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Journal of Materials Science & Technology 2021年第1期60卷 147-155页

作者： Haoxuan Wang Shouye Wang Yejie Cao wen liu Yiguang Wang Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’anShaanxi 710072PR China School of Materials Science and Engineering Zhengzhou UniversityZhengzhouHenan 450052PR China Institute of Advanced Structure Technology Beijing Institute of TechnologyHaidian District 100081BeijingPR China

In this work,high-entropy ceramics(Hf_(0.25) Zr_(0.25)Ta_(0.25)Nb_(0.25))C(HZTNC) and HZTNC doped with 20 vol%SiC(HZTNC-SiC) were fabricated by spark plasma *** oxidation behavior was investigated over the temperature range of 1300-1500℃ for up to 60 *** HZTNC and HZTNC-SiC exhibited good oxidation resistance,and their weight change as a function of oxidation time obeyed a parabolic *** XRD,microstructure observation,and elemental mapping analysis of the oxide layers,it was found that the formation of Nb_(2) Zr_(6) O_(17),Hf_(6) Ta_(2) O_(17),and(Ta,Nb)_(2) O_(5) mixed-oxide layers effectively protected the matrix from further *** began to appear on the oxide layer of HZTNC at high temperatures after 60 min of ***,the addition of SiC in HZTNC suppressed these microcracks at high temperatures due to the active oxidation of *** with the oxides formed on HZTNC,the additional formation of Hf(Zr)SiO_(4) on HZTNC-SiC could further improve its oxidation resistance over HZTNC ceramics.

关键词： High-entropy carbide Oxidation resistance Oxidation mechanism

Characterization of bacterial community dynamics in a full-scale drinking water treatment plant

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Journal of Environmental Sciences 2017年第1期29卷 21-30页

作者： Cuiping Li Fangqiong Ling Minglu Zhang wen-Tso liu Yuxian Li wenjun liu School of Environment Tsinghua UniversityBeijing 100084China. Department of Civil and Environment Engineering University of Illinois at Urbana-ChampaignUrbanaIL 62801USA School of Food and Chemical Engineering Beijing Technology and Business UniversityBeijing 100048China Water Quality Monitoring Center Beijing Waterworks GroupBeijing 100085China

Understanding the spatial and temporal dynamics of microbial communities in drinking water systems is vital to securing the microbial safety of drinking *** objective of this study was to comprehensively characterize the dynamics of microbial biomass and bacterial communities at each step of a full-scale drinking water treatment plant in Beijing,*** bulk water and biofilm samples on granular activated carbon（GAC） were collected over 9 *** proportion of cultivable cells decreased during the treatment processes,and this proportion was higher in warm season than cool season,suggesting that treatment processes and water temperature probably had considerable impact on the R2 A cultivability of total bacteria.16 s rRNA gene based 454 pyrosequencing analysis of the bacterial community revealed that Proteobacteria predominated in all *** GAC biofilm harbored a distinct population with a much higher relative abundance of Acidobactena than water *** coordinate analysis and one-way analysis of similarity indicated that the dynamics of the microbial communities in bulk water and biofilm samples were better explained by the treatment processes rather than by sampling time,and distinctive changes of the microbial communities in water occurred after GAC ***,20 distinct OTUs contributing most to the dissimilarity among samples of different sampling locations and 6 persistent OTUs present in the entire treatment process flow were ***,our findings demonstrate the significant effects that treatment processes have on the microbial biomass and community fluctuation and provide implications for further targeted investigation on particular bacteria populations.

