检索结果-南通市图书馆

Effect of swirling flow on platelet concentration distribution in small-caliber artificial grafts and end-to-end anastomoses

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2011年第5期27卷 833-839页

作者： Fan Zhan Yu-Bo Fan xiao-yan Deng Key Laboratory for Biomechanics and Mechanobiologyof Ministry of Education School of Biological Science and Medical EngineeringBeihang University 100191 Beijing China

Platelet concentration near the blood vessel wall is one of the major factors in the adhesion of platelets to the *** our previous studies,it was found that swirling flows could suppress platelet adhesion in small-caliber artificial grafts and end-to-end *** order to better understand the beneficial effect of the swirling flow,we numerically analyzed the near-wall concentration distribution of platelets in a straight tube and a sudden tubular expansion tube under both swirling flow and normal flow *** numerical models were created based on our previous experimental *** simulation results revealed that when compared with the normal flow,the swirling flow could significantly reduce the near-wall concentration of platelets in both the straight tube and the expansion *** present numerical study therefore indicates that the reduction in platelet adhesion under swirling flow conditions in small-caliber arterial grafts,or in end-to-end anastomoses as observed in our previous experimental study,was possibly through a mechanism of platelet transport,in which the swirling flow reduced the near-wall concentration of platelets.

关键词： Platelet near-wall concentration · Swirling flow · Small-caliber arterial grafts · End-to-end anastomosis

Acidogenic sludge fermentation to recover soluble organics as the carbon source for denitrification in wastewater treatment： Comparison of sludge types

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2018年第4期12卷 25-32页

作者： Lin Lin Ying-yu Li xiao-yan Li Environmental Engineering Research Centre Departmelt of Civil Engineering The University of Hong Kong Pokfulam Hong Kong China Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery Graduate School at Shenzhcn Tsinghua University Shcnzhen 518055 China＊

For biological nitrogen （N） removal from wastewater, a sufficient organic carbon source is requested fbr denitrification. However. the organic carbon/nitrogen ratio in municipal wastcwatcr is becoming lower in recent years, which increases the demand for the addition of external organic carbon, e.g. methanol, in wastewater treatment. The volatile fatty acids （VFAs） produced by acidogenic fenncntation of sewage sludge can be an attractive alternative for methanol. Chemically enhanced primary sedimentation （CEPS} is an effective process that applies chemical coagulants to enhance the removal of organic pollutants and phosphorus from wastewater by sedimentation. In temls of the chemical and biological characteristics, the CEPS sludge is considerably different from the conventional primary and secondary sludge. In the present study, FeCI3 and PACI （polyalunfinum chloride） were used as the coagulants for CEPS treatment of raw sewage. The derived CEPS sludge （Fe-sludge and Al-sludge） was then processed with mcsophilic acidogenic fennentation to hydrolysc the solid organics and produce VFAs for organic carbon recovery, and the sludge acidogenesis efficiency was compared with that of the conventional primary sludge and secondary sludge. The results showed that the Fe-sludge exhibited the highest hydrolysis and acidogenesis efficiency, while the Al-sludge and secondary＇ sludge had lower hydrolysis efficiency than that of primary sludge. Utilizing ffie Fc-sludgc fermentation liquid as tbc carbon source for denitrificatiom more than 99%of nitrate removal was achieved in the main-stream wastewater treatment without any external carbon addition, instead of 35% obtained from the conventional process of primary sedimentation followed by the oxic/anoxic （O/A） treatment.

关键词： Sewage sludge Chemically enhanced primary sedimentation(CEPS) Acidogenic fermentation Organic carbon recovery Nitrogen removal

Networked collaborative pseudo-dynamic testing of a multi-span bridge based on NetSLab

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

Earthquake Engineering and Engineering Vibration 2009年第3期8卷 387-397页

作者： Cai Xinjiang Tian Shizhu Wang Dapeng xiao yan School of Civil Engineering Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Hunan University Changsha 410082 China Department of Civil Engineering University of Southern California Los Angeles California CA90089-2531 USA

Modem dynamic tests such as networked collaborative pseudo-dynamic testing （PDT） provide new tools to study the dynamic performance of large and complex structures. In this paper, several networked collaborative PDT systems established in China and abroad are introduced, including a detailed description of the first networked collaborative platform that involved the construction of a standardized demonstration procedure for networked collaborative PDT. The example is a multi-span bridge with RC piers retrofitted by FRP, and a networked structural laboratory （NetSLab） platform is used to link distributed laboratories located at several universities together. Substructure technology is also used in the testing. The characteristics, resource sharing and collaborative work of NetSLab are described, and the results illustrate that use of the NetSLab is feasible for studying the dynamic performance of multi-span bridge structures.

