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A straightforward and efficient electrochemical method for the anodic oxidative selenenylation of 2-(2-arylallyl)phenols and a 2-(3-arylbut-3-en-1-yl)phenol with diselenides under ambient air conditions has been outlined. This method allows for the synthesis of selenyl-dihydrobenzofurans and a chromane featuring a sterically hindered tetrasubstituted carbon center, demonstrated through 25 examples with yields reaching up to 98%. Initial mechanistic investigations suggest the likely participation of pivotal seleniranium cation species in regulating the reactivity. [ABSTRACT FROM AUTHOR]

As the models for studying defected graphene, π‐conjugated systems containing heptagonal rings have attracted increasing interest due to their dynamic behaviors, electronic properties, aromaticity, and solid‐state packing. Doping heptagon‐containing π‐conjugated systems with boron not only makes π‐conjugated systems with the boron‐doped heptagonal ring have structural similarity to their all‐carbon analogues, but also could significantly change their electronic properties and intermolecular interactions. This review summarizes research on the different synthetic routes to access boron‐doped heptagons including borepins, azaborepins, and oxaborepins, with the emphasis on the structure‐property relationships at the molecular level. [ABSTRACT FROM AUTHOR]

One‐pot solvothermal reaction of 2‐aminopyridine and triethyl orthoformate with Ni(OAc)2 ⋅ 4H2O afforded a one dimensional (1D) nickel coordination polymer {[Ni(Dpyf′)] ⋅ MeOH}n (Dpyf′=C11H9N4−), 1, which has been structurally characterized by using single crystal X‐ray crystallography. Complex 1 can be considered as a potential heterogeneous catalyst for nitroaldol (Henry) reaction for C−C bond formation. [ABSTRACT FROM AUTHOR]

A method of designing beam steering microstrip antennas using reconfigurable parasitic patches is proposed in this article. The first beam steering antenna is composed of a driven patch and two parasitic patches placed on the H‐plane of the antenna. The effect of the length and width of parasitic patches, and the spacing between the driven and parasitic elements on the radiation pattern of the antenna is analyzed in detail. The parasitic patch is loaded with a varactor in the center with its dc biasing network. By adjusting the capacitance value of the varactor, the electrical sized of the parasitic patch is changed to achieve beam steering. Maintained impedance matching can be obtained without compensation structure. An experimental antenna is designed and fabricated to verify the method. The measured return loss is better than 12 dB at the center frequency 2.4 GHz for all cases and the measured gain is from 6.5 to 7.6 dBi. The beam steering angles of the simulation and measured results are ±45° and ± 35°, respectively. [ABSTRACT FROM AUTHOR]

A novel thio-Ritter-type reaction of alkyl bromides, nitriles, and hydrogen sulfide has been explored, providing a straightforward approach toward functionally important thioamides. This transformation features a broad substrate scope, operational simplicity, use of available feedstock chemicals, and late-stage functionalizations of bioactive molecules. The reaction mechanism is also proposed. [ABSTRACT FROM AUTHOR]

The marine sulfur cycle is highly sensitive to redox environments at the Earth's surface. Fluctuations in atmospheric p O 2 level or marine redox environments are commonly associated with changes in seawater sulfate concentration, sulfate sulfur (S) and oxygen (O) isotopes. Thus, the marine S cycle through the Earth's ancient past provides a first-order constraint on the redox evolution of the Earth's surface. Reconstructions of the marine S cycle have been approached through analyses of various sulfate-bearing geological materials, such as sedimentary barite, evaporitic sulfate (e.g., gypsum), carbonate associated sulfate (CAS), and phosphate-associated sulfate (PAS) in phosphatic ores. These geological materials have their own pros and cons. In this study, we focus on PAS in Lingula brachiopods, which possess phosphatic shells and have a long evolutionary history since Cambrian times. Biogenic phosphate typically has a higher sulfate concentration than carbonate and phosphate ores, and is less vulnerable to diagenetic alteration. Here, we analyzed modern Lingula shells from the South China Sea and fossil Lingula shells collected from the Late Devonian Xiejingsi Formation of South China. Living and fossil Lingula shells have similar P/S ratios (PO 4 3−/SO 4 2−) of ∼76, and S and O isotopes of PAS (δ34S PAS and δ18O PAS) in each group show limited variations. For living Lingula shells, the mean values of δ34S PAS and δ18O PAS are +15.0 ± 1.5‰ and + 9.8 ± 0.4‰, respectively, which are ∼6‰ lower and comparable to those of modern seawater sulfate compositions (δ34S SW and δ18O SW-SO4), probably due to vital effects. For fossil Lingula shells, δ18O PAS (14.1 ± 0.9‰) is identical to coeval evaporite. The range of δ34S PAS is encompassed by the values of both coeval evaporite and CAS, but the mean value of δ34S PAS (29.5 ± 0.9‰) is higher. Thus, fossil Lingula shells show a good potential for reconstructing δ34S SW and δ18O SW-SO4 values. • Sulfate from modern Lingula shells, with stable P/S ratio, δ34S, and δ18O, can reconstruct δ34S and δ18O of seawater sulfate. • Seawater sulfate δ34S reconstructed by fossil Lingula shells are higher than the δ34S of coeval evaporite and CAS. • Phosphate associated sulfate from Lingula shells might be a more reliable achieve of seawater sulfate than evaporite and CAS. [ABSTRACT FROM AUTHOR]

In this article, a radiant metal block structure is proposed for designing reduced-size cavity-backed filtering antenna. The method of characteristic mode analysis is used to investigate the characteristic current modes of the cubic metal block, one of which can maintain a high inherent radiation capacity over a wideband. In addition, the radiation quality factor of the utilized mode is described in detail. Based on this characteristic current mode, metal block antennas with different bandwidths can be designed to realize broadside radiation. The proposed metal block antenna element can maintain stable radiation characteristics in the passband and the realized gain is greater than 9 dBi. To design the filtering antennas, the proposed metal block is cascaded with traditional resonant cavities. A third-order metal block filtering antenna array is fabricated for verification. The measurement results are basically consistent with the simulated ones. The maximum measurement gain is 12.85 dBi and the gain in the passband is flat. [ABSTRACT FROM AUTHOR]

