Research Progress of Detection Methods for Microplastics

Microplastics are plastic particles or fibers with a diameter of less than 5 mm,and they widely exist in the environment and pose potential risks to the ecosystem and human health.Microplastics detection can provide basic data for formulating effective environmental protection strategies.In this paper,the physical,chemical and biological detection methods of microplastics are reviewed,and the advantages and disadvantages of different methods are analyzed.The problems and challenges encountered in microplastics detection are analyzed,and the future research is discussed.

One-step green method to prepare progressive burning gun propellant through gradient denitration strategy

Gradiently denitrated gun propellant(GDGP)prepared by a“gradient denitration”strategy is obviously superior in progressive burning performance to the traditional deterred gun propellant.Currently,the preparation of GDGP employed a tedious two-step method involving organic solvents,which hinders the large-scale preparation of GDGP.In this paper,GDGP was successfully prepared via a novelty and environmentally friendly one-step method.The obtained samples were characterized by FT-IR,Raman,SEM and XPS.The results showed that the content of nitrate groups gradiently increased from the surface to the core in the surface layer of GDGP and the surface layer of GDGP exhibited a higher compaction than that of raw gun propellant,with a well-preserved nitrocellulose structure.The denitration process enabled the propellant surface with regressive energy density and good progressive burning performance,as confirmed by oxygen bomb and closed bomb test.At the same time,the effects of different solvents on the component loss of propellant were compared.The result showed that water caused the least component loss.Finally,the stability of GDGP was confirmed by methyl-violet test.This work not only provided environmentally friendly,simple and economic preparation of GDGP,but also confirmed the stability of GDGP prepared by this method.

Application of the catastrophe progression method in predicting coal and gas outburst

Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.

Numerical analysis of downward progressive landslides in long natural slopes with sensitive clay

Landslides occurring in sensitive clay often result in widespread destruction,posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation.Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms.While studies have extensively explored upward progressive landslides in sensitive clays,understanding downward progressive cases remains limited.In this study,we utilised the nodal integration-based particle finite element method(NPFEM)with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes,induced by surcharge loads near the crest.We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strainsoftening characteristics.The simulation results revealed the typical pattern for downward landslides,which typically start with a localised failure in proximity to the surcharge loads,followed by a combination of different types of failure mechanisms,including single flow slides,translational progressive landslides,progressive flow slides,and spread failures.Additionally,inclined shear bands occur within spread failures,often adopting distinctive ploughing patterns characterised by triangular shapes.The sensitive clay thickness at the base,the clay strength gradient,the sensitivity,and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement.Remarkably,some of these effects mirror those observed in upward progressive landslides,underscoring the interconnectedness of these phenomena.This study contributes valuable insights into the complex dynamics of sensitive clay landslides,shedding light on the intricate interplay of factors governing their behaviour and progression.

Research Progress and Identification Method of Apple Stress Resistance

In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.

Research Progress in Occupational Health Risk Assessment Methods in China

Traditional occupational disease control and prevention has remained prevalent in China over recent decades. There are appropriately 30,000 new case reports of occupational diseases annually. Although China has already established a series of occupational disease prevention programs, occupational health risk assessment （OHRA） strategies continue to be a limitation.

Present state,basic theories,methods and progresses of investigation and assessment on marine hazardous geology in China

The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and present-day studies of marine hazardous geology, a newly developing branch of geoscience, are well expatiated. Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations, assessment of marine hazardous geology, as well as its evolution, innovation, existing questions and future tasks are also introduced and presented. The concepts of 'hazard geology', geohazard', 'map of marine hazard geology', 'integrated evaluaton on seafloor stablity' are respectively discussed, including their definition, research objects, methods and contents. The types and classification of marine hazardous geology, principles and methods of marine hazardous geology map compilation, the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed.

