程Celeste
Experimental study of electrostatic precipitatorperformance and comparison with existingtheoretical prediction modelsS.H. Kim, K.W. Lee*Kwangju Institute of Science and Technology, Department of Environmental Science and Engineering,1 Oryong-dong, Puk-gu, Kwangju 500-712, South KoreaReceived 1 February 1999; received in revised form 21 May 1999; accepted 2 June 1999AbstractA laboratory-scale single-stage electrostatic precipitator (ESP) was designed, built andoperated in a wind tunnel. As a "rst step, a series of experiments were conducted to seek theoperating conditions for increasing the particle collection e$ciency by varying basic operatingparameters including the wire-to-plate spacing, the wire radius, the air velocity, the turbulenceintensity and the applied voltage. As the diameter of the discharging wires and the wire-toplatespacing are set smaller, the higher collection e$ciency has been obtained. In thesingle-stage multiwire ESP, there exists an optimum wire-to-wire spacing which providesmaximum particle collection e$ciency. As the air velocity increases, the particle collectione$ciency decreases. The turbulent #ow is found to play an important role in the relatively lowelectric "eld region. In the high electric "eld region, however, particles can be deposited on thecollection plates readily regardless of the turbulence intensity. The experimental results werecompared with existing theories and Zhibin and Guoquan (Aerosol Sci. Technol. 20 (1994)169}176) was identi"ed to be the best model for predicting the ESP performance. As the secondstep, the in#uence of particle contamination at the discharging electrode and at the collectionplates were experimentally measured. The methods were sought for keeping the high collectione$ciency of ESP over elapsed time by varying the magnitude of rapping acceleration, the timeinterval between raps, the types of rapping system (hammer/vibrator) and the particle reentrainment.The rapping e$ciency and the particle re-entrainment were increased withincreasing magnitude of rapping acceleration and time interval between raps. However, whenthe thickness of deposited #y ash layer is su$ciently high, the concentration of re-entrainedparticles starts decreasing abruptly due to the agglomeration force which can interact among0304-3886/99/$ - see front matter ( 1999 Elsevier Science B.V. All rights reserved.PII: S 0 3 0 4 - 3 8 8 6 ( 9 9 ) 0 0 0 4 4 - 3deposited particles. The combined rapping system is found more e!ective for removingdeposited particles than the hammer rapping system only. ( 1999 Elsevier Science B.V. Allrights reserved.Keywords: Electrostatic precipitation; Turbulent #ow; Rapping; Particle re-entrainment; Collection e$-ciency; Negative corona1. IntroductionElectrostatic precipitators (ESPs) are one of the most commonly employedparticulate control devices for collecting #y ash emissions from boilers, incineratorsand from many other industrial processes. They can operate in a wide range ofgas temperatures achieving high particle collection e$ciency compared with mechanicaldevices such as cyclones and bag "lters. The electrostatic precipitation processinvolves several complicated and interrelated physical mechanisms: creationof a non-uniform electric "eld and ionic current in a corona discharge, ionicand electronic charging of particles moving in combined electro- and hydrodynamic"elds, and turbulent transport of charged particles to a collectionsurface.Generally, the collection e$ciency of ESP decreases as the discharging electrodeand collection plates are contaminated with particulates. Thus, a rapping system isneeded for removing the collected particulates periodically. While there have beennumerous theoretical and experimental studies on particle collection characteristics ofelectrostatic precipitators, a relatively small number of the studies addressed thee!ects of particle accumulation both at the discharging electrodes and at the collectionplates. Both phenomena are known to in#uence adversely the performance ofelectrostatic precipitators. Many researchers, such as Deutsch [1], Cooperman [2],Leonard et al. [3], Khim et al. [4], Zhibin and Guoquan [5], and Kallio and Stock[6], conducted particle collection measurements of ESP. However, they concentratedmostly on the e!ects of both turbulent mixing and secondary wind in multiwiresingle-stage electrostatic precipitators. Speci"cally, Cooperman [2] considered reentrainmentand longitudinal turbulent mixing e!ects, Leonard et al. [3] the "nitedi!usivity, and Zhibin and Guoquan [7] the non-uniform air velocity pro"le. Amongthem, only Zhibin and Guoquan [7] measured the collection e$ciency of a singlestageESP covering a wide particle size range. Even though their experimental dataare considered to be practical and useful, their experimental conditions were notidenti"ed clearly.In the present study, well-de"ned collection e$ciency data for an ESP are presentedcovering the particle size range of 0.1}100 lm. The particles used in the present studycame from the Bo-Ryung power plant in Korea. In addition, the ESP performancewas evaluated in terms of optimum operating conditions. Finally, the optimumrapping conditions were sought under which the rapping e$ciency increases and theparticle re-entrainment decreases.4 S.