市售饮用纯净水微生物污染状况检测与分析

对2009-2011年360份饮用纯净水进行检测。结果显示饮用纯净水总合格率为93.1%。影响饮用纯净水卫生质量的主要微生物指标为菌落总数，微生物合格率春冬季高于夏秋季。2009-2011年连续3年饮用纯净水微生物检测合格率呈上升趋势。     

Optimal intervention under stress scenarios: A case of the Korean financial system

We consider optimal intervention methods under budget constraints when financial systems face economic shocks. We propose two policies formulated by mixed-integer linear programs where regulators inject cash into institutions. One is to minimize systemic losses, and the other is to minimize the number of defaulting institutions. Using publicly available data on the Korean financial system, we construct its entire network and apply stress scenarios to the system to compare the performances of intervention strategies and derive insights on their workings.     

Catalytic Platinum Nanoparticles Decorated with Subnanometer Molybdenum Clusters for Biomass Processing

The development of improved technologies for biomass processing into transportation fuels and industrial chemicals is hindered due to a lack of efficient catalysts for selective oxygen removal. Here we report that platinum nanoparticles decorated with subnanometer molybdenum clusters can efficiently catalyze hydrodeoxygenation of acetic acid, which serves as a model biomass compound. In contrast with monometallic Mo catalysts that are inactive and monometallic Pt catalysts that have low activities and selectivities, bimetallic Pt–Mo catalysts exhibit synergistic effects with high activities and selectivities. The maximum activity occurs at a Pt to Mo molar ratio of three. Although Mo atoms themselves are catalytically inactive, they serve as preferential binding anchors for oxygen atoms while a catalytic transformation proceeds on neighboring surface Pt atoms. Beyond biomass processing, Pt–Mo nanoparticles are promising catalysts for a wide variety of reactions that require a transformation of molecules with an oxygen atom and, more broadly, in other fields of science and technology that require tuning of surface–oxygen interactions.     

Determination of tensile strength of UHMWPE fiber-reinforced polymer composites

Quasi-static tensile test of UHMWPE fiber-reinforced composite laminate is challenging to perform due to low interlaminar shear strength and low coefficient of friction. Tensile tests proposed in the literature were conducted and limitations associated with each method led to the evolution of a new method. Tensile test of single-ply was realized as the best representative of tensile strength of a composite than tensile test of UHMWPE laminate. A fixture was developed for single-ply tests which increased friction and provided the mechanical constraint to slipping. The fixture is easy to fabricate and has provided repeatable results for eight grades of UHMWPE fiber-based (0/90) fabrics. Reported tensile strengths are in quite high range of 900–1500 MPa.     

Measuring densities of polymers by magneto-archimedes levitation

In magneto-Archimedes levitation, a polymer can be levitated to a balanced position, and its levitation height is mainly related to the density of the polymer. Here, a novel method for measuring the density of polymers based on magneto- Archimedes levitation is proposed. For a designed measurement device, an equation can be fitted by a series of experiments with standard density glass beads. Then, the polymer's density can be calculated via the equation. In this paper, a device with magnets at a distance of 60 mm was chosen as an example. Experimental results showed that the proposed method could measure all types of polymer with an accuracy of 0.002–0.01 g/cm³. Moreover, the proposed method can clearly distinguish between polymers with small density differences (<0.03 g/cm³). Because of its high accuracy, high sensitivity, low cost and convenience, the proposed method could be widely used in polymer testing, especially in density-based testing.     

High frequency circular translation pin-on-disc wear testing of UHMWPE using a ball-on-flat contact along a hypotrochoidal track

To intensify experimental research within the field of orthopaedic tribology, a three-station, dual motion, high frequency (25.3 Hz) circular translation pin-on-disc wear test device was recently introduced. In the present study, the pins were CoCr with a spherical, polished bearing surface of 28 mm radius, whereas the flat discs were conventional UHMWPE. This configuration was intended to simulate the wear mechanisms of total knee prostheses. The number of wear cycles run was as high as 200 million. The mean wear rate was 0.35 mg per one million cycles (0.77 mg/24 h) which corresponded to a mean wear factor of 3.5 × 10⁻⁶ mm³/Nm. The study provided further proof that a wear test for orthopaedic implant materials can be accelerated by substantially increasing the cycle frequency, provided that the sliding velocity remains close to the values obtained from biomechanical studies. Hence, the moderate frictional heating will not lead to unrealistic wear mechanisms.     

喷泉测试技术的推广应用

随着国民经济和城市建设的迅速发展及人民生活水平的不断提高,水景喷泉得到了广泛应用,市场的推动使许多企业从事水景喷泉工程安装和相关产品的生产,现已形成了行业规模,并得到了较快的发展。介绍了喷泉的发展历史,阐述了喷泉测试技术的内容,列举了喷泉测试技术的推广成果。     

“商品理化检验”实践教学的探讨与尝试

《商品理化检验》是商检技术专业一门实验性和应用性很强的专业基础课,既涉及理化、生物等多学科的理论与技术,又涉及一些相关法律法规、国际惯例等知识。结合本课程的教学实际,对商品理化检验实践课教学中课程体系建设、教学内容、教学方法等环节进行了探讨与尝试,以保证教学质量。     

肇庆市城区中年女性体育锻炼特征分析

通过对肇庆市城区100名中年女性体育锻炼活动的目的、内容、时间、场所，频率等方面的情况进行调查研究．结果发现：肇庆市城区群众体育近年来发展比较快，也存在经费匮乏、场地不足、体育健身活动缺乏专业人员指导等问题。现对其进行综合分析，为肇庆市城区群众体育发展提供参考。     

浅谈高校实验技术队伍建设

分析了高校实验技术队伍现状，论述了高等教育发展对实验技术队伍的新要求。提出以创新观念为载体、以改革运行和管理模式为手段，全面加强实验技术队伍建设。