检索结果-南通市图书馆

Journal of Rare Earths 2019年第8期37卷 895-902,I0005页

作者： Cansong Lu yanjun ma Jianwen Wang College of Pharmaceutical Sciences Soochow University

Rare earth elements(REEs)have been widely applied as efficient elicitors to improve production of biologically important secondary metabolites in ***,their effects on microbial secondary metabolites were seldom *** 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 ***^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 *** analysis shows that La^3+can induce the intracellular ROS(reactive oxygen species)accumulation with 2.33-fold higher contents of H2O2 in *** production induced by La^3+treatment can be suppressed by ROS *** analysis reveals that the elicitation of La^3+on HA accumulation is mediated by ROS generation to enhance expression of HA biosynthetical *** expression of ATP-binding cassette transporter gene(SbABC)for HA exudation is also regulated partially via ROS generated by NADPH *** results indicate that the enhanced HA production by La^3+might be mediated by ROS signaling *** results provide a basis for understanding REE elicitation on fungal metabolites and a practical biotechnological process for enhanced production of HA.

关键词： Lanthanum Shiraia bambusicola Hypocrellin A Reactive oxygen species Elicitation Rare earths

Atmospheric extinction properties in Shenyang,China

在线全文

学校读者我要写书评

暂无评论

Particuology 2015年第1期13卷 120-126页

作者： Ningwei Liu yanjun ma Jianzhong ma Yangfeng Wang Suying Yang Liguang Li Chinese Academy of Meteorological Sciences Nanjing University of Information Science & Technology Institute of Atmospheric Environment China Meteorological Administration

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.

关键词： Atmospheric visibility Extinction properties Extinction contributions Partide scattering

Strengthening mechanism of different morphologies of nanosized MSH on tribological performance of phosphate/MoS_(2) bonded solid lubricating coatings

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第11期12卷 2563-2575页

作者： Zhengchao XI Jianbo SUN Lei CHEN Haixia CUI yanjun ma Huidi ZHOU Jianmin CHEN State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Aerospace Research Institute of materials&Processing Technology Beijing 100076China

magnesium silicate hydroxides(MSHs)with granular,schistose,and tubular morphologies were separately incorporated to enhance the tribological properties of phosphate/MoS_(2) composite *** nano-schistose MSH demonstrated superior tribological performance due to its effective interactions with the worn surface and frictional synergies with solid *** 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 ***-schistose MSH facilitated the formation of a friction-induced multi-layer heterogenous slipping structure with layered solid lubricants at the friction ***,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 ***,the contact state between tribo-pairs was timely regulated and the invalidation of the nanocomposite slipping structure was effectively restrained during the friction *** a result,the service life of the phosphate composite coatings was significantly extended and further abrasion on the worn surface was notably reduced.

关键词： nano-sized magnesium silicate hydroxide(MSH) morphology regulation nanocomposite slipping structure tribo-film

Spatiotemporal Variations and Regional Transport of Air Pollutants in Two Urban Agglomerations in Northeast China Plain

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Geographical Science 2019年第6期29卷 917-933页

作者： LI Xiaolan HU Xiaoming SHI Shuaiyi SHEN Lidu LUAN Lan ma yanjun Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166China Center for Analysis and Prediction of Storms University of OklahomaNormanOK 73072USA School of Meteorology University of OklahomaNormanOK 73072USA State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Shenyang Regional Climatic Center Shenyang 110166China Chinese Academy of Meteorological Sciences Beijing 100081China

Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in *** variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to *** results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern *** such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in *** annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing *** the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological ***2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind *** O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are *** transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.

