bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical, photophysical and biological investigations of an organic charge transfer compound 2-aminobenzimidazolium-2-oxyisoindolate-1,3-dione-2-hydroxyisoindoline-1,3-dione
Authors: Mahendiran D. , Vinitha G. , Shobana S. , Viswanathan V. , Velmurugan D. , Rahiman A. Kalilur
Published: June 2016

The synthesized charge transfer compound exhibits excellent non-linear optical and biological properties.
Exploring the interaction of l-cysteine capped CuS nanoparticles with bovine serum albumin (BSA): a spectroscopic study
Authors: Prasanth S. , Rithesh Raj D. , Vineeshkumar T. V. , Thomas Riju K. , Sudarsanakumar C.
Published: June 2016

l-Cysteine capped copper sulfide nanoparticles with an average particle size of 6 nm were synthesized using a chemical co-precipitation method and their interactions with bovine serum albumin were explored using various spectroscopic techniques.
Self-assembly Z-scheme heterostructured photocatalyst of Ag2O@Ag-modified bismuth vanadate for efficient photocatalytic degradation of single and dual organic pollutants under visible light irradiation
Authors: Yang Qi , Chen Fei , Li Xiaoming , Wang Dongbo , Zhong Yu , Zeng Guangming
Published: June 2016

Simple synthesis, high photocatalytic activities, preferable photoelectric properties and a promising application in wastewater treatment.
CO2-in-PEG emulsion-templating synthesis of poly(acrylamide) with controllable porosity and their use as efficient catalyst supports
Authors: Xue Zhimin , Chang Weihong , Cheng Yan , Liu Jing , Li Jian , Zhao Wancheng , Mu Tiancheng
Published: June 2016

Porous poly(acrylamide)s nanoparticles prepared from CO2-in-PEG emulsions have high catalytic activity for benzene hydrogenation reaction.
Synthesis, crystal structure, DFT/TDDFT calculation, photophysical properties and DNA binding studies of morpholino moiety ligand based two Cu(ii) complexes in combination with carboxylates
Authors: Paul Aparup , Mistri Soumen , Bhunia Apurba , Manna Soumen , Puschmann Horst , Chandra Manna Subal
Published: June 2016

Two Cu(II) compounds have been characterized by structure analyses and DFT/TD-DFT calculations. Both the complexes potentially bind with CT-DNA and corresponding binding constants are in the order of 105 M−1.
Direct electrochemistry of cholesterol oxidase and biosensing of cholesterol based on PSS/polymeric ionic liquid–graphene nanocomposite
Authors: Wu Shuyao , Wang Yuxiang , Mao Hui , Wang Chong , Xia Lixin , Zhang Yu , Ge Hao , Song Xi-Ming
Published: June 2016

In this work, a new biosensor based on PSS/polymeric ionic liquids–graphene nanocomposite with excellent conductivity, favourable biocompatibility and good film-forming properties was constructed to detect cholesterol.
Protective effect of polysaccharides fractions from Sijunzi decoction in reserpine-induced spleen deficiency rats
Authors: Wang Ruijun , Peng Ying , Meng Hong , Li Xiaobo
Published: June 2016

Polysaccharide fraction S-3 from SJZD could mitigate effect in the reserpine-induced rats which was investigated with a comprehensive screening strategy.
New insights on energetic analysis of water adsorption isotherms of the Pelargonium graveolens: modeling, interpretations and pore sizes distribution based on statistical physics approach
Authors: Aouaini Fatma , Knani Salah , Ben Yahia Manel , Bahloul Neila , Ben Lamine Abdelmottaleb , Kechaou Nabil
Published: June 2016

The adsorption isotherm of the Pelargonium graveolens leaves simulated by the "the infinity multilayer model".
A new strategy for hydrogen storage using BNNS: simultaneous effects of doping and charge modulation
Authors: Seif Abdolvahab , Azizi Khaled
Published: June 2016

The adsorption behavior of hydrogen molecule (H2) on neutral and charged states of C-, Si- and P-doped boron nitride nanosheets (BNNSs), is investigated using density functional theory (DFT) method.
Experimental study and molecular dynamics simulation of dynamic properties and interfacial bonding characteristics of graphene/solution-polymerized styrene-butadiene rubber composites
Authors: Luo Yanlong , Wang Runguo , Zhao Suhe , Chen Yiyi , Su Huifang , Zhang Liqun , Chan Tung W. , Wu Sizhu
Published: June 2016

The effect of the vinyl content on microstructure, thermodynamics and dynamics properties of graphene/SSBR composites was investigated. SSBR with the highest vinyl content has the highest interfacial shear stress by pullout simulation.
Multi-stacked electrodes employing aluminum coated tissue papers and non-oxidized graphene nanoflakes for high performance lithium–sulfur batteries
Authors: Choi Jin-Hoon , Jung Ji-Won , Jung Su-Ho , Choi Chan Yong , Ryu Won-Hee , Jo Sung-Moo , Lim Dae-Soon , Jeon Seokwoo , Lee Hye-Moon , Kim Il-Doo
Published: June 2016

Here, we report a simple approach to Li/S battery cell modification by introducing multi-stacked reactivation layers of 1st-graphene flakes/2nd-Al coated tissue paper (GNFs/Al-coated Kimwipes) between a separator and a sulfur cathode.
A highly active bimetallic oxide catalyst supported on γ-Al2O3/TiO2 for catalytic wet peroxide oxidation of quinoline solutions under microwave irradiation
Authors: Zhang Bo , You Hong , Yang Zhongzhe , Wang Fei
Published: June 2016

