bluuebunny/crossref_metadata_2025 huggingface dataset:
Retarding the crystallization of PbI2for highly reproducible planar-structured perovskite solar cells via sequential deposition
Authors: Wu Yongzhen , Islam Ashraful , Yang Xudong , Qin Chuanjiang , Liu Jian , Zhang Kun , Peng Wenqin , Han Liyuan
Published: June 2014

A universally useful idea for preparing high quality perovskite films is proposed by retarding the crystallization of PbI2, which make possible highly reproducible planar structured perovskite solar cells.
A binuclear trimethylenemethane cobalt carbonyl providing the first example of a low-energy perpendicular structure with acyclic hydrocarbon ligands
Authors: Zeng Yi , Feng Hao , Xie Yaoming , King R. Bruce
Published: June 2014

Density functional theory predicts an unusual perpendicular structure for [μ-(CH2)3C]2Co2(CO)2with bridging η4-TMM ligands, terminal CO groups, and a relatively short Co–Co distance of ∼2.29 Å.
A coumarin-based sensitive and selective fluorescent sensor for copper(ii) ions
Authors: Yeh Jiun-Ting , Chen Wei-Chieh , Liu Shi-Rong , Wu Shu-Pao
Published: June 2014

A new coumarin-derived fluorescent probe (1) exhibited significant fluorescence quenching in the presence of Cu2+ ions.
Multifunctional non-viral gene vectors with enhanced stability, improved cellular and nuclear uptake capability, and increased transfection efficiency
Authors: Yang Zhe , Jiang Zhaozhong , Cao Zhong , Zhang Chao , Gao Di , Luo Xingen , Zhang Xiaofang , Luo Huiyan , Jiang Qing , Liu Jie
Published: June 2014

An mTAT-quaternary PPMS/DNA/NLS/PGA-g-PEG-mTAT system was developed to facilitate enhanced intracellular DNA delivery.
Magnetocaloric effect and slow magnetic relaxation in two dense (3,12)-connected lanthanide complexes
Authors: Han Song-De , Miao Xiao-Hong , Liu Sui-Jun , Bu Xian-He
Published: June 2014

We report two (3,12)-connected complexes with distorted cubic [Ln4O4] (Ln = Gd (1), Dy (2)) units as nodes bridged by in situ generated sulfate. 1 features a large magnetocaloric effect with −ΔSmaxm = 51.29 J kg−1 K−1, and 2 displays slow magnetic relaxation behavior.
Multifunctional pentacyclic triterpenoids as adjuvants in cancer chemotherapy: a review
Authors: Kamble Sarika M. , Goyal Sameer N. , Patil Chandragouda R.
Published: June 2014

The protective adjuvants in chemotherapy.
MnO2 nanoflakes anchored on reduced graphene oxide nanosheets as high performance anode materials for lithium-ion batteries
Authors: Cao Yong , Lin Xionggui , Zhang Chenglong , Yang Cheng , Zhang Qian , Hu Weiqiang , Zheng Mingsen , Dong Quanfeng
Published: June 2014

A MnO2 nanoflake–reduced graphene oxide (MnO2–rGO) composite was synthesized by a facile solution method.
Piezoelectric power generation of vertically aligned lead-free (K,Na)NbO3 nanorod arrays
Authors: Kang Pil Gu , Yun Byung Kil , Sung Kil Dong , Lee Tae Kwon , Lee Minbaek , Lee Nuri , Oh Seol Hee , Jo William , Seog Hae Jin , Ahn Chang Won , Kim Ill Won , Jung Jong Hoon
Published: June 2014

We demonstrate the potential of eco-friendly nanogenerators based on (K,Na)NbO3 nanorod arrays for high-output power generation at room temperature and elevated temperature.
Synthesis of monoglycosides, bisglycosides and open-chain ketoacetals from sugar derived exocyclic enol ethers
Authors: Das Soumendra Nath , K Praveen Krishna , Mandal Sukhendu Bikas
Published: June 2014

Pent-4-enofuranoside derivatives have been converted to glycosides and open-chain ketoacetals on treatment with various alcohols under acidic conditions.
Preparation of highly controlled nanostructured Au within mesopores using reductive deposition in non-polar environments
Authors: Kitahara Masaki , Kuroda Kazuyuki
Published: June 2014

We demonstrate a sophisticated and unique method of Au deposition exclusively inside mesoporous silica, in clear contrast to conventional methods requiring surface modification with organic functional groups interacting with Au.
Mercaptophenylboronic acid modified gold nanoparticle@silica bubbles for buoyant separation and specific enrichment of glycopeptides
Authors: Hu Junjie , Ma Rongna , Liu Fei , Chen Yunlong , Ju Huangxian
Published: June 2014

A buoyant separation method was proposed for specific enrichment of glycopeptides using mercaptophenylboronic acid modified gold nanoparticles @silica bubbles.
Novel metronidazole-sulfonamide derivatives as potent and selective carbonic anhydrase inhibitors: design, synthesis and biology analysis
Authors: Wang Zhong-Chang , Duan Yong-Tao , Qiu Han-Yue , Huang Wan-Yun , Wang Peng-Fei , Yan Xiao-Qiang , Zhang Shu-Feng , Zhu Hai-Liang
Published: June 2014

Metronidazole–sulfonamide derivatives, a new class of human carbonic anhydrase inhibitors (hCA), were designed, synthesized, isolated, and evaluated for their ability to inhibit the enzymatic activity of the isozymes hCA II and hCA IX.
Multifunctional particle coating by plasma process and its application to pollution control
Authors: Nasonova Anna , Kim Kyo-Seon
Published: June 2014

