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71.
S. Suresh Balaji M. Karnan M. Sathish 《Journal of Solid State Electrochemistry》2018,22(12):3821-3832
Here, the fast and shorter duration synthesis route was proposed for the production of N-doped graphene by supercritical fluid method involving ammonium oxalate as a source of nitrogen. Within the different proportions of graphene oxide and nitrogen source, the nitrogen-doped graphene formed from ammonium oxalate having nitrogen content of 3.3 wt% showed an enriched specific capacitance of 274 Fg?1 at 1 A/g in 20% KOH electrolyte. The long-term stability results obtained from galvanostatic charge-discharge in ammonium oxalate-based N-doped graphene revealed that 90% specific capacitance retention was achieved up to 10,000 cycles at 10 A/g. To examine the device proficiency, a full cell was fabricated and the performance was evaluated in two different approaches. Among the different media in aqueous electrolytes, the fabricated symmetric supercapacitor has achieved a maximum specific capacitance value of 160 F/g at 1 A/g in alkaline medium (20% KOH solution). Between 20% KOH solution and 1 M NaClO4 solution in acetonitrile, the fabricated symmetric supercapacitor exhibits an energy density of 26.5 Wh/kg as well as 5.5 Wh/kg in 1 M sodium perchlorate in acetonitrile solution and 20% KOH solution, respectively. 相似文献
72.
The highly electrophilic, 16-electron, coordinatively unsaturated [Ru(P(OMe)(OH)(2))(dppe)(2)][OTf](2) complex brings about the heterolytic activation of H(2)(g) and spontaneously generates HOTf. In addition, trans-[Ru(H)(P(OMe)(OH)(2))(dppe)(2)](+) and an unprecedented example of a phosphorous acid complex, [Ru(P(OH)(3))(dppe)(2)](2+), are formed. The [Ru(P(OMe)(OH)(2))(dppe)(2)][OTf](2) complex also cleaves the Si-H bond in EtMe(2)SiH in a heterolytic fashion, resulting in the trans-[Ru(H)(P(OMe)(OH)(2))(dppe)(2)](+) derivative. 相似文献
73.
Leung MK Viswanath MB Chou PT Pu SC Lin HC Jin BY 《The Journal of organic chemistry》2005,70(9):3560-3568
[structure: see text] Anti-[2.2](1,4)biphenylenophane (4) was synthesized from de Meijere's tetrabromo[2.2]paracyclophane (5) through a four-step reaction sequence. Although an average separation of 3.09 A between the inner ring of the biphenylene units is normal for [2.2]paracyclophanes, a bond distance of 1.54 Afor the ethano C-C bridge at room temperature is shorter than usual. In addition, trimethylsilyl-substituted anti-[2.2](1,4)biphenylenophane 8 sublimes at 220 degrees C under a pressure lower than 1 x10(-5) Torr without decomposition or thermal isomerization. The high thermal stability of 8 suggested that the ethano bridges of the biphenylenophanes are less strained than those of [2.2]paracyclophane. Bathochromic shifts are observed in their UV-vis absorption spectra. The phane state interactions of 4 and 8 were evidenced by the weak structureless fluorescent emission maximized at 537 and 550 nm in CH(2)Cl(2) along with longer relaxation lifetimes of 229 and 292 ps, respectively. 相似文献
74.
A list of powder phosphors used in the production of white colour lamps, UV lamps, high pressure mercury vapour lamps, tricolour lamps and special UV lamps is presented. The electronegativities and ionicity properties of these phosphors are evaluated based on their chemical formulae in each of the different categories of lamp phosphors discussed here. 相似文献
75.
76.
The time dependent performance of extended surfaces subjected to fouling is addressed in this work. Where fins are used for
augmenting boiling heat transfer, the interaction of local values of temperature excess, fouling resistance and surface characteristics
of the deposit can be quite complex. Taking typical asymptotic fouling growth parameters from literature for reverse solubility
salts, three kinds of fin geometry are analysed – rectangular, triangular and annular. For various values of the fin parameter
mL, the temperature distribution and variation of fouling resistance are obtained as a function of time. To interpret the
performance of a fouled fin, a new term `cleanliness efficiency' is introduced. The necessity of choosing an optimal value
of mL for the fin is also highlighted here. It is shown that for all three fin configurations, cleanliness efficiency differs
little, thus simplifying the geometry dependence. The approach set out in this work will help in the design of finned heat
exchangers subjected to fouling and thereby minimise their overdesign.
Received on 12 July 2000 相似文献
77.
The development of new efficient and environmental-friendly inorganic phosphors is highly important for phosphor-converted white light-emitting diodes and optoelectronic displays. In this paper, we report a novel and simple one-step solid-state reaction to synthesize lead-free cesium copper halide Cs3Cu2Br5 powders with bright blue emission around 460 nm. The preparation process is performed at low calcination temperatures (290–320 °C) and requires no complex apparatus, reagents, or techniques, and thus it holds great potential for mass production of halide emitters. The Cs3Cu2Br5 powder phosphors are characterized by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence excitation and emission spectroscopy, CIE color coordinates, color purity, photoluminescence quantum yield, and temperature-dependent emission spectra. The effect of calcination temperature on the photoluminescence properties of the as-prepared Cs3Cu2Br5 blue phosphors has been investigated and the air-stability property has also been discussed. Impressively, Cs3Cu2Br5 blue phosphors show outstanding stability toward air exposure exceeding one month (30 days). Our work will open a new and simple approach to obtain excellent halide emitters for future solid-state lighting and displays. 相似文献
78.
79.
Double insertion of CS2 into two Ru-H bonds of [(dppm)2Ru(H)2] (dppm = Ph2PCH2PPh2) affords the methanedithiolate complex [(dppm)2Ru(eta2-S2CH2)]. The methanedithiolate moiety has been functionalized using 2 equiv of RX resulting in bis(alkylthio)methane derivatives [(dppm)2Ru(RSCH2SR)][X]2. The bis(alkylthio)methane complex loses the bis(alkylthio)methane moiety under very mild conditions and in turn affords the [(dppm)2RuX2] complex from which the starting dihydride [(dppm)2Ru(H)2] has been regenerated via reaction with KOH/EtOH. On the other hand, insertion of CS2 into one Ru-H bond of [(dppe)2Ru(H)2] (dppe = Ph2PCH2CH2PPh2) followed by functionalization using RX results in alkyl dithioformate complex trans-[(dppe)2Ru(H)(SC(SR)H)][X]. In this case also, the alkyl dithioformate moiety gets eliminated under very mild conditions to afford the [(dppe)2Ru(H)(X)] derivative from which the starting dihydride has been regenerated via reaction with NaBH4. The reactions presented here constitute utilization of CS2 as a C1 synthetic source for the generation of useful organic compounds. 相似文献
80.