The Application of Layered Progressive Teaching Method in Nursing Teaching of Health Management Centre

Objective:To explore the clinical effect of the layered progressive teaching method in the process of nursing teaching in the health management centre.Methods:100 nursing students in the health management centre of our hospital were randomly divided into two groups from April 2018 to April 2019,in which students of the control group were treated with routine teaching,while those of the experimental group were treated with layered progressive teaching.Then,the teaching effect of the two groups was compared and analysed.Results:The assessment results of nursing students in the two groups were compared,in which the theoretical knowledge scores and practical operation scores of nursing students in the experimental group were(94.34±2.33)and(90.45±2.20)respectively.By contrast,the score of students in the control group was lower and the difference between the two groups was not significant(P<0.50).The teaching effect of students in the experimental group is more significant.Conclusion:During the process of nursing teaching in the Health Management Centre,the progressive teaching method showed a significant clinical effect and could effectively enhance students’scores.Therefore,it is positively significant for clinical development.

“Inverse Projection Method”Model in DEA to Measure Technological Progress

In view of the problems in measuring technological progress by DEA model, premias for DEA application is analyzed in this paper. An extended model of DEA is also raised for the cases running counter to the premisess. And precision about the results of the two models is analyzed.

Progress in Determination Methods of Degradation Rate in Ruminants

Degradation rate of feed proteins in rumen is a basic indicator of new intestinal protein system of ruminants. In this paper, determination methods of degradation rate in tureen including in-vivo method, nylon bag method and artificial rumen method are compared in order to provide a reference for animal nutrition.

Professionals’ Perceptions on Construction Progress Measurement Methods Used in Ghana

Progress measurement is cardinal for effective project delivery. It assesses the physical amount of completed work within budgeted cost and manpower performance at a specified stage of the project. Effective progress measurement facilitates progress monitoring, an inevitability for identifying early warning?signs and confirmation of structured work proceeding. Different progress measuring methods are available and used for construction projects. They range from the traditional to the contemporary ones like three-dimensional and four-dimensional models. This paper examines current progress measurement methods used in the Ghanaian construction industry. Eight commonly employed methods were identified from the literature?and?rated by sixty-two construction professionals, practicing with tier one construction firms and construction consultancy services. Relative Important Index ranking and Mann-Whitney?U?test statistics were used to rank and check the consistency of survey responses. Cost Ratio ranked?the?highest, followed by Supervisor’s Opinion and Units?Completed. The fourth-ranked method was Time Ratio, then Incremental Milestone before Start-Finish.?Weighted/Equivalent Units?was at?the penultimate with Earned Value Analysis ranked?the?lowest. The study will not only underscore the relevance of the current project progress measurement practices and provoke prolific debates on their merits, but will also serve as a precursor for critical evaluation of the methods with the view to identifying?barriers militating against realistic progress assessment of construction works.

Research progress on detection methods of the asymptomatic COVID- 19 infected persons

The global pandemic of COVID-19 has brought great harm and challenges to many countries and regions around the world.The majority of COVID-19 patients have typical clinical manifestations,but the number of asymptomatic infections is increasing as COVID-19 research continues and SARS-CoV-2 testing improves.Many asymptomatic COVID-19 patients with no obvious clinical symptoms are able to transmit the virus to others due to the presence of SARS-CoV-2 in their bodies,thus greatly accelerating the worldwide pandemic and posing great difficulty and threat to global epidemic prevention and control.Therefore,early detection and identification of asymptomatic infected persons through various testing methods are effective measures to control the COVID-19 pandemic.This article will provide a brief review of the available methods and techniques for detecting asymptomatic COVID-19 patients.

Research Progress about the Mixing Brine Method to Produce Low- Sodium Carnallite from Saline Lake Brine

Mixing brine method,which founded on the commonion effect,is widely used for low-sodium carnallite production.Compared with traditional carnallite preparation techniques,the mixing brine method possess a

Progress billing method of accounting for long-term construction contracts

This article questions the reliability of the amount of revenue recognized in the percentage of completion （POC） method of revenue recognition in construction industry and recommends a new method based on the progress billing which is more reliable. The most commonly used method of revenue recognition in the construction industry is the percentage of completion method （POC）, where the revenue is recognized on the basis of the percentage of work completed. The calculation of percentage of work completed is made on the basis of the cost incurred for the contract work during the financial period and the cost required for completion of the work as estimated by the contractor. Here, the acceptance of the product by the buyer （contractee） is not involved in recognizing the revenue. The reliability of the amount of revenue and its collectability can be assured only when the buyer accepts the product. The approval of the progress bill by the contractee is needed to assure the reliability and collectability and it must be the event that triggers the recognition of revenue.

