Drought stress is the main limiting plant growth factor in arid and semiarid regions.The Lanzhou lily(Lilium davidii var.unicolor)is the only sweet-tasting lily grown in these regions of China that offers highly edibl...Drought stress is the main limiting plant growth factor in arid and semiarid regions.The Lanzhou lily(Lilium davidii var.unicolor)is the only sweet-tasting lily grown in these regions of China that offers highly edible,medicinal,health,and ornamental value.The Tresor lily is an ornamental flower known for its strong resistance.Plants were grown under three different drought intensity treatments,namely,being watered at intervals of 5,15,and 25 d(either throughout the study or during specific growth stages).We measured the biomass,leaf area,photosynthetic response,chlorophyll content(SPAD value),and osmoregulation of both the Lanzhou lily and the Tresor lily(Lilium‘Tresor’).Additionally,we employed RNA sequencing(RNA-Seq)and qRT-PCR to investigate transcriptomic changes of the Lanzhou lily in response to drought stress.Results showed that under drought stress,the decreasing rate in the Lanzhou lily bulb weight was lower than the corresponding Tresor lily bulb rate;the net photosynthetic rate,transpiration rate,and stomatal conductance of the Lanzhou lily were all higher compared to the Tresor lily;osmoregulation constituents,such as glucose,fructose,sucrose,trehalose,and soluble sugar,in the Lanzhou lily were comparatively higher;PYL,NCED,and ERS genes were significantly expressed in the Lanzhou lily.Under moderate drought,the biosynthesis of flavonoids,circadian rhythms,and the tryptophan metabolism pathway of the Lanzhou lily were all significant.Under severe drought stress,fatty acid elongation,photosynthetic antenna protein,plant hormone signal transduction,flavone and flavonol biosynthesis,and the carotenoid biosynthesis pathway were all significant.The Lanzhou lily adapted to drought stress by coordinating its organs and the unique role of its bulb,regulating photosynthesis,increasing osmolyte content,activating circadian rhythms,signal transduction,fatty acid elongation metabolism,and phenylalanine and flavonoid metabolic pathways,which may collectively be the main adaptation strategy and mechanisms used by the Lanzhou lily under drought stress.展开更多
To differentiate between natural and anthropogenic particulate sources in the atmosphere in Lanzhou City, samples were collected in different sites. The dust flux was calculated and magnetic measurements were conducte...To differentiate between natural and anthropogenic particulate sources in the atmosphere in Lanzhou City, samples were collected in different sites. The dust flux was calculated and magnetic measurements were conducted. Results show a distinct pattern of variation of dust flux within a year and it agrees with the shifts of atmospheric circulation regime. The magnetic parameters indicate that natural sources are the major components of atmospheric particulate during late spring and early summer, while anthropogenic sources contribute much more during winter months. The data also support the earlier findings that magnetic parameters are effective for differentiating between particulate arising from natural sources such as soil erosion and from anthropogenic sources such as coal combustion.展开更多
ABSTRACT: At the study area of Xigu District in Lanzhou City, using RS & GIS as tools we apply Diversity, Dominance, Fragmentation , Isolation and so on to study the quantitative, fractal and spatial characters of...ABSTRACT: At the study area of Xigu District in Lanzhou City, using RS & GIS as tools we apply Diversity, Dominance, Fragmentation , Isolation and so on to study the quantitative, fractal and spatial characters of landscapes’ structures in the four sub-regions divided by the morphological features. Using the Fractal Theory to establish the fractal structure models, we analyze the complexity and stability of various landscapes’ distribution with fractal dimension value. The spatial distribution characteristics of landscape mosaic structure are also expounded. At the end of the paper we discuss the relevant problems on the main factors which control and effect on the spatial pattern of landscapes as well as on landscape optimization and management.展开更多
Over twenty thousand lightning location data obtained by using Lightning Location System(LLS) from Lanzhou and Beijing regions have been analysed to ascertain the characteristics of ground flashes in both regions. The...Over twenty thousand lightning location data obtained by using Lightning Location System(LLS) from Lanzhou and Beijing regions have been analysed to ascertain the characteristics of ground flashes in both regions. The strength of positive flashes is 5 times higher in Lanzhou than in Beijing. The strength of positive flashes is 3 times and 2.2 times as large as negative flashes in Beijing and in Lanzhou respectively. It has been found that the strength of positive and negative flashes is submitted to the normal distribution, and is independent of the characteristics of thunderstorm. So the lightning strength obtained by DF may be used to forecast the coming of thunderstorm. Although the stroke number in both regions decreases as exponent regulation, the maximum number of return stroke for one lightning in Beijing is more than that in Lanzhou. The peak flash rate occurs in late afternoon for both regions, but the maximum and minimum flash rate appeared an hour earlier in Beijing than in Lanzhou.The展开更多
