300 MW CFB锅炉旋风分离器改造数值模拟研究

旋风分离器分离性能会显著影响循环流化床锅炉的运行。为解决某300 MW循环流化床锅炉旋风分离器分离器性能差的问题,基于欧拉-拉格朗日框架,使用UGNX12.0软件对该300 MW循环流化床锅炉的炉膛、旋风分离器、返料阀按照实际尺寸1∶1建立全回路几何模型,根据实际参数设置边界条件,并通过Barracuda软件进行数值模拟,分析旋风分离器烟道入口各参数(入口烟道高度、入口烟道宽度、入口下倾角大小及中心筒插入深度)对旋风分离器效率及压降的影响;综合考虑分离器的分离效率、压降以及磨损量,提出了2个改造方案。仿真结果表明:炉膛内压力模拟值与实际值的偏差均在5%以内,模拟结果较为精确;2个方案在各负荷下均能提升旋风分离器分离性能,方案1满负荷下效率相较于较改造前提升了0.260%,压降降低了13.1 Pa,方案2满负荷下效率相较于改造前提升了0.240%,压降降低了53.7 Pa;随着负荷降低,旋风分离器效率提升逐渐不明显,在300、260和160 MW负荷下,方案1分别提升0.263%、0.178%和0.023%,方案2分别提升0.243%、0.174%和0.020%。

基于数据驱动技术的电力通信调度数字化管控系统研究

文章探讨数据驱动技术在电力通信调度中的应用潜力,并设计一套基于数据驱动技术的电力通信调度数字化管控系统。该系统综合运用图神经网络(Graph Neural Network,GNN)和深度强化学习等技术,实现对电力通信网络的实时感知、智能调度优化以及自动化管控。仿真实验结果表明,所设计的系统在提高网络资源利用效率和保障业务服务质量等方面具有显著优势。

Retrospective study of effect of whole-body vibration training on balance and walking function in stroke patients

BACKGROUND Dysfunction in stroke patients has been a problem that we committed to solve and explore.Physical therapy has some effect to regain strength,balance,and coordination.However,it is not a complete cure,so we are trying to find more effective treatments.AIM To observe the effect of whole-body vibration training(WVT)on the recovery of balance and walking function in stroke patients,which could provide us some useful evidence for planning rehabilitation.METHODS The clinical data of 130 stroke participants who underwent conventional rehabilitation treatment in our hospital from January 2019 to August 2020 were retrospectively analyzed.The participants were divided into whole-body vibration training(WVT)group and non-WVT(NWVT)group according to whether they were given WVT.In the WVT group,routine rehabilitation therapy was combined with WVT by the Galileo Med L Plus vibration trainer at a frequency of 20 Hz and a vibration amplitude of 0+ACY-plusmn+ADs-5.2 mm,and in the NWVT group,routine rehabilitation therapy only was provided.The treatment course of the two groups was 4 wk.Before and after treatment,the Berg balance scale(BBS),3 m timed up-and-go test(TUGT),the maximum walking speed test(MWS),and upper limb functional reaching(FR)test were performed.RESULTS After 4 wk training,in both groups,the BBS score and the FR distance respectively increased to a certain amount(WVT=46.08±3.41 vs NWVT=40.22±3.75;WVT=20.48±2.23 vs NWVT=16.60±2.82),with P<0.05.Furthermore,in the WVT group,both BBS score and FR distance(BBS:18.32±2.18;FR:10.00±0.92)increased more than that in the NWVT group(BBS:13.29±1.66;FR:6.16±0.95),with P<0.05.Meanwhile,in both groups,the TUGT and the MWS were improved after training(WVT=32.64±3.81 vs NWVT=39.56±3.68;WVT=12.73±2.26 vs NWVT=15.04±2.27,respectively),with P<0.05.The change in the WVT group(TUGT:17.49±1.88;MWS:6.79±0.81)was greater than that in the NWVT group(TUGT:10.76±1.42;MWS:4.84±0.58),with P<0.05.CONCLUSION The WVT could effectively improve the balance and walking function in stroke patients,which may be good for improving their quality of life.

Copper methanesulfonate-acetic acid as a novel catalytic system for tetrahydropyranylation of alcohols and phenols

A synergistic catalytic effect between copper methanesulfonate and acetic acid in tetrahydropyranylation of alcohols and phenol at room temperature under solvent free condition has been described. Both alcohols （primary, secondary and tertiary） and phenols reacted with 3,4-dihydro-2H-pyran smoothly to afford the corresponding tetrahydropyranyl ethers in good yields.

