检索结果-南通市图书馆

Influence of mill modulus control gain on vibration in hot rolling mills

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第5期27卷 528-536页

作者： Jie-bin Qi Xin-xin Wang xiao-qiang yan School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

The rolling mill vibration is characterized by the coupling effects among mechanical,electrical,hydraulic and interfacial *** influence of the mill modulus control gain in automatic gauge control on the vibration in hot rolling mills was ***,an experiment related to the mill modulus control gain was carried out in the hot rolling mill process,and it was found that the rolling mill vibration increases with the mill modulus control ***,based on the Sims rolling force method,the coupling dynamic model was established to explain this ***,the influence of mill modulus control gain on the vibration was analyzed numerically on the basis of the coupling dynamic ***,the agreement between the experimental results and the simulation results was confirmed and the measure reducing the mill modulus control gain was obtained to relieve mill vibration.

关键词： Rolling mill vibration Coupling dynamic model Automatic gauge control Mill modulus control gain Vibration suppression

Intestinal microecology-based treatment for inflammatory bowel disease:Progress and prospects

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 2023年第1期11卷 47-56页

作者： Xia-xiao yan Dong Wu Department of Gastroenterology State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical SciencesPeking Union Medical CollegeBeijing 100730China

Inflammatory bowel disease(IBD)is a chronic,recurrent,and debilitating disorder,and includes Crohn’s disease and ulcerative *** pathogenesis of IBD is closely associated with intestinal dysbiosis,but has not yet been fully *** and environmental factors can influence IBD patients’gut microbiota and metabolism,disrupt intestinal barriers,and trigger abnormal immune *** have reported the alteration of gut microbiota and metabolites in IBD,providing the basis for potential therapeutic *** microbiota-based treatments such as pre/probiotics,metabolite supplementation,and fecal microbiota transplantation have been extensively studied,but their clinical efficacy remains *** the intestinal barrier and promoting mucosal healing have also been *** here review the current clinical trials on intestinal microecology and discuss the prospect of research and practice in this field.

关键词： Inflammatory bowel disease Probiotics Prebiotics Intestinal metabolites Fecal microbiota transplantation Intestinal barrier

Optic disc coloboma associated with macular retinoschisis: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 2022年第20期10卷 6966-6973页

作者： Wei Zhang xiao-yan Peng Beijing Ophthalmology and Visual Science Key Laboratory Beijing Institute of OphthalmologyBeijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100005China

BACKGROUND To report an unusual case of bilateral optic disc coloboma associated with macular retinoschisis in the left *** SUMMARY A 37-year-old woman presented with complaints of blurred and distorted vision in her left eye for more than 1 *** examination demonstrated choroidal atrophy around the optic disc in both eyes,with a cup-to-disc ratio of *** retinal detachment in the macular area of the left *** eye macular blood flow imaging optical coherence tomography(Angio-OCT)showed macular retinal serous ***-face OCT showed that the canal gully-like structure formed by the defect of the optic disc nerve fiber layer between the optic disc and macula,serous detachment area was connected with the enlarged optic disc coloboma through the canal gully-like structure,and the fluid leaked from the enlarged and thinned optic disc coloboma into the retinal layer of the macular *** with optic disc abnormalities and macular degeneration must be monitored *** the follow-up period,the use of optic disc stereography and 3D-OCT,en-face,and Angio-OCT imaging can clarify the correlation between macular retinoschisis and optic disc *** Macular retinoschisis may be owing to the combined force of disc edge loss,enlarged optic disc coloboma,the canal gully-like structure formed by the defect of the nerve fiber layer around the optic disc,and the traction of the posterior vitreous cortex.

关键词： Optic disc coloboma Macular retinoschisis Optical coherence tomography Case report

The mechanism of liquid dispersing from a cylinder driven by central dynamic shock loading

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第4期17卷 1313-1325页

作者： Lei Li xiao-xia Lu xiao-bin Ren Ye-jun Ren Shou-tian Zhao xiao-fang yan State Key Laboratory of NBC Protection for Civilian Beijing102205China School of Aerospace Engineering Tsinghua UniversityBeijing100084China

A systematic investigation on the mechanism of dynamic liquid dispersing process via theoretical and experimental approach is *** experiments include weak and strong constrained scenarios using the high-speed camera technique and the flash X-ray radiography *** on dynamic analysis,one-dimensional characteristics analysis and some numerical simulations on the propagating processes of blast waves before the container shell rupturing,further and detailed analyses of the experimental results are *** effects of the liquid viscosity on the dynamic dispersing flow are also analyzed,and the spall fracture mechanism is ***,the dominating forces determining the dispersing liquid flow are revealed,that is,the stretching and shearing action due to the interaction of two reflecting rarefaction waves in opposite propagating *** influence of container shell strength on the dispersing liquid flow is also investigated,and the characters of cavitation layered in liquid before shell rupturing are *** revealed that different shell material results in different cavitating *** the different cavitating layers drive the different dynamic liquid dispersing process coming into *** metastable liquid states caused by pressure drop and cavitation generation are discussed.

