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| 1 | Pressure fluctuation propagation of a pump turbine at pump mode under low head condition显示文摘Pressure fluctuation at the vaneless space and vanes passages is one of the most important problems for the stable operation of a pump turbine.The fluctuation appears in any operating condition.Much research has been done on the pressure fluctuation of hydraulic machinery.However,the details of pressure fluctuation propagation of the pump turbine at the pump mode have not been revealed.The modern pump turbine with high water head requires the runner to be'flat',which would induce pressure fluctuation more easily than the low head pump turbine.In this article,a high head pump turbine model is used as the research object.As the pressure fluctuation at off-design point is more serious than at the design point,the low head condition is chosen as the research condition.Pressure fluctuation at the vaneless space and vanes passages is predicted by the computational fluid dynamics method based on k-?shear stress transport model.The experiment conducted on the test rig of the Harbin Institute of Large Electrical Machinery is used to verify the simulation method.It proves that the numerical method is a feasible way to research the fluctuation under this operating condition.The pressure fluctuation along the passage direction is analyzed at time and frequency domains.It is affected mainly by the interaction between the runner and vanes.In the circumferential direction,the influence of the special stay vane on the pressure fluctuation is got.The amplitude in the high-pressure side passage of that vane is lower than that in the other side.The study provides a basic understanding of the pressure fluctuation of a pump turbine and could be used as a reference to improve the operation stability of it. | GUO Lei LIU JinTao WANG LeQin QIN DaQing WEI XianZhu | 2014 | Science China(Technological Sciences)2014,57,4: | 19 |
| 2 | The effect of applied voltages on the structure,apatite-inducing ability and antibacterial ability of micro arc oxidation coating formed on titanium surface显示文摘The micro arc oxidation(MAO)coatings with different concentrations of Ca,P and Zn elements are successfully formed on the titanium substrate at the different applied voltages.After MAO treatment,the MAO coating exhibits the porous surface structure and composed of anatase and rutile TiO2 phases.Meanwhile,the average size and density of micro-pores on the MAO coatings have been modified via the adjusting the applied voltages.In addition,the contents of the incorporated elements such as Zn,Ca and P elements in the MAO coatings have been optimized.The bonding strength test results reveal that the MAO coating shows higher bonding strength,which is up to 45±5 MPa.Compared to the pure Ti plate,the MAO coating formed at 350 and 400 V show good apatite-inducing ability.Meanwhile,the MAO coating containing Zn,Ca and P elements have better antibacterial ability for E.coli and S.aureus.Thus,the incorporation of Zn,Ca and P elements was an effective method to improve the antibacterial ability.Moreover,the concentrations of Zn,Ca and P elements could be adjusted with the changing of the applied voltages.As a result,the enhancement of the antibacterial ability on the MAO coating surfaces was depended on the comprehensive effect of the incorporated elements and the surface property of MAO coatings. | Qing Du Daqing Wei Yaming Wang Su Cheng Shang Liu Yu Zhou Dechang Jia | 2018 | Bioactive Materials2018,3,4: | 6 |
| 3 | Entropy Production Analysis for Hump Characteristics of a Pump Turbine Model显示文摘The hump characteristic is one of the main problems for the stable operation of pump turbines in pump mode.However,traditional methods cannot reflect directly the energy dissipation in the hump region.In this paper,3D simulations are carried out using the SST k-ω turbulence model in pump mode under different guide vane openings.The numerical results agree with the experimental data.The entropy production theory is introduced to determine the flow losses in the whole passage,based on the numerical simulation.The variation of entropy production under different guide vane openings is presented.The results show that entropy production appears to be a wave,with peaks under different guide vane openings,which correspond to wave troughs in the external characteristic curves.Entropy production mainly happens in the runner,guide vanes and stay vanes for a pump turbine in pump mode.Finally,entropy production rate distribution in the runner,guide vanes and stay vanes is analyzed for four points under the 18 mm guide vane opening in the hump region.The analysis indicates that the losses of the runner and guide vanes lead to hump characteristics.In addition,the losses mainly occur in the runner inlet near the band and on the suction surface of the blades.In the guide vanes and stay vanes,the losses come from pressure surface of the guide vanes and the wake effects of the vanes.A new insight-entropy production analysis is carried out in this paper in order to find the causes of hump characteristics in a pump turbine,and it could provide some basic theoretical guidance for the loss analysis of hydraulic machinery. | LI Deyou GONG Ruzhi WANG Hongjie XIANG Gaoming WEI Xianzhu QIN Daqing | 2016 | Chinese Journal of Mechanical Engineering2016,29,4: | 4 |
