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Dynamic and Static Characteristics of Double Push rods Electromechanical Converter

Chinese Journal of Mechanical Engineering 2019年第4期32卷 116-126页

作者： Xuping Wang Long Quan Shiyi Luan Xiaoqing Xu College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan 030024China Institute of Mechanical Engineering Taiyuan University ofTechnology Taiyuan 030024 China

Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical converter with double push rods is proposed in this paper, which can simultaneously output two electromagnetic forces, can push or pull the valve core and sleeve according to the current direction and realize rapid operation of load. According to the electromagnetic principle and the magnetic circuit analysis method, the mathematical model and equivalent circuit of the electromechanical converter with double push rods are established. Through the finite element simulation model of the electromechanical converter with double push rods with the same magnetization directions, the changing rules of its magnetic field distribution and force–displacement behaviors are studied and analyzed. According to the analysis results, the electromagnetic mechanical parameters and mechanical structure of the electromechanical converter with double push rods are determined, and the prototype is made. The test platform for the push-pull characteristics of the electromechanical converter with double push rods is built, and its static and dynamic characteristics are tested and analyzed. The results show that the thrust and pull output characteristics of the internal and external push rods are basically consistent with the simulation output, and proportional to the current density of the coil;the push-pull hysteresis of internal and external push rods output force is less than 5%;and the dynamic time response characteristics of the displacement and force are obtained. The hysteresis e ect of output force is improved e ectively through the H bridge drive control circuit modulated by PWM. Compared with the displacement response of a singlewinding electromagnet with a similar volume, it can e ectively improve the dynamic displacement response. Followup work will further optimize th

关键词： Moving coil motor Double push rods electromagnet Proportional solenoid valve Response characteristics

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Research on Ultrafine Tungsten Carbide-Cobalt(WC-Co) Cemented Carbide rods of Miniature Drills for Highly Integrated Printed Circuit Board(PCB)

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Journal of Materials Science & Technology 2005年第3期21卷 353-356页

作者： Xiaoliang SHI, Gangqin SHAO, Xinglong DUAN and Runzhang YUAN State Key Laboratory of Advanced Technology for Materials Synthesis & Processing, Wuhan University of Technology, Wuhan 430070, China Lab. of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Nanocrystalline tungsten carbide-cobalt (WC-Co) composite powders produced through spray thermal decomposition-continuous reduction and carburization technology were used to prepare φ3.25 mm×38 mm ultrafine tungsten carbide-cobalt (WC-Co) cemented carbide rods through vacuum sintering plus sinterhip technology. The microstructure, Vickers hardness, density and Rockwell A hardness (HRA), transverse rupture strength (TRS), saturated magnetization and coercivity force were tested. The results show that the average grain size of the sintering body prepared through vacuum sintering plus sinterhip technology was 430 nm; transverse rupture strength (TRS) was 3850 MPa; Vickers hardness was 1890 and Rockwell A hardness of sintering body was 93. High strength and high hardness ultrafine WC-Co cemented carbide rods used to manufacture printed circuit board (PCB) drills were obtained.

关键词： Nanocrystalline Composite powder Cemented carbide rods

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Release of Nestorone from Biodegradable rods System in vitro

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 4-7页

作者：曹成波 School of Chemistry and Chemical Engineering Shandong University

To study the controlled effect of poly （lactic acid）（PLA）, poly lactic-coglycolic （PLGA） and ethylenediamine （EDA）-maleic anhydride （MAH） modified PLA （EMPLA） for in vitro release of nestorone, rods were prepared using the solvent evaporation method. Amount of drug release in vitro was determined by UV spectrophotometry. Effects of rods diameter, the molecular weight of PLA, the drug percentage and the hydrophilicity of polymers on the release of biodegradable nestorone rods in vitro were investigated. It is indicated that the controlled effect of the biodegradable rods for the release of nestorone in vitro is good. The amount of drug released every week from rods in different diameter is similar to one another. The amount of drug released every week and the accumulative drug released during 12 week were almost in direct proportion with the drug percentage of the rods. The amount of drug released every week is increased as the decreasing of PLA molecular weight. As the hydrophlicity of polymer is improved, the rate of drug release every week is accelerated. The studies show that the plausibility of controlled release of nestorone from PLA, PLGA and EMPLA rods imply the possibility of their application as a controlled delivery system for nestorone. The results show that the greater the molecular weight of PLA is, the slower its degradation is and the slower the drug released; the greater the percentage of nestorone is, the more quickly the drug release. An increase of the hydrophilicity of the polymers will increase their degradation rate and leads to a fast drug release. Anyhow, these rods systems should be further evaluated in vivo.

