期刊文献+
共找到107,719篇文章
< 1 2 250 >
每页显示 20 50 100
Linear relationship between reactivity and the reciprocal of uranium concentration in thermal‑spectrum molten salt reactors
1
作者 Chang-Qing Yu Gui-Feng Zhu +7 位作者 Shu-Yang Jia Yang Zou Rui Yan Jian Guo Ya-Fen Liu Bo Zhou Xue-Chao Zhao Xiao-Han Yu 《Nuclear Science and Techniques》 2026年第2期208-222,共15页
Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain... Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of ^(235) U;similarly,the reciprocal of ^(235)U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors. 展开更多
关键词 Molten salt reactor REACTIVITY Uranium concentration Cross sections LINEAR
在线阅读 下载PDF
pH-dependent electrochemical oxidation of 5-hydroxymethylfurfural:Reaction mechanism,catalyst design,and reactor design across alkaline to acidic media
2
作者 Peiyun Zhou Xikang Zhao +2 位作者 Yang Song Ruixiang Ge Haohong Duan 《Smart Molecules》 2026年第1期45-67,共23页
The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,effic... The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,efficiency,and catalyst stability are strongly dependent on the electrolyte pH environment.Under alkaline conditions,high OH−concentration facilitates preferential aldehyde group oxidation and efficient deprotonation,enabling highly efficient synthesis of 2,5-furandicarboxylic acid,but simultaneously induces HMF self-degradation and complicates product separation.As pH decreases,the reaction mechanism shifts toward enhanced hydroxymethyl oxidation,leading to intermediate accumulation(such as 5-hydroxymethyl-2-furancarboxylic acid,2,5-diformylfuran,and 5-formyl-2-furancarboxylic acid)with challenging selectivity control and significantly slowed reaction kinetics.This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions.Addressing the distinct reaction characteristics and core challenges in alkaline,near-neutral,and acidic media,we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects.Future research should focus on process integration(with tailored reactor design)for energy consumption reduction in alkaline systems,targeted synthesis of diverse oxidation products in near-neutral systems,and innovative catalyst development for acidic systems,thereby advancing the efficiency,selectivity,and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst,reactor,and process. 展开更多
关键词 biomass valorization electrocatalyst design full pH HMF electrooxidation reaction mechanism reactor design
在线阅读 下载PDF
Conceptual design and preliminary feasibility study of fluid‑driven suspended control rods for molten salt reactors
3
作者 Jin‑Tong Cao Gui‑Feng Zhu +4 位作者 Chang‑Qing Yu Ya‑Fen Liu Yang Zou Rui Yan Hong‑Jie Xu 《Nuclear Science and Techniques》 2026年第1期225-243,共19页
