[Objective] The aim was to study the characteristics of accumulative potato biomass in different sowing dates and their relationships with the climate factors in Tianshui City.[Method] Based on the potato sowing exper...[Objective] The aim was to study the characteristics of accumulative potato biomass in different sowing dates and their relationships with the climate factors in Tianshui City.[Method] Based on the potato sowing experiment by installments in Tianshui agrometeorological experiment station in 2009,the potato's growth periods in every sowing date were contrasted with the average sowing period.Moreover,the climate resources' occupied amounts,the accumulative progresses of tuber's fresh biomass in every growth period were contrasted with the average sowing period.[Result] The results showed that the days of whole growth period in every sowing date tended to be same with the average period.The accumulative temperature's occupied amounts of every critical temperature had little difference,but the solar radiation and precipitation had great difference.The nonlinearity correlation between tuber's fresh biomass accumulation and the accumulative temperature (≥10℃) was obvious.When the accumulative temperature(≥10℃) was about 1 100℃,it was the turning point which the accumulative velocity of tuber's fresh biomass changed.The accumulation of tuber's fresh biomass in every sowing date had little difference before the inflorescence formation period.After the inflorescence formation period,the accumulative velocity of potato tuber's fresh biomass in the sowing date which was 7 days later than the average sowing period was greater than other sowing dates.[Conclusion] The optimum sowing date of potato should be in the end of early April.It had the negative effects to promote potato's yield by sowing early and too late.展开更多
Based on monitoring data of air quality and corresponding meteorological observation data in Zhumadian City during 2013-2015,temporalspatial distribution characteristics and influence factors of air pollution were ana...Based on monitoring data of air quality and corresponding meteorological observation data in Zhumadian City during 2013-2015,temporalspatial distribution characteristics and influence factors of air pollution were analyzed. The results showed that >Grade II of pollution occupied a certain proportion in Zhumadian City throughout the year,and annual pollution probabilities at three stations were 11%,11% and 6%; serious pollution occurred for six times at three stations,and they all occurred in autumn and winter; pollution probabilities at three stations in autumn and winter were 18%,17% and 12%,and pollution situation in autumn and winter was more serious than that in spring and summer,and seasonal sequence of pollution frequency from low to high was spring,summer,autumn and winter. Seen from three monitoring stations,there was little difference between new and old industrial zones. Since Branch II of China Meheco Topfond Pharma Co.,Ltd. which represented largescale pollution source took pollution prevention measures,pollution was relatively light,but serious pollution was easy to appear. Seen from temporal change of pollutant concentration,monthly distribution characteristics of three kinds of air pollutants( SO_2,NO_2 and PM_(10)) showed typical one-peak-one valley pattern,and peak occurred during December-January,while valley was during July-August. Due to straw burning,monthly change curve of PM_(10) concentration had two peaks in June and October. Dekad change characteristics of three kinds of air pollutants also showed one-peak-one-valley pattern,and peak occurred from middle dekad of December to middle dekad of January,while valley was from early dekad of July to last dekad of August. The concentration correlation among three kinds of pollutants was the most significant at station 3.Additionally,concentration correlation was significant in autumn and winter,but was relatively weaker in spring and summer. The correlation between pollutant concentration and meteorological factors in the same period was the most significant in autumn,followed by winter. Negative correlation between horizontal visibility and pollutant concentration was extremely significant in winter. There was positive correlation between air pressure and pollutant concentration in summer and autumn,while the correlation was unobvious in winter and spring. There was negative correlation between air temperature and pollutant concentration,which was the most significant in autumn. Negative correlation between relative humidity and pollutant concentration was significant in summer and autumn. Total cloud cover showed significantly positive correlation with pollutant concentration in winter,but the correlation was unobvious in other seasons. Average wind velocity and NO_2 concentration maintained significantly negative correlation in whole year,and there was significantly negative correlation between average wind velocity and concentrations of other two kinds pollutants in winter,but the correlation was worse in other seasons.展开更多
Incidence of Armillaria infection was quantified based on site factors in New Zealand Pinus radiata plantations.A linear multiple regression model was derived to predict infection levels of Armillaria root rot.Factors...Incidence of Armillaria infection was quantified based on site factors in New Zealand Pinus radiata plantations.A linear multiple regression model was derived to predict infection levels of Armillaria root rot.Factors positivily associated with the infection were:previous vegetation（native bush,pine）;soil type（pumice）;landform （valley,gully,flat）and the interaction between them.This model could assist in management planning with regard to the predisposition of particular stand to Armillaria infection.Keywods:Armillaria root rot,Disease incidence,Site factors,Quantification,Pinus radiata.展开更多
Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phen...Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phenology and to evaluate the effect of climatic factors on flowering, fruiting and seed production. Data on vegetative and repro- ductive characters were monitored from 2016 individuals of Panax wangianus population in Law Lyngdoh, Smit sacred grove in Nongkrem, Shillong, India. Leaflet area was measured by a planimeter. Size variables of both vegetative and reproductive traits in different age classes were measured. Climatic factors were recorded from 2007 to 2009. Age was recorded by counting the number of bud scale scars on the rhizome. Light intensity and relative humidity were measured using a photometer, LiCor Model LI-189 and thermohygrometer respectively. Different climatic variables are correlated with vegetative and reproductive phenological events. Statistical analysis revealed that a strong positive correlation was observed between the age versus vegetative and reproductive characters, except 1%–2% plants showed neoteny. Morphological variations were observed in natural conditions on the basis of the number of prong and carpellate conditions. Phenological status revealed that most of the individuals of the age class 35–50 years and above 50 years contributed the most to flowering, fruiting and seed production. Age class was significant to predict the size of the plant and its reproductive capacity. Climatic factors such as temperature, precipitation and relative humidity show synergistic effect on both the vegetative and reproductive phases in Panax wangianus in the undisturbed Nongkrem sacred grove. The color of flowers of P. wangianus also varied depending upon the sunlight intensity. Therefore, in the view of conservationand management, the age class of 35–50 years and above 50 years is the most important for population sustainability.展开更多
WRKY proteins are members of a family of transcription factors in higher plants that function in plant responses to various physiological processes.We identified 120 candidate WRKY genes from Gossypium raimondii with ...WRKY proteins are members of a family of transcription factors in higher plants that function in plant responses to various physiological processes.We identified 120 candidate WRKY genes from Gossypium raimondii with corresponding expressed sequence tags in at least one of four cotton species,Gossypium hirsutum,Gossypium barbadense,Gossypium arboreum,and G.raimondii.These WRKY members were anchored on 13 chromosomes in G.raimondii with uneven distribution.Phylogenetic analysis showed that WRKY candidate genes can be classified into three groups,with 20 members in group I,88 in group II,and 12 in group III.The88 genes in group II were further classified into five subgroups,groups IIa–e,containing 7,16,37,15,and 13 members,respectively.We characterized diversity in amino acid residues in the WRKY domain and/or other zinc finger motif regions in the WRKY proteins.The expression patterns of WRKY genes revealed their important roles in diverse functions in cotton developmental stages of vegetative and reproductive growth and stress response.Structural and expression analyses show that WRKY proteins are a class of important regulators of growth and development and play key roles in response to stresses in cotton.展开更多
Based on 266 strong ground motion records, an attenuation relationship was developed for both absolute and relative input energy spectra. The comparison of the two kinds of input energy spectra constructed from the at...Based on 266 strong ground motion records, an attenuation relationship was developed for both absolute and relative input energy spectra. The comparison of the two kinds of input energy spectra constructed from the attenuation relationship was made in this paper. The results show that there is little difference between the absolute input energy spectra and relative input energy spectra at the periods of 0.5-1.0 s for elastic systems and at the period of 0.5 s for inelastic systems. The absolute input energy spectra are much larger than relative input energy spectra in very short period range but some less than relative input energy spectra in long period range. It is also found that the ductility factor has a significant effect on both absolute and relative input energy spectra. The absolute input energy spectra increase with the increasing of ductility factor in the period range of less than 0.3 s but decrease in the period range of larger than 0.3 s. The absolute input energy spectra for different ductility factor are almost equivalent at the period about 0.3 s, but for relative input energy spectra, the period is about 0.5 s. The effect of ductility on the relative input energy spectra in the short period range is much larger than that on the absolute input energy spectra, especially on the softer site class.展开更多
Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlatio...Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor （CCF） and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk＇w and slope S of CCF were obtained, from which the correlation coefficients of lgk＇w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw＇ increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.展开更多
