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64篇 您的检索式:作者名="Yang Mingjun"
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1Sensitivity of surface air temperature change to land use/cover types in China显示文摘Using CRU high resolution grid observational temperature and ERA40 reanalysis surface air temperature data during 1960-1999, we investigated the sensitivity of surface air temperature change to land use/cover types in China by subtracting the reanalysis from the observed surface air temperature (observation minus reanalysis, OMR). The results show that there is a stable and systemic impact of land use/cover types on surface air temperature. The surface warming of each land use/cover type reacted differently to global warming. The OMR trends of unused land (≥0.17℃/decade), mainly comprised by sandy land, Gobi and bare rock gravel land, are obviously larger than those of the other land use/cover types. The OMR over grassland, farmland and construction land shows a moderate decadal warming about 0.12℃ /decade, 0.10℃/decade, 0.12 ℃ /decade, respectively. Woodland areas do not show a significant warming trend (0.06 ℃ /decade). The overall assessment indicates that the surface warming is larger for areas that are barren and anthropogenically developed. The better the vegetation cover, the smaller the OMR warming trend. Responses of surface air temperature to land use/cover types with similar physical and chemical properties and biological processes have no significant difference. The surface air temperature would not react significantly until the intensity of land cover changes reach a certain degree. Within the same land use/cover type, areas in eastern China with intensive human activities exhibit larger warming trend. The results provide observational evidence for modeling research on the impact of land use/cover change on regional climate. Thus, projecting further surface climate of China in regional scale should not only take greenhouse gas increase into account, but also consider the impact of land use/cover types and land cover change.YANG XuChao ZHANG YiLi LIU LinShan ZHANG Wei DING MingJun WANG ZhaoFeng 2009Science China Earth Sciences2009,52,8:21
2Control of Rice Embryo Development, Shoot Apical Meristem Maintenance, and Grain Yield by a Novel Cytochrome P450显示文摘被子植物种子通常由二主要部分组成:胚胎和内乳。然而,分子的机制 underlyingembryo 和内乳发展仍然保持大部分未知,特别地在米饭,模型谷物。这里,我们报导 identificationand 米饭巨人胚胎(GE ) 基因的功能的描述。GE 的变化在种子导致了一个大胚胎,它被胚鳞房间的过多的扩大引起。embryonic 以后 growthof ge 幼苗严重地由于有缺点的射击被禁止顶端的分裂组织(SAM ) 维护。基于地图的克隆表明 thatGE 编码对 endoplasmic 蜂窝胃局部性的 CYP78A 亚科 P450 monooxygenase。GE 在 scutellar 上皮主要被表示,在胚胎和内乳之间的接口区域。Overexpressionof GE 支持了细胞增长并且提高了米饭植物生长和谷物产量,但是减少了胚胎尺寸,建议 GE 为协调米饭胚胎和内乳开发是批评的。而且,转基因的 Arabidopsis 植物 overexpressing AtCYP78A10,一个 GE 相当或相同的事物,也生产的更大的种子,在一起调整种子 development.Taken 为 P450s 的 CYP78A 亚科暗示一个保存角色,我们的结果显示 GE 在调整胚胎发展和 SAM maintenance.Key 词起关键作用:Weibing Yang Mingjun Gao Xin Yin Jiyun Liu Yonghan Xu Longjun Zeng Qun Li Shubiao Zhang Junmin Wang Xiaoming Zhang Zuhua He 2013Molecular Plant2013,6,6:16
3NUMERICAL SIMULATION OF FLOW THROUGH ORIFICE ENERGY-DISSIPATORS IN XIAOLANGDI FLOOD-DISCHAR-GE TUNNEL显示文摘The cavitation of orifi ces is one of the main problems of the Xiaolangdi flood discharge tunnels. Along with the decompression experiment, the flow field was calculated in this paper by using an axis-symmetrical k-ε turbulence model. The calculated pressur e distribution was compared with the measured data and in agreement with each ot her. The calculated results show that few of the cavitation bubbles generating a t the orifice edge can reach the wall under the calculation condition, the force applied on the orifice surface and the flow pattern before the orifice may be i mproved obviously by adding the vortex elimination ring at the upper side of the orifice.Qu, Jingxue Xu, Weilin Yang, Yongquan Wang, Wei Diao, Mingjun 2000Journal of Hydrodynamics2000,12,3:14