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25Fig. 1. Schematic diagram of the wind tunnel for the eight wired single-stage ESP performance test.2. Review of theoretical models2.1. Particle chargingFig. 1 shows the laboratory-scale electrostatic precipitator. The particle chargingsystem consists of discharge wires with diameter (D8) and two grounded parallelplates of length (¸). A high negative voltage (<8) is applied to the corona dischargewires, and suspended particles of diameter (d1) #ow with air between the plates ata velocity (;) in the y-direction. In the whole range of particle sizes, both "eldcharging and di!usion charging mechanisms contribute to signi"cant charges [8,9].In these theoretical analyses, it is nearly correct to sum the rates of charging from thetwo mechanisms and then solve for the particle charging as follows:dq1dt"q4q A1!qq4B2#d21eN04 S8k¹pmexpA! 2qed1k¹B (1)where q1 is the particle charge, q4 is the saturation charge,N0 is the average number ofmolecules per unit volume, e is the electronic charge ("1.6]10~19 C), b is the ionmobility ("1.4]10~4 m2/V s), e0 is the permittivity of free space ("8.85]10~12 F/m), d1 is the diameter of particle, k is the Boltzmann constant ("1.38]10~23 J/K), ¹ is the absolute temperature ("293 K), m is the mass of a particle("(p/6)d31o1), and o1 is the particle density ("2.25]103 kg/m3).2.2. Theoretical models of particle collection ezciencyTheoretical models of ESPs were provided by Deutsch [1], Cooperman [2],Leonard et al. [3], Zhibin and Guoquan [7] and others. The Deutsch model forS.H. Kim, K.W. Lee / Journal of Electrostatics 48 (1999) 3}25 5calculating the particle collection in an ESP assumes complete mixing by turbulent#ow and thereby uniform concentration pro"les. In order to improve the drasticassumption of in"nite di!usivity in the Deutsch model, many researchers tried todevelop "nite di!usivity models by dealing with the convective-di!usion equationwith various boundary conditions.Cooperman [2] developed a theory which modi"es the Deutsch model to accountfor the e!ects of turbulence and particle turbulent di!usion. The major limitations ofthe Cooperman model lie absence of a general method to estimate the re-entrainmentfactor and the particle di!usivity. Leonard et al. [3] developed a more complicatedtwo-dimensional model using the method of the separation of variables from theconvective-di!usion equation. He assumed uniformity of velocity components ofcharged particles and particle di!usivity. This assumption fails to adequately describethe particle di!usivity near the collection plates, where it is governed mainly by themolecular transport and, therefore, the di!usivity near the wall is signi"cantly lowerthan the di!usivity in the turbulent core. Zhibin and Guoquan [7] suggested a newmodel for the single-stage ESP which takes into account the e!ect of turbulencemixing by electric wind. Predicted collection e$ciencies of the above theoreticalmodels are summarized as follows:gDe"1!exp(!De), (2)gCoo"1!expC;¸2D!SG A;¸2DB2#(1!R)PeA¸=B2HD, (3)gLeo"1!P10PA m!DeJ2De/PeBdm, (4)gZhi"1!S Pe4pDeP10expC!Pe4De(m!De)2Ddm, (5)where
悠闲小猫
编译 冯维维
Science , 23 July 2021, Vol 373, Issue 6553
《科学》 2021年7月23日，第373卷，6553期
天体物理学 Astrophysics
Peta–electron volt gamma-ray emission from the Crab Nebula
来自蟹状星云的高能光子
作者：The LHAASO Collaboration
链接：
摘要
蟹状星云含有一颗脉冲星，它能激发周围的气体释放出高能辐射。脉冲星的年轻及其附近的位置使得该星云成为天空中最亮的伽马射线源。
作者报道了这种源在1012到1015电子伏的能量下的观察结果，扩展了这种原型物体的光谱。
他们将这些数据与较低能量下的观测数据结合起来，以模拟辐射过程的物理过程。多波长数据可以用同步辐射和逆康普顿散射的结合来解释。
Abstract
The Crab Nebula contains a pulsar that excites the surrounding gas to emit high-energy radiation. The combination of the pulsar's youth and nearby location makes the nebula the brightest gamma-ray source in the sky. Cao et al. report observations of this source at energies of tera– to peta–electron volts, extending the spectrum of this prototypical object. They combine these data with observations at lower energies to model the physics of the emission process. The multiwave-length data can be explained by a combination of synchrotron radiation and inverse Compton scattering.
Upper mantle structure of Mars from InSight seismic data
“洞察号”地震数据揭示火星上地幔结构
作者：Amir Khan, Savas Ceylan, William B. Banerdt, etc.
链接：
摘要
两年来，“洞察号”着陆器一直在记录火星上的地震数据，这些数据对了解火星的结构和热化学状态至关重要。作者利用8个低频火星地震的直接（P和S）和地表反射（PP、PPP、SS和SSS）体波相的观测，将内部结构限制在800公里的深度。
他们发现了一种与低速带相容的结构，该低速带与热岩石圈比地球上厚得多，这可能与远震距离上的弱s波阴影带有关。通过结合地震约束和地球动力学模型，作者预测，相对于原始地幔，地壳的产热元素更丰富，是原始地幔的13 - 20倍。
这种富集比伽玛射线地表测绘所建议的要大，并且具有中等到高的地表热流。
Abstract
For 2 years, the InSight lander has been recording seismic data on Mars that are vital to constrain the structure and thermochemical state of the planet. We used observations of direct (P and S) and surface-reflected (PP, PPP, SS, and SSS) body-wave phases from eight low-frequency marsquakes to constrain the interior structure to a depth of 800 kilometers. We found a structure compatible with a low-velocity zone associated with a thermal lithosphere much thicker than on Earth that is possibly related to a weak S-wave shadow zone at teleseismic distances. By combining the seismic constraints with geodynamic models, we predict that, relative to the primitive mantle, the crust is more enriched in heat-producing elements by a factor of 13 to 20. This enrichment is greater than suggested by gamma-ray surface mapping and has a moderate-to-elevated surface heat flow.
