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双吲哚基多孔聚合物的宽pH范围染料吸附性能与机理研究
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作者 吴紫琪 徐业伟 +7 位作者 郑敏 毛扬庆 朱家丽 杨春燕 赵兵 周明如 梁书恩 常冠军 《高分子学报》 北大核心 2025年第10期1777-1790,共14页
鉴于阳离子染料引发的水体污染问题日益严峻,本研究致力于开发一种高效的吸附剂以应对这一挑战.采用一步法策略,以3,3'-二吲哚甲烷为原料,经Friedel-Crafts烷基化反应构建了具有供电子亚甲基功能化的吲哚基多孔有机聚合物(PDIM).选... 鉴于阳离子染料引发的水体污染问题日益严峻,本研究致力于开发一种高效的吸附剂以应对这一挑战.采用一步法策略,以3,3'-二吲哚甲烷为原料,经Friedel-Crafts烷基化反应构建了具有供电子亚甲基功能化的吲哚基多孔有机聚合物(PDIM).选用亚甲基蓝(MB)作为典型阳离子染料对其吸附性能与机理进行系统探究.相较于现有报道材料中存在的p H局限性,PDIM在pH=2~12的范围内对MB表现出卓越的吸附能力,其最大吸附容量达621.92 mg/g,仅30 min内即可达到最大吸附量的87%,80 min实现吸附平衡.同时,PDIM对MB表现出优异的选择性吸附能力,且在多种共存离子干扰下仍保持稳定的吸附性能.此外,PDIM还具有良好的可重复使用性.吸附机制研究表明,PDIM对MB的吸附主要依赖于阳离子-π相互作用和π-π相互作用,其中亚甲基的引入有效增强了PDIM与MB之间的非键作用.特别地,PDIM对其他阳离子染料在宽pH范围内同样具有优异的吸附性能,表明PDIM在处理阳离子染料污染时具有广泛的适用性. 展开更多
关键词 吲哚基多孔聚合物 亚甲基 吸附 宽pH范围 阳离子-Π相互作用 Π-Π相互作用
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可拉伸胆甾相液晶弹性体的图案化及力致变色
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作者 闵政 吉波 +1 位作者 秦朗 俞燕蕾 《功能高分子学报》 北大核心 2025年第5期389-399,共11页
胆甾相液晶弹性体(CLCE)是一种具有周期性螺旋结构的光子晶体材料,兼具光学各向异性和力致变色特性,在柔性光子器件等领域前景广阔,然而,制备图案化CLCE仍面临挑战。本文基于巯基-迈克尔加成反应,合成了聚合度可控、不同链长的温敏变色... 胆甾相液晶弹性体(CLCE)是一种具有周期性螺旋结构的光子晶体材料,兼具光学各向异性和力致变色特性,在柔性光子器件等领域前景广阔,然而,制备图案化CLCE仍面临挑战。本文基于巯基-迈克尔加成反应,合成了聚合度可控、不同链长的温敏变色胆甾相液晶齐聚物(CLCO),系统探索了其液晶相结构与结构色之间的构效关系。利用温度诱导胆甾相-近晶相的相转变效应,实现CLCO结构色覆盖红、绿、蓝三原色区间(波长变化范围(Δλ)为126 nm);在不同温度下通过局部光聚合制备了图案化的可拉伸CLCE;通过降低液晶单体及手性掺杂剂中丙烯酸酯基团与硫醇扩链剂中巯基的物质的量之比(n(Acrylate)/n(Thiol)),可以提高CLCO的聚合度,并降低CLCE的交联密度,使其断裂伸长率提升至200%,力致变色范围覆盖可见光区。本文不仅为CLCE的结构色动态调控与图案化提供了新思路,还为其在信息加密、防伪等领域的应用奠定了材料基础。 展开更多
关键词 胆甾相液晶弹性体 结构色 齐聚物 力致变色 图案化
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Inherent potential of mitochondria-targeted interventions for chronic neurodegenerative diseases
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作者 min Zhou min zheng +8 位作者 Siyao Liang Maomao Li Jiarui Ma Shiyu Zhang Xinyao Song Yonglin Hu Yuhong Lyu Xingkun Ou Changwu Yue 《Neural Regeneration Research》 2026年第4期1409-1427,共19页
The cure rate for chronic neurodegenerative diseases remains low,creating an urgent need for improved intervention methods.Recent studies have shown that enhancing mitochondrial function can mitigate the effects of th... The cure rate for chronic neurodegenerative diseases remains low,creating an urgent need for improved intervention methods.Recent studies have shown that enhancing mitochondrial function can mitigate the effects of these diseases.This paper comprehensively reviews the relationship between mitochondrial dysfunction and chronic neurodegenerative diseases,aiming to uncover the potential use of targeted mitochondrial interventions as viable therapeutic options.We detail five targeted mitochondrial intervention strategies for chronic neurodegenerative diseases that act by promoting mitophagy,inhibiting mitochondrial fission,enhancing mitochondrial biogenesis,applying mitochondria-targeting antioxidants,and transplanting mitochondria.Each method has unique advantages and potential limitations,making them suitable for various therapeutic situations.Therapies that promote mitophagy or inhibit mitochondrial fission could be particularly effective in slowing disease progression,especially