检索结果-南通市图书馆

Minimum spouting velocity of flat-base spouted fluid bed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2018年第1期16卷 27-36页

作者： Esmail R. Monazam Ronald W. Breault Justin Weber ky Layfield National Energy Technology Laboratory U. S. Department of Energy 3610 Collins Ferry Rd. Morgantown WV26507-0880 USA REM Engineering Services PLLC 3537 Collins Ferry Rd. Morgantown WV26505 USA

Experiments were performed on spout characteristics of a cylindrical spout-fluidized bed （i.D. = 10 cm） with different static heights and two materials （A1203 and high density polyethylene）. Results of minimum spouting velocity obtained in this study were compared with reported correlations for both spouted and spout-fluidized beds. Considerable discrepancies were found between the values obtained using different model equations as well as with respect to experimental results. Based on the Mathur-Gishler correlation, a new correlation is proposed for calculating the minimum spouting velocity that introduces the ratio U/Umf. it was found that the minimum spouting velocity decreases with increasing fluidizing gas velocity （U/Umf）. The pressure drop at the point of minimum spouting velocity is also correlated using this dimensionless group and is presented in this work. This investigation demonstrates that the use of correlations reported in the literature that focus primarily on conical bottom spouted beds are not applicable to fiat-bottom spouted and spout-fluidized beds.

关键词： Spouted bed Spout-fluidized bed Minimum spouting velocity Flat-bottom spouted bed

Face Mask Recognition for Covid-19 Prevention

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第11期73卷 3251-3262页

作者： Trong Hieu Luu Phan Nguyen ky Phuc Zhiqiu Yu Duy Dung Pham Huu Trong Cao College of Engineering Can Tho UniversityCan Tho city910900Viet Nam international University-Vietnam National University Vietnam National UniversityHoChiMinh City70000Vietnam Department of industrial Management National Taiwan University of Science and TechnologyTaipei10607Taiwan

in recent years,the COViD-19 pandemic has negatively impacted all aspects of social *** to ease in the infected method,i.e.,through small liquid particles from the mouth or the nose when people cough,sneeze,speak,sing,or breathe,the virus can quickly spread and create severe problems for people’s *** to some research as well as World Health Organization(WHO)recommendation,one of the most economical and effective methods to prevent the spread of the pandemic is to ask people to wear the face mask in the public space.A face mask will help prevent the droplet and aerosol from person to person to reduce the risk of virus *** simple method can reduce up to 95%of the spread of the ***,this solution depends heavily on social consciousness,which is sometimes *** order to improve the effectiveness of wearing face masks in public spaces,this research proposes an approach for detecting and warning a person who does not wear or misuse the face *** approach uses the deep learning technique that relies on GoogleNet,AlexNet,and VGG16 *** results are synthesized by an ensemble method,i.e.,the bagging *** the experimental results,the approach represents a more than 95%accuracy of face mask recognition.

关键词： Face mask detection deep learning AlexNet GoogLeNet VGG16 ensemble method

Brewers' rice modulates oxidative stress in azoxymethanemediated colon carcinogenesis in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2015年第29期21卷 8826-8835页

作者： Bee Ling Tan Mohd Esa Norhaizan ky Huynh Swee Keong Yeap Hamzah Hazilawati Karim Roselina Department of Nutrition and Dietetics Faculty of Medicine and Health Sciences Universiti Putra Malaysia Research Centre of Excellent Nutrition and Non-Communicable Diseases Faculty of Medicine and Health Sciences Universiti Putra Malaysia Laboratory of Molecular Biomedicine Institute of Bioscience Universiti Putra Malaysia Department of Cell and Molecular Biology Faculty of Biotechnology and Biomolecular Sciences Universiti Putra Malaysia Department of Veterinary Pathology and Microbiology Faculty of Veterinary Medicine Universiti Putra Malaysia Department of Food Technology Faculty of Food Science and Technology Universiti Putra Malaysia

