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Effect of Carbon Dioxide (CO_2) Controlled Atmosphere on Superoxide Dismutase (SOD) Activity of Three Storage Pests in Chinese Medicinal Materials 被引量:2
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作者 李灿 《Plant Diseases and Pests》 CAS 2011年第4期43-45,共3页
[ Objective ] The paper was to study the effect of controlled atmosphere stress of carbon dioxide ( CO2 ) on Superoxide dismutase (SOD) activity of in- sect, so as to analyze the biological mechanism of the action... [ Objective ] The paper was to study the effect of controlled atmosphere stress of carbon dioxide ( CO2 ) on Superoxide dismutase (SOD) activity of in- sect, so as to analyze the biological mechanism of the action of controlled atmosphere stress on insect. [ Method] Using nitrotetrazolium blue chloride (NBT) light reduction method, SOD activity of drugstore beetle ( Stegobium panlceum ), cigarette beetle ( Lasioderma serricorne) and coffee bean beetle (Araecerus fasciculatus) was studied, and the stress response of the enzyme under controlled atmosphere stress of CO2 was analyzed. [ Result ] SOD activity of drugstore beetle, cigarette beetle and coffee bean beetle exposed to controlled atmosphere stress of high concentrations of CO2 for 3 and 6 h had certain degree of increase, and the activity sig- nificantly increased from 2.011±0.954,2.664±0.218 and 1.458±0.718 to 3. 135±0. 105,3.050±0.673 and 2.975±0.229 U/(per pest · 30 min) after treat- ment for 6 h. [ Conclusion] Controlled atmosphere stress of high concentrations of CO2 had certain activation effect on SOD activity of storage pest in Chinese me- dicinal material within the context of sub-lethal events. The results could enrich the insecticidal mechanism of controlled atmosphere and theoretical system of analy- sis on insect resistance to controlled atmosphere. 展开更多
关键词 Chinese medicinal materials Storage pest Superoxide dismulase Enzyme activity co2 controlled atmosphere China
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CO_(2)气调对不同品种哈密瓜采后品质特征的影响
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作者 王宏宇 丁旭 +4 位作者 潘娜 苗泽 刘涛 李喜宏 姜瑜倩 《食品研究与开发》 CAS 2024年第18期114-121,共8页
以2个山东哈密瓜品种‘晓蜜25号’及‘玫珑’为材料,研究不同CO_(2)浓度气体调控(controlled atmosphere,CA)下不同品种哈密瓜的采后品质特征变化。结果表明:随着贮藏时间的延长,不同CO_(2)浓度处理能够有效延缓不同品种哈密瓜失重率的... 以2个山东哈密瓜品种‘晓蜜25号’及‘玫珑’为材料,研究不同CO_(2)浓度气体调控(controlled atmosphere,CA)下不同品种哈密瓜的采后品质特征变化。结果表明:随着贮藏时间的延长,不同CO_(2)浓度处理能够有效延缓不同品种哈密瓜失重率的上升,保持果实的硬度,延缓可溶性固形物以及可滴定酸含量的下降,提高过氧化物酶和过氧化氢酶的活性,延缓丙二醛含量的上升,保持抗氧化能力并在贮藏结束时仍维持较好的品质。这些结果表明,采后维持CA条件有助于改善哈密瓜的品质,延长贮藏期。 展开更多
关键词 哈密瓜 气体调控 Co_(2) 抗氧化 贮藏
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H_(2)O气氛下富油煤热解过程的反应分子动力学模拟
