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排序方式: 共有920条查询结果,搜索用时 15 毫秒
831.
Shofarul Wustoni Craig Combe David Ohayon Mahmood Hassan Akhtar Iain McCulloch Sahika Inal 《Advanced functional materials》2019,29(44)
Alkali‐metal ions, particularly sodium (Na+) and potassium (K+), are the messengers of living cells, governing a cascade of physiological processes through the action of ion channels. Devices that can monitor, in real time, the concentrations of these cations in aqueous media are in demand not only for the study of cellular machinery, but also to detect conditions in the human body that lead to electrolyte imbalance. In this work, conducting polymers are developed that respond rapidly and selectively to varying concentrations of Na+ and K+ in aqueous media. These polymer films, bearing crown‐ether‐functionalized thiophene units specific to either Na+ or K+, generate an electrical output proportional to the cation type and concentration. Using electropolymerization, the ion‐selective polymers are integrated as the gate electrode of an organic electrochemical transistor (OECT). The OECT current changes with respect to the concentration of the ion to which the polymer electrode is selective. Designed as a single, miniaturized chip, the OECT enables the selective detection of the cations within a physiologically relevant range. These electrochemical ion sensors require neither ion‐selective membranes nor a reference electrode to operate and have the potential to surpass existing technologies for the detection of alkali‐metal ions in aqueous media. 相似文献
832.
MD. Shahrukh Adnan Khan Kazi Mahtab Kadir Khandaker Sultan Mahmood Md. Ibrahim Ibne Alam Ainun Kamal Md. Mamoon Al Bashir 《电子科技学刊:英文版》2019,17(4):300-316
The paper investigates a few of the major areas of the next generation technological advancement, “smart city planning concept”. The areas that the paper focuses are vehicle to grid (V2G), sun to vehicle (S2V), and vehicle to infrastructure (V2I). For the bi-directional crowd energy single entity concept, V2G and building to grid (B2G) are the primary parts of distributed renewable generation (DRG) under smart living. This research includes an in-depth overview of this three major areas. Next, the research conducts a case analysis of V2G, S2V, and V2I along with their possible limitations in order to find out the novel solutions for future development both for academia and industry levels. Lastly, few possible solutions have been proposed to minimize the limitations and to develop the existing system for future expansion. 相似文献
833.
Guan-Yeow Yeap Wan-Sinn Yam Masato M. Ito Yumika Takahashi Yoshiyuki Nakamura Wan Ahmad Kamil Mahmood Peng-Lim Boey Shafida Abd Hamid Ewa Gorecka 《Liquid crystals》2007,34(5):649-654
A new homologous series of 7-acyloxy-3-(4-acyloxyphenyl)-4H-1-benzopyran-4-ones was synthesized and characterized by elemental analysis and spectroscopic techniques along with thermal behaviour study using differential scanning calorimetry. Texture observation was performed under the polarizing optical microscope from which the derivatives were found to exhibit different molecular organizations as exemplified by various mesophases. Whilst the compounds containing butanoyloxy and hexanoyloxy groups behave as nematogens, the other compounds with heptanoyloxy and longer side chains show a SmC phase. The octadecanoyloxy derivative was the only member showing a monotropic SmC phase. The difference in phase behaviour is discussed based on the molecular structure and the presence of a lateral dipole which can be associated with the intermolecular interaction within the mesophase. 相似文献
834.
Moslem Mansour Lakouraj Mahmood Tajbakhsh Farhad Ramzanian-Lehmali Keyvan Ghodrati 《Monatshefte für Chemie / Chemical Monthly》2008,45(7):537-541
Oxidative deprotection of trimethylsilyl and tetrahydropyranyl ethers, and deprotection of phenylhydrazones, semicarbazones,
and oximes to their corresponding carbonyl compounds carried out in water at reflux condition using ionene supported peroxodisulfates
is reported. The reagents are recyclable and products are obtained in excellent yield under environmentally benign conditions
without overoxidation to carboxylic acid. 相似文献
835.
836.
