yong‐Chang , Zhang Zheng , Li Bin
Published: December 2017

A compact broadband circularly polarised (CP) aperture antenna is proposed. In order to broaden the CP bandwidth, a pair of perturbation slots is introduced to generate a higher order mode (quasi‐TE31) for CP radiation. With three resonant modes working simultaneously a wider CP bandwidth is obtained. Besides, with some modifications to the ground plane, the antenna is miniaturised while keeping its wideband CP performance. The measured CP working bandwidth is 76.6% (2.9–6.5 GHz) with the antenna size of 43 mm × 43 mm, which means a 71% CP bandwidth increment and a 47% size reduction compared with the original CP aperture antenna.
Comments on ‘Stabilisation conditions for fuzzy control of uncertain fractional order non‐linear systems with random disturbances’
Authors: Zhang Xuefeng , Liu Yangyang
Published: December 2017

This shows that sufficient conditions of theorems in the above study cannot be derived by the proof method presented by the authors. The reason analysis is discussed in detail. Counterexamples are given to validate the conclusion.
Perceptually motivated enhancement method for non‐uniformly illuminated images
Authors: Pu Tian , Wang Shuhang
Published: December 2017

Non‐uniformly illuminated images often suffer from low visibility in dark areas. Traditional methods usually enhance non‐uniformly illuminated images by bringing out the details in the dark areas, but easily result in over‐enhancement. Motivated by the Weber contrast model, the authors propose a perceptually inspired image enhancement method, which treats an image as a product of a luminance mapping (LM) transfer function and a contrast measure (CM) transfer function. The contribution of this proposed method is two‐fold. Firstly, they propose a progressive LM transfer function based on the sensitivity of the human visual system to emphasise changes at low brightness level and attenuates changes at high brightness levels. Secondly, they introduce a CM transfer function, which is based on a special implementation of a neural model of the human visual receptive field, to improve local intensity contrast. Experimental comparisons with some state‐of‐the‐art methods show that the proposed method can achieve both contrast enhancement and visual fidelity preservation.
Voltage balance optimisation among subsystems of wind‐photovoltaic‐ES hybrid generating system
Authors: Wu Han , Li Yan , Lu Zongxiang , Tang Haiyan
Published: December 2017

Wind‐photovoltaic‐energy storage (ES) hybrid generating system has numerous reactive power sources. It is crucially important for coordinated control of these reactive power sources. According to the test results, there are unbalanced control problem in subsystem voltage of the hybrid generating system. The problem caused reactive power circulation and loop current. A subsystem voltage balance optimisation strategy is proposed to solve the problem. The case study shows the efficiency of the proposed strategies.
Advanced control strategy and its controllable area for doubly fed wind farm integrated into power systems with VSC‐HVDC transmission under grid fault
Authors: Ouyang Jinxin , Li Mengyang , Tang Ting , Zheng Di , Yu Rui , Zhang Xi , Xiong Xiaofu
Published: December 2017

Doubly fed wind farms are usually integrated into power systems with voltage source converter‐based high‐voltage direct current (VSC‐HVDC). An overvoltage is produced in the DC side of VSC‐HVDC when the fault occurs at the grid side, which could cause the system collapse. Some methods are proposed to restrain the overvoltage by changing the frequency of wind farm. However, the impacts caused by the frequency variation on doubly fed induction generator (DFIG) have not been considered. Here, the transient characteristics of DFIG under frequency change were analysed. The frequency controllable margin of a DFIG was obtained according to the limit of rotor current and rotor speed. An ascending frequency strategy of a wind farm side voltage source converter was proposed with consideration of the controllable margin. The effectiveness of the proposed control strategy for fault ride‐through was verified by simulations in Matlab/Simulink.
Study on detection of blade imbalance for DFIG WTS based on spectrum analysis of Hilbert modulus
Authors: Jixing Qiu , Guodong Xu , Junbing Tao , Jing Yang
Published: December 2017

