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241.
了解微量元素经由土壤-植物-人体链的基本、性质与变化过程,大有助于人体健康与环境保护。本书集中过去30多年的知识,提供最新数据及有关食物链的基本内容,附有引证文献资料共有68页(P.451-518)之多。 相似文献
242.
243.
Haolin Zhu Ashish Dhall Subrata Mukherjee Ashim K. Datta 《Transport in Porous Media》2010,84(2):335-369
A thermomechanical theory for multiphase transport in unsaturated swelling porous media is developed on the basis of Hybrid
Mixture Theory (saturated systems can also be modeled as a special case of this general theory). The aim is to comprehensively
and non-empirically describe the effect of viscoelastic deformation on fluid transport (and vice versa) for swelling porous
materials. Three phases are considered in the system: the swelling solid matrix s, liquid l, and air a. The Coleman–Noll procedure is used to obtain the restrictions on the form of the constitutive equations. The form of Darcy’s
law for the fluid phase, which takes into account both Fickian and non-Fickian transport, is slightly different from the forms
obtained by other researchers though all the terms have been included. When the fluid phases interact with the swelling solid
porous matrix, deformation occurs. Viscoelastic large deformation of the solid matrix is investigated. A simple form of differential-integral
equation is obtained for the fluid transport under isothermal conditions, which can be coupled with the deformation of the
solid matrix to solve for transport in an unsaturated system. The modeling theory thus developed, which involves two-way coupling
of the viscoelastic solid deformation and fluid transport, can be applied to study the processing of biopolymers, for example,
soaking of foodstuffs and stress-crack predictions. Moreover, extension and modification of this modeling theory can be applied
to study a vast variety of problems, such as drying of gels, consolidation of clays, drug delivery, and absorption of liquids
in diapers. 相似文献
244.
Non-linear internal damping in rotating cylindrical shafts leads to isotropic non-linear circulatory and dissipative force fields. Orbital instability in such class of systems arises when the regenerative work due to circulatory forces exceeds the dissipative work done over an orbit. In this paper, stability condition for rotor shafts with polynomial type non-linear internal damping is derived and also it is shown that distortion of the critical orbit, which results in larger change in orbital path as compared to the change in enclosed area, may lead to stable orbit at normally unstable operating conditions. This principle is applied to stabilize a simple rotor with discontinuous stiffness characteristics, which come into effect on exceeding some threshold displacement of the rotor itself. 相似文献
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249.
A. Mukherjee S. Kamila V. Chakravortty 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(3):799-801
Extraction studies of uranium(VI) by the binary mixture of PC88A and benzimidazole show an antagonistic behavior in the concentration
range 10−5–10−6M of PC88A and 0.005M of benzimidazole. Antagonism is observed due to the deprotonation of PC88A by benzimidazole forming
an adduct resulting in the virtual removal of PC88A from the system. 相似文献
250.
Asim K. Das Sudhin K. Mondal Goutam Mukherjee 《Reaction Kinetics and Catalysis Letters》2001,73(2):257-265
Cetylpyridinium chloride (CPC) inhibits the Cr(VI) oxidation of ethanol and propan-1-ol while sodium dodecyl sulfate (SDS)
catalyzes the title reactions. At higher values of the [surfactant], the rate attains a limiting value. The micellar effect
has been explained by considering the preferential partitioning of the reactants in terms of the suggested mechanism. Applicability
of the Menger-Portnoy model and Piszkiewicz model to explain the observed micellar effect has been examined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献