关键词： Shell effects Reflected rarefaction waves Liquid spall fracture Liquid dispersing Shock waves Cavitation layered

Electroactive Shape Memory Cyanate/Polybutadiene Epoxy Composites Filled with Carbon Black

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2016年第4期34卷 466-474页

作者： Kun Wang 朱光明 xiao-gang yan Fang Ren xiao-ping Cui Department of Applied Chemistry Northwestern Polytechnical UniversityXi'an 710129China

Electroactive shape memory composites were synthesized using polybutadiene epoxy （PBEP） and bisphenol A type cyanate ester （BACE） filled with different contents of carbon black （CB）. Dynamic mechanical analysis （DMA）, scanning electron microscopy （SEM）, electrical performance and electroactive shape memory behavior were systematically investigated. It is found that the volume resistivity decreased due to excellent electrical conductivity of CB, in turn resulting in good electroactive shape memory properties. The content of CB and applied voltage had significant influence on electroactive shape memory effect of developed BACE/PBEP/CB composites. Shape recovery can be observed within a few seconds with the CB content of 5 wt% and voltage of 60 V. Shape recovery time decreased with increasing content of CB and voltage. The infrared thermometer revealed that the temperature rises above the glass transition temperature faster with the increase of voltage and the decrease of resistance.

关键词： Electroactive shape memory behaviors Cyanate ester Carbon black Electrical performance.

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第1期49卷 229-230页

作者： TANG xiao-yan Padma Kant Shukla Department of Physics Shanghai Jiao Tong University Shanghai 200240 China Institut fur Theoretische Physik IV Fakultat fur Physik und Astronomie Ruhr-Universitat Bochum D-44870 Bochum Germany School of Physics University of KwaZulu-Natal 4000 Durban South Africa

Applying the classical Lie symmetry approach to the barotropic and quasi-geostrophic potential vorticity equation without forcing and dissipation on a β-plane channel, we find a new symmetry, which is not presented in a previous work [F. Huang, Commun. Theor. Phys. （Beijing, China） 42 （2004） 903]. A general finite transformation group is obtained based on the full Lie point symmetry, Furthermore, two new types of similarity reduction solutions are obtained.

关键词： Lie symmetry similarity reductions potential vorticity equation

Drying and preheating processes of iron ore pellets in a traveling grate

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 535-540页

作者： Jun-xiao Feng Yu Zhang Hai-wei Zheng xiao-yan Xie Cai Zhang School of Mechanical Engineering University of Science and Technology B~ijing Beijing 100083 China

A mathematical model of drying and preheating processes in a traveling grate was presented based on the laws of mass, momen- tum, heat transfer, and drying semiempirical relations. A field test was systematically carried out in a traveling grate. The effects of pellet diameter, moisture, grate velocity, and inlet gas temperature on the pellet bed temperature were studied. The average relative error between actual measurements and simulations is less than 7.97%, indicating the validity of the model.

关键词： iron ores pelletizing drying preheating numerical methods field test

Relapsing polychondritis with isolated tracheobronchial involvement complicated with Sjogren's syndrome:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第19期10卷 6563-6570页

作者： Jun-yan Chen xiao-yan Li Chen Zong Department of Pulmonary and Critical Care Medicine The Second Hospital of Shanxi Medical UniversityTaiyuan 030000Shanxi ProvinceChina

BACKGROUNDRelapsing polychondritis (RP) is a rare, long-term, and potentially life-threateningdisease characterised by recurrent paroxysmal inflammation that can involve anddestroy the cartilage of the external ear, nose, larynx, and *** SUMMARYWe here report a case of RP involving solely the tracheobronchial cartilage ring(and not the auricular. nasal or articular cartilage) complicated by Sjögren's syndrome in a 47-year-old female whose delayed diagnosis caused a sharpdecline in pulmonary function. After corticosteroid treatment, her pulmonaryfunction *** such cases, our experience suggested that 18F-fluorodeoxyglucose positronemission tomography/computed tomography (18F-FDG PET/CT) and fiberopticbronchoscopy should be used to diagnose airway chondritis as relapsing polychondritisin the early phase of disease.

关键词： Relapsing polychondritis Tracheobronchial involvement 18F-fluorodeoxyglucose positron emission tomography/computed tomography Fiberoptic bronchoscopy Case report

Correlation Between Microstructure and Mechanical Properties of 2219-T8 Aluminum Alloy Joints by VPTIG Welding

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 Metallurgica Sinica(English Letters) 2017年第5期30卷 438-446页

作者： Lan-Qiang Niu xiao-yan Li Liang Zhang xiao-Bo Liang Mian Li College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

In this study, 2219-T87 aluminum alloys were butt welded by the double-pass tungsten inert gas arc welding process. And the softening behavior of fusion zone（FZ） and heat-affected zone（HAZ） was evaluated with the analysis of welding temperature field, grain size, alloying element distribution and precipitates evolution. Results show that the two FZs are almost the weakest regions in the joint, where the microhardness value is 76 and 78 HV, respectively. Microhardness of the HAZ generally grows along with increasing distance from fusion line except a valley value at the distance of about 4.5 mm. The mean grain size of two FZs is about 74.4 and 79.2 lm, whereas 41.5, 44.9 and 43.4 lm for the two measured HAZs and base metal（BM）, respectively. There is about 60.4% and 54.2% Cu consumed in the coarse whitish particles of FZs that have little strengthening effect, while the percentage is about 24.6% of BM that is almost the same as HAZ. A large number of strengthening phases h0 distribute dispersively in BM, whereas hardly any precipitates exist in FZ and HAZ adjacent to FZ. So the coarsening of grain size, reduction and segregation of alloying element content, and the precipitate evolution are regarded as the main causes of softening in FZ, while the precipitate evolution is the main factor of softening in HAZ.

关键词： 2219-T87 Aluminum alloy TIG welding Fusion zone Heat-affected zone Softening behavior