In this article, high selectivity filtering antennas are designed based on a mixed-mode cavity resonator, which is formed by adding a short-circuited metal cylinder at the center of a rectangular cavity. The resonant and coupling characteristics of the proposed resonator are analyzed in detail. The operating modes of the mixed-mode cavity are TE102 mode, TE012 mode, and quasi-TEM mode, which can be utilized to design filtering antennas with different transmission zero distributions. To demonstrate the concept, three slot antennas with 3rd-order filtering performance are designed and simulated, where two transmission zeros are introduced to improve the selectivity. Furthermore, a 5th-order filtering antenna array based on the mixed-mode resonator is designed and fabricated. The measured results are consistent with the simulated results, showing that a gain of greater than 13 dBi is achieved. [ABSTRACT FROM AUTHOR]

In this article, a method for designing a tunable coaxial filtering antenna is presented. The proposed filtering antenna has a simple structure, consisting of a standard waveguide and some metal cylinders. Instead of utilizing traditional coupling irises, an all-cylinder coupling structure is employed for flexible tuning. Thus, the center frequency and bandwidth of the coaxial filtering antenna can be conveniently tuned by adjusting the lengths of the cylinders. Theoretical analysis and design process of the filtering antenna are given in detail. A third-order tunable filtering antenna with Chebyshev response is designed to verify this method. The tunable range of the center frequency is from 9.25 to 10.75 GHz, and the tunable range of the fractional bandwidth (FBW) is from 2% to 8%. The measured gain of the antenna is flat and greater than 6.5 dBi along the tuning range. In addition, the antenna maintains good impedance and radiation characteristics throughout the tuning range. [ABSTRACT FROM AUTHOR]

A method of designing beam-steerable patch antennas with wide stopband suppression is proposed in this article. The wide stopband suppression characteristic is realized by designing suitable parallel coupled lines and open-circuited stubs. The beam steering characteristic is achieved by using a driven patch and two pairs of metal walls vertically placed on both sides of the driven antenna. By controlling the different states of the switching PIN diodes loaded between metal walls, the stable beam steering characteristic can be obtained over the entire operating bandwidth. An experimental antenna is designed and manufactured to validate the approach. The beam steering angles of the simulation and measurement results are ±30°. Moreover, in the three proposed operating states, the out-of-band suppression from 2.6 GHz to 10 GHz is more than 16 dB. The proposed antenna can achieve the characteristic of both wide stopband suppression and beam steering. In addition, the proposed antenna is able to maintain good impedance characteristics during beam steering and maintain stable beam over the entire operating bandwidth. [ABSTRACT FROM AUTHOR]

Herein, the construction of 3-indolemalononitriles via base-promoted tandem decarboxylative propargylation/aromatization cascade of ethynyl benzoxazinanones with N,N -disubstituted aminomalononitriles has been developed. This protocol features mild reaction conditions, high efficiency and no need of transition metals. Various 3-indolemalononitriles can be obtained in moderate to excellent yields from readily available starting materials. More importantly, this method can be further applied to the synthesis of a wide range of indole products, paving the way for the development of new bioactive molecules. [Display omitted] Herein, the construction of 3-indolemalononitriles via base-promoted tandem decarboxylative propargylation/aromatization cascade of 4-ethynyl benzoxazinones with N,N -disubstituted aminomalononitriles has been developed. This protocol features mild reaction conditions, high efficiency and no need of transition metals. Various 3-indolemalononitriles can be obtained in moderate to excellent yields from readily available starting materials. More importantly, this method can be further applied to the synthesis of a wide range of complex indole products. [ABSTRACT FROM AUTHOR]

Gene therapy is the most effective treatment option for diseases, but its effectiveness is affected by the choice and design of gene carriers. The genes themselves have to pass through multiple barriers in order to enter the cell and therefore require additional vectors to carry them inside the cell. In gene therapy, peptides have unique properties and potential as gene carriers, which can effectively deliver genes into specific cells or tissues, protect genes from degradation, improve gene transfection efficiency, and enhance gene targeting and biological responsiveness. This paper reviews the research progress of peptides and their derivatives in the field of gene delivery recently, describes the obstacles encountered by foreign materials to enter the interior of the cell, and introduces the following classes of functional peptides that can carry materials into the interior of the cell, and assist in transmembrane translocation of carriers, thus breaking through endosomal traps to enable successful entry of genetic materials into the nucleus of the cell. The paper also discusses the combined application of peptide vectors with other vectors to enhance its transfection ability, explores current challenges encountered by peptide vectors, and looks forward to future developments in the field. [Display omitted] [ABSTRACT FROM AUTHOR]

Based on the static capacitance-voltage (${C}-{V}$) model, a new analytical frequency-dependent ${C}-{V}$ model of thin-film transistors (TFTs) is derived from a modified transmission line method (TLM), which is built by embedding an equivalent circuit corresponding to the trapped electrons effect into the traditional TLM. The proposed model is well verified by the measured ${C}-{V}$ characteristics of bottom-gated indium-zinc–oxide (IZO) TFTs with ${W} / {L} =100 \boldsymbol {\mu }{\text {m}} /10 \boldsymbol {\mu }\text {m}$ and ${W} / {L} =100 \boldsymbol {\mu }\text {m} /40 \boldsymbol {\mu }\text {m}$ , where frequencies vary from 1 kHz to 1 MHz. The cutoff frequency of metal oxide TFTs is furthermore analyzed based on the proposed model compared with the traditional TLM. [ABSTRACT FROM AUTHOR]

In this communication, a high-selectivity and high-gain filtering slot antenna operating in $X$ -band is designed based on a triple-mode cavity resonator. Three modes of the cavity resonator, namely, TE101, TE011, and TM110, are excited by properly selecting the position and size of the coupling aperture. By adjusting the frequency and external coupling of the three modes, transmission zero can be introduced on both sides of the passband, achieving high selectivity of antenna gain. Because the cavity has a high unload quality factor, the radiation efficiency in the passband is high and flat. In order to increase the gain of the filtering waveguide antenna, a grid-slotted patch is added on the top of the slot. To demonstrate the concept, an $X$ -band waveguide filtering antenna is designed and fabricated. Measured results show the filtering antenna can obtain a gain of greater than 8.5 dBi in the frequency range of 9.8–10.2 GHz. [ABSTRACT FROM AUTHOR]

