bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation of catalytically active materials from a liquid metal precursor
Authors: Hoshyargar Faegheh , Khan Husnaa , Kalantar-zadeh Kourosh , O'Mullane Anthony P.
Published: July 2015

A facile route to prepare catalytically active materials from a liquid metal alloy is introduced. Sonication of liquid galinstan (GaInSn) in alkaline solution or treating it with reducing agents generates In : Sn rich microspheres that are catalytically active for electron transfer reactions such as potassium ferricyanide and 4-nitrophenol reduction.
An asymmetric alkynylation/hydrothiolation cascade: an enantioselective synthesis of thiazolidine-2-imines from imines, acetylenes and isothiocyanates
Authors: Ranjan Alok , Mandal Anupam , Yerande Swapnil G. , Dethe Dattatraya H.
Published: July 2015

A multicomponent reaction in the presence of a catalytic chiral copper–pybox complex proceeds enantioselectively to give thiazolidine-2-imines.
Real-time visual determination of the flux of hydrogen sulphide using a hollow-channel paper electrode
Authors: Li Li , Zhang Yan , Liu Fang , Su Min , Liang Linlin , Ge Shenguang , Yu Jinghua
Published: July 2015

A novel 3D microfluidic paper-based turn-on electrochemiluminescence origami cyto-device with hollow channels is developed and applied for real-time visual determination of H2S released from multiple cancer cells for the first time.
Solution-processed new porphyrin-based small molecules as electron donors for highly efficient organic photovoltaics
Authors: Chen Song , Xiao Liangang , Zhu Xunjin , Peng Xiaobing , Wong Wai-Kwok , Wong Wai-Yeung
Published: July 2015

A series of new A–D–A structural 5,15-dialkylated porphyrin-cored small molecules have been developed as donors in bulk heterojunction organic solar cells, and the highest power conversion efficiency of 6.49% has been achieved.
Supramolecular open-framework architectures based on dicarboxylate H-bond acceptors and polytopic cations with three/four N–H+donor units
Authors: Mouchaham Georges , Gualino Marion , Roques Nans , Duhayon Carine , Brandès Stéphane , Sutter Jean-Pascal
Published: July 2015

Supramolecular assemblages based on cationic H-donors and anionic H-acceptors have been envisioned to elaborate organic open frameworks.
On the nature of M–CO(lone pair)⋯π(arene) interactions in the solid state of fluorinated oxaphosphirane complexes
Authors: Murcia-García Cristina , Bauzá Antonio , Frontera Antonio , Streubel Rainer
Published: July 2015

The X-ray structures of several oxaphosphirane tungsten(0) complexes exhibit interesting intramolecular W–CO(lone pair)ċπ(arene) interactions that have been rationalized by means of high-level DFT calculations and the CSD.
Synergistically enhanced photocatalytic and chemotherapeutic effects of aptamer-functionalized ZnO nanoparticles towards cancer cells
Authors: Han Zhou , Wang Xinhuan , Heng Chenglin , Han Qiusen , Cai Shuanfei , Li Jingying , Qi Cui , Liang Wei , Yang Rong , Wang Chen
Published: July 2015

Multifunctional aptamer–ZnO–Dox nanoconjugates have been successfully constructed for targeted photocatalytic and chemotherapy against cancer cells.
Unusual Mn coordination and redox chemistry in the high capacity borate cathode Li7Mn(BO3)3
Authors: Roos Julian , Eames Christopher , Wood Stephen M. , Whiteside Alexander , Saiful Islam M.
Published: July 2015

The recently discovered lithium-rich cathode material Li7Mn(BO3)3 has a high theoretical capacity and an unusual tetrahedral Mn2+ coordination.
The charge/discharge mechanism and electrochemical performance of CuV2O6 as a new anode material for Li-ion batteries
Authors: Ma Jianjun , Ni Shibing , Zhang Jicheng , Yang Xuelin , Zhang Lulu
Published: July 2015

CuV2O6/NG is demonstrated to be a new ideal anode material for Li-ion batteries.
Physiological concentrations of albumin favor drug binding
Authors: Tatlidil D. , Ucuncu M. , Akdogan Y.
Published: July 2015

We exploit the direct measurements of spin labeled drugs to study drug binding to/release from protein using EPR spectroscopy.
Ecodesign of organic photovoltaic modules from Danish and Chinese perspectives
Authors: Espinosa Nieves , Laurent Alexis , Krebs Frederik C.
Published: July 2015

The ecodesign of an OPV solar park is reported covering the complete life cycle: manufacturing, use and disposal stages. For the first time the life cycle inventory for such a technology is provided for its use in future LCA and EIA studies. Recommendations with the aim to influence PV policy and decision makers are given.
Environmental safety of cholinium-based ionic liquids: assessing structure–ecotoxicity relationships
Authors: Santos J. I. , Gonçalves A. M. M. , Pereira J. L. , Figueiredo B. F. H. T. , e Silva F. A. , Coutinho J. A. P. , Ventura S. P. M. , Gonçalves F.
Published: July 2015

Ecotoxicity of cholinium-based ionic liquids.
Producing hierarchical porous carbon monoliths from hydrometallurgical recycling of spent lead acid battery for application in lithium ion batteries
Authors: He Xiong , Peng Xiaoyu , Zhu Yuxuan , Lai Chao , Ducati Caterina , Kumar R. Vasant
Published: July 2015

An environmentally clean process to recycle the paste from a spent lead acid battery (LAB) is further developed to produce a porous carbon anode material for a lithium ion battery (LIB) which is under increasing focus as the solution for future energy storage and distribution networks.
Eco-friendly synthesis of diverse and valuable 2-pyridones by catalyst- and solvent-free thermal multicomponent domino reaction
Authors: Poudel Tej Narayan , Lee Yong Rok , Kim Sung Hong
Published: July 2015

