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31.
The method of hydride generation atomic fluorescence spectrometry (HG-AFS) was optimised for determination of selenium in food supplements. Due to the high and varied content of Cu, Mg and Zn in the samples, the standard addition method was found to be the most appropriate. The reliability of the method was checked by the independent method of radiochemical neutron activation analysis, and good agreement was found between the two methods. HG-AFS is simple and rapid for Se determination in food supplements based on minerals. Agreement between the selenium values found and declared was worse than 10% in 9 out of 13 supplements. Furthermore, 2 of the 14 supplements did not comply with the recommendations stated in the 27th edition of the U.S. Pharmacopoeia, which states that minerals and vitamins in food supplements should be in the range of 90 and 200% of the declared value. 相似文献
32.
Proficiency testing involves the performance of test procedures on routine samples by a number of laboratories. Interlaboratory proficiency testings provide multiple benefits to participants since they play a key-role in the total quality control of laboratory activities. They serve as a means of self-improving, as a mechanism of continuing education and as a source of information for accreditation agencies. This review highlights basic principles, benefits, criteria and capabilities of a proficiency testing programme for food analysis laboratories as well as their role in the implementation of rapidly developing food control legislation. 相似文献
33.
高脂饮食对小鼠脂肪代谢和矿物元素代谢的影响 总被引:1,自引:0,他引:1
为探讨高脂饮食对小鼠脂肪代谢和矿物元素代谢的影响,用昆明(KM)小鼠24只,出生28 d后随机分成2组,各12只,分别给予高脂饲料与普通饲料,饲养至第9周眼球取血处死,取皮下、腹腔、肠系膜脂肪,毛,肝,血,计算体质量脂肪质量比,测定毛、肝、血中Zn、Ca、Cu、Mn、Mg、Fe含量。结果表明,高脂饮食小鼠体质量增加(P<0.05),单位腹腔脂肪及血Ch显著性增加(P<0.01)。肝Zn、Cu、Mg、Fe、Mn显著降低(P<0.01),血凝块Zn升高(P<0.05),Cu降低(P<0.05),毛Mg降低(P<0.05)。提示高脂饮食引起体质量与血脂增加,脂肪堆积,矿物元素代谢紊乱;不同器官矿物元素的代谢紊乱有差异,以肝脏最显著。 相似文献
34.
食品质量与安全是政府、食品行业以及消费者十分关注的问题。为了保证食品质量与安全,需要对食品中的风险因子进行检测。传统的分析方法如生物化学方法和仪器分析方法(色谱法、色谱-质谱法)存在前处理比较复杂,耗时,对样品具有破坏性及无法获取目标物空间信息等缺点。因此,开发快速,无损,实时和可视化的检测技术十分重要,这也是食品领域研究的热点。近年来,高光谱成像技术融合了成像和光谱两种技术,可以作为一种用于食品质量和安全评估的非破坏性和实时检测的工具。拉曼光谱成像技术可以同时获得待测物的光谱和空间信息,具有快速,无损和低成本等优点,在食品安全评价和质量控制中也得到了成功应用。质谱成像技术不需要标记和染色,即可实现样品组织表面待测物的可视化和高通量分析。它作为一种分子可视化技术,可以获得食品中营养成分及内、外源性有害物质的空间分布信息,在食品领域也表现出良好的应用前景。本文检索了近几年国内外发表的成像技术在食品研究中的相关文献,介绍了高光谱成像技术、拉曼光谱成像技术和质谱成像技术的原理,并综述了它们在食品安全与质量控制中的应用。此外,本文分析和讨论了这几种成像技术的优缺点,并对成像技术在食品领域的发展前景做出了展望。 相似文献
35.
36.
