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1.
A sensitive catalytic method is developed for the spectrophotometric determination of oxalic acid. The procedure is based on the effect of oxalate on the oxidation of Victoria blue B by dichromate in dilute sulfuric acid medium. The reaction is quantitatively estimated by measuring the decrease in absorbance of Victoria blue B at the maximum wavelength of 610nm after quenching the reaction with tap water. The factors effecting the sensitivity and reproducibility of the reaction were studied. The method is not interfered with by foreign species generally associated with oxalate and oxalic acid. The described method is simple, specific, inexpensive and suitable for oxalic acid concentrations of between 0.06 and 9.0µgmL–1. It was validated with satisfactory results by determining oxalic acid content in water extracts from plant materials such as spinach and Lathyrus sativus.  相似文献   
2.
The metabolite profiling of saffron (Crocus sativus L.) from several countries was measured by using ultra-performance liquid chromatography combined with high resolution mass spectrometry (UPLC-HR MS). Multivariate statistical analysis was employed to distinguish among the several samples of C. sativus L. from Greece, Italy, Morocco, Iran, India, Afghanistan and Kashmir. The results of this study showed that the phytochemical content in the samples of C. sativus L. were obviously diverse in the different countries of origin. The metabolomics approach was deemed to be the most suitable in order to evaluate the enormous array of putative metabolites among the saffron samples studied, and was able to provide a comparative phytochemical screening of these samples. Several markers have been identified that aided the differentiation of a group from its counterparts. This can be important for the selection of the appropriate saffron sample, in view of its health-promoting effect which occurs through the modulation of various biological and physiological processes.  相似文献   
3.
LaIl{1Tussalivlts(L.salivus)isleguminouscropcultivatedinlndia,BangladeshandEthiopia,whereitisamajorproteinsourceforpeopleinthelowestincomegroups"'.However,excessiveingestionofthispulsecanleadtoirreversibleparalysisofthelegs-adiseaseknownasneurolathyrisn1orlathyrism.Thecausativeagentwasreportedtobethenon-proteinaminoacid,3-N-L-oxalyl-2,3-diaminopropioniacid(o-ODAP,sometimes,referredtoasBOAA)','.Thea-isomerofODAP,2-N-oxalyl-2,3-diaminopropionicacid,hasbeenshowntobenontoxictochicksandmice…  相似文献   
4.
在大田条件下,研究了重茬净、微生物菌剂、锦能菌宝、自制活性生物肥料4种不同微生物肥料对西红花产量、代谢物和根际微生物生态的影响。结果表明,与对照组相比,施用微生物肥料后,根际土壤中好酸性的细菌呈减少趋势,而嗜中性或碱性的细菌呈增加趋势,4种微生物肥料均能提高西红花有效球比例,表明增施微生物肥料具有缓解西红花连作障碍的功效。同时,增施重茬净、微生物菌剂、锦能菌宝和自制活性生物肥料分别引起2,3,3和13种代谢物含量上调和2,3,2和4种代谢物含量下调。  相似文献   
5.
Pickled radish (Raphanus sativus) is a traditional Asian ingredient, but the traditional method takes decades to make this product. To optimize such a process, this study compared the saponin content of pickled radishes with different thermal processing and traditional processes (production time of 7 days, 10 years, and 20 years) and evaluated the effects of different thermal processes on the formation of radish saponin through kinetics study and mass spectrometry. The results showed that increasing the pickling time enhanced the formation of saponin in commercial pickled radishes (25 °C, 7 days, 6.50 ± 1.46 mg g−1; 3650 days, 23.11 ± 1.22 mg g−1), but these increases were lower than those induced by thermal processing (70 °C 30 days 24.24 ± 1.01 mg g−1). However, it was found that the pickling time of more than 10 years and the processing temperature of more than 80 °C reduce the saponin content. Liquid chromatography–mass spectrometry (LC-MS) analysis showed that the major saponin in untreated radish was Tupistroside G, whereas treated samples contained Asparagoside A and Timosaponin A1. Moreover, this study elucidated the chemical structure of saponins in TPR. The findings indicated that thermal treatment could induce functional saponin conversion in plants, and such a mechanism can also be used to improve the health efficacy of plant-based crops.  相似文献   
6.
