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Graphene field-effect transistors (FETs) have attracted tremendous attention owing to the single-atomic-layer thickness and high electron mobility for potential applications in next-generation electronics. With regards to switching methodology, the electric-field-induced metal-insulator transition offers a new strategy to produce a large on/off current ratio through reversible electrochemical hydrogenation of the graphene channels. Therefore, the performance of such electrochemical graphene FETs greatly relies on the kinetics of hydrogenation reaction. Here, we show that the switching time can be systemically controlled by the applied gate voltages and geometries of graphene channels. The turn-on and turn-off time display an exponential dependence on the gate voltages, manifesting the dominated Tafel-form kinetics of hydrogenation reaction in a two-dimensional limit. Moreover, the turn-off time is inversely proportional to the channel width but independent of the length, while the turn-on time relies on both the width and length, as well as the off-state gate voltage and duration. Our work improves the response time to the magnitude of tens of microseconds and advances the application of graphene-based electronic devices.

Coastal sediments are considered as hotspots of microplastics (MPs), with substantial MPs stocks found in blue carbon habitats such as mangroves and tidal marshes, where wave-damping vegetation reduces sediment erosion and enhances accretion. Here, we examined the effects of such bio-geomorphic feedbacks in shaping MPs burial, through a year-round field study in a mangrove habitat along the coast of South China. The results revealed that MPs abundance decreased significantly with the increase of cumulative sediment erosion as the strength of bio-geomorphic feedbacks declined. More shapes and colors of MPs were found at locations with weaker waves and less sediment erosion, where the average particle size was also higher. Our findings highlight the importance of bio-geomorphic feedbacks in affecting both the abundance and characteristics of the buried MPs. Such knowledge extends our understanding of MPs transport and burial from the perspective of bio-geomorphology, which is essential to assess and predict MPs accumulation patterns as well as its impacts on ecosystem functioning of the blue carbon habitats.

We present the first results of a custom low-noise silicon photodiode detector designed for use with X-ray capillary optics. This system is intended to perform as a smaller, lighter, and low-powered alternative to currently existing X-ray telescope technologies. The detector has an active area with a diameter of 100 $\mu \text{m}$ , and its small size leads to a low capacitance of well under 1 pF and a leakage current of 1 pA or less at the depletion voltage. We tested the detector with both a discrete preamp and an ultralow-noise front-end application-specific integrated circuit (ASIC). The front-end ASIC, developed at Brookhaven National Laboratory, was designed for low-capacitance detectors but had not been previously tested with a detector. Here, we discuss the detector design, the experimental setup, and the resulting detector performance. Using radioactive laboratory sources, we measure a full-width at half-maximum (FWHM) of 211 ± 8 eV at 5.9 keV with the ASIC and are able to set the threshold as low as 0.6 keV.

Designing and constructing hierarchical and stimuli-responsive motorized nanocar systems to perform useful tasks on-demand is highly imperative towards molecular nanotechnology. In this work, a most simplified two-wheel nanocar was successfully prepared through a facile strategy of coordination-directed self-assembly. The nanocar meso-AgL2 features a central pseudo square-planar Ag(I) which was bridged by two enantiomeric motors as the wheels that ensure the car moves in the same direction when observed externally. Thanks to the electronic push–pull characteristic of L and 3ILCT triplet sensitization, this nanocar can be driven by visible light up to 500 nm. Furthermore, it could be disassembled into individual motor elements through the addition of pyridine, thus allowing dynamic regulation over the function of the nanocar. Importantly, our STM imaging results showed very organized tilted layered structures for meso-AgL2 on highly oriented pyrolytic graphite (HOPG) that are quite similar to its crystalline ones, paving the way for future single molecule manipulations. The nanocar reported here represents the first example of integrating individual motors into a hierarchical motorized nanocar system via the facile coordination-directed self-assembly method and may offer a good starting point to realize its robotic functions, e.g., metal transportation and release.

