Research on Power Quality Evaluation Based on Radar Chart Method and Fuzzy Membership Degree

Aiming at the current limit value of six steady-state energy indexes, the current radar method is used for reference. A method of comprehensive evaluation of power quality based on improved radar method is proposed, which improves the power quality index Type radar pattern to represent the steady-state indicator. Each of the main indicators corresponds to a partial ring, and the angle of the annular portion is mainly affected by the size of the weight. Compared with the previous radar map method to maintain the independence of the indicators and a single indicator of the binding data assessment. The method has the advantages of good feasibility.

Constructing demonstration zones to promote the implementation of Sustainable Development Goals

After the United Nations Agenda 2030 was officially launched in September 2015,governments around the world have taken actions to implement the ambitious plan.This paper summarizes the actions and policies taken in China for promoting the implementation of the UN’2030 Agenda for Sustainable Development,with emphasis on promoting the development of demonstration zones for delivery of the Sustainable Development Goals(SDGs).The Chinese government has taken two types of measures.One is to formulate a series of national plans and strategies and the other is to construct pilot and demonstration zones.Two approaches were presented to optimize the selection criteria for demonstration zones:a problem-based approach;and a major function-based approach.Both provided priority regions and major themes for selection and construction of demonstration zones.Suggestions for promoting the development of demonstration zones include:(1)building a monitoring system for the implementation of SDGs in each demonstration zone and establishing an open online platform to track the progress;(2)forming an effective stakeholder participation mechanism.The experiences in constructing innovation-driven demonstration zones are insightful for other countries to take practical actions in the delivery of SDGs.

The equivalent model of controller in synchronous frame to stationary frame

The system controlled in synchronous frame is commonly used. However, it is a problem how to transform the controller in synchronous frame to stationary frame. This paper deduces the stationary frame equivalent model of arbitrarily controller in synchronous frame. The equivalent model can reflect the control performance of the input signal at different frequency accurately. The unified frequency-domain model of the overall system can be established using the equivalent model, and the guidance for frequency analysis and stability analysis can be provided. Theoretical derivation and simulation results verify the correctness and generality of the equivalent model.

基于CT平扫的影像组学特征预测急性大脑中动脉闭塞机械取栓术后造影剂外渗的价值

目的探讨基于CT平扫的影像组学特征预测单侧大脑中动脉闭塞性卒中患者血管内机械取栓术造影剂外渗的应用价值。方法收集2015年12月至2022年12月经上海交通大学医学院苏州九龙医院临床诊断为大脑中动脉血栓并行血管内机械取栓术的患者96例,其中渗出组67例,非渗出组29例,所有病例以7∶3的比例随机分为训练集(67例)与测试集(29例),应用ITK-SNAP软件对CT平扫图像进行感兴趣区域勾画,提取影像组学特征;使用Mann-Whitney U检验、Pearson相关与最小绝对收缩和选择算子进行特征筛选。在训练集与测试集使用随机森林与极限梯度提升进行建模,分别绘制受试者操作特征曲线,计算曲线下面积(AUC)、敏感度、特异度及最佳阈值,应用决策曲线分析评估所得到模型的临床应用价值。结果通过筛选得到6个最大预测效能影像组学特征,随机森林的训练模型具有最高的预测效能,该模型在训练集AUC值为0.997,95%CI:0.990~1.000,准确性、敏感度、特异度及最佳阈值分别为97.0%、97.8%、95.2%及0.700,决策曲线显示模型阈值在0.5~0.9的区间内具有较高的临床净收益。结论基于CT平扫的影像组学特征对大脑中动脉血栓患者机械取栓术后的造影剂外渗具有较高的预测价值。

Near infrared emissions from both high efficient quantum cutting (173%) and nearly-pure-color upconversion in NaY(WO_(4))_(2):Er^(3+)/Yb^(3+) with thermal management capability for silicon-based solar cells