Ferrous methanesulfonate as an efficient and recyclable catalyst for chemoselective synthesis of 1,1-diacetate from aldehydes

Ferrous methanesulfonate catalysing the conversion of aromatic, heteroaromatic, unsaturated, and aliphatic aldehydes to 1,1- diacetates at room temperature under solvent-free condition has been developed. The catalytic activity of seventeen metal methanesulfonates was compared under the same condition, ferrous methanesufonate proved to be the best. It can be easily recovered and reused for several times without distinct deterioration in catalytic activity. During the competitive protection between a ketone and an aldehyde group with Ac20, 1,1-diacetate formed exclusively with the aldehyde group. 2009 Min Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and reused many times. The reaction was mild and efficient with good to high yields.

Counter-ion insertion of chloride in Mn3O4 as cathode for dual-ion batteries: A new mechanism of electrosynthesis for reversible anion storage

Irreversible reductive insertion of Zn2+transforms Mn3O4 such that the resulting Zn0.2Mn3O4 exhibits highly reversible storage properties of chloride ions,thus rendering Zn0.2Mn3O4 an excellent cathode of aqueous dual-ion batteries.With Zn2+trapped,Zn0.2Mn3O4 delivers the chloride-storage capacity over 200 mAh/g at an average potential of 1.6 V vs Zn2+/Zn by reversibly forming a new ionic compound equivalent to Zn0.2Mn3O4Cl1.7.Electrochemical quartz crystal microbalance results suggest chloride as the primary charge carrier in the reversible oxidative anion insertion.The Mn3O4 anion-hosting cathode couples with Zn metal anode in a full-cell dual-ion battery,demonstrating stable cycling in practical pouch cells with an energy density of 150 Wh/kg based on the mass of both electrodes.

Metastasis to the thyroid gland from primary breast cancer presenting as diffuse goiter:A case report and review of literature

BACKGROUND Metastasis to the thyroid gland(TM)from primary breast cancer is uncommon and usually presents as thyroid nodules;however,diffuse goiter without thyroid nodules is the first sign of TM in rare cases.Skip metastases(SMs)to the lymph nodes in breast cancer,defined as discontiguous higher-level metastases in the absence of lower levels of contiguous metastases,have been reported in the contralateral cervical area of the primary tumor site in rare cases.CASE SUMMARY A 49-year-old previously healthy Chinese woman was diagnosed with right lateral invasive ductal carcinoma and underwent neoadjuvant chemotherapy treatment and bilateral mastectomy with axillary lymph node dissection.No malignancy of the left breast or axillary or distant metastases were identified preoperatively.However,enlarged left cervical lymph nodes were detected 36 mo after surgery,and rapidly enlarging thyroid glands without nodules were detected 42 mo after surgery.Fine-needle aspiration cytology was performed on the left cervical lymph nodes and left lobe of the thyroid,which were both revealed to contain metastases from the primary breast cancer.Additionally,the immunostaining profiles changed in the process of metastases.The patient was discharged with the NP(vinorelbine and cisplatin)regimen for subsequent treatment,and stable disease was determined when the curative effect was evaluated.CONCLUSION Diffuse goiter may be the first sign of TM,and enlarged lymph nodes in the contralateral cervical area may be SMs of primary breast cancer.

Preparation and properties of Os–Ir–Al alloy for impregnated tungsten cathodes

Os–Ir–Al alloy was fabricated by powder metallurgy technique.IrAl and OsIr interalloys were synthesized to reduce the Al evaporation and ensure the composition of the ternary alloy.Analysis on microstructures shows that each component is distributed homogeneously,and the green density reaches 94.9%.Ba–W cathodes with Os–Ir–Al alloy magnetic sputtered on the tips are prepared and directly current density tests are carried out on these cathodes.It is found that at 1,050℃,the average zero field emission density of the cathode reaches up to 20 Aácm-2.The improvements of cathodic current density and stability may indicate the prosperous application of Os–Ir–Al alloy on cathode.

