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1.
Two new organic–inorganic hybrid compounds
[\text Cu\textI ( \text en ) 2 ( \text H 2 \text O )] 2 { ( \text SiW\textVI 1 1 \text W\textV 1\text O 40 ) 2 [ \text Cu\textII ( \text en ) 2 ( \text H 2 \text O )] 2 [\text Cu\textII ( \text en ) 2 ] 2 }·6 \text H 2 \text O [{\text{Cu}}^{\text{I}} \left( {\text{en}} \right)_{ 2} \left( {{\text{H}}_{ 2} {\text{O}}} \right)]_{ 2} \left\{ {\left( {{\text{SiW}}^{\text{VI}}_{ 1 1} {\text{W}}^{\text{V}}_{ 1}{\text{O}}_{ 40} } \right)_{ 2} \left[ {{\text{Cu}}^{\text{II}} \left( {\text{en}} \right)_{ 2} \left( {{\text{H}}_{ 2} {\text{O}}} \right)\left] {_{ 2} } \right[{\text{Cu}}^{\text{II}} \left( {\text{en}} \right)_{ 2} } \right]_{ 2} } \right\}{\cdot}6 {\text{H}}_{ 2} {\text{O}} ( 1) and (H 2
L) 2[SiW 12O 40]·H 2O ( 2) [en = ethylenediamine, L = 1,4-bis(3-pyridinecarboxamido)benzene], have been hydrothermally synthesized and characterized by IR, elemental analyses,
TG analysis, and single-crystal X-ray diffraction. Structural analyses indicate that compound 1 exhibits an interesting three-dimensional(3D) cross-like supramolecular network through arrangement of a 1D organic–inorganic
hybrid chain
{ ( \text SiW\textVI 1 1 \text W\textV 1 \text O 40 ) 2 [ \text Cu\textII ( \text en ) 2 ( \text H 2 \text O )] 2 [\text Cu\textII ( \text en ) 2 ] 2 } 2- . \left\{ {\left( {{\text{SiW}}^{\text{VI}}_{ 1 1} {\text{W}}^{\text{V}}_{ 1} {\text{O}}_{ 40} } \right)_{ 2} \left[ {{\text{Cu}}^{\text{II}} \left( {\text{en}} \right)_{ 2} \left( {{\text{H}}_{ 2} {\text{O}}} \right)\left] {_{ 2} } \right[{\text{Cu}}^{\text{II}} \left( {\text{en}} \right)_{ 2} } \right]_{ 2} } \right\}^{ 2- } . The compound 2 consists of protonated L ligand and [SiW 12O 40] 4− anion. The protonated L ligands have been extended into a 2D network via hydrogen-bonding interactions. The guest [SiW 12O 40] 4− clusters have been incorporated into the square voids of the 2D host network as templates. The electrochemical behavior and
electrocatalysis of compound 2 bulk-modified carbon paste electrode ( 2-CPE) have been studied. 相似文献
2.
P-octyl polyethylene glycol phenyl ether (Triton X-100) and cetyltrimethylammonium bromide (CTAB) were mixed to be used as
surfactant for preparing reverse microemulsion with n-hexane, n-hexanol and water. Effects of weight ratio of the two surfactants, temperature, concentrations of water and cosurfactant
on the conductivity were studied. The results indicate that the conductivity of the mixed surfactants reverse microemulsion
is greatly higher than that of the single surfactant system. The reverse microemulsion has been modified to be with good conductivity.
The weight ratio of the two surfactants, temperature, concentrations of water and cosurfactant have obvious effects on the
conductivity of the reverse microemulsion. Furthermore, the electrochemical behavior of potassium ferricyanide [K 3Fe(CN) 6] in the mixed surfactants reverse microemulsion was investigated by cyclic voltammetry. The result shows that the redox processes
of
\text Fe( \text CN ) 6 3- / \text Fe( \text CN ) 6 4- {{\text{Fe}}\left( {\text{CN}} \right)_{ 6}}^{ 3- } / {{\text{Fe}}\left( {\text{CN}} \right)_{ 6}}^{ 4-} present good reversibility and are controlled by diffusion in the system. 相似文献
3.