A theoretical model for describing the bias-dependent transient and steady-state behavior of dark current in hydrogenated amorphous silicon (a-Si:H) p–i–n photodiode has been developed. An analytical expression for the bias-dependent steady-state thermal generation current is derived by solving the continuity equations for both electrons and holes. The model for describing transient dark current in a-Si:H p–i–n photodiode is developed by considering the depletion of electrons from the i-layer and carrier injection through p–i interface. For photodiodes that have very good junction properties, the high initial dark current decreases with time monotonously and reaches a plateau. However, in case of poor junctions, the injection current can be the dominating mechanism for transient leakage current at relatively high biases, the dark current decays initially and then rises to a steady-state value. The proposed physics-based dark current model is compared with published experimental results on several photodiodes. The comparison of the model with the experimental data allows an estimate of active dopant concentration in the p-layer and the defect density in the midgap of i-layer. 相似文献
837.
Puri Novelti Anggraeni Nurul Huda Mahmood Josselin Berthod Nicolas Chaussonniere Laurent My Hiroyuki Yomo 《Wireless Personal Communications》2008,45(3):369-384
Technological advances coupled with regulatory initiative for more efficient utilization of radio spectrum resulted in the
introduction of dynamic spectrum access enabled radio called Cognitive Radio (CR). A CR network is allowed to access a frequency
band owned by primary user, which can provide higher throughput and better serviceability in wireless networks. The availability
of multiple primary bands requires a CR network to select the best operating band which can maximize the total system performance.
The selection should be made according to heterogenous properties of primary bands which offer different maximum data rate
for secondary use and generate diverse traffic pattern. In this paper, assuming such heterogenous primary bands for secondary
use, simple and distributed dynamic channel selection strategies are proposed and evaluated. In addition, we introduce a measurement
metric for interference experienced by primary users due to secondary network’s access in primary band. We investigate the
impact of different channel selection strategies and parameters on the primary and secondary performance.
相似文献
Hiroyuki YomoEmail: |
838.
Ghasem Firouzzadeh Pasha Sakineh Asghari Mahmood Tajbakhsh Mojtaba Mohseni 《中国化学会会志》2019,66(6):660-667
A series of bicyclopyrazolones were synthesized from the condensation reaction of methyl 4‐oxotetrahydro‐2H‐thiopyran‐3‐carboxylate with hydrazine derivatives in ethanol. All synthesized products were characterized by FT‐IR, 1H, and 13C NMR spectral data, elemental analyses, and mass spectrometry. The antibacterial and antifungal activities of these compounds were evaluated against Staphylococcus aureus and Bacillus subtilis as Gram‐positive bacteria, Escherichia coli and Pseudomonas aeruginosa as Gram‐negative bacteria, and the fungus Candida albicans. The results revealed that bicyclopyrazolones including an aryl or aryl sulfonyl group in the N‐2 position of the pyrazolone moiety are the most effective against all the microorganisms studied in this work. 相似文献
839.
Shahid Adeel Khalid Mahmood Zia Muhammad Abdullah Mahwish Salman Mohammad Zuber 《Natural product research》2019,33(14):2060-2072
Natural products with therapeutic nature are nowadays warmly welcomed in textiles. Current study is concerned with isolation of tannin from neem bark (Azadirachta indica) and its application onto silk fabric. For improvement in shades, chemical & bio-mordants have been employed at optimal dyeing conditions. It is found that methanolic extract of pH 5 obtained 8 g dye powder after US Treatment for 30 min has given high color strength if used to dye irradiated silk for 65 min at 75 °C. Bio-mordanting using herbal plants has improved the color characteristics as compared to chemical mordants used. ISO standards for color fastness reveal that herbal based bio-mordants have improved the rating from good to excellent as compared to chemical mordants used. It is concluded that US treatment has not only isolate the colorant for neem bark under mild condition but also given excellent characteristic using bio mordants onto silk fabrics. 相似文献
840.
In this article, studies are made on frost formation and flow over a fin and tube heat exchanger due to natural convection for various conditions of relative humidity, air ambient temperature, and mean refrigerant temperature. The results include frost deposition, steps of frost formation, and its effect on heat transfer rate for different conditions. The results show that frost is formed only on the tip of the fins with higher thickness from top to bottom due to small distance between the fins. Frost causes to trap the air which increases the thermal resistance and reduces heat transfer in the system. 相似文献