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The transient electromagnetic (TEM) method has long been applied in tunnel advanced prediction. However, it remains questionable to what extent a geologic anomaly body will influence the induced electromagnetic response in front of the heading face. The dilemma is partly because observed TEM data are frequently interpreted by empirical formulas or proportional relationships, and a quantitative measurement has not been established. In this paper, we strive to understand the TEM characteristics from a 3D finite-element time-domain (FETD) modeling aspect. The modeling algorithm is based on unstructured space meshing and unconditional stable time discretization, which ensures its accuracy and stability. The modeling algorithm is verified by a half-space model, in which the misfit of late-time channels that we are concerned with is generally below 1%. The algorithm has also been utilized to carry out the TEM response of tunnel models with different types of TEM devices. Through model studies, we find that both the traditional central-loop device and the recently developed weak-coupling opposing-coil device are feasible in tunnel advanced detection. Nevertheless, the latter type of device better distinguishes low-resistivity anomalies at 30 m ahead of the heading face with a relative difference (between models with and without the anomaly) of more than 1000% at certain time channels, compared with only a 10% difference of the central-loop device. Also, we conclude that the vertical electromagnetic field component should be recorded and interpreted together with the horizontal field to provide more convincing results. [ABSTRACT FROM AUTHOR]

Oscillation fault is a kind of aircraft fault which has a great influence on flight safety, aircraft structure and system control. This paper analyzes the causes and influencing factors of aircraft oscillation fault, and defines the design path and monitoring level of oscillation fault monitoring, proposes a design and verification method of oscillation fault monitor, and verifies its feasibility by applying it to a certain type of flight control system. This result has a good guiding role for the design and test verification of the aircraft flight control system oscillation fault monitor, can support the flight control system oscillation fault test, and verify the compliance of the oscillation fault monitor with the design requirements and corresponding airworthiness terms. [ABSTRACT FROM AUTHOR]

Abstract: Four new donor-π-acceptor (D-π-A) dyes (P1, P2, P3, P4) were synthesized, characterized and applied in dye-sensitized solar cells (DSSCs). Poly(p-phenylenevinylene) (PPV) or Bisthien PPV was used as donor, ethilenic link or thiophene as π-bridge, and Cadmium complexes or Nickel complexes as acceptor in these D-π-A type sensitizers. The introduction of the polymerization of π system and the metal complexes has greatly increased the light absorption. Increasing the number of thienyl group in the molecule to a certain extent was effective in further lowering both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels to attain higher open-circuit voltage (V oc). Among them, P3-based cell shows excellent photovoltaic performance and power conversion efficiency up to 2.25% under AM 1.5G irradiation (100 mW cm−2). [Copyright &y& Elsevier]

Four polymeric metal complexes ( P1- P4) based on 1,10-phenanthroline metal complexes and alkylfluorene or alkoxybenzene were synthesized by the Heck coupling reaction and were developed for dye-sensitized solar cell applications. The target dyes use alkoxybenzene or alkylfluorene as the electron donor, a C=C moiety as the π linker, and the phenanthroline derivative complex was used as the electron acceptor. Bipyridine derivatives were ancillary ligands as well as providing anchoring groups. The thermal, photophysical, electrochemical and photovoltaic properties of these copolymers were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), C-V curves and I-V curves. Dye-sensitized solar cells with these polymeric metal complexes as dye sensitizers exhibited considerable power conversion efficiencies (PCE). The dyes containing alkoxybenzenes ( P3, P4) exhibited higher PCE values than the corresponding target polymers containing alkylfluorenes ( P1, P2), The dye P3 showed the maximal power conversion efficiency of 2.12 % ( Jsc = 4.91 mA/cm2, Voc = 0.69 V, FF = 62.5). In addition, the four polymers possessed excellent stabilities, and their thermal decomposition temperatures all exceeded 300 °C, indicating that these polymeric metal complexes are suitable for the fabrication processes of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Four main chain polymeric metal complexes ( P1-P4) based on 8-hydroxyquinoline metal complexes have been synthesized by the Heck coupling and characterized by gel-permeation chromatography, Fourier transform infrared spectroscopy, proton-nuclear magnetic resonance, thermogravimetric analysis, ultraviolet-visible absorption, photoluminescence spectroscopy, elemental analysis, and cyclic voltammetry. The applications of these polymers as dye sensitizers in dye-sensitized solar cells (DSSCs) are also studied. The study results show that the solar cells have good device performance with power conversion efficiency of P1-P4 up to 2.17, 2.04, 2.45, and 2.18%, respectively. The highest power conversion efficiency of DSSCs is up to 2.45%, for P3 consisting of alkoxy benzene unit and Cd-metal complex under the illumination of air mass 1.5 G, 100 mW cm−2. POLYM. COMPOS., 34:1629-1639, 2013. © 2013 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) have attracted interest from chemists in recent years because of their unique advantages: low cost, simple preparation technologies, and high efficiency. Three main chain polymeric metal complexes F, P1, and P2 connected with thienyl(8-hydroxyquinoline)-Cadmium (II) complexes have been synthesized by Heck coupling and characterized by Gel Permeation Chromatography, Fourier transform infrared, 1H NMR, thermogravimetric analysis, TGA, UV-vis, cyclic voltammetry, photoluminescence (PL) emission spectra, and the application of dye sensitizers in DSSCs has been studied. The DSSCs exhibited good performance with a power conversion efficiency of up to 1.77%, under simulated air mass 1.5 G solar irradiation. They possess good stabilities, indicating the polymeric metal complexes are suitable for the fabrication processes of optoelectronic devices. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Four main chain polymeric metal complexes (P1-P4) based on 1,10-phenanthroline metal complexes via the Heck coupling have been synthesized and characterized by Fourier transform infrared spectroscopy, 1H NMR, UV-Vis absorption, photoluminescence spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, elemental analysis, and cyclic voltammetry. To investigate their photovoltaic properties, the dye-sensitized solar cells based on these polymers dyes are studied, under the illumination of AM 1.5G, 100 mW/cm2. The study results show the four polymers exhibit good thermally stable and the solar cells based on them have good device performance, and the maximum power conversion efficiency is up to 0.735% for the solar cells based on P3 with a short-circuit current ( Jsc) of 1.68 mA/cm2 and an open-circuit voltage ( Voc) of 0.62 V. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Four novel donor − π-bridge − acceptor (D − π − A) polymeric metal complexes (P1-P4) based on 8-hydroxyquinoline metal complexes were synthesized and tested for their performance in dye-sensitized (DSSCs). The polymeric metal complexes dyes use alkoxy benzene or alkyl fluorene as the electron donor and C=C as π linker; the 8-hydroxyquinoline derivative complex part was used as the electron acceptor and diaminomaleonitrile was used as ancillary ligand. The two strongly electron-withdrawing cyano groups in the polymer structure can provide an efficient in the between donor and acceptor parts. The thermal, photophysical, electrochemical and photovoltaic properties of these copolymers were investigated by TGA, differential scanning calorimetry, cyclic voltammetry and cureent density-voltage curves, and the results showed that dye containing complex Zn(II) and alkoxy benzene unit benefited the generation of photocurrent and open-circuit voltages, and a maximum power conversion efficiency of 1.91% (P2) was obtained, with an open-circuit voltage of 0.71 V, a short-circuit current density of 4.23 mA cm−2, and a fill factor of 38.6% under AM1.5G irradiation. The study results also show that the four polymers exhibit good , indicating that these polymeric metal complexes are suitable for the fabrication processes of optoelectronic devices. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]