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《世界有色金属》2006,(8):30-30
老挝位于东南亚地区,北临柬埔寨,南靠中国,西面是越南,东南部是缅甸,东北部是泰国,是一个国土面积仅有237,000平方公里的小国。2005年,人口总数为6,200,000。老挝是亚太地区最贫穷的国家之一,已知的矿产资源有铝土矿,黏土,煤,铜,白云石,黄金,石墨,石膏,石灰岩,石盐,蓝宝石,银,锡,及锌等。老挝2005年的国内生产总值增长率为7.3%,2004年增长率为6.3%。老挝具有得天独厚的地质环境优势,潜在的矿产有:锑,石棉,铋,钴,铁矿,瓷土,铅,褐煤,镁,钼,钾碱,硅沙,及钨等。另外,该国很可能储藏有煤,铜,黄金,铁矿,钾碱,岩盐,及锡等。据老挝工业及手工业部(M… 相似文献
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FENG Changgen ZHUO Xiaoxi LIU Xia 《中国稀土学报(英文版)》2009,27(5):717-722
A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr,Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catalysts obtained were characterized by Fourier trans-form infrared spectra, UV-vis spectra, powder X-ray diffraction, and scanning electron microscopy, indicating that the structure of K11[Ln(PW11O39)2] and polyvinyl alcohol remained intact, respectively. The photocatalysts exhibited efficient catalytic activity to degrade methyl orange, Congo Red, Ponceau 2R. The maximal degradation conversions of the three kinds of dyes were 99.58%, 47.61%, 72.42%, respectively. 相似文献
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在香港校园里,常常有这么一群特殊的人,她们每天早早地来到学校,为学生测量体温,观摩学校早会,协助管理图书,课余为学生讲故事,中午帮学生盛饭,甚至为学校编辑刊物,放学为低年级学生辅导作业……俨然是学校的正式教师,其实是学生家长,她们为学校,帮老师做了很多事情,都是义务的,没有任何报酬,在香港,通常把她们称之为“家长义工”。 相似文献
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业绩略低于预期第三季度公司实现营业收入1471394万元,同比上涨30.67%,净利润91950万元,同比下降26.9%,每股收益0.30元,前三季度实现营业收入4154476万元,同比上涨45.46%,净利润369876万元,同比增长13.76%,每股收益1.22元,业绩略低于市场的普遍预期。 相似文献
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提出了用火焰原子吸收光谱法测定金锭中Cu,Ag,Fe,Pb,Bi,Sb的方法。用乙酸乙脂萃取分离金,水相浓缩后测定6种待测元素,方法的检出限:Cu,Ag,Fe为0.021mg/L,Pb,Bi,Sb为0.24mg/L;回收率94%~106%;RSD小于10.6%。该方法快速、简便,样品用量少,测定结果与ICP AES法和国家标准方法一致。 相似文献
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T Tanaka S Ito R Higashino Y Fukuta Y Fukuda M Takei T Kurimoto H Tamaki 《Canadian Metallurgical Quarterly》1998,91(5):229-235
In an in vitro study, the use of sealers and liners (Fuji varnish, Vitrabond, Vitremer, Paama 2, All-Bond 2, or Resinomer) significantly reduced the amount of marginal leakage around amalgam (Permite C or Lojic Plus) and gallium (Galloy) alloy restorations. This reduction in marginal leakage was produced by all sealers and liners tested, and there were no statistically significant differences between these materials. Unlined restorations of Permite C had significantly less marginal leakage than Galloy or Lojic Plus. Unlined Lojic Plus restorations had the greatest amount of marginal leakage. The experimental method used in the present study proved to be suitable for quantitative comparison of marginal leakage of different dental materials. 相似文献
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BI Kettner R Aurisch JC Rückert D Sandrock DL Munz 《Canadian Metallurgical Quarterly》1998,39(12):2141-2144
Chylothorax can occur secondary to traumatic lesions of the thoracic duct caused by chest injuries, surgical procedures involving the pleural space, neoplasms or malformations of the lymphatics. METHODS: Lymphatic leakage sites were localized by scintigraphy after oral administration of the 123I-labeled long-chain fatty acid derivative iodophenyl pentadecanoic acid (IPPA). We report on three patients with different lymphatic leakage sites and on one normal control subject. RESULTS: IPPA scintigraphy localized the lymphatic leakage site correctly in all three patients. In two of them, the method even guided the successful surgical treatment of the leakage. CONCLUSION: This approach is suitable for detecting lymphatic leakages of intestinal origin. 相似文献
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Ming-Cheng Chen Yi-Lin Jan Peng-Chi Peng Chung-Yue Wang 《Canadian Metallurgical Quarterly》2007,21(6):465-471
