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Spatio-temporal characteristics of population and economy in transitional geographic space at the southern end of"Hu Huan-yong Line" 被引量:3
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作者 DENG Wei CHENG Yu-fang +3 位作者 YU Huan PENG Li KONG Bo HOU Yu-ting 《Journal of Mountain Science》 SCIE CSCD 2022年第2期350-364,共15页
"Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human be... "Hu Huan-yong Line(Hu Line)"depicts a geographical pattern of China’s population distribution.Its essence is the regionality of humanland relationship and reflects basic characteristics and laws of human beings’adaptation to the natural environment.With the development of the times and the progress of modern science and technology,especially the rapid urbanization and construction of transportation network system in China,the connection between economic and geographical space has been continuously strengthened.The geographical transition zones from mountain areas to plains,i.e.,transitional geographical space,have promoted the changes in human-land relationships through population migration and agglomeration.Taking Sichuan-Yunnan provinces at the southern end of Hu Line as study area,this study analyzed the spatial correlation between population distribution and economy in this region,explored the pattern of geographical agglomeration and deagglomeration,and explained the changing characteristics of humanland relationship in transitional geographic space using global Moran’s I index,global regression model(GRM)and geographically weighted regression(GWR).The results show that population and Gross Domestic Product(GDP)have significant spatial dependence to this region,with obvious aggregation in geographical distribution and positive autocorrelation;comparing with the general least square model,the GWR model incorporating spatial effect was more suitable for revealing the distribution characteristics of geographical elements,with fine results and better fitting;the spatial model of population and GDP as well as the spatio-temporal evolution model of their changes,all of them strongly indicated that Normalized Difference Vegetation Index(NDVI)and road density were important factors governing the spatial differentiation of population and economy;under the rapid development of regional economy and continuous evolution of urban-rural relations,rural transformation and spatial reconstruction promoted the change of population migration and agglomeration. 展开更多
关键词 Hu Huan-yong Line Spatial correlation Geographically weighted regression population distribution Transitional geographic space
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Population Spatial Distribution Based on Luojia 1-01 Nighttime Light Image:A Case Study of Beijing 被引量:1
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作者 SUN Lu WANG Jia CHANG Shuping 《Chinese Geographical Science》 SCIE CSCD 2021年第6期966-978,共13页
With the continuous development of urbanization in China,the country’s growing population brings great challenges to urban development.By mastering the refined population spatial distribution in administrative units,... With the continuous development of urbanization in China,the country’s growing population brings great challenges to urban development.By mastering the refined population spatial distribution in administrative units,the quantity and agglomeration of population distribution can be estimated and visualized.It will provide a basis for a more rational urban planning.This paper takes Beijing as the research area and uses a new Luojia1-01 nighttime light image with high resolution,land use type data,Points of Interest(POI)data,and other data to construct the population spatial index system,establishing the index weight based on the principal component analysis.The comprehensive weight value of population distribution in the study area was then used to calculate the street population distribution of Beijing in 2018.Then the population spatial distribution was visualize using GIS technology.After accuracy assessments by comparing the result with the WorldPop data,the accuracy has reached 0.74.The proposed method was validated as a qualified method to generate population spatial maps.By contrast of local areas,Luojia 1-01 data is more suitable for population distribution estimation than the NPP/VIIRS(Net Primary Productivity/Visible infrared Imaging Radiometer)nighttime light data.More geospatial big data and mathematical models can be combined to create more accurate population maps in the future. 展开更多
