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润滑耐磨耐蚀功能一体化有机黏结涂层的研究进展 被引量:1
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作者 陈明锴 陈磊 +3 位作者 马彦军 张定军 周惠娣 陈建敏 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第4期182-190,共9页
随着现代化装备技术的快速发展,高端机械装备服役工况变得愈加复杂苛刻,磨损与腐蚀耦合损伤加速了高端机械装备运动部件的损伤失效,导致装备服役寿命大幅缩减,带来了严重的安全问题。润滑耐磨耐蚀功能一体化有机黏结涂层克服了润滑耐磨... 随着现代化装备技术的快速发展,高端机械装备服役工况变得愈加复杂苛刻,磨损与腐蚀耦合损伤加速了高端机械装备运动部件的损伤失效,导致装备服役寿命大幅缩减,带来了严重的安全问题。润滑耐磨耐蚀功能一体化有机黏结涂层克服了润滑耐磨涂层和防腐蚀涂层的单一功能局限,为解决运动部件的磨损和腐蚀问题提供了有效方案。文中首先探讨了关键运动部件面临复杂服役工况的严峻挑战、材料磨损与腐蚀耦合的损伤机制;然后分别由黏结剂、填料和润滑剂3个方面介绍了目前润滑耐磨耐蚀功能一体化有机黏结涂层的研究进展,对涂层的组成结构与力学性能、摩擦学性能、耐腐蚀性能间的构效关系进行了分析,并对不同涂层的局限性进行了概述;之后详细总结了润滑耐磨耐蚀功能一体化涂层的应用现状;最后对润滑耐磨耐蚀功能一体化涂层的发展方向进行展望。 展开更多
关键词 磨损-腐蚀 减摩耐磨 耐蚀 功能一体化 有机黏结涂层
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紫外光固化聚氨酯丙烯酸酯粘结剂的优化设计 被引量:8
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作者 马彦军 冶银平 +3 位作者 陈磊 万宏启 周惠娣 陈建敏 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2018年第5期111-115,共5页
采用红外光谱对聚氨酯丙烯酸酯(PUA)涂料的紫外固化过程进行定量分析;测试了不同配方和固化条件下涂膜的摆杆硬度、柔韧性和抗冲击性;考察了γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对粘结剂附着力的影响,并对其作用机制进行了分析。... 采用红外光谱对聚氨酯丙烯酸酯(PUA)涂料的紫外固化过程进行定量分析;测试了不同配方和固化条件下涂膜的摆杆硬度、柔韧性和抗冲击性;考察了γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对粘结剂附着力的影响,并对其作用机制进行了分析。结果表明,固化过程中C=C双键发生聚合,其转化率反映了涂膜的固化程度;增大光强、减少稀释剂用量和延长固化时间均有利于提高双键转化率和摆杆硬度;随着光引发剂浓度的增加,双键转化率先增后减;增大二官能PUA比例能够提高涂膜柔韧性和抗冲击性;KH570能够改善涂膜附着力,加入量越大改善效果越明显,且静置对附着力有很大影响;其作用机制是KH570分子中的双键与丙烯酸双键发生聚合,羟基与基底间形成氢键作用。 展开更多
关键词 聚氨酯丙烯酸酯 紫外光固化 Γ-甲基丙烯酰氧基丙基三甲氧基硅烷 附着力
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Lanthanum elicitation on hypocrellin A production in mycelium cultures of Shiraia bambusicola is mediated by ROS generation 被引量:2
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作者 Cansong Lu yanjun ma Jianwen Wang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第8期895-902,I0005,共9页
Rare earth elements(REEs)have been widely applied as efficient elicitors to improve production of biologically important secondary metabolites in plants.However,their effects on microbial secondary metabolites were se... Rare earth elements(REEs)have been widely applied as efficient elicitors to improve production of biologically important secondary metabolites in plants.However,their effects on microbial secondary metabolites were seldom reported.In this study,lanthanum(LaCl3)was used as an elicitor in mycelium cultures of Shiraia bambusicola to stimulate the production of hypocrellin A(HA),a promising photosensitizer for anticancer photodynamic therapy.La^3+at 1.0 g/L not only increases HA content by 2.50-fold in mycelia,but stimulates HA exudation to the medium with the highest production(225.05 mg/L)on day 6.Further analysis shows that La^3+can induce the intracellular ROS(reactive oxygen species)accumulation with 2.33-fold higher contents of H2O2 in mycelium.HA production induced by La^3+treatment can be suppressed by ROS scavengers.Further analysis reveals that the elicitation of La^3+on HA accumulation is mediated by ROS generation to enhance expression of HA biosynthetical genes.The expression of ATP-binding cassette transporter gene(SbABC)for HA exudation is also regulated partially via ROS generated by NADPH oxidase.These results indicate that the enhanced HA production by La^3+might be mediated by ROS signaling pathway.Our results provide a basis for understanding REE elicitation on fungal metabolites and a practical biotechnological process for enhanced production of HA. 展开更多
关键词 LANTHANUM Shiraia bambusicola HYPOCRELLIN A Reactive oxygen species ELICITATION RARE earths
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中国城市中大气分粒级的粒子数浓度与每日死亡率 被引量:2
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作者 Xia Meng yanjun ma +6 位作者 Renjie Chen Zhijun Zhou Bingheng Chen Haidong Kan 张伊人 汪源 金泰廙 《环境与职业医学》 CAS 北大核心 2014年第4期324-328,共5页