Molten salt reactors,being the only reactor type among Generation Ⅳ advanced nuclear reactors that utilize liquid fuels,offer inherent safety,high-temperature,and low-pressure operation,as well as the capability for ... Molten salt reactors,being the only reactor type among Generation Ⅳ advanced nuclear reactors that utilize liquid fuels,offer inherent safety,high-temperature,and low-pressure operation,as well as the capability for online fuel reprocessing.However,the fuel-salt flow results in the decay of delayed neutron precursors(DNPs)outside the core,causing fluctuations in the effective delayed neutron fraction and consequently impacting the reactor reactivity.Particularly in accident scenarios—such as a combined pump shutdown and the inability to rapidly scram the reactor—the sole reliance on negative temperature feedback may cause a significant increase in core temperature,posing a threat to reactor safety.To address these problems,this paper introduces an innovative design for a passive fluid-driven suspended control rod(SCR)to dynamically compensate for reactivity fluctuations caused by DNPs flowing with the fuel.The control rod operates passively by leveraging the combined effects of gravity,buoyancy,and fluid dynamic forces,thereby eliminating the need for an external drive mechanism and enabling direct integration within the active region of the core.Using a 150 MWt thorium-based molten salt reactor as the reference design,we develop a mathematical model to systematically analyze the effects of key parameters—including the geometric dimensions and density of the SCR—on its performance.We examine its motion characteristics under different core flow conditions and assess its feasibility for the dynamic compensation of reactivity changes caused by fuel flow.The results of this study demonstrate that the SCR can effectively counteract reactivity fluctuations induced by fuel flow within molten salt reactors.A sensitivity analysis reveals that the SCR’s average density exerts a profound impact on its start-up flow threshold,channel flow rate,resistance to fuel density fluctuations,and response characteristics.This underscores the critical need to optimize this parameter.Moreover,by judiciously selecting the SCR’s length,number of deployed units,and the placement we can achieve the necessary reactivity control while maintaining a favorable balance between neutron economy and heat transfer performance.Ultimately,this paper provides an innovative solution for the passive reactivity control in molten salt reactors,offering significant potential for practical engineering applications. 展开更多
关键词 Molten salt reactor DNP flow-induced reactivity Passive control Suspended control rod
在线阅读 下载PDF
Mass transfer and kinetic behavior studies on cycloaddition of carbon dioxide with propylene oxide catalyzed by ionic liquid in microchannel reactor
4
作者 Yiqian Yang Yu Chen +4 位作者 Gang Wang Hanwen Yan Lili Wang Shuguang Xiang Chunshan Li 《Chinese Journal of Chemical Engineering》 2026年第1期187-197,共11页