In the quest to study the fundamental nature of matter and the universe, high-energy physics (HEP) experiments often operate in extreme conditions that lie well outside the standard operating range of integrated circuits (ICs). Two prominent examples of such extreme environments are 1) the irradiation levels experienced at high luminosity colliders and 2) operation at cryogenic temperatures [1]. Cryogenic electronics is a broad term that encompasses circuits operating at temperatures below the standard operating limit (m55 dC in the case of military grade electronics), all of the way down to millikelvin, as in the case of superconducting circuits. Cryogenic circuits have a long history [2] and have found applications in a broad spectrum of applications, such as infrared focal plane arrays, positron emission tomography, and quantum science. While CMOS circuits have been reliably operated at deep-cryogenic temperatures (l 4.2 K), this article focuses on applications down to liquid nitrogen (77 K) and provides an overview of the design considerations, benefits, and unique challenges pertaining to cryogenic CMOS ICs for large HEP experiments.

Coastal sediments, recognized as a major sink for microplastics (MPs), are subject to frequent physical disturbances, such as wave disturbance and associated sediment dynamics. Yet it remains poorly understood how wave disturbance regulates MPs accumulation in such a dynamic environment. Here, we examined the effects of waves and their interactions with material density and burial depth on the retention of MPs in coastal sediments, through manipulative experiments in a mangrove habitat along the coast of South China. The results clearly revealed that stronger waves removed more buried MPs from the sediments. Moreover, storms can have disproportional effects on MPs retention by inducing large waves and strong sediment erosion. We also demonstrated that MPs retention generally increased linearly with growing material density and non-linearly with raised burial depth in the sediment. Overall, our findings highlight the importance of both external and internal factors in shaping MPs retention in coastal ecosystems like mangroves, which is essential to assess and predict MPs accumulation patterns as well as its impacts on ecosystem functioning of such blue carbon habitats.

The quantum anomalous Hall (QAH) effect in magnetic topological insulator (TI) represents a new state of matter originated from the interplay between topology and magnetism. The defining characteristics of the QAH ground state are the quantized Hall resistivity ($\rho_{yx}$) and vanishing longitudinal resistivity ($\rho_{xx}$) in the absence of external magnetic field. A fundamental question concerning the QAH effect is whether it is merely a zero-magnetic-field quantum Hall (QH) effect, or if it can host unique quantum phases and phase transitions that are unavailable elsewhere. The most dramatic departure of the QAH systems from other QH systems lies in the strong magnetic disorders that induce spatially random magnetization. Because disorder and magnetism play pivotal roles in the phase diagram of two-dimensional electron systems, the high degree of magnetic disorders in QAH systems may create novel phases and quantum critical phenomena. In this work, we perform systematic transport studies of a series of magnetic TIs with varied strength of magnetic disorders. We find that the ground state of QAH effect can be categorized into two distinct classes: the QAH insulator and anomalous Hall (AH) insulator phases, as the zero-magnetic-field counterparts of the QH liquid and Hall insulator in the QH systems. In the low disorder limit of the QAH insulator regime, we observe a universal quantized longitudinal resistance $\rho_{xx} = h/e^{2}$ at the coercive field. In the AH insulator regime, we find that a magnetic field can drive it to the QAH insulator phase through a quantum critical point with distinct scaling behaviors from that in the QH phase transition. We propose that the transmission between chiral edge states at domain boundaries, tunable by disorder and magnetic fields, is the key for determining the QAH ground state., Comment: 17 pages, 5 figures

XL-Calibur is a balloon-borne hard X-ray polarimetry mission, the first flight of which is currently foreseen for 2021. XL-Calibur carries an X-ray telescope consists of consists of 213 Wolter I grazing-incidence mirrors which are nested in a coaxial and cofocal configuration. The optics design is nearly identical to the Hard X-ray Telescope (HXT) on board the ASTRO-H satellite. The telescope was originally fabricated for the Formation Flying Astronomical Survey Telescope (FFAST) project. However, the telescope can be used for XL-Calibur, since the FFAST project was terminated before completion. The mirror surfaces are coated with Pt/C depth-graded multilayers to reflect hard X-rays above 10 keV by Bragg reflection. The effective area of the telescope is larger than 300 cm^2 at 30 keV. The mirrors are supported by alignment bars in the housing, and each of the bars has a series of 213 grooves to hold the mirrors. To obtain the best focus of the optics, the positions of the mirrors have to be adjusted by tuning the positions of the alignment bars. The tuning of the mirror positions is conducted using the X-ray beam at the synchrotron facility SPring-8 BL20B2, and this process is called optical tuning. First the positions of the second reflectors are tuned, and then those of the first reflectors are tuned. We did the first optical tuning in Jan 2020. The second tuning will be planned between April to July, 2020. This paper reports the current status of the hard X-ray telescope for XL-Calibur.