4Climate change in Mt. Qomolangma region since 1971显示文摘Using monthly average, maximum, minimum air temperature and monthly precipitation data from 5 weather stations in Mt. Qomolangma region in China from 1971 to 2004, climatic linear trend, moving average, low-pass filter and accumulated variance analysis methods, the spatial and temporal patterns of the climatic change in this region were analyzed. The main findings can be summarized as follows: (1) There is obvious ascending tendency for the interannual change of air temperature in Mt. Qomolangma region and the ascending tendency of Tingri, the highest station, is the most significant. The rate of increasing air temperature is 0.234 oC/decade in Mt. Qomolangma region, 0.302 oC/decade in Tingri. The air temperature increases more strongly in non-growing season. (2) Compared with China and the global average, the warming of Mt. Qomolangma region occurred early. The linear rates of temperature increase in Mt. Qomolangma region exceed those for China and the global average in the same period. This is attributed to the sensitivity of mountainous regions to climate change. (3) The southern and northern parts of Mt. Qomolangma region are quite different in precipitation changes. Stations in the northern part show increasing trends but are not statistically significant. Nyalam in the southern part shows a decreasing trend and the sudden decreasing of precipitation occurred in the early 1990s. (4) Compared with the previous studies, we find that the warming of Mt. Qomolangma high-elevation region is most significant in China in the same period. The highest automatic meteorological comprehensive observation station in the world set up at the base camp of Mt. Qomolangma with a height of 5032 m a.s.l will play an important role in monitoring the global climate change.YANG Xuchao ZHANG Yili ZHANG Wei YAN Yuping WANG Zhaofeng DING Mingjun CHU Duo 2006Journal of Geographical Sciences2006,16,3:12
5Recent Progress in Dual-Polarization Radar Research and Applications in China显示文摘Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have been successfully utilized to investigate precipitation microphysics and improve radar quantitative precipitation estimation(QPE).The recent progress in dual-pol radar research and applications in China is summarized in four aspects.Firstly,the characteristics of several representative dual-pol radars are reviewed.Various approaches have been developed for radar data quality control,including calibration,attenuation correction,calculation of specific differential phase shift,and identification and removal of non-meteorological echoes.Using dual-pol radar measurements,the microphysical characteristics derived from raindrop size distribution retrieval,hydrometeor classification,and QPE is better understood in China.The limited number of studies in China that have sought to use dual-pol radar data to validate the microphysical parameterization and initialization of numerical models and assimilate dual-pol data into numerical models are summarized.The challenges of applying dual-pol data in numerical models and emerging technologies that may make significant impacts on the field of radar meteorology are discussed.Kun ZHAO Hao HUANG Mingjun WANG Wen-Chau LEE Gang CHEN Long WEN Jing WEN Guifu ZHANG Ming XUE Zhengwei YANG Liping LIU Chong WU Zhiqun HU Sheng CHEN 2019Advances in Atmospheric Sciences2019,36,9:12
6Antibacterial Performance of a Cu-bearing Stainless Steel against Microorganisms in Tap Water显示文摘Tap water is one of the most commonly used water resources in our daily life. However, the increasing water contamination and the health risk caused by pathogenic bacteria, such as Staphylococcus aureus and Escherichia coli have attracted more attention. The mutualism of different pathogenic bacteria may diminish antibacterial effect of antibacterial agents. It was found that materials used for making pipe and tap played one of the most important roles in promoting bacterial growth. This paper is to report the performance of an innovative type 304 Cu-bearing stainless steel(304Cu SS) against microbes in tap water. The investigation methodologies involved were means of heterotrophic plate count, contact angle measurements, scanning electron microscopy for observing the cell and subtract surface morphology,atomic absorption spectrometry for copper ions release study, and confocal laser scanning microscopy used for examining live/dead bacteria on normal 304 stainless steel and 304 Cu SS. It was found that the surface free energy varied after being immersed in tap water with polar component and Cu ions release.The results showed 304 Cu SS could effectively kill most of the planktonic bacteria(max 95.9% antibacterial rate), and consequently inhibit bacterial biofilms formation on the surface, contributing to the reduction of pathogenic risk to the surrounding environments.Mingjun Li Li Nan Dake Xu Guogang Ren Ke Yang 2015Journal of Materials Science & Technology2015,31,3:10