The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here... The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here,we proposed a microchannel reaction system for the CO_(2) cycloaddition reaction catalyzed by ionic liquid within an aqueous environment.The effect of liquid flow rate,temperature and residence time on gas-liquid flow pattern,catalytic performance and mass transfer were systematically investigated.The results revealed that the PC generation rate reached 560.11 mmol·ml^(−1)·h^(−1)at a 50 cm of flow distance under reaction conditions of 105℃,2.5 MPa,QG=176 ml·min^(−1) and QL=0.3 ml·min^(−1).Variations in mass transfer rate and reaction rate at different flow distances were experimentally studied.The reaction efficiency gradually decreased with increasing flow distance,which were attributed to the reduction of mass transfer caused by decreasing bubble velocity.Optimizing bubble velocity at an appropriate position enhanced reaction efficiency by improving mass transfer,achieving a 97.7%PC yield within 2.85 min.Furthermore,a kinetic model coupling intrinsic kinetics with gas-liquid mass transfer was developed for CO_(2) cycloaddition reaction.The kinetic model was applied to predict PC reaction rates in microchannel reactors at various temperatures and liquid flow rates,achieving an average relative error of 9.6%. 展开更多
关键词 Co_(2)cycloaddition Ionic liquid Microchannel reactor Mass transfer Kinetic model
在线阅读 下载PDF
Efficient control and removal of laser‑generated aerosol particles by combining water spray with pre‑injection of electrical charged mist for nuclear reactor decommissioning
5
作者 Ruicong Xu Avadhesh Kumar Sharma +6 位作者 Zeeshan Ahmed Ravinder Kumar Laffolley Hugo Ryo Yokoyama Shuichiro Miwa Shunichi Suzuki Atsushi Kosuge 《Nuclear Science and Techniques》 2026年第1期244-262,共19页
Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generat... Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control. 展开更多
关键词 Laser-induced aerosol generation Aerosol removal Electrically charging mist AGGLoMERATIoN Water spray scavenging reactor decommissioning
在线阅读 下载PDF
Comparing of small and large optimal tapered cascades for supplying enriched uranium for fresh fuel production in the equilibrium cycle of a nuclear power reactor
6
作者 S.L.Mirmohammadi J.Safdari A.A.Ghorbanpour Khamseh 《Nuclear Science and Techniques》 2026年第3期208-234,共27页
One of the main issues in designing optimum tapered cascades for uranium enrichment for annual fuel production in a power reactor is whether to employ large(fat)or small(thin)cascades.What will be the permissible and ... One of the main issues in designing optimum tapered cascades for uranium enrichment for annual fuel production in a power reactor is whether to employ large(fat)or small(thin)cascades.What will be the permissible