bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and synthesis of a novel trinuclear palladium(ii) complex containing an oxime chelate ligand: determining the interaction mechanism with the DNA groove and BSA site I by spectroscopic and molecular dynamics simulation approaches
Authors: Karami Kazem , Lighvan Zohreh Mehri , Barzani Somayeh Asgari , Faal Ali Yeganeh , Poshteh-Shirani Marziyeh , Khayamian Taghi , Eigner Václav , Dušek Michal
Published: August 2015

The trinuclear Pd(II) complex containing an oxime ligand showed significant interaction with both CT-DNA and BSA.
A nanodrop on the surface of a lubricating liquid covering a rough solid surface
Authors: Berim Gersh O. , Ruckenstein Eli
Published: August 2015

A two-component fluid consisting of a lubricating fluid (LF) that covers a rough solid surface (surface decorated by periodic array of identical pillars) and a test fluid (TF) as a nanodrop over LF is considered.
The development of a short route to the API ropinirole hydrochloride
Authors: Yousuf Zeshan , Richards Andrew K. , Dwyer Andrew N. , Linclau Bruno , Harrowven David C.
Published: August 2015

A four-step, three-stage synthesis of the API ropinirole hydrochloride has been developed from a commercially available naphthalene derivative.
Intramolecular catalyst transfer polymerisation of conjugated monomers: from lessons learned to future challenges
Authors: Grisorio Roberto , Suranna Gian Paolo
Published: August 2015

Eleven years after the first reports on intramolecular catalyst transfer polycondensations, this review aims to critically recap on the fundamental “lessons” that can be learned from the historic literature as well as from the fervid activity that has emerged in the last three years.
Cyclometallation of the NNN pincer ligand in complexes of platinum
Authors: DeMott Jessica C. , Dekarske John R. , McCulloch Billy J. , Ozerov Oleg V.
Published: August 2015

Platinum complexes of the diimino/carbazolyl NNN pincer ligand have been prepared and characterized. Facile cyclometallation of the mesityl substituent was observed.
Study on formation and properties of Al–Li–Sm alloy containing whiskers in molten salts
Authors: Ji De-Bin , Yan Yong-De , Zhang Mi-Lin , Li Xing , Yang Xue , Jing Xiao-Yan , Han Wei , Xue Yun , Zhang Zhi-Jian , Hartmann Thomas
Published: August 2015

An Al–Li–Sm alloy containing whiskers was obtained by galvanostatic electrolysis in LiCl–KCl melts after the addition of 10 wt% SmCl3 on a liquid aluminum electrode at 973 K.
Gold microsheets having nano/microporous structures fabricated by ultrasonic-assisted cyclic galvanic replacement
Authors: Pienpinijtham P. , Sornprasit P. , Wongravee K. , Thammacharoen C. , Ekgasit S.
Published: August 2015

Ultrasonic-assisted cyclic galvanic replacement is proposed to produce nano/microporous gold microsheets that can potentially be used as surface-enhanced Raman scattering (SERS) substrates.
Restraining deactivation of hierarchical zeolite supported NiW catalysts in the HDS of thiophene
Authors: Wang Y. , Lancelot C. , Lamonier C. , Yang M. , Sun Y. , Morin J. C. , Rives A.
Published: August 2015

Improvement of the catalytic performances in thiophene HDS on NiW sulfides catalysts supported on commercial Beta (NiW/HB) and hierarchical Beta (NiW/HB-M) were studied by mechanical mixture with γ-Al2O3 (NiW/Al2O3) or Na+-exchange of the zeolites.
Design, synthesis and diversification of natural product-inspired hydantoin-fused tetrahydroazepino indoles
Authors: Barve Indrajeet J. , Dalvi Prashant B. , Thikekar Tushar Ulhas , Chanda Kaushik , Liu Yu-Li , Fang Chiu-Ping , Liu Chia-Chen , Sun Chung-Ming
Published: August 2015

A facile and efficient synthesis of novel oxo, thio and seleno hydantoin fused tetrahydroazepino [4,5-b]indoles was reported.
Theoretical study of synergistic effects between anion–π and metal–Lp interactions
Authors: Gao Meng , Gao Guanqing , Li Qingzhong , Yang Xin , Li Wenzuo , Cheng Jianbo
Published: August 2015

Interesting cooperativity effects are observed when the anion–π and coinage-metal–Lp interactions coexist in the same multicomponent.
A sensitive immobilization-free electrochemical assay for T4PNK activity based on exonuclease III-assisted recycling
Authors: Wang Yonghong , Wu Yaohui , Wang Yuanqing , Zhou Bo , Wu Shun
Published: August 2015

This work develops a novel, immobilization-free, simple and sensitive electrochemical platform for the detection of T4PNK activity based on λ-exo and exonuclease III-assisted signal amplification.
Fe3O4-decorated single-walled carbon nanohorns with extraordinary microwave absorption property
Authors: Cui Longbin , Liu Yang , Wu Xiaohui , Hu Ziqi , Shi Zujin , Li Huanjun
Published: August 2015

Single-walled carbon nanohorns (SWCNHs) are seldom used as electromagnetic (EM) wave absorption materials due to their inferior impedance matching resulting from their high dielectric constant.
Flower-like Bi2S3/Bi2MoO6 heterojunction superstructures with enhanced visible-light-driven photocatalytic activity
Authors: Zhang Junlei , Zhang Lisha , Yu Nuo , Xu Kaibing , Li Shijie , Wang Huanli , Liu Jianshe
Published: August 2015