关键词 Luojia1-01 nighttime light image principal component analysis points of interest landuse type data population spatial distribution
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Population dynamics of Acartia pacifica (Copepoda:Calanoida):the importance of benthic-pelagic coupling
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作者 JIANG Xiaodong WANG Guizhong LI Shaojing 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第6期88-98,共11页
The seasonal occurrence of Acartia pacifica ( Copepoda: Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003. The numher of viable eggs in the sedi... The seasonal occurrence of Acartia pacifica ( Copepoda: Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003. The numher of viable eggs in the sediment increased from January to May with the increase in the numher of planktonic females. When the population ofA. pacifica disappeared from the water cohinm, the number of eggs in the sediment began to decrease and reached a low value due to lack of input. The peak of nauplii abundance occurred when the hatching potential of eggs from the sediment was high under the natural environment from February to June. The hatching of resting eggs of A. pacifica was essentially temperature-dependent after suspension, while photoperied regimes had no significant effect on the hatching. The mean density of subitaneeus eggs was 1. 122 0 g/cm^3 with a standard deviation (SD) of 0. 000 2 g/cm^3. The mean density of diapause eggs was 1. 151 2 g/cm^3 with a SD of 0.000 1 g/cm^3. The sinking rates of subitaneons eggs ranged from 19.55 to 26.17 m/d, while those of diapause eggs ranged from 30.29 to 31.28 m/d. The comparison of the egg deposition time and egg hatching time suggested that in most cases virtually all subitaneous eggs of A. pacifica would settle to the bottom before their hatching even though the eggs have high potential to hatch. The evidence was provided that the seasonal dynamics of A. pacifica is accompanied by benthic-pelagic coupling. 展开更多
关键词 population dynamics benthic - pelagic coupling Acartia pacifica
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Special Plan for Population,Employment and Social Security Between 2001-2005
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《China Population Today》 2002年第1期2-4,共3页
关键词 Security Special Plan for population Employment and Social Security Between 2001-2005
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Birth outcomes and pregnancy complications of women with uterine leiomyoma—a population-based case-control study
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作者 Ferenc Bánhidy Nándor ács +1 位作者 Erzsébet H. Puhó Andrew E. Czeizel 《Health》 2010年第6期566-574,共9页
Objective Uterine leiomyoma is not a rare pathological condition in pregnant women;thus the aim of the study was to evaluate the recent progress in the treatment of these pregnant women on the basis of the association... Objective Uterine leiomyoma is not a rare pathological condition in pregnant women;thus the aim of the study was to evaluate the recent progress in the treatment of these pregnant women on the basis of the association of leiomyoma in pregnancy (LP) with pregnancy complications and birth outcomes including structural birth defects, i.e. congenital abnormalities (CA) in the offspring. Design Cases with CA and matched controls without CA in the population-based Hungarian Case-Control Surveillan- ce System of Congenital Abnormalities (HCC SCA) were