To detect the impellor imbalance of double fed induction generator (DFIG) wind turbines (WTs), a spectrum analysis of Hilbert modulus based on stator current signal has been proposed. The current‐based detection method is cost‐effective and valuable in engineering applications. According to the models of DFIG WTs and coordinate transformations, this study presents the expressions of stator current in three‐phase static coordinates under imbalance condition. In addition, the fault frequency (f 1 ± f m) is derived evidently. The blade imbalance fault can be diagnosed by extracting f m (shaft rotating frequency) component based on the Hilbert transformation. Furthermore, the detecting process only works in constant speed stage and f m, which is also called 1P frequency, is invariable. Experimental tests on commercial 1.5 MW DFIG WTs have been taken for verifying the detecting algorithm proposed above. Finally, it is effective to recognise the blade imbalance with the advantages of cost and system reliability.
Ocean Energy Comprehensive Utilization System of Water‐electricity Cogeneration
Authors: Wanjun Wang , Fuyuan Wang , Xiangyu Li , Yongqiang Zhu , Ruihua Xia
Published: December 2017

Ocean energy is one of the renewable energy sources. Ocean thermal energy is the most abundant in marine energy, so it has a good development prospect. At present, the main way to use ocean energy is power generation. However, it has disadvantages: low efficiency and high energy consumption. In view of the above shortcomings, this study puts forward a new type of ocean energy comprehensive utilisation system of water–electricity cogeneration. The system is based on the ocean thermal energy conversion: wave energy power generation and solar pond are integrated in the system. The basic principle and working process were analysed, and the energy consumption and the product of the system were calculated. As shown in the calculation results, it is effective to reduce energy consumption and improve the system efficiency. The research of this study has valuable reference for the development of ocean energy in the future.
Equivalent modelling of wind farm for small‐signal stability analysis in weak power system
Authors: He Xiuqiang , Geng Hua , Yang Geng , Zou Xin , Li Yanan
Published: December 2017

This study proposes a novel equivalent modelling method of wind farm (WF), which can be used for small‐signal stability analysis and researches on damping control of low‐frequency oscillation. First, a complete WF model described with a set of differential algebraic equations is established, then its linearised model is obtained at one of the steady‐state operating points. Next, the eigenanalysis and the modal participation factor (MPF) analysis methods are adopted to evaluate the low‐frequency oscillation modes and the corresponding modal participation in each wind turbine generator (WTG). A feature vector for each WTG, describing its oscillation characteristics, is extracted based on the MPFs. Afterwards, all WTGs are clustered into some groups via a clustering algorithm, then the WTGs in the same groups are aggregated into a single WTG, using the weighted summation method. Furthermore, the criterion for the validity of the equivalent model is studied. The proposed modelling and validation methods are verified by simulations.
Fast optimal power allocation algorithm for multi‐terminal AC/DC hybrid grids with wind power integration
Authors: Guo Xiaoqian , Qiao Ying , Lu Zongxiang , Wu Linlin , Xu Man
Published: December 2017

The multi‐terminal AC/DC hybrid grid is a promising alternative for the integration and transmission of large‐scale wind power. Optimal power allocation (OPA), to distribute the active power between AC and DC transmission lines in order to minimise the power losses, is a significant problem to be solved. A new simplified OPA algorithm for multi‐terminal AC/DC hybrid grids is proposed. By simplifying and linearising the power flow model of AC and DC grids, the mathematical expression of power losses is expressed as a multivariate quadratic function, whose minimum value can be directly obtained with the Lagrange multiplier method. Simulations of a four‐terminal AC/DC hybrid grid with wind power integration are carried out by using MATLAB, and the simulation results validate the effectiveness of the proposed algorithm.
Analysis of short circuit characteristic of hybrid wind farm group based on artificial short circuit test
Authors: Zhao Peng , Jia Jing , Wang Ruiqi , Luan Fengkui , Yu Peng , Zhao Xianqiao , Li Guanglei
Published: December 2017

In order to verify the wind farm short circuit current characteristic and its influence to power grid due to large‐scale wind farms integration on Rongcheng power station, three‐phase and single‐phase short circuit tests were carried out. Using the above ‘unit‐integrated‐wind farm‐grid’ modelling methodology, the model can be established in the simulation platform PSASP. Based on the simulation model, the change mechanism of short circuit current is analysed. By comparing the short circuit current characteristics of different type wind turbines with the field test data from the digital fault recorder, the wind turbine's contributions to the system short circuit current are determined detailed with squirrel cage induction generator, doubly fed induction generator, and permanent magnet synchronous generator. In addition, the short circuit current characteristics of wind farm are summarised and deepen understood from the field test data. With the analysis result, Shandong Rongcheng wind farm short circuit field test would have very good reference and directive significance for large‐scale wind power centralised integration to the actual power grid.
Very short‐term prediction model for photovoltaic power based on improving the total sky cloud image recognition
Authors: Xiang Zhu , Ji Wu , Hai Zhou , Jie Ding , Fang Cui , Xin Zhao
Published: December 2017