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作者 黄淄博 刘倩如 +2 位作者 刘红 周文静 魏进家 《煤田地质与勘探》 EI CAS CSCD 北大核心 2024年第7期189-199,共11页
【目的】我国富油煤资源丰富,通过热解技术可将其转化为能源产品(化学品、气体或液体燃料等),缓解我国油气资源的对外依存程度。深入认识热解过程中的产物变化规律和反应机理,对于煤炭清洁高效转化工艺的研究至关重要。【方法】采用反... 【目的】我国富油煤资源丰富,通过热解技术可将其转化为能源产品(化学品、气体或液体燃料等),缓解我国油气资源的对外依存程度。深入认识热解过程中的产物变化规律和反应机理,对于煤炭清洁高效转化工艺的研究至关重要。【方法】采用反应分子动力学(ReaxFF MD)模拟探究富油煤(长焰煤)热解过程以及H_(2)O气氛对热解产物分布的影响和作用机制。【结果和结论】结果表明,富油煤(长焰煤)热解的温度范围为1200~2800 K,热解过程主要分为热解(1200~2000 K)和缩聚(2000~2800 K)两个阶段。在热解阶段,随着温度的升高,煤分子快速裂解,焦炭产物不断减少,焦油和气体产物不断增加;在缩聚阶段,焦油产物之间发生缩聚反应生成焦炭,同时释放小分子气体,导致焦油产物减少,焦炭和气体产物增加。因此,提高热解温度、延长热解时间可得到更多的气体产物,而提升焦油产量的关键则是抑制缩聚反应发生。在高温缩聚阶段引入H_(2)O气氛热解,结果表明,H_(2)O能够有效地促进煤分子的裂解,随着H_(2)O占比的增加,煤热解体系中C―C键减少,C―H和C―O键增加。分析二者之间的交互作用发现,煤热解产生的自由基与H_(2)O反应,促进H_(2)O分子分解,H_(2)O分解产生的H•和OH•又进一步促进煤裂解,并与煤热解产物反应,生成更多的焦油和气体。研究加深了对富油煤热解过程的理解,对煤炭资源的清洁高效利用具有一定指导意义。 展开更多
关键词 富油煤 热解 反应机理 H_(2)o气氛 反应分子动力学
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NH_(3)-(NH_(4))_(2)SO_(4)体系隔膜电解铜电化学研究
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作者 杨建英 唐施阳 +2 位作者 杨平 李树超 杨建广 《中国有色冶金》 CAS 北大核心 2024年第2期121-128,共8页
PCB板(印刷电路板)剪裁铣削渣中含有金属铜和铝,且塑料含量高,采用电化学溶解隔膜电积工艺可以实现铜的剥离并得到高品位阴极铜。该工艺具有流程短、电流效率高、产品纯度高等优点,具有广阔的应用前景,但其电化学机理尚不明确,本文以PC... PCB板(印刷电路板)剪裁铣削渣中含有金属铜和铝,且塑料含量高,采用电化学溶解隔膜电积工艺可以实现铜的剥离并得到高品位阴极铜。该工艺具有流程短、电流效率高、产品纯度高等优点,具有广阔的应用前景,但其电化学机理尚不明确,本文以PCB制造过程中产生的含铜固废作为阳极,采用钛板为阴极,在NH_(3)-(NH_(4))_(2)SO_(4)体系中采用隔膜电解工艺进行了一系列试验,包括不同铵盐体系、氨/硫酸铵体系中不同电极、氨/硫酸铵体系不同电解液组成的电化学行为曲线以及NH_(3)-(NH_(4))_(2)SO_(4)体系电沉积铜的控制步骤、成核机理等。结果表明,氨/硫酸铵体系中电积铜的起始还原电位最低,电积时电耗较低,且该体系中氢的析出电位均较负,可避免因析出氢气降低阴极电流效率的副反应;NH_(3)-(NH_(4))_(2)SO_(4)体系中Cu^(2+)在钛电极表面的电沉积反应为不可逆过程,且为双电子一步转移过程,控制步骤为扩散控制;Cu^(2+)在钛电极上的成核机理接近于瞬时成核。该研究成果可为NH_(3)-(NH_(4))_(2)SO_(4)体系隔膜电解铜工艺提供理论参考。 展开更多
关键词 PCB含铜废料 NH_(3)-(NH_(4))_(2)So_(4)-H_(2)o体系 隔膜电解 电化学机理 成核机理 控制步骤
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Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery
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作者 Xi-Dao Wu Peng Xiao +2 位作者 Bei Liu Guang-Jin Chen Jian-Hua Pang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期974-986,共13页
CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fractio... CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely researched.In this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil recovery.Firstly,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT cell.Subsequently,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary tube.Furthermore,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were analyzed.The results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) emulsion.An inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was confirmed.CO_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water cut.Eventually,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,respectively.This work may provide guidelines for EOR using CO_(2) emulsions with high water cut. 展开更多