Multifunctional particle coating by Plasma-Enhanced Chemical Vapor Deposition (PECVD) and its application are presented in this review.
Controllable growth of SnS2/SnO2 heterostructured nanoplates via a hydrothermal-assisted self-hydrolysis process and their visible-light-driven photocatalytic reduction of Cr(vi)
Authors: Mao Liyuan , Li Jingjing , Xie Yunlong , Zhong Yijun , Hu Yong
Published: June 2014

A novel and facile hydrothermal-assisted self-hydrolysis route has been proposed for the controllable preparation of SnS2/SnO2 heterostructured nanoplates (HNPs), which exhibit enhanced photoactivity in the reduction of aqueous Cr(vi).
High pressure superconducting phase of BI3: an ab initio study
Authors: Duan Defang , Huang Xiaoli , Chen Changbo , Tian Fubo , Bao Kuo , Li Da , Liu Yunxian , Yu Hongyu , Liu Bingbing , Cui Tian
Published: June 2014

Planar BI3 molecule transforms to dimer B2I6 (P21/c) under high pressure. Its superconductivity is mainly attributed to iodine vibrations.
A dioxadithiaazacrown ether–BODIPY dyad Hg2+ complex for detection of l-cysteine: fluorescence switching and application to soft material
Authors: Kaur Navdeep , Kaur Paramjit , Singh Kamaljit
Published: June 2014

A Hg2+ coordinate complex of a 1,4-dioxa-7,13-dithia-10-azacyclopentadecane–BODIPY dyad recognises l-cysteine (cys) via reversible complexation/decomplexation and show switching of fluorescence upon sequential addition of Hg2+ and cys in solution as well as in hydrogel.
Hierarchical cystine flower based electrochemical genosensor for detection of Escherichia coli O157:H7
Authors: Pandey Chandra Mouli , Tiwari Ida , Sumana Gajjala
Published: June 2014

Synthesis and self-assembly of cystine flowers on gold electrode for biosensing application.
An Efficient synthesis of Weinreb amides and ketones via palladium nanoparticles on ZIF-8 catalysed carbonylative coupling
Authors: Thanh Dang Tuan , Chen Anqi , Majeed Seayad Abdul
Published: June 2014

Palladium nanoparticles on ZIF-8 as a robust and recyclable catalyst for Weinreb amide and ketone synthesis through carbonylative coupling.
Highly selective and efficient extraction of lignin in kraft pulp by aqueous ionic liquids for enhanced bleaching properties
Authors: Pang Zhiqiang , Chen Jiachuan , Dong Cuihua , Yang Guihua
Published: June 2014

Aqueous ionic liquids (ILs) that selectively extract lignin in kraft pulp under benign conditions were reported.
Nonuniform growth and topological defects in the shaping of elastic sheets
Authors: Bende Nakul P. , Hayward Ryan C. , Santangelo Christian D.
Published: June 2014

We demonstrate that shapes with zero Gaussian curvature, except at singularities, produced by the growth-induced buckling of a thin elastic sheet are the same as those produced by the Volterra construction of topological defects in which edges of an intrinsically flat surface are identified.
Simple and highly efficient chiral dopant molecules possessing both rod- and arch-like units
Authors: Kishikawa Keiki , Aoyagi Shota , Kohri Michinari , Taniguchi Tatsuo , Takahashi Masahiro , Kohmoto Shigeo
Published: June 2014

A simple chiral dopant molecule, (R)-1, possessing both rod- and arch-like units was prepared. It showed extremely large helical twisting powers (+123 to +228 μm−1) with P-helicity in nematic liquid crystal phases.
Graphitic carbon nitride nano-emitters on silicon: a photoelectrochemical heterojunction composed of earth-abundant materials for enhanced evolution of hydrogen
Authors: Lublow M. , Fischer A. , Merschjann C. , Yang F. , Schedel-Niedrig Th. , Veyan J.-F. , Chabal Y. J.
Published: June 2014

Graphitic carbon nitride is a promising heterogeneous catalyst for light-induced generation of hydrogen.
Multifunctional graphene sheet–nanoribbon hybrid aerogels
Authors: Wang Chunhui , He Xiaodong , Shang Yuanyuan , Peng Qingyu , Qin Yuyang , Shi Enzheng , Yang Yanbing , Wu Shiting , Xu Wenjing , Du Shanyi , Cao Anyuan , Li Yibin
Published: June 2014

Highly porous and elastic aerogels consisting of graphene sheets and nanoribbons can be used as adsorbents and supercapacitor electrodes.
Hydrophobic conjugated microporous polymer as a novel adsorbent for removal of volatile organic compounds
Authors: Wang Junhui , Wang Gang , Wang Wanqiu , Zhang Zhongshen , Liu Zhaotie , Hao Zhengping
Published: June 2014

Conjugated microporous polymers with a micro/mesoporous structure exhibit a hydrophobic nature and represent a promising adsorbent of VOCs under humid conditions.
Branch-structured Bi2S3–CNT hybrids with improved lithium storage capability
Authors: Zhao Yang , Liu Tingting , Xia Hui , Zhang Ling , Jiang Jiaxing , Shen Ming , Ni Jiangfeng , Gao Lijun
Published: June 2014

A hierarchical, branched Bi2S3–CNT hybrid was fabricated through a facile sonochemical approach which exhibited outstanding Li-storage capability.
From melamine–resorcinol–formaldehyde to nitrogen-doped carbon xerogels with micro- and meso-pores for lithium batteries
Authors: Liu Xichuan , Li Shaomin , Mei Jun , Lau Woon-Ming , Mi Rui , Li Yinchuan , Liu Hao , Liu Limin
Published: June 2014