A flower-like Bi2S3/Bi2MoO6 heterojunction has been prepared via a solvothermal method and it exhibits stable and remarkable enhanced photocatalytic activity.
The contribution of friction to electrorheological properties of a chrysanthemum-like particle suspension
Authors: Dong Xufeng , Ma Ning , Yang Hui , Han Baoguo , Qi Min
Published: August 2015

The enhancement of inter-particle friction force is an important reason for the significant ER performance of a chrysanthemum-like particle-based ER suspension.
Highly efficient colorimetric detection of ATP utilizing a split aptamer target binding strategy and superior catalytic activity of graphene oxide–platinum/gold nanoparticles
Authors: Zhang Siqi , Wang Kun , Li Jiali , Li Zhenyu , Sun Ting
Published: August 2015

The specific binding of ATP and its aptamer linked the split aptamer-modified GO/PDDA/PtAuNPs and magnetic beads together. Using magnetic separation, TMB was catalyzed into a colored product by nanocomposites, which enabled rapid detection of ATP.
Synthesis and characterization of a novel fluorinated bismaleimide via a nucleophilic addition–elimination reaction and its polymeric networks
Authors: Wu Jingbo , Xi Yang , McCandless Gregory T. , Kulikov Oleg V. , Menon Remya , Novak Bruce M.
Published: August 2015

A novel fluorinated bismaleimide, OFCP-BMI, was designed and readily synthesized via the nucleophilic addition–elimination reaction of octafluorocyclopentene with maleimide-functionalized phenol.
A fluorescence on–off sensor for Cu2+and its resultant complex as an off–on sensor for Cr3+in aqueous media
Authors: Gao Yunling , Shu Jieming , Zhang Cong , Zhang Xiang , Chen Haiyan , Yao Kejian
Published: August 2015

A coumarin–quinoline based fluorescence “on–off–on” sensor detects Cu2+and Cr3+in aqueous media and MCF-7 cells.
One-pot synthesis of ordered mesoporous silica encapsulated polyoxometalate-based ionic liquids induced efficient desulfurization of organosulfur in fuel
Authors: Zhang Ming , Li Meng , Chen Qi , Zhu Wenshuai , Li Hongping , Yin Sheng , Li Yanan , Li Huaming
Published: August 2015

Reaction procedure of desulfurization system.
Water sorption properties of room-temperature ionic liquids over the whole range of water activity and molecular states of water in these media
Authors: Dahi A. , Fatyeyeva K. , Chappey C. , Langevin D. , Rogalsky S. P. , Tarasyuk O. P. , Marais S.
Published: August 2015

The water sorption behavior for various RTILs ([C4C1im][BF4], [C4C1im][PF6], [C6C1im][PF6], [C4im][DBP], [C4im][BEHP] and [Et3HN][CF3SO3]) was studied over the whole range of water activity using a continuous gravimetric method and ATR-IR measurements.
Plasma-assisted highly efficient synthesis of Li(Ni1/3Co1/3Mn1/3)O2cathode materials with superior performance for Li-ion batteries
Authors: Jiang Qianqian , Xu Lei , Huo Jia , Zhang Han , Wang Shuangyin
Published: August 2015

We, for the first time, prepared layered Li(Ni1/3Co1/3Mn1/3)O2by a novel oxygen plasma-assisted solid-state approach, which almost shows the best performance among ternary cathode materials for Li-ion batteries.
Exploiting XPS for the identification of sulfides and polysulfides
Authors: Fantauzzi Marzia , Elsener Bernhard , Atzei Davide , Rigoldi Americo , Rossi Antonella
Published: August 2015

The identification of surface sulfide and polysulfide species based on the curve fitting of S2p photoelectron spectra and, for the first time, of X-ray excited S KLL Auger spectra has been performed.
Effect of the molecular structure and surface charge of a bismuth catalyst on the adsorption and photocatalytic degradation of dye mixtures
Authors: Wang Shurong , Teng Fei , Zhao Yunxuan
Published: August 2015

Diagram of interaction of MO with MB (RhB) in dye mixture solutions.
Polyhydroxylated GdDTPA-derivatives as high relaxivity magnetic resonance imaging contrast agents
Authors: Tei Lorenzo , Barge Alessandro , Galli Matteo , Pinalli Roberta , Lattuada Luciano , Gianolio Eliana , Aime Silvio
Published: August 2015

Novel GdDTPA-like complexes bearing differently branched, highly hydrophilic, gluconyl moieties were synthesized to obtain high relaxivity agents (∼20 mM−1 s−1 at 25 °C) over a wide range of imaging fields (0.5–3 T).
Dendrimer confined Pt nanoparticles: electro-catalytic activity towards the oxygen reduction reaction and its application in polymer electrolyte membrane fuel cells
Authors: Arunchander A. , Peera S. Gouse , Parthiban V. , Akula Srinu , Kottakkat Tintula , Bhat Santoshkumar D. , Sahu Akhila Kumar
Published: August 2015

Pt-DENs have been synthesized and immobilized on ester and anhydride functionalized Vulcan XC-72R. These catalysts are utilized as fuel cell cathodes and significant enhanced performances have been achieved with the Pt loading of 0.2 mg cm−2.
Preparation of glucose-responsive and fluorescent micelles via a combination of RAFT polymerization and chemoenzymatic transesterification for controlled release of insulin
Authors: Li Lei , Jiang Guohua , Du Xiangxiang , Chen Hua , Liu Yongkun , Huang Qin , Kong Xiangdong , Yao Juming
Published: August 2015

