Nonlinear Control of Magnetically Coupled Rodless Cylinder Position Servo System

Magnetically coupled rodless cylinders are widely used in the coordinate positioning of mechanical arms,electro-static paintings,and other industrial applications.However,they exhibit strong nonlinear characteristics,which lead to low servo control accuracy.In this study,a mass-flow equation through the valve port was derived to improve the control performance,considering the characteristics of the dynamics and throttle-hole flow.Subsequently,a fric-tion model combining static,viscous,and Coulomb friction with a zero-velocity interval was proposed.In addition,energy and dynamic models were set for the experimental investigation of the magnetically coupled rodless cylin-der.A nonlinear mathematical model for the position of the magnetically coupled rodless cylinder was proposed.An incremental PID controller was designed for the magnetically coupled rodless cylinder to control this system,and the PID parameters were adjusted online using RBF neural network.The response results of the PID parameters based on the RBF neural network were compared with those of the traditional incremental PID control,which proved the superiority of the optimization control algorithm of the incremental PID parameters based on the RBF neural network servo control system.The experimental results of this model were compared with the simulation results.The average error between the established model and the actual system was 0.005175054(m),which was approximately 2.588%of the total travel length,demonstrating the accuracy of the theoretical model.

High responsivity photodetectors based on graphene/WSe_(2) heterostructure by photogating effect

Graphene, with its zero-bandgap electronic structure, is a highly promising ultra-broadband light absorbing material.However, the performance of graphene-based photodetectors is limited by weak absorption efficiency and rapid recombination of photoexcited carriers, leading to poor photodetection performance. Here, inspired by the photogating effect, we demonstrated a highly sensitive photodetector based on graphene/WSe_(2) vertical heterostructure where the WSe_(2) layer acts as both the light absorption layer and the localized grating layer. The graphene conductive channel is induced to produce more carriers by capacitive coupling. Due to the strong light absorption and high external quantum efficiency of multilayer WSe_(2), as well as the high carrier mobility of graphene, a high photocurrent is generated in the vertical heterostructure. As a result, the photodetector exhibits ultra-high responsivity of 3.85×10~4A/W and external quantum efficiency of 1.3 × 10~7%.This finding demonstrates that photogating structures can effectively enhance the sensitivity of graphene-based photodetectors and may have great potential applications in future optoelectronic devices.

Core-Shell Semiconductor-Graphene Nanoarchitectures for Efficient Photocatalysis:State of the Art and Perspectives

Semiconductor photocatalysis holds great promise for renewable energy generation and environment remediation,but generally suffers from the serious drawbacks on light absorption,charge generation and transport,and structural stability that limit the performance.The core-shell semiconductorgraphene(CSSG)nanoarchitectures may address these issues due to their unique structures with exceptional physical and chemical properties.This review explores recent advances of the CSSG nanoarchitectures in the photocatalytic performance.It starts with the classification of the CSSG nanoarchitectures by the dimensionality.Then,the construction methods under internal and external driving forces were introduced and compared with each other.Afterward,the physicochemical properties and photocatalytic applications of these nanoarchitectures were discussed,with a focus on their role in photocatalysis.It ends with a summary and some perspectives on future development of the CSSG nanoarchitectures toward highly efficient photocatalysts with extensive application.By harnessing the synergistic capabilities of the CSSG architectures,we aim to address pressing environmental and energy challenges and drive scientific progress in these fields.

Type-Ⅱ Core/Shell Nanowire Heterostructures and Their Photovoltaic Applications

Nanowire-based photovoltaic devices have the advantages over planar devices in light absorption and charge transport and collection.Recently,a new strategy relying on type-Ⅱ band alignment has been proposed to facilitate efficient charge separation in core/shell nanowire solar cells.This paper reviews the type-Ⅱ heterojunction solar cells based on core/shell nanowire arrays,and specifically focuses on the progress of theoretical design and fabrication of type-Ⅱ Zn O/Zn Se core/shell nanowire-based solar cells.A strong photoresponse associated with the type-Ⅱ interfacial transition exhibits a threshold of 1.6 e V,which demonstrates the feasibility and great potential for exploring all-inorganic versions of type-Ⅱ heterojunction solar cells using wide bandgap semiconductors.Future prospects in this area are also outlooked.