Both yield and quality of Lanzhou lily(Lilium davidii var. unicolor) are seriously affected by continuous cropping. We attempted to understand the effects of intercropping on the obstacles associated with continuous c...Both yield and quality of Lanzhou lily(Lilium davidii var. unicolor) are seriously affected by continuous cropping. We attempted to understand the effects of intercropping on the obstacles associated with continuous cropping of Lanzhou lily(Lilium davidii var. unicolor). The changes of rhizosphere microbial biomass and diversity in interplanting and monoculturing systems were studied by using the Illumina Hi Seq sequencing technique. The contents and composition of lily root exudates were measured by gas chromatography–mass spectrometer(GC–MS). The intercropping results of Lanzhou lily showed:(1) There was no difference in the composition of the rhizosphere soil microbes at the phylum level, but the relative abundance of the microbes decreased; and the relative abundance of harmful fungi such as Fusarium sp. increased. The relative abundance of Pleosporales sp. and other beneficial bacteria were reduced. After OTU(operational taxonomic unit)clustering, there were some beneficial bacteria, such as Chaetomium sp., in the lily rhizosphere soil in the interplanting system that had not existed in the single-cropping system. We did not find harmful bacteria that had existed in the single-cropping systm in the rhizosphere soil of interplanting system. The above results indicated that the changes of relative abundance of soil fungi and bacteria in lily rhizosphere soil was not conducive to improving the ecological structure of rhizosphere soil microbes. At the same time, the microbial composition change is very complex—beneficial and yet inadequate at the same time.(2) Root exudates provide a matrix for the growth of microorganisms. Combined with the detection of root exudates, the decrease in the composition of the root exudates of the lily was probably the reason for the decrease of the relative abundance of microbes after intercropping. At the same time, the decrease of the relative content of phenolic compounds, which inhibit the growth of microorganisms, did not increase the relative content of rhizosphere soil microorganisms. Changes in amino acids and total sugars may be responsible for the growth of Fusarium sp.. The results showed that the intercropping pattern did not noticeably alleviate the obstacle to continuous cropping of Lanzhou lily, and the change of microbial biomass and diversity was even unfavorable. However, the emergence of some beneficial bacteria, the disappearance of harmful fungi, and other changes with intercropping are in favor of alleviation of obstacles to continuous cropping of Lanzhou lily.展开更多
Air quality was improved considerably and the so-called"Lanzhou Blue"appeared frequently in Lanzhou due to implementation of some strict emission-control measures in recent years.To better understand whether...Air quality was improved considerably and the so-called"Lanzhou Blue"appeared frequently in Lanzhou due to implementation of some strict emission-control measures in recent years.To better understand whether the concentration of each air pollutant had decreased significantly and then give some suggestions as to urban air-quality improvement in the near future,the variations of the Air Quality Index(AQI)and six criterion air pollutants(PM_(2.5),PM_(10),CO,SO_2,NO_2,and O_3)at five state-controlled monitoring sites of Lanzhou were studied from 2013 to 2016.The AQI,PM_(2.5),PM_(10),and SO_2 gradually decreased from 2013 to 2016,while CO and NO_2 concentrations had slightly increasing trends,especially in urban areas,due to the large number of motor vehicles,which had an annual growth rate of 30.87%.The variations of the air pollutants in the no-domestic-heating season were more significant than those in the domestic-heating season.The increase of ozone concentration for the domestic-heating season at a background station was the most significant among the five monitoring sites.The vehicle-exhaust and ozone pollution was increasingly severe with the rapid increase in the number of motor vehicles.The particulate-matter pollution became slight in the formerly highly polluted Lanzhou City.Some synergetic measures in urban and rural areas of Lanzhou should be taken by the local government in the near future to control fine particulate-matter(PM_(2.5))and ozone pollution.展开更多
Very recently D.Vukicevic et al.[8]introduced a new topological index for a molecular graph G named Lanzhou index as∑_(u∈V(G))d_(u)d^(2)_(u),where d_(u)and d_(u)denote the degree of vertex u in G and in its compleme...Very recently D.Vukicevic et al.[8]introduced a new topological index for a molecular graph G named Lanzhou index as∑_(u∈V(G))d_(u)d^(2)_(u),where d_(u)and d_(u)denote the degree of vertex u in G and in its complement respectively.Lanzhou index Lz(G)can be expressed as(n-1)M_(1)(G)-F(G),where M_(1)(G)and F(G)denote the first Zagreb index and the forgotten index of G respectively,and n is the number of vertices in G.It turns out that Lanzhou index outperforms M_(1)(G)and F(G)in predicting the logarithm of the octanol-water partition coefficient for octane and nonane isomers.It was shown that stars and balanced double stars are the minimal and maximal trees for Lanzhou index respectively.In this paper,we determine the unicyclic graphs and the unicyclic chemical graphs with the minimum and maximum Lanzhou indices separately.展开更多