An eco-friendly protocol for diverse and functionalized 2-pyridone derivatives via a multicomponent reaction under catalyst- and solvent-free conditions has been developed.
A smart device for label-free and real-time detection of gene point mutations based on the high dark phase contrast of vapor condensation
Authors: Zhang Junqi , Fu Rongxin , Xie Liping , Li Qi , Zhou Wenhan , Wang Ruliang , Ye Jiancheng , Wang Dong , Xue Ning , Lin Xue , Lu Ying , Huang Guoliang
Published: July 2015

A smart device for label-free and real-time detection of gene point mutation-related diseases was developed based on the high dark phase contrast of vapor condensation.
Supersoft lithography: candy-based fabrication of soft silicone microstructures
Authors: Moraes Christopher , Labuz Joseph M. , Shao Yue , Fu Jianping , Takayama Shuichi
Published: July 2015

Leveraging techniques from the confectionary industry, we develop a candy-based process to fabricate microstructures in intrinsically soft silicone materials (E ≈ 1 kPa), and demonstrate the utility of this approach by developing a simple technique to measure forces generated by contractile microtissues.
Electronic and structural properties of polymers based on phenylene vinylene and thiophene units. Control of the gap by gradual increases of thiophene moieties
Authors: Sánchez C. O. , Sobarzo P. , Gatica N.
Published: July 2015

Polymers with phenylene vinylene bonded to thiophene showed different absorption profiles, high thermal stability and a crystalline structure. The HOMO–LUMO can be tuned.
Highly stable and re-dispersible nano Cu hydrosols with sensitively size-dependent catalytic and antibacterial activities
Authors: Zhang Yu , Zhu Pengli , Li Gang , Wang Wenzhao , Chen Liang , Lu Daoqiang Daniel , Sun Rong , Zhou Feng , Wong Chingping
Published: July 2015

Size-controllable nano Cu hydrosols with high stability and re-dispersibility were successfully synthesized. In addition, obvious size-dependent and superior catalytic and antibacterial activities of Cu hydrosols were observed.
A pressure sensor based on the orientational dependence of plasmonic properties of gold nanorods
Authors: Fu Lishun , Liu Yiding , Wang Wenshou , Wang Mingsheng , Bai Yaocai , Chronister Eric L. , Zhen Liang , Yin Yadong
Published: July 2015

A novel pressure sensor has been developed by taking advantage of the orientational dependence of localized surface plasmon resonance of gold nanorods embedded in a polymer matrix.
Towards the continuous production of high crystallinity graphene via electrochemical exfoliation with molecular in situ encapsulation
Authors: Chen Chia-Hsuan , Yang Shiou-Wen , Chuang Min-Chiang , Woon Wei-Yen , Su Ching-Yuan
Published: July 2015

A fast and continuous electrochemical method with melamine additives is able to efficiently exfoliate graphite into high-quality graphene sheets. The hydrophilic force facilitated exfoliation and protection, leading to high yield production of larger size crystallinity of graphene sheets.
A pentacene monolayer trapped between graphene and a substrate
Authors: Zhang Qicheng , Peng Boyu , Chan Paddy Kwok Leung , Luo Zhengtang
Published: July 2015

A graphene-assisted method was developed to fabricate a molecular monolayer in the 2D interfaces utilizing the impermeability of graphene.
Polytopic bis(oxazoline)-based ligands for recoverable catalytic systems applied to the enantioselective Henry reaction
Authors: Angulo Beatriz , García José I. , Herrerías Clara I. , Mayoral José A. , Miñana Ana C.
Published: July 2015

Polytopic chiral ligands based on bis(oxazoline) motifs can be efficiently used to prepare recoverable catalytic systems for Henry reactions using a release–capture strategy.
Elusive 2H-1,2-oxasiletes through reactions of an isolable dialkylsilylene with diazocarbonyl compounds
Authors: Dong Zhaowen , Xiao Xu-Qiong , Li Zhifang , Lu Qiong , Lai Guoqiao , Kira Mitsuo
Published: July 2015

The reactions of isolable dialkysilylene 1 with compounds 5 and 6 gave elusive silacycles, 2H-1,2-oxasiletes 2 and 3, respectively, with releasing dinitrogen. In contrast, six-membered cyclic diazo compound 8 was obtained in a good yield by the reaction of 1 with less reactive 7.
Nitrile-substituted thienyl and phenyl units as building blocks for high performance n-type polymer semiconductors
Authors: Xiong Yu , Qiao Xiaolan , Li Hongxiang
Published: July 2015

Conjugated polymers containing nitrile-substituted thienyl and phenyl units displayed high electron mobility under ambient conditions.
Dual-mode antifouling ability of PVDF membrane with a surface-anchored amphiphilic polymer
Authors: Chen Yongliang , Zhao Xinzhen , He Chunju
Published: July 2015

Surface-anchored PDMS-g-PEG effectively improved the dual-mode antifouling properties of PVDF membrane.
Optical properties of armchair graphene nanoribbons with Stone–Wales defects and hydrogenation on the defects
Authors: Wang Min , Wang Yu Chen , Zhao Hai Xing , Song Si Xing
Published: July 2015

Armchair graphene nanoribbons display interesting optical properties with the existence of Stone–Wales defects and hydrogenation on the defects.
Effect of zeolite pore structure on the diffusion and catalytic behaviors in the transalkylation of toluene with 1,2,4-trimethylbenzene
Authors: Li Yanchun , Wang Hao , Dong Mei , Li Junfen , Qin Zhangfeng , Wang Jianguo , Fan Weibin
Published: July 2015

The effect of zeolite pore structure on catalytic properties in the transalkylation of toluene with 1,2,4-trimethylbenzene is investigated by studying the diffusion process and reaction mechanism.
Molecular dynamics simulations of self-assembled peptide amphiphile based cylindrical nanofibers
Authors: Tekin E. Deniz
Published: July 2015