By analyzing the pollutant concentrations over the urban area and over the rural area of the city of Lanzhou, Gansu Province, China, the relationships between the daytime inversion intensity and the pollutant concentr...By analyzing the pollutant concentrations over the urban area and over the rural area of the city of Lanzhou, Gansu Province, China, the relationships between the daytime inversion intensity and the pollutant concentration in the atmospheric boundary layer （ABL） are studied with the consideration of wind speed and direction, potential temperature, specific humidity profiles, pollutant concentration in the ABL, the surface temperature, and global radiation on the ground. It was shown that the daytime inversion is a key factor in controlling air pollution concentration. A clear and positive feedback process between the daytime inversion intensity and the air pollutants over the city was found through the analysis of influences of climatic and environmental factors. The mechanisms by which the terrain and air pollutants affect the formation of the daytime inversion are discussed. The solar radiation as the essential energy source to maintain the inversion is analyzed, as are various out-forcing factors affecting the inversion and air pollutants. At last, a physical frame of relationships of air pollution with daytime inversion and the local and out-forcing factors over Lanzhou is built.展开更多
For an anti-plane problem, the differential operator is self-adjoint and the corresponding eigenfunctions belong to the Hilbert space. The orthogonal property between eigenfunctions （or between the derivatives of eig...For an anti-plane problem, the differential operator is self-adjoint and the corresponding eigenfunctions belong to the Hilbert space. The orthogonal property between eigenfunctions （or between the derivatives of eigenfunctions） of anti-plane problem is exploited. We developed for the first time two sets of radius-independent orthogonal integrals for extraction of stress intensity factors （SIFs）, so any order SIF can be extracted based on a certain known solution of displacement （an analytic result or a numerical result）. Many numerical examples based on the finite element method of lines （FEMOL） show that the present method is very powerful and efficient.展开更多
In the cooperation model of leading enterprise + farmer,channel stability is always a prominent problem. Based on previous researches,taking farmers in Hainan region as investigation object,the influence factors of ch...In the cooperation model of leading enterprise + farmer,channel stability is always a prominent problem. Based on previous researches,taking farmers in Hainan region as investigation object,the influence factors of channel stability of leading enterprise + farmer are studied by combining the background of formal contract and using the combination method of theory and demonstration. Contract item design,trading cost,product specificity,power structure,information asymmetry and social relationship are contained in analytic framework to establish theoretic model. Research results show that in formal channel management,when contract clause design is more explicit,product specificity is stronger,power structure is more balanced,information share degree is higher,and trading cost is lower,channel is more stable,and farmer's willing to renew contract is stronger. Meanwhile,social relationship plays stronger regulation role.展开更多
With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects...With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed.展开更多
This study shows that the stock-recruitment relationship (SRR) for Pacific bluefin tuna and the Pacific stock of Japanese sardine can be expressed by the same SRR model. That is, (environmental factors), where Rt and ...This study shows that the stock-recruitment relationship (SRR) for Pacific bluefin tuna and the Pacific stock of Japanese sardine can be expressed by the same SRR model. That is, (environmental factors), where Rt and St-1 denote the recruitment in year t and spawning stock biomass in year t - 1, and f(.) is a function that evaluates the effect of environmental factors in year t. The simulations showed that when the fluctuation in environmental factors cyclically changed, 1) the shape of the apparent SRR assumed clockwise loops for the shorter maturity age of fish, and 2) the apparent SRR comprised scattered anticlockwise loops for the longer maturity age of fish. These features coincided well with those observed. This finding gives us a new paradigm in SRR, which is far different from the concept that has predominated in the field for more than 60 years.展开更多
Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, th...Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, this paper puts forward suggestions concerning effective interactive management of relationship marketing from the organization.展开更多
We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quart...We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quarter （PCQ） method while understory vegetation was sampled in 1.5-m circular quadrats. Cedrus deodara is the national symbol of Pakistan and was dominant in the sampled communities. Because environmental variables determine vegetation types, we analyzed and evaluated edaphic and topographic factors. DCA-Ordination showed the major gradient as an amalgam of elevation （p〈0.05） and slope （p〈0.01） as the topographic factors correlated with species distribution. Soil variables were the factors of environmental significance along DCA axes. However, among these factors, Mg2＋ , K ＋ and N2＋ contributed not more than 0.054% 0.20% and 0.073%, respectively, to variation along the first ordination axis. We conclude that the principal reason for weak or no correlation with many edaphic variables was the anthropogenic disturbance of vegetation. The understory vegetation was composed of perennial herbs in most communities and was most dense under the tree canopy. The understory vegetation strongly regulates tree seedling growth and regeneration patterns. We recommend further study of the understory vegetation using permanent plots to aid development of forest regeneration strategies.展开更多