[背景]大气颗粒物-9健康结局之间的相关性已在全球范围内广为报道。然而,有关不同粒径颗粒物对健康影响的研究却十分有限。[目的]以中国沈阳为例,探索不同粒径颗粒物的数量浓度(particle number concentrations,PNCs)与每日死亡率... [背景]大气颗粒物-9健康结局之间的相关性已在全球范围内广为报道。然而,有关不同粒径颗粒物对健康影响的研究却十分有限。[目的]以中国沈阳为例,探索不同粒径颗粒物的数量浓度(particle number concentrations,PNCs)与每日死亡率之间的关系。[方法]研究时间为2006年12月1日至2008年11月30日,分别收集每日死因别死亡率和直径为0.25~10岬颗粒物的每日PNCs。用基于半泊松回归的广义相加模型来评估PNCs-9死亡率之间的相关性,同时采用自然样条平滑函数校正随时间变化的协变量、长期趋势及季节性趋势。[结果]在研究时间内,归因于非意外的自然死亡、心血管疾病和呼吸系统疾病的平均每日死亡数分别为67、32和7。直径为0.25-0.50gm的颗粒物PNCs与总死亡率和心血管疾病死亡率明显相关,但与呼吸系统疾病死亡率无明显相关性。与冷季相比,暖季里PNCs效应估计值较大,并且效应值随着颗粒物粒径的减小而增加。0.25~0.28p,m、O.35~0.40μm和0.45—0.50gm的颗粒物PNCs每增加1个IQR浓度,与之相关的总死亡风险分别增大2.41%(95%CI:1.23%~3.58%)、1.31%(95%CI:0.52%~2.09%)和0.45%(95%CI:0.04%-0.87%)。校正大气颗粒物和气态污染物的质量浓度后,这种相关性仍然保持稳定。[结论]研究结果提示,直径〈0.5μm的颗粒物可能是空气污染颗粒中导致不良健康影响的最主要成分,并且对健康的不利影响随着颗粒直径的减小而增加。 展开更多
关键词 质量浓度 日死亡率 函数 中国 大气颗粒物 呼吸系统疾病 心血管疾病 疾病死亡率
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中国城市空气中分粒级的粒子数浓度与每日死亡率
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作者 Xia Meng yanjun ma +3 位作者 Renjie Chen Zhijun Zhou Bingheng Chen Haidong Kan 《环境与职业医学》 CAS 北大核心 2014年第2期115-115,共1页
[背景]空气中的颗粒与健康结局之间的关联已在全球范围内广为报道。然而,有关不同大小的颗粒对健康影响的信息却十分有限。[目的]探讨在中国沈阳,分粒级粒子数浓度(PNCs)与每日死亡率之间的关联。
关键词 日死亡率 浓度 粒子 空气 中国 城市 健康结局
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Multilevel air quality evolution in Shenyang:Impact of elevated point emission reduction
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作者 Xiaolan Li Guiqian Tang +6 位作者 Liguang Li Weijun Quan Yangfeng Wang Ziqi Zhao Ningwei Liu Ye Hong yanjun ma 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第3期300-310,共11页
Visibility observed at different altitudes is favorable to understand the causes of air pol-lution.We conducted 4-years of observations of visibility at 2.8 and 60 m and particulate matter(PM)concentrations from 2015 ... Visibility observed at different altitudes is favorable to understand the causes of air pol-lution.We conducted 4-years of observations of visibility at 2.8 and 60 m and particulate matter(PM)concentrations from 2015 to 2018 in Shenyang,a provincial city in Northeast China.The results indicated that visibility increased with the increasing height in winter(especially at night),and decreased with height in summer(especially at the daytime).PM concentration exhibited opposite vertical variation to visibility,reflecting that visibility de-grades with the increase of aerosol concentration in the air.The radiosonde meteorological data showed that weak turbulence in the planetary boundary layer(PBL)in winter favored aerosols'accumulation near the surface.Whereas in summer,unstable atmospheric con-ditions,upper-level moister environment,and regional transport of air pollutants resulted in the deterioration of upper-level visibility.Inter-annual variation in the two-level visibility indicated that the upper-level visibility improved more significantly than low-level visibil-ity,much likely due to the reduction in emission of elevated point sources in Shenyang.Our study suggested that strengthening the control of surface non-point emissions is a promis-ing control strategy to improve Shenyang air quality. 展开更多
关键词 Aerosol pollution Atmospheric visibility Planetary boundary layer Northeast China Vertical evolution
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Strengthening mechanism of different morphologies of nanosized MSH on tribological performance of phosphate/MoS_(2) bonded solid lubricating coatings
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作者 Zhengchao XI Jianbo SUN +4 位作者 Lei CHEN Haixia CUI yanjun ma Huidi ZHOU Jianmin CHEN 《Friction》 SCIE EI CAS CSCD 2024年第11期2563-2575,共13页
