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101.
This paper discusses the current state and future prospects of backward production linkages to the manufacturing sector in the Angolan oil and gas industry. The paper finds that local value-added links are currently limited to labour and to a lesser degree in basic services. However, there is a realistic and strategic potential for local manufacturing linkages to expand in the oilfield services sector of the industry, which in turn can stimulate industrial development. For this to be achieved, the factors that are currently constraining the expansion and deepening of linkages have to be addressed, namely, a weak local content strategy, a weak local skills and industrial base and the integration of industrial and oil sector policies. 相似文献
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103.
以Bi(NO3)3·5H2O、KI和g-C3N4为前驱体,采用常温沉淀法制备Bi5O7I/g-C3N4Z型异质结复合光催化剂,表征其光吸收性能、微观形貌、光生电子-空穴的分离效率等特性,研究新型光催化剂对RhB的可见光催化降解性能,探讨其可见光催化过程活性基团种类以及作用机理.结果表明:利用沉淀法合成Bi5O7I/g-C3N4的条件为:Bi(NO3)3·5H2O、KI和g-C3N4的投加量分别为4.85g、1.66g和1.61g,乙二醇的用量为50mL,反应液的pH值为12,反应搅拌速度为200r/min,反应温度为25℃.Bi5O7I/g-C3N4异质结无杂相生成且纯度高,异质结复合发生在g-C3N4的(002)晶面和Bi5O7I的(203)晶面,但g-C3N4和Bi5O7I的化学结构未受影响.Bi5O7I/g-C3N4呈三维纳米花瓣形貌结构,为光生电子-空穴的迁移提供了大量的接触位点.Bi5O7I的g-C3N4掺杂改性使其光催化活性显著增强,其光吸收边缘由425nm红移至462nm,Bi5O7I/g-C3N4的能带排列结构与Z型异质结匹配,促进了光生电子-空穴的分离.其光电流密度(11.5mA/cm)约为g-C3N4和Bi5O7I对应值的2.66倍和1.47倍.Bi5O7I/g-C3N4对罗丹明B的可见光催化降解率为93.9%,显著高于g-C3N4(58%)和Bi5O7I(49.7%)的降解效果,其光催化氧化活性主要来自羟基基团、超氧基团和光生空穴等中间态自由基. 相似文献
104.
以γ-Al_2O_3作为载体,采用浸渍热分解法制备了Sn、Mn、Cu、Pb单组分氧化物和Sn-Ce-Sb复合氧化物粒子电极。通过对酸性橙II(AOII)的降解实验,以及采用重复试验和扫描电镜(SEM)、紫外光谱扫描等方法,探讨了粒子电极材料的性能。研究结果表明:Sn/γ-Al_2O_3相比于Mn/γ-Al_2O_3、Cu/γ-Al_2O_3、Pb/γ-Al_2O_3等单组分氧化物粒子电极表现出了更好的电催化活性和稳定性。掺杂Ce、Sb后电极表面晶体粒径细小且分布均匀,有利于提高Sn/γ-Al_2O_3粒子电极的性能。电流密度为20 m A/cm2,曝气量0.5 L/min反应条件下,反应3 h后Sn-Ce-Sb/γ-Al_2O_3粒子电极对AOII的去除率为100%,TOC的去除率达84.2%,重复使用5次后TOC去除率仍保持在80%以上。表明Sn-Ce-Sb/γ-Al_2O_3粒子电极具有较好的应用前景。 相似文献
105.
通过在镀液中添加表面活性剂AEO-7,以不锈钢为基体,利用阳极氧化法制备了改性PbO2电极.同时,在结晶紫模拟废水中对比了改性前后PbO2电极的阳极极化曲线和塔菲尔曲线,并对质量浓度为10 mg·L-1的结晶紫模拟废水进行了电催化降解实验.实验结果表明,制备的改性PbO2电极对结晶紫废水的降解显示出了较好的电催化活性,最佳电解实验条件为:电解电流密度30 mA·cm-2,支持电解质Na2SO4浓度5g·L-1,处理温度35℃,在此条件下电解40 min后,结晶紫的去除率可达到90%以上. 相似文献
106.
The terms of trade debate initiated by Raul Prebisch and Hans Singer over 60 years ago continues to this day and is unlikely to be resolved soon. However, even if Prebisch and Singer are right and the terms of trade of countries exporting primary products are falling, to suggest that these countries should diversify away from the production of mineral commodities and other primary products, as many have done, may be poor policy advice, encouraging countries to abandon a promising source of wealth with which to foster economic development. 相似文献
107.
C. Le Caignec N. Winer M. Boceno C. Delnatte G. Podevin J. M. Liet M. P. Quere M. Joubert J. M. Rival 《黑龙江环境通报》2003,23(12):981-984
We report the prenatal diagnosis of a fetus with sacrococcygeal teratoma and facial dysmorphism attributed to a constitutional terminal deletion of chromosome 7q and partial trisomy of chromosome 2p likely resulting from a de novo balanced translocation. The cytogenetic abnormality was diagnosed prenatally after sonographic detection of teratoma and confirmed on peripheral blood cells at birth. The newborn died of post-operative complications at seven days of age. FISH analysis demonstrated haploinsufficiency of HLXB9, a gene identified in the triad of a presacral mass (teratoma or anterior meningocele), sacral agenesis, and anorectal malformation, which constitutes the Currarino syndrome. Despite the absence of other features of the triad, the teratoma observed in the fetus we describe might represent a partial form of Currarino syndrome. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
108.
109.
Ashutosh Bahugun Madhuri K. Lily Ashok Munjal Ravindra N. Singh Koushalya Dangwal 《环境科学学报(英文版)》2011,23(6):975-982
A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene (DBT) was isolated from diesel contaminated
soil. The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7 (NCBI GenBank Accession No. GQ496620)
using 16S rDNA gene sequence analysis. The desulfurized product of DBT, 2-hydroxybiphenyl (2HBP), was identified and
confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively.
The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr, exponentially
increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT. However, further growth
resulted into DBT degradation. The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase
within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization
pathway of DMT-7. In addition, Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole
source of sulfur such as benzothiophene, 3,4-benzo DBT, 4,6-dimethyl DBT, and 4,6-dibutyl DBT. Therefore, Lysinibacillus sphaericus
DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol. 相似文献
110.
采用Fe(NO)3.39H2O和FeSO.47H2O混凝剂处理模拟大红染料废水,通过改变各药剂投加量及废水pH值,考察其对废水COD和色度的去除效果。实验结果表明:两种混凝剂在处理大红染料废水中都表现出了较好的脱色性能,而Fe(NO3)3.9H2O的去除性能较FeSO.47H2O更为优越。Fe(NO)3.39H2O对染料废水的脱色作用十分显著,所有的脱色率都在86%以上。当投加量为0.18 g时,脱色率达最大值93.3%;当投加量为0.24 g时,COD去除率为63.6%。FeSO.47H2O对废水色度的去除效果好于COD的去除。其最佳投加量为1.5 g,此时,脱色率达82.4%;当投加量为0.9 g时,COD去除率为51.8%。Fe(NO)3.39H2O在pH为5.0~9.0之间处理效果都较好,当pH=8时,其脱色率最高,为93.4%;FeSO.47H2O在pH为6.0~8.0之间最佳,当pH=8时,脱色率最高为83.2%。 相似文献