Due to the cloud cover, the power generation of photovoltaic power plant will reduce suddenly, that may lead to instability of the grid and bring some risks. Cloud observation is often used in the very shortterm prediction of photovoltaic power. However, in the haze weather, The quality of the total sky image will fall, the cloud recognition effect is reduced, further leads to decreased levels of photovoltaic power prediction.This study presents a photovoltaic power prediction algorithm,which takes into account the image quality decline caused by haze. So the algorithm improves the precision of photovoltaic power generation. Firstly, the extraction method using discrete Fourier transform checks whether clouds exist or not, and computing in the position of the solar facula, and then fix the facula. Next, using piece wise linear transformation algorithm for cloud enhancement, and then generate intensity layered cloud stain chart. Finally, the relationship between cloud and radiation is used to realise the very short‐term prediction of photovoltaic power. The experimental results show that the algorithm has a very good universality, and the cloud image can be identified by the fog and haze, therefore it improves the accuracy of the ultra‐short term prediction of photovoltaic power.
Modelling of multi‐VSCs in DC voltage control timescale for small‐signal stability analysis
Authors: Huang Yunhui , Tang Aihong , Xiong Binyu , Huang Yong , Tang Haiyan , Li Yan
Published: December 2017

This study investigates modelling of multi‐voltage source converters (VSCs) in DC voltage control timescale for small‐signal stability analysis. Multi‐VSCs stability in a DC voltage timescale is impacted due to the coupling among their control systems and grid dynamics. With considering control loops interactions and grid dynamics, multi‐VSCs’ small‐signal model is proposed for stability analysis. Control loops contain DC voltage control loop, terminal voltage control loop and phase‐locked loop. Furthermore, VSC control dynamics and grid dynamics are separated. Besides, eigenvalues analysis are conducted to analysis multi‐VSCs stability in DC voltage control timescale. Impacts of grid strength and control loops dynamics on the stability of multi‐VSCs are verified.
Power Supply Company purchase’ portfolio optimisation considering electric vehicle charging load forecasting
Authors: Li Yahong , Ren Hui
Published: December 2017

In recent years, a large number of electric vehicles (EVs) were used and the deployment of EVs will lead to an increase in load and load uncertainty, which introduces volume risk in the bilateral contracts. In order to assess and hedge the risk, the EVs charging load model and the Power Supply Company purchase’ portfolio optimisation model are proposed. A linear programming problem for the Power Supply Company purchase’ portfolio optimisation with conditional value at risk (CVaR) have been formulated, and it contains load uncertainty caused by EVs load, price fluctuation, and the expected cost of errors. This study analyses optimal portfolio allocations to different markets, efficient frontier of CVaR, and the influence of different EVs market penetration levels on the portfolio strategy. The analysis results show that risk of the market increases as the EVs market penetration level increases. Power Supply Company may hedge risk through adjusting the optimal portfolio allocation to different electricity markets.
Physical activity of the selected nearly isotropic comets with perihelia at large heliocentric distance
Authors: Kulyk I. , Rousselot P. , Korsun P. P. , Afanasiev V. L. , Sergeev A. V. , Velichko S. F.
Published: December 2017

Context.The systematic investigation of comets in a wide range of heliocentric distances can contribute to a better understanding of the physical mechanisms that trigger activity at large distances from the Sun and reveals possible differences in the composition of outer solar system bodies belonging to various dynamical groups.

Aims.We seek to analyze the dust environment of the selected nearly isotropic comets with a perihelion distance between 4.5 and 9.1 au, where sublimation of water ice is considered to be negligible.

Methods.We present results of multicolor broadband photometric observations for 14 distant active objects conducted between 2008 and 2015 with various telescopes. Images obtained with broadband filters were used to investigate optical colors of the cometary comae and to quantify physical activity of the comet nuclei.

