Maintenance Scheduling with Delay-time Modelling: An Overview

Effective maintenance is a key for infrastructures′ high operational reliability. The integration of corrective repairs and schedule-based failure preventions has been a mainstream of modern maintenance, and an associated policy-making technique, delay-time modelling, is overviewedin this paper for optimising the maintenance cost-efficiency in different practical scenarios, including imperfect, opportunistic and nested maintenance. A few typical examples of its applications in minimising maintenance operating expenses are discussed in this paper and their results are explained to better demonstrate the benefits of the technique. This work aims to prepare for the future applications of the delay-time modelling in railway maintenance policy making.     

Single metal atom decorated photocatalysts: Progress and challenges

Photocatalysis has attracted intense attention due to its potential to solve the energy resource problem and environmental issues.The single metal atom decorated photocatalysts as a rising star become more and more popular because of the unique advantages of superior catalytic activities and ultrahigh atom utilization efficiency.The key function of single metal atom catalysts in photocatalytic reactions is boosting surface redox reactions by utilizing photogenerated charges,and has been verified by various spectroscopic and microscopic techniques.Nevertheless,the activities of the single metal atoms highly depend on the binding environment in the host photocatalyst that affect the adsorption and activation of reactants as well as the reaction energy barrier.Herein,this mini review summarizes recent progress on single metal atom decorated photocatalysts,and discusses the roles of the single metal atom catalysts in different types of host photocatalysts including organic,carbon-based and inorganic materials.The remaining challenges and future perspectives on the stability and activities of single atom catalysts in photocatalytic processes are elaborated in the end.We believe that this mini review will provide valuable overview on synthetic methods of different single atom photocatalysts for researchers towards future development of highly efficient photocatalysts.     

Steering the future

<正>Chinese President Xi Jinping affirms to push forward the implementation of national standardization strategy for harmonized and sustainable development in the long run.Standardization work has been stressed more than ever at the strategic level,so as to meet the new developmental needs ranging from industry,governance,environment,society and even the path to globalization.Strategy relates to the direction of the future and requires a conception of top-level     

FluidFM for single-cell biophysics

Fluidic force microscopy(FluidFM),which combines atomic force microscopy(AFM)with microchanneled cantilevers connected to a pressure controller,Is a technique allowing the realization of force-sensitive nanopipette under aqueous conditions.FluidFM has unique advantages in simultaneous three-dimensional manipulations and mechanical measurements of biological specimens at the micro-/nanoscale.Over the past decade,FluidFM has shown its potential in biophysical assays particularly in the investigations at single-cell level,offering novel possibilities for discovering the underlying mechanisms guiding life activities.Here,we review the utilization of FluidFM to address biomechanical and biophysical issues in the life sciences.Firstly,the fundamentals of FluidFM are represented.Subsequently,the applications of FluidFM for biophysics at single-cell level are surveyed from several facets,including single-cell manipulations,single-cell force spectroscopy,and single-cell electrophysiology.Finally,the challenges and perspectives for future progressions are provided.     

For the Grassroots Needs, For the Market Demand——Interview with CNIS President Ma Lincong

"Innovation driving,serving development",the theme of the national conference on standardization has been put forward in a very objective and timely manner,pointing out the direction for the standardization work of all aspects in the further.Innovation is definitely needed in the national standardization work. There has been a distinctive difference between China and foreign countries in respect of the standardization administration.Concretely speaking,the standardization work is administrated by governmental authority in China,i.e.uniformly managed by SAC and jointly undertaken by industrial standardization organizations of relevant ministries.     

Atomically dispersed N-coordinated Fe-Fe dual-sites with enhanced enzyme-like activities

Replacement of enzymes with nanomaterials such as atomically dispersed metal catalysts is one of the most crucial steps in addressing the challenges in biocataiysis.Despite the breakthroughs of single-atom catalysts in enzyme-mimicking,a fundamental investigation on the development of an instructional strategy is still required for mimicking biatomic/multiatomic active sites in natural enzymes and constructing synergistically enhanced metal atom active sites.Herein,Fe₂NC catalysts with atomically dispersed Fe-Fe dual-sites supported by the metal-organic frameworks-derived nitrogen-doped carbon are employed as biomimetic catalysts to perform proof-of-concept investigation.The effect of Fe atom number toward typical oxidase(cytochrome C oxidase,NADH oxidase,and ascorbic acid oxidase)and peroxidase(NADH peroxidase and ascorbic acid peroxidase)activities is systematically evaluated by experimental and theoretical investigations.A peroxo-like O₂ adsorption in Fe₂NC nanozymes could accelerate the O-O activation and thus achieve the enhanced enzyme-like activities.This work achieves the vivid simulation of the enzyme active sites and provides the theoretical basis for the design of high-performance nanozymes.As a concept application,a colorimetric biosensor for the detection of S^2- in tap water is established based on the inhibition of enzyme-like activity of Fe₂NC nanozymes.     

