bluuebunny/crossref_metadata_2025 huggingface dataset:
Intermolecular interactions in molecular crystals: what’s in a name?
Authors: Edwards Alison J. , Mackenzie Campbell F. , Spackman Peter R. , Jayatilaka Dylan , Spackman Mark A.
Published: March 2017

Structure–property relationships are the key to modern crystal engineering, and for molecular crystals this requires both a thorough understanding of intermolecular interactions, and the subsequent use of this to create solids with desired properties. There has been a rapid increase in publications aimed at furthering this understanding, especially the importance of non-canonical interactions such as halogen, chalcogen, pnicogen, and tetrel bonds. Here we show how all of these interactions – and hydrogen bonds – can be readily understood through their common origin in the redistribution of electron density that results from chemical bonding. This redistribution is directly linked to the molecular electrostatic potential, to qualitative concepts such as electrostatic complementarity, and to the calculation of quantitative intermolecular interaction energies. Visualization of these energies, along with their electrostatic and dispersion components, sheds light on the architecture of molecular crystals, in turn providing a link to actual crystal properties.
Selective conversion of 5-hydroxymethylfurfural to cyclopentanone derivatives over Cu–Al2O3 and Co–Al2O3 catalysts in water
Authors: Ramos Rubén , Grigoropoulos Alexios , Perret Noémie , Zanella Marco , Katsoulidis Alexandros P. , Manning Troy D. , Claridge John B. , Rosseinsky Matthew J.
Published: March 2017

The production of cyclopentanone derivatives from 5-hydroxymethylfurfural using non-noble metal based catalysts is reported for the first time.
Synthesis, characterization, and radioprotective activity of α,β-unsaturated aryl sulfone analogs and their Tempol conjugates
Authors: Zhou Nan , Feng Tian , Shen Xin , Cui Jiahui , Wu Rangxin , Wang Libin , Wang Siwang , Zhang Shengyong , Chen Hui
Published: March 2017

Some novel α,β-unsaturated aromatic sulfone analogs and Tempol conjugates are prepared and evaluated for their radioprotective activity, revealing that the agents have both prophylactic and mitigation effects against radiation damage.
One-step exfoliation and fluorination of g-C3N4 nanosheets with enhanced photocatalytic activities
Authors: Ma Fukun , Sun Changlong , Shao Yongliang , Wu Yongzhong , Huang Baibiao , Hao Xiaopeng
Published: March 2017

A one-step route for the exfoliation and fluorination of g-C3N4 nanosheets is presented and the F-C3N4 nanosheets show enhanced photocatalytic activities.
A yellowish-green-light-controllable nitric oxide donor based on N-nitrosoaminophenol applicable for photocontrolled vasodilation
Authors: Okuno Hana , Ieda Naoya , Hotta Yuji , Kawaguchi Mitsuyasu , Kimura Kazunori , Nakagawa Hidehiko
Published: March 2017

A novel yellowish-green-light-controllable NO donor,NO-Rosa, was synthesized. WithNO-Rosa, NO release in cells and NO-induced vasodilation were photocontrolled.
Different-sized black phosphorus nanosheets with good cytocompatibility and high photothermal performance
Authors: Fu Haidi , Li Zhibin , Xie Hanhan , Sun Zhengbo , Wang Beike , Huang Hao , Han Guangli , Wang Huaiyu , Chu Paul K. , Yu Xue-Feng
Published: March 2017

As a new kind of two-dimensional (2D) material, black phosphorus (BP) has attracted explosive interest in biomedical applications.
Epitaxial growth and cationic exchange properties of layered KNb3O8thin films
Authors: Waroquet A. , Demange V. , Hakmeh N. , Perrière J. , Freslon S. , Députier S. , Guilloux-Viry M.
Published: March 2017

The KNb3O8potassium triniobate phase is a layered compound that shows excellent photocatalytic activity, intercalation properties and electrochemical performances. K–Sn exchange of KNb3O8films leads to decrease the optical gap towards visible range.
Three-dimensional electro-Fenton oxidation of N-heterocyclic compounds with a novel catalytic particle electrode: high activity, wide pH range and catalytic mechanism
Authors: Hou Baolin , Ren Bozhi , Deng Renjian , Zhu Guocheng , Wang Zhenghua , Li Zhi
Published: March 2017

A novel three-dimensional (3D) heterogeneous electro-Fenton (EF) system with sludge deserved activated carbon from sewage and iron sludge (SAC-Fe) as catalytic particle electrodes (CPEs) was constructed in this study.
Graphene oxide/Fe3O4/SO3H nanohybrid: a new adsorbent for adsorption and reduction of Cr(vi) from aqueous solutions
Authors: Alizadeh Abdolhamid , Abdi Gisya , Khodaei Mohammad Mehdi , Ashokkumar Muthupandian , Amirian Jhaleh
Published: March 2017

A sulfonated magnetic graphene oxide (SMGO) hybrid was successfully synthesized via the nucleophilic substitution reaction and characterized.
Correction: A strategy for integrated pharmacokinetic study of cardiovascular herbal medicines based on chemiluminescence and HPLC-MS/MS assays: a case using Danshen injection
Authors: Yao Hong , Shi Peiying , Huang Xiaomei , Shen Zhenhuang , Su Ya , Yang Chunlei , Zhu Meilan , Huang Liying , Liu Ailin , Lin Xinhua
Published: March 2017

