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Abstract: A 10-pole self-equalized high-temperature superconducting (HTS) filter is presented in this paper. The filter has a fractional bandwidth of 0.51% at 1955MHz, simulated in Sonnet, and is fabricated using double-sided Tl2Ba2CaCu2O8 film on 0.5mm thick LaAlO3 substrates. The filter consists of 10 novel quasi-lumped resonators and an additional microstrip which is used to realize the real-axis transmission zeros (TZs). The simulated group delay ripple over the central 55% of the filter’s passband is 5.6ns, and a close result of phase response is achieved in laboratory test. The measured insertion loss of the filter is less than 0.2dB, the out-of-band rejection is better than 75dB and the slope is better than 22dBMHz−1 at band edge. [Copyright &y& Elsevier]

Abstract: An open-ended dielectric resonator method and experimental apparatus for measuring microwave surface resistance of the high T c superconducting thin films are reported. Making use of two sapphire rods the quality factor related to the losses of the resonator except its superconducting part can be evaluated. The R s value of an individual superconducting thin film can be determined without any assistance of other superconducting films or calibrators. This measurement provides a convenient and absolute approach for R s-measurement of high T c superconducting thin films. Also the error in the R s-measurement with the method was discussed. [Copyright &y& Elsevier]

Abstract: Long intrinsic Josephson junction arrays (3.4mm) were successfully fabricated in misaligned Tl2Ba2CaCu2O8 thin films grown on 20° vicinal substrates. The array consists of about 7.7×105 intrinsic Josephson junctions. The I–V characteristic was recorded and compared with that of a 6μm long array. The inductance of the ultra-long junction array in zero-voltage state was observed and measured directly. The measured value is basically consistent with the theoretically calculated result, confirming that the inductance is mainly due to the Josephson effect. The inductance from the Josephson effect is one order of magnitude larger than that from other effects, suggesting a new idea of the use of intrinsic Josephson junction arrays as new type of inductors with small size and large inductance. [Copyright &y& Elsevier]

Abstract: This paper presents a comprehensive methodology to model the assembly process of flip chip on flex interconnections with non-conductive adhesives (NCAs). The methodology combines experimental techniques for material characterization, finite element modeling, and model validation. A non-conductive adhesive has been characterized using several techniques. A unique experimental technique has been developed to measure the cure shrinkage. A 2D axisymmetric finite element model is used for analysis of flip chip on flex package with the non-conductive adhesive (NCA), which takes into account assembly force, cure shrinkage, adhesive modulus buildup, removal of assembly force, and cooling down to room temperature. The relationship between the bump contact resistance and the bump pressure has been established through the development of a dedicated experimental setup, which uses a micro-force tester combined with a digital multimeter and a nano-voltmeter. The process modeling has been validated by comparing the predicted bump contact resistance value and the measured bump contact resistance value after assembly process. The approach developed in this paper can be used to provide guidelines with respect to adhesive material properties, assembly process parameters, and good reliability performances. [Copyright &y& Elsevier]

Abstract: Acidic phosphate ester (APES) bearing polysilsesquioxane precursor was prepared employing the ring-opening reaction of (3-glycidoxypropyl)trimethoxysilane (GPTMS) with acidic phosphate monoester carrying long hydrophilic tail. Doped with APES, polyaniline emeraldine base (PANI) was successfully dissolved or dispersed in water, and a free-standing film with electrical conductivity as high as 0.05S/cm was available. The obtained film showed water-resistance due to the confinement from inorganic networks of amorphous polysilsesquioxane characterized by 29Si-MAS NMR spectrum. When the conductive film was soaked in water for 14 days, its electrical conductivity showed a little decline at the first stage of 6 days, and a considerably long platform existed at the following stage. However, for the film without polysilsesquioxane network, the electrical conductivity showed a sharp decline, and the film was broken into pieces for only 1 day soaking. Covalently linked with inorganic network of polysilsesquioxane by Ph name="sbnd" />C bond, thermal stability of the conductive polyaniline was also improved compared with that of the conductive hybrid film from physical blending. [Copyright &y& Elsevier]

Abstract: High quality Tl2Ba2CaCu2O8 (Tl-2212) superconducting thin films are prepared on both sides of 2in. LaAlO3(001) substrates by off-axis magnetron sputtering and post-annealing process. XRD measurements show that these films possess pure Tl-2212 phase with C-axis perpendicular to the substrate surface. The thickness unhomogeneity of the whole film on the 2in. wafer is less than 5%. The superconducting transition temperatures Tcs of the films are around 105K. At zero applied magnetic field, the critical current densities Jcs of the films on both sides of the wafer were measured to be above 2×106A/cm2 at 77K. The microwave surface resistance Rs of film was as low as 350μΩ at 10GHz and 77K. In order to test the suitability of Tl-2212 thin films for passive microwave devices, 3-pole bandpass filters have been fabricated from double-sided Tl-2212 films on LaAlO3 substrates. [Copyright &y& Elsevier]

Abstract: We report measurements of third-order optical nonlinearity of the 90GeS2–5Ga2S3–5CdS (in mol%) chalcogenide glass using the femtosecond time-resolved optical Kerr gate technique at 820 nm. The third-order nonlinear susceptibility was estimated to be as large as 1.0×10−12 esu. The full width at half maximum of the Kerr signal was 150 fs, implying that the sample had a response faster than 120 fs. Its response was dominantly assigned to the ultrafast distortion of the electron cloud. This glass sample is promising in future all-optical switching devices. [Copyright &y& Elsevier]

