bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification of genetic influences on adiposity between 36 and 63 years of age by physical activity and smoking in the 1946 British Birth Cohort Study
Authors: Johnson W , Ong K K , Elks C E , Wareham N J , Wong A , Muniz-Terrera G , Hardy R ,   on behalf of the MRC NSHD scientific and data collection teams
Published: September 2014

Background:

Previous studies reporting on the interaction between physical activity and genetic susceptibility on obesity have been cross-sectional and have not considered the potential influences of other lifestyle behaviours. The aim of this study was to examine modification of genetic influences on changes across age in adiposity during mid-adulthood by physical activity and smoking.

Methods:

The sample comprised 2444 participants who were genotyped for 11 obesity variants and had body mass index (BMI), waist circumference-to-height ratio (WHtR), physical activity and smoking measures at 36, 43, 53 and 60–64 years of age. A genetic risk score (GRS) comprising the sum of risk alleles was computed. Structural equation models investigated modification of the longitudinal GRS associations by physical activity (active versus inactive) and smoking (non-smoker versus smoker), using a latent linear spline to summarise BMI or WHtR (multiplied by 100) at the age of 36 years and their subsequent rates of change over age.

Results:

Physical activity at the age of 36 years attenuated the GRS associations with BMI and WHtR at the same age (P-interaction 0.009 and 0.004, respectively). Further, physical activity at the age of 53 years attenuated the GRS association with rate of change in BMI between 53 and 63 years of age (by 0.012 kg m−2 per year (95% confidence interval (CI): 0.001, 0.024), P-interaction 0.004). Conversely, smoking at the age of 43 years showed a trend towards augmenting the GRS association with rate of change in WHtR between 43 and 63 years of age (by 0.012 (95% CI: 0.001, 0.026), P-interaction 0.07). Estimated GRS effect sizes were lowest at all ages in the healthiest group (e.g., active non-smokers).

Conclusions:

Healthy lifestyle behaviours appeared to attenuate the genetic influence on changes across age in BMI and central adiposity during mid-adulthood. An active lifestyle and not smoking may have additive effects on reducing the genetic susceptibility to obesity in adults.
Pressurized liquid extraction as an alternative to the Soxhlet extraction procedure stated in the US EPA method TO-13A for the recovery of polycyclic aromatic hydrocarbons adsorbed on polyurethane foam plugs
Authors: Masala Silvia , Rannug Ulf , Westerholm Roger
Published: September 2014

PLE quicker and more convenient alternative than EPA Soxhlet method TO-13A for extraction of PAHs from atmospheric PUF samples.
Development of a method for the identification of organic contaminants in vinyl chloride monomer (VCM) by TD-GC-MS and multivariate analysis
Authors: dos Santos Fábio Neves , Horiuchi Lucas Nao , Pereira Pedro Afonso P.
Published: September 2014

VCM was analyzed for impurities, using TDA-GC-MS and PCA multivariate analysis; nineteen substances were identified; significant differences were found in the VCM, depending on the point in the process where samples were collected.
A second-order fluorimetric approach based on a boron dipyrromethene tetraamide derivative for Hg(ii) chemosensing in water and fish samples
Authors: Lozano Valeria A. , Muñoz de la Peña Arsenio , Escandar Graciela M.
Published: September 2014

A new fluorimetric method is described for the determination of Hg(ii), based on the selectivity of a boron dipyrromethene tetraamide derivative towards this ion, in combination with second-order chemometric analysis, to deal with matrix interferents.
A new class of electrocatalysts of supporting Pt on an Engel–Brewer alloy substrate: a demonstration for oxidation of ethylene glycol
Authors: Yang X. F. , Xu W. , Li M. , Koel B. E. , Chen J. G.
Published: September 2014

A Pt monolayer supported on an Engel–Brewer alloy, Hf–Ir, is highly active in oxidizing ethylene glycol into CO2. This enhanced performance originates from the lattice mismatch between surface Pt and the Hf–Ir support and the highly reducible Hf oxide adjacent to Pt sites.
Vesicular aptasensor for the detection of thrombin
Authors: Müller Andreas , König Burkhard
Published: September 2014

Self-assembled phospholipid vesicles are functionalized with thrombin-binding aptamers using a thiol-click reaction.
Straightforward installation of carbon–halogen, carbon–oxygen and carbon–carbon bonds within metal–organic frameworks (MOF) via palladium-catalysed direct C–H functionalization
Authors: Liu Tao , Li Da-Qiang , Wang Si-Yu , Hu Yong-Zhou , Dong Xiao-Wu , Liu Xin-Yuan , Che Chi-Ming
Published: September 2014

The straightforward C–H functionalization of UiO-67-dcppy materials was achieved by a palladium catalysed activation with high conversion and good regioselectivity.
A ratiometric fluorescent pH sensor based on nanoscale metal–organic frameworks (MOFs) modified by europium(iii) complexes
Authors: Lu Ye , Yan Bing
Published: September 2014

We report a new ratiometric fluorescent pH sensor based on postsynthetically modified nanoscale MOF-253. By a PSM, two types of Eu3+ with different characteristic excitation wavelengths are realized in MOF-253. The pH sensor requires no calibration because only one of the two types of Eu3+ is affected by the pH variation.
Formal synthesis of kingianin A based upon a novel electrochemically-induced radical cation Diels–Alder reaction
Authors: Moore Jonathan C. , Davies E. Stephen , Walsh Darren A. , Sharma Pallavi , Moses John E.
Published: September 2014