We present the first results of a custom low-noise silicon pixel detector designed for use with X-ray capillary optics, coupled with an ultra low-noise front-end application specific integrated circuit (ASIC). This system is intended to perform as a smaller, lighter, more sensitive, and low-powered alternative to currently existing X-ray telescope technologies. The detector has an active area of 100 microns, and its small size leads to a low capacitance of well under 1 pF and a leakage current of less than 1 pA. The front-end ASIC, developed at Brookhaven National Laboratory, was designed for low capacitance detectors but had not been previously tested with a detector. Here we discuss the detector design, the experimental setup of this detector and ASIC, and preliminary results. Using radioactive lab sources, we measure a FWHM of 211±8 eV at 5.9 keV and are able to set the threshold as low as 0.6 keV.

The accretion-powered X-ray pulsar GX 301-2 was observed with the balloon-borne X-Calibur hard X-ray polarimeter during late December 2018, with contiguous observations by the NICER X-ray telescope, the Swift X-ray Telescope and Burst Alert Telescope, and the Fermi Gamma-ray Burst Monitor spanning several months. The observations detected the pulsar in a rare apastron flaring state coinciding with a significant spin-up of the pulsar discovered with the Fermi GBM. The X-Calibur, NICER, and Swift observations reveal a pulse profile strongly dominated by one main peak, and the NICER and Swift data show strong variation of the profile from pulse to pulse. The X-Calibur observations constrain for the first time the linear polarization of the 15-35 keV emission from a highly magnetized accreting neutron star, indicating a polarization degree of (27+38-27)% (90% confidence limit) averaged over all pulse phases. We discuss the spin-up and the X-ray spectral and polarimetric results in the context of theoretical predictions. We conclude with a discussion of the scientific potential of future observations of highly magnetized neutron stars with the more sensitive follow-up mission XL-Calibur., Comment: Accepted for publication in the Astrophysical Journal. 20 pages, 19 figures, 4 tables

Graphene is of interest in the development of next-generation electronics due to its high electron mobility, flexibility and stability. However, graphene transistors have poor on/off current ratios because of the absence of a bandgap. One approach to introduce an energy gap is to use hydrogenation reaction, which changes graphene into insulating graphane with sp3 bonding. Here we show that an electric field can be used to control conductor-to-insulator transitions in microscale graphene via a reversible electrochemical hydrogenation in an organic liquid electrolyte containing dissociative hydrogen ions. The fully hydrogenated graphene exhibits a lower limit sheet resistance of 200 Gohm/sq, resulting in graphene field-effect transistors with on/off current ratios of 10^8 at room temperature. The devices also exhibit high endurance, with up to one million switching cycles. Similar insulating behaviours are also observed in bilayer graphene, while trilayer graphene remains highly conductive after the hydrogenation. Changes in the graphene lattice, and the transformation from sp2 to sp3 hybridization, is confirmed by in-situ Raman spectroscopy, supported by first-principles calculations., Comment: 20 pages, 4 figures

The quantum anomalous Hall effect in magnetic topological insulators provides an ideal platform for building topological phases and devices. Here we construct a bilayer structure consisting of two magnetic topological insulator films with drastically different coercive field. In the intermediate field regime, the two quantum anomalous insulators have opposite spin orientation and counter-propagating edge states, thus realizing a synthetic quantum spin Hall phase. Multi-terminal transport measurements show that a moderate magnetic field can tune the system between chiral and helical edge state transport regimes. The interlayer transport realizes quantized spin-biased resistance, and the coupling between the two edges can be tuned by an epitaxially grown spacer layer in a sandwich structure. The tunable chiral and helical edge states in the quantum anomalous Hall bilayer may find unique applications in spintronics and topological quantum computation.