We carried out united-atom molecular dynamics simulations to understand the structural properties of peptide amphiphile (PA)-based cylindrical nanofibers and the factors that play a role in the “Self-Assembly” process on some specific nanofibers.
Design, preparation and characterization of a new ionic liquid, 1,3-disulfonic acid benzimidazolium chloride, as an efficient and recyclable catalyst for the synthesis of tetrahydropyridine under solvent-free conditions
Authors: Abbasi Mohsen
Published: July 2015

In the present work, 1,3-disulfonic acid benzimidazolium chloride as a new ionic liquid, is synthesized, and characterized by studying its FT-IR, 1H NMR, 13C NMR as well as mass spectra.
Rational design of polyaniline/MnO2/carbon cloth ternary hybrids as electrodes for supercapacitors
Authors: Zhao Xin , Chen Chaoyi , Huang Zilong , Jin Lei , Zhang Junxian , Li Yingzhi , Zhang Lili , Zhang Qinghua
Published: July 2015

A ternary hybrid was fabricated by sequentially depositing polyaniline and MnO2 on carbon cloth. It displayed a unique porous structure and possessed a good electrochemical performance with a high areal capacitance of 421.6 mF cm−2 (0.2 mA cm−2).
Tooth lead levels as an estimate of lead body burden in rats following pre- and neonatal exposure
Authors: Arora Manish , Hare Dominic J.
Published: July 2015

Accurate assessment of early life lead exposure requires an accessible and reliable biomarker.
Thermoresponsive antimicrobial wound dressings via simultaneous thiol-ene polymerization and in situ generation of silver nanoparticles
Authors: Abdali Zahra , Yeganeh Hamid , Solouk Atefeh , Gharibi Reza , Sorayya Marziyeh
Published: July 2015

Thermoresponsive and antimicrobial wound dressingviathiol-ene polymerization reaction.
Photoassisted hetero-Fenton degradation mechanism of Acid Blue 74 by a γ-Fe2O3catalyst
Authors: Cao Shanshan , Kang Feifei , Li Ping , Chen Rufen , Liu Hui , Wei Yu
Published: July 2015

Fusiform-like γ-Fe2O3exhibits excellent catalytic performance for the degradation of Acid Blue 74 under the irradiation of visible light and it retained 100% degradation capacity for AB 74 after 6 cycles.
A copper complex covalently grafted on carbon nanotubes and reduced graphene oxide promotes oxygen reduction reaction activity and catalyst stability
Authors: Wang Ru-Chun , Yin Tian-Liang , Wei Ping-Jie , Liu Jin-Gang
Published: July 2015

Covalent immobilization of a copper complex on CNTs or rGO remarkably improves the catalyst ORR activity and stability compared with that of the physisorbed counterparts, and proximal dinuclear Cu sites on flat rGO effectively promote the oxygen 4e− reduction process.
Fabrication and properties of low crystallinity nanofibrillar cellulose and a nanofibrillar cellulose–graphene oxide composite
Authors: Lou Hongming , Zhu Duming , Yuan Long , Lin Houkeng , Lin Xuliang , Qiu Xueqing
Published: July 2015

Nanofibrillar cellulose of low crystallinity and a nanofibrillar cellulose–graphene oxide composite with excellent properties were fabricated in a facile way.
Optimization and prediction of the electron–nuclear dipolar and scalar interaction in1H and13C liquid state dynamic nuclear polarization
Authors: Wang X. , Isley III W. C. , Salido S. I. , Sun Z. , Song L. , Tsai K. H. , Cramer C. J. , Dorn H. C.
Published: July 2015

Solution-state dynamic nuclear polarization (DNP) is a powerful tool for hyperpolarization and the study of intermolecular interactions in solution.
Highly porous graphitic carbon and Ni2P2O7for a high performance aqueous hybrid supercapacitor
Authors: Senthilkumar Baskar , Khan Ziyauddin , Park Seungyoung , Kim Kyoungho , Ko Hyunhyub , Kim Youngsik
Published: July 2015

A high energy hybrid capacitor fabricated from highly porous graphitic carbon and novel electrode material Ni2P2O7delivers a maximum energy density of 65 W h kg−1at a power density of 800 W kg−1, good rate capability and cycling stability in an aqueous Na-ion based electrolyte.
A two-step strategy to clarify the roles of a solution processed PFN interfacial layer in highly efficient polymer solar cells
Authors: Sun Qianqian , Zhang Fujun , Wang Jian , An Qiaoshi , Zhao Chen , Li Lingliang , Teng Feng , Hu Bin
Published: July 2015

Incorporation of a two-step strategy to prepare PFN interfacial layer is demonstrated as an efficient method to improve the performance of polymer solar cells (PSCs).
A new mild, clean and highly efficient method for the preparation of graphene quantum dots without by-products
Authors: Zhu Chong , Yang Siwei , Wang Gang , Mo Runwei , He Peng , Sun Jing , Di Zengfeng , Kang Zhenhui , Yuan Ningyi , Ding Jianning , Ding Guqiao , Xie Xiaoming
Published: July 2015

We demonstrated that graphene oxide can be oxidized and cut into graphene quantum dots by hydroxyl radicals which is obtained by catalytic decomposition of hydrogen peroxide with a tungsten oxide nanowire catalyst.
Preparation of Bodipy–ferrocene dyads and modulation of the singlet/triplet excited state of bodipy via electron transfer and triplet energy transfer
Authors: Wu Xueyan , Wu Wenting , Cui Xiaoneng , Zhao Jianzhang , Wu Mingbo
Published: July 2015