The application of electrochemical reactions in natural product synthesis has burgeoned in recent years. We herein report a formal synthesis of the complex and dimeric natural product kingianin A, which employs an electrochemically-mediated radical cation Diels–Alder cycloaddition as the key step.
Photo- and thermo-activated electron transfer system based on a luminescent europium organic framework with spectral response from UV to visible range
Authors: Chen Hengjun , Zheng Guiming , Li Min , Wang Yifang , Song Yang , Han Conghui , Dai Jingcao , Fu Zhiyong
Published: September 2014

A dual stimuli-responsive system with spectral response from UV to the visible region was constructed by introducing methyl viologen into a luminescent Eu-MOF with a compact packing mode.
N-Acetylglucosamine-based efficient, phase-selective organogelators for oil spill remediation
Authors: Mukherjee Somnath , Shang Congdi , Chen Xiangli , Chang Xingmao , Liu Kaiqiang , Yu Chunmeng , Fang Yu
Published: September 2014

Two simple, eco-friendly and efficient carbohydrate gelators have been created for instant selective gelation of oil from oil–water mixtures to combat marine oil spills.
Properties and reactivities of nonheme iron(iv)–oxo versus iron(v)–oxo: long-range electron transfer versus hydrogen atom abstraction
Authors: Karamzadeh Baharan , Singh Devendra , Nam Wonwoo , Kumar Devesh , de Visser Sam P.
Published: September 2014

Computational studies show that the perceived nonheme iron(v)–oxo is actually an iron(iv)–oxo ligand cation radical species.
Peptide stapling techniques based on different macrocyclisation chemistries
Authors: Lau Yu Heng , de Andrade Peterson , Wu Yuteng , Spring David R.
Published: September 2014

This review analyses how the choice of macrocyclisation chemistry can influence the biological properties and applications of stapled peptides.
Diketopyrrolopyrrole: brilliant red pigment dye-based fluorescent probes and their applications
Authors: Kaur Matinder , Choi Dong Hoon
Published: September 2014

The review summarizes the recent development of various DPP-based fluorescent probes for tracing biologically and environmentally important species.
Structural modulation in two CuII-based MOFs by synergistic assembly involving the mixed-ligand synthetic strategy and the solvent effect
Authors: Li Yun-Wu , Li Da-Cheng , Xu Jian , Hao Hong-Guo , Wang Su-Na , Dou Jian-Min , Hu Tong-Liang , Bu Xian-He
Published: September 2014

A synergistic assembly involving the mixed-ligand synthetic strategy and the solvent effect was successfully applied to tune two CuII-based MOFs. 1 represents a cds topology, while 2 is built by three distinct {Cu4} clusters as SBUs.
A perspective on the production of dye-sensitized solar modules
Authors: Fakharuddin Azhar , Jose Rajan , Brown Thomas M. , Fabregat-Santiago Francisco , Bisquert Juan
Published: September 2014

An overview of the state of the art dye solar module technology and innovations required for further development is presented.
A single serving of blueberry (V. corymbosum) modulates peripheral arterial dysfunction induced by acute cigarette smoking in young volunteers: a randomized-controlled trial
Authors: Del Bo’ Cristian , Porrini Marisa , Fracassetti Daniela , Campolo Jonica , Klimis-Zacas Dorothy , Riso Patrizia
Published: September 2014

Cigarette smoking causes oxidative stress, hypertension and endothelial dysfunction.
A magnetically separable palladium catalyst containing a bulky N-heterocyclic carbene ligand for the Suzuki–Miyaura reaction
Authors: Wang Z. , Yu Y. , Zhang Y. X. , Li S. Z. , Qian H. , Lin Z. Y.
Published: September 2014

Bulky NHC ligands were employed for preparing magnetic palladium catalysts, which showed excellent activity, stability and reusability towards the Suzuki–Miyaura reaction.
Microwave-assisted heating synthesis: a general and rapid strategy for large-scale production of highly crystalline g-C3N4with enhanced photocatalytic H2production
Authors: Yuan Yu-Peng , Yin Li-Sha , Cao Shao-Wen , Gu Li-Na , Xu Geng-Sheng , Du Pingwu , Chai Hua , Liao Yu-Sen , Xue Can
Published: September 2014

g-C3N4can be fabricated in minutes for enhanced photocatalytic H2production through a microwave-assisted heating urea process.
A biomass-derived safe medium to replace toxic dipolar solvents and access cleaner Heck coupling reactions
Authors: Strappaveccia Giacomo , Ismalaj Ermal , Petrucci Chiara , Lanari Daniela , Marrocchi Assunta , Drees Martin , Facchetti Antonio , Vaccaro Luigi
Published: September 2014

γ-Valerolactone (GVL) is an excellent reaction medium, derived from biomasses, which can replace classic dipolar aprotic media such as DMF or NMP.
High-precision measurements of tungsten stable isotopes and application to earth sciences
Authors: Breton Thomas , Quitté Ghylaine
Published: September 2014

A new method for high precision measurements of W stable isotopes by MC-ICPMS enables to discriminate small mass-dependent fractionations, with applications in numerous fields of earth, planetary and environmental sciences.
Criticality of surface topology for charge-carrier transport characteristics in two-dimensional borocarbonitrides: design principles for an efficient electronic material
Authors: Banerjee Swastika , Pati Swapan K.
Published: September 2014

A computational investigation based on ab initio DFT combined with the Boltzmann transport equation enlightens the principle for maximizing mobility and the possibility of obtaining a particular (electron/hole) conduction polarity of borocarbonitrides.
Anion binding of a neutral bis(cyclopeptide) in water–methanol mixtures containing up to 95% water
Authors: Sommer Fabian , Kubik Stefan
Published: September 2014

