bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plots of modal field distribution in circular dielectric waveguide
Authors: Xia Tian , Chew Weng Cho 
Published: August 2015

ABSTRACTA method to plot the modal field distributions in the circular dielectric waveguides is discussed in this article. By tracing the directions of fields, closed contours of the fields can be formed in dielectric waveguides. This method is a simple and general approach to plot and visualize the field distributions of the waveguides if the solutions of fields can be found. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2599–2601, 2015
A slotted hollow ring element for Ku‐band high‐efficiency circularly polarized reflectarrays
Authors: Chen Hong‐Wei , Zhang Guang‐Qiu , Lei Xue , Wu Jun‐Mo 
Published: August 2015

ABSTRACTBased on the idea of a single‐layer multiresonance structure for a linearly polarized reflectarray, a novel slotted hollow ring element is presented for Ku‐band high‐efficiency circularly polarized reflectarrays. The appropriate geometry parameters are determined by studying the effects of incident angle on the element reflection coefficient. Compared to the conventional microstrip ring element, it can provide a broader CP bandwidth and more accurate phase compensation. Then, using the angular rotation technique, an offset 137‐element reflectarray operating at 12 GHz is designed and fabricated to demonstrate the superior performance of the element. The measured result shows that the reflectarray offers a maximum efficiency of 66.13% at 12.3 GHz. Meanwhile, the efficiency is better than 60% over a 16.8% bandwidth (11.1–13.1 GHz). The overlapping 1‐dB gain bandwidth and 3‐dB axial‐ratio bandwidth can reach 20%. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2629–2632, 2015
A compact zeroth‐order resonator based on CRLH via‐less CPW‐fed
Authors: Nilotpal  , Upadhyay Dileep Kr. , Mishra G. K. 
Published: August 2015

ABSTRACTA novel compact coplanar waveguide (CPW)‐fed zeroth‐order resonator (ZOR) is reported in this article. The zeroth‐order mode is required to reduce the resonator's size. The composite right/left handed transmission line (CRLH TL) structure is designed on a single layer via‐less CPW‐fed, which reduces the fabrication complexity and makes the structure more feasible. The resonator has a compact size of 21.6 × 5.2 mm2. The measured insertion loss and return loss of the resonator are −0.72 dB and −21.3 dB, respectively at the resonant frequency, 2.80 GHz. The performance of the proposed ZOR is compared with the previously reported ZORs. All the performance parameters of the resonator are evaluated by full‐wave electromagnetic simulator IE3D, based on the method of moments (MoM) and all the results are verified by measurement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2576–2580, 2015
Design of a miniaturized‐element frequency selective surface
Authors: Lin Bao‐Qin , Zhao Shang‐hong , Da Xin‐yu , Fang Ying‐wu , Ma Jia‐jun , Zhu Zi‐Hang 
Published: August 2015

ABSTRACTAn effective approach to design miniaturized‐element frequency selective surface (FSS) is presented. The FSS is based on an original Jerusalem cross‐shaped slot one, whereas there is a metallic patch array with the same period laid over it. An equivalent circuit model analysis is presented to provide an insightful design procedure for the miniaturization. Numerical simulations indicate that one prototype of the designed FSS has been much compacter in size, the unit size is miniaturized to only 0.0371λ × 0.0371λ, where λ represents the resonant wavelength in free space; moreover, the miniaturization performance is stable with respect to different polarizations and incident angles. In addition, after the amelioration of the unit cell structure, the unit size is consumedly miniaturized to 0.0094λ × 0.0094λ. Finally, the prototype FSS is fabricated and measured, a good agreement between the measured and simulated results is observed. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2572–2576, 2015
Phase shifter designing base on half mode substrate integrated waveguide with reconfigurable quality
Authors: Kuhestani Hamed , Naser‐Moghadasi Mohammad , Maleki Mahshid , Zarrabi Ferdows B. 
Published: August 2015

ABSTRACTIn this article, a novel phase shifter base on half mode substrate integrated waveguide (HMSIW) whose characteristics can be reconfigured electronically by simply loading it with electromagnetic bandgap (EBG) unit cells at 9.5 GHz is presented. The prototype of phase shifter contains a HMSIW as a transmission line and four metamaterial structure as a load on the one side of the transmission line. These loads with junctions (or PIN diode) can be connected to HMSIW. To obtain different radar bit‐phases for S21, we change the situation of junctions (or PIN diode). For demonstration purposes, controllable phase shifters are designed, fabricated, and measured to give excellent performance for X‐band applications. The phase shifter has bandwidth around 0.38% at 9.55 GHz. Design method is based on simulation of EBG cells in different position and changing reactance of the phase shifting elements which help us to modify our phase shifter for different phases. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2562–2567, 2015
Microstrip line‐fed fractal antenna with a high fidelity factor for UWB imaging applications
Authors: Islam M. M. , Islam M. T. , Samsuzzaman M. , Faruque M. R. I. , Misran N. 
Published: August 2015