Bodipy–ferrocene dyads were prepared for reversible electrochemical switching of the singlet excited state (fluorescence), as well as the triplet excited states of Bodipy.
A non-canonical ESCRT pathway, including histidine domain phosphotyrosine phosphatase (HD-PTP), is used for down-regulation of virally ubiquitinated MHC class I
Authors: Parkinson Michael D.J. , Piper Siân C. , Bright Nicholas A. , Evans Jennifer L. , Boname Jessica M. , Bowers Katherine , Lehner Paul J. , Luzio J. Paul
Published: July 2015

The Kaposi's sarcoma-associated herpes virus (KSHV) K3 viral gene product effectively down-regulates cell surface MHC class I. K3 is an E3 ubiquitin ligase that promotes Lys63-linked polyubiquitination of MHC class I, providing the signal for clathrin-mediated endocytosis. Endocytosis is followed by sorting into the intralumenal vesicles (ILVs) of multivesicular bodies (MVBs) and eventual delivery to lysosomes. The sorting of MHC class I into MVBs requires many individual proteins of the four endosomal sorting complexes required for transport (ESCRTs). In HeLa cells expressing the KSHV K3 ubiquitin ligase, the effect of RNAi-mediated depletion of individual proteins of the ESCRT-0 and ESCRT-I complexes and three ESCRT-III proteins showed that these are required to down-regulate MHC class I. However, depletion of proteins of the ESCRT-II complex or of the ESCRT-III protein, VPS20 (vacuolar protein sorting 20)/CHMP6 (charged MVB protein 6), failed to prevent the loss of MHC class I from the cell surface. Depletion of histidine domain phosphotyrosine phosphatase (HD-PTP) resulted in an increase in the cell surface concentration of MHC class I in HeLa cells expressing the KSHV K3 ubiquitin ligase. Rescue experiments with wild–type (WT) and mutant HD-PTP supported the conclusion that HD-PTP acts as an alternative to ESCRT-II and VPS20/CHMP6 as a link between the ESCRT-I and those ESCRT-III protein(s) necessary for ILV formation. Thus, the down-regulation of cell surface MHC class I, polyubiquitinated by the KSHV K3 ubiquitin ligase, does not employ the canonical ESCRT pathway, but instead utilizes an alternative pathway in which HD-PTP replaces ESCRT-II and VPS20/CHMP6.
Augmented vagal heart rate modulation in active hypoestrogenic pre-menopausal women with functional hypothalamic amenorrhoea
Authors: O'Donnell Emma , Goodman Jack M. , Morris Beverly L. , Floras John S. , Harvey Paula J.
Published: July 2015

Compared with eumenorrhoeic women, exercise-trained women with functional hypothalamic amenorrhoea (ExFHA) exhibit low heart rates (HRs) and absent reflex renin–angiotensin-system activation and augmentation of their muscle sympathetic nerve response to orthostatic stress. To test the hypothesis that their autonomic HR modulation is altered concurrently, three age-matched (pooled mean, 24±1 years; mean ± S.E.M.) groups of women were studied: active with either FHA (ExFHA; n=11) or eumenorrhoeic cycles (ExOv; n=17) and sedentary with eumenorrhoeic cycles (SedOv; n=17). Blood pressure (BP), HR and HR variability (HRV) in the frequency domain were determined during both supine rest and graded lower body negative pressure (LBNP; −10, −20 and −40 mmHg). Very low (VLF), low (LF) and high (HF) frequency power spectra (ms2) were determined and, owing to skewness, log10-transformed. LF/HF ratio and total power (VLF + LF + HF) were calculated. At baseline, HR and systolic BP (SBP) were lower (P<0.05) and HF and total power were higher (P<0.05) in ExFHA than in eumenorrhoeic women. In all groups, LBNP decreased (P<0.05) SBP, HF and total power and increased (P<0.05) HR and LF/HF ratio. However, HF and total power remained higher (P<0.05) and HR, SBP and LF/HF ratio remained lower (P<0.05) in ExFHA than in eumenorrhoeic women, in whom measures did not differ (P>0.05). At each stage, HR correlated inversely (P<0.05) with HF. In conclusion, ExFHA women demonstrate augmented vagal yet unchanged sympathetic HR modulation, both at rest and during orthostatic stress. Although the role of oestrogen deficiency is unclear, these findings are in contrast with studies reporting decreased HRV in hypoestrogenic post-menopausal women.
Fully direct‐write dispenser printed dipole antenna on woven polyester cotton fabric for wearable electronics applications
Authors: Li Y. , Torah R. , Beeby S. , Tudor J.
Published: July 2015

A novel technique of direct‐write dispenser printing on fabrics is introduced which is applied to realise a dipole antenna for wearable electronic applications. The challenge of digitally printing a conductive layer of <20 µm thickness on polyester cotton, which has a surface roughness of the order of 150 µm, is met using only direct‐write dispenser printing. An interface paste, which was originally developed for screen printing, is dispenser printed in selected areas of the fabric to smooth its surface before printing the conductive layer on top of it. Neither screen nor photolithographic masks are needed for any deposition stage, so dispenser printing offers a direct‐write technique for electronic functions on fabrics. Fully dispenser printed dipole antennas have been fabricated on standard polyester cotton fabrics and the measured results from a vector network analyser are discussed.
Compact UWB BPF with notch band based on SW‐HMSIW
Authors: Li Jiao , Ding Chen , Wei Feng , Wei Shi Xiao
Published: July 2015

