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The existing active power decoupling methods for single-phase current source rectifiers (SCSRs) usually involve a lot of additional semiconductor devices or energy storage units, which is adverse to cost and efficiency. This study proposes an active power decoupling method to buffer the double-frequency ripple power. The main circuit is configured by adding only a decoupling capacitor and a diode to the traditional SCSR. Compared with the existing ones, the added components are minimised. The operating principle and modulation scheme are described. A closed-loop control method is developed to enhance twice the line frequency ripple power compensation performance. The guide for the selection of the decoupling capacitance is also discussed. Simulations and experimental results are presented to show the effectiveness of the method.

This study presents an active third-harmonic injection indirect matrix converter (3HI2MC) topology with dual three-phase outputs. The presented 3HI2MC has the advantages of sinusoidal input and output currents, bi-directional power flow, and can provide two sets of three-phase outputs, whose frequencies and amplitudes can be regulated independently. Compared with the conventional indirect matrix converter (IMC), the input reactive power control range is extended significantly, and the converter can even work as a static compensator. Moreover, a maximal voltage transfer ratio of 0.866 is achievable under all operation conditions. Furthermore, operations of the rectifier and inverters are independent. Thus, for a 3HI2MC system containing multiple voltage-source-type inverters (VSIs), modulation and control task can be implemented flexibly by a separate controller for each VSI, while it is difficult for the conventional IMCs to achieve such a goal. All of the features above make 3HI2MC competitive for the applications that require multiple three-phase outputs such as multiple drives. After describing the topology structure, operating principles and control algorithm in detail, simulation and experimental results are presented to demonstrate the validity and effectiveness of the proposed topology.

This study proposes a new power decoupling circuit applied to the single-phase current source converter (SCSC). Differing from the existing power decoupling technologies, the proposed power decoupling circuit could be viewed as a controlled voltage source in series with the DC inductor, and work with SCSC independently. That facilitates the separate design of the modulation schemes and the control algorithms for the power decoupling circuit and SCSC, and reduces the operation restrictions imposed by requirements. The fundamental principle of the proposed converter is analysed, and the voltage reference requirement for the buffer capacitor is investigated. To guarantee high input current quality of SCSC, a control method, where the input current is treated as a virtual control input, is proposed. Finally the effectiveness of this topology is verified by the simulations and experimental results.

Transformer-less single-phase grid-tied inverter is attractive due to low cost, high efficiency, and small size. However, leakage current and second-order ripple power have to be well dealt with. Because the leakage current is a potential threat for body safety and the ripple power will decrease overall efficiency and system reliability. Both issues become obstacles for practical applications. This paper proposes a method to achieve leakage current suppression and ripple power reduce simultaneously. The main circuit is formed by adding an extra arm and a decoupling capacitor to the traditional single-phase voltage source inverter. The additional arm is controlled to keep the common voltage constant and divert the ripple power to the decoupling capacitor. A decoupled control method is also developed to achieve independent control of power factor correction and power decoupling. Finally, simulation results are presented to show the effectiveness.

Bulky capacitors are usually needed to buffer the double-frequency ripple power (DFRP) in single-phase power factor correction (PFC) rectifier. It is important to reduce the capacitance requirements for improving the system reliability and power density. In this paper a control method for capacitive idling converter based PFC (CIC-PFC) rectifier is proposed. The DFPR is diverted to the energy transfer capacitor and stored by swinging its voltage. Then, the required capacitance is reduced. Compared with other active power decoupling methods, the proposed is cost-effective as no extra hardware is added. The paper also discusses the selection of the energy transfer capacitor by comprehensively considering the voltage stress, cost, volume, current ripples, and power losses. Finally, experimental results are presented to show the effectiveness.

This paper proposes a single-phase power factor correction (PFC) rectifier to achieve high power factor, wide output voltage range, and ripple power decoupling without using electrolytic capacitors. It consists of two parts: PFC circuit and output voltage regulation circuit. The load side is involved in both parts, which is different from the regular two-stage conversion structure. The proposed rectifier can be directly applied to low voltage cases due to the wide output voltage range. And the decoupling capacitor voltage can be smaller than the peak grid voltage, which reduces the voltage stress. Besides, the low-frequency ripple power buffer is implemented without a dedicated power-buffering controller. This paper first introduces the circuit structure, operation principles, and control method. Then, the system design consideration is given. Finally, the effectiveness of the proposed topology is verified by the simulations and experimental results.