in the early stages.In contrast,those that enhance mitochondrial biogenesis and apply mitochondria-targeting antioxidants may offer great benefits during the middle stages of the disease by improving cellular antioxidant capacity and energy metabolism.Mitochondrial transplantation,while still experimental,holds great promise for restoring the function of damaged cells.Future research should focus on exploring the mechanisms and effects of these intervention strategies,particularly regarding their safety and efficacy in clinical settings.Additionally,the development of innovative mitochondria-targeting approaches,such as gene editing and nanotechnology,may provide new solutions for treating chronic neurodegenerative diseases.Implementing combined therapeutic strategies that integrate multiple intervention methods could also enhance treatment outcomes. 展开更多
关键词 Alzheimer's disease amyotrophic lateral sclerosis calcium homeostasis oxidative stress Huntington's disease mitochondrial dysfunction MITOCHONDRIA MITOPHAGY neurodegenerative diseases Parkinson's disease targeted therapy
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Formation of highly toxic p-benzoquinones byproducts during ozonation of cresols
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作者 Weixu Tang Jianjian Wei +5 位作者 Shuting Wang Qiang Cheng Aroob Abid Jia Gu min zheng Dehua Ma 《Journal of Environmental Sciences》 2025年第8期495-508,共14页
This study aims to identify the highly non-specific toxic by-products during ozonation of three cresols in wastewater.In ozonated effluents,biotoxicity increased along with increasing reaction time,followed by a gradu... This study aims to identify the highly non-specific toxic by-products during ozonation of three cresols in wastewater.In ozonated effluents,biotoxicity increased along with increasing reaction time,followed by a gradual decrease.The peak biotoxicity for ozonated o-cresol(o-C),m-cresol(m-C),and p-cresol(p-C)was estimated to be 17.4,14.8 and 5.5 times higher than that of untreated wastewater,respectively.A redox-directed approach with high-resolution mass spectrometry detection and toxicity prediction revealed that monomeric para-benzoquinones(p-BQs),hydroxylated p-BQs,and dimeric p-BQs in ozonated cresols were the primary contributors to the increased toxicity.Calculations based on density functional theory indicated formation pathways of p-BQs byproducts,e.g.,the formation of 2-methyl-p-benzoquinone was likely induced by ozone molecules rather than hydroxyl radicals in ozonated o-C and m-C,and the formation of p-BQs during ozonation of p-C was attributed to the oxidation of methyl group to carboxyl group and subsequent decarboxylation initiated by hydroxyl radicals.Electron paramagnetic resonance and spin density calculation showed that the presence of carbon-centered cresoxyl radicals was responsible for dimeric p-BQs formation.Collectively,these results underscore significant contribution of non-halogenated p-BQs to non-specific toxicity increase in ozonated effluents. 展开更多
关键词 OZONATION CRESOLS Highly toxic byproducts P-BENZOQUINONES Quantum chemical calculations