Magnesium silicate hydroxides(MSHs)with granular,schistose,and tubular morphologies were separately incorporated to enhance the tribological properties of phosphate/MoS_(2) composite coatings.The nano-schistose MSH de... Magnesium silicate hydroxides(MSHs)with granular,schistose,and tubular morphologies were separately incorporated to enhance the tribological properties of phosphate/MoS_(2) composite coatings.The nano-schistose MSH demonstrated superior tribological performance due to its effective interactions with the worn surface and frictional synergies with solid lubricants.Incorporation of nano-schistose MSH decreased the friction coefficient of composite coatings by about 34.7%and increased the anti-wear performance of composite coatings by about thirteen times.Nano-schistose MSH facilitated the formation of a friction-induced multi-layer heterogenous slipping structure with layered solid lubricants at the friction interface.Moreover,tribo-chemical reactions between nano-schistose MSH and worn surface promoted the in-situ formation of a cermet supporting film,and this also induced the gradual in-situ formation of a lubrication film on the top of worn surface.Consequently,the contact state between tribo-pairs was timely regulated and the invalidation of the nanocomposite slipping structure was effectively restrained during the friction process.As a result,the service life of the phosphate composite coatings was significantly extended and further abrasion on the worn surface was notably reduced. 展开更多
关键词 nano-sized magnesium silicate hydroxide(MSH) morphology regulation nanocomposite slipping structure tribo-film
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Characteristics of Boundary Layer Structure during a Persistent Haze Event in the Central Liaoning City Cluster, Northeast China 被引量:13
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作者 Xiaolan LI Yangfeng WANG +4 位作者 Lidu SHEN Hongsheng ZHANG Hujia ZHAO Yunhai ZHANG yanjun ma 《Journal of Meteorological Research》 SCIE CSCD 2018年第2期302-312,共11页
The characteristics of boundary layer structure during a persistent regional haze event over the central Liaoning city cluster of Northeast China from 16 to 21 December 2016 were investigated based on the measurements... The characteristics of boundary layer structure during a persistent regional haze event over the central Liaoning city cluster of Northeast China from 16 to 21 December 2016 were investigated based on the measurements of particulate matter(PM) concentration and the meteorological data within the atmospheric boundary layer(ABL). During the observational period, the maximum hourly mean PM_(2.5) and PM10 concentrations in Shenyang, Anshan, Fushun, and Benxi ranged from 276 to 355 μg m–3 and from 378 to 442 μg m–3, respectively, and the lowest hourly mean atmospheric visibility(VIS) in different cities ranged from 0.14 to 0.64 km. The central Liaoning city cluster was located in the front of a slowly moving high pressure and was mainly controlled by southerly winds. Wind speed(WS) within the ABL(〈 2 km) decreased significantly and WS at 10-m height mostly remained below 2 m s–1 during the hazy episodes, which was favorable for the accumulation of air pollutants. A potential temperature inversion layer existed throughout the entire ABL during the earlier hazy episode [from 0500 Local Time(LT) 18 December to 1100 LT 19 December], and then a potential temperature inversion layer developed with the bottom gradually decreased from 900 m to 300 m. Such a stable atmospheric stratification further weakened pollutant dispersion. The atmospheric boundary layer height(ABLH) estimated based on potential temperature profiles was mostly lower than 400 m and varied oppositely with PM_(2.5) in Shenyang. In summary, weak winds due to calm synoptic conditions, strong thermal inversion layer, and shallow atmospheric boundary layer contributed to the formation and development of this haze event.The backward trajectory analysis revealed the sources of air masses and explained the different characteristics of the haze episodes in the four cities. 展开更多
关键词 haze event thermal inversion layer atmospheric boundary layer Northeast China
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Low levels of low-density lipoprotein cholesterol and cognitive decline 被引量:5
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作者 Rong Hua yanjun ma +2 位作者 Chenglong Li Baoliang Zhong Wuxiang Xie 《Science Bulletin》 SCIE EI CSCD 2021年第16期1684-1690,M0004,共8页