This paper presents a 10-bit 100MS/s analog to digital converter (ADC) that based on successive approximation (SAR) algorithm. This ASIC is to fulfill the requirement of Hadronic Calorimeter (HCal) upgrade: custom cost-efficient high sampling digitizer electronics and capable of continuous operation mode. The designed chip is developed by using the TSMC 65nm CMOS technology. The post-layout simulations show this ADC could achieve peak signal to noise and distortion ratio (SNDR) of 58 dB at Nyquist rate input frequency and power consumption of 3.5 mW. The peak effective number of bits (ENOB) is 9.6 bits, equivalent to the figure of merit of 45 fJ/conversion step.

As a prototype of Deep Underground Neutrino Experiment far detector, ProtoDUNE single-phase Liquid Argon (LAr) Time Projection Chamber (TPC) sits in H4 beam line at CERN to characterize detector response. It consists of 6 full-size Anode Plane Assemblies (APAs) plus 18 Cathode Plane Assembly (CPA) modules to form two 3.6-m drift regions with a total of 15,360 readout channels. To achieve a good signal-to-noise ratio with this noble liquid detector (770ton LAr), cold electronics developed at BNL for extremely low temperature (77K–89K) operation is an optimal solution, which decouples the electrode and cryostat design from the readout design. With CMOS front end ASICs integrated with the TPC electrodes, the electronic noise is independent of the fiducial volume and much lower than with readout electronics at room temperature. In addition, signal digitization and multiplexing to high-speed links inside the cryostat result in large reduction in the quantity of cables and the number of cryostat penetrations, giving the designers of both the TPC and the cryostat the freedom to choose the optimum configurations. By April 2018, we have successfully instrumented 6 APAs with cold electronics, and the results of the integration test before the final installation in the cryostat look very promising.

Low dropout (LDO) voltage regulators, which provide a clean supply for analog and mixed-signal systems, are essential to low-noise front-end electronics in high energy physics experiments and beyond. This paper analyzes the noise sources in an LDO where the input referred noise of the error amplifier is the dominant noise source. Implemented in 65 nm technology, the LDO presented here regulates a noisy 1.5 V supply and outputs a stable and low-noise nominal 1.175 V voltage with load current ranging from a few milliamp up to 150 mA. The design achieves higher than 75% power efficiency at both room and cryogenic temperatures at maximum load, with more than 40 dB power supply rejection up to 400 kHz. The simulated RMS noise from 10 Hz to 100 kHz is less than 2 µV at room temperature and less than 1 µV at 77 K. The regulator requires an external capacitance of 50 µF for stability. A number of next-generation detectors can greatly benefit from having this voltage regulator directly integrated in the front-end application-specific integrated circuits (FE-ASICs) working at room and cryogenic temperatures.

A low-power, low-noise pixel readout application-specific-integrated-circuit (ASIC) prototype with embedded in-pixel photo-diode was developed for a novel pixelated-scintillator-based X-ray detector, capable of spectral energy discrimination and suitable for low dose whole body CT imaging. The ASIC includes 8-by-16 channels to read out negative charges detected by the built-in photodiodes, at a pitch size of 250 µm to achieve good spatial and energy resolution energy of detected photons. Each channel of the ASIC provides low-noise charge amplification, high-order shaping with baseline stabilization, discrimination, extraction of amplitude including neighbor channels, multiplexing, and dissipates ~0.6 mW. The measured equivalent noise charge (ENC) is about 20 rms electrons at 500 ns peaking time. The ASIC with built-in photodiodes has demonstrated high sensitivity to light.