Results.The activity level was estimated withAfρparameters ranging between 95 ± 10 cm and 9600 ± 300 cm. Three returning comets were less active than the dynamically new comets. Dust production rates of the comet nuclei were estimated between 1 and 100 kg s−1based on some assumptions about the physical properties of dust particles populating comae. The measured colors point out reddening of the continuum for all the comets. The mean values of a normalized reflectivity gradient within the group of the comets amount to 14 ± 2% per 1000 Å and 3 ± 2% per 1000 Å in the BV and VR spectral domains, respectively. The comae of the dynamically new comets, which were observed on their inbound legs, may be slightly redder in the blue spectral interval than comae of the comets observed after the perihelion passages. The dynamically new comets observed both pre- and post-perihelion, seem to have higher production rates post-perihelion than pre-perihelion for similar heliocentric distances.
The ALMA-PILS survey: 3D modeling of the envelope, disks and dust filament of IRAS 16293–2422
Authors: Jacobsen S. K. , Jørgensen J. K. , van der Wiel M. H. D. , Calcutt H. , Bourke T. L. , Brinch C. , Coutens A. , Drozdovskaya M. N. , Kristensen L. E. , Müller H. S. P. , Wampfler S. F.
Published: December 2017

Context. The Class 0 protostellar binary IRAS 16293–2422 is an interesting target for (sub)millimeter observations due to, both, the rich chemistry toward the two main components of the binary and its complex morphology. Its proximity to Earth allows the study of its physical and chemical structure on solar system scales using high angular resolution observations. Such data reveal a complex morphology that cannot be accounted for in traditional, spherical 1D models of the envelope.

Aims. The purpose of this paper is to study the environment of the two components of the binary through 3D radiative transfer modeling and to compare with data from the Atacama Large Millimeter/submillimeter Array. Such comparisons can be used to constrain the protoplanetary disk structures, the luminosities of the two components of the binary and the chemistry of simple species.

Methods. We present 13CO, C17O and C18O J = 3–2 observations from the ALMA Protostellar Interferometric Line Survey (PILS), together with a qualitative study of the dust and gas density distribution of IRAS 16293–2422. A 3D dust and gas model including disks and a dust filament between the two protostars is constructed which qualitatively reproduces the dust continuum and gas line emission.

Results. Radiative transfer modeling in our sampled parameter space suggests that, while the disk around source A could not be constrained, the disk around source B has to be vertically extended. This puffed-up structure can be obtained with both a protoplanetary disk model with an unexpectedly high scale-height and with the density solution from an infalling, rotating collapse. Combined constraints on our 3D model, from observed dust continuum and CO isotopologue emission between the sources, corroborate that source A should be at least six times more luminous than source B. We also demonstrate that the volume of high-temperature regions where complex organic molecules arise is sensitive to whether or not the total luminosity is in a single radiation source or distributed into two sources, affecting the interpretation of earlier chemical modeling efforts of the IRAS 16293–2422 hot corino which used a single-source approximation.

Conclusions. Radiative transfer modeling of source A and B, with the density solution of an infalling, rotating collapse or a protoplanetary disk model, can match the constraints for the disk-like emission around source A and B from the observed dust continuum and CO isotopologue gas emission. If a protoplanetary disk model is used around source B, it has to have an unusually high scale-height in order to reach the dust continuum peak emission value, while fulfilling the other observational constraints. Our 3D model requires source A to be much more luminous than source B; LA ~ 18 L⊙ and LB ~ 3 L⊙.
Influence of galactic arm scale dynamics on the molecular
composition of the cold and dense ISM
Authors: Ruaud M. , Wakelam V. , Gratier P. , Bonnell I. A.
Published: December 2017

Aim. We study the effect of large scale dynamics on the molecular composition of the dense interstellar medium during the transition between diffuse to dense clouds.

Methods. We followed the formation of dense clouds (on sub-parsec scales) through the dynamics of the interstellar medium at galactic scales. We used results from smoothed particle hydrodynamics (SPH) simulations from which we extracted physical parameters that are used as inputs for our full gas-grain chemical model. In these simulations, the evolution of the interstellar matter is followed for ~50 Myr. The warm low-density interstellar medium gas flows into spiral arms where orbit crowding produces the shock formation of dense clouds, which are held together temporarily by the external pressure.

Results. We show that depending on the physical history of each SPH particle, the molecular composition of the modeled dense clouds presents a high dispersion in the computed abundances even if the local physical properties are similar. We find that carbon chains are the most affected species and show that these differences are directly connected to differences in (1) the electronic fraction, (2) the C/O ratio, and (3) the local physical conditions. We argue that differences in the dynamical evolution of the gas that formed dense clouds could account for the molecular diversity observed between and within these clouds.