AiM: To investigate the mechanistic action of brewers' rice in regulating the Wnt/nuclear factor-kappa B(NF-κB)/Nrf2-signaling pathways during colon carcinogenesis in male Sprague-Dawley ***: Male Sprague-Dawley rats were randomly divided into the following five groups(six rats in each group):(G1) normal,(G2) azoxymethane(AOM) alone,(G3) AOM + 10%(weight(w)/weight(w)) brewers' rice,(G4) AOM + 20%(w/w) brewers' rice, and(G5) AOM + 40%(w/w) brewers' rice. They were intraperitoneally administered 15 mg/kg body weight of AOM in saline once weekly over a twoweek period and treated with an American institute of Nutrition(AiN)-93 G diet containing 10%, 20%, and 40%(w/w) brewers' rice. The m RNA levels of glycogen synthase kinase 3β(GSK 3β), β-catenin, key inflammation markers, nuclear factor E2-related factor 2(Nrf2), and heme oxygenase-1(HO-1)-dependent transcriptional activity were assessed by quantitative real-time polymerase chain reaction analyses. The colon superoxide dismutase, malondialdehyde, and nitric oxide levels were also analyzed to assess the antioxidant effect of these treatments. The results were analyzed using one-way analysis of variance(ANOVA), and a P value of idered ***: The overall analyses demonstrated that the dietary administration of brewers' rice in AOM-induced rat colon carcinogenesis resulted in the transcriptional upregulation of GSK 3β, inducible nitric oxide synthase(i NOS), Nrf2, and HO-1. We discovered that the dietary administration of brewers' rice downregulated the β-catenin and NF-κB m RNA levels. A significant reduction in β-catenin expression was found in the groups administered with 20%(0.611 ± 0.034) and 40%(0.436 ± 0.045)(w/w) brewers' rice compared with that of the group treated with AOM alone(1.000 ± 0.064)(P ion was significantly lower between the AOM-alone group(1.000 ± 0.048) and those groups fed with diets containing 10%(w/w) brewers' rice(0.255 ± 0.022), 20%

关键词： Brewers' rice Nuclear factor-kappa B Coloncancer β-catenin nuclear factor E2-related factor 2

insulinoma presenting with postprandial hypoglycemia and a low body mass index:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第18期8卷 4169-4176页

作者： Dana Prídavková Matej Samoš Roman kyčina Katarína Adamicová Michal Kalman Margita Belicová Marián Mokáň Clinic of internal Medicine Ⅰ Comenius University in BratislavaJessenius Faculty of Medicine in MartinMartin 03601Slovakia Clinic of Surgery and Transplant Center Comenius University in BratislavaJessenius Faculty of Medicine in MartinMartin 03601Slovakia Department of Pathological Anatomy Comenius University in BratislavaJessenius Faculty of Medicine in MartinMartin 03601Slovakia

BACKGROUND insulinomas are the most common type of functioning endocrine neoplasms of the pancreas presenting hypoglycemic *** characteristically develop symptoms while fasting,but some patients have reported symptoms only in the postprandial *** and prolonged hypoglycemic episodes can reduce the awareness of adrenergic symptoms,and patients may have amnesia,which delays *** SUMMARY We describe a case of a 24-year-old underweight patient who showed hypoglycemic symptoms for almost 6 *** patients with insulinoma characteristically develop symptoms while fasting,this young man had hypoglycemic symptoms up to one hour postprandially,especially after highsugar meals and after physical *** fasting tests and imaging methods performed at local hospitals were evaluated as negative for abnormal ***,brown adipose tissue exhibited increased metabolic activity,and some muscle groups had histological changes as indicated by positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed *** deficiency was also histologically *** patient’s symptoms progressed over the years and occurred more frequently,i.e.,several times a month,and the patient had reduced awareness of adrenergic *** follow-up fasting test was positive,and the imaging results showed a tumor in the head of the *** patient underwent laparotomy with enucleation of the *** Weight gain and fasting hypoglycemia are not necessarily characteristics of *** prolonged cases,adrenergic symptoms can be suppressed.