Zn(II) and Cd(II) coordination polymers constructed from a new angular bis-pyridyl-bis-amide ligand and naphthalene-1,4-dicarboxylic acid (1,4-H2NDC), {[Zn2(L)(1,4-NDC)2]·2H2O} [L = 4,4′-oxybis(N-(pyridin-3-ylmethyl)benzamide)], 1, and {[Cd2(L)(1,4-NDC)2]·EtOH}, 2, have been solvothermally synthesized and structurally characterized by using single-crystal X-ray diffraction. While complex 1 displays a 2D double layer with the rare (46·64)-5 L4 topology, complex 2 shows a 3D framework with a new (4·5·6)(45·55·69·7·8) topology. Both complexes 1 and 2 display luminescence properties and 2 exhibits a high sensitivity toward the detection of Fe3+ ions with a Ksv value of 1.9 × 104 M−1. The quenching effect can most probably be ascribed to the interactions between the metal ions and the amide carbonyl oxygen atoms. [ABSTRACT FROM AUTHOR]

A method of designing a printed filtering dipole antenna using codesign of bandpass filter (BPF) and antenna is proposed in this article. The printed dipole antennas consist of two identical arms, which are placed on the opposite sides of the substrate. One arm of the dipole is used to construct the half-wavelength resonator of a typical BPF, and thus filtering and radiation performance can be obtained simultaneously. A third-order filtering dipole antenna is designed and analyzed in detail to demonstrate the codesign method. The measured S11 of the filtering dipole antenna is less than −11 dB in the range of 0.94–1.094 GHz and the peak gain is 7.8 dBi. To extend this design method, a third-order ±45° dual-polarized filtering dipole antenna is designed and measured. The measured S11 and S22 of the ±45° dual-polarized filtering dipole antenna are both less than −11 dB in the range of 0.94–1.08 GHz. Besides, the isolation between them is higher than 20 dB in the passband. The measured radiation patterns show that the dual-polarized filtering dipole antenna would be a potential candidate for base stations. [ABSTRACT FROM AUTHOR]

This paper deals with robust ε-quasi optimal solutions for a class of nonsmooth optimization problems with uncertain data. Under some mild assumptions, we first establish, by using robust optimization (i.e. worst-case) approach, approximate optimality conditions for this uncertain nonsmooth optimization problem. Then, we introduce a Mixed-type robust approximate dual problem of this uncertain optimization problem, and explore their relationships. Moreover, using a scalarization method, we derive optimality conditions for robust weakly approximate efficient solutions for an uncertain nonsmooth multiobjective optimization problem. We also obtain approximate duality theorems for the uncertain nonsmooth multiobjective optimization problem. [ABSTRACT FROM AUTHOR]

In this article, we present a design method of high-selectivity filtering antennas based on a dual-probe feeding structure. The first stage of the filtering circuit consists of two or three coupled resonators which are then coupled to the radiating patch acting as the last resonator of the filter. Cross-coupling is used to obtain transmission zero, and thus the selectivity of the filtering antennas is improved. A cascaded triplet (CT) filtering patch antenna, which produces a radiation zero at the high-frequency edge of the passband, and a cascaded quadruplet (CQ) filtering patch antenna, which produces radiation zeros at both edges of the passband, are designed for verification. The process of designing the filtering patch antenna is given in detail. The designed CT filtering patch antenna has a bandwidth of 1.029–1.17 GHz and a radiation zero at 1.19 GHz. The designed CQ filtering patch antenna has a bandwidth of 1.029–1.17 GHz and two radiation zeros at 1.012 and 1.19 GHz, respectively. The peak gain of the CT filtering patch antenna is 9.35 dBi and that of the CQ filtering patch antenna is 9.16 dBi. A dual-polarized CQ filtering patch antenna is fabricated, showing a good performance in measurement. [ABSTRACT FROM AUTHOR]

A method for expanding the bandwidth of slot and patch antennas is proposed in this article. The use of grid‐slotted patch helps to improve the impedance matching of the antenna, thus the bandwidth can be extended. The design process and an analysis of using a grid of slots to increase the bandwidth of a slot antenna is first given. The simulated S11 of the broadband slot antenna is less than −11 dB in the range of 2.6 to 3.42 GHz. To further demonstrate the method, an aperture‐coupled patch antenna with grid‐slotted patch is designed. The measured S11 of the broadband patch antenna is less than −10 dB in the range of 1.95 to 4.15 GHz and the peak gain is 9.6 dBi. [ABSTRACT FROM AUTHOR]

In this paper, several Turán-type inequalities for the more generalized Mittag-Leffler function are proved. In addition, we also gave affirmative answers to two open problems posed by Mehrez and Sitnik. [ABSTRACT FROM AUTHOR]

One-pot solvothermal reactions of 2-aminopyridine, triethylorthoformate and sodium hydroxide with CuX (X = Br, and I) in dimethylformamide (DMF) and methanol (MeOH) afforded extended metal chains based on the linear tetracopper units, {[Cu4Br2(Dpyf)2]·DMF}n, 1, and [Cu4I2(Dpyf)2]n, 2, which were structurally identified by X-ray crystallography. Complexes 1 and 2 present closed-shell Cu(I)–Cu(I) interactions that are supported by formamidinate ligands, resulting in a face-to-side configuration and a face-to-face configuration, respectively, for the tetranuclear units. Complexes 1 and 2 represent the first example of one-dimensional (1D) coordination polymers that are based on linear tetracopper units. Moreover, complexes 1 and 2 can be regarded as copper(I) halide aggregates with the unique Cu4Br2 2+ and Cu4I2 2+ cations extending into a 1D zigzag chain and a looped chain, respectively. Complexes 1 and 2 show broad emissions at 570 and 549 nm, respectively, which can most probably be ascribed to 3d(Cu) → π* metal to ligand charge transfer. Reversible crystal-to-crystal transformation and luminescence change were observed for complex 1 upon solvent exchange, which can be regarded as a potential luminescent sensor for selective detection of water and methanol. [ABSTRACT FROM AUTHOR]

