Analysis and Online Diagnosis on Plugging Fault of Servo Valve in Electro-hydraulic Regulating System of Steam Turbine

Through the study on the output signals of the electro-hydraulic regulating system in the thermal power plant, a novel method for online diagnosis of the plugging fault in the servo valve is presented. With the use of the AMESIM software, the changes of the piston displacement, the oil pressure, the magnitude attenuation and the phase lag of the system under different plugging states are studied after simulation. Besides, the influences of the symmetrical and unsymmetrical plugging on the system are also compared and the characteristic table is given. The duo-neural network is put forward to achieve an online diagnosis on the plugging fault of the servo valve. The first level of network helps to make the qualitative diagnosis of the plugging position while the second level is for the quantitative diagnosis of the degree of the plugged position. The research results show that plugging at different positions exerts different influences on the performance of the system. The unsymmetrical plugging mainly affects the regulation time while the symmetrical plugging leads to great changes in the magnitude attenuation and the phase lag.

Dynamic plugging regulating strategy of pipeline robot based on reinforcement learning

Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the pipeline and PIPR. In this paper, we propose a dynamic regulating strategy to reduce the plugging-induced vibration by regulating the spoiler angle and plugging velocity. Firstly, the dynamic plugging simulation and experiment are performed to study the flow field changes during dynamic plugging. And the pressure difference is proposed to evaluate the degree of flow field vibration. Secondly, the mathematical models of pressure difference with plugging states and spoiler angles are established based on the extreme learning machine (ELM) optimized by improved sparrow search algorithm (ISSA). Finally, a modified Q-learning algorithm based on simulated annealing is applied to determine the optimal strategy for the spoiler angle and plugging velocity in real time. The results show that the proposed method can reduce the plugging-induced vibration by 19.9% and 32.7% on average, compared with single-regulating methods. This study can effectively ensure the stability of the plugging process.

Regulating^(*)COOH intermediate via amino alkylation engineering for exceptionally effective photocatalytic CO_(2) reduction

Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target products.Engineering the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant challenge.In this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) reduction.Experimental characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic process.Notably,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%.

Adaptive Optimal Output Regulation of Interconnected Singularly Perturbed Systems With Application to Power Systems

This article studies the adaptive optimal output regulation problem for a class of interconnected singularly perturbed systems(SPSs) with unknown dynamics based on reinforcement learning(RL).Taking into account the slow and fast characteristics among system states,the interconnected SPS is decomposed into the slow time-scale dynamics and the fast timescale dynamics through singular perturbation theory.For the fast time-scale dynamics with interconnections,we devise a decentralized optimal control strategy by selecting appropriate weight matrices in the cost function.For the slow time-scale dynamics with unknown system parameters,an off-policy RL algorithm with convergence guarantee is given to learn the optimal control strategy in terms of measurement data.By combining the slow and fast controllers,we establish the composite decentralized adaptive optimal output regulator,and rigorously analyze the stability and optimality of the closed-loop system.The proposed decomposition design not only bypasses the numerical stiffness but also alleviates the high-dimensionality.The efficacy of the proposed methodology is validated by a load-frequency control application of a two-area power system.

Research on Regulation Method of Energy Storage System Based on Multi-Stage Robust Optimization

To address the scheduling problem involving energy storage systems and uncertain energy,we propose a method based on multi-stage robust optimization.This approach aims to regulate the energy storage system by using a multi-stage robust optimal control method,which helps overcome the limitations of traditional methods in terms of time scale.The goal is to effectively utilize the energy storage power station system to address issues caused by unpredictable variations in environmental energy and fluctuating load throughout the day.To achieve this,a mathematical model is constructed to represent uncertain energy sources such as photovoltaic and wind power.The generalized Benders Decomposition method is then employed to solve the multi-stage objective optimization problem.By decomposing the problem into a series of sub-objectives,the system scale is effectively reduced,and the algorithm’s convergence ability is improved.Compared with other algorithms,the multi-stage robust optimization model has better economy and convergence ability and can be used to guide the power dispatching of uncertain energy and energy storage systems.