基金Supported by The Special Project of Service Industry in National Science & Technology Ministry (GYHY200806021)
文摘[Objective] The aim was to study the characteristics of accumulative potato biomass in different sowing dates and their relationships with the climate factors in Tianshui City.[Method] Based on the potato sowing experiment by installments in Tianshui agrometeorological experiment station in 2009,the potato's growth periods in every sowing date were contrasted with the average sowing period.Moreover,the climate resources' occupied amounts,the accumulative progresses of tuber's fresh biomass in every growth period were contrasted with the average sowing period.[Result] The results showed that the days of whole growth period in every sowing date tended to be same with the average period.The accumulative temperature's occupied amounts of every critical temperature had little difference,but the solar radiation and precipitation had great difference.The nonlinearity correlation between tuber's fresh biomass accumulation and the accumulative temperature (≥10℃) was obvious.When the accumulative temperature(≥10℃) was about 1 100℃,it was the turning point which the accumulative velocity of tuber's fresh biomass changed.The accumulation of tuber's fresh biomass in every sowing date had little difference before the inflorescence formation period.After the inflorescence formation period,the accumulative velocity of potato tuber's fresh biomass in the sowing date which was 7 days later than the average sowing period was greater than other sowing dates.[Conclusion] The optimum sowing date of potato should be in the end of early April.It had the negative effects to promote potato's yield by sowing early and too late.
文摘Based on monitoring data of air quality and corresponding meteorological observation data in Zhumadian City during 2013-2015,temporalspatial distribution characteristics and influence factors of air pollution were analyzed. The results showed that >Grade II of pollution occupied a certain proportion in Zhumadian City throughout the year,and annual pollution probabilities at three stations were 11%,11% and 6%; serious pollution occurred for six times at three stations,and they all occurred in autumn and winter; pollution probabilities at three stations in autumn and winter were 18%,17% and 12%,and pollution situation in autumn and winter was more serious than that in spring and summer,and seasonal sequence of pollution frequency from low to high was spring,summer,autumn and winter. Seen from three monitoring stations,there was little difference between new and old industrial zones. Since Branch II of China Meheco Topfond Pharma Co.,Ltd. which represented largescale pollution source took pollution prevention measures,pollution was relatively light,but serious pollution was easy to appear. Seen from temporal change of pollutant concentration,monthly distribution characteristics of three kinds of air pollutants( SO_2,NO_2 and PM_(10)) showed typical one-peak-one valley pattern,and peak occurred during December-January,while valley was during July-August. Due to straw burning,monthly change curve of PM_(10) concentration had two peaks in June and October. Dekad change characteristics of three kinds of air pollutants also showed one-peak-one-valley pattern,and peak occurred from middle dekad of December to middle dekad of January,while valley was from early dekad of July to last dekad of August. The concentration correlation among three kinds of pollutants was the most significant at station 3.Additionally,concentration correlation was significant in autumn and winter,but was relatively weaker in spring and summer. The correlation between pollutant concentration and meteorological factors in the same period was the most significant in autumn,followed by winter. Negative correlation between horizontal visibility and pollutant concentration was extremely significant in winter. There was positive correlation between air pressure and pollutant concentration in summer and autumn,while the correlation was unobvious in winter and spring. There was negative correlation between air temperature and pollutant concentration,which was the most significant in autumn. Negative correlation between relative humidity and pollutant concentration was significant in summer and autumn. Total cloud cover showed significantly positive correlation with pollutant concentration in winter,but the correlation was unobvious in other seasons. Average wind velocity and NO_2 concentration maintained significantly negative correlation in whole year,and there was significantly negative correlation between average wind velocity and concentrations of other two kinds pollutants in winter,but the correlation was worse in other seasons.
文摘Incidence of Armillaria infection was quantified based on site factors in New Zealand Pinus radiata plantations.A linear multiple regression model was derived to predict infection levels of Armillaria root rot.Factors positivily associated with the infection were:previous vegetation（native bush,pine）;soil type（pumice）;landform （valley,gully,flat）and the interaction between them.This model could assist in management planning with regard to the predisposition of particular stand to Armillaria infection.Keywods:Armillaria root rot,Disease incidence,Site factors,Quantification,Pinus radiata.