7Increased activity of MdFRK2, a high-affinity fructokinase, leads to upregulation of sorbitol metabolism and downregulation of sucrose metabolism in apple leaves显示文摘To investigate the functions of fructokinase(FRK)in apple(Malus domestica)carbohydrate metabolism,we cloned the coding sequences of MdFRK1 and MdFRK2 from the‘Royal Gala’apple.The results showed that MdFRK2 expression was extremely high in shoot tips and young fruit.Analyses of heterologously expressed proteins revealed that MdFRK2 had a higher affinity for fructose than did MdFRK1,with Km values of 0.1 and 0.62 mM for MdFRK2 and MdFRK1,respectively.The two proteins,however,exhibited similar Vmax values when their activities were significantly inhibited by high concentrations of fructose.MdFRK2 ectopic expression was associated with a general decrease in fructose concentration in transgenic lines.In leaves,increased FRK activity similarly resulted in reduced concentrations of glucose and sucrose but no alterations in sorbitol concentration.When compared with those in the untransformed control,genes involved in sorbitol synthesis(A6PR)and the degradation pathway(SDH1/2)were significantly upregulated in transgenic lines,whereas those involved in sucrose synthesis(SPS1)and other degradation processes(SUSY4,NINV1/2,and HxK2)were downregulated.The activity of enzymes participating in carbohydrate metabolism was proportional to the level of gene expression.However,the growth performance and photosynthetic efficiency did not differ between the transgenic and wild-type plants.These results provide new genetic evidence to support the view that FRK plays roles in regulating sugar and sorbitol metabolism in Rosaceae plants.Jingjing Yang Lingcheng Zhu Weifang Cui Chen Zhang Dongxia Li Baiquan Ma Lailiang Cheng Yong-Ling Ruan Fengwang Ma Mingjun Li 2018Horticulture Research2018,5,1:9
8Formation mechanism of a smooth, defectfree surface of fused silica optics using rapid CO2 laser polishing显示文摘Surface defects introduced by conventional mechanical processing methods can induce irreversible damage and reduce the service life of optics applied in high-power lasers.Compared to mechanical processing,laser polishing with moving beam spot is a noncontact processing method,which is able to form a defect-free surface.This work aims to explore the mechanism of forming a smooth,defect-free fused silica surface by high-power density laser polishing with coupled multiple beams.The underlying mechanisms of laser polishing was revealed by numerical simulations and the theoretical results were verified by experiments.The simulated polishing depth and machined surface morphology were in close agreement with the experimental results.To obtain the optimized polishing quality,the effects of laser polishing parameters(e.g.overlap rate,pulse width and polishing times)on the polishing quality were experimentally investigated.It was found that the processing efficiency of fused silica materials by carbon dioxide(CO2)laser polishing could reach 8.68 mm2 s−1,and the surface roughness(Ra)was better than 25 nm.Besides,the cracks on pristine fused silica surfaces introduced by initial grinding process were completely removed by laser polishing to achieve a defect-free surface.The maximum laser polishing rate can reach 3.88μm s−1,much higher than that of the traditional mechanical polishing methods.The rapid CO2 laser polishing can effectively achieve smooth,defect-free surface,which is of great significance to improve the surface quality of fused silica optics applied in high-power laser facilities.Linjie Zhao Jian Cheng Mingjun Chen Xiaodong Yuan Wei Liao Qi Liu Hao Yang Haijun Wang 2019International Journal of Extreme Manufacturing2019,1,3:8