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Efficient and economic H_(2)O_(2)electrosynthesis via two-electron oxygen reduction reaction enabled by dynamically reconstructed Mn(^(*)OH)-N_(3)O-C motif and coupled alcohol oxidation
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作者 Wei Liu Rui Chen +7 位作者 Zhiyuan Sang min zheng Zhenxin Li Jiahuan Nie Qiao Jiang Lichang Yin Feng Hou Ji Liang 《Journal of Energy Chemistry》 2025年第9期675-684,I0018,共11页
Hydrogen peroxide(H_(2)O_(2))electrosynthesis via two-electron oxygen reduction reaction(2e-ORR)is a promising alternative for the energy-intensive anthraquinone process.However,the instability of the catalytic metal ... Hydrogen peroxide(H_(2)O_(2))electrosynthesis via two-electron oxygen reduction reaction(2e-ORR)is a promising alternative for the energy-intensive anthraquinone process.However,the instability of the catalytic metal sites in the state-of-the-art metal single-atom catalysts(M-SACs)hinders their further industrial applications,and the high potential and valueless oxygen product of the conventional anodic oxygen evolution reaction(OER)further limit the economic efficiency of this technology.To address this,a dynamically local structure reconstruction strategy is proposed to in situ transfer the active sites from unstable metal sites to the stable surrounding carbon sites for efficient and durable 2e^(-)ORR electrocatalysis.For the as-designed Mn-N_(3)O-C catalyst,by reconstructing Mn sites into Mn(^(*)OH),the Mn sites were passivated and carbon sites adjacent to the O atom were verified to be the actual active sites by in situ characterization and theoretical calculation.Consequently,Mn-N_(3)O-C exhibited>80%Faradaic efficiency and superior long-term durability over 100 h for H_(2)O_(2)electrosynthesis at~120 mA cm^(-2).In addition,coupling anodic ethylene glycol oxidation reaction(EGOR)further improves the efficiency and economic viability of the H_(2)O_(2)electrosynthesis system.This two-pronged strategy thus opens up a new opportunity for the development of stable H_(2)O_(2)electrosynthesis with low energy consumption and superior economic performance. 展开更多
关键词 Hydrogen peroxide Two-electron oxygen reduction reaction Single-atom catalysts Local structure reconstruction Ethylene glycol oxidation reaction
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Tailoring nanoscale primary silicon in laser powder bed fusion for high-performance lithium-ion battery anodes
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作者 Li Cao min zheng +3 位作者 Guochen Dong Jiejie Xu Rongshi Xiao Ting Huang 《Journal of Materials Science & Technology》 2025年第8期278-287,共10页
Silicon-based anodes,utilizing nanosized silicon materials,hold great promise for the next-generation of lithium-ion batteries due to their high capacity and stable expansion.This study aims to address challenges in t... Silicon-based anodes,utilizing nanosized silicon materials,hold great promise for the next-generation of lithium-ion batteries due to their high capacity and stable expansion.This study aims to address challenges in traditional slurry-coated anodes,such as agglomeration and low adhesive strength,through the application of laser powder