关键词 Co_(2)/H_(2)o emulsion High water cut Co_(2) mobility control Enhanced oil recovery
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Effect of sintering atmosphere on corrosion resistance of Ni/(NiFe_2O_4-10NiO) cermet inert anode for aluminum electrolysis 被引量:3
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作者 田忠良 郭伟昌 +2 位作者 赖延清 张凯 李劼 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第11期2925-2929,共5页
A comparative study on the corrosion resistance of 17Ni/(NiFe2O4-10NiO) cermet inert anode prepared in differentsintering atmospheres was conducted in Na3AlF6-Al2O3 melt. The results indicate that the corrosion rate... A comparative study on the corrosion resistance of 17Ni/(NiFe2O4-10NiO) cermet inert anode prepared in differentsintering atmospheres was conducted in Na3AlF6-Al2O3 melt. The results indicate that the corrosion rates of NiFe2O4-based cermetanodes prepared in the vacuum and the atmosphere with oxygen content of 2×10^-3 (volume fraction) are 6.46 and 2.71 cm/a,respectively. Though there is a transition layer with lots of holes or pores, a densified layer is formed on the surface of anode due tosome reactions producing aluminates. For the anode prepared in the atmosphere with oxygen content of 2×10^-3, the thickness of thedensification layer (about 50 μm) is thicker than that (about 30 μm) formed on the surface of anode prepared in the vacuum. Thecontents of NiO and Fe(II) in NiFe2xO4-y-z increase with the decrease of oxygen content in sintering atmosphere, which reduces thecorrosion resistance of the material. 展开更多
关键词 sintering atmosphere corrosion resistance NiFe2o4-based cermet inert anode aluminum electrolysis
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OXIDATION BEHAVIOR OF KOVAR ALLOY IN CONTROLLED ATMOSPHERE 被引量:10
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作者 D. W. Luo Z.S. Shen 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第6期409-418,共10页
Controlled oxidation experiments were performed on Kovar alloy by changing oxidation atmosphere, temperature, and exposure time to produce films with different oxide type and thickness. The results indicated that sing... Controlled oxidation experiments were performed on Kovar alloy by changing oxidation atmosphere, temperature, and exposure time to produce films with different oxide type and thickness. The results indicated that single Fe3O4 and single FeO were respectively obtained when Kovar alloy was oxidized in N2-2.31%H2O-0.95%H2 at 500℃ and in N2-2.31%H2O-0.5%H2 at 1000℃, and all kinetic curves followed linear relation; mixed oxides of FeO and Fe3O4 formed when Kovar was oxidized in N2-2.31%H2O at 1000℃and parabolic kinetics were obeyed. Analysis of metallographic cross section of oxides indicated that oxygen diffusion inward through the oxide scale is responsible for intergranular oxide, which had formed beneath the oxide scales when the oxide products were mixed oxides of FeO and Fe3O4, and which did not occur when the oxide was single FeO or Fe3O4. The oxidation model was also established. 展开更多
关键词 Kovar alloy oxidation controlled atmosphere H2-H2o-N2
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Effects of Application of Controlled Release Nitrogen Fertilizer on N_2O Emission in Slope Cultivated Land with Purple Soil
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作者 欧阳平 林超文 +4 位作者 刘海涛 朱波 罗付香 朱永群 张建华 《Agricultural Science & Technology》 CAS 2017年第3期452-455,482,共5页
In order to study effects of application of contmllE=d release fertilizer on ni- trous oxide (N2O) emission in slope cultivated land with purple soil, four treatments including the control group (CK), urea (UR),... In order to study effects of application of contmllE=d release fertilizer on ni- trous oxide (N2O) emission in slope cultivated land with purple soil, four treatments including the control group (CK), urea (UR), controlled release nitrogen fertilizer (CR), and controlled release nitrogen fertilizer+urea (25%CR, 75%UR) were set up, and their impacts on maize yield, surface runoff and nitrogen loss in the growth pe- riod of maize and N2O emission were studied. The results show that maize yield, surface runoff, nitrogen loss from subsurface flow, and N2O emission in the control group was far lower than that in the fertilization treatments, revealing that fertilization was the main reason for nitrogen loss and N2O emission. Among the four treat- ments, nitrogen loss from subsurface flow in the treatment CR was the highest, up to 31.7 kg/hm^2, but N2O emission was 0.35 kg/hm^2, which was 37% less than that in the treatment UR. Nitrogen loss from subsurface flow in the treatment 25% CR was the lowest, only 20.9 kg/hm^2, and N2O emission was 15% less than that in the treatment UR. Nitrogen was slowly released from controlled release nitrogen fertilizer in the growth period, and controlled release nitrogen fertilizer could reduce N2O emis- .sion from slope cultivated land due to low content of soil inorganic nitrogen, but it could increase the nitrogen loss from subsurface flow. Therefore, the combination of controlled release fertilizer and urea can not only reduce N2O emission but also de- crease nitrogen loss from subsurface flow. 展开更多