Solvothermal reactions of Cd(II) salts and naphthalene-1,4-dicarboxylic acid (1,4-H2NDC) with bis(N-pyrid-3-ylmethyl)adipoamide, L1, and bis(N-pyrid-3-ylmethyl)suberoamide, L2, afforded three Cd(II) coordination polymers, {[Cd(L1)(1,4-NDC)(H2O)]·H2O}n, 1, {[Cd(L2)(1,4-NDC)]·2H2O}n, 2, and {[Cd2(L2)(1,4-NDC)2]·3H2O}n, 3, which have been structurally characterized using single-crystal X-ray crystallography. Complex 1 forms a 2D layer with 44-sql topology, whereas 2 and 3 are 3D frameworks with rare {32·62·72}{32·65·73}2-4,5T61 and unique {32·54}{34·46·58·66·74}-sqc776 topologies, respectively. Complex 2 undergoes reversible crystal-to-crystal transformation to 3, while irreversible structural transformations from 1 to 2 and 3 to 1 can be carried out by linker exchange. Reorientation of the amide oxygen atoms that results in the change of the ligand conformation is proposed for the initiation of the crystal-to-crystal transformation. Complex 3 represents a unique example of a coordination polymer that is able to undergo both crystal-to-crystal transformation and linker exchange. [ABSTRACT FROM AUTHOR]

A novel broadband three-input four-output ($3 \times 4$) Butler matrix is proposed in this communication. The proposed Butler matrix achieves equal power division and −90°, 0°, and +90° phase differences between output signals in the 2–4 GHz frequency range. By using the $3 \times 4$ Butler matrix as a four-element antenna array feed network, a broadside beam and two symmetrical beams are realized over a wideband frequency range. The proposed Butler matrix has been verified by measurements of S-parameters and radiation patterns using the broadband four-element antenna array. The measurement results are in good agreement with the simulation results. In addition, the proposed $3 \times 4$ Butler matrix can be extended for use with antenna arrays with a higher number of beams. [ABSTRACT FROM AUTHOR]

2D coordination complexes [Cd(1,3-pbpa)(1,3-PDA)] n , 1 and [Cd(1,3-pbpa)(OBA)·2H 2 O] n , 2 , exhibit rare {84·122}{8}2-2,4L2 topology, and [Cd(1,3-pbpa)(1,4-BDC)(H 2 O)·EtOH·H 2 O] n , 3 shows a new topology having point symbol {12}{4·125}{4}. Desolvated product of 2 exhibits a better H 2 and CO 2 sorption compared to the activated product of 1 , indicating the effect of ligand type on the adsorption properties of 2D complexes. Solvothermal reactions of Cd(CH 3 COO) 2 and 2,2′-(1,3-phenylene)-bis(N-pyridin-3-yl)acetamide (1,3-pbpa) with 1,3-phenylenediacetic acid (1,3-H 2 PDA), 4,4′-oxybis(benzoic acid) (4,4′-H 2 OBA) and 1,4-benzenedicarboxylic acid (1,4-H 2 BDC) afforded [Cd(1,3-pbpa)(1,3-PDA)] n , 1 , [Cd(1,3-pbpa)(OBA)·2H 2 O] n , 2 , and [Cd(1,3-pbpa)(1,4-BDC)(H 2 O)·EtOH·H 2 O] n , 3 , respectively, which were structurally characterized as two-dimensional (2D) coordination polymers. Complexes 1 and 2 show the rare {84·122}{8}2-2,4L2 topology, whereas complex 3 adopts a new topology with a point symbol of {12}{4·125}{4}, which can be further simplified as the 44- sql topology and the 63- hcb topology, respectively. Desolvated product of 2 shows a moderate uptake of CO 2 and a good selectivity over N 2 , which also exhibits a better H 2 and CO 2 sorption compared to the activated product of 1 , indicating the effect of ligand type on the adsorption properties of 2D complexes with the 44- sql topology. Thermal gravimetric analysis (TGA) and the solid state luminescence properties of 1 – 3 have also been investigated. [ABSTRACT FROM AUTHOR]

This paper proposes a duplex dual circularly polarized antenna, using four half-Vivaldi antennas to form a sequential rotation array, which can generate circular polarization by sequential feeding. A mental cavity and half of a Vivaldi antenna form a new Vivaldi antenna. The Vivaldi antenna has broadband characteristics to cover the uplink and downlink bands and is compact with an area of 0. 69 λ c × 0. 69 λ c . To achieve duplex dual circular polarization, a feeding network that can sequentially output + 90 ° and − 90 ° is designed. The feeding network, which contains two broadband power dividers, two directional couplers and two phase-shifters, generates the sequential feeding signals for sequential rotation group array with equal amplitude and ± 90 ° phase difference. Both the impedance bandwidth and the 3 dB axial ratio bandwidth of the transmitter and receiver can cover the band of 10–15 GHz. The gain of the antenna is higher than 5.75 dBi. The isolation between the receive and the transmit ports can reach 25.49 dB or higher in the uplink band. [ABSTRACT FROM AUTHOR]

The total variation (TV) regularization has been widely used in statistically iterative cone-beam computed tomography (CBCT) reconstruction, showing ability to preserve object edges. However, the TV regularization can also produce staircase effect and tend to over-smooth the reconstructed images due to its piecewise constant assumption. In this study, we proposed to use the structure tensor total variation (STV) that penalizes the eigenvalues of the structure tensor for CBCT reconstruction. The STV penalty extends the TV penalty, with many important properties maintained such as convexity and rotation and translation invariance. The STV penalty utilizes gradient information more effectively and has a stronger ability to capture local image structural variation. The objective function was constructed with the penalized weighted least-square (PWLS) strategy and the gradient descent (GD) method was used to optimize the objective function. Besides, we investigated whether the norms involved in the STV penalty affected the reconstruction performance and found that the l1-norm gave the better performance than the l2-norm and l ∞-norm. We also examined performance of the STV penalties constructed using different kernel functions and found that the STV with the Gaussian kernel had the best performance, and the STVs with Uniform, Logistic, and Sigmoid kernels had similar performance to each other. We evaluated our reconstruction method with the STV penalty on computer simulated phantoms and physical phantoms. The results demonstrated that STV led to better reconstruction performance than TV, both visually and quantitatively. For the Catphan 600 physical phantom, the STV1 penalty was 175% and 623% better than the low-dose FDK and the high-dose FDK, and 14% better than the TV penalty at the matched noise level, according to the average contrast-to-noise ratio (CNR); while for the Compressed Sensing simulation phantom, the peak signal to noise ratio (PSNR) of reconstructed results using STV1, STV2, and STV ∞ were 40.67 dB, 38.72 dB, and 37.40 dB, respectively, all being significantly better than 36.84 dB using TV. [ABSTRACT FROM AUTHOR]

