5,6-Dimethyl-4-phenyl-2H-pyran-2-one

In the title compound, C13H12O2, the dihedral angle between the pyran­one and phenyl rings is 57.55 (9)°. In the crystal, the mol­ecules are linked by π–π stacking inter­actions between the parallel pyran­one rings of neighboring mol­ecules with distances of 3.5778 (11) Å and 3.3871 (11) Å between the planes. C—H⋯O interactions also occur

ZOOTAXA

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catena-Poly[[(2,2′-bipyridine-κ2 N,N′)cadmium]-μ3-4-nitro­phthalato-κ4 O:O′,O′′:O′′′]

In the title polymeric compound, [Cd(C8H3NO6)(C10H8N2)]n, two O atoms from both carboxyl­ate groups of a nitro­phthalate anion coordinate to the CdII cation, forming a seven-membered chelate ring and two carboxyl­ate O atoms from another two nitro­phthalate anions and a 2,2′-bipyridine ligand coordinate to the Cd cation to complete the distorted octa­hedral coordination geometry. The carboxyl­ate groups of the nitro­phthalate anion adopt a syn–anti bridging mode, linking adjacent CdII cations and forming a polymeric chain running along the a axis. Weak intra- and inter­molecular C—H⋯O hydrogen bonding is present in the crystal structure

Two types of generalized integrable decompositions and new solitary-wave solutions for the modified Kadomtsev-Petviashvili equation with symbolic computation

The modified Kadomtsev-Petviashvili (mKP) equation is shown in this paper to be decomposable into the first two soliton equations of the 2N-coupled Chen-Lee-Liu and Kaup-Newell hierarchies by respectively nonlinearizing two sets of symmetry Lax pairs. In these two cases, the decomposed (1+1)-dimensional nonlinear systems both have a couple of different Lax representations, which means that there are two linear systems associated with the mKP equation under the same constraint between the potential and eigenfunctions. For each Lax representation of the decomposed (1+1)-dimensional nonlinear systems, the corresponding Darboux transformation is further constructed such that a series of explicit solutions of the mKP equation can be recursively generated with the assistance of symbolic computation. In illustration, four new families of solitary-wave solutions are presented and the relevant stability is analyzed.Comment: 23 page

Radio Polarization of BL Lacertae objects

In this paper, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio frequencies, we studied the polarization properties for 47 BL Lacertae objects(38 radio selected BL Lacertae objects, 7 X-ray selected BL Lacertae, and two inter-middle objects (Mkn 421 and Mkn 501), and found that (1) The polarizations at higher radio frequency is higher than those at lower frequency, (2) The variability of polarization at higher radio frequency is higher than those at lower frequency, (3) The polarization is correlated with the radio spectral index, and (4) The polarization is correlated with core-dominance parameter for those objects with known core-dominance parameters suggesting that the relativistic beaming could explain the polarization characteristic of BL Lacs.Comment: 5 pages, 3 figures, 1 table. PASJ, in pres

Covert Laparoscopic Cholecystectomy: A New Minimally Invasive Technique

To further improve our developed transumbilical endoscopic surgery (TUES), we developed a completely covert laparoscopic cholecystectomy (LC). Twelve cases of LC were recruited for this new approach. First, a 10-mm trocar was placed above the umbilicus for inserting the laparoscope. Two 5-mm trocars were then placed near the right and left ends of the superior margin of the suprapubic hair. After the 5-mm 30° laparoscope was shifted to the left suprapubic trocar, the harmonic scalper, electric hook, and grasper were inserted either through the 10-mm umbilical trocar or through the right suprapubic trocar. All gallbladders were successfully removed without intraoperative complications. The mean operating time was 28.5±5.7min (range 20-45min). All patients felt well after surgery and did not need postoperative analgesia. They resumed free oral intake 6h after the procedure. All patients were satisfied with the appearance of the incisions, which were completely hidden in the umbilicus and suprapubic hair. The approach we developed has overcome both external instrument interference around the umbilicus and the loss of triangulation in the operative field. It is relatively simpler than a typical TUES and offers better cosmetic results

Programmable Photonic Simulator for Spin Glass Models

Spin glasses featured by frustrated interactions and metastable states have important applications in chemistry, material sciences and artificial neural networks. However, the solution of the spin glass models is hindered by the computational complexity that exponentially increases with the sample size. Photonic Ising machines based on spatial light modulation can speed up the calculation by obtaining the Hamiltonian from the modulated light intensity. However, the large-scale generalization to various spin couplings and higher dimensions is still elusive. Here, we develop a Fourier-mask method to program the spin couplings in photonic Ising machines. We observe the phase transition of the two-dimensional Mattis model and the J$\mathrm{_1}$-J$\mathrm{_2}$ model and study the critical phenomena. We also demonstrate that the three-dimensional Ising model, which has not been analytically solved, can be effectively constructed and simulated in two-dimensional lattices with Fourier masks. Our strategy provides a flexible route to tuning couplings and dimensions of statistical spin models, and improves the applicability of optical simulation in neural networks and combinatorial optimization problems

A polymorph of diaqua­bis(pyrazine-2-carboxyl­ato-κ2 N 1,O)copper(II)

The title compound, [Cu(C5H3N2O2)2(H2O)2], is a new polymorph of the previously reported compound [Klein et al. (1982 ▶). Inorg. Chem. 21, 1891–1897]. The CuII atom, lying on an inversion center, is coordinated by two N atoms and two O atoms from two pyrazine-2-carboxyl­ate ligands and by two water mol­ecules in a distorted octa­hedral geometry with the water mol­ecules occupying the axial sites. Inter­molecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds connect the complex mol­ecules into a two-dimensional layer parallel to (10), whereas the previously reported polymorph exhibits a three-dimensional hydrogen-bonded network

A Trace-restricted Kronecker-Factored Approximation to Natural Gradient

Second-order optimization methods have the ability to accelerate convergence by modifying the gradient through the curvature matrix. There have been many attempts to use second-order optimization methods for training deep neural networks. Inspired by diagonal approximations and factored approximations such as Kronecker-Factored Approximate Curvature (KFAC), we propose a new approximation to the Fisher information matrix (FIM) called Trace-restricted Kronecker-factored Approximate Curvature (TKFAC) in this work, which can hold the certain trace relationship between the exact and the approximate FIM. In TKFAC, we decompose each block of the approximate FIM as a Kronecker product of two smaller matrices and scaled by a coefficient related to trace. We theoretically analyze TKFAC's approximation error and give an upper bound of it. We also propose a new damping technique for TKFAC on convolutional neural networks to maintain the superiority of second-order optimization methods during training. Experiments show that our method has better performance compared with several state-of-the-art algorithms on some deep network architectures