Selectivity of a synthetic anion receptor reverses from strongly coordinating sulfate to weakly coordinating iodide anions upon increasing the water content of the solution.
Synthesis of squaraine-based alternated π-conjugated copolymers: from conventional cross-coupling reactions to metal-free polycondensation
Authors: Oriou J. , Ng F. , Hadziioannou G. , Garbay G. , Bousquet M. , Vignau L. , Cloutet E. , Brochon C.
Published: September 2014

Low band-gap π-conjugated copolymers based on squaraine units can be synthesized through classical Suzuki and Stille cross-coupling reactions (in blue), or through a metal-free polycondensation (in green).
Crosslinking of low density polyethylene with octavinyl polyhedral oligomeric silsesquioxane as the crosslinker
Authors: Wu Jiachun , Wu Zi Liang , Yang Hongmei , Zheng Qiang
Published: September 2014

We report a new strategy for the crosslinking of LDPE using octavinyl polyhedral oligomeric silsesquioxane as the crosslinker, which dramatically decreases the amount of dicumyl peroxide and thus avoids the chain scission, scorch, and production of small pores in the conventional peroxide crosslinking strategy.
Molecular design of the amphiphilic AB diblock copolymer toward one-step synthesis of amino-group functionalized large pore mesoporous silica
Authors: Xu Dongpo , Yao Yuan , Han Lu , Che Shunai
Published: September 2014

A functionalized mesoporous silica with an amino group loading amount of 3.1 mmol g−1 and a pore size of 27.5 nm was achieved by the co-structure directing agent (CSDA) method using poly(styrene)-b-poly(acrylic acid) (PS-b-PAA) as the template.
Plasmonic cavities derived from silver nanoparticles atop a massed silver surface for surface enhancement Raman scattering
Authors: Cheng Shu-Chun , Wen Ten-Chin , Lan Yung-Chiang
Published: September 2014

Various plasmonic cavities (PC) are formed by positioning silver nanocubes or nanospheres on a massed silver surface, being magnificently useful for surface enhancement Raman scattering (SERS) application.
Toward transmembrane anionophores based on rigid bis(choloyl) conjugates: reversal of the ion selectivity by appended polyamines
Authors: Lu Yong-Ming , Deng Li-Qun , Chen Wen-Hua
Published: September 2014

A bis(polyamine)-appending rigid linker-tethered bis(choloyl) conjugate was synthesized as a potent anionophore with high selectivity for iodide over the other monoanionic ions.
A bifunctional electrocatalyst α-MnO2-LaNiO3/carbon nanotube composite for rechargeable zinc–air batteries
Authors: Ma Hongyun , Wang Baoguo
Published: September 2014

α-MnO2-LaNiO3/CNTs as one integrated hybrid exhibits enhanced reactivity towards ORR and OER. Electrons are directly transferred by the CNT conductor.
Hydroxysafflor yellow A induces apoptosis in MCF-7 cells by blocking NFκB/p65 pathway and disrupting mitochondrial transmembrane potential
Authors: Li YuYing , Wu Yanzi , Guan Yingying , Wang ZhuanHua , Zhang Liwei
Published: September 2014

The molecular mechanisms and the possible effects of hydroxysafflor yellow A (HSYA) on the induction of apoptosis in the human breast cancer MCF-7 cells were investigated.
Transition metal free synthesis of 2,4,6-trisubstituted pyrimidines via Cope-type hydroamination of 1,4-diarylbuta-1,3-diynes
Authors: Singha Raju , Ray Jayanta K.
Published: September 2014

We have developed an efficient and transition metal free methodology for the synthesis of 2,4,6-trisubstituted pyrimidines by the Cope-type hydroamination reaction of 1,4-diarylbuta-1,3-diynes with amidines in DMSO solvent.
Fe-catalyzed cycloaddition of indoles and o-phthalaldehyde for the synthesis of benzo[b]carbazoles with TMSCl- or acid-responsive properties
Authors: Zou Jin-Feng , Wang Hu , Li Li , Xu Zheng , Yang Ke-Fang , Xu Li-Wen
Published: September 2014

The indolyl benzo[b]carbazoles achieved by iron catalysis via sequential carbon–carbon bond-forming reaction could be used as fluorescent sensors for TMSCl and acids.
Equisetumone, a novel 4-5-olide secocaryophyllane sesquiterpene from Equisetum palustre
Authors: Wei Zuo-Fu , Chen Yung-Husan , Sung Ping-Jyun , Wang Guey-Horng , Liou Jing-Ru , Wang Sheng-Yang , Chang Shang-Tzen , Zu Yuan Gang , Chiang Michael Y. , Fu Yu-Jie , Chang Fang-Rong
Published: September 2014

Equisetumone (1), an unprecedented sesquiterpenoid, which possesses a novel 4,5-olide tricyclic trans-caryophyllane skeleton, was isolated from the Equisetum palustre fern.
Intramolecular C–O/C–S bond insertion of α-diazoesters for the synthesis of 2-aryl-4H-benzo[d][1,3]oxazine and 2-aryl-4H-benzo[d][1,3]thiazine derivatives
Authors: Reddy B. V. Subba , Babu R. Anji , Ramana Reddy M. , Reddy B. Jagan Mohan , Sridhar B.
Published: September 2014

An intramolecular C–O/C–S insertion of 2-(2-arylamidophenyl)-2-diazoacetate/2-diazo-2-(2-arylthioamidophenyl)acetate is achieved using 10 mol% Cu(OTf)2 to generate benzoxazines/benzothiazines.
Reversible pH-responsive helical nanoribbons formed using camptothecin
Authors: Ma Mingfang , Xing Pengyao , Xu Shengguang , Li Shangyang , Chu Xiaoxiao , Hao Aiyou
Published: September 2014

