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要十分审慎地对待“影响因子” 被引量:12
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作者 杨乐 《中国科学院院刊》 2004年第2期147-148,共2页
关键词 “影响因子” 浮躁风气 科学引文指数 学术评价 学术论文
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Temporal-spatial Changes in Inner Mongolian Grassland Degradation during Past Three Decades 被引量:10
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作者 张清雨 吴绍洪 +1 位作者 赵东升 戴尔阜 《Agricultural Science & Technology》 CAS 2013年第4期676-683,共8页
[Objective] This study aimed to analyze the temporal-spatial variation of Inner Mongolian grassland degradation during past three decades. [Method] The dis- tribution characteristics of grassland were described by lan... [Objective] This study aimed to analyze the temporal-spatial variation of Inner Mongolian grassland degradation during past three decades. [Method] The dis- tribution characteristics of grassland were described by land use types supervised classification with TM/ETM. Then, temporal-spatial changes of grassland coverage were quantified by the mean of maximum vegetation coverage in last 30 years. Lastly, the grassland degradation reasons were explored through statistic analysis between the grassland coverage and precipitation, temperature and grazing intensity. [Result] The grassland degradation index of Inner Mongolia was increased from 1.38 to 1.68, and the smallest was 1.28 in 2005s. Grassland degradation and improve- ment were concurrent after 1980s, but grassland degradation was the major change trend for Inner Mongolia grassland. The area of grassland degradation was enlarged from 18.08×10^4 km2 in 1980s to 22.47×10^4 km2 in 2010s on the whole and distribu- tion range was shifted from central-eastern to west in Inner Mongolia that mainly distributed on Hulun Buir and Xilin Gol grassland in 1980s and Ordos and Alax grassland in 2010s. The grassland area of degradation had a rising trend form 1980s to 1995s, then reduced to 10.8x104 km2 in 2005s, and decreased in 2010s, which mainly speared in the west of Xilin Gol grassland. [Conclusion] Inner Mongo-lian grassland degradation were become more seriously in last 30 years because that temperature, precipitation and graze intensities change, which not performance on decreasing coverage but grassland areas. 展开更多
关键词 Grassland degradation Temporal-spatial change Influencing factor Inner Mongolia
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Correlation Analysis between Fruit Cracking and Influencing Factors in Apricot 被引量:3
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作者 聂国伟 李凯 +7 位作者 田永强 戴桂林 张晓萍 杨晓华 宋永宏 李静江 赵武娟 吕景丽 《Agricultural Science & Technology》 CAS 2017年第11期2001-2005,2013,共6页
In this study, 14 representative apricot cultivars in the production were selected as the experimental materials, and their fruit cracking characteristics, as well as the correlations between fruit cracking and influe... In this study, 14 representative apricot cultivars in the production were selected as the experimental materials, and their fruit cracking characteristics, as well as the correlations between fruit cracking and influencing factors (e.g., pedcarp structure, mineral elements contents, DW/FW ratio and soluble sugar content) were analyzed to provide some reference for systematic study on fruit cracking mecha- nism of apricot. The results showed the cultivars with small orderly-and compactlyarranged epidermal cells were difficult to crack, while the cultivars with big disorderly-and loosely-arranged epidermal cells were easy to crack. There was no significant correlation between pericarp thickness and cracking index. The correlations between cracking and mineral elements contents of apricot fruit were in the order as Ca 〉 Zn 〉 Mn 〉 Fe 〉 K 〉 Mg 〉 Cu. The cracking index of apricot fruit was significantly negatively correlated with Ca content, was weakly correlated with Zn and Mn contents, and was uncorrelated with Fe, K, Mg and Cu contents. Ca deficiency was the main factor affecting the fruit cracking in apricot. Under the same conditions, the higher the water content is, the lower the cracking index is; and the higher the soluble sugar content is, the higher the cracking index is. 展开更多
关键词 APRICOT Influencing factors CRACKING Correlation analysis
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Dynamics models of soil organic carbon 被引量:7
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作者 杨丽霞 潘剑君 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第4期323-330,共8页
As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and... As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China. 展开更多
关键词 Soil carbon Soil organic carbon Dynamic model
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Research Progress on Methane Emission from Cropland 被引量:2
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作者 周艳飞 金涛 《Agricultural Science & Technology》 CAS 2017年第2期357-360,364,共5页