Rapid industrialization and urbanization have led to the most serious habitat degradation in China,especially in the loess hilly area of the Yellow River Basin,where the ecological environment is relatively fragile.Th...Rapid industrialization and urbanization have led to the most serious habitat degradation in China,especially in the loess hilly area of the Yellow River Basin,where the ecological environment is relatively fragile.The contradiction between economic development and ecological environment protection has aroused widespread concern.In this study,we used the habitat quality of Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST-HQ)model at different scales to evaluate the dynamic evolution characteristics of habitat quality in Lanzhou City,Gansu Province of China.The spatiotemporal variations of habitat quality were analyzed by spatial autocorrelation.A Geographical Detector(Geodetector)model was used to explore the driving factors that influencing the spatial differentiation of habitat quality,including natural factors,socio-economic factors,and ecological protection factors.The results showed that the habitat quality index of Lanzhou City decreased from 0.4638 to 0.4548 during 2000-2018.The areas with reduced the habitat quality index were mainly located in the Yellow River Basin and Qinwangchuan Basin,where are the main urban areas and the new economic development areas,respectively.The spatial distribution of habitat quality presented a trend of high in the surrounding areas and low in the middle,and showed a significant positive spatial autocorrelation.With the increase of study scale,the spatial distribution of habitat quality changed from concentrated to dispersed.The spatial differentiation of habitat quality in the study area was the result of multiple factors.Among them,topographic relief and slope were the key factors.The synergistic enhancement among these driving factors intensified the spatial differentiation of habitat quality.The findings of this study can provide a scientific basis for land resources utilization and ecosystem restoration in the arid and semi-arid land.展开更多
By using the waveform data recorded during the site survey of Lanzhou Seismic Array, the author calculated and analyzed the correlation of the signal and noise between the site pairs and found that the ideal radii of ...By using the waveform data recorded during the site survey of Lanzhou Seismic Array, the author calculated and analyzed the correlation of the signal and noise between the site pairs and found that the ideal radii of the two concentric rings for Lanzhou Seismic Array were 380 m and 1500 m, respectively. According to the radius limit and other requirements, nine sites were chosen to make a seismic array, and then the detection and location ability of the array were estimated.展开更多
Here,we describe a new primitive Erinaceidae species,Oligoechinus lanzhouensis n.gen.n.sp.,based on a specimen from late Oligocene strata of the Lanzhou Basin,Gansu Province.Its characteristics are as follows:the M1 w...Here,we describe a new primitive Erinaceidae species,Oligoechinus lanzhouensis n.gen.n.sp.,based on a specimen from late Oligocene strata of the Lanzhou Basin,Gansu Province.Its characteristics are as follows:the M1 width is longer than the length,the metastyle extends far disto-labially,the posterior margin has strong curve and a distinct metaconule that is connected to the protocone by a postprotocrista is located in the centre of the tooth.The posterior arm of the metaconule is poorly developed.In the P4,the pterion of the metastyle is less developed and the metacone is carinate.In addition,O.lanzhouensis has a premolar larger than the canine tooth(P2>C)and P3 had no molarisation,characters also possessed by Erinaceus.Overall,O.lanzhouensis was similar to Mioechinus based on architectural tooth features,demonstrating a closed genetic relationship.Fossil Erinaceidae are relatively rare before the Miocene.The discovery of O.lanzhouensis provides an important insight into the origin of Mioechinus in China and the early evolution of the Erinaceidae.Our analysis shows that a relatively recent ancestor of Mioechinus had probably existed in the early Oligocene and that O.Lanzhouensis was likely an ancestral type of Mioechinus gobiensis,and its systematic position should be located at a transitional position between Amphechinus and Mioechinus.展开更多
The Quantougou(QTG) Fauna in central Lanzhou Basin is an important late Mid-Miocene fauna on the northeastern Tibetan Plateau margin,but its numerical age remains a matter of debate.Here,we present a new magnetostrati...The Quantougou(QTG) Fauna in central Lanzhou Basin is an important late Mid-Miocene fauna on the northeastern Tibetan Plateau margin,but its numerical age remains a matter of debate.Here,we present a new magnetostratigraphic record for a fluvio-lacustrine section to further constrain the age of the QTG Fauna.Results suggest that the studied section spans from polarity chrons C5Cn.2n to C5 n.2n or C5 An.1n,with ages of ca.16.5 Ma to 10 Ma or 16.5 Ma to 12 Ma.The QTG Fauna is located at the top of polarity chron C5r.3 r or C5 Ar.2 r,which corresponds to an age of 11.7 Ma or 12.8 Ma for the fauna.Accordingly,the associated Myocricetodontinae(a subfamily of Gerbillidae,Rodentia) is suggested to have appeared in the Lanzhou Basin at 11.7 Ma or 12.8 Ma,which is the oldest Myocricetodontinae in East Asia but is still much younger than the ~20 Ma appearance of this subfamily in West and South Asia.Our age data support the interpretation that East Asian Myocricetodontinae originated from South Asia.The QTG fauna further suggest a dry and open grassland environment,which is consistent with global cooling after the Mid-Miocene Climatic Optimum.展开更多