Piotr Ziba Agnieszka Skara Emilia Berna Agata Krakowska Katarzyna Sukowska-Ziaja Edward Kunicki Magorzata Suchanek Boena Muszyska 《Molecules (Basel, Switzerland)》2021,26(11)
The use of substrates supplemented with minerals is a promising strategy for increasing the nutraceutical value of Pleurotus spp. The current research was performed to analyze the effect of substrate supplementation with magnesium (Mg) salts on the Mg content, biomass, and chemical composition of pink oyster mushroom (Pleurotus djamor) fruiting bodies. Before inoculation, substrate was supplemented with MgCl2 × 6 H2O and MgSO4, both salts were applied at three concentrations: 210, 420, and 4200 mg of Mg per 2 kg of substrate. The harvest period included three flushes. Substrate supplementation with 4200 mg of Mg caused the most significant decrease in mushroom productivity, of about 28% for both Mg salts. The dry matter content in fruiting bodies was significantly lower in the treatment in which 210 mg of Mg was applied as MgSO4 in comparison to the control. Supplementation effectively increased the Mg content in fruiting bodies of P. djamor by 19–85% depending on the treatment, and significantly affected the level of remaining bioelements and anions. One hundred grams of pink oyster fruiting bodies, supplemented with Mg salts, provides more than 20% of the Mg dietary value recommended by the Food and Drug Administration (FDA); thus, supplementation can be an effective technique for producing mushrooms that are rich in dietary Mg. Although P. djamor grown in supplemented substrate showed lower productivity, this was evident only in the fresh weight because the differences in dry weight were negligible. Mg supplementation increased the antioxidant activity of the fruiting bodies, phenolic compounds, and some amino acids, including L-tryptophan, and vitamins (thiamine and l-ascorbic acid). 相似文献
37.
AbstractHerein the bioaccessibility of Mn, Cu, Zn, Cd, and Pb, selected from essential and toxic elements, was determined in commercially sold vegetable purees intended for infant and toddler consumption. Chemical fractionation studies using water, acetone, diethyl ether, chloroform:methanol, and n-hexane were employed to predict the importance of the protein and lipid parts of a matrix to assess the bioaccessibility data. In addition, in-vitro gastrointestinal digestion was performed to determine the bioaccessibility of the elements using a five level, three factor central composite design (CCD) to maximize the elemental solubility. The total elemental concentrations in all of the fractions were determined by inductively coupled plasma – mass spectrometry (ICP-MS). Based on the consumption of one jar of vegetable/rice-based baby food, Zn was 1.3% of the recommended dietary allowance and Mn was 4.2% of the adequate intake level, while Cu was almost 100% of the adequate intake level. Additionally, Pb was always below the detection limit and Cd was sometimes under the detection limit for the percent bioaccessibility. However, in some samples, Cd was as high as 80% of the tolerable weekly intake level depending on the body weight. 相似文献
38.
建立了一种同时检测塑料食品接触材料中13种紫外吸收剂的超高效合相色谱法。以甲醇为溶剂对塑料食品接触材料样品进行超声提取,经C18固相萃取柱净化,过0.22 μm有机滤膜,采用超高效合相色谱仪分析。选择ACQUTY UPC2 HSS C18 SB色谱柱(150 mm×3.0 mm,1.8 μm),以超临界二氧化碳为流动相,异丙醇为改性剂进行梯度洗脱,在最优色谱条件下,13种紫外吸收剂能够在4 min内实现有效分离。结果表明,在各自线性范围内,13种紫外吸收剂的线性关系良好,标准曲线相关系数不低于0.9985,检出限(S/N=3)为0.05~0.15 mg/kg,加标回收率为86.8%~115.7%,相对标准偏差为0.73%~5.61%。该方法快速简便,准确可靠,同时大大减少了有机溶剂的消耗,可用于塑料食品接触材料中13种紫外吸收剂的快速检测。 相似文献
39.
Hiroshi Iwase 《Analytica chimica acta》2002,463(1):21-29
Determination of small amounts of the fat-soluble species Vitamin A (VA) (2.5 μg/g) and β-carotene (9 μg/g) from emulsified nutritional supplements containing 50 kinds of co-existing compounds and a fat content between 2000 and 8000 times higher was performed by solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with fluorescence detection set at ex. 350 nm and em. 480 nm, and visible detection at 450 nm using an Inertsil ODS 80A (5 μm) analytical column. Mobile phases of methanol-ethanol (50:50) and acetonitrile-ethanol (70:30) were used for the both vitamins. A Bond Elut C18 cartridge was chosen for SPE after comparison with eight other types of SPE cartridge. Retention time of VA and β-carotene was 7 and 8 min, respectively, giving a limit of detection of ca. 0.1 ng per injection at a signal-to-noise ratio 3:1. Recoveries of VA and β-carotene were over 90% by the standard addition method. Relative standard deviation of VA and β-carotene were ca. 2.9 (n=5) and 2.3% (n=5), respectively. 相似文献
40.
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