Periodic arrays of negative capacitance shunted piezoelectric patches are employed to control the band gaps of phononic beams. The location and the extent of induced band gap depend on the mismatch in impedance generated by each patch. The total impedance mismatch is determined by the added mass and stiffness of each patch as well as the shunting electrical impedance. Therefore, the band gap of the shunted phononic beam can be actively tuned by appropriately selecting the value of negative capacitance. The control of the band gap of phononic beam with negative capacitive shunt is demonstrated numerically by employing transfer matrix method. The result reveals that using negative capacitive shunt to tune the band gap is effective.

Herein, we report an excellent, supported Ru(III)-ChCl/AC catalyst with lower Ru content, where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination. The prepared heterogeneous Ru-10%ChCl/AC catalyst shows excellent activity and long-term stability. In this system, ChCl provides an environment for the ChRuCl4 to be stabilized as Ru(III), thus suppressing the reduction of the active species and the aggregation of ruthenium species during the reaction. The interaction between reactants and catalyst species was investigated by catalyst characterizations in combination with DFT calculations to disclose the effect of the ChRuCl4 complex and ChCl on the catalytic performance. This inexpensive, efficient, and long-term catalyst is a competitive candidate for application in the hydrochlorination industry.

In this paper, a novel series of 2-aminofuro[2,3-d]yrimidin-4(3H)-one derivatives were prepared via aza-Wittig reaction of iminophosphorane 3 with aromatic isocyanate and subsequent reaction with various amine under mild condition in 78%～90% yields. The structures of these compounds were confirmed by mass spectral data, 1 H NMR, IR and elemental analysis. Compound 5c was further analyzed by single crystal X-ray diffraction. The in vitro antitumor activities of compounds 5 were analyzed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) standard method, and compound 5f showed the best inhibition activities against A459 with IC 50 18.4 μmol/L.

The spiro pyrrolidin-3,3'-oxindole core is a privileged skeleton that is found in many natural products and biologically active molecules. For its construction, the [3＋2] cycloaddition of 2π component 3-alkenyl-oxindoles with 3π component azomethine ylides is one of the most effective strategies. Since the pioneering work of Gong and co-workers, great effort has been devoted to the development of asymmetric [3＋2] cycloadditions with azomethine ylides as the dipole synthon, and impressive progress has been achieved. In contrast, there is no report about higher-order [8＋2] cycloaddition of 3-alkenyl-oxindoles with azaheptafulvenes as the 8π dipole synthons, which is an effective way to build cycloheptatriene-fused pyrrolidin-3,3'-oxindole derivatives with three contiguous stereocenters, including a spiro-quaternary chiral carbon atom. Herein, the azaheptafulvenes is developed as a new dipole synthon with 3-alkenyl-oxindoles to construct pyrrolidin-3,3'-oxindoles derivatives for the first time. In the presence of 1 mol% of chiral N,N'-dioxide L6-Ni(II) complex, the asymmetric [8＋2] cycloaddition performs well, affording functionalized cycloheptriene-fused pyrrolidin-3,3'-oxindoles derivatives in excellent yields (90%～99%), diastereoselectivities (up to 97∶3 dr), and enantioselectivities (92%～99% ee) under mild conditions. A representative procedure for the asymmetric [8＋2] cycloaddition is as follows: to a test tube, the catalyst solution (1 mol% , in THF) was added, and the THF was evaporated by oil pump. N-Boc-3-alkenyl-oxindole 2a and 0.5 mL of CH 2 Cl 2 were added sequentially under air (N 2 atmosphere is not necessary). The reaction solution was stirred at 35 ℃ for 0.5 h, then the 8π component azaheptafulvene 1a (1.05 equiv.) was added. The mixture continued stirring at 35 ℃ until N-Boc-3-alkenyl-oxindole 2a was consumed (detected by TLC). Finally, the corresponding product 3a was purified by flash chromatography on basic Al 2 O 3 [V(petroleum)/V(CH 2 Cl 2)/V(EtOAc)＝8∶8∶1].

Tight focus of a radially polarized and amplitudemodulated annular multi-Gaussian beam *Chen Jian-Nong( ) a) † , Xu Qin-Feng( ) a) , and Wang Gang( ) b)