The relationship between microenvironmentalfactors,i.e.,cigarette smoking,alcohol drinking,coal burning for cooking and warming,and risk oflung cancer in Lanzhou City was investigated witha case-control study,1982-198...The relationship between microenvironmentalfactors,i.e.,cigarette smoking,alcohol drinking,coal burning for cooking and warming,and risk oflung cancer in Lanzhou City was investigated witha case-control study,1982-1988.Seventy patients,aged 21-77,with histologically confirmed lungcancer,and 70 hospital control。展开更多
On August 3,2021,the Changqing ethane-to-ethylene project owned by the PetroChina Lanzhou Petrochemical Company(LPC)had been put on stream to crank out qualified ethylene product.The construction of this project,locat...On August 3,2021,the Changqing ethane-to-ethylene project owned by the PetroChina Lanzhou Petrochemical Company(LPC)had been put on stream to crank out qualified ethylene product.The construction of this project,located in the Yuheng Industrial Park of Yulin city,Shaanxi province,was kicked off in June 2019,with the total investment amounting to around 10.4 billion RMB.The project mainly consists of an 800 kt/a unit for manufacturing ethylene from ethane cracking,the downstream two 400 kt/a polypropylene units,and a 20 kt/a unit for manufacture of 1-hexene.展开更多
The Lanzhou index of a graph <em>G</em> is defined as the sum of the product between <img src="Edit_267e1b98-b5dd-40b4-b5f0-c9e5e012d359.bmp" alt="" /> and square of <em>d&l...The Lanzhou index of a graph <em>G</em> is defined as the sum of the product between <img src="Edit_267e1b98-b5dd-40b4-b5f0-c9e5e012d359.bmp" alt="" /> and square of <em>d<sub>u</sub></em> over all vertices <em>u</em> of <em>G</em>, where <em>d<sub>u</sub></em> and <img src="Edit_0cc51468-628a-4a8a-8205-eec1f93624aa.bmp" alt="" /> are respectively the degree of <em>u</em> in <em>G</em> and the degree of <em>u</em> in the complement graph <img src="Edit_2027b773-bcdd-4cbc-b746-bd9b93390798.bmp" alt="" />of <em>G</em>. <em>R</em>(<em>G</em>) is obtained from <em>G</em> by adding a new vertex corresponding to each edge of <em>G</em>, then joining each new vertex to the end vertices of the corresponding edge. Lanzhou index is an important topological index. It is closely related to the forgotten index and first Zagreb index of graphs. In this note, we characterize the bound of Lanzhou index of <em>R</em>(<em>T</em>) of a tree <em>T</em>. And the corresponding extremal graphs are also determined.展开更多
PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristic...PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristics of the concentration change and to study the relationship between meteorological elements and PM10/PM2.5 in Lanzhou New District in January,2018.Meanwhile,the concentration changes of PM2.5 and PM10 were predicted by wavelet analysis combined with BP neural network.The results show that:(1)Due to the cold front process in winter,PM2.5 was negatively correlated with the water vapor mixing rate.PM10 was positively correlated with air temperature and negatively correlated with air pressure.(2)There was an inversion layer in the atmosphere near the high value day of PM2.5 and PM10,the surface was controlled by low pressure,low wind speed,and the situation of low value day of PM2.5 was the opposite.On the day of high value of PM10,the air temperature below 600 hPa was higher,and the wind speed near the surface was also higher.(3)Wavelet analysis combined with BP(Back Propagation)neural network had a good prediction effect on PM2.5,which could basically reflect the hourly change of PM2.5 concentration.However,the simulation effect of PM10 was poor,and the input parameters of surrounding pollutants should be added to improve the prediction effect.展开更多
Clarifying the formation mechanism of poor settlements is the " pathological" basis for urban regeneration and poverty governance.On the basis of scientific determination of 155 poor settlements in Lanzhou C...Clarifying the formation mechanism of poor settlements is the " pathological" basis for urban regeneration and poverty governance.On the basis of scientific determination of 155 poor settlements in Lanzhou City,this paper classified their types and analyzed the characteristics of their quantity distribution and density distribution. From the perspective of spatial and social interaction,and combined the internal factors and external factors,this paper put forward the formation mechanism of poor settlements,namely,superposition of unit society collapse and physical environment degradation,interaction between differentiation of residents' income and reform of housing institution,interweaving between urban discontinuous planning and jumping construction,coupling between passive urbanization and active urbanization,and derivation of lagged economic development and unique regional culture.展开更多
Usually each famous city has a cultural highlight such as Tiananmen Square in Beijing and the sculpture of mermaid in Copenhagen. Lanzhou city in northwest China, has a special sign—a big watermill being turned slowl...Usually each famous city has a cultural highlight such as Tiananmen Square in Beijing and the sculpture of mermaid in Copenhagen. Lanzhou city in northwest China, has a special sign—a big watermill being turned slowly by the Yellow River. Watermill was used for irrigation in ancient China. Situated on the upper reaches of the Yellow River and with展开更多
The Lanzhou No.3 Worsted Co. Ltd.is one of the backbone enterprises inChina’s textiles industry. In recentyears, proceeding from the enterprise’ssituation, the Company has comprehensivelyconducted the economic opera...The Lanzhou No.3 Worsted Co. Ltd.is one of the backbone enterprises inChina’s textiles industry. In recentyears, proceeding from the enterprise’ssituation, the Company has comprehensivelyconducted the economic operation of asimulated market, shifted its operationalideology, and development pattern by takingscience and technology as the mainstay,展开更多
