扁藻细胞电镜观察的制样技术

以海洋单细胞微藻亚心型扁藻为材料 ,对海水水样中活体单细胞微藻的亚显微结构观察样品的制备技术进行了探索。选用 2 .5 %的戊二醛固定液和 1 %的锇酸固定液对样品进行双固定的技术 ;先酒精后丙酮按浓度梯度顺次进行脱水 ;再用Epon81 2环氧树脂作为包埋剂进行包埋 ;最后经过醋酸铀 -枸橼酸铅双染色后将切片用透射电镜进行亚显微结构的形态观察。采用本方法进行水样中活体样品的电镜制片 ,拍得清晰度较高的电镜照片 ,并通过照片对水样中运动细胞透射电镜样品制备技术进行了分析。     

铁矿石中微量铜的测定方法研究

现行的铁矿石中微量铜的测定方法,是用双环己酮草酰双腙(BCO)与Cu2+反应显色,然后进行吸光度测定.本法对已有的方法进行了改进:采用OH-离子沉淀去除Fe3+、A l3+,在pH值为8.5~9.3的环境下让Cu2+与BCO进行显色反应.研究证实:改进后的方法分析可靠,测定快速,能满足一般化验室对铁矿石中微量铜的测定需要.     

高校图书馆服务意识五大误区样态侧视

服务是高校图书馆立馆之本,也是图书馆最主要的工作,图书馆的生存与发展与自身提供的服务质量息息相关,但在我国高校图书馆实际服务过程中,总有一些偏离本身职能的现象出现,对这些普遍现象的理性分析与探讨,正是本文欲涉及的主要内容.参考文献4.     

中小型图书馆人力资源管理创新

本文针对中小型图书馆人力资源管理这一主题，论述了传统人事管理的现状、滞后的原因以及人力资源管理的内涵和对策。     

Impact Factors and the Central Limit Theorem: Why citation averages are scale dependent

Citation averages, and Impact Factors (IFs) in particular, are sensitive to sample size. Here, we apply the Central Limit Theorem to IFs to understand their scale-dependent behavior. For a journal of n randomly selected papers from a population of all papers, we expect from the Theorem that its IF fluctuates around the population average μ, and spans a range of values proportional to $\sigma /\sqrt{n}$, where σ² is the variance of the population's citation distribution. The $1/\sqrt{n}$ dependence has profound implications for IF rankings: The larger a journal, the narrower the range around μ where its IF lies. IF rankings therefore allocate an unfair advantage to smaller journals in the high IF ranks, and to larger journals in the low IF ranks. As a result, we expect a scale-dependent stratification of journals in IF rankings, whereby small journals occupy the top, middle, and bottom ranks; mid-sized journals occupy the middle ranks; and very large journals have IFs that asymptotically approach μ. We obtain qualitative and quantitative confirmation of these predictions by analyzing (i) the complete set of 166,498 IF & journal-size data pairs in the 1997–2016 Journal Citation Reports of Clarivate Analytics, (ii) the top-cited portion of 276,000 physics papers published in 2014–2015, and (iii) the citation distributions of an arbitrarily sampled list of physics journals. We conclude that the Central Limit Theorem is a good predictor of the IF range of actual journals, while sustained deviations from its predictions are a mark of true, non-random, citation impact. IF rankings are thus misleading unless one compares like-sized journals or adjusts for these effects. We propose the Φ index, a rescaled IF that accounts for size effects, and which can be readily generalized to account also for different citation practices across research fields. Our methodology applies to other citation averages that are used to compare research fields, university departments or countries in various types of rankings.     

建筑结构质量缺陷与质量事故界定

主要从理论上界定质量缺陷和质量事故，并探讨减少质量缺陷、避免质量事故之对策。     

Performance differences when using 26- and 29-inch-wheel bikes in Swiss National Team cross-country mountain bikers

The purpose of this study was to analyse the effect of bike type – the 26-inch-wheel bike (26“ bike) and the 29-inch-wheel bike (29“ bike) – on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26“ bike and three trials on a 29“ bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29“ bike (section A) or the 26“ bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes’ experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29“ bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29“ bike as better for performance in general, passing obstacles and traction. The 29“ bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26“ bike.     

军人症状自评量表测评的元分析

目的：整合军人症状自评测验的研究结果，探索普遍性结论。方法：通过中国期刊网搜索以SCL-90为工具对军人的调查研究报告，进行元分析。结果：以全国常模为对照组，平均效应值都大于0但较低，以军人常模为对照组，平均效应量都为负值，说明全国常模可能由于年代的原因略偏低、军人常模偏高；军人的精神病性因子分较高。结论：症状自评量表在我国被非常广泛地应用于正常人群，但仍存许多问题需要研究和规范。     

分光光度法测定海带中的碘

讨论了用Fe^2＋-邻二氮菲体系分光光度法间接测定海带中微量碘含量的方法。本实验以NH4Fe（SO4）2作为氧化剂，使用邻二氮菲作为显色剂，通过测得吸光度与Fe^2＋溶液浓度成线性关系，可间接测定海带提取溶液中I^-的浓度。该法具有准确度高，重现性好，简便快速的特点，是测定海带中微量碘的一种较理想的方法。     

Alterations in autonomic cardiac modulation in response to normobaric hypoxia

Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% F_IO₂). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnrMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO₂ occurred with reduced F_IO₂, along with a rise in heart rate (Cohen’s d?=?1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% F_IO₂. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% F_IO₂) decrease in lnTP (d?=?1.84 [1.74–1.94]), and SampEn (d?=?0.98 [0.83–1.12]) and an increase in DFA-α₁ (d?=?0.72 [0.60–0.84]) from normoxia at 9.8% F_IO₂. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ～9.8% F_IO₂ (～6000?m equiv.), below which significant alterations in autonomic control occur.