Underwater acoustic metamaterial based on double Dirac cone characteristics in rectangular phononic crystals

We theoretically construct a rectangular phononic crystal(PC) structure surrounded by water with C2vsymmetry, and then place a steel rectangular scatterer at each quarter position inside each cell. The final complex crystal has two forms:the vertical type, in which the distance s between the center of the scatterer and its right-angle point is greater than 0.5 a,and the transverse type, in which s is smaller than 0.5 a(where a is the crystal constant in the x direction). Each rectangular scatterer has three variables: length L, width D, and rotation angle θ around its centroid. We find that, when L and D change and θ is kept at zero, there is always a linear quadruply degenerate state at the corner of the irreducible Brillouin zone. Then, we vary θ and find that the quadruply degenerate point splits into two doubly-degenerate states with odd and even parities. At the same time, the band structure reverses and undergoes a phase change from topologically non-trivial to topologically trivial. Then we construct an acoustic system consisting of a trivial and a non-trivial PC with equal numbers of layers, and calculate the projected band structure. A helical one-way transmission edge state is found in the frequency range of the body band gap. Then, we use the finite-element software Comsol to simulate the unidirectional transmission of this edge state and the backscattering suppression of right-angle, disorder, and cavity defects. This acoustic wave system with rectangular phononic crystal form broadens the scope of acoustic wave topology and provides a platform for easy acoustic operation.

Textural differences based on apparent diffusion coefficient maps for discriminating pT3 subclasses of rectal adenocarcinoma

BACKGROUND The accuracy of discriminating pT3a from pT3b-c rectal cancer using highresolution magnetic resonance imaging(MRI)remains unsatisfactory,although texture analysis(TA)could improve such discrimination.AIM To investigate the value of TA on apparent diffusion coefficient(ADC)maps in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors.METHODS This was a case-control study of 59 patients with pT3 rectal adenocarcinoma,who underwent diffusion-weighted imaging(DWI)between October 2016 and December 2018.The inclusion criteria were:(1)Proven pT3 rectal adenocarcinoma;(2)Primary MRI including high-resolution T2-weighted image(T2WI)and DWI;and(3)Availability of pathological reports for surgical specimens.The exclusion criteria were:(1)Poor image quality;(2)Preoperative chemoradiation therapy;and(3)A different pathological type.First-order(ADC values,skewness,kurtosis,and uniformity)and second-order(energy,entropy,inertia,and correlation)texture features were derived from whole-lesion ADC maps.Receiver operating characteristic curves were used to determine the diagnostic value for pT3b-c tumors.RESULTS The final study population consisted of 59 patients(34 men and 25 women),with a median age of 66 years(range,41-85 years).Thirty patients had pT3a,24 had pT3b,and five had pT3c.Among the ADC first-order textural differences between pT3a and pT3b-c rectal adenocarcinomas,only skewness was significantly lower in the pT3a tumors than in pT3b-c tumors.Among the ADC second-order textural differences,energy and entropy were significantly different between pT3a and pT3b-c rectal adenocarcinomas.For differentiating pT3a rectal adenocarcinomas from pT3b-c tumors,the areas under the curves(AUCs)of skewness,energy,and entropy were 0.686,0.657,and 0.747,respectively.Logistic regression analysis of all three features yielded a greater AUC(0.775)in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors(69.0%sensitivity and 83.3%specificity).CONCLUSION TA features derived from ADC maps might potentially differentiate pT3a rectal adenocarcinomas from pT3b-c tumors.

Photoexcitation of Dihydroquinazolinone Anionic Compounds:Difluoroalkylarylation and Difluoroalkylamination of Alkenes

The direct excitation of dihydroquinazolinone(DHQ)anions by visible light has been demonstrated by photophysical experiments.The excited-state DHQ anion serves as both a potent reductant and a radical precursor in a redox neutral radical cascade,circumventing the use of an external photoredox catalyst.Various gem-difluoroalkyl radicals(CF_(2)H and CF_(2)R)are produced from the excited-state DHQ anions,leading to the first example of intermolecular 1,2-difluoroalkylarylation(CF_(2)H-and CF_(2)R-arylation)of alkenes in overall redox-neutral manner.Similarly,1,2-difluoroalkylamination of styrenes has also been realized,offering a practical pathway for the preparation of diverseβ-CF_(2)H amines.This general and efficient strategy for the generation of CF_(2)H and CF_(2)R radicals exhibits great potential for applications in drug discovery.

