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911.
LF炉冶炼超低硫钢的工艺条件 总被引:5,自引:1,他引:5
提出了采用热力学计算分析确定LF炉冶炼超低硫钢工艺条件的方法·分析表明,可通过提高炉渣碱度、强化渣钢脱氧、控制渣钢原始硫质量分数和渣质量,来实现超低硫钢的冶炼·150tLF炉生产实践表明,在原始钢水硫平均为00146%条件下,通过控制规定的工艺条件,经LF处理后的钢水硫质量分数平均可达00044%·再经VD处理后,可实现成品硫质量分数为00027%的超低硫钢生产·在上述条件基础上,将原始硫质量分数控制在00058%以下或保证渣金硫的分配比在250以上或采用双渣操作,LF炉可精炼0002%以下极低硫钢 相似文献
912.
在分析信息技术教育是教育发展的一个重要趋势的基础上,进一步剖析中国中小学信息技术教育发展中存在的主要问题,提出新世纪发展中国信息技术教育要更新教育观念、加大资金投入力度、有效整合现有资源、加强师资队伍建设,要改革教学方法,采用开设专门的信息技术课的教学模式实施中小信息技术教育。 相似文献
913.
PGE patterns of ores of Dajing Cu-polymetallic deposit in Linxi County,Inner Mongolia: Indicator to source of metallogenic elements 总被引:1,自引:0,他引:1
By comparing PGE patterns of sulfide ores with that of basic-ultrabasic dikes occurring in the Dajing Cu-polymetallic deposit,
we discover that there are similar positive slopes between the basic-ultrabasic dikes and the black ores composed mainly of
sphalerite and galena, reflecting affinity of their source. The PGE patterns of the yellow ores composed basically of chalcopyrite,
arsenopyrite and pyrite are actually different. One is close to the pattern of the mantle lherzolite, and others resemble
the pattern of the basic rocks. However, the concentrations of Ru are higher in the yellow ores, reflecting that sulfur attains
or approaches saturation in their parent magma. The PGE characteristics of ores and dikes show that the magmas derived from
the deep of crust and the metallogenic elements were supplied mainly by growth material of the crust. In addition, the mantle-derived
magma also offered some elements. 相似文献
914.
A novel organic disulfide, N, N′-dithiobis(3-nitroaniline)(1) was prepared by the reaction of 3-nitroaniline with sulfur monochloride
in chloroform. Compound 1 was reduced by zinc powder to give N, N′-dithiobis(1,3-phenylenediamine) (2). Poly N, N′-dithiobis
(1,3-phenylenediamine) (3) was prepared by electrochemical polymerization of compound 2 and its basic electrochemical behavior
is discussed.
Foundation item: Supported by the National Natural Science Foundation of China (29833090)
Biography: Li Zao-ying (1949-), female, Professor, research direction: synthesis and properties of organic cathode materials
of rechargeable lithium batteries. 相似文献
915.
916.
A circular DNA molecule, designated as DNAβ, was identified in tobacco plants infected with Tobacco leaf curl virus (TLCV) isolates Y5 and Y8 by PCR using primers based on the conserved region of the two reported DNAβ sequences of whitefly-transmitted
geminiviruses (WTGs). The complete nucleotide sequences of DNAβ of Y5 and Y8 (TLCV DNAβ) were determined. Y5 DNAβ comprises
1333 nucleotides encoding 8 predicted ORFs with 4 ORFs in virion-sense DNA and 4 ORFs in complementary-sense DNA; Y8 DNAβ
consists of 1338 nucleotides encoding 7 predicted ORFs with 4 ORFs in virion-sense DNA and 3 ORFs in complementary-sense DNA.
TLCV DNAβ has little sequence homology to DNA-A of TLCV., except that it shares conserved TAATATTAC loop sequence with TLCV
DNA-A. Sequence comparison showed that Y5 DNAβ shared 85% sequence homology with Y8 DNAβ, and both Y5 DNAβ and Y8 DNAβ had
relatively low sequence identity (51%–65%) with the reported DNAβ molecules associated with Ageratum yellow vein virus and Cotton leaf curl virus. The immunotrapping PCR and whitefly transmission tests showed that DNAβ molecule could be encapsidated in virus particle
and transmitted by Bemisia tabaci. This is the first report of DNAβ associated with WTGs in China. 相似文献
917.
ZJHOU Yan HU Songnian Huang Xiaowei Zhou Haijun TAN Xinyu PENG Xiaozhong QIANG Boqin Yuan Jiangang 《自然科学进展(英文版)》2002,12(6)
cDNA libraries from aborted human 3-month fetal brain,adult rat and mouse brain were constructed by using a yZAP express cDNA library construction kin.Low molecular weight fragments of the second strand cDNASA were removed by flowing through the Sepharose CL-4B column and the frractionated long,Middle,Short fragments and the combined fragments weire respectively inserted into clone vectors to construct the cDNA libraries of the brain of human 3-month fetus.The 5'ends of 1200 clones from each of human fetal brain cDNA libraries were sequenced.A total of 894 ESTs were obtained and some full-length clones were squenced.By andalyaing the se-quences,12 novel full-length cDNAs were obtained. 相似文献
918.
A mutant strain of E.coli showing strong green fluorescence is obtained during the study of cloning and expression of blue fluorescent protein gene bfp. A recombinant plasmid pHN122 has been isolated. It is demonstrated by enzyme digestion, subcloning and sequence analysis that it contains both of bfp and gfpK79R mutant genes. The results of spectrometric analysis show that GFPK79R expressed by pHN122 is the same as the wild type GFP, but its fluorescent intensity is increased 1.25~2.44-fold. 相似文献
919.
The U-Pb isotope compositions of rutile, omphacite and garnet in the eclogite from the Jinheqiao area in the Southern Dabie ultrahigh-pressure metamorphic zone were analyzed. The consistent high precision U-Pb age (218 ±(1.2) Ma of rutile in eclogite from the Dabie Mountains was obtained by two ways of isochron and common Pb correction based on the composition of omphacite. This proves that the omphacite in eclogite has a U/Pb ratio (μ = 2.8) low enough to be used for common Pb correction in the analyses of rutile. Under the rapid cooling condition (40℃/Ma) the closure temperature for U-Pb diffusion in rutile is about 470℃. Thus, this U-Pb age of rutile proves that 218 Ma should be the cooling age of eclogite at 470℃ instead of the peak metamorphic age. 相似文献
920.
Qinian Zhou 《科学通报(英文版)》2002,47(14):1170-1171
On the basis of our previous work, a configuration of H
5
+
has been presented that is a square center structure, and the energy for the structure of H
5
+
has been obtained by IACQM. The result showed that there is an extreme energy Ee: −2.45981 [2 Ry] atR = 2.50a
0. It indicates that the square center structure of H
5
+
system has the certain stability, which is a possible configuration of H
5
+
. 相似文献