Novel multi-scaled porous nitrogen-doped carbon is synthesized by enriching the simple R–F method with: addition of melamine and PEO–PPO–PEO micelles for nitrogen-doping and duct percolation; integration of the CO2 activation process for the most critical formation of abundant 2 nm pores.
Facile preparation of gadolinium(iii) chelates functionalized carbon quantum dot-based contrast agent for magnetic resonance/fluorescence multimodal imaging
Authors: Ren Xianyan , Liu Lihua , Li Yu , Dai Qin , Zhang Ming , Jing Xinli
Published: June 2014

Gadolinium(iii) chelate-functionalized carbon quantum dots having good magnetic resonance response and photoluminescence properties were prepared, which can be used for multimodal imaging.
Effect of solvent vapour annealing on polymer thin films and application in nonlinear optical fields
Authors: Wang Shiwei , Su Wanli , Li Yunhui , Zhang Rongwei , Wang Xibin , Zhang Daming
Published: June 2014

Solvent vapour annealed (SVA) technique was successfully used in controlling the morphology of polymer thin film blending with low molecular weight chromophoric (LMWC) molecules.
Amino-decorated lanthanide(iii) organic extended frameworks for multi-color luminescence and fluorescence sensing
Authors: Hao Ji-Na , Yan Bing
Published: June 2014

Four luminescent lanthanide–organic frameworks (Ln = Eu3+, Tb3+, Sm3+ and Dy3+), isostructural to MOF-LIC-1(Gd), are assembled. Multiple colors are obtained for the system and white-light emission is realized by the single component Sm(iii) framework. Most interestingly, Eu-MOF performs highly selective and sensitive luminescence sensing of Al3+.
Multiple ecto-nucleoside triphosphate diphosphohydrolases facilitate intracellular replication of Legionella pneumophila
Authors: Riedmaier Patrice , Sansom Fiona M. , Sofian Trifina , Beddoe Travis , Schuelein Ralf , Newton Hayley J. , Hartland Elizabeth L.
Published: June 2014

Legionella pneumophila is an opportunistic pathogen that replicates within alveolar macrophages resulting in the onset of severe atypical pneumonia. Previously we have identified Lpg1905, a eukaryotic-type ecto-NTPDase (nucleoside triphosphate diphosphohydrolase) from L. pneumophila that was required for optimal intracellular replication and virulence in a mouse lung infection model. In the present study, we characterized the activity of a second eukaryotic-type NTPDase, Lpg0971, from L. pneumophila. We observed that recombinant Lpg0971 hydrolysed only ATP and exhibited divalent cation preference for manganese (II) ions. Similar to lpg1905, an lpg0971 mutant carrying the plasmid pMIP was attenuated in a mouse lung infection model and impaired for replication in human macrophages and amoebae. Increased trafficking of the LCV (Legionella-containing vacuole) to a LAMP-1 (lysosome-associated membrane protein-1)-positive compartment was observed for both the lpg1905 and lpg0971 mutants carrying pMIP. Complementation with either lpg1905 or lpg0971 restored intracellular replication, suggesting that a minimum level of ATPase activity was required for this function. A double lpg1905/0971 mutant was not more impaired for intracellular replication than the single mutants and complementation of the double mutant with lpg0971, but not lpg1905, restored intracellular replication. This suggested that although the NTPDases have overlapping activities they have distinct functions. Unlike many eukaryotic-type proteins from L. pneumophila, neither Lpg1905 nor Lpg0971 were translocated into the host cell by the Dot/Icm (defective in organelle trafficking/intracellular multiplication) type IV secretion system. Overall our data suggest that the ability of L. pneumophila to replicate in eukaryotic cells relies in part on the ability of the pathogen to hydrolyse ATP within an intracellular compartment.
Hybrid algorithm for traction transformer differential protection based on intrinsic mode function energy entropy and correlation dimension
Authors: Tian Xingjun , Li Yunhua , Li Xiaqing
Published: June 2014

This study addresses fault identification in differential protection of a V/x‐type traction transformer used in a high‐speed railway. To quickly and accurately identify an internal short circuit in a traction transformer, a hybrid algorithm is developed that combines intrinsic mode function (IMF) energy entropy with the correlation dimension from chaos theory. IMF energy entropy and correlation dimension are sufficiently fast and sensitive to reflect the dynamic changes in the differential‐current signal from the traction transformer using different metrics; thus, this hybrid method can effectively identify an internal short circuit and magnetising inrush. Real‐time simulations and actual measurements of faults illustrate the validity of the proposed method.
High speed directional relaying algorithm based on the fundamental frequency positive sequence superimposed components
Authors: Gu Bin , Tan Jiancheng , Wei Hua
Published: June 2014

The conventional travelling wave protection is susceptible to the high frequency transient quantities, which can reduce the protection reliability. A directional‐relay algorithm based on positive sequence superimposed components is proposed in this study. In microprocessor relays, the extraction of fundamental frequency voltages and currents is, conventionally, provided by phasor estimation methods such as the Fourier algorithm. The common required time for fault detection in these relays is approximately one to two cycles. This study presents a high‐speed algorithm for the extraction of fundamental frequency positive sequence voltages and currents superimposed components based on Park transformation. In the meantime, specially designed high speed algorithms to solve the difficult problems that exist in a real system are proposed. Extensive simulations are performed to evaluate the performance of the proposed algorithm. The results show that the algorithm is fast and reliable for power transmission line protections. Also it is immune to fault resistances and system condition.
High‐speed distributed acquisition network for fast transient measurement
Authors: Liu Karl Yanchao , Siew W.H. , Stewart Robert W. , Li Qingmin
Published: June 2014