and optimal ranges of the number of machines that can be used in a cascade?For the first time,the permissible and optimal ranges of the number of gas centrifuges that can be utilized in a cascade were investigated using two types of centrifuges,and the performance of small and large tapered cascades was discussed.The particle swarm optimization algorithm(PSO)has been used to optimize tapered cascades.The results show:(1)For the first centrifuge,41 cascades(91≤n≤4897)and for the second centrifuge,49 cascades(18≤n≤3839)with small and large sizes can be used in enrichment facilities,and the best cascade for them has 530(with 23 stages)and 39(with 7 stages)centrifuges,respectively.(2)For both centrifuges,when 600≤n(number of centrifuges=n),the large cascade performance changes are relatively insignificant.(3)For both types of gas centrifuges,the annual los s of separation power in enrichment facilities is approximately 1.25%-4.82%of the total separation work required. 展开更多
关键词 Small tapered cascade(thin) Large tapered cascade(fat) Enriched uranium fuel Power reactor PSo algorithm
在线阅读 下载PDF
Correction:Uncertainty and sensibility analysis of loss-of-forced-cooling accidents for 150-MWt molten salt reactors
7
作者 Kai Wang Chao-Qun Wang +2 位作者 Qun Yang Zhao-Zhong He Na-Xiu Wang 《Nuclear Science and Techniques》 2026年第5期394-394,共1页
Correction to:Nuclear Science and Techniques(2025)36:111 https://doi.org/10.1007/s41365-025-01681-9.In the sentence beginning‘The weights of the parameters used for the…’in this article,the text‘RCSs’should have ... Correction to:Nuclear Science and Techniques(2025)36:111 https://doi.org/10.1007/s41365-025-01681-9.In the sentence beginning‘The weights of the parameters used for the…’in this article,the text‘RCSs’should have read‘SCRs’.In Table 7 of this article,the column header ρ_fuel was incorrect and should have read CPv_fuel.For completeness and transparency,the old incorrect version and the corrected version of Table 7 are displayed below. 展开更多
关键词 uncertainty analysis molten salt reactors loss forced cooling accidents nuclear science techniques weights parameters sensitivity analysis
在线阅读 下载PDF
Unveiling the fluid dynamics and mass transfer processes in a spatially confined flow-through electrochemical reactor
8
作者 Yunqing Zhu Yirong Hao +3 位作者 Tian Wang Fan Pan Hongtao Yu Junfeng Niu 《Journal of Environmental Sciences》 2026年第2期528-536,共9页
Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed f... Electrocatalytic oxidation is a promising technology for wastewater treatment,but poor mass transfer and low current efficiency impaded its engineering applications.To address these issues,researchers have developed flow-through electrochemical reactors(FERs)primarily based on porous electrodes,where the pore structure significantly impacts the electrochemical reaction.Therefore,this study