The natural antitumor drug camptothecin was found to self-assemble into helical nanoribbons in aqueous solution. The formation and disappearance of the helical nanoribbons can be tuned reversibly through changing the pH value of the solution.
Integration of a silk fibroin based film as a luminescent down-shifting layer in ITO-free organic solar cells
Authors: Prosa Mario , Sagnella Anna , Posati Tamara , Tessarolo Marta , Bolognesi Margherita , Cavallini Susanna , Toffanin Stefano , Benfenati Valentina , Seri Mirko , Ruani Giampiero , Muccini Michele , Zamboni Roberto
Published: September 2014

A bio-derived silk-fibroin film doped with a luminescent dye and its application as luminescent down-shifting layer in organic solar cells.
Liposomal nanohybrid cerasomes for controlled insulin release
Authors: Jin Yushen , Li Yanyan , Pan Hongjie , Dai Zhifei
Published: September 2014

This study reported a facile fabrication of a reproducible and injectable cerasomal insulin formulation by encapsulating insulin into cerasomes via one-step construction.
Modeling of thermocapillary flow to purify single-walled carbon nanotubes
Authors: Song Jizhou , Lu Chaofeng , Zhang Chenxi , Jin Sung Hun , Li Yuhang , Dunham Simon N. , Xie Xu , Du Frank , Huang Yonggang , Rogers John A.
Published: September 2014

Single walled carbon nanotubes (SWNTs) are of significant interest in the electronic materials research community due to their excellent electrical properties.
Durable hydrogen evolution from water driven by sunlight using (Ag,Cu)GaSe2photocathodes modified with CdS and CuGa3Se5
Authors: Zhang Li , Minegishi Tsutomu , Nakabayashi Mamiko , Suzuki Yohichi , Seki Kazuhiko , Shibata Naoya , Kubota Jun , Domen Kazunari
Published: September 2014

The multilayer structure enhances the hydrogen evolution from water under simulated sunlight.
Comment on “Intracellular stresses in patterned cell assemblies” by M. Moussus et al., Soft Matter, 2014, 10, 2414
Authors: Tambe Dhananjay T. , Butler James P. , Fredberg Jeffrey J.
Published: September 2014

To quantify intercellular stresses in a cell sheet, Moussus et al. have recently proposed an approach which may lead to significant simplification of the calculations required for stress recovery. The purpose of this comment is to assess the validity and to highlight the implications of this approach.
Lattice-Boltzmann simulations of droplet evaporation
Authors: Ledesma-Aguilar Rodrigo , Vella Dominic , Yeomans Julia M.
Published: September 2014

We validate lattice-Boltzmann simulations as a means of studying evaporation phenomena in complex geometries.
Novel graphene-like nanosheet supported highly active electrocatalysts with ultralow Pt loadings for oxygen reduction reaction
Authors: Li Zesheng , Li Yunyong , Jiang San Ping , He Guoqiang , Shen Pei Kang
Published: September 2014

Novel active graphene-like nanosheet supported ultralow Pt catalysts of Pd10Pt1 (Pt skin structure) nanoparticles have been made as highly active and stable catalysts for the oxygen reduction reaction.
Metal–organic complexes as redox candidates for carbon based pseudo-capacitors
Authors: Borenstein Arie , Fleker Ohad , Luski Shalom , Benisvy Laurent , Aurbach Doron
Published: September 2014

We present metal–organic complexes as a new type of redox active materials for pseudo-capacitors.
Efficient energy transfer from ZnO to Nd3+ ions in Nd-doped ZnO films deposited by magnetron reactive sputtering
Authors: Balestrieri Matteo , Colis Silviu , Gallart Mathieu , Ferblantier Gérald , Muller Dominique , Gilliot Pierre , Bazylewski Paul , Chang Gap Soo , Slaoui Abdelillah , Dinia Aziz
Published: September 2014

Sputtered ZnO thin films doped with Nd present efficient down-shifting properties.
Twisted microropes for stretchable devices based on electrospun conducting polymer fibers doped with ionic liquid
Authors: Lin Da-Peng , He Hong-Wei , Huang Yuan-Yuan , Han Wen-Peng , Yu Gui-Feng , Yan Xu , Long Yun-Ze , Xia Lin-Hua
Published: September 2014

Highlighting the novelty of the work: ionic-liquid-doped PEDOT twisted fibers exhibit a higher conductivity and show a repeatable cycle loop of tensile-resilience.
Combination effect of polar solvent treatment on ZnO and polyfluorene-based polymer blends for highly efficient blue-based hybrid organic–inorganic polymer light-emitting diodes
Authors: Lee Seungjin , Lee Bo Ram , Kim Ji-Seon , Song Myoung Hoon
Published: September 2014

Device efficiency is enhanced by the combination effect of polar solvent treatment on ZnO and hole trap using F8:TFB blend.
Reduced roughness for improved mobility in benzodipyrrolidone-based, n-type OFETS
Authors: Rumer J. W. , Rossbauer S. , Planells M. , Watkins S. E. , Anthopoulos T. D. , McCulloch I.
Published: September 2014

Six phenyl-flanked benzodipyrrolidone-based copolymers are designed, synthesised and characterised. Three exhibit backbone in-plane curvature or out-of-plane twisting, while the other three remain planar and co-linear. While the first three appear less crystalline by X-ray diffraction, they afford a smoother solid-state film surface topology and increased electron mobility in top-gate, bottom-contact OFETs.
Cooperative waiting‐time reduction for cognitive radio networks using Stackelberg game
Authors: Ouyang Fengchen , Ge Jianhua , Hou Jun
Published: September 2014