Thickness and structure of the martian crust from InSight seismic data
“洞察号”地震数据揭示火星地壳厚度和结构
作者：Brigitte Knapmeyer-Endrun, Mark P. Panning, Felix Bissig, W. Bruce Banerdt, etc.
链接：
摘要
行星的地壳见证了行星的形成和演化 历史 ，但对于火星来说，还没有对地壳厚度的绝对测量。作者利用火星地震记录和周围波场确定了洞察号登陆点下方地壳的结构。
通过分析在地下界面反射和转换的地震相，他们发现观测结果与模型相符，至少有两个界面，也可能有三个界面。如果第2个界面为地壳边界，厚度为20 5公里；如果第3个界面为地壳边界，厚度为39 8公里。
全球重力和地形图允许对整个星球进行这种点测量，显示火星地壳的平均厚度在24到72公里之间。独立的体积组成和地球动力学约束表明，较厚的模型与观测到的浅层地壳产热元素的丰度一致，而较薄的模型则需要在深度上更大的浓度。
Abstract
A planet’s crust bears witness to the history of planetary formation and evolution, but for Mars, no absolute measurement of crustal thickness has been available. Here, we determine the structure of the crust beneath the InSight landing site on Mars using both marsquake recordings and the ambient wavefield. By analyzing seismic phases that are reflected and converted at subsurface interfaces, we find that the observations are consistent with models with at least two and possibly three interfaces. If the second interface is the boundary of the crust, the thickness is 20 5 kilometers, whereas if the third interface is the boundary, the thickness is 39 8 kilometers. Global maps of gravity and topography allow extrapolation of this point measurement to the whole planet, showing that the average thickness of the martian crust lies between 24 and 72 kilometers. Independent bulk composition and geodynamic constraints show that the thicker model is consistent with the abundances of crustal heat-producing elements observed for the shallow surface, whereas the thinner model requires greater concentration at depth.
Seismic detection of the martian core
火核的地震探测
作者：Simon C. Stähler, Amir Khan, W. Bruce Banerdt, Suzanne E. Smrekar
链接：
摘要
一颗行星的地质 历史 线索包含在它的内部结构中，尤其是它的核心。作者利用“洞察号”地震数据探测到来自火星核-地幔边界的地震波反射，并将其与大地测量数据进行反演，将液态金属核的半径限制在1830 40公里。
巨大的地核表明火星地幔在矿物学上类似于地球上的上地幔和过渡带，但与地球不同的是没有以桥曼石为主的下地幔。我们推断出核的平均密度为每立方厘米5.7至6.3克，这就需要大量的轻元素溶解在铁镍核中。
从洞察号的位置上看到的地震核心阴影覆盖了火星表面的一半，包括大多数潜在的活跃区域。这可能限制了可探测到的火星地震的数量。
Abstract
Clues to a planet’s geologic history are contained in its interior structure, particularly its core. We detected reflections of seismic waves from the core-mantle boundary of Mars using InSight seismic data and inverted these together with geodetic data to constrain the radius of the liquid metal core to 1830 40 kilometers. The large core implies a martian mantle mineralogically similar to the terrestrial upper mantle and transition zone but differing from Earth by not having a bridgmanite-dominated lower mantle. We inferred a mean core density of 5.7 to 6.3 grams per cubic centimeter, which requires a substantial complement of light elements dissolved in the iron-nickel core. The seismic core shadow as seen from InSight’s location covers half the surface of Mars, including the majority of potentially active regions—e.g., Tharsis—possibly limiting the number of detectable marsquakes.
粒子物理学 Particle Physics
Coherent manipulation of an Andreev spin qubit
安德烈夫自旋量子位的相干操纵
作者：M. Hays, V. Fatemi, D. Bouman, J. Cerrillo, S. Diamond, K. Serniak, T. Connolly, P. Krogstrup, J. Nygård, A. Levy Yeyati, A. Geresdi, M. H. Devoret
链接：
摘要
到目前为止，发展量子信息处理系统最有希望的固态方法是基于超导电路的循环超电流和操纵半导体量子点中电子的自旋特性。
作者结合了这两种方法的可取之处，超导电路的可扩展性和量子点的紧凑空间，来设计和制造超导自旋量子比特。
这个所谓的安德烈夫自旋量子位提供了开发一个新的量子信息处理平台的机会。
Abstract
To date, the most promising solid-state approaches for developing quantum information-processing systems have been based on the circulating supercurrents of superconducting circuits and manipulating the spin properties of electrons in semiconductor quantum dots. Hays et al. combined the desirable aspects of both approaches, the scalability of the superconducting circuits and the compact footprint of the quantum dots, to design and fabricate a superconducting spin qubit (see the Perspective by Wendin and Shumeiko). This so-called Andreev spin qubit provides the opportunity to develop a new quantum information processing platform.