bed fusion(LPBF).The process involves fabricating an Al-Si-Cu alloy layer on a Cu foil current collector,followed by dealloying to create a porous Si-Cu anode.Simulated and experimental results demonstrate successful alloy layer formation through optimized laser spot(55μm)and powder sizes(1-5μm).Controlled cooling produces primary Si particles ranging from 150 nm to 1μm.The resulting microstructure enhances electrochemical performance,particularly by tailoring the size of primary Si.The resultant porous Si-Cu anode,featuring uniformly distributed primary Si(200 nm)metallurgically bonded with Cu networks,exhibits an initial coulombic efficiency of 83% and a remarkable capacity retention of 80% after 300 cycles at 2 C.In-situ and ex-situ observations confirm the crucial role of anode architecture in performance enhancement.This study elucidates the influence of the LPBF microstructure on anode performance and broadens the potential application of laser powder bed fusion in battery manufacturing. 展开更多
关键词 LPBF DEALLOYING Primary Si Microstructure LIBS
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Research and application of thermosensitive Pickering emulsion with X-ray and ultrasound dual-modal imaging functions for intra-arterial embolization treatment
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作者 Ling Li Anran Guo +6 位作者 Haixia Sun Yanbing Zhao Qing Yao Ling Zhang Peng Shi Hongan Tian min zheng 《Journal of Pharmaceutical Analysis》 2025年第4期759-774,共16页
Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging an... Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging and the birth of“X-ray-free”technologies,we designed a new dual-mode imaging material of dimethoxy tetraphenyl ethylene(DMTPE)via emulsification by mixing poly(N-isopropylacrylamide-co-acrylic acid)(PNA)with lipiodol and fluorocarbons,which was evaluated for temperature sensitivity,stability,and dual-mode visualization in vitro.Additionally,blood vessel casting embolization and renal artery imaging were assessed in healthy rabbits.In a rabbit model with a VX2 tumor,the effectiveness of TAE for treating HCC was examined,with an emphasis on evaluating long-term outcomes of embolization and its effects on tumor growth,necrosis,and proliferation through imaging techniques.In vitro experiments confirmed that the temperature-sensitive dual-oil-phase Pickering emulsion had good flow,stable contrast,and embolism when the oil-to-oil ratio and water-to-oil ratio were both 7:3(v/v)and stabilized with 8%PNA.Similarly,in vivo,arterial embolization confirmed the excellent properties of DMTPE prepared at the abovementioned ratios.It was observed that DMTPE not only has an antitumor effect but can also achieve dual imaging using X-rays and ultrasound,making it a promising excellent vascular embolization material for TAE in tumor treatment. 展开更多
关键词 Dual-modal imaging Temperature sensitivity Pickering emulsion Transcatheter arterial embolization
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Small nanoparticles bring big prospect: The synthesis, modification,photoluminescence and sensing applications of carbon dots 被引量:2
