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101.
102.
We modeled nisin's anticlostridial activity and assessed the antagonistic or potentiating influences of food ingredients. The model systems contained yeast extract, proteose peptone, and glucose; were supplemented with protein (0.075, 0.75, 7.5% w/v), phospholipid (0.075, 0.75, 7.5% w/v), or soluble starch (5, 17.5, 30% w/v); and were adjusted to pH 5.5, 6.0, or 6.5. Samples inoculated with 104/mL spores were incubated at 15, 25, or 35°C. Statistical analysis developed an equation (r2= 0.76) that modeled the response and identified temperature as the most significant (α 0.001) variable. Nisin lost effectiveness with increasing temperature. Nisin concentration had significant positive and phospholipid negative, linear effects. Many interactive effects were significant (α 0.20). Nisin inhibited C. botulinum until its residual level dropped below a threshold, which decreased from 154 IU/mL at 35°C to 12 IU/mL at 15°C. 相似文献
103.
Wide variability exists with respect to how breast cancer survivors respond to common psychological and psychosocial challenges of their disease, ranging from posttraumatic stress disorder to posttraumatic growth. This cross-sectional study examined contextual, disease-related, and intraindividual predictors of posttraumatic growth in 224 randomly selected breast cancer survivors. A series of hierarchical regression analyses found that age at diagnosis, marital status, employment, education, perceived intensity of disease, and active coping accounted for 34%, 35%, and 28% of the variance in growth in relationships with others, new possibilities, and appreciation for life. These findings suggest that a more comprehensive model of growth will be helpful in understanding the various factors that play a role in breast cancer survivors' perception of psychological and psychosocial growth. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
张田林 《青岛科技大学学报(自然科学版)》1994,(3)
DCPTA是近年来新发现的一种植物生长调节剂。对农作物具有明显的增产增质效果。文中就其新的合成方法进行了研究。 相似文献
105.
106.
107.
108.
The growth of high quality Hg0.8Cd0.2Te bulk single crystals by CVT, combined with an in-situ seeding technique, is reported here for the first time. For this
purpose, a temperature difference of 590° → 540° C with a gradient of 40°-50° C/cm at the solid-vapor interface, and about
0.1 atm of HgI2 as a transport agent, were employed. The bulk crystals have the expected stoichiometry and compositional homogeneity. Etch
pit densities of 104-105 cm−2 on the (111) face and hitherto unreported etch pits on the (100) face were observed in this work. Possible origins of the
sub-grain structure are discussed. 相似文献
109.
The inherently nonlinear phenomenon of fatigue crack propagation is modeled as a linear random process. To a first approximation, simple, nonstationary time series models are introduced and standard techniques for determining the parameters of autoregressive integrated moving-average processes are applied. Multiplicative time series models are next utilised for the representation of a group of crack history curves. Implementation of the models on the Virkler experimental data set yields satisfactory results. Reliable Gaussian approximations to the distribution of the time required by a crack to reach a specified critical length are obtained, and the usefulness of the approach is demonstrated when updating lifetime predictions after periodic inspections. 相似文献
110.
The growth of carbide particles in TiC-XC-2 vol.% Ni and TiC-XC-30 vol.% Ni alloys, where X=Zr, Cr, W, Ta and Mo, was fitted
to an equation of the form d3-do
3=Kt. The grain growth behavior during liquid phase sintering at 1673K decreased markedly with the addition of Mo2C or WC, changed little for TaC, and increased with the addition of ZrC or Cr3C2. The grain contiguity decreased with increasing Ni content in the TiC−Mo2C−Ni alloy and was greater in the alloys with smaller growth rate constant. Consequently, the effect of carbide addition on
the grain growth of 2 vol.% Ni alloys was found to be similar to that of 30 vol.% Ni alloys. The grain growth mechanism could
be explained by the effect of contiguous carbide grain boundaries in restricting the overall grain growth, as well as the
area of the solid/liquid interfaces in the alloy by the usual solution/reprecipitation model. 相似文献