systematically investigated the impact of different pore sizes on the fluid dynamics,current potential distribution,mass transfer processes,and degradation performance of FERs.Computational Fluid Dynamics(CFD)results indicated that smaller pore sizes(10μm,30μm,and 60μm)significantly enhanced convective effects within the fluid,reduced short fluid paths and dead volume regions within the microchannels,and facilitated mass transfer processes.Additionally,smaller pore sizes were conducive to a uniform distribution of current density.Furthermore,Fe(CN)_(6)^(4−)oxidation experiments revealed that the current density at a pore size of 160μm was notably lower than that at 10μm,indicating slower mass transfer of Fe(CN)_(6)^(4−)within larger channels.Calculations based on experimental results demonstrated that the mass transfer rate at a pore size of 10μm was six times than that at 160μm,further confirming the enhancing effect of smaller pore sizes on the mass transfer process.Lastly,experiments on tetracycline degradation showed that at a residence time of 90 s,the removal efficiencies of tetracycline were 80%and 39.1%for porous electrodes with pore sizes of 10μm and 160μm,respectively,demonstrating the superior removal efficiency of smaller pore sizes for tetracycline degradation. 展开更多
关键词 Electrocatalytic oxidation technology Flow-through electrochemical reactor Computational fluid dynamics Mass transfer processes Current density distribution Porous electrode
原文传递
有机肥和生物菌剂对菜地土壤N_(2)O排放及土壤团聚体的影响 被引量:1
9
作者 马静 陆昕昱 +1 位作者 宋俊杰 孙丽英 《农业环境科学学报》 北大核心 2026年第1期251-261,共11页
为探究不同施肥处理对菜地土壤N_(2)O排放、产量及土壤团聚体的影响,本研究以南京地区菜地为研究对象,设置不施氮肥(CK)、施化学氮肥(U)、化学氮肥和生物菌剂配施(UM)、有机肥替代25%化学氮肥(O)、有机肥替代25%化学氮肥和生物菌剂配施(... 为探究不同施肥处理对菜地土壤N_(2)O排放、产量及土壤团聚体的影响,本研究以南京地区菜地为研究对象,设置不施氮肥(CK)、施化学氮肥(U)、化学氮肥和生物菌剂配施(UM)、有机肥替代25%化学氮肥(O)、有机肥替代25%化学氮肥和生物菌剂配施(OM)5个处理。采用静态暗箱-气相色谱法,观测菜地土壤N_(2)O的排放,并分析不同施肥处理对菜地土壤N_(2)O排放量、综合温室效应(GWP)、温室气体排放强度(GHGI)、产量、土壤团聚体组成、经济效益等的影响。结果表明:与U处理相比,O处理土壤N_(2)O累积排放量增长了12.70%,UM和OM处理土壤N_(2)O累积排放量均有所降低,其中,UM处理降低了16.67%,OM处理显著降低了23.81%(P<0.05)。在各施肥处理中,OM处理产量最高,为11.9 t·hm^(-2),O处理次之,为11.2 t·hm^(-2)。此外,O和OM处理降低了<0.25 mm团聚体占比,提高了土壤中大团聚体占比,增加了土壤团聚体稳定性。研究表明,有机肥配施生物菌剂处理可以减缓菜地土壤N_(2)O排放并提高作物产量和经济效益,是实现农业低碳高产的一种可行性措施。 展开更多
关键词 有机肥 生物菌剂 N_(2)o 团聚体 产量
在线阅读 下载PDF
副溶血弧菌O10:K4血清型O抗原基因簇的序列特征与分子血清型数据库构建
10
作者 俞骅 郑之北 +4 位作者 李钧 黄振洲 赵盼 曾令怡 郑伟 《疾病监测》 北大核心 2026年第1期87-93,共7页
目的分析副溶血弧菌O10:K4血清型O抗原基因簇的分子特征,并构建基于基因组的分子血清型预测数据库。方法从美国国家生物技术信息中心Assembly数据库获取副溶血弧菌O抗原基因簇序列,使用blastn、fastANI、Sourmash和p i x y工具分析序列... 目的分析副溶血弧菌O10:K4血清型O抗原基因簇的分子特征,并构建基于基因组的分子血清型预测数据库。方法从美国国家生物技术信息中心Assembly数据库获取副溶血弧菌O抗原基因簇序列,使用blastn、fastANI、Sourmash和p i x y工具分析序列相似性和多态性,使用g u b b i n s进行重组分析,并构建了副溶血弧菌分子血清型预测数据库。结果O10:K4的O抗原基因簇(OL10V1)与传统O10血清型基因簇(OL10)序列差异显著,而与OL4最为相似。公共数据库中116个OL10V1全长序列仅存在1个单核苷酸突变。OL10V1携带的IS1634和ISVa2转座酶基因广泛分布于弧菌属,提示该变异体可能通过水平基因转移形成。结论本研究揭示了O10:K4血清型快速传播的潜在分子机制,构建的分子血清型数据库可为基因组监测和溯源提供关键技术支撑。 展开更多
