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| 1 | ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES显示文摘磨车轮的自动赔偿在干燥磨擦穿被在网上基于的一幅图象完成测量方法。一种基于 PC 的电荷耦合的设备图象识别系统被设计,它检测磨擦车轮表面的地形学变化。侧面数据,对应于 wear 和地形学,被使用处理方法的一幅数字图象测量。磨擦车轮穿被分析磨擦车轮边的位置偏差评估。在网上穿赔偿根据措施结果被完成。精确察觉和自动赔偿系统集成于磨机器的一条开的结构计算机数值控制曲线。实际应用被执行曲线磨擦完成精确。试验性的结果证实建议技术,和联机察觉精确性的好处是不到 5 瓮。磨擦机器根据进程内的磨擦车轮错误赔偿提供更高的精确。 | WAN Daping HU Dejin WU Qi ZHANG Yonghong | 2006 | Chinese Journal of Mechanical Engineering2006，19，4： | 10 |
| 2 | Simultaneous pyridine biodegradation and nitrogen removal in an aerobic granular system显示文摘Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor(SBR) based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the majority of pyridine was removed, while denitrification occurred at early stage of the cycle when oxygen consumption was aggravated. The effect of several key operation parameters, i.e., air flow rate, influent NH_4^+-N concentration,influent p H and pyridine concentration, on nitritation, pyridine degradation and total nitrogen(TN) removal, was systematically investigated. The results indicated that high air flow rate had a positive effect on both pyridine degradation and nitritation but a negative impact of overhigh air flow rate. With the increase of NH_4^+ dosage, both nitritation and TN removal could be severely inhibited. Slightly alkaline condition, i.e., pH 7.0–8.0, was beneficial for both pyridine degradation and nitritation. High pyridine dosage often resulted in the delay of both pyridine degradation and nitritation. Besides, extracellular polymeric substances production was affected by air flow rate, NH_4^+ dosage, pyridine dosage and p H.In addition, high-throughput sequencing analysis demonstrated that Bdellovibrio and Paracoccus were the dominant species in the aerobic granulation system. Coexistence of pyridine degrader, nitrification related species, denitrification related species, polymeric substances producer and self-aggregation related species was also confirmed by highthroughput sequencing. | Xiaodong Liu Shijing Wu Dejin Zhang Jinyou Shen Weiqing Han Xiuyun Sun Jiansheng Li Lianjun Wang | 2018 | Journal of Environmental Sciences2018，30，5： | 7 |
| 3 | Exact solutions of dispersion equation for MHD waves with short-wavelength modification显示文摘Dispersive magnetohydrodynamic (MHD) waves with short-wavelength modification have an important role in transforming energy from waves into particles.In this paper,based on the two-fluid mode,a dispersion equation,including the short-wavelength effect,and its exact solution are presented.The outcome is responsible for the short-wavelength modification versions of the three ideal MHD modes (i.e.the fast,slow and Alfve'n).The results show that the fast and Alfve'n modes are modified considerably by the shortwavelength effect mainly in the quasi-parallel and quasi-perpendicular propagation directions,respectively,while the slow mode can be affected by the short-wavelength effect in all propagation directions.On the other hand,the dispersive modification occurs primarily in the finite-β regime of 0.001 < β < 1 for the fast mode and in the high-β regime of 0.1 < β < 10 for the slow mode.For the Alfve'n mode,the dispersive modification occurs from the low-β regime of β < 0.001 through the high-β regime of β > 1. | CHEN Ling WU DeJin | 2011 | Chinese Science Bulletin2011，56，10： | 4 |
| 4 | The evidence for the evolution of interplanetary small flux ropes: Boundary layers显示文摘We have examined the Wind data in 1996 and identified 21 small interplanetary magnetic flux ropes(SIMFRs),and all the 21 SIMFRs have boundary layer structures.The durations of the boundary layers varied from several minutes to 30 minutes.These boundary layers also have properties of high proton temperature,density,and plasma beta.These boundary layers are formed by magnetic reconnections.In addition,in three events magnetic reconnections were occurring inside the boundary layers.It indicates that the flux rope structures have propagated for some period of time,and their boundaries were still evolving through interaction with the background solar wind.Namely it is very possible that the SIMFRs came from the solar corona. | FENG HengQiang WANG JieMin WU DeJin | 2012 | Chinese Science Bulletin2012，57，12： | 3 |
