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91.
Three new monodimensional hybrid metal (Ti, In, Al) fluorides are synthesized with ethylenediamine (en) as a templating agent in solvothermal conditions assisted by microwave heating. All structures involve inorganic chains built up from TiO2F4 octahedra connected by two opposite O2− vertices in [H2en]·(TiOF4) (I), from InF6(H2O) pentagonal bipyramids linked by F–F edges in [H2en]·(InF4(H2O))2·H2O (II) and from (Al7F30)9− polyanions sharing two opposite AlF6 octahedra in [H2en]3·(Al6F24) (III). I is tetragonal, P4/ncc, a = 12.761(3) Å, c = 8.041(3) Å; II is orthorhombic, F2dd, a = 6.904(5) Å, b = 16.559(5) Å, c = 19.777(4) Å and III is monoclinic, P21/n, a = 9.387(2) Å, b = 6.710(2) Å, c = 21.513(6) Å, β = 97.18(3)°. 相似文献
92.
The antiviral drug acyclovir (Ac, 1) was treated with triplet excited ketones, which have been generated in thermal decomposition of 3-(hydroxymethyl)-3,4,4-trimethyl-1,2-dioxetane (HTMD), in the dark. Three major oxidation products were detected by means of spectroscopic measurements. The products were (2-hydroxyethoxy) methyl spiroiminodihydantoin (2), (2-hydroxyethoxy) methyl (amino)-2-imino-1,2-dihydroimidazole-5-one (3), and 2,2-diamino-4-[(2-hydroxyethoxy) methyl) amino)-5-[2H]-oxazolone (4). Equal amounts of type I and type II photooxidation products were found, as could be established by comparison with predominant type I (riboflavin) and type II (rose bengal) photosensitizers. The concentration and time profiles for the HTMD-induced oxidation of Ac were also determined. The participation of singlet oxygen in HTMD-induced oxidation was confirmed by the substantial D(2)O effect in the formation of spiroiminodihydantoin (2). 相似文献
93.
Adil Misir 《Applied mathematics and computation》2010,216(5):1375-1382
In this paper we present an “iteration” technique for a class of differential equation having the form z″=λz, where λ is a function in C∞. We show that we can construct not only the general solution of the reduced wave equation but also the general solution of the Riccati differential equation by using this iteration technique if the given function λ is satisfies the condition
94.
Hamid Reza Moradi Mohsen Erfanian Omidvar Muhammad Adil Khan Kazimierz Nikodem 《Aequationes Mathematicae》2018,92(1):25-37
In this paper we use basic properties of strongly convex functions to obtain new inequalities including Jensen type and Jensen–Mercer type inequalities. Applications for special means are pointed out as well. We also give a Jensen’s operator inequality for strongly convex functions. As a corollary, we improve the Hölder-McCarthy inequality under suitable conditions. More precisely we show that if \(Sp\left( A \right) \subset \left( 1,\infty \right) \), then and if \(Sp\left( A \right) \subset \left( 0,1 \right) \), then for each positive operator A and \(x\in \mathcal {H}\) with \(\left\| x \right\| =1\).
相似文献
$$\begin{aligned} {{\left\langle Ax,x \right\rangle }^{r}}\le \left\langle {{A}^{r}}x,x \right\rangle -\frac{{{r}^{2}}-r}{2}\left( \left\langle {{A}^{2}}x,x \right\rangle -{{\left\langle Ax,x \right\rangle }^{2}} \right) ,\quad r\ge 2 \end{aligned}$$
$$\begin{aligned} \left\langle {{A}^{r}}x,x \right\rangle \le {{\left\langle Ax,x \right\rangle }^{r}}+\frac{r-{{r}^{2}}}{2}\left( {{\left\langle Ax,x \right\rangle }^{2}}-\left\langle {{A}^{2}}x,x \right\rangle \right) ,\quad 0<r<1 \end{aligned}$$
95.
Adil Bagirov Conny Clausen Michael Kohler 《Computational Optimization and Applications》2010,45(1):159-179
The problem of the estimation of a regression function by continuous piecewise linear functions is formulated as a nonconvex,
nonsmooth optimization problem. Estimates are defined by minimization of the empirical L
2 risk over a class of functions, which are defined as maxima of minima of linear functions. An algorithm for finding continuous
piecewise linear functions is presented. We observe that the objective function in the optimization problem is semismooth,
quasidifferentiable and piecewise partially separable. The use of these properties allow us to design an efficient algorithm
for approximation of subgradients of the objective function and to apply the discrete gradient method for its minimization.
We present computational results with some simulated data and compare the new estimator with a number of existing ones. 相似文献
96.
RHA-Al, RHA-Ga and RHA-In catalysts were synthesized by the direct incorporation of aluminum, gallium and indium ions, respectively,
into rice husk ash (RHA) silica at room temperature using the sol–gel method. The prepared catalysts were characterized by
physicochemical methods, viz. N2-adsorption, XRD, FT-IR, SEM-EDX, ICP-MS and Solid-state NMR. These catalysts were used to study the tert-butylation of benzene (Bz) and some substituted benzenes with tert-butyl chloride (TBC). The reaction was proposed to proceed initially through the radical mechanism and subsequently the tert-butyl cation was formed, which in turn attacks the benzene ring for the formation of tert-butyl benzene (TBB) and di-tert-butyl benzene (DTBB) via the SN1 mechanism (main reaction). However, a proton elimination reaction (side reaction) also occurred, resulting in the formation
of isobutene dimers (IBD) and isobutene trimers (IBT). The extent of these side products were found to decrease significantly
with time, indicating the reversibility of the oligomerization reactions. The catalysts were stable against leaching and were
reusable several times but with observable drop in catalytic activity. RHA-Ga lost almost 20% of its activity after each run,
whereas, RHA-In was stable until the 3rd run and then lost ~13% of its activity at the 5th run. The deactivation was suggested
to be induced by the poisoning effect of the bulky side products. 相似文献
97.