Methane is an important greenhouse gas, and farmland is one of the im- portant emission sources of methane. Therefore, it's important to study the discharge of methane from cropland. This paper reviewed the methane e... Methane is an important greenhouse gas, and farmland is one of the im- portant emission sources of methane. Therefore, it's important to study the discharge of methane from cropland. This paper reviewed the methane emission from agricultural ecosystem, the factors controlling CH4 fluxes from soil, such as water regime, the soil characteristics, and the type and amount of applied fertilizers and so on, the management for mitigation of CH4 emission from cropland, especially from paddy field, and put forward some research suggestions on methane emission in the future. The objective of this paper is to provide reference for controlling methane emission in cropland. 展开更多
关键词 Methane emission Influence factor CROPLAND Research advance
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Study on the Influencing Factors and the Root Mechanism in Cutting Process of Prunus humilis(Bge). Sok
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作者 杨秀峰 李凤兰 +2 位作者 孙旭红 佟伟霜 胡宝忠 《Agricultural Science & Technology》 CAS 2009年第2期113-117,共5页
A procedure for cutting Prunus humilis(Bge). Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting ac... A procedure for cutting Prunus humilis(Bge). Sok was comprehensively studied in this paper. It was found that the key factors involved in this procession were medium, rooting accelerator, concentration of rooting accelerator and type of shoot. The results showed that send was used as mediums; Treatment with 1 000 mg/L AST rooting powder No. 2 and semi-woody shoots were the optimal materials for cutting, and the rooting rate reached 88.1%. Anatomical study on rooting of Prunus hum#is(Bge). Sok cutting has been carded out by the paraffin section method. The observation result shows that the adventitious root primordium of Prunus humili$(Bge). Sok cutting belongs to the type of induced root primordium. The adventitiousroot primordium originates from the cross region of vascular cambium and pith rays. 展开更多
关键词 Prunus humilis(Bge). Sok Green shoot cutting Adventitious roots ANATOMY
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A Preliminary Study on the Establishment of AFLP Reaction System in Spinach
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作者 孟淑春 梅燚 +1 位作者 郭军 刘玲 《Agricultural Science & Technology》 CAS 2012年第2期268-272,298,共6页
[Objective] This study aimed to establish an AFLP reaction system for spinach. [Method] Modified CTAB method was used for DNA extraction from six varieties of spinach. Experimental conditions in enzyme digestion and l... [Objective] This study aimed to establish an AFLP reaction system for spinach. [Method] Modified CTAB method was used for DNA extraction from six varieties of spinach. Experimental conditions in enzyme digestion and ligation, pre-amplification and selective amplification in the AFLP reaction system were analyzed and optimized. [Result] The results showed that: (1) enzyme digestion had better effects in the PCR instrument than in a water bath and it was not sensitive to the digestion time and DNA concentrations; (2) a total volume of 20 μl, containing 1.2 μl of Mg2+ (25 mmol/L), 1.6 μl of dNTPs (2.5 mmol/L) and 0.2 μl of Taq-polymerase (5 U/μl) was the optimal condition for pre-amplification and selective amplification reactions. [Conclusion] The AFLP system established in this study was stable and efficient, which provided a theoretical basis for AFLP molecular marker analysis of genetic relationship between spinach varieties and genetic breeding. 展开更多
关键词 SPINACH AFLP Impact factor
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Influential factors on the exchange rate of dissolved inorganic nutrients at the sediment-water interface in Jiaozhou Bay, China 被引量:3
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作者 王修林 蒋凤华 +2 位作者 石晓勇 祝陈坚 韩秀荣 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2007年第3期270-276,共7页
Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the se... Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the sediment-water interface in the Jiaozhou Bay. Major factors influencing the exchange rates are discussed in detail, which include the dissolved inorganic nutrient concentrations in porewater (Cpw), water and clay contents, and grain size of the sediments (CH2O, Cclay and GSsed). The results may provide insight into the dynamics of nutrient transport and the environmental capacity of nutrients in Jiaozhou Bay, and should be beneficial to solving the problems caused by excessive nutrient input this area. 展开更多
关键词 influential factor exchange rate dissolved inorganic nutrients sediment-water interface Jiaozhou Bay
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Characterization of Pyrolytic Lignin Extracted from Bio-oil 被引量:5
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作者 JIANG Xiaoxiang Naoko Ellis ZHONG Zhaoping 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第6期1018-1022,共5页