Correction for ‘A strategy for integrated pharmacokinetic study of cardiovascular herbal medicines based on chemiluminescence and HPLC-MS/MS assays: a case using Danshen injection’ by Hong Yao et al., RSC Adv., 2017, 7, 13570–13583.
Targeting the tumour microenvironment with an enzyme-responsive drug delivery system for the efficient therapy of breast and pancreatic cancers
Authors: Renoux Brigitte , Raes Florian , Legigan Thibaut , Péraudeau Elodie , Eddhif Balkis , Poinot Pauline , Tranoy-Opalinski Isabelle , Alsarraf Jérôme , Koniev Oleksandr , Kolodych Sergii , Lerondel Stéphanie , Le Pape Alain , Clarhaut Jonathan , Papot Sébastien
Published: March 2017

A drug delivery system targeting the tumour microenvironment produces outstanding therapeutic efficacy on triple-negative mammary and pancreatic models.
A binary metal organic framework derived hierarchical hollow Ni3S2/Co9S8/N-doped carbon composite with superior sodium storage performance
Authors: Liu Xinye , Zou Feng , Liu Kewei , Qiang Zhe , Taubert Clinton J. , Ustriyana Putu , Vogt Bryan D. , Zhu Yu
Published: March 2017

The carbonization and sulfurization of a hierarchical hollow MOF leads to anode materials with exceptional performance in Na+ batteries with high cycle stability and rate performance.
Dendritic nanotubes self-assembled from stiff polysaccharides as drug and probe carriers
Authors: Meng Yan , Zou Siwei , Jiang Meijuan , Xu Xiaojuan , Tang Ben Zhong , Zhang Lina
Published: March 2017

AF1-constructed DNTs have promising prospects as carriers, especially in the fields of drug and probe delivery systems.
A core–shell metal–organic-framework (MOF)-based smart nanocomposite for efficient NIR/H2O2-responsive photodynamic therapy against hypoxic tumor cells
Authors: Cai Hui-Juan , Shen Ting-Ting , Zhang Jian , Shan Chang-Fu , Jia Jian-Guo , Li Xiang , Liu Wei-Sheng , Tang Yu
Published: March 2017

In this work, core–shell MOF-based smart nanocomposite UCNPs/MB@ZIF-8@catalase has been constructed for bio-imaging and efficient NIR/H2O2-responsive photodynamic therapy against hypoxic tumor cells.
Electrochemiluminescence resonance energy transfer (ERET) towards trinitrotoluene sensor based on layer-by-layer assembly of luminol-layered double hydroxides and CdTe quantum dots
Authors: Li Zhixiong , Zhou Yuqiong , Yan Dongpeng , Wei Min
Published: March 2017

Electrochemiluminescence (ECL) resonance energy transfer (ERET) systems have shown excellent potential in analysis and detection fields because of the supersensitivity, high level of controllability, and amplified signal.
pH controllable photocurrent switching and molecular half-subtractor calculations based on a monolayer composite film of a dinuclear RuII complex and graphene oxide
Authors: Meng T. T. , Xue L. X. , Wang H. , Wang K. Z. , Haga M.
Published: March 2017

A monolayer film composed of graphene oxide and a dinuclear Ru(ii) complex, acts as multiple logic gates performing half-subtractor molecular computations by using pH and potential as inputs and photocurrent as output.
Methodology to locate and quantify radial winding deformation in power transformers
Authors: Mitchell Steven D. , Welsh James S.
Published: March 2017

Frequency response analysis (FRA) is a tool that can be used to detect changes within the structural geometry of a transformer. One application of FRA is to detect winding displacement after the transformer experiences an overcurrent event. This paper proposes a methodology which will facilitate both locating and quantifying winding deformation. The procedure is based on the fitting of a Gray Box transformer model to FRA measurements which were recorded both before and after the fault. Subtle variation in key parameters of the model can then be used to quantify winding deformation severity. The research will demonstrate the applicability of this approach to a wide range of transformer applications by using FRA from a modified 1.3 MVA distribution transformer, and assessing the change in key parameters relative to the emulated buckling introduced to the windings. The authors propose that this approach is ideally suited for use within an automated diagnostic system which will locate, diagnose and quantify winding deformation within power transformers.
Parallel combinatory multicarrier modulation in underwater acoustic communications
Authors: Lu Qin , Hu Xiaoyi , Wang Deqing , Zhou Shengli
Published: March 2017

Parallel combinatory multicarrier (PCMC) modulation is a generalisation of the legacy multicarrier frequency shift keying (FSK) scheme, where for each group of M subcarriers, more than one (say L) subcarriers are chosen for simultaneous transmission. The PCMC scheme provides an effective way to increase the spectral efficiency while maintaining non‐coherent detection at the receiver. This study provides an in‐depth study of the PCMC scheme with emphasis on how to couple with binary or non‐binary channel coding. One favourable system configuration is identified, having parameters (L,M) = (4,8), which increases the spectral efficiency by 50% relative to the most efficient FSK scheme from the FSK family. Coupled with non‐binary low‐density parity‐check (LDPC) coding over the Galois field GF(64), the PCMC scheme with (L,M) = (4,8) is shown to have robust performance in multipath fading channels.
EMI and ground leakage current reduction in single‐phase grid‐connected power converter
Authors: Hedayati Mohammad Hassan , John Vinod
Published: March 2017