12-Tungstophosphoric acid supported on montmorillonite K10 (PWA/mont-K10) catalysed Pechmann condensation reaction was reported.
The catalyst was characterized by XRD, FTIR, UV–Vis DRS, surface area and pore size analysis, TGA and acidity by DRIFTS using
pyridine. The morphology of the catalyst was studied by SEM. The activity of mont-K10, mont-KSF,
\textSO 4 2 - \mathord | / |
\vphantom \textSO 4 2 - \textZrO 2 \textZrO 2 {{{\text{SO}}_{ 4}^{{ 2 {-}}} } \mathord{\left/ {\vphantom {{{\text{SO}}_{ 4}^{{ 2 {-}}} } {{\text{ZrO}}_{ 2} }}} \right. \kern-\nulldelimiterspace} {{\text{ZrO}}_{ 2} }} , 12-tungstophosphoric acid, and PWA/mont-K10 was investigated by condensation reaction of resorcinol with ethyl acetoacetate
in the absence of solvent. Effect of molar ratio, amount of catalyst, reaction temperature and time on the yield of 7-hydroxy-4-methylcoumarin
had been investigated on PWA/mont-K10. PWA/mont-K10 catalysed condensation of ethyl acetoacetate with phenol and a few substituted
phenols had also been carried out to yield corresponding coumarins. The recycled catalyst showed reduced activity after single
use. 15 wt% PWA on mont-K10 was found to be effective for synthesis of coumarin derivatives without employing any solvent. 相似文献
4.
A new type analog memory cell with variable output voltage has been proposed and its performance examined. The cell construction is $$\begin{gathered} {\text{Ag|RbAg}}_{\text{4}} {\text{I}}_{\text{5}} {\text{|(Ag}}_{\text{2}} {\text{Se)}}_{{\text{0}} \cdot {\text{925}}} {\text{(Ag}}_{\text{3}} {\text{PO}}_{\text{4}} {\text{)}}_{{\text{0}} \cdot {\text{075}}} {\text{|RbAg}}_{\text{4}} {\text{I}}_{\text{5}} {\text{|Ag}} \hfill \\ {\text{ }} \uparrow \hfill \\ {\text{ Pt}} \hfill \\ \end{gathered} $$ in which (Ag 2Se) 0.925(Ag 3PO 4) 0.075 is a mixed conductor exhibiting high ionic and electronic conductivity at room temperature. The potential difference between the silver electrode and the platinum electrode depends on the silver activity in the mixed conductor, and it is changed by passing the current between one silver electrode and the platinum electrode. The output voltage of the cell is changed in the range of 150 to 0 mV. At open circuit, the memorized cell voltage decreased by only 1% over several hours. 相似文献
5.
The metal–organic framework $ ^{3}_{\infty } \left[ {{\text{Cu}}_{3} \left( {\text{CN}} \right)_{3} \cdot \left( {\text{pyz}} \right)_{ 2} } \right] $ ∞ 3 [ Cu 3 ( CN ) 3 · ( pyz ) 2 ] , 1, ( pyz pyrazine) was prepared in water/acetonitrile solvent at ambient temperature from the adducts K 3[Cu(CN) 4], pyrazine and Me 2SnCl 2. The structure of 1 consists of four-coordinate Cu(1) sites exhibiting a distorted tetrahedral geometry and the linear two-coordinate Cu(2) sites. Notably distorted cages, [Cu 8(CN) 4(pyz) 4], [Cu 8(CN) 6(pyz) 2] and [Cu 6(CN) 2(pyz) 4], can be considered as the basic building blocks of the structure of 1. Box-like structures create inextricably interpenetrated equivalent 3D-frameworks. The structure and spectroscopic properties of 1 were also investigated by thermal analysis and IR, mass, UV/Vis and fluorescence spectra. 相似文献
6.