evaluated. Only women with prospectively and medically recorded LP in prenatal maternity logbook and medically recorded birth outcomes (gestational age, birth weight, CA) were included to the study. Setting the HCCSCA, 1980-1996 contained 22,843 cases with CA and 38,151 matched controls without CA. Population Hungarian pregnant women and their informative offspring: live births, stillbirths and prenatally diagnosed malformed fetuses. Methods Comparison of birth outcomes of ca- ses with matched controls and pregnancy com- plications of pregnant women with or without LP. Main outcome measures Pregnancy complications, mean gestational age at delivery and birth weight, rate of preterm birth, low birthweight, CA. Results A total of 34 (0.15%) cases had mothers with LP compared to 71 (0.19%) controls. There was a higher incidence of threatened abortion, placental disorders, mainly abruption placentae and anaemia in mothers with LP. There was no significantly higher rate of preterm birth in the newborns of women with LP but their mean birth weight was higher and it associated with a higher rate of large birthweight newborns. A higher risk of total CA was not found in cases born to mothers with LP (adjusted OR with 95% CI = 0.7, 0.5-1.1), the spe- cified groups of CAs were also assessed versus controls, but a higher occurrence of women with LP was not revealed in any CA group. Con- clusions Women with LP have a higher risk of threatened abortion, placental disorders and anaemia, but a higher rate of adverse birth outcomes including CAs was not found in their offspring. 展开更多
关键词 Uterine LEIOMYOMA in Pregnant WOMEN Pregnancy Complications PRETERM BIRTH Large BIRTH weight Congenital Abnormalities population-BASED CASE-CONTROL Study
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Fine Mapping of qTGW3-1,a QTL for 1000-Grain Weight on Chromosome 3 in Rice 被引量:5
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作者 ZHANG Qiang YAO Guo-xin +4 位作者 HU Guang-long CHEN Chao TANG Bo ZHANG Hong-liang LI Zi-chao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第6期879-887,共9页
The QTL qTGW3-1 was located on chromosome 3 of rice (Oryza sativa L.) and associated with the 1 000-grain weight (TGW) according to the result of our earlier study. With the objective of fine mapping of this locus... The QTL qTGW3-1 was located on chromosome 3 of rice (Oryza sativa L.) and associated with the 1 000-grain weight (TGW) according to the result of our earlier study. With the objective of fine mapping of this locus, we developed a F2 population consisting of 3 428 plants derived from the cross between TGW-related near isogenic line DL017 (BC3F4 generation of GSL 156×Nipponbare) and the recurrent parent Nipponbare. Using six microsatellites, this QTL was delimited between RM5477 and RM6417. Markers MM 1455 and MM 1456 within this region were used for further mapping of this QTL. Finally, qTGW3-1 was fine-mapped into a 89-kb interval between RM5477 and MM1456, which locates in the BAC clone AC107226 harboring five putative candidate genes. 展开更多
关键词 RICE 1 000-grain weight QTL mapping near isogenic line (NIL) population
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APPLICATION OF GEOGRAPHICAL PARAMETER DATABASE TO ESTABLISHMENT OF UNIT POPULATION DATABASE 被引量:4
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作者 WUXi-zhi DONGChun +2 位作者 ZHAORong LIUJi-ping WANGGui-xin 《Chinese Geographical Science》 SCIE CSCD 2003年第1期34-38,共5页
Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurr... Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurricane, earthquake, flood, drought etc., or a decision-making, such as setting up a broadcasting transmitter, building a chemical plant etc., we have to evaluate the total population in the region influenced by a calamity or a project. In this paper, a method is put forward to evaluate the population in such special region. Through exploring the correlation of geographical parameters and the distribution of people in the same region by means of quantitative analysis and qualitative analysis, unit population database (1km× 1km) is established. In this way, estimating the number of people in a special region is capable by adding up the population in every grid involved in this region boundary. The geographical parameters are obtained from topographic database and DEM database on the scale of 1: 250 000. The fundamental geographical parameter database covering county administrative boundaries and 1km × 1km grid is set up and the population database at county level is set up as well. Both geographical parameter database and unit population database are able to oiler sufficient conditions for quantitative analysis. They will have important role in the research fields of data mining (DM), Decision-making Support Systems (DSS), and regional sustainable development. 展开更多
关键词 geographical parameter database unit population database quantitative analysis weight coefficient standardized weight coefficient
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Excessive 5-year weight gain predicts metabolic syndrome development in healthy middle-aged adults 被引量:1
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作者 Jong-Dar Chen Pau-Chung Chen 《World Journal of Diabetes》 SCIE CAS 2011年第1期8-15,共8页
AIM:To quantitatively examine the impacts of an easyto-measure parameter-weight gain-on metabolic syndrome development among middle-aged adults. METHODS:We conducted a five-year interval observational study.A total of... AIM:To quantitatively examine the impacts of an easyto-measure parameter-weight gain-on metabolic syndrome development among middle-aged adults. METHODS:We conducted a five-year interval observational study.A total of 1384 middle-aged adults not meeting metabolic syndrome(MetS)criteria at the initial screening were included in our analysis.Baseline data such as MetS-components and lifestyle factors were collected in 2002.Body weight and MetS-components were measured in both 2002 and 2007.Participants were classified according to proximal quartiles of weight gain(WG)in percentages(%WG≤1%,1%< %WG≤5%,5%<%WG≤10%and%WG>10%, defined as:control,mild-WG,moderate-WG and severe-WG groups,respectively)at the end of the follow-up. Multivariate models were used to assess the association between MetS outcome and excessive WG in the total population,as well as in both genders. RESULTS:In total,175(12.6%)participants fulfilled MetS criteria within five years.In comparison to the control group,mild-WG adults had an insignificant risk for MetS development while adults having moderate-WG had a 3.0-fold increased risk for progression to MetS [95%confidence interval(CI),1.8-5.1],and this risk was increased 5.4-fold(95%CI,3.0-9.7)in subjects having severe-WG.For females having moderate-and severe-WG,the risk for developing MetS was 3.6(95% CI,1.03-12.4)and 5.5(95%CI,1.4-21.4),respectively. For males having moderate-and severe-WG,the odds ratio for MetS outcome was respectively 3.0(95%CI, 1.6-5.5)and 5.2(95%CI,2.6-10.2). CONCLUSION:For early-middle-aged healthy adults with a five-year weight gain over 5%,the severity of weight gain is related to the risk for developing metabolic syndrome. 展开更多
关键词 EXCESS weight gain Metabolic syndrome MIDDLE-AGED adults FOLLOW-UP WORKER population
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STRUCTURE,MOLECULAR WEIGHT AND BIOACTIVITIES OF(1→3)-β-D-GLUCANS AND ITS SULFATED DERIVATIVES FROM FOUR KINDS OF LENTINUS EDODES 被引量:5
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作者 UnursaikhanSurenjav 张俐娜 +3 位作者 Xiao-juanXu MeiZhang PeterChiKeungCheung Fan-boZeng 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第3期327-336,共10页