Polymeric micelles with glucose-responsive and fluorescent features have been synthesized using a one-pot method via a combination of RAFT polymerization and chemoenzymatic tranesterification for controlled release of insulin in vitro.
Exceptional electrical and thermal transport properties in tunable all-graphene papers
Authors: Liu Lin , Bian Xing-Ming , Tang Jin , Xu Hong , Hou Zhi-Ling , Song Wei-Li
Published: August 2015

Tunable electrical and thermal conductivity in all-graphene papers suggests a conceptually novel stage toward advanced graphene materials in thermal management.
4a,8a-Azaboranaphthalene-4-yl phosphine ligands: synthesis and electronic modulation in Suzuki–Miyaura coupling reactions
Authors: Sun Feiye , Huang Min , Zhou Zhaohui , Fang Xiangdong
Published: August 2015

Design, synthesis and characterization of new BN-aromatic phosphine ligands are presented, demonstrating moderate catalytic activity in Suzuki reactions of C–Cl bond.
Catalytic applications of {[HMIM]C(NO2)3}: as a nano ionic liquid for the synthesis of pyrazole derivatives under green conditions and a mechanistic investigation with a new approach
Authors: Zolfigol Mohammad Ali , Afsharnadery Fatemeh , Baghery Saeed , Salehzadeh Sadegh , Maleki Farahnaz
Published: August 2015

1-Methylimidazolium trinitromethanide {[HMIM]C(NO2)3} as a nano structure ionic liquid was applied for the synthesis of pyrazole derivatives with high yields under mild and green conditions.
A zwitterionic surface with general cell-adhesive and protein-resistant properties
Authors: Chen Xingyu , Shang Hui , Cao Shuqin , Tan Hong , Li Jianshu
Published: August 2015

A choline phosphate functionalized surface is proved to have general cell-adhesive and protein-resistant properties, which give it potential for biomaterials.
A porous metal–organic cage constructed from dirhodium paddle-wheels: synthesis, structure and catalysis
Authors: Chen Lianfen , Yang Tao , Cui Hao , Cai Tao , Zhang Li , Su Cheng-Yong
Published: August 2015

A porous metal–organic cage (MOC-Rh-1) with Rh–Rh bonds has been prepared, which can act as a heterogeneous catalyst and promote the intramolecular C–H amination of azides.
The golden gate to photocatalytic hydrogen production
Authors: Kalisman Philip , Houben Lothar , Aronovitch Eran , Kauffmann Yaron , Bar-Sadan Maya , Amirav Lilac
Published: August 2015

We demonstrate improved efficiency for the photocatalytic water splitting reduction half reaction by employing Au–Pt bimetallic cocatalysts.
Near-infrared luminescent CaTiO3:Nd3+ nanofibers with tunable and trackable drug release kinetics
Authors: Li Xiang , Zhang Qiuhong , Ahmad Zeeshan , Huang Jie , Ren Zhaohui , Weng Wenjian , Han Gaorong , Mao Chuanbin
Published: August 2015

Nd3+ doped CaTiO3 nanostructures serve as a promising drug delivery platform with the potential to monitor drug release kinetics by detecting the tissue-penetrating NIR emission.
Microwave non‐contact imaging of subcutaneous human body tissues
Authors: Kletsov Andrey , Chernokalov Alexander , Khripkov Alexander , Cho Jaegeol , Druchinin Sergey
Published: August 2015

A small‐size microwave sensor is developed for non‐contact imaging of a human body structure in 2D, enabling fitness and health monitoring using mobile devices. A method for human body tissue structure imaging is developed and experimentally validated. Subcutaneous fat tissue reconstruction depth of up to 70 mm and maximum fat thickness measurement error below 2 mm are demonstrated by measurements with a human body phantom and human subjects. Electrically small antennas are developed for integration of the microwave sensor into a mobile device. Usability of the developed microwave sensor for fitness applications, healthcare, and body weight management is demonstrated.
Compact dual‐band antenna with a lumped capacitor for wireless local area network applications
Authors: Lee Min‐Jae , Ahn Jung‐Ho , Kim Young‐Sik
Published: August 2015

This study presents a compact dual‐band antenna for wireless local area network (WLAN) applications. The proposed antenna consists of small striplines on both sides of a substrate and a lumped capacitor on the top side to reduce the antenna size. As a folded monopole‐type resonance is occurred in 5 GHz band, the proposed antenna yields dual‐band characteristics. The resonant mechanism is also analysed using the equivalent circuit model. Electric characteristics of the proposed antenna such as radiation patterns, peak gains, and radiation efficiencies, are presented through the simulation and measurement under various conditions. The antenna size is only 5 × 9 mm2. The proposed antenna can cover both WLAN bands of 2.4 and 5 GHz.
Low‐quiescent‐current flexible mode buck–boost converter
Authors: Cheng Li‐Ye , Lai Xinquan , Shi Ling‐Feng
Published: August 2015

In this study, a mode‐flexible buck/boost converter with four operation modes aiming at improving efficiency and extending battery life in portable devices is proposed. When the battery supply decreases or increases, the transition is smooth and the mode can be chosen flexible. High efficiency is obtained because of the introduction of buck–boost mode in pulse‐width modulation and the burst mode under light load. The converter can work in an appropriate mode according to the current sensing block, which is suitable for lithium battery and power bank. Whole chip obtains 35 μA low‐quiescent current in standby mode and 45 μA low‐quiescent current in burst mode. Experimental results show that the peak efficiency is 95% at an output 1 A when the supply voltage is 4.2 V. The peak output ripple is 60 mV in BURST mode and 20 mV in constant current mode.
Controllers for eliminating the ac components in the circulating current of modular multilevel converters
Authors: Darus Rosheila , Pou Josep , Konstantinou Georgios , Ceballos Salvador , Agelidis Vassilios Georgios
Published: August 2015