| 4 | Inhibiting Hv1 channel in peripheral sensory neurons attenuates chronic inflammatory pain and opioid side effects显示文摘Both opioids and nonsteroidal anti-inflammatory drugs(NSAIDS)produce deleterious side effects and fail to provide sustained relief in patients with chronic inflammatory pain.Peripheral neuroinflammation(PN)is critical for initiation and development of inflammatory pain.A better understanding of molecular mechanisms underlying PN would facilitate the discovery of new analgesic targets and the development of new therapeutics.Emerging evidence suggests that peripheral sensory neurons are not only responders to painful stimuli,but are also actively engaged in inflammation and immunity,whereas the intrinsic regulatory mechanism is poorly understood.Here we report the expression of proton-selective ion channel Hv1 in peripheral sensory neurons in rodents and humans,which was previously shown as selectively expressed in microglia in mammalian central nervous system.Neuronal Hv1 was up-regulated by PN or depolarizing stimulation,which in turn aggravates inflammation and nociception.Inhibiting neuronal Hv1 genetically or by a newly discovered selective inhibitor YHV98-4 reduced intracellular alkalization and ROS production in inflammatory pain,mitigated the imbalance in downstream SHP-1-pAKT signaling,and also diminished pro-inflammatory chemokine release to alleviate nociception and morphine-induced hyperalgesia and tolerance.Thus,our data reveal neuronal Hv1 as a novel target in analgesia strategy and managing opioids-related side effects. | Qiansen Zhang Yimin Ren Yiqing Mo Peipei Guo Ping Liao Yuncheng Luo Jie Mu Zhuo Chen Yang Zhang Ya Li Linghui Yang Daqing Liao Jie Fu Juwen Shen Wei Huang Xuewen Xu Yanyan Guo Lianghe Mei Yunxia Zuo Jin Liu Huaiyu Yang Ruotian Jiang | 2022 | Cell Research2022,32,5: | 3 |
| 5 | Characteristics of remaining oil viscosity in water-and polymer-flooding reservoirs in Daqing Oilfield显示文摘The experimental analysis of 21 crude oil samples shows a good correlation between high molecular-weight hydrocarbon components (C 40+) and viscosity.Forty-four remaining oil samples extracted from oil sands of oilfield development coring wells were analyzed by high-temperature gas chromatography (HTGC),for the relative abundance of C 21-,C 21-C 40 and C 40+ hydrocarbons.The relationship between viscosity of crude oil and C 40+ (%) hydrocarbons abundance is used to expect the viscosity of remaining oil.The mobility characteristics of remaining oil,the properties of remaining oil,and the next displacement methods in reservoirs either water-flooded or polymer-flooded are studied with rock permeability,oil saturation of coring wells,etc.The experimental results show that the hydrocarbons composition,viscosity,and mobility of remaining oil from both polymer-flooding and water-flooding reservoirs are heterogeneous,especially the former.Relative abundance of C 21- and C 21-C 40 hydrocarbons in polymer-flooding reservoirs is lower than that of water-flooding,but with more abundance of C 40+ hydrocarbons.It is then suggested that polymer flooding must have driven more C 40- hydrocarbons out of reservoir,which resulted in relatively enriched C 40+,more viscous oils,and poorer mobility.Remaining oil in water-flooding reservoirs is dominated by moderate viscosity oil with some low viscosity oil,while polymer-flooding mainly contained moderate viscosity oil with some high viscosity oil.In each oilfield and reservoir,displacement methods of remaining oil,viscosity,and concentration by polymer-solution can be adjusted by current viscosity of remaining oil and mobility ratio in a favorable range.A new basis and methods are suggested for the further development and enhanced oil recovery of remaining oil. | XU ZhengShun,ZHANG JuHe,FENG ZiHui,FANG Wei & WANG FengLan Exploration and Development Research Institute,Daqing Oilfield Company Ltd.,Daqing 163712,China | 2010 | Science China Earth Sciences2010,53,1: | 3 |