关键词： dynamic tests networked pseudo-dynamic testing multi-span bridges RC short piers FRP NetSLab

A novel diffusion model considering curvature radius at the bonding interface in a titanium/steel explosive clad plate

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第9期22卷 956-965页

作者： Hai-tao Jiang Qiang Kang xiao-qian yan National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing China Railway Materials Technologies Company Limited

This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.

关键词： explosive bonding metal cladding diffusion models interfaces heat treatment

Discrete-time charge analysis for a digital RF charge sampling mixer

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第4期11卷 307-314页

作者： Yun PAN Ning GE xiao-lang yan xiao-peng YU Institute of VLS1 Design Zhejiang University Hangzhou 310027 China Department of Electronic Engineering Tsinghua University Beijing 100084 China

This paper presents an approach for analyzing the key parts of a general digital radio frequency(RF) charge sampling mixer based on discrete-time charge *** cascade sampling and filtering stages are analyzed and expressed in theoretical *** effects of a pseudo-differential structure and CMOS switch-on resistances on the transfer function are addressed in *** DC-gain is restrained by using the pseudo-differential *** transfer gain is reduced because of the charge-sharing time constant when taking CMOS switch-on resistances into *** unfolded transfer gains of a typical digital RF charge sampling mixer are analyzed in different cases using this approach.A circuit-level model of the typical mixer is then constructed and simulated in Cadence SpectreRF to verify the *** work informs the design of charge-sampling,infinite impulse response(ⅡR) filtering,and finite impulse response(FIR) filtering *** discrete-time approach can also be applied to other multi-rate receiver systems based on charge sampling techniques.

关键词： Digital RF Charge sampling Discrete-time Pseudo-differential Switch-on resistance

The roles of microRNAs in regulating root formation and growth in plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第4期21卷 901-916页

作者： yan xiao-xiao LIU Xiang-yang CUI Hong ZHAO Ming-qin College of Tobacco Science Henan Agricultural University/National Tobacco Cultivation and Physiology and Biochemistry Research Center/Key Laboratory for Tobacco Cultivation of Tobacco IndustryZhengzhou 450002P.R.China

MicroRNAs(miRNAs) are small(ca. 20-24 nucleotides) non-coding RNAs that have recently been recognized as key post-transcriptional modulators of gene expression;and they are involved in many biological processes in plants, such as root growth and development. The miRNAs regulate root elongation, lateral root(LR) formation and adventitious root(AR) development in response to hormone signaling, nutrient uptake and biotic/abiotic stress. This review provides multiple perspectives on the involvement of miRNAs in regulating root growth and development in plants. We also discuss several crucial mechanisms of miRNAs, their relationships with transcription factors and the target gene-mediated hormone signaling interactions in the regulation of root growth and development.

关键词： microRNAs adventitious root lateral root primary root

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

Repairing whole facial nerve defects with xenogeneic acellular nerve grafts in rhesus monkeys

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

Neural Regeneration Research 2022年第5期17卷 1131-1137页

作者： Guo-Chen Zhu Da-Jiang xiao Bi-Wen Zhu yan xiao Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina Department of Otorhinolaryngology-Head and Neck Surgery Affiliated Wuxi Clinical College of Nantong UniversityWuxiJiangsu ProvinceChina College of Animal Science&Technology Zhongkai University of Agriculture and EngineeringGuangzhouGuangdong ProvinceChina Department of Pathology Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical UniversityWuxiJiangsu ProvinceChina

Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically,both in terms of branching a single trunk and in connecting multiple branches of an extratemporal ***,in the clinical treatment of facial nerve defects,allogeneic donors are *** this experiment,we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve *** monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft *** the autograft group,the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve,and in the xenogeneic acellular nerve graft group,this was done using a xenogeneic acellular nerve graft with *** of facial symmetry,nerve-muscle electrophysiology,retrograde transport of labeled neuronal tracers,and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement,and that they could actively close their eyelids *** degree of recovery from facial paralysis reached House-Brackmann grade II in both *** muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each *** Gold-labeled neurons could be detected in the facial nuclei on the injured *** staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves.A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron *** together,our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effec

关键词： acellular nerve compound muscle action potentials facial nerve defect facial symmetry monkey nerve graft nerve regeneration retrograde labeling test synaptophysin xenogeneic

Optic disc coloboma associated with macular retinoschisis: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