Inhibited nonradiative decay at all exciton densities in monolayer semiconductors
在单层半导体的所有激子密度下抑制无辐射衰减
作者：Hyungjin Kim, Shiekh Zia Uddin, Naoki Higashitarumizu, Eran Rabani, Ali Javey
链接：
摘要
由于激子发生非辐射湮灭，单层过渡金属二卤族的光致发光量子产额在高发射强度下普遍下降。作者指出，这一过程在这些材料中通过它们的联合态密度的van Hove奇点共振放大。
然而，小的机械应变（约0.5%）的应用改变了van Hove奇点，抑制了非辐射过程。在剥离的硫化钼、硫化钨和硒化钨单分子层以及化学气相沉积的厘米级硫化钨单分子层中，都可以看到高激子密度下的近统一光致发光量子产额。
Abstract
The photoluminescence quantum yield in monolayer transition metal dichalcogenides generally drops at high emission intensities because the excitons undergo nonradiative annihilation. Kim et al. show that this process is resonantly amplified in these materials by van Hove singularities in their joint density of states. However, application of small mechanical strains ( 0.5%) shifted the van Hove singularities and suppressed the nonradiative processes. Near-unity photoluminescence quantum yield at high exciton densities was seen in exfoliated monolayers of molybdenum sulfide, tungsten sulfide, and tungsten selenide, as well as centimeter-scale tungsten sulfide monolayers grown by chemical vapor deposition.
Atomically resolved single-molecule triplet quenching
原子分辨单分子三态猝灭
作者：Jinbo Peng, Sophia Sokolov, Daniel Hernangómez-Pérez, Ferdinand Evers, Leo Gross4, John M. Lupton, Jascha Repp
链接：
摘要
分子的非平衡三重态在光催化、有机光伏和光动力治疗等方面发挥着重要作用。作者通过引入原子力显微镜中的电子泵浦探针方法，报告了直接测量单个并五苯分子在绝缘表面上的三重态寿命的原子分辨率。
如果氧分子在近距离内共吸附，可以观察到三重态寿命的强烈猝灭。通过单分子操作技术，与氧分子的不同排列被创造出来，并以原子精度表征，允许分子排列与淬灭三重态的寿命直接相关。
这种单分子长寿命三联体的电寻址，结合原子尺度的操作，为控制和研究局部自旋-自旋相互作用提供了以前未 探索 的途径。
Abstract
The nonequilibrium triplet state of molecules plays an important role in photocatalysis, organic photovoltaics, and photodynamic therapy. We report the direct measurement of the triplet lifetime of an inpidual pentacene molecule on an insulating surface with atomic resolution by introducing an electronic pump-probe method in atomic force microscopy. Strong quenching of the triplet lifetime is observed if oxygen molecules are coadsorbed in close proximity. By means of single-molecule manipulation techniques, different arrangements with oxygen molecules were created and characterized with atomic precision, allowing for the direct correlation of molecular arrangements with the lifetime of the quenched triplet. Such electrical addressing of long-lived triplets of single molecules, combined with atomic-scale manipulation, offers previously unexplored routes to control and study local spin-spin interactions.
生态学 Ecology
Innovation and geographic spread of a complex foraging culture in an urban parrot
城市鹦鹉复杂觅食文化的创新和地理传播
作者：Barbara C. Klump, John M. Martin, Sonja Wild, Jana K. Hörsch, Richard E. Major, Lucy M. Aplin
链接：
摘要
文化创新的出现、传播和建立可以促进对人类变化的适应性反应。作者描述了一个发展适应城市环境的文化的假定案例：野生硫冠凤头鹦鹉打开家庭垃圾箱。
社区科学报告的空间网络分析揭示了通过 社会 学习，鹦鹉打开从澳大利亚郊区的3个垃圾箱到悉尼市区44个垃圾箱的地理分布。对160个直接观察结果的分析揭示了个体风格和特定地点的差异。
作者描述了从创新的传播到地理变异的出现的完整路径，证明了鹦鹉的觅食文化，并表明了鹦鹉文化复杂性的存在。垃圾箱的打开与人类提供的机会直接相关，突出了文化促进对人类变化的行为反应的潜力。
Abstract
The emergence, spread, and establishment of innovations within cultures can promote adaptive responses to anthropogenic change. We describe a putative case of the development of a cultural adaptation to urban environments: opening of household waste bins by wild sulphur-crested cockatoos. A spatial network analysis of community science reports revealed the geographic spread of bin opening from three suburbs to 44 in Sydney, Australia, by means of social learning. Analysis of 160 direct observations revealed inpidual styles and site-specific differences. We describe a full pathway from the spread of innovation to emergence of geographic variation, evidencing foraging cultures in parrots and indicating the existence of cultural complexity in parrots. Bin opening is directly linked to human-provided opportunities, highlighting the potential for culture to facilitate behavioral responses to anthropogenic change.