| 6 | Tocilizumab in patients with moderate or severe COVID-19: a randomized, controlled, open-label, multicenter trial显示文摘Tocilizumab has been reported to attenuate the“cytokine storm”in COVID-19 patients.We attempted to verify the effectiveness and safety of tocilizumab therapy in COVID-19 and identify patients most likely to benefit from this treatment.We conducted a randomized,controlled,open-label multicenter trial among COVID-19 patients.The patients were randomly assigned in a 1:1 ratio to receive either tocilizumab in addition to standard care or standard care alone.The cure rate,changes of oxygen saturation and interference,and inflammation biomarkers were observed.Thirty-three patients were randomized to the tocilizumab group,and 32 patients to the control group.The cure rate in the tocilizumab group was higher than that in the control group,but the difference was not statistically significant(94.12%vs.87.10%,rate difference 95%CI−7.19%–21.23%,P=0.4133).The improvement in hypoxia for the tocilizumab group was higher from day 4 onward and statistically significant from day 12(P=0.0359).In moderate disease patients with bilateral pulmonary lesions,the hypoxia ameliorated earlier after tocilizumab treatment,and less patients(1/12,8.33%)needed an increase of inhaled oxygen concentration compared with the controls(4/6,66.67%;rate difference 95%CI−99.17%to−17.50%,P=0.0217).No severe adverse events occurred.More mild temporary adverse events were recorded in tocilizumab recipients(20/34,58.82%)than the controls(4/31,12.90%).Tocilizumab can improve hypoxia without unacceptable side effect profile and significant influences on the time virus load becomes negative.For patients with bilateral pulmonary lesions and elevated IL-6 levels,tocilizumab could be recommended to improve outcome. | Dongsheng Wang Binqing Fu Zhen Peng Dongliang Yang Mingfeng Han Min Li Yun Yang Tianjun Yang Liangye Sun Wei Li Wei Shi Xin Yao Yan Ma Fei Xu Xiaojing Wang Jun Chen Daqing Xia Yubei Sun Lin Dong Jumei Wang Xiaoyu Zhu Min Zhang Yonggang Zhou Aijun Pan Xiaowen Hu Xiaodong Mei Haiming Wei Xiaoling Xu | 2021 | Frontiers of Medicine2021,15,3: | 2 |
| 7 | Toxicity mechanisms and bioavailability of copper to fish based on an adverse outcome pathway analysis显示文摘Copper(Cu)exists in a variety of forms in different aquatic environments,and affects their bioavailability.In this study we provide a systematic review on toxicity of Cu which focuses on identifying evidence in the mechanisms of Cu toxicity,and apply an adverse outcome pathway(AOP)analysis to identify multiple potential mechanisms and their interactions of Cu toxicity to fish.This analysis process included the mechanisms of behavior toxicant,oxidative toxicant,ion regulation disruption toxicity,as well as endocrine disruption toxicity.It was found that at low levels of Cu exposure,swimming,avoid predators,locating prey and other sensory functions will be impaired,and the organism will suffer from metabolic alkalosis and respiratory acidosis following the inhibition of the carbonic anhydrase active.The main pathway of acute toxicity of Cu to fish is the inhibition of the Na^(+)/K^(+)-ATPase enzyme,and lead to reduced intracellular sodium absorption,as well as Cu-induced increased cell permeability,in turn resulting in increased sodium ion loss,leading to cardiovascular collapse and respiratory insufficiency.The endocrine disruption toxicity of Cu to fish caused growth inhibition and reproductive reduction.In addition,there are several key pathways of Cu toxicity that are affected by hardness(e.g.,Ca^(2+))and intracellular DOC concentrations,including inhibiting Cu-induction,improving branchial gas exchange,altering membrane transport functions,decreasing Na+loss,and increasing Na+uptake.The results of the AOP analysis will provide a robust framework for future directed research on the mechanisms of Cu toxicity. | Wei Liao Ziwei Zhu Chenglian Feng Zhenfei Yan Yajun Hong Daqing Liu Xiaowei Jin | 2023 | Journal of Environmental Sciences2023,,5: | 1 |
| 8 | Characteristic and in vitro bioactivity of a microarc-oxidized TiO2-based coating after chemical treatment显示文摘 | Wei Daqing Zhou Yu J ia Dechang | 2007 | Acta Bioma-terialia2007,3,: | 1 |
| 9 | Chemical etching of micro-plasma oxidized titania film on titanium alloy and apatite deposited on the surface of modified titania film in vitro显示文摘 | Daqing Wei Yu Zhou Yaming Wang Dechang Jia | 2007 | Thin Solid Films2007,,8: | 1 |
| 10 | Characteristic of microarc oxidized coatings on titanium alloy formed in electrolytes containing chelate complex and nano-HA显示文摘 | Daqing Wei Yu Zhou Yaming Wang Dechang Jia | 2006 | Applied Surface Science2006,,11: | 1 |
