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Effect of bubble morphology and behavior on power consumption in non-Newtonian fluids’aeration process

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Chinese Journal of Chemical Engineering 2024年第1期65卷 243-254页

作者： Xiemin Liu Jing Wan Jinnan Sun Lin Zhang Feng Zhang Zhibing Zhang Xinyao Li zheng zhou Key Laboratory of Mesoscopic Chemistry of Ministry of Education(MOE) School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116045China

Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm.

关键词： Non-Newtonian fluids aeration process Power consumption Volumetric mass transfer rate Bubble size

Abomasal infusion of branched-chain amino acids or branched-chain keto-acids alter lactation performance and liver triglycerides in fresh cows

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1145-1157页

作者： Kristen Gallagher Isabelle Bernstein Cynthia Collings David Main Ghayyoor Ahmad Sarah Naughton Jayasimha Daddam Vengai Mavangira Mike Vandehaar zheng zhou Department of Animal Science Michigan State UniversityEast Lansing 48824USA Department of Veterinary Diagnostic and Production Animal Medicine Ames 50011USA

Background Dairy cows are at high risk of fatty liver disease in early lactation,but current preventative measures are not always *** with fatty liver have lower circulating branched-chain amino acid(BCAA)concentra-tions whereas cows with high circulating BCAA levels have low liver triglyceride(TG).Our objective was to determine the impact of BCAA and their corresponding ketoacids(branched-chain ketoacids,BCKA)on production performance and liver TG accumulation in Holstein cows in the first 3 weeks *** Thirty-six multiparous Holstein cows were used in a randomized block design *** were abomasally infused for the first 21 d postpartum with solutions of 1)saline(CON,n=12);2)BCA(67 g valine,50 g leu-cine,and 34 g isoleucine,n=12);and 3)BCK(77 g 2-ketovaline calcium salt,57 g 2-ketoleucine calcium salt,and 39 g 2-ketoisoleucine calcium salt,n=12).All cows received the same *** effects were determined using PROC GLIMMIX in *** No differences were detected for body weight,body condition score,or dry matter intake averaged over the first 21 d *** receiving BCK had significantly lower liver TG concentrations compared to CON(6.60%vs.4.77%,standard error of the mean(SEM)0.49)during the first 3 weeks of *** of BCA increased milk yield(39.5 vs.35.3 kg/d,SEM 1.8),milk fat yield(2.10 vs.1.69 kg/d,SEM 0.08),and lactose yield(2.11 vs.1.67 kg/d,SEM 0.07)compared with *** to CON,cows receiving BCA had lower plasma glucose(55.0 vs.59.2 mg/dL,SEM 0.86)but higherβ-hydroxybutyrate(9.17 vs.6.00 mg/dL,SEM 0.80).Conclusions Overall,BCAA supplementation in this study improved milk production,whereas BCKA supplementa-tion reduced TG accumulation in the liver of fresh cows.

关键词： Branched-chain amino acids Branched-chain ketoacids Fatty liver Fresh cow

Layered niobium carbide enabling excellent kinetics and cycling stability of Li-Mg-B-H hydrogen storage material Layered niobium carbide enabling excellent kinetics

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Rare Metals 2024年第3期43卷 1153-1166页

作者： Li-Wen Lu Hui Luo Guang-Xu Li Yun Li Xin-Hua Wang Cun-Ke Huang Zhi-QiangLan Wen-zheng zhou Jin Guo Mohammad Ismail Hai-Zhen Liu Guangxi Novel Battery Materials Research Center of Engineering Technology Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science and TechnologyGuangxi UniversityNanning530004China State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures Nanning530004China School of Mechanical and Electrical Engineering Quzhou College of TechnologyQuzhou324000China Department of Materials Science and Engineering Zhejiang UniversityHangzhou310027China Faculty of Ocean Engineering Technology and Informatics Universiti Malaysia Terengganu21030Kuala NerusTerengganuMalaysia Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China

The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage ***,the slow kinetics and poor cycling stability severely restrict its practical *** this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the Li-Mg-B-H *** milled 2LiH+MgB_(2)composites were initially hydrogenated to obtain the 2LiBH_(4)+MgH_(2)*** 2LiBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2LiBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and LiBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2LiBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th ***_(2)C keeps stable in the composite and acts as an efficient catalyst for the Li-Mg-B-H *** is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the Li-Mg-B-H *** work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the Li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.