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作者 Pengli Gao Zhigang Xie min zheng 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第4期1659-1672,共14页
As a new type of carbon-based fluorescent nanomaterials, carbon dots(CDs) are provided with the advantages of small size, excellent photoluminescence(PL) property, easy surface modification, robust stability,good wate... As a new type of carbon-based fluorescent nanomaterials, carbon dots(CDs) are provided with the advantages of small size, excellent photoluminescence(PL) property, easy surface modification, robust stability,good water solubility and biocompatibility, which endow them with great potential in sensing. In this review, we first describe the preparation of CDs from different starting materials via various techniques, and pre-/post-modification strategies to modulate their PL properties. Second, we outline the optical properties of CDs, including UV-vis absorption and PL, especially the PL mechanisms of CDs are presented in detail from the size effect, molecular state, surface state and defect state. Third, we summarize the research progress of CDs in sensing environmental pollutants, bioactive substances, biological microenvironments,bacteria and viruses via different mechanisms. In addition, we envision the future development trends and prospects for CDs-based nanosensors. We believe that this type of small nanoparticles will bring about big prospect in the near future. 展开更多
关键词 Carbon dots SYNTHESIS MODIFICATION Mechanisms SENSING
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Metathesis of 1-butene and 2-butene to propene over Re_2O_7 supported on macro-mesoporous γ-alumina prepared via a dual template method 被引量:2
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作者 Lei Sang Sheng-Li Chen +5 位作者 Guimei Yuan min zheng Ju You Aicheng Chen Rui Li Lanjing Chen 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第2期105-108,共4页
Macro-mesoporous γ-alumina support(MMA) was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,resp... Macro-mesoporous γ-alumina support(MMA) was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3. 展开更多
关键词 butene metathesis PROPENE rhenium oxide polystyrene microspheres macro-mesoporous alumina
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Synthesis of Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ) and its catalytic performance on dry methane reforming 被引量:1
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作者 Dingwen Kang Jie Yu +3 位作者 Wenhui Ma min zheng Yunfei He Pengfei Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第6期585-593,共9页
In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts o... In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts on dry methane reforming was evaluated in a fixed-bed reactor at 550/650 ℃ and atmosphere pressure. Cu/Ni loading was investigated as an influencing factor, which led to 5 cases of samples according to the different Cu/Ni mass ratios. The catalysts were characterized by X-ray diffraction(XRD), field emissionscanning electron microscope(FE-SEM), Brunauer-Emmett-Teller(BET) measurement, X-ray photoelectron spectroscopy(XPS), hydrogen-based temperature-programmed reduction(H_2-TPR) and thermos gravimetric analyzer(TGA). The results show that the methane conversion increases, the resistance against metal sintering increases and the carbon deposition drops after the copper is introduced. This optimum performance can be obtained under Case 3(Cu:Ni:LSCM = 1:3:6 in mass ratio). 展开更多