Waiting time occupies an important position in user's quality‐of‐service (QoS) evaluation system. However, in conventional overlay cognitive radio networks (CRN), the secondary users are not permitted to transmit any personal information whenever the spectrum is occupied by primary users. It follows that the waiting time of users depends heavily on the primary spectrum occupancy, which, in turn, cannot guarantee the QoS of the secondary users. To remedy this, a game theoretical cooperative waiting‐time reducing method (CWTRM) is proposed in a self‐generated CRN to meet users’ waiting‐time demands. The proposed scheme divides the users to temporary primary and secondary groups instead of introducing an extraneous secondary network. Specifically, waiting users are served as temporary secondary users. The cooperation between them and the temporary primary users is proceeded in each frame to make reuse of the unused time fractions, thereby reducing the global waiting time of the network. The optimal relay power, pricing and corresponding cooperating strategies are determined with the utilisation of Stackelberg game and Hungarian method. Finally, the superiority of the proposed CWTRM over non‐cooperative schemes is validated through simulations.
Access point selection mechanism to circumvent rogue access points using voting‐based query procedure
Authors: Shrestha Rakesh , Nam Seung Yeob
Published: September 2014

One of the challenging issues in wireless network is rogue access point (RAP) detection and mitigation. The authors propose a new access point (AP) selection mechanism to keep wireless users from RAPs. A centralised server called AP registration centre (APRC) maintains a list of authorised APs, and a wireless user can check if a specific AP is legitimate by querying APRC about its legitimacy in a secure way using the concept of voting and signal strength‐based authentication. The authors compare their scheme with a timing‐based scheme and the experiment results show that our scheme detects RAPs accurately with lower false positives and false negatives.
Current output hard‐switched full‐bridge DC/DC converter for wind energy conversion systems
Authors: Fan Shixiong , Pu Tianjiao , Liu Guangyi , Ma Weiwei , Li Lixin , Williams Barry
Published: September 2014

A current output hard‐switched full‐bridge (HSFB) converter is presented with an intermediate high‐frequency transformer as an option of a wind energy conversion system (WECS). The wind turbine simulator, based on an induction machine driving a three‐phase permanent magnet synchronous generator, simulates practical wind turbine characteristics. A comparative analysis of electrical stresses on the switches of the boost converter and the current output HSFB converter is carried out at different wind speeds and maximum operational power point based on their mathematical models. The control system of the current output HSFB converter is illustrated. Then two dynamic responses of the combined mechanical and electrical systems of the WECS are investigated, under wind speed step changes. Simulation and experimental results demonstrate the feasibility and stability of a current output HSFB converter‐based WECS.
Enhanced model of the doubly fed induction generator‐based wind farm for small‐signal stability studies of weak power system
Authors: Xi Xinze , Geng Hua , Yang Geng
Published: September 2014

This study proposes an enhanced model of the doubly fed induction generator (DFIG)‐based wind farm (WF) for small‐signal stability (SSS) studies of weak power system. This model consists of a wind turbine, a drive train, a simplified generator/converter module and associated controls. As analysed and verified in this study, the dynamics of the phase‐locked‐loop and the rotor current loop are important for accurate SSS studies of the weak power system involving the DFIG‐based WF and thus should be modelled appropriately. The enhanced model is validated by eigenvalue analysis and time‐domain simulations. Compared with the detailed model, the WT3 model provided by General electric (GE) energy and the conventional model, the enhanced model presents high precision and satisfactory simplification for SSS studies. As the application of the enhanced model, a case study is carried out to explore the impact of WF ancillary voltage/frequency controls on SSS of the weak grid. As indicated in this study, the WF ancillary controls exert distinct impact on SSS. New lightly damped power oscillations can be introduced. Therefore extra measures should be considered if the ancillary controls are required by the WF in order to satisfy the future grid codes.
Wavelet packet transform‐based time of arrival estimation method for orthogonal frequency division multiplexing ultra‐wideband signal
Authors: Guo Yong
Published: September 2014

This study discusses the estimation of time of arrival (TOA) used for ranging and positioning applications in orthogonal frequency division multiplexing ultra‐wideband‐ (OFDM‐UWB) based system. The correlation‐based method applied for impulse radio‐UWB (IR‐UWB) is not suitable for OFDM‐UWB because OFDM‐UWB signal is much longer than IR‐UWB in time domain. This study proposes a new method for TOA estimation of OFDM‐UWB signal based on wavelet packet transform (WPT). The author's method estimates TOA of OFDM‐UWB signal through the time information of the frequency band of UWB, which is one of the branches of WPT decomposition of the oversampled received baseband signal. It does not need the whole OFDM signal to estimate TOA of UWB signal because every segment of OFDM‐UWB signal in time domain contains all information of UWB frequency band; therefore the resolution of TOA is improved. Signal‐to‐noise ratio can also be improved because WPT decomposes the power of additive white Gaussian noise equally in all wavelet packet branches, and false alarm rate can be controlled. The author's method is robust in that it can counter narrow band noise and impulse noise effectively. Numerical results show our method is effective for accurate estimation of TOA for OFDM‐UWB signal.
Friction compensation of servo system based on terminal switching function
Authors: Lin Xue , Wang Zhonghua
Published: September 2014

Based on the LuGre friction model, a sliding mode adaptive controller is presented to compensate for the friction in the servo system. The terminal switching function is selected as the sliding mode surface, which can make the error of the system converge to the equilibrium point in finite time. The main analytical result is a stability theorem for the proposed controller which can achieve asymptotical stability of the closed‐loop system. Furthermore, the transient performance of the system is analytically quantified. To support the theoretical concepts, the authors present dynamic simulations for the proposed control scheme.
Retrieval of unknown sinusoidal signals through the measurement of chaotic signals
Authors: Obregón‐Pulido Guillermo , Torres‐González Angel , Solís‐Perales Gualberto , Cárdenas‐Rodríguez Roberto
Published: September 2014