As a prototype of Deep Underground Neutrino Experiment far detector, ProtoDUNE single-phase liquid argon Time Projection Chamber will sit in H4 beam line at CERN to study detector response to particles. It consists of 6 full-size Anode Plane Assemblies (APAs) plus 2 Cathode Plane Assemblies (CPAs) to form two 3.6m drift regions with total 15,360 readout channels. To achieve optimal noise performance, readout electronics developed for extremely low temperatures (77K-89K) operation has been studied with an integral design concept of APA, cold electronics, feed-through, plus warm interface electronics with local diagnostic following strict isolation and grounding rules. By the end of September 2017, the first full-size APA has been integrated with readout electronics successfully for the coming cold integration test at CERN.

Though many firms still believe that passive environmental strategies are sufficient, it is pertinent that they move beyond this belief and take a proactive supply chain-wide environmental stance so as to create a sustainable environment. In this paper, we seek to extend current work within green supply chain management by considering multiple green supply chain capabilities and performance measures. We hypothesise the linkage between environmental orientation, green supply chain capabilities and performance by drawing upon stakeholder theory and natural resource-based view. More importantly, our study is the first to distinguish between product and process-related capabilities in the green supply chain area and study their direct and mediating role with respect to environmental and financial performance measures. Using survey data collected from 256 Chinese-based high-tech firms, we analyse several hypothesised relationships. Our results provide strong support for the significant role that green product ...

Quantum anomalous Hall (QAH) effect is a quantum Hall effect that occurs without the need of external magnetic field. A system composed of multiple parallel QAH layers is an effective high Chern number QAH insulator and the key to the applications of the dissipationless chiral edge channels in low energy consumption electronics. Such a QAH multilayer can also be engineered into other exotic topological phases such as a magnetic Weyl semimetal with only one pair of Weyl points. This work reports the first experimental realization of QAH multilayers in the superlattices composed of magnetically doped (Bi,Sb)$_2$Te$_3$ topological insulator and CdSe normal insulator layers grown by molecular beam epitaxy. The obtained multilayer samples show quantized Hall resistance $h/Ne$$^2$, where $h$ is the Planck's constant, $e$ is the elementary charge and $N$ is the number of the magnetic topological insulator layers, resembling a high Chern number QAH insulator., Comment: 9 pages, 3 figures

We present a low-power, low-noise prototype pixel readout application specific integrated circuit (ASIC) for hyperspectral enegy-resolving X-ray imaging detectors. The ASIC provides 16-by-16 channels to read out positive and negative charges from 16-by-16 heagonal silicon or CZT detector arrays, at a pitch size of $250 \mu \mathrm{m}$, to achieve good spatial resolution and the ability to record the energy of a detected photon as well as its position. The readout is done by bumpbonding the anodes to the inputs of the ASIC. Each channel of the ASIC provides low-noise charge amplification, high-order shaping with baseline stabilization, discrimination, extraction of amplitude (with neighbour channels), multiplexing, and dissipates $\sim0.6$ mW. A smart readout of the triggered pixel and its adjacent six pixels in the hexagonal configuration allows reconstruction of events with charge sharing correction, and can be used to estimate the depth of the photon interaction and to suppress background events. The target equivalent noise charge (ENC) is $\sim10$ electrons for silicon detector pixel and $\sim15$ electrons for CZT detector pixel.

ProtoDUNE-SP and SBND are both liquid argon (LAr) TPCs for neutrino experiments, they share many common development of cold electronics system. Cold electronics decouples the electrode and cryostat design from the readout design. With front-end (FE) electronics integrated with detector electrodes, the noise is independent of the fiducial volume (signal cable lengths), and much lower than with warm electronics. ProtoDUNE-SP cold electronics mainly consists of 960 FE ASICs, 960 ADC ASICs and 120 cold FPGAs to form 120 Front End Mother Board (FEMB) assemblies. Each FEMB assembly is made up of an analog mother board (AM) and an FPGA mezzanine (FM). An AM has 128 channels with 8 FE ASICs and 8 ADC ASICs designed by BNL for 77K-300K operation and long lifetime with low power consumption. The FM multiplexes and transmits 128 channels of data through four 1 Gb/s serial links to the warm interface electronics. SBND cold electronics mainly consists of 120 FEMB assemblies. The SBND design is exploring two different options, the dual gain ADC option and the commercial ADC option. Market survey and cold screening tests for the op-amp and commercial ADC have been performed to evaluate the feasibility of two options, with focus on the commercial ADC lifetime study currently. An integration test stand with 40% APA (Anode Plane Assembly) has been built at BNL, following the DUNE isolation and grounding rules, to characterize the performance of cold electronics system. The ProtoDUNE-SP installation at CERN is going well, 20 FEMB assemblies have been installed on the first APA successfully, to prepare for the data taking in 2018. SBND front-end readout electronics design will be finalized in 2018, to get ready for the data taking in 2020.

