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A facile method for preparing hierarchical carbon composites that contain activated carbon (AC), carbon nanospheres (CNSs), and carbon nanotubes (CNTs) for use as the electrode material in supercapacitors (SCs) was developed. The CNS/CNT network enabled the formation of three‐dimensional conducting pathways within the highly porous AC matrix, effectively reducing the internal resistance of an SC electrode. The specific capacitance, cyclability, voltage window, temperature profile during charging/discharging, leakage current, gas evolution, and self‐discharge of the fabricated SCs were systematically investigated and the optimal CNS/CNT ratio was determined. A 2.5 V floating aging test at 70 °C was performed on SCs made with various hierarchical carbon electrodes. Electrochemical impedance spectroscopy, postmortem electron microscopy, Raman spectroscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy analyses were conducted to examine the electrode aging behavior. A hierarchical carbon architecture with an appropriate AC/CNS/CNT constituent ratio could significantly improve charge‐discharge performance, increase cell reliability, and decrease the aging‐related degradation rate. [ABSTRACT FROM AUTHOR]

This article proposes a design of miniaturized high selectivity band‐pass filter by using a dual‐mode patch resonator with two pairs of uniform slots set in the four corners. The effect of the pairs of the slots on the resonant modes of the square patch resonator is investigated first. For filter design, the slots set in the four corners of the patch resonator are provided as the perturbation elements to tune the resonant modes and thus form the filter response. The pairs of the slots reduce the fundamental resonant frequency and thus miniaturize the filter size. The designed filter is simulated and measured at 1.95 GHz for the fifth generation applications with narrow bandwidth. High band selectivity is obtained due to the creation of transmission zeros near the passband edges. The filter performances are measured by network analyzer and the results are discussed. [ABSTRACT FROM AUTHOR]

Dextrans are widely used as additives in food, pharmaceutical, and cosmetics because of their hydrophilicity, biocompatibility, and low toxicity. These features allow the use of dextrans to modify the surface of nanoparticles to improve cell compatibility for biomedical applications. Additionally, dextran molecules covalently bound with fluorescent dyes are frequently used as tracers in animal studies. These facts show that dextrans are useful compounds for biomedicine-related applications and research. Our aim was to explore a facile way to generate dextran-derived nanoparticles with photoluminescent property for the use in fluorescence imaging of bacteria and cancer cells. Dextran-encapsulated gold nanoclusters (AuNCs@dextran) were generated through a one-pot reaction by stirring dextrans and aqueous tetrachloroauric acid overnight. The generated AuNCs exhibit bright and green photoluminescence under the illumination of an ultraviolet lamp ( λ = 365 nm), and high cell biocompatibility was found as well. Therefore, the generated AuNCs can be used as fluorescence tracers and nanoprobes. We explored the suitability of AuNCs@dextran as labeling agents for bacteria, such as Staphylococcus aureus and Escherichia coli. After the bacteria were labeled by AuNCs@dextran, they became quite visible under a fluorescence microscope. Additionally, we demonstrated that nanocomposites composed of AuNCs@dextran and silica beads can be readily internalized by cancer cells. The nanocomposites can be readily detected in the cells through their photoluminescence, suggesting possible applications in drug delivery and fluorescence imaging. [ABSTRACT FROM AUTHOR]

Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95±0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ∼630 nm (λexcitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ∼2×106 cells/mL. [ABSTRACT FROM AUTHOR]

Lots of lithium ion battery (LIB) products contain lithium metal oxide LiNi5Co2Mn3O2 (LNCM) as the positive electrode's active material. The stable surface of this oxide results in high resistivity in the battery. For this reason, conductive carbon-based materials, including acetylene black and carbon black, become necessary components in electrodes. Recently, carbon nano-tube (CNT) has appeared as a popular choice for the conductive carbon in LIB. However, a large quantity of the conductive carbon, which cannot provide capacity as the active material, will decrease the energy density of batteries. The ultra-high cost of CNT, compared to conventional carbon black, is also a problem. In this work, we are going to introduce long-length carbon nano-tube s(L-CNT) into electrodes in order to design a reduced-amount conductive carbon electrode. The whole experiment will be done in a 1Ah commercial type pouch LIB. By decreasing conductive carbon as well as increasing the active material in the positive electrode, the energy density of the LNCM-based 1Ah pouch type LIB, with only 0.16% of L-CNT inside the LNCM positive electrode, could reach 224 Wh/kg and 549 Wh/L, in weight and volume energy density, respectively. Further, this high energy density LIB with L-CNT offers stable cyclability, which may constitute valuable progress in portable devices and electric vehicle (EV) applications. [ABSTRACT FROM AUTHOR]

In this paper, we develop a bandpass filter using a stub-loaded stepped impedance resonator (SLSIR) and calculate the even and odd resonant modes of this type of resonator using the input impedance/admittance analysis. In this study, two impedance ratios and two length ratios are operated as the design parameters for controlling the resonant modes of the SLSIR. Several resonant mode variation curves operating three resonant modes with different impedance ratios and two length ratios are developed. By tuning the desired impedance ratios and length ratios of the SLSIRs, compact ultra-wideband (UWB) bandpass filters (BPFs) can be achieved. Two examples of the UWB BPFs are designed in this study. The first example is UWB filter with a wide stopband and the second one is dual UWB BPF, namely, with UWB performance and a notch band. The first filter is designed for a UWB response from 3.1 to 5.26 GHz having a stopband from 5.3 to 11 GHz, with an attenuation level better than 18 dB. The second filter example is a dual UWB BPF with the frequency range from 3.1 to 5 GHz and 6 to 10.1 GHz using two sets of the proposed SLSIR. The measured results have insertion loss of less than 1 dB, and return loss greater than 10 dB. Furthermore, the coupling structures and open stub of the SLSIR also provide several transmission zeros at the skirt of the passbands for improving the passband selectivity. [ABSTRACT FROM AUTHOR]

Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95±0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ∼630 nm (λexcitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ∼2×106 cells/mL. [ABSTRACT FROM AUTHOR]