基于"互联网+"生物化学新教学模式的建立

The rapid development of internet technology has made the access to knowledge more convenient and diverse, which is both an opportunity and a challenge for traditional teaching methods. By analyzing and comparing the characteristics of four advanced teaching methods and techniques, and addressing the specific curriculum features and students' situation, a new mixed teaching model was constructed by Traditional Classroom Teaching Model (TCTM), Small Private Online Course (SPOC) and Flipping Classroom Model (FCM). The proportion of the three teaching methods was about 50%:35%:15%, respectively. By striving to combine their strengths and develop students' learning and reasoning ability gradually, the proposed mode achieved a satisfactory teaching effect.     

基于LabVIEW和PXI的某装备组合故障诊断系统设计

为了解决某装备电子组合故障诊断过程中诊断效率低的问题,设计并研制了基于LabVIEW软件和PXI总线技术的电子组合故障诊断系统。首先,采用PXI总线技术和多通道转换测试技术,将大量被测参数送到固定的测试点;其次,使用LabVIEW编程语言,将组合的所有被测参数一次性全部获取、储存与显示,并依据技术指标给出故障诊断结果和故障排除方法。实验结果表明,该系统具有数据获取快、测试效率高、故障诊断准等优点;经实践应用证明,该故障诊断系统操作简单、携带方便,是对某型装备电子组合进行测试和诊断的理想工具。     

Simultaneous determination of anthracyclines and taxanes in human serum using online sample extraction coupled to high performance liquid chromatography with UV detection

An online SPE‐LC method that can determine both anthracyclines and taxanes simultaneously in human serum samples is reported. The entire method of extraction, separation and UV detection was achieved online by column switching between an SPE column (Biotrap 500 (20×4 mm)) and an analytical column (Zorbax XDB C18, 150×4.6 mm, 5 μm) with a 23 min total cycle time. The method is linear (r²>0.998) over the range of 0.5–25 μg/mL. The analytes of interest are retained on the SPE column with good recovery (84–117%), while proteins and other serum components elute to waste. This online clean‐up is much faster (150 s) and less manual than traditional off‐line extraction methods. Using 0.1 mL spiked serum samples, the LOQ was 0.5 μg/mL. Intra‐ and inter‐day precision were acceptable (≤15% RSD) at and above the LOQ. The method was applied to the analysis of serum samples from patients undergoing chemotherapy with these agents.     

The structural evolution of an online discussion network

A discussion network is an important kind of social network, and it has been researched by many scholars in recent years. In this paper, we mainly studied its structural evolution based on an empirical study of a famous online discussion that happened in China in 2008. We found that the scale growth of the network shows an S shape, the degree distribution represents the power law in the first halfway, and the network shows a degree of disassortativity characteristic. We also classified the most active participants into different groups by their opinions and studied the structural evolution of opposite groups. It was observed that the evolution of nodes in each group were very similar, but the evolution of densities were obviously different. Specifically, we found that the most active participants preferred to converse with those belonging to the opposite groups at the beginning and tended to converse with anybody regardless of group as the discussion network grew. In the paper, these evolution patterns are revealed, and future lines of research are also considered.     

Multivariate curve resolution: a method of evaluating the kinetics of biotechnological reactions

In biotechnology, strong emphasis is placed on the development of wet chemical analysis and chromatography to separate target components from a complex matrix. In bioprocessing, the development of single compound biosensors is an important activity. The advantages of these techniques are their high sensitivity and specificity. Inline or online monitoring by means of spectroscopy has the potential to be used as an “all-in-one” analysis technique for biotechnological studies, but it lacks specificity. Multivariate curve resolution (MCR) can be used to overcome this limitation. MCR is able to extract the number of components involved in a complex spectral feature, to attribute the resulting spectra to chemical compounds, to quantify the individual spectral contributions, and to use this quantification to develop kinetic models for the process with or without a priori knowledge. After a short introduction to MCR, two applications are presented. In the first example, the spectral features of hemp are monitored and analysed during growth. MCR provides unperturbed spectra on the activity of, for example, lignin and cellulose during plant development. In a second example, the kinetics of a laccase enzyme-catalysed degradation of aromatic hydrocarbons are calculated from UV/VIS spectra.     

