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Hydrothermal decomposition of pentachlorophenol in subcritical and supercritical water with sodium hydroxide addition 被引量:4
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作者 PRABOWO Benedictus VERIANSYAH Bambang KIM Jae-Duck 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第6期663-666,共4页
Hydrothermal decomposition of pentachlorophenol (PCP, C6HC150), as the probable human carcinogen, was investigated in a tubular reactor under subcritical and supercritical water with sodium hydroxide (NaOH) additi... Hydrothermal decomposition of pentachlorophenol (PCP, C6HC150), as the probable human carcinogen, was investigated in a tubular reactor under subcritical and supercritical water with sodium hydroxide (NaOH) addition. The experiments were conducted at a temperature range of 30(0-420℃ and a fixed pressure of 25 MPa, with a residence time that ranged from 10 s to 70 s. Under the reaction conditions, the initial PCP concentrations were varied from 0.25 to 1.39 mmol/L, and the NaOH concentrations were varied from 2.5 to 25 times of the concentrations of PCP. The result of this study showed that PCP conversion in supercritical water was highly dependent on the reaction temperature, residence time, and NaOH concentration. PCP conversion in subcritical water is, however, only dependent on reaction temperature. NaOH concentration and residence times were found to have little effect on PCP conversion in subcritical condition. It was found that NaOH concentration affected the dechlorinations of PCP in the supercritical water. The intermediates detected were proposed to be tetrachlorophenol and trichlorophenol, respectively. 展开更多
关键词 PENTACHLOROPHENOL hydrothermal decomposition supercritical water suberitical water
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Supercritical as well as subcritical Hopf bifurcation in nonlinear flutter systems 被引量:1
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作者 陈衍茂 刘济科 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第2期199-206,共8页
The Hopf bifurcations of an airfoil flutter system with a cubic nonlinearity are investigated, with the flow speed as the bifurcation parameter. The center manifold theory and complex normal form method are Used to ob... The Hopf bifurcations of an airfoil flutter system with a cubic nonlinearity are investigated, with the flow speed as the bifurcation parameter. The center manifold theory and complex normal form method are Used to obtain the bifurcation equation. Interestingly, for a certain linear pitching stiffness the Hopf bifurcation is both supercritical and subcritical. It is found, mathematically, this is caused by the fact that one coefficient in the bifurcation equation does not contain the first power of the bifurcation parameter. The solutions of the bifurcation equation are validated by the equivalent linearization method and incremental harmonic balance method. 展开更多
关键词 nonlinear flutter Hopf bifurcation supercritical subcritical limit cycle oscillation
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Existence of Supercritical Hopf Bifurcation on a Type-Lorenz System
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作者 Evodio Muñoz-Aguirre Jorge Alvarez-Mena +2 位作者 Pablo Emilio Calderón-Saavedra Josué Ramírez-Ortega Francisco Gabriel Hernández-Zamora 《Journal of Applied Mathematics and Physics》 2023年第3期780-789,共10页
