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991.
R. Menningen A. Steinemann et J. Rüfenacht 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1969,20(6):995
Sans résumé 相似文献
992.
W. Czysz F. Jancik W. Schmidt I. Helms R. H. S. et al. 《Fresenius' Journal of Analytical Chemistry》1989,335(5):508-512
AbstractsGeneral analytical chemistry
Inorganic analysis 相似文献993.
E. Svatek W. Czysz F. Jancik R. H. S. B. R. Glutz et al. 《Fresenius' Journal of Analytical Chemistry》1988,330(6):559-562
Referate2 Spezielle Produkte und Anwendungsgebiete
2.4 Umweltrelevante Matrices 相似文献994.
Small amounts of tungsten can be determined by atomic absorption spectrometry, after reduction with tin(II) and separation of the thiocyanate complex into methyl isobutyl ketone. The organic phase is aspirated into an acetylene-nitrous oxide flame There are no interferences from 1000-fold amounts of Zr or Cr(III), 200-fold amounts of U or Ti. 100-fold V or 10-fold Mo. Interference from large amounts of iron(III) is avoided by prior reduction. The method was successfully applied to the determination of tungsten in steels and zirconium alloys. 相似文献
995.
We prove that every finite undirected graph is a full subgraph of a rigid graph. Our construction proceeds on taking a family of “mutually rigid” graphs and attaching them to the vertices of a given graph in a one-to-one manner; then the vertices are fixed on their place. Actually, the new graph is “strongly rigid”, which enables us to show that the category of all graphs containing a given finite graph as a full subgraph is binding. 相似文献
996.
W. Schmidt W. Czysz E. Sebastiani F. Jancik B. R. Glutz et al. 《Fresenius' Journal of Analytical Chemistry》1988,332(5):496-500
Abstracts2 Particuler products and fields of application
2.6 Foods 相似文献997.
A maximum output power of 20.6 W at 2.825 μm from an erbium-doped all-fiber laser is reported, which we believe is the highest output power for this laser transition in single-mode operation. The slope efficiency of the passively cooled laser was up to 35.4% with respect to the absorbed pump power. Accounting for an estimated round-trip intracavity loss of 1.3 dB, we calculated a theoretical conversion efficiency of 39.5%, which is 15% higher than the Stokes efficiency of 34.3%. We believe this is the first experimental confirmation of the predicted pump energy recycling for this fiber laser. The narrow laser linewidth varied from 0.09 to 0.16 nm from low to maximum output power. 相似文献
998.
Réal A. Carbonneau Gilles CaporossiPierre Hansen 《European Journal of Operational Research》2011,212(1):213-222
Exact global optimization of the clusterwise regression problem is challenging and there are currently no published feasible methods for performing this clustering optimally, even though it has been over thirty years since its original proposal. This work explores global optimization of the clusterwise regression problem using mathematical programming and related issues. A mixed logical-quadratic programming formulation with implication of constraints is presented and contrasted against a quadratic formulation based on the traditional big-M, which cannot guarantee optimality because the regression line coefficients, and thus errors, may be arbitrarily large. Clusterwise regression optimization times and solution optimality for two clusters are empirically tested on twenty real datasets and three series of synthetic datasets ranging from twenty to one hundred observations and from two to ten independent variables. Additionally, a few small real datasets are clustered into three lines. 相似文献
999.
Maddouri Kamel Azzouzi Faiçal Triki Houria Bouguerra Abdesselam Amara Korba Sabiha 《Nonlinear dynamics》2021,103(3):2793-2803
Nonlinear Dynamics - We investigate the inhomogeneous higher-order nonlinear Schrödinger (INHLS) equation including cubic–quintic–septic (CQS) nonlinear terms and gain or loss with... 相似文献
1000.
通过抽样调查,了解重庆市环境缺碘地区居民的饮食习惯,分析了膳食因素对人群尿碘水平的影响,为制订地方性碘缺乏病综合防治措施提供依据.采用24 h膳食回顾法,对重庆市两县居民的膳食摄人情况进行现况调查,比较各营养素摄入量.结果表明,两地膳食结构属于东方膳食模式,璧山县各营养素摄入量高于云阳县.结论:蛋白质、能量、维生素等缺... 相似文献