ABSTRACTA printed microstrip line‐fed fractal antenna is presented with a high fidelity factor for UWB applications. The antenna structure of electrical dimension 0.24 λ × 0.33 λ at lower frequency 3.1 GHz is made of a fractal patch, a slotted partial ground plane, and a microstrip feed, which is fabricated on FR4 material of low cost and dielectric. Measured results demonstrates that the fractal antenna achieves fractional bandwidth of 117.88% covering the frequency range from 3.1 GHz to more than 12 GHz with a maximum gain 3.54 dBi at 6.25 GHz. An acceptable analogy is observed between measured and simulation results. The high fidelity factor, sharply surface current distribution, time domain performances, acceptable gain, and nearly omnidirectional radiation characteristic have validated the appropriateness of this proposed fractal antenna for UWB and microwave imaging applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2580–2585, 2015
Miniaturized triple‐band antennas with high isolation for mimo antenna system applications
Authors: Kuo Chi‐Jung , Liou Chong‐Yi , Mao Shau‐Gang 
Published: August 2015

ABSTRACTIn this article, a miniaturized multiband antenna for multiple input and multiple output (MIMO) system is proposed. The proposed structure consists of two methods to obtain size reduction with a meandering monopole antenna and a quarter‐wavelength slot antenna. The antenna element is implemented on a FR4 PCB with dimensions of 20.6 × 29.5 × 0.8 mm3 for USB dongle applications. Measurements show that the isolation is below l0 dB and |S11| and |S22| is smaller than −6 dB at 2.5 GHz, 3.5 GHz, and 5.5 GHz. To evaluate the mutual coupling effect of MIMO system, the correlation coefficients are determined by the measured scattering parameters. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2555–2558, 2015
An UWB slot antenna without stub tuning
Authors: Jardon‐Aguilar Hildeberto , Tirado‐Mendez Jose Alfredo , Flores‐Leal Ruben 
Published: August 2015

ABSTRACTA slot omnidirectional wide‐band antenna without stub tuning is proposed. The antenna is fed with a slot waveguide, performing from 1.9 to 6.6 GHz and gain from 2 to 5 dB over the bandwidth. One of the main advantages is the small amount of parameters of the structure to modify and optimize, reducing the design complexity. The idea emerges from a complement of an UWB planarized elliptical monopole. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2658–2662, 2015
Triple band two‐segment cylindrical dielectric resonator antenna with a novel microstrip feed for WLAN/WIMAX applications
Authors: Sharma Anand , Gangwar Ravi Kumar 
Published: August 2015

ABSTRACTIn this letter, a triple band two‐segment cylindrical dielectric resonator antenna with a partial ground plane is investigated. Proposed antenna is excited by a novel microstrip feed that having a microstrip line along with two ring patches. Proposed triple band antenna has been analyzed, studied, and optimized using Ansoft HFSS simulation software. Prototype of proposed structure has been fabricated and tested. Good agreement has been obtained between simulated and measured parameters. The proposed design operates in three different frequency bands, that is, 2.3–2.5 GHz; 3.2–3.8 GHz; 4.67–7.0 GHz with the fractional bandwidth of 8.33%; 17.14%, and 39.93%, respectively. Proposed antenna is able to cover three frequency bands for different wireless applications (WLAN [2.4/5.2/5.8 GHz] and WiMAX [3.5/5.5 GHz] bands). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2649–2655, 2015
Micromachined 60 GHz postsupported patch antenna with flip‐chip interconnect
Authors: Deng Changjiang , Liu Wendong , Hao Qing , Feng Zhenghe 
Published: August 2015

ABSTRACT:This letter presents the design of a micromachined patch antenna operating at 60‐GHz band. The radiating patch and the feedline network are designed on the quartz glass (SiO2) and silicon (Si) substrate layers, respectively. An air gap, which is supported by four nonconductive posts and one solder ball, is added between the two substrate layers to reduce dielectric loss. The utilization of transparent quartz glass is helpful in alignment, and the feedline network is universal in patch array design. A 1 × 2 patch array is designed to verify the concept of array design. The measured −10 dB bandwidth of the proposed array is 2.7 GHz (56.5–59.2 GHz). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2706–2710, 2015
Three‐dimensional information storage of polymer doped with nano‐silver
Authors: Cai Jianwen , Huang Wenhao 
Published: August 2015