In this paper, a system of Lorenz-type ordinary differential equations is considered and, under some assumptions about the parameter space, the presence of the supercritical non-degenerate Hopf bifurcation is demonstr... In this paper, a system of Lorenz-type ordinary differential equations is considered and, under some assumptions about the parameter space, the presence of the supercritical non-degenerate Hopf bifurcation is demonstrated. The technical tool used consists of the Central Manifold theorem, a well-known formula to calculate the Lyapunov coefficient and Hopf’s Theorem. For particular values of the parameters in the parameter space established in the main result of this work, a graph is presented that describes the evolution of the trajectories, obtained by means of numerical simulation. 展开更多
关键词 Lorenz-Type system subcritical Hopf Bifurcation supercritical Hopf Bifurcation Hopf Theorem
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Buried Hydrothermal Systems:The Potential Role of Supercritical Water,“ScriW”,in Various Geological Processes and Occurrences in the Sub-Surface
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作者 Martin Hovland Hakon Rueslatten Hans Konrad Johnsen 《American Journal of Analytical Chemistry》 2014年第2期128-139,共12页
It is well known that seawater that migrates deep into the Earth’s crust will pass into its supercritical domain at temperatures above 407°C and pressures above 298 bars. In the oceanic crust, these pressures ar... It is well known that seawater that migrates deep into the Earth’s crust will pass into its supercritical domain at temperatures above 407°C and pressures above 298 bars. In the oceanic crust, these pressures are attained at depths of 3 km below sea surface, and sufficiently high temperatures are found near intruding magmas, which have temperatures in the range of 800°C to 1200°C. The physico-chemical behaviour of seawater changes dramatically when passing into the supercritical domain. A supercritical water vapour (ScriW) is formed with a density of 0.3 g/cc and a strongly reduced dipolar character. This change in polarity is causing the ScriW to lose its solubility of the common sea salts (chlorides and sulphates) and a spontaneous precipitation of sea salts takes place in the pore system. However, this is only one of many cases where the very special properties of ScriW affect its surroundings. The objective of this paper is to increase awareness of the many geological processes that are initiated and governed by ScriW. This includes interactions between ScriW and its geological surroundings to initiate and drive processes that are of major importance to the dynamics and livelihood of our planet. ScriW is the driver of volcanism associated with subduction zones, as ScriW deriving from the subduction slab is interacting with the mantle rocks and reducing their melting point. ScriW is also initiating serpentinization processes where olivines in the mantle rocks (e.g. peridotite) are transformed to serpentine minerals upon the uptake of OH-groups from hydrolysed water. The simultaneous oxidation of Fe2+ dissolved from iron-bearing pyroxenes and olivines leads to the formation of magnetite and hydrogen, and consequently, to a very reducing environment. ScriW may also be the potential