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101.
102.
Tijen Tanyalcin Diler Aslan Yusuf Kurtulmus Nalan Gökalp Kamil Kumanlioğlu 《Accreditation and quality assurance》2000,5(9):383-387
In this study the reference intervals for folate and vitamin B12 were estimated according to the National Committee for Clinical Laboratory Standards Approved Guideline C28-A and International
Federation of Clinical Chemistry recommendations. The study included 155 women and 124 men between ages 18–40. The health
status was confirmed by history, physical examination and a questionnaire. The central 95% reference intervals of serum folate
and vitamin B12 for women, determined non-parametrically, were found to be 3.9–18.1 ng/ml and 101–666.7 pg/ml, respectively.
The reference values of serum folate and vitamin B12 for men were also found to be 2,5–17.6 ng/ml and 100–699.57 pg/ml, respectively.
We did not observe subclass differences between females and males.
Received: 15 April 2000 · Accepted: 15 April 2000 相似文献
103.
V. I. Slyn’ko 《International Applied Mechanics》2008,44(6):683-694
Stability conditions for a holonomic impulsive mechanical system with two degrees of freedom in the critical case of one pair
of complex-conjugate multipliers are established. An analog of the first Lyapunov exponent is calculated
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 6, pp. 105–117, June 2008. 相似文献
104.
基于IP核开发模式的高校集成电路设计发展策略研究 总被引:1,自引:0,他引:1
针对当前集成电路领域企业缺少原始技术积累、高校成果转化困难的问题,提出一种以IP核合作方式促进高校集成电路设计加快发展、实现高校企业双赢的创新机制。高校作为我国IC产业链中不可缺少的一部分,以西安交通大学SoC设计中心近十年来的发展历程为案例进行分析,提出基于IP核开发的高校集成电路设计发展的具体策略。 相似文献
105.
一种新的两道工序柔性流水车间排序问题 总被引:1,自引:0,他引:1
本文针对F_2(p),h11.1|m_1=1,m_2=μ≥2|C_(max)这一问题给出了几种近似算法,并对每种近似算法进行了最坏情形分析,给出了最坏情形界. 相似文献
106.
Frances Y. Kuo Grzegorz W. Wasilkowski Henryk Wo
niakowski 《Journal of Approximation Theory》2008,152(2):135-160
We study the worst case setting for approximation of d variate functions from a general reproducing kernel Hilbert space with the error measured in the L∞ norm. We mainly consider algorithms that use n arbitrary continuous linear functionals. We look for algorithms with the minimal worst case errors and for their rates of convergence as n goes to infinity. Algorithms using n function values will be analyzed in a forthcoming paper.We show that the L∞ approximation problem in the worst case setting is related to the weighted L2 approximation problem in the average case setting with respect to a zero-mean Gaussian stochastic process whose covariance function is the same as the reproducing kernel of the Hilbert space. This relation enables us to find optimal algorithms and their rates of convergence for the weighted Korobov space with an arbitrary smoothness parameter α>1, and for the weighted Sobolev space whose reproducing kernel corresponds to the Wiener sheet measure. The optimal convergence rates are n-(α-1)/2 and n-1/2, respectively.We also study tractability of L∞ approximation for the absolute and normalized error criteria, i.e., how the minimal worst case errors depend on the number of variables, d, especially when d is arbitrarily large. We provide necessary and sufficient conditions on tractability of L∞ approximation in terms of tractability conditions of the weighted L2 approximation in the average case setting. In particular, tractability holds in weighted Korobov and Sobolev spaces only for weights tending sufficiently fast to zero and does not hold for the classical unweighted spaces. 相似文献
107.
Zhuang Tao 《Acta Mechanica Sinica》1987,3(1):73-81
In recent years, some investigators discussed the applicability of the HRR theory for engineering materials based on the results
of numerical analyses and experimental studies. In the present paper, the finite element method is employed to analyze the
crack tip fields of the engineering elastic-plastic material with a variety of geometry configurations of cracked specimens
from elastic state to intensely general yielded state in the plane strain case. The results indicate that the HRR theory loses
its validity of application for engineering elastic-plastic materials in the plane strain case. The reasons for this are analyzed.
A dual-parameter fracture criterion is suggested for this case. 相似文献
108.
Soil aggregate stability as a key indicator of soil structure, is a product of interactions between soil environment, management practices, and land use patterns. The objective of this study was to analyze the impact of various land use patterns on soil aggregate stability in Sichuan Basin of southwestern China. The dry- and water-stable aggregate size distributions were determined by manual dry sieving procedure and Yoder's wet sieving procedure, respectively, while microaggregates and its mechanical and chemical stabilities by Kachisky's method, oscillator method, and citrate-dithionate (C-D) reagent method, separately. The results indicated that fractal dimension and surface fractal dimension were useful indicators to reflect soil aggregate distribution. Land use patterns have an obvious influence on soil aggregate stability. In the study area, water stability, mechanical stability, and chemical stability followed the sequence, Barren landforestlandorchardcropland, and the original stability and collapse velocity were sensitive to soil properties and soil structure. The difference of aggregate stability under different land use patterns is mainly due to the intensity of human disturbance and cultivation. Improper land use patterns will lead to breakdown of unstable aggregates, producing finer and more-easily transportable particles and microaggregates. In the future, inappropriate cultivation and land use patterns should be changed to protect soil structure, to improve soil aggregate stability and soil fertility in Sichuan Basin. 相似文献
109.
110.
平面连续体多工况应力约束下结构拓扑优化的有无复合体方法 总被引:7,自引:1,他引:7
本文在[4]的基础上,按“有无复合体”模型对应力的约束下多工况平面连续体结构拓扑优化的求解进行研究,提出了“工况影响系数”的概念,用于“病态荷载”问题的识别的解决,获得了令人满意的数值结果。 相似文献