The influence of CO 2 and H 2O on the activity of 4% Sr-La 2O 3 mimics that observed with pure La 2O 3, and a reversible inhibition of the rate is observed. CO 2 causes a greater effect, with decreases in rate of about 65% with O 2 present and 90% in its absence, while with H 2O in the feed, the rate decreased around 35-40% with O 2 present or absent. The influence of these two reaction products on kinetic behavior can be described by assuming competitive adsorption on the surface, incorporating adsorbed CO 2 and H 2O in the site balance, and using rate expressions previously proposed for this reaction over Sr-promoted La 2O 3. In the absence of O 2, the rate expression is $$r_{N_2 } = \frac{{k'P_{{\text{NO}}} P_{{\text{CH}}_{\text{4}} } }}{{{\text{(1 + }}K_{{\text{NO}}} P_{{\text{NO}}} {\text{ + }}K_{{\text{CH}}_{\text{4}} } P_{{\text{CH}}_{\text{4}} } {\text{ + }}K_{{\text{CO}}_{\text{2}} } P_{{\text{CO}}_{\text{2}} } {\text{ + }}K_{{\text{H}}_{\text{2}} {\text{O}}} P_{{\text{H}}_{\text{2}} {\text{O}}} {\text{)}}^{\text{2}} }},$$ which yields a good fit to the experimental data and gives optimized equilibrium adsorption constants that demonstrate thermodynamic consistency. With O 2 in the feed, nondifferential changes in reactant concentrations through the reactor bed were accounted for by assuming integral reactor behavior and simultaneously considering both CH 4 combustion and CH 4 reduction of NO, which provided the following rate law for total CH 4 disappearance: $$(r_{{\text{CH}}_{\text{4}} } )_{\text{T}} = \frac{{k'_{{\text{com}}} P_{{\text{CH}}_{\text{4}} } P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} + k'_{{\text{NO}}} P_{{\text{NO}}} P_{{\text{CH}}_{\text{4}} } P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} }}{{{\text{(1 + }}K_{{\text{NO}}} P_{{\text{NO}}} {\text{ + }}K_{{\text{CH}}_{\text{4}} } P_{{\text{CH}}_{\text{4}} } {\text{ + }}K_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} P_{{\text{O}}_{\text{2}} }^{{\text{0}}{\text{.5}}} {\text{ + }}K_{{\text{CO}}_{\text{2}} } P_{{\text{CO}}_{\text{2}} } {\text{ + }}K_{{\text{H}}_{\text{2}} {\text{O}}} P_{{\text{H}}_{\text{2}} {\text{O}}} {\text{)}}^{\text{2}} }}.$$ The second term of this expression represents N 2 formation, and it again fit the experimental data well. The fitting constants in the denominator, which correspond to equilibrium adsorption constants, were not only thermodynamically consistent but also provided entropies and enthalpies of adsorption that were similar to values obtained with other La 2O 3-based catalysts. Apparent activation energies typically ranged from 23 to 28 kcal/mol with O 2 absent and 31-36 kcal/mol with O 2 in the feed. With CO 2 in the feed, but no O 2, the activation energy for the formation of a methyl group via interaction of CH 4 with adsorbed NO was determined to be 35 kcal/mol. 相似文献
7.
In order to investigate the partial electronic conduction in the high oxide ion conductor of the system Bi 2O 3-Y 2O 3 under low oxygen pressure, e.m.f. and polarization methods were employed. Although the electrolyte was decomposed when the \(P_{{\text{O}}_{\text{2}} }\) was lower than the equilibrium \(P_{{\text{O}}_{\text{2}} }\) of Bi, Bi 2O 3 mixture at each temperature, the ionic transport number was found to be close to unity above that \(P_{{\text{O}}_{\text{2}} }\) . The hole conductivity ( σ p) and the electron conductivity ( σ p) could be expressed as follows, $$\begin{gathered} \sigma _p \Omega cm = 5 \cdot 0 \times 10^2 \left( {P_{O_2 } atm^{ - 1} } \right)^{{1 \mathord{\left/ {\vphantom {1 4}} \right. \kern-\nulldelimiterspace} 4}} \exp \left[ { - 106 kJ\left( {RT mol} \right)^{ - 1} } \right] \hfill \\ \sigma _p \Omega cm = 3 \cdot 4 \times 10^5 \left( {P_{O_2 } atm^{ - 1} } \right)^{ - {1 \mathord{\left/ {\vphantom {1 4}} \right. \kern-\nulldelimiterspace} 4}} \exp \left[ { - 213 kJ\left( {RT mol} \right)^{ - 1} } \right] \hfill \\ \end{gathered} $$ These values were much lower than the oxide ion conductivity under ordinary oxygen pressure. 相似文献
8.
