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A Numerical Study on the Effect of the Backflow Hole Position on the Performances of a Self-Priming Pump

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1103-1122页

作者： dongwei wang Lijian Cao Weidong wang Jiajun Hu School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou730050China Sanlian Pump Industry Co. Ltd.Ma’anshan243000China

A self-priming pump is a centrifugal pump that has the ability to prime itself. Typically, its performance dependson the configuration of its reflux hole. In this study, the ANSYS FLUENT software is used to investigate the effectsof three different radial positions of the reflux hole on gas-liquid two-phase distribution, pressure pulsation, andimp during self-priming. The research results indicate that: (1) The effective channel size for the reflux liquid toenter the volute varies depending on the location of the reflux hole. The effect of the impeller rotation on thereflux liquid becomes more obvious as the setting distance of the reflux aperture decreases. (2) The position ofthe reflux hole significantly affects the gas phase mass fraction inside the impeller, resulting in a significant reductionin the time it takes for the mass fraction to exceed 80%. (3) The position of the reflux hole significantly affectsthe average pressure on each monitoring surface. (4) Placing the reflux hole at a excessively distant radial distancecan result in an excessive vertical component. (5) The self-priming performance of the pump can be improved tosome extent by placing the return hole at a small radial distance.

关键词： Self-priming pump self-priming time numerical calculation gas-liquid two-phase flow

Alignment of Nanoscale Single-Walled Carbon Nanotubes Strands

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Nano-Micro Letters 2011年第3期3卷 146-152页

作者： Danna Yang Lin wang Xiaoxian Zhang dongwei wang Zhiqiang Shen Sai Li School of Chemical Engineering Sichuan University Academy of Military Medical sciences Chinese PLA Center for Disease Control & Prevention

Depositing single-walled carbon nanotubes(SWNTs) with controllable density, pattern and orientation on electrodes presents a challenge in today's research. Here, we report a novel solvent evaporation method to align SWNTs in patterns having nanoscale width and micronscale length. SWNTs suspension has been introduced dropwise onto photoresist resin microchannels; and the capillary force can stretch and align SWNTs into strands with nanoscale width in the microchannels. Then these narrow and long aligned SWNTs patterns were successfully transferred to a pair of gold electrodes with different gaps to fabricate carbon nanotube field-effect transistor(CNTFET). Moreover, the electrical performance of the CNTFET show that the SWNTs strands can bridge different gaps and fabricate good electrical performance CNTFET with ON/OFF ratio around 106. This result suggests a promising and simple strategy for assembling well-aligned SWNTs into CNTFET device with good electrical performance.

关键词： Single-walled carbon nanotubes Microchannel Capillary force Carbon nanotube field effect transistor

Optimized design of the 4TSQ-2 sugar beet top cutting machine

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 111-116页

作者： Fangyan wang Zhenyu Zhang Yongfei Pan Yuliang Yun dongwei wang College of Mechanical and Electrical Qingdao Agricultural UniversityQingdao 266109China

To solve the problems faced by 4TSQ-2 sugar beet top cutting machine,*** structure,high power consumption and high manufacturing cost,the multi-roller mechanism for leaves removal and fixed-thickness cutting method was *** five-factor and two-level tests,the structure configuration of the leaf removal device was optimized,and the scheme of two roller shafts defoliation,the roller shaft rotation speed of 800 r/min and the forward speed of 0.8 m/s were *** the working process and mechanical analysis of the top cutting device,the cutting device with the slant profiling plate structure characterized by a profiling angle of 25°-45°for the profiling plate and a cutting angle of 20°-40°was *** the two-factor and three-level experiments,the profiling angle of profiling plate of the top cutting device was 35°,and the cutting angle was 30°.Compared with the 4TSQ-2 sugar beet top cutting machine before optimization,the structure size of the machine was reduced by 30%,the weight was reduced by 15%,the cost was reduced by 25%,the qualified rate of top cutting wad was increased by 2.6%,and the push over rate of sugar beet was reduced by 0.5%.Besides,each index met the index requirements of beet top cutting harvest.

关键词： beet harvest leaves cleaning top cutting structure optimization

Assessment of potential dermal and inhalation exposure of workers to the insecticide imidacloprid using whole-body dosimetry in China

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Journal of Environmental Sciences 2015年第1期27卷 139-146页

作者： Lidong Cao Bo Chen Li Zheng dongwei wang Feng Liu Qiliang Huang Institute of Plant Protection Chinese Academy of Agricultural Sciences College of Plant Protection Shandong Agricultural University School of Chemistry and Chemical Engineering Nanjing University