A compact ultra‐wideband (UWB) bandpass filter (BPF) with a notch band based on a slow‐wave half‐mode substrate‐integrated waveguide (SW‐HMSIW) is proposed. The proposed SW‐HMSIW is believed to be the first ever reported. Similar to the slow‐wave substrate‐integrated waveguide (SW‐SIW), SW‐HMSIWs can achieve highpass characteristics, while the lateral width is reduced by about 50%. To obtain the UWB response, three spiral compact microstrip resonant cells are etched on the SW‐HMSIW as a lowpass filter. Moreover, a short‐circuited quarter wavelength L‐type resonator is used to achieve a notch band. To validate the design theory, a compact UWB BPF is designed and fabricated. The simulated results are compared with the measured results, and good agreement is reported.
Small‐area DAC using adaptive body bias scheme for AMOLED data driver ICs
Authors: Kim Seung‐Tae , Kwon Oh‐Kyong
Published: July 2015

A small‐area digital‐to‐analogue converter (DAC) using an adaptive body bias scheme is proposed for active‐matrix organic light‐emitting diode (AMOLED) data driver ICs. The proposed scheme adjusts the body bias applied to the P‐type (PMOS) decoder according to the average picture level (APL) and maintains a low on‐resistance of the PMOS decoder at a high APL. This enables reduction of the DAC area by realising the upper‐half decoder using only PMOS switches, unlike conventional DACs which use both PMOS and N‐type switches. A 20‐channel data driver IC is fabricated using a 0.18 µm HVCMOS technology with 1.8 V/18 V devices. The proposed DAC occupies 33% less area than the conventional DAC and the measured differential nonlinearity and integral nonlinearity are +0.09/−0.1 and +0.36/−0.47 LSB, respectively.
Voltage booster scheme for enhancing the fault ride‐through of wind turbines
Authors: Goweily Khaled , El Moursi Mohamed Shawky , Abdel‐Rahman Mohamed , Badr Mohamed A.L.
Published: July 2015

This study presents a new scheme for a continuously variable (CV) series braking resistor (SBR) with independent per phase controller. The CV‐SBR is a CV and not stepwise. A novelty of the work presented is that the CV‐SBR operates on the whole range of wind speeds. The proposed scheme is applicable to fault ride‐through (FRT) of fixed speed wind turbines (FSWTs). The CV‐SBR scheme is compared to the single‐step (SS) and multi‐steps (MS) SBRs. The CV‐SBR scheme is modelled and simulated in PSCAD/EMTDC™. The performance of the wind turbine is studied for balanced and unbalanced fault scenarios. The CV‐SBR scheme is advantageous over the other two candidates with its ability to limit the fault current and reduce the turbine speed deviation at any wind speed. The CV‐SBR is employed with a static synchronous compensator (STATCOM) to allow FRT of FSWT connected to weak grid during nearby faults and to deliver the reactive current required by some grid codes. The CV‐SBR scheme is successful in reducing voltage disturbance's consequences on the generator's mechanical system. Simulation results show that the CV‐SBR allows FRT of FSWT connected to weak grid where the STATCOM alone is not able to sufficiently enhance the FRT of FSWT during nearby faults.
New potential energy surface for the HCS+–He system and inelastic rate coefficients
Authors: Dubernet Marie-Lise , Quintas-Sánchez Ernesto , Tuckey Philip
Published: July 2015

A new high quality potential energy surface is calculated at a coupled-cluster single double triple level with an aug-cc-pV5Z basis set for the HCS+–He system. This potential energy surface is used in low energy quantum scattering calculations to provide a set of (de)-excitation cross sections and rate coefficients among the first 20 rotational levels of HCS+ by He in the range of temperature from 5 K to 100 K. The paper discusses the impact of the new ab initio potential energy surface on the cross sections at low energy and provides a comparison with the HCO+–He system. The HCS+–He rate coefficients for the strongest transitions differ by factors of up to 2.5 from previous rate coefficients; thus, analysis of astrophysical spectra should be reconsidered with the new rate coefficients.
High-pressure polymorphism as a step towards high density structures of LiAlH4
Authors: Huang Xiaoli , Duan Defang , Li Xin , Li Fangfei , Huang Yanping , Wu Gang , Liu Yunxian , Zhou Qiang , Liu Bingbing , Cui Tian
Published: July 2015

Two high density structures β- and γ-LiAlH4 are detected in LiAlH4, a promising hydrogen storage compound, upon compression in diamond anvil cells, investigated with synchrotron X-ray diffraction and first-principle calculations. The joint of the experimental and theoretical results has confirmed the sequence of the pressure-induced structural phase transitions from α-LiAlH4 (space group P21/c) to β-LiAlH4 (P21/c-6C symmetry), and then to γ-LiAlH4 (space group Pnc2), which are not reported in previous literatures. At the α to β transition point for LiAlH4, the estimated difference in cell volume is about 20%, while the transformation from β to γ phase is with a volume drop smaller than 1%. The α to β phase transition is accompanied by the local structure change from a AlH4 tetrahedron into a AlH6 octahedron, which contributes to a large volume collapse.
Origin of abnormally sharp features in collision-induced spectra of cryosolutions
Authors: Herrebout W. A. , van der Veken B. J. , Kouzov A. P. , Filippov N. N.
Published: July 2015

A weak, paradoxically narrow resonance feature (shortly, the r-line) near the O2 fundamental frequency in the collision-induced absorption spectrum of oxygen dissolved in liquid argon and liquid nitrogen (T = 89 K) is resolved for the first time. An accurate band shape fitting routine to separate the r-line from the by-far more intense diffuse background and to study its behavior versus the oxygen mole fraction x which ranged from 0.03 up to 0.23 has been elaborated. At small x (≲0.07), the r-line intensity was found to scale as x2 leaving no doubt that it is due to the solute-solute (O2–O2) interactions. In line with our results on the pH2–LNe cryosystem [Herrebout, Phys. Rev. Lett. 101, 093001 (2008)], the Lorentzian r-line shape and its extraordinary sharpness (half width at half height ≈ 1 cm−1) are indicative of the motional narrowing of the relative solute-solute translational spectrum. As x is further raised, ternary solute-solute interactions impede the r-line growth in the O2–LAr spectrum because of the cancellation effect [J. Van Kranendonk, Physica 23, 825 (1957)]. Theoretical arguments are given that multiple interactions between the solutes should finally destroy the solute-solute induced r-line when the mixed solution approaches the limit of the pure liquid (x = 1). Interestingly, the nonbinary effects are too weak to appreciably affect the quadratic r-line scaling in the O2–LN2 cryosystem which persists up to x = 0.23. It is emphasized that studies of the resonant features in the collision-induced spectra of binary cryosolutions open up unique opportunities to spectroscopically trace the microscopic-scale diffusion.
Computation of the binding free energy of peptides to graphene in explicit water
Authors: Welch Corrinne M. , Camden Aerial N. , Barr Stephen A. , Leuty Gary M. , Kedziora Gary S. , Berry Rajiv J.
Published: July 2015