starter and driver of the poorly understood mud and asphalt volcanism;both submarine and terrestrial. Furthermore, the lack of polarity of the water molecules in ScriW gives the ScriW vapour the potential to dissolve organic matter and petroleum. The same applies to supercritical brines confined in subduction slabs. If these supercritical water vapours migrate upwards to reach the critical point, the supercritical vapour is condensed into steam and dissolved petroleum is partitioned from the water phase to become a separate fluid phase. This opens up the possibility of transporting petroleum long distances when mixed with ScriW. Therefore, we may, popularly, say that ScriW drives a gigantic underground refinery system and also a salt factory. It is suggested that the result of these processes is that ScriW is rejuvenating the world’s ocean waters, as all of the ocean water circulates into the porous oceanic crust and out again in cycles of less than a million years. In summary, we suggest that ScriW participates in and is partly responsible for: 1) Ocean water rejuvenation and formation;2) Fundamental geological processes, such as volcanism, earthquakes, and meta-morphism (including serpentinization);3) Solid salt production, accumulation, transportation, and (salt) dome formation;4) The initiation and driving of mud, serpentine, and asphalt volcanoes;5) Dissolution of organic matter and petroleum, including transportation and phase separation (fractionation), when passing into the subcritical domain of (liquid) water. 展开更多
关键词 supercritical Seawater hydrothermal Salt Model Rifting Sediment Basins Salt Precipitation from supercritical Seawater Petroleum Migration VOLCANISM Mud Volcanoes
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Comparative evaluation for catalytic gasification of petroleum coke and asphaltene in subcritical and supercritical water 被引量:1
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作者 Rachita Rana Sonil Nanda +3 位作者 Aimee Maclennan Yongfeng Hu Janusz A.Kozinski Ajay K.Dalai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第4期107-118,共12页
Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnate... Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnated activated carbon(Ni/AC)was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions(650°C,15 wt%and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon–hydrogen–nitrogen–sulfur(CHNS)analysis,thermogravimetric and differential thermogravimetric analysis(TGA/DTA),scanning electron microscopy(SEM),Fourier-Transform Infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD)and X-ray absorption spectroscopy(XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke(8.04 mmol/g).In particular,supercritical water gasification using 5 wt%Ni/AC at 650°C with 15 wt%feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H_2from asphaltene and petroleum coke,respectively.Under the same conditions,the respective CH_4yields from catalytic gasification of asphaltene and petroleum coke were 2.54and 1.07 mmol/g.Nonetheless,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification. 展开更多
关键词 ASPHALTENE Petroleum COKE subcritical WATER supercritical WATER Gasification CHAR
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Synthesis of Sub-micrometer Lithium Iron Phosphate Particles for Lithium Ion Battery by Using Supercritical Hydrothermal Method