Chaotic dynamical systems are extremely sensitive to initial conditions and their behaviour is unpredictable. On the other hand, in regulation theory, an exosystem is available when it is known; however, if it is unknown, it should be estimated with any adaptable recognition technique. This Letter presents a perturbed chaotic oscillator by an unknown sinusoidal signal, in which the perturbed signal is estimated by measuring the output of the chaotic oscillator.
Robust leakage‐based distributed precoder for cooperative multicell systems
Authors: Castanheira Daniel , Silva Adão , Gameiro Atílio
Published: September 2014

Coordinated multipoint (CoMP) from long term evolution (LTE)‐advanced is a promising technique to enhance the system spectral efficiency. Among the CoMP techniques, joint transmission has high communication requirements, because of the data sharing phase through the backhaul network, and coordinated scheduling and beamforming reduces the backhaul requirements, since no data sharing is necessary. Most of the available CoMP techniques consider perfect channel knowledge at the transmitters. Nevertheless for practical systems this is unrealistic. Therefore in this study the authors address this limitation by proposing a robust precoder for a multicell‐based systems, where each base station (BS) has only access to an imperfect local channel estimate. They consider both the case with and without data sharing. The proposed precoder is designed in a distributed manner at each BS by maximising the signal‐to‐leakage‐and‐noise ratio of all jointly processed users. By considering the channel estimation error in the design of the precoder, they are able to reduce considerably the impact of these errors in the system's performance. The results show that the proposed scheme has improved performance especially for the high signal‐to‐noise ratio regime, where the impact of the channel estimation error may be more pronounced.
Optimal packing size of non-ligated CdSe nanoclusters for microstructure synthesis
Authors: Tefera Anteneh G. , Mochena Mogus D. , Johnson Elijah , Dickerson James
Published: September 2014

Structural and electrostatic properties of nanoclusters of CdSe of diameter 1–2 nm are studied with first principle calculations to determine the optimal size for synthesizing microstructures. Based on robustness of the core structure, i.e., the retention of tetrahedral geometry, hexagonal ring structure, and overall wu¨rtzite structure to surface relaxations, we conclude that nanoclusters of ∼2 nm diameter are the best candidates to form a dense microstructure with minimal interstitial space. Se-terminated surfaces retain a zigzag structure as Se atoms are pulled out and Cd atoms are pulled in due to relaxation, therefore, are best suited for inter-nanocluster formations.
Early time implosion symmetry from two-axis shock-timing measurements on indirect drive NIF experiments
Authors: Moody J. D. , Robey H. F. , Celliers P. M. , Munro D. H. , Barker D. A. , Baker K. L. , Döppner T. , Hash N. L. , Berzak Hopkins L. , LaFortune K. , Landen O. L. , LePape S. , MacGowan B. J. , Ralph J. E. , Ross J. S. , Widmayer C. , Nikroo A. , Giraldez E. , Boehly T.
Published: September 2014

An innovative technique has been developed and used to measure the shock propagation speed along two orthogonal axes in an inertial confinement fusion indirect drive implosion target. This development builds on an existing target and diagnostic platform for measuring the shock propagation along a single axis. A 0.4 mm square aluminum mirror is installed in the ablator capsule which adds a second orthogonal view of the x-ray-driven shock speeds. The new technique adds capability for symmetry control along two directions of the shocks launched in the ablator by the laser-generated hohlraum x-ray flux. Laser power adjustments in four different azimuthal cones based on the results of this measurement can reduce time-dependent symmetry swings during the implosion. Analysis of a large data set provides experimental sensitivities of the shock parameters to the overall laser delivery and in some cases shows the effects of laser asymmetries on the pole and equator shock measurements.
Enthalpy and high temperature relaxation kinetics of stable vapor-deposited glasses of toluene
Authors: Bhattacharya Deepanjan , Sadtchenko Vlad
Published: September 2014

Stable non-crystalline toluene films of micrometer and nanometer thicknesses were grown by vapor deposition at distinct rates and probed by fast scanning calorimetry. Fast scanning calorimetry is shown to be extremely sensitive to the structure of the vapor-deposited phase and was used to characterize simultaneously its kinetic stability and its thermodynamic properties. According to our analysis, transformation of vapor-deposited samples of toluene during heating with rates in excess 105 K s−1 follows the zero-order kinetics. The transformation rate correlates strongly with the initial enthalpy of the sample, which increases with the deposition rate according to sub-linear law. Analysis of the transformation kinetics of vapor-deposited toluene films of various thicknesses reveal a sudden increase in the transformation rate for films thinner than 250 nm. The change in kinetics seems to correlate with the surface roughness scale of the substrate. The implications of these findings for the formation mechanism and structure of vapor-deposited stable glasses are discussed.
Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading
Authors: Lambert P. K. , Hustedt C. J. , Vecchio K. S. , Huskins E. L. , Casem D. T. , Gruner S. M. , Tate M. W. , Philipp H. T. , Woll A. R. , Purohit P. , Weiss J. T. , Kannan V. , Ramesh K. T. , Kenesei P. , Okasinski J. S. , Almer J. , Zhao M. , Ananiadis A. G. , Hufnagel T. C.
Published: September 2014