In power substations, switching operations of circuit breakers and disconnect switches generate transient electromagnetic emissions, which may interfere with the normal operations of electronic equipments. This study introduces the design of a novel wireless transient measurement system for measuring or monitoring transient electromagnetic emissions in power substations. Unlike traditional transient measurement systems that use several standalone waveform recording equipment, the presented system, adopting novel network measurement concept, works as a truly automatically controlled interactive data acquisition multi‐node network, and has the ability to provide time‐correlated data from numerous sensors. The accuracy of time correlation is smaller than 1.4 μs. As a result, it provides excellent scalability and is well suited for the measurement of analogue signals spread over a large physical space with time synchronisation. Another major difference is that the new system uses wireless links and programmable devices to replace cables and data acquisition equipment of currently available systems, thus making the new measurement system more compact, flexible and much more powerful. The designed measurement units could do both time‐domain measurement and real time spectrum analysis.
Uncertainty handling in power system expansion planning under a robust multi‐objective framework
Authors: Alizadeh Behnam , Jadid Shahram
Published: June 2014

In this study, a substantial idea has been reviewed which is useful in the investigation of the planning uncertainties. The concept relies on the optimality of an expansion plan in different conditions rather than the condition it has been optimised for. The method is developed in a manner that can be used in all sub‐systems (i.e. generation, transmission and distribution) expansion planning. However, in this study the idea has been assessed for generation expansion planning (GEP). Cost and reliability have been considered as two major objectives of the planning and robustness has been added as a supplementary objective. The method can deal with uncertainty in both coefficients of the objective functions and the constraints. Two GEP models, one static and the other dynamic, have been proposed to examine the performance of the method in the uncertainty handling. In addition, the efficiency of the Taguchi's orthogonal array testing method has been compared with Monte Carlo simulation in the scenario generation. Two case studies have been provided to simplify the justification on the efficiency of the method.
Calculation of cable thermal rating considering non‐isothermal earth surface
Authors: Purushothaman Sujit , de León Francisco , Terracciano Matthew
Published: June 2014

The study presents an algorithm to compute the heat transfer coefficient for thermal cable rating when modelling the non‐isothermal earth surface with the additional wall method. The position of the fictitious images is computed analytically by recognising that the complex geometrical arrangement can be converted into a much simpler one using the Fourier transform. This allows for the estimation of the heat transfer coefficient with simple formulas. The resulting equations are very easy to implement and are entirely compatible with the standardised methods (IEC and IEEE) for rating power cables. Hundreds of finite elements simulations have been performed to validate the proposed method which yielded results with typical differences of <5% for standard installations.
Gridded duo‐lateral position sensitivity detector with high linearity to low energetic electrons in vacuum environment
Authors: Esebamen Omeime Xerviar , Thungström Göran , Nilsson Hans‐Erik , Lundgren Anders
Published: June 2014

Characterising a position sensitive detector in a vacuum environment without beam position monitoring devices can be challenging and expensive. With this in mind, the authors have designed and fabricated a duo‐lateral position sensitive detector (PSD) incorporated with simple and inexpensive surface features. It was evaluated using scanning electron microscopy. To assist in pinpointing precise positioning as well as acting as path guide during the sweeping of electrons, multiple grids were lithographically patterned on the top layer of the duo‐lateral PSD. By sweeping electrons along two axes of the detector, the position detection error of both axes was determined from the signals recorded using a transimpedance amplification circuit. They were able to characterise the linearity over the x ‐ and y ‐axis of the PSD and the results show a very high linearity over two‐dimensions of the PSD's active area and that accurate beam monitoring for spectroscopic measurement without additional beam position monitoring devices is possible.
Analysis of three‐component decomposition to compact polarimetric synthetic aperture radar
Authors: Guo Rui , He Wei , Zhang Shuangxi , Zang Bo , Xing Meng‐dao
Published: June 2014

The compact polarimetric (CP) synthetic aperture radar (SAR) data is directly decomposed into three canonical components involving surface, double‐bounce and volume, which avoids the approximated quad‐polarimetric reconstruction based on several promising assumptions. Through several algebraic operations, the three‐component decomposition under CP modes (π/4 mode and right circular transmit, linear receive (CTLR) mode) is deduced. With the experiments by using two classical data sets – San Francisco data from AIRSAR system and Oberpfaffenhofen data from ESAR system, the feasibility and flexibility of the CP decomposition are validated. Also, it has been found that the use of CP data can be further extended into many other polarimetric applications, and the three‐component decomposition can achieve a better result with CTLR mode than with π/4 mode.
Improving the accuracy of local frequency estimation for interferometric synthetic aperture radar interferogram noise filtering considering large coregistration errors
Authors: Guo Jiao , Zhang Weitao , Liu Yanyang , Fu Longsheng
Published: June 2014

