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71.
72.
为了了解玉米纤维纯纺纱捻系数、玉米纤维混纺纱混纺比对成纱强伸性能的影响,纺制了13种捻系数的18.2tex玉米纤维纯纺纱,不同混纺比例的18.2tex玉米纤维腈纶纤维混纺纱、玉米纤维大豆纤维混纺纱,测试了成纱断裂强力、断裂伸长率、断裂功及初始模量等强伸性能指标。结果表明:玉米纤维纯纺纱的临界捻系数在405.9附近;在玉米纤维腈纶纤维混纺纱中,随着玉米纤维含量从0增至100%,成纱强力呈非线性关系逐渐下降;对于玉米纤维大豆纤维混纺纱,随着玉米纤维含量的增加,成纱强力逐渐下降,当玉米纤维含量在90%左右时,强力处于最低谷,且低于玉米纤维纯纺纱。 相似文献
73.
Yanni Chen Dezhao Kong Liqiang Liu Shanshan Song Hua Kuang Chuanlai Xu 《Food Analytical Methods》2016,9(4):905-914
A sensitive class-specific monoclonal antibody against tetracyclines (TCs) was generated and used to develop an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic assay for TC, oxytetracycline (OTC), and chlortetracycline (CTC) detection in milk and honey samples. The dynamic range of detection for TC in ELISA was 0.26–2.00 μg L?1 with an IC50 of 0.72 μg L?1. The IC50 value of OTC and CTC was 3.2 and 6.4 μg L?1, respectively. The recovery of TC, OTC, and CTC in milk samples was 82–102, 91–105, and 90–101 %, respectively, and 88–101, 89–101, and 89–95 % in honey samples, respectively. In the immunochromatographic assay, the cutoff values for TC, OTC, and CTC were 15, 15, and 50 μg L?1 in milk, respectively, and 40, 40, and 40 μg L?1 in honey, respectively. The results revealed that ELISA and the immunochromatographic assay can be applied for the rapid and sensitive detection of TC, OTC, and CTC in milk and honey samples. 相似文献
74.
Xiangli Kong Stefan Kasapis Ping Zhu Zhongquan Sui Jinsong Bao Harold Corke 《International Journal of Food Science & Technology》2016,51(2):509-518
Fourteen hull‐less barley cultivars, collected from four major cultivated areas in China, were employed to investigate the structural and physicochemical properties of their starches in this study. Relatively wide variations in physicochemical properties of the starches were observed. Amylose content ranged from 23.1% to 30.0%, swelling power and water solubility index ranged from 12.8 to 19.9 g g?1 and 12.7% to 23.7% respectively. Peak viscosity was from 170 to 346 Rapid Visco Unit (RVU), peak temperature (Tp) of starch gelatinisation was from 55.6 to 61.8 °C and enthalpy of starch retrogradation ranged from 0.3 to 3.1 J g?1. Weight‐based chain‐length proportions of fa, fb1, fb2 and fb3 in amylopectins ranged from 21.65% to 24.95%, 44.48% to 49.44%, 15.56% to 17.19% and 9.83% to 16.66% respectively. Correlation analyses showed that amylose content was inversely related to pasting parameters and enthalpy of gelatinisation. Pasting properties and amylopectin structures were the most important parameters to differentiate starch properties among different hull‐less barley cultivars in this study. This work will be useful for exploring applications of Chinese hull‐less barley starches in food and non‐food industries. 相似文献
75.
小麦发芽过程中抑制根叶芽生长的研究 总被引:2,自引:0,他引:2
对氢氧化钠、甲醛、赤霉酸、溴酸钾等浸麦过程中的添加剂的添加量进行了研究,并将其对小麦芽的影响进行了比较。研究结果表明:氢氧化钠对于小麦芽生长的影响不显著,甲醛可以显著抑制根芽的生长,对叶芽的影响不显著;赤霉酸可以显著促进根芽和叶芽的生长,溴酸钾对小麦发芽有抑制作用。赤霉酸作为发芽促进剂的理想添加量为0.25ppm,采用甲醛(0.15%)与赤霉酸(0.25ppm)结合使用以及赤霉酸(0.25ppm)与溴酸钾(125ppm)结合处理,都可以在不影响麦芽溶解的情况下降低制麦损失2.0%左右。 相似文献
76.
