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101.
Shahid Iqbal Le Thai Duy Hyunwoo Kang Ranveer Singh Mohit Kumar Jucheol Park Hyungtak Seo 《Advanced functional materials》2021,31(46):2102567
To realize the potential of Mott transition of multiphasic vanadium oxides (VOx) for memory applications, the development of VOx memtransistors on SiO2 wafer is introduced. Through electrical characterizations, the volatile memory behaviors of the VOx memtransistors are observed in both two- and three-terminal measurements. Their capacitive memory and resistive switching mechanisms are strongly related to the mixed VOx/SiO2 interface (called VSiOx). VSiOx supports the Mott transition in VOx at low bias voltages (<0.5 V), leading to the low power consumption of the memtransistor. Moreover, the fast switching time (≈35 ns) and tunable memory retention with the synaptic functions (potentiation and depression) of the memtransistors (by using the gate and drain biases) are demonstrated. Overall, the findings open up major opportunities for constructing ultrafast and femto-joule power-consuming neuromorphic devices. 相似文献
102.
The use of the evolutionary heuristic simulated evolution for the optimization of the multi-dimensional vector bin packing problem, which is encountered in several industrial applications, is described. These applications range from production planning and steel fabrication to assignment of virtual machines (VMs) onto physical hosts at cloud-based data centers. The dimensions of VMs can include demands of CPU, memory, bandwidth, disk space etc. The generalized goodness functions that aid traversing the search space in an intelligent manner are designed to cater to the multidimensional nature of items (VMs). The efficiency of heuristics is tested by considering phase transition in the generation of difficult test cases. The quality of the heuristics is judged by determining how close the solution is to the estimated lower bound. A new implementation of a tighter lower bound is proposed. Experiments show that superior quality results are obtained by employing the proposed strategy. 相似文献
103.
Dehydrogenation of ethane to ethylene via radical pathways enhanced by alkali metal based catalyst in oxysteam condition
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The dehydrogenation of ethane to ethylene in the presence of oxygen and water was conducted using Na2WO4/SiO2 catalyst at high temperatures. At 923 K, the conversion rate without water was proportional to ethane pressure and a half order of oxygen pressure, consistent with a kinetically relevant step where an ethane molecule is activated with dissociated oxygen on the surface. When water was present, the ethane conversion rate was drastically enhanced. An additional term in the rate expression was proportional to a quarter of the oxygen pressure and a half order of the water pressure. This mechanism is consistent with the quasi‐equilibrated OH radical formation with subsequent ethane activation. The attainable yield can be accurately described by taking the water contribution into consideration. At high conversion levels at 1073 K, the C2H4 yield exceeded 60% in a single‐pass conversion. The C2H4 selectivity was almost insensitive to the C2H6 and O2 pressures. © 2016 American Institute of Chemical Engineers AIChE J, 63: 105–110, 2017 相似文献
104.
The thermal conductivity, thermal diffusivity, and heat capacity per unit volume of dunite rocks taken from Chillas near Gilgit,
Pakistan, have been measured simultaneously using the transient plane source technique. The temperature dependence of the
thermal transport properties was studied in the temperature range from 303 K to 483 K. Different relations for the estimation
of the thermal conductivity are applied. A proposed model for the prediction of the thermal conductivity as a function of
temperature is also given. It is observed that the values of the effective thermal conductivity predicted by the proposed
model are in agreement with the experimental thermal conductivity data within 9%. 相似文献
105.