Control of the circulating currents in a modular multilevel converter (MMC) is an integral part of its operation as the circulating currents have a significant impact on the rating of the power devices, losses and also capacitor voltage ripples. This study proposes two methods to control the circulating currents in the phase‐legs of the MMC to their minimum dc value through elimination of the low‐order harmonic components in the circulating current. The first method acts directly on the ac harmonics of the circulating current allowing the dc component to establish naturally, whereas the second one directly controls the current to its dc reference. Simulations and experimental results from a laboratory prototype demonstrate the operating principles of the two methods and validate their performance.
Nanoscale dispersion of delaminated sheets of layered double hydroxides in polyvinyl acetate
Authors: Chen Jianjun , He Mingping , Wang Yulin , Hu Wei , Lv Liang
Published: August 2015

The delamination of layered double hydroxides (LDHs) was supposed to be achieved in a microemulsion composed of octane, N ‐lauroyl‐glutamate, butanol and water. In the X‐ray diffraction patterns of LDHs, the diffraction peaks at low angle regions disappeared when the amount of octane reached a proper degree in the microemulsion, indicating that LDH layers might be delaminated, which is further proved by carbonate‐exchange experiments. Furthermore, polyvinyl acetate/LDH nanocomposites were prepared via in situ intercalative polymerisation, in which vinyl acetate monomer was dispersed onto the sheets of delaminated LDHs, followed by thermal polymerisation. The thermal stability of the nanocomposites was improved compared with the polymer matrix, and the enhanced extent of the thermal stability increased with increasing loading amounts of delaminated LDHs.
Non-invasive probe diagnostic method for electron temperature and ion current density in atmospheric pressure plasma jet source
Authors: Kim Young-Cheol , Kim Yu-Sin , Lee Hyo-Chang , Moon Jun-Hyeon , Chung Chin-Wook , Kim Yunjung , Cho Guangsup
Published: August 2015

The electrical probe diagnostics are very hard to be applied to atmospheric plasmas due to severe perturbation by the electrical probes. To overcome this, the probe for measuring electron temperature and ion current density is indirectly contacted with an atmospheric jet source. The plasma parameters are obtained by using floating harmonic analysis. The probe is mounted on the quartz tube that surrounds plasma. When a sinusoidal voltage is applied to a probe contacting on a quartz tube, the electrons near the sheath at dielectric tube are collected and the probe current has harmonic components due to probe sheath nonlinearity. From the relation of the harmonic currents and amplitude of the sheath voltage, the electron temperature near the wall can be obtained with collisional sheath model. The electron temperatures and ion current densities measured at the discharge region are in the ranges of 2.7–3.4 eV and 1.7–5.2 mA/cm2 at various flow rates and input powers.
Effect of vacancies on the structure and properties of Ga2(Se0.33Te0.67)3
Authors: Abdul-Jabbar N. M. , Forrest T. R. , Gronsky R. , Bourret-Courchesne E. D. , Wirth B. D.
Published: August 2015

Ga2(Se0.33Te0.67)3 belongs to a family of materials with large intrinsic vacancy concentrations that are being actively studied due to their potential for diverse applications that include thermoelectrics and phase-change memory. In this article, the Ga2(Se0.33Te0.67)3 structure is investigated via synchrotron x-ray diffraction, electron microscopy, and x-ray absorption experiments. Diffraction and microscopy measurements showed that the extent of vacancy ordering in Ga2(Se0.33Te0.67)3 is highly dependent on thermal annealing. It is posited that stoichiometric vacancies play a role in local atomic distortions in Ga2(Se0.33Te0.67)3 (based on the fine structure signals in the collected x-ray absorption spectra). The effect of vacancy ordering on Ga2(Se0.33Te0.67)3 material properties is also examined through band gap and Hall effect measurements, which reveal that the Ga2(Se0.33Te0.67)3 band gap redshifts by ≈0.05 eV as the vacancies order and accompanied by gains in charge carrier mobility. The results serve as an encouraging example of altering material properties via intrinsic structural rearrangement as opposed to extrinsic means, such as doping.
Engineering the mechanical properties of ultrabarrier films grown by atomic layer deposition for the encapsulation of printed electronics
Authors: Bulusu A. , Singh A. , Wang C. Y. , Dindar A. , Fuentes-Hernandez C. , Kim H. , Cullen D. , Kippelen B. , Graham S.
Published: August 2015