We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ∼103–104 s−1 in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10–20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (∼40 μs) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.
Theoretical estimates of the anapole magnetizabilities of C4H4X2 cyclic molecules for X=O, S, Se, and Te
Authors: Pagola G. I. , Ferraro M. B. , Provasi P. F. , Pelloni S. , Lazzeretti P.
Published: September 2014

Calculations have been carried out for C4H4X2 cyclic molecules, with X=O, S, Se, and Te, characterized by the presence of magnetic-field induced toroidal electron currents and associated orbital anapole moments. The orbital anapole induced by a static nonuniform magnetic field B, with uniform curl \documentclass[12pt]{minimal}\begin{document}${{\bm C}}=\nabla \times {{\bm B}}$\end{document}C=∇×B, is rationalized via a second-rank anapole magnetizability tensor aαβ, defined as minus the second derivative of the second-order interaction energy with respect to the components Cα and Bβ. The average anapole magnetizability \documentclass[12pt]{minimal}\begin{document}$\overline{a}$\end{document}a¯ equals \documentclass[12pt]{minimal}\begin{document}$-\overline{\chi }$\end{document}−χ¯, the pseudoscalar obtained by spatial averaging of the dipole-quadrupole magnetizability χα,βγ. It has different sign for D and L enantiomeric systems and can therefore be used for chiral discrimination. Therefore, in an isotropic chiral medium, a homogeneous magnetic field induces an electronic anapole \documentclass[12pt]{minimal}\begin{document}${\cal A}_{\alpha }$\end{document}Aα, having the same magnitude, but opposite sign, for two enantiomorphs.
A six-dimensional potential energy surface for Ru(0001)(2×2):CO
Authors: Füchsel Gernot , Tremblay Jean Christophe , Saalfrank Peter
Published: September 2014

We present a new global ground state potential energy surface (PES) for carbon monoxide at a coverage of 1/4, on a rigid Ru(0001) surface [Ru(0001)(2×2):CO]. All six adsorbate degrees of freedom are considered. For constructing the PES, we make use of more than 90 000 points calculated with periodic density functional theory using the RPBE exchange-correlation functional and an empirical van der Waals correction. These points are used for interpolation, utilizing a symmetry-adapted corrugation reducing procedure (CRP). Three different interpolation schemes with increasing accuracy have been realized, giving rise to three flavours of the CRP PES. The CRP PES yields in agreement with the DFT reference and experiments, the atop position of CO to be the most stable adsorption geometry, for the most accurate interpolation with an adsorption energy of 1.69 eV. The CRP PES shows that diffusion parallel to the surface is hindered by a barrier of 430 meV, and that dissociation is facilitated but still activated. As a first “real” application and further test of the new potential, the six-dimensional vibrational Schrödinger equation is solved variationally to arrive at fully coupled, anharmonic frequencies and vibrational wavefunctions for the vibrating, adsorbed CO molecule. Good agreement with experiment is found also here. Being analytical, the new PES opens an efficient way towards multidimensional dynamics.
An enhanced Fourier law derivable from the Boltzmann transport equation and a sample application in determining the mean-free path of nondiffusive phonon modes
Authors: Ramu Ashok T. , Ma Yanbao
Published: September 2014

An enhanced Fourier law that we term the unified nondiffusive-diffusive (UND) phonon transport model is proposed in order to account for the effect of low-frequency phonon modes of long mean-free path that propagate concomitantly to the dominant high-frequency modes. The theory is based on spherical harmonic expansions of the phonon distribution functions, wherein the high-frequency mode distribution function is truncated at the first order in the expansion, while the low-frequency mode distribution function, which is farther out of thermal equilibrium, is truncated at the second order. As an illustrative application, the predictions of the proposed model are compared with data from a recent experiment that utilized the transient gratings method to investigate the deviation of thermal transport in a silicon membrane from the predictions of the Fourier law. The good fit of the experimental effective thermal conductivity (ETC) with the analytical solution derived in this work yields quantitative information about the mean-free path of the dominant low-frequency heat-transfer mode in silicon.
A Schamel equation for ion acoustic waves in superthermal plasmas
Authors: Williams G. , Verheest F. , Hellberg M. A. , Anowar M. G. M. , Kourakis I.
Published: September 2014

An investigation of the propagation of ion acoustic waves in nonthermal plasmas in the presence of trapped electrons has been undertaken. This has been motivated by space and laboratory plasma observations of plasmas containing energetic particles, resulting in long-tailed distributions, in combination with trapped particles, whereby some of the plasma particles are confined to a finite region of phase space. An unmagnetized collisionless electron-ion plasma is considered, featuring a non-Maxwellian-trapped electron distribution, which is modelled by a kappa distribution function combined with a Schamel distribution. The effect of particle trapping has been considered, resulting in an expression for the electron density. Reductive perturbation theory has been used to construct a KdV-like Schamel equation, and examine its behaviour. The relevant configurational parameters in our study include the superthermality index κ and the characteristic trapping parameter β. A pulse-shaped family of solutions is proposed, also depending on the weak soliton speed increment u0. The main modification due to an increase in particle trapping is an increase in the amplitude of solitary waves, yet leaving their spatial width practically unaffected. With enhanced superthermality, there is a decrease in both amplitude and width of solitary waves, for any given values of the trapping parameter and of the incremental soliton speed. Only positive polarity excitations were observed in our parametric investigation.
Upgrade of the electron beam ion trap in Shanghai
Authors: Lu D. , Yang Y. , Xiao J. , Shen Y. , Fu Y. , Wei B. , Yao K. , Hutton R. , Zou Y.
Published: September 2014