Ground leakage current in a power converter is a major concern, which has stringent limitations due to safety concerns. Presence of high‐frequency pulses, with high dv/dt due to switching actions in common‐mode (CM) voltage, result in injection of current waveforms with large di/dt spikes into the ground and causes high electromagnetic interference (EMI) noise level. In this study, a new method is proposed to make the CM voltage, of a single‐phase grid‐connected inverter, sinusoidal and free of high‐frequency pulses. The proposed method consists of two parallel connected H‐bridge power converters, which uses unipolar pulse width modulation (PWM) with carrier interleaving angle of 180°. The proposed method reduces the ground leakage current by more than an order of magnitude. A novel modification to the LCL filter is proposed which further reduces the leakage current by 48%. It is shown that these modifications make the overall system insensitive to circuit non‐idealities. Experimental results based on ground leakage current measurements on a 7.5 kW parallel single‐phase PWM rectifier are presented. These results validate the effectiveness of the proposed method.
Performance improvements of wire fault diagnosis approach based on time‐domain reflectometry
Authors: de Paulis Francesco , Boudjefdjouf Hamza , Bouchekara Houssem R.E.H. , Orlandi Antonio , Smail Mostafa Kamel
Published: March 2017

The aim of this study is to improve the performance of a wire fault diagnosis approach based on time‐domain reflectometry (TDR). In this approach, the TDR response collected from measurements for a given (faulty) coaxial cable network is used as a reference for the cable network model response computed by an accurate analytical transmission line (ATL) method. The ATL model is iteratively tuned according to the outcome of the optimisation algorithm proposed. The advantage of the proposed ATL method over the more classic finite difference time‐domain method is the extremely faster computational time which represents a significant factor for the diagnosis of faults in wiring networks. The proposed ATL method accurately provides the features of the resistance–inductance–conductance–capacitance‐based model of a RG‐58 coaxial cable employed as a device under test. The ATL model has been validated by comparison with measurement based and circuit simulations. Furthermore, seven experiments have been investigated in order to evaluate the performance of the ATL method for the diagnosis of wiring networks. The obtained results reveal that the ATL method together with the efficient optimisation algorithm is a reliable, efficient and fast method for the diagnosis of wiring networks.
Selective Aerobic Oxidation of Primary Alcohols to Aldehydes
Authors: Shibuya Masatoshi , Furukawa Keisuke , Yamamoto Yoshihiko
Published: March 2017

The 2-azaadamantane-N-oxyl (AZADO)- and 9-azanoradamantane-N-oxyl (nor-AZADO)-catalyzed selective oxidation of primary alcohols to the corresponding aldehydes is described. The use of tert-butyl nitrite as the co-catalyst enables efficient aerobic oxidation in MeCN instead of previously reported AcOH; this is important for the selectivity of the reaction. The addition of a solution of saturated aqueous NaHCO3 after the completion of the reaction was effective to suppress the overoxidation of the product to the corresponding carboxylic acid during the workup.
Synthesis of Secosterols as an Arena for C–H Functionalization and C–C Manipulation Tactics
Authors: Heretsch Philipp , Heinze Robert
Published: March 2017

The chemical synthesis of secosterols is an arena for the application of C–H functionalization methods as well as C–C manipulations. Studies on the innate reactivity of synthetic intermediates to undergo C–C scissions and rearrangements can shed light on biosynthetic pathways, or, provide proof for biosynthetic proposals. Examples of the authors work (synthesis of the 14,15-secosterol strophasterol A), as well as examples from current literature (Tian’s synthetic work on 13,14:14,15-disecosterols glaucogenins C and D, and Baran’s synthesis of 9,10-secosterol cortistatin A) are discussed.

1 Introduction

2 The Synthesis of Strophasterol A Employing the Concept of Innate Reactivity

3 Synthetic Work in the Glaucogenin Family of Natural Products

4 The Synthesis of Cortistatin A Using a Radical Ring Expansion

5 Conclusion
Is There a Role for Placental Cultures in Cases of Clinical Chorioamnionitis Complicating Preterm Premature Rupture of Membranes?
Authors: Many Ariel , Orbach Rotem , Shapira Udi , Amit Sharon , Grisaru-Soen Galia , Mandel Dror , Shinar Shiri , Fouks Yuval
Published: March 2017

Objective To assess the role of placental cultures in cases of preterm premature rupture of membranes (PPROM) complicated by chorioamnionitis and to determine the effect of positive cultures on short-term neonatal outcomes.

Design A retrospective single-center study. The medical records of all women with PPROM between January 1, 2011, and December 31, 2015, were reviewed. Cases were divided into placental culture positive (group A) and placental culture negative (group B) groups. Maternal and pregnancy characteristics as well as short-term neonatal outcomes were compared between groups.

Results During the 5-year study period, 61 cases of clinical chorioamnionitis complicating PPROM were diagnosed: 25 cases were culture positive (group A) and 36 were culture negative (group B). Neonatal outcome measures, including Apgar score at 5 minutes (p = 0.028; odds ratio [OR]: 5.27; confidence interval [CI]: 1.19–23.34), respiratory distress syndrome (p = 0.026; OR: 4.11; CI: 1.18–14.25), and neonatal infection (p < 0.0001; OR: 11.59; CI: 3.37–39.87) were significantly more common in group A newborns, regardless of gestational age at delivery as was the composite neonatal outcome (p = 0.017; OR: 7.35: CI: 1.42–37.79). Placental isolates were primarily Streptococci and Escherichia coli.