Direct deposition of barrier films by atomic layer deposition (ALD) onto printed electronics presents a promising method for packaging devices. Films made by ALD have been shown to possess desired ultrabarrier properties, but face challenges when directly grown onto surfaces with varying composition and topography. Challenges include differing nucleation and growth rates across the surface, stress concentrations from topography and coefficient of thermal expansion mismatch, elastic constant mismatch, and particle contamination that may impact the performance of the ALD barrier. In such cases, a polymer smoothing layer may be needed to coat the surface prior to ALD barrier film deposition. We present the impact of architecture on the performance of aluminum oxide (Al2O3)/hafnium oxide (HfO2) ALD nanolaminate barrier films deposited on fluorinated polymer layer using an optical calcium (Ca) test under damp heat. It is found that with increasing polymer thickness, the barrier films with residual tensile stress are prone to cracking resulting in rapid failure of the Ca sensor at 50 °C/85% relative humidity. Inserting a SiNx layer with residual compressive stress between the polymer and ALD layers is found to prevent cracking over a range of polymer thicknesses with more than 95% of the Ca sensor remaining after 500 h of testing. These results suggest that controlling mechanical properties and film architecture play an important role in the performance of direct deposited ALD barriers.
External control of electron energy distributions in a dual tandem inductively coupled plasma
Authors: Liu Lei , Sridhar Shyam , Zhu Weiye , Donnelly Vincent M. , Economou Demetre J. , Logue Michael D. , Kushner Mark J.
Published: August 2015

The control of electron energy probability functions (EEPFs) in low pressure partially ionized plasmas is typically accomplished through the format of the applied power. For example, through the use of pulse power, the EEPF can be modulated to produce shapes not possible under continuous wave excitation. This technique uses internal control. In this paper, we discuss a method for external control of EEPFs by transport of electrons between separately powered inductively coupled plasmas (ICPs). The reactor incorporates dual ICP sources (main and auxiliary) in a tandem geometry whose plasma volumes are separated by a grid. The auxiliary ICP is continuously powered while the main ICP is pulsed. Langmuir probe measurements of the EEPFs during the afterglow of the main ICP suggests that transport of hot electrons from the auxiliary plasma provided what is effectively an external source of energetic electrons. The tail of the EEPF and bulk electron temperature were then elevated in the afterglow of the main ICP by this external source of power. Results from a computer simulation for the evolution of the EEPFs concur with measured trends.
Topographically generated internal waves and boundary layer instabilities
Authors: Soontiens Nancy , Stastna Marek , Waite Michael L.
Published: August 2015

Flow over topography has been shown to generate finite amplitude internal waves upstream, over the topography and downstream. Such waves can interact with the viscous bottom boundary layer to produce vigorous instabilities. However, the strength and size of such instabilities depends on whether viscosity significantly modifies the wave generation process, which is usually treated using inviscid theory in the literature. In this work, we contrast cases in which boundary layer separation profoundly alters the wave generation process and cases for which the generated internal waves largely match inviscid theory. All results are generated using a numerical model that simulates stratified flow over topography. Several issues with using a wave-based Reynolds number to describe boundary layer properties are discussed by comparing simulations with modifications to the domain depth, background velocity, and viscosity. For hill-like topography, three-dimensional aspects of the instabilities are also discussed. Decreasing the Reynolds number by a factor of four (by increasing the viscosity), while leaving the primary two-dimensional instabilities largely unchanged, drastically affects their three-dimensionalization. Several cases at the laboratory scale with a depth of 1 m are examined in both two and three dimensions and a subset of the cases is scaled up to a field scale 10-m deep fluid while maintaining similar values for the background current and viscosity. At this scale, increasing the viscosity by an order of magnitude does not significantly change the wave properties but does alter the wave’s interaction with the bottom boundary layer through the bottom shear stress. Finally, two subcritical cases for which disturbances are able to propagate upstream showcase a set of instabilities forming on the upstream slope of the elevated topography. The time scale over which these instabilities develop is related to but distinct from the advective time scale of the waves. At a non-dimensional time when instabilities have formed in the field scale case, no instabilities have yet formed in the lab scale case.
The g-factor of quasi-two-dimensional electrons in InAs/InGaAs/InAlAs inserted-channels
Authors: Pakmehr Mehdi , Khaetskii A. , McCombe B. D. , Bhandari N. , Cahay M. , Chiatti Olivio , Fischer S. F. , Heyn C. , Hansen W.
Published: August 2015

We have measured the Landau-level spin-splitting of two-dimensional electrons in the composite InAs/InGaAs channels of two InAs/InGaAs/InAlAs heterostructures with different alloy compositions by magnetotransport and THz magneto-photoconductivity in magnetic fields up to 10 T. The structures differ importantly in the mobility of the channel, the electron density and the composition of the barriers. The magnitudes of the experimental g-factors for B along the quantization axis and their anisotropies are larger by at least a factor of 2 than the corresponding calculated single particle values. The angular dependence of many-body exchange contributions and the effects of broadening of Landau–level densities of states are necessary for understanding this behaviour. We find evidence for a marked decrease of the exchange contribution at low perpendicular magnetic fields in the higher mobility sample from coincidence measurements, but no indications of such behaviour in the lower mobility sample.
Fast and robust control of nanopositioning systems: Performance limits enabled by field programmable analog arrays
Authors: Baranwal Mayank , Gorugantu Ram S. , Salapaka Srinivasa M.
Published: August 2015

This paper aims at control design and its implementation for robust high-bandwidth precision (nanoscale) positioning systems. Even though modern model-based control theoretic designs for robust broadband high-resolution positioning have enabled orders of magnitude improvement in performance over existing model independent designs, their scope is severely limited by the inefficacies of digital implementation of the control designs. High-order control laws that result from model-based designs typically have to be approximated with reduced-order systems to facilitate digital implementation. Digital systems, even those that have very high sampling frequencies, provide low effective control bandwidth when implementing high-order systems. In this context, field programmable analog arrays (FPAAs) provide a good alternative to the use of digital-logic based processors since they enable very high implementation speeds, moreover with cheaper resources. The superior flexibility of digital systems in terms of the implementable mathematical and logical functions does not give significant edge over FPAAs when implementing linear dynamic control laws. In this paper, we pose the control design objectives for positioning systems in different configurations as optimal control problems and demonstrate significant improvements in performance when the resulting control laws are applied using FPAAs as opposed to their digital counterparts. An improvement of over 200% in positioning bandwidth is achieved over an earlier digital signal processor (DSP) based implementation for the same system and same control design, even when for the DSP-based system, the sampling frequency is about 100 times the desired positioning bandwidth.
A theoretical method to compute sequence dependent configurational properties in charged polymers and proteins
Authors: Sawle Lucas , Ghosh Kingshuk
Published: August 2015

