低热值煤气加臭技术

针对低热值煤气中ＣＯ含量高、使用危险性大的情况，叙述了加臭的必要性以及加臭剂的选择和用量及加臭工艺。     

燃气加臭技术介绍

阐述燃气加臭工作在燃气应用中的重要性,介绍燃气加臭的标准,常用加臭剂,自流式,旁通式,喷射泵法的闭合式等几种典型的燃气加臭工艺,分析了各种工艺的技术特点和应用前景。     

有毒燃气加臭浅析

1　燃气加臭问题的概述我国城市燃气 ,除了采用天然气、矿井气、石油伴生气、液化石油气等气源外 ,把一氧化碳含量较高的煤制气 (有毒煤气 )作为城市气源也有很大的发展。煤制气中一氧化碳含量较多 ,生产供应中发生事故和中毒的危险性也就越大 ,为了解决一氧化碳含量较高的城市煤气使用安全问题 ,最根本的办法是将煤气中的一氧化碳脱除 ( 3%以下 )。对煤气进行加臭是国外已成熟的安全技术措施之一 ,是目前可行的过渡办法。2　加臭剂与加臭的具体办法2 1　加臭剂要求加臭剂本身及其燃烧产物对人体无毒害 ,能够完全燃烧 ,燃烧后不生成有害或…     

低热值煤气加臭技术

低热值煤气CO含量高,使用危险性大,加臭是一种确保用气安全的有效措施、该文对加臭剂的选择;加臭量的确定;以及加臭工艺作了介绍。     

城镇燃气加臭技术

随着“西气东输”的发展,中国越来越多的城市开始使用天然气,城镇燃气行业得到了迅速发展。对城镇燃气的加臭标准、加臭剂的种类等进行了综述。     

城镇燃气加臭技术及其发展应用

城镇燃气加臭通常情况是为了能够对人们进行警示,使得用户在燃气使用的时候,能够具有更高的安全性,使得用户的用气更加合理,这就需要对城镇燃气加臭剂发展历程和合理的加臭点以及加臭频率等方面加以研究和分析,并且不断对加臭技术加以优化处理。     

液化天然气的加臭运用

本文通过对液化天然气加臭重要性的揭示,提出选择臭味剂的原则要求及其品种和剂量,并据此设计出燃气加臭设施及工艺;最后建议应尽快制定出燃气加臭质量的国家标准,以进一步提高其安全可靠性。     

天然气加臭剂在居民生活用气中的用途及重要性

四氢噻吩是国际上发达国家广泛使用的燃气味添加剂,俗称"加臭剂"。英文名称:Tetrahydrothiophene,英文缩写:THT,无色透明油状液体,是一种含硫饱和杂环化合物,不易被空气氧化,化学性质稳定。挥发性较低,但总能产生稳定的、不易散发的臭味(空气中存在0.01ppm既能闻到),它对燃气设备、运输管道垫片等材质没有腐蚀性,对人体嗅觉不会产生习惯性钝化,也不引起咳嗽、头痛、催泪等刺激反应。因此,可作为城市燃料气,如天然气、液化石油气和以氢、一氧化碳为主要成份的燃气等燃料气体的臭味剂。     

缓释氧剂的制备及其在黑臭水体治理方面的应用研究

采用聚乙烯醇(PVA)为包埋剂,制备了以火山渣为填充剂、过氧化钙(CaO_2)为氧源的缓释氧剂,旨在为黑臭水体治理提供一种高效可行的方式。通过清水实验和黑臭水体实验,研究了缓释氧剂的释氧性能及其在污染物去除方面的作用。结果表明,相较粉末状过氧化钙,缓释氧剂的释氧得到有效控制,且对pH的影响相对减弱。在2 L的黑臭水体中投加6.08 g缓释氧剂后,DO峰值达5.16 mg/L,且19 d内仍维持在2 mg/L以上,COD由145.99 mg/L降至28.6 mg/L,总磷去除率达95%以上。表明缓释氧剂能显著改善黑臭水体上覆水的溶氧状态,且对COD和总磷的去除有积极的促进作用。     