Conclusion Placental cultures may be an essential predictor of neonatal morbidity in PPROM and may contribute to the modification of neonatal treatment.
Annularly grooved membrane combined with rood beam piezoresistive pressure sensor for low pressure applications
Authors: Li Chuang , Cordovilla Francisco , Ocaña José L.
Published: March 2017

A novel structural piezoresistive pressure sensor with annularly grooved membrane combined with rood beam has been proposed for low pressure measurements based on silicon substrate. In this study, a design method, including the model design, dimensions optimization, and performance prediction of the novel structure sensor, is presented. The finite element method has been used to analyze the stress distribution of sensitive elements and the deflection of membrane. On the basis of simulation results, the relationships between structural dimension variables and mechanical performance are deduced, which make the fabrication processes more efficient. According to statistics theory, the coefficient of determination R2 and residual sum of squares are introduced to indicate whether the fitting equations and curves match well with the simulation results. After that, a series of the optimal membrane dimensions are determined. Compared with other structural sensors, the optimized sensor achieves the best overall properties as it mitigates the contradiction between sensitivity and linearity. The reasons why the proposed sensor can maximize sensitivity and minimize nonlinearity are also discussed. By localizing more strain energy in the high concentrated stress profile and creating partially stiffened membrane, the proposed sensor has achieved a high sensitivity of 34.5 (mV/V)/psi and a low nonlinearity of 0.25% FSS. Thus, the proposed structure sensor will be a proper choice for low pressure applications less than 1 psi.
Solution identification and quantitative analysis of fiber-capacitive drop analyzer based on multivariate statistical methods
Authors: Chen Zhe , Qiu Zurong , Huo Xinming , Fan Yuming , Li Xinghua
Published: March 2017

A fiber-capacitive drop analyzer is an instrument which monitors a growing droplet to produce a capacitive opto-tensiotrace (COT). Each COT is an integration of fiber light intensity signals and capacitance signals and can reflect the unique physicochemical property of a liquid. In this study, we propose a solution analytical and concentration quantitative method based on multivariate statistical methods. Eight characteristic values are extracted from each COT. A series of COT characteristic values of training solutions at different concentrations compose a data library of this kind of solution. A two-stage linear discriminant analysis is applied to analyze different solution libraries and establish discriminant functions. Test solutions can be discriminated by these functions. After determining the variety of test solutions, Spearman correlation test and principal components analysis are used to filter and reduce dimensions of eight characteristic values, producing a new representative parameter. A cubic spline interpolation function is built between the parameters and concentrations, based on which we can calculate the concentration of the test solution. Methanol, ethanol, n-propanol, and saline solutions are taken as experimental subjects in this paper. For each solution, nine or ten different concentrations are chosen to be the standard library, and the other two concentrations compose the test group. By using the methods mentioned above, all eight test solutions are correctly identified and the average relative error of quantitative analysis is 1.11%. The method proposed is feasible which enlarges the applicable scope of recognizing liquids based on the COT and improves the concentration quantitative precision, as well.
Characterization of iron doped indium phosphide as a current blocking layer in buried heterostructure quantum cascade lasers
Authors: Nida S. , Hinkov B. , Gini E. , Faist J.
Published: March 2017

This work analyzes transport through metal organic chemical vapour deposition grown Iron doped Indium Phosphide (InP:Fe) for use as a current blocking layer in buried heterostructure Quantum Cascade Lasers. The nature of Iron incorporation in InP and electrical transport properties of InP:Fe is investigated via simulation and compared with measurement. Through simulations, we are able to predict the threshold for the onset of current rise in test structures due to avalanche injection of carriers. In addition, the benefit of InAlAs barriers inserted in InP:Fe layers is investigated and found to reduce the leakage current at lower biases while delaying the onset of avalanche. In buried heterostructure configuration, we have determined that non ideal regrowth profiles make the structure more susceptible to high field effects such as avalanche injection and trap filling that induce leakage currents.
On the separation mechanics of accelerating spheres
Authors: Fernando John N. , Marzanek Mathew , Bond Clinton , Rival David E.
Published: March 2017

The instantaneous drag forces and wake mechanics of an accelerating sphere have been investigated experimentally. Drag forces are first compared to the circular flat plate, which is characterized by stable and Reynolds-number independent vortex-ring formation during accelerations from rest. For the sphere, vortex-ring formation is shown to be greatly suppressed by the time-dependent movement of the separation line during start-up towards the steady-state position, which induces strong vortex-body interactions. Next, inviscid theory is used to predict the state of the pressure-gradient field around a sphere during accelerations from a non-zero initial velocity. The azimuthal point of separation extracted from experimental data for the subcritical cases is found to be strongly correlated with the start of the adverse pressure gradient predicted by theory. For the supercritical cases, the point of separation is unaffected by the imposed accelerations and remains at the steady-state position. The results suggest that accelerations can only be exploited to delay flow separation at Reynolds numbers with steady separation points near the apex, where the tangential accelerations are the largest.
Return of target material ions leads to a reduced hysteresis in reactive high power impulse magnetron sputtering: Model
Authors: Kadlec Stanislav , Čapek Jiří
Published: March 2017