Bio-oil is a new liquid fuel produced by fast pyrolysis,which is a promising technology to convert bio-mass into liquid. Pyrolytic lignin extracted from bio-oil,a fine powder,contributes to the instability of bio-oil.... Bio-oil is a new liquid fuel produced by fast pyrolysis,which is a promising technology to convert bio-mass into liquid. Pyrolytic lignin extracted from bio-oil,a fine powder,contributes to the instability of bio-oil. The paper presents the structural features of three kinds of pyrolytic lignin extracted from bio-oil with different methods(WIF,HMM,and LMM) . The pyrolytic lignin samples are characterized by Fourier transform infrared spectrometer(FTIR) and X-ray photoelectron spectroscopy(XPS) . FTIR data indicate that the three pyrolytic lignin samples have similar functional groups,while the absorption intensity is different,and show characteristic vibra-tions of typical lignocellulosic material groups O H(3340-3380 cm-1) ,C H(2912-2929 cm-1) and C O(1652-1725 cm-1) . Comparison in the region(3340-3380 cm-1) indicates that WIF has more O H stretch groups than HMM and LMM. The carbon spectra are fitted to four peaks:C1,C C or C H,BE 283.5 eV;C2,C OR or C OH,BE 284.5-285.8 eV;C3,C O or HO C OR,BE 286.10-287.10 eV;C4,O C O,BE 287.5-287.7 eV. The absence of C1,C C or C H indicates the dominant polymerization structure of aro-matic carbon in pyrolytic lignin samples. For HMM and WIF,C2a and C2b can not be separated,so there is no free hydroxyl group in the samples. The oxygen peaks are also fitted to four peaks:O1,OH,BE = 530.3 eV;O2,RC O,BE 531.45-531.72 eV;O3,O C O,BE = 532.73-533.74 eV;O4,H2O,BE 535 eV. The absence of O1 and O4 indicates that little hydroxyl groups and adsorbed water are present in the samples. 展开更多
关键词 BIO-OIL pyrolytic lignin Fourier transform infrared spectrometer X-ray photoelectron spectroscopy
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Advances in the Study of Protein Quality Traits and Main Influencing Factors of Wheat in China 被引量:2
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作者 李娜娜 蒲艳艳 +5 位作者 孔维国 宫永超 贾文斌 辛富刚 于彦丽 丁汉凤 《Agricultural Science & Technology》 CAS 2015年第8期1653-1659,共7页
Wheat, the third major grain crop in China, is an important source of hu- man proteins. Wheat quality and yield has a direct impact on the development of agricultural economy and food industry. Investigating and impro... Wheat, the third major grain crop in China, is an important source of hu- man proteins. Wheat quality and yield has a direct impact on the development of agricultural economy and food industry. Investigating and improving protein quality of wheat has become a key to solving the contradiction. This paper reviewed the exist- ing literature published at home and abroad, analyzed the present situation and ex- isting problems of wheat protein quality in China, summarized the latest research progress about genetic models, main influencing factors, and correlations between protein quality traits and other traits, discussed current issues in the improvement of wheat protein quality, and proposed suggestions for breeding high-quality wheat, aiming at providing theoretical basis for genetic improvement, planting structure ad- justment and efficient production of high-quality wheat. 展开更多
关键词 WHEAT Quality analysis Genetic model Influencing factor Quality im-provement ADVANCE
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Influence factors on activity of Ru–Zn catalysts in selective hydrogenation of benzene 被引量:1
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作者 Qi Zhang Xuhua Yan +1 位作者 Peng Zheng Zhengbao Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第3期294-300,共7页
Selective hydrogenation of benzene is an atom economic green route to produce cyclohexene. The control of Zn species is the key to the catalytic performance of Ru–Zn catalysts. The influences of ZnO crystals on selec... Selective hydrogenation of benzene is an atom economic green route to produce cyclohexene. The control of Zn species is the key to the catalytic performance of Ru–Zn catalysts. The influences of ZnO crystals on selective hydrogenation of benzene were explored. A series of Ru–Zn catalysts with different Zn contents and ZnO morphologies were prepared by changing the amount of NaOH in the co-precipitation process. The catalysts were characterized by N_2 physisorption, X-ray powder diffraction(XRD), inductively coupled plasma optical emission spectrometer(ICP-OES), scanning electron microscope(SEM), temperature-programmed reduction(H_2-TPR)and Malvern laser particle size analyzer. It is found that with increasing the amount of NaOH, the Zn content first increased then decreased, and the ZnO crystals changed from relatively thicker pyramidal-shaped crystals to slimmer needle-shaped crystals. The catalyst had the highest Zn content(22.1%) and strongest interaction between ZnO crystals and Ru particles at pH 10.6 of the solution after reduction. As a result, it had the lowest activity. The activity of Ru–Zn catalysts is affected by both the Zn content and the interaction between ZnO crystals and Ru particles. The effect of reduction time was also investigated. Prolonging the reduction time caused no significant growth of ZnO crystals but the aggregation of catalyst particles and growth of Ru nanocrystals, thus resulting in the decrease of catalytic activity. 展开更多