关键词 Cu/Ni-LSCM Characterization DRY METHANE REFORMING Carbon DEPOSITION RARE earths
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Preparation of mesoporous alumina with large pore size and their supported rhenium oxide catalysts in metathesis of 1-butene and 2-butene to propene 被引量:1
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作者 Lei Sang Sheng-Li Chen +5 位作者 Guimei Yuan zheng Zhou Rui Li Aicheng Chen min zheng Ju You 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第3期352-359,共8页
Mesoporous γ-aluminas with large pore size (up to 19 nm, denoted as MAI9) are prepared from dispersed pseudo-boehmite using pluronic P123 as template. It is found that these mesoporous alumina supported rhenium oxi... Mesoporous γ-aluminas with large pore size (up to 19 nm, denoted as MAI9) are prepared from dispersed pseudo-boehmite using pluronic P123 as template. It is found that these mesoporous alumina supported rhenium oxide catalysts were more active and have far longer working life-span in gas-phase metathesis of 1-butene and 2-butene to propene than rhenium oxide on conventional alumina with small pore size (5 nm). At 60 ℃ and atmospheric pressure with WHSV = 1 h^-1, the similar stable conversions of butene (ca. 55%) for all the 13 wt% Re207/alumina catalysts were obtained near the chemical equilibrium, and the stable working life-spans of Re2OT/MA19 were far longer than that of Re2O7/A1203, being about 70 h and 20 h, respectively. 展开更多
关键词 mesoporous alumina rhenium oxide METATHESIS BUTENE PROPENE
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疏水改性纳米氧化镁对短氟碳链泡沫性能影响
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作者 欧红香 闵政 +3 位作者 薛洪来 曹海珍 毕海普 王钧奇 《化工进展》 EI CAS CSCD 北大核心 2024年第9期5177-5184,共8页
为了解决短氟碳链泡沫稳定性差的缺点,采用硬脂酸对氧化镁纳米颗粒(MNPs)疏水改性得到不同水接触角的G-MNPs,研究疏水改性MNPs对短氟碳链泡沫性能和灭火性能的影响。采用硬脂酸对MNPs分别改性60min、90min、120min和150min,测试了G-MNP... 为了解决短氟碳链泡沫稳定性差的缺点,采用硬脂酸对氧化镁纳米颗粒(MNPs)疏水改性得到不同水接触角的G-MNPs,研究疏水改性MNPs对短氟碳链泡沫性能和灭火性能的影响。采用硬脂酸对MNPs分别改性60min、90min、120min和150min,测试了G-MNPs表面形态、粒径分布、疏水性、热稳定性以及溶液分散度,研究了疏水改性对泡沫稳定性、发泡能力、泡沫粗化、灭火性能和抗烧性能等的影响。结果表明,硬脂酸疏水改性时间为120min时,改性MNPs水接触角最大,达到138.4°;G-MNPs表面形貌粗糙度增加,颗粒粒径增大,高温下热稳定性良好;疏水改性对泡沫溶液表面张力和黏度几乎没有影响;疏水角为90.0°时,G-MNPs泡沫溶液发泡性能、稳定性能、灭火性能、抗烧性能达到最佳。 展开更多
关键词 硬脂酸 疏水改性 纳米氧化镁 短氟碳链泡沫 灭火性能
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Analysis of Transmission Loss in Droop Control of a Multi-Terminal HVDC System
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作者 Xiaodong Zhao Kang Li min zheng 《Journal of Power and Energy Engineering》 2014年第4期564-572,共9页