A tendency to disappearing hysteresis in reactive High Power Impulse Magnetron Sputtering (HiPIMS) has been reported previously without full physical explanation. An analytical model of reactive pulsed sputtering including HiPIMS is presented. The model combines a Berg-type model of reactive sputtering with the global HiPIMS model of Christie-Vlček. Both time and area averaging is used to describe the macroscopic steady state, especially the reactive gas balance in the reactor. The most important effect in the presented model is covering of reacted parts of target by the returning ionized metal, effectively lowering the target coverage by reaction product at a given partial pressure. The return probability of ionized sputtered metal has been selected as a parameter to quantify the degree of HiPIMS effects. The model explains the reasons for reduced hysteresis in HiPIMS. The critical pumping speed was up to a factor of 7 lower in reactive HiPIMS compared to the mid-frequency magnetron sputtering. The model predicts reduced hysteresis in HiPIMS due to less negative slope of metal flux to substrates and of reactive gas sorption as functions of reactive gas partial pressure. Higher deposition rate of reactive HiPIMS compared to standard reactive sputtering is predicted for some parameter combinations. Comparison of the model with experiment exhibits good qualitative and quantitative agreement for three material combinations, namely, Ti-O2, Al-O2, and Ti-N2.
Growth of Fe3Si/Ge/Fe3Si trilayers on GaAs(001) using solid-phase epitaxy
Authors: Gaucher S. , Jenichen B. , Kalt J. , Jahn U. , Trampert A. , Herfort J.
Published: March 2017

Ferromagnetic Heusler alloys can be used in combination with semiconductors to create spintronic devices. The materials have cubic crystal structures, making it possible to grow lattice-matched heterojunctions by molecular beam epitaxy. However, the development of devices is limited by the difficulty of growing epitaxial semiconductors over metallic surfaces while preventing chemical reactions, a requirement to obtain abrupt interfaces and achieve efficient spin-injection by tunneling. We used a solid-phase epitaxy approach to grow crystalline thin film stacks on GaAs(001) substrates, while preventing interfacial reactions. The crystallized Ge layer forms superlattice regions, which are caused by the migration of Fe and Si atoms into the film. X-ray diffraction and transmission electron microscopy indicate that the trilayers are fully crystalline, lattice-matched, and have ideal interface quality over extended areas.
Ion distribution and ablation depth measurements of a fs-ps laser-irradiated solid tin target
Authors: Deuzeman M. J. , Stodolna A. S. , Leerssen E. E. B. , Antoncecchi A. , Spook N. , Kleijntjens T. , Versluis J. , Witte S. , Eikema K. S. E. , Ubachs W. , Hoekstra R. , Versolato O. O.
Published: March 2017

The ablation of solid tin surfaces by a 800-nanometer-wavelength laser is studied for a pulse length range from 500 fs to 4.5 ps and a fluence range spanning from 0.9 to 22 J/cm2. The ablation depth and volume are obtained employing a high-numerical-aperture optical microscope, while the ion yield and energy distributions are obtained from a set of Faraday cups set up under various angles. We found a slight increase of the ion yield for an increasing pulse length, while the ablation depth is slightly decreasing. The ablation volume remained constant as a function of pulse length. The ablation depth follows a two-region logarithmic dependence on the fluence, in agreement with the available literature and theory. In the examined fluence range, the ion yield angular distribution is sharply peaked along the target normal at low fluences but rapidly broadens with increasing fluence. The total ionization fraction increases monotonically with fluence to a 5%–6% maximum, which is substantially lower than the typical ionization fractions obtained with nanosecond-pulse ablation. The angular distribution of the ions does not depend on the laser pulse length within the measurement uncertainty. These results are of particular interest for the possible utilization of fs-ps laser systems in plasma sources of extreme ultraviolet light for nanolithography.
1-kV vertical Ga2O3 field-plated Schottky barrier diodes
Authors: Konishi Keita , Goto Ken , Murakami Hisashi , Kumagai Yoshinao , Kuramata Akito , Yamakoshi Shigenobu , Higashiwaki Masataka
Published: March 2017

Ga2O3 field-plated Schottky barrier diodes (FP-SBDs) were fabricated on a Si-doped n−-Ga2O3 drift layer grown by halide vapor phase epitaxy on a Sn-doped n+-Ga2O3 (001) substrate. The specific on-resistance of the Ga2O3 FP-SBD was estimated to be 5.1 mΩ·cm2. Successful field-plate engineering resulted in a high breakdown voltage of 1076 V. A larger-than-expected effective barrier height of 1.46 eV, which was extracted from the temperature-dependent current–voltage characteristics, could be caused by the effect of fluorine atoms delivered in a hydrofluoric acid solution process.
Characteristics of a micro-gap argon barrier discharge excited by a saw-tooth voltage at atmospheric pressure
Authors: Li Xuechen , Zhang Qi , Jia Pengying , Chu Jingdi , Zhang Panpan , Dong Lifang
Published: March 2017

Using two water electrodes, a micro-gap dielectric barrier discharge excited by a saw-tooth voltage is investigated in atmospheric pressure argon. Through electrical and optical measurements, it is found that, at a lower driving frequency, a stepped discharge mode is obtained per half voltage cycle. Moreover, the duration and amplitude of the current plateau increase with the increase in the applied peak voltage. With the increase in the driving frequency, the stepped discharge mode transits into a pulsed one after a multi-peak mode. During this process, a diffuse discharge at a lower frequency transits into a filamentary one at a higher frequency. Temporal evolutions of the discharges are investigated axially based on fast photography. It is found that the stepped mode is in atmospheric pressure Townsend discharge (APTD) regime. However, there is a transition from APTD to atmospheric pressure glow discharge for the pulsed mode. Spectral intensity ratio of 391.4 nm to 337.1 nm is used to determine the averaged electron energy, which decreases with increasing peak voltage or driving frequency.
Comparing the soft x-rays transport in Si and Ge-sandwich targets by measuring transmission flux
Authors: Zhang Lu , Li Liling , Guo Liang , Jing Longfei , Lin Zhiwei , Qing Bo , Li Zhichao , Li Hang , Kuang Longyu , Zheng Jianhua , Zhang Jiyan , Yang Jiamin , Jiang Shaoen , Ding Yongkun
Published: March 2017