In this paper, a single-phase current-source bidirectional converter topology for V2G applications is proposed. The proposed converter consists of a single-phase current-source rectifier (SCSR) and an auxiliary switching network (ASN). It offers bidirectional power flow between the battery and the grid in the buck or boost mode and expands the output voltage range, so that it can be compatible with different voltage levels. The topology structure and operating principles of the proposed converter are analyzed in detail. An indirect control algorithm is used to realize the charging and discharging of the battery. Finally, the semiconductor losses and system efficiency are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

Four complexes of composition [Cd(4-Apha)2]n (1), [Zn2(4-Apha)4(H2O)2]·2H2O (2), [Zn(4-Apha)(CH3COO)]n (3), and [Zn4(4-Apha)4(CH3COO)4(H2O)]n·2nCH3OH (4) (4-AphaH = 4-aminophenylhydroxamic acid) have been synthesized in different solvents and characterized by X-ray diffraction, IR spectroscopy, thermal analysis and elemental analysis. X-ray crystal analysis reveals that these complexes exhibit four varieties of structures. Complex 1 displays a 1-D chain structure, and complex 2 is binuclear. Complexes 3 and 4 possess different 3-D structures. Fluorescence emissions are observed for complexes 1, 2 and 4 in solid state.

To adapt the battery voltage and increase charging efficiency in vehicle to grid (V2G) systems, an ac/dc matrix converter topology is presented. Aim to solve the problem of relatively large charging current ripple in the classical current space vector modulation strategy, a sectional optimized modulation strategy, is proposed, which can reduce the charging current ripple within the whole output range. And the comparative analysis is carried out between them. A simple controller with active damping is briefly introduced; it can work at two charging modes: constant voltage charging and constant current charging. The simulation and experimental results demonstrate the validity and effectiveness of the proposed method.

Two copper(I) complexes of compositions [Cu(HL)I]2·EtOH (1) and [Cu(HL)3]I·MeOH (2) were synthesized via the reactions of HL [HL = 2(4,5-diphenyl-1H-imidazol-2-yl)pyridine] and CuI in EtOH and MeOH, respectively, under solvothermal conditions. The complexes were characterized by X-ray single crystal diffraction, IR spectroscopy, and elemental analysis. Compounds 1 and 2 are catalytically active towards ketalization reaction, giving various ketals under mild conditions.

Syntheses and structures of five imido-bridged dinuclear titanium complexes and two (bis)ligand-coordinated mononuclear titanium complexes are reported. Addition of 1 or 2 equiv. of Schiff base ligand (((1H-pyrrol-2-yl)methylene)amino)-2,3-dihydro-1H-inden-2-ol (H2L) to Ti(NMe2)4 resulted in transamination with 4 equiv. of dimethylamides generating a (bis)ligand-coordinated complex Ti(L)2 (1). Treatment of Ti(NMe2)4 with 1 equiv. of tBuNH2 followed by addition of 1 equiv. of H2L afforded an imido-bridged complex [Ti(L)(NtBu)]2 (2). 1:1:1:1 reaction of Ti(NMe2)4/RNH2/H2L/py(or phen) produced imido-bridgedcomplexes [Ti(L)(NPh)(py)]2 (3), [Ti(L)(4-F-PhN)(py)]2·Tol (4·Tol), [Ti(L)(4-Cl-PhN)(py)]2·Tol·THF (5·Tol·THF), [Ti(L)(4-Br-PhN)(py)]2·Tol (6·Tol) and a (bis)ligand-coordinated complex Ti(L)2·phen (7) (py = pyridine, phen = 1,10-phenanthroline). Attempts to prepare the monomeric titianium imido complexes were unsuccessful. DFT studies show that the assumed compound which contains Ti = N species is less stable than imido-bridged Ti-N(R)-Ti complexes, providing the better understanding of the experimental results.