A new heterogeneous wet oxidation catalyst, Cu–Ni bimetallic oxides supported on γ-Al2O3/TiO2, was synthesized using a wet impregnation method
Superior electrocatalytic activity of ultrathin PtPdBi nanowires towards ethanol electrooxidation
Authors: Zhang Xiao-Ting , Zhou Lin-Nan , Shen Yan-Yan , Liu Hong-Tao , Li Yong-Jun
Published: June 2016

Ultrathin PtxPd93−xBi7 alloy nanowires were synthesized by one-pot wet-chemical method. Optimized Pt55Pd38Bi7 exhibits superior electrocatalytic activity and long-term durability towards ethanol oxidation.
Tuneable cellular-structured 3D graphene aerogel and its effect on electromagnetic interference shielding performance and mechanical properties of epoxy composites
Authors: Wan Yan-Jun , Yu Shu-Hui , Yang Wen-Hu , Zhu Peng-Li , Sun Rong , Wong Ching-Ping , Liao Wei-Hsin
Published: June 2016

Controllable 3D graphene aerogel–epoxy composites (GA–EP) were fabricated. The pore size and morphology of GA were tuned using varied graphene oxide (GO) size and the macroproperties of GA–EP can be tailored by changing the size of GO sheets.
Heterogeneous photooxidation of sulfur dioxide in the presence of airborne mineral dust particles
Authors: Park J. Y. , Jang M.
Published: June 2016

Heterogeneous photocatalytic oxidation of SO2on the surface of Arizona dust particles was investigated in the absence and the presence of NOxand O3under varying humidity using a 2-m3indoor photoirradiation chamber.
Fabrication and photocatalytic performances of BiOCl nanosheets modified with ultrafine Bi2O3 nanocrystals
Authors: Zhang Xu , Xu Guangqing , Hu Jiajia , Lv Jun , Wang Jianmin , Wu Yucheng
Published: June 2016

Well-distributed Bi2O3 nanocrystals were deposited on BiOCl nanosheets for enhancing the photocatalytic performance.
Self-assembly of fluorescent diimidazolium salts: tailor properties of the aggregates changing alkyl chain features
Authors: Billeci Floriana , D'Anna Francesca , Marullo Salvatore , Noto Renato
Published: June 2016

Self assembly of fluorescent diimidazolium NDI salts showed properties of aggregates changing with alkyl chain length, with an odd–even effect.
One-pot synthesis of carbon dot-entrenched chitosan-modified magnetic nanoparticles for fluorescence-based Cu2+ ion sensing and cell imaging
Authors: Kumar Amit , Chowdhuri Angshuman Ray , Laha Dipranjan , Chandra Soumen , Karmakar Parimal , Sahu Sumanta Kumar
Published: June 2016

In this work, a new synthetic approach is developed for the synthesis of fluorescent magnetic nanoparticles which are explored for the detection of mostly abundant transition metal Cu2+ ions and cell imaging.
Straightforward synthesis of diverse dipyrazolylmethane derivatives and their application for fluorescence sensing of Cu2+ ions
Authors: Kaliraj Kaliappan , Xia Likai , Edison Thomas Nesakumar Jebakumar Immanuel , Lee Yong Rok
Published: June 2016

Various dipyrazolylmethanes were synthesized and nitro-substituted compound displayed an excellent turn-off fluorescence sensing property for the detection of Cu2+ ions.
Effective charge separation and enhanced photocatalytic activity by the heterointerface in MoS2/reduced graphene oxide composites
Authors: Zhang Long , Sun Lan , Liu Shuai , Huang Yuhong , Xu Kewei , Ma Fei
Published: June 2016

The MoS2/rGO exhibits enhanced photocatalytic activity for degradation of RhB due to effective separation of photo-generated electron–hole pairs by heterointerface.
Monitoring the nanostructure of a hydrogenated fullerene-like film by pulse bias duty cycle
Authors: Liu Guangqiao , Zhou Yan , Zhang Bin , Gao Kaixiong , Qiang Li , Zhang Junyan
Published: June 2016

The fullerene-like (FL) nanostructure is extremely important for hydrogenated carbon films that exhibit excellent mechanical properties and ultralow friction in ambient air, but the details of the contributing nanostructures are not well understood.
Three dimensional iron oxide/graphene aerogel hybrids as all-solid-state flexible supercapacitor electrodes
Authors: Khattak Abdul Muqsit , Yin Huajie , Ghazi Zahid Ali , Liang Bin , Iqbal Azhar , Khan Niaz Ali , Gao Yan , Li Lianshan , Tang Zhiyong
Published: June 2016

Three dimensional iron oxide/graphene aerogel hybrid (Fe2O3/GA) was synthesized and used as electrode materials in flexible supercapacitor devices, which show high specific capacitance of 440 F g−1 with 89% capacitance retention after 2200 cycles.
Regularities of deep deoxidization of molten ionic chlorides in reactive gas atmosphere
Authors: Cherginets V. L. , Rebrova T. P. , Naumenko V. A. , Rebrov A. L. , Yurchenko O. I.
Published: June 2016

The process of the removal of oxide ion admixtures by the action of CCl4 vapor (carbochlorination) from chloride melts of KCl–NaCl (0.5 : 0.5), BaCl2–KCl (0.26 : 0.74) and KCl–LiCl (0.41 : 0.59) was studied by a potentiometric method.
Band gap energies for white nanosheets/yellow nanoislands/purple nanorods of CeO2
Authors: Zhou Guangdong , Yao Yanqing , Zhao Xusheng , Liu Xiaoqing , Sun Bai , Zhou Ankun
Published: June 2016