Mid-Z dopant in ablator is very important in point design targets. In this paper, we develop a method to evaluate the soft x-ray transport of doped material with one dimensional planar target. The targets are designed as sandwich, so that the mid-layer is heated by M band, shock and thermal wave. The transmission fluxes from heated targets are measured with band-pass x-ray diodes. The Si and Ge dopants are evaluated with this method. The experimental results show that 1–1.6 keV x-ray transmission flux through Si-sandwich is higher than that through Ge-sandwich all the time. Also, the comparison of opacities shows that the opacity of Si is lower than that of Ge in the range of 1–1.6 keV, which is consistent with the experimental results.
Study of dynamical behaviour of the plasma in a dc non-transferred plasma torch using fast imaging
Authors: Goyal Vidhi , Ravi G. , Bandyopadhyay P. , Banerjee S. , Yugesh V. , Mukherjee S.
Published: March 2017

The dynamical behaviour of the plasma in a dc non-transferred plasma torch is the result of complex interactions between various forces acting on the plasma column. We have studied this behaviour in a novel experiment comprising a low power (∼25 kW) torch and fast imaging diagnostics. The nitrogen gas plasma torch was operated at atmospheric pressure for a wide range of gas flow rates (20–60 lpm) and currents (70–120 A). A strong axial external magnetic field (100–500 G) was introduced and end-on images of the plasma column were captured using a high speed camera of frame rate ∼117 000 fps. The studies have yielded dominant role of external magnetic on the arc root dynamics. The column is clearly distinguishable in three main parts: central plasma, cathode-anode junction, and radial component of column that attaches to the anode. The dynamics of the column, especially the angular rotational speed of the radial part of the column, is analyzed in detail in terms of the forces that act upon it. The nature of the arc root attachment is observed to vary with variation in main experimental parameters, such as current, magnetic field, and flow. Arguments are invoked to explain the observed phenomena and a model of the physical processes is presented to explain the phenomena.
Highly accurate nuclear and electronic stopping cross sections derived using Monte Carlo simulations to reproduce measured range data
Authors: Wittmaack Klaus , Mutzke Andreas
Published: March 2017

We have examined and confirmed the previously unexplored concept of using Monte Carlo calculations in combination with measured projected ranges of ions implanted in solids to derive a quantitative description of nuclear interaction and electronic stopping. The study involved 98 ranges of 11B in Si between 1 keV and 8 MeV, contained in 12 sets of 10 different groups. Systematic errors by up to ±8% were removed to establish a refined data base with 93 ranges featuring only statistical uncertainties (±1.8%). The Monte Carlo calculations could be set up to reproduce the refined ranges with a mean ratio 1.002 ± 1.7%. The input parameters required for this very high level of agreement are as follows. Nuclear interaction is best described by the Kr-C potential, but in obligatory combination with the Lindhard-Scharff (LS) screening length. Up to 300 keV, the electronic stopping cross section is proportional to the projectile velocity, Se = kSe,LS, with k = 1.46 ± 0.01. At higher energies, Se falls progressively short of kSe,LS. Around the Bragg peak, i.e., between 0.8 and 10 MeV, Se is modeled by an adjustable function serving to tailor the peak shape properly. Calculated and measured isotope effects for ranges of 10B and 11B in Si agree within the experimental uncertainty (±0.25%). The range-based Se,R(E) reported here predicts the scarce experimental data derived from the energy loss in projectile transmission through thin Si foils to within 2% or better. By contrast, Se(E) data of available stopping power tables exhibit deviations from Se,R(E) between −40% and +14%.
Impact of In doping on GeTe phase-change materials thin films obtained by means of an innovative plasma enhanced metalorganic chemical vapor deposition process
Authors: Szkutnik P. D. , Aoukar M. , Todorova V. , Angélidès L. , Pelissier B. , Jourde D. , Michallon P. , Vallée C. , Noé P.
Published: March 2017

We investigated the deposition and the phase-change properties of In-doped GeTe thin films obtained by plasma enhanced metalorganic chemical vapor deposition and doped with indium using a solid delivery system. The sublimated indium precursor flow rate was calculated as a function of sublimation and deposition parameters. Indium related optical emission recorded by means of optical emission spectroscopy during deposition plasma allowed proposing the dissociation mechanisms of the [In(CH3)2N(CH3)2]2 solid precursor. In particular, using an Ar + H2 + NH3 deposition plasma, sublimated indium molecules are completely dissociated and do not induce by-product contamination by addition of nitrogen or carbon in the films. X-ray photoelectron spectroscopy evidences the formation of In-Te bonds in amorphous as-deposited In-doped GeTe films. The formation of an InTe phase after 400 °C annealing is also evidenced by means of X-ray diffraction analysis. The crystallization temperature Tx, deduced from monitoring of optical reflectivity of In-doped GeTe films with doping up to 11 at. % slightly varies as a function of the In dopant level with a decrease of Tx down to a minimum value for an In doping level of about 6–8 at. %. In this In doping range, the structure of crystallized In-GeTe films changes and is dominated by the presence of a crystalline In2Te3 phase. Finally, the Kissinger activation energy for crystallization Ea is showing to monotonically decrease as the indium content in the GeTe film is increased indicating a promising effect of In doping on crystallization speed in memory devices while keeping a good thermal stability for data retention.
Resonant optical properties of AlGaAs/GaAs multiple-quantum-well based Bragg structure at the second quantum state
Authors: Chen Y. , Maharjan N. , Liu Z. , Nakarmi M. L. , Chaldyshev V. V. , Kundelev E. V. , Poddubny A. N. , Vasil'ev A. P. , Yagovkina M. A. , Shakya N. M.
Published: March 2017