The characteristic properties of graphene make it useful in an assortment of applications. One particular application—the use of graphene in biosensors—requires a thorough understanding of graphene-peptide interactions. In this study, the binding of glycine (G) capped amino acid residues (termed GXG tripeptides) to trilayer graphene surfaces in aqueous solution was examined and compared to results previously obtained for peptide binding to single-layer free-standing graphene [A. N. Camden, S. A. Barr, and R. J. Berry, J. Phys. Chem. B 117, 10691–10697 (2013)]. In order to understand the interactions between the peptides and the surface, binding enthalpy and free energy values were calculated for each GXG system, where X cycled through the typical 20 amino acids. When the GXG tripeptides were bound to the surface, distinct conformations were observed, each with a different binding enthalpy. Analysis of the binding energy showed the binding of peptides to trilayer graphene was dominated by van der Waals interactions, unlike the free-standing graphene systems, where the binding was predominantly electrostatic in nature. These results demonstrate the utility of computational materials science in the mechanistic explanation of surface-biomolecule interactions which could be applied to a wide range of systems.
Density perturbation theory
Authors: Palenik Mark C. , Dunlap Brett I.
Published: July 2015

Despite the fundamental importance of electron density in density functional theory, perturbations are still usually dealt with using Hartree-Fock-like orbital equations known as coupled-perturbed Kohn-Sham (CPKS). As an alternative, we develop a perturbation theory that solves for the perturbed density directly, removing the need for CPKS. This replaces CPKS with a true Hohenberg-Kohn density perturbation theory. In CPKS, the perturbed density is found in the basis of products of occupied and virtual orbitals, which becomes ever more over-complete as the size of the orbital basis set increases. In our method, the perturbation to the density is expanded in terms of a series of density basis functions and found directly. It is possible to solve for the density in such a way that it makes the total energy stationary even if the density basis is incomplete.
Stability of compressible streamwise vortices
Authors: Hiejima Toshihiko
Published: July 2015

A sufficient condition for instability of full compressible inviscid streamwise vortices has been derived using asymptotic analysis with large wavenumbers. Based on the nature of instability, the obtained growth rate is described using an entropy instability term, a spiral instability term, a helicity instability term, and an acoustic instability term. The entropy instability term correlates with compressibility. The spiral instability term is reasonably expressed by the axial and azimuthal velocities and their wavenumbers. The helicity instability term depends on the helicity profiles. In particular, the unstable condition for wake-type flows is satisfied when they possess a negative helicity in the profiles. The acoustic instability term depends on the local speed of sound. Linear and nonlinear numerical simulations are used to validate the instability conditions. The effect of the helicity instability is shown to be significantly strong by the simulations.
Dean-flow-coupled elasto-inertial three-dimensional particle focusing under viscoelastic flow in a straight channel with asymmetrical expansion–contraction cavity arrays
Authors: Yuan D. , Zhang J. , Yan S. , Pan C. , Alici G. , Nguyen N. T. , Li W. H.
Published: July 2015

In this paper, 3D particle focusing in a straight channel with asymmetrical expansion–contraction cavity arrays (ECCA channel) is achieved by exploiting the dean-flow-coupled elasto-inertial effects. First, the mechanism of particle focusing in both Newtonian and non-Newtonian fluids was introduced. Then particle focusing was demonstrated experimentally in this channel with Newtonian and non-Newtonian fluids using three different sized particles (3.2 μm, 4.8 μm, and 13 μm), respectively. Also, the effects of dean flow (or secondary flow) induced by expansion–contraction cavity arrays were highlighted by comparing the particle distributions in a single straight rectangular channel with that in the ECCA channel. Finally, the influences of flow rates and distances from the inlet on focusing performance in the ECCA channel were studied. The results show that in the ECCA channel particles are focused on the cavity side in Newtonian fluid due to the synthesis effects of inertial and dean-drag force, whereas the particles are focused on the opposite cavity side in non-Newtonian fluid due to the addition of viscoelastic force. Compared with the focusing performance in Newtonian fluid, the particles are more easily and better focused in non-Newtonian fluid. Besides, the Dean flow in visco-elastic fluid in the ECCA channel improves the particle focusing performance compared with that in a straight channel. A further advantage is three-dimensional (3D) particle focusing that in non-Newtonian fluid is realized according to the lateral side view of the channel while only two-dimensional (2D) particle focusing can be achieved in Newtonian fluid. Conclusively, this novel Dean-flow-coupled elasto-inertial microfluidic device could offer a continuous, sheathless, and high throughput (>10 000 s−1) 3D focusing performance, which may be valuable in various applications from high speed flow cytometry to cell counting, sorting, and analysis.
The application of multilayer elastic beam in MEMS safe and arming system
Authors: Li Guozhong , Shi Gengchen , Sui Li , Yi Futing , Wang Bo
Published: July 2015

