A new method for identifying flow pattern of spouted fluidized bed by coupling Hilbert-Huang transform characteristics of differential pressure signals in different zones

On a cold spouted fluidized bed,this study compares the characteristic differences in intrinsic mode function(IMF)energy and Hilbert–Huang spectrum between the spout zone and annulus zone under different combinations of spouted gas and fluidized gas flow rates for five typical flow patterns.The energy distribution characteristics under different flow patterns are also analyzed.The Hilbert–Huang spectrum and IMF energy of pressure difference signals exhibit distinct variations in different zones as the flow pattern changes.Moreover,there exists a correlation between the energy in the middle-frequency range and the flow pattern.Leveraging the K-means algorithm,the middle-frequency range energy of IMFs in the spout zone and annulus zone is subjected to clustering analysis,leading to the identification of partition boundaries for each flow pattern.Based on this,a flow pattern identification method of spouted fluidized bed coupled with middle-frequency range energy in spout zone and annulus zone is proposed,which has very high identification accuracy.

门冬胰岛素30注射液治疗2型糖尿病的疗效及安全性比较:多中心、随机、开放、平行对照Ⅲ期临床研究

目的探讨门冬胰岛素30注射液锐舒霖®30和诺和锐®30治疗2型糖尿病的疗效及安全性。方法本研究为多中心、随机、开放、平行、阳性药物对照Ⅲ期临床研究。纳入2018年10月10日至2021年1月5日来自国内35家研究中心口服药治疗血糖控制不佳的2型糖尿病患者,按照3∶1的比例根据区组随机方法分配至锐舒霖®30组和诺和锐®30组。治疗24周后,比较2组受试者治疗前后糖化血红蛋白(HbA1c)、空腹血糖(FPG)、标准餐后2 h静脉血糖(2hPG)的变化,以及低血糖事件和不良事件发生率、门冬胰岛素特异性抗体阳性率。有效性指标分析采用全分析集和符合方案集,安全性指标分析采用安全性数据集。组内比较采用配对t检验,组间比较采用独立样本t检验、χ2检验或Wilcoxon秩和检验。结果本研究共纳入受试者588例,完全符合方案病例528例(锐舒霖®30组395例,诺和锐®30组133例),全分析集和安全性数据集583例(锐舒霖®30组439例,诺和锐®30组144例),符合方案集515例(锐舒霖®30组386例,诺和锐®30组129例)。经过24周治疗后,锐舒霖®30组和诺和锐®30组的HbA1c分别下降1.73%±1.27%和1.77%±1.40%,FPG分别下降(2.34±2.69)和(2.68±2.84)mmol/L,2hPG分别下降(4.37±4.59)和(4.81±4.43)mmol/L,差异均无统计学意义(P>0.05)。治疗24周时,锐舒霖®30组和诺和锐®30组低血糖事件的发生率[分别为74.3%(326/439)和68.1%(98/144)]、不良事件发生率[分别为68.1%(299/439)和66.7%(96/144)]与门冬胰岛素特异性抗体阳性率[分别为51.9%(228/439)和50.7%(73/144)]相近,差异均无统计学意义(P>0.05)。结论锐舒霖®30和诺和锐®30控制血糖的总体疗效相当,具有良好的安全性,在临床上有应用价值。

Activation of hydrogen peroxide by molybdenum disulfide as Fenton-like catalyst and cocatalyst:Phase-dependent catalytic performance and degradation mechanism