We present an ultra low-noise front-end application specific integrated circuit (ASIC) developed for high purity germanium (HPGe) p-type point-contact (PPC) detectors operating in liquid nitrogen (LN) for low background experiments. The ASIC provides low-noise charge amplification for an input range of 100 eV to 50 keV, anti-aliasing filtering while preserving a minimum of ~60 ns event rise time, an analog output buffer to drive the cold/warm interface, and is fabricated in a commercial 180-nm CMOS technology. Given a full depletion capacitance of the HPGe PPC as low as ~100 fF, the ASIC achieves the lowest possible equivalent noise charge (ENC) ~3.9 electrons at $2 \mu {s}$ at LN temperature, and dissipates ~9 mW.

A study of hot-carrier effects (HCE) on the 180-nm CMOS device lifetime has been performed at 300 K and 77 K for Liquid Argon Time Projection Chamber (LAr TPC). Two different measurements were used: accelerated lifetime measurement under severe electric field stress by the drain-source voltage Vds, and a separate measurement of the substrate current as a function of 1/Vds. The former verifies the canonical very steep slope of the inverse relation between the lifetime and the substrate current, and the latter confirms that below a certain value of Vds a lifetime margin of several orders of magnitude can be achieved for the cold electronics TPC readout. The low power ASIC design for LAr TPC falls naturally into this domain, where hot-electron effects are negligible. Lifetime of digital circuits (ac operation) is extended by the inverse duty factor 1/(fclockteff) compared to dc operation. This factor is large (> 100) for deep submicron technology and clock frequency needed for TPC readout. As an additional margin, Vds may be reduced by ~ 10%. Extremely low failure rate (incidence) in previous large experiments demonstrates that surface mount circuit board technology withstands very well even multiple abrupt immersion in liquid nitrogen applied in board testing, and that the total failure incidence in continuous operation over time is very low.

We present VMM1, the first prototype of a family of front-end ASICs designed for the ATLAS muon upgrade. The ASIC will operate with MICROMEGAS and TGC detectors, providing charge and timing measurements along with other features including sub-hysteresis discrimination, address of the first event in real time, and digital output per channel for Time-over-Threshold measurements. The shaper, designed via the concept of Delayed Dissipative Feedback (DDF), supports analog dynamic ranges in excess of 10 \thinspace000. With a capacitance of 200 pF and a nominal peaking time of 25 ns, the ASIC offers resolution of charge and timing better than 1 fC and 1 ns, respectively, for input charges up to 2 pC. Designed in a commercial 130 nm technology it dissipates about 4.5 mW per channel.

