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A Study of the Distribution and Accumulation of Major Nutrient Elements in Different Densities of Eucalyptus grandis 被引量:5
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作者 王丽 龙汉利 +3 位作者 郭洪英 辜云杰 肖兴翠 盛玉珍 《Agricultural Science & Technology》 CAS 2017年第6期1062-1066,共5页
This study was conducted to investigate the distribution and accumulation of major elements of 5-year-old Eucalyptus grandis forests with the densities of 556 trees/hm2 and 1 667 trees/hm2. The results showed that: ... This study was conducted to investigate the distribution and accumulation of major elements of 5-year-old Eucalyptus grandis forests with the densities of 556 trees/hm2 and 1 667 trees/hm2. The results showed that: (1) The distribution of ma- jor nutrient element contents in various organs of the E. grandis with the 2 densi- ties was nearly the same, and the ranked order was leaf〉tree trunk〉branch or branchlet〉fruit〉bark. (2) From the distribution of nutrient elements and organic mat- ter in the trunk, P, K, Mg and Ca contents presented basically a trend of increasing with the trunk height increasing. And the organic matter content increased with the trunk height increasing in the low density stand, while the result was opposite in the high density stand. Furthermore, N content increased with the trunk height increas- ing in the low density stand, but the content in the high density stand exhibited a trend of decreasing at first, increasing then and increasing at the last. (3) From the distribution of biomass, the ranked order was tree trunk〉bark or branch〉branchlet〉 leaf〉fruit. And (4) The accumulated amounts of major nutrient elements in various organs under the 2 stand densities was nearly same. Ca content was the highest in the 2 kinds of plantations, followed by N, K, Mg and P contents. Ca content was 601.78 kg/hm2 in the low density stand and 1 204. 43 kg/hm2 in the high density stand. 展开更多
关键词 Eucalyptus grandis Stand density Nutrient elements DISTRIBUTION
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Effect of Different Sowing Dates and Densities on Individual Morphological Development of Super Short-season Insect-resistant Cotton 被引量:4
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作者 李金才 唐光雷 李存东 《Agricultural Science & Technology》 CAS 2011年第4期533-536,共4页
[Objective] The paper was to explore the effect of different sowing dates and densities on individual morphological development of super short-season insect-resistant cotton,confirm their effects on vegetative and rep... [Objective] The paper was to explore the effect of different sowing dates and densities on individual morphological development of super short-season insect-resistant cotton,confirm their effects on vegetative and reproductive growth of cotton,so as to provide theoretical and practical guidance for sowing date and density management of cotton planting in Jidong cotton growing region in Yellow River Basin.[Method] With super short-season insect-resistant cotton"546"as materials,the effects of different sowing dates(sowing dateⅠ:May 20;sowing dateⅡ:June 2;sowing date Ⅲ:June 14)and densities(low density:120 000 plants/hm2;middle density:150 000 plants/hm2;high density:180 000 plants/hm2)on individual morphological development of super short-season insect-resistant cotton were explored.[Result] Different sowing dates and density treatments significantly affected the individual morphological development of super short-season insect-resistant cotton"546".The effectiveness of sowing date was higher than the effectiveness of density,and the effectiveness of sowing date on development of number of individual fruit branches was higher than that on plant height and stem diameter.[Conclusion] The regulation of sowing date and density during the cultivation process of super short-season insect-resistant cotton "546" in Jidong cotton growing region in Yellow River Basin could effectively promote vegetative and reproductive growth of cotton,strengthening its production base. 展开更多
关键词 Sowing date DENSITY Super short-season insect-resistant cotton Individual morphological development
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Effects of Different Transplanting Densities on Yield and Yield Components of Japonica Longke 16 被引量:1
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作者 曾林 苏文斌 +7 位作者 陆顺生 张朝钟 赵应平 宋云飞 戈芹英 万卫东 王勤 田文伟 《Agricultural Science & Technology》 CAS 2016年第11期2582-2585,共4页
[Objective] This study was conducted to improve unit yield of rice in Longyang District and find the relationship between transplanting density and rice yield. [Method] Under the condition of field plot test, effects ... [Objective] This study was conducted to improve unit yield of rice in Longyang District and find the relationship between transplanting density and rice yield. [Method] Under the condition of field plot test, effects of cultivation density on yield and yield components were investigated with japonica rice Longke 16 as a test material. [Result] Under a planting density of 2.7-3.3×10^5 clusters/hm^2, equivalent to a density of seedlings with tillers of 5.4-6.6×10^5/hm^2, the yield reached 11 250-12 000 kg/hm^2. [Conclusion] Longke 16 is a japonica rice variety with good comprehensive characters, and rational dense planting and accurate quantitative cultivation could give full play to its high yield potential. 展开更多
关键词 Lonqke 16 DENSITY YIELD Yield component Japonica rice
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Effect of Fertilizing Level and Planting Densities on Yield and Nitrogen Utilization in Maize 被引量:1
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作者 谭华 邹成林 +7 位作者 郑德波 黄爱花 莫润秀 韦新兴 吴永升 蒋维萍 韦慧 黄开健 《Agricultural Science & Technology》 CAS 2015年第3期504-509,共6页