This study deals with the problem of estimating the local frequencies for interferometric synthetic aperture radar (InSAR) phase image (i.e. interferogram) noise filtering considering large coregistration errors. The estimation of local frequencies is frequently applied to achieving high performance of interferometric phase noise filtering, which is a key step in InSAR processing procedures. Unfortunately, the generated interferograms suffer seriously from coregistration errors especially for complicated topographies, thus imposing strong limits on the accuracy of local frequencies estimation by the existing methods. Taking large coregistration errors into account, the proposed method makes full use of the neighbouring pixels to construct joint pixel vector and take the separation extent of the signal and noise subspaces as the criterion to accurately estimate the local frequencies so that the effects of the envelope misalignment can be mitigated. Theoretical analysis and the simulated data as well as the real ERS‐1/2 data show that the presented method has the ability to provide accurate estimation of local frequencies even if the coregistration error reaches one pixel.
Error model estimation for airborne beacon‐based surveillance
Authors: Panken Adam D. , Kochenderfer Mykel J.
Published: June 2014

A next‐generation aircraft collision avoidance system under development is designed to reduce unnecessary alerts while reducing the risk of mid‐air collision. Current and future collision avoidance systems rely upon range, bearing and altitude information from airborne, beacon‐based surveillance. Realistic models of surveillance error characteristics are needed in order to develop and certify the safety and performance of these systems. Prior models of bearing measurements assumed uncorrelated Gaussian noise. This study explains how hidden Markov models can be used to capture the time‐correlated error characteristics exhibited by recorded surveillance data. Simulations show the impact of this higher‐fidelity model on predicted collision avoidance performance.
Enhancement of radio frequency device's contact test using a novel method
Authors: Hu Cheng‐Nan , Chen Wen‐Ju , Ko Hsuan‐Chung
Published: June 2014

This investigation describes novel automatic test equipment for verifying the electric contact of radio frequency (RF) traces between RF devices by, for example, the opens and shorts test. An equivalent circuit for modelling the RF device incorporating RF traces with contact impedance is applied for theoretical analysis of the prototype design. The effectiveness of the proposed novel test methodology is then validated. The measured data from experimental testing of RF devices attained in production runs precisely address the contact issue using the novel methodology presented here.
Method for modelling of fluxgate sensor including the geometry influence
Authors: Li Juping , Liu Shibin , Guo Bo , Hou Xiaowei , Yang Shanglin , Qiu Songsong
Published: June 2014

This study proposes a new method of SPICE modelling of fluxgate sensor that considers the geometry of the fluxgate. The main advantage of the method, vis‐a‐vis the traditional model using demagnetisation factor, is that the inhomogeneity of the magnetisation is taken into consideration. The parameters including magnetic performance of core, the geometry of the fluxgate can be regulated easily. The proposed method was tested for a rod shape core fluxgate, showing a good agreement with experiment results.
Fetal heart beat detection by Hilbert transform and non‐linear state‐space projections
Authors: Wei Zheng , Xueyun Wei , Jian Jian Zhong , Hongxing Liu
Published: June 2014

This study describes an integrated approach for fetal heart beat detection from abdominal ECG signals. The signal is first processed by the first‐order difference operation, and then, the envelope of the differentiated signal is given by the Hilbert transform, which indicates both the maternal and fetal heart beats. After that, the non‐linear state‐space projections is applied to the envelope signal to remove the maternal heart beats, obtaining the fetal heart beats envelope. The validity and performance of the described method are confirmed through experiments on real ECG data. A comparison with the well‐known independent component analysis method has also been presented.
Discrimination of internal fault from magnetising inrush current in power transformers based on sine‐wave least‐squares curve fitting method
Authors: Ahmadi Mohammad , Samet Haidar , Ghanbari Teymoor
Published: June 2014

This study deals with a method for discrimination between magnetising inrush and internal fault currents in three‐phase transformers based on sine‐wave curve fitting. A sine wave is fitted to the normalised differential current by using the least‐squares technique for each phase. The difference between the normalised differential currents and the fitted signals are calculated, which are hereafter named residual signals (RSs). Maximum range of the RSs variations is utilised for the definition of a simple criterion. Based on this criterion, the discrimination is realised within less than a half cycle of power frequency. In order to eliminate the impact of the current transformer (CT) saturation on the performance of the proposed technique, the currents are compensated by a CT saturation compensation algorithm in the first step. The proposed method is evaluated and compared with some well‐known methods by a large number of simulation and experimental data. Furthermore, the proposed algorithm is evaluated in the case of a transformer, which is fed through a feeder with series capacitors. The results confirm that reliability, accuracy and speed response of the proposed technique is more than the other methods.
Electronic correlation without double counting via a combination of spin projected Hartree-Fock and density functional theories
Authors: Garza Alejandro J. , Jiménez-Hoyos Carlos A. , Scuseria Gustavo E.
Published: June 2014

Several schemes to avoid the double counting of correlations in methods that merge multireference wavefunctions with density functional theory (DFT) are studied and here adapted to a combination of spin-projected Hartree-Fock (SUHF) and DFT. The advantages and limitations of the new method, denoted SUHF+fcDFT, are explored through calculations on benchmark sets in which the accounting of correlations is challenging for pure SUHF or DFT. It is shown that SUHF+fcDFT can greatly improve the description of certain molecular properties (e.g., singlet-triplet energy gaps) which are not improved by simple addition of DFT dynamical correlation to SUHF. However, SUHF+fcDFT is also shown to have difficulties dissociating certain types of bonds and describing highly charged ions with static correlation. Possible improvements to the current SUHF+fcDFT scheme are discussed in light of these results.
A stochastic reorganizational bath model for electronic energy transfer
Authors: Fujita Takatoshi , Huh Joonsuk , Aspuru-Guzik Alán
Published: June 2014