Fluorobenzene diluted low-density electrolyte for high-energy density and high-performance lithium-sulfur batteries

The mass fraction of electrolytes is the crucial factor affecting the energy density of lithium-sulfur(Li-S)batteries. Due to the high porosity within the C/S cathode, high concentration of polysulfides, and side reaction in lithiun metal anode under lean electrolyte, it is extremely challenging to improve performance while reducing the electrolyte volume. Here, we report a novel electrolyte with relatively low density(1.16 g cm^(-2)), low viscosity(1.84 m Pa s), and high ionic conductivity, which significantly promotes energy density and cyclability of Li-S batteries under practical conditions. Moreover, such electrolyte enables a hybrid cathode electrolyte interphase(CEI) and solid electrolyte interface(SEI) layer with plentiful Li F, which leads to fast kinetics of ions transport and stable cyclability even under low temperatures.Compared to Li-S batteries in electrolyte employing 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether(TTE) diluent, the ultra-thick cathode(20 mg cm^(-2)) shows a high capacity of 9.48 m Ah cm^(-2)and excellent capacity retention of 80.3% over 191 cycles at a low electrolyte-to-sulfur ratio(E/S = 2) and negative-to-positive capacity ratio(N/P = 2.5), realizing a 19.2% improvement in energy density in coin cells(from 370 to 441 Wh kg^(-1)) and a high energy density up to 467 Wh kg^(-1) in pouch cells. This study not only provides guidance for the electrolyte design but also paves the way for the development of high performance Li-S batteries under practical conditions.

Application and effect evaluation on Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in cataract daytime operation nursing

Background:To explore the application effect of Acknowledge-Introduce-Duration-Explanation-Thank you(AIDET)communication mode in reducing anxiety and improving the care services satisfaction of the patients.Methods:The 100 cases undergoing cataract daytime operation from February to July 2019 were divided into test group and control group.The test group conducted health education and nursing care for patients during admission,pre-operation,post-operation,and discharge according to the AIDET communication mode.And the control group was given health education and nursing care to the patients according to the traditional way of communication.Results:The difference of the socioeconomic information between these two groups showed no statistical significance.The care services satisfaction score in the test group was statistically higher than that in the control group(P<0.05).The Self-Rating Anxiety Scale(SAS)score in the test group was significantly lower than that in the control group(P<0.01).This result indicated that the patients suffered less anxiety with the AIDET mode of communication.Conclusions:The application of AIDET communication mode to the nursing service of cataract daytime operation can reduce the tension and anxiety of the patients from the treatment and improve their satisfaction to care services.

A model cathode for mechanistic study of organosulfide electrochemistry in Li-organosulfide batteries

Organosulfides offer new opportunities for high performance lithium-sulfur(Li-S)batteries because of materials abundance,versatile structures and unique properties.Yet,their redox kinetics as well as cycling performance need to be further improved.Employing redox mediators is a highly effective strategy to address above challenges.However,the underlying mechanism in this chemistry is so far insufficiently explored.Here,phenyl disulfide(Ph S–SPh)and phenyl diselenide(Ph Se–Se Ph)are used as a model system for mechanistic understanding of organosulfide electrochemistry,particularly the rate acceleration.Profiling the reaction thermodynamics and charge-discharge process reveals redox of both S–S and C–S bonds,as well as that the coupling between radical exchange and electrochemical redox is the key to enhance the sulfur kinetics.This study not only establishes a basic understanding of orgaonsulfide electrochemistry in Li-S batteries,but also points out a general strategy for enhancing the kinetics of sulfur electrodes in electrochemical devices.