The reactions of K 3[Cu(CN) 4], R 3SnCl and bipodal ligands, where R = (n-Bu) 3SnCl and L = quinoxaline (qox) and R = Me 3SnCl and L = quinazoline (qaz) afford the red needle crystals of
¥3 [ \text Cu2 ( \text CN ) 2 m\text-( qox) ] 2 {}_{\infty }^{3} \left[ {{\text{Cu}}_{2} \left( {\text{CN}} \right)_{2} \mu {\text{-(qox)}}} \right]_{2} , 1 and the orange needle crystals of [Cu 2(CN) 2μ(qaz)] n, 2. 1 was subjected to single crystals X-ray study while 2 was investigated by IR, 1H NMR and mass spectra as well as TGA. The crystal structure of 1 exhibits puckered CuCN chains connected by qox molecules forming 2D-sheets. The 2D-sheets contain hexagonal nets stacked
in A···A···A fashion. The paralleled sheets are close packed via extensive H-bonds, π–π stacking, strong Cu-Cu interaction
and short Cu–C contacts which develop 3D-network. Unique rhombic [Cu 2(μ 3-CN) 2] motifs result as consequence of interwoven of the 2D-sheets. The structure of 2 exhibits different XRPD pattern than that of 1 although, the two structures have the same Cu:CN:L stoichiometric ratio. The emission spectra of 1 and 2 display bands around 390, 420 and 475 nm corresponding to MC transition, 1(n,π*) → S o and MLCT, respectively. Thus, 1 and 2 can be considered as examples of room-temperature luminescent Cu-containing polymers which can be used in applications as
molecular sensing systems. Also, the oxidative degradation of Metanil Yellow (MY) dye has been investigated by hydrogen peroxide
catalyzed by 1 or 2. The catalytic activity of 1 is more pronounced than that of 2. 相似文献
9.
The value of the ratio \(\gamma _{{\text{Cu}}^{{\text{2 + }}} } /\gamma _{{\text{Ag}}^{\text{ + }} }^2 \) ( \(\gamma _{{\text{Cu}}^{{\text{2 + }}} } ,\gamma _{{\text{Ag}}^{\text{ + }} } \) -are the mean activity coefficients of copper and silver ions, respectively) was calculated from the measured emf of the cell $${\text{Cu(Hg)|H}}_{\text{2}} {\text{SO}}_{\text{4}} {\text{ (}}c_{\text{x}} {\text{)}} - {\text{CuSO}}_{\text{4}} {\text{ (}}c_{\text{y}} {\text{)|Hg}}_{\text{2}} {\text{SO}}_{\text{4}} {\text{, Hg}}$$ and the solubility of Ag 2SO 4 in H 2SO 4 ( c x) and CuSO 4 ( c y) solutions. The concentration of H 2SO 4 in the solution was varied from 0.5 to 2.1 mol dm ?3 that of CuSO 4 from 0.4 mol dm ?3 to saturation. The results were presented as a function: $$\frac{{\gamma _{{\text{Cu}}^{{\text{2 + }}} } }}{{\gamma _{{\text{Ag}}^{\text{ + }} }^2 }} = a_0 + a_1 c_{\text{x}} + a_2 c_{\text{y}} + a_3 c_{\text{x}}^{\text{2}} + a_4 c_{\text{x}} c_{\text{y}} + a_5 c_{\text{y}}^2 .$$ This function allows the estimation of the equilibrium silver ion concentration \(c_{{\text{Ag}}^{\text{ + }} }^{{\text{eq}}} \) in solutions containing both H 2SO 4 and CuSO 4 in the presence of metallic copper. The function is also very useful for the estimation of the \(c_{{\text{Ag}}^{\text{ + }} }^{{\text{eq}}} \) near a working copper electrode. 相似文献
10.