关键词： nestorone PLA PLGA EMPLA rods in vitro release

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Growing spine deformities: Are magnetic rods the final answer?

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世界骨科杂志：英文版 2017年第4期8卷 295-300页

作者： Ashok N Johari Amit S Nemade Enable International Center for Paediatric Musculoskeletal Care

Treatment paradigms for Early Onset Scoliosis have changed from fusion to fusionless methods as the harmful effects of early fusion on the growing spine and thorax were realized. Magnetic rods are a recent addition to fusionless technology for controlling scoliosis in a growing spine. The clinical evidence base on magnet driven growth rods(MDGR) has accumulated over the last 4 years. It has implications for reduction in the number of repeat surgeries required with similar complications as the traditional growth rods(TGR) and at a higher initial cost. However in terms of patient psyche and avoidance of repeat surgeries which are necessary with the TGR, MDGR treatment works out less expensive in the long run with definitely better patient comfort. The authors look at the available literature coupled with their own experience to discuss the current status, limitations and future prospects for this type of technology.

关键词： Growing spine Magnet driven growth rods Magnetic growth rods Growth rods Early Onset Scoliosis

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Loop Ileostomy and Colostomy—A Comparison between Supporting Plastic rods and Epicutaneous or Subcutaneous Silicon Drains

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Surgical Science 2011年第5期2卷 252-256页

作者： Mike Ralf Langenbach Stefan Sauerland Eiyad Issa Claudia Nitschke Hubert Zirngibl 不详

Purpose: Beside the conventional plastic rods, different techniques and materials have been proposed in the last years to prevent the loop from retraction into the abdominal cavity. The aim of this retrospective comparative study was to assess three different techniques of loop support. Methods: The study included 65 pa- tients who had loop ileostomy or colostomy formed. Depending on the decision of the operating surgeon, one of three techniques was chosen to fixate the stoma loop: an epicutaneous plastic rod (group 1, n = 14), an epicutaneous suture-fixated silicone drain (group 2, n = 27), or a subcutaneous silicone drain (group 3, n = 24). Results: The majority of patients (85%) received loop ileostomy. Pain intensity was significantly (p = 0.0014) different among the three groups. A total of 19 patients (30%) suffered a complication. There was a tendency towards less complications if the stoma was secured by a silicone drain with epicutaneous fixation. Comfort with stoma care was significantly different, with group 3 experiencing the best results. Conclusions: Using a subcutaneously tunnelled silicon drain as a stoma bridge results in less complications, less pain and higher satisfaction as compared to the conventional plastic rod. Conventional plastic rods should be avoided.

关键词： Ileostomy Colostomy Drains Plastic rods

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Anti-rods/rings autoantibody generation in hepatitis Cpatients during interferon-α/ribavirin therapy

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World Journal of Gastroenterology 2016年第6期22卷 1966-1974页

作者： Gerson Dierley Keppeke S John Calise Edward KL Chan Luis Eduardo C Andrade Rheumatology Division Escola Paulista de MedicinaUniversidade Federal de São PauloSP 04023-062Brazil Department of Oral Biology University of FloridaGainesvilleFL 32610-0424United States 3 Immunology DivisionFleury Medicine and Health Laboratories São PauloSP 04102-050Brazil