Abstract Recently, uniformly valid asymptotic solutions of rod eutectic growth for liquid-solid interface slopes at triple phase junction being the normal order have been presented in reference (Li and Xu, 2017). In this work, analytical calculations of rod eutectic growth during directional solidification for liquid-solid interface of small order are performed. The purpose is to study the liquid-solid interfacial shape and average undercooling of rod eutectic growth. We give the mathematical formulation of rod eutectic growth for the general case. The steady solutions of rod eutectic growth are obtained by using asymptotic expansion method and matching method. The relationship of the overall average interfacial undercooling with the rod eutectic spacing is presented. The overall average interfacial undercooling always exists a minimum value at the minimum-undercooling spacing, and the minimum-undercooling spacing is slightly smaller than one given by Jackson and Hunt. We also analyze the effect of pulling speeds and thermal gradients on the interfacial shapes for the case of the minimum-undercooling spacing. [ABSTRACT FROM AUTHOR]

The syntheses, structures and thermal properties of six coordination polymers based on semi-rigid N,N′ -bis(3-pyridinyl)terephthalamide ( L 1 ), flexible N,N′ -di(3-pyridyl)adipoamide ( L 2 ) and N,N′ -di(3-pyridyl)suberoamide ( L 3 ) and auxiliary dicarboxylate ligands, [M( L 1 )(AIPA)·2H 2 O] n , (M = Ni, 1 ; Co, 2 ; H 2 AIPA = 5-acetamido isophthalic acid), [Ni( L 2 )(AIPA)(H 2 O) 2 ] n , 3 , [Co( L 2 ) 0.5 (AIPA)(H 2 O)] n , 4 , [Co( L 3 )(2,4-PDC)(H 2 O)] n (2,4-H 2 PDC = 2,4-pyridinedicarboxylic acid), 5 , and [Co( L 3 )(5-Br-IPA)(H 2 O)] n (5-Br H 2 IPA = 5-bromoisophthalic acid), 6 , are reported, which have been structurally characterized by X-ray crystallography. Complexes 1 and 2 are isomorphous, forming 3D nets with the new (4⋅6⋅8)(4⋅6 4 ⋅8 5 ) topology, which can be further simplified as self-catenated networks with the (4 24 ⋅6 4 )-8T2 topology, while 3 is a 1D looped chain and 4 and 6 show 2D layers with the (4 2 ⋅6 3 ⋅8)(4 2 ⋅6)-3,4L83 and (4 4 ⋅6 2 )- sql topologies, respectively. Moreover, complex 5 shows quadruple-strained helices formed by cobalt ions and L 3 ligands, which are supported by 2,4-PDC 2- anions to construct the rare single-walled metal-organic nanotubes that are supported by extensive N H --O and O H --O hydrogen bonds. The roles of ligand flexibility and the identity of the metal ion in the formation of 1 – 6 as well as their thermal properties are discussed. [ABSTRACT FROM AUTHOR]

Cone-beam computed tomography (CBCT) plays an important role in radiation therapy. Statistical iterative reconstruction (SIR) algorithms with specially designed penalty terms provide good performance for low-dose CBCT imaging. Among others, the total variation (TV) penalty is the current state-of-the-art in removing noises and preserving edges, but one of its well-known limitations is its staircase effect. Recently, various penalty terms with higher order differential operators were proposed to replace the TV penalty to avoid the staircase effect, at the cost of slightly blurring object edges. We developed a novel SIR algorithm using a neural network for CBCT reconstruction. We used a data-driven method to learn the “potential regularization term” rather than design a penalty term manually. This approach converts the problem of designing a penalty term in the traditional statistical iterative framework to designing and training a suitable neural network for CBCT reconstruction. We proposed using transfer learning to overcome the data deficiency problem and an iterative deblurring approach specially designed for the CBCT iterative reconstruction process during which the noise level and resolution of the reconstructed images may change. Through experiments conducted on two physical phantoms, two simulation digital phantoms, and patient data, we demonstrated the excellent performance of the proposed network-based SIR for CBCT reconstruction, both visually and quantitatively. Our proposed method can overcome the staircase effect, preserve both edges and regions with smooth intensity transition, and provide reconstruction results at high resolution and low noise level. [ABSTRACT FROM AUTHOR]

Solvothermal reactions of HgX2 salts with the new bis-pyridyl-bis-amide ligand 2,2′-(1,3-phenylene)-bis(N-(pyridin-3-yl)acetamide) (1,3-pbpa) in acetonitrile afforded the complexes [Hg(1,3-pbpa)X2]n (X = Cl, 1; Br, 2; I, 3), while the complexes [Hg(1,3-pbpa)X2·MeCN]n (X = Br, 4; I, 5) were obtained by layering solutions of HgX2 and 1,3-pbpa at room temperature. Complexes 1 and 2 are isostructural one-dimensional (1D) helical chains different from the 1D helical chain 3 in spans, which are 18.0, 18.3 and 29.1 Å, respectively. Upon solvent adoption and removal, complexes 2 and 3 undergo reversible structural transformation into the 1D mesohelical chains 4 and 5 with spans of 29.1 and 29.9 Å, respectively. Pyridyl ring rotation and amide group reorientation are proposed for the structural transformation accompanied by a simultaneous change in luminescence. The structural transformation in 2 and 4 represents a unique example of elastic 1D helical chains that show stretching during the process. The roles of halide anions in the structural changes and the luminescence properties of 1–5 are also discussed. [ABSTRACT FROM AUTHOR]