In China, although improvements to the pesticide registration process have been made in la thirty years, no occupational exposure data are required to obtain a commercial license for pesticide product. Consequently, notably little research has been conducted to establish a exposure assessment procedure in China. The present study monitored the potential derm operator exposure from knapsack electric sprayer wheat field application of imidacloprid Liaocheng City, Shandong Province and in Xinxiang City, Henan Province, China, usin whole-body dosimetry. The potential inhalation exposure was determined using a person air pump and XAD-2 sample tubes. The analytical method was developed and validate including such performance parameters as limits of detection and quantification, linear rang recovery and precision. The total potential dermal and inhalation exposures were 14.20, 16.815.39 and 20.78 mL/hr, respectively, for the four operators in Liaocheng and Xinxian corresponding to 0.02% to 0.03% of the applied volume of spray solution. In all trials, the low part（thigh, lower leg） of the body was the most contaminated, accounting for approximate76% to 88% of the total exposure. The inhalation exposure was less than 1% of the tot exposure. Such factors as the application pattern, crop type, spray equipment, operat experience and climatic conditions have been used to explain the exposure distribution ov the different parts of the body. As indicated by the calculated Margin of Exposure, the typic wheat treatment scenarios when a backpack sprayer was used are considered to be safe terms of imidacloprid exposure.

关键词： Potential dermal and inhalation exposure Insecticide imidacloprid Whole body dosimetry Margin of exposure China

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基于EDEM的驱动耙旋耕装置的分析与试验

农机化研究 2025年第3期47卷 16-21页

作者：董成李想尚书旗王东伟何晓宁李绪李墨贤王如正青岛农业大学机电工程学院山东青岛266109

为提高动力驱动耙碎土过程中的效率和碎土率,在现有结构基础上,分析了动力耙耙刀碎土原理,构建了碎土耙刀-土壤动力学模型,并对动力驱动耙刀具长度和角度进行设计。同时,利用EDEM软件以动力驱动耙耙刀转动速度、耙刀外倾角度、耙刀长度... 详细信息

为提高动力驱动耙碎土过程中的效率和碎土率,在现有结构基础上,分析了动力耙耙刀碎土原理,构建了碎土耙刀-土壤动力学模型,并对动力驱动耙刀具长度和角度进行设计。同时,利用EDEM软件以动力驱动耙耙刀转动速度、耙刀外倾角度、耙刀长度为影响因素,以碎土率为检测指标,进行响应面仿真分析试验。试验结果表明:耙刀转动速度对碎土率影响极显著,耙刀外倾角和长度对碎土率影响比较显著;耙刀倾角为34.7°、耙刀转速为320 r/min、耙刀长度为28 cm时,耙刀装置处于最优工作状态。研究结果可为动力驱动耙的开发研究提供参考。

关键词：动力驱动耙 EDEM 耙刀-土壤动力学模型碎土率

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γ-Aminobutyric acid alleviates litchi thaumatin-like protein-induced inflammation and reduces gut microbial translocation

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Food Science and Human Wellness 2024年第5期13卷 3043-3053页

作者： Yao wang dongwei wang Kai wang Min Zhao Cizhou Li Yu wang Xuwei Liu Lei Zhao Zhuoyan Hu Guangdong Provincial Key Laboratory of Food Quality and Safety College of Food ScienceSouth China Agricultural UniversityGuangzhou 510642China Guangzhou wanglaoji Lychee Industry Development Co. Ltd.Guangzhou 510623China

Previous research reported litchi thaumatin-like protein(LcTLP)could lead to inflammation,which is a factor causing the adverse reactions after excessive intake of *** a main amino acid in litchi pulp,γ-aminobutyric acid(GABA)was found with anti-inflammatory ***,this study aimed to investigate the effects of GABA on LcTLP-induced inflammation through RAW264.7 macrophages and C57BL mice *** vitro study showed GABA could effectively regulate the level of inflammatory cytokines(interleukin(IL)-1β,IL-6,IL-10,and prostaglandin E2)and Ca2+in cells,and inhibit the phosphorylation of p65,IκB,p38,c-Jun N-terminal kinase(JNK)and extracellular signal-regulated kinase(ERK).These results indicate GABA alleviated inflammation through nuclear factor-κB and mitogen-activated protein kinase pathway signaling *** vivo experiment was performed to verify the anti-inflammatory effect of GABA,and the results demonstrated that GABA reduced the inflammation and oxidative stress in the liver of LcTLP-treated mice,as it down-regulated the pro-inflammatory cytokines,malondialdehyde,aspartate transferase,and alanine *** relative expression of phosphorylated p38,JNK and ERK in mice liver with GABA treatment were reduced to 65%,39%and 80%of the control group,***,GABA treatment enriched probiotic bacteria and decreased pathogenic bacteria in mice gut,which reveals GABA could effectively reduce the translocation of gut microbiota.