过氧化钙在城镇黑臭水体修复中的作用

我国城镇水体污染严重,本文根据城镇黑臭水体污染与生态修复治理技术现状,分析得出水体缺氧是导致城镇水体黑臭污染的主要原因以及复氧措施在治理黑臭水体时的重要性,介绍了水体原位复氧具有对水体扰动小、修复效果明显和不产生二次污染等优点,但常规复氧措施存在工程规模大、设备运行昂贵和后期仪器维护贵等问题。结合CaO₂在黑臭水体原位治理过程的高效释氧、强化微生物活性及释放羟基自由基等特性,简述了CaO₂对黑臭水体中有机物、重金属、氮磷营养元素及硫化物等污染物的去除机理与修复效果;通过归纳CaO₂在黑臭水体修复过程中的不足,建议在CaO₂对污染物的降解机理和缓释型CaO₂复合释氧剂等方面应加强研究;指出缓释型CaO₂复合释氧剂在城镇黑臭水体生态修复治理中具有重要实际意义。     

四氢噻吩的生产技术与市场分析

四氢噻吩是城市燃气的首选加臭剂,随着我国西气东输等工程的建设成功,其市场前景广阔.文章介绍了四氢噻吩的生产工艺和市场情况,并对四氢噻吩的发展提出了良好建议.     

Odorant binding protein homologues of the malaria mosquito Anopheles gambiae; possible orthologues of the OS-E and OS-F OBPs OF Drosophila melanogaster

Twenty-nine Anopheles gambiae candidate Odorant Binding Proteins (OBPs) were characterized for similarity to OBPs of Drosophila melanogaster and other insects. Twenty-five of these sequences were identified by BLAST searching the A. gambiae genome database. Several A. gambiae sequences were significantly similar to the D. melanogaster OBPs OS-E/OS-F, LUSH and PBPRP2/PBPRP5. Exon boundary comparisons suggests that two A. gambiae genes are orthologues of OS-E and OS-F, justifying the names AgamOS-E (EAA01090, AF437886) and AgamOS-F (EAA14641, AF437884). If these are orthologues, then the gene duplication establishing the OS-E and OS-F lineages predated the divergence of mosquitoes and flies. The identification of orthologous OBPs and other chemosensory genes between D. melanogaster and A. gambiae should accelerate the transfer of physiological and behavioral information between these two species.     

Knockdown of <Emphasis Type="Italic">Microplitis mediator</Emphasis> Odorant Receptor Involved in the Sensitive Detection of Two Chemicals

Odorant receptors are thought to play critical roles in the perception of chemosensory stimuli by insects. The primary method to address the functions of odorant receptors in insects is to use in vitro binding assays between the receptors and potential chemical stimuli. We injected MmedOrco dsRNA into the abdominal cavity of a braconid wasp, Microplitis mediator, and assayed for expression of this gene 72 h after treatment (RNAi). Quantitative real-time PCR demonstrated that the level of mRNA expression in MmedOrco dsRNA-treated M. mediator was significantly reduced (>90%) when compared with water-treated controls. Furthermore, electroantennogram (EAG) responses of M. mediator to two chemical attractants, nonanal and farnesene, were also reduced significantly (~70%) in RNAi-treated M. mediator when compared to controls. RNAi-treated M. mediator also responded by walking/flying at a lower rate to both chemicals when compared with controls in a Y-tube olfactometer bioassay, which provides direct evidence that MmedOrco plays an important role in perception of nonanal and farnesene in M. mediator.     

Odorant Binding Characteristics of Three Recombinant Odorant Binding Proteins in Microplitis mediator (Hymenoptera: Braconidae)