关键词 ZnO morphology BENZENE Selective hydrogenation CO-PRECIPITATION CYCLOHEXENE
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Effect of montmorillonite on hydrate-based methane separation from mine gas 被引量:7
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作者 ZHANG Qiang WU Qiang +2 位作者 ZHANG Hui ZHANG Bao-yong XIA Ting 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期38-50,共13页
Three types of mine gas samples were used in the solutions of tetrahydrofuran(THF),sodium dodecyl sulfate(SDS)and THF-SDS with/without MMT respectively to investigate the effect of montmorillonite(MMT)on separation ch... Three types of mine gas samples were used in the solutions of tetrahydrofuran(THF),sodium dodecyl sulfate(SDS)and THF-SDS with/without MMT respectively to investigate the effect of montmorillonite(MMT)on separation characteristics of methane recovered from mine gas based on hydrate method.The partition coefficient,separation factor and recovery rate were used to evaluate the effects of MMT,and the selection factor was primarily proposed to define the selectivity of mine gas hydrate in the relative target gases.The experimental results indicate that MMT could improve the following factors including hydration separation factor,the selection factor,the partition coefficient,and the recovery rate.Furthermore,the effect of SDS on the function of MMT is analyzed in the process of hydration separation.Finally,due to the results of the experiment,it is concluded that MMT hydration mechanism explores the effect of MMT enrichment methane from mine gas. 展开更多
关键词 mine gas HYDRATE MONTMORILLONITE separation effect partition coefficient separation factor recovery rate selection factor
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An extended assessment of bowel habits in a general population
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作者 Gabrio Bassotti Massimo Bellini +5 位作者 Filippo Pucciani Renato Bocchini Antonio Bove Pietro Alduini Edda Battaglia Paolo Bruzzi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2004年第5期713-716,共4页
AIM:Bowel habits are difficult to study, and most data on defecatory behaviour in the general population have been obtained on the basis of recalled interview. The objective assessment of this physiological function a... AIM:Bowel habits are difficult to study, and most data on defecatory behaviour in the general population have been obtained on the basis of recalled interview. The objective assessment of this physiological function and its pathological aspects continues to pose a difficult challenge. The aim of this prospective study was to objectively assess the bowel habits and related aspects in a large sample drawn from thegeneral population.METHODS: Over a two-month period 488 subjects were prospectively recruited from the general population and asked to compile a daily diary on their bowel habits and associated signs and symptoms (the latter according to Rome Ⅱ criteria). A total of 298 (61%) participants returned a correctly compiled record, so that data for more than 8000 patient-days were available for statistical analysis.RESULTS:The average defecatory frequency was once per day (range of 0.25-3.25) and was similar between males and females.However, higher frequencies of straining at stool (P=0.001), a feeling of incomplete emptying and/or difficult evacuation (P=0.0001), and manual manoeuvres to facilitate defecation (P=0.046) were reported by females as compared to males.CONCLUSION:This study represents one of the first attempts to objectively and prospectively assess bowel habits in a sample of the general population over a relatively long period of time. The variables we analyzed are coherent with the criteria commonly used for the clinical assessment of functional constipation, and can provide a useful adjunt for a better evaluation of constipated patients. 展开更多
关键词 DEFECATION Health Behavior ADULT Age Distribution CONSTIPATION Female Humans Male Middle Aged Prospective Studies Sex Distribution
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Influence factors on thermal conductivity of ammonia-water nanofluids 被引量:4
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作者 杨柳 杜垲 张小松 《Journal of Central South University》 SCIE EI CAS 2012年第6期1622-1628,共7页