关键词 副溶血弧菌 o10:K4血清型 o抗原基因簇 水平基因转移 分子血清型
原文传递
小麦秸秆与生物炭配比对石灰性潮土N_(2)O气体排放的影响
11
作者 吕金岭 张燕 +4 位作者 纪朝凤 骆晓声 李太魁 肖强 董文旭 《农业资源与环境学报》 北大核心 2026年第2期424-433,共10页
为探明秸秆与秸秆生物炭配比对典型碱性土壤N_(2)O排放的影响,本研究以石灰性潮土为研究对象,设置CK(空白对照)、CK200(200 mg·kg^(-1)硫酸铵溶液,以N计,下同)、C(小麦秸秆生物炭+CK200)、S(小麦秸秆+CK200)以及三种组合方式(3/4SC... 为探明秸秆与秸秆生物炭配比对典型碱性土壤N_(2)O排放的影响,本研究以石灰性潮土为研究对象,设置CK(空白对照)、CK200(200 mg·kg^(-1)硫酸铵溶液,以N计,下同)、C(小麦秸秆生物炭+CK200)、S(小麦秸秆+CK200)以及三种组合方式(3/4SC、1/2SC和1/4SC)共计7个处理,开展室内培养试验。结果显示,小麦秸秆与秸秆生物炭配比显著促进了石灰性潮土N_(2)O气体排放,尤其3/4SC处理的N_(2)O累积排放量达到1459μg·kg^(-1),是S处理的2.0倍;其次为1/2SC处理,N_(2)O累积排放量为909μg·kg^(-1),是S处理的1.2倍;再次为1/4SC处理,N_(2)O排放略高于S处理,但无显著差异(P>0.05);而C处理的N_(2)O累积排放量显著低于S处理,仅是S处理的0.72倍。线性相关性结果显示,除CK处理外,氮添加处理的N_(2)O排放量与NO_(2)^(-)-N和NO_(3)^(-)-N含量存在显著的线性相关性(P<0.05),而与NH_(4)^(+)-N含量无显著的线性相关性(P>0.05);同时发现,相比S处理,1/2SC和C处理的AOA和nirS、nirK、nosZ功能基因的丰度显著降低(P<0.05),但AOB功能基因丰度无明显差异,说明生物炭对石灰性潮土硝化作用中氨氧化过程影响不大;1/2SC和C处理相比S处理拥有更低的反硝化功能基因nirS、nirK和nosZ拷贝数(P<0.05),说明秸秆生物炭添加抑制石灰性潮土反硝化功能微生物的丰度;同时1/2SC处理的(nirS+nirK)与nosZ的比值(6.6)高于S处理(5.3)和C处理(4.8),说明全量炭添加可以抑制石灰性潮土反硝化过程N_(2)O的产生,但两者配比可能加剧反硝化过程N_(2)O的产生。研究表明,小麦秸秆与秸秆生物炭配比在常规氮添加下并未抑制石灰性潮土N_(2)O气体排放,甚至加剧N_(2)O的排放,纯秸秆生物炭还田更有益于石灰性潮土N_(2)O的减排。 展开更多
关键词 小麦秸秆 生物炭 配比 N_(2)o排放量 石灰性潮土 功能基因
在线阅读 下载PDF
镍/可见光协同催化的溴代芳烃与醇的C—O键偶联反应
12
作者 高山 解鑫 刘元红 《有机化学》 北大核心 2026年第1期266-278,共13页
研究了镍/可见光协同催化的溴代芳烃/杂芳烃与醇的C—O键偶联反应.在456 nm蓝光的照射下,以有机光敏剂2,4,5,6-四(9-咔唑基)间苯二腈(4CzIPN)或者2,4,5,6-四(二苯胺基)间苯二腈(4DPAIPN)为光催化剂,以乙二醇二甲醚溴化镍(NiBr2•DME)、... 研究了镍/可见光协同催化的溴代芳烃/杂芳烃与醇的C—O键偶联反应.在456 nm蓝光的照射下,以有机光敏剂2,4,5,6-四(9-咔唑基)间苯二腈(4CzIPN)或者2,4,5,6-四(二苯胺基)间苯二腈(4DPAIPN)为光催化剂,以乙二醇二甲醚溴化镍(NiBr2•DME)、配体和碱为协同催化体系,高效地实现了烷基芳基醚类化合物的合成.该反应的可能历程为:Ni(0)中间体先与溴代芳烃发生氧化加成,再与醇进行配体交换;生成的Ni(II)中间体被激发态光催化剂氧化为Ni(III)中间体,继而发生还原消除反应.该反应具有良好的底物适用性,可以用于苄醇、一级醇与二级醇的转化,且官能团兼容性较好. 展开更多
关键词 镍催化 可见光 C—o键偶联 烷基芳基醚
原文传递
活性炭负载纳米铁材料对人工湿地脱氮和N_(2)O排放的影响
13
作者 郝桂珍 范慧双 +2 位作者 张南南 李振河 徐利 《环境工程技术学报》 北大核心 2026年第1期148-157,共10页
人工湿地是污水处理厂尾水深度处理的有效手段,但尾水中碳氮比(C/N)较低且化学需氧量(COD)难以被利用,导致传统人工湿地处理该类尾水时存在硝化、反硝化反应不完全的问题,且有大量N_(2)O气体(温室气体)产生并逸出至大气,生态效益欠佳。... 人工湿地是污水处理厂尾水深度处理的有效手段,但尾水中碳氮比(C/N)较低且化学需氧量(COD)难以被利用,导致传统人工湿地处理该类尾水时存在硝化、反硝化反应不完全的问题,且有大量N_(2)O气体(温室气体)产生并逸出至大气,生态效益欠佳。针对该问题,制备了活性炭负载纳米铁材料Fe-AC,设计构建了三组人工湿地(CW1、CW2、CW3),分别填加纯砾石(空白对照)、砾石+3%Fe-AC、砾石+8%Fe-AC,模拟污水处理厂尾水的低C/N水质,利用铁与碳两极间的电位差形成的微电解原理强化人工湿地的脱氮过程,探究不同Fe-AC投加比例对人工湿地脱氮和N_(2)O减排的影响,并分析其影响机制。结果表明:Fe-AC在人工湿地中可自发形成原电池释放电子和[H],作为电子供体促进氮的转化和提高微生物的活性。在人工湿地模拟进水COD 28 mg/L、TN 18 mg/L,即C/N=1.5的条件下,CW1、CW2、CW3的出水COD分别稳定在6.0、4.5、4.0 mg/L,去除率达到72%、83%、85%;总氮(TN)浓度分别稳定在14.0、0.5、0.4 mg/L,去除率达到22%、97%、97%,加入Fe-AC的人工湿地对COD和TN的去除效果显著;CW1、CW2和CW3的N_(2)O排放量分别为1 330.87、629.86、576.49μg/(m^(2)·h),与空白对照组(CW1)相比,CW2和CW3对N_(2)O的减排率分别达到52.72%和56.52%,加入Fe-AC对人工湿地N_(2)O的减排效果明显;加入Fe-AC的CW2和CW3内部拟杆菌门和甲基营养型菌属的丰度明显提高,其他与反硝化和有机物降解有关的功能菌也得到筛选和优化。综合三组人工湿地的运行效果,CW2中加入3%的Fe-AC即可满足对人工湿地脱氮效果的提升和N_(2)O气体的减排,比CW3中8%的Fe-AC更加经济合理。 展开更多
关键词 人工湿地 铁碳微电解 低碳氮比 N_(2)o 反硝化
在线阅读 下载PDF
