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排序方式: 共有29条查询结果,搜索用时 15 毫秒
1.
巴旦杏中脂肪酸的测定   总被引:5,自引:1,他引:4  
采用气相色谱仪进行定量分析,气-联质联用仪进行定性分析,巴旦杏中脂肪酸进行了测定,并探讨了样品处理方法和气-质联用仪的分析条件,得到了较为满意的分析结果。  相似文献   
2.
The adsorption of the antibiotic amoxicillin at low concentration levels (µg?L?1 order) from aqueous solution on almond shell ashes has been investigated, either by kinetic or equilibrium assays. The effect of the adsorbent amount, initial concentration of the antibiotic, particle diameter (dp) and temperature were considered to evaluate the adsorption capacity of the adsorbent. The results showed that amoxicillin sorption is dependent on these four factors. The adsorption process was relatively fast and equilibrium was established in about 12 hours. The optimum parameters for an initial concentration of 450?µg?L?1 were 50?mg of adsorbent, 303?K and dp?<?600?µm. A comparison of kinetic models showed that pseudo-second order kinetics provides the best correlation of the experimental data. Isotherm data adjusted better to Langmuir equation, with an adsorption capacity of 2.5?±?0.1?mg?g?1 at 303?K. The desorption process was also evaluated (maximum efficiency of 5%). Thermodynamic parameters were calculated and the negative value of ΔH0 and ΔG0 showed that adsorption was exothermic and a spontaneous process.  相似文献   
3.
本文以小鼠细胞SCE和微核率为指标评价了杏仁对抗肿瘤药环磷酰胺和遗传毒物3-甲基胆蒽诱变性的抑制效应,发现中药杏仁无致突变性,而且,对上述两种强诱变剂均有抑制作用。实验结果说明杏仁对突变具有一定和防护作用,并提示杏仁有望成为肿瘤化疗药物毒副作用的拮抗剂。  相似文献   
4.
底物中硅原子对苦杏仁醇腈酶催化不对称转氰反应的影响   总被引:1,自引:0,他引:1  
 对比研究了不同条件下苦杏仁醇腈酶催化乙酰基三甲基硅烷及其碳结构类似物3,3-二甲基-2-丁酮的转氰反应. 结果表明,苦杏仁醇腈酶催化乙酰基三甲基硅烷转氰反应的初速率及对映体选择性均高于其碳结构类似物在同一条件下的对应值. 动力学研究结果表明,苦杏仁醇腈酶催化乙酰基三甲基硅烷转氰反应的表观动力学参数为Km=27.12 mmol/L和vmax=7.05 mmol/(L·h),活化能为51.92 kJ/mol. 苦杏仁醇腈酶催化3,3-二甲基-2-丁酮转氰反应的表观动力学参数为Km=146.58 mmol/L和vmax=2.52 mmol/(L·h),活化能为75.04 kJ/mol. 根据硅原子的特性及酶反应机理合理解释了实验结果.  相似文献   
5.
用不同的不确定度分析方法对杏仁饼菌落总数检测结果进行了不确定度评定.并分别对检测结果给出合理取值范围.合并样本标准差的评定方法比单一样本平均值标准差评定方法实用性更强.更适合于每一个样本的检测结果.随着检测结果的不断增加.可随时加入到合并样本中.重新计算合并样本标准差.更新检测结果取值范围.  相似文献   
6.