Research Progress on the Association Between Gut Microbiota and Respiratory System Diseases

This paper aims to review the association between gut microbiota and respiratory system diseases, and explore their potential mechanisms and clinical significance. Gut microbiota, as an important microbial ecosystem in the human body, has profound effects on host health. Recent studies have shown that the imbalance of gut microbiota is closely related to the occurrence and development of respiratory system diseases, including asthma, chronic obstructive pulmonary disease (COPD), and pneumonia. We comprehensively analyzed the current research progress and found that gut microbiota may affect respiratory system diseases through various pathways, including immune regulation, inflammatory responses, and airway mucus secretion. Additionally, environmental factors, lifestyle, and dietary habits are also closely related to gut microbiota and respiratory system health. Understanding the relationship between gut microbiota and respiratory system diseases not only helps to reveal the mechanisms of disease occurrence but also provides a theoretical basis for the development of new treatment strategies. Future research should focus on exploring the types and functions of gut microbiota, conducting clinical trials based on this, investigating the effects of gut microbiota modulation on the treatment and prevention of respiratory system diseases, and providing new directions for personalized medicine.

The Barrier of the Child and Parent Expected Models for Entering the School System-A Secondary Publication

The recognition of the positive value of student diversity and their right to full participation are key aspects of inclusion as a means of managing heterogeneity of the school population from an equality perspective.As the school cannot welcome the diversity of children without including their families,the same logic needs to apply to the relationship between the school and parents,particularly in the current environment where the school-family partnership appears as a privileged institutional leverage in the fight against inequalities at school.Based on an ethnographical study exploring how the relationship between the school and the families builds up in a Swiss school located in a context of strong cultural diversity,this paper interrogates how the school norm can be the main limitation to the inclusion of students and parents who are unfamiliar with the school.Derived from field observations and interviews,our results show how the teachers tend to approach their relationship with new students and their parents from the standpoint of narrowly defined expected models,leading them to engage in a vain attempt to conform the students and parents when they deviate from these models.The possibility of entering the school system for students and parents unfamiliar with school is hindered by the exclusive and excluding normativity on which the models of the child and the parent expected by the teachers are grounded.Based on these observations,we discuss how an inclusive approach seems to us to require in the first place a necessary process of decentering from the school and teachers,as a condition for recognition of the actual child and parent.

Effects of regulating intestinal microbiota on anxiety symptoms: A systematic review

Background Anxiety symptoms are common in mental diseases and a variety of physical disorders, especially in disorders related to stress. More and more basic studies have indicated that gut microbiota can regulate brain function through the gut-brain axis, and dysbiosis of intestinal microbiota was related to anxiety. However, there is no specific evidence to support treatment of anxiety by regulating intestinal microbiota. Aims To find evidence sup porting improvement of anxiety symptoms by regulation of intestinal microbiota. Methods This systematic review of randomised controlled trials was searched based on the following databases: PubMed, EMBASE, the Cochrane Library, OVID, Web of Knowledge, China National Knowledge Infrastructure (CNKI), Wanfang Data, VIP databases and SinoMed. The retrieval time dated back to 25 July 2018. Then we screened research literatures based on established inclusion and exclusion criteria. Quality evaluation for each included study was done using the Cochrane risk of bias and the Jadad scale. Results A total of 3334 articles were retrieved and 21 studies were included which contained 1503 subjects. In the 21 studies, 15 chose probiotics as interventions to regulate intestinal microbiota and six chose non-probiotic ways such as adjusting daily diets. Probiotic supplements in seven studies contained only one kind of probiotic, two studies used a product that contained two kinds of probiotics and the supplements used in the other five studies included at least three kinds of probiotics. In the studies that used treatment as usual plus interventions regulating intestinal flora (IRIF) as interventions (five studies), only non-probiotic ways were effective (two studies), which means 40% of studies were effective;in the studies that used IRIF alone (16 studies, 11 studies used probiotic ways and 5 studies used non-probiotic ways), 56% of studies could improve anxiety symptoms, and 80% of studies that conducted the non-probiotic interventions were effective, while 45% of studies that used probiotic supplementations had positive effects on anxiety symptoms. Overall, 11 studies showed a positive effect on anxiety symptoms by regulating intestinal microbiota, which indicated 52% of the 21 studies were effective, and there were five studies that used probiotic supplements as interventions and six used non-probiotic interventions. In addition, it should be noted that six of seven studies showed that regulation of intestinal microbiota could treat anxiety symptoms, the rate of efficacy was 86%.Conclusions We find that more than half of the studies included showed it was positive to treat anxiety symptoms by regulation of intestinal microbiota. There are two kinds of interventions (probiotic and non-probiotic interventions) to regulate intestinal microbiota, and it should be highlighted that the non-probiotic interventions were more effective than the probiotic interventions. More studies are needed to clarify this conclusion since we still cannot run meta-analysis so far.

