首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   229篇
  免费   35篇
工业技术   264篇
  2022年   1篇
  2021年   42篇
  2020年   10篇
  2019年   19篇
  2018年   13篇
  2017年   20篇
  2016年   11篇
  2015年   13篇
  2014年   13篇
  2013年   13篇
  2012年   19篇
  2011年   12篇
  2010年   15篇
  2009年   7篇
  2008年   14篇
  2007年   6篇
  2006年   9篇
  2005年   5篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2000年   1篇
  1999年   3篇
  1998年   3篇
  1992年   1篇
  1990年   2篇
  1989年   1篇
  1987年   2篇
排序方式: 共有264条查询结果,搜索用时 31 毫秒
41.
Total (non-fractionated) kernel proteins and the prolamin fraction (soluble in 75% ethanol) were extracted from oat (Avena sativa) var. Flämingstern kernel and from buckwheat (Fagopyrum esculentum) var. Kora kernel. As for buckwheat, extraction was effective only after kernel dehulling which allowed the removal of tannins and phenolic compounds that form complexes with proteins during extraction. The extracted proteins were analyzed using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Gels of the prolamin fractions of oat and buckwheat were used as reference gels in order to detect prolamins on gels of total kernel proteins. The occurrence of 26 and 29 spots corresponding to prolamins was found on gels of total oat proteins and on gels of total buckwheat proteins, respectively. The electrophoretic images of oat and buckwheat prolamins revealed organized subregions containing spots with similar isoelectric points (pI) and various molecular weights (MW), mostly on oat prolamin gels and spots of similar molecular weights with various isoelectric points, mostly on buckwheat prolamin gels. Such organized subregions can be used as identifiers for the occurrence of prolamin fractions in total proteins (particularly as regards buckwheat proteins).  相似文献   
42.
The formation of metal-encapsulated carbon nanomaterials by using metallic catalysts (iron, cobalt, and nickel) has been studied. Moreover, these materials were coated with silica surface modified by (3-Aminopropyl)-trimethoxysilane (APTS). Each intermediate structure was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The surface morphology of silica-coated carbon nanomaterials was analyzed by scanning electron microscopy (SEM). The modified, APTS–silica surface was additionally characterized by Fourier transform infrared spectroscopy (FT-IR), elemental (EA), and thermogravimetric analysis (TGA).  相似文献   
43.
44.
45.
The article concerns the optimization of the shape and location of non-circular passages cooling the blade of a gas turbine. To model the shape, four Bezier curves which form a closed profile of the passage were used. In order to match the shape of the passage to the blade profile, a technique was put forward to copy and scale the profile fragments into the component, and build the outline of the passage on the basis of them. For so-defined cooling passages, optimization calculations were carried out with a view to finding their optimal shape and location in terms of the assumed objectives. The task was solved as a multi-objective problem with the use of the Pareto method, for a cooling system composed of four and five passages. The tool employed for the optimization was the evolutionary algorithm. The article presents the impact of the population on the task convergence, and discusses the impact of different optimization objectives on the Pareto optimal solutions obtained. Due to the problem of different impacts of individual objectives on the position of the solution front which was noticed during the calculations, a two-step optimization procedure was introduced. Also, comparative optimization calculations for the scalar objective function were carried out and set up against the non-dominated solutions obtained in the Pareto approach. The optimization process resulted in a configuration of the cooling system that allows a significant reduction in the temperature of the blade and its thermal stress.  相似文献   
46.
A simple method, using permanent modifiers, has been developed for chromium (Cr) determination in food of plant origin by the slurry sampling graphite furnace atomic absorption spectrometry. In particular comparison of the action of Mg(NO3)2, iridium (Ir)/niobium (Nb) and iridium (Ir)/tungsten (W) was examined. Finally, for chromium determination in food, the mixture of 2 μg of Ir with 10 μg of Nb was used as permanent modifier. The analytical procedure was optimised carefully on the basis of the data from pyrolysis and atomisation temperature curves studies. The results obtained for four certified reference materials using external calibration with aqueous standards were in good agreement with the certified values. The precision and accuracy of Cr determination by the described method were also acceptable: the RSD were lower than 10% and recoveries for CRMs were in the range of 95-103%. The characteristic mass for chromium was determined to be 3.9 pg and the detection limit for the optimised procedure at the 0.75% (w/v) slurry concentration - 86.6 ng g−1.  相似文献   
47.