The present study was conducted to assess the effects of propolis flavonoid used as adjuvant on the immune response of Landrace-Yorkshire hybrid sows immunized with an inactivated vaccine of porcine parvovirus (PPV). Thirty Landrace-Yorkshire hybrid sows were randomly assigned to one of 3 groups, and the sows in two adjuvant groups were intramuscular injected PPV vaccine with 2.0 mL propolis flavonoid adjuvant (PA) or oilemulsion adjuvant (OA), respectively. After that, serum hemagglutination inhibition antibody titers, specific IgM, IgA and IgG subclasses were measured to estimate the humoral immunity for the adjuvant effects of propolis flavonoid, as well as peripheral lymphopoiesis activity, and lymphocyte factor concentrations of Th1 and Th2 for cellular immune responses. Results indicated in a significant enhancing effect of PA on concentrations of IgM, IgG2, IgG3, IL-2 and IFN-γ comparing to OA. Especially in improving the effect of Th1 cellular immune response, the PA was superior to OA. These findings suggested that PA can significantly enhance the immune responses against PPV vaccine and could be exploited to a new PPV vaccine in sows.

In this paper, the reactive dynamics properties of the reactions Ba + C6H5Br and Ba + m-C6H4CH3Br were studied by means of the quasi-classical trajectory method based on the London-Eyring-Polanyi-Sato potential energy surfaces. The vibrational distributions, reaction cross sections, rotational alignments of the products BaBr all were obtained. The peak values of the vibrational distributions are located at ν = 0 for the reactions Ba + C6H5Br and Ba + m-C6H4CH3Br when the collision energies are 1.09 and 1.10 eV, respectively. The reaction cross sections increase with the increasing collision energy, which changes from 0.6 to 1.5 eV. The product rotational alignments deviate from −0.5 and firstly increase and then decrease while the collision energy is increasing, just like that of Heavy+Light-Light system.

A honeycomb porous microchannel cooling system for electronics cooling was proposed in this article. The design, fabrication, and test system configuration of the microchannel heat sink were summarized. Preliminary experimental investigation was conducted to understand the characteristics of heat transfer and cooling performance under steady single-phase flow. In the experiments, a brass microchannel heat sink was attached to a test heater with 8 cm2 area. The experimental results show that the cooling system is able to remove 18.2 W/cm2 of heat flux under 2.4 W pumping power, while the junction wall temperature is 48.3°C at the room temperature of 26°C. Extensive experiments in various operation conditions and parameters for the present cooling system were also conducted. The experimental results show that the present cooling system is able to perform heat dissipation well.

This paper reports the results of quasiclassical trajectory calculation on extended London-Eyring-Polanyi-Sato potential energy surface for the reaction between Ba atom and HI . The rotational distribution, vibrational distribution, reaction cross section, and rotational alignment are all obtained and they are under detailed discussion for product BaI . The calculated results are in good agreement with the experimental results.

The reaction dynamics of the Ca(1S0,3P) + CHCl3 → CaCl + CHCl2 has been studied by means of quasi-classical trajectory (QCT) calculation based on a constructed extended London–Eyring–Polanyi–Sato (LEPS) potential energy surface (PES). The vibrational distribution, reaction cross-section and rotational alignment are all obtained, which are under detailed discussion for product CaCl. The calculated results show that the product CaCl vibrational population peaks are located at ν = 13 (for the ground state) and ν = 12 (for the excited states) at collision energy 2.302 kcal/mol. This product vibrational distribution agrees well with the experimental one in Ref. [K.L. Han, G.Z. He, N.Q. Lou, Chem. Phys. Lett. 178 (1991) 528]. The cross-section decreases thoroughly with the increasing of the collision energy at the range from 1.5 kcal/mol to 20.6 kcal/mol. We have obtained 〈 P 2 ( J ′ · K ) 〉 values deviating much from −0.5 and changing interestingly with collision energies.