Lentinan samples,(1→3)-β-D-glucans containing 4.6-15.2 wt% proteins,coded as L-I_1 L-I_2 L-I_3 and L-I_4(L-I)were isolated from four kinds of Lentinus edodes.These glucans were treated with acetone to remove the pro... Lentinan samples,(1→3)-β-D-glucans containing 4.6-15.2 wt% proteins,coded as L-I_1 L-I_2 L-I_3 and L-I_4(L-I)were isolated from four kinds of Lentinus edodes.These glucans were treated with acetone to remove the protein in orderto obtain free protein glucans coded as LNP-I_1,LNP-I_2.LNP-I_3 and LNP-I_4(LNP-I).The free-protein polysaccharideswere sulfated to give derivatives(S-LNP-I)with degree of substitution(DS)from 0.4-0.8.The structural features andweight-average molecular weight(M_w)of the samples were investigated by using infrared spectroscopy,elemental analysis,^(13)C-NMR,size exclusion chromatography combined with laser light scattering(SEC-LLS)and viscometry.The effects ofstructure and conformation of the polysaccharides on antitumor activities were assayed in vivo(Sarcoma 180 solid tumors)and in vitro(Sarcoma 180,HL-60,MCF-7 and Vero tumors).The results indicated that the predominant species of thesamples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethylsulfoxide(DMSO)as single-flexible chains.Interestingly,the antitumor activities of LNP-I are lower than those of the nativeglucans(L-I),whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I.The resultsreveal that the binding of protein,sulfated modification and the triple helix conformation are important factors in theenhancement of the antitumor activities of polysaccharides on the whole. 展开更多
关键词 (1→3)-β-D-glucans Lentinus Edodes Molecular weight PROTEIN Sulfated derivative Antitumor activity.
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Comparison of Low Stress Mechanical Properties of Light Weight Wool and Wool Blend Fabrics using the KES-F and FAST Instruments 被引量:1
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作者 王革辉 张渭源 +1 位作者 Postle Ron Phillips David 《Journal of China Textile University(English Edition)》 EI CAS 2000年第4期99-102,共4页
This study compares the test results of the FAST (Fabric Assurance by Simple Testing) with those of the KES - F (Kawabata Evaluation Systems for Fabrics) for a range of nineteen light weight wool and wool blend fabric... This study compares the test results of the FAST (Fabric Assurance by Simple Testing) with those of the KES - F (Kawabata Evaluation Systems for Fabrics) for a range of nineteen light weight wool and wool blend fabrics in terms of the low - stress mechanical properties of bending, shear, and tensile deformation. It is found that there are very significant correlations between the corresponding parameters for extensibility and shear rigidity obtained from the test results of the two systems. The correlation between the values of bending rigidity obtained from the two systems is only moderate. Furthermore, for the fabrics tested in this study, the values of bending rigidity, shear rigidity, and extensibility measured using the KES - F instruments are higher than those of the corresponding parameters measured using the FAST instruments. The linear regression equation is given for each pair of corresponding parameter. 展开更多
关键词 low stress MECHANICAL properties the KES - F SYSTEM the FAST SYSTEM light weight WOOL FABRICS
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ON THE m^(th) ORDER DIFFERENCE SEQUENCE SPACE OF GENERALIZED WEIGHTED MEAN AND COMPACT OPERATORS 被引量:1
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作者 Metin BASARIR Emrah Evren KARA 《Acta Mathematica Scientia》 SCIE CSCD 2013年第3期797-813,共17页
In this article, using generalized weighted mean and difference matrix of order m, we introduce the paranormed sequence space l(u, v, p; △(m)), which consist of the sequences whose generalized weighted △(m)-di... In this article, using generalized weighted mean and difference matrix of order m, we introduce the paranormed sequence space l(u, v, p; △(m)), which consist of the sequences whose generalized weighted △(m)-difference means are in the linear space l(p) defined by I.J.Maddox. Also, we determine the basis of this space and compute its α-, β- and γ-duals. Further, we give the characterization of the classes of matrix mappings from l(u, v, p, △(m)) to l∞, c, and co. Finally, we apply the Hausdorff measure of noncompacness to characterize some classes of compact operators given by matrices on the space lp(U, v, △(m)) (1 ≤ p 〈 ∞). 展开更多