Conclusions. This study shows the importance of past physical conditions in establishing the chemical composition of the dense medium.
Rate of convergence of the Nesterov accelerated gradient method in the subcritical case α ≤ 3
Authors: Attouch Hedy , Chbani Zaki , Riahi Hassan
Published: December 2017

In a Hilbert space setting ℋ, given Φ : ℋ → ℝ a convex continuously differentiable function, and α a positive parameter, we consider the inertial dynamic system with Asymptotic Vanishing Damping
(AVD)α     ẍ(t) + α/tẋ(t) + ∇Φ(x(t)) = 0.

Depending on the value of α with respect to 3, we give a complete picture of the convergence properties as t → +∞ of the trajectories generated by (AVD)α, as well as iterations of the corresponding algorithms. Indeed, as shown by Su-Boyd-Candès, the case α = 3 corresponds to a continuous version of the accelerated gradient method of Nesterov, with the rate of convergence Φ(x(t)) − min Φ = O(t−2) for α ≥ 3. Our main result concerns the subcritical case α ≤ 3, where we show that Φ(x(t)) − min Φ = O(t−⅔α). This overall picture shows a continuous variation of the rate of convergence of the values Φ(x(t)) − minℋ Φ = O(t−p(α)) with respect to α > 0: the coefficient p(α) increases linearly up to 2 when α goes from 0 to 3, then displays a plateau. Then we examine the convergence of trajectories to optimal solutions. As a new result, in the one-dimensional framework, for the critical value α = 3, we prove the convergence of the trajectories. In the second part of this paper, we study the convergence properties of the associated forward-backward inertial algorithms. They aim to solve structured convex minimization problems of the form min {Θ := Φ + Ψ}, with Φ smooth and Ψ nonsmooth. The continuous dynamics serves as a guideline for this study. We obtain a similar rate of convergence for the sequence of iterates (xk): for α ≤ 3 we have Θ(xk) − min Θ = O(k−p) for all p < 2α/3, and for α > 3 Θ(xk) − min Θ = o(k−2). Finally, we show that the results are robust with respect to external perturbations.
Rectal Trauma: Evidence-Based Practices
Authors: Clemens Michael , Peace Kaitlin , Yi Fia
Published: December 2017

The management of rectal trauma has often been lumped in with colon trauma when, in fact, it is a unique entity. The anatomic nature of the rectum (with its intra- and extraperitoneal segments) lends itself to unique circumstances when it comes to management and treatment. From the four Ds (debridement, drainage, diversion, and distal irrigation), the management of rectal trauma has made some strides in light of the experiences coming out of the recent conflicts overseas as well as some rethinking of dogma. This article will serve to review the anatomy and types of injuries associated with rectal trauma. A treatment algorithm will also be presented based on our current literature review. We will also address controversial points and attempt to give our opinion in an effort to provide an update on an age-old problem.
Evaluation of the New DIN Standard for Quality Assurance of Diagnostic Displays – Technical Review DIN 6868-157
Authors: Entz Kathrin , Sommer Alexander , Lenzen Horst
Published: December 2017

Acceptance and regular constancy tests are necessary to ensure the quality of diagnostic displays. In November 2014, a new standard (DIN 6868-157) was published which defines the test procedure and limiting values. There are several substantial changes compared with the previous standard DIN V 6868-57, i. e. considering the complete image display system including workstation and application software instead of only the displays. Since its publication, the new standard has raised many questions. This technical review aims to show the strengths and weaknesses of the new standard. Positive aspects are the introduction of a limiting value for the illuminance and the extension of the interval for constancy tests from 3 to 6 six months. The daily constancy test on the other hand, raises several problems and should be replaced by a randomized test. Additionally, the medical relevance is critically questioned and an overview of software for the quality assurance will be given.

Key points 

Citation Format
How do Parents Perceive the Initial Medical Consultation on their Child’s Developmental Disorder?
Authors: Hotopp Lena , Spindler Ulrike , Bach Vivien , Hornemann Frauke , Syrbe Steffen , Andreas Anna , Merkenschlager Andreas , Kiess Wieland , Bernhard Matthias , Bertsche Thilo , Neininger Martina , Bertsche Astrid
Published: December 2017

Background A developmental disorder of a child has a major impact on the affected families’ lives. However, data about the parents’ perception of the revealing of the diagnosis is scarce.

Patients and Methods Parents of children with developmental disorder treated as outpatients in a university hospital were interviewed about the initial medical consultation concerning the diagnosis of their child.