Ten coordination polymers constructed from divalent metal salts, polycarboxylic acids, and bis-pyridyl-bis-amide ligands with different donor atom positions and flexibility are reported. They were structurally characterized by single-crystal X-ray diffraction. The ten coordination polymers are as follows: (1) {[Ni(L1)(3,5-PDA)(H2O)3].2H2O}n (L1 = N,N'-di(3-pyridyl)suberoamide, 3,5-H2PDA = 3,5-pyridinedicarboxylic acid); (2) {[Ni2(L1)2(1,3,5-HBTC)2(H2O)4].H2O}n (1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid); (3) {[Ni(L2)(5-tert-IPA)(H2O)2].2H2O}n (L2 = N,N'-di(3-pyridyl)adipoamide, 5-tert-H2IPA = 5-tert-butylisophthalic acid); (4) [Ni(L3)1.5(5-tert-IPA)]n (L3 = N,N'-di(4-pyridyl)adipoamide); (5) [Co(L1)(1,3,5-HBTC)(H2O)]n; (6) {[Co3(L1)3(1,3,5-BTC)2(H2O)2].6H2O}n; (7) [Cu(L4)(AIPA)]n (L4 = N,N'-bis(3-pyridinyl)terephthalamide, H2AIPA = 5-acetamido isophthalic acid); (8) {[Cu(L2)0.5(AIPA)].MeOH}n; (9) {[Zn(L4)(AIPA)].2H2O}n; and (10) {[Zn(L2)(AIPA)].2H2O}n. Complex 1 forms a 1D chain and 2 is a two-fold interpenetrated 2D layer with the sql topology, while 3 is a 2D layer with the hcp topology and 4 shows a self-catenated 3D framework with the rare (42.67.8)-hxg-d-5-C2/c topology. Different Co/1,3,5-H3BTC ratios were used to prepare 5 and 6, affording a 2D layer with the sql topology and a 2D layer with the (4.85)2(4)2(83)2(8) topology that can be further simplified to an hcp topology. While complex 7 is a 2D layer with the (42.66)-3,5L2 topology and 8 is a 2-fold interpenetrated 3D framework with the pcu topology, complexes 9 and 10 are self-catenated 3D frameworks with the (424.64)-8T2 and the (44.610.8)-mab topologies, respectively. The effects of the identity of the metal center, the ligand isomerism, and the flexibility of the spacer ligands on the structural diversity of these divalent coordination polymers are discussed. The luminescent properties of 9 and 10 and their photocatalytic effects on the degradation of dyes are also investigated. [ABSTRACT FROM AUTHOR]

A simple and convenient procedure for the preparation of valuable bis-1,3-dicarbonyl-substituted methane compounds and their derivatives has been developed using inert dichloromethane as one-carbon source in good to excellent yields. [Display omitted] A simple and convenient procedure for the preparation of valuable bis-1,3-dicarbonyl-substituted methane compounds and their derivatives has been developed using inert dichloromethane as one-carbon source in good to excellent yields. The advantages of this protocol are mild reaction conditions, easily scalable and good functional group compatibility. Moreover, the use of cyclic secondary amine as the promoter avoids the presence of transition metal catalysts and oxidants. [ABSTRACT FROM AUTHOR]

Solvothermal reactions of HgX2 with 2,2'-(1,2-phenylene)-bis(N-pyridin-3-yl)acetamide, L, in ethanol afforded [Hg(L)X2] n (X = Cl, 1; Br, 2; I, 3), which are isostructural one-dimensional (1D) zigzag chains, while layering reactions of a ethanoic solution of L with a methanoic solution and an acetonitrile solution of HgI2, respectively, gave 1D helical chains [Hg(L)I2·MeOH] n , 4, and [Hg(L)I2·MeCN] n , 5. In marked contrast to 1 and 2, the iodide-containing 3 is able to exhibit reversible structural transformation with 4 and 5 by adsorption and desorption of methanol and acetonitrile, suggesting the importance of N-H--X and Hg--X interactions in the evaluation of structural transformation. Moreover, complexes 4 and 5 exhibit reversible crystal to crystal transformation triggered by solvent exchange. Complexes 3-5 represent a unique example that the solvents show a significant effect on folding and unfolding of the HgI2 single-stranded helical coordination polymers. [ABSTRACT FROM AUTHOR]

The synthesis, structures and properties of five new coordination polymers containing isomeric N , N ′-di(pyridyl)suberoamide and polycarboxylate ligands, {[Cd(1,3-BDC)( L 1 )]·H 2 O} n [ L 1 = N , N ′-di(3-pyridyl)suberoamide; 1,3-H 2 BDC = benzene-1,3-dicarboxylic Acid] 1 ; [Cd(5-OH-IPA)( L 1 )] n (5-OH-IPA = 5-hydroxyisophthalic Acid), 2 ; {[Cd 3 (1,3,5-BTC) 2 ( L 1 ) 3 (H 2 O) 3 ]·8H 2 O} n (1,3,5-H 3 BTC = 1,3,5-benzenetricarboxylic Acid), 3 ; [Cd(5-Br-IPA)( L 2 )] n [ L 2 = N , N′ -di(4-pyridyl)suberoamide; 5-Br-H 2 IPA = 5-bromoisophthalic Acid], 4 ; [Cd(5- tert -IPA)( L 2 ) 0.5 ] n (5- tert -H 2 IPA = 5- tert -butylisophthalic acid), 5 , are reported, which have been characterized by single crystal X-ray diffraction. Complexes 1 and 2 show 2D double layers with the 3,5L2 topology and 3 reveals a 3D structure with the rare 3,4,4T90 topology. Complex 4 is a twofold interpenetrated 2D layer with a 2,6L1 topology and 5 shows a 3D coordination network with a rare 4,6T136 topology. In 5 , the L 2 ligand adopts a unique tetradentate bonding mode through two pyridyl nitrogen and two amide oxygen atoms. The structure-directing role roles of the substituent groups on the polycarboxylate ligands in determining the structural diversity are discussed. Their thermal and luminescent properties are also investigated. [ABSTRACT FROM AUTHOR]

