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高非线性光子晶体光纤中布拉格光栅的制作 被引量:10
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作者 桑新柱 余重秀 +2 位作者 王葵如 M.k.islam 吕乃光 《光学精密工程》 EI CAS CSCD 北大核心 2005年第6期633-636,共4页
采用相位掩模版法实验研究了高非线性掺锗光子晶体光纤中布拉格光栅的制作。实验中采用的光子晶体光纤的非线性系数约为12 W-1km-1,模场直径约为2.4 mm。分析了布拉格光栅的反射率随着曝光脉冲数的变化,随着曝光脉冲数的增加其反射率逐... 采用相位掩模版法实验研究了高非线性掺锗光子晶体光纤中布拉格光栅的制作。实验中采用的光子晶体光纤的非线性系数约为12 W-1km-1,模场直径约为2.4 mm。分析了布拉格光栅的反射率随着曝光脉冲数的变化,随着曝光脉冲数的增加其反射率逐渐达到饱和,继续增加曝光量发射率开始下降。实验验证了可以在高非线性光子晶体中写入布拉格光栅,得到光栅的反射率为44.4%,这对于研究光纤布拉格光栅的非线性效应和应用具有重要意义。讨论了影响布拉格光栅写入效率的因素。 展开更多
关键词 光子晶体光纤 布拉格光栅 非线性
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ICRF Experiments and Potential Formation on the GAMMA 10 Tandem Mirror
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作者 M.ICHIMURA T.CHO +14 位作者 H.HIGAkI M.HIRATA H.HOJO T.IMAI k.ISHII M.k.islam A.ITAkURA I.kATANUMA J.kOHAGURA Y.NAkASHIMA T.NUMAkURA T.SAITO Y.TATEMATSU M.WATANABE M.YOSHIkAWA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第1期87-90,共4页
Target plasmas, on which the formation of the electrostatic potentials and the improvement of the confinement are studied, are produced with ICRF in the GAMMA 10 tandem mirror. The ion temperature of more than 10 keV ... Target plasmas, on which the formation of the electrostatic potentials and the improvement of the confinement are studied, are produced with ICRF in the GAMMA 10 tandem mirror. The ion temperature of more than 10 keV has been achieved in relatively low density plasmas. When the strong ICRF heating is applied, it is observed that the high frequency and the low frequency fluctuations are excited and suppress the increase of the plasma parameters. Recently, a new high power gyrotron system has been constructed and the ECRH power in plug extends up to 370 kW. The improvement of the confinement due to the formation of the potential in the axial direction and the strong radial electric field shear has been observed. 展开更多
关键词 tandem mirror ICRF plasma production FLUCTUATIONS potential formation
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孟加拉国温室气体排放量清查:初步结果
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作者 Ahsan Uddin Ahmed k.islam +1 位作者 M.Reazuddin 王其冬 《人类环境杂志》 1996年第4期299-303,共5页
本文给出1990年孟加拉国温室气体源和汇的清查结果。因为二氧化碳(CO_2)被认为是导致全球气候变化的主要原因,而能源的使用是CO_2最大的排放源,所以本文着重分析孟加拉国的能源系统。同时分析了森林的碳排放和碳吸收。由农业、牲畜和城... 本文给出1990年孟加拉国温室气体源和汇的清查结果。因为二氧化碳(CO_2)被认为是导致全球气候变化的主要原因,而能源的使用是CO_2最大的排放源,所以本文着重分析孟加拉国的能源系统。同时分析了森林的碳排放和碳吸收。由农业、牲畜和城市垃圾填埋地的垃圾释放的甲烷(CH_4)也包括在内。在1990年,使用化石燃料排放的CO_2有15.5Tg。森林导致的碳排放也进行了计算。在1990年,大约5.46Tg C被发现是从采伐或消耗森林资源而排放的。另一方面,森林吸收了大约12.32Tg C。根据这些数据(不包括竹子),在1990年,孟加拉国森林起着净碳汇的作用,容量为6.86Tg碳。1990年水稻种植导致的CH_4排放在257~622Gg之间,中间值为439Gg。牲畜排放的CH_4大约为453Gg。大约5.92Gg的CH_4排放是来自天然气的泄漏、井口燃烧和输配过程。孟加拉国主要城市地区的垃圾填埋地排放的CH_4大约为74Gg。 展开更多
关键词 孟加拉国 温室效应气体 气体排放量
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Charge-Transfer and SERS Coupling on TiO2
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作者 Syed k. islam Antonio Ponte 《American Journal of Analytical Chemistry》 2023年第11期519-530,共12页
We report the SERS enhancements of Raman forbidden surface modes of TiO<sub>2</sub> in different sized TiO<sub>2</sub> crystals. This current study utilizes the relationship between the vibroni... We report the SERS enhancements of Raman forbidden surface modes of TiO<sub>2</sub> in different sized TiO<sub>2</sub> crystals. This current study utilizes the relationship between the vibronic coupling and the degree of charge-transfer to explain the differences of Surface Enhanced Raman Scattering (SERS) enhancements. Our study shows a direct correlation between the degree of charge-transfer and vibronic coupling. This relationship suggests that charge-transfer between the N-719 dye and TiO<sub>2</sub> due to vibronic coupling plays a fundamental role in SERS enhancements. Furthermore, this study shows a strong dependence of the enhancements of the N-719 dye molecular modes to that of the surface modes. This indicates that the mechanism that governs the enhancements of the surface modes in TiO<sub>2</sub> crystals most likely also dictates the enhancements of the N-719 dyes. 展开更多
关键词 CHARGE-TRANSFER Vibronic Coupling Fano Profile TiO2 Sur-face Modes
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Proteomic Analysis Shows Constitutive Secretion of MIF and p53-associated Activity of COX-2-/-Lung Fibroblasts 被引量:2
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作者 Mandar Dave Abul B.M.M.k.islam +3 位作者 Roderick V.Jensen Agueda Rostagno Jorge Ghiso Ashok R.Amin 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2017年第6期339-351,共13页
