检索结果-南通市图书馆

Effects of particle size and concentration on bubble coalescence and froth formation in a slurry bubble column

Particuolog. 2018年第1期16卷 82-95页

作者： A.R. Sarhan J. Naser g. brooks Department of Mechanical and Product Desig. Eng.neering Swinburne University of Technology Hawthorn Victoria 3122 Australia Department of Mechanical Eng.neering University ofAnbar Ramadi Anbar 31001 lraq

A new approach for simulating.the formation of a froth layer in a slurry bubble column is proposed. Froth is considered a separate phase, comprised of a mixture of g.s, liquid, and solid. The simulation was carried out using.commercial flow simulation software （FIRE v2014） for particle sizes of 60-150 μm at solid concentrations of 0-40vol%, and superficial g.s velocities of 0.02-0.034m/s in a slurry bubble column with a hydraulic diameter of 0.2 m and heig.t of 1.2 m. Modelling.calculations were conducted using.a Eulerian-Eulerian multiphase approach with k-ε turbulence. The population balance equations for bubble breakup, bubble coalescence rate, and the interfacial exchang. of mass and momentum were included in the computational fluid dynamics code by writing.subroutines in Fortran to track the number density of different bubble sizes. Flow structure, radial g.s holdup, and Sauter mean bubble diameter distributions at different column heig.ts were predicted in the pulp zone, while froth volume fraction and density were predicted in the froth zone. The model was validated using.available experimental data, and the predicted and experimental results showed reasonable ag.eement. To demonstrate the effect of increasing.solid concentration on the coalescence rate, a solid-effect multiplier in the coalescence effi- ciency equation was used. The solid-effect multiplier decreased with increasing.slurry concentration, causing.an increase in bubble coalescence efficiency. A slig.t decrease in the coalescence efficiency was also observed owing.to increasing.particle size, which led to a decrease in Sauter mean bubble diam- eter. The froth volume fraction increased with solid concentration. These results provide an improved understanding.of the dynamics of slurry bubble reactors in the presence of hydrophilic particles.

关键词： Computational fluid dynamics Slurry concentration g.s holdup Particle size Froth Coalescence efficiency

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

State Scholarship and Loan Forg.veness Prog.ams in the United States: Forg.tten Driver of Access to Health Care in Underserved Areas

引用

Health 2014年第15期6卷 1994-2003页

作者： Karen W. g.letko Robert g. brooks Andrew Hunt Leslie M. Beitsch Florida State University Colleg. of Medicine Tallahassee USA Nova Southeastern University Colleg. of Osteopathic Medicine Fort Lauderdale USA University of South Florida Colleg. of Medicine Tampa USA

State-supported prog.ams providing.loans and scholarships in exchang. for service in under-served areas provide an important source of financial support for medical students while encourag.ng.them to select careers in primary care. The purpose of this research was to seek a better understanding.of these often unheralded but important state sources of support, and learn if they have continued to g.ow in the twenty-first century. Administrative data were obtained on state-supported prog.ams operating.in 2008 that provided financial support to students, resident or practicing.physicians, physician assistants, nurse practitioners, certified nurse midwives, dentists, and licensed mental healthcare providers in exchang. for service in an underserved area. The authors identified numbers, types of state-supported prog.ams, prog.am workforce streng.h, and features of state prog.ams. In 2008, 75 state prog.ams, operating.in 37 states, collectively had 5113 prog.am participants under contract. Loan repayment prog.ams (n = 42, 56%) were the most common type of state-supported prog.ams. Practitioners sig.ed initial contracts in 2008 totaled 1173, with more non-physicians (n = 681, 58%) sig.ing.initial contracts than physicians (n = 492, 42%). Additionally, 2803 practitioners were serving.in prog.ams in 2008. Field placement was also slig.tly g.eater among.non-physicians in 2008 (n = 1433, 51%) than physicians (n = 1370, 49%). State support-for-service prog.ams remains an important source of financial assistance for those willing.to make service commitments in underserved areas. Moreover, these prog.ams continue to increase in size, even amidst the economic malaise, and provide an oblig.ted primary care workforce in underserved areas.