关键词 controlled release fertilizer N2o emission Purple soil Slope cultivatedland
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Effect of sintering atmosphere on composition and properties of NiFe_2O_4 ceramic 被引量:1
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作者 田忠良 张腾 +2 位作者 刘恺 赖延清 李劼 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期450-454,共5页
Ni Fe2O4 ceramics were prepared in different sintering atmospheres. The phase compositions, microstructures and mechanical properties were studied. The results show that the stoichiometric compound Ni Fe2O4 cannot be ... Ni Fe2O4 ceramics were prepared in different sintering atmospheres. The phase compositions, microstructures and mechanical properties were studied. The results show that the stoichiometric compound Ni Fe2O4 cannot be obtained in vacuum or atmospheres with oxygen contents of 2×10-5, 2×10-4 and 2×10-3, respectively. All the samples sintered in above-mentioned atmospheres contain phases of Ni Fe2O4 and Ni O. With increasing oxygen content, Ni Fe2O4 content in the ceramic increases, while Ni O content appears a contrary trend. In vacuum, Ni Fe2O4 ceramic has average grain size of 3.94 μm, and bending strength of85.12 MPa. The changes of the phase composition and mechanical properties of Ni Fe2O4 based cermets are mainly caused by the alteration of their properties of Ni Fe2O4 ceramic. 展开更多
关键词 NiFe2o4 ceramic MICRoSTRUCTURE mechanical property sintering atmosphere
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Effect of sintering atmosphere on corrosion resistance of NiFe2O4 ceramic in Na3AlF6-Al2O3 melt
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作者 田忠良 杨凯 +2 位作者 赖延清 张凯 李劼 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第9期1929-1933,共5页
A comparative study on the corrosion resistance of NiFe_2O_4 ceramic inert anode for aluminum electrolysis prepared in the different sintering atmosphere was carried out in Na_3AlF_6-Al_2O_3 melt.The results show that... A comparative study on the corrosion resistance of NiFe_2O_4 ceramic inert anode for aluminum electrolysis prepared in the different sintering atmosphere was carried out in Na_3AlF_6-Al_2O_3 melt.The results show that the corrosion rates of NiFe_2O_4 ceramic inert anodes prepared in the vacuum and the atmosphere with oxygen content of 1×10^(-2) are 6.08 cm/a and 2.59 cm/a,respectively.A densification layer is formed at the surface of anode due to some reactions which produce aluminates.For the anode prepared in the atmosphere with oxygen content of 1×10^(-2),the thickness of the densification layer(about 50 μm) is thicker than that(about 20 μm) formed at the surface of anode prepared in the vacuum.The content of NiO and Fe(Ⅱ) in Ni(Ⅱ)x Fe(Ⅱ)1-x Fe(Ⅲ)_2O_4 increases with the decrease of the oxygen content of sintering atmosphere,which reduces the corrosion resistance of the material. 展开更多