生命科学 Life Science
Enterically derived high-density lipoprotein restrains liver injury through the portal vein
肠内高密度脂蛋白通过门静脉抑制肝损伤
作者：Yong-Hyun Han, Emily J. Onufer, Li-Hao Huang, Robert W. Sprung, W. Sean Davidson, Rafael S. Czepielewski, Mary Wohltmann, Mary G. Sorci-Thomas, Brad W. Warner, Gwendalyn J. Randolph
链接：
摘要
高密度脂蛋白（HDL）对胆固醇代谢很重要，可能具有抗炎和抗菌特性。虽然HDL主要由肝脏产生，但肠道也是一个来源。
作者在小鼠实验中发现，肠道高密度脂蛋白不会进入体循环。而是以HDL3的形式，通过肝门静脉直接输送到肝脏。在那里，它将细菌的脂多糖从肠道中隔离出来，这些脂多糖会引发炎症和肝脏损伤。
在各种肝损伤模型中，肠道高密度脂蛋白的丢失加重了病理。相比之下，提高肠道高密度脂蛋白的药物可改善疾病结果。HDL - 3在门静脉血液中富集，提示肠内HDL可能是治疗肝病的靶点。
Abstract
High-density lipoprotein (HDL) is important for cholesterol metabolism and may have anti-inflammatory and antimicrobial properties. Although HDL is mainly produced by the liver, the intestine is also a source. Han et al. show in mice that intestinal HDL is not routed to the systemic circulation. Rather, in the form of HDL3, it is directly transported to the liver through the hepatic portal vein. There, it sequesters bacterial lipopolysaccharide from the gut that can trigger inflammation and liver damage. In various models of liver injury, loss of enteric HDL exacerbated pathology. By contrast, drugs elevating intestinal HDL improved disease outcomes. HDL3 is enriched in human portal venous blood, suggesting that enteric HDL may be targetable for the treatment of liver disease.
Retinal waves prime visual motion detection by simulating future optic flow
视网膜波通过模拟未来光流实现视觉运动检测
作者：Xinxin Ge, Kathy Zhang, Alexandra Gribizis, Ali S. Hamodi, Aude Martinez Sabino, Michael C. Crair
链接：
摘要
当一只老鼠在森林的地面上向前奔跑时，它所经过的风景是向后流动的。作者的研究表明，发育中的小鼠视网膜提前实践了眼睛在小鼠移动时必须处理的东西。
视网膜活动的自发波与几天后在环境中实际运动时产生的波形相同。这种自发的模式活动改善了大脑上丘细胞的反应能力，上丘接收来自视网膜的神经信号以处理方向性信息。
Abstract
As a mouse runs forward across the forest floor, the scenery that it passes flows backwards. Ge et al. show that the developing mouse retina practices in advance for what the eyes must later process as the mouse moves. Spontaneous waves of retinal activity flow in the same pattern as would be produced days later by actual movement through the environment. This patterned, spontaneous activity refines the responsiveness of cells in the brain's superior colliculus, which receives neural signals from the retina to process directional information.
华师小超
因为字数超过一万字了 所以中文里稍微删减了一点 反正你是写英文的对吧 只看下面英文就行了关于磁电选矿相关应用的论文根据矿石中不同矿物的物理、化学性质，把矿石破碎磨细以后，采用重选法、浮选法、磁选法、电选法等，将有用矿物与脉石矿物分开，并使各种共生的有用矿物尽可能相互分离，除去或降低有害杂质，以获得冶炼或其他工业所需原料的过程。关于磁选设备的进展，已有若别，在物料中加选矿使有用组分富集，减少冶炼或其他加工过程中的燃料、运输等的消耗，使低品位的贫矿石能得到经济利用。选矿试验所得数据，是矿床评价及建厂设计的主要依据。从脉石中有时从其他矿物中分选出金属矿物或有价值的别种矿物的机械加工方法.With regard to the application of magnetic beneficiation related papersAccording to the different mineral ores physical, chemical nature of the ore broken ground, the use of re-election law, flotation, magnetic separation method, electricity election law, will be useful minerals and gangue mineral separately, and a variety of symbiotic useful minerals as far as possible, separate, remove or reduce harmful impurities in order to obtain smelting or other industrial raw materials needed to process. With regard to the progress of magnetic separation equipment, are already a number of specialized assessmentReference 〔 'a 41, here only collected on a magnetic separation and informationComprehensive comments.1.1 weak magnetic characteristics of the progress of low intensity magnetic separation is to useHigh-performance chin iron boron magnets to create a higher field-strength magnetic drumElection machine, drum magnetic separator and pre-selection of large chunk magnetiteStone, the development is conducive to improve the concentrate grade of weak magnetic separator.Chin iron boron magnets (Nd: Fel knife) is the largest energy product can beTatsu 3.18X10 "(T A / m), about drilling alloy shirt(SmCo.) Maximum energy product (1.59X10 "T A / m) ofz-fold [51, silver ferrite (Sro.6Fe20,) the largest energy product(0.326X105T A / m) 10 times. Therefore, the use ofChin-Fe-B Magnetic Separator line easy to raise the field strength and performance.Germany, for example, with hinge rod iron boron permanent magnet developed 'Permos'Drum magnetic separator magnetic induction of up to 0.4 ~ 0.5T,Materials can be used wet-dry election or an election can also be more idealStrong magnetic separator used to remove material to a strong magnetic materialQuality 〔6 '. British Boxmag - Rapid Rail Limited with hingeBoron magnets developed 'Magnadrum' Drum SeparatorMagnetic field up to 0.3 ~ 0.4T, for sorting industrial mineralsAnd abrasive powder 〔 'J. As equipment such as large-scale examples, IState Institute of Ma On Shan mine CTDG1210 following the development of largeDiameter magnetic separator, he developed a greater CTDGIS16 typeDiameter of the magnetic separator [3], the use of money-Fe-B magnetic system, cylinder surface-pingBoth the magnetic field up to 0.4T, for sorting large magnetiteShek. Anshan Black Design and Research Institute of Mining and Metallurgy Shandong Zhang家洼cooperation in the development of iron ore a price 1400mmx1600mm electromagnetic water-cooled magnetic pulley 【.