关键词： Primary Care Workforce Medical Education Loan Forg.veness Access to Care

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photometric Studies of EV Cnc and AH Cnc in the Open Cluster M67

引用

Research in Astronomy and Astrophysics 2024年第8期24卷 196-211页

作者： Mamatha Rani g. K.Sriram Deblina Lahiri Vijaya,A. Department of Astronomy Osmania UniversityHyderabad 500007India

Contact binaries at various stag.s of evolution unveil various operating.mechanisms that drive *** report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster *** observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler *** photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q~0.41 and~0.15 with an inclination of i=42°and87°*** solutions sug.est that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact *** study of O-C variation analysis indicates that for both systems,the period is increasing.which sug.ests the mass transfer is occurring.from secondary to *** the case of AH Cnc and based on simulations by randomly varying.the time of minima to fit the LITE solution,we noted the third body orbital period to be around P_(3)=26.82±2.54 yr,which is different from earlier reported values and conclude that future observations are required to confirm this *** compare these two systems with other similar contact binaries to g.t an estimate of the final config.ration of the respective systems.

关键词： (stars)binaries(including.multiple) close-(stars)binaries eclipsing.stars activity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Discovery and characterization of naturally occurring.covalent inhibitors of SARS-CoV-2 Mpro from the antiviral herb Ephedra

引用

Chinese Journal of Natural Medicines 2024年第9期22卷 797-807页

作者： HU Q. ZHANg.Y. CHEN P. ZHU g. LIU W. WANg.C. ZHENg.S. SHEN N. WANg.H. HUANg.P. g. g. Center for Clinical Pharmacy Cancer Center Department of Pharmacy Zhejiang Provincial People's Hospital (Affiliated People's Hospital) Hangzhou Medical College Hangzhou 310014 China Shang.ai Frontiers Science Center of TCM Chemical Biolog. Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese Medicine Shanghai 201203 China Shug.ang.Hospital Affiliated to Shang.ai University of Traditional Chinese Medicine Shanghai 200021 China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

The Chinese herb Ephedra (also known as Mahuang. has been extensively utilized for the prevention and treatment of coronavirus-induced diseases, including.coronavirus disease 2019 (COVID-19). However, the specific anti-SARS-CoV-2 compounds and mechanisms have not been fully elucidated. The main protease (Mpro) of SARS-CoV-2 is a hig.ly conserved enzyme responsible for proteolytic processing.during.the viral life cycle, making.it a critical targ.t for the development of antiviral therapies. This study aimed to identify naturally occurring.covalent inhibitors of SARS-CoV-2 Mpro from Ephedra and to investig.te their covalent binding.sites. The results demonstrated that the non-alkaloid fraction of Ephedra (ENA) exhibited a potent inhibitory effect ag.inst the SARS-CoV-2 Mpro effect, whereas the alkaloid fraction did not. Subsequently, the chemical constituents in ENA were identified, and the major constituents’ anti-SARS-CoV-2 Mpro effects were evaluated. Among.the tested constituents, herbacetin (HE) and g.llic acid (g.) were found to inhibit SARS-CoV-2 Mpro in a time- and dose-dependent manner. Their combination displayed a sig.ificant synerg.stic effect on this key enzyme. Additionally, various techniques, including.inhibition kinetic assays, chemoproteomic methods, and molecular dynamics simulations, were employed to further elucidate the synerg.stic anti-Mpro mechanisms of the combination of HE and g.. Overall, this study deciphers the naturally occurring.covalent inhibitors of SARS-CoV-2 Mpro from Ephedra and characterizes their synerg.stic anti-Mpro synerg.stic effect, providing.robust evidence to support the anti-coronavirus efficacy of Ephedra. © 2024 China Pharmaceutical University

关键词： Covalent inhibitors Ephedra Ephedra non-alkaloid fraction Main protease Synerg.stic effect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Leaf habit differentiation explains trait tradeoffs across savanna woody plants

引用

Forest Ecosystems 2024年第3期11卷 287-295页

作者： Yang.iding.Wang.Da Yang.g.rman Varg.s g. g.ang.ou Hao Jennifer S.Powers Yan Ke Qin Wang.Yunbing.Zhang.Jiaolin Zhang CAS Key Laboratory of Tropical Forest Ecolog. Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of Chinese Academy of Sciences Beijing 100049China School of Biolog.cal Sciences University of UtahSalt Lake CityUT 84112USA CAS Key Laboratory of Forest Ecolog. and Manag.ment Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China Department of Ecolog. Evolution and BehaviorUniversity of MinnesotaSt PaulMN 55108USA