Three new thioglucosides, (4E)‐5‐{6‐O‐[(2E)‐3‐(4‐hydroxy‐3‐methoxyphenyl)prop‐2‐enoyl]‐β‐glucopyranosylsulfanyl}pent‐4‐enenitrile ( 1 ), (4E)‐5‐{6‐O‐[(2E)‐3‐(4‐hydroxy‐3,5‐dimethoxyphenyl)prop‐2‐enoyl]‐β‐glucopyranosylsulfanyl}pent‐4‐enenitrile ( 2 ) and its (4Z)‐isomer 3 , were isolated from the seeds of Raphanus sativus L. (radish), together with two known compounds. Their structures were determined by spectroscopic methods, including UV/VIS, 1D‐ and 2D‐NMR, FAB‐ and HR‐FAB‐MS experiments.  相似文献   
7.
建立高通量的高效液相色谱法同时检测15种西红花中非法添加色素,对于阳性样品采用液相色谱–质谱联用法确证。采用Poroshell 120 EC–C18色谱柱(100 mm×4.6 mm,2.7 μm)分离,以甲醇–0.02 mol/L乙酸铵溶液(用氨水调pH至5.9±0.05)进行梯度洗脱,流量为1.2 mL/min,柱温为35 ℃,以450 nm和500 nm双波长检测。缓冲盐pH值和流动相流量对色谱条件影响大,需严格控制。该方法重现性好,各物质分离度均大于1.5,标准曲线的线性相关系数r为0.998~1.000,样品高、中、低浓度的加标回收率为70.1%~93.1%,测定结果的相对标准偏差为1.2%~6.6%(n=6),检出限为0.01~0.05 mg/kg。该方法精密度良好,分析时间短,分析结果稳定,可用于中药材西红花中15种非法添加色素的快速筛查和含量测定,同时能为相关部门制定监督抽检中药材染色掺伪的补充检验方法。  相似文献   
8.
在大田条件下,研究了重茬净、微生物菌剂、锦能菌宝、自制活性生物肥料4种不同微生物肥料对西红花产量、代谢物和根际微生物生态的影响。结果表明,与对照组相比,施用微生物肥料后,根际土壤中好酸性的细菌呈减少趋势,而嗜中性或碱性的细菌呈增加趋势,4种微生物肥料均能提高西红花有效球比例,表明增施微生物肥料具有缓解西红花连作障碍的功效。同时,增施重茬净、微生物菌剂、锦能菌宝和自制活性生物肥料分别引起2,3,3和13种代谢物含量上调和2,3,2和4种代谢物含量下调。  相似文献   
9.
The expression of biosynthesis controlling genes of crocin and safranal in saffron (Crocus sativus) can be influenced by ultrasonic waves. Sterilized saffron corms were cultured in a ½-MS medium supplemented by 2-4-D and BAP. Saffron callus cells were treated with ultrasonic waves in a cellular suspension culture under optimal growth conditions. The samples were collected at 24 and 72 hours after treatment in three replications. The secondary metabolites were measured by high-performance liquid chromatography and the gene expression was analysed by the real-time polymerase chain reaction. Results indicate that this elicitor can influence the expressions of genes CsBCH, CsLYC and CsGT-2; the ultrasonic waves acted as an effective mechanical stimulus to the suspension cultures. The analysis of variance of the ultrasonically produced amounts of safranal and crocin indicates that there is a significant difference between once- and twice-treated samples in that the amount of safranal was the highest within the samples taken from the twice-treated suspension culture at 72 h after the ultrasound treatment, and the crocin was maximised after 24 h passed the twice-applied ultrasound treatment.  相似文献   
10.
At present, the development of new agri-food products, including flavored meat products presented in ready-to-eat vacuum packs, is encouraged. The addition of ingredients used as flavoring agents creates the need to be able to determine the volatile compounds responsible for their characteristic aroma. The aim of this study is to propose, develop, and validate a new method that uses headspace-stir bar sorptive extraction-gas chromatography/mass spectrometry (HS-SBSE-GC/MS) to determine the saffron aroma in cured ham flavored with this spice. Results showed that safranal was the main volatile compound that could be identified and quantified in cured ham flavored with saffron. This analytical method was adequate in terms of linearity, selectivity, sensitivity, and accuracy. To our knowledge, this is the first time that an HS-SBSE-GC/MS method for determining the saffron aroma of flavored cured ham has been developed and validated, and it is of interest to agri-food industries.  相似文献   
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