关键词： Hydrogen storage Lithium borohydride Magnesium hydride Nb_(2)C MXene

研究生缘何想退学?——基于扎根理论的硕士研究生退学意向研究

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研究生教育研究 2024年第2期 29-36,67页

作者：周静周正哈尔滨师范大学教育科学学院哈尔滨150025

退学意向是预测退学行为的最佳前因变量,通过扎根理论方法探究影响硕士研究生退学意向产生的因素及其生成机理,发现人际裹挟、资源阙如、制度规约作为外界刺激因素,加剧了硕士生个体的风险感知及负性情绪体验,从而产生退学意向。基于此... 详细信息

退学意向是预测退学行为的最佳前因变量,通过扎根理论方法探究影响硕士研究生退学意向产生的因素及其生成机理,发现人际裹挟、资源阙如、制度规约作为外界刺激因素,加剧了硕士生个体的风险感知及负性情绪体验,从而产生退学意向。基于此,提出相应解决策略,包括从外部出发,构建多元化支持体系,消减外界不利诱因;从硕士生自身出发,提升个体风险抵抗力,善用情绪调节策略。

关键词：退学退学意向硕士研究生

Improvement in hydrogen storage performance of MgH_(2) by vanadium doped with ZIF-8 derived a single-atom catalyst V-N-C

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Rare Metals 2024年第6期43卷 2623-2635页

作者： Fei-Fan Hong Wei-Tao Shi Ruo-Lin Zhao Yi Fan Zi-Qi Liu Si-Zhi Ding Hai-Zhen Liu Wen-zheng zhou Jin Guo Zhi-Qiang Lan Guangxi Novel Battery Materials Research Center of Engineering Technology and Center on Nanoenergy Research Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationCarbon Peak and Neutrality Science and Technology Development InstituteSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Nanning Engineering Technology Research Center for Power Transmission System of New Energy Vehicle Transportation CollegeNanning UniversityNanning 530200China

Herein,the successful preparation of a singleatom catalyst V-N-C using vanadium-doped zeolitic imidazolate framework(ZIF)-8 as a precursor is *** experimental results showed that the V-N-C had a good promoting effect on the hydrogen storage performance of MgH_(2),and the optimal addition amount of V-N-C was 10wt%.The hydrogenation and dehydrogenation apparent activation energies of 10 wt%V-N-C-catalyzed MgH_(2)were reduced by 44.9 and 53.5 kJ·mol^(-1),respectively,compared to those of additive-free MgH_(2).The 10 wt%V-N-C-catalyzed MgH_(2)could reabsorb 5.92 wt%of hydrogen in 50 min at 150℃,with a capacity retention rate of 99.1%after 30 cycles of hydrogen absorption and *** analysis showed that V-N-C was partially transformed into VN and metallic V when it was milled with MgH_(2);the in-situ-formed VN and metallic V played an important role in improving the hydrogen storage performance of MgH_(2).This approach provides a potential solution for obtaining high-performance Mg-based hydrogen storage materials through synergistic interactions between V,N and C.

关键词： MgH_(2) Hydrogen storage materials Catalyst Hydrogen storage perormance

Distributions and accumulation mechanisms of helium in petroliferous basins

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Science China Earth Sciences 2024年

作者： Pengpeng LI Quanyou LIU Dongya ZHU Di ZHU zheng zhou Xiaoqi WU Qingqiang MENG Jiahao LV Yu GAO Institute of Energy Peking University Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Petroleum Exploration & Production Research Institute SINOPEC Beijing Energy Research Institute Qilu University of Technology (Shandong Academy of Sciences) Lancaster Environment Centre Lancaster University Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

Helium is an irreplaceable strategic mineral resource,and commercial helium-rich gas fields （He>0.1%） worldwide are typically discovered serendipitously during hydrocarbon exploration *** to an analysis of 75 helium-rich gas fields and 1048 natural gas samples worldwide,helium in natural gas generally exhibits“scarce”,“accompanying”,and“complex”properties,and helium-rich gas fields often occur at depths1%）.However,geological reserves in the former two types of gas fields are mainly in the range of 10～7–1011m3,whereas in the latter,they are only in the range of 10～5–10～*** are nevertheless notable disparities in the genesis and migration patterns between helium and gaseous *** necessitates carriers （such as formation water,hydrocarbon fluids,N2,mantle-derived fluids,etc.） during both accumulation and long-distance migration processes,where migration conduits are not confined to sedimentary strata,and may extend to the basin’s basement,lower crust,and even lithospheric ***,the accumulation conditions of both helium and gaseous hydrocarbons are generally considered *** presence of gaseous hydrocarbons facilitates both the rapid exsolution of helium within helium-containing fluids and subsequent efficient aggregation in gaseous hydrocarbons,while both reduce helium diffusion and diminish escape *** terms of caprock,gypsum,salt,and thick shale as sealing layers contribute to the long-term preservation of helium over geological *** helium-rich gas fields,predominantly crust-derived gas fields,are primarily concentrated in uplifted zones of ancient cratonic basins and their *** on a diagram of the He concentration versus He/N2ratio,crust-derived helium fields can be categorized as basement,combined basement-sedimentary rock,and sedimentary rock helium supply ***

