有没有综述性的文章，介绍扫描电镜，场发射显微镜，原子力显微镜等

电子显微镜技术发展综述

摘要：本文论述了电子显微镜的发展现状及历史，介绍了目前较为先进的数种电子显微镜的结构、原理以及其在生物学领域的应用情况，并对其在组织学研究中的应用进行探讨。 关键词：电子显微镜；组织学研究 引言：显微技术是一门对于物质微小区域进行化学成分分析、显微形貌观察、微观结构测定的一门专门的显微分析技术。20世纪30年代，透射电子显微镜（TEM）的发明标志着电子显微技术的诞生，人们可以进一步地研究物质的超微结构。电子显微技术在普通光学显微技术基础上进一步拓宽了人们的观测视野，在各个领域发挥了重要的作用，被广泛应用于科学领域。在生物学研究领域，电子显微技术推进了组织学，细胞生物学，分子生物学等学科的发展，因而具有不可替代的崇高地位。

一、电子显微镜技术

1.1电子显微镜的定义与组成 电子显微镜，简称电镜，是根据电子光学原理，用电子束和电子透镜代替光束和光学透镜，使物质的细微结构在非常高的放大倍数下成像的仪器[1]电子显微镜由镜筒、真空装置和电源柜三部分组成。镜筒主要有电子源、电子透镜、样品架、荧光屏和探测器等部件，这些部件通常是自上而下地装配成一个柱体。①电子透镜：用来聚焦电子，是电子显微镜镜筒中最重要的部件。一般使用的是磁透镜，有时也有使用静电透镜的。它用一个对称于镜筒轴线的空间电场或磁场使电子轨迹向轴线弯曲形成聚焦，其作用与光学显微镜中的光学透镜（凸透镜）使光束聚焦的作用是一样的，所以称为电子透镜。光学透镜的焦点是固定的，而电子透镜的焦点可以被调节，因此电子显微镜不象光学显微镜那样有可以移动的透镜系统。现代电子显微镜大多采用电磁透镜，由很稳定的直流励磁电流通过带极靴的线圈产生的强磁场使电子聚焦。②电子源：是一个释放自由电子的阴极，栅极，一个环状加速电子的阳极构成的。阴极和阳极之间的电压差必须非常高，一般在数千伏到3百万伏之间。它能发射并形成速度均匀的电子束，所以加速电压的稳定度要求不低于万分之一。③样品架：样品可以稳定地放在样品架上。此外往往还有可以用来改变样品（如移动、转动、加热、降温、拉长等）的装置。④探测器：用来收集电子的信号或次级信号。

1.2基本原理 不同类型的电子显微镜成像原理各有差异，但均是利用电磁场来偏转、聚焦电子束，再依据电子与物质作用的原理来研究物质的构造。其中透射式电子显微镜产生的电子束经聚光镜会聚后均匀照射到试样上的待观察区域，入射电子与试样物质相互作用，由于试样很薄，绝大部分电子穿透试样，其强度分布与所观察试样区的形貌、组织、结构一一对应。投射出试样的电子经三级磁透镜放大投射在观察图形的荧光屏上，荧光屏将电子强度分布转化为人眼可见的光强分布，于是在荧光屏上显出与试样形貌、组织、结构相应的图像。扫描电子显微镜（SEM）是聚焦电子束在线圈驱动下对试样表面逐点栅网式扫描成像，成像信号为二次电子、背散射电子或吸收电子。二次电子信号被探测器收集转换成电讯号，经处理后得到反应试样表面形貌的二次电子像。背散射电子成像反映样品的元素分布，及不同相成分区域的轮廓。此外由于电子的德布罗意波长较短，分辨率比光学显微镜高的很多，可以达到0.1～0.2nm，放大倍数从几万到百万倍。