Regulatory Effects of Zuogui Pill on Apoptosis of Follicles in Rats Injured by 60Co-γRays Based on PI3K/Akt/m TOR Signaling Pathway

[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.

A Study of Innovative Education Practice Model to Strengthen the Training of Educational and Teaching Ability for Normal-school Students

Educational practice is far from being paid enough attention to in normal colleges and universities in China, and it has become aweak link in normal education. This problem is mainly manifested in the following aspects: the concept and content of educationalpractice lag behind the educational reform;the time of educational practice is too short;and the practice base is lacking. Therefore,innovative education practice mode is extremely important. In this paper, the problems existing in the educational practice ofnormal universities in China were analyzed, and the main countermeasures for the reform of the educational practice model ofnormal universities were put forward.

The study of the influence of network resources on English Teaching under the background of informatization

As an international language, English plays an extremely important role, and it has become the lingua franca of the world. For a long time, inefficiency exists in teaching or learning. Under the learning environment surrounded by native speakers, English, as a symbolic system, appears dull, or even because there is no information given appropriate experience and it becomes abstract. Many students are reluctant to learn after learning for a time, because it is difficult for reality, and it is not easy to consolidate, that 45 minutes of English learning environment also appears to be a little frustrated, as many students who have been admitted to the University said during the learning process of the entire university, they spent seventy percent of their energy to foreign language learning rather than their own major. This not only illustrates the importance of English teaching but also shows its difficult nature, the main reason is our bad English language teaching environment, there is a lack of communication in English language environment, however, the network information and the development of modern multimedia technology has greatly improve the English teaching environment. How to use the Internet information and multimedia technologies to create English learning environment, to optimize English teaching methods and to improve the quality of English teaching.

预后营养指数评估弥漫性大B细胞淋巴瘤患者预后的临床价值

目的:探讨预后营养指数(prognostic nutritional index,PNI)与弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)患者临床特征及预后之间的关系。方法:回顾性收集2010年6月至2016年6月于天津市人民医院收治的82例初治DLBCL患者的临床资料,计算PNI值,采用受试者工作特征曲线(ROC)计算Youden指数,获取PNI最佳分界值,分析不同PNI水平与患者临床特征、治疗疗效及预后的关系。结果:全组患者PNI均值为43.93±5.86,当PNI值为44.15时,Youden指数最大,敏感度为74.6%,特异度为67.2%。低PNI组(<44.15)和高PNI组(≥44.15)患者分别占38例(46.3%)和44例(53.7%),PNI水平与患者的ECOG PS评分、Ann Arbor分期、IPI评分、LDH水平等均有相关性(均P<0.05)。低PNI组患者化疗总有效率低于高PNI组(65.8%vs.86.4%),且差异具有统计学意义(χ^2=4.848,P=0.028)。全组患者3年生存率为69.1%,低PNI组1、2、3年生存率分别为86.8%、67.8%和56.9%,均低于高PNI组96.7%、89.5%和80.2%,差异具有统计学意义(χ^2=9.421,P=0.002)。单因素分析显示患者PNI值<44.15、ECOG PS评分≥2分、IPI评分>2分、分期Ⅲ~Ⅳ期、外周血淋巴细胞计数<1.0×10^9/L对预后有影响(均P<0.05),多因素分析显示PNI值<44.15和Ⅲ/Ⅳ期为影响该组患者的独立预后不良因素(P=0.006,0.011)。结论:PNI值可作为DLBCL患者简便可行的临床预后指标。

A Study of New Ways of Professional Development of Rural Teachers Supported by Information Technology

Teacher professional development has been put forward since the 1980s. After nearly 30 years of theoretical research and practical exploration, it has become a common concern of many countries in the world. It is the mainstream discourse of teacher education reform. As a special group of teachers in our country, the professional development of rural teachers is directly related to the improvement of the quality of education in rural schools. In this paper, information technology was briefly analyzed, and the problems in the professional development of teachers in rural schools were discussed;finally, strategies of rural school teachers' professional development supported by information technology were put forward.