关键词 sintering atmosphere corrosion NiFe2o4 ceramic inert anode aluminum electrolysis
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CO_(2)气调处理对鲜莲贮藏品质的影响 被引量:3
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作者 舒小芳 郜海燕 +2 位作者 韩延超 房祥军 陈杭君 《中国食品学报》 EI CAS CSCD 北大核心 2023年第2期243-253,共11页
为研究CO_(2)气调处理对鲜莲采后贮藏品质的影响,以“十里荷一号”鲜莲为试材,在4℃、5%O_(2)条件下,分别采用不同CO_(2)(4%,8%和12%)贮藏鲜莲20 d,测定其外观及营养品质。结果表明:4%CO_(2)处理虽可降低莲子的失重率和褐变度,但淀粉消... 为研究CO_(2)气调处理对鲜莲采后贮藏品质的影响,以“十里荷一号”鲜莲为试材,在4℃、5%O_(2)条件下,分别采用不同CO_(2)(4%,8%和12%)贮藏鲜莲20 d,测定其外观及营养品质。结果表明:4%CO_(2)处理虽可降低莲子的失重率和褐变度,但淀粉消耗较为严重,贮藏20 d后淀粉含量(98.01 mg/g)比对照组(104.99 mg/g)低6.98 mg/g;8%CO_(2)处理在贮藏结束时褐变度、失重率、还原糖含量分别为1.63,8.54%,0.76%,过氧化物酶(POD)和多酚氧化酶(PPO)活性分别为163.44 U/(min·g)和99.63 U/(min·g),均显著低于对照组和其它气调处理组(P<0.05),而淀粉含量为119.68 mg/g,显著高于其它处理组(P<0.05)。12%CO_(2)处理使莲子受到高浓度CO_(2)伤害,贮藏20 d后其a*值(-10.03)高于对照组(-12.68),而b*值(24.95)低于对照组(28.03),褐变程度也比对照组更明显。本研究结果表明,5%O_(2)+8%CO_(2)为较适宜新鲜莲子贮藏保鲜的气调参数。该处理在减少莲子营养物质消耗和表皮护绿等方面也表现出积极作用,研究结果为研发鲜莲采后保鲜技术提供了参考。 展开更多
关键词 鲜莲 Co_(2) 气调处理 贮藏品质
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高CO_2对嗜卷书虱的致死作用及其行为反应 被引量:5
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作者 丁伟 赵志模 +2 位作者 王进军 程伟霞 李隆术 《西南农业大学学报(自然科学版)》 CSCD 北大核心 2002年第5期398-401,共4页
以重要的储藏物害虫嗜卷书虱Liposcelisbostrychophila为试虫 ,对其卵、1~ 4龄若虫、成虫等虫态在高CO2 (35 %CO2 ∶2 1%O2 ∶4 4 %N2 )气调作用下的急性致死及行为反应进行了系统研究。结果表明 :嗜卷书虱不同虫态对CO2 的敏感性由大... 以重要的储藏物害虫嗜卷书虱Liposcelisbostrychophila为试虫 ,对其卵、1~ 4龄若虫、成虫等虫态在高CO2 (35 %CO2 ∶2 1%O2 ∶4 4 %N2 )气调作用下的急性致死及行为反应进行了系统研究。结果表明 :嗜卷书虱不同虫态对CO2 的敏感性由大到小依次为 1龄若虫、2龄若虫、4龄若虫、3龄若虫、成虫和卵 ;其致死中时 (LT50 )分别为 4 .4 0 0 1,4 .75 10 ,5 .4 4 72 ,6 .0 5 91,9.4 6 4 3,39.36 77h。嗜卷书虱的卵经高CO2 气调处理后 ,初孵时间和若虫的发育历期受到明显影响 ,处理 3.5d ,卵及若虫的发育历期分别向后推迟 3.85d和 1.72d。嗜卷书虱的成虫对高CO2 气调处理表现出麻醉反应特点 ,其麻醉程度随着气调处理时间的延长而加重。麻醉后的苏醒反应也表现出一定的规律性 :随着处理时间的延长 ,试虫的起始苏醒时间后延 ,当处理时间达到一定长度时 (成虫的LT50 为 9.4 6h) 。 展开更多
关键词 致死作用 嗜卷书虱 行为反应 储粮害虫 麻醉作用 气调处理 二氧化碳 苏醒反应
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中央储备粮绵阳直属库CO_2气调储粮工程的建设 被引量:10
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作者 涂杰 郭道林 +8 位作者 王双林 高影 丁朝明 张华昌 杨昭 马洪林 何其乐 曹乐钦 龙立光 《粮食储藏》 2002年第4期43-47,共5页
本文介绍了在四川绵阳建造的具有国际先进水平的 2栋CO2 气调储粮示范仓的仓房密封技术、工艺流程、CO2 浓度监测系统、智能通风控制系统及目前已达到的初步效果。
关键词 中央储备粮绵阳直属库 co2 气调 储粮工程 密封技术 二氧化碳
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高浓度CO_2气调防治谷蠹及杂拟谷盗的研究 被引量:18
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作者 邓永学 赵志模 李隆术 《粮食储藏》 2002年第1期3-6,共4页