9Study of the permeability characteristics of porous media with methane hydrate by pore network model显示文摘The permeability in the methane hydrate reservoir is one of the key parameters in estimating the gas production performance and the flow behavior of gas and water during dissociation.In this paper,a three-dimensional cubic pore-network model based on invasion percolation is developed to study the effect of hydrate particle formation and growth habit on the permeability.The variation of permeability in porous media with different hydrate saturation is studied by solving the network problem.The simulation results are well consistent with the experimental data.The proposed model predicts that the permeability will reduce exponentially with the increase of hydrate saturation,which is crucial in developing a deeper understanding of the mechanism of hydrate formation and dissociation in porous media.Haifeng Liang Yongchen Song Yu Liu Mingjun Yang Xing Huang 2010Journal of Natural Gas Chemistry2010,19,3:7
10Vegetation change in the Mt. Qomolangma Nature Reserve from 1981 to 2001显示文摘Based on the NOAA AVHRR-NDVI data from 1981 to 2001, the digitalized China Vegetation Map (1:1,000,000), DEM, temperature and precipitation data, and field investiga- tion, the spatial patterns and vertical characteristics of natural vegetation changes and their influencing factors in the Mt. Qomolangma Nature Reserve have been studied. The results show that: (1) There is remarkable spatial difference of natural vegetation changes in the Mt. Qomolangma Nature Reserve and stability is the most common status. There are 5.04% of the whole area being seriously degraded, 13.19% slightly degraded, 26.39% slightly im- proved, 0.97% significantly improved and 54.41% keeping stable. The seriously and slightly degraded areas, which mostly lie in the south of the reserve, are along the national bounda- ries. The areas of improved vegetation lie in the north of the reserve and the south side of the Yarlung Zangbo River. The stable areas lie between the improved and degraded areas. Degradation decreases with elevation. (2) Degeneration in the Mt. Qomolangma Nature Re- serve mostly affects shrubs, needle-leaved forests and mixed forests. (3) The temperature change affects the natural vegetation changes spatially while the integration of temperature changes, slopes and aspects affects the natural vegetation change along the altitude gradi- ents. (4) It is the overuse of resources that leads to the vegetation degeneration in some parts of the Mt. Qomolangma Nature Reserve.ZHANG Wei ZHANG Yili WANG Zhaofeng DING Mingjun YANG Xuchao LIN Xuedong LIU Linshan 2007Journal of Geographical Sciences2007,17,2:7
11Potassium Uptake and Transport in Apple Roots Under Drought Stress显示文摘As one of the most important mineral nutrient elements, potassium(K^+) plays an important role in many plant physiological processes and determines both the yield and quality of crops. There are two typical gene families that regulate K^+transport in higher plants, including K^+channels and K^+transporters. However, little is known about how these channels and transporters divide their work in response to drought stress. In this study, the hydroponic experiment was conducted on Malus hupehensis. The K^+content was found to decrease in response to drought stress in M. hupehensis, the aboveground decreased by 34.15% and the underground decreased by 3.97%. Meanwhile, the root morphology change was detected by scanning the root system. Under conditions of drought, the genes encoding K^+transporters were upregulated including MdCHX1.3, MdCHX4.11, MdCHX4.8, MdCHX4.9, Md HKT1, and MdHAK3.2. The net influx of K^+was inhibited by 19.47% with the action of K^+channel inhibitors(CsCl), however a significant decrease(80.99%; P < 0.05) was found in roots exposed to a PM H+-ATPase(orthovanadate) inhibitor by utilizing a non-invasive micro-test technique. The trend of H+efflux was similar to that of K^+. The data suggested that the positive influx of K^+through the transporter accounted for the main K^+uptake under drought stress. These results suggest that we can improve the uptake of K^+by purposely up-regulating specific K^+transporters under drought stress. This process may improve growth, yield, quality, and stress tolerance in apple trees.Jianguo Qi Simin Sun Lin Yang Mingjun Li Fengwang Ma Yangjun Zou 2019Horticultural Plant Journal2019,5,1:6
