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A regular graph is semisymmetric if its automorphism group acts transitively on the edge set but not on the vertex set. In this article, we give a complete list of connected semisymmetric graphs of square‐free order and valency 5. The list consists of a single graph, the incidence graph of a generalized hexagon of order (4,4) $(4,4)$, and an infinite family arising from some groups with cyclic Fitting subgroup. [ABSTRACT FROM AUTHOR]

A bipartite graph is said to be biprimitive if its bipartition preserving automorphism group acts primitively on each part of the graph. In this paper, a complete classification is given for biprimitive edge-transitive pentavalent graphs. In particular, it is proved that, up to isomorphism, there exists a unique biprimitive semisymmetric pentavalent graph, which is the incidence graph of a generalized hexagon of order (4 , 4). [ABSTRACT FROM AUTHOR]

Abstract In this paper, based on the calculation using GAP, we give a classification result on arc-transitive Cayley digraphs of finite simple groups. Let G be a finite simple group and S ⊂ G ∖ { 1 } with | S | = 3 , S ≠ S − 1 and G = 〈 S S − 1 〉. If the Cayley digraph Γ = Cay (G , S) is arc-transitive, then Γ is either normal or isomorphic to one of 382 Cayley digraphs of the alternating group A 47. Further, we consider the underlying graphs and standard double covers of these 382 Cayley digraphs, and then we get 172 (non-isomorphic) half-transitive Cayley graphs of valency 6, and 144 semisymmetric cubic graphs. [ABSTRACT FROM AUTHOR]

Elastic wave in the seabed caused by low frequency noise radiated from ship is called ship seismic wave and can be used to identify ship target. In order to obtain the propagation features of ship seismic wave in shallow sea with thick sediment, this paper introduces an algorithm for synthetic seismogram aroused by low frequency point sound source in shallow sea based on Biot's wave theory for saturated porous media. Numerical calculation of synthetic seismogram at seafloor was carried out at a typical shallow sea environment with thick sediment. According to the results of numerical examples, the time series of seismic wave at seafloor is mostly composed of interface wave and leaky modes. The interface wave can propagate to far distance with small attenuation when the source frequency is very low. When the source frequency increases, the interface wave can no longer propagate to far distance like the leaky modes because the attenuation of sediment increases rapidly with frequency. The porosity and permeability of sediment in shallow sea have some influence on the dispersion characteristic of seismic wave at seafloor. [ABSTRACT FROM AUTHOR]

A graph is called 2-planar if it can be drawn in the plane such that each edge is crossed by at most other two edges. The weight of an edge is the sum of degrees of its ends. In the present paper, we focus on 3-connected 2-planar graphs with minimum degree 6 and show the existence of edges with weight at most 30 by a discharging process. [ABSTRACT FROM AUTHOR]

For a finite set V and a positive integer k with [ABSTRACT FROM AUTHOR]

Let $G$ be a finite group with $\mathsf{soc}(G)=\text{A}_{c}$ for $c\geq 5$. A characterization of the subgroups with square-free index in $G$ is given. Also, it is shown that a $(G,2)$-arc-transitive graph of square-free order is isomorphic to a complete graph, a complete bipartite graph with a matching deleted or one of $11$ other graphs. [ABSTRACT FROM AUTHOR]

An edge-transitive graph $$\varGamma $$ is called alternatively connected if a subgroup G of the automorphism group of $$\varGamma $$ has two orbits on the arc set of $$\varGamma $$ , and there exists an alternative walk (with respect to a given G-orbit on arcs) between every pair of vertices of $$\varGamma $$ . Employing the standard double covers of digraphs, we give some basic properties of alternatively connected edge-transitive graphs. The main result of this paper is a reduction result on alternatively connected edge-transitive graphs of square-free order. As an application of this result, we give a characterization for alternatively connected edge-transitive graphs of square-free order and valency 6. It is proved that such a graph is either a circulant or constructed from $$\mathrm{PSL}(2,p)$$ . [ABSTRACT FROM AUTHOR]

This paper is one of a series of papers devoted to characterizing edge-transitive graphs of square-free order. It presents a complete list of locally-primitive arc-transitive graphs of square-free order and valency d ∈ { 5 , 6 , 7 } . [ABSTRACT FROM AUTHOR]

A regular graph is said to be semisymmetric if it is edge-transitive but not vertex-transitive. In this paper, we give a complete list of connected semisymmetric cubic graph of square-free order, which consists of one single graph of order 210 and four infinite families of such graphs. [ABSTRACT FROM AUTHOR]