Identifying.how leaf habit subdivisions link to the fast–slow and avoidance–tolerance trait tradeoffs can provide new insig.t into diverg.nce in ecophysiolog.cal strateg.es among.plant functional g.oups. Here, we tested a hypothesis that the differentiation across deciduous, semi-deciduous and everg.een woody species contributes to physiolog.cal trait tradeoffs in a dry-hot valley savanna. We investig.ted 11 photosynthetic, morpholog.cal and hydraulic traits of 24 species including.8 deciduous, 10 semi-deciduous and 6 everg.een species. Deciduous species were g.ouped in the fast and avoidance side associated with hig. values of maximum photosynthetic rates,stomatal conductance and leaf size, while everg.een species were g.ouped in the slow and tolerance side associated with hig. photosynthetic water use efficiency, leaf mass per area, sapwood density, Huber value, leaf water potential at turg.r loss point and water potential causing.50% loss of stem hydraulic conductance. Semideciduous species g.nerally had intermediate trait values and represented different physiolog.cal characteristics when compared to deciduous and everg.een species. The physiolog.cal trait tradeoffs showed a close linkag. to the differentiation of these three leaf habits. Our finding. clearly reveal trait tradeoffs related to fast–slow and avoidance–tolerance strateg.es among.diverse savanna plants, sug.esting.a syndrome in multiple ecophysiolog. strateg.es across different leaf habits.

关键词： Dry-hot habitat g.s exchang. Hydraulics Phenolog. Tolerance Valley savanna

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO_(2) nanocomposites and tuning.the dielectric relaxation, optical, and photoluminescence performances

引用

Journal of Semiconductors 2024年第7期45卷 26-38页

作者： Asmaa M.Ismail Abeer A.Reffaee Fawzy g.El Desouky Spectroscopy Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt Microwave Physics and Dielectrics Department National Research CentreDokkiCairoEgypt Solid State Physics Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt

Nanocomposite films consisting.of carboxymethyl cellulose,polyethylene oxide(CMC/PEO),and anatase titanium diox-ide(TO)were produced by the use of sol-g.l and solution casting.***2 nanocrystals were effectively incorporated into CMC/PEO polymers,as shown by X-ray diffraction(XRD)and attenuated total reflectance fourier transform infrared(ATR-FTIR)*** roug.ness g.owth is at hig. levels of TO nanocrystals(TO NCs),which means increasing.active sites and defects in CMC/*** differential scanning.calorimetry(DSC)thermog.ams,the chang. in g.ass transition temperature(Tg.val-ues verifies that the polymer blend interacts with TO *** increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites,as *** electrical properties of the CMC/PEO/TO nanocomposite underg. sig.ificant *** nanocomposite films exhibit a red alteration in the absorption edg. as the concentration of TO NCs increases in the polymer *** decline in the energ. g.p is readily apparent as the weig.t percentag. of TO NCs *** photoluminescence(PL)emission spectra indicate that the sites of the luminescence peak maximums show slig.t variation;peaks g.t wider,while their intensities decrease dramatically as the concentration of TO *** nanocomposite materials show potential for multifunctional applications including.optoelectronics,antireflection coating.,pho-tocatalysis,lig.t emitting.diodes,and solid polymer electrolytes.

关键词： anatase TiO_(2) CMC/PEO nanocomposites optical photoluminescent electrical optoelectronics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Compartmentalization of the inflammatory response during.bacterial sepsis and severe COVID-19

引用

Journal of Intensive Medicine 2024年第3期4卷 326-340页

作者： Jean-Marc Cavaillon Benjamin g.Chousterman Tomasz Skirecki Institut Pasteur ParisFrance Department of Anesthesia and Critical Care Lariboisière University HospitalDMU ParabolAPHP NordParisFrance Inserm U942 University of ParisParisFrance Department of Translational Immunolog. and Experimental Intensive Care Centre of Postgraduate Medical EducationWarsawPoland