12In-situ observation for formation and dissociation of carbon dioxide hydrate in porous media by magnetic resonance imaging显示文摘The study of formation and dissociation of CO 2 hydrate in porous media was characterized by magnetic resonance imaging (MRI) system in in situ conditions. This work simulated porous media by using glass beads of uniform size. The growth and dissociation habit of CO2 hydrate was observed under different temperature and pressure conditions. The induction time and the hydrate saturation during the growth and dissociation process in different sizes of porous media were obtained by using the MRI signal intensity. The results indicate that hydrate growth rate and the induction time are affected by the size of porous media, pressure, and degree of supercooling. There are three hydrate growth stages, i.e., initial growth stage, rapid growth stage and steady stage. In this study,the CO2 hydrate forms preferentially at the surface of vessel and then gradually grows inward. The hydrate tends to cement the glass beads together and occupies the pore gradually. As the hydrate decomposes gradually, the dissociation rate increases to the maximum and then decreases to zero.CHENG ChuanXiao ZHAO JiaFei SONG YongChen ZHU ZiHao LIU WeiGuo ZHANG Yi YANG MingJun YU XiChong 2013Science China Earth Sciences2013,56,4:5
13Dissociation characteristics of methane hydrate using depressurization combined with thermal stimulation显示文摘Methane hydrate is considered as a potential energy source in the future due to its abundant reserves and high energy density.To investigate the influence of initial hydrate saturation,production pressure,and the temperature of thermal stimulation on gas production rate and cumulative gas production percentage,we conducted the methane hydrate dissociation experiments using depressurization,thermal stimulation and a combination of two methods in this study.It is found that when the gas production pressures are the same,the higher the hydrate initial saturation,the greater change in hydrate reservoir temperature.Therefore,it is easier to appear the phenomenon of icing and hydrate reformation when the hydrate saturation is higher.For example,the reservoir temperature dropped to below zero in depressurization process when the hydrate saturation was about 37%.However,the same phenomenon didn’t appear as the saturation was about 12%.This may be due to more free gas in the reservoir with hydrate saturated of 37%.We also find that the temperature variation of reservoir can be reduced effectively by combination of depressurization and thermal stimulation method.And the average gas production rate is highest with combined method in the experiments.When the pressure of gas production is 2 MPa,compared with depressurization,the average of gas production can increase 54%when the combined method is used.The efficiency of gas production is very low when thermal stimulation was used alone.When the temperature of thermal stimulation is 11℃,the average rate of gas production in the experiment of thermal stimulation is less than 1/3 of that in the experiment of the combined method.Mingjun Yang Zhanquan Ma Yi Gao Lanlan Jiang 2019Chinese Journal of Chemical Engineering2019,27,9:5
14Numerical studies of hydrate dissociation and gas production behavior in porous media during depressurization process显示文摘In this study,a numerical model is developed to investigate the hydrate dissociation and gas production in porous media by depressurization.A series of simulation runs are conducted to study the impacts of permeability characteristics,including permeability reduction exponent,absolute permeability,hydrate accumulation habits and hydrate saturation,sand average grain size and irreducible water saturation.The effects of the distribution of hydrate in porous media are examined by adapting conceptual models of hydrate accumulation habits into simulations to govern the evolution of permeability with hydrate decomposition,which is also compared with the conventional reservoir permeability model,i.e.Corey model.The simulations show that the hydrate dissociation rate increases with the decrease of permeability reduction exponent,hydrate saturation and the sand average grain size.Compared with the conceptual models of hydrate accumulation habits,our simulations indicate that Corey model overpredicts the gas production and the performance of hydrate coating models is superior to that of hydrate filling models in gas production,which behavior does follow by the order of capillary coating>pore coating>pore filling>capillary filling.From the analysis of t1/2,some interesting results are suggested as follows:(1) there is a 'switch' value(the'switch'absolute permeability) for laboratory-scale hydrate dissociation in porous media,the absolute permeability has almost no influence on the gas production behavior when the permeability exceeds the 'switch' value.In this study,the 'switch' value of absolute permeability can be estimated to be between 10 and 50 md.