Odorant binding proteins (OBPs) are believed to be important for transporting semiochemicals through the aqueous sensillar lymph to the olfactory receptor cells within the insect antennal sensilla. In this study, three new putative OBP genes, MmedOBP8-10, were identified from a Microplitis mediator (Hymenoptera: Braconidae) antennal cDNA library. Quantitative real-time PCR (qRT-PCR) analysis revealed that all three of the OBP genes were expressed mainly in the antennae of adult wasps. The three OBPs were recombinantly expressed in Escherichia coli and purified by Ni ion affinity chromatography. Fluorescence competitive binding assays were performed using N-phenyl-naphthylamine as a fluorescent probe and 45 small organic compounds as competitors. These assays demonstrated that the three M. mediator OBPs can bind a broad range of odorant molecules with different binding affinities. They can bind the following ligands: nonane, farnesol, nerolidol, nonanal, β-ionone, acetic ether, and farnesene. In a Y-tube assay with these ligands as odor stimuli and paraffin oil as a control, all ligands, except nerolidol and acetic ether, were able to elicit behavioral responses in adult M. mediator. The wasps were significantly attracted to β-ionone, nonanal, and farnesene and repelled by nonane and farnesol. The results of this work provide insight into the chemosensory functions of the OBPs in M. mediator.     

Age and Mating Status Do Not Affect Transcript Levels of Odorant Receptor Genes in Male Antennae of Heliothis virescens and Heliothis subflexa

In biological systems, it is expected that gene expression levels generally will correlate with temporally varying physiological and biological needs, and that gene expression levels could regulate biological capabilities. In moth species, male response to female sex pheromones often is affected by moth age and mating status. Odorant receptors (ORs) expressed in neurons within male antennae are critical for detecting the female pheromones. Therefore, we hypothesized that the expression level of these receptor proteins would be affected by age and mating status of male moths. We examined expression levels of two OR genes that are preferentially expressed in the male antennae of Heliothis virescens (HvOR13 and HvOR15) and Heliothis subflexa (HsOR13 and HsOR15). Antennae were dissected from virgin males at 2 h, 1 d, 2 d, 4 d, and 8 d. We also dissected antennae from 4-d-old mated males. We found that age had no effect on expression levels of either OR in either species, except for a small difference in HsOR15 expression between 2 h and 8-d-old virgin males. Furthermore, we found no effect of mating status on expression level of these ORs in either species. We discuss these findings in relationship to studies of age and mating status effects on male electrophysiological and behavioral response to female pheromones, and contrast our results to studies on the effects of age and mating status on gene expression of pheromone receptor proteins and pheromone binding proteins in other moths.     

Molecular Characterization,Expression Pattern,and Ligand-Binding Property of Three Odorant Binding Protein Genes from Dendrolimus tabulaeformis

Odorant binding proteins (OBPs) play important roles in insect olfactory processes. The Chinese pine caterpillar moth, Dendrolimus tabulaeformis (Lepidoptera, Lasiocampidae) is a serious economic pest in China, and the pheromones of this species have been identified to monitor their presence. However, the molecular mechanisms by which D. tabulaeformis perceive pheromones and host volatiles remain unknown. In this study, we identified and characterized three new OBPs, including one pheromone binding protein (PBP1) and two general odor binding proteins (GOBPs), from antennal cDNA of D. tabulaeformis. The deduced amino acid sequences of DtabPBP1, DtabGOBP1, and DtabGOBP2 revealed mature proteins of 140, 147, and 140 amino acids, respectively. Each has six cysteine residues in conserved positions relative to other known OBPs. Amino-acid alignments indicated that the two GOBPs are more conserved (DtabGOBP1 is 52.9–67.4 % identical to orthologs from other Lepidoptera, and DtabGOBP2 is 55.2–81.8 % identical) than the PBP (32.5–46.0 %). Real-time PCR indicated tissue- and sex-specific expression patterns of the three genes. DtabPBP1 was mainly expressed in the antennae of males, whereas female antennae had only 1.09 % the expression in male antennae. Both DtabGOBP1 and DtabGOBP2 were more highly expressed in antennae than in other tissues, while DtabGOBP1 was more abundant in male antennae and DtabGOBP2 in female antennae. In addition, the binding specificities of the three proteins were investigated, and all three OBPs exhibited high binding affinities for the pheromone component (5Z,7E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr). This suggests a role in binding pheromone for GOBPs, as well as PBP1, in D. tabulaeformis.     