关键词 Paranormed sequence spaces difference sequence spaces weighted mean α- β γ-duals matrix mappings Hausdorff measure of noncompactness compactoperators
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Stem Population and Tissue Replacement of <i>Urochloa</i>in Different Phenological Stages
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作者 María de los Ángeles Maldonado Peralta Adelaido Rafael Rojas García +4 位作者 Jessica Lizbeth Ruíz Clavel Herminio Aniano Aguirre Filiberto Magadan Olmedo Leopoldo Jorge Castañeda Uriel Mondragón Calderón 《American Journal of Plant Sciences》 2020年第8期1296-1306,共11页
The objective of the present investigation was to evaluate the<i><span style="font-family:Verdana;"> Urochloa</span></i><span style="font-family:Verdana;"> Insurgent, ... The objective of the present investigation was to evaluate the<i><span style="font-family:Verdana;"> Urochloa</span></i><span style="font-family:Verdana;"> Insurgent, Piata and Signal grasses by varying the phenology in the attributes: stem population dynamics, tissue replacement, leaf:stem relation and weight per stem. The data were analyzed using a completely randomized block design with arrangement in divided plots and four replications, the procedure used was PROC GLM from SAS. The Signal grass presented higher stem density with an average of 450 m</span><sup><span style="font-family:Verdana;">?2</span></sup><span style="font-family:Verdana;"> stems, while the meadow with Insurgent grass registered the lowest stem density throughout the investigation, with an average of 320 m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;"> stems;furthermore, in this treatment, the stem density tended to increase slowly over time (P = 0.05). The Insurgente and signal grasses showed rapid leaf elongation from day 21 of regrowth with 123 and 104 cm stem</span><sup><span style="font-family:Verdana;">?1</span></sup><span style="font-family:Verdana;">, while in Piata the accelerated leaf elongation was on day 14 with 113 cm stem</span><sup><span style="font-family:Verdana;">?1</span></sup><span style="font-family:Verdana;"> where it remained active its growth until day 56 (P > 0.05). As the regrowth age was increasing, the population dynamics of stems and weight per stem were increasing;in Insurgent and signal the leaf elongation and net growth increased to a maximum point to start declining;however, in Piata grass was increasing without decreasing. The trend of the leaf:stem relation was decreasing as the test progressed and senescence increased from day 21 of regrowth.</span> 展开更多
关键词 Urochloa Stem population Leaf Elongation weight Per Stem
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Manufacturing of Ultra-high Molecular Weight Polyethylene Fiber Reinforced Tape and the Loss of Strength
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作者 胡祖明 刘兆峰 《Journal of China Textile University(English Edition)》 EI CAS 1999年第4期92-94,共3页
Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-... Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85% after it undergothe process. 展开更多
关键词 Ultra - high molecular weight POLYETHYLENE fiber REINFORCED material TAPE IMPREGNATION
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Preparation of High Molecular Weight Poly(L-lactide-co-caprolactone)(85-15)
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作者 湛雪辉 申雄军 +2 位作者 LI Zhaohui LI Xia CAO Fen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第1期139-143,共5页
Poly(L-lactide-co-caprolactone)(85-15)[P(LLA-CL)(85-15)] was synthesized from high purity L-lactide and e-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by infrar... Poly(L-lactide-co-caprolactone)(85-15)[P(LLA-CL)(85-15)] was synthesized from high purity L-lactide and e-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by infrared spectrum and IH-NMR spectrum. The synthesized P(LLA-CL)(85-15) is a random copolymer. The influences of polymerization temperature, polymerization time, dosage of initiator and polymerization pressure on the weight average molecular weight and the polydispersity index of P(LLA-CL)(85-15) were investigated. The optimum preparation conditions of P(LLA-CL)(85-15) are: the polymerization pressure is less than 0.5 Pa, the polymerization temperature is 130 ~C, the n(M)/n(I) ratio is 8 000/1, and the polymerization time is 36 h. Under the condition, the weight-average molecular weight of prepared P(LLA-CL)(85-15) is 65.6x 104, and molecular weight distribution coefficient is 1.15. 展开更多