Environmentally induced fluctuations of the optical gap play a crucial role in electronic energy transfer dynamics. One of the simplest approaches to incorporate such fluctuations in energy transfer dynamics is the well known Haken-Strobl-Reineker (HSR) model, in which the energy-gap fluctuation is approximated as white noise. Recently, several groups have employed molecular dynamics simulations and excited-state calculations in conjunction to account for excitation energies’ thermal fluctuations. On the other hand, since the original work of HSR, many groups have employed stochastic models to simulate the same transfer dynamics. Here, we discuss a rigorous connection between the stochastic and the atomistic bath models. If the phonon bath is treated classically, time evolution of the exciton-phonon system can be described by Ehrenfest dynamics. To establish the relationship between the stochastic and atomistic bath models, we employ a projection operator technique to derive the generalized Langevin equations for the energy-gap fluctuations. The stochastic bath model can be obtained as an approximation of the atomistic Ehrenfest equations via the generalized Langevin approach. Based on this connection, we propose a novel scheme to take account of reorganization effects within the framework of stochastic models. The proposed scheme provides a better description of the population dynamics especially in the regime of strong exciton-phonon coupling. Finally, we discuss the effect of the bath reorganization in the absorption and fluorescence spectra of ideal J-aggregates in terms of the Stokes shifts. We find a simple expression that relates the reorganization contribution to the Stokes shifts – the reorganization shift – to the ideal or non-ideal exciton delocalization in a J-aggregate. The reorganization shift can be described by three parameters: the monomer reorganization energy, the relaxation time of the optical gap, and the exciton delocalization length. This simple relationship allows one to understand the physical origin of the Stokes shifts in molecular aggregates.
A high frequency resonance gravity gradiometer
Authors: Bagaev S. N. , Bezrukov L. B. , Kvashnin N. L. , Krysanov V. A. , Oreshkin S. I. , Motylev A. M. , Popov S. M. , Rudenko V. N. , Samoilenko A. A. , Skvortsov M. N. , Yudin I. S.
Published: June 2014

A new setup OGRAN—the large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare events—gravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS.
Origin of yielding in metallic glass: Stress-induced flow
Authors: Liu Z. Y. , Chen M. W. , Liu C. T. , Yang Y.
Published: June 2014

Yielding in crystalline metals is well known to be governed by dislocation dynamics; however, the structural origin of yielding in metallic glasses (MGs) still remains as an issue of intense debate despite that substantial research efforts have been expended. In this Letter, based on well-designed cyclic microcompression tests, we provide compelling experimental evidence revealing that yielding of MGs is essentially a stress-induced viscous flow process, during which the measured viscosity ranges from 1014 Pa·s to 1011 Pa·s and decreases with the increase of applied stress, resembling the “shear-thinning” behavior of non-Newtonian liquids. This stress-induced non-Newtonian flow finally leads to shear instability, which manifests itself as the phenomenon of delayed yielding common to a variety of MGs.
Thermography pattern analysis and separation
Authors: Gao Bin , Bai Libing , Woo W. L. , Tian Guiyun
Published: June 2014

Analysis of thermography spatial-transient patterns has considerable potential to enable automatic identification and quantification of defects in non-destructive testing and evaluation. This Letter proposes a non-negative pattern separation model for eddy current pulsed thermography to automatically extract important spatial and time patterns according to the transient thermal sequences without any pre-training or prior knowledge. In particular, the method is scale-invariant, such that large differences in surface emissivity, hot spots, and cool areas with dynamic range of thermal contrast can be extracted. Finally, an artificial slot in a steel sample with shining, black strip on the surface is tested to validate the proposed method.
Employing time-resolved terahertz spectroscopy to analyze carrier dynamics in thin-film Cu2ZnSn(S,Se)4 absorber layers
Authors: Guglietta Glenn W. , Choudhury Kaushik Roy , Caspar Jonathan V. , Baxter Jason B.
Published: June 2014

We report the application of time-resolved terahertz spectroscopy (TRTS) to measure photoexcited carrier lifetimes and mobility, and to determine recombination mechanisms in Cu2ZnSn(S,Se)4 (CZTSSe) thin films fabricated from nanocrystal inks. Ultrafast time resolution permits tracking the evolution of carrier density to determine recombination rates and mechanisms. The carrier generation profile was manipulated by varying the photoexcitation wavelength and fluence to distinguish between surface, Shockley-Read-Hall (SRH), radiative, and Auger recombination mechanisms and determine rate constants. Surface and SRH recombination are the dominant mechanisms for the air/CZTSSe/SiO2/Si film stack. Diffusion to, and then recombination at, the air-CZTSSe interface occurred on the order of 100 picoseconds, while SRH recombination lifetimes were 1–2 nanoseconds. TRTS measurements can provide information that is complementary to conventional time-resolved photoluminescence measurements and can direct the design of efficient thin film photovoltaics.
Traps signature in steady state current-voltage characteristics of organic diode
Authors: Rizvi S. M. H. , Mantri P. , Mazhari B.
Published: June 2014

Traps cause distortion in current-voltage (I−V) characteristics of an organic diode due to their voltage dependent occupancy. The present work describes a technique that uses the change in slope of I−V characteristics due to increased filling of traps to create a sharply defined peak that allows ready visualization of presence of traps even when their direct impact on I−V is not clearly evident. It is also shown that the signatures of exponential and single/Gaussian traps are significantly different thereby allowing them to be easily differentiated. Simulation and experimental results with P3HT and P3HT:PCBM diodes are presented that highlight the usefulness of the proposed technique.
X-ray diffraction on the X-cut of a Ca3TaGa3Si2O14 single crystal modulated by a surface acoustic wave
Authors: Irzhak D. , Roshchupkin D.
Published: June 2014