ABSTRACTFemtosecond laser three‐dimensional optical storage is an important method to realize high‐density optical storage. Based on femtosecond laser microexplosion optical information storage principle, the information was written and readout with Titanium sapphire femtosecond pulsed laser, the storage experiments were performed in the polymer doped with nano‐silver, 11‐layer optical information storage was achieved, the information point spacing was 2 μm and the information layer spacing 14 μm. The experiments showed that polymeric materials doped with nano‐silver can be used for femtosecond laser three‐dimensional optical storage and this had laid a solid foundation for high density and ultrahigh density optical information storage. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2662–2665, 2015
Reference values for ultrasonograpy of peripheral nerves
Authors: Qrimli Mohammad , Ebadi Hamid , Breiner Ari , Siddiqui Hafsah , Alabdali Majed , Abraham Alon , Lovblom Leif E. , Perkins Bruce A. , Bril Vera 
Published: August 2015

ABSTRACTIntroduction: High‐resolution ultrasonography (HRU) is a novel method that provides morphological information about peripheral nerves. We aimed to determine reference values for nerve cross‐sectional area (CSA) on HRU. Methods: One hundred healthy volunteers had HRU of median, radial, ulnar, fibular, tibial, sural, and superficial fibular nerves at defined sites. The CSA was measured and the effects of age, gender, and body mass index (BMI) were evaluated. Results: CSA values in healthy subjects are described. CSA is larger in lower limb motor nerves than in sensory nerves at similar sites, and the CSA tends to be symmetrical. The strongest effect on CSA was for age, although gender and BMI had some effects. Conclusions: This study provides normative values for HRU, and it suggests that further research with age‐ and gender‐specific distributions must be a key priority in the development of HRU for use as a diagnostic test for peripheral nerve diseases. Muscle Nerve 53: 538–544, 2016
Higher‐order accurate integration of implicit geometries
Authors: Fries Thomas‐Peter , Omerović Samir 
Published: August 2015

SummaryA unified strategy for the higher‐order accurate integration of implicitly defined geometries is proposed. The geometry is represented by a higher‐order level‐set function. The task is to integrate either on the zero‐level set or in the sub‐domains defined by the sign of the level‐set function. In three dimensions, this is either an integration on a surface or inside a volume. A starting point is the identification and meshing of the zero‐level set by means of higher‐order interface elements. For the volume integration, special sub‐elements are proposed where the element faces coincide with the identified interface elements on the zero‐level set. Standard Gauss points are mapped onto the interface elements or into the volumetric sub‐elements. The resulting integration points may, for example, be used in fictitious domain methods and extended finite element methods. For the case of hexahedral meshes, parts of the approach may also be seen as a higher‐order marching cubes algorithm. Copyright © 2015 John Wiley & Sons, Ltd.
Gastric bypass alters both glucose‐dependent and glucose‐independent regulation of islet hormone secretion
Authors: Salehi Marzieh , Woods Stephen C. , D'Alessio David A. 
Published: August 2015

ObjectiveRoux‐en‐Y gastric bypass surgery (GB) is characterized by accentuated but short‐lived postprandial elevations of blood glucose and insulin. This profile has been attributed to effects of relative hyperglycemia to directly stimulate β‐cells and an augmented incretin effect. An additional glucose‐independent stimulation of insulin secretion in GB subjects was hypothesized.MethodsFifteen subjects with prior GB, six matched obese non surgical controls, and seven lean individuals were recruited. Islet hormones were measured before and after meal ingestion during hyperinsulinemic hypoglycemic clamps to minimize the direct effects of glycemia and glucose‐dependent gastrointestinal hormones on insulin secretion.ResultsThe GB subjects had less suppression of fasting β‐cell secretion during the insulin clamp compared to controls. In addition, meal‐induced insulin secretion increased in the GB subjects but not controls during fixed sub‐basal glycemia. In contrast, the glucagon responses to hypoglycemia and meal ingestion were lower in the GB subjects than controls.ConclusionsAmong subjects with GB, the response of insulin and glucagon secretion to decreasing blood glucose is blunted, but meal‐induced insulin secretion is stimulated even at fixed systemic sub‐basal glycemia. These findings indicate that, following GB, islet hormone secretion is altered as a result of factors beyond circulatory glucose levels.
Nonlinearities in protein space limit the utility of informatics in protein biophysics
Authors: Rackovsky S. 
Published: August 2015