Reflections on the Professional Development of Rural Teachers Supported by Information Technology

The rapid development of information technology has brought vitality to rural education, rural teachers should not only seriously deal with it, but also face greater impact and challenges. According to the basic quality structure and main influencing factors of teachers' professional development, questionnaires and interview outlines were designed for 650 rural teachers in ethnic minority areas of Southeast Chongqing to investigate the current situation of rural teachers' professional knowledge and the status of teachers' professional development support system in this study, and then countermeasures were proposed for the current problems, with a view to providing theoretical reference for the development and implementation of modern education.

Probe into Post Practice of Normal School Students in Local Universities

As an important measure of educational reform,post practice can not only improve the practical skills of normal university students in education and teaching,but also relieve the pressure of teachers.Based on this,the Questionnaire for Internship Students and the way of stratified sampling with random sampling were used to conduct a questionnaire survey for Internship Students in Sichuan Normal University in this study;and the problems existing in normal students'post practice were analyzed,then some suggestions were proposed to enhance the practicability and effectiveness of the post practice of normal students in Colleges and universities.

Dynamic shielding of bacterial outer membrane vesicles for safe and efficient chemo-immunotherapy against tumors

Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver drugs.However,the severe systemic inflammatory response triggered by OMVs upon intravenous(i.v.)injection has limited their application.Here,we developed a safe and effective strategy by conjugating doxorubicin-loaded serum albumin(SA-DOX,AD)onto the surface of OMVs using a matrix metalloproteinase(MMP)-cleavable peptide linker(cL).This approach enabled the dynamic shielding of OMVs to reduce the systemic side effects while simultaneously enhancing the anti-tumor effects through chemo-immunotherapy.Specifically,the resulting OMV-cL-AD formulation exhibited significantly enhanced accumulation at the tumor site after i.v.administration,facilitated by the SA decoration on the OMVs surface.Subsequently,the shield on the OMV-cL-AD was cleaved by the over-expressed MMP in the TME,leading to the release of both OMVs and AD.This process provided OMV-induced immunotherapy and DOX-induced chemotherapy,resulting in synergistic tumor inhibition.In conclusion,our work demonstrated the potential of OMV-cL-AD as an effective immunochemotherapy strategy that can prolong the survival time of mice without inducing side effects.

Effects of music therapy on the anxiety level and physiological responses of patients undergoing ophthalmic surgery:A systematic review and meta-analysis

Objective:To evaluate the effectiveness of music therapy on the anxiety level and physiological response of patients undergoing ophthalmic surgery.Methods:Relevant randomized controlled trials that compared the combined effect of music therapy for patients undergoing ophthalmic surgery were included.Four English databases and three Chinese databases were searched from inception to Jan.2022.Two reviewers independently performed data extraction and risk of bias assessments.The Cochrane Collaboration tool was used to assess the risk of bias.Meta-analysis was performed using Review Manager 5.3.The outcomes were overall anxiety,blood pressure,heart rate and pain.Results:A total of 11 trials with 1,469 participants were included in the meta-analysis.Compared to standard care,music therapy had a good effect on reducing the anxiety levels of patients undergoing ophthalmic surgery(P<0.05).The results also suggested that music therapy produced a significant improvement in blood pressure(P<0.05)and heart rate(P<0.05).The visual analogue scale(VAS)showed that music therapy significantly reduced pain compared to standard care(P<0.05).Conclusions:This meta-analysis provided evidence that music therapy has an obvious effect on relieving anxiety levels,while it is also more effective in alleviating pain and improving physiological responses than standard care alone.Our findings may provide accurate evidence-based guidance for the clinical implementation of music therapy.In the future,more high-quality studies are required for verifying these results.

