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为了揭示我国商业腐乳中生物胺存在形式和水平,采用丹磺酰氯柱前衍生结合高效液相色谱法(HPLC)对我国市售的20个品牌白方腐乳和20个品牌红方腐乳中的生物胺含量进行了分析。结果表明,我国市售的腐乳中存在的主要生物胺为酪胺、组胺、腐胺、色胺、β-苯乙胺和尸胺,其平均含量分别为73.7 mg/kg、43.7 mg/kg、38.5 mg/kg、27.7 mg/kg、5.4 mg/kg和5.4 mg/kg;每种生物胺在白方腐乳中的含量均显著高于红方腐乳(P<0.05),前者的酪胺、组胺、腐胺、色胺、β-苯乙胺和尸胺的平均含量分别为后者的1.6、1.9、3.4、3.3、2.3和3.0倍;且每种生物胺的水平在同一类型不同品牌腐乳之间均呈现高度差异化。  相似文献   
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Scombrotoxin fish poisoning remains the primary cause of seafood poisoning outbreaks despite preventive guidelines. The purpose of this study was to investigate the use of pH for the control of growth and histamine formation by histamine‐producing bacteria in fish muscle. We examined pH effects on growth and histamine formation in tuna fish infusion broth and in inoculated tuna and mahi‐mahi fish muscle. Histamine production was significantly less for all bacterial strains at pH 8.5 compared to pH 5.5 in tuna fish infusion broth with no significant difference in growth. Elevated pH due to phosphate treatment of fish muscle tissues significantly reduced histamine formation with no effect on the growth of histamine‐producing bacteria. This study revealed that phosphate treatment of mahi‐mahi and tuna fish muscle resulted in significantly lower histamine production over 4 d of storage at 10 °C. Phosphate treatment of fish muscle may serve as a secondary barrier in addition to FDA recommended time and temperature controls for reducing public health concerns of scombrotoxin fish poisoning.  相似文献   
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从鲭鱼体内分离7株生物胺产生菌,其中3株菌可以产生色胺,4株菌可以产生2-苯乙胺,4株菌可以产生腐胺,1株菌可以产生尸胺,3株菌可以产生组胺,1株菌可以产生酪胺。组胺生成量较高的No.1菌株形态学、生理生化分析及菌种鉴定结果表明该菌株极有可能为侵肺巴斯德氏菌,可信度为99.9%。  相似文献   
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根据GB/T 20768-2006鱼和虾有毒生物胺的测定原理,建立不确定度评定数学模型,评估该方法在分析过程中的不确定度来源,计算检测过程中引入的各个不确定度分量,并计算检测结果的合成不确定度和扩展不确定度。  相似文献   
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A novel 4-arm poly(ethylene glycol)-b-poly(disulfide histamine) copolymer was synthesized by Michael addition reaction of poly(ethylene glycol) (PEG) vinyl sulfone and amine-capped poly(disulfide histamine) oligomer, being denoted as 4-arm PEG-SSPHIS. This copolymer was able to condense DNA into nanoscale polyplexes (<200 nm in average diameter) with almost neutral surface charge (+(5–10) mV). Besides, these polyplexes were colloidal stable within 4 h in HEPES buffer saline at pH 7.4 (physiological environment), but rapidly dissociated to liberate DNA in the presence of 10 mM glutathione (intracellular reducing environment). The polyplexes also revealed pH-responsive surface charges which markedly increased with reducing pH values from 7.4–6.3 (tumor microenvironment). In vitro transfection experiments showed that polyplexes of 4-arm PEG-SSPHIS were capable of exerting enhanced transfection efficacy in MCF-7 and HepG2 cancer cells under acidic conditions (pH 6.3–7.0). Moreover, intravenous administration of the polyplexes to nude mice bearing HepG2-tumor yielded high transgene expression largely in tumor rather other normal organs. Importantly, this copolymer and its polyplexes had low cytotoxicity against the cells in vitro and caused no death of the mice. The results of this study indicate that 4-arm PEG-SSPHIS has high potential as a dual responsive gene delivery vector for cancer gene therapy.  相似文献   
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建立一种快速测定水产食品中组胺的丹磺酰氯柱前衍生反相高效液相色谱方法。该方法中样品经三氯乙酸 提取、丹磺酰氯衍生,C18反相色谱柱分离,以70%乙腈和30%超纯水为流动相进行等度洗脱,254 nm波长处紫外检 测。结果显示,组胺保留时间为5.5 min,组胺在1~500 μg/mL范围内线性系数为0.999 9,仪器检出限(RSN=3)为 0.5 μg/mL,定量限(RSN=10)为1.0 μg/mL,且重复性良好;采用该方法测定了16 种水产品和19 种水产加工食品中 的组胺,结果显示含量在0~682.22 mg/kg之间;样品添加不同质量浓度组胺的回收率为89.54%~101.92%。结果表 明,该方法快速准确、灵敏度高、重复性好,适用于水产食品中组胺的测定。采用该方法检测了鲣鱼、鲭鱼和蓝圆 鲹在不同温度条件下的组胺变化情况,结果发现,3 种鱼在低温贮藏条件下的组胺含量明显低于高温贮藏条件下的 含量,表明低温贮藏可有效抑制组胺产生。  相似文献   
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The profile of major biogenic amines was investigated in Indian mackerel packed in modified atmosphere for up to 12 days at 5 ± 1°C. Beheaded and gutted Indian mackerel was packed under different carbon dioxide compositions to study the effects on biogenic amines formation. The treatments were control air (C), vacuum packaging (VP), 30% CO2/65% N2/5% O2 (M30C), 60% CO2/35% N2/5% O2 (M60C), 80% CO2/15% N2/5% O2 (M80C) and 100% CO2 (M100C). Each amine responded differently to different CO2 levels. After 12 days of storage, concentrations of histamine were reduced by 6.4%, 8.5%, 70.3%, 78.8% and 90.2% in fish packed under VP, M30C, M60C, M80C and M100C, respectively as compared with control air. Changes in putrescine and cadaverine showed a similar pattern. Gas mix of M30C and VP stimulated the formation of tyramine reaching 203 and 172 ppm, respectively. Higher composition of CO2 had a significant inhibitory effect on tyramine concentration (p < 0.05). There were parallel increases of putrescine and spermidine in C, VP and M30C. No significant effect of CO2 was observed on spermine (p > 0.05). After 9 days of storage, more than 300 ppm of histamine was detected in mackerel packed in VP and M30C; therefore, these atmospheres pose a histamine intoxication risk. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
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为探讨葡萄糖对快速发酵虾头酱中组胺的抑制作用,提高其安全性,本论文以新鲜虾头为原料,采用外接微生物快速发酵工艺,分别向虾头酱中添加2%、4%和6%葡萄糖,检测了虾头酱发酵过程中组胺含量的变化。对虾头酱发酵期间的TVB-N含量、氨基酸态氮及pH的变化进行了探讨,通过比较理化指标、菌落总数以及感官评价分析虾头酱的品质。结果表明,葡萄糖的添加能显著降低组胺的生成,添加2%、4%和6%的葡萄糖分别能降低54.6%、57.2%和43.2%的组胺;葡萄糖的添加一定程度上促进了TVB-N的生成,增加了产品总糖含量以及降低了氨基酸态氮的含量和pH,但并不影响蛋白质、脂肪、水分及菌落总数的含量;感官评价表明,产品风味相似度较高,葡萄糖的添加能明显抑制产品的氨气味。因此,虾头酱中添加2%、4%和6%的葡萄糖能降低组胺含量以及减少氨气味,同时产品也保持较高的品质特性。  相似文献   
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