Elite maize hybrid Guidan0810 was selected as material, and the effects of fertilizing level and planting densities on yield and nitrogen utilization were dis- cussed in the study. In field experiments as per double-c... Elite maize hybrid Guidan0810 was selected as material, and the effects of fertilizing level and planting densities on yield and nitrogen utilization were dis- cussed in the study. In field experiments as per double-cropping system, 4 main plots (fertilization levels) and 6 subplots (planting densities) were set in a split plot design. The results suggested that yield had close relationship with fertilization levels and planting densities. Different fertilization levels and planting densities significantly affected yield. With the increase of nitrogen fertilization, nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen physiological efficiency declined. Under the same fertilization level, nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen physiological efficiency grew a little with the increase of planting density, so nitrogen efficiency could be improved by regulating planting density. The results also showed that A2 (including N 225.0 kg/hm2, P205 75.0 kg/hm^2, K20 187.5 kg/hm^2) matching to B3 (52 500 plants/hm^2) or B4(60 000 plants/hm^2) was a better design, which could obtain a higher yield in the range of 7 913.2-8 207.8 kg/hm2, respectively. 展开更多
关键词 Maize hybrid Fertilizing level Planting density Effects
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Effect of Chemical Regulation on Maize in Different Cultivation Densities 被引量:1
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作者 陈志峰 陈小文 +2 位作者 祁鑫 刘向阳 董学会 《Agricultural Science & Technology》 CAS 2011年第5期691-694,717,共5页
[Objective] This study aimed at investigating the effect of chemical regulation on maize cultivated in different densities.[Method] By taking maize hybrids Xundan 20 and Zhongnongda 4 as materials,the effect of chemic... [Objective] This study aimed at investigating the effect of chemical regulation on maize cultivated in different densities.[Method] By taking maize hybrids Xundan 20 and Zhongnongda 4 as materials,the effect of chemical regulation on the yield,yield component factors and plant morphology of the two hybrids planting in Northern and Northeastern China were studied,respectively.[Result] Chemical Yuhuangjin could control maize stalks,lower the plant height and the ear height,make internodes below the spike more coarse and enhance its lodging-resistance.In addition,chemical regulation could increase the optimum cultivation density by 7 500 plants/hm2 more than traditional cultivation.[Conclusion] This paper provided theoretical reference for cultivating high-yield maize. 展开更多
关键词 DENSITY MAIZE Chemical regulation
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Analysis on Differences in Photosynthetic Characteristics of Korla Fragrant Pear among Different Planting Densities 被引量:1
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作者 牛莹莹 廖康 +3 位作者 贾杨 庞洪翔 徐桂香 江振斌 《Agricultural Science & Technology》 CAS 2015年第5期862-867,共6页
[Objective] The aim of this study was to explore the differences in photosynthetic characteristics of Korla fragrant pear among different planting densities,providing a basis for the improvement of fruit yield and qua... [Objective] The aim of this study was to explore the differences in photosynthetic characteristics of Korla fragrant pear among different planting densities,providing a basis for the improvement of fruit yield and quality of Korla fragrant pear in production. [Method] The net photosynthetic rates, photoresponse curves and CO2 response curves of Korla fragrant pear under six different planting densities were determined using Li-6400 XT portable photosynthesis system. [Result] There were significant differences in photosynthetic parameters of Korla fragrant pear among six different planting densities. The net photosynthetic rate of Korla fragrant pear was highest under the planting density of 4.0 m × 6.0 m. At the planting density of4.0 m×6.0 m, when the light intensity reached 1 800 μmol/(m^2·s), the net photosynthetic rate of Korla fragrant pear reached the peak [19.326 μmol/(m^2·s)], and the apparent quantum yield, carboxylation efficiency and dark respiration rate all reached the maximum values; at the planting density of 6.0 m ×7.0 m, Korla fragrant pear showed lower light compensation point and CO2 compensation point, but higher light saturation point. At the planting density of 3.0 m ×5.0 m, Korla fragrant pear had higher light saturation point. [Conclusion] Among the six different planting densities,Korla fragrant pear with planting density of 4.0 m ×6.0 m showed the highest net photosynthetic rate. It suggested that Korla fragrant pear, at the planting density of4.0 m ×6.0 m, had stronger utilization capacity for low light and low-concentration CO2. Therefore, the Korla fragrant pear with the planting density of 4.0 m ×6.0 m has the highest photosynthesis efficiency, and the planting density of 4.0 m ×6.0 m is the most ideal planting density for Korla fragrant pear. 展开更多
关键词 Korla fragrant pear Planting density PHOTOSYNTHESIS Response curve
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All-solid-state flexible asymmetric supercapacitors with high energy and power densities based on NiCo_2S_4@MnS and active carbon 被引量:3
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作者 Zhiguo Zhang Xiao Huang +3 位作者 Huan Li Hongxia Wang Yingyuan Zhao Tingli Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第6期1260-1266,共7页