Role of mitochondria in regulating micro RNA activity and its relevance to the central nervous system

Mitochondria serve as the powerhouse of cells,respond to cellular demands and stressors,and play an essential role in cell signaling,differentiation,and survival.Aberrant mitochondria function has been linked to diverse and complex human diseases such as neurodegenerative diseases,cancers,myopathies,premature aging,and metabolic syndromes（Nunnari and Suomalainen,2012）.

Water hammer protection for diversion systems in front of pumps in long-distance water supply projects

For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up.

Mesenchymal stem cell-derived exosomes regulate microglia phenotypes:a promising treatment for acute central nervous system injury

There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progression.In acute CNS injury,brain microglia are among the first cells to respond and play a critical role in neural repair and regeneration.However,microglial activation can also impede CNS repair and amplify tissue damage,and phenotypic transformation may be responsible for this dual role.Mesenchymal stem cell(MSC)-derived exosomes(Exos)are promising therapeutic agents for the treatment of acute CNS injuries due to their immunomodulatory and regenerative properties.MSC-Exos are nanoscale membrane vesicles that are actively released by cells and are used clinically as circulating biomarkers for disease diagnosis and prognosis.MSC-Exos can be neuroprotective in several acute CNS models,including for stroke and traumatic brain injury,showing great clinical potential.This review summarized the classification of acute CNS injury disorders and discussed the prominent role of microglial activation in acute CNS inflammation and the specific role of MSC-Exos in regulating pro-inflammatory microglia in neuroinflammatory repair following acute CNS injury.Finally,this review explored the potential mechanisms and factors associated with MSCExos in modulating the phenotypic balance of microglia,focusing on the interplay between CNS inflammation,the brain,and injury aspects,with an emphasis on potential strategies and therapeutic interventions for improving functional recovery from early CNS inflammation caused by acute CNS injury.

Review of peri-urban agriculture as a regional ecosystem service

The peri-urban area possesses mixed characteristics of rural and urban areas,i.e.,agricultural,and built-up land.This review explains various themes and concepts of peri-urban areas and the importance of peri-urban agriculture(PUA)as an ecosystem service(ES)for their surrounding areas.The methodological approach is a systematic literature search and explanatory review of books and journal articles.The focus of the discussion is as follows:(1)quantification of review results,(2)urbanization pressures,peri-urban,and governance,(3)two different concepts about the peri-urban area,(4)protection of PUA and their resilience,and(5)role of PUA in providing ESs to other regions.The review shows that PUA is more crucial in urban areas than in rural areas in terms of food supply,ecology and biodiversity preservation,disaster mitigation,and recreation.One of the primary causes of PUA loss is massive urban expansion,which entails the conversion of agricultural land in peri-urban areas into built-up land.Hence,we suggest that every country should develop a peri-urban management policy.We argue that sociocultural biases in PUA have resulted in many institutional constraints on peri-urban management being incorporated within existing political and regulatory frameworks,including planning practices and longstanding laws and regulations.

New Type Regulating Valve Applied in Cooling System of Blast Furnace

A new type regulating valve with the cooling mode of constant temperature difference water supply, temperature difference self operated regulating valve, was introduced into blast furnace cooling system to overcome shortcomings of the cooling mode of constant flow rate water supply. The results show that the temperature difference between inlet and outlet water of cooling wall can be decreased greatly and steadily, and the water supply for blast furnace cooling can be reduced considerably.

Recent advances in regulating the performance of acid oxygen reduction reaction on carbon-supported non-precious metal single atom catalysts

Developing high performance and low-cost catalysts for oxygen reduction reaction(ORR)in challenging acid condition is vital for proton-exchange-membrane fuel cells(PEMFCs).Carbon-supported nonprecious metal single atom catalysts(SACs)have been identified as potential catalysts in the field.Great advance has been obtained in constructing diverse active sites of SACs for improving the performance and understanding the fundamental principles of regulating acid ORR performance.However,the ORR performance of SACs is still unsatisfactory.Importantly,microenvironment adjustment of SACs offers chance to promote the performance of acid ORR.In this review,acid ORR mechanism,attenuation mechanism and performance improvement strategies of SACs are presented.The strategies for promoting ORR activity of SACs include the adjustment of center metal and its microenvironment.The relationship of ORR performance and structure is discussed with the help of advanced experimental investigations and theoretical calculations,which will offer helpful direction for designing advanced SACs for ORR.