ABSTRACTWe examine the utility of informatic‐based methods in computational protein biophysics. To do so, we use newly developed metric functions to define completely independent sequence and structure spaces for a large database of proteins. By investigating the relationship between these spaces, we demonstrate quantitatively the limits of knowledge‐based correlation between the sequences and structures of proteins. It is shown that there are well‐defined, nonlinear regions of protein space in which dissimilar structures map onto similar sequences (the conformational switch), and dissimilar sequences map onto similar structures (remote homology). These nonlinearities are shown to be quite common—almost half the proteins in our database fall into one or the other of these two regions. They are not anomalies, but rather intrinsic properties of structural encoding in amino acid sequences. It follows that extreme care must be exercised in using bioinformatic data as a basis for computational structure prediction. The implications of these results for protein evolution are examined. Proteins 2015; 83:1923–1928. © 2015 Wiley Periodicals, Inc.
Machine‐learning scoring functions to improve structure‐based binding affinity prediction and virtual screening
Authors: Ain Qurrat Ul , Aleksandrova Antoniya , Roessler Florian D. , Ballester Pedro J. 
Published: August 2015

Docking tools to predict whether and how a small molecule binds to a target can be applied if a structural model of such target is available. The reliability of docking depends, however, on the accuracy of the adopted scoring function (SF). Despite intense research over the years, improving the accuracy of SFs for structure‐based binding affinity prediction or virtual screening has proven to be a challenging task for any class of method. New SFs based on modern machine‐learning regression models, which do not impose a predetermined functional form and thus are able to exploit effectively much larger amounts of experimental data, have recently been introduced. These machine‐learning SFs have been shown to outperform a wide range of classical SFs at both binding affinity prediction and virtual screening. The emerging picture from these studies is that the classical approach of using linear regression with a small number of expert‐selected structural features can be strongly improved by a machine‐learning approach based on nonlinear regression allied with comprehensive data‐driven feature selection. Furthermore, the performance of classical SFs does not grow with larger training datasets and hence this performance gap is expected to widen as more training data becomes available in the future. Other topics covered in this review include predicting the reliability of a SF on a particular target class, generating synthetic data to improve predictive performance and modeling guidelines for SF development. WIREs Comput Mol Sci 2015, 5:405–424. doi: 10.1002/wcms.1225This article is categorized under:

Computer and Information Science > Chemoinformatics
Hydrothermal Synthesis, Crystal Structures, and Catalytic Properties of Three Coordination Polymers Containing ­Flexible Bis(benzimidazole) and Dicarboxylate Ligands
Authors: Hu Ju‐Meng , Liu Yong‐Guang , Van Hecke Kristof , Cui Guang‐Hua 
Published: August 2015

AbstractThree metal‐organic coordination polymers, namely {[Cd(L1)(1,2‐chdc)]·2H2O}n (1), {[Ni(L2)(1,2‐chdc)]·H2O}n (2), and [Cd(L2)(npht)]n (3) [L1 = 1,2‐bis(2‐methylbenzimidazol‐1‐ylmethyl)benzene, L2 = 1,2‐bis(5,6‐dimethylbenzimidazol‐1‐ylmethyl)benzene, 1,2‐H2chdc = 1,2‐cyclohexanedicarboxylic acid, H2npht = 3‐nitrophthalic acid] were synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction methods, IR spectroscopy, TGA, and elemental analysis. In compound 1, two 1,2‐chdc2– ligands connect two neighboring Cd atoms to form a dinuclear [Cd2(1,2‐chdc)2] subunit, which is further linked by L1 ligands to construct a 1D ladder‐like chain. Compound 2 exhibits a 2D (4,4) coordination network with {44.62} topology, whilst compound 3 shows a 1D helical chain structure. The fluorescence, UV/Vis diffuse reflection spectra, and catalytic properties of complexes 1–3 for the degradation of the congo red azo dye in a Fenton‐like process are investigated.
The Syntheses, Structures, and Magnetic Properties of Four 2D Lanthanide(III)‐naphthalenedicarboxylic Complexes
Authors: Lu Ying‐Bing , Chen Lei‐Peng , Zhang Shi‐Yong , Lian Ping , Xie Yong‐Rong 
Published: August 2015