关键词： Heterotrophic plate count Flow cytometry 454 pyrosequencing Bacterial community Dynamics

Comparative studies on promotional effect of Pr_(6)O_(11),Nd_(2)O_(3)and Sm_(2)O_(3)on Ni-SiO_(2) for pressurized carbon dioxide reforming of methane

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Journal of Rare Earths 2023年第6期41卷 830-838,I0002页

作者： Bin Li Ting Li Yong-Shan Xiao Zhong-wen liu Key Laboratory of Syngas Conversion of Shaanxi Province School of Chemistry&Chemical EngineeringShaanxi Normal UniversityXi'an 710119China

The 7 wt%rare earth metal oxide promoted Ni-SiO_(2) catalysts of Ni-7Pr_(6)O_(11)-SiO_(2),Ni-7Nd_(2)O_(3)-SiO_(2),and Ni-7Sm_(2)O_(3)-SiO_(2) were prepared by the complex-decomposition method,and were comparatively evaluated for pressurized carbon dioxide reforming of methane(CRM)under severe conditions of 750℃,1.0 MPa,CH_(4)/CO_(2)=1,and gas hourly space velocity of 53200 mL/(g·h).The addition of rare earth metal oxide does not affect the Ni dispersion,and all of the catalysts show similarly high Ni dispersion of16.0%±0.2%.As a result,all of the catalysts are highly active for pressurized CRM,the initial CH_(4) conversions of which approach the thermodynamic equilibrium(47.0%±0.2%).In contrast,a clearly favorable effect of the added rare earth metal oxide on the stability of Ni-SiO_(2)was revealed from the CRM results for a time-on-stream of 50 h,and the highest stability without an observable decrease in the conversions of CH_(4)and CO_(2)was obtained over Ni-7Sm_(2)O_(3)-SiO_(2).Based on the characterization results of thermogravimetric differential scanning calorimetry(TG-DSC)and transmission electron microscopy(TEM),the improved stability of Ni-7Pr_(6)O_(11)-SiO_(2),Ni-7Nd_(2)O_(3)-SiO_(2),and Ni-7Sm_(2)O_(3)-SiO_(2)for pressurized CRM was manifested mainly as the suppressed formation of carbon nanotubes over the catalyst surface,the extent of which is dependent on the specific rare earth metal ***,the consecutive temperature programmed surface reaction of CH_(4),CO_(2),and O_(2)over Ni-7Sm_(2)O_(3)-SiO_(2)vigorously reveals that the addition of Sm_(2)O_(3)into Ni-SiO_(2)inhibits the CH_(4)decomposition but enhances the oxidization of the carbon species by CO_(2),leading to the well-balanced rates for forming and removing the coke over Ni-7Sm_(2)O_(3)-SiO_(2).These findings are not only beneficial to deeply understanding the promotional effect of rare earth metal oxides on Ni-based catalysts for CRM,but also important for extending the application of

关键词： Carbon dioxide Methane Pressurized reforming Rare earth metal oxide Nickel

Separation of tungsten and molybdenum with solvent extraction using functionalized ionic liquid tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1769-1776页

作者： Fei Cao Wei Wang De-zhou Wei wen-gang liu School of Resource and Civil Engineering Northeastern UniversityShenyang 110819China Zhengzhou Institute of Multipurpose Utilization of Mineral Resources CAGSZhengzhou 450006China Key Laboratory for Polymetallic Ores’Evaluation and Utilization MNRZhengzhou 450006China

Functionalized ionic liquids(FILs)as extractants were employed for the separation of tungsten and molybdenum from a sulfate solution for the first *** effects of initial pH,extractant concentration,metal concentrations in the feed were comprehensively *** results showed that tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate([A336][Cyanex272])could selectively extract W over Mo at an initial pH value of 5.5;the best separation factorβ_(W/Mo) of 25.61 was obtained for a solution with low metal concentrations(WO3:2.49 g/L,Mo:1.04 g/L).The[A336][Cyanex272]system performed effectively for solutions of different W/Mo molar ratios and different metal ion concentrations in the *** chemical reaction between[A336][Cyanex272]and W followed the ion association mechanism,which was further proved by the Fourier-transform infrared(FTIR)spectra of loaded[A336][Cyanex272]and the free *** stripping experiments indicated that 95.48%W and 100.00%Mo were stripped using a 0.20 mol/L sodium hydroxide ***,the selective extractions of W and Mo from two synthetic solutions of different high metal concentrations were obtained;the separation factorβW/Mo reached 23.24 and 17.59 for the first and second solutions,*** results suggest the feasibility of[A336][Cyanex272]as an extractant for the separation of tungsten and molybdenum.