An AlGaAs/GaAs multiple-quantum-well based resonant Bragg structure was designed to match the optical Bragg resonance with the exciton-polariton resonance at the second quantum state in the GaAs quantum wells. The sample structure with 60 periods of AlGaAs/GaAs quantum wells was grown on a semi-insulating GaAs substrate by molecular beam epitaxy. Angle- and temperature-dependent photoluminescence, optical reflectance, and electro-reflectance spectroscopies were employed to study the resonant optical properties of the Bragg structure. Broad and enhanced optical and electro-reflectance features were observed when the Bragg resonance was tuned to the second quantum state of the GaAs quantum well excitons, manifesting a strong light-matter interaction. From the electro-optical experiments, we found the electro-reflectance features related to the transitions of x(e2-hh2) and x(e2-hh1) excitons. The excitonic transition x(e2-hh1), which is prohibited at zero electric field, was allowed by a DC bias due to the brake of symmetry and increased overlap of the electron and hole wave functions caused by the electric field. By tuning the Bragg resonance frequency, we have observed the electro-reflectance feature related to the second quantum state up to room temperature, which evidences a robust light-matter interaction in the resonant Bragg structure.
Enhanced pyroelectric properties of Pb0.3Ca0.15Sr0.55TiO3 ceramic with first-order dominated phase transition under low bias field
Authors: Han Liuyang , Guo Shaobo , Yan Shiguang , Cao Fei , Guo Weili , Yao Chunhua , Dong Xianlin , Wang Genshui
Published: March 2017

We introduce a system of ferroelectric materials, Pb0.3CaxSr0.7-xTiO3 [PCST(x), x = 0.00, 0.05, 0.10, and 0.15], which exhibit good pyroelectric properties near room temperature. The enhanced field-induced pyroelectric coefficient of PCST(0.15) reached 81.8 × 10−8 C/cm2 K and it exhibited the largest voltage response with a dynamic black-body radiation measurement under a DC bias field of 200 V/mm. Systematic dielectric and phase transition analysis of the PCST(x) ceramics demonstrated that the phase transition gradually changed from a second-order to first-order dominated one with increasing Ca ion substitution. The enhanced pyroelectric properties under such a low bias field in the vicinity of room temperature of the PCST(0.15) ceramic are highly desirable for infrared detecting applications.
Synthesis and magnetic study of magnetically hard-soft SrFe12-yAlyO19 - x Wt.% Ni0.5Zn0.5Fe2O4 nanocomposites
Authors: Neupane D. , Ghimire M. , Adhikari H. , Lisfi A. , Mishra S. R.
Published: March 2017

Pure phase exchange coupled nanocomposites of magnetically hard-soft oxides, (hard) SrFe12-yAlyO19 -(soft) x Wt.% Ni0.5Zn0.5Fe2O4 were prepared via one-pot autocombustion method. The hard-phase magnetic anisotropy was systematically varied via Al3+ doping and magnetic properties of the nanocomposites were assessed as a function of magnetic soft-phase content in the nanocomposite. As synthesized, ferrites were assessed for phase composition, crystallinity, and magnetic properties by using XRD and VSM respectively. Exchange coupling behavior was observed in nanocomposites for all soft phase content in the low field region up to 1200 Oe. Also, exchange coupling was observed to weaken with increase in Al3+ content in the hard phase of the composite. As a result of hard-soft exchange coupling, the saturation magnetization, reduced remanence, and Curie temperature were observed to be higher than those of pure SrFe12O19 hexaferrite. The present study is novel in its approach of tuning magnetic parameters of exchange-spring nanocomposites via systematically controlling magnetic parameters of the hard phase and content of the soft phase.
High-resolution nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using gas permeable mold
Authors: Takei Satoshi , Hanabata Makoto
Published: March 2017

We report high-resolution (150 nm) nanopatterning of biodegradable polylactide by thermal nanoimprint lithography using dichloromethane as a volatile solvent for improving the liquidity and a porous cyclodextrin-based gas-permeable mold. This study demonstrates the high-resolution patterning of polylactic acid and other non-liquid functional materials with poor fluidity by thermal nanoimprinting. Such a patterning is expected to expand the utility of thermal nanoimprint lithography and fabricate non-liquid functional materials suitable for eco-friendly and biomedical applications.
Magnetic losses in Si-Fe alloys for avionic applications
Authors: Cardelli E. , Faba A. , Pompei M. , Quondam Antonio S.
Published: March 2017

This paper presents an experimental analysis of the rotational power losses of the magnetic materials of transformers, motors and actuators used in avionic environment. A large frequency range is investigated using a suitable experimental test frame developed to measure the power losses for a circular magnetization. The results about different silicon iron alloys with different textures and thickness are considered and compared.
Influence of exchange on signal-to-noise ratio in [CoX/Pt]4 media
Authors: Zhao Zhen , Li Jiangnan , Wang Longze , Wei Dan
Published: March 2017