The photon band gap energies and spin–orbit coupling states of white nanosheets, purple nanorods and yellow nanoislands of CeO2.
Design of magnesium phosphate cement based composite for high performance bipolar plate of fuel cells
Authors: Hao Wenbin , Ma Hongyan , Lu Zeyu , Sun Guoxing , Li Zongjin
Published: June 2016

A magnesia phosphate cement based composite was designed and produced as the construction material of bipolar plate for PEM fuel cells. The optimized formula of the composite was [M/P = 8, W/C = 0.25, G 40%, CF 1%, MW-CNTs 2%, FA replacement 40%].
Synthesis of α,β-unsaturated ketones from alkynes and aldehydes over Hβ zeolite under solvent-free conditions
Authors: Mameda Naresh , Peraka Swamy , Kodumuri Srujana , Chevella Durgaiah , Banothu Rammurthy , Amrutham Vasu , Nama Narender
Published: June 2016

A facile Hβ zeolite-catalyzed approach has been developed for the synthesis of α,β-unsaturated ketones from alkynes and aldehydes under solvent-free conditions.
Regioselective Heck reaction catalyzed by Pd nanoparticles immobilized on DNA-modified MWCNTs
Authors: Hajipour Abdol R. , Khorsandi Zahra , Farrokhpour Hossein
Published: June 2016

This is the first report of regioselective Heck reaction of aryl iodides with 2,3-dihydrofuran using heterogonous nanocatalyst.
Probing the structural and magnetic properties of a new family of centrosymmetric dinuclear lanthanide complexes
Authors: Jiang Y. , Holmberg R. J. , Habib F. , Ungur L. , Korobkov I. , Chibotaru L. F. , Murugesu M.
Published: June 2016

A series of centrosymmetric dinuclear lanthanide complexes, including GdIII(1), Dy​III(2), Ho​III(3), Er​III(4) and YbIII(5), have been synthesized and studied for the effects of lanthanide contraction on their magnetic properties.
The effect of charge alteration and flexibility on the function and structural stability of sweet-tasting brazzein
Authors: Jafari S. Shahrbanoo , Jafarian Vahab , Khalifeh Khosrow , Ghanavatian Parisa , Shirdel S. Akram
Published: June 2016

To identify the structural and functional roles of Glu9 located at the first loop of sweet-tasting brazzein, two different mutants (E9K and E9G) of the minor form of brazzein were designed and constructed.
Embedding electron-deficient nitrogen atoms in polymer backbone towards high performance n-type polymer field-effect transistors
Authors: Dai Ya-Zhong , Ai Na , Lu Yang , Zheng Yu-Qing , Dou Jin-Hu , Shi Ke , Lei Ting , Wang Jie-Yu , Pei Jian
Published: June 2016

The low LUMO level and the conformation-locked planar backbone provide polymer AzaBDOPV-2T with electron mobilities over 3.22 cm2 V−1 s−1 tested in air.
Directed peptide amphiphile assembly using aqueous liquid crystal templates in magnetic fields
Authors: van der Asdonk Pim , Keshavarz Masoumeh , Christianen Peter C. M. , Kouwer Paul H. J.
Published: June 2016

Controlling structure formation of functional supramolecular materials by using aqueous liquid crystalline templates in magnetic fields.
Sunlight driven self-healing, reshaping and recycling of a robust, transparent and yellowing-resistant polymer
Authors: Xu Wei Min , Rong Min Zhi , Zhang Ming Qiu
Published: June 2016

Repeated self-healing, reshaping and recycling of a transparent crosslinked polyurethane are enabled by a sunlight triggered reversible disulfide exchange reaction.
Titanium dioxide nanotrees for high-capacity lithium-ion microbatteries
Authors: Wen Wei , Wu Jin-Ming , Jiang Yin-Zhu , Bai Jun-Qiang , Lai Lu-Lu
Published: June 2016

TiO2nanotrees with an optimal phase structure, high surface area and structural hierarchy are fabricated by a facile synthetic strategy to achieve high performance Li-ion microbatteries.
A multifunctional nanoplatform for lysosome targeted delivery of nitric oxide and photothermal therapy under 808 nm near-infrared light
Authors: Xiang Hui-Jing , Guo Min , An Lu , Yang Shi-Ping , Zhang Qian-Ling , Liu Jin-Gang
Published: June 2016

NIR light induced spatiotemporal delivery of NO to lysosome accompanied by hyperthermia was realized.
UV-assisted synthesis of long-wavelength Si-pyronine fluorescent dyes for real-time and dynamic imaging of glutathione fluctuation in living cells
Authors: Nie Hailiang , Qiao Liang , Yang Wen , Guo Bingpeng , Xin Fangyun , Jing Jing , Zhang Xiaoling
Published: June 2016

Long-wavelength Si-pyronine fluorescent dyes are synthesized for reversible, real-time and dynamic imaging of glutathione fluctuation in living cells.
A dual-fluorescent nano-carrier for delivering photoactive ruthenium polypyridyl complexes
Authors: Shi Hongdong , Fang Tiantian , Tian Yao , Huang Hai , Liu Yangzhong
Published: June 2016

A photo-responsive diagnostic conjugate was generated by loading a photoactive polypyridyl ruthenium complex onto a dual-fluorescent nanocarrier, resulting in photo-induced cytotoxicity.
A lysosome-targeted and ratiometric fluorescent probe for imaging exogenous and endogenous hypochlorous acid in living cells
Authors: Ren Mingguang , Deng Beibei , Zhou Kai , Kong Xiuqi , Wang Jian-Yong , Xu Gaoping , Lin Weiying
Published: June 2016