The Lanzhou Petrochemical MachineryPlant is a large backbone enterprisefor producing oil drilling/miningmachinery and oil refining and chemicalequipment. It was built under China’s FirstFive-Year Plan. Through its de...The Lanzhou Petrochemical MachineryPlant is a large backbone enterprisefor producing oil drilling/miningmachinery and oil refining and chemicalequipment. It was built under China’s FirstFive-Year Plan. Through its developmentover the past three decades, it has becomethe largest domestic manufacturing base foroil drilling/mining machinery and oil refiningand chemical equipment, The plant now hasa total staff of over 11,000 and owns over2,100 sets of main production equipment.展开更多
Autumn is a season of harvest. In autumn the sweet smell of fruit coming from the stalls lining the streets and lanes in Lanzhou, capital of Gansu Province, permeates the air. Lanzhou is true to its name—the "ci...Autumn is a season of harvest. In autumn the sweet smell of fruit coming from the stalls lining the streets and lanes in Lanzhou, capital of Gansu Province, permeates the air. Lanzhou is true to its name—the "city of fruit." Located where the Loess Plateau and Qinghai and Tibetan Plateau meet, nature is somewhat unkind and there is only 320mm of rain each year over large tracts of yellow earth. But long hours of sunshine and great difference展开更多
基金the Gansu Science and Technology Major Project(Grant No.182D2NA010)the Science and Technology Service Network Initiative of the Chinese Academy of Sciences(Grant No.KFJ-STS-QYZD-120)the Key R&D plan of the Ningxia Hui Autonomous Region(Grant No.2019BBF02018)for the funding they provided。
文摘Drought stress is the main limiting plant growth factor in arid and semiarid regions.The Lanzhou lily(Lilium davidii var.unicolor)is the only sweet-tasting lily grown in these regions of China that offers highly edible,medicinal,health,and ornamental value.The Tresor lily is an ornamental flower known for its strong resistance.Plants were grown under three different drought intensity treatments,namely,being watered at intervals of 5,15,and 25 d(either throughout the study or during specific growth stages).We measured the biomass,leaf area,photosynthetic response,chlorophyll content(SPAD value),and osmoregulation of both the Lanzhou lily and the Tresor lily(Lilium‘Tresor’).Additionally,we employed RNA sequencing(RNA-Seq)and qRT-PCR to investigate transcriptomic changes of the Lanzhou lily in response to drought stress.Results showed that under drought stress,the decreasing rate in the Lanzhou lily bulb weight was lower than the corresponding Tresor lily bulb rate;the net photosynthetic rate,transpiration rate,and stomatal conductance of the Lanzhou lily were all higher compared to the Tresor lily;osmoregulation constituents,such as glucose,fructose,sucrose,trehalose,and soluble sugar,in the Lanzhou lily were comparatively higher;PYL,NCED,and ERS genes were significantly expressed in the Lanzhou lily.Under moderate drought,the biosynthesis of flavonoids,circadian rhythms,and the tryptophan metabolism pathway of the Lanzhou lily were all significant.Under severe drought stress,fatty acid elongation,photosynthetic antenna protein,plant hormone signal transduction,flavone and flavonol biosynthesis,and the carotenoid biosynthesis pathway were all significant.The Lanzhou lily adapted to drought stress by coordinating its organs and the unique role of its bulb,regulating photosynthesis,increasing osmolyte content,activating circadian rhythms,signal transduction,fatty acid elongation metabolism,and phenylalanine and flavonoid metabolic pathways,which may collectively be the main adaptation strategy and mechanisms used by the Lanzhou lily under drought stress.
文摘To differentiate between natural and anthropogenic particulate sources in the atmosphere in Lanzhou City, samples were collected in different sites. The dust flux was calculated and magnetic measurements were conducted. Results show a distinct pattern of variation of dust flux within a year and it agrees with the shifts of atmospheric circulation regime. The magnetic parameters indicate that natural sources are the major components of atmospheric particulate during late spring and early summer, while anthropogenic sources contribute much more during winter months. The data also support the earlier findings that magnetic parameters are effective for differentiating between particulate arising from natural sources such as soil erosion and from anthropogenic sources such as coal combustion.
基金Under the auspices of the National Natural Science Foundationof China(No. 40171069).
文摘ABSTRACT: At the study area of Xigu District in Lanzhou City, using RS & GIS as tools we apply Diversity, Dominance, Fragmentation , Isolation and so on to study the quantitative, fractal and spatial characters of landscapes’ structures in the four sub-regions divided by the morphological features. Using the Fractal Theory to establish the fractal structure models, we analyze the complexity and stability of various landscapes’ distribution with fractal dimension value. The spatial distribution characteristics of landscape mosaic structure are also expounded. At the end of the paper we discuss the relevant problems on the main factors which control and effect on the spatial pattern of landscapes as well as on landscape optimization and management.
