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131.
SDH光通信设备工程测试 总被引:1,自引:0,他引:1
结合实际介绍了SDH光通信设备工程测试项目和测试方法,及相关的技术指标,包括平均发送光功率测试、接收机灵敏度测试、接收机过载功率测试、误码测试、抖动和漂移测试、定时同步测试、保护倒换测试、开销和维护信号测试、网管功能测试等。 相似文献
132.
Kerstin Skog Åsa Eneroth & Maria Svanberg 《International Journal of Food Science & Technology》2003,38(3):313-323
Hamburgers and chicken fillets were cooked in convection ovens, deep‐fried or contact fried and analysed for mutagenic activity using the Ames test. For the three different convection ovens, the cooking parameters studied included the presence of steam, air velocity, air temperature and holding time. For deep‐frying and contact frying, the cooking parameters included cooking temperature and cooking time. In cooked hamburgers, mutagenic activity was only detected in those that had been deep‐fried. In chicken fillets, mutagenic activity was detected in samples prepared with all cooking methods, being highest in the deep‐fried samples. Factorial analysis indicated that heat transfer was the most important factor affecting mutagenic activity. High temperature and high air velocity in the convection ovens enhanced mutagenic activity. The presence of steam reduced the mutagenic activity, except when high temperature was used in combination with high air velocity. In chicken fillets, high mutagenic activity correlated to high weight loss during cooking. Pan‐fried chicken fillets were analysed using high performance liquid chromatography (HPLC) and the mutagenic/carcinogenic heterocyclic amines 2‐amino‐3,8‐dimethylimidazo[4,5‐f ]‐quinoxaline (MeIQx), 2‐amino‐1‐methyl‐6‐phenylimidazo‐[4,5‐b]‐pyridine (PhIP) and the co‐mutagenic heterocyclic amine Norharman (9H‐pyrido[3,4‐b]‐indole) were identified. The HPLC fractions were tested for mutagenic activity and, apart from the mutagenic fractions corresponding to MeIQx and PhIP, several mutagenic fractions were detected that did not correspond to known heterocyclic amines. 相似文献
133.
2005年初,水电十四局承担了漫湾二期水电站和小湾水电站蜗壳的制造任务。蜗壳钢材选用国产600 MPa级别高强钢,为了全面综合地考核该级别钢种的材料强度和安全裕度,检验模拟大型蜗壳焊接制造工艺的可靠性。对国产的WDB620高强钢进行了可焊性和制造工艺性试验研究,并在国内首次设计、制造模拟压力容器并对其进行水压试验和爆破试验。研究成果通过中国水电集团公司鉴定,结论为该课题研究成果达到国内选进水平。 相似文献
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These studies investigated self-regulation and subjective experience of time from the perspective of the regulatory resource model. Studies 1-2 showed that participants who were instructed to regulate their emotions while viewing a film clip perceived that the film lasted longer than participants who did not regulate their emotions. In Study 3, participants provided time estimates during a resource-depleting or nondepleting task. Subsequent task persistence was measured. Time perceptions mediated the effect of initial self-regulation on subsequent self-regulated performance. In Study 4, participants performed either a resource-depleting or a nondepleting thought-listing task and then performed a different regulatory task. Compared with nondepleted participants, depleted participants persisted less on the 2nd task but estimated that they had persisted longer. Subjective time estimates statistically accounted for reduced persistence after depletion. Together, results indicate people believe that self-regulatory endeavors last overly long, a belief that may result in abandonment of further self-control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
138.
经对胜利油田近三年来典型井例测试资料分析评价及其增产措施效果分析认为,有三类地层压裂增油效果很好:地层物性相对较好的常压系统且存在严重堵塞的储层;物性较好的常压地层;高压低渗透储层。有两类地层酸化效果很好:灰岩、白云岩裂缝、低产低渗透储层;物性较好且存在严重污染堵塞的储层。其它地层压裂、酸化一般是无效的。 相似文献
139.
Patrick Musonda 《Computational statistics & data analysis》2008,52(4):1942-1957
Second-order expressions for the asymptotic bias and variance of the log relative incidence estimator are derived for the self-controlled case series model in a simplified scenario. The dependence of the bias and variance on factors such as the relative incidence and ratio of risk to observation period are studied. Small-sample performance of the estimator in realistic scenarios is investigated using simulations. It is found that, in scenarios likely to arise in practice, asymptotic methods are valid for numbers of cases in excess of 20-50 depending on the ratio of the risk period to the observation period and on the relative incidence. The application of Monte Carlo methods to self-controlled case series analyses is also discussed. 相似文献
140.
We report here a non-enzymatic detecting electrode strip for fast monitoring of uric acid in human whole blood. A single-use amperometric uric acid sensor strip, incorporating a three-electrode configuration, has been fabricated on a polypropylene substrate using low cost screen-printing (thick-film) technology. Both the working and counter electrodes were prepared by screen-printing commercial carbon ink. The integration on the same support of pseudo-reference electrode was obtained by screen-printing a commercial silver ink and subsequent electrochemical pretreatment. Simply by placing a 20 μl human whole blood drop on the strip is enough for uric acid analysis by square-wave voltammetry. Real human whole blood samples were analyzed by this method and compared to the phosphotungstic acid clinical test procedure with satisfactory results. 相似文献