High Voltage Direct Current (HVDC) electric power transmission is a promising technology for integrating offshore wind farms and interconnecting power grids in different regions. In order to maintain the DC voltage, d... High Voltage Direct Current (HVDC) electric power transmission is a promising technology for integrating offshore wind farms and interconnecting power grids in different regions. In order to maintain the DC voltage, droop control has been widely used. Transmission line loss constitutes an import part of the total power loss in a multi-terminal HVDC scheme. In this paper, the relation between droop controller design and transmission loss has been investigated. Different MTDC layout configurations are compared to examine the effect of droop controller design on the transmission loss. 展开更多
关键词 MTDC HVDC VSC TRANSMISSION LOSS Droop CONTROL
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含瓦斯煤经典扩散模型数学关系研究 被引量:4
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作者 薛洪来 闵政 温哲 《煤矿安全》 CAS 北大核心 2024年第10期1-8,共8页
含瓦斯煤扩散模型形式多样,而模型之间的数学关系有待明确。研究了20种经典的含瓦斯煤扩散模型,根据模型特点将其分为常规扩散模型、动态扩散模型和经验扩散模型3类,通过等价、近似数学转换发现同类扩散模型存在数学关系。为了探究3类... 含瓦斯煤扩散模型形式多样,而模型之间的数学关系有待明确。研究了20种经典的含瓦斯煤扩散模型,根据模型特点将其分为常规扩散模型、动态扩散模型和经验扩散模型3类,通过等价、近似数学转换发现同类扩散模型存在数学关系。为了探究3类扩散模型之间的关系,以常规扩散模型为基础,基于煤体分形孔隙结构特性建立了动态扩散系数模型,通过观察扩散系数与时间的关系进而推导出了动态扩散系数模型,建立了动态扩散模型与常规扩散模型的数学关系;以煤基质立方体几何模型为假设条件,结合Fick定律与动态扩散模型,推导出了经验扩散模型,建立了经验扩散模型与动态扩散模型的关系。 展开更多
关键词 含瓦斯煤 瓦斯扩散 扩散模型 经典模型 数学关系
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纳米氢氧化镁对无氟泡沫灭火剂性能的影响
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作者 陈合敏 欧红香 +3 位作者 薛洪来 闵政 曹海珍 王钧奇 《化工进展》 EI CAS CSCD 北大核心 2024年第11期6390-6396,共7页
以聚醚改性三硅氧烷、CTAB为表面活性剂,以纳米氢氧化镁、黄原胶为稳泡剂制备无氟泡沫灭火剂,采用L9(34)正交表分析泡沫溶液表面张力、发泡性能及稳泡性能,选用正交优化后的泡沫配方进行灭火和抗烧实验研究。研究结果表明:复配体系泡沫... 以聚醚改性三硅氧烷、CTAB为表面活性剂,以纳米氢氧化镁、黄原胶为稳泡剂制备无氟泡沫灭火剂,采用L9(34)正交表分析泡沫溶液表面张力、发泡性能及稳泡性能,选用正交优化后的泡沫配方进行灭火和抗烧实验研究。研究结果表明:复配体系泡沫溶液黏度较低,在1.00~1.21mPa·s之间;由质量分数为0.8%的CTAB与12%的聚醚改性三硅氧烷组成的泡沫溶液表面张力最低,为19.73mN/m;聚醚改性三硅氧烷与CTAB协同作用,增强了溶液发泡性能与泡沫稳定性,当纳米氢氧化镁的质量分数为0.5%时,溶液的发泡高度最优,达到207mm,25%析液时间从205s增长到216s;用质量分数为1.2%CTAB、12%聚醚改性三硅氧烷、0.5%纳米氢氧化镁及0.05%黄原胶制备的泡沫灭火剂扑灭油盘面积为0.25m^(2)的正庚烷火,灭火时间为107s,抗烧时间达到372s。 展开更多
关键词 纳米氢氧化镁 表面活性剂 泡沫稳定性 灭火性能 无氟泡沫灭火剂
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Tackling the proton limit under industrial electrochemical CO_(2)reduction by a local proton shuttle
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作者 Tianye Shao Kang Yang +4 位作者 Sheng Chen min zheng Ying Zhang Qiang Li Jingjing Duan 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期233-243,共11页
Industrial CO_(2)electroreduction has received tremendous attentions for resolution of the current energy and environmental crisis,but its performance is greatly limited by mass transport at high current density.In th... Industrial CO_(2)electroreduction has received tremendous attentions for resolution of the current energy and environmental crisis,but its performance is greatly limited by mass transport at high current density.In this work,an ion‐polymer‐modified gas‐diffusion electrode is used to tackle this proton limit.It is found that gas diffusion electrode‐Nafion shows an impressive performance of 75.2%Faradaic efficiency in multicarbon products at an industrial current density of 1.16 A/cm^(2).Significantly,in‐depth electrochemical characterizations combined with in situ Raman have been used to determine the full workflow of protons,and it is found that HCO_(3)^(−)acts as a proton pool near the reaction environment,and HCO_(3)^(−)and H_(3)O^(+)are local proton donors that interact with the proton shuttle−SO_(3)^(−)from Nafion.With rich proton hopping sites that decrease the activation energy,a“Grotthuss”mechanism for proton transport in the above system has been identified rather than the“Vehicle”mechanism with a higher energy barrier.Therefore,this work could be very useful in terms of the achievement of industrial CO_(2)reduction fundamentally and practically. 展开更多
