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81.
82.
Palm-oil-in-water emulsions were prepared with mixtures of Tween 40 and Span 40 in various proportions. Stability and droplet-size
distribution of the emulsions were monitored. Interfacial tensions of the palm oil/water interface were also determined in
the presence of these emulsifier mixtures. Emulsifying efficiency of the emulsifier mixtures was assessed. No synergistic
effect of Tween 40 (sorbitan monopalmitate with 18–22 moles of ethylene oxide) and Span 40 (sorbitan monopalmitate) was found
on interfacial tension. Tween 40 alone (hydrophilic-lipophilic balance value 15.6) at 1.0% w/w gave palm oil emulsions that
were stable for more than 30 d at 60°C. Emulsifier mixtures of Tween 40 and Span 40 with hydrophilic-lipophilic balance values
in the range of 8.0–8.6 produced stable emulsions only at much higher emulsifier-mixture concentrations. The inherent nature
of the oil and the accompanying natural surface-active materials present in the oil can influence the prevailing conditions
at the oil/water interface and alter composition of the interfacial film and hence its stability. 相似文献
83.
多菌灵、硫及三环唑混配成悬浮剂,对抑制稻瘟病菌的菌丝生长、分生孢子萌发、附着胞的形成、产孢能力及纹枯病菌菌丝生长等都具有较明显的协同增效作用,协同作用比率(SR)分别为1.64、5.58、4.30、1.81及1.73。混配剂集合了多菌灵、硫及三环唑的优点,并显示出耐雨水冲刷、持效期长的特点。田间试验亦表明其防病增产作用比较显著。 相似文献
84.
介绍了混炼硅橡胶的基本配合过程和硫化体系,着重比较了间歇法和连续法两种混炼工艺的生产效率及对硅橡胶硫化胶性能的影响,讨论了6种过氧化物硫化剂的特点及适应范围。 相似文献
85.
86.
87.
氧化铝原料纯度高,熔点高,不被氢氟酸—硫酸所分解,但能迅速熔解于热的硫—磷混酸溶液中。控制溶液中硫—磷混酸的浓度,并在氧化钠系列标准溶液中配入等量的硫—磷混酸,即可在火焰光度计上直接测量氧化钠的含量。 相似文献
88.
Masaru Takahashi Tetsu Nakatani Shinji Iwamoto Tsunenori Watanabe Masashi Inoue 《Applied catalysis. B, Environmental》2007,70(1-4):73-79
The solvothermal reaction of mixtures of aluminum isopropoxide (AIP) and gallium acetylacetonate (Ga(acac)3) directly yielded the mixed oxides of γ-Ga2O3-Al2O3. In the solvothermal synthesis, the crystal structure of mixed oxides was controlled by the initial formation of γ-Ga2O3 nuclei. The mixed oxides prepared in diethylenetriamine have extremely high activities for selective catalytic reduction (SCR) of NO with methane as a reducing agent. With increasing crystallite size of the spinel structure, the catalytic activity increased. The ratio of the amount of methane consumed by combustion to total methane conversion was proportional to the density of acid sites on the surface of the mixed oxides. The mixed oxide catalysts prepared in diethylenetriamine had lower densities of acid sites and showed a higher methane-efficiency for CH4-SCR than those prepared in other solvents. These catalysts maintained their high activity even when the reaction was carried out under the severe conditions (i.e., high space velocity and low NO concentration). 相似文献
89.
In this paper, we investigate the mixed H2/H∞ robust model predictive control (RMPC) for polytopic uncertain systems, which refers to the infinite horizon optimal guaranteed cost control (OGCC). To fully use the capability of actuators, we adopt a saturating feedback control law as the control strategy of RMPC. As the saturating feedback control law can be effectively represented by the convex hull of a group of auxiliary linear feedback laws, the auxiliary feedback laws allow us to design the actual feedback control law without consideration of the input constraints directly to achieve the improved performance. Moreover, we suggest the relative weights on the actual and auxiliary feedback laws to the RMPC, which in turn improves the closed-loop system performance. Furthermore, an off-line design of the proposed RMPC is also developed to make it more practical. Numerical studies demonstrate the effectiveness of the proposed algorithm. 相似文献
90.
Zhong-Ni Wang Gan-Zuo Li Jian-Hai Mu Wen-Xia Zhang 《Journal of surfactants and detergents》2002,5(4):391-396
The interaction and synergism of some polyoxyethylenated fatty alcohol ether (POE) nonionic surfactants (C12E2, C12E3, C10E5, C10E7, where Cx indicates number of carbon atoms in the chain and Ey indicates number of oxyethylene glycol ethers) with trioxyethylenated dodecyl sulfonate (C12E3S) in mixed monolayer formation at the surface and in mixed micelle formation in aqueous solutions were studied at 25 and
40°C by calculating interaction parameters (βα, βM) from surface tension-concentration data by use of Rosen's equations based on the nonideal solution theory. All the systems
investigated adapt reasonably well to the nonideal model, with negative values of βσ and βM (where M means micelle and σ refers to the air-liquid interface) indicating a favorable interaction between the mixed surfactants.
Either at a monolayer or in a mixed micelle, the attractive interaction becomes stronger when the alkyl chain in the POE surfactant
is longer, i.e., when the POE becomes more hydrophobic. The interaction increases in the order C10E7<C10E5<C12E3, C12E2. For the two C10E
n
(n= 5,7)/C12E3S systems, as temperature increases from 25 to 40°C, the interaction increases in a mixed micelle, but it decreases in a mixed
monolayer. Synergism in mixed micelle formation exists for C12E3S/C10E
n
mixtures when X1
M
, the mole fraction of POE in a mixed micelle, is ≈0.4–0.8, whereas synergism does not occur in the systems of C12E3S/C12E
m
due to the large difference between CMC1 and CMC2, i.e., large |In(C
1
M
/C
2
M
)| value (where CMC=critical micelle concentration). The degree of synergism in mixed micelle formation is temperature independent
and is 0.23, 0.18, and close to zero for C10E5/C12E3S, C10E7/C12E3S, and C12E
m
(m=2,3)/C12E3S systems, respectively. Synergism in surface tension reduction effectiveness occurs in C12E3S/C12E2 and C12E3S/C12E3 systems. The mole fractions of POE in the solution phase are 0.302 and 0.333 for the two mixtures at the point of maximum
synergism. 相似文献