In longitudinal hard disk drives, the medium Signal-to-Noise Ratio (SNR) is higher with better grain segregation or lower inter-grain exchange. In current energy assisted magnetic recording system, multilayer perpendicular media are utilized; thus, it is significant to study the influence of grain segregation on SNR, as well as the relevant percolation phenomenon, to give suggestions on the recording media design. In this study, micromagnetic recording models of Microwave Assisted Magnetic Recording (MAMR) is built up to calculate SNR to find optimized [CoX/Pt]4 media parameters such as the inter-grain exchange Agb and the anisotropy orientation distribution αθ, with different field generation layer (FGL) saturation in the spin torque oscillator (STO). The constrained relationship between Agb and αθ in MAMR have been estimated, and the medium SNR will be optimized in the perpendicular [CoX/Pt]4 with a proper but not lowest exchange.
Low temperature Cu-Cu bonding using copper nanoparticles fabricated by high pressure PVD
Authors: Wu Zijian , Cai Jian , Wang Qian , Wang Junqiang
Published: March 2017

Copper nanoparticles (Cu NPs) fabricated by physical vapor deposition (PVD) were introduced in Cu-Cu bonding as surface modification. The bonding structure with Ti adhesive/barrier layer and Cu substrate layer was fabricated on both surfaces first. Loose structure with Cu NPs was then deposited by magnetron sputtering in a high pressure environment. Solid state Cu-Cu bonding process was accomplished at 200°C for 3min under the pressure of 20MPa. Die shear test was carried out and an average bonding strength of 36.75MPa was achieved. The analysis of fracture surface revealed a high-reliability bonding structure. According to cross-sectional observations, a void-free intermediate Cu layer with thickness around 10nm was obtained. These results demonstrated that a reliable low temperature time-saving Cu-Cu bonding was realized by Cu NPs between the bonding pairs. This novel bonding method might be one of the most attractive techniques in the application of ultra-fine pitch 3D integration.
Responses of dairy cows to short-term heat stress in controlled-climate chambers
Authors: Garner J. B. , Douglas M. , Williams S. R. O. , Wales W. J. , Marett L. C. , DiGiacomo K. , Leury B. J. , Hayes B. J.
Published: March 2017

The objective of the present research was to describe the physiological and production responses of lactating dairy cows during and after sudden exposure to temperate-climate heat-wave conditions, compared with cows in thermoneutral conditions. Twelve lactating multiparous Holstein–Friesian dairy cows were housed in controlled-climate chambers for 4 days. Six were exposed to a short-term temperature and humidity challenge (THc, diurnal temperature and humidity fluctuations inducing moderate heat stress; temperature humidity index 74–84) and six cows were exposed to thermoneutral conditions (THn, temperatur humidity index 55–61). Cows were also measured during a 7-day pre-experimental and 14-day post-experimental period. Physiological indicators of heat stress were measured, including rectal and vaginal temperature and respiration rate, which indicated that the THc in controlled-climate chambers induced moderate heat stress. The cows exposed to the 4-day THc reduced their milk yield by 53% and their dry-matter intake by 48%, compared with the cows in the THn treatment. Milk yield of THc cows returned to pre-experimental milk yield by Day 7 and dry-matter intake by Day 4 of the post-experimental period. The short-term heat challenge induced metabolic adaptations by mobilising adipose tissue, as indicated by increased non-esterified fatty acids, and amino acids from skeletal muscle, as indicated by increased urea nitrogen to compensate for reduced nutrient intake and increased energy expenditure. Endocrine responses included greater prolactin concentrations, which is associated with thermoregulation and water metabolism. The cows exposed to THc displayed production and physical responses that facilitated lower metabolic heat production and greater heat dissipation in an attempt to maintain homeostasis during the short-term heat exposure. These results indicated that the conditions imposed on the cows in the controlled-climate chambers were sufficient to induce heat-stress responses and adversely affected production in the lactating dairy cow, and the delay between the return to normal feed intake and milk yield following the heat challenge suggests a period of metabolic recovery was occurring.
Can concentrations of trans octadecenoic acids in milk fat be used to predict methane yields of dairy cows?
Authors: Moate P. J. , Williams S. R. O. , Deighton M. H. , Hannah M. C. , Jacobs J. L. , Wales W. J.
Published: March 2017

There is a need to develop simple, accurate methods for predicting methane emissions, yields and intensities of dairy cows. Several studies have focussed on the relationship between the concentrations of trans-10 plus trans-11 C18:1 fatty acids in milk fat and methane yield. The aim of the present study was to perform a meta-analysis to quantify relationships between the concentrations of various trans isomers of C18:1 in milk fat and methane emissions (g/day), methane yield (g/kg dry-matter intake) and methane intensity (g/kg energy-corrected milk yield). Data were from seven experiments encompassing 23 different diets and 220 observations of milk fatty acid concentrations and methane emissions. Univariate linear mixed-effects regression models were fitted to the data with the linear term as a fixed effect and with experiment and observation within experiment as random effects. Concentrations of trans-9, trans-10, trans-11 and trans-10 plus trans-11 isomers of C18:1 were poorly related to methane emissions, yields and intensities, with the best relationships being between trans-10 C18:1 and methane emissions (R2 = 0.356), trans-10 C18:1 and methane yield (R2 = 0.265) and trans-10 plus trans-11 C18:1 and methane intensity (R2 = 0.124). The data indicated that the relationships between trans-10 C18:1 and methane metrics were not linear, but were biphasic and better described by an exponential model. However, even exponential models poorly fitted the data. It is concluded that the concentrations of trans isomers of C18:1 have limited potential to accurately predict methane emissions, yields or intensities of dairy cows.