The elemental composition of honey is correlated with the botanical provenience of nectar, pollen, and honeydew that are collected and ripened by bees. In addition to this, the geographical origin related to the locality of an apiary, the soil composition, and climatic conditions may contribute to the origin of elements in honey. The environmental pollution or other anthropogenic processes and activities also have an effect on the quality and the safety of honey since they may be accompanying sources that lead to its contamination and the presence of various trace elements (Cd, Cr, Cu, Fe, Ni, Pb, and Zn). This review article covers the literature devoted to the analysis of honey carried out by the most popular and commonly utilized flame atomic absorption and emission spectrometry, which was published from 1999 to 2011. Various aspects of such analysis are treated in detail, including ways of the sample preparation, the calibration, and the quality assurance of results. In addition, methods and results related to the fractionation analysis of elements in honey by means of chromatographic and non-chromatographic approaches are described.  相似文献   
48.
The study of chemical composition and dough rheology changes in sieve‐classified two fractions (up to 60 and 60–240 μm particles) of wheat flour was the subject of this study. The straight grade flours were obtained by the milling of three Polish varieties of spring wheat, differing in ?? abbreviation? (PSI) values. The flours were separated with the use of a SZ‐1 laboratory sifter. The yield of fine fraction was in the range 50.0–55.7%. The obtained fractions were assayed for the content and composition of free lipids, gluten proteins, damaged starch, ash, water absorption and amylograph viscosity. Dough rheology (extrusion in OTMS cell, alveograph and farinograph tests) and baking trials were also performed. The content of free lipids, including the non‐polar and phospholipids was lower and the content of glycolipids was higher in fine flours. Those fractions were more rich in linoleic acid but the lower content of oleic and linolenic acids resulted in a higher oxidizability index of free lipids. Fine flours contained less ash and significantly more damaged starch. At the same time, they were characterized by a higher content of wet gluten, water absorption, amylograph viscosity and better dough parameters. This was reflected in the bread volume, which was higher by 6.3–10.7%. The influence of the changes in composition and the content of free lipids upon the rheology of the dough after the 90 days flour storage has not been defined unambiguously and requires further research.  相似文献   
49.
The aim of the work was to assess the impact of vegetable and spice addition on the acrylamide content and antioxidant activity of extruded cereal crisps. The foods were based on grain ingredients, such as brown rice, whole grain flour, wheat bran, with different vegetables. Products from one group contained green vegetables, such as broccoli and zucchini; garlic was included as a flavour additive (0.75–1.50%). The second group of crisps consisted of similar cereal ingredients with pumpkin and cinnamon; additionally ginger was included as a flavour additive (0.75–1.50%). The results indicate that the production of a new, innovative product with appropriate nutritional value and acceptable quality is a complex process. The production process significantly changed the nutritional value of the product. The content of acrylamide in zucchini and broccoli crisps was relatively low; ranging from 78 to 86 μg/kg of product. The addition of garlic did not significantly affect the acrylamide content in the final product. For cereal–pumpkin crisps, the acrylamide content was 7 times higher in comparison with zucchini and broccoli products. The acrylamide content in pumpkin and ginger crisps exceeded the benchmark level. The antioxidant activity of the pumpkin product was significantly higher (p < 0.05) than for crisps with green vegetables.  相似文献   
50.
Abscisic acid plays a pivotal role in the abiotic stress response in plants. Although great progress has been achieved explaining the complexity of the stress and ABA signaling cascade, there are still many questions to answer. Mutants are a valuable tool in the identification of new genes or new alleles of already known genes and in elucidating their role in signaling pathways. We applied a suppressor mutation approach in order to find new components of ABA and abiotic stress signaling in Arabidopsis. Using the abh1 (ABA hypersensitive 1) insertional mutant as a parental line for EMS mutagenesis, we selected several mutants with suppressed hypersensitivity to ABA during seed germination. Here, we present the response to ABA and a wide range of abiotic stresses during the seed germination and young seedling development of two suppressor mutants—soa2 (suppressor of abh1 hypersensitivity to ABA 2) and soa3 (suppressor of abh1 hypersensitivity to ABA 3). Generally, both mutants displayed a suppression of the hypersensitivity of abh1 to ABA, NaCl and mannitol during germination. Both mutants showed a higher level of tolerance than Columbia-0 (Col-0—the parental line of abh1) in high concentrations of glucose. Additionally, soa2 exhibited better root growth than Col-0 in the presence of high ABA concentrations. soa2 and soa3 were drought tolerant and both had about 50% fewer stomata per mm2 than the wild-type but the same number as their parental line—abh1. Taking into account that suppressor mutants had the same genetic background as their parental line—abh1, it was necessary to backcross abh1 with Landsberg erecta four times for the map-based cloning approach. Mapping populations, derived from the cross of abh1 in the Landsberg erecta background with each suppressor mutant, were created. Map based cloning in order to identify the suppressor genes is in progress.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号