1.3技术发展史 世界上第一台电子显微镜（透射式电子显微镜（TEM））由德国科学家Ruska和Knoll于1931年研制成功。二战后，Ruska继续对TEM进行研究改进，并制造出了放大倍数在10万倍以上的显微镜，并因此获得了诺贝尔物理学奖。在TEM的基础上，英国工程师Charles于1952年发明了世界上第一台扫描电子显微镜（SEM）。扫描电镜主要是针对具有高低差较大、粗糙不平的厚块试样进行观察，因而在设计上突出了景深效果，一般用来分析断口以及未经人工处理的自然表面；而透射电镜则突出的是高分辨率，使用透射电镜观察样品能获得高分辨率的超微结构图像，在材料科学和生物学上应用较多，同时也是病理学上的诊断工具，该技术的关键是超薄切片的制备。在这以后场发射扫描电子显微镜（FE-SEM）、场离子显微镜（FIM）、低能电子衍射（LEED）、俄歇谱仪（AES）、光电子能谱（ESCA）等相继诞生，在各科学领域的研究中起重要作用。 1981年G．Binnig和H．Rohrer成功研制了世界上第一台扫描隧道显微镜（STM），并因此获得诺贝尔物理奖．它的出现，使人类第一次能够实时地观察单个原子在物质表面的排列状态和与表面电子行为有关的物理、化学性质，被国际科学界公认为80年代世界十大科技成就之一。扫描隧道显微镜(STM)是利用导体针尖与样品之间的隧道电流，并用精密压电晶体控制导体针尖沿样品表面扫描，从而能以原子尺度记录样品表面形貌的新型仪器．其分辨率已达到1nm～2nm，用它可研究各种金属、半导体和生物样品的表面形貌，也可研究表面沉积、表面原子扩散、表面粒子的成核和生长，吸附和脱附等。 在STM出现以后，又陆续发展了一系列工作原理相似的新型显微技术，包括原子力显微镜（AFM）、横向力显微镜（LFM）等，这类基于探针对被测样品进行扫描成像的显微镜统称为扫描探针显微镜（SPM）。扫描探针显微镜是纳米测量学、纳米表征与测量方法中最重要最基本的手段。它能以原子级的探针和被测样品表面作为工作的主要元件，在X和y两个方向上完成探针与样品之间的扫描，同时在Z方向的升降来模拟样品表面的起伏。用探针与样品间的相互作用所产生的物理量的数值随样品表面起伏的变化来达到观察样品表面形貌的目的。这种仪器分辨率高，横向分辨率可达0．1nm，纵向分辨率可达0．01nm，可以直接观察测定样品的三维图像，可以在大气、真空甚至液体中，在高温或低温下进行观测。检测时可以不与样品接触，故不会损伤样品，也不需要电子束照射，因而不会对样品造成辐射损伤。

二、我国电子显微镜技术的发展 1958年，我国成功地研制了第一台电子显微镜，1988年中国科学院白春礼和 姚俊恩研制出了我国的第一台STM。[2] 2000年,中国电子显微镜学会统计中国大陆保有量不到2000台,中国加入WTO后,经济大发展,科研教育以及产业构都在升级目前，我国电子显微镜市场每年以近百套的数量在增长，可以预期，在未来数年内中国电子显微镜市场容量将居世界首位。 中国市场的电子显微镜，日本电子的市场占有率超过50%，排在首位。紧随其后的是FEI（原飞利浦电镜部）、日本日立（天美代理）、德国Carl Zeiss（原德国LEO）和日本岛津。而在国产厂家方面，主要是中科科仪、南京江南光电和上海电子光学技术研究所，产品主要集中在低端的扫描电子显微镜市场。就市场总体情况而言，国产电镜国内市场占有率不足10%。由此可见我国国产电子显微镜还有较大幅度的提升空间。从种类上看扫描电镜占目前中国电子显微镜总保有量的63.61%，透射电镜则为36.39%，可见扫描电镜在我国有着更为广泛的用户基础。[3]