金属助剂对邻二甲苯氧化制苯酐催化剂影响的研究进展

介绍了邻二甲苯氧化制苯酐的反应机理及其催化剂的制备、评价与分析方法,重点就金属助剂对催化剂影响的研究进展进行了分析。结果表明,添加金属助剂可改变V-Ti系催化剂的活性、稳定性和对苯酐的选择性,其中Rb、K、Sb的引入可减少邻二甲苯的深度氧化,提高催化剂对苯酐的选择性;Nb、Sn、W和Cs的引入会改变催化剂表面的酸性位点和浓度,对催化剂的活性和选择性造成不同影响;Zr的引入提高了催化剂的热稳定性和选择性;稀土元素La、Pr、Sm、Nd的引入可提高苯酐的收率和选择性。     

官能化乙丙橡胶的制备和表征

用２,５－二甲基－２,５－二叔丁基过氧基己烷为引发剂,甲基丙烯酸环氧丙酯（ＧＭＡ）、马来酸酐（ＭＡＨ）和丙烯酸（ＡＡ）为接枝单体,对三元乙丙橡胶（ＥＰＤＭ）和二元乙丙橡胶（ＥＰＲ）进行熔融接枝,接枝产物用ＦＴＩＲ、１３Ｃ－ＮＭＲ等进行了表征,并用化学滴定方法对接枝率进行了测定。实验结果表明,影响接枝率和凝胶质量分数的主要因素为乙丙橡胶的化学结构、引发剂和单体的用量、反应时间及温度等。接枝单体反应活性大小依次为ＧＭＡ,ＡＡ,ＭＡＨ。     

MOCVD生产废料中镓、铟提取工艺及其动力学研究

近年来，LED以其节能及环境友好等特性被广泛运用于各类照明领域。作为LED产品关键部件，采用金属有机气相沉积(MOCVD)生产外延片过程产生大量的生产废料。随着LED行业的快速发展，绿色、清洁回收MOCVD生产废料备受关注。本研究以硫酸为浸出剂，重点研究了MOCVD生产废料中Ga和In元素的浸出行为和浸出动力学。通过对浸出试剂种类、H2SO4浓度、固液比、浸出温度和浸出时间等参数的过程优化，在H2SO4浓度3 mol/L、固液比50 g/L、温度80℃、反应2 h的最佳工艺条件下，Ga和In的浸出率仅为67.50%和91.46%。动力学研究表明，在293.15~333.15 K温度范围内，Ga和In的浸出动力学符合收缩核模型，浸出过程受表面化学反应和外扩散混合控制。同时，XRD和SEM-EDS结果也印证了符合收缩核模型。在293.15~333.15 K温度范围内，Ga和In的浸出活化能分别为25.7和21.7 kJ/mol。基于对Ga和In浸出行为的动力学分析，提出并验证了MOCVD生产废料强化焙烧-浸出工艺的可行性。研究结果表明，强化焙烧-酸浸工艺可以使Ga和In的浸出率分别由67.50%和91.46%提升至88.27%和98.32%，并得到了氧化镓副产品。本研究结果有望为MOCVD生产废料的工业化资源循环提供基础数据支撑和新路径选择。     

氧化锌烟尘碳基还原同步回收铅锡

采用碳基还原实现氧化锌烟尘中铅锡与锌的同步分离回收,考察了预处理脱氟氯硫(Na2CO3碱洗、煅烧)和配加添加剂(CaO、膨润土)对碳基还原过程铅锡挥发率的影响。结果表明,当烟尘未经预处理,实验条件为温度1300℃、焦粉用量14.04%和保温时间120min时,铅锡挥发率分别为78.58%和95.97%。同一实验条件下,相比于无预处理,碱洗和煅烧均能使铅锡挥发率降低。烟尘经碱洗后,铅锡挥发率分别降至12.97%、16.99%;煅烧使铅锡挥发率分别降至30.46%、57.83%。CaO用量增加有利于降低铅锡挥发率,当CaO用量为5%时,铅锡挥发率分别降至32.16%、57.7%;膨润土用量增加促进铅挥发率的降低,对锡挥发率无明显影响,当膨润土用量为5%时,铅锡挥发率分别降至37.44%、83.25%。采用该工艺,最终同时获得铅锡合金(Pb＞70%,Sn＞5%)和粗锌(Zn＞63%,Pb＞9%)。