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Mass spectrometry (MS) is a formidable analytical tool for the analysis of non-polar to polar compounds individually and/or from mixtures, providing information on the molecular weights and chemical structures of the analytes. During the last more than one-decade, ambient ionization mass spectrometry (AIMS) has developed quickly, producing a wide range of platforms and proving scientific improvements in a variety of domains, from biological imaging to quick quality control. These methods have made it possible to detect target analytes in real time without sample preparation in an open environment, and they can be connected to any MS system with an atmospheric pressure interface. They also have the ability to analyze explosives, illicit drugs, disease diagnostics, drugs in biological samples, adulterants in food and agricultural products, reaction progress, and environmental monitoring. The development of novel ambient ionization techniques, such as probe electrospray ionization, paper spray ionization, and fiber spray ionization, employed even at picolitre to femtolitre solution levels to provide femtogram to attogram levels of the target analytes. The special characteristic of this ambient ion source, which has been extensively used, is the noninvasive property of PESI of examination of biological real samples. The results in the current review supports the idea that AIMS has emerged as a pioneer in MS-based approaches and that methods will continue to be developed along with improvements to existing ones in the near future.

Mass spectrometry (MS) has become an essential analytical method in every sector of science and technology. Because of its unique ability to provide direct molecular structure information on analytes, an extra method is rarely required. This review describes fabrication of a variable-pressure hollow cathode discharge (HCD) ion source for MS in detection, quantification and investigation of gas-phase ion molecule reactions of explosives and related compounds using air as a carrier gas. The HCD ion source has been designed in such a way that by altering the ion source pressures, the system can generate both HCD and conventional GD. This design enables for the selective detection and quantification of explosives at trace to ultra-trace levels. The pressure-dependent HCD ion source has also been used to investigate ion-molecule reactions in the gas phase of explosives and related compounds. The mechanism of ion formation in explosive reactions is also discussed.

According to the Report of Drug Situation in China (2020), the growth rate of the number of drug abusers in China has decreased, but the number of drug abusers is still large. An efficient screening method is necessary for controlling drug abuse. As an important type of biological sample, urine is widely used for the rapid screening of drug addicts. However, because of the complex composition, low content, and strong interference from the body's metabolism, the detection of drugs in urine remains a challenge. Traditional rapid screening techniques such as immunocolloidal gold analysis have a high false positive rate and insufficient quantitative capability. In addition, laboratory mass spectrometry methods require complicated time-consuming sample pre-processing and strict environmental conditions, and hence, are unsuitable for on-site rapid analysis. In recent years, various direct ionization mass spectrometry techniques such as direct analysis in real time (DART), desorption electrospray ionization (DESI), and dielectric barrier discharge ionization (DBDI) have advanced rapidly. These techniques have been applied to public safety, food safety, environmental detection, etc. In contrast to traditional ionization mass spectrometry methods, these direct ionization techniques allow for the

In product low-carbon design, intelligent decision systems integrated with certain classification algorithms recommend the existing design cases to designers. However, these systems mostly dependent on prior experience, and product designers not only expect to get a satisfactory case from an intelligent system but also hope to achieve assistance in modifying unsatisfactory cases. In this article, we proposed a new categorization method composed of static and dynamic classification based on extension theory. This classification method can be integrated into case-based reasoning system to get accurate classification results and to inform designers of detailed information about unsatisfactory cases. First, we establish the static classification model for cases by dependent function in a hierarchical structure. Then for dynamic classification, we make transformation for cases based on case model, attributes, attribute values, and dependent function, thus cases can take qualitative changes. Finally, the applicability of proposed method is demonstrated through a case study of screw air compressor cases.

In order to evaluate the quality of hardware products comprehensively and objectively, an evaluation model of extension multilevel optimization about hardware products has been established. The model was based on analyzing the quality management of hardware enterprises and took the hardware valve as an example. The solving process firstly used scale index and the first evaluation in restricting and reducing the scope of evaluation so as to improve solving efficiency. Then the values of correlation function, correlation degree, standard correlation degree and the optimization were calculated. Finally the comprehensive evaluation results could be got objectively through comparative analyzing these values. The results indicated that higher degree of satisfaction program would be obtained by applying the multilevel optimization evaluation method of product. And the products quality largely depended on its production stage. Thereby it aided the production managers to do the right choice.