不同前处理方法对花生粕酶解液中黄曲霉毒素含量的影响 总被引:1,自引:0,他引:1
研究了弱碱高温处理法、H_2O_2处理法和不同过滤介质去除黄曲霉毒素的效果。结果表明,弱碱高温处理对原料中的黄曲霉毒素有较好的去除效果,花生粕经过121℃,pH10,60min处理,黄曲霉毒素的破坏率高达84.5%,最终酶解上清液中黄曲霉毒素的含量为0.344ng/mL,达到欧盟安全标准;用H_2O_2处理,低浓度H_2O_2对于黄曲霉毒素的破坏很少,当浓度达到1600mg/kg,酶解上清液中的黄曲霉毒素达到0.104ng/mL,相对于不加H_2O_2处理的酶解上清液,其黄曲霉毒素减少率达94.87%,但高浓度的H_2O_2处理不利干酶解的进行;对于不同的过滤介质,以活性碳吸附去毒效果较好,但同时氨态氮的损失率高达7.03%。综合考虑实验的各方面因素,如成本问题以及脱毒后酶解的蛋白回收率和氨态氮含量问题,选择先在121℃,pH10条件下处理60min,酶解48h,然后用普通滤纸过滤进行脱毒处理,此时酶解上清液中的黄曲霉毒素达到0.244ng/mL。 相似文献
77.
Weijun Kong Cheng Jin Wei Liu Xiaohe Xiao Yanling Zhao Zulun Li Ping Zhang Xingfeng Li 《Food chemistry》2010
A reverse phase ultra-performance liquid chromatography coupled with evaporative light scattering detection (UPLC–ELSD) method was successfully established for simultaneous determination of five bile acid derivatives in Calculus Bovis and its medicinal preparations using a Waters Acquity UPLC T3 C18 column (2.1 × 50 mm, 1.8 μm) with gradient elution of 0.2% aqueous formic acid and acetonitrile. The influence of liquid flow-rate and column temperature, gas flow-rate and drift tube temperature on resolution was investigated to get the optimized parameters and conditions. This method was validated according to the regulatory guidelines with respect to precision, accuracy and linearity. Under optimum conditions, the five analytes were baseline separated in 11 min with detection and quantification limits ranged in 3.0–6.0 ng and 6.0–18.0 ng, respectively, which provided about a twofold reduction in analysis time and good efficiency and sensitivity by comparing a conventional high performance liquid chromatography (HPLC) method. 相似文献
78.
79.
The rate of photooxidation (lambda, 300-800 nm) of the polycyclic aromatic hydrocarbon chrysene was significantly enhanced in aqueous suspensions of the smectite clay, Laponite RD, relative to its rate of photolysis in aqueous solution. The photodegradation of chrysene is reported at pH 8.30, at several different ionic strengths that correlate to freshwater and saltwater. The kinetics of chrysene loss are first order in chrysene. The photodegradation products 1,4-chrysenediol, 1,4-chrysenequinone, phthalic acid, and 2-formyl benzoic acid have been positively identified and quantified against analytical standards. The mechanism of chrysene degradation was probed by comparing the effects of added methanol, bicarbonate, diazabicyclooctane, chloride, bromide, and iodide on the rate of chrysene photooxidation. Chrysene photooxidation was suppressed by diazabicylooctane and halide ions but was unaffected by methanol or bicarbonate, implying that 1O2 played a significant role in its removal. The overall rate of chrysene loss was governed by the salinity of the solution and the extent of surface coverage. The steady-state concentration of singlet oxygen was measured and varied positively with chrysene loading but was reduced dramatically at salinities comparable to the marine environment. The relative contributions of Cl-, Br-, and I- to the reduction in [1O2]ss are reported, with I- the most effective 1O2 quencher. The implication of the research is that photoprocessing of particle-bound PAHs may fall off as rapidly as they are transported into marine environments. A predictive kinetic model for the photodegradation of adsorbed chrysene is presented. 相似文献
80.