| 5 | Basic Plasma Processes in Solar-Terrestrial Activities显示文摘Within the known universe,more than 99%of all observable matter is plasma,a state often highly dynamic and far from thermal,as well as mechanical,equilibrium.In particular,for our own solar-terrestrial system,various plasma active phenomena frequently occur such as solar flares,coronal plasma heating,solar wind acceleration,and coronal mass ejections in the solar atmosphere;interplanetary magnetic clouds and collisionless shock waves in interplanetary space;and | WU DeJin FENG HengQiang | 2012 | Chinese Science Bulletin2012，57，12： | 2 |
| 6 | Effects of inelastic collisions on Alfvn waves in partially ionized plasmas显示文摘Based on a three-component description of partially ionized plasmas(i.e.,electrons,ions,and neutral atoms),effects of inelastic collisions between ions(neutrals)and electrons on Alfve′n waves(AWs)in a partially ionized plasma are studied.It is shown that for a fixed ionizability(i)or a fixed inelastic collision parameter(v,i.e.,the ratio of the inelastic to elastic collision frequency),the damping rate of AWs has a peak value round kz vA/min*1,where kz is the parallel wavenumber of AWs,vA is the Alfve′n velocity,and min is the elastic collision frequency between ions and neutrals.On the other hand,the damping rate of AWs decreases monotonously with the ionizabilityi for a fixed inelastic collision parameter,but has a peak value when the inelastic collision parameter varies for sufficiently small ionizability(i\0:1).For sufficiently large ionizability(i[0:1),it is found that the damping rate decreases with the inelastic collision parameter.The results may help us to understand the physics of AWs in partially ionized plasmas. | Bing Li Ling Chen Dejin Wu | 2014 | Chinese Science Bulletin2014，59，8： | 1 |
| 7 | Effects of power-law spectrum behaviors of nonthermal electrons on a ring-beam maser instability显示文摘The electron-cyclotron maser(ECM) emission driven by nonthermal electrons is one of the most crucial mechanisms responsible for radio emissions in magnetized planets,for the interplanetary medium(IPM) and for the laboratory microwave generation devices.Major astrophysical observations demonstrate that nonthermal electrons frequently have a negative power-law spectrum with a lower energy cutoff and anisotropic distribution in the velocity space.In this paper,the effects of power-law spectrum behaviors of electrons on a ring-beam maser emission are considered.The results show that the growth rates of O1 and X2 modes decrease rapidly for small(the dispersion of momentum u).Because of the lower energy cutoff behavior,the nonthermal electrons with large still can excite the ECM instability efficiently.The present analysis also includes the effects of parameter β(βu 0 is the dispersion of perpendicular momentum u ⊥,u 0 the average value of u) on the instability.The growth rate of X2 mode decreases with parameter ν 0(ν 0 = u ⊥0 /u 0,u ⊥0 is the average value of u ⊥).But for O1 mode,the relationship between the growth rate and ν 0 is complicated.It also shows that the growth rates are very sensitive to frequency ratio Ω(frequency ratio of electron cyclotron frequency to plasma frequency). | TANG JianFei WU DeJin YAN YiHua | 2012 | Science China(Physics,Mechanics & Astronomy)2012，55，4： | 1 |
| 8 | Saturation level of Alfvén waves driven by Kelvin–Helmholtz instability显示文摘Alfve′n waves(AWs) can play an important role in the macroscopic dynamics as well as in the microscopic wave–particle interaction in various magnetoplasma environments. A very wide observed range of the relative amplitude of magnetic fluctuations of AWs from lower than 10-3in the terrestrial magnetosphere up to *1in the solar wind implies the complexity of saturation mechanisms of AWs. Taking account of the ion-neutral collision damping in a partially ionized plasma, the saturation level of AWs driven by the Kelvin–Helmholtz(K–H) instability is investigated in this paper. The intensified magnetic field due to the excited AWs may result in the saturation of the excited AWs when the growth rate is balanced by the damping rate. An equation determining the saturation level of the AWs is obtained. The results show that, for a fixed-frequency wave, the saturation level of the AWs considerably increases as the ionization degree increases as well as the sheared-flow velocity. On the other hand, for a fixed ionization degree the saturation level of the AWs slightly increases as the plasma b increases but decreases as the wave frequency increases. These results have potential importance for us to estimate the saturation level of AWs in space and astrophysical plasmas. | Ling Chen Dejin Wu Guoqing Zhao Jing Huang | 2014 | Chinese Science Bulletin2014，59，28： | 0 |