In this study, two new approaches for due date assignment in job shops are evaluated. Proposed approaches use statistical prediction techniques for dynamic prediction of job flowtimes in a job shop environment as the job arrives to the shop floor. Primary objective of this research is to compare the performance of the proposed due date assignment model (PDDAM) with several conventional due date assignment models (CDDAM). For this purpose, simulation models are developed and comparisons of the PDDAM and CDDAM are made in terms of the mean absolute percent error (MAPE), mean percent error (MPE) and mean tardiness (MT). Simulation experiments showed that for many test conditions, PDDAM dominates CDDAM. Therefore, case by case findings are summarized in the paper. 相似文献
98.
Solid-phase extraction (SPE) columns packed with materials based on molecularly imprinted polymers (MIPs) were used to develop selective separation and preconcentration for Ni(II) ion from aqueous solutions. SPE is more rapid, simple and economical method than the traditional liquid-liquid extraction. MIPs were used as column sorbent to increase the grade of selectivity in SPE columns. In this study, we have developed a polymer obtained by imprinting with Ni(II) ion as a ion-imprinted SPE sorbent. For this purpose, NI(II)-methacryloylhistidinedihydrate (MAH/Ni(II)) complex monomer was synthesized and polymerized with cross-linking ethyleneglycoldimethacrylate to obtain [poly(EGDMA-MAH/Ni(II))]. Then, Ni(II) ions were removed from the polymer getting Ni(II) ion-imprinted sorbent. The MIP-SPE preconcentration procedure showed a linear calibration curve within concentration range from 0.3 to 25 ng/ml and the detection limit was 0.3 ng/ml (3 s) for flame atomic absorption spectrometry (FAAS). Ni(II) ion-imprinted microbeads can be used several times without considerable loss of adsorption capacity. When the adsorption capacity of nickel imprinted microbeads were compared with non-imprinted microbeads, nickel imprinted microbeads have higher adsorption capacity. The Kd (distribution coefficient) values for the Ni(II)-imprinted microbeads show increase in Kd for Ni(II) with respect to both Kd values of Zn(II), Cu(II) and Co(II) ions and non-imprinted polymer. During that time Kd decreases for Zn(II), Cu(II) and Co(II) ions and the k′ (relative selectivity coefficient) values which are greater than 1 for imprinted microbeads of Ni(II)/Cu(II), Ni(II)/Zn(II) and Ni(II)/Co(II) are 57.3, 53.9, and 17.3, respectively. Determination of Ni(II) ion in sea water showed that the interfering matrix had been almost removed during preconcentration. The column was good enough for Ni determination in matrixes containing similar ionic radii ions such as Cu(II), Zn(II) and Co(II). 相似文献
99.
A white rot fungus species Lentinus sajor-caju biomass was entrapped into alginate gel via a liquid curing method in the presence of Ca(II) ions. The biosorption of cadmium(II) by the entrapped live and dead fungal biomass has been studied in a batch system. The heat-treatment process enhanced the biosorption capacity of the immobilized fungal biomass. The effect of initial cadmium concentration, pH and temperature on cadmium removal has been investigated. The maximum experimental biosorption capacities for entrapped live and dead fungal mycelia of L. sajur-caju were found to be 104.8±2.7 mg Cd(II) g−1 and 123.5±4.3 mg Cd(II) g−1, respectively. The kinetics of cadmium biosorption was fast, approximately 85% of biosorption taking place within 30 min. The biosorption equilibrium was well described by Langmuir and Freundlich adsorption isotherms. The change in the biosorption capacity with time is found to fit pseudo-second-order equations. Cadmium binding properties of entrapped fungal preparations have been determined applying the Ruzic equations. Since the biosorption capacities are relatively high for both entrapped live and dead forms, they could be considered as suitable biosorbents for the removal of cadmium in wastewater treatment systems. The biosorbents were reused in three consecutive adsorption/desorption cycles without significant loss in the biosorption capacity. 相似文献
100.
Musarat Jan Aijaz Ahmad Dar Adil Amin Nuzhat Rehman Ghulam Mohammad Rather 《Colloid and polymer science》2007,285(6):631-640
The study is focused on evaluation of clouding phenomena of the aqueous single nonionic surfactant system Triton X-100 (TX-100)
and its mixed systems with anionic aerosol-OT (AOT) and cationic dodecylpyridinium chloride (DPC) in presence of hydrophobic
ions furnished by sodium salts of carboxylic acids, viz., sodium ethanoate, sodium propanoate, sodium butanoate, and sodium
hexanoate and the respective carboxylic acids [ethanoic acid, propanoic acid, butanoic acid, and hexanoic acid]. The influence
of salts on the cloud point (CP) has been explained on the basis of salt effect as well as the solubilization of higher alkyl
chain hydrophobic ions furnished by these salts. Moreover, the co- and counterion effect has been taken into account to explain
the variation of the CP in the mixed systems. However, the effect of acids on CP has been explained in the light of their
aqueous solubility and their partitioning ability between octanol and water as reflected by their K
OW values. 相似文献