To promote the application of almond expellers, sweet almond expeller globulin (amandin) was extracted for the preparation of bioactive peptides. After dual enzymatic hydrolysis, Sephadex G-15 gel isolation, reverse-phase high-performance liquid chromatography purification and ESI-MS/MS analysis, two novel peptides Val-Asp-Leu-Val-Ala-Glu-Val-Pro-Arg-Gly-Leu (1164.45 Da) and Leu-Asp-Arg-Leu-Glu (644.77 Da) were identified in sweet almond expeller amandin hydrolysates. Leu-Asp-Arg-Leu-Glu (LDRLE) of excellent zinc-chelating capacity (24.73 mg/g) was selected for preparation of peptide-zinc chelate. Structural analysis revealed that zinc ions were mainly bonded to amino group and carboxyl group of LDRLE. Potential toxicity and some physicochemical properties of LDRLE and Val-Asp-Leu-Val-Ala-Glu-Val-Pro-Arg-Gly-Leu (VDLVAEVPRGL) were predicted in silico. The results demonstrated that both LDRLE and VDLVAEVPRGL were not toxic. Additionally, zinc solubility of LDRLE-zinc chelate was much higher than that of zinc sulphate and zinc gluconate at pH 6.0–10.0 and against gastrointestinal digestion at 37 °C (p < 0.05). However, incubation at 100 °C for 20–60 min significantly reduced zinc-solubility of LDRLE-zinc chelate. Moreover, the chelate showed higher zinc transport ability in vitro than zinc sulphate and zinc gluconate (p < 0.05). Therefore, peptides isolated from sweet almond expeller amandin have potential applications as ingredient of zinc supplements.  相似文献   
7.
小白杏杏仁油的酶法提取及脂肪酸组成分析   总被引:2,自引:0,他引:2  
本文采用中性蛋白酶对新疆小白杏杏仁油脂进行了水解提取,并对提取油脂的脂肪酸组成进行了气相色谱分析。主要探讨了酶解pH值、温度、反应时间以及酶用量4个因素对油脂提取率的影响。研究表明:当中性蛋白酶用量为2000IU/g杏仁,酶解pH 7.5,温度60℃的条件下,酶解2.0h后,杏仁油脂总提取率达88.81%;杏仁油的气相色谱脂肪酸分析表明:小白杏杏仁油主要由不饱和脂肪酸组成,可达油脂总量的91.07%,其中主要为油酸和亚油酸,含量分别为40.92%和49.30%。  相似文献   
8.
甜杏仁中微量元素及氨基酸成分的分析   总被引:6,自引:0,他引:6  
用电感耦合等离子体发射光谱仪、氨基酸分析仪分别测定甜杏仁中的微量元素及氨基酸的含量,结果显示含有17种氨基酸,总量为27.259 g.100g-1,人体必需的八种氨基酸种类齐全,总量为8.691 g.100g-1;并含有多种人体必需的微量元素。  相似文献   
9.
A procedure for the pre-concentration of Cu(II), Fe(III), Mn(II) and Zn(II) is described utilising a minicolumn of natural cellulose (almond bark) modified with fungus (Rhizopus oryzae) prior to their determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). The optimum pre-concentration conditions such as pH and flow rate for the analytes have been investigated. The analytes were quantitatively retained on the column between pH 6 and 8. Elution was made with 10 mL 1 M HCl solution. Under the optimum conditions, recoveries were found as 97 ± 3%, 96 ± 3%, 98 ± 3% and 94 ± 2% for Cu(II), Fe(III), Mn(II) and Zn(II), respectively, at 95% confidence level. The detection limits obtained from preconcentration of 50 mL of blank solutions (n = 11) were 1.6, 1.8, 2.8 and 1.2 µg L?1 for Cu(II), Fe(III), Mn(II) and Zn(II), respectively. Relative standard deviations (RSD) of the recoveries for five replicate analyses were lower than 3%. The proposed method was validated by analysing certified reference materials (Peach Leaves SRM 1547 and Fish Tissue IAEA-407). Determination of the Cu(II), Fe(III), Mn(II) and Zn(II) in K?z?l?rmak River water, green beans, beans leave and tomato leaves and fish (Tinca tinca) tissue samples was performed by the proposed method.  相似文献   
10.
原子荧光光谱法测定野生杏仁中的微量硒   总被引:2,自引:0,他引:2  
用原子荧光光谱法测定野生杏仁中的微量硒,对酸度、还原剂浓度等条件进行了试验。硒含量在0~10μg/L内与原子荧光强度线性相关,线性方程为Y=16.03X 36.28,相关系数r=0.9998,硒的的检出限为0.5μg/L,加标回收率为95%~105%,测定结果的相对标准偏差(n=6)小于5.0%。  相似文献   
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