〕, the average magnetic field for the cylinder surface0.24T, handling capacity up to 200t / h, used for pre-selectionOne of the magnetite 350mm stone, eight months from the original 667,000 tExcluding iron ore 11.97% of the 75,000 t tailings, a total increaseEconomic benefits of 534,200 yuan. In order to improve the sorting equipmentThe effect of the comprehensive utilization of mineral emei Institute conventional magnetic separationTrough improve magnetic 〔a re-election machine,〕 its groove from the upper body coneCylindrical-shaped change, permanent magnetic ferrite by the lower part of Round TowerShape changed to the upper part of the overall magnetic lines scattered formation of multi-storey circular magnetic system,Field strength distribution of 12 ~ 0kA / m, and equipped with the concentration of self -Control system can be sub-constituency pulp concentration of control in 30% ~Between 35 percent, the device in the application of Shougang Qian'an Iron effectFruit is: with the improvement of processes, improved sorting tabletsDegrees, with the previous fine sieve fine grinding process compared to that in millCapacity, concentrate grade and iron recovery under the same conditions,Increased the production capacity of 27.66%. This equipment has been developedFor the price 300,600,1500,1800,2500 mm SeriesProducts. In order to improve the concentrate grade, Beijing Mining and Metallurgical Research totalHospital developed a Bk a drum magnetic field more than 1021〔Kawasaki machine. It adopted a very open 7 magnetic lines and downstream type electionBox, fill in the election together with me in Central and exclusive premium coarse tailings,Feeder terminal located in the overflow weir and exclusive fine-grained tailings, so that shipped with the tubeLine of magnetic material has always been the reverse flow of cleanAchieve the purpose of concentrate grade. The aircraft in Nanfen Iron MineConcentrator industrial test results show that with the price 105Ommx21OOmm half compared to current-type magnetic separator, a high concentrate grade2.04 percent, sorting efficiency 10.28%, while the magnetic iron backLow yield of only 0.19 intestine.It is worth noting that the former Soviet Union to study electrochemicalLaw regulating the process of strengthening the magnetic 'Kawasaki. Research in the laboratory doSet of refractory ores and oxide ores, the first paragraph of the low intensity magnetic separationBefore using the electrode of the role of the most promising, concentrate grade will be provided as1.1% ~ 1,4%, iron recovery rate of 4.5 percent raise, 6.4%, Weak magnetic separation tailings in strong magnetic regulated before, ironAnd improve the recovery rate of l%, 2.4%. Easy selection of ore,Polarization effect, the first and the second paragraph of the magnetic iron recoveryRates were increased by only 0.2%, 2.8% and 0.1% ~ 2Called. It is believed that the effect is due to the different nature of the ore, magneticOf different intensity and mineral composition. Also as a result of ore oxygenSubstances fixed potential value and exchange current value and restore the cathodeResponse to the current limit of different degrees.1.2 Strong magnetic strong magnetic equipment were limited mainly toPermanent magnet and electromagnetic roller or belt strong magnetic separator. BritainRapid Ltd. BOxmag with a hinge iron boron permanent magnet systemCreating a 'Magnaroll' Roll Magnetic Separator [ '〕, including the roll diameterGong Gong 75mm and 100mm in two specifications, respectively, for the OfficeThe rationale for fine-grained and coarse-grained materials. It is expected to pass an area of the magnetic fieldOften for the 0.9 ~ 1.0T, and loop generated by the high gradient,Sorting performance roller magnetic induction machine is superior, the typical applicationIncluding the purification of silica sand and feldspar, improve the quality and Tao AndalusiteFine porcelain material dry iron. The former Soviet Union developed a rotating magneticField Separator roller 〔 ',,, also known as electric sorting device. TheMain loser is expected by the belt and with the following configuration and with parallelConstitute a permanent magnet roll. Magnetic roller by the permanent magnet composed of three parts, inPermanent magnet poles of the Ministry of Law and roll to the vertical axis, before and after the permanent magnetBody of law to the magnetic axis and roll into a 45 "angle, forming the same levelFace in three directions of the magnetic field, magnetic field for the roll surface 0.45T. PointsElectoral principle is the use of non-magnetic conductive particles in rotating magnetic rollerRotating magnetic field generated by the driving force for transforming the role of pay and non-derivativeXinhua particle separation of aircraft being used for non-ferrous metal processing residue fromRecovery of scrap and waste aluminum, copper and other metal particles, conductor productionPurity and recovery of goods are up more than 94 percent. China's MaHill Mining Research Institute, following the development of Cs-1-type roller magnetic separatorAfter the development of a Cs-2 electromagnetic induction strong magnetic rollerMachine 〔''], the roll diameter and effective length of 380mm were smartAnd 1468mm, parallel twin-roll configuration, with a total of four sub-election,Magnetic field can be between 0.4 ~ 1.78T regulation, excitation, ChuanActin and were air-cooled power 4.23kw, 13xZkw and0.09 justice Zkw. The aircraft used in Meishan Iron sorting 12 ~Chek Ling ZMM one of the indicators of iron ore is iron ore30.40%, the