Molybdenum disulfide(Mo S_(2))has attracted great attention in hydrogen peroxide(H_(2)O_(2))activation as a Fenton-like catalyst and cocatalyst,but the distinct mechanism of generating^(·)OH remains unclear.In this paper,the metallic 1T phase and semiconducting 2H phase of Mo S_(2)nanosheets were prepared and applied in MoS_(2)/H_(2)O_(2)and MoS_(2)/Fe^(2+)/H_(2)O_(2)systems with and without light irradiation.Compared with2H-MoS_(2),1T-MoS_(2)exhibited superior removal rates in degrading organic pollutants in the two systems under light irradiation.However,the phase had little effect on activating H_(2)O_(2)in the Mo S_(2)/H_(2)O_(2)system under dark conditions.This is because it was difficult for the surface^(·)OH_(ads)generated in the Mo S_(2)/H_(2)O_(2)system to diffuse into solution,while the^(·)OH_(free)radicals were mainly responsible for degrading organic pollutants.When introducing light irradiation,external energy may accelerate the desorption of^(·)OH_(ads)into^(·)OH_(free.)Interestingly,the conversion between Mo^(4+)and Mo^(5+)triggered the decomposition of H_(2)O_(2)in the Fenton-like reaction,while the cycle of Mo^(4+)/Mo^(6+)promoted the regeneration of Fe^(3+)when employing 1T-MoS_(2)as a cocatalyst.Meanwhile,the 1T-MoS_(2)catalysts exhibited excellent stability and ability to degrade various organics in the two systems.This work offers deeper insight into the Mo S_(2)-based Fenton-like and cocatalytic mechanisms.

西格列他钠与西格列汀单药治疗2型糖尿病患者的随机、双盲、Ⅲ期临床试验(CMAS)

西格列他钠(Chiglitazar,CGZ)是新型过氧化物酶体增殖物激活受体(PPAR)全激动剂,在针对2型糖尿病(T2DM)患者的前期探索性临床研究中已初步显示良好的疗效与安全性特征.本Ⅲ期临床试验比较CGZ与西格列汀(SGT)在经生活方式控制血糖不佳的T2DM患者中的有效性和安全性.患者随机(1:1:1)接受CGZ 32 mg(n=245)、CGZ 48 mg(n=246)或SGT 100 mg(n=248)治疗24周.CGZ 32 mg组、48 mg组与SGT 100 mg组在主要疗效终点指标——24周糖化血红蛋白(HbA_(1c))较基线变化值上分别为-1.40%、-1.47%和-1.39%,CGZ两组与SGT组为非劣效.CGZ具有更强降低空腹和餐后2 h血糖及空腹胰岛素的趋势.三组总体不良事件发生率相似,CGZ 48 mg组轻度水肿略增加,CGZ两组均有轻度体重增加.试验结果表明,西格列他钠对生活方式控制血糖不佳的T2DM患者具有总体良好的疗效和安全性,为这一PAR全激动剂治疗T2DM提供了确证性临床试验证据.

Characteristics of atmospheric volatile organic compounds in urban area of Beijing: Variations, photochemical reactivity and source apportionment

Atmospheric volatile organic compounds(VOCs)were observed by an on-line gas chromatography-flame ionization detector monitoring system from November 2016 to August 2017 in Beijing.The average concentrations were winter(40.27±25.25μg/m3)>autumn(34.25±19.90μg/m3)>summer(32.53±17.39μg/m3)>spring(24.72±17.22μg/m3).Although benzene(15.70%),propane(11.02%),ethane(9.32%)and n-butane(6.77%)were the most abundant species,ethylene(14.07%)and propene(11.20%)were the key reactive species to ozone formation potential(OFP),and benzene,toluene,ethylbenzene,mxylene+p-xylene and o-xylene(54.13%)were the most reactive species to secondary organic aerosol formation potential(SOAFP).The diurnal and seasonal variations indicated that diesel vehicle emission during early morning,gasoline vehicle emission at the traffic rush hours and coal burning during the heating period might be important sources.Five major sources were further identified by positive matrix factorization(PMF).The vehicle exhaust(gasoline exhaust and diesel exhaust)was found to be contributed most to atmospheric VOCs,with 43.59%,41.91%,50.45%and 43.91%,respectively in spring,summer,autumn and winter;while solvent usage contributed least,with 11.10%,7.13%,14.00%and 19.87%,respectively.Biogenic emission sources(13.11%)were only identified in summer.However,both vehicle exhaust and solvent usage were identified to be the key sources considering contributions to the OFP and SOAFP.Besides,the contributions of combustion during heating period and gasoline evaporation source during warm seasons to OFP and SOAFP should not be overlooked.