In order to investigate the mechanism of nanoparticles enhancing the heat and mass transfer of the ammonia-water absorption process,several types of binary nanofluids were prepared by mixing Al2O3 nanoparticles with p... In order to investigate the mechanism of nanoparticles enhancing the heat and mass transfer of the ammonia-water absorption process,several types of binary nanofluids were prepared by mixing Al2O3 nanoparticles with polyacrylic acid(PAA),TiO2 with polyethylene glycol(PEG 1000),and TiN,SiC,hydroxyapatite(noodle-like) with PEG 10000 to ammonia-water solution,respectively.The thermal conductivities were measured by using a KD2 Pro thermal properties analyzer.The influences of surfactant and ammonia on the dispersion stabilities of the binary nanofluids were investigated by the light absorbency ratio index methods.The results show that the type,content and size of nanoparticles,the temperature as well as the dispersion stability are the key parameters that affect the thermal conductivity of nanofluids.For the given nanoparticle material and the base fluid,the thermal conductivity ratio of the nanofluid to the ammonia-water liquid increases as the nanoparticle content and the temperature are increased,and the diameter of nanoparticle is decreased.Furthermore,the thermal conductivity ratio increases significantly by improving the stabilities of nanofluids,which is achieved by adding surfactants or performing the proper ammonia content in the fluid. 展开更多
关键词 binary nanofluids AMMONIA-WATER thermal conductivity size effect dispersion stability
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Influencing Factors of Seed Long-distance Dispersal on a Fragmented Forest Landscape on Changbai Mountains,China 被引量:1
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作者 ZHAO Fuqiang QI Lin +1 位作者 FANG Lei YANG Jian 《Chinese Geographical Science》 SCIE CSCD 2016年第1期68-77,共10页
Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, pr... Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas. 展开更多
关键词 seed long-distance dispersal (LDD) forest fragmentation patch property wind dispersal Changbai Mountains
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Rutting influencing factors and prediction model for asphalt pavements based on the factor analysis method 被引量:4
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作者 Liu Gang Chen Leilei +1 位作者 Qian Zhendong Zhou Xiayang 《Journal of Southeast University(English Edition)》 EI CAS 2021年第4期421-428,共8页
To clarify the importance of various influencing factors on asphalt pavement rutting deformation and determine a screening method of model indicators,the data of the RIOHTrack full-scale track were examined using the ... To clarify the importance of various influencing factors on asphalt pavement rutting deformation and determine a screening method of model indicators,the data of the RIOHTrack full-scale track were examined using the factor analysis method(FAM).Taking the standard test pavement structure of RIOHTrack as an example,four rutting influencing factors from different aspects were determined through statistical analysis.Furthermore,the common influencing factors among the rutting influencing factors were studied based on FAM.Results show that the common factor can well characterize accumulative ESALs,center-point deflection,and temperature,besides humidity,which indicates that these three influencing factors can have an important impact on rutting.Moreover,an empirical rutting prediction model was established based on the selected influencing factors,which proved to exhibit high prediction accuracy.These analysis results demonstrate that the FAM is an effective screening method for rutting prediction model indicators,which provides a reference for the selection of independent model indicators in other rutting prediction model research when used in other areas and is of great significance for the prediction and control of rutting distress. 展开更多
关键词 asphalt pavement rutting prediction influencing factors RIOHTrack full-scale track factor analysis method
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Vertical Crustal Displacements Due to Surface Fluid Changes
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作者 ZHANG Shiyu ZHONG Min 《Geo-Spatial Information Science》 2007年第4期260-264,共5页
Using the model data for surface mass changes of the atmosphere, ocean, soil moisture and snow depth, the vertical crustal displacements of 25 ficual stations in China were calculated according to the loading theory. ... Using the model data for surface mass changes of the atmosphere, ocean, soil moisture and snow depth, the vertical crustal displacements of 25 ficual stations in China were calculated according to the loading theory. From the spectral analysis of the results, we can see that the periods of displacements are 12 months and the semi-periods are 6 months. The results also show that the maximum seasonal displacements can reach 20 mm and even larger. The covariance analyses and significance tests show that the coefficients of 96 percent of the stations are significant at the 0.1 significance level. The results show that one of the reasons of the vertical crustal displacements is the changing surface fluid loads. 展开更多
关键词 vertical crustal displacements fluid loading effects GPS significance analysis
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A quantitative BP neural network analysis of the relationships between ΣREE content and impact factors in the Beibu Gulf