A complex with the formula [CuL(H 2O) 2]{[CuL][Fe(CN) 6]} 2·2H 2O, where L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, has been synthesized and crystallographically characterized. The structure is composed of a one-dimensional zigzag chain of
units, and [CuL(H 2O) 2] 2+ units. The one-dimensional zigzag chain extents through
linkages. The adjacent two polymer chains are linked by the
hydrogen bonding between [CuL(H 2O) 2] 2+ and [Fe(CN) 6] 3–, forming a 3D supramolecular structure with inner hydrophilic channels. Magnetic susceptibility measurements show no exchange interaction between the Cu(II) and Fe(III) ions due to the longer
(axial) bond length. 相似文献
11.
The primary objective of modifying cotton fabric was to impart bactericidal properties to attract various fields such as defence,
space and textile industrial applications. Chemically initiated graft copolymerization of 4-vinyl pyridine (4-VP) and acrylonitrile
(AN) onto cotton fabric was carried out using ceric ammonium nitrate as a redox initiator. Optimum conditions pertaining to
maximum percentage of grafting were evaluated as a function of concentration of initiator [CAN], concentration of nitric acid,
monomer concentration, water, temperature and reaction time. Maximum grafting of 4-VP (51.63%) and AN (69.23%) was obtained
respectively at optimum
[ \text CAN ] = 2.738 ×10 - 2 \left[ {\text{CAN}} \right] = 2.738 \times {10^{ - 2}} and 2.19 × 10 −2 moles/L,
[ 4 - \text VP ] = 47.55 ×10 - 22\text moles/\text L \left[ {4 - {\text{VP}}} \right] = 47.55 \times {10^{ - 22}}{\text{moles}}/{\text{L}} ,
[ \text AN ] = 18.85 ×10 - 22\text moles/\text L \left[ {\text{AN}} \right] = 18.85 \times {10^{ - 22}}{\text{moles}}/{\text{L}} ,
[ \text HN\text O3 ] = 11.9 ×10 - 2 \left[ {{\text{HN}}{{\text{O}}_3}} \right] = 11.9 \times {10^{ - 2}} and 89.5 × 10 −22 moles/L in 20 and 25 ml of water at an optimum temperature 70 °C and 60 °C with in 180 and 120 min. Antibacterial properties
were induced into the modified cotton fabric by treating the grafted fabric with benzyl chloride. The grafted and quaternized
copolymer were characterized by FTIR and Thermogravimetrical analysis. The bactericidal action of cotton fabric was tested
by filtration test and it was observed that fabric grafted with 4-VP was more effective and efficient antibacterial as compared
to AN grafted cotton sample. 相似文献
12.
A complex with the formula [CuL(H 2O) 2]{[CuL][Fe(CN) 6]} 2·2H 2O, where L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, has been synthesized and crystallographically characterized. The structure is composed of a one-dimensional zigzag chain of $\left\{ {[{\text{CuL}}][{\text{Fe(CN)}}_{\text{6}} ]} \right\}_2^{2 - } $ units, and [CuL(H 2O) 2] 2+ units. The one-dimensional zigzag chain extents through ${\text{Cu}}{\kern 1pt} - {\kern 1pt} {\text{CN}} - {\kern 1pt} {\text{Fe}}{\kern 1pt} - {\kern 1pt} {\text{CN}} - {\kern 1pt} {\text{Cu}}$ linkages. The adjacent two polymer chains are linked by the ${\text{O}}{\kern 1pt} - {\kern 1pt} {\text{H}}{\kern 1pt} \cdot \cdot \cdot {\kern 1pt} {\text{N}}{\kern 1pt} \equiv {\kern 1pt} {\text{C}}{\kern 1pt} - $ hydrogen bonding between [CuL(H 2O) 2] 2+ and [Fe(CN) 6] 3?, forming a 3D supramolecular structure with inner hydrophilic channels. Magnetic susceptibility measurements show no exchange interaction between the Cu(II) and Fe(III) ions due to the longer ${\text{Cu}}{\kern 1pt} - {\kern 1pt} {\text{N}}$ (axial) bond length. 相似文献
13.