Elastic wave in the seabed caused by low frequency noise radiated from ship is the so-called ship seismic wave which can be used to identify ship target. In order to obtain the propagation characteristics of ship seismic wave in shallow sea with thick porous sediment, a 3D staggered grid finite difference algorithm for calculating seismic wave at seafloor is presented based on Biot wave theory for porous elastic sediment. Numerical calculation of seismic wave caused by low frequency sound source in a typical shallow sea environment is carried out. The calculated results show that the components of seismic wave in the near field include not only fast P-wave, slow P-wave and S-wave transmitted into the sediment, but also an interface wave which propagates nearby the seafloor. However in the far field, the wave components of seismic wave are mainly normal modes and interface wave, the former propagates mainly in the waveguide of sea water and the latter propagates along the seafloor. [ABSTRACT FROM AUTHOR]

A classification of connected vertex-transitive cubic graphs of square-free order is provided. It is shown that such graphs are well-characterized metacirculants (including dihedrants, generalized Petersen graphs, Möbius bands), or Tutte's 8-cage, or graphs arisen from simple groups PSL(2, p). [ABSTRACT FROM AUTHOR]

For the target performing relatively uniform linear motion in the fuze phase, a velocity vector estimation algorithm is proposed based on least square method using the measurements of Doppler velocities and angles of multiple scattering points obtained by the seeker radar. The estimation can be used to predict the explosion point and detonation time, thereby greatly enhancing the fuze performance. Numerical simulations have demonstrated the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Abstract: Let be a connected cubic Cayley graph, and let be the automorphism group of . It is proved in this note that either has non-trivial core in , or the stabilizer of a vertex of is non-abelian. [Copyright &y& Elsevier]

The hydroxyl-terminated polybutadiene (HTPB) possessing high content of 1,4-units was synthesized by anionic polymerization of butadiene, using alkyllithium containing silicon-protected hydroxyl group as initiator and cyclohexane as solvent. The polymers were characterized by GPC, IR and 1H-NMR. The mechanical properties of cured films were also evaluated. The results show that the content of 1,4-units for HTPBs made by anionic polymerization reaches up to 90%. The molecular weight distribution is very narrow (≤ 1.05). The functionality of hydroxyl groups approaches 2. Compared with free radical HTPB, the elongation at break of anionic HTPB films increased by 70%, while the tensile strength remained nearly unchanged. This new HTPB can be very useful in solid propellant. [ABSTRACT FROM AUTHOR]

Abstract: This paper gives a characterization of connected cubic -transitive Cayley graphs. It is shown that, for , every connected cubic -transitive Cayley graph is a normal cover of one of 13 graphs: three 3-transitive graphs, four 4-transitive graphs and six 5-transitive graphs. Moreover, the argument in this paper also gives another proof for a well-known result which says that all connected cubic arc-transitive Cayley graphs of finite non-abelian simple groups are normal except two 5-transitive Cayley graphs of the alternating group . [Copyright &y& Elsevier]

Abstract: A graph is said to be half-transitive if its automorphism group acts transitively on the vertex set and edge set but intransitively on the arc set. In this paper, we construct infinitely many primitive half-transitive graphs with automorphism groups being the symmetric groups of prime degrees, and show that there exists at least one primitive half-transitive graph of valency 2p for a prime p no less than 7 and . As a byproduct of our construction, infinitely many primitive 2-arc-regular Cayley graphs are given. [Copyright &y& Elsevier]

Abstract: A characterisation is given of edge-transitive Cayley graphs of valency 4 on odd number of vertices. The characterisation is then applied to solve several problems in the area of edge-transitive graphs: answering a question proposed by Xu [Automorphism groups and isomorphisms of Cayley graphs, Discrete Math. 182 (1998) 309–319] regarding normal Cayley graphs; providing a method for constructing edge-transitive graphs of valency 4 with arbitrarily large vertex-stabiliser; constructing and characterising a new family of half-transitive graphs. Also this study leads to a construction of the first family of arc-transitive graphs of valency 4 which are non-Cayley graphs and have a ‘nice’ isomorphic 2-factorisation. [Copyright &y& Elsevier]

In this paper, we study finite primitive permutation groups with a small suborbit. Based on the classification result of Quirin [Math. Z. 122 (1971) 267] and Wang [Comm. Algebra 20 (1992) 889], we first produce a precise list of primitive permutation groups with a suborbit of length 4. In particular, we show that there exist no examples of such groups with the point stabiliser of order 2436, clarifying an uncertain question (since 1970s). Then we analyse the orbital graphs of primitive permutation groups with a suborbit of length 3 or of length 4. We obtain a complete classification of vertex-primitive arc-transitive graphs of valency 3 and valency 4, and we prove that there exist no vertex-primitive half-arc-transitive graphs of valency less than 10. Finally, we construct vertex-primitive half-arc-transitive graphs of valency 2k for infinitely many integers k, with 14 as the smallest valency. [Copyright &y& Elsevier]