Low-carbon performance as well as the quality and cost of a new product are normally emphasized in the early phase of low-carbon design for products. Although the TRIZ method and Extenics theory can be applied separately to solve contradiction problems in design field, these two methods have their weaknesses in applications. The purpose of this study is to provide a novel model for accelerating the preliminary low-carbon design by integrating the TRIZ and Extenics methods. Analysis tools and knowledge base tools of TRIZ are adopted to generate generic strategies; basic-element theory and dependent function of Extenics are used to qualitatively and quantitatively describe the conflict problem in a formalized model, and detailed transformation operations are employed to achieve the feasible design solutions. Innovative design schemes for two kinds of conflict problems of the screw air compressor demonstrate the effectiveness of the proposed method.

To quickly coordinate conflicts in product performance design, a transformation bridge method was proposed. Specifically, the design problems of performance conflicts were analyzed in terms of the quantification and collaboration. Based on the analysis, the mathematical models for conflict resolution and correlation function were developed. Thus the relationship between performance and design variables could be identified, and then used for searching similar cases from a repository. In addition, a core solution was developed by identifying the correlation among performance, combining the collaborative resolution method and case-based reasoning. The transformation bridge method was leveraging the extensibility of the basic-elements. Furthermore, the method for obtaining revised solutions was developed based on extension theory in particular the transformation operator and the cyclic transformation based on performance constraints, as the core of the approach to product performance optimization. The viability is evaluated in a case of screw air compressor design.

The conflict problem of performance have to be solved when optimizing the product performance design parameters, which weakens other performances because of the optimization of certain performance. Therefore an extension transformation method is put forward to research the conflict resolution. The conflict problem of performance design is analyzed with the new customer needs of product performance parameters and the structure change of product performance module. And project design description and formalized basic-element expression of conflict problem are done. Then the transformation rules between performance and structure feature are found out. The coupling correlation functions of multidimensional performance and comprehensive evaluation model of generated programs are established. Thus the resolution steps and process of conflict problems are given. Finally taking the oil chainsaw as an example, resolution process of the opposite problem among chainsaw vibration, stiffness and noise is analyzed. As proved, the method can effectively eliminate conflict problem of product performance. And it provides a reference method in solving other conflict problems in the design process.

Customer participation is common in cooperative design, which facilitates the understanding and addressing of customers’ requirements. Case-based Reasoning (CBR) is an effective method for quickly finding cases that may address customers’ requirements. The challenges for applying CBR to fulfill customers’ requirements at an early design stage include the complexity of requirements representation, the conflicts between different requirements, and the development of similarity measures for retrieval. This paper presents our work on the representation of both qualitative and quantitative requirements on product performance on the basis of fuzzy matter-element. On that basis, a similarity measure is developed using the side-distance in extension theory, to achieve accurate retrieval and effective conflict resolution. A case study of a screw air compressor is used to evaluate the proposed description method and the similarity measure. It is shown that the proposed methods are viable and effectively address the conflict resolution issue.

Traditional product data mining methods are mainly focused on the static data. Performance requirements are generally met as possible by finding some cases and changing their structures. However, when one is satisfied with the structures changed, the other effects are not taken into account by analyzing the correlations; that is, design conflicts are not identified and resolved. An approach to resolving the conflict problems is proposed based on propagation analysis in Extension Theory. Firstly, the extension distance is improved to better fit evaluating the similarity among cases, then, a case retrieval method is developed. Secondly, the transformations that can be made on selected cases are formulated by understanding the conflict natures in the different performance requirements, which leads to the extension transformation strategy development for coordinating conflicts using propagation analysis. Thirdly, the effects and levels of propagation are determined by analyzing the performance values before and after the transformations, thus the co-existing conflict coordination strategy of multiple performances is developed. The method has been implemented in a working prototype system for supporting decision-making. And it has been demonstrated the feasible and effective through resolving the conflicts of noise, exhaust, weight and intake pressure for the screw air compressor performance design.