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941.
Ionic liquids (ILs), also referred to as molten salts, have found application as electrolytes for batteries and super-capacitors,
in electroplating baths, as designer solvents, and as reaction media. A few of the desired properties of a super-capacitor
electrolyte are nonflammability, thermal stability, and electrochemical stability. ILs containing aromatic cations have been
shown to have low viscosity which results in a high electrochemical conductivity. There is a delicate balance between increasing
the thermal stability, or decreasing the melting point, and increasing the electrochemical conductivity of the IL. This study
focuses on pyridinium fluorohydrogenate, [pyridine · H+][H2F3]−. Pyridinium fluorohydrogenate has been synthesized by the reaction of pyridine and anhydrous hydrofluoric acid. This IL has
a relatively high electrical conductivity (~98 mS · cm−1 at 23 °C), a wide electrochemical window, and a boiling point of 186 °C. A stable gel can also be formed by combining [pyridine · H+][H2F3]− and a super absorbent polymer such as polyacrylic acid. The gel adds mechanical stability to the matrix while not greatly
affecting the conductivity of the IL. 相似文献
942.
Paramjit Kaur Divya Sareen Sandeep Kaur Kamaljit Singh 《Inorganic chemistry communications》2009,12(3):272-275
A triarylmethane dye 1 detects CN? from water and shows remarkable selectivity over other anions and dramatic color changes, in solution as well as when dyed. The pH stability of 1 in the range of 1.2–10.7 offers additional advantage in the sensing process under physiological conditions. 相似文献
943.
A variety of iron-metallated functional porphyrins have been synthesized and their catalytic activity to oxidize polycyclic aromatic hydrocarbons, (PAHs) using hydrogen peroxide as oxidant was investigated. It was found that iron-metallated porphyrins bearing strong electronegative groups at β-pyrrolic positions show an exceptionally high catalytic efficiency. 相似文献
944.
B. K. Sarkar A. S. Verma R. C. Gupta K. Singh 《International Journal of Thermophysics》2010,31(3):620-629
Using photoacoustic spectroscopy, the composition-dependent absorption coefficient (α), thermal diffusivity (σ), and optical bandgap (E
g) of Zn1−x
Mn
x
Te diluted magnetic semiconductor have been measured. For higher Mn compositions, the absorption spectrum of the Zn–Mn–Te
system consists of three regions, viz., the high absorption region, the exponential region, and the weak absorption tail.
The bandgap follows a nonlinear variation with composition, showing a downward bowing with a minimum around x = 0.31 as a consequence of the electro-negativity difference between the substituted atoms. The composition-dependent band-edge
effective mass of the carriers does not show the bowing behavior indicating that the momentum matrix is not the same for all
the Zn1−x
Mn
x
Te alloys due to different lattice constants. The absorption spectra show that the transition is allowed and direct. 相似文献
945.
946.
947.
The paper decribes results of mathematical investigations into the prediction of mine water inflows to longwall coal workings. Numerical calculations are reported on the basis of experimentally deduced hydraulic conductivities above longwall panels. The effect of longwall working on hydraulic conductivities is investigated by mathematical analyses of stress and failure. Numerical calculations of mine water inflows are reported on the basis of mathematically inferred hydraulic conductivities. Results are correlated with field data. 相似文献
948.
The Laplace-Stieltjes (LS) transform for the distribution of time to first system failure (TFSF), transition probability, availability and mean time to system failure have been derived for two unit repairable redundant standby system with perfect as well as imperfect switchover condition. General expressions for computing various reliability performance indices have been obtained by using Markov Renewal techniques considering general distributions for time to failure and time to repair for the units. 相似文献
949.
K Singh 《Canadian Metallurgical Quarterly》1997,51(7):226-230
Although oxygen (O2) is needed to the body, partially reduced forms of O2 and some of their derivatives collectively called reactive oxygen species (ROS), are highly toxic prooxidants to the body. To prevent ROS toxicity body's endogenous and exogenous antioxidants (AOS) act in concert. To maintain health a balance between pro and anti oxidants is very necessary. 相似文献
950.
The numbers are staggering. In a chilling report, the U.S. Institute of Medicine (10M) estimates that somewhere between 44,000 and 98,000 Americans die each year from "avoidable medical errors" costing the nation about US$17 billion to US$29 billion annually. Errors include failing to make timely and accurate diagnosis, selecting improper treatment, and following a treatment plan incorrectly. For example, hospital staff might give the wrong drug or dosage, or a surgeon might operate on the wrong body part. Errors in surgery or emergency treatment can be especially serious. The root causes of these errors are inadequate training, poor processes, and information systems that don't expose patient information at relevant times - sometimes leading to confusion about the patient's identity or the intended procedures. Network technologies show great promise in solving some of the dangerous and tragic "avoidable medical errors" that currently plague the health care industry. 相似文献