文摘Over twenty thousand lightning location data obtained by using Lightning Location System(LLS) from Lanzhou and Beijing regions have been analysed to ascertain the characteristics of ground flashes in both regions. The strength of positive flashes is 5 times higher in Lanzhou than in Beijing. The strength of positive flashes is 3 times and 2.2 times as large as negative flashes in Beijing and in Lanzhou respectively. It has been found that the strength of positive and negative flashes is submitted to the normal distribution, and is independent of the characteristics of thunderstorm. So the lightning strength obtained by DF may be used to forecast the coming of thunderstorm. Although the stroke number in both regions decreases as exponent regulation, the maximum number of return stroke for one lightning in Beijing is more than that in Lanzhou. The peak flash rate occurs in late afternoon for both regions, but the maximum and minimum flash rate appeared an hour earlier in Beijing than in Lanzhou.The
基金funded by Lanzhou Branch of the Chinese Academy of Sciences institutional cooperation program(2BY52BI61)the Key program of Chinese Academy of Sciences(22Y622AM1)
文摘Both yield and quality of Lanzhou lily(Lilium davidii var. unicolor) are seriously affected by continuous cropping. We attempted to understand the effects of intercropping on the obstacles associated with continuous cropping of Lanzhou lily(Lilium davidii var. unicolor). The changes of rhizosphere microbial biomass and diversity in interplanting and monoculturing systems were studied by using the Illumina Hi Seq sequencing technique. The contents and composition of lily root exudates were measured by gas chromatography–mass spectrometer(GC–MS). The intercropping results of Lanzhou lily showed:(1) There was no difference in the composition of the rhizosphere soil microbes at the phylum level, but the relative abundance of the microbes decreased; and the relative abundance of harmful fungi such as Fusarium sp. increased. The relative abundance of Pleosporales sp. and other beneficial bacteria were reduced. After OTU(operational taxonomic unit)clustering, there were some beneficial bacteria, such as Chaetomium sp., in the lily rhizosphere soil in the interplanting system that had not existed in the single-cropping system. We did not find harmful bacteria that had existed in the single-cropping systm in the rhizosphere soil of interplanting system. The above results indicated that the changes of relative abundance of soil fungi and bacteria in lily rhizosphere soil was not conducive to improving the ecological structure of rhizosphere soil microbes. At the same time, the microbial composition change is very complex—beneficial and yet inadequate at the same time.(2) Root exudates provide a matrix for the growth of microorganisms. Combined with the detection of root exudates, the decrease in the composition of the root exudates of the lily was probably the reason for the decrease of the relative abundance of microbes after intercropping. At the same time, the decrease of the relative content of phenolic compounds, which inhibit the growth of microorganisms, did not increase the relative content of rhizosphere soil microorganisms. Changes in amino acids and total sugars may be responsible for the growth of Fusarium sp.. The results showed that the intercropping pattern did not noticeably alleviate the obstacle to continuous cropping of Lanzhou lily, and the change of microbial biomass and diversity was even unfavorable. However, the emergence of some beneficial bacteria, the disappearance of harmful fungi, and other changes with intercropping are in favor of alleviation of obstacles to continuous cropping of Lanzhou lily.
基金supported by Natural Science Foundation of China(41605103)Youth Innovation Promotion Association,CAS(2017462)+1 种基金CAS"Light of West China"Program,Opening Project of Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3)(FDLAP16005)the Excellent Post-Doctoral Program(2016LH0020)
文摘Air quality was improved considerably and the so-called"Lanzhou Blue"appeared frequently in Lanzhou due to implementation of some strict emission-control measures in recent years.To better understand whether the concentration of each air pollutant had decreased significantly and then give some suggestions as to urban air-quality improvement in the near future,the variations of the Air Quality Index(AQI)and six criterion air pollutants(PM_(2.5),PM_(10),CO,SO_2,NO_2,and O_3)at five state-controlled monitoring sites of Lanzhou were studied from 2013 to 2016.The AQI,PM_(2.5),PM_(10),and SO_2 gradually decreased from 2013 to 2016,while CO and NO_2 concentrations had slightly increasing trends,especially in urban areas,due to the large number of motor vehicles,which had an annual growth rate of 30.87%.The variations of the air pollutants in the no-domestic-heating season were more significant than those in the domestic-heating season.The increase of ozone concentration for the domestic-heating season at a background station was the most significant among the five monitoring sites.The vehicle-exhaust and ozone pollution was increasingly severe with the rapid increase in the number of motor vehicles.The particulate-matter pollution became slight in the formerly highly polluted Lanzhou City.Some synergetic measures in urban and rural areas of Lanzhou should be taken by the local government in the near future to control fine particulate-matter(PM_(2.5))and ozone pollution.
基金Supported by the National Natural Science Foundation of China(11871256)the Chinese-Croatian bilateral project(7-22)。
文摘Very recently D.Vukicevic et al.[8]introduced a new topological index for a molecular graph G named Lanzhou index as∑_(u∈V(G))d_(u)d^(2)_(u),where d_(u)and d_(u)denote the degree of vertex u in G and in its complement respectively.Lanzhou index Lz(G)can be expressed as(n-1)M_(1)(G)-F(G),where M_(1)(G)and F(G)denote the first Zagreb index and the forgotten index of G respectively,and n is the number of vertices in G.It turns out that Lanzhou index outperforms M_(1)(G)and F(G)in predicting the logarithm of the octanol-water partition coefficient for octane and nonane isomers.It was shown that stars and balanced double stars are the minimal and maximal trees for Lanzhou index respectively.In this paper,we determine the unicyclic graphs and the unicyclic chemical graphs with the minimum and maximum Lanzhou indices separately.
基金This research was supported by the National Natural Science Foundation of China(41961029)the Gansu Construction Science and Technology Soft Science Project of China(JK2022-16).