X-ray polarimetry has seen a growing interest in recent years. Improvements in detector technology and focusing X-ray optics now enable sensitive astrophysical X-ray polarization measurements. These measurements will provide new insights into the processes at work in accreting black holes, the emission of X-rays from neutron stars and magnetars, and the structure of AGN jets. X-Calibur is a balloon-borne hard X-ray scattering polarimeter. An X-ray mirror with a focal length of 8 m focuses X-rays onto the detector, which consists of a plastic scattering element surrounded by Cadmium-Zinc-Telluride detectors, which absorb and record the scattered X-rays. Since X-rays preferentially scatter perpendicular to their polarization direction, the polarization properties of an X-ray beam can be inferred from the azimuthal distribution of scattered X-rays. A close alignment of the X-ray focal spot with the center of the detector is required in order to reduce systematic uncertainties and to maintain a high photon detection efficiency. This places stringent requirements on the mechanical and thermal stability of the telescope structure. During the flight on a stratospheric balloon, X-Calibur makes use of the Wallops Arc-Second Pointer (WASP) to point the telescope at astrophysical sources. In this paper, we describe the design, construction, and test of the telescope structure, as well as its performance during a 25-hour flight from Ft. Sumner, New Mexico. The carbon fiber-aluminum composite structure met the requirements set by X-Calibur and its design can easily be adapted for other types of experiments, such as X-ray imaging or spectroscopic telescopes., 19 pages, 20 figures, submitted to Journal of Astronomical Instrumentation

With the increased applications of zinc oxide (ZnO) nanoparticles (NPs), the toxicity of ZnO NPs arouses great concerns from the nano community and the general public. In this study, we report the toxicity of ZnO NPs (30 nm) to the rat olfactory system after intranasal instillation revealed by non-invasive magnetic resonance imaging (MRI). MRI scans were performed on a 4.7-T scanner at 1, 2, 3 and 7 days post-exposure, and the histological changes of the rat olfactory epithelium were evaluated. The influences of chemical component and dispersant of the NPs were also investigated. In addition, an olfactory behavior test was performed. The MRI and histological results indicated that ZnO NPs induced significant damages to the olfactory epithelium, including disruption of the olfactory epithelial structures and inflammation. The destruction of mitochondria in epithelial cells was observed under transmission electron microscopy (TEM), suggesting that the possible toxicological mechanism might involve cellular energy metabolic dysfunction. Further, the lesion of the olfactory epithelium disturbed sniffing behaviors of the treated animals. The results suggest that MRI is potentially useful as a screening tool to assess the consequence of occupational exposure of ZnO NPs. Caution should therefore be taken during the use and disposal of ZnO NPs to prevent the unintended public health impacts. Copyright (C) 2012 John Wiley & Sons, Ltd.

We start with an analysis of the configurations commonly adopted to implement linear shapers. We show that, once the ENC from the charge amplifier is defined, the dynamic range of the system is set by the voltage swing and the value of the capacitance realizing the poles. The configuration used to realize the poles has also an impact, and those configurations based on passive components in feedback are expected to offer a higher dynamic range than the ones that use both active and passive components, like scaling mirrors. Finally, we introduce the concept of delayed dissipative feedback (DDF), which consists of delaying the resistive feedbacks from the furthest available nodes along the shaping chain. We will show that, in order to implement semi-Gaussian shapers, a small capacitor in positive feedback is required. The DDF technique can overcome some of the limitations of the more classical configurations. For example, in a third order shaper a factor of two higher dynamic range can be obtained or, at equal dynamic range, about 25% of the capacitance is needed (i.e. about 30% of the area in practical cases).

This study investigated crucial green supply chain management (GSCM) capability dimensions and firm performance based on electronics-related manufacturing firms in Taiwan. On the basis of a factor analysis, six green supply chain management dimensions were identified: green manufacturing and packaging, environmental participation, green marketing, green suppliers, green stock, and green eco-design. According to their factor scores in the GSCM dimensions, a cluster analysis subsequently assigned responding firms into four groups, namely, the weak GSCM oriented group, the green marketing oriented group, the green supplier oriented group, and the green stock oriented group. Differences in firm performance and GSCM dimensions among groups were examined. Results indicated that the green marketing oriented group performed best. Based on the resource-based view (RBV), the capability of the green marketing oriented group was considered to be the deployment of a collection of resources that enables it to successfully compete against rivals. The importance of green marketing as a GSCM capability and strategic asset/critical resources for electronics-related manufacturing firms to obtain a competitive edge is therefore highlighted in this study.