| 9 | Electromagnetic ion-cyclotron instability driven by combined loss-cone and temperature anisotropy distribution of suprathermal ions显示文摘Electromagnetic ion cyclotron (EMIC) waves,particularly their generation and excitation mechanisms,have been a subject of wide interest because of their potential importance in ion acceleration and heating.In this work,the parameter-dependence of EMIC instabilities is investigated with a combined loss-cone and temperature anisotropy distribution for suprathermal ions.The calculation of the linear growth rate of EMIC waves with an arbitrary propagation angle is presented.The results show that the growth rates of EMIC waves propagating quasi-perpendicular to the ambient magnetic field increase as the loss-cone parameter α increases,whereas the growth rates of EMIC waves propagating quasi-parallel to the ambient magnetic field increase as the temperature anisotropy parameter AT increases.This indicates that the free energies associated with the loss-cone and temperature anisotropic distributions are primarily responsible for the excitation of the quasi-perpendicular and parallel propagating EMIC waves,respectively,and provides us with a more comprehensive understanding of excitation and generation mechanisms for EMIC waves in space plasmas. | HUA YuePing WU DeJin WANG DeYu | 2011 | Chinese Science Bulletin2011，56，3： | 0 |
| 10 | Euler potentials'discontinuity in the presence of field line-aligned currents显示文摘Since their use in the study of charged particle motion in the 1960s,Euler potentials(α ,β)have been widely employed as magnetic field coordinates in both space plasma and fusion plasma studies.People related them to magnetic vector potential A via the relation A=α▽β subject to gauge condition A·B=0(B is the magnetic induction).For a given magnetic field,the Euler potentials are often constructed with the relation B·△ S=△α△βon a surface that crosses the field lines,where △ S is the area-element surrounding by two line-elements corresponding to the changes in α and β,then mapping the values of α and βalong field lines into space.In this short paper,we show that in the presence of field line-aligned currents,the mapping does not work and the orthogonality gauge condition is not satisfied. | HUANG TianSen WU DeJin | 2012 | Chinese Science Bulletin2012，57，12： | 0 |
| 11 | The Oblique Alfvén Ion Beam Instability in the Earth’s Ion Foreshock显示文摘How ions evolve in the Earth’s ion foreshock is a basic problem in the heliosphere community,and the ion beam instability is usually proposed to be one major mechanism affecting the ion dynamics therein.This work will perform comprehensive analyses of the oblique ion beam instability in the Earth’s ion foreshock.We show that in addition to two well-known parallel instabilities (i.e.,the parallel fast-magnetosonic whistler instability and the parallel Alfvén ion cyclotron instability),the oblique Alfvén ion beam (OA/IB) instability can also be triggered by free energy relating to the relative drift d V between the solar wind proton and reflected proton populations.For slow d V (e.g.,d V■2.2V_(A),where VAdenotes the Alfvén speed),it only triggers the OA/IB instability.When d V■2.2V_(A),the growth rate in the OA/IB instability can be about 0.6 times the maximum growth rate in parallel instabilities.Moreover,this work finds the existence of two types of OA/IB instabilities.The first one appears at slow d V and in the small wavenumber region at fast d V,and this instability can be described by the cold fluid model.The second one arises in large wavenumber regions at fast d V,and this instability only appears in warm plasmas.Furthermore,through the energy transfer rate method,we propose that the OA/IB instability is driven by the competition among the Landau and cyclotron wave-particle interactions of beam protons,the cyclotron wave-particle interaction of core protons,and the Landau wave-particle interaction of electrons.Because oblique waves can experience significant damping,the importance of the OA/IB instability may be the effective heating of ions in the Earth’s foreshock. | Yuhang Yao Jinsong Zhao Huasheng Xie Wen Liu Dejin Wu | 2023 | Research in Astronomy and Astrophysics2023，23，2： | 0 |