文摘Rapid industrialization and urbanization have led to the most serious habitat degradation in China,especially in the loess hilly area of the Yellow River Basin,where the ecological environment is relatively fragile.The contradiction between economic development and ecological environment protection has aroused widespread concern.In this study,we used the habitat quality of Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST-HQ)model at different scales to evaluate the dynamic evolution characteristics of habitat quality in Lanzhou City,Gansu Province of China.The spatiotemporal variations of habitat quality were analyzed by spatial autocorrelation.A Geographical Detector(Geodetector)model was used to explore the driving factors that influencing the spatial differentiation of habitat quality,including natural factors,socio-economic factors,and ecological protection factors.The results showed that the habitat quality index of Lanzhou City decreased from 0.4638 to 0.4548 during 2000-2018.The areas with reduced the habitat quality index were mainly located in the Yellow River Basin and Qinwangchuan Basin,where are the main urban areas and the new economic development areas,respectively.The spatial distribution of habitat quality presented a trend of high in the surrounding areas and low in the middle,and showed a significant positive spatial autocorrelation.With the increase of study scale,the spatial distribution of habitat quality changed from concentrated to dispersed.The spatial differentiation of habitat quality in the study area was the result of multiple factors.Among them,topographic relief and slope were the key factors.The synergistic enhancement among these driving factors intensified the spatial differentiation of habitat quality.The findings of this study can provide a scientific basis for land resources utilization and ecosystem restoration in the arid and semi-arid land.
文摘By using the waveform data recorded during the site survey of Lanzhou Seismic Array, the author calculated and analyzed the correlation of the signal and noise between the site pairs and found that the ideal radii of the two concentric rings for Lanzhou Seismic Array were 380 m and 1500 m, respectively. According to the radius limit and other requirements, nine sites were chosen to make a seismic array, and then the detection and location ability of the array were estimated.
基金supported by the National Natural Science Foundation of China(No.41290253)
文摘Here,we describe a new primitive Erinaceidae species,Oligoechinus lanzhouensis n.gen.n.sp.,based on a specimen from late Oligocene strata of the Lanzhou Basin,Gansu Province.Its characteristics are as follows:the M1 width is longer than the length,the metastyle extends far disto-labially,the posterior margin has strong curve and a distinct metaconule that is connected to the protocone by a postprotocrista is located in the centre of the tooth.The posterior arm of the metaconule is poorly developed.In the P4,the pterion of the metastyle is less developed and the metacone is carinate.In addition,O.lanzhouensis has a premolar larger than the canine tooth(P2>C)and P3 had no molarisation,characters also possessed by Erinaceus.Overall,O.lanzhouensis was similar to Mioechinus based on architectural tooth features,demonstrating a closed genetic relationship.Fossil Erinaceidae are relatively rare before the Miocene.The discovery of O.lanzhouensis provides an important insight into the origin of Mioechinus in China and the early evolution of the Erinaceidae.Our analysis shows that a relatively recent ancestor of Mioechinus had probably existed in the early Oligocene and that O.Lanzhouensis was likely an ancestral type of Mioechinus gobiensis,and its systematic position should be located at a transitional position between Amphechinus and Mioechinus.
基金This study was supported financially by the National Natural Science Foundation of China(Nos.41704071,41290253)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0707)+2 种基金Chinese Academy of Sciences“Light of West China”Program(XAB2018B04)Australian Research Council grant DP190100874We thank David Heslop for checking our reversal test result.
文摘The Quantougou(QTG) Fauna in central Lanzhou Basin is an important late Mid-Miocene fauna on the northeastern Tibetan Plateau margin,but its numerical age remains a matter of debate.Here,we present a new magnetostratigraphic record for a fluvio-lacustrine section to further constrain the age of the QTG Fauna.Results suggest that the studied section spans from polarity chrons C5Cn.2n to C5 n.2n or C5 An.1n,with ages of ca.16.5 Ma to 10 Ma or 16.5 Ma to 12 Ma.The QTG Fauna is located at the top of polarity chron C5r.3 r or C5 Ar.2 r,which corresponds to an age of 11.7 Ma or 12.8 Ma for the fauna.Accordingly,the associated Myocricetodontinae(a subfamily of Gerbillidae,Rodentia) is suggested to have appeared in the Lanzhou Basin at 11.7 Ma or 12.8 Ma,which is the oldest Myocricetodontinae in East Asia but is still much younger than the ~20 Ma appearance of this subfamily in West and South Asia.Our age data support the interpretation that East Asian Myocricetodontinae originated from South Asia.The QTG fauna further suggest a dry and open grassland environment,which is consistent with global cooling after the Mid-Miocene Climatic Optimum.
文摘The relationship between microenvironmentalfactors,i.e.,cigarette smoking,alcohol drinking,coal burning for cooking and warming,and risk oflung cancer in Lanzhou City was investigated witha case-control study,1982-1988.Seventy patients,aged 21-77,with histologically confirmed lungcancer,and 70 hospital control。
文摘On August 3,2021,the Changqing ethane-to-ethylene project owned by the PetroChina Lanzhou Petrochemical Company(LPC)had been put on stream to crank out qualified ethylene product.The construction of this project,located in the Yuheng Industrial Park of Yulin city,Shaanxi province,was kicked off in June 2019,with the total investment amounting to around 10.4 billion RMB.The project mainly consists of an 800 kt/a unit for manufacturing ethylene from ethane cracking,the downstream two 400 kt/a polypropylene units,and a 20 kt/a unit for manufacture of 1-hexene.