concentrate grade and recoveries were44.05% and 78.75%, a single-year cost-effective equipmentFor 630,000 yuan. With different roller magnetic separator. Ferromagnetism with teethBoard or the ball wet media as a result of strong magnetic separator structure is complicated,High cost, coupled with the type of large development remains is to promoteApplications and improve and perfect. SHP a strong magnetic separator 2000In Qidashan Iron Ore has been applied 〔'' ', SQC-6 -2770-type strong magnetic separator in Masteel satisfied people Gushan Iron Mine production flowCheng, Gong-1500 Shuangli Central strong magnetic separator further in Kunming SteelBy the popularization and application of 〔'5] SHP-keung, a 3200-type magnetic separatorThe improvements include 〔'']: magnetic angle from 83 "to 70., MagnetizingCoil replaced by the air-cooled, such as oil-cooling. Rather meaningful is that QueenslandSteel plate medium level of tooth ring magnetic separator and the ball vertical ring magnetic mediaMachine with the same test sample were compared [1 '〕, the results of tableThat the tooth plate flat ring of iron concentrate grade and recoveries wereAbout 4% and 8%, but the vertical ring-type magnetic properties as a result of the reverse flushingMaterial, which is not easy to plug for the screening, the following rough, rinse waterPressure and lack of strict water quality requirements, more reliable operation.1.3 HGMS in the magnetic field of high gradient magneticStudy of the election is still occupies an important position, and made significant JinExhibition. Svoboda described a new type of high gradient magnetic separatorI''〕 plane, the aircraft using short-term water-cooled magnetic coil system, the magnetic field for1.ZT, input power 110kw, from South Africa University of theWitwatersrand gold and uranium tailings recovery, capacity 30t / h. FormerThe Soviet Union the new joint company克里沃罗格selection and black metalBeneficiation Research Institute developed a 600-type 3KM small magneticSorting machine 〔 'Lu'. Kai loaded aircraft using electromagnetic magnetic lines and mesh135 ~ x51 ~ punching screen for sorting media magnetic induction for the 0.5T, processing capacity of up to 30Ot / h, forEnterovirus 95 to deal with a fineness of 0.045 magic. N edge of the iron oxide stoneRock. Copper-rich Zambia's high gradient magnetic separator toTo the attention recently with the background magnetic field 1.3T, sorting cans footInch 23mmx32mmx104mm (effective volume 42ml,Filling 5% 50 ~ 10, that is, steel wool m high horizontal magnetic field gradientMagnetic devices, to 5 ~ 38 al m ore of copper concentrate and madeExperimental research on t ',', in the feed flow rate of 7cm / s and cleaning velocity14cm / s under the conditions of separation twice before a magnetic productsChalcopyrite and bornite content from 72 to 86 percent called backThe yield was 82%; after a magnetic products, copper contentFrom 16%.Increased to 44 percent, and the recovery was 72 enterovirus. In China,HGMS who has been cross-industrial applications period, workers from China and South AfricaIndustry, universities and Ganzhou, Jiangxi Institute of cooperation in the development of nonferrous metallurgyThe SLON a 1000 vertical ring pulsating high gradient magnetic separator has beenThe development of a r500 type SLON 〔 '. ', Its diameter by sorting1ooomm to 150omm, mail handling capacity t / h to30t / h, and structural improvements, performance has increased, the firstTaiwan SLON a 1500-type magnetic separator installed in 1989 regardlessMountain iron ore, to deal with slime and strong magnetic separation tailings, such as fine-grained RefractoryMixed materials, the original estimated annual economic benefit is 1.06 million yuan'''',Inter reached 1.08 million yuan. Passed technical appraisal in 1990 afterThe mine has ordered a 1500-type SLON a pulsating high ladderSeparator degrees. The past two years, also iron ore and copper GongchanglingCopper applications were recorded in the five and a one SLON1500 vertical ring pulsating high gradient magnetic separator. On the pulse of high-OssetiaMagnetic principle degrees were also made to further explore 〔 "]. Zhongnan EngineeringIndustry University of Pangushan Tungsten fine mud of pulsating high gradient magnetic separator testA post-mortem studies also received a good indicator of 'Chuan: containing the WO30.74%Tungsten fine mud at the right time under the conditions of separation, to be with WO3Volume of 17.90 percent and 73.78 percent recovery rate of Scheelite; and non -Pulsating high gradient magnetic separator compared to the high concentrate grade 13.99%,The recovery rate was only 1.09 percent lower. By the Central South University and aldehyde hillsMunicipal Science and Technology Development Center, developed in cooperation CL Kazunori 500mmVibration cycle high gradient magnetic separator''〔 "to fill China's highRidge soil HGMS blank. It's tank tracks and well-differentiatedDo not for 500mm and 300mm, the magnetic field up to ZT, power consumptionAbout 220kw, handling about Zt / h. Industrial tests showed thatIt's exciting and good cooling performance, can effectively remove highRidge soil micro-paramagnetic iron particles, a significant increase in high -Ridge soil and into a white porcelain, can produce better economic