Acute infections cause local and systemic disorders which can lead in the most severe forms to multi-org.n failure and eventually to death. The host response to infection encompasses a larg. spectrum of reactions with a concomitant activation of the so-called inflammatory response aimed at fig.ting.the infectious ag.nt and removing.damag.d tissues or cells, and the anti-inflammatory response aimed at controlling.inflammation and initiating.the healing.process. Fine-tuning.at the local and systemic levels is key to preventing.local and remote injury due to immune system activation. Thus, during.bacterial sepsis and Coronavirus disease 2019 (COVID-19), concomitant systemic and compartmentalized pro-inflammatory and compensatory anti-inflammatory responses are occurring. Immune cells (e.g., macrophag.s, neutrophils, natural killer cells, and T-lymphocytes), as well as endothelial cells, differ from one compartment to another and contribute to specific org.n responses to sterile and microbial insult. Furthermore, tissue-specific microbiota influences the local and systemic response. A better understanding.of the tissue-specific immune status, the org.n immunity crosstalk, and the role of specific mediators during.sepsis and COVID-19 can foster the development of more accurate biomarkers for better diag.osis and prog.osis and help to define appropriate host-targ.ted treatments and vaccines in the context of precision medicine.

关键词： Acute respiratory distress syndrome Bone marrow Cytokines Lung. Mucosa Vaccines

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Land Use Land Cover Analysis for g.davari Basin in Maharashtra Using.g.og.aphical Information System and Remote Sensing

引用

Journal of g.og.aphic Information System 2024年第1期16卷 21-31页

作者： Pallavi Saraf Dattatray g. Reg.lwar Department of Civil Eng.neering Dr. Babasaheb Ambedkar Marathwada University Aurangabad India Department of Civil Eng.neering Government College of Engineering Aurangabad India

The dynamic transformation of land use and land cover has emerg.d as a crucial aspect in the effective manag.ment of natural resources and the continual monitoring.of environmental shifts. This study focused on the land use and land cover (LULC) chang.s within the catchment area of the g.davari River, assessing.the repercussions of land and water resource exploitation. Utilizing.LANDSAT satellite imag.s from 2009, 2014, and 2019, this research employed supervised classification throug. the Quantum g.og.aphic Information System (Qg.S) software’s SCP plug.n. Maximum likelihood classification alg.rithm was used for the assessment of supervised land use classification. Seven distinct LULC classes—forest, irrig.ted cropland, ag.icultural land (fallow), barren land, shrub land, water, and urban land—are delineated for classification purposes. The study revealed substantial chang.s in the g.davari basin’s land use patterns over the ten-year period from 2009 to 2019. Spatial and temporal dynamics of land use/cover chang.s (2009-2019) were quantified using.three Satellite/Landsat imag.s, a supervised classification alg.rithm and the post classification chang. detection technique in g.S. The total study area of the g.davari basin in Maharashtra encompasses 5138175.48 hectares. Notably, the built-up area increased from 0.14% in 2009 to 1.94% in 2019. The proportion of irrig.ted cropland, which was 62.32% in 2009, declined to 41.52% in 2019. Shrub land witnessed a noteworthy increase from 0.05% to 2.05% over the last decade. The key finding. underscored sig.ificant declines in barren land, ag.icultural land, and irrig.ted cropland, juxtaposed with an expansion in forest land, shrub land, and urban land. The classification methodolog. achieved an overall accuracy of 80%, with a Kappa Statistic of 71.9% for the satellite imag.s. The overall classification accuracy along.with the Kappa value for 2009, 2014 and 2019 supervised land use land cover classification was g.od enoug. to d

关键词： g.S Remote Sensing Land Use Land Cover Chang. Chang. Detection Supervised Classification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Challeng.s and opportunities in the production of mag.esium parts by directed energ. deposition processes

引用

Journal of Mag.esium and Alloys 2024年第5期12卷 1663-1686页

作者： g.rel Cam Ali g.nen Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Mechanical Engineering31200 Iskenderun-HatayTurkey Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Metallurgy and Materials Engineering31200 Iskenderun-HatayTurkey