This work presents a receiver front-end that targets mobile video applications, and integrates a dual-band LNA, a current-mode passive mixer, a reference Gilbert mixer, and a digitally-controlled oscillator providing the quadrature LO signal for the mixers. The conversion gain and thermal noise performances of the current-mode passive mixer are studied. Design tradeoffs among noise, linearity, and conversion gain are performed. Measured performance of the receiver front-end shows a flicker noise corner of 70 kHz, a noise figure (NF) of 4.4 dB, an input third-order intermodulation product (IIP3) of −2 dBm, and DCO phase noise of −128 dBc/Hz at 1-MHz offset. The receiver consumes less than 24 mA of current in a 1.2-V 90-nm standard digital CMOS process. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2138–2142, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23587

A loss-control tuning loop for Q-enhanced LC filters based on a voltage-controlled filter (VCF) is presented. The main factors affecting the tuning accuracy in this tuning scheme, including mismatches and frequency tuning errors, are discussed. The tuning scheme was implemented for a 1.5-V, 6-GHz Q-enhanced LC filter on a UMC 0.18-mum standard CMOS process. The design and measurement results are given. Effective loss control of the filter over process tolerances is demonstrated

Cadmium Zinc Telluride and Cadmium Telluride are the detector materials of choice for the detection of X-rays in the X-ray energy band E >= 5keV with excellent spatial and spectral resolution and without cryogenic cooling. Owing to recent breakthroughs in grazing incidence mirror technology, next-generation hard X-ray telescopes will achieve angular resolution between 5 and 10 arc seconds - about an order of magnitude better than that of the NuSTAR hard X-ray telescope. As a consequence, the next generation of X-ray telescopes will require pixelated X-ray detectors with pixels on a grid with a lattice constant of, Comment: 10 pages, 16 figures; Proceedings of the SPIE 2014

In this study, we investigated the dynamic distribution processes of Mn(2+) in rat brain using magnetic resonance imaging (MRI) after an intra-arterial (IA) injection of MnCl2 and following the breaking of the blood-brain barrier (BBB).Adult male Sprague-Dawley (SD) rats were employed in the study. After the rats were anesthetized with urethane, 25% mannitol was administrated into the right internal carotid artery (ICA) in order to disrupt the BBB, 50 mmol/l (10 mg/kg) of MnCl2 was then injected into ICA prior to the MRI assay. The MRI was performed at 7 T for a continuous 2 hours following the administration of MnCl2. Image reconstruction and analysis were performed using the Statistical Parametric Mapping (SPM) software.As time progressed, the Mn(2+) enhanced signal intensity showed a gradual increase with a maximum increase at 10 minutes following MnCl2 administration, and began to decline after 10 minutes. From 30 minutes to 2 hours, the signal-enhanced region became more homogeneous, and the signal-enhanced range spread to the contralateral area up to 2 hours after MnCl2 administration.These results will help future research to select an appropriate time point to perform functional MRI for different types of activity-induced manganese (AIM) MRI research studies. These findings will allow researchers to discriminate intended, stimulation-specific enhanced signal from unintended, nonspecific enhanced signals.

We present here the measurements of the first prototype VMM1 ASIC designed at Brookhaven National Laboratory in 130 nm CMOS and fabricated in spring 2012. The 64-channel ASIC features a novel design for use with several types of micropattern gas detectors. The data driven system measures peak amplitude and timing information in tracking mode and first channel hit address in trigger mode. Several programmable gain and integration times allows the flexibility to work with Micromegas, Thin Gap Chambers (TGCs), and Gas Electron Multiplier (GEM) detectors. The IC design architecture and features will be presented along with measurements characterizing the performance of the VMM1 such as noise, linearity of the response, time walk, and calibration range. The concept for use with Micromegas in ATLAS Upgrade will also be covered including characterization under test beam conditions.

New silicon drift detector (SDD) arrays are being developed for use as extraterrestrial X-ray spectrometers. For the first time these SDDs have been produced on low resistivity, n-type silicon, with a thinner thickness than normal, effectively ensuring their radiation hardness in anticipation of operation in potentially harsh radiation environments (such as those found around Jupiter). To achieve low-energy X-ray response, a thin entrance window was produced using a double implantation technology. The design, fabrication and performance of these detectors are presented here.