For a group G and a subset S of G which does not contain the identity of G, the Cayley digraph Cay(G, S) is called normal if R(G) is normal in Aut(Γ). In this paper, we investigate the normality of Cayley digraphs of finite simple groups with out-valency 2 and 3. We give several sufficient conditions for such Cayley digraphs to be normal. By using this result, we consider the digraphical regular representations of finite simple groups. [ABSTRACT FROM AUTHOR]

A graph is edge-primitive if its automorphism group acts primitively on the edge set, and $2$ -arc-transitive if its automorphism group acts transitively on the set of $2$ -arcs. In this paper, we present a classification for those edge-primitive graphs that are $2$ -arc-transitive and have soluble edge-stabilizers. [ABSTRACT FROM AUTHOR]

A graph is edge-primitive if its automorphism group acts primitively on the edge set. In this short paper, we prove that a finite 2-arc-transitive edge-primitive graph has almost simple automorphism group if it is neither a cycle nor a complete bipartite graph. We also present two examples of such graphs, which are 3-arc-transitive and have faithful vertex-stabilizers. [ABSTRACT FROM AUTHOR]

A graph is edge-transitive if its automorphism group acts transitively on the edge set. In this paper, we investigate the automorphism groups of edge-transitive graphs of odd order and twice prime valency. Let Γ be a connected graph of odd order and twice prime valency, and let G be a subgroup of the automorphism group of Γ. In the case where G acts transitively on the edge set and quasiprimitively on the vertex set of Γ, we prove that either G is almost simple, or G is a primitive group of affine type. If further G is an almost simple primitive group, then, with two exceptions, the socle of G acts transitively on the edge set of Γ. [ABSTRACT FROM AUTHOR]

C14H19NO4, monoclinic, C2/c (no. 15), a = 30.10(1) Å, b = 5.308(2) Å, c = 20.369(8) Å, ( = 117.027(6)°, V = 2898.5 Å3, Z = 8, Rgt(F) = 0.0449, wRref(F2) = 0.1336, T = 296 K. [ABSTRACT FROM AUTHOR]

C12H7F3O2S, triclinic, P1̅ (no. 2), a = 11.092(2) Å, b = 12.928(2) Å, c = 14.071(2) Å, α = 114.708(2)°, β = 104.991(2)°, γ = 90.827(2)°, V = 1753.2 Å3, Z = 6, Rgt (F) = 0.0374, wRref (F2 ) = 0.1101, T = 296 K. [ABSTRACT FROM AUTHOR]

A graph is symmetric if its automorphism group acts transitively on both the vertex and the arc sets. Stimulated by Lorimer's work on symmetric graphs of prime valency, we make a further investigation on the structural properties of the automorphism groups of connected symmetric graphs with prime valency. Also, as an application, we give a classification for symmetric graphs of prime valency arising from a class of almost simple groups. [ABSTRACT FROM AUTHOR]

Abstract: A classification is given for connected edge-transitive tetravalent Cayley graphs of square-free order. The classification shows that, with a few exceptions, a connected edge-transitive tetravalent Cayley graph of square-free order is either arc-regular or edge-regular. It thus provides a generic construction of half-transitive graphs of valency 4. [Copyright &y& Elsevier]

It is shown that each subgroup of odd index in an alternating group of degree at least 10 has all insoluble composition factors to be alternating. A classification is then given of 2-arc-transitive graphs of odd order admitting an alternating group or a symmetric group. This is the second of a series of papers aiming towards a classification of 2-arc-transitive graphs of odd order. [ABSTRACT FROM AUTHOR]