| 12 | Treatment for arteriovenous malformation of the brain Comparison between microsurgery and gamma knife显示文摘BACKGROUND: Microsurgery and gamma knife are the mainly ways to treat arteriovenous malformation of brain in grade Spetzler-Martin Ⅰ–Ⅲ; however,therapeutic effects of them need to be further studied. OBJECTIVE: To compare the therapeutic effects between microsurgery and gamma knife on the treatment of arteriovenous malformation of brain in grade Spetzler-Martin Ⅰ–Ⅲ. DESIGN: Retrospective analysis. SETTING: Department of Neurosurgery,the Third Hospital Affiliated to Sun Yat-sen University; Guangdong Microinvasion Center. PARTICIPANTS: A total of 86 patients with arteriovenous malformation of the brain were selected from the Department of Neurosurgery,the Third Hospital Affiliated to Sun Yat-sen University and Guangdong Microinvasion Center from January 1997 to February 2007. After DSA,CT and/or MRI examinations,patients were evaluated in grade Spetzler-Martin Ⅰ–Ⅲ. All patients were divided into microsurgery group (n = 34) and gamma knife group (n =52). There were 22 males and 12 females in the microsurgery group and their mean age was 26 years,while there were 34 males and 18 females in the gamma knife group and their mean age was 28 years. The grade of Spetzler-Martin was comparable in the two groups. All their relatives provided the confirmed consent and the study was allowed by ethics committee of our hospital. METHODS: Under complete anesthesia,patients were given microsurgery and the operative approach was chosen based on diseased regions. Firstly,feeding artery was blocked; secondly,it was separated along band of gliosis between malformation vessel mass and brain tissue; finally,draining vein was cut off and malformation vessel mass was resected. On the other hand,patients in the gamma knife group received Leksell-2300B gamma knife treatment. Leksell-G stereotaxis headframe was installed; GE1.5TMR scanning device was used for localization; r-Plan5.2 workstation was used for target design and dosage program; Leksell B gamma knife was used during the whole operative procedure. The target was 1–4 and peripheral dosage was 12–28 Gy. At 0.5,1 and 2 years after operation,angiography was used to detect vascular occlusion in the two groups. Meanwhile,focal hemorrhage and new neurological function defect (including hemiplegic paralysis,language disorder,cerebellar function disorder,increasing frequency of epilepsy,etc.) were also observed. MAIN OUTCOME MEASURES: Rate of vascular occlusion,focal hemorrhage and neurological function defect at different time points after operation. RESULTS: All 86 patients were involved in the final analysis. Vascular nest of patients in the microsurgery group disappeared completely; while,two patients (6%,2/34) had new neurological function defect but did not have rehaemorrhagia and death after operation. On the other hand,vascular nest of 43 patients (83%,43/52) in the gamma knife group disappeared completely,and 8 (15%,8/52) had new neurological function defect. There was significant difference between the two groups (χ2=2.63,P < 0.05). Six patients (12%,6/52) in the gamma knife group had rehaemorrhagia after operation,and one (2%,1/52) died. CONCLUSION: Both microsurgery and gamma knife have great effects on the treatment of arteriovenous malformation of brain in grade Spetzler-Martin Ⅰ–Ⅲ; however,the therapeutic effects of microsurgery are superior to those of gamma knife. | Dejin Shi Ying Guo Wen sheng Li Zhuopeng Ye Hui Wang Gang Chen Shengling Wu | 2007 | Neural Regeneration Research2007，2，10： | 0 |
| 13 | Magnetic Fine Structures in the Solar Corona and Their Heating by Kinetic Alfven Waves显示文摘太阳是我们原子反应在它的中心附近释放的最近的星和精力被在内的光子搬运内部 -71% 太阳的半径 R= 6. | WU Dejin CHEN Ling | 2011 | Bulletin of the Chinese Academy of Sciences2011，25，3： | 0 |
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