The result of X-ray diffraction study on a single crystal of the calcium-gallogermanate family Ca3TaGa3Si2O14 (CTGS) modulated by a surface acoustic wave (SAW) is presented. The power flow angle for SAW propagating along the X2 axis of the X-cut in CTGS was measured. The rocking curves for the CTGS crystal were recorded at different amplitudes of an input high frequency electric signal on interdigital transducer used to excite a SAW. Based on the data obtained, intensity dependence of diffraction satellites on the amplitude of electric signal exciting a SAW was built. Numerical simulation of the crystal rocking curves and dependence of diffraction satellite intensities on the SAW amplitude enabled the selection of a set of material constants at which the most complete coincidence of experimental and calculated results is observed.
Low temperature sensitive intensity-interrogated magnetic field sensor based on modal interference in thin-core fiber and magnetic fluid
Authors: Wu Jixuan , Miao Yinping , Song Binbin , Lin Wei , Zhang Hao , Zhang Kailiang , Liu Bo , Yao Jianquan
Published: June 2014

A fiber-optic magnetic field sensor based on the thin-core modal interference and magnetic fluid (MF) has been proposed and experimentally demonstrated. The magnetic field sensor is spliced with a thin-core fiber (TCF) between two conventional single-mode fibers immersed into the MF. The transmission spectra of the proposed sensor under different magnetic field intensities have been measured and theoretically analyzed. The results show that the magnetic field sensitivity reaches up to −0.058 dB/Oe with the linear range from 75 Oe to 300 Oe. Due to the small thermal expansion of the TCF material, the attenuation wavelength and the transmission power remain almost unchanged as the temperature varies. The proposed magnetic field sensor has several advantages such as intensity-interrogation, low temperature sensitivity, low cost, compact size, and ease of fabrication. And particularly, the temperature cross-sensitivity could be effectively resolved, which makes it a promising candidate for strict temperature environments. Therefore, it would find potential applications in the magnetic field measurement.
High quality semipolar (11¯02) AlGaN/AlN quantum wells with remarkably enhanced optical transition probabilities
Authors: Ichikawa S. , Iwata Y. , Funato M. , Nagata S. , Kawakami Y.
Published: June 2014

Adjusting the growth conditions from those for c-plane growth realizes high-quality semipolar (11¯02) AlGaN/AlN quantum wells (QWs) with atomically smooth surfaces and abrupt interfaces on AlN substrates. Upon comparing the optical properties to those of c-plane QWs using time-integrated and time-resolved photoluminescence spectroscopy, the estimated internal electric field is much smaller in (11¯02) AlGaN/AlN QWs than in c-plane QWs. Thus, (11¯02) AlGaN/AlN QWs have narrower emission line widths and remarkably faster radiative recombination lifetimes, realizing highly efficient deep ultraviolet emissions.
Dependence of effective internal field of congruent lithium niobate on its domain configuration and stability
Authors: Das Ranjit , Ghosh Souvik , Chakraborty Rajib
Published: June 2014

Congruent lithium niobate is characterized by its internal field, which arises due to defect clusters within the crystal. Here, it is shown experimentally that this internal field is a function of the molecular configuration in a particular domain and also on the stability of that particular configuration. The measurements of internal field are done using interferometric technique, while the variation of domain configuration is brought about by room temperature high voltage electric field poling.
Early results of microwave transmission experiments through an overly dense rectangular plasma sheet with microparticle injection
Authors: Gillman Eric D. , Amatucci W. E.
Published: June 2014

These experiments utilize a linear hollow cathode to create a dense, rectangular plasma sheet to simulate the plasma layer surrounding vehicles traveling at hypersonic velocities within the Earth's atmosphere. Injection of fine dielectric microparticles significantly reduces the electron density and therefore lowers the electron plasma frequency by binding a significant portion of the bulk free electrons to the relatively massive microparticles. Measurements show that microwave transmission through this previously overly dense, impenetrable plasma layer increases with the injection of alumina microparticles approximately 60 μm in diameter. This method of electron depletion is a potential means of mitigating the radio communications blackout experienced by hypersonic vehicles.
Ambipolar and non-ambipolar diffusion in an rf plasma source containing a magnetic filter
Authors: Lafleur T. , Aanesland A.
Published: June 2014

By placing a magnetic filter across a rectangular plasma source (closed at one end with a ceramic plate and an rf antenna, and terminated at the opposite end by a grounded grid), we experimentally investigate the effect of conducting and insulating source walls on the nature of the plasma diffusion phenomena. The use of a magnetic filter creates a unique plasma, characterized by a high upstream electron temperature (Teu∼5 eV) near the rf antenna and a low downstream electron temperature (Ted∼1 eV) near the grid, which more clearly demonstrates the role of the source wall materials. For conducting walls a net ion current to ground is measured on the grid, and the plasma potential is determined by a mean electron temperature within the source. For insulating walls the plasma potential is determined by the downstream electron temperature (i.e., Vp∼5.2Ted in argon), and the net current to the grid is exactly zero. Furthermore, by inserting a small additional upstream conductor (that can be made floating or grounded through an external circuit switch), we demonstrate that the plasma potential can be controlled and set to a low (Vp∼5.2Ted), or high (Vp∼5.2Teu) value.
Effect of inserted Si p-n junction on GaN-based photo-electrochemical CO2 conversion system
Authors: Yotsuhashi Satoshi , Deguchi Masahiro , Yamada Yuka , Ohkawa Kazuhiro
Published: June 2014

