A simple one-step PCR method for the identification between European and American razor clams species

A specific multiplex polymerase chain reaction (PCR) was applied to differentiate samples of razor clams Ensisarcuatus, Ensissiliqua, Ensisdirectus, and Ensismacha. Universal primers were used for the amplification of internal transcribed spacer 1 (ITS-1) in each species. The alignment of the obtained sequences was the basis for the specific design of species-specific reverse primers (ITSArSil-R, ITSDir-R, and ITSMa-R) located in the ITS-1 region. A multiplex PCR using each specific primer together with a common forward primer allowed identification of razor clam species by means of the different sizes of the species-specific amplicons separated in an agarose gel electrophoresis. This work provides a simple, reliable and rapid protocol for the accurate identification of Ensis species. The present methodology can be very useful for traceability of the species and to reinforce labelling regulations.     

三轴数控机床静态精度设计研究进展

国内三轴数控机床存在精度低和可靠性差的问题,而机床精度和可靠性可通过合理的静态精度设计方法得以保证.机床静态精度设计方法包括加工精度稳健设计方法和静态几何精度设计方法,针对两种精度设计方法的衔接合理性和工程应用实用性低的问题,在深入调研机床静态精度设计研究成果的基础上,从机床空间误差建模、平动轴几何误差元素辨识、关键几何误差元素溯源和加工精度稳健设计以及静态几何精度设计这5个关键问题着手,分别给出具体的解决方法,并形成一套完整的三轴数控机床静态精度设计系统实施方案,为完善机床几何精度设计和静态几何精度设计提供了参考.     

Optical measuring equipments. Part II: Measurement traceability and experimental study

Part II of this study is essentially an experimental development of the previously shown theoretical model. Based on the model for calibrating the “vision subsystem” developed in part I, an example of measuring and calculating uncertainties that ensures the traceability of the measurements is presented here. The Monte Carlo method is used as a tool for estimating uncertainties and the effectiveness of the proposed method is experimentally verified by measuring a calibrated line scale. Finally, the validity of the calibration parameters of the “vision subsystem” is determined.     

Quantifying impacts on the measurement uncertainty in flow calibration arising from dynamic flow effects

Traceability of the measurement units in fluid flow metering, as the state-of-the-art approach, is practiced as a so-called element-by-element method which relies upon the idealistic assumption that the measurement process in a flow calibration facility can be run under exact steady-state conditions, that is, absolutely no fluctuations of the flow quantities are assumed to occur during the flow measurement process. Practical experiences, combined with a model-based analytical view of the measurement process in a flow standard, have revealed that dynamic impacts on the measurement uncertainty due to flowrate fluctuations have to be taken into account, in addition to the steady-state traceability chain.     

爆炸物品示踪剂抗侵蚀试验研究

爆炸物品示踪技术是由我国自主研发的新技术,该技术的研发成功攻克了一项国际难题,填补了爆炸物品安全管控领域的一项技术空白,实现了对爆炸物品的跟踪、溯源、安检、打非等目标(其中包括炸后溯源),为爆炸物品安全管理提供了一种综合治理手段。该技术的核心是示踪剂,示踪剂的价值在于化学编码。为确保化学编码持久不变,化学稳定性是先决条件。分别用去离子水、0.1mol/L盐酸、1mol/L盐酸和硝酸铵水溶液,分别在120℃、110℃、100℃、90℃等温度条件下,对示踪剂进行侵蚀试验,以样品的特征荧光和特征谱图两个指标在侵蚀前后的变化情况作为依据,研究示踪剂的稳定性。试验结果表明,经侵蚀之后,示踪剂的特征荧光和特征谱图均无明显变化,说明示踪剂的稳定性优良。优良的稳定性为示踪剂的研发成功奠定了基础。     

Blockchain for trustworthy provenances: A case study in the Australian aquaculture industry

We explore the potential for a blockchain ledger to record supply chain provenances in an inherently trustworthy manner. The use of blockchain in this setting may allow for traceability of products through the supply chain without fear that an item’s provenance is fraudulent or has been tampered with. We compare the desirable properties of a blockchain ledger to those of a traditional database. We also consider challenges to the trustworthiness of a provenance idiosyncratic to the context of supply chains. We present a case study in which we conduct a series of semi-structured interviews with members of the prawn aquaculture industry in Australia. This industry was chosen as it stands to gain from robust provenances due to international competition. We find that blockchain based technology is unlikely to deliver substantial gains to the industry when compared to alternatives. Rather, most gains are likely to arise from the industry becoming digitalized, which would be a precondition for any blockchain technology to be operational.     

Geographic origin of meat—elements of an analytical approach to its authentication

This review article discusses recent analytical developments with respect to the determination of the geographic origin of raw meat. The main emphasis is laid on lamb, beef and poultry. So far, some methods have shown quite promising potential (e.g. stable isotope ratios, trace elements), others have remained unsatisfactory in their discriminating power to authenticate the geographic origin of meat (e.g. microbiological profile, sensory traits, volatile compounds). Other methods (e.g. animal genotype, gross chemical composition) could be auxiliary criteria as they help to determine related indicators such as feeding or housing conditions but not directly the origin. The complexity of this question is large. An integrated approach simultaneously addressing various species and production characteristics such as environment, animal husbandry conditions, breed, feeding and drinking water has to be developed. Strategies have to be different for global and micro-regional scales.     

Requirements Engineering-Based Conceptual Modelling

The software production process involves a set of phases where a clear relationship and smooth transitions between them should be introduced. In this paper, a requirements engineering-based conceptual modelling approach is introduced as a way to improve the quality of the software production process. The aim of this approach is to provide a set of techniques and methods to capture software requirements and to provide a way to move from requirements to a conceptual schema in a traceable way. The approach combines a framework for requirements engineering (TRADE) and a graphical object-oriented method for conceptual modelling and code generation (OO-Method). The intended improvement of the software production process is accomplished by providing a precise methodological guidance to go from the user requirements (represented through the use of the appropriate TRADE techniques) to the conceptual schema that properly represents them (according to the conceptual constructs provided by the OO-Method). Additionally, as the OO-Method provides full model-based code generation features, this combination minimises the time dedicated to obtaining the final software product.     

匿名代理签名方案的研究与改进

对谷利泽等提出的匿名代理签名方案进行密码学分析,指出该方案是不安全的,不能抵抗原签名人的伪造攻击和公钥替换攻击,并给出改进的匿名代理签名方案。改进的方案具有不可否认性,以及抵抗原签名人的伪造攻击和公钥替换攻击等优点。     

一个群签名方案的安全性分析与改进

最近陈少真等人提出了一种具有前向安全和有效撤销成员性质的群签名方案,该方案通过在签名中增加一个验证取消展示实现对成员的撤销。分析了陈方案设计的缺陷,给出了一种改进的成员撤销算法。在强RSA和离散对数假设下,证明了改进方案的有效性和安全性。