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作者 张艳洁 杨艳芳 +1 位作者 王学勇 李帅三 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第2期234-237,共4页
A supercritical hydrothermal method was employed to prepare sub-micrometer LiFePO4particles with high purity and crystallinity.The structure and morphology of LiFePO4particles were characterized by X-ray diffraction a... A supercritical hydrothermal method was employed to prepare sub-micrometer LiFePO4particles with high purity and crystallinity.The structure and morphology of LiFePO4particles were characterized by X-ray diffraction and scanning electron microscope.The electrochemical tests were carried out to determine the reversible capacity,rate and cycling performance of the LiFePO4particles as cathode material for lithium ion battery.Experimental results show that solvent and calcining time have significant effects on purity,size and morphology of LiFePO4particles.Mixed solvent contained deionized water and ethanol is conducive to synthesize smaller and more uniform particles.The size of LiFePO4particles as-prepared is about 100-300 nm.The specific discharge capacities of the LiFePO4particles are 151.3 and 128.0 mA·h·g?1 after first cycle at the rates of 0.1 and 1.0 C,respectively.It retains 95.0%of the initial capacity after 100 cycles at 1.0 C. 展开更多
关键词 LIFEPO4 supercritical hydrothermal synthesis lithium iron
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喷嘴参数对超临界水热燃烧特性影响的模拟
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作者 王芝安 兰忠 马学虎 《化工学报》 EI CSCD 北大核心 2024年第6期2190-2200,共11页
反应器喷嘴的作用是维持水热火焰在复杂流场中保持稳定。建立内预热式蒸腾壁反应器(IPTWR)内甲醇超临界水热燃烧过程计算流体力学模型,分析了喷嘴的材料热物性和结构参数对进料混合特性及火焰结构的影响规律。结果表明,喷嘴材料传热特... 反应器喷嘴的作用是维持水热火焰在复杂流场中保持稳定。建立内预热式蒸腾壁反应器(IPTWR)内甲醇超临界水热燃烧过程计算流体力学模型,分析了喷嘴的材料热物性和结构参数对进料混合特性及火焰结构的影响规律。结果表明,喷嘴材料传热特性的提高使水热火焰朝高温和广域的方向发展;氧气-辅热混合段直径由18 mm减小到14 mm,反应器轴向温度峰值由954.84 K升高到981.60 K,火焰位置向远端移动;随着喷嘴缩进深度减小,水热火焰逐渐向喷嘴出口聚拢,表现为火焰收缩现象。在此喷嘴结构参数范围内小直径的短氧气-辅热混合流道有助于水热火焰的温度升高和聚拢稳定。结果可为内预热式蒸腾壁反应器的喷嘴设计提供理论指导。 展开更多
关键词 喷嘴 反应器 超临界水 水热火焰 计算流体力学
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锌灰资源化回收及超临界水热合成纳米氧化锌系统工艺
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作者 刘璐 王树众 +4 位作者 刘伟 张宝权 刘慧 刘辉 赵君安 《西安交通大学学报》 EI CAS CSCD 北大核心 2024年第3期193-203,共11页
为了对锌灰进行资源化回收及对其经济性进行分析,将湿法回收工艺和超临界水热合成技术相结合,将锌灰生成价值较高的纳米氧化锌产品,采用Aspen Plus软件平台,建立了完整的系统工艺,并分析了系统运行过程中的物料成本及能耗成本。在硫酸... 为了对锌灰进行资源化回收及对其经济性进行分析,将湿法回收工艺和超临界水热合成技术相结合,将锌灰生成价值较高的纳米氧化锌产品,采用Aspen Plus软件平台,建立了完整的系统工艺,并分析了系统运行过程中的物料成本及能耗成本。在硫酸浓度为2 mol·L^(-1)、固液比为1∶8、浸出温度为50℃、浸出时间为2 h、搅拌器转速为300 r·min^(-1)的条件下,锌灰中锌的浸出率达到了95%以上。除杂过程除去了Fe、Al、Ni、Cu等杂质,除杂后的溶液中锌的质量分数达到了97%。利用锌灰浸出液在400℃和25 MPa的超临界条件下,合成了平均粒径为26 nm的纳米氧化锌,晶体结晶度良好,纯度较高。通过与纯物料所合成的纳米氧化锌进行对比,验证了该技术的可行性,显著提升了系统运行的经济性。 展开更多
关键词 锌灰资源化回收 超临界水热合成 纳米氧化锌 高值化利用
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一类肿瘤-免疫模型的稳定性与Hopf分支分析 被引量:1
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作者 赵浛弛 李杰梅 《吉林大学学报(理学版)》 CAS 北大核心 2024年第2期189-196,共8页
考虑一类肿瘤-免疫模型,讨论其平衡点的存在性条件,并利用特征方程分析各平衡点的局部动力学稳定性,证明该模型在相应条件下会发生Hopf分支.通过计算第一Lyapunov系数得出:如果系数不为零,则模型发生Hopf分岔;如果系数小于零,则分岔是... 考虑一类肿瘤-免疫模型,讨论其平衡点的存在性条件,并利用特征方程分析各平衡点的局部动力学稳定性,证明该模型在相应条件下会发生Hopf分支.通过计算第一Lyapunov系数得出:如果系数不为零,则模型发生Hopf分岔;如果系数小于零,则分岔是超临界的;如果系数大于零,则分岔是次临界的.最后利用数值模拟验证理论分析结果. 展开更多
关键词 肿瘤-免疫模型 稳定性 HOPF分支 超临界 次临界
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超临界水热合成纳米氧化锌的动力学及聚乙烯吡咯烷酮耦合作用机理研究