关键词： Brown adipose tissue Glycogen deficit Hypoglycemia insulinoma Underweight Case report

Dietary selenium requirement of yellowtail kingfish (<i>Seriola lalandi</i>)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2013年第6期4卷 68-75页

作者： ky Trung Le Ravi Fotedar Department of Environment and Agriculture Curtin University Perth Australia

The dietary selenium (Se) requirement of yellowtail kingfish (Seriola lalandi) in normal and infected conditions was investigated. The fish were fed one of five experimental diets;a control un-supplemented diet (3.35 mg/kg Se) or diets supplemented with Se to provide 4.86, 5.38, 5.85 or 6.38 mg/kg Se. After feeding for 6 weeks, the fish were challenged by Vibrio anguillarum immersion and then observed for 4 weeks. Supplementation of Se had no effect on feed intake, feed conversion ratio and survival over 6 weeks of feeding;however, it significantly increased growth and Se content in muscle tissues. The optimal Se level for maximal growth of yellowtail kingfish estimated by second order regression was 5.56 mg/kg. Following the bacterial challenge, the immune-stimulating effects of Se were demonstrated in lysozyme and bactericidal activities, and there was a corresponding increase in survival and antibody response by supplementation of Se at ≥2 mg/kg (measured Se of ≥5.38 mg/kg). Under normal and infectious conditions, antioxidant capacity of fish measured as glutathione peroxidase activity increased by supplementation of Se. During post-challenge period, haematocrits were higher in the fish fed Se supplemented diets than the fish fed the control diet, while more macrophage aggregates were seen in the control group than in the others. Furthermore, there was evidence of myopathy in fish fed the diet without Se supplementation. Therefore, the results indicated that the optimal dietary Se requirement of yellowtail kingfish is 5.56 mg/kg.

关键词： Selenium Requirement Vibrio anguillarum Yellowtail Kingfish

On the Uniqueness of Heat Flow of Harmonic Maps and Hydrodynamic Flow of Nematic Liquid Crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2010年第6期31卷 921-938页

作者： Fanghua LiN Changyou WANG Courant institute of Mathematical Sciences New York University New York NY 10012 USA Department of Mathematics University of Kentucky Lexington KY 40506 USA.

For any n-dimensional compact Riemannian manifold (M,g) without boundary and another compact Riemannian manifold (N,h), the authors establish the uniqueness of the heat flow of harmonic maps from M to N in the class C([0,T),W1,n). For the hydrodynamic flow (u,d) of nematic liquid crystals in dimensions n = 2 or 3, it is shown that the uniqueness holds for the class of weak solutions provided either (i) for n = 2, u ∈ Lt∞ L2x∩L2tHx1, ▽P∈ Lt4/3 Lx4/3 , and ▽d∈ L∞t Lx2∩Lt2Hx2; or (ii) for n = 3, u ∈ Lt∞ Lx2∩L2tHx1∩ C([0,T),Ln), P ∈ Ltn/2 Lxn/2 , and ▽d∈ L2tLx2 ∩ C([0,T),Ln). This answers affirmatively the uniqueness question posed by Lin-Lin-Wang. The proofs are very elementary.

关键词： Hydrodynamic flow Harmonic maps Nematic liquid crystals Uniqueness

Spatial fading channel emulation for over-the-air testing ofmillimeter-wave radios:concepts and experimental validations

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

Frontiers of information Technology & Electronic Engineering 2021年第4期22卷 548-559页

作者： Wei FAN Lassi HENTiLA Pekka kyOTi Antenna Propagation and Millimeter-wave Systems(APMS)Section Department of Electronic SystemsAalborg UniversityAalborg 9220Denmark Keysight Technologies Finland Oy Oulu 90014Finland Centre for Wireless Communications University of OuluOulu 90014Finland

Millimeter-wave(mmWave)communication is regarded as the key enabling component for fifth-generation(5G)cellular systems due to the large available spectrum *** make mmWave new radio(NR)a reality,tremendous efforts have been exerted from the industry and *** evaluation of mmWave NR is a mandatory step and the key to ensuring the success of mmWave 5G ***-the-air(OTA)radiated method of testing mmWave NR in laboratory conditions is highly attractive,since it facilitates virtual field testing of mmWave devices in realistic propagation *** this paper,we first discuss the need for and challenges in OTA measurement of mmWave 5G NR under fading channel *** that,two promising candidate solutions,i.e.,wireless cable and multi-probe anechoic chamber(MPAC),are *** principles,applicability for mmWave NR,and main challenges are ***,preliminary experimental validation results in a frequency range 2 anechoic chamber are demonstrated for the wireless cable and MPAC methods at 28 GHz.