We have developed the first small-molecule based, lysosomal-targeted ratiometric fluorescent HClO probe (Lyso-HA). Fluorescence imaging shows that it is suitable for ratiometric visualization of exogenous and endogenous HClO at lysosomes in living cells.
High performance Cu/Cu2O nanohybrid electrocatalyst for nonenzymatic glucose detection
Authors: Cheng Xiqing , Zhang Jun , Chang Hucheng , Luo Liqiang , Nie Fuqiang , Feng Xinjian
Published: June 2016

Described herein are Cu/Cu2O nanohybrids preparedviapotential oscillation, and their high performance for nonenzymatic glucose detection applications.
Agglutination of bacteria using polyvalent nanoparticles of aggregation-induced emissive thiophthalonitrile dyes
Authors: Schmidt Bettina , Sankaran Shrikrishnan , Stegemann Linda , Strassert Cristian A. , Jonkheijm Pascal , Voskuhl Jens
Published: June 2016

A novel class of aggregation-induced emissive bis(phenylthio)phthalonitrile dyes were synthesized.
Percolation threshold-inspired design of hierarchical multiscale hybrid architectures based on carbon nanotubes and silver nanoparticles for stretchable and printable electronics
Authors: Zhao Songfang , Li Jinhui , Cao Duxia , Gao Yongju , Huang Wangping , Zhang Guoping , Sun Rong , Wong Ching-Ping
Published: June 2016

Highly conductive, sensitive, stretchable, and fully printed hybrid composites are fabricated to detect sign language via strain-sensing behavior.
Deep red MGe4O9:Mn4+(M = Sr, Ba) phosphors: structure, luminescence properties and application in warm white light emitting diodes
Authors: Liang Sisi , Shang Mengmeng , Lian Hongzhou , Li Kai , Zhang Yang , Lin Jun
Published: June 2016

The structure, luminescence and practical application of Mn4+doped MGe4O9(M = Ba, Sr) non-rare earth phosphors are investigated.
A giant negative piezoresistance effect in 3C-SiC nanowires with B dopants
Authors: Li Xiaoxiao , Chen Shanliang , Ying Pengzhan , Gao Fengmei , Liu Qiao , Shang Minghui , Yang Weiyou
Published: June 2016

We reported the giant negative piezoresistance behaviors of B-doped 3C-SiC nanowires with a gauge factor up to −620.5.
Current Perspectives on Minimal and Mild Permanent Hearing Loss in Children
Authors: Tharpe Anne Marie
Published: June 2016

Over the last several decades, audiologists, speech-language pathologists (SLPs), and educators have learned a great deal about the impact of permanent minimal/ mild hearing loss (MMHL) on children. Once considered a problem that could be easily managed by preferential positioning of the listener relative to the talker of interest or, in the case of school-age children, preferential classroom seating, research has accumulated over the last several decades concluding that children with MMHL are at risk of significant educational and psychosocial challenges. Despite the term minimal, no longer is a MMHL viewed as being inconsequential. The following sections will describe our current knowledge about MMHL in children and what we have left to discover.
Highly accurate capacitor‐free LDO with sub‐1 V −120 dB PSRR bandgap voltage reference
Authors: Abbasizadeh H. , Hayder A.S. , Lee K.Y.
Published: June 2016

A low dropout (LDO) voltage regulator operated at 5 V power supply, along with a bandgap reference (BGR) voltage circuit with high power‐supply rejection ratio (PSRR) is introduced. In the suggested LDO circuit, a low‐pass filter for creating a common gate to transmit supply voltage to the power transistor gate is used. During deployment of the RC filter, an artificial resistor with a value of infinity is utilised, which in addition to reduce the chip occupied area, improves the performance of the low‐pass filter at frequencies close to DC, and thus improves the PSRR at these frequencies. In addition, the high PSRR of the circuit is mediated by a low‐voltage current mode regulator at the heart of the bandgap circuitry, which isolates the bandgap voltage from power supply variations and noise. The isolating current mirrors create an internal regulated voltage (Vreg) for BGR core and op‐amp rather than the VDD. These current mirrors reduce the impact of supply voltage variations. The circuit topology is discussed and simulation results are provided. The LDO is also stable without an output capacitor.
S‐shaped periodic defected ground structures to reduce microstrip antenna array mutual coupling
Authors: Wei Kun , Li Jianying , Wang Ling , Xing Zijian , Xu Rui
Published: June 2016

A novel S‐shaped periodic defected ground structure (PDGS) is proposed to reduce mutual coupling between antenna elements. Coplanar placed antenna elements work at the same frequency band with centre frequency 2.57 GHz. Centre‐to‐centre distance between the antenna elements is 50 mm which is ∼0.43λ. The PDGS is three S‐shaped defected ground structure units placed between microstrip antenna elements. By using the proposed PDGS, more than 40 dB mutual coupling reduction between microstrip antenna elements is achieved.
Compact dual‐band bandpass filters using complementary split‐ring resonators with closely spaced passbands
Authors: Liu Shuai , Xu Jun , Xu Zhi‐Tao
Published: June 2016

