455 research outputs found
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Why Chinatown has Gentrified Later than Other Communities in Downtown Manhattan: A Planning History
Manhattan's Chinatown is the oldest and used to be the largest Chinese community in the East Coast of the United States. Since the repeal of the Chinese Exclusion Acts in 1940s, it experiences great expansion, tremendous population influx and significant real estate redevelopment. As a community located next door to the world class financial district, Chinatown has been under the pressure of gentrification for decades, people keep on moving to the outer-borough communities. However, Chinatown is still a low income community and persists highly mix- used land use pattern, comparing with other downtown Manhattan communities. Why Chinatown has gentrified later that other communities in downtown Manhattan? To answer the questions, this planning history study examined four cases in the second half of 20 century, which are Chinatown Street Revitalization Study of 1976, Special Manhattan Bridge District of 1982, East Village/Lower East Side Rezoning of 2008 and Establishment of Chinatown Business Improvement District of 2011. Based on discoveries, a group of recommendations were provided for Chinatown community groups; among them are preparing a Section 197a plan, promoting Chinatown with the goal to make it the "Downtown for Asian Population", and doing "inside work" and "playing with the rule"
In situ investigations of the phase change behaviour of tungsten oxide nanostructures
This study appraises the use of in-situ diffraction and spectroscopy techniques, complemented with ex-situ electron microscopy analyses, to investigate the geometry and phase change behaviour of bundled ultrathin W18O49 nanowires and WO3 nanoparticles. Our in-situ X-ray diffraction (XRD) results have shown that the phase transition of WO3 nanoparticles occurs in sequence as the temperature increases, from monoclinic (room temperature) → orthorhombic (350 ºC) → tetragonal (800 °C), akin to bulk WO3; however, W18O49 nanowires remain stable as the monoclinic phase up to 500 °C, after which complete oxidation to WO3 and transformation to the orthorhombic β-phase at 550 °C is observed. The in-situ Raman spectroscopy investigations have shown that as the temperature increases, the Raman peaks downshift toward lower wavenumbers in both structures, which can be attributed to the increased bond lengths in the lattice. We have also demonstrated that the Raman shift at 187.6 cm-1 can be used as a fingerprint band for the phase transition from the γ- to the β-phase of the WO3 nanoparticle. Furthermore, WO3 nanoparticles exhibit the γ- to β-phase conversion at 275 °C, which is about 75 °C lower than the relaxation temperature of 350 °C for the monoclinic γ-W18O49 nanowires. We propose that this fundamental phase transition understanding can offer important guidance for the design and development of WOx-based nanodevices by defining their allowed operating conditions
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Odorant Inhibition in Mosquito Olfaction.
How chemical signals are integrated at the peripheral sensory system of insects is still an enigma. Here we show that when coexpressed with Orco in Xenopus oocytes, an odorant receptor from the southern house mosquito, CquiOR32, generated inward (regular) currents when challenged with cyclohexanone and methyl salicylate, whereas eucalyptol and fenchone elicited inhibitory (upward) currents. Responses of CquiOR32-CquiOrco-expressing oocytes to odorants were reduced in a dose-dependent fashion by coapplication of inhibitors. This intrareceptor inhibition was also manifested in vivo in fruit flies expressing the mosquito receptor CquiOR32, as well in neurons on the antennae of the southern house mosquito. Likewise, an orthologue from the yellow fever mosquito, AaegOR71, showed intrareceptor inhibition in the Xenopus oocyte recording system and corresponding inhibition in antennal neurons. Inhibition was also manifested in mosquito behavior. Blood-seeking females were repelled by methyl salicylate, but repellence was significantly reduced when methyl salicylate was coapplied with eucalyptol
A Unified Weight Initialization Paradigm for Tensorial Convolutional Neural Networks
Tensorial Convolutional Neural Networks (TCNNs) have attracted much research
attention for their power in reducing model parameters or enhancing the
generalization ability. However, exploration of TCNNs is hindered even from
weight initialization methods. To be specific, general initialization methods,
such as Xavier or Kaiming initialization, usually fail to generate appropriate
weights for TCNNs. Meanwhile, although there are ad-hoc approaches for specific
architectures (e.g., Tensor Ring Nets), they are not applicable to TCNNs with
other tensor decomposition methods (e.g., CP or Tucker decomposition). To
address this problem, we propose a universal weight initialization paradigm,
which generalizes Xavier and Kaiming methods and can be widely applicable to
arbitrary TCNNs. Specifically, we first present the Reproducing Transformation
to convert the backward process in TCNNs to an equivalent convolution process.
Then, based on the convolution operators in the forward and backward processes,
we build a unified paradigm to control the variance of features and gradients
in TCNNs. Thus, we can derive fan-in and fan-out initialization for various
TCNNs. We demonstrate that our paradigm can stabilize the training of TCNNs,
leading to faster convergence and better results.Comment: Accepted in ICML 202
A generic method to synthesise graphitic carbon coated nanoparticles in large scale and their derivative polymer nanocomposites
A versatile Rotary Chemical Vapour Deposition (RCVD) technique for the in-situ synthesis of large scale carbon-coated non-magnetic metal oxide nanoparticles (NPs) is presented, and a controllable coating thickness varying between 1–5 nm has been achieved. The technique has significantly up-scaled the traditional chemical vapour deposition (CVD) production for NPs from mg level to 10 s of grams per batch, with the potential for continuous manufacturing. The resulting smooth and uniform C-coatings sheathing the inner core metal oxide NPs are made of well-crystallised graphitic layers, as confirmed by electron microscopy imaging, electron dispersive spectrum elemental line scan, X-ray powder diffractions and Raman spectroscopy. Using nylon 12 as an example matrix, we further demonstrate that the inclusion of C-coated composite NPs into the matrix improves the thermal conductivity, from 0.205 W∙m−1∙K−1 for neat nylon 12 to 0.305 W∙m−1∙K−1 for a 4 wt% C-coated ZnO composite, in addition to a 27% improvement in tensile strength at 2 wt% addition
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