关键词 poly(L-lactide-co-caprolactone)(85-15) COPOLYMERIZATION high molecular weight characterization
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Coordinated Development of Population, Economy and Environment System and Diagnosis of Its Obstacle Factors in Nanjing
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作者 Liu Binglin Jiang Shengnan +3 位作者 Xu Minghui Xing Yun Wu Haotian Li Lu 《Meteorological and Environmental Research》 CAS 2019年第5期38-42,共5页
Promoting the coordinated development of regional population,economy and environment is beneficial to the realization of sustainable development.Based on the construction of evaluation index system of coordinated deve... Promoting the coordinated development of regional population,economy and environment is beneficial to the realization of sustainable development.Based on the construction of evaluation index system of coordinated development of systems,the entropy weight-TOPSIS method and coupling coordination model,the coordinated development degree of population,economy and environment system in Nanjing was measured,and the temporal variation characteristics of each subsystem and their coordinated development degree form 1997 to 2016 were analyzed.The results showed that the development of population,economy system and environment system in Nanjing was generally in a continuous upward trend.Among them,the economy system developed fastest.The coordinated development degree of population,economy system and environment system in Nanjing was constantly increasing but still at a low level;the degree was only in the primary coordination phase,and its type was environment lagging.The economy subsystem and environment subsystem were important factors restricting the development of population,economy and environment in Nanjing,and the main obstacle factor was the production of industrial solid waste.The results above can provide a scientific basis for promoting the coordinated development of population,economy and environment system in Nanjing and achieving regional sustainable development. 展开更多
关键词 population economy and environment system COORDINATED development degree of systems Entropy weight-TOPSIS OBSTACLE factors NANJING
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油菜-小麦邻作模式对麦蚜主要天敌种群动态以及小麦生产的影响 被引量:9
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作者 费晓东 李川 +1 位作者 张青文 赵章武 《植物保护》 CAS CSCD 北大核心 2011年第6期186-190,共5页
麦蚜是危害我国小麦生产的重要害虫。本试验探索了油菜-小麦邻作模式以及小麦单作模式对麦蚜主要天敌发生的影响,以小麦和油菜交界处向两边各在0、2、4、6、8、16m处设立试验小区,记录麦蚜主要天敌发生数量以及测定小麦株高、穗长、穗... 麦蚜是危害我国小麦生产的重要害虫。本试验探索了油菜-小麦邻作模式以及小麦单作模式对麦蚜主要天敌发生的影响,以小麦和油菜交界处向两边各在0、2、4、6、8、16m处设立试验小区,记录麦蚜主要天敌发生数量以及测定小麦株高、穗长、穗重、千粒重,揭示油菜-小麦邻作模式对小麦生产的影响。结果表明:随着油菜的成熟,瓢虫逐渐向油菜-小麦邻近处转移,且迁移的最有效距离为4m;对邻作小麦田蚜茧蜂数量最高峰当日数据进行分析,发现除最高的0m(2009年)和4m(2010年)处外,其他各距离之间不存在显著差异,而单作田各距离之间蚜茧蜂数量上的差异不明显;相比于小麦单作模式,油菜-小麦邻作显著提高了小麦的株高、穗长、穗重、千粒重。总之,油菜-小麦邻作模式有利于麦蚜主要天敌向小麦田转移,并能提高小麦的产量和生物量。 展开更多
关键词 邻作 天敌 种群动态 千粒重
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小麦粒重基因TaGW2-6A编码区等位变异与抗旱性的关系 被引量:1
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作者 李扬 李立群 +6 位作者 高欣 杨璐 寇程 吕千 刘天红 杜登峰 李学军 《中国农业科学》 CAS CSCD 北大核心 2015年第21期4209-4218,共10页