| 11 | User participation in an academic social networking service: A survey of open group users on mendeley显示文摘 | Jeng Wei He Daqing Jiang Jiepu | 2015 | Journal of the Association for Information Science and Technology2015,66,5: | 1 |
| 12 | Mechanical properties and deformation mechanisms of a novel fine-grained Mg-Gd-Y-Ag-Zr-Ce alloy with high strength-ductility synergy显示文摘Grain boundary precipitation and segregation play an important role in determining mechanical properties of Mg alloys. In the present work, we studied work focuses on the strengthening and deformation mechanism of coarse-grained(CG) and fine-grained(FG) Mg-Gd-Y-Ag-Zr-Ce alloy. The CG alloy is strengthened by means of age-strengthening with the formation of both basal plate γ' and prismatic plate β’ precipitates in the grain interior. While the strengthening of FC alloy is completed by intergranular alloying segregation and intragranular precipitates γ' and β’. The segregation of alloying elements at the grain boundary and formation of sub-micron particles can stabilize the grain boundary and suppress the intergranular deformation. Consequently, dislocations could be trapped near γ' and β’ precipitates in the grain interior. Unlike CG alloys, the FG alloys exhibit a heterogeneous transition from elastic to plastic deformation via the Lüders plateau. The rapid gliding dislocation multiplications and fine-grained size are necessary and sufficient conditions for the Lüders strains. Our work provides the insights on the evolution of fine-grained microstructure and helps for the design of Mg alloys with good mechanical properties. | Xiaofei Cui Wei Fu Daqing Fang Guangli Bi Zijun Ren Shengwu Guo Suzhi Li Xiangdong Ding Jun Sun | 2021 | Journal of Materials Science & Technology2021,,7: | 1 |
| 13 | The Mitochondrial K-ATP Channel Opener, Diazoxide, Prevents Ischemia-Reperfusion Injury in the Rabbit Spinal Cord显示文摘 | Glen Roseborough Daqing Gao Lei Chen Michael A. Trush Shaoyu Zhou G. Melville Williams Chiming Wei | 2006 | The American Journal of Pathology2006,,5: | 1 |
| 14 | Characteristic and in vitro bioactivity of a microarc-oxidized TiO2-based coating after chemical treatment显示文摘 | Wei Daqing Zhou Yu Jia Dechang | 2007 | Acta Biomaterialia2007,3,5: | 1 |
| 15 | Existence of Positive Solutions for Volterra Intergo-differential Equations 显示文摘 | Jiang Daqing Wei Junjie | 2001 | Acta Mathematica Scientia2001,,21: | 1 |
| 16 | Characteristic and in vitro bioactivity of a microarc-oxidized TiO 2 -based coating after chemical treatment显示文摘 | Daqing Wei Yu Zhou Dechang Jia Yaming Wang | 2007 | Acta Biomaterialia2007,,5: | 1 |
| 17 | Biomimetic apatite deposited on microarc oxidized anatase-based ceramic coating显示文摘 | Daqing Wei Yu Zhou Dechang Jia Yaming Wang | 2007 | Ceramics International2007,,5: | 1 |
| 18 | Effect of ap- plied voltage on the structure of microarc oxidized TiO2 - based bioceramic films 显示文摘 | Wei Daqing Zhou Yu Jia Dechang | 2007 | Materials Chemistry and Physics2007,104,: | 1 |
| 19 | Heterogeneous fiberous structured Mg-Zn-Zr alloy with superior strength-ductility synergy显示文摘Here we reported a heterogeneous fiberous structured Mg-5.6Zn-0.6Zr(wt%)alloy obtained by conventional extrusion method,which exhibited high yield strength of∼345 MPa,ultimate tensile strength of∼370 MPa,and high tensile strain of∼20.5%,superior to most of the Mg-Zn based alloys reported so far.The extraordinarily high mechanical properties were mainly attributed to the heterogeneous fiberous structure consisting of alternating coarse-and fine-grain layers.Grains in the different layers grew into the neighboring layers,ensuring a good layer bonding.A high Schmid factor and geometric compatibility factor for pyramidal slip led to full slip transfer between the neighboring coarse grains and fine grains,which could help to release the stress concentration and avoid early fracture.The profuse acti-vatedglide dislocations could render the unprecedented high tensile strain.The constraint by the hard fine-grain domains made the soft coarse-grain domains strong like the hard fine-grain domains,as well as the nanoscale precipitates pinning dislocations,contributed to the high strength.The hetero-geneous microstructure design was shown to have synergistic improvement in strength-ductility balance,which could be an inspiring strategy to improve mechanical properties of hexagonal close-packed(hcp)metals. | Wei Fu Pengfei Dang Shengwu Guo Zijun Ren Daqing Fang Xiangdong Ding Jun Sun | 2023 | Journal of Materials Science & Technology2023,,3: | 1 |
| 20 | The response of turbulent flow to the disturbance of a vibrating ribbon 显示文摘 | Zhang Daqing Shu Wei | 1996 | ACTA MECHANCIA SINACA1996,12,3: | 1 |