将谷蠹Rhyzoperthadominica (Fab .)成虫及杂拟谷盗TriboliumconfusumJacquelinduval卵、幼虫、蛹和成虫分别暴露于 35 %CO2 和 11%O2 ,35 %CO2 和 2 1%O2 ,75 %CO2 和 11%O2 ,75 %CO2 和 2 1%O2 四种气调环境中 12、2 4、36、4 8、6 0... 将谷蠹Rhyzoperthadominica (Fab .)成虫及杂拟谷盗TriboliumconfusumJacquelinduval卵、幼虫、蛹和成虫分别暴露于 35 %CO2 和 11%O2 ,35 %CO2 和 2 1%O2 ,75 %CO2 和 11%O2 ,75 %CO2 和 2 1%O2 四种气调环境中 12、2 4、36、4 8、6 0、72、84、96、10 8、12 0小时 ,结果表明谷蠹成虫对四种气调环境都很敏感 ,其LT50 分别为 34 6、4 2 0、18 6、17 8小时。杂拟谷盗成虫较耐35 %CO2 、11%O2 及 35 %CO2 、2 1%O2 气调环境 ,处理 12 0小时后 ,成虫死亡率低于 12 %。卵及幼虫对四种气调环境较为敏感 ,蛹对 35 %CO2 、11%O2 的耐受性比 35 %CO2 、2 1%O2 强 ,前者LT50 为 2 2 4 8 3小时 ,后者为 12 4 5小时。杂拟谷盗卵、幼虫、蛹及成虫对四种气调环境敏感顺序为 :卵 >幼虫 >蛹 > 展开更多
关键词 谷蠹 杂拟谷盗 二氧化碳 储粮害虫 气调防治
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O_(2)/CO_(2)/H_(2)O气氛下CO燃烧机理的分子动力学模拟研究
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作者 叶荣 林乐平 +4 位作者 熊晟熙 周巍 洪迪昆 马仑 郭欣 《锅炉技术》 北大核心 2023年第3期45-51,共7页
采用反应分子动力学(ReaxFF MD)模拟方法研究了O_(2)/CO_(2)/H_(2)O气氛下CO的燃烧。结果表明:根据化学平衡原理,高浓度CO_(2)抑制CO的氧化,同时CO_(2)在高温下参与反应CO_(2)+H—→CO+OH,进一步抑制CO氧化。在较低温度条件下,较高浓度H... 采用反应分子动力学(ReaxFF MD)模拟方法研究了O_(2)/CO_(2)/H_(2)O气氛下CO的燃烧。结果表明:根据化学平衡原理,高浓度CO_(2)抑制CO的氧化,同时CO_(2)在高温下参与反应CO_(2)+H—→CO+OH,进一步抑制CO氧化。在较低温度条件下,较高浓度H_(2)O的三体效应显著,抑制了CO氧化。另一方面,在较高温度条件下,H_(2)O参与的H_(2)O+H—→H_(2)+OH和H_(2)O+O—→OH+OH反应占据其化学作用的主导地位,进而促进CO氧化。随着O_(2)浓度的增加,CO的氧化速度加快。 展开更多
关键词 ReaxFF力场 o_(2)/Co_(2)/H_(2)o气氛 分子动力学 Co燃烧
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H_(2)O对O_(2)/H_(2)O条件下HCN氧化影响的反应分子动力学模拟
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作者 洪迪昆 翟晓明 郭欣 《动力工程学报》 CAS CSCD 北大核心 2023年第3期300-306,共7页
采用ReaxFF MD方法研究了高浓度H_(2)O的化学作用对O_(2)/H_(2)O气氛下HCN氧化反应的影响,将不同温度下反应后HCN含量分布的实验结果与ReaxFF MD模拟结果进行对比,分析了O_(2)/N2和O_(2)/H_(2)O气氛下HCN反应速率、O和OH自由基分布以及C... 采用ReaxFF MD方法研究了高浓度H_(2)O的化学作用对O_(2)/H_(2)O气氛下HCN氧化反应的影响,将不同温度下反应后HCN含量分布的实验结果与ReaxFF MD模拟结果进行对比,分析了O_(2)/N2和O_(2)/H_(2)O气氛下HCN反应速率、O和OH自由基分布以及CO和CO_(2)产物分布,并通过含氮物种的演变路径和分布规律揭示了H_(2)O对NO生成的影响机理。结果表明:在1100~1350K实验温度范围内HCN含量的分布结果与1500~2500K模拟温度范围内的结果相吻合;H_(2)O增加了OH自由基含量,从而促进了HCN的氧化以及CO向CO_(2)的转化;尽管H_(2)O增强了HCN—→HOCN—→NH2—→HNO—→NO路径对NO生成的贡献,却大大减弱了HCN—→CN—→N—→NO路径对NO生成的贡献,从而整体上抑制了NO的生成。 展开更多
关键词 o_(2)/H_(2)o气氛 HCN氧化 反应分子动力学 No
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H_(2)O/空气气氛下碳酸钙催化煤气化特性的研究
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作者 李玉才 郭效军 +1 位作者 朱啟进 司稳琴 《煤化工》 CAS 2023年第3期116-119,136,共5页
为改善煤的气化特性,在常压中试固定床上,研究了H2O/空气气氛下CaCO_(3)催化剂与石嘴山煤共气化的产气特性,并采用SEM和XRD对原煤和残焦进行表征。结果表明:气化温度800℃,当CaCO_(3)负载质量分数为2%时,H2和CO生成量最高,分别占煤气组... 为改善煤的气化特性,在常压中试固定床上,研究了H2O/空气气氛下CaCO_(3)催化剂与石嘴山煤共气化的产气特性,并采用SEM和XRD对原煤和残焦进行表征。结果表明:气化温度800℃,当CaCO_(3)负载质量分数为2%时,H2和CO生成量最高,分别占煤气组分体积分数的41.98%和26.66%,煤气热值最大,为9.05 MJ/m3;与原煤相比,添加CaCO_(3)可使煤气化温度降低约50℃;气化后的残焦中出现了CaCO_(3)、微弱的CaS、钙长石,表明CaCO_(3)有一定的固硫作用,由于残焦表面的CaCO_(3)有团聚现象,分散性较差,导致其催化效果较弱。 展开更多