Metal Organic Framework Crystals in Mixed‐Matrix Membranes: Impact of the Filler Morphology on the Gas Separation Performance
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Anahid Sabetghadam Beatriz Seoane Damla Keskin Nicole Duim Tania Rodenas Salman Shahid Sara Sorribas Clément Le Guillouzer Guillaume Clet Carlos Tellez Marco Daturi Joaquin Coronas Freek Kapteijn Jorge Gascon 《Advanced functional materials》2016,26(18):3154-3163
Mixed‐matrix membranes comprising NH2‐MIL‐53(Al) and Matrimid or 6FDA‐DAM have been investigated. The metal organic framework (MOF) loading has been varied between 5 and 20 wt%, while NH2‐MIL‐53(Al) with three different morphologies, nanoparticles, nanorods, and microneedles has been dispersed in Matrimid. The synthesized membranes have been tested in the separation of CO2 from CH4 in an equimolar mixture. At 3 bar and 298 K for 8 wt% MOF loading, incorporation of NH2‐MIL‐53(Al) nanoparticles leads to the largest improvement compared to nanorods and microneedles. The incorporation of the best performing filler, i.e., NH2‐MIL‐53(Al) nanoparticles, into the highly permeable 6FDA‐DAM has a larger effect, and the CO2 permeability increases up to 85% with slightly lower selectivities for 20 wt% MOF loading. Specifically, these membranes have a permeability of 660 Barrer with a CO2/CH4 separation factor of 28, leading to a performance very close to the Robeson limit of 2008. Furthermore, a new non‐destructive technique based on Raman spectroscopy mapping is introduced to assess the homogeneity of the filler dispersion in the polymer matrix. The MOF contribution can be calculated by modeling the spectra. The determined homogeneity of the MOF filler distribution in the polymer is confirmed by focused ion beam scanning electron microscopy analysis. 相似文献
106.
107.
Iftikhar S Dahbour S Nauman S 《Hemodialysis international. International Symposium on Home Hemodialysis》2007,11(4):392-397
Nonconvulsive status epilepticus is defined as a mental status change from baseline of at least a 30-min duration associated with constant or near-continuous ictal discharges on an electroencephalogram (EEG). Nonconvulsive status epilepticus is an often-overlooked diagnosis as a cause of acute confusional state. There are few case reports in dialysis patients. We are reporting 5 patients on chronic dialysis treatment who presented with an acute confusional state. Nonconvulsive status epilepticus was diagnosed by EEG and response to intravenous benzodiazepines. We recommend early EEG to be considered in the evaluation of dialysis patients with an acute confusional state. 相似文献
108.
Khurshid Salman Arif Saqib Iqbal Hafiza Mehwish Akbar Qurrat Ul Ain Yousaf Shahid 《Food science and biotechnology》2020,29(2):243-249
Food Science and Biotechnology - Current study was designed to evaluate sensory and textural quality characteristics of chapatti, a commonly consumed flat bread in South-Asia in relation to flour... 相似文献
109.
110.
Meharg AA Scrimgeour C Hossain SA Fuller K Cruickshank K Williams PN Kinniburgh DG 《Environmental science & technology》2006,40(16):4928-4935
We present data showing that arsenic (As) was codeposited with organic carbon (OC) in Bengal Delta sediments as As and OC concentrations are highly (p < 0.001) positively correlated in core profiles collected from widely dispersed geographical sites with different sedimentary depositional histories. Analysis of modern day depositional environments revealed that the As-OC correlations observed in cores are due to As retention and high OC inputs in vegetated zones of the deltaic environment. We hypothesize that elevated concentrations of As occur in vegetated wetland sediments due to concentration and retention of arsenate in aerated root zones and animal burrows where copious iron(III) oxides are deposited. On burial of the sediment, degradation of organic carbon from plant and animal biomass detritus provides the reducing conditions to dissolve iron(III) oxides and release arsenite into the porewater. As tubewell abstracted aquifer water is an invaluable resource on which much of Southeast Asia is now dependent, this increased understanding of the processes responsible for As buildup and release will identify, through knowledge of the palaeosedimentary environment, which sediments are at most risk of having high arsenic concentrations in porewater. Our data allow the development of a new unifying hypothesis of how As is mobilized into groundwaters in river flood plains and deltas of Southeast Asia, namely that in these highly biologically productive environments, As and OC are codeposited, and the codeposited OC drives As release from the sediments. 相似文献