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排序方式: 共有61条查询结果,搜索用时 15 毫秒
1.
Ovshinsky SR Young RT Allred DD DeMaggio G Van der Leeden GA 《Physical review letters》1987,58(24):2579-2581
2.
This document reviews the most relevant mass spectrometry approaches to selenium (Se) speciation in high-Se food supplements in terms of qualitative and quantitative Se speciation and Se-containing species identification, with special reference to high-Se yeast, garlic, onions and Brazil nuts. Important topics such as complexity of Se speciation in these materials and the importance of combining Se-specific detection and molecule-specific determination of the particular species of this element in parallel with chromatography, to understand their nutritional role and cancer preventive properties are critically discussed throughout. The versatility and potential of mass spectrometric detection in this field are clearly demonstrated. Although great advances have been achieved, further developments are required, especially if speciatedcertified reference materials (CRMs) are to be produced for validation of measurements of target Se-containing species in Se-food supplements. 相似文献
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种植沙生植物--沙棘改善内蒙古地区生态环境 总被引:2,自引:0,他引:2
结合内蒙古地区现状,对沙棘的生物学和生态学特性、沙棘属植物化学成分和微量元素及种植沙生植物——沙棘的重要性和必要性进行了详细的研究和探讨。研究表明,沙棘属植物具有极强的生态适应性并富含多种营养成分和生物活性物质,并以耐干旱、耐瘠薄、萌蘖及固氮能力强等特点被称为治理非宜林地水土流失、改善生态环境的先锋树种。种植沙棘是治理内蒙古脆弱生态环境最经济、最有效的措施,是贫瘠的不毛之地发展经济、增加收入的经济树种。另外.种植沙棘的技术简便,容易掌握,投资少,见效快。 相似文献
6.
以内蒙古地区沙棘果实为原料,研究了提取黄色素的工艺条件,同时对该色素的性质进行了初步探讨。结果表明,以95%的乙醇溶液作浸提剂,提取的黄色素浓度最高,工艺流程简单易行,且无毒,无污染。对提取的黄色素进行的性质试验表明,沙棘黄色素对光、热具有较好的稳定性,适用于酸性或弱碱性的食品中,葡萄糖、氧化剂(H2O2)、还原剂(Na2SO3)等食品添加剂均无明显影响以上结果为这种优良天然色素的开发与应用提供了参考。 相似文献
7.
Schmidt KS Filippov DV Meeuwenoord NJ van Der Marel GA van Boom JH Lippert B Reedijk J 《Angewandte Chemie (International ed. in English)》2000,39(2):375-377
Cross-linking ability is possible with the oligonucleotide-tethered, monofunctional trans-Pt(II) complex shown. It was synthesized by a novel solid-phase approach comprising conjugation of immobilized tetrathymidylic acid with a trans-a(2)Pt(II) building unit, ammonolysis, and transformation of the resulting complex (R=1-N-cyclohexylmethylthyminate) into the chloro derivative (R=Cl). a=NH(2)CH(3), T=thymine. 相似文献
8.
José M. Goenaga Ana Gayol Raquel G. Concha Miguel Iglesias José M. Resa 《Monatshefte für Chemie / Chemical Monthly》2007,138(5):403-436
Summary. Speeds of sound, densities, and refractive indices of the binary mixtures containing ethanol+(2-methyl-1-propanol, 2-methyl-1-butanol,
1-pentanol, or 3-methyl-1-butanol) were measured at 288.15 ≤ T/K ≤ 323.15 and atmospheric condition in the whole compositional range. The effect of temperature was analyzed by several
chemical terms. 相似文献
9.
M. C. Louzao A. Alfonso A. G. Cabado A. M. Botana X. Goenaga M. R. Vieytes L. M. Botana 《Fresenius' Journal of Analytical Chemistry》1994,349(6):465-468
The gonyautoxin group is the major component in mussels contaminated by paralytic shellfish poison in red tides from the west coast of Spain. This study describes the stability of the gonyautoxins stored at different temperatures in acidic solution. The toxins were extracted from contaminated mussels Mytilus galloprovincialis Lmk and purified through BioRex 70. The stability of the gonyautoxins was analyzed by high-performance liquid chromatography. The experiments demonstrated that gonyautoxin 6 is the most unstable toxin in any condition and at temperatures lower than 4°C there is no important change in the other toxins in the first year of storage. At temperatures higher than 0°C, gonyautoxin 2 and gonyautoxin 3 were the most stable of the gonyautoxin group. The results indicate that, at least without further manipulation, these toxins can be safely stored in acidic conditions at low temperatures. 相似文献
10.
When a time harmonic electromagnetic wave impinges on a slaba certain portion of the wave creates heat within the slab throughdipolar and ohmic heating. The electrical and thermal propertiesof the material dictate the dynamical nature of the heatingprocess, as well as the steady-state temperature profile. Thematerial considered here is a slab of fluid. We consider thecase where the fluid is bounded by thin rigid layers of transparentmaterial. The steady-state heating profile governs the typesof convective motions that can occur and also affects the stabilitycharacteristics of temperature, pressure and velocity perturbationsintroduced in the slab. The main objective here is to examinesuch stability characteristics, initially in the linear regime.Both rigid-rigid and rigid-free configurations are considered. 相似文献