Raising photoelectric conversion efficiency and enhancing heat management are two critical concerns for siliconbased solar cells.In this work,efficient Yb^(3+) infrared emissions from both quantum cutting and upconversion were demonstrated by adjusting Er^(3+) and Yb^(3+) concentrations,and thermo-manage-applicable temperature sensing based on the luminescence intensity ratio of two super-low thermal quenching levels was discovered in an Er^(3+)/Yb^(3+) codoped tungstate system.The quantum cutting mechanism was clearly decrypted as a two-step energy transfer process from Er^(3+) to Yb^(3+).The two-step energy transfer efficiencies,the radiative and nonradiative transition rates of all interested 4 f levels of Er^(3+) in NaY(WO_(4))_(2) were confirmed in the framework of Föster-Dexter theory,Judd-Ofelt theory,and energy gap law,and based on these obtained efficiencies and rates the quantum cutting efficiency was furthermore determined to be as high as 173%in NaY(WO_(4))_(2):5 mol%Er^(3+)/50 mol%Yb^(3+) sample.Strong and nearly pure infrared upconversion emission of Yb3+under 1550 nm excitation was achieved in Er^(3+)/Yb^(3+)co-doped NaY(WO_(4))_(2) by adjusting Yb^(3+) doping concentrations.The Yb^(3+) induced infrared upconversion emission enhancement was attributed to the efficient energy transfer ^(4)I_(11/2)(Er^(3+))+^(2)F_(7/2)(Yb^(3+))→^(4)I_(15/2)(Er^(3+))+^(2)F_(5/2)(Yb^(3+))and large nonradiative relaxation rate of ^(4)I_(9/2).Analysis on the temperature sensing indicated that the NaY(WO_(4))_(2):Er^(3+)/Yb^(3+)serves well the solar cells as thermos-managing material.Moreover,it was confirmed that the fluorescence thermal quenching of ^(2)H_(11/2)/^(4)S_(3/2) was caused by the nonradiative relaxation of ^(4)S_(3/2).All the obtained results suggest that NaY(WO_(4))_(2):Er^(3+)/Yb^(3+) is an excellent material for silicon-based solar cells to improve photoelectric conversion efficiency and thermal management.

Small particles,big effects:How nanoparticles can enhance plant growth in favorable and harsh conditions

By 2050,the global population is projected to reach 9 billion,underscoring the imperative for innovative solutions to increase grain yield and enhance food security.Nanotechnology has emerged as a powerful tool,providing unique solutions to this challenge.Nanoparticles(NPs)can improve plant growth and nutrition under normal conditions through their high surface-to-volume ratio and unique physical and chemical properties.Moreover,they can be used to monitor crop health status and augment plant resilience against abiotic stresses(such as salinity,drought,heavy metals,and extreme temperatures)that endanger global agriculture.Application of NPs can enhance stress tolerance mechanisms in plants,minimizing potential yield losses and underscoring the potential of NPs to raise crop yield and quality.This review highlights the need for a comprehensive exploration of the environmental implications and safety of nanomaterials and provides valuable guidelines for researchers,policymakers,and agricultural practitioners.With thoughtful stewardship,nanotechnology holds immense promise in shaping environmentally sustainable agriculture amid escalating environmental challenges.

Acoustic emission characteristics of damage evolution of multi-scale fiber reinforced rubberized concrete under uniaxial compression and tension after being subjected to high temperatures

Recently developed multi-scale fiber(i.e.,CaCO3 whisker,polyvinyl alcohol(PVA)fiber,and steel fiber)reinforced rubberized concrete exhibits excellent mechanical properties and spalling resistance at high temperatures.Measurement of macro properties such as strength and Young’s modulus cannot reveal and characterize damage mechanisms,particularly those relating to the multi-scale fiber strengthening effect.In this study,acoustic emission(AE)technology is applied to investigate the impact of multi-scale fiber on the damage evolution of rubberized concrete exposed to high temperatures,under the uniaxial compression and tension loading processes.The mechanical properties,AE event location,peak frequency,b-value,the ratio of rise time to amplitude(RA),average frequency(AF)values,and AE energy of specimens are investigated.The results show that the number of events observed using AE gradually increases as the loading progresses.The crumb rubber and fibers inhibit the generation and development of the cracks.It is concluded that both the peak frequency and b-value reflect the extension process of cracks.As the cracks develop from the micro scale to the macro scale,the peak frequency tends to be distributed in a lower frequency range,and the b-value decreases gradually.At the peak stress point,the AE energy increases rapidly and the b-value decreases.The specimens without multi-scale fibers exhibit brittle failure,while the specimens with fibers exhibit ductile failure.In addition,adding multi-scale fibers and crumb rubber increases the peak frequency in the medium and high frequency ranges,indicating a positive effect on inhibiting crack development.After being subjected to high temperatures,the maximum and minimum b-values decrease,reflecting an increase in the number of initial cracks due to thermal damage.Meanwhile,the RA and AF values are used to classify tensile and shear cracks.The specimens fracture with more shear cracks under compression,and there are more tensile cracks in specimens with multi-scale fibers under tension.