三、电子显微镜技术的未来发展趋势

3.1远程电子显微镜技术 自上世纪九十年代以来，随着计算机技术和网络技术的发展，远程电子显微镜逐渐出现，它可以将实验室现场获得的实时信息展现给远端用户，使其可以通过互联网实时观看样品图像，并远程操作仪器来完成实验。[4] 远程电子显微镜技术的关键在于图像的采集、压缩和传输。在图像采集方面，现在的电子显微镜已经有了长足的进步。老式的电子显微镜多采用数码相机和视频采集卡来采集图像，新式电子显微镜多采用VGA采集卡进行图像采集并已成为未来发展趋势。此外运用软件来采集图像的新方式也逐渐出现。早期，图像的压缩使用的是JPEG图像压缩法，即远端用户所见的是一系列独立的静态样品图像。现在，随着技术的发展，MPEG4和H.264等视频压缩算法被逐渐运用到了样品图像的压缩。现在，样品图像的传输主要通过TCP协议和UDP协议，但其占用带宽过大，传输效果并不理想。为了改善传输性能，专门的数据传输系统“金字塔”式网络传输模型以及专有传输网络正在研究之中，同时这也是现阶段远程电子显微镜的改进方向。 1990年，Carl Zmola等人实现了对SEM的样品图像网络传输，首次建立了远程电镜的样品图像实时传输系统。随后，美国各大学相继建立了各自的SEM远程系统。样品传输的效能也有了长足进步，最初，在800Mb的光纤网络中，样品图像的传输效能是每17秒传送1帧。到了2000年，在1~2Mb的网络中，样品图像的传输可以达到每秒传送5帧。在技术上尚有很大程度的提升空间。 在中国，尽管各大院校及研究机构中有数千台电子显微镜，但仍不能满足日益增长的应用需求，因此远程电子显微镜技术的研究对于中国是很有应用价值的。

3.2低温电子显微镜技术 低温电子显微镜技术是应用冷冻(物理)方法制备生物样品并进行观察的技术，因而在生物学组织学中的应用较为广泛。与常规电镜技术(化学方法)相比较，其可最大程度地维持样品在生活时的生理状态，可运用于生物大分子的动态过程研究以及细胞核组织的三维结构分析。

3.3低温电镜下的三维重构技术 电子显微镜的三维成像技术是电子显微和计算机完美结合的产物，它利用电子显微镜收集样品的二维投影图像，经过计算机处理重构出样品的三维空间结构。三维成像技术在生物学领域的应用十分广泛，尤其体现在对蛋白质的三维结构分析上。早期的三维成像技术主要使用重金属盐溶液对样品进行染

ABSTRACT

A number of different pyrites in Late Permian sulfur-containing coals and some associated rocks in Sichuan province of southw estern China have been studied system-atically by optical microscope，SEM and STM for crystal shape，distribution，morphology and atomic struc- ture. The chemical composition w ere analyzed using by EPMA，INAA techniques. The results in- dicated that there are different pyrite paragenesis and desulfurization properties in the different types of sulfur － containing coals formed on different depositional environments. Super micro- scopes reveal that there is colloidal pyrite in coal. The microanalysis show s that the several types of pyrite have difference in element composition and physical and technological property such as susceptibility etc. The crystallization of pyrite plays an important role in concentration of major elements.

INTRODUCTION

Investigation on the sulfur in coal may date back to the begining of this century ( Thissen， 1919White，1913) in America. In recent tw enty years，more and more articles，reports and books about sulfur have been published. Key studies of sulfur in coal include CasagrandeBer- nerCohen et al in AmericaHunt in AustriliaKizilstein in Russia and so on.

Tw o-thirds of total sulfur in the high sulfur coals in China are dominated by inorganic sul- fur，at least 95% of w hich consists of iron sulfide. Therefore，researches on pyrite，a major carri- er of sulfur w hich influnces the quality of coal，have increasingly attracted coal technologists' attention. Nantong of Sichuan province is one of the important coal production area in south- w estern China，w hich is one of the high sulfur coal regions in China. Our reseach objective is to study the character of pyrites in coal and associated rock，such as their distributions，physical and physic-chemical properties etc. ，and to supply fundamental data for coal desulfurization technology，coal processing and utilizations.

SULFUR FORMS IN SICHUAN COAL

Objective coal seams of our investigated fields are Toulianzi coal of Wuyi coal mine at Anxian county，#5 and #6 seams of Nantong coal field at Chongqing，C2 seam of Muchuan county. Basically they represent for several types of coal containing different sulfur forms in Sichuan province. Table 1 show s sulfur forms of coals at different sites.

Table 1 The Sulfur Forms in Different Coals of Sichuan Province，China

Generally，w hen total sulfur content( St. d) is less than 0. 5% ，the main sulfur form in coal is organic sulfur ( Hunt，1987) . But C2 coal seam at Muchuan countuy mainly contains inorgan- ic sulfur w hich occupys 63. 08% of total sulfur. From continental to marine environment，total sulfur content in coal increases，the sulfur forms are different. The sulfur form in coal formed on tidal flat is mainly in the form of iron sulfide( Sp. d) . The Wuyi and Nantong #6 coal seams is rich in organic sulfur( So. d) . Both of them are influenced by roof rock of lime-stone or mud-lime stone of marine facies. Moreover，there is a trend that organic sulfur content increases w ith the increases of total sulfur，and pyritic sulfur is the main form of sulfur in many Sichuan coals.