Two compact dual‐band bandpass filters based on open complementary split‐ring resonators (OCSRRs) with stub loaded are presented. Both of the stub‐loaded open‐loop resonators can achieve two resonant modes, and each of the resonators generate a passband. Thus, a small ratio of two passbands central frequencies can be obtained. Moreover, the two resonant modes of the outer ring are λ/4 resonators, so the OCSRR exhibits a compact size. Meanwhile, the characteristics of dual‐mode resonators can be discussed by using even‐/odd‐mode analysis. The proposed filters exhibit four transmission zeros, one or two of which can be introduced between the two passbands. To verify the theory, two filters with zeros of different locations are designed, fabricated and measured. The test results indicate good agreement with simulated ones.
Experimental verification of on‐chip CMOS fractional‐order capacitor emulators
Authors: Tsirimokou G. , Psychalinos C. , Elwakil A.S. , Salama K.N.
Published: June 2016

The experimental results from a fabricated integrated circuit of fractional‐order capacitor emulators are reported. The chip contains emulators of capacitors of orders 0.3, 0.4, 0.5, 0.6 and 0.7 with nano‐Farad pseudo‐capacitances that can be adjusted through a bias current. Two off‐chip capacitors are used to set the bandwidth of each emulator independently. The chip was designed in Austria microsystems (AMS) 0.35μ CMOS.
Point match refinement through rigidity constraint and vote
Authors: Liu Yonghuai , Zhao Yitian , Li Longzhuang , Han Jiwan
Published: June 2016

Feature extraction and matching has been widely used for the registration of overlapping partial shapes. However, the established tentative point matches (TPMs) usually include a large proportion of false ones due to a number of factors: imaging noise, occlusion, repetitive structures, and cluttered background. To apply the rigidity constraint to refine these TPMs in three main steps is proposed. First, a set of one‐to‐many point matches is established, then use them to vote against each other, and finally select such TPMs with the same surface type, the minimum error, and the most votes significantly more than the second most ones as the more reliable ones. A comparative study using real data captured by a Microsoft Kinect sensor shows that the refinement is successful.
Algorithm for energy‐efficiency optimisation in secure MIMO systems
Authors: Liu Jian , Hu Bing , Fang Lulu
Published: June 2016

In this study, the authors study energy‐efficiency (EE) optimisation of three‐node multiple‐input–multiple‐output wiretap channels. In particular, they aim to maximise EE by optimising the transmit covariance under the constraint of transmit power consumption. Such optimisation problems are non‐convex and difficult to solve. Here, they propose a novel optimisation algorithm, which is very different from previous approaches, with guaranteed convergence to the Karush–Kuhn–Tucker point. In particular, through a channel improvement argument and an intelligent bounding technique, they first obtain a min–max reformulation of their original problem. Then, based on the idea of alternative optimisation, they derive two sub‐problems from it. To solve these two problems, they used the efficient barrier Newton and the gradient projection methods. The outcome from this last step is a semi‐closed‐form solution for the two sub‐problems. The numerical results obtained from the proposed algorithm represent better performances than the existing methods.
Green two‐tiered wireless multimedia sensor systems: an energy, bandwidth, and quality optimisation framework
Authors: Vo Nguyen‐Son , Ha Dac‐Binh , Canberk Berk , Zhang Junqing
Published: June 2016

In wireless multimedia sensor systems (WMSSs), the devices are equipped with multiple energy‐constrained camera sensors (CSs) distributed over bandwidth‐constrained and lossy wireless channels, in catastrophe‐prone areas. Meanwhile, multimedia applications, e.g. video streaming, require considerable energy and bandwidth resources to gain long lifetime and high streaming quality. This study proposes an energy, bandwidth, and quality (EBQ) optimisation framework for green two‐tiered WMSSs. The first tier contains the CSs and the second tier includes cluster heads (CHs) selected from the CSs with higher available energy and processing capacity. In the EBQ optimisation framework, a rate allocation optimisation problem is formulated under given constraints of available backhaul bandwidth of the CHs and quality of received videos at base stations (BSs). This problem is solved for optimal encoding rates to packetise each video captured from different environments into multiple descriptions for transmission. Consequently, the average energy consumption per CS is minimised for long lifetime while conserving the bandwidth of the CHs and guaranteeing high quality of received videos for the purpose of monitoring at the BSs. Simulations demonstrate that the proposed EBQ optimisation framework can efficiently enhance the performance of green two‐tiered WMSSs in terms of minimum energy consumption, bandwidth efficiency, and high quality.
Passivity and passification for switching Markovian jump systems with time‐varying delay and generally uncertain transition rates
Authors: Qi Wenhai , Gao Xianwen , Kao Yonggui
Published: June 2016

This study deals with the problem of passivity and passification for switching Markovian jump systems with time‐varying delay and generally uncertain transition rates. The considered systems could be viewed as Markovian jump linear systems governed by a piecewise‐constant transition rate matrix, which is subject to a high level average dwell time switching. The time delay is considered as time‐varying and meets the requirements of the upper and lower bounds. The generally uncertain transition rates cover uncertain transition rates and partly known transition rates as two special cases. First, sufficient conditions, which guarantee the exponential mean‐square stability and stochastic passivity of the underlying systems, are presented by resorting to average dwell time approach. Second, the design of the stabilising controller is given further. Moreover, an improved controller design method, which could provide efficiency and practicability, is further developed. All the proposed conditions are given in the form of linear matrix inequalities. Finally, practical examples illustrate the validity of the obtained results.
Regional pole placement of wind turbine generator system via a Markovian approach
Authors: Lin Zhongwei , Liu Jizhen , Zhang Weihai , Niu Yuguang
Published: June 2016