Chronic inflammation associated with hepatitis C virus(HCV) infection can lead to disabling liver diseases with progression to liver cirrhosis and hepatocellular carcinoma. Despite the recent availability of more effective and less toxic therapeutic options, in most parts of the world the standard treatment consists of a weekly injection of pegylated interferon α(IFN-α) together with a daily dose of ribavirin. HCV patients frequently present circulating non-organ-specific autoantibodies demonstrating a variety of staining patterns in the indirect immunofluorescence assay for antinuclear antibodies(ANA). Between 20% to 40% of HCV patients treated with IFN-α and ribavirin develop autoantibodies showing a peculiar ANA pattern characterized as rods and rings(RR) structures. The aim of this article is to review the recent reports regarding RR structures and anti-rods/rings(antiRR) autoantibody production by HCV patients after IFN-α/ribavirin treatment. Anti-RR autoantibodies first appear around the sixth month of treatment and reach a plateau around the twelfth month. After treatment completion, anti-RR titers decrease/disappear in half the patients and remain steady in the other half. Some studies have observed a higher frequency of anti-RR antibodies in relapsers, i.e., patients in which circulating virus reappears after initially successful therapy. The main target of anti-RR autoantibodies in HCV patients is inosine-5'-monophosphate dehydrogenase 2(IMPDH2), the rate-limiting enzyme involved in the guanosine triphosphate biosynthesis pathway. Ribavirin is a direct IMPDH2 inhibitor and is able to induce the formation of RR structures in vitro and in vivo. In conclusion, these observations led to the hypothesis that anti-RR autoantibody production is a human model of immunologic tolerance breakdown that allows us to explore the humoral autoimmune response from the beginning of the putative triggering event: exposure to ribavirin and interferon.

关键词： rods and rings autoantibodies Hepatitis C ribavirin Interferon-α

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Functionalization of AuMSS nanorods towards more effective cancer therapies

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Nano Research 2019年第4期12卷 719-732页

作者： Carolina F. Rodrigues Telma A. Jacinto Andre F. Moreira Elisabete C. Costa Sonia P. Miguel Ilidio J. Correia CICS-UBI -Centro de Investigagao em Ciencias da Saude Universidade da Beira Interior Covilhd 6200-506 Portugal CIEPQF - Departamento de Engenharia Quimica Universidade de Coimbra Rua 13 Silvio Lima Coimbra 3030-790 Portugal

The applicatio n of nano particles as selective drug delivery platforms arises as one the most promising therapeutic strategies in the biomedical field. Such systems can encapsulate drugs, prevent its premature degradation, transport and promote the drugs specific delivery to the target site. Among the different nanostructures, gold-core mesoporous silica shell (AuMSS) nanorods have been one of the most explored due to their unique physical and chemical properties. The mesoporous silica biocompatibility, high surface area that can be easily functionalized, tubular pores that can store the drugs, conjugated with the intrinsic capacity of gold nanorod to absorb near-infrared radiation, allows the combination of hyperthermia (i.e., photothermal effect) with drug delivery, making them a nanoplatforms with a huge potential for cancer therapy. Nevertheless, the successful applicati on of AuMSS nanoparticles as an effective can cer nano medicine is hindered by the uncon trolled release of the therapeutic payloads, limited blood circulation time and unfavorable pharmacokinetics. In this review, an overview of the modificati ons performed to improve the AuMSS nano rods applicati on in nanom edicine is provided, highlighting the practical approaches that enhaneed the AuMSS nanorods targeting, responsiveness to different stimuli, and blood circulation time. Further, the basics of AuMSS nano rods syn thesis procedures, gen eral properties, and its applicati on in can cer therapy are also described.