THE DISTRIBUTION OF PYRITES IN COAL

Macroscopically there are rarely single crystal or film pyrite in low sufur coal formed in al- luvial sw amp at Muchuan. How ever，there are a lot of nodular，lenticular，pisolitic，chrysan- themun-like，massive，vein-like pyrites etc. in Nantong #5，#6 coal seam w here sulfur is accu- mulated on transitional facies. At the low er part of Wuyi high sulfur coal seam，there are a lot of fine disseminated pyrites show ing lamellar structure，but no pyrite can be seen by naked eye at the middle and upper part. Nodular pyrite occasionally contains marcasite and pyritized organism and biological relics.

Microscopically，there are single crystals and aggregates，framboid and its aggregates， globular，nodular，pore-nodular，biological，massive，vein，rod-like pyrites and marcasites in coals. Table 2 show s the quantitative statistics of 300 iron sulfide particles. Obviously，pyrites in Muchuan coal are mainly framboidal w hich are mostly associated w ith clay，and partly epigene- tic vein-like pyrite. In Nantong coal，there are a lot of nodular and cell-infilling pyrites. The py- rites in Wuyi coal are mainly euhedral crystal and framboid and their aggregates ( figure 1 － a) . Euhedral crystals are mostly octahedron. Wuyi coal contains more marchasites( figure 1 － b) . In general，framboidal morphology is present in all salinites. Similarly，framboidal pyrites in Sichuan coal are seen in all depositional facies. Using scanning electron microscope( SEM ) ，w e have observed pyritized Desulfovibrio，rod-chain bacteria，fine coccoides etc. . There are also a lot of pyritized algae such as Permocalculus Sinica，and Rhodophyceae. The crystal shapes of pyrite such as cube，octahedron，pentagonal dodecahedron and their combination can be easily observed by SEM. The cubic pyrite tends to distribute in continental facies，w hile the others are mostly devoloped in marine sediment，e. g. octahedron pyrite in Wuyi coal w as formed in ma- rine facies. The results are similar to that reported by Anchun Li et al( 1991) . Marcasite is usual- ly lamellar. Morever，crystal imprint，crack，grow lamination，defect，erosion relic and other mat- ter on crystal face have been seen by SEM. Especially colloid like structure，w hich devoloped in nodular pyrite，also has been observed. Coal pyrites，microscopically，contain a lot of pore pyrites，pyritized organisms and marcasites.

Table 2 Microanalysis of iron sulfide in coal

Table 2 show s that the pyrite particles in Muchuan coal are basically not liberated. In Nan- tong coal，1 ～ 5μm pyrite particles are dominant. The quantities of + 100μm pyrite particles in Nantong #6 coal are much more than those in other coals. The liberated pyrite in this size is as high as 44. 1% . In Wuyi coal，70% of pyrite particles are not liberated in 1 ～ 5μm size fraction. It results in difficulty in desulfurization. Wuyi coal also contains high organic sul- fur. therefore it is very important to study the properties of pyrites.

STM ANALYSIS ON SURFACE OF COAL PYRITES

Scanning tunneling microscope ( STM ) is an effective tool for the analysis of material sur- face. It directly reflects the image and structure of substance surface from 3μm to 1A scale. Eggleston( 1990，1992) and Fan ( 1991) successfully studied pyrite from other sources except in coal by using STM. In order to explain the difference in physical properties such as magnetic and oxidation ones of different pyrites，w e studied surface properties of pyrites w ith STM. The follow ings are our results and explanations:

Seven coal pyrites and tw o ore pyrites have been examined by CSTM -9000 scanning tunne- ling microscope for topography in constant-current mode and for atomic image in constant-hight mode. The scanning ranges are 2000X2000A to 3X3μm for topography. The granular，pellet， framboid-like，rod，fibre，bandary，milk colloidal and smooth，level，uneven etc. structure had been observed on the surface of pyrite crystal or fracture by STM. On the crystal face，oxidative corrosion pit ( relics) are often observed. Generally，on fine granular surface of pyrite，fine grains are in order w hich is gradually grow n into laminalars，w hile large granular grains are at random on coarse，and uneven surfurce of pyrite，w hich may be caused by surface corro- sion. The STM images of fracture surface of pyrites in coal show that pyrite of good crystaliza- tion is granular grain ( figure 1 － c) ，w hile nodular pyrite of poor crystalization displays more smooth and milk-colloid like face( figure 1 － d) . The above results observed by SEM indicate that there may be colloid pyrite in coal.