This retrospective study investigated the clinical application of sequential therapy with transarterial chemoembolization (TACE) and CT-guided radiofrequency ablation (RFA) using a bipolar needle in treating hepatocellular carcinoma (HCC) tumors of different sizes. The study included patients (N = 46) with HCC from Shengjing Hospital of China Medical University who had received TACE and RFA from November 2012 to November 2013. Eligible patients had an Eastern Cooperative Oncology Group (ECOG) score of 0-1, a Child-Pugh grade of A-B, and no contradictions for TACE and/or RFA. Fifty one hepatic lesions of varying sizes were treated with TACE followed by RFA. Clinical response and 1- and 2-year survival rates were assessed. The frequency of complete and incomplete ablation following therapy was significantly different across the varying RFA pin numbers and the maximum diameter of the lesion (p ≤ 0.001). A greater percentage (97.3%) of lesions that were ≤3 cm in diameter were completely ablated compared with lesions that were 3-5 cm (88.9%) and >5 cm in diameter (20%). The median survival time of patients was 16.5 months, and the 1- and 2-year survival rates were 95.7% and 69.3%, respectively. There were only a limited number of complications, all of which were minor. These included hemothorax (4.3%), abdominal hemorrhage (10.9%), and abdominal hemorrhage with minor pneumothorax (2.2%). This study found that the sequential treatment with TACE and CT-guided RFA using a bipolar needle is effective and well tolerated in patients with HCC and that the effectiveness of treatment is dependent on tumor size. [ABSTRACT FROM AUTHOR]

The novel benzoxazine monomer containing phosphorus has been synthesized based on multifunctional amine route from bis(4-aminophenyl)phenylphosphate, p-cresol and formaldehyde. Subsequently, the benzoxazine monomer was thermo-cured into polybenzoxazine containing phosphorus. The chemical structures were identified by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR). The curing reaction was monitored by differential scanning calorimetry (DSC) and FT-IR. The thermal and flame-retardant properties of obtained polybenzoxazine were evaluated by dynamic mechanical thermal analysis (DMA), thermal gravimetric analysis (TGA) and oxygen index meter, respectively. The results show that the novel polybenzoxazine has high limiting oxygen index (38.1) and glass transition temperature (232°C). [ABSTRACT FROM AUTHOR]

Background: Ovarian cancer is the most leading cause of death and the third most common gynecologic malignancy in women. Traditional chemotherapy has inevitable drawbacks of nonspecific tumor targeting, high toxicity, and poor therapeutic efficiency. In order to overcome such shortcomings, we prepared a novel nano-carrier drug-delivery system to enhance the anti-tumor efficiency. Methods: In vitro characterizations of nano-carriers were determined by TEM, DLS. Cell viability was measured by MTT method. RT-PCR was performed to measure the expression of FARα in three ovarian cancer cell lines. The drug-release study and the uptaken study were measured in vitro. The pharmacokinetic and the drug distribution study were verified by HPLC methods in vivo. The enhanced anti-tumor efficiency of FA-NP was evaluated by the tumor inhibitory rate in vivo. Results: Paclitaxel (PTX)-loaded nanoparticles (NPs) (PTX-PEG-PLA-NP and PTX-PEG-PLA-FA-NP) were prepared successfully, and the drug-release study showed that the cumulative release rates of NP groups were much less than free PTX group. The pharmacokinetic study showed that the elimination phase of two kinds of NP groups were much longer than that of PTX group. The drug distribution in different tissues showed that the peak-reach time was 2 h in the PTX group and 6 h in both NP groups. All of these results confirmed the excellent slow-release effects of both kinds of nano-carriers. More importantly, we confirmed that PTX-PEG-PLA-FA-NP had greater uptake by SK-OV-3 cells than PTX-PEG-PLA-NP and free PTX in vitro. A drug-distribution study of tumor-bearing mice demonstrated that the PTX concentration of tumor tissues in the PTX-PEG-PLA-FA-NP group was 3 times higher than the other two groups. PTX-PEG-PLA-FA-NP was uptaken much more by SK-OV-3 cells than PTX-PEG-PLA-NP and free PTX. Eventually, based on the slow-release effect and tumor-targeting characteristics of PTX-PEG-PLA-FA-NP, a cytotoxicity test indicated that PTX-PEG-PLA-FA-NP was much more toxic to SK-OV-3 cells than the controls. The tumor inhibitory rate in the PTX-PEG-PLA-FA-NP group of tumor-bearing mice was about 1.5 times higher than the controls. The tumor targeting and anti-tumor efficiency of PTX-PEG-PLA-FA-NP were confirmed both in vitro and in vivo. Conclusions: We developed an ovarian cancer targeting nano-carrier drug delivery system successfully, which showed perfect ovarian cancer targeting and anti-tumor effect, thus have the potential to be a new therapy strategy for ovarian cancer patients. [ABSTRACT FROM AUTHOR]

The title compound, C14H11BrN2O2, was synthesized by the reaction of 5-bromo­salicylaldehyde with benzoyl­hydrazine. Inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains running along the a axis. The crystal packing is further stabilized by van der Waals forces. [ABSTRACT FROM AUTHOR]