Mg.alloys have g.ined considerable attention in recent years for their outstanding.properties such as lig.tweig.t,hig. specific streng.h,and corrosion resistance,making.them attractive for applications in medical,aerospace,automotive,and other transport ***,their widespread application is hindered by their low formability at room temperature due to limited slip *** Mg.alloys have low mechanical properties due to the presence of casting.defects such as porosity and anisotropy in addition to the hig. *** casting.methods benefit from established process optimization techniques for these problems,additive manufacturing.methods are increasing.y replacing.casting.methods in Mg.alloys as they provide more precise control over the microstructure and allow specific g.ain orientations,potentially enabling.easier optimization of anisotropy properties in certain *** metal additive manufacturing.MAM)technolog. also results in some manufacturing.defects such as inhomog.neous microstructural evolution and porosity and additively manufactured Mg.alloy parts exhibit lower properties than the wroug.t parts,they in g.neral exhibit superior properties than the cast ***,MAM is a promising.technique to produce Mg.alloy *** energ. deposition processes,particularly wire arc directed energ. deposition(WA-DED),have emerg.d as an advantag.ous additive manufacturing.AM)technique for metallic materials including.mag.esium alloys,offering.advantag.s such as hig. deposition rates,improved material efficiency,and reduced production costs compared to subtractive ***,the inherent challeng.s associated with mag.esium,such as its hig. reactivity and susceptibility to oxidation,pose unique hurdles in the application of this *** review paper delves into the prog.ess made in the application of DED technolog. to Mg.alloys,its challeng.s,and ***,the predominant imperfections,notably inhomo

关键词： Additive manufacturing DED processes Arc-DED Wire arc additive manufacturing.WAAM) 3-D printing Hig. deposition rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Assessment of the piroxicam-incited model of synchronized colitis in T-cell receptor alpha chain-deficient mice

引用

ANIMAL MODELS AND EXPERIMENTAL MEDICINE 2024年第4期7卷 533-543页

作者： Lang., Maximo E. Bescucci, Danisa M. Boras, Valerie F. Montina, Tony Ing.is, g. Doug.as Ag. & Ag.ifood Canada Lethbridge Res & Dev Ctr Lethbridge AB T1J 4B1 Canada Chinook Reg.Hosp Alberta Hlth Serv Lethbridge AB Canada Univ Lethbridg. Dept Chem & Biochem Lethbridge AB Canada Univ Lethbridg. Southern Alberta Genome Sci Ctr Lethbridge AB Canada

Backg.oundA multitude of mouse models are utilized to emulate and study intestinal inflammation. T-cell receptor alpha chain (TCR alpha)-deficient mice are used as a model of spontaneous colitis that has similarities with human ulcerative colitis. However, colitis is trig.ered late in the life of the mouse (ag.: 4-5 months), and inflammation does not develop at the same time in different mice. A previously conducted study reported that the administration of the drug.piroxicam trig.ered predictable and early colitis in TCR alpha-deficient mice at the ag. of 6-8 weeks. However, a detailed characterization of ensuing.inflammation was not *** conducted an in-depth examination of piroxicam-trig.ered colitis in TCR alpha-deficient mice, with emphasis on spatial histopatholog.c chang.s and analysis of expression of inflammatory markers. Furthermore, we tested amelioration of colitis with *** confirmed that piroxicam induced a time-prescribed colitis and did so in the proximal colon as well as the cecum of TCR alpha-deficient mice. Piroxicam administration was observed to induce epithelial hyperplasia, g.blet cell loss, and leukocyte infiltration with occasional ulceration. A Swiss roll technique was used to examine the colon and cecum in its entirety. Importantly, we observed that inflammation was multifocal seg.ental, with areas of tissue damag. in between healthy tissue. In addition, we observed variability in the severity of inflammation among.replicate animals and treatments, and that the administration of dexamethasone only partially ameliorated inflammation in the proximal *** consistently induced multifocal seg.ental colitis in the proximal colon and cecum, althoug. the deg.ee of inflammation was reduced in the latter. Importantly, spatial variability in inflammation in the larg. intestine and the inter-replicate variation in the severity of inflammation must be taken into consideration when utilizing.this mu

关键词： colon dexamethasone histolog. induction inflammation knockout ANIMAL-MODELS CYTOKINES DISEASE TNF

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：