We have obtained some atomic images in constant-hight mode of STM ( figure 1 － e) ，they are not very nice and distinct，this is because that the pyrite is covered by an oxidational film. After the fresh surface of pyrite are covered w ith silica-oil，w e clearly observed the atomic structure of pyrite surface，and the zigzag chains in some parts. The interatomic distances reveal that the observed surface is in { 210 } direction of pyrite crystal. Eggleston and Fan observed { 100} and{ 110} direction of pyrite crystal surface.

In summary，STM is a new and effective technique for probing surface topography，struc- ture，crystal grow ing，atomic structure as w ell as surface oxidation and corrosion. STM and SEM directly prove that colloid pyrite exists indeed.

EPMA ANALYSIS OF PYRITES IN COAL

Electron probe microscope analysis( EPMA) is a method for composition analysis. The pre- cision of EPMA is 1% to 0. 1% . In this study，860-EDX EPMA of Link Coporation in U. K. and WDX-2A EPMA of Microspec Coporation in U. S. A w ere used. The latter has a bet- ter precision. Some conclusions about EPMA analysis of pyrite in coal are as follow ing.

Fig. 1 Microphotograph of iron sulfides in coals and associated rocks.

1. Ordinarily，besides Fe and S，pyrite in coal often contains Si，Al，Ca，Mg，Ti，Zr，Nb. The content of those elements in pyrite are proportional to those in matrix vitrinite. The Co，Ni，Cu， Pb etc，w hich can constitute the crystal latitices of pyrite，are minor in concentration，but they occur none or little in matrix vitrinite. In general，as crystal is transformed to framboid and cell- infilling pyrite，associated elements increase gradually.

2. In same coal seam，S content and S / Fe atomic ratio: euhedral crystal >cell-infilling >circular shape >framboidal increase in the order of pyrite. This indicates that crystalization plays a role in sulfur enrichment. Either S or Fe in nodular pyrite is richer in centre than that at the edge. Apparently nucleation plays a major role in nodular pyrite formation. The framboidal pyrite in Muchuan coal has very high of S / Fe atomic ratio( >5) . It contains a large amount of Co，Ni etc. ，and Co / Fe atomic ratio is near to 3 /4. So some parts of framboids are not pyrite. Because framboid pyrite particle is small，the determined value influenced by matrix substance is usually lower than actual value. It is only considered as referential value. But S / Fe ratio is less influ- enced.

3. High S / Fe ratio of pyrite devoloped in matrix vitrinite w as found to be 6 to 17. The S / Fe ratio of pyrite is proportional to the organic sulfur of desmocollinite. The Fe content of the desmocollinite in high sulfur coal is relatively low.

INAA ANALYSIS OF PYRITES IN COAL AND ASSOCIATED ROCK

Instrumental Neutron Activation Analysis( INAA ) has the advantages of high sensitivity， good accuracy，multielemental analysis and non-destruction. We used INAA to measure trace elements，and associated elements of pyrite for searching the genesis，physical properties of pyrite. Nine coal pyrite and tw o ore pyrite samples are analysed by INAA in Institute of High Energy Physics，Academia Sinica ( 11 ) . Table 3 is part of the INAA results，it reveals the follow ing facts:

1. The elements in pyrites of different coals are different paragenetic types，e. g. in the py- rite of Nantong #6 coal，∑REE，∑3 ( sum of lithogenic element) are very low ，w hile Ni，Zn， Na are higher. There are a large amount of associated elements such as Mn，Cr，∑2，V，Ba，Ca， Mg etc. in the matrix-like pyrite of Nantong.

2. In the pyrite from coal and associated rock，macroscopically，from crystal to chrysanthe- man，nodular，vein-like and matrix-like pyrite，Fe content decreases gradually，and Co，Mn， ∑REE and other assoociated elements increase as the crystalizational degree of pyrite becomes w orses. The w orse the pyrite crystal the higher the ∑3 lithogenic elements.