Polyacetylene films, contacted with platinum mesh, have been polarized anodically in aqueous H 2SO 4, HClO 4, HBF 4 and H 2F 2 of medium concentrations (30–70 wt%). Two oxidation peaks are observed, the equivalents of which are 1 $${\text{(1) 0}}{\text{.045 F mol}}^{ - {\text{1}}} {\text{ CH (2) 0}}{\text{.23 F mol}}^{ - {\text{1}}} {\text{ CH}}$$ The potential of the Process 1 decreases linearly with increasing acid concentration by 20–40 mV mol ?1 dm ?3, while the potential of Peak 2 exhibits normal Nernst behaviour (about + 60 mV decade ?1. Process 1 is partially reversible, while Process 2 is totally irreversible. From these findings for Process 1 we conclude the reversible insertion of anions into the polyacetylene host lattice, which is primarily oxidized to the polyradical cation, with the co-insertion of acid molecules HA to yield the insertion compound [(CH) +· yA ?· vyHA] x y?4.5% and v=1.5 for H 2SO 4 and HClO 4. In the course of Process 2, the polymer is irreversibly oxidized according to $$( - ^ \cdot {\text{CH}} \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot ^ \oplus {\text{ CH}} - )_{x/2} + 2{\text{H}}_{\text{2}} {\text{O}} \to ( - \mathop {\text{C}}\limits_{\mathop \parallel \limits_{\text{O}} } \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot \mathop {\text{C}}\limits_{\mathop \parallel \limits_{\text{O}} } - )_{x/2} + 6{\text{H}}^{\text{ + }} + 5e^ - $$ As this process occurs to some extent even in the potential region of Process 1, a continuous degradation of the host lattice occurs upon cycling. 相似文献
14.
The influence of temperature in the range 25 to 80°C on the dissolution of tin was investigated in an acidic solution at pH4 containing 0.1 to 1 m NaCl. The corrosion current is slightly dependent on both the temperature and the Cl – ion concentration. The main dissolution characteristics of tin are
相似文献
15.
Electrospinning technique was used to prepare $ {\text{PVP}}/\left[ {{\text{Y}}\left( {{\text{NO}}_{ 3} } \right)_{ 3} + {\text{Yb}}\left( {{\text{NO}}_{ 3} } \right)_{ 3} + {\text{Er}}\left( {{\text{NO}}_{ 3} } \right)_{ 3} + {\text{Al}}\left( {{\text{NO}}_{ 3} } \right)_{ 3} } \right] $ composite nanobelts and novel structures of Y 3Al 5O 12:Er 3+, Yb 3+ (denoted as YAG:Er 3+, Yb 3+ for short) nanobelts have been successfully fabricated after calcination of the relevant composite nanobelts at 900 °C for 8 h. YAG:Er 3+, Yb 3+ nanobelts were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy. XRD analysis indicated that YAG:Er 3+, Yb 3+ nanobelts were cubic in structure with space group I a3d. SEM analysis and histograms revealed that the width of YAG:Er 3+, Yb 3+ nanobelts was ca. 1.8 ± 0.37 μm under the 95 % confidence level, and the thickness was ca. 81.8 nm. Up-conversion emission spectra analysis manifested that YAG:Er 3+, Yb 3+ nanobelts respectively emitted strong green and red emissions centering at 522, 554 and 648 nm under the excitation of a 980-nm diode laser. The green emissions were assigned to the energy levels transitions of $ ^{ 2} {\text{H}}_{ 1 1/ 2} ,^{ 4} {\text{S}}_{ 3/ 2} \to^{ 4} {\text{I}}_{ 1 5/ 2} $ of Er 3+ ions, and the red emission originated from the energy levels transition of $ ^{ 4} {\text{F}}_{ 9/ 2} \to ^{ 4} {\text{I}}_{{{\text{l5}}/ 2}} $ of Er 3+ ions. The up-conversion luminescence of YAG:Er 3+, Yb 3+ nanobelts doped with various concentrations of Yb 3+ and Er 3+ was studied and the optimum molar ratio of Yb 3+ to Er 3+ was found to be 15:1. CIE analysis demonstrated that color-tuned luminescence can be obtained by adjusting doping concentrations of Yb 3+ and Er 3+ ions, which could be applied in the fields of optical telecommunication and optoelectronic devices. The up-conversion luminescent mechanism and the formation mechanism of YAG:Er 3+, Yb 3+ nanobelts were also proposed. 相似文献
16.