文摘Panax wangianus （Syn. Panax pseudoginseng） S. C. Sun （Araliaceae） is a critically endangered, medicinal plant of North-East India. The objective of this study was to determine how plant size affects flowering phenology and to evaluate the effect of climatic factors on flowering, fruiting and seed production. Data on vegetative and repro- ductive characters were monitored from 2016 individuals of Panax wangianus population in Law Lyngdoh, Smit sacred grove in Nongkrem, Shillong, India. Leaflet area was measured by a planimeter. Size variables of both vegetative and reproductive traits in different age classes were measured. Climatic factors were recorded from 2007 to 2009. Age was recorded by counting the number of bud scale scars on the rhizome. Light intensity and relative humidity were measured using a photometer, LiCor Model LI-189 and thermohygrometer respectively. Different climatic variables are correlated with vegetative and reproductive phenological events. Statistical analysis revealed that a strong positive correlation was observed between the age versus vegetative and reproductive characters, except 1%–2% plants showed neoteny. Morphological variations were observed in natural conditions on the basis of the number of prong and carpellate conditions. Phenological status revealed that most of the individuals of the age class 35–50 years and above 50 years contributed the most to flowering, fruiting and seed production. Age class was significant to predict the size of the plant and its reproductive capacity. Climatic factors such as temperature, precipitation and relative humidity show synergistic effect on both the vegetative and reproductive phases in Panax wangianus in the undisturbed Nongkrem sacred grove. The color of flowers of P. wangianus also varied depending upon the sunlight intensity. Therefore, in the view of conservationand management, the age class of 35–50 years and above 50 years is the most important for population sustainability.
基金financially supported in part by the National Science Foundation of China(31171590)the Specialized Research Fund for the Doctoral Program of Higher Education of China(20090097110010)+1 种基金the Natural Science Foundation of Jiangsu Province,China(BK2010065)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘WRKY proteins are members of a family of transcription factors in higher plants that function in plant responses to various physiological processes.We identified 120 candidate WRKY genes from Gossypium raimondii with corresponding expressed sequence tags in at least one of four cotton species,Gossypium hirsutum,Gossypium barbadense,Gossypium arboreum,and G.raimondii.These WRKY members were anchored on 13 chromosomes in G.raimondii with uneven distribution.Phylogenetic analysis showed that WRKY candidate genes can be classified into three groups,with 20 members in group I,88 in group II,and 12 in group III.The88 genes in group II were further classified into five subgroups,groups IIa–e,containing 7,16,37,15,and 13 members,respectively.We characterized diversity in amino acid residues in the WRKY domain and/or other zinc finger motif regions in the WRKY proteins.The expression patterns of WRKY genes revealed their important roles in diverse functions in cotton developmental stages of vegetative and reproductive growth and stress response.Structural and expression analyses show that WRKY proteins are a class of important regulators of growth and development and play key roles in response to stresses in cotton.
基金supported by National Natural Science Foundation of China(611750 68,61472168,61163004)Natural Science Foundation of Yunnan Province(2013FA130)Talent Promotion Project of Ministry of Science and Technology(2014HE001)
基金Natural Science Foundation of Heilongjiang Province (E0221)Commonweal Foundation of the Ministry of Science and Technology of China (2001DIB20098).
文摘Based on 266 strong ground motion records, an attenuation relationship was developed for both absolute and relative input energy spectra. The comparison of the two kinds of input energy spectra constructed from the attenuation relationship was made in this paper. The results show that there is little difference between the absolute input energy spectra and relative input energy spectra at the periods of 0.5-1.0 s for elastic systems and at the period of 0.5 s for inelastic systems. The absolute input energy spectra are much larger than relative input energy spectra in very short period range but some less than relative input energy spectra in long period range. It is also found that the ductility factor has a significant effect on both absolute and relative input energy spectra. The absolute input energy spectra increase with the increasing of ductility factor in the period range of less than 0.3 s but decrease in the period range of larger than 0.3 s. The absolute input energy spectra for different ductility factor are almost equivalent at the period about 0.3 s, but for relative input energy spectra, the period is about 0.5 s. The effect of ductility on the relative input energy spectra in the short period range is much larger than that on the absolute input energy spectra, especially on the softer site class.
基金This work was supported by the National Basic Research Program of China (2003CB415002) and the China Postdoctoral Science Foundation (No. 2003033486) and the Natural Science Research Fund of University in Jiangsu (04KJB150149)
文摘Sixteen indole derivatives have been computed at B3LYP/6-31 IG^＊＊ level using density functional theory （DFF）. Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor （CCF） and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk＇w and slope S of CCF were obtained, from which the correlation coefficients of lgk＇w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw＇ increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices.