Results Parents of 210 children agreed to take part in the study. 35/210 (17%) had to be excluded from the study as they were not able to remember the initial medical consultation, or claimed there was either no initial medical consultation or they did not attend it. The diagnosis of developmental disorder was made in median 4 months (Q25/Q75: 0/12; min/max: 0/63) after the parents had noticed the first symptoms. According to the parents, options to support the development of the child were the most frequently addressed topic in the initial medical consultation (119/175, 68%). Some parents wished more empathy (19/175, 11%), and less medical terminology (12/175, 7%). 114/175 (65%) of parents rated the initial medical consultation as “very good” or “good”. After their initial medical consultation, 66/175 (38%) of the parents had open questions mainly concerning the prognosis of the disease. Sources of information that were used after the consultation were most often the treating physician (150/175, 86%) and the internet (133/175, 76%).

Conclusion Generally, parents perceive the initial medical consultation on the developmental disorder of their child well. Nevertheless, many parents state that they had unanswered questions after the consultation. The internet is one of the main sources parents use to answer those questions.
Das Bundeszentrum für Ernährung (BZfE) – neuer Akteur für
Ernährungsfragen
Authors: Büning-Fesel Margareta
Published: December 2017

Bundesminister Christian Schmidt hat zum 1. Februar 2017 ein Bundeszentrum für Ernährung
(BZfE) in der Bundesanstalt für Landwirtschaft und Ernährung (BLE) in Bonn
eingerichtet.
Von kalten und hitzigen Herzen
Authors: Mayer Arnold
Published: December 2017

In der Traditionellen Europäischen Medizin (TEM) wirkt das Herz als Regulationszentrum für das Lebensprinzip Sanguis und damit als Schlüsselorgan für das Ineinanderwirken von Soma und Psyche und die Verbreitung der Vitalkräfte. Stressoren beeinträchtigen immer auch das Herz bis hin zum Broken-Heart-Syndrom. Umgekehrt haben kardiale Störungen immer auch psychische Folgen. Die TEM kennt zahlreiche Phytotherapeutika zur Behandlung psychosomatischer Herzstörungen, beispielsweise das Kalte oder das Hitzige Herz.
Akutstationäre Versorgung – Routinedatenanalyse zum Sturzrisiko
Authors: Bretzke Pascal
Published: December 2017

Jacobi L et al. Epidemiologie und Vorhersage des Sturzrisikos von Patienten in der akutstationären Versorgung: Analyse von Routinedaten eines
Universitätsklinikums. Z Evid Fortbild Qual Gesundh wesen 2017; 120: 9–15

Das Phänomen Sturz ist ein in allen Bereichen der Gesundheitsversorgung relevantes Problem. Stürze sind ein bedeutender Risikofaktor für
Frakturen, insbesondere bei älteren Menschen. Die patientenassoziierten Folgen sind diffizil und resultieren aus längeren
Behandlungszeiträumen, einer verminderten Lebensqualität oder einer vorzeitigen Mortalität. Ziel dieser Arbeit ist es,
versorgungsepidemiologische Daten zur Sturzhäufigkeit, Risikofaktoren und Güte eingesetzter Sturzrisikoassessments auszuwerten.
Stress im Erbgut
Authors: Sonnentag Marlies
Published: December 2017

Faktoren wie Stress, Angst, Traumata und Mangelzustände wirken sich ebenso auf die Genaktivität aus wie positive soziale Bindungen, man spricht von Epigenetik. Zu den epigenetischen Belastungsfolgen zählen beschleunigte Alterung, erhöhte Stresssensitivität, aber auch Insulinresistenz, Tumorerkrankungen, Bindungs- und Gedächtnisstörungen. Die An- oder Abschaltung von DNA-Sequenzen ist vererbbar, aber unter günstigen Einflüssen reversibel.
Auf-regen und Aus-regen
Authors: Casagrande C
Published: December 2017

Wenn Behandelnde gesund bleiben wollen, müssen sie Mittel und Wege finden, den eigenen Geist und Körper im Gleichgewicht zu halten. Die DHZ-Kolumne von HP Christina Casagrande.
The Combination of Fosfomycin, Metronidazole, and Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor is Stable in vitro and Has Maintained Antibacterial Activity
Authors: Fonnes Siv , Holzknecht Barbara , Gasbjerg Lærke , Weisser Johan , Hallberg Hanne , Arpi Magnus , Rosenberg Jacob
Published: December 2017

Background Treatment of secondary peritonitis includes surgery and antimicrobial agents. Antimicrobial agents are often administered intravenously, however, the alternative route intraperitoneal administration could be considered. Investigations must be conducted prior to clinical application. Therefore, we aimed to investigate the combination of fosfomycin, metronidazole, and recombinant human granulocyte-macrophage colony-stimulating factor with regard to its chemical properties and the solution’s stability. In addition, the antibacterial effect of the mixed drug solution was compared with the effect of the individual antibacterial agents.