Tendon corrosion and the leakage of water through the grouting voids are important contributors to the degradation of prestressed concrete (PC) bridges. Therefore, leakage inspections are beneficial in determining whether a tendon is corroding. This work addresses the inspection of duct leakages on PC bridges using a special multiple neutron source method. This approach is based on the principle of elastic collision between fast neutrons and hydrogen atoms during the emergence of thermalization. Multiple neutron sources should be combined with multiple detectors and an appropriately extended detection time. The probability of capturing thermal neutrons can thus be increased to inspect PC duct leakage. An equation was derived from a combination of theoretical studies and experimental outcomes as a reference for properly selecting the numbers of neutron sources and detectors as well as the detection time. The experimental results show that this approach increases the detection depth of leakage within concrete. 相似文献
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The high death rate for those patients undergoing pancreatoduodenectomy, which is a result of leakage of biliary and pancreatic anastomoses in most instances, justifies the study of this technique for rebuilding the alimentary tract. The use of two separate intestinal loops for the biliary and pancreatic anastomoses is the basis of this method. This technique reduces the morbidity and the death rates which are the result of leakage in either anastomosis because it separates biliary and pancreatic fistulas. 相似文献
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钢厂高炉煤气管道长期使用后,腐蚀严重,常常发生渗漏,且高炉煤气一氧化碳含量高,具有高毒性,必须停气及时进行处理。而实际生产中发生高炉煤气管道渗漏后,是无法进行及时停气处理的。本文简要叙述了高炉煤气管道不停气处理方法。 相似文献
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通过分析接触法制酸装置关键部位的泄漏原因及所产生的危害,结合实际堵漏案例介绍了一种新型的浓酸区域漏酸在线处理技术,认为该在线堵漏技术是硫酸装置消除跑、冒、滴、漏的有效手段,可为同行业的堵漏处理提供参考。 相似文献
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低压漏电保护在金属矿山的使用越来越普遍。分析了中性点接地和中性点不接地2种接地方式的漏电特点、区别及其漏电保护原理,提出金属矿山低压漏电保护使用中存在的问题和产生的原因,介绍了适用于金属矿山漏电保护的JD低压漏电保护系统。工程实践表明:JD低压漏电保护系统能够使变电所出线和设备终端实现分级选择性漏电保护。 相似文献
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Ashish Agrawal Swapnil C. Kor Abhik R. Choudhary Mahesh K. Agarwal Subhashis Kundu Vineet R. Tripathi 《钢铁冶炼》2016,43(10):744-751
The water cooled tuyere noses, through which hot blast is blown into the furnace, are exposed to very high temperature region of raceway inside the furnace. As a result the chances of rupture of cooling pipes within the tuyere nose are significantly high. The rupture causes water dripping into the furnace and if it continues and unnoticed for a prolonged period it lowers down the local raceway temperature and thus adversely affects the product hot metal and slag quality. Moreover, with heavy water leakage, there is a danger of explosion; monitoring of the cooling water is therefore essential. Despite the availability of water flow metre at each tuyere it is difficult to identify the leaking tuyere at the early stage unless the rupture size grows bigger and so the leakage. In several cases the furnace is forced to shut down to manually inspect the leakage occurring without prior knowledge of the exact tuyere number. Identification of water leakage at an early stage is therefore necessary to prevent process disturbances due to chilling of the furnace and avoid the unscheduled downtime for tuyere replacement. This paper presents a method to identify the water leakage from tuyere nose cooling circuit in blast furnace and the adverse effect of water leakage on the performance of the blast furnace. A system called water leak detection system is developed for different blast furnaces in Tata Steel Jamshedpur to monitor the water leakage through tuyere nose and identify the exact leaking tuyere based on a dimensionless number called leak detection factor. 相似文献