关键词 industrial CO_(2)electroreduction proton donor proton pool proton shuttle proton transport mechanism
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基于DDES的离心泵蜗壳内部涡动力学研究 被引量:11
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作者 敏政 朱月龙 +1 位作者 黎义斌 张梅 《西华大学学报(自然科学版)》 CAS 2019年第4期16-21,共6页
为研究离心泵蜗壳内部涡结构、涡演化的过程,基于DDES湍流模型和涡动力学的涡量对离心泵多工况下的旋涡运动进行非定常数值模拟。研究表明:对比外特性数值预测和试验数据,两者差值在允许的范围内,表明延迟分离涡方法的可靠性;对比涡量云... 为研究离心泵蜗壳内部涡结构、涡演化的过程,基于DDES湍流模型和涡动力学的涡量对离心泵多工况下的旋涡运动进行非定常数值模拟。研究表明:对比外特性数值预测和试验数据,两者差值在允许的范围内,表明延迟分离涡方法的可靠性;对比涡量云图,DDES湍流模型较RNGk-ε湍流模型能清晰地看到由大旋涡破裂而成的小旋涡,能更好地模拟精细流场结构;蜗壳内的旋涡主要集中在进口和隔舌附近,旋涡随着流体一起运动,在运动的过程中,大旋涡破裂为许多小旋涡,同时涡量逐渐减小;随着流量的增加,流道内旋涡的分布范围逐渐减少,同时涡量也逐渐减小;在蜗壳第三断面处,沿径向取3个压力脉动监测点,发现随着直径的增大,压力脉动幅度逐渐减弱,同时隔舌位置的压力脉动远大于蜗壳其他位置。 展开更多
关键词 离心泵 蜗壳 DDES模型 涡动力学 压力脉动
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HL638-WJ-84型水轮机增容改造及数值预测 被引量:2
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作者 敏政 岳巧萍 +1 位作者 田亚平 韩伟 《兰州理工大学学报》 CAS 北大核心 2018年第2期65-69,共5页
在无合适的新型转轮替代老转轮的情况下,可以采用减少叶片数以及切割叶片出水边的方法得到易于实施的改型转轮,从而达到增容改造目的.运用三维建模软件Pro/E进行建模,ICEM进行网格划分(非结构化网格),选用标准k-ω流模型以及SIMPLEC算法... 在无合适的新型转轮替代老转轮的情况下,可以采用减少叶片数以及切割叶片出水边的方法得到易于实施的改型转轮,从而达到增容改造目的.运用三维建模软件Pro/E进行建模,ICEM进行网格划分(非结构化网格),选用标准k-ω流模型以及SIMPLEC算法,Fluent 14.5进行水轮机全流道定常模拟计算,可以得到比较准确的水轮机外特性预测结果.水轮机全流动数值模拟计算可以为增容改造方案的可行性提供依据.以HL638-WJ-84型水轮机为研究对象,以减少转轮叶片数且切割出水边为改型方案,数值模拟了不同工况下改型前后水轮机的内部流动.外特性结果表明:改造后水轮机的最优效率区向大流量区域偏移,当转轮运行在限制工况时,改型后转轮出力比改造前增加16.35%.据此方案改造转轮,机组实际增容23%. 展开更多
关键词 转轮 增容改造 数值模拟 叶片数 切割叶片
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减少叶片数后水轮机水力性能的CFD预估及应用 被引量:1
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作者 敏政 田亚平 +2 位作者 张学光 朱月龙 韩伟 《兰州理工大学学报》 CAS 北大核心 2019年第2期58-62,共5页
针对小型径流式电站卧式水轮机在夏季汛期运行中频繁堵塞而影响正常发电的问题,从增加水轮机出力与过流能力的角度考虑减少叶片数进行改造.利用数值模拟的方法对不同工况下改造前后的水轮机全流道进行数值计算,研究改造前后叶片表面的... 针对小型径流式电站卧式水轮机在夏季汛期运行中频繁堵塞而影响正常发电的问题,从增加水轮机出力与过流能力的角度考虑减少叶片数进行改造.利用数值模拟的方法对不同工况下改造前后的水轮机全流道进行数值计算,研究改造前后叶片表面的压力分布,着重分析改造前后叶片数对水轮机水力性能和气蚀性能的影响,得到改造前后的水轮机动力学差异.减少叶片数,叶片间开口增大,机组的防堵塞性能得到改善.计算结果还表明改造后机组可增容6%,最优工况点向大流量区偏移.所得结果可用于HLD06A-WJ-84水轮机的实际改造并指导电站的运行. 展开更多
关键词 混流式水轮机 叶片数 流道堵塞 数值模拟 增容改造
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低比转速泵反转透平性能换算修正方法 被引量:3
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作者 王晓晖 夏正廷 +2 位作者 敏政 郝艳 匡开林 《流体机械》 CSCD 北大核心 2019年第10期24-29,共6页
离心泵反转作透平(PAT)可回收液体能量。泵工况和透平工况流量、扬程换算关系Ht/Hp、Qt/Qp是PAT选型设计与性能预测的关键,而现有的换算关系对低比转速PAT误差较大。通过分析放大系数及速度滑移对低比转速PAT性能换算关系的影响,得到一... 离心泵反转作透平(PAT)可回收液体能量。泵工况和透平工况流量、扬程换算关系Ht/Hp、Qt/Qp是PAT选型设计与性能预测的关键,而现有的换算关系对低比转速PAT误差较大。通过分析放大系数及速度滑移对低比转速PAT性能换算关系的影响,得到一种性能换算的修正方法。对比转速为33~86的8台PAT采用数值模拟软件FLUENT 17.0进行数值计算,分别得出其扬程、流量换算关系的修正系数。该修正系数与比转速的关系通过多项式拟合得到。采用已公开的7台低比转速PAT试验结果验证,与其他方法相比采用该修正系数计算的Ht/Hp、Qt/Qp误差约减小3%~15%。针对低比转速PAT的选型设计和性能预测该方法可提供理论指导。 展开更多
关键词 离心泵 泵反转液力透平 低比转速 换算关系 修正系数
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