Design and test of a wheel-belt type cotton stalk puller

During the harvesting process,rigid materials are prone to causing damage to the cotton stalks,which will increase the risk of stalk breakage.A cotton stalk pulling component that blends stiff and flexible materials was devised to lower the breaking rate.The cotton stalk pulling component was made up of rollers and flexible belts that pull the stalks using clamping force and the forward speed of the tractor.The influence of various factors in the equipment on the harvesting effect of cotton stalks were analyzed through response surface experiments,and a multiple quadratic regression response surface model with missing pulling rate and breakage rate as response values was established.The significant of influencing factors on the breaking rate of cotton stalks are in a descending order as:the angle of cotton stalk pulling,tractor’s forward speed,and the clamping speed of the cotton stalk component.The working parameters of the wheel-belt type cotton stalk pulling machine have been optimized using the response surface combination experimental method,and the optimal parameter combination was obtained as:tractor forward speed of 4.5 km/h,cotton stalk pulling angle of 60°,and clamping speed of the cotton stalk pulling component of 349 r/min.The results of validation experiments showed that the missing pulling rate of cotton stalks was 5.06%and the breakage rate was 13.12%,indicating a good harvesting effect of the cotton stalks.The model was reasonable and the performance parameters could meet the relevant inspection requirements.The results can provide a reference for further research on the technology of flexible cotton stalk pulling.

Review of Real-time Simulation of Power Electronics

Real-time simulation of power electronics has been recognized by the industry as an effective tool for developing power electronic devices and systems.Since there is no energy transfer during the course of the usage,real-time simulation has a lot of advantages in the process of development and experimentation.From the perspective of real-time simulation,this paper focuses on the main problems in modeling accuracy,system bandwidth and stability,limitations on communication interface and energy interface,and the cost of platform construction.Finally,we provide further research directions.

Carrier dynamic overlapping switching frequency optimal pulse width modulation method for modular multilevel converters

Modular multilevel converters(MMCs) operate in the low modulation index region in many applications.However, when utilized at the low modulation index region, large harmonics appear in the output voltage, which degrade the performance of the MMC. To improve the harmonic characteristic in the low modulation index, the carrier dynamic overlapping switching frequency optimal pulse width modulation(CDOSFOPWM) method is proposed for the MMC here. The whole modulation index region is divided into three regions: high modulation index region, middle modulation index region, and low modulation index region. The carrier amplitude, carrier overlap ratio, and frequency of triangular carriers are chosen dynamically according to the modulation index region of the modulation signals, to achieve the optimal harmonic characteristic in the whole modulation index region and maintain the switching loss. The number of on-state submodules(SMs) can be calculated by CDOSFOPWM, and the selection of SMs is performed by a reducing switching frequency voltage balancing algorithm. Finally, the proposed method is verified by simulation and experimental results.

Engineering two-dimensional metal oxides and chalcogenides for enhanced electro-and photocatalysis

Two-dimensional(2D)metal oxides and chalcogenides(MOs&MCs)have been regarded as a new class of promising electro-and photocatalysts for many important chemical reactions such as hydrogen evolution reaction,CO_(2) reduction reaction and N2 reduction reaction in virtue of their outstanding physicochemical properties.However,pristine 2D MOs&MCs generally show the relatively poor catalytic performances due to the low electrical conductivity,few active sites and fast charge recombination.Therefore,considerable efforts have been devoted to engineering 2D MOs&MCs by rational structural design and chemical modification to further improve the catalytic activities.Herein,we comprehensively review the recent advances for engineering technologies of 2D MOs&MCs,which are mainly focused on the intercalation,doping,defects creation,facet design and compositing with functional materials.Meanwhile,the relationship between morphological,physicochemical,electronic,and optical properties of 2D MOs&MCs and their electro-and photocatalytic performances is also systematically discussed.Finally,we further give the prospect and challenge of the field and possible future research directions,aiming to inspire more research for achieving high-performance 2D MOs&MCs catalysts in energy storage and conversion fields.

East Asian paleoclimate change in the Weihe Basin (central China) since the middle Eocene revealed by clay mineral analysis

Obtaining a continuous sedimentary record of Cenozoic East Asian paleoclimate change is key to understand the origin,evolution and driving mechanism of the East Asian monsoon and climate change.Based on the continuous Cenozoic fluvial and lacustrine sedimentary sequence in the Weihe Basin,central China,we carried out research on the content and crystal parameters of clay minerals.The paleoclimate change since the middle Eocene was reconstructed accordingly.The results show that smectite and illite are the dominant clay minerals in fluvial-lacustrine sediments of Weihe Basin.The crystallinity of illite,the chemical index of illite,the ratio of smectite to illite and chlorite decrease gradually,which indicates that chemical weathering in the Weihe River watershed stepwise weakened since the middle Eocene,under the background of a semi-arid and semi-humid climate.The formation of palygorskite may be affected by a weak diagenesis.In this case,the content of smectite and the illite crystallinity caused by the weathering in the corresponding period may be actually higher than that of the current,which indicates that the climate in the Weihe Basin region was relatively warm and humid from the middle Eocene to Pliocene.With the decrease of Cenozoic global temperature and the continuous accumulation of sediments,the intensity of chemical weathering in the Weihe Basin gradually weakened,and the East Asian monsoon climate gradually evolved until becoming dry in the Quaternary.Evidence from clay minerals also indicates that the aridification in the Weihe Basin from the late Eocene to the Oligocene may be a response to the global cooling event at the Eocene-Oligocene transition.