In this paper, a new approach for a multilayer elastic beam to provide a driving force and driving distance for a MEMS safe and arming system is presented. In particular this is applied where a monolayer elastic beam cannot provide adequate driving force and driving distance at the same time in limited space. Compared with thicker elastic beams, the bilayer elastic beam can provide twice the driving force of a monolayer beam to guarantee the MEMS safe and arming systems work reliably without decreasing the driving distance. In this paper, the theoretical analysis, numerical simulation and experimental verification of the multilayer elastic beam is presented. The numerical simulation and experimental results show that the bilayer elastic provides 1.8–2 times the driving force of a monolayer, and a method that improves driving force without reducing the driving distance.
Magnetically tunable alternating current electrical properties of x La0.7Sr0.3MnO3–(1 − x) ErMnO3 (x = 0.1, 0.3, and 0.5) multiferroic nanocomposite
Authors: Debnath Rajesh , Dey P. , Singh Swati , Roy J. N. , Mandal S. K. , Nath T. K.
Published: July 2015

Detailed magnetically tunable ac electrical properties of x La0.7Sr0.3MnO3 (LSMO)–(1 − x) ErMnO3 (EMO) (x = 0.1, 0.3, and 0.5) multiferroic nanocomposites have been studied at 300 K in presence of varying magnetic field (Happl), applied both in parallel and perpendicular configuration with respect to the measuring electric field. AC electrical properties have exhibited significant variation with Happl for all composites, whereas for parallel configuration of Happl such effect is very feeble for x = 0.3 composite. We have attributed this anisotropic behavior to the demagnetization effect in the sample. In contrast, for x = 0.1 and 0.5 composites, no such anisotropy effect is experimentally evidenced. Impedance and real part of impedance have been found to decrease with Happl at low frequency (f) region. We attribute this observation to the depinning of the magnetic domain walls from the grain boundaries pinning centers and thereby enhancing the spin dependent transport in the composite. For x = 0.3 composite, Nyquist plots have been fitted considering dominant contributions of LSMO and EMO grain boundaries and the interface region between them. However, for x = 0.1 composite, it corresponds to EMO grain boundaries and grain boundary interface region. The relaxation frequency (fR) is observed to shift at higher/lower f region in perpendicular/parallel configuration of Happl for x = 0.3 composite. This opposite variation of fRs with Happl for perpendicular and parallel configurations has been attributed to two competing factors of Happl induced enhancement of inductive part and Happl enhanced spin dependent transport causing fast relaxation processes in the sample. For x = 0.1 composite, in both configurations of Happl, fRs is shifting towards high f region, which has been discussed in terms of dominant role of spin dependent transport.
Electron-phonon interaction and scattering in Si and Ge: Implications for phonon engineering
Authors: Tandon Nandan , Albrecht J. D. , Ram-Mohan L. R.
Published: July 2015

We report ab-initio results for electron-phonon (e-ph) coupling and display the existence of a large variation in the coupling parameter as a function of electron and phonon dispersion. This variation is observed for all phonon modes in Si and Ge, and we show this for representative cases where the initial electron states are at the band gap edges. Using these e-ph matrix elements, which include all possible phonon modes and electron bands within a relevant energy range, we evaluate the imaginary part of the electron self-energy in order to obtain the associated scattering rates. The temperature dependence is seen through calculations of the scattering rates at 0 K and 300 K. The results provide a basis for understanding the impacts of phonon scattering vs. orientation and geometry in the design of devices, and in analysis of transport phenomena. This provides an additional tool for engineering the transfer of energy from carriers to the lattice.
Effect of electrode spacing on the density distributions of electrons, ions, and metastable and radical molecules in SiH4/NH3/N2/He capacitively coupled plasmas
Authors: Kim Ho Jun , Yang Wonkyun , Joo Junghoon
Published: July 2015

Semiconductor fabrication often requires the deposition of hydrogenated silicon nitride (SiNxHy) film using SiH4/NH3/N2/He capacitively coupled plasma (CCP) discharge. As analysis of the discharge geometry is essential to understanding CCP deposition, the effect of electrode spacing on the two-dimensional distributions of electrons, ions, and metastable and radical molecules was analyzed numerically using a fluid model. The simulation shows that the spatial variations in the ionization rates near the sheath become more obvious as the electrode spacing increases. In addition, as molecule-molecule gas-phase reactions are significantly affected by the local residence time, large electrode spacings are associated with significant volumetric losses for positive ions. Consequently, an increase of the electrode spacing leads axial density profiles of ions to change from bell shaped to double humped. However, NH4+ persistently maintains a bell-shaped axial density profile regardless of the degree of electrode spacing. We set the mole fraction of NH3 to only 1% of the total flow at the inlet, but NH4+ is the most abundant positive ion at the large electrode spacings. As the gas flow can transport the radicals around the space between the electrodes, we found that radical density distribution shifts toward the grounded electrode. The shift becomes pronounced as the electrode spacing increases. Finally, to validate our model, we compared the calculated deposition rate profile with the experimental data obtained along the wafer radius. According to our numerical results, the SiNxHy deposition rate decreases by approximately 16% when the electrode spacing increases from 9 to 20 mm.
Two color pumping of the Rb D2 line laser (780 nm) through the photoassociation of Rb-Ar or Rb-Xe thermal pairs: Realization of a quantum efficiency above one
Authors: Mironov A. E. , Goldshlag W. , Eden J. G.
Published: July 2015