(2) An optimum value of initial effective water saturation Sw,e exists where hydrate dissociation rate reaches the maximum and the optimum value largely coincides with the value of irreducible water saturation S wr,e.For the case of Sw,Swr,e,there are different control mechanisms dominating the process of hydrate dissociation and gas production.Xuke Ruan Mingjun Yang Yongchen Song Haifeng Liang Yanghui Li 2012Journal of Natural Gas Chemistry2012,21,4:3
15Antibacterial behavior and related mechanisms of martensitic Cu-bearing stainless steel evaluated by a mixed infection model of Escherichia coli and Staphylococcus aureus in vitro显示文摘Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)are the most typical pathogenic bacteria with a significantly high risk of bio-contamination,widely existing in hospital and public places.Recent studies on antibacterial materials and the related mechanisms have attracted more interests of researchers.However,the antibacterial behavior of materials is usually evaluated separately on the single bacterial strain,which is far from the practical condition.Actually,the interaction between the polymicrobial communities can promote the growing profile of bacteria,which may weaken the antibacterial effect of materials.In this work,a 420 copper-bearing martensitic stainless steel(420 CuSS)was studied with respect to its antibacterial activity and the underlying mechanism in a co-culturing infection model using both E.coli and S.au reus.Observed via plating and counting colony forming units(CFU),Cu releasing,and material characterization,420 CuSS was proved to present excellent antibacterial performance against the mixed bacteria with an approximately 99.4%of antibacterial rate.In addition,420 CuSS could effectively inhibit the biofilm formation on its surfaces,resulting from a synergistic antibacterial effect of Cu ions,Fe ions,reactive oxygen species(ROS),and proton consumption of bacteria.Mingjun Li Li Nan Chunyong Liang Ziqing Sun Lei Yang Ke Yang 2021Journal of Materials Science & Technology2021,,3:3
16Progress and trends in hydrate based desalination(HBD) technology:A review显示文摘The shortage of freshwater boosts the development of seawater desalination technology. As a novel method, the hydrate based desalination technology has been put forward for decades and achieved considerable development in the past years. This review focuses on the experimental progress at the aspects of the hydrate former choice, formation promotion and ion removal efficiency and conceptive innovation of hydrate separation and energy utilization. It should be noted that gaseous hydrate former with low formation pressure and insoluble liquid hydrate former are worthy for further study. Besides, the water migration caused by propane deserves to be investigated much more deeply for the potential value of wide application. Moreover, the utilization proposal of LNG cold energy brings more possibility of commercial application. In a word, the hydrate based desalination technology is hopefully an environment friendly, low-cost and widely used desalination technology in the near future.Jianan Zheng Fanbao Cheng Yuanping Li Xin Lü Mingjun Yang 2019Chinese Journal of Chemical Engineering2019,27,9:3
17Analysis of molecular variation in porcine reproductive and respiratory syndrome virus in China between 2007 and 2012显示文摘In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2(Nsp2) and glycoprotein 5(GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.Yuhang Cao Hongsheng Ouyang Mingjun Zhang Fuwang Chen Xin Yang Daxing Pang Linzhu Ren 2014Virologica Sinica2014,29,3:2
18Privacy Preserving Hop-distance Computation in Wireless Sensor Networks显示文摘XIAO Mingjun HUANG Liusheng XU Hongli WANG Yang PEI Zegen 2010Chinese Journal of Electronics2010,19,1:2
19The status of natural gas hydrate research in China: A review显示文摘Song Yongchen Yang Lei Zhao Jiafei Liu Weiguo Yang Mingjun Li Yanghui 2014Renewable and Sustainable Energy Reviews2014,31,:1
20Synthesis of 6-Arylsubstitued Pyrazolopyrimidine显示文摘LIU Ju WANG Yang JIANG Mingjun 2011Liaoning Univ ( Nat Sci)2011,38,4:1
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