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作者 赵君安 刘璐 +2 位作者 王树众 刘慧 杨健乔 《西安交通大学学报》 EI CAS CSCD 北大核心 2024年第11期156-163,共8页
为了获得超临界水热合成过程中纳米氧化锌的结晶动力学机理及表面改性作用机理,分析了温度、时间驱动下的结晶动力学曲线,获得了纳米氧化锌在成核、生长过程的速率及活化能。同时采用聚乙烯吡咯烷酮(PVP)对氧化锌进行原位表面改性,通过... 为了获得超临界水热合成过程中纳米氧化锌的结晶动力学机理及表面改性作用机理,分析了温度、时间驱动下的结晶动力学曲线,获得了纳米氧化锌在成核、生长过程的速率及活化能。同时采用聚乙烯吡咯烷酮(PVP)对氧化锌进行原位表面改性,通过分析不同比例PVP和KOH作用下合成的氧化锌形貌,获得了PVP和KOH的耦合作用机理。实验结果表明:纳米氧化锌在成核过程中的活化能为603.06 kJ·mol^(-1),在生长过程中的活化能为63.10 kJ·mol^(-1),在成核阶段比生长阶段消耗的能量更多;在前驱物、KOH、PVP的物质的量浓度比为1∶3∶2时合成了粒径最小的纳米氧化锌颗粒,平均粒径为6.9 nm;当KOH、PVP的浓度比过高时,纳米氧化锌颗粒表面过量的PVP使其成为凝胶类沉积物,形成一种团聚体从而导致合成纳米颗粒的粒径变大。 展开更多
关键词 超临界水热合成 纳米氧化锌 结晶动力学 表面改性
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污泥焚烧灰中磷在超临界CO_(2)水热液中迁移转化
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作者 刘心怡 李爱民 傅泽刚 《大连理工大学学报》 CAS CSCD 北大核心 2024年第4期346-352,共7页
基于超临界CO_(2)水热液具有强酸性,且传质性能好,易于分离回收和可调控等优点,提出了超临界CO_(2)水热液浸出污泥焚烧灰(incinerated sewage sludge ash, ISSA)中磷的新方法.研究了ISSA中磷在超临界CO_(2)水热液中的迁移转化行为.考察... 基于超临界CO_(2)水热液具有强酸性,且传质性能好,易于分离回收和可调控等优点,提出了超临界CO_(2)水热液浸出污泥焚烧灰(incinerated sewage sludge ash, ISSA)中磷的新方法.研究了ISSA中磷在超临界CO_(2)水热液中的迁移转化行为.考察了ISSA中磷形态及其矿物相,研究了压力、反应时间和液固比对ISSA中磷迁移转化的影响,并分析了超临界CO_(2)优秀的传质效果、反应中碳酸盐的生成以及ISSA表面反应位点的增加对ISSA中磷迁移转化速率的影响.结果表明:ISSA中磷含量高,且以非磷灰石无机磷(NAIP)为主;在压力为8.7 MPa、反应时间为60 min、液固比为20 mL/g的超临界CO_(2)水热液中,ISSA中磷的浸出率可达67.5%.该方法可替代目前酸碱顺序提取中的酸浸出工艺,在大幅缩短磷浸出时间的同时,提高了磷的浸出率,并彻底避免了重金属的浸出.该研究能够为绿色高效磷回收技术的开发提供理论依据和数据支持. 展开更多
关键词 污泥焚烧灰 磷回收 超临界CO_(2)水热液 磷形态
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Modeling Blood Flow in Veins of Uniform Properties (Giraffe Jugular Vein)
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作者 Rogers Omboga Amenya Johanna Kibet Sigey +1 位作者 Geoffrey Moriaso Ole Maloiy David Mwangi Theuri 《Open Journal of Biophysics》 2024年第2期132-153,共22页
This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The ... This paper models the giraffe’s jugular veins as a uniform collapsible tube from a rigid skull. The equations governing one-dimensional steady flow through such a tube for various conditions have been developed. The effects of inertial and inclination angles that have not been discussed previously have been included. It has been shown that different flows for a uniform tube (vein) are possible. However, this flow matches that of a jugular vein which is supercritical, and the steady solution has been given by the balance between the driving forces of gravity and the viscous resistance to the flow at the right atrium of the heart must be sub-critical for a fixed right-atrium pressure which means that an elastic jump is required to return the flow to sub-critical from the supercritical flow upstream this type of relationship gives rise to flow limitation at the same time given any right atrium fixed pressure there exists a maximum flow rate which when exceeded the boundary conditions of the flow do not hold boundary conditions at the right atrium are not satisfied hence making the steady flow impossible this mechanism of flow limitation is slightly different from the other one in that causes airways through forced expiration from the observation made it is clearly shown that there is an intravascular pressure difference with a change in height. 展开更多
关键词 Blood Flow Jugular Vein Cross-Sectional Area supercritical subcritical JUMP
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超/亚临界水处理技术研究进展