Thermal state calculation of chamber in small thrust liquid rocket engine for steady state pulsed mode

This paper presents a method of thermal state calculation of combustion chamber in small thrust liquid rocket engine. The goal is to predict the thermal state of chamber wall by using basic parameters of engine: thrust level, propellants, chamber pressure, injection pattern, film cooling parameters, material of wall and their coating, etc. The difficulties in modeling the startup and shutdown processes of thrusters lie in the fact that there are the conjugated physical processes occurring at various parameters for non-design conditions. A mathematical model to predict the thermal state of the combustion chamber for different engine operation modes is developed. To simulate the startup and shutdown processes, a quasi-steady approach is applied by replacing the transient process with time-variant operating parameters of steady-state processes. The mathematical model is based on several principles and data commonly used for heat transfer modeling: geometry of flow part, gas dynamics of flow, thermodynamics of propellants and combustion spices, convective and radiation heat flows, conjugated heat transfer between hot gas and wall, and transient approach for calculation of thermal state of construction. Calculations of the thermal state of the combustion chamber in single-turn-on mode show good convergence with the experimental results. The results of pulsed modes indicate a large temperature gradient on the internal wall surface of the chamber between pulses and the thermal state of the wall strongly depends on the pulse duration and the interval.

Multicomponent Tandem Polymerization of Aromatic Alkynes, Carbonyl Chloride, and Fischer's Base toward Poly(diene merocyanine)s

Summary of main observation and conclusion Multicomponent polymerization(MCP)is a popular tool to construct polymers with diverse structure,simple operation,and high efficiency,which faces the challenges of limited product structures.Multicomponent tandem polymerization(MCTP),combining two or multiple reactions in a one-pot fashion,could expand the scope of MCP and enrich the polymer structures.Herein,a one-pot three-component tandem polymerization of diynes,carbonyl chloride,and Fischer's base has been developed to afford conjugated poly(diene merocyanine)s with mild condition,satisfactory molecular weights(Mw up to 10900 g/mol)and yields(up to 81%).The polymers enjoy good solubility and high thermal stability.The unique emission behavior of the model compound and polymer show that they are aggregation-induced emission(AIE)-active,suggesting that the diene merocyanine moiety is a potential AIEgen.This MCTP shows great potential in the preparation of functional polymer materials,which could build new AlE functional units directly from the polymerization,demonstrating its synthetic simplicity and elegance.

Y_(2)O_(3)modification on nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)with improved electrochemical performance in lithium-ion batteries

Doping and coating are frequently employed for the improvement of the properties of Ni-rich NCM materials.In this work,we prepared stable LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)materials modified withY_(2)O_(3)via a wet chemical method.In order to investigate the action mechanism ofY_(2)O_(3)on NCM811,we analyzed the micro structures using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Also,to study the electrochemical performances,we conducted a charge/discharge test and cyclic voltammetry.Our results show thatY_(2)O_(3)modified NCM811 materials have good thermal stability,and proper content ofY_(2)O_(3)can effectively prevent the materials from damaging and significantly improve the electrochemical properties of the materials.Particularly,1%Y2 O3 modified NCM811 material show much better cycling performance than other samples.During cycling at 1.0 C the 1%Y2 O3 modified NCM811 shows capacity retention of 90.1%after 100 cycles,which is higher than 69.4%for pristine NMC811.We examined the microstructures of the materials before and after circulation.Using the SEM results,we conclude that structural changes are among the key factors that lead to the degradation of the electrochemical properties of materials.