Reactions of N,N'-bis(pyridine-4-yl)formamidine (4-Hpyf) with HgX2 (X = Cl, Br, and I) afforded the formamidinate complex {[Hg(4-pyf)2].(THF)}n, 1, and the formamidine complexes {[HgX2(4-Hpyf)].(MeCN)}n (X = Br, 2; I, 3), which have been structurally characterized by X-ray crystallography. Complex 1 is a 2D layer with the {44.62}-sql topology and complexes 2 and 3 are helical chains. While the helical chains of 2 are linked through N-H...Br hydrogen bonds, those of 3 are linked through self-complementary double N-H...N hydrogen bonds, resulting in 2D supramolecular structures. The 4-pyf- ligands of 1 coordinate to the Hg(II) ions through one pyridyl and one adjacent amine nitrogen atoms and the 4-Hpyf ligands of 2 and 3 coordinate to the Hg(II) ions through two pyridyl nitrogen atoms, resulting in new bidentate binding modes. Complexes 1-3 provide a unique opportunity to envisage the effect of the halide anions of the starting Hg(II) salts on folding and unfolding the Hg(II) coordination polymers. Density function theory (DFT) calculation indicates that the emission of 1 is due to intraligand π→π * charge transfer between two different 4-pyf- ligands, whereas those of 2 and 3 can be ascribed to the charge transfer from non-bonding p-type orbitals of the halide anions to π * orbitals of the 4-pyf- ligands (n→π *). The gas sorption properties of the desolvated product of 1 are compared with the Cu analogues to show that the nature of the counteranion and the solvent-accessible volume are important in determining their adsorption capability. [ABSTRACT FROM AUTHOR]

A series of coordination networks constructed from divalent metal ions, N,N ′-di(3-pyridyl)adipoamide ( L ) and phenylenediacetate ligands, including [Co( L ) 0.5 (1,2-pda)(H 2 O)] n (1,2-H 2 pda = 1,2-phenylenediacetic acid), 1 , [Co( L )(1,4-pda)] n (1,4-H 2 pda = 1,4-phenylenediacetic acid), 2 , [Ni 2 ( L ) 2 (1,2-pda) 2 (H 2 O) 2 ·4.5H 2 O] n , 3 , [Ni( L )(1,4-pda)(H 2 O) 0.5 ·2.5H 2 O] n , 4 , [Zn( L ) 0.5 (1,2-pda)] n , 5 , [CdBr( L )(1,2-pda) 0.5 ] n , 6 , and [CdI( L )(1,2-pda) 0.5 ] n , 7 , have been synthesized by hydrothermal reactions and structurally characterized by single crystal X-ray diffraction. Complexes 1 , 2 and 5 adopt the (4 2 ,6 3 ,8)(4 2 ,6)-3,4L83, (4 2 ,6 7 ,8)(4 2 ,6)-3,5L2 and (4 2 ,6 3 ,8)(4 2 ,6)-3,4L83 topologies, respectively, while 3 and 4 show the (4 8 ,6 7 )-6T2 and (4 8 ,6 7 )- sqc26 topologies, respectively, and both 6 and 7 display the (4 12 ,6 3 )- pcu topology. The L ligands in 3 adopt three different conformations, while the pda 2− ligands in 5 adopts the rare cis -conformation and those in the other complexes exhibit the trans -conformation. Moreover, the pda 2− ligands in complexes 1 , 2 and 5 display the μ 3 bonding mode to afford the 2D layer structures, in contrast to those in the other complexes that show the μ 4 and/or μ 2 bonding modes to form the 3D frameworks. The conformations of the L ligands are subject to the changes of metal ions and pda 2− ligands, resulting in various types of structure for 1 – 7 . Temperature-dependent PXRD patterns of complexes 1 , 3 and 4 indicate that their structural transformations upon removal of the water molecules are irreversible. The emission spectra of 6 and 7 reveal that the lower electronegativity of the iodide relative to the bromide has a significant effect on the bathochromic shift. [ABSTRACT FROM AUTHOR]

Functionalized silole with chiral structure was synthesized by convenient hydrosilylation reaction of 1-methyl-2,3,4,5-tetraphenyl-1 H -silole with 1,1′-binaphthyl-2,2′-diol (BINOL) derivative. The new functionalized silole is aggregation-induced emission (AIE) luminogen and shows chiral character of BINOL. The designed compound demonstrates highly potential to detect explosive in aqueous suspension because of its special steric structure. [ABSTRACT FROM AUTHOR]

Autotransporters (ATs) are associated with pathogenesis of Avian Pathogenic Escherichia coli (APEC). The molecular characterization of APEC ATs can provide insights about their relevance to APEC pathogenesis. Here, we characterized a conventional autotransporter UpaB in APEC DE205B genome. The upaB existed in 41.9 % of 236 APEC isolates and was predominantly associated with ECOR B2 and D. Our studies showed that UpaB mediates the DE205B adhesion in DF-1 cells, and enhances autoaggregation and biofilm formation of fimbria-negative E. coli AAEC189 (MG1655Δ fim) in vitro. Deletion of upaB of DE205B attenuates the virulence in duck model and early colonization in the duck lungs during APEC systemic infection. Furthermore, double and triple deletion of upaB, aatA, and aatB genes cumulatively attenuated DE205B adhesion in DF-1 cells, accompanying with decreased 50 % lethal dose (LD) in duck model and the early colonization in the duck lungs. However, DE205BΔ upaB/Δ aatA/Δ aatB might 'compensate' the influence of gene deletion by upregulating the expression of fimbrial adhesin genes yqiL, yadN, and vacuolating autotransporter vat during early colonization of APEC. Finally, we demonstrated that vaccination with recombinant UpaB, AatA, and AatB proteins conferred protection against colisepticemia caused by DE205B infection in duck model. [ABSTRACT FROM AUTHOR]

Electroanalytical, structural, and microanalytical techniques are combined to demonstrate the first clear and convincing case of electrochemical storage by Al‐ion intercalation in a Prussian blue analog host. In addition, a high power asymmetric capacitor using Al‐ion intercalation is demonstrated. Al, Fe, and Cu elemental maps of intercalated Al0.18 K0.02Cu[Fe(CN)6]0.7·3.7H2O obtained by transmission electron microscopy (TEM) energy‐dispersive X‐ray spectroscopy (EDX) area scan are shown. [ABSTRACT FROM AUTHOR]