A general formalism to compute configurational properties of proteins and other heteropolymers with an arbitrary sequence of charges and non-uniform excluded volume interaction is presented. A variational approach is utilized to predict average distance between any two monomers in the chain. The presented analytical model, for the first time, explicitly incorporates the role of sequence charge distribution to determine relative sizes between two sequences that vary not only in total charge composition but also in charge decoration (even when charge composition is fixed). Furthermore, the formalism is general enough to allow variation in excluded volume interactions between two monomers. Model predictions are benchmarked against the all-atom Monte Carlo studies of Das and Pappu [Proc. Natl. Acad. Sci. U. S. A. 110, 13392 (2013)] for 30 different synthetic sequences of polyampholytes. These sequences possess an equal number of glutamic acid (E) and lysine (K) residues but differ in the patterning within the sequence. Without any fit parameter, the model captures the strong sequence dependence of the simulated values of the radius of gyration with a correlation coefficient of R2 = 0.9. The model is then applied to real proteins to compare the unfolded state dimensions of 540 orthologous pairs of thermophilic and mesophilic proteins. The excluded volume parameters are assumed similar under denatured conditions, and only electrostatic effects encoded in the sequence are accounted for. With these assumptions, thermophilic proteins are found—with high statistical significance—to have more compact disordered ensemble compared to their mesophilic counterparts. The method presented here, due to its analytical nature, is capable of making such high throughput analysis of multiple proteins and will have broad applications in proteomic studies as well as in other heteropolymeric systems.
The Faraday instability in miscible fluid systems
Authors: Diwakar S. V. , Zoueshtiagh Farzam , Amiroudine Sakir , Narayanan Ranga
Published: August 2015

The Faraday instability arising in distinct miscible fluid layers, when the parametric forcing is parallel to the gravity vector, is analysed. A time-dependent density gradient is established from the moment the fluid layers are placed in contact with one another. The operating parameters in a miscible Faraday system are the frequency of parametric forcing and the wait time between the initial contact of fluids and the commencement of oscillations. Using a linearized theory that invokes a quasi-steady approximation, the vibrational threshold required for the onset of Faraday instability is evaluated for these parameters and several observations are made. First, the criticality is observed to occur at a sub-harmonic frequency. Second, the large magnitude of the concentration gradient at early wait times is found to make the thin layers highly unstable. Third, the stability increases with forcing frequency, owing to the increased dissipation of the resulting choppy waves. All these observations qualitatively agree with experiments. Finally, a calculation reveals that an increase in gravity increases the critical wavelength of flow onset and results in the reduction of critical input acceleration.
Spatially confined low-power optically pumped ultrafast synchrotron x-ray nanodiffraction
Authors: Park Joonkyu , Zhang Qingteng , Chen Pice , Cosgriff Margaret P. , Tilka Jack A. , Adamo Carolina , Schlom Darrell G. , Wen Haidan , Zhu Yi , Evans Paul G.
Published: August 2015

The combination of ultrafast optical excitation and time-resolved synchrotron x-ray nanodiffraction provides unique insight into the photoinduced dynamics of materials, with the spatial resolution required to probe individual nanostructures or small volumes within heterogeneous materials. Optically excited x-ray nanobeam experiments are challenging because the high total optical power required for experimentally relevant optical fluences leads to mechanical instability due to heating. For a given fluence, tightly focusing the optical excitation reduces the average optical power by more than three orders of magnitude and thus ensures sufficient thermal stability for x-ray nanobeam studies. Delivering optical pulses via a scannable fiber-coupled optical objective provides a well-defined excitation geometry during rotation and translation of the sample and allows the selective excitation of isolated areas within the sample. Experimental studies of the photoinduced lattice dynamics of a 35 nm BiFeO3 thin film on a SrTiO3 substrate demonstrate the potential to excite and probe nanoscale volumes.
Performance of JT-60SA divertor Thomson scattering diagnostics
Authors: Kajita Shin , Hatae Takaki , Tojo Hiroshi , Enokuchi Akito , Hamano Takashi , Shimizu Katsuhiro , Kawashima Hisato
Published: August 2015

For the satellite tokamak JT-60 Super Advanced (JT-60SA), a divertor Thomson scattering measurement system is planning to be installed. In this study, we improved the design of the collection optics based on the previous one, in which it was found that the solid angle of the collection optics became very small, mainly because of poor accessibility to the measurement region. By improvement, the solid angle was increased by up to approximately five times. To accurately assess the measurement performance, background noise was assessed using the plasma parameters in two typical discharges in JT-60SA calculated from the SONIC code. Moreover, the influence of the reflection of bremsstrahlung radiation by the wall is simulated by using a ray tracing simulation. The errors in the temperature and the density are assessed based on the simulation results for three typical field of views.
Hard-sphere melting and crystallization with event-chain Monte Carlo
Authors: Isobe Masaharu , Krauth Werner
Published: August 2015