The relationship between low levels of serum low-density lipoprotein cholesterol(LDL-C)and subsequent cognitive decline remains unclear.The present study aimed to evaluate the longitudinal association between low LDL-... The relationship between low levels of serum low-density lipoprotein cholesterol(LDL-C)and subsequent cognitive decline remains unclear.The present study aimed to evaluate the longitudinal association between low LDL-C levels and cognition decline in the context of the current aggressive guideline-recommended targets(LDL-C levels less than 55 mg/dL for individuals at very high risk of cardiovascular events,and less than 70 mg/dL for high risk individuals).Data from wave 13(2016)to wave 14(2018)of the Health and Retirement Study(HRS)were utilized.LDL-C concentrations measured at wave 13 were categorized into 5 levels,reflecting currently recommended values for lipid lowering treatment.Of 7129 included participants(mean age:69.0±9.9 years,60.3%female),we found that compared to participants with LDL-C levels of 70.0-99.9 mg/dL,those with LDL-C levels of<55 mg/dL had significantly slower 2-year decline rates in global cognitive function(0.244 point/year;95%confidence interval(CI):0.065-0.422;P=0.008),working memory(0.068 point/year;95%CI:0.004-0.133;P=0.038),and borderline significantly in episodic memory(0.155 point/year;95%CI:-0.004-0.315;P=0.057).Similarly,significantly slower decline rates were observed in those with LDL-C levels of 55.0-69.9 mg/dL.The present study demonstrated that compared with LDL-C levels 70.0-99.9 mg/dL,low LDL-C levels(<70 mg/dL,especially<55 mg/dL)were associated with significantly slower cognitive decline in population-based setting.Future randomized controlled trials are warranted to ascertain the safety and benefit of current aggressive guideline-recommended targets on cognitive function. 展开更多
关键词 Low-density lipoprotein cholesterol Cognitive decline Longitudinal cohort study The Health and Retirement Study
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Comparison of Two Air Pollution Episodes over Northeast China in Winter 2016/17 Using Ground-Based Lidar 被引量:6
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作者 yanjun ma Hujia ZHAO +9 位作者 Yunsheng DONG Huizheng CHE Xiaoxiao LI Ye HONG Xiaolan LI Hongbin YANG Yuche LIU Yangfeng WANG Ningwei LIU Cuiyan SUN 《Journal of Meteorological Research》 SCIE CSCD 2018年第2期313-323,共11页
This study analyzes and compares aerosol properties and meteorological conditions during two air pollution episodes in 19–22(E1) and 25–26(E2) December 2016 in Northeast China. The visibility, particulate matter... This study analyzes and compares aerosol properties and meteorological conditions during two air pollution episodes in 19–22(E1) and 25–26(E2) December 2016 in Northeast China. The visibility, particulate matter(PM) mass concentration, and surface meteorological observations were examined, together with the planetary boundary layer(PBL) properties and vertical profiles of aerosol extinction coefficient and volume depolarization ratio that were measured by a ground-based lidar in Shenyang of Liaoning Province, China during December 2016–January 2017.Results suggest that the low PBL height led to poor pollution dilution in E1, while the high PBL accompanied by low visibility in E2 might have been due to cross-regional and vertical air transmission. The PM mass concentration decreased as the PBL height increased in E1 while these two variables were positively correlated in E2. The enhanced winds in E2 diffused the pollutants and contributed largely to the aerosol transport. Strong temperature inversion in E1 resulted in increased PM2.5 and PM10 concentrations, and the winds in E2 favoured the southwesterly transport of aerosols from the North China Plain into the region surrounding Shenyang. The large extinction coefficient was partially attributed to the local pollution under the low PBL with high ground-surface PM mass concentrations in E1,whereas the cross-regional transport of aerosols within a high PBL and the low PM mass concentration near the ground in E2 were associated with severe aerosol extinction at high altitudes. These results may facilitate better understanding of the vertical distribution of aerosol properties during winter pollution events in Northeast China. 展开更多