Multiple fields manipulation on nitride material structures in ultraviolet light-emitting diodes

As demonstrated during the COVID-19 pandemic,advanced deep ultraviolet(DUV)light sources(200–280 nm),such as AlGaN-based light-emitting diodes(LEDs)show excellence in preventing virus transmission,which further reveals their wide applications from biological,environmental,industrial to medical.However,the relatively low external quantum efficiencies(mostly lower than 10%)strongly restrict their wider or even potential applications,which have been known related to the intrinsic properties of high Al-content AlGaN semiconductor materials and especially their quantum structures.Here,we review recent progress in the development of novel concepts and techniques in AlGaNbased LEDs and summarize the multiple physical fields as a toolkit for effectively controlling and tailoring the crucial properties of nitride quantum structures.In addition,we describe the key challenges for further increasing the efficiency of DUV LEDs and provide an outlook for future developments.

准固相转化机制硫正极

随着电动汽车及便携式电子产品的迅速发展,对于高能量密度电池体系的需求越来越迫切,然而传统锂离子电池正极材料的能量密度发展逼近理论极限,因此发展下一代电池体系迫在眉睫。硫正极具有理论比容量高、来源广泛和成本低廉等优点,成为研究热点之一。硫正极在常规醚类电解液中为溶解-沉积机制,会产生“穿梭效应”,造成活性物质不可逆损失、电池库仑效率低和循环寿命短等问题。为了缓解“穿梭效应”,通常采用物理限域、化学吸附和反应加速剂等方式,但都没有从根本解决该问题。准固相转化机制可以彻底避免多硫化物溶解流失,受到研究者的广泛关注。本文综述了微孔碳、正极表面SEI膜和电解液调控等途径构建准固相转化机制硫正极的代表性工作,总结了研究意义和电化学特征;针对准固相转化硫正极本征动力学慢的问题,提出加快反应动力学的方案;有助于提高长循环性能,从而促进锂硫电池实用化。

Optical non-destructive techniques for small berry fruits: A review

Small berries including strawberry and blueberry are extensively consumed fruits with great economic values due to their characteristic flavor and appearance as well as potential health benefits.This review elaborated the optical non-destructive techniques viz.Vis-NIR spectroscopy,computer vision system,hyperspectral imaging,multispectral imaging,laser-induced method and thermal imaging,and their applications for quality and safety control of small berry fruits.The discussion regarding the photoacoustic technique,X-ray technique,Terahertz spectroscopy,odor imaging,micro-destructive testing and smart mobile terminal-based analyzer was also presented.Furthermore,we proposed our personal understanding of the technical challenges and further trends for these optical non-destructive techniques:1)owing to the relatively low detection limit,the so-called micro-destructive techniques may be alternative to the traditional non-destructive techniques in both practical and fundamental research;2)we suggest that the research articles like“collecting data first,and then modeling the relevant properties of agricultural products by machine learning”should be less produced in related fields.That's because such research methods are likely to be suspected of“cheating”.It is recommended that some modeling competitions can be carried out in the agricultural engineering field to avoid or reduce the“cheating”model.

Evolution of single nanobubbles through multi-state dynamics

Nanobubble is a rising research field,which attracts more and more attentions due to its potential applications in medical science,catalysis,electrochemistry and etc.To better implement these applications,it is urgent to understand one of the most important mechanisms of nanobubbles,the evolution.However,few attentions have been paid in this aspect because of the methodology difficulties.Here we successfully used dark-field microscopy to study the evolution process of single nanobubbles generated from formic acid dehydrogenation on single Pd-Ag nanoplates.We found some of the nanobubbles in this system can exhibit three distinct states representing different sizes,which can transform among each other.These transitions are not direct but through some intermediate states.Further kinetic analysis reveals complicated mechanisms behind the evolution of single nanobubbles.The results acquired from this study can be applicable to nanobubble systems in general and provide insights into the understanding of mechanisms affecting the stability of nanobubbles and their applications.