AbstractFour Ln‐NDC coordination polymers [Ln(NDC)(HNDC)(H2O)] (Ln = La (1), Pr (2), Nd (3), Sm (4), H2NDC = 1,4‐naphthalenedicarboxylic acid) were hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, and single‐crystal X‐ray diffraction. Compounds 1–4 are isomorphous, and their structures display a layer constructed from a Ln‐organic chain and NDC2– ligand, in which the H2NDC ligands adopt two different acidity‐dependent types and coordination modes: HNDC1– with μ‐η1:η1 and NDC2– with μ‐η1:η2:η1:η2. The 3D supramolecular networks of 1–4 are mainly controlled by hydrogen bonds interactions. The magnetic susceptibilities of complexes 2–4 reveal overall antiferromagnetic interactions between the LnIII ions. In addition, thermogravimetric analysis of compound 2 is described.
A New N‐Trityl‐Substituted Aminopyridinato Titanium Catalyst for Hydroamination and Hydroaminoalkylation Reactions – Unexpected Intramolecular C–H Bond Activation
Authors: Lühning Lars H. , Brahms Christian , Nimoth Jelte P. , Schmidtmann Marc , Doye Sven 
Published: August 2015

AbstractSterically demanding 2,6‐bis(tritylamino)pyridine is used for the synthesis of a mono(2,6‐diaminopyridinato) titanium complex that undergoes unexpected intramolecular C–H bond activation to give access to an unusual 1‐titanaisoindoline derivative. Both titanium complexes do not show high catalytic activity for hydroaminoalkylation reactions of alkenes but exceptional results are obtained in the field of alkene, alkyne, and allene hydroamination including room temperature activity for intramolecular alkene hydroamination, excellent regioselectivity of intermolecular alkyne and allene hydroamination as well as selectivity for hydroamination over hydroaminoalkylation during cyclization reactions of primary aminoalkenes.
The Double Molybdate Rb2Ba(MoO4)2: Synthesis, Crystal Structure, Optical, Thermal, Vibrational Properties, and Electronic Structure
Authors: Zhou Molin , Jiang Xingxing , Li Chao , Lin Zheshuai , Yao Jiyong , Wu Yicheng 
Published: August 2015

AbstractThe double molybdate Rb2Ba(MoO4)2 was synthesized by high temperature solid‐state reaction. According to the single‐crystal X‐ray diffraction structure determination, it is isostructural to the mineral Palmierite K2Pb(SO4)2 in the trigonal space group Rm. Its structure can be described as layers of MoO4 tetrahedra corner‐sharing with distorted BaO6 octahedra, while the layers are separated by bi‐layers of rubidium cations in 10‐coordinate environment. UV/Vis‐NIR spectroscopy measurement indicates that Rb2Ba(MoO4)2 has an indirect bandgap of 4.40 eV, comparable to the calculated value 4.21 eV. The DSC test demonstrates the melting point and incongruent melting characteristic of the title compound. About seven narrow Raman lines were observed in the Raman spectrum recorded for Rb2Ba(MoO4)2 powder sample.
The Missing Link: Manganese Complexes with Sterically Demanding Pyrrolyl Ligands
Authors: Kreye Markus , Freytag Matthias , Daniliuc Constantin G. , Jones Peter G. , Walter Marc D. 
Published: August 2015

AbstractReaction of NaPyrtBu2 [PyrtBu2 = 2, 5‐(Me3C)2C4H2N] and KPyrtBu2Me2 [PyrtBu2Me2 = 2, 5‐(Me3C)2‐3, 4‐Me2C4N] with MnI2(thf)3 resulted in the isolation of the first bis(pyrrolyl)manganese(II) complexes. However, different coordination modes are realized depending on the identity of the Pyr‐ligand. For example, the MnII atom is κN coordinate in [(κN‐PyrtBu2)2Mn] (1‐Mn), whereas several different species were isolated with the more bulky PyrtBu2Me2 ligand. Depending on the reaction conditions the κN‐coordinate complex [(κN‐PyrtBu2Me2)2Mn] (2‐Mn′) is initially formed, but converts on sublimation to the η3 coordinate isomer [(η3‐PyrtBu2Me2)2Mn] (2‐Mn′). In some cases we could also identify a THF adduct of 2‐Mn to give [(κN‐PyrtBu2Me2)(η2‐PyrtBu2Me2)Mn(thf)] [2‐Mn(thf)], in which one PyrtBu2Me2 ligand binds in a κN coordination mode, while the other is best described as η2‐PyrtBu2Me2. These complexes were characterized by elemental analyses and X‐ray diffraction studies. Density functional theory (DFT) computations confirm that the potential energy surface between the different hapticities is rather flat for these MnII high‐spin species (S = 5/2).