关键词 H_(2)o/空气气氛 CaCo_(3) 负载量 气化温度 煤气热值 产气组成
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Ca/Fe添加剂对焦炭在H_(2)O+CO_(2)气氛中溶损反应的影响
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作者 窦明辉 韩嘉伟 +2 位作者 孙洋 孙章 梁英华 《工程科学学报》 EI CSCD 北大核心 2023年第11期1859-1867,共9页
为了探究富氢高炉内Ca/Fe基高反应性焦炭的溶损反应特性,以CO_(2)(N_(2))载带不同摩尔比例H_(2)O蒸气(0~30%)进行焦炭溶损实验,通过分析尾气中CO和H_(2)的含量,研究Ca/Fe添加剂对焦炭在H_(2)O+CO_(2)混合气氛下碳溶反应和水煤气反应的影... 为了探究富氢高炉内Ca/Fe基高反应性焦炭的溶损反应特性,以CO_(2)(N_(2))载带不同摩尔比例H_(2)O蒸气(0~30%)进行焦炭溶损实验,通过分析尾气中CO和H_(2)的含量,研究Ca/Fe添加剂对焦炭在H_(2)O+CO_(2)混合气氛下碳溶反应和水煤气反应的影响.研究表明,焦炭在H_(2)O+CO_(2)和H_(2)O+N_(2)两种气氛下的焦炭反应性随H_(2)O蒸气载带率增加呈线性关系,焦炭在H_(2)O+CO_(2)气氛中溶损反应的拟合斜率k值明显小于在H_(2)O+N2气氛中的k值,H_(2)O+CO_(2)混合气氛中H_(2)O和CO_(2)与焦炭反应存在竞争关系.而且基础焦炭(BC)反应性的实验与理论的差值明显小于Ca/Fe基焦炭(BC+Ca、BC+Fe)的差值,表明Ca/Fe添加剂影响了CO_(2)和H_(2)O与焦炭共同反应时的竞争关系.基于两种气氛下速率常数的差异提炼了两个抑制因子αCO_(2)/H_(2)O和αH_(2)O/CO_(2),αCO_(2)/H_(2)O定量表征CO_(2)对C+H_(2)O反应的抑制程度,αCO_(2)/H_(2)O定量表征H_(2)O对C+CO_(2)反应的抑制程度,BC、BC+Fe、BC+Ca三种焦炭的而提高了中催化活性物质为铁酸钙和硅铝酸钙,Ca/Fe元素在焦炭中赋存形式的不同导致了Ca/Fe添加剂对焦炭溶损反应催化效果的差异性. 展开更多
关键词 焦炭 Ca/Fe添加剂 溶损反应 H_(2)o+Co_(2)混合气氛 催化 抑制因子
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顶板高位定向钻孔瓦斯(CO_(2))治理技术研究与应用
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作者 柴发英 赵龙 张玉生 《中国煤炭》 2023年第4期35-40,共6页
海石湾煤矿是罕见的煤与瓦斯(CO_(2))突出矿井,为进一步降低工作面回风流和上隅角瓦斯(CO_(2))浓度,设计在62241工作面回风巷施工顶板高位大直径定向钻孔抽采采空区瓦斯(CO_(2)),以孔代巷,解决回采工作面采空区瓦斯(CO_(2))涌出问题;结... 海石湾煤矿是罕见的煤与瓦斯(CO_(2))突出矿井,为进一步降低工作面回风流和上隅角瓦斯(CO_(2))浓度,设计在62241工作面回风巷施工顶板高位大直径定向钻孔抽采采空区瓦斯(CO_(2)),以孔代巷,解决回采工作面采空区瓦斯(CO_(2))涌出问题;结合“竖三带”理论,对大直径高位定向钻孔最佳布孔范围进行了分析和确定,通过定向钻进技术使钻孔分布在煤层顶板回采断裂带(“O”型圈)内,保障工作面回采过程中的瓦斯抽采通道。顶板高位大直径定向钻孔在平面上的布置距离回风巷10~70 m(控制工作面倾斜长度1/3);高程布置距离煤层顶板16~28 m,有效降低了工作面回采时上隅角和回风流中的瓦斯(CO_(2))浓度。工程应用表明,大直径顶板高位定向钻孔在瓦斯(CO_(2))治理的效果、成本、施工效率等方面均优于传统高位普通拦截钻孔。 展开更多
关键词 o”型圈 高位定向钻孔 瓦斯(Co_(2))突出矿井 治理技术 海石湾煤矿
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NH_(3)/O_(2)/H_(2)O混合物着火特性的动力学分析
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作者 余良可 张尚琳 +1 位作者 许强 朱镜瑾 《能源研究与管理》 2023年第3期64-71,共8页
为了探讨NH_(3)在O_(2)/H_(2)O氛围下的着火行为与NOx分布,利用Chemkin-Pro动力学软件对NH_(3)在不同氧气体积分数(21%~30%)和掺水率(0~30%)下的着火延迟时间进行了计算。结果表明,随着氧气体积分数增加,着火过程的H、O和OH活性自由基... 为了探讨NH_(3)在O_(2)/H_(2)O氛围下的着火行为与NOx分布,利用Chemkin-Pro动力学软件对NH_(3)在不同氧气体积分数(21%~30%)和掺水率(0~30%)下的着火延迟时间进行了计算。结果表明,随着氧气体积分数增加,着火过程的H、O和OH活性自由基浓度和NOx生成量单调递增,NH_(3)的着火延迟时间单调递减。H_(2)O对NH_(3)的着火呈现低温抑制和高温促进的作用,同时在全温度范围降低活性自由基和NOx的生成。随着温度升高,NH_(2)基的加氧反应(NH_(2)+O_(2)=H_(2)NO+O)对着火的促进作用超过H_(2)NO(H_(2)NO+O_(2)=HNO+HO_(2))成为最显著的。链终止反应NH_(2)+NO=N2+H_(2)O、NH_(2)+NO_(2)=N2O+H_(2)O抑制反应活性,不利于OH池的建立。第三体基元反应NO+H(M)=HNO(+M)和NO+OH(+M)=HONO(M)主要贡献NO的形成。NO的消耗主要通过反应NO+HO_(2)=NO_(2)+OH、NH_(2)+NO=NNH+OH和NH+NO=N2O+H。 展开更多
关键词 o_(2)/H_(2)o氛围 化学动力学 着火延迟时间 No
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