Regulating and tonifying spleen and kidney traditional Chinese medicine in the treatment of chronic uric acid nephropathy: A systematic review

Objective:To systematically evaluate the efficacy and safety of traditional Chinese medicine for regulating spleen and kidney.Methods:We developed a search strategy and then retrieved the database including CNKI,Wanfang data knowledge service platform,VIP journals resource integration service platform,PubMed,Embasefor randomized controlled trial of regulating spleen and kidney traditional Chinese medicine compared with conventional western medicine in the treatment of chronic uric acid nephropathy.The search deadline was set to June 30,2020.For the included literature,we applied the cochrane collaboration network risk bias assessment tool to evaluate the methodological quality,and evaluated the level of evidence according to GRADE standards.Quantitative data was analyzed by RevMan5.3 software,and trial sequential analysis method was used to analyze its efficiency.Results:A total of 709 cases in 10 articles were included.Compared with the control group,the related traditional Chinese medicine group improved the effective rate[RR=1.45,95%CI(1.32,1.58)],reduced the level of UA[MD=-36.24,95%CI(-41.03,-31.45)],BUN[SMD=-1.27,95%CI(-1.47,-1.07)]and SCR[MD=-36.33,95%CI(-55.79,-16.87),P=0.0003],the difference between the two groups was statistically significant(P<0.05).There was no evidence that a significant adverse reaction occurred.The results of TSA analysis showed that the Chinese medicine group had definite evidence for improving the efficiency.According to the GRADE evaluation criteria,the efficiency,UA,BUN and SCR outcome indicators were extremely low-quality evidence.Conclusions:Traditional Chinese medicine for regulating spleen and kidney in the treatment of chronic uric acid nephropathy improved efficiency,reduced the level of UA,BUN,SCR.Meanwhile,the therapy was proved to be safe.Nevertheless,the conclusions need further high-quality evidence to support.

The QseB/QseC two-component system contributes to virulence of Actinobacillus pleuropneumoniae by downregulating apf gene cluster transcription

Actinobacillus pleuropneumoniae(APP)is the major pathogen of porcine contagious pleuropneumoniae(PCP).The QseB/QseC two-component system(TCS)consists of the regulator QseB and the kinase QseC,which relates to quorum sensing(QS)and virulence in some bacteria.Here,we investigated the role of QseB/QseC in apf gene cluster(apfABCD)expression of APP.Our results have showed that QseB/QseC TCS can potentially regulate the expression of apf gene cluster.The△qseBC,△apfA,△apfB,△apfC and△apfD strains are more sensitive to acidic and osmotic stressful conditions,and exhibite lower biofilm formation ability than wild-type(WT)strain,whereas the complemented strains show similar phenotype to the wr strain.In additon,the mutants have defective antiphagocytosis,adhesion and invasion when they come into contact with the host cells.In experimental animal models of infection,mice infected with△qseBC,△apfA,△apfB,△apfC and △apfD strains showed lower mortality and bacterial loads in the lung and the blood than those infected with wr strain.In conclusion,our results suggest that QseB/QseC TCS contributes to stress resistance,biofilm formation,phagocytosis,adhesion,invasion and virulence by downregulating expression of apf gene cluster in A.pleuropneumoniae.

Tree-based ecosystem services supply and multifunctionality of church forests and their agricultural matrix near Lake Tana,Ethiopia

Ecosystem services(ES)are the connection between nature and society,and are essential for the well-being of local communities that depend on them.In Ethiopia,church forests and the surrounding agricultural matrix supply numerous ES.However,the ES delivered by both land use types have not yet been assessed simultaneously.Here we surveyed both church forests and their agricultural matrices,aiming to quantify,compare and unravel the drivers underlying tree-based ES supply,density and multifunctionality.We found that almost all church forests and half of the agricultural matrices provided high ES densities.ES multifunctionality was higher in the agricultural matrices,suggesting that people deliberately conserve or plant multifunctional tree species.Furthermore,the supply of all categories of ES was positively correlated with church forest age(p-value<0.001)in the agricultural matrix,while the extent of church forest was positively correlated with the density of all categories ecosystem services score in the church forests(p-value<0.001).Our results can be used to prioritize conservation efforts at sites that provide high levels of ES supply,ES density and ES multifunctionality,and to prioritize restoration efforts at sites with low levels thereof.