The wind turbine generator system (WTGS) is usually linearised around operating points, and traditional control techniques concentrate on local dynamic response nearby each operating point. However, the actual wind speed is switching frequently between different operating points, which could cause a serious negative influence on the stability and dynamic response of WTGS. To overcome this disadvantage, this study proposes a systematic method to combine the switching rule into the control design to improve the dynamic response of the mechanical side of WTGS. Through modelling the WTGS driven by the switching wind speed into a class of linearised Markovian jump controlled systems, the regional pole placement technique is developed for such a class of systems and applied on improving the dynamic response of WTGS. Combined with the H∞ control, the proposed method can achieve better wind energy conversion efficiency and reduce the power volatility efficiently. Through combining the analysis on the actual historical wind speed into the control design, simulation results for a 2 MW wind turbine show the effectiveness of the proposed method.
Online fault compensation control based on policy iteration algorithm for a class of affine non‐linear systems with actuator failures
Authors: Zhao Bo , Liu Derong , Li Yuanchun
Published: June 2016

In this study, a novel online fault compensation control scheme based on policy iteration (PI) algorithm is developed for a class of affine non‐linear systems with actuator failures. The control scheme consists of a PI algorithm and a fault compensator. For fault‐free dynamic models, the PI algorithm is developed to solve the Hamilton–Jacobi–Bellman equation by constructing a critic neural network, and then the approximate optimal control policy can be derived directly. Alternatively, the actuator failure is reconstructed adaptively to achieve online fault compensation without the fault detection and isolation mechanism. The closed‐loop system is proved to be asymptotically stable via Lyapunov's direct method. Two numerical simulation examples are given to demonstrate the effectiveness of the proposed fault compensation control scheme.
Adaptive control of time‐varying uncertain non‐linear systems with input delay: a Hamiltonian approach
Authors: Sun Weiwei , Fu Baozeng
Published: June 2016

The adaptive control problem of a class of time‐varying non‐linear systems with uncertainties and input delay is addressed via a Hamiltonian approach in this study. The delay is assumed to be a constant and the uncertainties are small parametric perturbations. First, the non‐linear system is equivalently transformed into a Hamiltonian system form and the Casimir‐like function is proposed to help shaping the Hamiltonian as a candidate of Lyapunov function in the extended systems. Second, the adaptive control problem is investigated based on the time‐varying dissipative Hamiltonian system with input delay. The feedback controller is designed to guarantee the stability of the closed‐loop system for all admissible uncertainties, as well as constant delay. Sufficient conditions are presented to ensure the rationality of the proposed control law, which are derived based on Lyapunov function method. Stabilisation problem is also considered while there are no uncertain parameters in the delay non‐linear systems. Finally, several examples are presented to illustrate the effectiveness of the results obtained in this study.
Stability of two‐dimensional Roesser systems with time‐varying delays via novel 2D finite‐sum inequalities
Authors: Van Hien Le , Trinh Hieu
Published: June 2016

This study considers the problem of stability analysis of discrete‐time two‐dimensional (2D) Roesser systems with interval time‐varying delays. New 2D finite‐sum inequalities, which provide a tighter lower bound than the existing ones based on 2D Jensen‐type inequalities, are first developed. Based on an improved Lyapunov–Krasovskii functional, the newly derived inequalities are then utilised to establish delay‐range‐dependent linear matrix inequality‐based stability conditions for a class of discrete time‐delay 2D systems. The effectiveness of the obtained results is demonstrated by numerical examples.
Dynamic output feedback control for fast sampling discrete‐time singularly perturbed systems
Authors: Liu Wei , Wang Zhiming , Dai Haohui , Naz Mehvish
Published: June 2016

This study is concerned with the dynamic output feedback control problem for fast sampling discrete‐time singularly perturbed systems using the singular perturbation approach. Sufficient conditions in terms of linear matrix inequalities (LMIs) are presented to guarantee the existence of a dynamic output feedback controller for the corresponding slow and fast subsystems, respectively. The controller gains and the corresponding coefficient matrices can be obtained via solving the proposed LMIs. Thus, not only the high dimensionality and the ill condition are alleviated, but also the regularity restrictions attached to the Riccati‐based solutions are avoided. The theoretical result demonstrates that the composite dynamic output feedback control designed through those of the slow and fast subsystems can stabilise the full‐order discrete‐time singularly perturbed systems. Finally, two real world practical examples are provided to show the effectiveness of the obtained results.
Linear programming‐based robust model predictive control for positive systems
Authors: Zhang Junfeng , Zhao Xudong , Zuo Yan , Zhang Ridong
Published: June 2016

This study investigates the problem of robust model predictive control for positive systems under a new model predictive control framework. A robust model predictive control method is presented in this study for uncertain positive systems. A state‐feedback control law that robustly stabilises the underlying system is designed by using linear programming. Different from the traditional model predictive control technique, the authors' proposed model predictive control framework employs a linear infinite horizon objective function and a linear Lyapunov function rather than quadratic performance indices and quadratic Lyapunov functions commonly used in the literature. Compared with existing design techniques for positive systems, the present approach owns the following advantages: (i) it gives a locally optimal control strategy which approaches to actual operation conditions and the control law is designed by solving a locally optimal control problem at each time step, (ii) it can explicitly deal with constraints of the systems, and (iii) the controller can be easily designed via linear programming without any additional constraints. An practical example is provided to verify the validity of the theoretical findings.
Active yaw control in a horizontal axis wind system without requiring wind direction measurement
Authors: Karakasis Nektarios , Mesemanolis Athanasios , Nalmpantis Thomas , Mademlis Christos
Published: June 2016