Methods The drugs were mixed to an aqueous solution. Basic chemical investigations of pH, precipitation, and calculated osmolarity of the drug combination were conducted. Fosfomycin and metronidazole’s chemical stability was investigated using High Pressure Liquid Chromatography-Mass Spectrometry. Microbiological investigations using the agar cup method were carried out to measure the antibacterial effect of fosfomycin and metronidazole.

Results The aqueous solution of the combination of the three drugs had a pH of 7.46–7.62, which was stable during 24 h, was without precipitation, and had a calculated osmolarity of 293 mOsm/l. High Pressure Liquid Chromatography-Mass Spectrometry found stable concentrations of fosfomycin and metronidazole both alone and in combination during 24 h. The antibacterial effect of the drug combination solution was similar to the antibacterial effects of fosfomycin and metronidazole alone.

Conclusion The drug combination had neutral and stable pH, was iso-osmotic, and had stable concentrations during 24 h of storage. The antibacterial effect of fosfomycin and metronidazole were not altered when the drugs were mixed.
Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma
Authors: Upadhyay J. , Palczewski A. , Popović S. , Valente-Feliciano A.-M. , Im Do , Phillips H. L. , Vušković L.
Published: December 2017

An apparatus and a method for etching of the inner surfaces of superconducting radio frequency (SRF) accelerator cavities are described. The apparatus is based on the reactive ion etching performed in an Ar/Cl2 cylindrical capacitive discharge with reversed asymmetry. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity was used. The single cell cavity was mechanically polished and buffer chemically etched and then rf tested at cryogenic temperatures to provide a baseline characterization. The cavity’s inner wall was then exposed to the capacitive discharge in a mixture of Argon and Chlorine. The inner wall acted as the grounded electrode, while kept at elevated temperature. The processing was accomplished by axially moving the dc-biased, corrugated inner electrode and the gas flow inlet in a step-wise manner to establish a sequence of longitudinally segmented discharges. The cavity was then tested in a standard vertical test stand at cryogenic temperatures. The rf tests and surface condition results, including the electron field emission elimination, are presented.
Some conditional probabilities in the TASEP with second class particles
Authors: Lee Eunghyun
Published: December 2017

In this paper, we consider the totally asymmetric simple exclusion process (TASEP) with second class particles that consists of k first class particles and N − k second class particles. We assume that all first class particles are initially located to the left of the leftmost second class particle. Under this assumption, we find the probability that the first class particles are at x, x + 1, …, x + k − 1 and these positions are still to the left of the leftmost second class particle at time t. If we additionally assume that the initial positions of the particles are 1, …, N, that is, step initial condition, then the formula of the probability does not depend on k and is very similar to a formula for the TASEP (without second class particles) with step initial condition.
Theoretical and experimental study of the dark signal in CMOS image sensors affected by neutron radiation from a nuclear reactor
Authors: Xue Yuanyuan , Wang Zujun , He Baoping , Yao Zhibin , Liu Minbo , Ma Wuying , Sheng Jiangkun , Dong Guantao , Jin Junshan
Published: December 2017

The CMOS image sensors (CISs) are irradiated with neutron from a nuclear reactor. The dark signal in CISs affected by neutron radiation is studied theoretically and experimentally. The Primary knock-on atoms (PKA) energy spectra for 1 MeV incident neutrons are simulated by Geant4. And the theoretical models for the mean dark signal, dark signal non-uniformity (DSNU) and dark signal distribution versus neutron fluence are established. The results are found to be in good agreement with the experimental outputs. Finally, the dark signal in the CISs under the different neutron fluence conditions is estimated. This study provides the theoretical and experimental evidence for the displacement damage effects on the dark signal CISs.
A neural-network potential through charge equilibration for WS2: From clusters to sheets
Authors: Hafizi Roohollah , Ghasemi S. Alireza , Hashemifar S. Javad , Akbarzadeh Hadi
Published: December 2017