3. The difference betw een coal-and ore-pyrite is that ∑3 and ∑REE content is low in ore- pyrite，and As and∑1 is rich，especially for hydrothermal type of pyrite( No. 39) . 4. Table 3 show s some relations betw een INAA results and susceptibility of pyrite. Mn is closely proportional to susceptibility of pyrite. Mg，Co，Ca etc. in coal-pyrite have a relation w ith susceptibility，w hile ore-pyrites，w hich are rich in As，have low magnetic property. ∑2 ( Mn， Co，Ni，Cr) elements，∑3 elements have a relation w ith susceptibility of pyrites.

Apparently，the susceptibility of coal pyrites are all higher than that of ore pyrites. So High Gradient Magnet selection ( HGMS ) technology can remove coal pyrite better than ore py- rite. The magnet analyses of coals indicate that susceptibilities of bituminous coal are all negative valuew hile anthracitous coals are all positive value w hich are approximate to those of coal py- rites. therefore HGMS is more suitable for the desulfurization of coking coals. We are continuing to undertake study on those fields. Here is only the brief conclusion.

CONCLUSIONS

The follow ing conclusions can be draw n from the above analysis:

1. The sulfur content in limnic coal is very poor w hich is the main property of framboidal pyrite. The marine-continent transitional facies coal is rich in sulfur，w hich is mainly in the form of inorganic sulfur. The nodular and cell-infilling pyrite are main types of pyrite and pyrite particles are large. The marine facies coal has high sulfur content，w hich is rich in high organic sulfur. Monocrystal，framboid pyrite and marcasite particles are small. Nodular pyrite often contains more marcasite，pyritized organisms and relics.

Table3 PartINAA Element Results and Susceptibility of Pyrites

Note: 1. INAA unit is ppm. Susceptibility unit is 10-7 eum /g.2.∑i = Cu +As +Se +Sb +Zn∑2 = Co + Ni+ Cr+Mn∑3 = Na + Al+Ca +Mg∑ REE = La +Ce +Nd +Sm +Eu +Tb +Yb +Lu.3. - is that element hasn't been determined by INAA.

2. Liberation analyses show that the pyrite in transitional facies coal contains more librated particles，w hile marine coal has less amount of liberated pyrite. Nantong coal contains more nodular pyrites，in w hich pyrite particles is larger and liberated. It is predicted that they possess good behavior for physical desulfurization. But Wuyi coal contains more fine crystal，framboid and pyrites are not liberated. Moreover it has very high organic sulfur，so its desulfurization behavior must be very poor.

3. By STM ，w e clearly obtain atomic image on { 210} surface of pyrite，this is another new result follow ing the studies by Eggleston and Fan for{ 100} and{ 110} of pyrite crystal sur- face respectively. Moreover，w e have observed several pyrite structures such as granular，ban- dary，milk colloid-like pyrite，as w ell as corrosoion pit and oxidational film. STM ，SEM directly prove that colloid pyrite exists in coal. STM is a very potential technique for the study of pyrite.

4. The composition analyses show : As the pyrite crystallinity become better，Fe，S and S / Fe in coal pyrite increase，the associated elements decrease. There are Si，Al，Ca，Mg，Ti，Zr，Nb etc. in coal pyrite. The pyrite w ith high S / Fe ratio grow s in desmocollinite w hich S / Fe atomic ratio is 6 － 17. The S / Fe ratio of pyrite is proportional to the organic sulfur in desmocollinite.

5. The susceptibility of coal pyrites are much higher than that of ore pyrites. The suscepti- bility of coal pyrite has a relation w ith Mn，Co，Mg，Ca etc. elements. Bituminous coals have negative value of susceptibility，anthracite coals positive. HGMS is more suitable for the desulfu- rization of bituminous coals.

ACKNOWLEDGEMENTS

The authors express thanks to Institute of High Energy Physics of Academia Sinica，the University of Science and Technoloy of Beijing，Mr. Libing Liao，China University of Geosci- ence for their help w ith the use of facilities. We also w ish to acknow ledge financial support from National Natural Science Foundation of China and Genaral National Coal Cooperation of China.

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( 本文由唐跃刚、任德贻合著，原载 Processing and Utilization of High-sulfur Coals Ⅴ，( Coal Science and Technology 21) ，1993 年)

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