This study presents an improved active yaw control technique for a horizontal‐axis wind turbine that is driven by a full power converter system with maximum power point tracking control. The turbine is aligned to the wind direction through the error between the rotor speed determined by the optimal tip speed ratio and the real rotor speed commanded by the maximum power point tracking control. Thus, the implementation of the yaw control is not based on the measurement of the wind direction and therefore, it is not influenced by inaccuracies that may be caused by the vortex flow downstream of the blades. The proposed yaw control method is intended for large turbines, since larger increase in the generated electric energy can be attained. However, since it is cost‐effective, it is affordable to be applied in low power wind systems. Selective simulation and experimental results are presented in order to demonstrate the effectiveness and the resulting improvements of the proposed control scheme. The simulation analysis is conducted in a large wind turbine with permanent magnet synchronous generator and the experimental verification in a low power real wind system with squirrel cage induction generator. However, it can also be applied to a doubly fed induction generator.
High intensity vacuum ultraviolet and extreme ultraviolet production by noncollinear mixing in laser vaporized media
Authors: Todt Michael A. , Albert Daniel R. , Davis H. Floyd
Published: June 2016

A method is described for generating intense pulsed vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) laser radiation by resonance enhanced four-wave mixing of commercial pulsed nanosecond lasers in laser vaporized mercury under windowless conditions. By employing noncollinear mixing of the input beams, the need of dispersive elements such as gratings for separating the VUV/XUV from the residual UV and visible beams is eliminated. A number of schemes are described, facilitating access to the 9.9–14.6 eV range. A simple and convenient scheme for generating wavelengths of 125 nm, 112 nm, and 104 nm (10 eV, 11 eV, and 12 eV) using two dye lasers without the need for dye changes is described.
Development of a compact, fiber-coupled, six degree-of-freedom measurement system for precision linear stage metrology
Authors: Yu Xiangzhi , Gillmer Steven R. , Woody Shane C. , Ellis Jonathan D.
Published: June 2016

A compact, fiber-coupled, six degree-of-freedom measurement system which enables fast, accurate calibration, and error mapping of precision linear stages is presented. The novel design has the advantages of simplicity, compactness, and relatively low cost. This proposed sensor can simultaneously measure displacement, two straightness errors, and changes in pitch, yaw, and roll using a single optical beam traveling between the measurement system and a small target. The optical configuration of the system and the working principle for all degrees-of-freedom are presented along with the influence and compensation of crosstalk motions in roll and straightness measurements. Several comparison experiments are conducted to investigate the feasibility and performance of the proposed system in each degree-of-freedom independently. Comparison experiments to a commercial interferometer demonstrate error standard deviations of 0.33 μm in straightness, 0.14 μrad in pitch, 0.44 μradin yaw, and 45.8 μrad in roll.
Controlling chaos-assisted directed transport via quantum resonance
Authors: Tan Jintao , Zou Mingliang , Luo Yunrong , Hai Wenhua
Published: June 2016

We report on the first demonstration of chaos-assisted directed transport of a quantum particle held in an amplitude-modulated and tilted optical lattice, through a resonance-induced double-mean displacement relating to the true classically chaotic orbits. The transport velocity is controlled by the driving amplitude and the sign of tilt, and also depends on the phase of the initial state. The chaos-assisted transport feature can be verified experimentally by using a source of single atoms to detect the double-mean displacement one by one, and can be extended to different scientific fields.
Low resistivity ZnO-GO electron transport layer based CH3NH3PbI3 solar cells
Authors: Ahmed Muhammad Imran , Hussain Zakir , Mujahid Mohammad , Khan Ahmed Nawaz , Javaid Syed Saad , Habib Amir
Published: June 2016

Perovskite based solar cells have demonstrated impressive performances. Controlled environment synthesis and expensive hole transport material impede their potential commercialization. We report ambient air synthesis of hole transport layer free devices using ZnO-GO as electron selective contacts. Solar cells fabricated with hole transport layer free architecture under ambient air conditions with ZnO as electron selective contact achieved an efficiency of 3.02%. We have demonstrated that by incorporating GO in ZnO matrix, low resistivity electron selective contacts, critical to improve the performance, can be achieved. We could achieve max efficiency of 4.52% with our completed devices for ZnO: GO composite. Impedance spectroscopy confirmed the decrease in series resistance and an increase in recombination resistance with inclusion of GO in ZnO matrix. Effect of temperature on completed devices was investigated by recording impedance spectra at 40 and 60 oC, providing indirect evidence of the performance of solar cells at elevated temperatures.
Global solutions to the two-dimensional Riemann problem for a system of conservation laws
Authors: Pang Yicheng , Cai Shaohong , Zhao Yuanying
Published: June 2016

We study the global solutions to the two-dimensional Riemann problem for a system of conservation laws. The initial data are three constant states separated by three rays emanating from the origin. Under the assumption that each ray in the initial data outside of the origin projects exactly one planar contact discontinuity, this problem is classified into five cases. By the self-similar transformation, the reduced system changes type from being elliptic near the origin to being hyperbolic far away in self-similar plane. Then in hyperbolic region, applying the generalized characteristic analysis method, a Goursat problem is solved to describe the interactions of planar contact discontinuities. While, in elliptic region, a boundary value problem arises. It is proved that this boundary value problem admits a unique solution. Based on these preparations, five explicit solutions and their corresponding criteria can be obtained in self-similar plane.
Platinum/yttrium iron garnet inverted structures for spin current transport
Authors: Aldosary Mohammed , Li Junxue , Tang Chi , Xu Yadong , Zheng Jian-Guo , Bozhilov Krassimir N. , Shi Jing
Published: June 2016

