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991.
Dots for Dummies     
Quantum dots pose an interesting problem in which three complications- disorder, interaction and finite size- come together. I describe progress that can be made by combining Random Matrix Theory (RMT) and the Renormalization Group (RG) to attack the problem.  相似文献   
992.
A simple anaerobic digestion (AD) model was formulated with emphasis on understanding the microbial activity during AD. The model was formulated according to two main rules that regulate the microbial growth. The first rule was maintaining the elemental continuity of macronutrients C, H, N, O, P, and S. The second rule satisfied the thermodynamics of the main AD catabolic reactions: acidogenesis and both acetotrophic and hydrogenotrophic methanogenesis. Accordingly, the stoichiometric parameters were evaluated as functions of the bacterial yield. The model also considered the enzymatic hydrolysis of solid waste. For a known solid waste composition, experimental data was utilized to estimate microbial initial concentrations, yields and kinetics, i.e., to achieve better understanding of the main AD microbial activity. The model was applied to three sets of batch experiments focusing on anaerobic dairy manure degradation. The model predicted the degradation dynamics, estimated the bacterial concentration in different inoculums, and evaluated the effect of inoculum ratios in speeding up the degradation. Elemental continuity based formulation of the model evaluated additional components that are necessary for future studies of macronutrients recovery, limitation/toxic effects, and chemical equilibrium.  相似文献   
993.
IntroductionBoththestudiesonthelow-dimensionmaterialsofmodifiedPbTiO3andpurePbTiO3werecarriedoutsynchronously,theauthorshopedtostrengthenthephysicochemicalproper-tiesofthematerialsinsomerespectsbymeansofchangingdesignmodificationscheme.Amongthenumero…  相似文献   
994.
Molecular orbital calculations are reported for the monoxides, XO, of group 14 elements (X = C, Si, Ge and Sn) and for both isomers, XOH+ and HXO+, of the protonated monoxides. Structure optimisation has been carried out using the Density Functional Theory employing the B3LYP procedure and at both Hartree-Fock and MP2 (full) levels, all with a variety of medium-sized Gaussian basis sets. In all XO molecules the oxygen atom is the preferred site for protonation, except when X = C where HCO+ is the lower energy isomer. Barriers to interconversion between the two isomers XOH+ and HXO+ are over-estimated by the Hartree-Fock calculations, but with wave functions that include electron correlations they generally fall into the range 27-44 kcal mol−1. Proton affinities increase as the atomic number of X increases, and values calculated by averaging over all wave functions that include electron correlation, give the following proton affinities: for CO, 141.5; for SiO, 189.3; for GeO, 196.1; and for SnO, 215.6 (all in kcal mol−1).  相似文献   
995.
本文考察指标集为d维欧氏空间Rd的子集类c的Wiener过程W的样本轨道性质.在某些情形中,对0<an≤nd,an是不减的且an/nd是不增的假设下,求得函数Ψn使给出了Wiener测度在Rd的VC类的界,它也推广了Csorgo-Revesz关于Wiener过程增量的结果于这一一般情形.  相似文献   
996.
We investigate the existence of stable charged metallic bubbles using the shell correction method. We find that for a given mesoscopic system of n atoms of a given metal and (positive) elementary charges, a metallic bubble turns out to have a lower total energy than a compact spherical cluster, whenever the charge number q is larger than a critical charge number qc. For a magic number (n-q) of free electrons, the spherical metallic bubble may become stable against fission. Received: 17 November 1997 / Revised: 28 May 1998 / Accepted: 20 July 1998  相似文献   
997.
有机锗Ge-132是一种具有多种生理活性的功能免疫调节剂,已广泛用于保健,临床。随着各国对锗的研究不断深入,对其质量要求越来越高,从有机锗的生产角度出发,本文对原有工艺进行了许多改进,使有机锗的品质,产率,生产效率均有不同程度的提高,而生产成本大幅降低,并对原工艺不能处理的副产品进行综合回收,消除污染,取得可观的社会与经济效益。  相似文献   
998.
In the first part of this paper we let M be a stable homogeneous model and we prove a nonstructure theorem for the class of all elementary submodels of M, assuming that M is ‘unsuperstable’ and has Skolem functions. In the second part we assume that M is an unstable homogeneous model of large cardinality and we prove a nonstructure theorem for the class of all elementary submodels of M.  相似文献   
999.
软岩巷道开巷初期围岩变形灰色模型预测的研究   总被引:5,自引:0,他引:5  
应用灰色系统理论对软岩巷道开巷初期围岩变形进行了预测,通过实例说明用GM(1,1)模型和双向差分模型预测巷道的围岩变形都是简单可行的。对GM(1,1)模型进行了改进,建立了具有较小原点误差的改进的GM(1,1)的模型,并且给出了双向差分模型,GM(1,1)模型与其改进模型对软巷道围岩变形预测结果的比较,为灰色系统理论用于软岩巷道开巷初始围岩及支扩变形预测的实践进行了新的探讨,它将在软岩工程未来行为的预测方面起着重要的参考作用。  相似文献   
1000.
This paper proposes an approach for prescribing the inter-related decisions that prescribe a process plan for a series of dual head placement machines. The goal is to provide a means of rapidly prescribing a process plan that seeks to minimize cycle time (equivalently, maximize throughput rate) by balancing workloads assigned to heads when assembling a given type of circuit card. Our approach decomposes process planning decisions into four related problems. This paper explores list-processing heuristics for the first of these problems and adapts an optimizing method for the fourth. It also integrates these two methods with others to optimize the second and third of these problems, reporting computational tests that evaluate the overall approach to all four problems and assessing the degree to which the decomposition approach is able to balance workloads assigned and the run time required to do so. Resulting cycle times are also analyzed. These test results demonstrate that the overall approach provides a means of prescribing effective process plans within a run time acceptable to process planners.  相似文献   
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