The employment of 2-(imidazo[1,5-a]pyridin-3-yl)phenol (HIPP) in ZnII and CoII coordination chemistry is reported. A series of complexes of compositions, [Zn(HIPP)2Cl2] (1), [Zn2(IPP)4] (2), [Co2(HIPP)4(SO4)2] (3), [Co3(IPP)6] (4) and [Co2(IPP)2(CH3COO)2]n (5), have been synthesized via choosing appropriate metal salts and different solvents. Complexes of various nuclearities are obtained: from mono-, di-, trinuclear complexes to 1-D chain polymer. UV-vis absorption properties have been investigated and rationalized by DFT and TDDFT calculations. In addition, luminescence studies suggested strong emission for 1, 2 and 3 in the solid state at room temperature. Variable temperature (2.0–300 K) magnetic studies for 3, 4 and 5 indicate weak antiferromagnetic coupling between the metal centers in 3 and 5, and weak ferromagnetic CoII···CoII exchange interactions in 4.

The employment of 2-(imidazo[1,5-a]pyridin-3-yl)phenol (HIPP) in ZnII and CoII coordination chemistry is reported. A series of complexes of compositions, [Zn(HIPP)2Cl2] (1), [Zn2(IPP)4] (2), [Co2(HIPP)4(SO4)2] (3), [Co3(IPP)6] (4), and [Co2(IPP)2(CH3COO)2]n (5), have been synthesized via choosing appropriate metal salts and different solvents. Complexes of various nuclearities are obtained from mono-, di-, trinuclear complexes to 1-D chain polymer. UV–vis absorption properties have been investigated and rationalized by density functional theory and time-dependent DFT calculations. In addition, luminescence studies suggested strong emissions for 1, 2, and 3 in the solid state at room temperature. Variable temperature (2.0–300 K) magnetic studies for 3, 4, and 5 indicate weak antiferromagnetic coupling between the metal centers in 3 and 5, and weak ferromagnetic CoII⋯CoII exchange interactions in 4.

An efficient strategy for the synthesis of a wide variety of coordination complexes has been developed. The synthetic protocol involves a solvothermal in situ metal–ligand reaction of picolinaldehyde, ammonium acetate, and transition-metal ions, leading to the generation of 12 coordination complexes supported by a novel class of substituted 1-pyridineimidazo[1,5-a]pyridine ligands (L1–L5). The ligands L1–L5 were afforded by metal-mediated controllable conversion of the aldehyde group of picolialdehyde into a ketone and secondary, tertiary, and quaternary carbon centers, respectively. Complexes of various nuclearities were obtained: from mono-, di-, and tetranuclear to 1D chain polymers. The structures of the in situ formed complexes could be controlled rationally via the choice of appropriate starting materials and tuning of the ratio of the starting materials. The plausible mechanisms for the formation of the ligands L1–L5 were proposed.

The flow and heat transfer integrated performance for the developing laminar air tube flow inserted with the ringy porous media was studied numerically. Its mechanisms of enhancing heat transfer were also analyzed using the principle of field synergy. The results showed that inserting ringy porous media in the core of developing laminar tube flow can improve the flow and heat transfer performance effectively, and the highest value of PEC is up to 2. The optimal radius of the center aperture of the porous inserts is 1.0mm. Furthermore, a high porosity is recommended when using porous media for heat transfer enhancement.

A honeycomb porous micro channel cooling system for cooling of electronic chips was proposed. Experimental investigation was conducted to determine the heat transfer characteristics and cooling performance of this micro channel cooling system. The heat transfer capabilities of the cooling system with different pipe diameters, different working media and various pumping power were evaluated. The influences of working flow rate and test system on the cooling performance were also analyzed experimentally. The results showed that the better cooling capability of the system not only relied on the increasing pump power, but also the agreement between pumps diameters and system pipes diameters. The thermo-physical characters and mass flow rate of the working fluid were also important to the system performance.Copyright © 2009 by ASME

A honeycomb porous micro channel cooling system for cooling of electronic chips is proposed in this paper. The design, fabrication, test system configuration of the micro channel heat sink is summarized. Preliminary experimental investigation is conducted to determine the heat transfer characteristics and cooling performance under steady single-phase flow of water liquid. In the experiments, the brass micro channel heat sink is attached to a test heater with 8cm2 area, the experimental results show that the cooling system can effectively remove the heat flux of 18.2W/cm2 under 2.4W pumping power, while the junction-wall temperature is 48.3°C at the room temperature of 26°C. The experimental results show that the present cooling system has good performance.Copyright © 2009 by ASME