关键词： criteria air pollutant meteorological condition regional transport urban agglomeration of Northeast China

Characteristics of Boundary Layer Structure during a Persistent Haze Event in the Central Liaoning City Cluster, Northeast China

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2018年第2期32卷 302-312页

作者： Xiaolan LI Yangfeng WANG Lidu SHEN Hongsheng ZHANG Hujia ZHAO Yunhai ZHANG yanjun ma Institute of Atmospheric Environment China Meteorological Administration Shenyang 110166 Shenyang Regional Climatic Center Shenyang 110166 Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beijing 100871

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 *** backward trajectory analysis revealed the sources of air masses and explained the different characteristics of the haze episodes in the four cities.

关键词： haze event thermal inversion layer atmospheric boundary layer Northeast China

A Usable Selection Range Standard Based on Test Suite Reduction Algorithms

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2010年第3期15卷 261-266页

作者： ma yanjun ZHAO Zhigang LIANG Yuchen YUN maojin College of Information Engineering Qingdao University Qingdao 266071 Shandong China College of Computing Blekinge Institute of Technology Karlskrona 37179 Blekinge Sweden College of Physics Science Qingdao University Qingdao 266071 Shandong China

In this paper, we analyze the features and distinctions of 6 classical algorithms： greedy algorithm （G）, greedy evolution algorithm （GE）, heuristics algorithm （H）, greedy heuristic G （GRE）, integer linear programming algorithm （ILP） and genetic algorithm （GA） to ensure the main influencing factors-the performance of algorithms and the running time of algorithms. What＇s more, we would not only present a research design that aims at gaining deeper understanding about the algorithm classification and its function as well as their distinction, but also make an empirical study in order to obtain a practical range standard that can guide the selection of reduction algorithms. When the size of a test object （product of test requirements and test cases） is smaller than 2000×2000, G algorithm is the commonly recommended algorithm. With the growth of test size, the usage of GE and GRE becomes more general.

关键词： test suite reduction algorithms influencing factor selection standard

Multilevel air quality evolution in Shenyang:Impact of elevated point emission reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第3期34卷 300-310页

作者： Xiaolan Li Guiqian Tang Liguang Li Weijun Quan Yangfeng Wang Ziqi Zhao Ningwei Liu Ye Hong yanjun ma Institute of Atmospheric Environment China Meteorological AdministrationNo.388 Changbai South RoadShenyangLiaoning 110166China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei Beijing 100089China

Visibility observed at different altitudes is favorable to understand the causes of air *** 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 *** 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 *** radiosonde meteorological data showed that weak turbulence in the planetary boundary layer(PBL)in winter favored aerosols'accumulation near the *** in summer,unstable atmospheric con-ditions,upper-level moister environment,and regional transport of air pollutants resulted in the deterioration of upper-level ***-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 *** study suggested that strengthening the control of surface non-point emissions is a promis-ing control strategy to improve Shenyang air quality.

关键词： Aerosol pollution Atmospheric visibility Planetary boundary layer Northeast China Vertical evolution

Numerical simulation for the coupling effect of local atmospheric circulations over the area of Beijing,Tianjin and Hebei Province

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2009年第3期52卷 382-392页

作者： LIU ShuHua LIU ZhenXin LI Ju WANG YinChun ma yanjun SHENG Li LIU HePing LIANG FuMing XIN GuoJun WANG JianHua Department of Atmospheric Sciences School of PhysicsPeking UniversityBeijing 100871China Institute of Beijing Urban Meteorology China Meteorological AdministrationBeijing 100089China Institute of Shenyang Atmospheric Environment China Meteorological AdministrationShenyang 110016China Department of Physics Atmospheric Sciences&General ScienceJackson State UniversityP.O.Box 17660JacksonMS 39217-0195USA