30-80 nm thick yttrium iron garnet (YIG) films are grown by pulsed laser deposition on a 5 nm thick sputtered Pt atop gadolinium gallium garnet substrate (GGG) (110). Upon post-growth rapid thermal annealing, single crystal YIG(110) emerges as if it were epitaxially grown on GGG(110) despite the presence of the intermediate Pt film. The YIG surface shows atomic steps with the root-mean-square roughness of 0.12 nm on flat terraces. Both Pt/YIG and GGG/Pt interfaces are atomically sharp. The resulting YIG(110) films show clear in-plane uniaxial magnetic anisotropy with a well-defined easy axis along 〈001〉 and a peak-to-peak ferromagnetic resonance linewidth of 7.5 Oe at 9.32 GHz, similar to YIG epitaxially grown on GGG. Both spin Hall magnetoresistance and longitudinal spin Seebeck effects in the inverted bilayers indicate excellent Pt/YIG interface quality.
Low-Reynolds-number rising of a bubble near a free surface at vanishing Bond number
Authors: Guémas Marine , Sellier Antoine , Pigeonneau Franck
Published: June 2016

This work considers a nearly spherical bubble and a nearly flat free surface interacting under buoyancy at vanishing Bond number Bo. For each perturbed surface, the deviation from the unperturbed shape is asymptotically obtained at leading order on Bo. The task appeals to the normal traction exerted on the unperturbed surface by the Stokes flow due to a spherical bubble translating toward a flat free surface. The free surface problem is then found to be well-posed and to admit a solution in closed form when gravity is still present in the linear differential equation governing the perturbed profile through a term proportional to Bo. In contrast, the bubble problem amazingly turns out to be over-determined. It however becomes well-posed if the requirement of horizontal tangent planes at the perturbed bubble north and south poles is discarded or if the term proportional to Bo is omitted. Both previous approaches turn out to predict for a small Bond number, quite close solutions except in the very vicinity of the bubble poles. The numerical solution of the proposed asymptotic analysis shows in the overlapping range Bo=O(0.1) and for both the bubble and the free surface perturbed shapes, a good agreement with a quite different boundary element approach developed in Pigeonneau and Sellier [“Low-Reynolds-number gravity-driven migration and deformation of bubbles near a free surface,” Phys. Fluids 23, 092102 (2011)]. It also provides approximated bubble and free surface shapes whose sensitivity to the bubble location is examined.
Resolving the nanostructure of plasma-enhanced chemical vapor deposited nanocrystalline SiOx layers for application in solar cells
Authors: Klingsporn M. , Kirner S. , Villringer C. , Abou-Ras D. , Costina I. , Lehmann M. , Stannowski B.
Published: June 2016

Nanocrystalline silicon suboxides (nc-SiOx) have attracted attention during the past years for the use in thin-film silicon solar cells. We investigated the relationships between the nanostructure as well as the chemical, electrical, and optical properties of phosphorous, doped, nc-SiO0.8:H fabricated by plasma-enhanced chemical vapor deposition. The nanostructure was varied through the sample series by changing the deposition pressure from 533 to 1067 Pa. The samples were then characterized by X-ray photoelectron spectroscopy, spectroscopic ellipsometry, Raman spectroscopy, aberration-corrected high-resolution transmission electron microscopy, selected-area electron diffraction, and a specialized plasmon imaging method. We found that the material changed with increasing pressure from predominantly amorphous silicon monoxide to silicon dioxide containing nanocrystalline silicon. The nanostructure changed from amorphous silicon filaments to nanocrystalline silicon filaments, which were found to cause anisotropic electron transport.
Active stabilization of a diode laser injection lock
Authors: Saxberg Brendan , Plotkin-Swing Benjamin , Gupta Subhadeep
Published: June 2016

We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser’s transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.
Ab initio modeling of zincblende AlN layer in Al-AlN-TiN multilayers
Authors: Yadav S. K. , Wang J. , Liu X.-Y.
Published: June 2016

An unusual growth mechanism of metastable zincblende AlN thin film by diffusion of nitrogen atoms into Al lattice is established. Using first-principles density functional theory, we studied the possibility of thermodynamic stability of AlN as a zincblende phase due to epitaxial strains and interface effect, which fails to explain the formation of zincblende AlN. We then compared the formation energetics of rocksalt and zincblende AlN in fcc Al through direct diffusion of nitrogen atoms to Al octahedral and tetrahedral interstitials. The formation of a zincblende AlN thin film is determined to be a kinetically driven process, not a thermodynamically driven process.
Anomalous temperature dependence of layer spacing of de Vries liquid crystals: Compensation model
Authors: Merkel K. , Kocot A. , Vij J. K. , Stevenson P. J. , Panov A. , Rodriguez D.
Published: June 2016

Smectic liquid crystals that exhibit temperature independent layer thickness offer technological advantages for their use in displays and photonic devices. The dependence of the layer spacing in SmA and SmC phases of de Vries liquid crystals is found to exhibit distinct features. On entering the SmC phase, the layer thickness initially decreases below SmA to SmC (TA–C) transition temperature but increases anomalously with reducing temperature despite the molecular tilt increasing. This anomalous observation is being explained quantitatively. Results of IR spectroscopy show that layer shrinkage is caused by tilt of the mesogen's rigid core, whereas the expansion is caused by the chains getting more ordered with reducing temperature. This mutual compensation arising from molecular fragments contributing to the layer thickness differs from the previous models. The orientational order parameter of the rigid core of the mesogen provides direct evidence for de Vries cone model in the SmA phase for the two compounds investigated.