废弃煤矿巷道CO_(2)“封存-利用”技术探索及转化效率研究
14
作者 来兴平 雷彤 +3 位作者 张楠 胡添龙 介凯 刘旭超 《西安科技大学学报》 北大核心 2026年第1期15-26,共12页
为应对全球二氧化碳减排的需求,探索利用废弃煤矿地下空间实现CO_(2)封存与资源化利用的新路径,以提升其环境与资源效益。提出了包含捕集、封存、转化、分离系统的废弃煤矿巷道CO_(2)“封存-利用”一体化技术,基于几何相似理论与固体氧... 为应对全球二氧化碳减排的需求,探索利用废弃煤矿地下空间实现CO_(2)封存与资源化利用的新路径,以提升其环境与资源效益。提出了包含捕集、封存、转化、分离系统的废弃煤矿巷道CO_(2)“封存-利用”一体化技术,基于几何相似理论与固体氧化物电解池(SOEC)技术构建巷道反应硐室与实验室微型反应腔之间尺度映射关系,形成室内试验-井下应用的参数对应体系;通过开展恒电流共电解试验以及气相色谱对气体成分分析,系统揭示反应温度与CO_(2)/H_(2)O气体比例对CO_(2)转化效率的影响。结果表明:在保持A/V不变的条件下,巷道反应硐室尺寸为2.4 m×6 m×3.6 m,对应有效反应面积为384 m^(2);法拉第效率随着温度的升高呈现出“先下降后升高”的特征,随着CO_(2)/H_(2)O气体比例的增加而降低,CO_(2)转化率随着温度升高而显著提升,随着CO_(2)/H_(2)O气体比例增加而降低,在温度为850℃、气体比例CO_(2)∶H_(2)O=1∶1的共电解条件下,CO_(2)实现最优转化效率,转化率达72.22%,法拉第效率为61.77%。研究为实现废弃煤矿巷道CO_(2)封存与高值化利用提供了理论依据与技术支撑。 展开更多
关键词 废弃煤矿 固体氧化物电解池 Co_(2)/H_(2)o共电解 法拉第效率 Co_(2)转化率 相似理论
在线阅读 下载PDF
一步法制备Ag_(2)O/Cl-GCN聚氨酯泡沫及其光敏抗菌活性
15
作者 陈黄琴 张洋林 +3 位作者 周士忠 刘坤 唐冬旭 李月生 《湖北科技学院学报》 2026年第2期106-114,共9页
为开发具备优异光敏抗菌功能的新型聚氨酯泡沫材料,本研究通过在聚氨酯(PU)合成过程中引入不同浓度(1 wt%、2 wt%、5 wt%)氧化银/氯掺杂石墨相氮化碳(Ag_(2)O/Cl-GCN)填料,一步法制备Ag_(2)O/Cl-GCN改性聚氨酯泡沫(APU),并同时赋予其高... 为开发具备优异光敏抗菌功能的新型聚氨酯泡沫材料,本研究通过在聚氨酯(PU)合成过程中引入不同浓度(1 wt%、2 wt%、5 wt%)氧化银/氯掺杂石墨相氮化碳(Ag_(2)O/Cl-GCN)填料,一步法制备Ag_(2)O/Cl-GCN改性聚氨酯泡沫(APU),并同时赋予其高效可见光抗菌能力。系统考察了填料浓度对APU泡沫材料热性能、抗菌性能(光照/黑暗条件)及细胞毒性的影响。采用热重分析、傅立叶变换红外光谱、X射线衍射、扫描电子显微镜、平板计数法、MTT及细胞活死染色等种表征技术进行分析。结果表明:相较于空白PU,所有APU泡沫均展现出显著的抗菌性能,抗菌率与Ag_(2)O/Cl-GCN填料浓度正相关,且光照下抗菌效果远优于黑暗条件。然而,填料添加量增加导致材料细胞毒性相应上升。综合权衡抗菌效能与生物安全性,2 wt%添加量的APU展现出最优综合性能。Ag_(2)O/Cl-GCN复合硬质聚氨酯泡沫材料具有优异的光敏抗菌性能和良好的生物相容性,有望成为各种医疗用品、汽车内饰等领域的理想材料。 展开更多
关键词 聚氨酯泡沫 光敏抗菌 抗菌性能 Ag_(2)o/Cl-GCN
在线阅读 下载PDF
基于P&T/GC-O-MS的食品包装材料挥发性异味成分释放行为研究
16
作者 王维刚 吕颖华 +6 位作者 唐桂芳 陈瑶 周芸 孟冬玲 黄世杰 张峻松 梁淼 《包装工程》 北大核心 2026年第5期80-89,共10页
目的确定食品包装材料中的挥发性异味物质,研究其释放动力学特性。方法采用吹扫捕集-气相色谱嗅闻质谱法(P&T/GC-O-MS)优化食品包装材料中挥发性成分鉴定方法,结合释放动力学模型分析异味成分在不同温度下的释放行为。结果吹扫捕集... 目的确定食品包装材料中的挥发性异味物质,研究其释放动力学特性。方法采用吹扫捕集-气相色谱嗅闻质谱法(P&T/GC-O-MS)优化食品包装材料中挥发性成分鉴定方法,结合释放动力学模型分析异味成分在不同温度下的释放行为。结果吹扫捕集条件对包装材料中挥发性成分释放量的影响从主到次顺序为样品杯温度、吹扫流量、萃取液体积、解吸温度,通过单因素和正交实验确定的最佳吹扫捕集条件为吹扫流量43 mL/min、样品杯温度33℃、萃取液体积15 mL、解吸温度245℃;利用GC-O法共嗅辨鉴定出12种异味物质,其中丁酸丁酯和壬醛的气味强度最高,乙酸丙酯、己醛、4-苯基-1-环己烯和丁基羟基甲苯的气味强度次之;不同吹扫温度下挥发性异味成分的平均释放速率均在0~5 min内最高,随后整体呈降低趋势,一级释放动力学模型可较好地描述异味物质的释放过程,随吹扫温度升高,释放速率常数k值由0.053升高至0.091,半衰期逐步降低,异味成分的释放活化能为15.06 kJ/mol。结论利用P&T/GC-O-MS建立了食品包装材料中挥发性异味成分的分析方法,鉴定出12种挥发性异味物质,明确了异味成分的释放动力学行为,为食品包装材料异味成分的分析鉴定及贮存条件确定提供参考与依据。 展开更多
关键词 食品包装材料 异味成分 吹扫捕集 气相色谱嗅闻 释放动力学
在线阅读 下载PDF
影响ENSO与夏季西北太平洋异常环流跨季节联系的关键因子
17
作者 赵妍 王璐 +3 位作者 程一峰 孙明 陈晓龙 朱嬿 《大气科学学报》 北大核心 2026年第2期258-271,共14页
夏季西北太平洋上的气旋性或反气旋性异常环流(简称西北太平洋异常环流,western North Pacific anomalous circulation,WNPAC)与前冬厄尔尼诺-南方涛动(El Niño-Southern Oscillation,ENSO)之间存在显著的跨季节联系,对东亚夏季气... 夏季西北太平洋上的气旋性或反气旋性异常环流(简称西北太平洋异常环流,western North Pacific anomalous circulation,WNPAC)与前冬厄尔尼诺-南方涛动(El Niño-Southern Oscillation,ENSO)之间存在显著的跨季节联系,对东亚夏季气候的季节预测至关重要。冬季ENSO与夏季WNPAC(简称ENSO-WNPAC)的相关性具有不稳定性,但导致这一现象的气候系统内部变率关键因子及相应的机理尚不明确。本研究利用两套独立的、大样本集合模拟的试验数据(FGOALS-LE和CESM-LE),通过对比成员间差异,揭示了影响ENSO-WNPAC相关性变化的关键因子和物理机制。研究结果表明,ENSO不同衰退类型事件发生比例的变化是导致ENSO-WNPAC相关性强弱变化的关键因子:ENSO-WNPAC相关性强(弱)时,对应较多(少)的慢速衰退型ENSO事件和较少(多)的持续性ENSO事件,而快速衰退型ENSO事件的比例则没有明显差异。进一步研究发现,ENSO事件衰退速度的变化可能与ENSO海温异常经向尺度的宽窄有关。 展开更多