Using the model system MM5.V3 and multi-layer grid nesting technique, we have done a multi-scale numerical simulation over the area of Beijing, Tianjin and Hebei Province to analyze the temperature and wind field there and study its local circulations. The results show a coupling effect of Urban Heat Island Circulation (UHIC), Mountain Valley Breeze (MVB) and Sea Land Breeze (SLB) occurs in this area when the synoptic system is weak. The SLB can penetrate deep into the mainland for about 200 km when it is blooming. MVB can extend to south and cover almost the whole plain area in Beijing. Both MVB and SLB are diurnal periodical; meanwhile the phase of MVB drops behind that of SLB for about six hours. As a local circulation, the UHIC weakens the two circulations above, and it also has a diurnal period. As a result, the coupling effect of circulations reveals not only different features in spring-summer period and autumn-winter period in a year but also the difference between early morn- ing to noonday and afternoon to night in a day. We noted the diffusion of contamination over the area around Beijing, and found the steady presence of a transport routine of contamination over North-China throughout the year caused by the Coupling Effect mentioned above. This find is important for studying the environment pollution in this area.

关键词： Beijing-Tianjin-Hebei Mountain Valley Breeze Sea Land Breeze urban heat island circulation numerical simulation

Comparison of Two Air Pollution Episodes over Northeast China in Winter 2016/17 Using Ground-Based Lidar

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2018年第2期32卷 313-323页

作者： yanjun ma Hujia ZHAO Yunsheng DONG Huizheng CHE Xiaoxiao LI Ye HONG Xiaolan LI Hongbin YANG Yuche LIU Yangfeng WANG Ningwei LIU Cuiyan SUN Institute of Atmospheric Environment China Meteorological Administration Shenyang 110016 Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 State Key Laboratory of Severe Weather/Institute of Atmospheric Composition Chinese Academy of Meteorological Sciences Beijing 100081 Dalian Municipal Meteorological Observatory Dalian 116001 Jinan Center of Aviation Control Jinan 250107

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 *** 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.

关键词： aerosol pollution ground-based lidar Northeast China

Urotensin Ⅱ promotes monocyte chemoattractant protein-1 expression in aortic adventitial fibroblasts of rat

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2014年第10期127卷 1907-1912页

作者： Zhang Yonggang Bao Shilin Kuang Zejian ma yanjun Hu Yanchao mao Yanyan Department of Cardiology Second Affiliated Hospital ShantouUniversity Medical College Shantou Guangdong 515041 China Cardiovascular Laboratory Centre for Translational MedicineShantou University Medical College Shantou Guangdong 515041China Department of Cardiovascular Diseases First Affiliated Hospital Shantou University Medical College Shantou Guangdong 515041 China

Background Urotensin Ⅱ （Ull）,a potent vasoconstrictive peptide,is able to stimulate phenotypic differentiation of adventitial *** study aimed to determine the effect of UII on monocyte chemoattractant protein-1 （MCP1） expression in rat aortic adventitial fibroblasts,so as to explore possible mechanisms in the development of vascular *** Growth-arrested adventitial fibroblasts were incubated in serum-free medium with UII （1010-10-7 mol/L） and inhibitors of signal transduction pathways for 1 to 24 ***-1 mRNA and protein expression and secretion were determined by RT-PCR,Western blotting analysis and enzyme-linked immunosorbent assay （ELISA）,*** UII dose-and time-dependently promoted MCP-1 mRNA and protein expression and secretion in cells,with maximal effect at 10-8 mol/L at 3 hours for mRNA expression,24 hours for protein expression in the cells,and 12 hours for protein secretion from the ***,the UII effects were significantly inhibited by treatment with its receptor antagonist SB710411,Rho kinase inhibitor Y27632,protein kinase C （PKC） inhibitor H7,mitogen-activated protein kinase inhibitor PD98059,calcineurin inhibitor cyclosporine A,and the Ca2＋channel blocker *** UII may stimulate MCP-1 expression in rat aortic adventitial fibroblasts through its receptor and Rho kinase,PKC,mitogen-activated protein kinase,calcineurin and Ca2＋ channel signal transduction,thus contributing to adventitial inflammation.

关键词： urotensin Ⅱ monocyte chemoattractant protein-1 adventitial fibroblasts signal transduction