Research Progress on the Pharmacological Effects and Quality Analysis Methods of Bupleurum

Bupleurum has been used as traditional medicine in China,Japan,South Korea,and other Asian countries for more than 2,000 years.The crude extracts and pure compounds isolated from Bupleurum have a variety of biological activities,such as anti-inflammatory,anti-cancer,antipyretic,antibacterial,anti-viral,liver protection,neuroprotection,and immune regxilation.The pharmacological effects of Bupleurum have been classified and summarized in this paper by consulting literatures at home and abroad.At the same time,the quality analysis methods of bupleurum,including high-performance liquid chromatography,thin layer chromatography,ultra-high-performance liquid chromatography mass spectrometry,UPLC-QTOF-MS,and so on,are discussed.This paper provides a reference for further research,development,and application of Bupleurum.

Research progress of heat-clearing and dampness-removing method to improve the inflammatory microenvironment of gout

Gout is a metabolic bone and joint disease caused by purine metabolism disorder.The disturbance of inflammatory microenvironment caused by monosodium urate(MSU)deposition is an important pathological mechanism of gout occurrence and development.In the understanding of Traditional Chinese medicine(TCM),the interaction of"dampness","heat"and"stasis"is the main pathogenesis of gout,and the method of clearing heat and removing dampness is the main treatment method of TCM for gout.In recent years,studies have found that heat-clearing and dampness-removing method can improve the TCM symptom score of gout patients,especially in the body tiredness,dry mouth and dry throat,short yellow urine,thirsty,etc.,which are the characteristics of dampness and heat syndrome,this may be related to the fact that the TCM heat-clearing and dampness-removing method in the treatment of gout removes the appearance of dampness and heat,improves the inflammatory microenvironment of gout and restores the normal metabolic function of human body.This paper deeply explores the specific mechanism of TCM heat-clearing and dampness-removing method to improve the inflammatory microenvironment of gout,which can provide new ideas for the diagnosis and treatment of clinical gout.

Sintering Densification of Boron Carbide Materials and Their Research Progress

Boron carbide(B_(4)C)has excellent high-temperature oxidation resistance,high hardness,low relative density,high melting point and excellent abrasive resistance,which is widely used in fields such as refractories,wear-resistant materials and lightweight protective materials.The research progress and application of B_(4)C materials in China and overseas in recent years were summarized.The influences of sintering processes(pressureless sintering,hot-pressing sintering,hot isostatic pressing sintering,spark plasma sintering and microwave sintering)and sintering additives(simple substances,oxides and carbides)on the B_(4)C densification were analyzed.The development of B_(4)C materials was prospected.

山药淀粉的改性及其在食品工业中的应用研究进展

介绍了近年来国内外山药淀粉的改性方法,综述了改性山药淀粉在乳制品、食品添加剂、功能性食品和食品包装中的应用,旨在为山药资源的开发利用提供参考。

循序渐进式教学方法在“Python程序设计”课程中的应用

针对Python课程教学过程中存在的课时不足、Python语言的学习难度分层递增等问题,文章提出教师可以通过举一反三、归纳梳理、知识迁移、融入应用、对比分析、项目实践的方法开展系统而有效的编程教学,采用逐级巩固的循序渐进式教学方法,引导学生逐步掌握Python的知识和技术要领。

防风传统炮制方法与现代炮制工艺的研究进展

防风始载于《神农本草经》,且被誉为上品之药。古书及各朝代名医推崇防风的主要功效有解表和祛风等,对由风寒所引起的关节疼痛、头疼、风湿痛等症有治疗效果。李时珍写有“其功疗风最要,故名”,对其名称的由来进行了解释。防风作为一味有悠久应用历史的祛风要药,其炮制的历史也久远且方法众多,除目前仍然采用的炒防风、炭防风和蜜防风外,历代古籍文献记载其他炮制方法还有酒浸、炙制、麸炒、煮制法等。笔者通过查阅大量的古今文献并进行梳理,对防风的传统炮制方法进行概述,并对其现代炮制工艺进行总结,有助于规范防风炮制技艺、优化防风炮制工艺,为提高中药材资源的合理利用提供理论依据。