Aqueous decoupling batteries: Exploring the role offunctional ion-exchange membrane

The relentless pursuit of sustainable and safe energy storage technologies hasdriven a departure from conventional lithium-based batteries toward other relevantalternatives. Among these, aqueous batteries have emerged as a promisingcandidate due to their inherent properties of being cost-effective, safe,environmentally friendly, and scalable. However, traditional aqueous systemshave faced limitations stemming from water's narrow electrochemical stabilitywindow (-1.23 V), severely constraining their energy density and viability inhigh-demand applications. Recent advancements in decoupling aqueous batteriesoffer a novel solution to overcome this challenge by separating the anolyteand catholyte, thereby expanding the theoretical operational voltage windowto over 3 V. One key component of this innovative system is the ion-selectivemembrane (ISM), acting as a barrier to prevent undesired crossover betweenelectrolytes. This review provides a comprehensive overview of recent advancementsin decoupling aqueous batteries, emphasizing the application of varioustypes of ISMs. Moreover, we summarize different specially designed ISMs andtheir performance attributes. By addressing the current challenges ISMs face,the review outlines potential pathways for future enhancement and developmentof aqueous decoupling batteries.

Dynamic analysis of tethered defunct satellites with solar panels

A precise dynamic model for towing and removing a defunct satellite with solar panels in orbit using a tethered net often has low computational efficiency owing to the complex contact and collision between the net and panels,which is not conducive to research.To solve this problem,a“single main tether–multiple subtether”bifurcation structure with beads was employed as the tethered net model.This study investigated the dynamics of tethered defunct satellites with solar panels,particularly the behavior of the attitude of the tethered satellite,oscillation of the main tether,and vibration of solar panels under different conditions.The results showed that different attachment configurations of the subtethers and the flexibility of the main tether have an evident impact on the dynamic characteristics of the system.

Adverse Effects of Opioid Analgesics in Osteoarthritis Treatment:A Global Meta-Analysis,2000-2022

Osteoarthritis(OA)treatment commonly depends on nonsteroidal anti-inflammatory drugs and opioid medications.Nevertheless,the clinical use of opioids is controversial due to their adverse effects and addiction potential.This study,drawing on 24 randomized controlled trials(RCTs)with a total of 9,586 patients,thoroughly explored the various side effects associated with opioid use in OA treatment.The results provide additional insight into the non-addictive risks of opioids and may assist clinicians in their judicious use,potentially fostering the advancement of safer treatment options.By reducing the risks of misuse and addiction,public health and safety can be enhanced.

Measuring and preventing alcohol use and related harm among young people in Asian countries:a thematic review

Background:The paper reviews alcohol consumption patterns and alcohol-related social and health issues among 15-29-year old young people in Asian countries,and discusses strategies for preventing and controlling alcohol use and related harms.Methods:We searched Google Scholar,PubMed,and Web of Science for reports,reviews and journal articles published in English between 1st Jan 1990 and 31st August 2016.Results:Forty-one reports,reviews and journal papers were identified and included in the final review.The current drinking levels and prevalence among young people are markedly different between eight included Asian countries,ranging from 4.2%in Malaysia to 49.3%in China.In a majority of the selected Asian countries,over 15%of total deaths among young men and 6%among young women aged 15-29 years are attributable to alcohol use.Alcohol use among young people is associated with a number of harms,including stress,family violence,injuries,suicide,and sexual and other risky behaviours.Alcohol policies,such as controlling sales,social supply and marketing,setting up/raising a legal drinking age,adding health warning labels on alcohol containers,and developing a surveillance system to monitor drinking pattern and risky drinking behaviour,could be potential means to reduce harmful use of alcohol and related harm among young people in Asia.Conclusions:The review reveals that drinking patterns and behaviours vary across eight selected Asian countries due to culture,policies and regional variations.The research evidence holds substantial policy implications for harm reduction on alcohol drinking among young people in Asian countries-especially for China,which has almost no alcohol control policies at present.

Antagonistic interaction between Trichoderma asperellum and Phytophthora capsici in vitro