Raman investigations were carried out for various compositions of chalcogenide glasses in the GeS2–Ga2S3–CdS system. Addition of Ga2S3 into GeS2 results in the formation of metal–metal bonds and edge-shared GaS4/2 tetrahedra. Ge2+ ions may surround [GaS4/2]1− tetrahedra acting as charge compensators. Upon the addition of CdS into the GeS2–Ga2S3 system, the number of the metal–metal bonds and edge-shared GaS4/2 tetrahedra decreases, resulting in the formation of corner-shared tetrahedra with non-bridging sulfurs (NBS). Cd2+ ions can be dissolved into the glass network as charge compensators for these NBS and exited few [GaS4/2]1− tetrahedra. The high solubility of CdS is ascribed to the dissociation of metal–metal bonds and edge-shared tetrahedra in these Ga-containing glasses. [Copyright &y& Elsevier]

Very thin Tl2Ba2CaCu2Ox (Tl-2212) superconducting films with thickness < 100 nm have been fabricated on LaAlO3 (0 0 1) substrates using dc magnetron sputtering and post-annealing process in pure argon. For a 100 nm thick film, Tc and Jc (77 K, 0 T) show the values of 105.3 K and 2.33 × 106 A/cm2, respectively. A 30 nm thick film with Tc>100 K shows smooth surface morphology and high quality epitaxy. A 20 nm thick film revealed full transition to superconductivity at temperature of 98.7 K. The superconductivity and surface morphology of the very thin film deteriorated rapidly as the film thickness below 20 nm. A 6 nm thick Tl-2212 film was not found to be superconducting at temperature down to 15 K. In our experiments the critical film thickness leading to degradation of the superconducting properties was 20 nm. [Copyright &y& Elsevier]

Highlights: [•] Sloping steps were observed under microwave irradiation. [•] The dV/dI–I curves showed the bump variation. [•] The dV/dI–V curves showed the step voltage variation. [ABSTRACT FROM AUTHOR]

Ozone has become the main factor affecting the air quality in the Pearl River Delta (PRD) in recent years, and a clear understanding source of ozone pollution is a top priority of ozone pollution prevention. However, the vertical distribution of tropospheric ozone in the PRD is poorly understood. Based on daily ozone sounding data obtained in Yangjiang (111°58'00" E, 21°50'00" N), Guangdong Province, from 18 November tjo 3 December 2013, the detailed vertical distribution of tropospheric ozone and its influencing factors were determined and compared with weekly autumn ozone profile data obtained at the Hong Kong Observatory (HKO) and corresponding tropospheric column ozone (TCO) datasets from the Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) onboard satellite AURA. Overall, the ozone profiles observed in Yangjiang are in accordance with those of the HKO in terms of the vertical structure. The TCO values are 34.2 ± 4.0 and 34.3 ± 4.6 DU, respectively, that are, 4 DU higher than those of satellite data, indicating that the OMI/MLS product underestimates the TCO level in the PRD region. The Yangjiang ozone profiles indicate significant variations in the ozone vertical structure and concentration during the observation period. A significant ozone peak permanently occurs in the lower troposphere at 1.1 ± 0.4 km above the surface. The vertical structural difference is mainly reflected in the presence of low-ozone strata (below 30 ppbv) near the tropopause and ozone peaks and high-ozone stratification in the middle and upper troposphere. The average ozone peak concentrations in the lower, middle, and upper troposphere are 65.2 ± 9.9, 57.8 ± 7.7, 71.8 ± 13.6 ppbv, respectively, which are higher than the average ground-level ozone concentration (48.9 ± 9.4 ppbv). Based on the analysis of the profile characteristics, weather conditions, and backward trajectories, it can be concluded that the low-ozone strata near the tropopause are caused by the regional transport of the tropical air mass from the tropical cyclone storm area. Potential vorticity analysis shows that stratosphere-troposphere exchange (STE) is the main reason for the formation of the ozone peaks and its varying concentrations in the middle and upper troposphere. Photochemical reactions represent the main factor affecting the ozone concentration in the lower troposphere. The STE is also an important factor affecting the ozone in the lower troposphere, leading to an increase in the surface ozone concentration by ~10.9 ppbv. Image 1 • The vertical distribution of tropospheric ozone at Yangjiang are firstly presented. • Tropical cyclone storm result in low ozone strata in the upper troposphere. • STE is the main factor causing the ozone peak in the middle and upper troposphere. • The contribution of stratospheric O 3 to surface O 3 is about 10.9 ppbv. [ABSTRACT FROM AUTHOR]

One of the issues in the railway field is the damage caused by wear and RCF which deeply affects wheel and rail. These phenomena are closely connected and directly impact both on vehicle dynamics (comfort, stability, safety, etc.) and on the costs (line management, maintenance, etc.), decreasing the useful life of wheel and rail. To face these problems and detect abnormal operating conditions, this work aims at developing a modelling approach for railway and tramway applications that effectively combines wear and RCF models. The former has been validated by means of on-field experimental data whereas the latter through specific laboratory tests carried out on a dedicated test-rig. The proposed approach is capable of simultaneously predicting both the profiles shape evolution due to wear and the total RCF damage along the wheel and rail profiles, reaching a good compromise between accuracy and efficiency. Thanks to the high numerical efficiency, the wear-RCF model can be easily implemented into complex multibody models of railway and tramway vehicles to perform large-scale simulations. • The new modelling approach allows the simultaneous calculation of wear and RCF on wheel and rail. • The model can be implemented into complex multibody models of railway vehicles. • The new RCF model evaluates the crack dimensions and the position of the crack along profiles. • The RCF law is experimentally developed through a specific test campaign on test rigs. [ABSTRACT FROM AUTHOR]