文摘The Lanzhou index of a graph <em>G</em> is defined as the sum of the product between <img src="Edit_267e1b98-b5dd-40b4-b5f0-c9e5e012d359.bmp" alt="" /> and square of <em>d<sub>u</sub></em> over all vertices <em>u</em> of <em>G</em>, where <em>d<sub>u</sub></em> and <img src="Edit_0cc51468-628a-4a8a-8205-eec1f93624aa.bmp" alt="" /> are respectively the degree of <em>u</em> in <em>G</em> and the degree of <em>u</em> in the complement graph <img src="Edit_2027b773-bcdd-4cbc-b746-bd9b93390798.bmp" alt="" />of <em>G</em>. <em>R</em>(<em>G</em>) is obtained from <em>G</em> by adding a new vertex corresponding to each edge of <em>G</em>, then joining each new vertex to the end vertices of the corresponding edge. Lanzhou index is an important topological index. It is closely related to the forgotten index and first Zagreb index of graphs. In this note, we characterize the bound of Lanzhou index of <em>R</em>(<em>T</em>) of a tree <em>T</em>. And the corresponding extremal graphs are also determined.
基金research and development plan of Gansu Province in 2018"Experimental study on atmospheric environment characteristics of near-ground boundary layer in Lanzhou New District serving fine functional zoning"(18YF1FA100)the Opening Fund of Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,CAS(Grant No.LPCC2018006)the Lanzhou City University Doctoral Research Initiation Fund(Grant No.LZCU-BS2019-13).
文摘PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristics of the concentration change and to study the relationship between meteorological elements and PM10/PM2.5 in Lanzhou New District in January,2018.Meanwhile,the concentration changes of PM2.5 and PM10 were predicted by wavelet analysis combined with BP neural network.The results show that:(1)Due to the cold front process in winter,PM2.5 was negatively correlated with the water vapor mixing rate.PM10 was positively correlated with air temperature and negatively correlated with air pressure.(2)There was an inversion layer in the atmosphere near the high value day of PM2.5 and PM10,the surface was controlled by low pressure,low wind speed,and the situation of low value day of PM2.5 was the opposite.On the day of high value of PM10,the air temperature below 600 hPa was higher,and the wind speed near the surface was also higher.(3)Wavelet analysis combined with BP(Back Propagation)neural network had a good prediction effect on PM2.5,which could basically reflect the hourly change of PM2.5 concentration.However,the simulation effect of PM10 was poor,and the input parameters of surrounding pollutants should be added to improve the prediction effect.
基金Supported by Young Scholar Project of Humanities and Social Science Foundation of Ministry of Education(14YJCZH212)
文摘Clarifying the formation mechanism of poor settlements is the " pathological" basis for urban regeneration and poverty governance.On the basis of scientific determination of 155 poor settlements in Lanzhou City,this paper classified their types and analyzed the characteristics of their quantity distribution and density distribution. From the perspective of spatial and social interaction,and combined the internal factors and external factors,this paper put forward the formation mechanism of poor settlements,namely,superposition of unit society collapse and physical environment degradation,interaction between differentiation of residents' income and reform of housing institution,interweaving between urban discontinuous planning and jumping construction,coupling between passive urbanization and active urbanization,and derivation of lagged economic development and unique regional culture.
文摘Usually each famous city has a cultural highlight such as Tiananmen Square in Beijing and the sculpture of mermaid in Copenhagen. Lanzhou city in northwest China, has a special sign—a big watermill being turned slowly by the Yellow River. Watermill was used for irrigation in ancient China. Situated on the upper reaches of the Yellow River and with
文摘The Lanzhou No.3 Worsted Co. Ltd.is one of the backbone enterprises inChina’s textiles industry. In recentyears, proceeding from the enterprise’ssituation, the Company has comprehensivelyconducted the economic operation of asimulated market, shifted its operationalideology, and development pattern by takingscience and technology as the mainstay,
文摘The Lanzhou Petrochemical MachineryPlant is a large backbone enterprisefor producing oil drilling/miningmachinery and oil refining and chemicalequipment. It was built under China’s FirstFive-Year Plan. Through its developmentover the past three decades, it has becomethe largest domestic manufacturing base foroil drilling/mining machinery and oil refiningand chemical equipment, The plant now hasa total staff of over 11,000 and owns over2,100 sets of main production equipment.
文摘Autumn is a season of harvest. In autumn the sweet smell of fruit coming from the stalls lining the streets and lanes in Lanzhou, capital of Gansu Province, permeates the air. Lanzhou is true to its name—the "city of fruit." Located where the Loess Plateau and Qinghai and Tibetan Plateau meet, nature is somewhat unkind and there is only 320mm of rain each year over large tracts of yellow earth. But long hours of sunshine and great difference