[目的]小麦籽粒大小及其在水、旱两种生态环境下的稳定性直接影响小麦的产量,研究小麦粒重与抗旱性的关系对品种高产稳产具有重要意义。探究粒重相关基因不同等位变异的抗旱性,进而确定抗旱高产的优异等位变异基因型,为利用该基因型进... [目的]小麦籽粒大小及其在水、旱两种生态环境下的稳定性直接影响小麦的产量,研究小麦粒重与抗旱性的关系对品种高产稳产具有重要意义。探究粒重相关基因不同等位变异的抗旱性,进而确定抗旱高产的优异等位变异基因型,为利用该基因型进行小麦抗旱高产品种分子标记辅助选择及性状的遗传改良提供理论依据。[方法]以小麦粒重基因Ta GW2-6A编码区不同等位变异的中国春和兰考大粒(977 bp多一个"T"碱基插入)为亲本构建的含有325个株系的RIL群体为研究材料,依据序列"T"碱基插入设计引物,利用高分辨率熔解曲线分析技术(high resolution melting curve,HRM)鉴定RIL群体中Ta GW2-6A编码区不同等位变异基因型,并对其PCR产物进行测序分析。在水、旱两种生态环境下,测定小麦开花期、灌浆中期和乳熟期的叶绿素荧光参数、茎秆可溶性糖含量、抗旱指数等与抗旱紧密相关的指标,考察粒长、粒宽、千粒重等粒重相关性状,并研究这些抗旱相关指标及粒重相关性状与小麦粒重基因Ta GW2-6A编码区不同等位变异基因型之间的相关性。[结果]高分辨率熔解曲线分析技术可以准确地将小麦RIL群体按Ta GW2-6A编码区不同等位变异分为兰考大粒基因型(TT)、中国春基因型(tt)以及杂合基因型(Tt),且PCR产物测序结果显示高分辨率熔解曲线的差异是由"T"碱基插入引起的。水、旱两种生态环境下,RIL群体中TT、Tt基因型材料与tt基因型材料相比,粒长、粒宽、千粒重等粒重相关性状以及叶绿素荧光参数、茎秆可溶性糖相关性状、抗旱指数等抗旱相关指标的差异普遍达到显著或极显著水平。旱胁迫下,小麦RIL群体不同基因型材料的粒长、粒宽、千粒重等粒重相关性状、叶绿素荧光参数除初始荧光Fo外均有所降低,而茎秆可溶性糖含量则有所增加。但TT、Tt基因型材料的粒长、粒宽、千粒重及叶绿素荧光参数的下降幅度普遍比tt基因型材料小,而茎秆可溶性糖的增加幅度比tt基因型材料大。旱胁迫下,tt基因型的茎秆可溶性糖积累效率(accumulation efficiency of stem soluble sugar content,AESSC)和转运效率(remobilization efficiency of stem soluble sugar content,RESSC)有所降低,而TT、Tt基因型的茎秆可溶性糖积累效率和转运效率则有所提高。[结论]小麦粒重基因Ta GW2-6A编码区"T"碱基插入等位变异是大粒的优异等位变异,与此同时,该等位变异也是抗旱的优异等位变异,且抗旱能力与晋麦47相近。 展开更多
关键词 小麦 RIL群体 TaGW2-6A等位变异 粒重基因 抗旱性
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Yield Increasing and Quality Improving Effects of Smash-ridging Method("4453" Effects) and Its Potential in Benefiting the Nation and the People 被引量:4
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作者 韦本辉 《Agricultural Science & Technology》 CAS 2014年第10期1767-1769,共3页
Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "... Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "4453" effects, as fol ows: "Four increases" include to increase loosen soil quantity in cultivation layers, soil nutri-ents use, "water pool" in soils, and "oxygen pool" in soils. Four reductions are to reduce soil erosion, carbon emission, salt content and heavy metal in soils. Five resistances refer to improve crop resistance capacity in terms of drought, high tem-perature, lower temperature, disease and lodging. Three improvements indicate to enhance photosynthetic efficiency over 10%, yield in 10%-30% and quality over 5%. lt is researched that without additional chemical fertilizer, yield could increase by 10% by labor force, animal, tractor or smash-ridging machine. What’s more, by smash-ridging cultivation, the depth can be 20 times or higher compared with tractor cultivation, with looser soils. lt is estimated that if smash-ridging cultivation is applied once in agricultural lands in China, present soil layers can be twice as deep as present. Specifical y, the thickness of loose soil-layers could be extended from 10-18 cm at present to 25-35 cm, and natural rainfal would increase by 40 bil ion cm3. After vitalization of soil nutrients, chemical fertilizer would decrease by 7 bil ion kg, and the increased c rops would feed more than 300 mil ion population as per yield at 7 50 kg/hm2. 展开更多
关键词 Smash-ridging technology Extension nationwide lncrease range in 10%-30% Supporting more 300 mil ion population"4453" effects Development potential
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中国区域发展不平衡的历史动态、表现和成因--东西差距和南北差距的视角 被引量:33
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作者 刘学良 续继 宋炳妮 《产业经济评论》 CSSCI 2022年第2期152-167,共16页
基于人口加权变异系数分解方法,本文分析了改革开放以来中国区域发展不平衡的历史动态,研究发现:我国区域发展不平衡程度在1978-1990年快速下降,1990-2003年上升,2003-2019年又再次下降,2013年来的区域发展不平衡程度是改革开放以来最... 基于人口加权变异系数分解方法,本文分析了改革开放以来中国区域发展不平衡的历史动态,研究发现:我国区域发展不平衡程度在1978-1990年快速下降,1990-2003年上升,2003-2019年又再次下降,2013年来的区域发展不平衡程度是改革开放以来最低水平;东西差距自2003年来持续下降,但到2019年东西差距对总体区域差距的贡献仍达46%;南方早在1993年就已实现对北方发展水平的超越,2008年以来南北差距再次快速扩大,但目前南北差距在总体差距中的贡献依然不超过10%。因此,我国区域发展差距主要体现为东中西部差距的结构特征并未发生根本改变。成分分解的结果显示,从产业角度看,北方工业的相对落后是2008年以来南北差距飞速扩大的主要原因;从收入角度看,南北差距扩大主要体现在南方在劳动者收入和企业盈利上的相对领先;从支出角度看,南方在居民消费支出、货物和服务净流出上长期具有优势,2003-2013年北方过度依赖高投资、高积累的发展模式,这一发展模式在2013年后无法持续,进一步推动了南北差距扩大。 展开更多
关键词 区域发展不平衡 东西差距 南北差距 加权变异系数二维分解
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多目标决策下的城市适度人口规模研究--以临沂市为例 被引量:1
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作者 周静 吴艳 《价值工程》 2022年第34期160-162,共3页
城市适度人口规模是可持续发展的关键。本文引出了城市适度人口规模的一种多目标决策方法,通过确定决策要素、赋予优先因子和权系数,建立基于社会资源供给水平、人居生态环境满意度、经济发展等多目标结构模型及决策条件,用来计算城市... 城市适度人口规模是可持续发展的关键。本文引出了城市适度人口规模的一种多目标决策方法,通过确定决策要素、赋予优先因子和权系数,建立基于社会资源供给水平、人居生态环境满意度、经济发展等多目标结构模型及决策条件,用来计算城市适度人口规模。 展开更多
关键词 适度人口规模 多目标决策 权重 优先因子
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