Collection efficiency of liquid‐based samplers for fungi in indoor air

This study assessed the collection efficiency (CE) of two popularly used sampling devices (BioSampler and Coriolis sampler) for fungal aerosols. Phosphate‐buffered saline (PBS) supplemented with or without surfactant (Tween‐20, Tween‐80, or Triton X‐100) and antifoam agent was prepared and used as collection liquids. The agar impactor (BioStage) was simultaneously operated with liquid‐based samplers to collect fungi from seven sites located at a university building, public library, and animal farming. Fungal concentrations determined by liquid samplers were divided by those by BioStage, and the ratio values represented CE. Results indicate that the CE of BioSampler was superior to that of Coriolis (P = 0.0001) and the PBS containing surfactant collected fungi better than that without surfactant (P < 0.0001), whereas antifoam agent showed no influence (P = 0.8). Moreover, fungal concentrations determined by BioSampler with surfactant‐added PBS were statistically indifferent from those by BioStage (P > 0.05) with a Spearman correlation coefficient of 0.81‐0.83 (P < 0.01). In addition to sampler and collection liquid, sampling location was also identified as a significant CE factor (P = 0.006), implying potential influences by fungal genera in the studied fields. Overall, BioSampler with surfactant‐supplemented PBS (eg, Triton X‐100) is recommended considering the great CE and compatibility with a variety of analytical assays.     

基于DTW改进算法的孤立词识别系统的仿真与分析

传统的DTW算法在进行孤立词语音识别时着重于时间规整和语音测度的计算，而没有对数据的可靠性和有效性进行分析。本文提出了一种改进的端点检测算法，并采用一种改进的DTW算法，在计算机上进行了仿真。实验结果表明采用改进后的DTW算法有效的降低了识别时间和存储数据量，提高了系统性能。     

对等网络中的信息安全

近年来，对等网络得到迅速发展，其广泛应用促进了信息技术的发展，也带来了一系列的安全问题。介绍了对等网络中若干安全问题，并针对这些问题，分析并给出了相应的安全保障策略，最后对P2P中的信息安全问题的未来做了展望。     

七里北地区钻井工程地质特征及提高钻速的技术途径

七里北潜伏构造南邻渡口河、北邻铁山坡,这些构造均在飞仙关鲕滩钻获良好的天然气,具有很好的勘探前景。七里北1井钻探表明,该井在飞仙关地层获天然气80×104m3,但储层埋藏深度达5600m,且侏罗系地层的钻井工程地质条件与相邻构造有显著差异,钻井速度低和钻具事故多这两大问题突出,严重制约了探井钻井速度。认真分析了七里北1井的钻井工程地质特征,有针对性地提出提高飞仙关探井钻井速度的技术途径,有利于解决钻井工程面临的突出问题,对加快该地区飞仙关鲕滩气藏的勘探速度有着重要意义。     

没有SDC的(t，n)门限秘密共享方案

利用椭圆曲线离散问题对数问题的难解性,给出了基于椭圆曲线密码体制的(t,n)门限秘密共享方案。基于门限秘密共享方案一般分为需要SDC和不需要SDC两类,在分布式环境下,一个被所有成员信任的SDC并不存在,不需要SDC的门限秘密共享方案的安全性得到很大的提高,该方案中由组成员共同生成群公钥和私有密钥。并给出了当新成员加入时,无SDC下的周期密钥分片的更新方案。还给出了一个本方案数据实例,最后对本方案的安全性进行了分析。     

Simplification of the Plasma Load of Negative-Pulse-Bias Source Used in Arc Ion Plating

Based on the voltage and current fluctuating phenomenon in the arc plasma load under the negative-pulse-bias, usingthe plasma physics theory and analysis of computer simulation expatiates that the nature of plasma load in vacuumarc plasma is a capacitance     

运动饮料配方设计概论

运动中，人体生理发生一系列的变化，包括水分损失、血糖／糖原消耗、电解质损失等，导致运动中／后的疲劳和运动能力下降。以运动中人体生理特点为基础，通过讨论运动前／中／后补充水、碳水化合物及电解质的问题，论证了运动饮料配方设计的原理依据。     

介孔材料制备及研究进展

介孔材料是一类孔径分布在1．5～50nm之间的多孔材料，具有比表面积大，孔隙率高，孔径分布窄，孔排布有序的特点，在催化、分离等领域具有广阔的应用前景。综述了介孔材料近些年在制备、应用、机理等方面的最新进展与前景展望。