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作者 ZHANG Wen-li HU Hao +2 位作者 LONG Jiang-ping XU Dong ZHOU Meng-jia 《Marine Science Bulletin》 CAS 2017年第1期52-66,共15页
The distribution characteristics of rare earth elements (REE) in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships bet... The distribution characteristics of rare earth elements (REE) in bottomsediments are influenced by many factors. Hence, conducting a quantitative analysis isdifficult. A qualitative analysis of the relationships between ΣREE content andprovenance, hydrodynamics, grain size and mineral distribution in the Beibu Gulf showsthat terrestrial rocks control the ΣREE composition. Both weaker hydrodynamics andfiner grain size lead to a higher ΣREE content. Relative curves revealing therelationships between individual impact factors and ΣREE content were obtained fromthe combination of qualitative and quantitative analyses of the BP neural network,which trained the position of samples, gravel content, sand content, silt content, claycontent and clay mineral content. The results are consistent with those of thequantitative analysis. The self-learning algorithm is automatically determined andcalculated quantitatively. The impact of each factor on REEs and how each factorcontrols the ΣREE distribution is identified. Thus, environmental changes and thegeological evolution of the region can be inferred based on curve variation and the geological evolution of the region can be inferred based on curve variation and theactual situation. This method also provides useful theoretical guidance for the analysisof REE enrichment and dispersion. 展开更多
关键词 REE impact factors quantitative analysis BP neural network controlvariable method
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Calculation of impact factor of vibrator oscillation in offset printing based on fuzzy controller and genetic algorithm
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作者 初红艳 Yang Junjing Cai Ligang 《High Technology Letters》 EI CAS 2015年第1期15-21,共7页
In the inking system of an offset printing press,a vibrator roller distributes ink not only in the circumferential direction but also in the axial direction.In the control process,if ink amount is determined only by t... In the inking system of an offset printing press,a vibrator roller distributes ink not only in the circumferential direction but also in the axial direction.In the control process,if ink amount is determined only by the dot area coverage without considering the impact of vibrator roller's oscillation,the printing colour quality will be reduced.This paper describes a method of calculating the impact factor of vibrator roller' s oscillation.First,the oscillation performance is analyzed and sample data of impact factor is got.Then,a fuzzy controller used for the calculation of the impact factor is designed,and genetic algorithm is used to optimize membership functions and obtain the fuzzy control rules automatically.This fuzzy controller can be used to calculate impact factors for any printing condition,and the impact factors can be used for ink amount control in printing process and it is important for higher printing colour quality and lowering ink and paper waste. 展开更多
关键词 offset printing colour quality control impact factor fuzzy control genetic algorithm
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An Experimental Study on the Wave-Induced Pore Water Pressure Change and Relative Influencing Factors in the Silty Seabed
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作者 LI Anlong LUO Xiaoqiao +2 位作者 LIN Lin YE Qing LI Chunyu 《Journal of Ocean University of China》 SCIE CAS 2014年第6期911-916,共6页
In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heigh... In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heights respectively. The study showed that water waves propagating over silty seabed can induce significant change of pore water pressure, and the amplitude of pore pressure depends on depth of buried soil layer, clay content and wave height, which are considered as the three influencing factors for pore water pressure change. The pressure will attenuate according to exponential law with increase of soil layer buried depth, and the attenuation being more rapid in those soil layers with higher clay content and greater wave height. The pore pressure in silty seabed increases rapidly in the initial stage of wave action, then decreases gradually to a stable value, depending on the depth of buried soil layer, clay content and wave height. The peak value of pore pressure will increase if clay content or depth of buried soil layer decreases, or wave height increases. The analysis indicated that these soils with 5% clay content and waves with higher wave height produce instability in bed easier, and that the wave energy is mostly dissipated near the surface of soils and 5% clay content in soils can prevent pore pressure from dissipating immediately. 展开更多
关键词 wave action silty seabed pore water pressure development influencing factor
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