The differential expression of two closelyassociated cyclooxygenase isozymes, COX-1 and COX-2, exhibited functions beyond eicosanoid metabolism. We hypothesized that COX-1 or COX-2 knockout lung fibroblasts may displa... The differential expression of two closelyassociated cyclooxygenase isozymes, COX-1 and COX-2, exhibited functions beyond eicosanoid metabolism. We hypothesized that COX-1 or COX-2 knockout lung fibroblasts may display altered protein profiles which may allow us to further differentiate the functional roles of these isozymes at the molecular level. Proteomic analysis shows constitutive production of macrophage migration inhibitory factor (MIF) in lung fibroblasts derived from COX-2 / but not wild-type (WT) or COX-1-/- mice. MIF was spontaneously released in high levels into the extracellular milieu of COX2 /- fibroblasts seemingly from the pre- formed intracellular stores, with no change in the basal gene expression of MIF. The secretion and regulation of MIF in COX-2-/- was "prostaglandin-independent." GO analysis showed that concurrent with upregulation of MIF, there is a significant surge in expression of genes related to fibroblast growth, FK506 binding proteins, and isomerase activity in COX-2 ! cells. Furthermore, COX-2-/- fibroblasts also exhibit a significant increase in transcriptional activity of various regu- lators, antagonists, and co-modulators of p53, as well as in the expression of oncogenes and related transcripts. Integrative Oncogenomics Cancer Browser (IntroGen) analysis shows downregulation of COX-2 and amplification of MIF and/or p53 activity during development of glioblastomas, ependymoma, and colon adenomas. These data indicate the functional role of the MIF-COX- p53 axis in inflammation and cancer at the genomic and proteomie levels in COX-2-ablated cells. This systematic analysis not only shows the proinflammatory state but also unveils a molecular signature of a pro-oncogenic state of COX-1 in COX-2 ablated cells. 展开更多
关键词 MIF P53 CYCLOOXYGENASES Cancer Proteomics
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Genomic,Lipidomic,and Metabolomic Analysis of Cyclooxygenase-null Cells:Eicosanoid Storm,Cross Talk,and Compensation by COX-1
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作者 Abul B.M.M.k.islam Mandar Dave +2 位作者 Sonia Amin Roderick V.Jensen Ashok R.Amin 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2016年第2期81-93,共13页
The constitutively-expressed cyclooxygenase 1(COX-1) and the inducible COX-2 are both involved in the conversion of arachidonic acid(AA) to prostaglandins(PGs).However,the functional roles of COX-1 at the cellul... The constitutively-expressed cyclooxygenase 1(COX-1) and the inducible COX-2 are both involved in the conversion of arachidonic acid(AA) to prostaglandins(PGs).However,the functional roles of COX-1 at the cellular level remain unclear.We hypothesized that by comparing differential gene expression and eicosanoid metabolism in lung fibroblasts from wild-type(WT) mice and COX-2^(-/-) or COX-1^(-/-) mice may help address the functional roles of COX-1 in inflammation and other cellular functions.Compared to WT,the number of specifically-induced transcripts were altered descendingly as follows:COX-2^(-/-) 〉 COX-1^(-/-) 〉 WT + IL-1β.COX-1^(-/-) or COX-2^(-/-) cells shared about 50%of the induced transcripts with WT cells treated with IL-1β,respectively.An interactive "anti-inflammatory,proinflammatory,and redox-activated" signature in the protein-protein interactome map was observed in COX-2^(-/-) cells.The augmented COX-1mRNA(in COX-2^(-/-) cells) was associated with the upregulation of mRNAs for glutathione S-transferase(GST),superoxide dismutase(SOD),NAD(P)H dehydrogenase quinone 1(NQO1),aryl hydrocarbon receptor(AhR),peroxiredoxin,phospholipase,prostacyclin synthase,and prostaglandin E synthase,resulting in a significant increase in the levels of PGE2,PGD2,leukotriene B4(LTB4),PGF(1α),thromboxane B2(TXB2),and PGF(2α).The COX-1 plays a dominant role in shifting AA toward the LTB4 pathway and anti-inflammatory activities.Compared to WT,the upregulated COX-1 mRNA in COX-2^(-/-) cells generated an "eicosanoid storm".The genomic characteristics of COX-2^(-/-) is similar to that of proinflammatory cells as observed in IL-1β induced WT cells.COX-1^(-/-) and COX-2^(-/-) cells exhibited compensation of various eicosanoids at the genomic and metabolic levels. 展开更多
关键词 PROSTAGLANDINS Metabolomics Lung fibroblasts Genomies Inflammation
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Pre-sowing treatments for improved germination and growth of two rare native species of Bangladesh
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作者 M.A.Hossain k.S.islam +2 位作者 N.Rajasree M.k.Hossain M.S.Alam 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第5期1277-1282,共6页
Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.... Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.Br.The hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid(H_2SO_4).Results indicate that G.pinnata showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail clipper.Rubbing with sand paper was the best pre-sowing treatment for V.glabrata,resulting a 80% germination rate and 30% germination energy.G.pinnata and V.glabrata seedlings from seeds soaked 24h in water resulted in maximum heights and collar diameters.These were significantly higher(at p〈0.05) than those of other treatments.The results indicate that scarification or nicking of seeds may have some negative impacts on seedling growth.Therefore,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth. 展开更多
关键词 GERMINATION Early seedling growth HEIGHT Native species Garuga pinnata Vitex glabrata
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