In the present work, we use a machine learning method to construct a high-dimensional potential for tungsten disulfide using a charge equilibration neural-network technique. A training set of stoichiometric WS2 clusters is prepared in the framework of density functional theory. After training the neural-network potential, the reliability and transferability of the potential are verified by performing a crystal structure search on bulk phases of WS2 and by plotting energy-area curves of two different monolayers. Then, we use the potential to investigate various triangular nano-clusters and nanotubes of WS2. In the case of nano-structures, we argue that 2H atomic configurations with sulfur rich edges are thermodynamically more stable than the other investigated configurations. We also studied a number of WS2 nanotubes which revealed that 1T tubes with armchair chirality exhibit lower bending stiffness.
Magnetic analysis of commercial hematite, magnetite, and their mixtures
Authors: Ahmadzadeh Mostafa , Romero Camila , McCloy John
Published: December 2017

Magnetic techniques are suitable to detect iron oxides even in trace concentrations. However, since several iron oxides may be simultaneously present in natural and synthetic samples, mixtures of magnetic particles and magnetic interactions between grains can complicate magnetic signatures. Among the iron oxide minerals, hematite (α-Fe2O3) and magnetite (Fe3O4) are the most common. In this work, different commercial hematite powders, normally used as Fe precursor in laboratory synthesis of Fe-containing oxides, were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). The effects of different concentrations of the hematite and magnetite on the magnetic properties of a set of mixtures (from 1 to 10 wt% magnetite) were then investigated by measuring the hysteresis loops, first order reversal curves (FORCs), thermal demagnetization, and isothermal remanent magnetization (IRM) curves. The three commercial hematite powders presented different magnetic behaviors mostly due to the effects of particle size. The magnetic results of mixtures reveal that it is very difficult to identify hematite magnetic signals by means of hysteresis loops, FORCs, or thermal demagnetization when even a small amount of magnetite (>5 wt%) is present due to magnetite’s high specific magnetization. However, IRM was found to be a sensitive method to determine the presence of hematite when magnetite is simultaneously present as high as 10 wt%.
Cloaking magnetic field and generating electric field with topological insulator and superconductor bi-layer sphere
Authors: Xu Jin
Published: December 2017

When an electric field is applied on a topological insulator, not only the electric field is generated, but also the magnetic field is generated, vice versa. I designed topological insulator and superconductor bi-layer magnetic cloak, derived the electric field and magnetic field inside and outside the topological insulator and superconductor sphere. Simulation and calculation results show that the applied magnetic field is screened by the topological insulator and superconductor bi-layer, and the electric field is generated in the cloaked region.
A first principles study on the electronic origins of silver segregation at the Ag-Au (111) surface
Authors: Hoppe Sandra , Müller Stefan
Published: December 2017

The special electronic structure of gold gives rise to many interesting phenomena, such as its color. The surface segregation of the silver-gold system has been the subject of numerous experimental and theoretical studies, yielding conflicting results ranging from strong Ag surface enrichment to Au surface segregation. Via a combined approach of density functional theory (DFT) and statistical physics, we have analyzed the segregation at the Ag-Au (111) surface with different Ag bulk concentrations. Interestingly, we observe a moderate Au surface segregation, which is due to a charge transfer from the less electronegative Ag to Au. Canonical Monte Carlo simulations suggest that the calculated concentration profile with a Au-enriched surface layer remains stable up to higher temperatures. However, the presence of adsorbed oxygen reverses the segregation behavior and leads to strong Ag enrichment of the surface layer.
Magnetically cooling achieves record low temperatures in Coulomb blockade thermometers
Authors: Tracy Samantha
Published: December 2017

Applying demagnetization cooling in a new way to Coulomb blockade thermometers reduces heat leaks and achieves a record cooling temperature.
Toward a unified theory of efficient, predictive, and sparse coding
Authors: Chalk Matthew , Marre Olivier , Tkačik Gašper
Published: December 2017

Significance

Sensory neural circuits are thought to efficiently encode incoming signals. Several mathematical theories of neural coding formalize this notion, but it is unclear how these theories relate to each other and whether they are even fully consistent. Here we develop a unified framework that encompasses and extends previous proposals. We highlight key tradeoffs faced by sensory neurons; we show that trading off future prediction against efficiently encoding past inputs generates qualitatively different predictions for neural responses to natural visual stimulation. Our approach is a promising first step toward theoretically explaining the observed diversity of neural responses.