In this paper, in the absence of any constraint qualifications, a sequential Lagrange multiplier rule condition characterizing optimality for a fractional optimization problem is obtained in terms of the $$\varepsilon $$ -subdifferentials of the functions involved at the minimizer. The significance of this result is that it yields the standard Lagrange multiplier rule condition for the fractional optimization problem under a simple closedness condition that is much weaker than the well-known constraint qualifications. A sequential condition characterizing optimality involving only subdifferentials at nearby points to the minimizer is also investigated. As applications, the proposed approach is applied to investigate sequential optimality conditions for vector fractional optimization problems. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the analgesic effects of remifentanil with fentanyl following pediatric cardiac surgery. Fifty patients were included in the study and were randomized into two groups. Patients in group R were given remifentanil (50 μg/ml) at an infusion rate of 0.07 μg/kg/min and with bolus doses of 0.25 μg/kg with a 5-min lockout time; group F patients received fentanyl (50 μg/ml) at an infusion rate of 0.1μg/kg/min and with bolus doses of 1 μg/kg with a 5-min lockout time. Pain was assessed using the Face, Legs, Activity, Cry, Consolability scale (FLACC scale), and sedation was assessed using the Ramsay sedation score. The number of boluses and demands, time to extubation, and side effects were analyzed. The FLACC scale, Ramsay sedation score, and mean extubation times were similar in the two groups. The total number of boluses and demands were significantly greater for group R than for group F. Itching as a side-effect was more severe in group F ( p < .05). NCA remifentanil and fentanyl offer similarly effective pain control after pediatric cardiac surgery, but remifentanil has fewer side effects than fentanyl, indicating the suitability of remifentanil for use in NCA systems. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we consider a DC infinite programming problem (P) with inequality constraints. By using the properties of the epigraph of the conjugate functions, we introduce some new notions of regularity conditions for (P). Under these new regularity conditions, we completely characterize the Fenchel–Lagrange duality and the stable Fenchel–Lagrange duality for (P). Similarly, we also completely characterize the Farkas-type results and the stable Farkas-type results for (P). As applications, we obtain the corresponding results for conic programming problems. [Copyright &y& Elsevier]

Graphene has attracted increasing attention in different scientific fields including catalysis. Via modification with foreign metal-free elements such as nitrogen, its unique electronic and spin structure can be changed and these doped graphene sheets have been successfully employed in some catalytic reactions recently, showing them to be promising catalysts for a wide range of reactions. In this review, we summarize the recent advancements of these new and interesting catalysts, with an emphasis on the universal origin of their catalytic mechanisms. We are full of hope for future developments, such as more precisely controlled doping methods, atom-scale surface characterization technology, generating more active catalysts via doping, and finding wide applications in many different fields. [ABSTRACT FROM AUTHOR]

By using the formula of the ε-sub differential for the sum of a convex function with a composition of convex functions, some necessary and sufficient optimality conditions for a DC programming problem involving a composite function are obtained. As applications, a composed convex optimization problem, a DC optimization problem, and a convex optimization problem with a linear operator are examined at the end of this paper. [ABSTRACT FROM AUTHOR]

In this article, gap functions for a generalized vector equilibrium problem (GVEP) with explicit constraints are investigated. Under a concept of supremum/infimum of a set, defined in terms of a closure of the set, three kinds of conjugate dual problems are investigated by considering the different perturbations to GVEP. Then, gap functions for GVEP are established by using the weak and strong duality results. As application, the proposed approach is applied to construct gap functions for a vector optimization problem and a generalized vector variational inequality problem. [ABSTRACT FROM AUTHOR]

Abstract: Compared to free Au nanoparticles, about 2-fold enhancement in SERS for the complex substrate of graphene-supported Au was observed via theoretical simulations. With the excitations of incident light, SERRS will play a more important role, giving an enhancement factor up to 10–100 for the supported Au compared to isolated Au. Electrons will transfer from graphene to Au and intend to gather on the upper surface of Au nanoparticles, strengthening both EM and CM. Meanwhile, the transferred electrons could raise the 6s orbital energy level of Au clusters up, increasing the probability for charge transfer from metal to probe molecules. [Copyright &y& Elsevier]

The vehicle delay tolerant networks (DTNs) make opportunistic communications by utilizing the mobility of vehicles, where the node makes delay-tolerant based 'carry and forward' mechanism to deliver the packets. The routing schemes for vehicle networks are challenging for varied network environment. Most of the existing DTN routing including routing for vehicular DTNs mainly focus on metrics such as delay, hop count and bandwidth, etc. A new focus in green communications is with the goal of saving energy by optimizing network performance and ultimately protecting the natural climate. The energy-efficient communication schemes designed for vehicular networks are imminent because of the pollution, energy consumption and heat dissipation. In this paper, we present a directional routing and scheduling scheme (DRSS) for green vehicle DTNs by using Nash Q-learning approach that can optimize the energy efficiency with the considerations of congestion, buffer and delay. Our scheme solves the routing and scheduling problem as a learning process by geographic routing and flow control toward the optimal direction. To speed up the learning process, our scheme uses a hybrid method with forwarding and replication according to traffic pattern. The DRSS algorithm explores the possible strategies, and then exploits the knowledge obtained to adapt its strategy and achieve the desired overall objective when considering the stochastic non-cooperative game in on-line multi-commodity routing situations. The simulation results of a vehicular DTN with predetermined mobility model show DRSS achieves good energy efficiency with learning ability, which can guarantee the delivery ratio within the delay bound. [ABSTRACT FROM AUTHOR]

This paper is concerned with gap functions of generalized vector variational inequalities (GVVI). By using scalarization approach, scalar-valued variational inequalities of (GVVI) are introduced. Some relationships between the solutions of (GVVI) and its scalarized versions are established. Then, by using these relationships and some mild conditions, scalar-valued gap functions for (GVVI) are established. [ABSTRACT FROM AUTHOR]

A natural "flow" over super-Brownian motions, which is not in Le Jan-Raimond framework on stochastic flows of measurable maps and kernels, is discovered in this paper. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we prove that via an operation “reducing”, every 3-connected representable matroid M with at least nine elements can be decomposed into a set of sequentially 4-connected matroids and three special matroids which we call freely-placed-line matroids, spike-like matroids and swirl-like matroids; more concretely, there is a labeled tree that gives a precise description of the way that M built from its pieces. [Copyright &y& Elsevier]