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霉变烟叶的GC-MS和FTIR分析及鉴别

光谱学与光谱分析 2025年第1期45卷 88-94页

作者：叶艳青张海瑜沈迪乐志伟吴玉萍孔光辉张建荣田孟玉陈建华张承明王晋云南民族大学化学与环境学院云南昆明650504 云南中烟工业责任公司技术中心云南昆明650106 红云红河烟草(集团)有限责任公司昆明卷烟厂云南昆明650231 云南省烟草农业科学研究院云南昆明650031

采用GC-MS和FTIR分析,结合PCA、PLS等多元分析方法,对霉变烟叶进行评价鉴别。GC-MS分析筛选得到2-乙基己醇等9个烟叶霉变标记物。通过4-羟基丁酸内酯等9个关键化合物构建的线性判别方程,可以实现烟叶霉变准确识别,初始验证准确率100%和... 详细信息

采用GC-MS和FTIR分析,结合PCA、PLS等多元分析方法,对霉变烟叶进行评价鉴别。GC-MS分析筛选得到2-乙基己醇等9个烟叶霉变标记物。通过4-羟基丁酸内酯等9个关键化合物构建的线性判别方程,可以实现烟叶霉变准确识别,初始验证准确率100%和留一交叉验证准确率为98.7%。FTIR研究表明,烟叶霉变过程中消耗了烟叶大量的碳水化合物、蛋白质和脂质等。GC-MS和FTIR,分别结合PCA和PLS-DA能实现霉变烟叶的有效判别。

关键词：霉变烟叶气相色谱-质谱联机傅里叶变换红外光谱多元统计分析

Influences of pore fluid on gas production from hydrate-bearing reservoir by depressurization

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Petroleum Science 2023年第2期20卷 1238-1246页

作者： Yi-Fei Sun Bo-Jian Cao Hong-Nan Chen Yin-Long Liu jin-rong Zhong Liang-Liang Ren guang-jin Chen Chang-Yu Sun Dao-Yi Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Division of Ocean Science and Technology Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenGuangdong 518055China School of Chemistry and Food Engineering Changsha University of Science&TechnologyChangshaHunan 410114China Oilfield Chemicals R&D Institute COSLHebei 065201China

In addition to the temperature and pressure conditions,the pore fluid composition and migration behavior are also crucial to control hydrate decomposition in the exploitation *** this work,to investigate the effects of these factors,a series of depressurization experiments were carried out in a visible one-dimensional reactor,using hydrate reservoir samples with water saturations ranging from 20%to 65%.The results showed a linear relationship between gas production rates and gas saturations of the reservoir,suggesting that a larger gas-phase space was conducive to hydrate decomposition and gas ***,the rapid water production in the early stage of hydrate exploitation could release more gas-phase space in the water-rich reservoir,which in turn improved the gas production ***,the spatiotemporal evolution of pore fluids could lead to partial accelerated decomposition or secondary formation of *** the unsealed reservoir,the peripheral water infiltration kept reservoir at a high water saturation,which hindered the overall production process and caused higher water ***,depressurization assisted with the N2 sweep could displace the pore water *** to the results,it is recommended that using the short-term N2 sweep as an auxiliary means in the early stage of depressurization to expand the gas-phase space in order to achieve the highest production efficiency.

关键词： CH4 hydrate Water saturation Depressurization Gas-phase space N2 sweep

On the asymptotic expressions of critical energy barrier in Prandtl-Tomlinson model

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International Journal of Smart and Nano Materials 2019年第2期10卷 107-115页

作者： rong-guang Xu Yuan Xiang Qi Rao Yongsheng Leng Department of Mechanical and Aerospace Engineering The George Washington UniversityWashingtonDCUSA

The Prandtl-Tomlinson(PT)model is the most widely used and successful minimalistic model to describe atomistic scale *** can describe the thermally activated,stress assistant process which shows stick-slip frictional *** relationship between the energy barrier and lateral force is critical to determine how the frictional force depends on velocity and *** is some confusion in the literature to derive such *** underlying assumption and approximations are not stated in a clear way and the rigorous derivations are *** study discusses the asymptotic behavior of the energy barrier as the support-spring coupling lowers it to zero and gives a detailed derivation of the asymptotic expression of the energy barrier within the framework of PT model.