关键词： gold nano rods silica surface modifications targeting cancer

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Optimization of the fuel rod＇s arrangement cooled by turbulentnanofluids flow in pressurized water reactor (PWR)

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Chinese Journal of Chemical Engineering 2017年第6期25卷 722-731页

作者： M. Hatami MJ.Z. Ganfi I. Sohrabiasl D. Jing International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'anJiaotong University Xi'an 710049 China Department of Mechanical Engineering Esfarayen University of Technology Esfarayen North Khorasan lran Department of Renewable Energies Engineering Faculty of New Sdences & Technologies University of Tehran Tehran lran Department of Mechanical Engineering Babol University of Technology Babol lran

In this paper, response surface methodology(RSM) based on central composite design(CCD) is applied to obtain an optimization design for the fuel rod's diameter and distance cooled by turbulent Al_2O_3–water nanofluid for a typical pressurized water reactor(PWR). Fuel rods and nanofluid flow between them are simulated 3D using computational fluid dynamics(CFD) by ANSYS-FLUNET package software. The RNG k–ε model is used to simulate turbulent nanofluid flow between the rods. The effect of different nanoparticles concentration is also investigated on the Nusselt number from heat transfer efficiency view point. Results reveal that when distance parameter(a) is in the minimum level and diameter parameter(r) is in the maximum possible level, cooling the rods will be better due to higher Nusselt number in this situation. Also, using the different nanoparticles on the cooling process confirms that Al_2O_3 averagely 17% and TiO_2 10% improve the Nusselt numbers.

关键词： Optimization Fuel rods Nanofluid Pressurized water reactor

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Acoustic Band Gaps in Three-Dimensional NaCl-Type Acoustic Crystals

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Chinese Physics Letters 2008年第8期25卷 2922-2925页

作者：方弄玉吴福根张欣 Department of Experiment Education Guangdong University of Technology Guangzhou 510006

We present the acoustic band gaps （ABGs） for a geometry of three-dimensional complex acoustic crystals： the NaCl-type structure. By using the super cell method based on the plane-wave expansion method （PWE）, we study the three configurations formed by water objects （either a sphere of different sizes or a cube） located at the vertices of simple cubic （SC） lattice and surrounded by mercury background. The numerical results show that ABGs larger than the original SC structure for all the three configurations can be obtained by adjusting the length-diameter ratio of adjacent objects but keeping the filling fraction （f = 0.25） of the unit cell unchanged. We also compare our results with that of 3D solid composites and find that the ABGs in liquid composites are insensitive to the shapes as that in the solid composites. We further prove that the decrease of the translation group symmetry is more efficient in creating the ABGs in 3D water-mercury systems.

关键词： 2-DIMENSIONAL PHONONIC CRYSTALS CUBIC ARRAYS STOP BANDS SYMMETRY BALLOONS rods

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Seeing red: color vision in the largemouth bass

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Current Zoology 2019年第1期65卷 43-52页

作者： Lisa D. MiTCHEM Shannon Stanis Muchu Zhou Ellis LoEw John M. Epifanio Rebecca C. Fuller Department of Animal Biology School of Integrative Biology University of Illinois Champaign IL 61820 USA Department of Biomedical Sciences and Section of Physiology College of Veterinary Medicine Cornell University Ithaca NY 14853 USA Illinois Natural History Survey Champaign IL 61820 USA

How animals visually perceive the environment is key to understanding important ecological behaviors, such as predation, foraging, and mating. This study focuses on the visual system properties and visual perception of color in the largemouth bass Micropterus salmoides. This study (1) documents the number and spectral sensitivity of photoreceptors,(2) uses these parameters to model visual perception, and (3) tests the model of color perception using a behavioral assay. Bass possess single cone cells maximally sensitive at 535 nm, twin cone cells maximally sensitive at 614 nm, and rod cells maximally sensitive at 528 nm. A simple model of visual perception predicted that bass should not be able to discern between chartreuse yellow and white nor between green and blue. In contrast, bass should be able to discern red from all achromatic (i.e., gray scale) stimuli. These predictions were partially upheld in behavioral trials. In behavioral trials, bass were first trained to recognize a target color to receive a food reward, and then tested on their ability to differentiate between their target color and a color similar in brightness. Bass trained to red and green could easily discern their training color from all other colors for target colors that were similar in brightness (white and black, respectively). This study shows that bass possess dichromatic vision and do use chromatic (i.e., color) cues in making visual-based decisions.

关键词： bass cones photoreceptors rods vision

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