关键词： tungsten molybdenum ionic liquid separation solvent extraction

A Compensation Algorithm for Large Element Characterizing the Damage Evolution Process and Its Application to Structure Collisions

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 315-331页

作者： wen liu Lele Zhang Yifan Ru Geng Chen Weiyuan Dou School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing100044China National International Science and Technology Cooperation Base Beijing Jiaotong UniversityBeijing100044China

When simulating the process from elastic–plastic deformation,damage to failure in a metal structure collision,it is necessary to use the large shell element due to the calculation efficiency,but this would affect the accuracy of damage evolution *** compensation algorithm adjusting failure strain according to element size is usually used in the damage model to deal with the *** this paper,a new nonlinear compensation algorithm between failure strain and element size was proposed,which was incorporated in the damage model GISSMO(Generalized incremental stress state dependent damage model)to characterize ductile *** associated material parameters were calibrated based on tensile experiments of aluminum alloy specimens with *** and experimental results show that the new compensation algorithm significantly reduces the dependence of element size compared with the constant failure strain model and the damage model with the linear compensation *** the axial splitting process of a circular tubular structure,the new compensation algorithm keeps the failure prediction errors low over the stress states ranging from shear to biaxial tension,and achieves the objective prediction of the damage evolution *** study demonstrates how the compensation algorithm resolves the contradiction between large element size and fracture prediction accuracy,and this facilitates the use of the damage model in ductile fracture prediction for engineering structures.

关键词： Compensation algorithm Element size Damage model Axial splitting

Silk microfibrous mats with long-lasting antimicrobial function

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Journal of Materials Science & Technology 2021年第4期63卷 203-209页

作者： Mi Wu wen liu Jinrong Yao Zhengzhong Shao Xin Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceLaboratory of Advanced MaterialsFudan UniversityShanghai 200433PR China

The controlled release of antibiotic drugs to injured sites has great advantages over the conventional intravenous administration of antibiotics,which is associated with systemic toxicity,for wound *** nanofibrous/microfibrous mats,with a similar structure to the native extracellular matrix,is a promising wound ***,drug-loaded halloysite nanotubes(HNTs)incorporated into regenerated silk fibroin(RSF)microfibrous mats were prepared by electrospinning to achieve sustained drug release and long-lasting antimicrobial protection.A broad-spectrum antibiotic,tetracycline hydrochloride(TCH),was selected as the model *** electron microscopic images revealed that the TCH-loaded HNTs were homogeneously embedded in the RSF electrospun microfibers without significant changes in *** drug release profiles showed that the RSF microfibrous mats with TCH-loaded HNTs exhibited a significantly reduced burst phase and a long release time over two weeks compared to the pure TCH-loaded HNTs and the TCH-loaded RSF microfibrous mats without *** results were attributed to the two-step release of TCH first from the HNTs and then RSF matrix in the electrospun ***,the antimicrobial properties of the RSF microfibrous mats with TCH-loaded HNTs were evaluated using both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli *** results demonstrated long-lasting antimicrobial activity for at least one week,showing the great potential of TCH-loaded RSF microfibrous mat as a wound dressing ***,these TCHloaded RSF microfibrous mats with excellent biocompatibility and sustained antimicrobial protection are extremely attractive systems for clinical applications.

关键词： loaded release sustained

Research on spatiotemporal change of ecological capacity and driving forces in the LRGR

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Chinese Science Bulletin 2007年第A02期52卷 74-81页

作者： wen MinXia liu ShiLiang CUI BaoShan State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China

纵的范围峡区域(LRGR ) 是为在中国的生物多样性保护的一个关键区域。另外它为富有的资源，复杂环境和脆弱的生态系统是著名的。在 LRGR，在生态的安全级别和生态的能力有大差别。人的骚乱和生态系统变化是重要的。分析生态的能力的空... 详细信息