关键词： Prandtl-Tomlinson model friction stick-slip friction force microscope

The impact of radicals in cold atmospheric plasma on the structural modification of gap junction:a reactive molecular dynamics study

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International Journal of Smart and Nano Materials 2019年第2期10卷 144-155页

作者： rong-guang Xu Zhitong Chen Michael Keidar Yongsheng Leng Department of Mechanical and Aerospace Engineering The George Washington UniversityWashingtonDCUSA

Cold atmospheric plasmas are currently gaining increasing attention for cancer ***,very limited studies regarding the interaction mechanisms between plasma species and tissues are *** report the interaction of plasma produced species(^(*)OH and HO_(2)^(*))with gap junction by employing reactive molecular dynamics *** results indicate ^(*)OH and HO_(2)^(*) radicals can chemically react with N-terminal of gap junction resulting in its structural *** are two breaking mechanisms being identified:C-N peptide bonds and C-C bonds can be damaged by ^(*)OH and HO_(2)^(*) radicals,*** findings could be particularly important for understanding the plasma-generated reactive species triggering bystander effect based on gap junction intercellular communication.

关键词： Cold atmospheric plasma reactive species molecular dynamics bystander effect gap junction

Fractionated and Confined Crystallization of Polybutene-1 in Immiscible Polypropylene/Polybutene-1 Blends

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Chinese Journal of Polymer Science 2018年第7期36卷 859-865页

作者： Yao Xu Chen-guang Liu Hua-rong Nie Ai-Hua He Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization Key Laboratory of Rubber-Plastics (Ministry of Education) School of Polymer Science and Engineering Qingdao University of Science and Technology

In this work, the crystallization of immiscible polypropylene （PP）/polybutene-1 （PB） blends, in particular the effect of crystal morphology of PP （HTC, high Tm component） on the subsequent crystallization behavior of PB （LTC, low Tm component） was studied. Herein, we firstly indicated that PP/PB blends were not completely compatible but characterized as the LCST-like phase diagram above the melting temperature of PP. Crystallization of PP at different crystallization temperatures brought about different PP crystal morphologies and PB was segregated and confined at different locations. Much larger-sized domain of PB component appeared in PP spherulites resulting from the effects of non-negligible phase separation and the slower PP crystallization rate as PP crystallized at high temperature. As temperature continued to fall below Tm of PB, the fractionated and confined crystallization of PB occurred in the framework of PP spherulites, reflected by the decreased crystallization temperature （To） of PB and the formation of form I＇ beside form II. Notably, if PP previously crystallized at high Tc, fractionated crystallization of PB became predominant and confined crystallization of PB became weak due to the much wider droplet-size distribution of PB domains.

关键词： Polypropylene Polybutene Confined crystallization Morphology

k_(eff)uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

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Nuclear Science and Techniques 2021年第11期32卷 105-118页

作者： rong-Rui Yang Yuan Yuan Chen Hao Ji Ma guang-Hao Liu Fundamental Science on Nuclear Safety and Simulation Technology Laboratory College of Nuclear Science and TechnologyHarbin Engineering UniversityHarbin 150001China Department of Reactor Technology Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBeijing 100089China

To benefit from recent advances in modeling and computational algorithms,as well as the availability of new covariance data,sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors(HTGRs).In particular,the contribution of nuclear data to the k_(eff)uncertainty is an important part of the uncertainty analysis of small-sized HTGR physical *** this study,a small-sized HTGR designed by China Nuclear Power Engineering Co.,*** selected for k_(eff)uncertainty analysis during full lifetime burnup *** of the cold zero power(CZP)condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation,depletion calculation,and sensitivity and uncertainty *** the sensitivity analysis,the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Track length importance Characterization(CLUTCH)method was applied to obtain sensitive information,and the "sandwich" method was used to quantify the k_(eff)*** also compared the k_(eff)uncertainties to other typical *** results show that ^(235)U is the largest contributor to k_(eff)uncertainty for both the CZP and depletion conditions,while the contribution of ^(239)Pu is not very significant because of the design of low discharge *** is worth noting that the radioactive capture reaction of ^(28)Si significantly contributes to the k_(eff)uncertainty owing to its specific fuel ***,the k_(eff)uncertainty during the full lifetime depletion process was relatively stable,only increasing by 1.12%owing to the low discharge burnup design of small-sized *** numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HTGR.