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作者 王丹君 山东明 +1 位作者 杨智云 陈刚 《山东化工》 CAS 2024年第5期122-125,共4页
超/亚临界水处理技术是一种绿色、高效的高级氧化技术,在工业废水、废弃物处理方面具有良好的技术优势和广阔的应用前景。综述了超/亚临界水处理技术,包括湿式氧化技术、超临界水氧化技术和超/亚临界水脱盐技术原理、研究进展和工业应用... 超/亚临界水处理技术是一种绿色、高效的高级氧化技术,在工业废水、废弃物处理方面具有良好的技术优势和广阔的应用前景。综述了超/亚临界水处理技术,包括湿式氧化技术、超临界水氧化技术和超/亚临界水脱盐技术原理、研究进展和工业应用,总结了超/亚临界水处理技术存在的问题,分析了导致问题的原因并讨论了相应的解决思路。 展开更多
关键词 湿式氧化 超临界水氧化 亚临界水 有机废水 高盐废水
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有机固废水热处理工艺方法及发展思考
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作者 张绍睿 魏国华 +1 位作者 石运鑫 何明月 《锅炉制造》 2024年第2期31-33,36,共4页
有机固废通常具有含水率高、能量密度低、不均质等特性,传统的生物法、焚烧法、填埋法等处理方式存在处理成本高、转化效率低、污染排放高等问题。利用水热处理技术处置有机固废,具有无需干燥预处理、处理效率高、反应温度低等优点,在... 有机固废通常具有含水率高、能量密度低、不均质等特性,传统的生物法、焚烧法、填埋法等处理方式存在处理成本高、转化效率低、污染排放高等问题。利用水热处理技术处置有机固废,具有无需干燥预处理、处理效率高、反应温度低等优点,在处理高含湿量物料上具备较大发展潜力。本文介绍了国内外有机固水热处理工艺方法的发展现状,对不同工艺路线进行了对比分析,最后提出了对有机固废水热处理工艺未来发展重点的思考。 展开更多
关键词 有机固废 水热碳化 水热液化 超临界水氧化
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Hopf Bifurcation Control in a Lorenz Type System 被引量:4
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作者 P. E. Calderon-Saavedra E. Munoz-Aguirre +1 位作者 J. Alvarez-Mena S. Gomez-Perez 《Journal of Applied Mathematics and Physics》 2018年第8期1704-1719,共16页
In this paper Hopf bifurcation control is implemented in order to change the bifurcation from supercritical to subcritical in a differential equations system of Lorenz type. To achieve this purpose: first, a region of... In this paper Hopf bifurcation control is implemented in order to change the bifurcation from supercritical to subcritical in a differential equations system of Lorenz type. To achieve this purpose: first, a region of parameters is identified where the system has a supercritical Hopf bifurcation;second, a class of non-linear feedback control laws is proposed;finally, it is shown that there are control laws which the disturbed system undergoes subcritical Hopf bifurcation. 展开更多
关键词 LORENZ Type systems BIFURCATION CONTROL HOPF BIFURCATION CONTROL subcritical and supercritical HOPF BIFURCATION
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Silicon carbide nanotubes with special morphology prepared by super critical hydrothermal method and photoluminescence character
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作者 郭池 唐元洪 +1 位作者 裴立宅 张勇 《Journal of Shanghai University(English Edition)》 CAS 2011年第6期538-541,共4页
Silicon carbide nanotubes(SiCNTs) with special morphology synthesized by supercritical hydrothermal method at 470 C and 8 MPa have been reported in this paper.SiCNTs with special morphology were characterized by tra... Silicon carbide nanotubes(SiCNTs) with special morphology synthesized by supercritical hydrothermal method at 470 C and 8 MPa have been reported in this paper.SiCNTs with special morphology were characterized by transmission electron microscopy(TEM) and high-resolution TEM(HRTEM).There are two kinds of silicon carbide with special morphology:One is oval SiCNTs with small aspect ratio,the other is bamboo cone-shape structure.SiCNTs have been analyzed by fluorescence spectrometer.The results indicate that the SiCNTs have strong photoluminescence(PL) property.The SiCNTs with oval shape are one kind of intermediate state of growth process of nanotube.The growth mechanism of silicon nanotubes has been proposed based on experiment data.The investigations of growth mechanism of SiCNTs with bamboo structure show that the defect produced in the growth process play the important role in SiCNTs with special structure. 展开更多