Eleven out of 13 disruption profiles (plots of dispenser density vs. male catch) from moth sex pheromone literature were consistent with a competitive-attraction mechanism, in which dispensers attract males and thereby divert them from females. Mean dispenser activity ( D
a) across all competitive-attraction cases was 0.04 ± 0.06 (SD); values ranged from 0.0005 for a tiny laminated flake dispenser of racemic disparlure targeting gypsy moth to 0.2 for polyethylene tube dispensers used against lightbrown apple moth. A dispenser application activity () can be calculated by multiplying D
a by the number of such dispensers applied per hectare of crop. The highest dispenser application activity () values approached 200 and corresponded to >99% inhibition of catches of male moths in monitoring traps. Relative to the scale, % inhibition of catches of male moths compressed and obscured large differences in when % disruption exceeded 90%. For cases of competitive attraction, these two efficacy scales can be interconverted by using the formula: . When disruptive point sources of pheromone were directly observed, male moths were seen approaching pheromone dispensers whose disruption profiles matched competitive attraction. Two cases fit non-competitive disruption mechanisms, which include camouflage, desensitization (adaptation and/or habituation), and sensory imbalance. In these cases, pheromone was released at rates higher than for cases of disruption by competitive attraction. Practical ramifications of the finding that competitive attraction appears to be the prevalent mechanism for moth mating disruption by pheromone point sources are listed. We believe that the congruence of diverse sets of mating disruption field data with explicit a priori predictions validates competitive-attraction theory. The analytical tools and principles governing competitive attraction that were uncovered during this study of mating disruption of moths should be generally applicable to competitive-attraction phenomena. 相似文献
17.
A new complex of the Keggin trilacunary
polyoxomolybdate (PMo 9) with Fe 3+ ions, having the formula (PFe 3Mo 9), has been synthesized and characterized by chemical analysis, FT-IR, Raman, UV-VIS-NIR and EPR spectroscopy, as well as
by magnetic susceptibility measurements. Cyclic voltammetry performed at different scan rates, pH and supporting electrolyte
composition, was used to investigate the electrochemical behaviour of the PFe 3Mo 9 complex in acidic medium and its electrocatalytic effect on H 2O 2 reduction. The voltammetric waves were assigned, and the enhanced electrocatalytic efficiency of PFe 3Mo 9 relative to PMo 9 was attributed to the presence of Fe atoms. 相似文献
18.
The metal iodides reduce partially the host coordination polymer of the type $ ^{ 3}_{\infty } \left[ {\left( {{\text{Me}}_{ 3} {\text{Sn}}} \right)_{ 3} {\text{Fe}}\left( {\text{CN}} \right)_{ 6} } \right] $ , I, to give new host–guest supramolecular coordination polymers (SCP). The physical and chemical characteristics of the new products were studied by elemental analyses, X-ray powder diffraction, IR, UV/Vis, and solid state NMR spectra. The host–guest SCP are [M x(Me 3Sn) 3Fe (1–x) IIIFe x II (CN) 6] n M = Li +·2H 2O, 1; Li +, 2; Na +, 3; K +, 4; Cu +, 5, [Li(Me 3Sn) 3Fe II(CN) 6] n, 6 and [(LiDEE) 0.9(Me 3Sn) 3Fe o.1 III Fe o.9 II (CN) 6] n, 7. The stoichiometry and nature of the guest depend on the type of the metal iodide and the reaction conditions. The polymeric nature of these SCP is due to the presence of trigonal bipyramidal configured structure which bridges between the single d-transition metal ions. The host–guest SCP containing the Li ions have been tested as electrodes to construct four different lithium-ion batteries. 相似文献
19.