基金supported by the National Science Foundation of China (Grant Nos.40830957 and 40575006)the joint research project of Gansu Province and Chinese Academy of Science named"Study on Atmosphere Pollution and its Countermeasure of Lanzhou City"
文摘By analyzing the pollutant concentrations over the urban area and over the rural area of the city of Lanzhou, Gansu Province, China, the relationships between the daytime inversion intensity and the pollutant concentration in the atmospheric boundary layer （ABL） are studied with the consideration of wind speed and direction, potential temperature, specific humidity profiles, pollutant concentration in the ABL, the surface temperature, and global radiation on the ground. It was shown that the daytime inversion is a key factor in controlling air pollution concentration. A clear and positive feedback process between the daytime inversion intensity and the air pollutants over the city was found through the analysis of influences of climatic and environmental factors. The mechanisms by which the terrain and air pollutants affect the formation of the daytime inversion are discussed. The solar radiation as the essential energy source to maintain the inversion is analyzed, as are various out-forcing factors affecting the inversion and air pollutants. At last, a physical frame of relationships of air pollution with daytime inversion and the local and out-forcing factors over Lanzhou is built.
基金Project supported by the National Natural Science Foundation of China (Nos. 59525813 and 19872066).
文摘For an anti-plane problem, the differential operator is self-adjoint and the corresponding eigenfunctions belong to the Hilbert space. The orthogonal property between eigenfunctions （or between the derivatives of eigenfunctions） of anti-plane problem is exploited. We developed for the first time two sets of radius-independent orthogonal integrals for extraction of stress intensity factors （SIFs）, so any order SIF can be extracted based on a certain known solution of displacement （an analytic result or a numerical result）. Many numerical examples based on the finite element method of lines （FEMOL） show that the present method is very powerful and efficient.
基金Supported by National Natural Science Foundation Item(71573100)
文摘In the cooperation model of leading enterprise + farmer,channel stability is always a prominent problem. Based on previous researches,taking farmers in Hainan region as investigation object,the influence factors of channel stability of leading enterprise + farmer are studied by combining the background of formal contract and using the combination method of theory and demonstration. Contract item design,trading cost,product specificity,power structure,information asymmetry and social relationship are contained in analytic framework to establish theoretic model. Research results show that in formal channel management,when contract clause design is more explicit,product specificity is stronger,power structure is more balanced,information share degree is higher,and trading cost is lower,channel is more stable,and farmer's willing to renew contract is stronger. Meanwhile,social relationship plays stronger regulation role.
文摘With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed.
文摘This study shows that the stock-recruitment relationship (SRR) for Pacific bluefin tuna and the Pacific stock of Japanese sardine can be expressed by the same SRR model. That is, (environmental factors), where Rt and St-1 denote the recruitment in year t and spawning stock biomass in year t - 1, and f(.) is a function that evaluates the effect of environmental factors in year t. The simulations showed that when the fluctuation in environmental factors cyclically changed, 1) the shape of the apparent SRR assumed clockwise loops for the shorter maturity age of fish, and 2) the apparent SRR comprised scattered anticlockwise loops for the longer maturity age of fish. These features coincided well with those observed. This finding gives us a new paradigm in SRR, which is far different from the concept that has predominated in the field for more than 60 years.
文摘Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, this paper puts forward suggestions concerning effective interactive management of relationship marketing from the organization.
基金supported by the Higher Education Commission of Pakistan
文摘We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quarter （PCQ） method while understory vegetation was sampled in 1.5-m circular quadrats. Cedrus deodara is the national symbol of Pakistan and was dominant in the sampled communities. Because environmental variables determine vegetation types, we analyzed and evaluated edaphic and topographic factors. DCA-Ordination showed the major gradient as an amalgam of elevation （p〈0.05） and slope （p〈0.01） as the topographic factors correlated with species distribution. Soil variables were the factors of environmental significance along DCA axes. However, among these factors, Mg2＋ , K ＋ and N2＋ contributed not more than 0.054% 0.20% and 0.073%, respectively, to variation along the first ordination axis. We conclude that the principal reason for weak or no correlation with many edaphic variables was the anthropogenic disturbance of vegetation. The understory vegetation was composed of perennial herbs in most communities and was most dense under the tree canopy. The understory vegetation strongly regulates tree seedling growth and regeneration patterns. We recommend further study of the understory vegetation using permanent plots to aid development of forest regeneration strategies.