We simulate crystallization and melting with local Monte Carlo (LMC), with event-chain Monte Carlo (ECMC), and with event-driven molecular dynamics (EDMD) in systems with up to one million three-dimensional hard spheres. We illustrate that our implementations of the three algorithms rigorously coincide in their equilibrium properties. We then study nucleation in the NVE ensemble from the fcc crystal into the homogeneous liquid phase and from the liquid into the homogeneous crystal. ECMC and EDMD both approach equilibrium orders of magnitude faster than LMC. ECMC is also notably faster than EDMD, especially for the equilibration into a crystal from a disordered initial condition at high density. ECMC can be trivially implemented for hard-sphere and for soft-sphere potentials, and we suggest possible applications of this algorithm for studying jamming and the physics of glasses, as well as disordered systems.
Thermal properties of halogen-ethane glassy crystals: Effects of orientational disorder and the role of internal molecular degrees of freedom
Authors: Vdovichenko G. A. , Krivchikov A. I. , Korolyuk O. A. , Tamarit J. Ll. , Pardo L. C. , Rovira-Esteva M. , Bermejo F. J. , Hassaine M. , Ramos M. A.
Published: August 2015

The thermal conductivity, specific heat, and specific volume of the orientational glass former 1,1,2-trichloro-1,2,2-trifluoroethane (CCl2F–CClF2, F-113) have been measured under equilibrium pressure within the low-temperature range, showing thermodynamic anomalies at ca. 120, 72, and 20 K. The results are discussed together with those pertaining to the structurally related 1,1,2,2-tetrachloro-1,2-difluoroethane (CCl2F–CCl2F, F-112), which also shows anomalies at 130, 90, and 60 K. The rich phase behavior of these compounds can be accounted for by the interplay between several of their degrees of freedom. The arrest of the degrees of freedom corresponding to the internal molecular rotation, responsible for the existence of two energetically distinct isomers, and the overall molecular orientation, source of the characteristic orientational disorder of plastic phases, can explain the anomalies at higher and intermediate temperatures, respectively. The soft-potential model has been used as the framework to describe the thermal properties at low temperatures. We show that the low-temperature anomaly of the compounds corresponds to a secondary relaxation, which can be associated with the appearance of Umklapp processes, i.e., anharmonic phonon-phonon scattering, that dominate thermal transport in that temperature range.
New progress of high-efficiency and low-emission 9HA combine cycle gas turbine power generation demonstration project
Authors: Ma Mingming , Yu Xin , Chen Tao
Published: August 2015

On July 10, 2014 in China's Great Hall of the People, the Harbin Electric Corporation and the General Electric Company launched an “Eco-Partnership” to cooperate on the design, manufacture, and demonstration of the world's best gas turbine combined cycle power plant (hereinafter “gas turbine”). The 9HA gas turbine will feature world-class, highly advanced technology, incorporating leading levels of efficiency along with a flexible operating profile and extremely low emissions of harmful pollutants. Once this product is commercialized, it has the potential to replace a large proportion of the current generation of power plants typically found in industrial plants in China coastal regions and the U.S.
EcoPartnership on water quality management and conservation in the U.S. and China
Authors: Anid Nada Marie , Panero Marta , Zheng Chunmiao , Liu Jie
Published: August 2015

New York Institute of Technology, Peking University, Wuhan University, the International Society for Water Solutions of the American Institute of Chemical Engineers, and an industrial partner HDR|HydroQual formed an EcoPartnership in 2013. The partners are jointly advancing innovative water quality models, real-time water monitoring tools and information systems, water scarcity and hydrologic simulations, and techniques for water management during hydraulic fracturing. These goals are being pursued through a combination of pilot demonstration projects, research on the next generation of technologies, and practical training and community outreach (through conferences and workshops). This comprehensive approach will help foster water quality, management, and conservation in China and the U.S.
Higher Poincaré lemma and integrability
Authors: Demessie G. A. , Sämann C.
Published: August 2015

We prove the non-abelian Poincaré lemma in higher gauge theory in two different ways. That is, we show that every flat local connective structure is gauge trivial. The first method uses a result by Jacobowitz [J. Differ. Geom. 13, 361 (1978)] which states solvability conditions for differential equations of a certain type. The second method extends a proof by Voronov [Proc. Am. Math. Soc. 140, 2855 (2012)] and yields the explicit gauge parameters connecting a flat local connective structure to the trivial one. Finally, we show how higher flatness appears as a necessary integrability condition of a linear system which featured in recently developed twistor descriptions of higher gauge theories.
Bayesian parametrization of coarse-grain dissipative dynamics models
Authors: Dequidt Alain , Solano Canchaya Jose G.
Published: August 2015

We introduce a new bottom-up method for the optimization of dissipative coarse-grain models. The method is based on Bayesian optimization of the likelihood to reproduce a coarse-grained reference trajectory obtained from analysis of a higher resolution molecular dynamics trajectory. This new method is related to force matching techniques, but using the total force on each grain averaged on a coarse time step instead of instantaneous forces. It has the advantage of not being limited to pairwise short-range interactions in the coarse-grain model and also yields an estimation of the friction parameter controlling the dynamics. The theory supporting the method is exposed in a practical perspective, with an analytical solution for the optimal set of parameters. The method was first validated by using it on a system with a known optimum. The new method was then tested on a simple system: n-pentane. The local molecular structure of the optimized model is in excellent agreement with the reference system. An extension of the method allows to get also an excellent agreement for the equilibrium density. As for the dynamic properties, they are also very satisfactory, but more sensitive to the choice of the coarse-grain representation. The quality of the final force field depends on the definition of the coarse grain degrees of freedom and interactions. We consider this method as a serious alternative to other methods like iterative Boltzmann inversion, force matching, and Green-Kubo formulae.
Geometry and symmetry of quantum and classical-quantum variational principles
Authors: Bonet Luz Esther , Tronci Cesare
Published: August 2015