关键词 silicon carbide nanotubes(SiCNTs) supercritical hydrothermal method photoluminescence(PL)
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温度-压力解耦对木质素水热过程中结构变化及解聚产物的影响 被引量:3
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作者 于士杰 赵鹏 +4 位作者 刘茂清 高宇 李清海 张衍国 周会 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2023年第8期1106-1113,I0004,共9页
本工作研究了水热过程中解耦的温度和压力对木质素的影响,评估了水热处理对于木质素结构的影响,评估了解耦温度和压力对于木质素水热过程液相产物的影响。结果表明,木质素全部由松柏醇的G型单体组成,水热处理后,木质素中的β-O-4酯键等... 本工作研究了水热过程中解耦的温度和压力对木质素的影响,评估了水热处理对于木质素结构的影响,评估了解耦温度和压力对于木质素水热过程液相产物的影响。结果表明,木质素全部由松柏醇的G型单体组成,水热处理后,木质素中的β-O-4酯键等C-O键发生断裂,甲氧基以及和含氧结构相连的脂肪族结构转化为脂肪族碳骨架。液相产物最初为香草醛和3-(4-羟基-3-甲氧基苯基)-1-丙醇,后续主要通过单体间的转化以及木质素末端愈创木基单元的β-O-4键的裂解为愈创木酚。解耦的高压会抑制木质素液相产物的产生,并且会降低产物中异丁香酚的选择性。本研究结果有望为木质素的水热转化过程工况的优化提供更为基础的认识和理解。 展开更多
关键词 生物质 碱木质素 水热转化 温度压力解耦 亚临界水
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基于不同提取方法的汉麻茎叶精油全组分鉴定及比较研究 被引量:1
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作者 李智宁 李飞飞 +4 位作者 宋梦娇 马艳妮 张丽先 张桃桃 魏悦 《天然产物研究与开发》 CAS CSCD 2023年第2期260-270,共11页
以汉麻茎叶为原料,分别采用水蒸馏提取法、亚临界萃取法以及超临界萃取法来获得汉麻精油,比较不同提取方法下获得的精油全组分的差异性、特征性。采用气相色谱-质谱法(GC-MS)对精油全组分进行鉴定分析,并通过NIST质谱库和人工解析对所... 以汉麻茎叶为原料,分别采用水蒸馏提取法、亚临界萃取法以及超临界萃取法来获得汉麻精油,比较不同提取方法下获得的精油全组分的差异性、特征性。采用气相色谱-质谱法(GC-MS)对精油全组分进行鉴定分析,并通过NIST质谱库和人工解析对所提取成分进行鉴别分析和相似度的检索,最后根据峰面积归一化法得出这三种提取方式下汉麻精油各组分的相对含量。三种提取方法下所得精油组分差异性明显,共计鉴定出154个成分,且含有13个共有成分,相似度均在80%以上。其中水蒸馏提取法共鉴定出89种,含量最高组分是大麻二酚(19.69%);亚临界萃取法鉴定出62种,含量最高组分是邻苯二甲酸二正辛酯(17.56%);超临界萃取法鉴定出59种,含量最高组分是油酸(22.50%)。三种方法所得精油组分种类和含量均有不同程度的差异:水蒸馏法获得的精油组分种类最多,多为烷烃、烯烃、醇类、醛类、倍半萜类等小分子化合物,而亚临界法和超临界法在一定程度上具有相似性,二者共有40个共有成分,多为酸类,醇类,酯类,酚类等高沸点化合物或大分子化合物,但含量差异明显。 展开更多
关键词 汉麻茎叶 精油 水蒸馏 亚临界 超临界 GC-MS
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基于均匀设计的花生油亚/超临界CO_(2)等压连续萃取分离工艺研究
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作者 侯凯文 郭建章 王威强 《中国粮油学报》 CAS CSCD 北大核心 2023年第11期129-133,共5页
采用均匀设计实验,研究了流量、压力、时间、分离温度4个变量在CO_(2)等压连续亚临界态萃取超临界态分离工艺中对花生油萃分率的影响,通过回归拟合,确定了最佳工艺条件:流量100 L/h,压力22 MPa,分离温度65℃,时间220 min,萃取温度30℃(... 采用均匀设计实验,研究了流量、压力、时间、分离温度4个变量在CO_(2)等压连续亚临界态萃取超临界态分离工艺中对花生油萃分率的影响,通过回归拟合,确定了最佳工艺条件:流量100 L/h,压力22 MPa,分离温度65℃,时间220 min,萃取温度30℃(定值),此工艺条件下花生油预测萃分率为26.02%,实际平均萃分率为35.02%。通过与传统花生萃取工艺对比,表明花生油亚/超临界CO_(2)等压连续萃取分离工艺具有广阔发展前景以及进步空间。 展开更多
关键词 亚临界CO_(2) 超临界CO_(2) 等压萃取分离 花生油 均匀实验
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超临界地热资源的地球物理分析--以鲜水河高温水热系统为例 被引量:2
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作者 张健 方桂 +1 位作者 何雨蓓 艾依飞 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2023年第2期698-712,共15页
鲜水河高温水热系统位于川西地热区,是我国重要的“水热型”地热资源区和高温地热发电工程建设选区,其深层超临界地热资源可以大幅提高热-功转换效率和地热发电能力,具有极大的应用价值.超临界地热资源是地热学的全新研究方向,研究深层... 鲜水河高温水热系统位于川西地热区,是我国重要的“水热型”地热资源区和高温地热发电工程建设选区,其深层超临界地热资源可以大幅提高热-功转换效率和地热发电能力,具有极大的应用价值.超临界地热资源是地热学的全新研究方向,研究深层超临界地热资源促进地热学拓宽研究领域,具有重要的科学意义.本文利用地球物理资料、地热地质资料,对鲜水河高温水热系统超临界水热流体构造条件、有利赋存部位、热结构与热状态开展计算分析.结果表明:鲜水河断裂带浅源小震群与深层超压热流体层相关,热泉群串珠状负重力异常圈闭之下超厚沉积地层是赋存深层超临界地热流体储层的有利构造部位;康定中谷-二道桥-榆林宫热水区的水源补给、热源补给、水热循环通道等地热地质条件优良,其下方存在酸性岩浆活动,是形成高温水热系统浅层热储、深层超临界热液区的重要热源条件.我们认为:鲜水河断裂带是深部热流体上升至浅表产生强烈水热活动的通道,沿此通道,在160~250℃温度区间,是鲜水河水热系统地热储层的赋存区域;在350~400℃温度区间,是深层超临界流体(H2O、CO_(2))的赋存区域;随温泉水大量溢出的高浓度CO_(2)地热气体,伴随出现pH值略小于7的弱酸性热水,其下方是形成深层超临界地热资源的有利区域. 展开更多
关键词 鲜水河断裂带 高温水热系统 超临界地热资源 地球物理分析
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