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坚持还是放弃?博士生退学意向的影响因素及其演变机制

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学位与研究生教育 2024年第3期 73-84页

作者：周静周正韩悦哈尔滨师范大学教育科学学院哈尔滨150025

基于扎根理论的研究范式,探索性地构建了博士研究生退学意向的影响因素及其演变机制。由于自我高估与学术低估间的认知错配,个体需求与供给现状间的供需失衡,预期设定与现实进程间的次序失控,使得博士研究生产生退学意向。外在环境与内... 详细信息

基于扎根理论的研究范式,探索性地构建了博士研究生退学意向的影响因素及其演变机制。由于自我高估与学术低估间的认知错配,个体需求与供给现状间的供需失衡,预期设定与现实进程间的次序失控,使得博士研究生产生退学意向。外在环境与内在加工在退学意向发展进程中发挥调节作用,最终导致博士研究生行为结果的不同与分化,表现为成功改写、失败懊悔、消极应付、积极转变四种类型。

关键词：博士研究生退学意向影响因素演变机制

Nomogram for predicting the risk of anxiety and depression in patients with non-mild burns

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World Journal of Psychiatry 2024年第8期14卷 1233-1243页

作者： Jie Chen Jian-Fei Zhang Xia Xiao Yu-Jun Tang He-Jin Huang Wen-Wen Xi Li-Na Liu zheng-zhou Shen Jian-Hua Tan Feng Yang Department of Burns and Plastic Surgery The Second Affiliated HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421001Hunan ProvinceChina Department of Beauty Surgery Nantong Shenmei Medical Beauty ClinicNantong 226001Jiangsu ProvinceChina Department of Respiratory and Critical Care Medicine The Second Affiliated HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421001Hunan ProvinceChina

BACKGROUND Post-burn anxiety and depression affect considerably the quality of life and recovery of patients;however,limited research has demonstrated risk factors associated with the development of these *** To predict the risk of developing post-burn anxiety and depression in patients with non-mild burns using a nomogram *** We enrolled 675 patients with burns who were admitted to The Second Affiliated Hospital,Hengyang Medical School,University of South China between January 2019 and January 2023 and met the inclusion *** patients were randomly divided into development(n=450)and validation(n=225)sets in a 2:1 *** and multivariate logistic regression analyses were conducted to identify the risk factors associated with post-burn anxiety and depression dia-gnoses,and a nomogram model was *** Female sex,age<33 years,unmarried status,burn area≥30%,and burns on the head,face,and neck were independent risk factors for developing post-burn anxiety and depression in patients with non-mild *** nomogram model demonstrated predictive accuracies of 0.937 and 0.984 for anxiety and 0.884 and 0.923 for depression in the development and validation sets,respectively,and good predictive *** and decision curve analyses confirmed the clinical utility of the *** The nomogram model predicted the risk of post-burn anxiety and depression in patients with non-mild burns,facilitating the early identification of high-risk patients for intervention and treatment.

关键词： Burn Post-burn anxiety Depression Risk prediction Nomogram model

宏基因组学分析深度处理阶段污水中细菌的赋存特征及其功能

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环境科学 2024年第4期45卷 2259-2267页

作者：胡健双王燕周政汪雅琴王秉政李激江南大学环境与土木工程学院无锡214122 江苏省厌氧生物技术重点实验室无锡214122 江苏高校水处理技术与材料协同创新中心苏州215009

为探究深度处理阶段污水中细菌的赋存特征及其功能,采集了污水深度处理阶段沿程各单元的进出水样品,并基于宏基因组学对污水中细菌的群落结构及功能进行了解析.结果表明,不同深度处理单元出水中细菌的多样性存在差异,臭氧接触池出水中... 详细信息

为探究深度处理阶段污水中细菌的赋存特征及其功能,采集了污水深度处理阶段沿程各单元的进出水样品,并基于宏基因组学对污水中细菌的群落结构及功能进行了解析.结果表明,不同深度处理单元出水中细菌的多样性存在差异,臭氧接触池出水中细菌的多样性最低;相比夏季,冬季深度处理阶段污水中细菌的丰富度和多样性较低.不同季节深度处理阶段污水中的细菌群落结构变化较大,反硝化滤池出水中的细菌群落结构与其它样品存在较大差异;变形菌门(41.5%~71.0%)是深度处理阶段污水中的主要优势菌门,其次是拟杆菌门(3.8%~16.2%);反硝化滤池出水中主要菌属有脱氯单胞菌(4.1%~7.4%)、弓形杆菌(3.0%~8.3%)和不动杆菌(2.3%~3.0%).在深度处理阶段各工艺出水中共发现了29种与氮代谢有关的功能基因,并且在各工艺出水中均检测到了与反硝化有关的功能基因,如nosZ、napA、nirK和norB等,表明深度处理阶段污水中的细菌具有持续脱氮的潜力.糖苷转移酶和糖苷水解酶是深度处理阶段主要的碳水化合物活性酶,深度处理阶段污水中的细菌表现出了对多种有机物的降解潜力.

关键词：污水深度处理宏基因组学细菌群落脱氮功能 KEGG基因数据库 CAZy数据库