Phytophthora capsici is a phytopathogen that causes a destructive pepper blight that is extremely difficult to control. Using a fungicide application against the disease is costly and relatively ineffective and there is also a huge environmental concern about the use of such chemicals. The genus Trichoderma has been known to have a potential biocontrol issue. In this paper we investigate the mechanism for causing the infection of T. asperellum against P. capsici. Tnchoderma sp. （isolate CGMCC 6422） was developed to have a strong antagonistic action against hyphae of P. capsici through screening tests. The strain was identified as T. asperellum through using a combination of morphological characteristics and molecular data. T. asperellum was able to collapse the mycelium of the colonies of the pathogen through dual culture tests by breaking down the pathogenic hyphae into fragments. The scanning electron microscope showed that the hyphae of T. aspere/lum surrounded and penetrated the pathogens hyphae, resulting in hyphal collapse. The results show that seven days after inoculation, the hyphae of the pathogen were completely degraded in a dual culture. T. asperel/um was also able to enter the P. capsici oospores through using oogonia and then developed hyphae and produced conidia, leading to the disintegration of the oogonia and oospores. Seven days after inoculation, an average 10.8% of the oospores were infected, but at this stage, the structures of oospores were still intact. Subsequently, the number of infected oospores increased and the oospores started to collapse. Forty-two days after inoculation, almost all the oospores were infected, with 9.3% of the structures of the oospores being intact and 90.7% of the oospores having collapsed.

Phase transition and heterogeneous strengthening mechanism in CoCrFeNiMn high-entropy alloy fabricated by laser-engineered net shaping via annealing at intermediate-temperature

High-entropy alloys(HEAs)have attracted tremendous attention owing to their controllable mechanical properties,whereas additive manufacturing(AM)is an efficient and flexible processing route for novel materials design.However,a profound appraisal of the fundamental material physics behind the strengthening of AM-printed HEAs upon low/intermediate-temperature annealing is essential.In this work,Co CrFe Ni Mn HEAs have been prepared using laser-engineered net shaping(LENS)and subsequently annealed at different temperatures.The Co Cr Fe Ni Mn HEA annealed at intermediate-temperature(873 K)exhibits a strong strain hardening capability,resulting in ultimate strength of 725 MPa and plasticity of 22%.A ternary heterogeneous strengthening mechanism is proposed to explain this phenomenon,in which equiaxed grains,columnar grains,andσprecipitates play different roles during tensile deformation.The resultant excellent strength and ductility can be ascribed to the heterostructure-induced mismatch.The equiaxed grains provide adequate grain boundaries(GBs),which induce dislocation plugging-up and entanglement;the columnar grains induce the onset and arrest of the dislocations for plastic deformation;and theσprecipitates hinder the movement of slip dislocations.The results provide new insights into overcoming the strength-ductility trade-off of LENS-printed HEAs with complex geometries.

Chemistry With N-Centered Radicals Generated by Single-Electron Transfer-Oxidation Using Photoredox Catalysis

This review covers the recent literature on oxidative generation of N-centered radicals using photoredox catalysis.The concept of proton-coupled electron transfer is briefly discussed.Applications of such reactive N-centered radicals in cascade processes comprising arene amidation,alkene amidation,C—C bond cleavage reactions,and remote C—H functionalization are addressed.In addition,novel reagents allowing for clean oxidative N-radical generation are discussed.

Nb_(2)CT_(x)MXene boosting PEO polymer electrolyte for all-solid-state Li-S batteries:two birds with one stone strategy to enhance Li+conductivity and polysulfide adsorptivity

All-solid-state lithium-sulfur(Li-S)battery is regarded as next-generation high energy density and safety battery system.The key challenge is to develop a compatible high-performance solid-state electrolyte.Herein,a two birds with one stone strategy is proposed to simultaneously enhance Li+conductivity and polysulfide adsorptivity of poly(ethylene oxide)(PEO)-based polymer electrolyte via the integration of Nb_(2)CT_(x)MXene.Moreover,the sheet size of Nb_(2)CT_(x)MXene is crucial for the enhancement of Li^(+)conductivity and polysulfide adsorptivity,attributing to the difference in a specific surface area related to the percolation effect.By tuning the sheet size of Nb_(2)CT_(x)MXene from 500-300 nm to below 100 nm,the ionic conductivity of the PEO electrolyte is increased to2.62×10^(-4)S·cm^(-1)with improved Li+transference number of 0.37 at 600C.Furthermore,theoretical calculation and X-ray photoelectron spectroscopy(XPS)conjointly prove that poly sulfides could be effectively adsorbed by Nb2CTxnanosheets via forming Nb-S bonding to inhibit their shuttle in the PEO framework.As a result,the all-solid-state Li-S cell exhibits an initial capacity of 1149 mAh·g^(-1)at 0.5C and good cycling stability with 491 mAh·g^(-1)after 200 cycles.The results demonstrate the necessity of polysulfide inhibition and the application of Nb_(2)CT_(x)MXene in PEO-based electrolytes for all-solid-state Li-S batteries.