关键词： Anti-inflammation Gut microbiota Litchi thaumatin-like protein Mitogen-activated protein kinase pathway γ-Aminobutyric acid

Lightweight design of peanut sowing machine frame based on finite element analysis

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International Journal of Agricultural and Biological Engineering 2023年第3期16卷 120-129页

作者： Yan Yu Linsong Diao dongwei wang Jiasheng wang Xiaomin wang Xiaozhi Tan Dazhi Yi College of Mechanical and Electrical Engineering Qingdao Agricultural UniversityQingdao 266109China

In order to reduce the weight and energy consumption of the whole machine against the heavy mechanical structure and excessive strength redundancy in current small-scale peanut seeders with one ridge and two rows,a finite element model of the frame was established and the static finite element analysis and modal analysis were conducted with ANSYS *** analysis that focuses on the size of intermediate support beams and other components was performed so as to set up a multi-objective optimization *** a size optimization and multi-objective optimization collaborative scheme was adopted so that the target was optimized by the Seagull Optimization Algorithm(SOA)to obtain the optimal *** on the results of the finite element analysis,the mechanical structure of the peanut seeder was optimized for lightweight ***,response surface plots and static structural analysis were applied for *** turned out that the maximum stress of the optimized structure was less than the allowable stress;the weight of the frame reduced by 32.5%after optimization;and the first-order natural frequency did not coincide with the engine input speed or working speed,thus no resonance will *** experiments showed that the qualified rate of row spacing was≥96%when operating at different speeds of different types of seeders;The seeding depth operation performance was stable,with an average qualified rate of seeding depth of≥92%;The performance of the seeders was also stable and reliable due to the lightweight prototype *** research outcomes can provide an effective technical reference and theoretical basis for the lightweight design of peanut seeders and for its continuous improvement as well in the future.

关键词： peanut sowing machine multi-objective optimization lightweight design finite element analysis optimization

Validation results of NmF2 and hmF2 derived from ionospheric density profiles of GNOS on FY-3C satellite

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Science China(Technological Sciences) 2018年第9期61卷 1372-1383页

作者： YANG GuangLin SUN YueQiang BAI WeiHua ZHANG XiaoXin LIU CongLiang MENG XiangGuang BI YanMeng wang dongwei ZHAO DanYang National Space Science Center China Academy of Sciences Beijing 100190 China Key Laboratory of Space Weather National Center for Space Weather China Meteorological Administration Beijing 100081 China National Satellite Meteorological Center Beijing 100081 China Beijing Key Laboratory of Space Environment Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The first Global Navigation Satellite System Occultation Sounder(GNOS) which is compatible of both Bei Dou System(BDS)and Global Positioning System(GPS) was successfully launched into orbit onboard the Feng Yun 3 C satellite(FY-3 C) on September 23, 2013, and it has already gathered a large amount of ionosphere radio occultation(RO) data so far. However, the detailed analysis and validation of GPS ionosphere RO data have not been done up to now. Therefore, this paper discusses the configuration of the FY-3 C GNOS, the methods and results of GPS ionosphere occultation processment, the quality analysis of the GPS ionosphere RO products, and the precision consistency between the GNOS GPS ionosphere RO product and ionosonde data. The peak electron density(Nm F2) correlation coefficient is 0.97, the corresponding standard deviation is 16.08%. The peak value altitude(hm F2) correlation coefficient is 0.89, and the corresponding standard deviation is 23.79 km. The in-orbit operation of GNOS provides a basis data set for the monitoring, forecasting and research of ionosphere's space weather.

关键词： radio occultation Global Navigation Satellite System BeiDou System ionosphere

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基于气流运送的榛子收获机设计与试验

农机化研究 2025年第3期47卷 70-76页

作者：时延鑫王东伟牟波何晓宁尚书旗纪瑞琪朱浩鞠鑫林青岛农业大学机电工程学院山东青岛266109 青岛市农业技术推广中心山东青岛266071

榛子多种植于丘陵山区,受地形影响大型收获机械难以在果树间工作,故成熟期落地榛子多由人工进行捡拾,工作效率低、成本高,制约了我国榛子产业的健康发展。针对这一问题,设计了一种基于气流运送的榛子收获机。该机采用气力式捡拾,通过气... 详细信息

榛子多种植于丘陵山区,受地形影响大型收获机械难以在果树间工作,故成熟期落地榛子多由人工进行捡拾,工作效率低、成本高,制约了我国榛子产业的健康发展。针对这一问题,设计了一种基于气流运送的榛子收获机。该机采用气力式捡拾,通过气送管道将榛子吸入到气吸沉降室内,经喂入滚筒送入脱苞、筛分滚筒进行榛子脱苞和脱苞后的物料筛分,再经清选舱装置进行杂质清选,完成落地榛子的收获。通过田间试验研究风机转速、气送管道移动速度和筛分滚筒转速对榛子收获捡拾率和含杂率的影响,结果表明:在风机转速3 500 r/min、筛分滚筒转速30 r/min和气送管道移动速度0.6 m/s下,收获质量最佳。

关键词：收获机气流运送脱苞筛分清选榛子