关键词： Spatial channel model Over-the-air(OTA)testing Wireless cable method Multi-probe anechoic chamber(MPAC)method FR2 validation

Recycled fibres and fibrous sludge as reinforcement materials in injection moulded polypropylene(PP)and poly(lactic acid)(PLA)composites

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

Journal of Bioresources and Bioproducts 2017年第3期2卷 116-122页

作者： Elina Pääkkönen Lisa Wikström Heidi Peltola kyösti Valta Elias Retulainen Department of Fibres and Biobased Materials VTT Technical Research Centre of Finland LtdKoivurannantie 1PO Box 1603JyväskyläFI-40101Finland Department of Fibres and Biobased Materials VTT Technical Research Centre of Finland LtdSinitaival 6PO Box 1300Tampere FI-33101Finland

Wood flour or sawdust is often used as filler in conventional wood plastic composite(WPC)***,there has been an increasing interest to the use of wood pulp fibres in reinforced plastic applications,because they can provide enhanced strength properties and better biodegradability characteristics for the *** research compares the effect of recycled fibres or side streams of paper as reinforcement in poly(lactic acid)(PLA)or polypropylene(PP)*** from liquid packaging board and non-deinked old newspapers,and fibrous sludge from recycling processes are compared with virgin softwood kraft pulp *** were produced by melt processing to a fibre content of 30%(or 10%fibrous sludge),and the mechanical properties were *** fibres provided comparable,or even higher,plastic reinforcement than virgin softwood *** PP composites,the differences in mechanical properties between different fibre types were relatively *** sludge decreased the mechanical performance of composites but can be considered as cheap filler in cases when mechanical properties are not *** possibility to use low-cost materials like recovered paper or deinking sludge in wood plastic composites is an interesting option for future sustainable applications.

关键词： Wood fibres Liquid packaging board Fibrous sludge Recycled fibres Biocomposite Mechanical properties

Localization and macroscopic instability in nanoporous metals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2022年第12期38卷 15-32页

作者： Zhangtao Sun Tianfu Guo Khalil i.Elkhodary Hang Yang Nian Zhou Shan Tan School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China institute of High Performance Computing A*STARSingapore 138632Singapore Department of Mechanical Engineering The American University in CairoNew Cairo 11835Egypt Department of Engineering Mechanics Dalian University of TechnologyDalian I16081China School of Materials and Energy Engineering Guizhou Institute of TechnologyGuiyang 550003China

Ductile fracture generally relates to microscopic voiding and to strain localization in metallic *** the void size is reduced to the nanoscale,size effects often lead to a different macroscopic plastic behavior from that established for the same material with larger *** example,irradiation of metallic materials can generate a large number of voids at the nanoscale,leading to complex deformation *** present work advances the understanding of strain localization in nanoporous metallic materials,connecting both the microscopic(nano-)and macroscopic *** explore the physical mechanisms at the nanoscale,molecular dynamics(MD)simulations were here carried out,capturing multiple nanovoids ***,a homogenized continuum theory based in Gurson's constitutive framework is proposed,which enables us to explore how localized behavior at the macroscopic scale *** homogenized model incorporates the surface tension associated with nanosized *** importance of this surface tension is illustrated by several parametric studies on the conditions of localization,when a specimen is subjected to uniaxial *** parametric studies show that for smaller nanovoid sizes,and for a hardening matrix material,shear localization onset is *** proposed homogenization model was then used to predict localization behavior captured by our MD *** yield stress and the localization strain predicted by our continuum model are in general agreement with the trends obtained by MD ***,based on our present study,experimental results of shear failure strain *** of irradiation for several metals could be qualitatively explained rather *** model can therefore help shed light on prolonging the operation limits and the lifetime of irradiated metallic materials under complex loading conditions.

关键词： Nanovoids MD simulations Localization Surface tension Shear band