An Overview on SARS‑CoV‑2(COVID‑19)and Other Human Coronaviruses and Their Detection Capability via Amplification Assay,Chemical Sensing,Biosensing,Immunosensing,and Clinical Assays

A novel coronavirus of zoonotic origin(SARSCoV-2)has recently been recognized in patients with acute respiratory disease.COVID-19 causative agent is structurally and genetically similar to SARS and bat SARS-like coronaviruses.The drastic increase in the number of coronavirus and its genome sequence have given us an unprecedented opportunity to perform bioinformatics and genomics analysis on this class of viruses.Clinical tests like PCR and ELISA for rapid detection of this virus are urgently needed for early identification of infected patients.However,these techniques are expensive and not readily available for point-of-care(POC)applications.Currently,lack of any rapid,available,and reliable POC detection method gives rise to the progression of COVID-19 as a horrible global problem.To solve the negative features of clinical investigation,we provide a brief introduction of the general features of coronaviruses and describe various amplification assays,sensing,biosensing,immunosensing,and aptasensing for the determination of various groups of coronaviruses applied as a template for the detection of SARS-CoV-2.All sensing and biosensing techniques developed for the determination of various classes of coronaviruses are useful to recognize the newly immerged coronavirus,i.e.,SARS-CoV-2.Also,the introduction of sensing and biosensing methods sheds light on the way of designing a proper screening system to detect the virus at the early stage of infection to tranquilize the speed and vastity of spreading.Among other approaches investigated among molecular approaches and PCR or recognition of viral diseases,LAMP-based methods and LFAs are of great importance for their numerous benefits,which can be helpful to design a universal platform for detection of future emerging pathogenic viruses.     

Standardization innovation is the foundation for enterprises'''' globalization

Beijing Futon Environmental Protection Power Co., Ltd. (Beijing Futon) is a hi-tech company specialized in light-duty diesel oil/gasoline engines manufacturing and marketing jointly invested by Futon Automobile, Suweifu, Beijing Tractor Company. Main product portfolio of Beijing Futon includes 4JB1, 4Y and 4D24. Beijing Futon has full understanding on the vital importance of standardization for an enterprise's current and future development. By rescheduling and repositioning its standardization work, enhancing organizational consciousness of standardization, speeding up standard adoption and pro-active participating in national standard stipulation and amendment work, the standardization work in Beijing Futon has been further strengthened. All these measures mentioned above helped Beijing Futon in improving its product competitive power, eliminating technical barriers restricting its product export trade as well as making initial preparation for its brand and product approaching the world market.     

Deep-learning-based nanowire detection in AFM images for automated nanomanipulation

Atomic force microscope(AFM)-based nanomanipulation has been proved to be a possible method for assembling various nanoparticles into complex patterns and devices.To achieve efficient and fully automated nanomanipulation,nanoparticles on the substrate must be identified precisely and automatically.This work focuses on an autodetection method for flexible nanowires using a deep learning technique.An instance segmentation network based on You Only Look Once version 3(YOLOv3)and a fully convolutional network(FCN)is applied to segment all movable nanowires in AFM images.Combined with follow-up image morphology and fitting algorithms,this enables detection of postures and positions of nanowires at a high abstraction level.Benefitting from these algorithms,our program is able to automatically detect nanowires of different morphologies with nanometer resolution and has over 90%reliability in the testing dataset.The detection results are less affected by image complexity than the results of existing methods and demonstrate the good robustness of this algorithm.     

Building the International Testing and Certification Service for Lightning Protection Products

Lightning Protective Devices Testing Center affiliated to Shanghai Lightning Protection Center (hereinafter referred to as “Testing Center”) is a third-party technical institution specialized in the testing of lightning protection equipment,which has passed the qualification certification and metrology accreditation of Certification and Accreditation Administratin of the People's Republic of China and is approved by China National Accreditation Service for Conformity Assessment Meanwhile,it is also a lightning products quality inspection institution authorized by Shanghai Municipal Bureau of Quality and Technical Superwsion and the only lightning products testing laboratory authorized by China Quality Certification Center.The Center has always attached great importance to the standardization work,and accumulated rich successful experiences in enhancing the testing capability and technical service level by means of standardization.     