Removal efficacy and mechanism of nitrogen and phosphorus by biological aluminum-based P-inactivation agent (BA-PIA)

In this study,aluminum-based P-inactivation agent(Al-PIA)was used as a high-efficiency microbial carrier,and the biological Al-PIA(BA-PIA)was prepared by artificial aeration.Laboratory static experiments were conducted to study the effect of BA-PIA on reducing nitrogen and phosphorus contents in water.Physicochemical characterization and isotope tracing method were applied to analyze the removal mechanism of nitrogen and phosphorus.High-throughput techniques were used to analyze the characteristic bacterial genus in the BA-PIA system.The nitrogen and phosphorus removal experiment was conducted for 30 days,and the removal rates of NH_(4)^(+)-N,TN and TP by BA-PIA were 81.87%,66.08%and 87.97%,respectively.The nitrogen removal pathways of BA-PIA were as follows:the nitrification reaction accounted for 59.0%(of which denitrification reaction accounted for 56.4%),microbial assimilation accounted for 18.1%,and the unreacted part accounted for 22.9%.The characteristic bacteria in the BA-PIA system were Streptomyces,Nocardioides,Saccharopolyspora,Nitrosomonas,and Marinobacter.The loading of microorganisms only changed the surface physical properties of Al-PIA(such as specific surface area,pore volume and pore size),without changing its surface chemical properties.The removal mechanism of nitrogen by BA-PIA is the conversion of NH_(4)^(+)-N into NO_(2)^(−)-N and NO_(3)^(−)-N by nitrifying bacteria,which are then reduced to nitrogen-containing gas by aerobic denitrifying bacteria.The phosphorus removal mechanism is that metal compounds(such as Al)on the surface of BA-PIA fix phosphorus through chemisorption processes,such as ligand exchange.Therefore,BA-PIA overcomes the deficiency of Al-PIA with only phosphorus removal ability,and has better application prospects.

Hepatitis B virus-associated follicular lymphoma presents T-cell inflamed phenotype and response to lenalidomide

Dear Editor,Follicular lymphoma(FL)represents the most common subtype of indolent non-Hodgkin's lymphoma(NHL)with distinct pathological,cytogenetic,and molecular features,accounting for 9.7%of NHLs in China[1].FL maintains a differentiation stage similar to germinal center(GC)B cells and is divided into grades 1,2,3A,and 3B[2].Up to 90%of FLs harbor the t(14;18)(q32;q21)/BCL2 apoptosis regula-tor(BCL2)-immunoglobulin heavy locus(IGH)transloca-tion and epigenetic modifier mutations,particularly lysine methyltransferase 2D(KMT2D)and CREB-binding pro-tein(CREBBP)[2].

BAF工艺预处理含微囊藻毒素微污染水源的微生物特征

以曝气生物滤池载体表面的生物膜为研究对象,通过镜检、磷脂脂肪酸（PLFA）测定、高通量454测序等手段研究了生物膜降解含氮有机物和微囊藻毒素-亮氨酸（MC-LR）的微生物特征.结果表明,低碳源的微污染水源中水生物膜的微生物群落极为丰富,形成了由好氧细菌组成的微生物群落,运行前2周有6大门类17大种属,3？4周增加到14大门类43大种属,还有线虫、草履虫、水蚤等原生动物;优势菌属有球衣菌属Sphaerotilus（2.41%？24.58%）、气单胞属Aeromonas（4.16%？12.59%）、黄杆菌属Cloacibacterium（1.85%？12.39%）、水杆菌属Aquabacterium（1.53%？6.76%）、噬氢菌属Hydrogenophaga（1.12%？5.9%）、嗜甲基菌属Methyloversatilis（0.53%？1.52%）、红杆菌属Rhodobacter（0.09%？1.39%）等.此外,投加0.16%T1菌剂芽孢杆菌后其含量增至1.97%,表明投加T1降解菌后芽孢杆菌迅速生长并成为优势种群,可强化降解MC-LR.

Superlow Power Consumption Artificial Synapses Based on WSe2 Quantum Dots Memristor for Neuromorphic Computing

As the emerging member of zero-dimension transition metal dichalcogenide,WSe2 quantum dots(QDs)have been applied to memristors and exhibited better resistance switching characteristics and miniaturization size.However,low power consumption and high reliability are still challenges for WSe_(2) QDs-based memristors as synaptic devices.