关键词 西北太平洋反气旋 厄尔尼诺-南方涛动 内部变率 大样本集合模拟
在线阅读 下载PDF
单能量成像联合O-MAR技术在优化金属植入物患者口咽CT图像质量中的价值
18
作者 马文涛 张永县 +2 位作者 郭森林 刘云福 康天良 《CT理论与应用研究(中英文)》 2026年第2期265-274,共10页
目的:探讨联合使用不同keV虚拟单能量成像(VMI)和金属伪影抑制(O-MAR)技术在优化口腔金属植入物患者口咽部CT图像质量中的应用价值。方法:模体研究:以Philips IQon Spectral CT临床口咽部扫描方案为基准,对Catphan600模体CTP528模块进... 目的:探讨联合使用不同keV虚拟单能量成像(VMI)和金属伪影抑制(O-MAR)技术在优化口腔金属植入物患者口咽部CT图像质量中的应用价值。方法:模体研究:以Philips IQon Spectral CT临床口咽部扫描方案为基准,对Catphan600模体CTP528模块进行扫描,分别开启和不开启O-MAR重建66 keV、80~160 keV(间隔20keV)单能量图像并测算调制传递函数(MTF)。临床研究:回顾性分析口咽部CT检查55例,其中含高密度伪影25例,低密度伪影30例,分别开启和不开启O-MAR重建常规影像(CI)、66 keV、80~160 keV的单能量图像。选择伪影最严重的层面为伪影层面,相邻不受伪影干扰的层面为参考层面,测算伪影层面兴趣区的伪影系数(AI),伪影层面与参考层面兴趣区的CT值偏差ΔAv,参考层面兴趣区的绝对对比度(AC)和对比噪声比(CNR)。采用Likert三分量表对图像进行伪影抑制能力、新生伪影情况及伪影抑制区组织可信度等3个维度进行主观评价。结果:模体研究:启用O-MAR对MTF值无影响,使用VMI较CI图像的MTF值有约3%小幅降低;O-MAR联合VMI(VMI_(MAR))使用时,高/低密度伪影的伪影系数和高密度伪影的CT值偏差随能量水平的升高而降低,平均值由CI图像的125.89/192.47和166.04 HU降低到160 keV时的27.61/18.30和10.36 HU。低密度伪影的CT值偏差在100keV时最小为平均-4.35 HU。单独使用VMI时,高/低密度伪影的伪影系数平均数分别在120/160 keV时最低为65.16/125.31,CT值偏差平均值在160 keV时最小为12.87/-46.11 HU。图像的AC/CNR均随能量等级的升高而降低。O-MAR联合VMI使用时,当能量水平达到120 keV后主观评分在3个维度上均达到3分;单独使用VMI时主观评分最高为2分。结论:使用VMI联合O-MAR技术可有效降低口腔金属植入物伪影对周围组织观察的影响,选择120 keV左右的VMI_(MAR)图像可兼顾伪影抑制效果和图像对比度。 展开更多
关键词 光谱CT 金属伪影抑制 虚拟单能图 金属伪影抑制
原文传递
基于GC-O-MS的酸凝、酶凝奶酪挥发性风味比较及氨基酸含量分析
19
作者 徐颖 王欢 +1 位作者 荣良燕 李儒仁 《中国乳品工业》 北大核心 2026年第2期36-43,共8页
为探讨中西方奶酪风味差异,文章采用感官评价结合气相色谱-嗅闻-质谱(Gas chromatography-olfactometry-mass spectrometry,GC-O-MS)技术,检测并比较了4种奶酪样品(SNL、CNL、WTB、ZNL)的挥发性风味物质及游离氨基酸含量。结果表明,共... 为探讨中西方奶酪风味差异,文章采用感官评价结合气相色谱-嗅闻-质谱(Gas chromatography-olfactometry-mass spectrometry,GC-O-MS)技术,检测并比较了4种奶酪样品(SNL、CNL、WTB、ZNL)的挥发性风味物质及游离氨基酸含量。结果表明,共检测到47种挥发性化合物,其中SNL和CNL分别含有24种和25种,WTB和ZNL分别含有16种和11种。SNL氨基酸含量最高,其次为CNL、WTB和ZNL。分析表明,ZNL具有显著的奶香、果香和烤面包香气,且酸属性得分较低,使其在整体香气平衡与协调上表现优异,喜好度评分最高。文章通过系统分析不同奶酪的挥发性化合物及氨基酸成分,为中西方奶酪的风味特征提供了数据支持,也为未来的产品开发和市场定位提供参考。 展开更多
关键词 奶酪 感官评价 气相色谱-嗅闻-质谱技术 挥发性风味物质
在线阅读 下载PDF
利拉鲁肽通过上调叉头框转录因子O3改善肾小管间质损伤机制的研究
20
作者 康惠敏 方昕 《中国糖尿病杂志》 北大核心 2026年第1期52-57,共6页
目的探讨利拉鲁肽(Lir)通过上调叉头框转录因子O3(FoxO3)改善肾小管间质损伤的机制。方法将24只C57BL/6小鼠分为正常对照(NC)、DM及Lir干预(Lir)组,每组8只。Masson及过碘酸希夫染色检测肾小管间质纤维化及肾小管损伤情况,免疫组织化学... 目的探讨利拉鲁肽(Lir)通过上调叉头框转录因子O3(FoxO3)改善肾小管间质损伤的机制。方法将24只C57BL/6小鼠分为正常对照(NC)、DM及Lir干预(Lir)组,每组8只。Masson及过碘酸希夫染色检测肾小管间质纤维化及肾小管损伤情况,免疫组织化学染色和Western blot检测肾脏中肾小管上皮细胞凋亡及FoxO3蛋白表达,试剂盒检测血肌酐(Scr)、BUN、胱抑素C(CysC)和中性粒细胞明胶酶相关脂质运载蛋白(NGAL)水平。结果DM组Scr、BUN、CysC、NGAL、蓝色胶原纤维面积百分比、肾小管损伤指数、活化的胱天蛋白酶3蛋白表达高于NC、Lir组(P<0.05),FoxO3阳性面积百分比低于NC、Lir组(P<0.05)。结论Lir可有效改善DM肾损伤,其潜在机制可能是通过上调FoxO3表达,减少肾小管上皮细胞凋亡,改善肾小管损伤,进而改善肾小管间质纤维化进展。 展开更多
关键词 胰高血糖素样肽-1受体激动剂 利拉鲁肽 叉头框转录因子o3 肾小管间质损伤
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部