and socialEffectiveness.On the high gradient magnetic separation theory, since 1973Watson made a number of magnetic particle collector concept 〔25 'have beenEstablished a fairly complete theory of magnetic collector. Recently,Svoboda, who according to the energy point of view to explore the high gradientNew theory of magnetic collector 〔26]. In his view, the paramagnetic particles inHigh gradient magnetic field and magnetic wire trap with a collision withSome of the overall role in a London for the role of van der Waals energy, double -Layer energy, with an average energy and shear stress on the particles ZuogongAnd of and derived by medium particle collector wire radius(Limited to particle size) and particle magnetization coefficient, strong magnetic fieldDegrees, medium wire magnetization and radius, fluid velocity and densityDegrees and the viscous coefficient of the relationship.1.4 superconducting magnetic superconducting magnetic separation has been into the large-scale chemicalIndustry application period. Eriez Magnetic company, following the United States in 1986Will be re-25 leaves, a diameter of 2134mm Tank superconducting magnetic separatorJ. M. Huber Corporation for kaolin processing plant purification of high -Ling soil after less than a year, the same company also ordered aRe-250t, the diameter of 3048 blade n Magic a similar superconducting high gradientSeparator 〔Sichuan, when the aircraft is being created, he orderedThird such equipment, according to plan was the first quarter of 1990Degrees installation operation. This is the world's largest superconducting magnetic separationMachines, superconducting magnet with a Nb叭Wirewound system, liquid helium coolingTo a 269 ℃, only the beginning of each cycle supply excitationCurrent, in 60 seconds, zero magnetic field can be increased to ZT, RanAfter having been able to maintain foreign to ZT magnetic field, weeks at the end of clearanceClosed, the magnets' return 'of power is about to start when the' through to 'Half power. The cost of superconducting magnetic than ordinary high gradient magneticSlightly more elections, the second piece of equipment production costs than the firstTaiwan slightly more. Germany KHD Humboldt has韦达格Will be a superconducting Descos sold Drum Separator TurkeyIts 〔:'3, used to a weak magnetic serpentine gangue and magnesiumMineral separation, ore particle size of 100 ~ 4 magic n magic. , Containing about 510220%, FeZ034 intestines, including stem-election once was 510:1.5% And Fe: O, 0.3% of magnesite concentrate rough. AircraftSpecifications for the price 120OmmxI500mm, the magnetic field up to 3.2T, the handling capacity of 10 belly / h, power consumption is about 1.skw h / t,Is one of the world's first for the coarse-grained superconducting magnetic separationMachine. Now expect the 'high temperature' superconductors to develop third-generation super -Magnetic sorting machine "'91.2 electric electionKelly and Spottiswood three papers with a comprehensiveReview of the theory of separation. The first review of the basis of principle,Including electrostatics; particle characteristics, namely, particle conductivity(Band theory, electron capture and other forms of electrical conductivity),The surface of semiconductor electronics in nature: particles or metal contactsThe equivalent circuit, fluid particle motion. The second assessmentDescribes the measurement of electrical particles and particle charge mechanism. XinhuaElectric field measurement, including measurement, Dutch power measurement, contact chargeCumulative volume measurement and conductivity measurement. Dutch electrical particles rationale packageIncluding corona charging, induction charging, friction charge, charge rate,Coehn law. The third review of the practice of electrostatic beneficiation,Including electrostatic concentrator theoretical analysis (stress analysis), StaticXinhua concentrator analysis of the experience, equipment parameters, sorting circuit,Three papers related to the literature 95. Xinhua election on I:. Arts andThere are some theoretical research reports. Additives have been used abroadA large amount of friction method charge at KCI and NaCIFrom. The Act the use of KCI and NaCI friction charged the differenceDo not, in the amount of materials in adding additives. So that the mobileLayer belt during transport friction charged, and then sorting machineKCI in a concentrate, KCI up to 92% concentrate grade, recoveryRate of 50%. A.L. Shalom and others discussed the non-allUniform electric field separation of the exchange of technology for liquid and gas media articlePieces under the sorting mechanism "in Sichuan, the establishment of electric field strength, the NetherlandsElectricity and Coulomb force and the ratio of inertial force of expression.Dressing to make a useful component enrichment, reducing smelting or other processing of fuel, transport and so on consumption, so that the poor low-grade ore will be economic use. Beneficiation test of the data is the deposit rating and the main basis for plant design.From the gangue minerals are sometimes separated from other selected metal minerals or other valuable minerals machining methods.
有整套做好的，可以提供的。。。助人为乐。。。引言：引言又称前言、序言和导言,用在论文的开头.引言一般要概括地写出作者意图,说明选题的目的和意义,并指出论文写作的
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