关键词： Small-sized HTGR SU analysis Nuclear data Burnup

DLF-YOLOF:an improved YOLOF-based surface defect detection for steel plate

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Journal of Iron and Steel Research International 2024年第2期31卷 442-451页

作者： guang-hu Liu Mao-xiang Chu rong-fen Gong Ze-hao Zheng School of Electronic and Information Engineering University of Science and Technology LiaoningAnshan114051LiaoningChina

Surface defects can affect the quality of steel *** methods based on computer vision are currently applied to surface defect detection of steel ***,their real-time performance and object detection of small defect are still *** improved object detection network based on You Only Look One-level Feature(YOLOF)is proposed to show excellent performance in surface defect detection of steel plate,called ***,the anchor-free detector is used to reduce the network ***,deformable convolution network and local spatial attention module are introduced into the feature extraction network to increase the contextual information in the feature ***,the soft non-maximum suppression is used to improve detection accuracy ***,data augmentation is performed for small defect objects during training to improve detection *** show the average precision and average precision for small objects are 42.7%and 33.5%at a detection speed of 62 frames per second on a single GPU,*** shows that DLF-YOLOF has excellent performance to meet the needs of industrial real-time detection.

关键词： Steel surface defects detection YOLOF Anchor-free detector Small object detection Real-time detection

Factors Influencing Thermal Conductivity in Diamond Film

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Chinese Physics Letters 1996年第9期13卷 700-702页

作者： GU Chang-zhi jin Zeng-sun WANG Chun-lei LÜXian-yi ZOU guang-tian ZHANG Ji-fa FANG rong-chun State Key Laboratory of Superhard Materials Jilin UniversityChangchun 130023 Department of Physics University of Science and Technology of ChinaHefei 230026

Diamond films were synthesized on Si substrate by electron-assisted chemical vapor deposition method using gas mixtures of methane(or acetone)and *** crystal structures of diamond films were obtained by synthesis with various deposition *** influences of various deposition conditions on thermal conductivity of diamond film were *** results show that large-grain(100)-oriented diamond films synthesized at lower concentration of methane and acetone have higher thermal conductivity,and thermal conductivity increases with the increasing in film thickness and the removal of the Sic layer on the back of the film,at last,annealing in ambience of hydrogen is advantageous to acquiring diamond film with high thermal conductivity.

关键词： film conductivity Diamond

The association of atrial fibrillation and dementia incidence: a meta-analysis of prospective cohort studies

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Journal of Geriatric Cardiology 2019年第3期16卷 298-306页

作者： Dao-Shen LIU jing CHEN Wei-Ming JIAN guang-rong ZHANG Zhi-rong LIU Department of Neurology Xijing Hospitalthe Fourth Military Medical UniversityXi’anShaanxiChina Department of Geriatrics Xijing Hospitalthe Fourth Military Medical UniversityXi’anShaanxiChina

Objectives To assess and synthesize the prospective cohort studies published so far on the association between atrial fibrillation (AF) and dementia *** We searched PubMed,Web of Science,and the Cochrane Library for potential studies published in English previous to April *** independent reviewers screened the search results for prospective cohort studies reporting the association between AF and dementia incidence in patients with normal cognitive function at baseline and not suffering from an acute *** Newcastle-Ottawa Scale was adopted to evaluate the quality of the included *** pooled hazard ratio (HR) of AF for dementia was calculated with the Comprehensive Meta-Analysis software,version *** and publication bias were assessed with the I2 test and funnel plot,*** We finally identified 11 prospective cohort studies covering 112,876 *** the included studies reported an adjusted HR obtained in multiple Cox regression *** qualities of the included studies ranged from moderate to *** pooled analysis with a fixed-effects model,AF was independently associated with dementia incidence (HR = 1.34,95% CI: 1.24–1.44).Subgroup analysis of studies considering anticoagulation as an important confounding factor achieved a similar *** on the I2 test and funnel plot,we did not detect obvious heterogeneity and publication bias in our ***-regression on age did not find significant *** The results of our meta-analysis further confirmed that AF was an independent risk factor for dementia in patients with normal baseline cognitive function not suffering from acute *** for dementia in AF patients and including dementia as an independent outcome in large AF treatment trials is warranted.

关键词： Atrial fibrillation Arrhythmias Cognitive impairment Dementia Meta-analysis