The lithium and sodium storage performances of phosphorus and its hierarchical structure

Recent preparation of black phosphorene and subsequent discovery of its excellent optical and electronic properties have attracted great attenti on,and ren ewed interest to phosphorus.Rece nt researches have indicated that phosphorus structures are promisi ng an odes for lithium-ion and sodium-ion batteries.A high theoretical capacity of 2,596 mAh·g^-1 was predicted for phosphorus according to the reaction of 3Li/Na+P→Li3P/Na3P.However,fast capacity degradation is accompanying with most phosphorus structures due to the low electronic conductivity and structural pulverization induced by large volume change in charging and discharging proceses.The electrochemical performances are significantly affected by the hierarchical structural design of phosphorus.A few reviews of phosphorus structures have been reported recent?However,no review about the electrochemical performances of phosphorus structures according to their hierarchical structures has been reported.First of all,phosphrus allotropes along with their structure and fundamental properties are briefly reviewed in this work.Secondly,the studies on lithiation/sodiation mechanism of red/black phosphorus are presented.Thirdly,a summary about the electrochemical performances of red/black phosphorus composites with different hierarchical structures is presented.Furthermore,the,development challenges and future perspectives of phosphorus structures as anodes for LIBs and SIBs are discussed.

Hemin-histamine-montmorillonite clay conjugate as a model biocatalyst to mimic natural peroxidase

We successfully synthesized the first hemin-montmorillonite bio-conjugate with an amino acid residue to mimic natural peroxidase enzyme. Histamine was intercalated in montmorillonite by cation exchange, then a hemin molecule was loaded onto the histamine-montmorillonite with an adsorption capacity of 7.0 mg g-1. The hemin-histamine-montmorillonite conjugate shows high peroxidase activity as indicated by the oxidation of guaiacol, which is attributed to the activation of hemin by Fe–N complex formation between the imidazole group in histamine and the iron ion in the hemin molecule. Temperature- dependent peroxidase activity for this synthesized biomimetic material indicates that raising the reaction temperature could significantly enhance the activity of the conjugate. The biomimetic catalyst has good reusability; nearly 100% activity can be retained after three cycles. Because montmorillonite clay is widely distributed in the environment, this material offers great potential for in situ and ex situ remediation of many organic contaminants in surface/subsurface soils.

Hemin associated to cetyltrimethylammonium broide micelles: a biomimetic catalyst for 2,4,6-trichlorophenol degradation

For the first time, an efficient, green, economical biomimetic catalyst(hemin-cetyltrimethylammonium bromide micelles) was discovered to degrade 2,4,6-trichlorophenol(TCP). The degradation experiments indicate that p H, temperature, the addition of 2-methylimidazole, and the amount of hydrogen peroxide influence the degradation process. Test of reusability revealed that CTAB micelles can protect hemin from destruction by H2O2 and that the materials can be recycled. This material can be of great use for waste-water treatment.

Preliminary study of groundwater denitrification using a composite membrane bioreactor

A composite membrane bioreactor(CMBR)integrating the immobilized cell technique and the membrane separation technology was developed for groundwater denitrification.The CMBR had two well mixed compartments with one filled with the nitratecontaining influent and the other with a dilute ethanol solution;the compartments were separated by the composite membrane consisting of a microporous membrane facing the influent and an immobilized cell membrane facing the ethanol solution.Nitrate and ethanol molecules diffused from the respective compartments into the immobilized cell membrane where nitrate was reduced to gaseous nitrogen by the denitrifying bacteria present there with ethanol as the carbon source.The microporous membrane was attached to one side of the immobilized cell membrane for retention of the disaggregated bacteria.Relative to the single dose of external ethanol,the twodose supplementation produced better treatment results as evidenced by the lower concentrations of NO_(3)^(-)-N and ethanol(as measured by total organic carbon)of the effluent.The batch treatment in CMBR removed most of the nitrate in the influent and attained a stable denitrification rate of 0.1 g·m^(-2)·h^(-1)for most of the 96-h cycles during the 30-cycle study.The effluent was essentially free of ethanol and nitrite nitrogen.