Mixed micellization behavior of dimeric cationic surfactants ethanediyl-1,2-bis(dimethyl alkyl ammonium bromide) ( m-2- m where m = 10, 12) with conventional single chain cationic surfactants like cetyltrimethyl ammonium bromide (CTAB), cetylpyridinium
chloride (CPC), tetradecyl dimethyl benzyl ammonium chloride (C14BCl) and cetyl dimethyl benzyl ammonium chloride (C16BCl)
were studied in aqueous and aqueous polyethylene glycol (PEG) solutions at 298.15, 308.15 and 318.15 K respectively using
conductometric and viscometric methods. In aqueous solutions, all the combinations (except 12-2-12 + CTAB) were found to behave
nonideally with mutual synergism which decreases with increase in temperature. Various thermodynamic parameters of micellization
like
\Updelta G\textm\texto {{\Updelta}}G_{\text{m}}^{\text{o}} ,
\Updelta H\textm\texto {{\Updelta}}H_{\text{m}}^{\text{o}} and
\Updelta S\textm\texto {{\Updelta}}S_{\text{m}}^{\text{o}} were evaluated and discussed. Similarly in presence of PEG, the thermodynamic properties like
\Updelta G\textt\texto {{\Updelta}}G_{\text{t}}^{\text{o}} ,
\Updelta H\textt\texto {{\Updelta}}H_{\text{t}}^{\text{o}} and
\Updelta S\textt\texto {{\Updelta}}S_{\text{t}}^{\text{o}} associated with the transfer of surfactant monomers from the medium consisting of polymer-free mixed micelles to polymer-bound
mixed micelles at various temperatures were also calculated. The negative values of
\Updelta H\textt\texto {{\Updelta}}H_{\text{t}}^{\text{o}} show that aggregation process is more exothermic than micellization whereas the negative values of
\Updelta S\textt\texto {{\Updelta}}S_{\text{t}}^{\text{o}} indicate that the presence of polymer bound mixed micelles decreases the degree of randomness of the system. Viscosity studies
show that in aqueous solutions all the combinations of 10-2-10/12-2-12 display negative departure in the relative viscosity
(η r) from additivity rule which decreases with increase in temperature. Similarly in the presence of 5% PEG solutions the magnitude
of the negative departure decreases for all the combinations and becomes positive in the case of C14BCl and CPC combinations
with the studied gemini surfactants at higher temperatures. 相似文献
20.
Intrinsic viscosity-number average molecular weight relationships have been measured, at 30C in benzene, for poly (n-octadecyl
acrylate) as [η]=2.72×10 −4 Mn 0.638 and for poly (N-n-octadecylacrylamide) as [η]=0.82×10 −4 Mn 0.676. Whole polymers of various molecular weights were prepared in benzene solution at 65C with dodecyl mercaptan as primary regulator.
By the use of these parameters, the molecular weight of such polymers and their homologs may now be measured by simple solution-viscosity
determinations.
In the expression {
} (relating degrees of polymerization {
} to the mercaptan/monomer ratio), intercept {
} and apparent transfer constant C s for n-octadecyl acrylate were 6.28×10 −3 and 0.68; for N-n-octadecylacrylamide 1.10×10 −3 and 0.62 respectively. These parameters permit preparation of homopolymers of chosen molecular weight.
Presented at the AOCS Meeting, Philadelphia, October 1966
E. Utiliz. Res. Devel. Div., ARS, USDA. 相似文献
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