This paper presents the geometric setting of quantum variational principles and extends it to comprise the interaction between classical and quantum degrees of freedom. Euler-Poincaré reduction theory is applied to the Schrödinger, Heisenberg, and Wigner-Moyal dynamics of pure states. This construction leads to new variational principles for the description of mixed quantum states. The corresponding momentum map properties are presented as they arise from the underlying unitary symmetries. Finally, certain semidirect-product group structures are shown to produce new variational principles for Dirac’s interaction picture and the equations of hybrid classical-quantum dynamics.
Synthesis of ultra-nano-carbon composite materials with extremely high conductivity by plasma post-treatment process of ultrananocrystalline diamond films
Authors: Yeh Chien-Jui , Manoharan Divinah , Chang Hsin-Tzer , Leou Keh-Chyang , Lin I-Nan
Published: August 2015

Needle-like diamond grains encased in nano-graphitic layers are an ideal granular structure of diamond films to achieve high conductivity and superior electron field emission (EFE) properties. This paper describes the plasma post-treatment (ppt) of ultrananocrystalline diamond (UNCD) films at low substrate temperature to achieve such a unique granular structure. The CH4/N2 plasma ppt-processed films exhibit high conductivity of σ = 1099 S/cm as well as excellent EFE properties with turn-on field of E0 = 2.48 V/μm (Je = 1.0 mA/cm2 at 6.5 V/μm). The ppt of UNCD film is simple and robust process that is especially useful for device applications.
Probing cis-trans isomerization in the S1 state of C2H2 via H-atom action and hot band-pumped IR-UV double resonance spectroscopies
Authors: Changala P. Bryan , Baraban Joshua H. , Merer Anthony J. , Field Robert W.
Published: August 2015

We report novel experimental strategies that should prove instrumental in extending the vibrational and rotational assignments of the S1 state of acetylene, C2H2, in the region of the cis-trans isomerization barrier. At present, the assignments are essentially complete up to ∼500 cm−1 below the barrier. Two difficulties arise when the assignments are continued to higher energies. One is that predissociation into C2H + H sets in roughly 1100 cm−1 below the barrier; the resulting quenching of laser-induced fluorescence (LIF) reduces its value for recording spectra in this region. The other difficulty is that tunneling through the barrier causes a staggering in the K-rotational structure of isomerizing vibrational levels. The assignment of these levels requires data for K values up to at least 3. Given the rotational selection rule K′ − ℓ′′ = ± 1, such data must be obtained via excited vibrational levels of the ground state with ℓ′′ > 0. In this paper, high resolution H-atom resonance-enhanced multiphoton ionization spectra are demonstrated to contain predissociated bands which are almost invisible in LIF spectra, while preliminary data using a hyperthermal pulsed nozzle show that ℓ′′ = 2 states can be selectively populated in a jet, giving access to K′ = 3 states in IR-UV double resonance.
Calculation of P,T-odd interaction constant of PbF using Z-vector method in the relativistic coupled-cluster framework
Authors: Sasmal Sudip , Pathak Himadri , Nayak Malaya K. , Vaval Nayana , Pal Sourav
Published: August 2015

The effective electric field experienced by the unpaired electron in the ground state of PbF, which is a potential candidate in the search of electron electric dipole moment due to some special characteristics, is calculated using Z-vector method in the coupled cluster single- and double- excitation approximation with four component Dirac spinor. This is an important quantity to set the upper bound limit of the electron electric dipole moment. Further, we have calculated molecular dipole moment and parallel magnetic hyperfine structure constant (A‖) of 207Pb in PbF to test the accuracy of the wavefunction obtained in the Z-vector method. The outcome of our calculations clearly suggests that the core electrons have significant contribution to the “atom in compound” properties.
The Yangtze-Mississippi river EcoPartnership: Bringing together two great rivers
Authors: Tansey Bob , Yimin Zhao , Bo Yang , Weizhi Yao , Daqing Chen , Weili Lou
Published: August 2015

How does one connect two of the most important rivers in the world? In the East, China's longest river, the Yangtze, stretches 6300 km from the Tibetan Plateau to the port of Shanghai. In the West, the longest river in the United States, the Mississippi, runs 5970 km from northern Minnesota down to the Gulf of Mexico. Both rivers play vital roles in the cultures and economies of their respective countries. Each river system gives life to a wealth of biodiversity while providing millions of people with drinking water, hydroelectric power, and a number of other services. The vitality of the Yangtze and Mississippi faces challenges, however, and the fisheries resources of these two great rivers face specific and common threats. That is why The Nature Conservancy and the Yangtze River Basin Fisheries Resources Management Commission (YFC) came together to form an EcoPartnership to help preserve the natural fisheries of these two great rivers. (Note: YFC recently became the Yangtze Fisheries Bureau, with fisheries responsibilities for all rivers in China from the Yangtze on south and greater administrative authority. The great rivers partnership logo uses the rubric of the Changjiang Fisheries Agency, retaining the Chinese pinyin for the name of the river.