关键词 aerosol pollution ground-based lidar Northeast China
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Atmospheric extinction properties in Shenyang,China 被引量:3
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作者 Ningwei Liu yanjun ma +3 位作者 Jianzhong ma Yangfeng Wang Suying Yang Liguang Li 《Particuology》 SCIE EI CAS CSCD 2015年第1期120-126,共7页
Atmospheric visibility impairment due to human activities is becoming increasingly significant in metropolitan 8henyang, China. In this study, hourly data of relevant factors throughout the year 2010 in Shenyang were ... Atmospheric visibility impairment due to human activities is becoming increasingly significant in metropolitan 8henyang, China. In this study, hourly data of relevant factors throughout the year 2010 in Shenyang were used to evaluate the local atmospheric extinction properties. The results show that the average coefficient of total extinction and aerosol single-scattering albedo in 2010 were 622.72 Mm^-1 and 0.87, respectively, values that are characteristic of the "municipal pollution type". Visibility is most impaired during winter and especially in January. The coefficient of total extinction exhibits a single daily cycle with a maximum at 5-6 am and a minimum at 3 pm. The mean extinction contributions of the constituents, from high to low, were particle scattering (87.49%), particle absorption, gas absorption, and gas scattering. The extinction contribution of gas molecules was little more than 4.5%, far smaller than that of particles. Scattering by particles was the main contributor to extinction, especially in the morning and around midnight. 展开更多
关键词 Atmospheric visibility Extinction properties Extinction contributions Partide scattering
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Deep learning algorithm using fundus photographs for 10-year risk assessment of ischemic cardiovascular diseases in China 被引量:11
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作者 yanjun ma Jianhao Xiong +15 位作者 Yidan Zhu Zongyuan Ge Rong Hua Meng Fu Chenglong Li Bin Wang Li Dong Xin Zhao Jili Chen Ce Rong Chao He Yuzhong Chen Zhaohui Wang Wenbin Wei Wuxiang Xie Yangfeng Wu 《Science Bulletin》 SCIE EI CSCD 2022年第1期17-20,M0003,共5页
Ischemic cardiovascular diseases(ICVD),including ischemic stroke and coronary heart disease,has become the top cause of death in China[11.A 10-year 1CVD risk prediction model in Chinese adults has been developed and v... Ischemic cardiovascular diseases(ICVD),including ischemic stroke and coronary heart disease,has become the top cause of death in China[11.A 10-year 1CVD risk prediction model in Chinese adults has been developed and validated,which involved seven parameters including sex,age,systolic blood pressure,total cholesterol,body mass index,current smoking status,and diabetes[2].Since this model requires information from questionnaire,invasive blood tests,and physical examinations,its practice in primary healthcare settings is limited[2]. 展开更多
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关于项目制基层实践及政策模式的研究
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作者 李小云 马彦军 朱永胜 《政治经济学季刊》 2023年第2期58-87,共30页
项目制作为一种基层治理模式,是分税制度改革以来最重要的财政转移支付手段之一,也是各级政府部门常见公共治理手段,对于满足基层公共服务需求和增进国家公共利益有着重要的现实意义,在巩固拓展脱贫攻坚成果同乡村振兴有效衔接中发挥了... 项目制作为一种基层治理模式,是分税制度改革以来最重要的财政转移支付手段之一,也是各级政府部门常见公共治理手段,对于满足基层公共服务需求和增进国家公共利益有着重要的现实意义,在巩固拓展脱贫攻坚成果同乡村振兴有效衔接中发挥了重要作用。但在项目实施的全周期中,各级政府在资源配置和政策目标间互动博弈,会产生项目谋划能力不足、绩效考核机制限制县级项目分配、地方债务扩张、监管机制不完善、运维管护能力弱、运营机制还不完善等困境。为深入研究基层项目制的运行逻辑、实践困境与治理路径,本文以深度访谈、参与式观察和案例追踪的方式,研究项目承载的政策意图和其表现出的政策模式,归纳出“竞争-分配”式双向配置的分析框架。研究表明,中国地方政府在项目制下存在三种政策模式,即市场扩展与长远眼光,选择性、目的化——创造竞争优势,管制与支持这三种政策模式。本文最后从制度建设、资金使用、产业发展、营商环境、预算审议、协同配合和项目分配等方面对项目申请及分配提出政策建议。 展开更多
关键词 项目制 项目申请 竞争-分配 政策模式
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