Effects of Water-cement Ratio and Hydration Heat Regulating Materials on Hydration Process of Early-age Cementitious Materials

By means of low-field nuclear magnetic resonance(LF-NMR),the transverse relaxation time(T_(2))signals of physically bound water in cement paste were monitored to indicate water content change and characterize the early-age hydration process.With the curves of the T_(2)signals and hydration time obtained,the hydration process could be divided into four typical periods using the null points of the second derivative curve,and the influences of water-cement ratio(w/c)and hydration heat regulating materials(HHRM)on hydration process were analyzed.The experimental results showed that the hydration rate of pure cement paste in accelerated period presented a positive correlation with w/c.Compared to pure cement paste,the addition of HHRM extended all four periods,and led to a much faster hydration rate in initial period as well as a slower rate in accelerated period.Finally,according to the LFNMR test results,the early-age hydration model of cementitious materials was proposed considering w/c and HHRM content.

Cross-kingdom regulation by plant-derived miRNAs in mammalian systems

MicroRNAs(miRNAs)are small noncoding RNA molecules ubiquitously distributed across diverse organisms,serving as pivotal regulators of genetic expression.Notably,plant-derived miRNAs have been demonstrated to have unique bioactivity and certain stability in mammalian systems,thereby facilitating their capacity for cross-kingdom modulation of gene expression.While there is substantial evidence supporting the regulation of mammalian cells by plant-derived miRNAs,several questions remain unanswered.Specifically,a comprehensive investigation of the mechanisms underlying the stability and transport of plant miRNAs and their cross-kingdom regulation of gene expression in mammals remains to be done.In this review,we summarized the origin,processing,and functional mechanisms of plant miRNAs in mammalian tissues and circulation,emphasizing their greater resistance to mammalian digestion and circulation systems compared to animal miRNAs.Additionally,we introduce four well-known plant miRNAs that have been extensively studied for their functions and mechanisms in mammalian systems.By delving into these aspects,we aim to offer a fundamental understanding of this intriguing field and shed light on the complex interactions between plant miRNAs and mammalian biology.

Genetic polymorphisms in genes regulating cell death and prognosis of patients with rectal cancer receiving postoperative chemoradiotherapy

Objective:The identification of biomarkers for predicting chemoradiotherapy efficacy is essential to optimize personalized treatment.This study determined the effects of genetic variations in genes involved in apoptosis,pyroptosis,and ferroptosis on the prognosis of patients with locally advanced rectal cancer receiving postoperative chemoradiotherapy(CRT).Methods:The Sequenom MassARRAY was used to detect 217 genetic variations in 40 genes from 300 patients with rectal cancer who received postoperative CRT.The associations between genetic variations and overall survival(OS)were evaluated using hazard ratios(HRs)and 95%confidence intervals(CIs)computed using a Cox proportional regression model.Functional experiments were performed to determine the functions of the arachidonate 5-lipoxygenase(ALOX5)gene and the ALOX5 rs702365 variant.Results:We detected 16 genetic polymorphisms in CASP3,CASP7,TRAILR2,GSDME,CASP4,HO-1,ALOX5,GPX4,and NRF2 that were significantly associated with OS in the additive model(P<0.05).There was a substantial cumulative effect of three genetic polymorphisms(CASP4 rs571407,ALOX5 rs2242332,and HO-1 rs17883419)on OS.Genetic variations in the CASP4 and ALOX5 gene haplotypes were associated with a higher OS.We demonstrated,for the first time,that rs702365[G]>[C]represses ALOX5 transcription and corollary experiments suggested that ALOX5 may promote colon cancer cell growth by mediating an inflammatory response.Conclusions:Polymorphisms in genes regulating cell death may play essential roles in the prognosis of patients with rectal cancer who are treated with postoperative CRT and may serve as potential genetic biomarkers for individualized treatment.