A novel heatsink based on a multilayer stack of thin metal plates with staggered honeycomb cells microchannels was investigated in this paper. A series of working-parametric tests such as different heat sink pipe diameter and pumping power were conducted for the microchannel cooling system to determine the heat transfer performance under small flow rate conditions. For the double fluid flow inlets and outlets heatsink design, experimental results showed that more uniform substrate temperature distribution was obtained than the single inlet and outlet ones. It showed that the heatsink design provided a good choice for electronic chips cooling applications.Copyright © 2009 by ASME

Active power decoupling methods are developed to deal with the inherent ripple power at twice the grid frequency in single-phase systems generally by adding active switches and energy storage units. They have obtained a wide range of applications, such as photovoltaic (PV) systems, light-emitting diodes (LEDs) drivers, fuel cell (FC) power systems, and electric vehicle (EV) battery chargers, etc. This paper provides a comprehensive review of active power decoupling circuit topologies. They are categorized into two groups in terms of the structure characteristics: independent and dependent decoupling circuit topologies. The former operates independently with the original converter, and the latter, however, shares the power semiconductor devices with the original converter partially and even completely. The development laws for the active power decoupling topologies are revealed from the view of “duality principle,” “switches sharing,” and “differential connection.” In addition, the exceptions and special cases are also briefly introduced. This paper is targeted to help researchers, engineers, and designers to construct some new decoupling circuit topologies and properly select existing ones according to the specific application.

Triaxial test is an important test in civil engineering. Soil specimen deformation needs edge location in triaxial test. Edge location accuracy has the limitation. The accuracy limitation is greater than 0.2 pixels by mathematical reasoning. In order to obtain high resolution of edge location, an improved test method is adopted to solve the limitation of edge location. According to the new test method, we take advantage of sub-pixel corner detection algorithm to locate the edge. Test results show that the accuracy is improved by five times than the old method. After long-term test, the radial accuracy steadily reaches 0.02 pixels and the axial accuracy steadily reaches 0.05 pixels.

Hydrothermal reaction of CuCl2·2H2O, 3-(pyridin-2-yl)imidazo[1,5-a]pyridine (HPIP) and formaldehyde, yielded a novel mixed-valence CuI/CuII complex [L1Cu2Cl2][Cu2Cl4]·2EtOH (1·2EtOH; L1 = tetrakis(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)methane). The in situ generated quaternary carbon-containing ligand L1 was derived from CuII-mediated quadruple coupling of HPIP and formaldehyde, where the three bonds of formaldehyde were totally cleaved. 1·2EtOH can also be prepared by replacing formaldehyde by formic acid, N,N-dimethylformamide, and glyoxal, respectively. When acetic acid, which usually serves as a radical reaction inhibitor, was introduced into the reaction systems, two CuI complexes [(L2)2Cu3](CuCl2)3·2EtOH (2·2EtOH) and L3Cu2Cl2 (3) (L2 = tris(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)methane, and L3 = 1,1,2,2-tetrakis(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)ethane) were afforded. The tertiary carbon-bearing ligands L2 and L3 were generated in situ via CuII-mediated controllable cleavage of two bonds of formaldehyde, N,N-dimethylformamide and glyoxal, respectively. The plausible mechanisms for the formation of the ligands L1–L3 were proposed.

The mononuclear title complex, [Ti(C(2)H(6)N)(2)(C(12)H(11)N(2))(2)], was synthesized by the reaction of 1-phenyl-N-[(pyrrol-2-yl)methyl-idene]methanamine with Ti(NMe(2))(4). The Ti(IV) atom is coordinated in a distorted octa-hedral geometry by four N atoms from two derivatized methanamine ligands and two N atoms from two dimethyl-amide ions. The dihedral angles between the pyrrole and phenyl rings in the bidentate ligands are 62.36 (9) and 78.32 (8)°. In the crystal, a weak π-π stacking inter-action [centroid-centroid distance = 3.864 (2) Å] involving centrosymmetrically related mol-ecules is observed.