We report on significantly improved GaN-based photo-electrochemical CO2 reduction system by inserting Si p-n junction. The device is introduced so as to raise the cathode potential which changes the reaction products qualitatively. It is discussed that the balance between cathode and anode reactions is essential to take the advantage of introduced device. We succeed in stoichiometric evaluation of oxygen evolution on the surface of GaN photo-electrode. When the reaction condition is optimized, we can realize the raised cathode potential, in which the chief reaction product of CO2 reduction changes from formic acid to hydrocarbons, such as methane (CH4) and ethylene (C2H4).
Nucleation of silicon nanocrystals in a remote plasma without subsequent coagulation
Authors: Doğan İlker , Weeks Stephen L. , Agarwal Sumit , van de Sanden Mauritius C. M.
Published: June 2014

We report on the growth mechanism of spherical silicon nanocrystals in a remote expanding Ar plasma using a time-modulated SiH4 gas injection in the microsecond time range. Under identical time-modulation parameters, we varied the local density of the SiH4 gas by changing its stagnation pressure on the injection line over the range of 0.1–2.0 bar. We observed that nanocrystals were synthesized in a size range from ∼2 to ∼50 nm with monocrystalline morphology. Smaller nanocrystals (∼2–6 nm) with narrower size distributions and with higher number densities were synthesized with an increase of the SiH4 gas-phase density. We related this observation to the rapid depletion of the number density of the molecules, ions, and radicals in the plasma during nanocrystal growth, which can primarily occur via nucleation with no significant subsequent coagulation. In addition, in our remote plasma environment, rapid cooling of the gas in the particle growth zone from ∼1500 to ∼400 K significantly reduces the coalescence rate of the nanoparticles, which makes the coagulation process highly unlikely. Our observations on nanocrystal formation via nucleation indicated that subsequent coagulation for further growth is not always an essential step on nanoparticle formation.
Acacia holosericea (Fabaceae) litter has allelopathic and physical effects on mission grass (Cenchrus pedicellatus and C. polystachios) (Poaceae) seedling establishment
Authors: Quddus Muhammad S. , Bellairs Sean M. , Wurm Penelope A. S.
Published: June 2014

Invasion of grass weeds is a major threat for ecosystems. Mission grass (Cenchrus pedicellatus and C. polystachios) vigorously competes with native vegetation and has become a serious problem in northern Australian savanna. A lower density of mission grass has been observed under the canopy of stands of native Acacia holosericea. We used a series of laboratory and shade house experiments to assess the potential for allelopathy and the role of litter on germination, emergence and seedling growth of these two species of mission grass. Different concentrations of aqueous leaf extract of A. holosericea were used to assess allelopathic effects on germination. Various depths and types of litter were used to investigate the allelopathic and physical effects of litter on emergence and growth of mission grass seedlings in the shade house. Results indicate that extracts did not affect germination of either species of mission grass but root growth of seedlings was affected. Emergence of seedlings in the shade house was affected by physical litter treatments but not by allelopathy. After emergence no negative effects on seedling growth were detected. Overall we found that there was no allelopathic effect on germination and that the negative effect on emergence was due to the physical properties of the litter. This effect on emergence increased with increasing depth of litter. Allelopathy slightly inhibited root growth but once seedlings emerged, litter tended to facilitate growth. This has implications for the ecological management of mission grass on disturbed lands, using strategies such as manipulation of litter cover through Acacia establishment.
Trichloroisocyanuric Acid/Triphenylphosphine-Mediated Synthesis of Benzimidazoles, Benzoxazoles, and Benzothiazoles
Authors: Rezazadeh Soodabeh , Akhlaghinia Batool , Razavi Nasrin
Published: June 2014

A new and efficient method for preparation of benzimidazoles, benzoxazoles, and benzothiazoles from reactions of different carboxylic acids with o-phenylenediamine, o-aminophenol, and o-aminothiophenol in the presence of triphenylphosphine/trichloroisocyanuric acid system is presented. The desired products have been characterised on the basis of spectral (infrared, NMR, mass spectrometry) data, and the mechanism of their formation is proposed. The remarkable advantages are the inexpensive and readily available reagent, simple procedure, mild conditions, and good-to-excellent yields.
Microwave-Assisted Synthesis of Ruthenium(II) Complexes with Trimethylsilylacetylene as Inhibitors against the Migration of Breast Cancer Cells
Authors: Zhang Zhao , Wang Ya-Jun , Wu Qiong , Wu Xiao-Hui , Sun Fu-Qiang , Wang Bao-Guo , Mei Wen-Jie , Chen Si-Dong
Published: June 2014

In the present study, two novel chiral ruthenium(ii) complexes with trimethylsilylacetylene (TMSA), Λ- and Δ-[Ru(bpy)2(p-TEPIP)](ClO4)2 (bpy = 2,2-bipyridine; p-TEPIP = 5-(2-(p-trimethylsilyl propargyl)-1H-imidazo[4,5-f][1,10] phenanthroline) (Λ-1 and Δ-1) were prepared using Sonogashira coupling reaction under microwave irradiation. We found that both Λ-1 and Δ-1 could inhibit the growth of highly metastatic human breast cancer cells (MDA-MB-231) with half-maximal inhibitory concentration (IC50) of 32.1 and 36.9 µM, respectively. Wound healing assay demonstrated that both isomers inhibited the migration of MDA-MB-231 cells. Both Λ-1 and Δ-1 compounds were found throughout the cell and were particularly enriched in the nucleus. Furthermore, we observed fragmentation of the nucleus leading to apoptosis. To conclude, it is clear that this type of chiral ruthenium(ii) complex with TMSA can induce apoptosis and thus inhibit the growth and migration of tumour cells.