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Sulfur of most iron ores, harmful to smelting , hinders in fluidity of slag in Blast furnace, damages furnace walls, pollutes air as So2, gas, and brings about hot shortness. So sulfur contents must be limited to 0.05 per cent im pig iron, and 0.02 per cent in steel making. I here think that sulfnr contents of iron must beremoved in the process of dresing.
The blind zone problem in three-layered sections in which the velocities of the individual layers increase with depth of their layers are solved based on the time-term equations. Blind zones are spaces which exist at every recorded refractor. In the blind zones, the traval times cannot be recorded as first arrivals. Therefore, if a blind zone is not taken into consideration, large errors in calculated refraction depths may occur. The results of the blind zone solution are as follows : 1. A blind zone may be evaluated by defining an intercept time for a blind zone velocity. 2. Blind zone depth may be evaluated by using standard time-term equations for layer thickness and depths.
The plenty of Pb and, Zn ores are produced in our country. Pure minerals, however, are rarely produced because most of them deposit in complicated state of coexistence of sulphides galena and zincblende. In view of this state, it is dificult for them to be fleated. Therefore, activation of galena with copper ions and floatability of the copper-activated galena in the presence of sulfide have been investigated by means of adsorption measurements and floatation tests, in order to elucidate the floatation behaivor of galena in block ore. The results obtained areas follows: (1) Activation of galena with copper ions proceeds according to the following exchange reaction, PbS+Cu^(2+) = CuS+Pb^(2+) which is controlled by the parabolic rate law. (2) Copper activation leads to an increase of the galena floatability, which may be caused not by an increase of uptake of collector, but by an increase of the nactive floatability of galena. (3) In galena-sphalerite mixture suspension, copper ion is abstracted by galena in preference to sphalerite, but the floatability of sphalerite remakably increases with copper activation and galena can not be separated by depressing sphalerite with sodium bisulfite. (4) In this case, galena can be floated from sphalerite by depressing the latter with sodium bisulfite together with zinc sulfate after a suitable extent of copper activation.
I manufactured WO3 from sheelite for Super-Hardness Alloy by the combination of Acid-decompsition method and Paratungstenammonia method. Here Acid-decomposition method is for industrial mass production, and Paratung-sten ammonia method, for high purity and pulverized powder.
This study was investigated to increase low grade anthracite which is produced in Hwasoon district into higher grade by economical methods. The results of the study are as follows; 1. This low grade anthracites were mixed with clay and low hardness shale. 2. We found that the calorie was increased by wet type (709kcal/kg) more than dry type (604kcal/kg) in gravity concentration, but its recovery rate lowered. 3. The degree of separation and recovery rate was the best -50+80 mesh and the lowest in -200mesh. 4. As the results of this study, we concluded that the low grade anthracite in this area was increased to about 804kcal/kg by this method alone, and dry type was more profitable than the wet type.
This research aims to develop lower-grade iron ores by the improvement of dressing technique and recovering by-products of iron ores. Today our country is using more iron. But on the contrary most of all iron deposits and iron ores are so poor that we are urgent to improve dressing technique and facilities. From these viewpoints, I studied on the improvement of dressing technique and dressing facilies for the rise in grade of poor iron ores. And I investigated the method getting rid of the harmful elements in the process of smelting.
Molybdenum di n-butoxy dithio phosphate as soluble lubricating oil additive for reducing wear and friction was investigate. The boundary lubricating effects of oil solutions of molybdenum di n-butoxy dithio phosphate, zinc di n-butyl dithio phosphate, and MoS(??) suspension compared through Timken and Four-Ball tests. As the results, the extreme pressure and antiwear properties of the solution of molybdenum di n-butoxy dithio phosphate was superior than the others. Also, the antioxidation and anti-corrosion effects for copper strip of oil added molybedenum di n-butoxy dithio phosphate was excellent especially.
This study investigates the geological distribution of limestone formations in the Jangsung area, of Chunnam, and compares them with other rocks and calculates the reserves through drilling and chemical analysis of samples. The geographical coordinates of the surveyed area are 126˚45'-126˚52' longitude by 35˚15'-35˚22' latitude. Fieldwork was conducted for proposed claim Nos. 89, 101, 111, 113, 123, 124,134, 135, and 144, in Damyang quadrangle. The rocks of the area are meta sediments known as a crystalline schist system, including muscovite schist, metaquartzite and sericite schist which were intruded by granite gneiss of an unkown period and by dykes of the Cretacious Period. The strikes of the crystalline schist svstem are mainly in the direction of N30E tO N80E and dip north wesltwardly. The sampling was carried across the strike of limestone and ten survey-lines was selected. Two hundred samples were analyzed and the average grades were as follows: CaO 43.34%, MgO3.81%, SiO_(2) 12.52%, R_(2)O_(3) 2.02%, Ig loss 38.37%. Seventeen drill sites which had been drilled by the Koryo Cement Company were chosen across the strike of limestone, and the average grades of limestene and dolomite were as follows: SiO_(2) 14.17%, R_(2)O_(3) 2.27%, CaO 40.27%, MgO 5.63%, Ig loss 37.60%. The probable reserves were calculated on the basis of mined areas and drill sites. The total probable reserves is 5,558,856 □.
용해성 윤활유 첨가제로서 molybdenum di-n-butoxydithiophosphate(MoDTP)의 마모 및 마찰감소에 대하여 시험하였다. Molybdenum di-n-butoxydithiophosphate(MoDTP), zinc di-n-butoxydithiophosphate(ZnDTP), 그리고 MoS_2의 현탁용액의 경계윤활 특성 효과를 Timken과 Four-Ball 시험을 통하여 비교한 결과, molybdenum di-n-butoxydithiophosphate 용액의 극압 및 내마모 성질이 다른 것 들보다 우수하였다. 또한 MoDTP가 첨가된 윤활유의 동판부식에 대한 산화안정성과 부식방지성 효과가 특히 양호하였다. Molybdenum di-n-butoxydithiophosphate was investigated as a soluble oil additive for reducing wear and friction. The boundary lubricating effects of oil solutions of molybdenum di-n-butoxydithiophosphate(MoDTP), zinc di-n-butoxydithiophosphate(ZnDTP), and MoS_2 supension were compared through Timken and Four-Ball testes. The results showed that extreme pressure and antiwear properties of the solution of molybdenum di-n-butoxydithiophosphate were superior to those of other additives. Also, the antioxidation and anticorrosion properties for copper strip in oil with added molybdenum di-n-butoxydithiophosphate were found to be especially excellent.