Over the last few years the Shanghai electron beam ion trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Applied Physics, first produced an electron beam in 2005. It could be tuned with electron energies between 1 and 130 keV and beam current up to 160 mA. After several years of operation, it was found that several modifications for improvements were necessary to reach the goals of better electron optics, higher photon detection, and ion injection efficiencies, and more economical running costs. The upgraded Shanghai-EBIT is made almost entirely from Ti instead of stainless steel and achieves a vacuum of less than 10−10 Torr, which helps to minimize the loss of highly changed ions through charge exchange. Meanwhile, a more compact structure and efficient cryogenic system, and excellent optical alignment have been of satisfactory. The magnetic field in the central trap region can reach up till 4.8 T with a uniformity of 2.77 × 10−4. So far the upgraded Shanghai-EBIT has been operated up to an electron energy of 151 keV and a beam current of up to 218 mA, although promotion to even higher energy is still in progress. Radiation from ions as highly charged as Xe53+, 54+ has been produced and the characterization of current density is estimated from the measured electron beam width.
Probing a dielectric resonator acting as passive sensor through a wireless microwave link
Authors: Friedt J.-M. , Boudot R. , Martin G. , Ballandras S.
Published: September 2014

Dielectric resonators, generally used for frequency filtering in oscillator loops, can be used as passive cooperative targets for wireless sensor applications. In the present work, we demonstrate such an approach by probing their spectral characteristics using a microwave RADAR system. The unique spectral response and energy storage capability of resonators provide unique responses allowing to separate the sensor response from clutter. Although the dielectric resonator is not designed for high temperature sensitivity, the accurate determination of the resonance frequency allows for a remote estimate of the temperature with Kelvin resolution.
Doping dependent magnetism and exchange bias in CaMn1−xWxO3 manganites
Authors: Markovich V. , Fita I. , Wisniewski A. , Puzniak R. , Mogilyansky D. , Naumov S. V. , Mostovshchikova E. V. , Telegin S. V. , Gorodetsky G. , Jung G.
Published: September 2014

Magnetic properties of CaMn1−xWxO3 (0 ≤ x ≤ 0.1) have been investigated, and the research was focused on the exchange bias (EB) phenomenon in CaMn0.93W0.07O3. Magnetic ground state was found to be dependent on tungsten doping level and the following states were distinguished: (i) G-type antiferromagnetic (AFM) state with a weak ferromagnetic (FM) component at x = 0 and 0.04; (ii) mostly orbitally ordered C-type AFM at x = 0.07 and 0.1. For the studied manganites, spontaneous magnetization increases sharply with increasing doping level reaching M0 ≈ 9.5 emu/g at T = 10 K for x = 0.04, and then decreases rapidly reaching zero for x = 0.1. Exchange bias effect, manifested by vertical and horizontal shifts in the hysteresis loop for field cooled sample, has been observed in CaMn0.93W0.07O3. Exchange bias field, coercivity, remanence asymmetry, and magnetic coercivity depend strongly on temperature, cooling field, and maximal measuring field. Horizontal and vertical shifts of magnetization loop sharply decrease with increasing temperature and vanish above 70 K, whereas coercivity and magnetic coercivity disappear only above 100 K (temperature of transition to the G-type AFM state). The exchange bias field HEB increases with increasing cooling field Hcool and goes through a broad maximum at 40 kOe, while the remanence asymmetry increases monotonously in the entire investigated cooling field range, up to 50 kOe. For the compound with x = 0.07, the size of the FM regions ≈2 nm was estimated from the dependence of exchange bias field HEB upon Hcool. It is suggested that the exchange bias originates from interface exchange coupling between small FM clusters and the G-type AFM phase inside the primary C-type orbitally ordered AFM phase.
Aqueous microsolvation of CdCl2: Density functional theory and Born-Oppenheimer molecular dynamics studies
Authors: Ramírez-Solís A. , Maron L.
Published: September 2014

We report a systematic study of aqueous microsolvation of CdCl2. The optimized structures and binding energies of the CdCl2-(H2O)n clusters with n = 1–24 have been computed at the B3PW91/6-31G** level. The solvation patterns obtained at the DFT level are verified at the MP2/AVTZ level for n < 6. Unlike HgCl2-(H2O)n case, where there are at most three Hg-Ow orbital interactions, Cd also establishes four equatorial orbital interactions with water for n > 6 leading to a planar square bipyramid hexacoordination around Cd. The first solvation shell is fully attained with 12 water molecules. At the same level of theory the water binding energies are much larger than those previously found for HgCl2 due to the stronger Cd-Ow interactions arising from the smaller core of Cd. For the largest system studied, CdCl2-(H2O)24, both penta- and hexa-coordination stable patterns around Cd are found. However, Born-Opphenheimer molecular dynamics simulations starting from these optimized geometries at 700 K reveal the greater stability of the Cd-pentacoordinated species, where a CdCl2-(H2O)3 trigonal bipyramid effective solute appears. The Cd-O(water) radial distribution function shows a bimodal distribution with two maxima at 2.4 Å and 4.2 Å, revealing the different coordination spheres, even with such a small number of solvating water molecules.
Note: A quartz cell with Pt single crystal bead electrode for electrochemical scanning tunneling microscope measurements
Authors: Xia Zhigang , Wang Jihao , Hou Yubin , Lu Qingyou
Published: September 2014

In this paper, we provide and demonstrate a design of a unique cell with Pt single crystal bead electrode for electrochemical scanning tunneling microscope (ECSTM) measurements. The active metal Pt electrode can be protected from air contamination during the preparation process. The transparency of the cell allows the tip and bead to be aligned by direct observation. Based on this, a new and effective alignment method is introduced. The high-quality bead preparations through this new cell have been confirmed by the ECSTM images of Pt (111).