纵的范围峡区域(LRGR ) 是为在中国的生物多样性保护的一个关键区域。另外它为富有的资源，复杂环境和脆弱的生态系统是著名的。在 LRGR，在生态的安全级别和生态的能力有大差别。人的骚乱和生态系统变化是重要的。分析生态的能力的空间与时间的变化具有重要性让管理实现生态的管理。作为一个盒子在 LRGR 核心区域拿县，在 GIS 的帮助下，我们使用了生态的脚印方法在二 scalesthe 学习生态的能力的空间与时间的变化城市的更大的规模和县的更小的规模。然后，我们讨论了由主要部件分析(PCA ) 影响了生态的能力的开车因素。结果证明生态的脚印，生态的能力和生态的安全级别在 LRGR 从县清楚地变化了到县。地区性的生态的能力从北方逐年减少了，南方到 LRGR 的中间。根据驱动力的分析，人均的生态的能力与人口， GDP，和另外的开车因素有否定关联。在这些因素之中，社会经济和人口在生态的能力上有很重要的影响。并且驾驶因素的空间变化决定了生态的能力的空间与时间的变化。

关键词：空间变化时间变化地区差异性生态系统影响因素纵向岭谷区

Improving dehydrogenation properties of Mg/Nb composite films via tuning Nb distributions

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Rare Metals 2017年第7期36卷 574-580页

作者： wen-Cheng Huang Jun Yuan Jin-Guo Zhang Jiang-wen liu Hui Wang liu-Zhang Ouyang Mei-Qin Zeng Min Zhu Key Laboratory of Advanced Energy Storage Materials of Guangdong Province School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640China

t To investigate the effect of Nb on the dehydro- genation properties of Mg-Nb composite films, Mg/Nb eight- layer film and Mg- 10 at% Nb alloy film with the similar Mg- to-Nb atomic ratio were prepared by magnetron sputtering. Results show that both Mg/Nb eight-layer film and Mg- 10 at% Nb alloy film exhibit excellent de/hydrogenation properties. Mg- 10 at% Nb alloy film starts to release hydrogen at 108 ℃, and its desorption peak temperature is lower to 146 ℃, which is much better than that of pure MgH2 under the same condi- tion. Scanning electron microscopy （SEM） results demon- strate that the dispersive Nb nanoparticles in Mg/Nb eight- layer film may serve as nucleation sites for Mg ←→ MgH2 reactions, which can provide channels for H diffusion. For Mg- 10 at% Nb alloy film, the uniform distributions of Nb can accelerate the hydrogen diffusion and effectively improve the dehydrogenation kinetics for MgH2. This study provides an enlightening way for designing and preparing Mg-based composite films with excellent dehydrogenation properties.

关键词： Hydrogen storage Mg-Nb Sputtering Thinfilm Kinetics

Spatial impact of organic matters from point sources on stream water quality

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Mining Science and Technology 2009年第2期19卷 256-261页

作者： liu wen-bao CHEN Dong-mei Department of Geography Queen＇s University Kingston Ontario K7L 3N6 Canada

To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a *** "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related *** results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to *** sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal *** addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.

关键词： waste treatment dissolved oxygen biological oxygen demand scenario testing sensitivity analysis

Chinese Medicine in Treatment of A Patient with Acute Extensive Anterior Myocardial Infarction Complicated by Shock after Percutaneous Coronary Intervention

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Chinese Journal of Integrative Medicine 2019年第5期25卷 366-369页

作者： LI Shi-bao SHENG Jin ZHOU Qi XING wen-long liu Hong-xu liu wen-xian Department of Cardiovascular Beijing Hospital of Traditional Chinese MedicineCapital Medical UniversityBeijing(100010)China Department of Cardiac Care Unit Beijing Anzhen HospitalCapital Medical UniversityBeijing(100029)China

Acute myocardial infarction(AMI)is a clinical syndrome of myocardial ischemia and necrosis caused by acute blocking of the coronary *** complicated by cardiogenic shock(CS),it has an extremely high mortality.(1,2)Early reperfusion therapy combined with left ventricular assist device(LVAD)can raise the survival rate to 58.8%–60.9%.(3)We report a case of successful treatment with integrated Chinese and Western medicine on acute extensive anterior myocardial infarction complicated by refractory CS.

关键词： Chinese Medicine Infarction Shock