工程建设中理化检验实验室监督检查中的误区

针对不同监理人员在实际监理过程中对施工承包商实验室监督检查时出现的不同理解及误区进行了系统分析,提出了基本解决方法,并指出了如何针对不同实验室(如土建实验室、金属实验室以及一方检测实验室、二方检测实验室和第三方检测实验室)开展实验室的监督及管理工作。此种问题的解决,有利于工程建设的顺利进行,同时可规范监理人员的监理活动,提高监理效率。     

The EBIT Calorimeter Spectrometer: A New, Permanent User Facility at the LLNL EBIT

The EBIT Calorimeter Spectrometer (ECS) is currently being completed and will be installed at the EBIT facility at the Lawrence Livermore National Laboratory in October 2007. The ECS will replace the smaller XRS/EBIT microcalorimeter spectrometer that has been in almost continuous operation since 2000. The XRS/EBIT was based on a spare laboratory cryostat and an engineering model detector system from the Suzaku/XRS observatory program. The new ECS spectrometer was built to be a low maintenance, high performance implanted silicon microcalorimeter spectrometer with 4 eV resolution at 6 keV, 32 detector channels, 10 μs event timing, and capable of uninterrupted acquisition sessions of over 60 hours at 50 mK. The XRS/EBIT program has been very successful, producing many results on topics such as laboratory astrophysics, atomic physics, nuclear physics, and calibration of the spectrometers for the National Ignition Facility. The ECS spectrometer will continue this work into the future with improved spectral resolution, integration times, and ease-of-use. We designed the ECS instrument with TES detectors in mind by using the same highly successful magnetic shielding as our laboratory TES cryostats. This design will lead to a future TES instrument at the LLNL EBIT. Here we discuss the legacy of the XRS/EBIT program, the performance of the new ECS spectrometer, and plans for a future TES instrument.      

Corrosion Detection in Pipelines Using Infrared Thermography: Experiments and Data Processing Methods

This article summarizes the main results of an investigation about the corrosion detection in pipelines by infrared thermography, a non-destructive testing and evaluation technique that allows a reliable and fast analysis of large surfaces. The experimental work has been carried out in laboratory on a specimen that has been manufactured using a piece of a real pipeline system for oil transportation. Defects of different kinds have been artificially introduced in such a system to be tested by thermography. The objective is the detection and analysis of the presence of water in the pipeline jacketing system, that is the cause of the corrosion under insulation. Standards indicate thermography as a technique for the detection of this last phenomena, even though a precise procedure is not defined up today. This work aims at contributing in the specification of such a procedure.     

Serum creatinine detection by a conducting-polymer-based electrochemical sensor to identify allograft dysfunction

Kidney transplant recipients who have abnormally high creatinine levels in their blood often have allograft dysfunction secondary to rejection. Creatinine has become the preferred marker for renal dysfunction and is readily available in hospital clinical settings. We developed a rapid and accurate polymer-based electrochemical point-of-care (POC) assay for creatinine detection from whole blood to identify allograft dysfunction. The creatinine concentrations of 19 blood samples from transplant recipients were measured directly from clinical serum samples by the conducting polymer-based electrochemical (EC) sensor arrays. These measurements were compared to the traditional clinical laboratory assay. The time required for detection was <5 min from sample loading. Sensitivity of the detection was found to be 0.46 mg/dL of creatinine with only 40 μL sample in the creatinine concentration range of 0 mg/dL to 11.33 mg/dL. Signal levels that were detected electrochemically correlated closely with the creatinine blood concentration detected by the UCLA Ronald Reagan Medical Center traditional clinical laboratory assay (correlation coefficient = 0.94). This work is encouraging for the development of a rapid and accurate POC device for measuring creatinine levels in whole blood.     

Factors Affecting the Permanence of Occupational Health and Safety Topics in Engineering Courses

This paper presents an evaluation of the permanence of changes introduced within the curriculum of the College of Engineering at Tufts University. These changes involved the integration of occupational health and safety engineering resource materials into existing course work. Employing this model, Tufts faculty members developed their own lectures, case studies and laboratory materials for integration into existing courses. The evaluation, that was based on structured interviews of participating faculty and the Dean of the College, suggests that the permanence of changes to curriculum is influenced by a set of intramural parameters within the academic milieu (student interest, available class time, interest on the part of the faculty and administration) as well as by extramural factors such as the increasing prominence of legal liability of practitioners, growing interest on the part of employers and lack of readily usable materials in standard texts concerning occupational health and safety. Recommendations for future activities in these areas are offered and discussed.     