A two color process for optical pumping of the Rb D2 line laser (λ = 780 nm) in Rb vapor-rare gas mixtures is demonstrated to yield an overall quantum efficiency > 1. Combining photoexcitation of the Rb D2 line blue satellite in Rb-Xe or Rb-Ar mixtures with free ← free optical pumping of the A2Π12←X2Σ12+ transition at large internuclear separation (R > 5 Å) also increases the laser efficiency and pump absorption coefficient, relative to the single color, B ← X pumped system, by a factor of 1.7 and more than an order of magnitude, respectively. Simultaneous photopumping of Rb-Xe thermal collision pairs at 760 nm (D2 satellite) and 794.3 nm results in a 780 nm (D2 line) laser with a quantum efficiency of 1.008 which corresponds to the removal of ∼102 cm–1 (12.6 meV) of thermal energy per emitted photon.
Runaway electron generation as possible trigger for enhancement of magnetohydrodynamic plasma activity and fast changes in runaway beam behavior
Authors: Pankratov I. M. , Zhou R. J. , Hu L. Q.
Published: July 2015

Peculiar phenomena were observed during experiments with runaway electrons: rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the electron cyclotron emission (ECE) signal (cyclotron radiation of suprathermal electrons). These phenomena were initially observed in TEXTOR (Tokamak Experiment for Technology Oriented Research), where these events only occurred in the current decay phase or in discharges with thin stable runaway beams at a q = 1 drift surface. These rapid changes in the synchrotron spot were interpreted by the TEXTOR team as a fast pitch angle scattering event. Recently, similar rapid changes in the synchrotron spot and its intensity that coincided with stepwise increases in the non-thermal ECE signal were observed in the EAST (Experimental Advanced Superconducting Tokamak) runaway discharge. Runaway electrons were located around the q = 2 rational magnetic surface (ring-like runaway electron beam). During the EAST runaway discharge, stepwise ECE signal increases coincided with enhanced magnetohydrodynamic (MHD) activity. This behavior was peculiar to this shot. In this paper, we show that these non-thermal ECE step-like jumps were related to the abrupt growth of suprathermal electrons induced by bursting electric fields at reconnection events during this MHD plasma activity. Enhancement of the secondary runaway electron generation also occurred simultaneously. Local changes in the current-density gradient appeared because of local enhancement of the runaway electron generation process. These current-density gradient changes are considered to be a possible trigger for enhancement of the MHD plasma activity and the rapid changes in runaway beam behavior.
Bonding between graphene and MoS2 monolayers without and with Li intercalation
Authors: Ahmed Towfiq , Modine N. A. , Zhu Jian-Xin
Published: July 2015

We performed density functional theory (DFT) calculations for a bi-layered heterostructure combining a graphene layer with a MoS2 layer with and without intercalated Li atoms. Our calculations demonstrate the importance of the van der Waals (vdW) interaction, which is crucial for forming stable bonding between the layers. Our DFT calculation correctly reproduces the linear dispersion, or Dirac cone, feature at the Fermi energy for the isolated graphene monolayer and the band gap for the MoS2 monolayer. For the combined graphene/MoS2 bi-layer, we observe interesting electronic structure and density of states (DOS) characteristics near the Fermi energy, showing both the gap like features of the MoS2 layer and in-gap states with linear dispersion contributed mostly by the graphene layer. Our calculated total DOS in this vdW heterostructure reveals that the graphene layer significantly contributes to pinning the Fermi energy at the center of the band gap of MoS2. We also find that intercalating Li ions in between the layers of the graphene/MoS2 heterostructure enhances the binding energy through orbital hybridizations between cations (Li adatoms) and anions (graphene and MoS2 monolayers). Moreover, we calculate the dielectric function of the Li intercalated graphene/MoS2 heterostructure, the imaginary component of which can be directly compared with experimental measurements of optical conductivity in order to validate our theoretical prediction. We observe sharp features in the imaginary component of the dielectric function, which shows the presence of a Drude peak in the optical conductivity, and therefore metallicity in the lithiated graphene/MoS2 heterostructure.
Fabrication and characterization of tunnel barriers in a multi-walled carbon nanotube formed by argon atom beam irradiation
Authors: Tomizawa H. , Yamaguchi T. , Akita S. , Ishibashi K.
Published: July 2015

We have evaluated tunnel barriers formed in multi-walled carbon nanotubes (MWNTs) by an Ar atom beam irradiation method and applied the technique to fabricate coupled double quantum dots. The two-terminal resistance of the individual MWNTs was increased owing to local damage caused by the Ar beam irradiation. The temperature dependence of the current through a single barrier suggested two different contributions to its Arrhenius plot, i.e., formed by direct tunneling through the barrier and by thermal activation over the barrier. The height of the formed barriers was estimated. The fabrication technique was used to produce coupled double quantum dots with serially formed triple barriers on a MWNT. The current measured at 1.5 K as a function of two side-gate voltages resulted in a honeycomb-like charge stability diagram, which confirmed the formation of the double dots. The characteristic parameters of the double quantum dots were calculated, and the feasibility of the technique is discussed.
A prototype of RK/200 quantum Hall array resistance standard on epitaxial graphene
Authors: Lartsev A. , Lara-Avila S. , Danilov A. , Kubatkin S. , Tzalenchuk A. , Yakimova R.
Published: July 2015

Epitaxial graphene on silicon carbide is a promising material for the next generation of quantum Hall resistance standards. Single Hall bars made of graphene have already surpassed their state-of-the-art GaAs based counterparts as an RK/2 (RK=h/e2) standard, showing at least the same precision and higher breakdown current density. Compared to single devices, quantum Hall arrays using parallel or series connection of multiple Hall bars can offer resistance values spanning several orders of magnitude and (in case of parallel connection) significantly larger measurement currents, but impose strict requirements on uniformity of the material. To evaluate the quality of the available material, we have fabricated arrays of 100 Hall bars connected in parallel on epitaxial graphene. One out of four devices has shown quantized resistance that matched the correct value of RK/200 within the measurement precision of 10−4 at magnetic fields between 7 and 9 T. The defective behaviour of other arrays is attributed mainly to non-uniform doping. This result confirms the acceptable quality of epitaxial graphene, pointing towards the feasibility of well above 90% yield of working Hall bars.