Mass spectrometric real-time monitoring of enzymatic glycosidic hydrolysis, enzymatic inhibition and enzyme complexes

The mass spectrometric development of an enzymatic assay resulting in enzymatic activity, its reaction pathway and its dissociation constant are described for the first time within a single experiment. The method combines the performance of a mass spectrometry-compatible enzyme assay with the direct detection of specific enzyme complexes using hen egg white lysozyme as a model. The continuous liquid-flow technique applied, when hyphenated with electrospray ionization (ESI)-time-of-flight (ToF)-mass spectrometry (MS), permitted the simultaneous detection of several substances involved in product screening as well as the direct observation of dissociation constants. Dissociation constants for the product inhibitor N, N', N'-triacetylchitotriose were calculated using a Scatchard plot (12 x 10(-6) M) and the law of mass action (18-24 x 10(-6) M), and these are in good agreement with constants obtained in earlier mass spectrometric (6-18 x 10(-6) M) or spectroscopic (6-8 x 10(-6) M) studies. Finally, the enzymatic hydrolysis of glycosidic substrate was monitored by ESI-ToF-MS in the presence of various inhibitors, thus leading to decreased activities in terms of their enzyme affinities. The associated inhibitor-enzyme complexes could be detected for up to lower micromolar K( d ) values.     

Online Ramsey games for triangles in random graphs

In the online F-avoidance edge-coloring game with r colors, a graph on n vertices is generated by randomly adding a new edge at each stage. The player must color each new edge as it appears; the goal is to avoid a monochromatic copy of F. Let N₀(F,r,n) be the threshold function for the number of edges that the player is asymptotically almost surely able to paint before he/she loses. Even when F=K₃, the order of magnitude of N₀(F,r,n) is unknown for r≥3. In particular, the only known upper bound is the threshold function for the number of edges in the offline version of the problem, in which an entire random graph on n vertices with m edges is presented to the player to be r edge-colored. We improve the upper bound for the online triangle-avoidance game with r colors, providing the first result that separates the online threshold function from the offline bound for r≥3. This supports a conjecture of Marciniszyn, Spöhel, and Steger that the known lower bound is tight for cliques and cycles for all r.     

clever or smart: Strategies for the online target date assignment problem

In this paper, we consider the Online Target Date Assignment Problem (OnlineTDAP) for general downstream problems, where the downstream cost are nonnegative, additive and satisfy the triangle inequality.We analyze algorithm smart, which was introduced by Angelelli et al. [3] and give its exact competitive ratio depending on the number of requests. Since the obtained competitive ratio is at most we answer the question posed in Angelelli et al. [4] if smart has a competitive ratio strictly less than 2.Moreover, we introduce a new algorithm called clever and show that this strategy has a competitive ratio of 3/2. We show that this is asymptotically optimal by proving that no online algorithm can perform better than 3/2−ε.     

基于集成学习的在线高维投资组合策略

文章结合机器学习中的交叉验证、在线学习和集成学习方法,对基于不同高维协方差估计量的投资策略权重进行动态组合,以获得优于传统投资组合策略的样本外表现.基于这一目标,文章对机器学习中比较前沿的在线加权集成(online weighted ensemble,OWE)算法的样本更新方式、学习模型和目标函数进行了替换和修改,改进后的mixed-OWE算法能够更好地适用于多组合的动态混合策略投资.通过数值模拟,文章将mixed-OWE应用在基于二次效用目标函数的投资问题上,结果表明其样本外表现优于传统静态方法.随后,文章进一步使用A股近10年的数据作为样本对mixed-OWE进行了全局最小方差组合投资,经过一定的参数调整后,mixed-OWE策略实现的组合方差优于其成分组合以及等权重组合.     

An adjustment scheme for nonlinear pricing problem with two buyers

We examine a contracting problem with asymmetric information in a monopoly pricing setting. Traditionally, the problem is modeled as a one-period Bayesian game, where the incomplete information about the buyers’ preferences is handled with some subjective probability distribution. Here we suggest an iterative online method to solve the problem. We show that, when the buyers behave myopically, the seller can learn the optimal tariff by selling the product repeatedly. In a practical modification of the method, the seller offers linear tariffs and adjusts them until optimality is reached. The adjustment can be seen as gradient adjustment, and it can be done with limited information and so that it benefits both the seller and the buyers. Our method uses special features of the problem and it is easily implementable.