Digital workplace transformation in the financial service sector: Investigating the relationship between employees' expectations and intentions

Digital workplace transformation goes beyond the adoption or non-adoption of technologies – it has far deeper effects in the context of re-designing a workplace. Future digital work implies not only a change of tools used in work activities, but it also often changes the very nature of the working activities and processes. Psychological needs of employees are important in this context: the need for autonomy, competence, and relatedness which affect the employees' motivation to accept the future workplace. More specifically, if employees have expectations that digital environment will enable them to accomplish better performance, bigger satisfaction and personal well-being more easily, they will be more motivated to support digital transformation. Thus, in our study we aim to investigate whether employee involvement, well-being and support to digital work foster digital transformation of the workplace. In doing so, we close the existing gap in literature and confirm that interpersonal relatedness in digital work environment has a significant influence on employees' performance and well-being. This, in turn, increases employees’ intentions to support digital workplace transformation. We believe this study will help pre-digital organizations to rethink their strategies according to employee involvement to respond to the challenges of digital transformation. The study also encourages scholars to investigate whether and how those factors are shaped differently due to COVID-19 pandemic context.     

Droplet and Microchamber‐Based Digital Loop‐Mediated Isothermal Amplification (dLAMP)

Digital loop‐mediated isothermal amplification (dLAMP) refers to compartmentalizing nucleic acids and LAMP reagents into a large number of individual partitions, such as microchambers and droplets. This compartmentalization enables dLAMP to be an excellent platform to quantify the absolute number of the target nucleic acids. Owing to its low requirement for instrumentation complexity, high specificity, and strong tolerance to inhibitors in the nucleic acid samples, dLAMP has been recognized as a simple and accurate technique to quantify pathogenic nucleic acid. Herein, the general process of dLAMP techniques is summarized, the current dLAMP techniques are categorized, and a comprehensive discussion on different types of dLAMP techniques is presented. Also, the challenges of the current dLAMP are illustrated together with the possible strategies to address these challenges. In the end, the future directions of the dLAMP developments, including multitarget detection, multisample detection, and processing nucleic acid extraction are outlined. With recently significant advances in dLAMP, this technology has the potential to see more widespread use beyond the laboratory in the future.     

Development of alternative plasma sources for cavity ring-down measurements of mercury

We have been exploring innovative technologies for elemental and hyperfine structure measurements using cavity ring-down spectroscopy (CRDS) combined with various plasma sources. A laboratory CRDS system utilizing a tunable dye laser is employed in this work to demonstrate the feasibility of the technology. An in-house fabricated sampling system is used to generate aerosols from solution samples and introduce the aerosols into the plasma source. The ring-down signals are monitored using a photomultiplier tube and recorded using a digital oscilloscope interfaced to a computer. Several microwave plasma discharge devices are tested for mercury CRDS measurement. Various discharge tubes have been designed and tested to reduce background interference and increase the sample path length while still controlling turbulence generated from the plasma gas flow. Significant background reduction has been achieved with the implementation of the newly designed tube-shaped plasma devices, which has resulted in a detection limit of 0.4 ng/mL for mercury with the plasma source CRDS. The calibration curves obtained in this work readily show that linearity over 2 orders of magnitude can be obtained with plasma-CRDS for mercury detection. In this work, the hyperfine structure of mercury at the experimental plasma temperatures is clearly identified. We expect that plasma source cavity ring-down spectroscopy will provide enhanced capabilities for elemental and isotopic measurements.     

双酚A的检测现状及其发展趋势

目的对国内外双酚A的检测现状进行综述分析,总结双酚A检测技术的发展趋势,为双酚A的检测提供更多参考。方法对现有的双酚A检测方法,即大型仪器联用、电化学法、比色法、拉曼散射法及其主要检测机理进行阐述;分析和总结国内外对双酚A检测的最新研究成果;从高效安全的双酚A检测方法的建立及其应用性、准确性等方面指出今后的发展趋势。结果对于双酚A检测方法的建立已呈现多样化、精准化趋势,检测方法的简便性、快捷性有待进一步提高。结论总结现有检测方法的特点,对未来检测趋势作出合理预估。