Electrode material based on a novel core–shell structure consisting of NiCoS(NCS) solid fiber core and Mn S(MS) sheet shell(NCS@MS) in situ grown on carbon cloth(CC) has been successfully prepared by a simple... Electrode material based on a novel core–shell structure consisting of NiCoS(NCS) solid fiber core and Mn S(MS) sheet shell(NCS@MS) in situ grown on carbon cloth(CC) has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor(ASC) is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly(vinyl alcohol)(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future. 展开更多
关键词 NiCo_2S_4@MnS core–shell structure FLEXIBLE All-solid-state supercapacitor High energy and power densities
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Brittleness index predictions from Lower Barnett Shale well-log data applying an optimized data matching algorithm at various sampling densities 被引量:1
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作者 David A.Wood 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第6期444-457,共14页
The capability of accurately predicting mineralogical brittleness index (BI) from basic suites of well logs is desirable as it provides a useful indicator of the fracability of tight formations.Measuring mineralogical... The capability of accurately predicting mineralogical brittleness index (BI) from basic suites of well logs is desirable as it provides a useful indicator of the fracability of tight formations.Measuring mineralogical components in rocks is expensive and time consuming.However,the basic well log curves are not well correlated with BI so correlation-based,machine-learning methods are not able to derive highly accurate BI predictions using such data.A correlation-free,optimized data-matching algorithm is configured to predict BI on a supervised basis from well log and core data available from two published wells in the Lower Barnett Shale Formation (Texas).This transparent open box (TOB) algorithm matches data records by calculating the sum of squared errors between their variables and selecting the best matches as those with the minimum squared errors.It then applies optimizers to adjust weights applied to individual variable errors to minimize the root mean square error (RMSE)between calculated and predicted (BI).The prediction accuracy achieved by TOB using just five well logs (Gr,ρb,Ns,Rs,Dt) to predict BI is dependent on the density of data records sampled.At a sampling density of about one sample per 0.5 ft BI is predicted with RMSE~0.056 and R^(2)~0.790.At a sampling density of about one sample per0.1 ft BI is predicted with RMSE~0.008 and R^(2)~0.995.Adding a stratigraphic height index as an additional (sixth)input variable method improves BI prediction accuracy to RMSE~0.003 and R^(2)~0.999 for the two wells with only 1 record in 10,000 yielding a BI prediction error of>±0.1.The model has the potential to be applied in an unsupervised basis to predict BI from basic well log data in surrounding wells lacking mineralogical measurements but with similar lithofacies and burial histories.The method could also be extended to predict elastic rock properties in and seismic attributes from wells and seismic data to improve the precision of brittleness index and fracability mapping spatially. 展开更多
关键词 Well-log brittleness index estimates Data record sample densities Zoomed-in data interpolation Correlation-free prediction analysis Mineralogical and elastic influences
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A Laboratory Study of the Effect of Temperature on Densities and Viscosities of Binary and Ternary Blends of Soybean Oil, Soy Biodiesel and Petroleum Diesel Oil 被引量:3
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作者 Oluwafunmilayo A. Aworanti Samuel E. Agarry Ayobami O. Ajani 《Advances in Chemical Engineering and Science》 2012年第4期444-452,共9页
The depletion of world petroleum reserves and the increased environmental concerns have stimulated the search for alternative sources for petroleum based fuel. The possibility of using vegetable oils as fuel has been ... The depletion of world petroleum reserves and the increased environmental concerns have stimulated the search for alternative sources for petroleum based fuel. The possibility of using vegetable oils as fuel has been recognized, however, due to its high viscosities and low volatilities makes it inefficient for most combustion engines and thus the need to get them chemically altered or transesterified to obtain fatty alkyl esters of the oil (biodiesel). In this study, binary and ternary blends of biodiesel were produced and the effect of temperature on their viscosity and density was investigated. Biodiesel was produced from soybean oil by transesterification of the oil with methanol using potassium hydroxide as a catalyst at a temperature of 60℃ in a batch reactor. Binary and ternary blends of the soy-biodiesel were prepared with soy bean oil and petroleum diesel fuel, respectively. Viscosities and densities of the binary and ternary blends were measured at different temperatures of 20℃ to 90℃ as to determine the effect of temperature on viscosities and densities of the blends. The properties of the soy-biodiesel produced were compared with ASTM standard and found to be within the limits. The results show that the viscosities and densities of both the binary and ternary blends are temperature dependent. The viscosities of binary and ternary blends decreased nonlinearly with temperature, while their densities decreased linearly with temperature. The variation of temperature with viscosity and density of the blends was correlated and the polynomial equation offered the best correlation between temperature and viscosity, while linear equation gave the best correlation between temperature and density. In conclusion, the efficiency of binary and ternary blends of biodiesel in combustion engines is dependent on the viscosity and density of the blends which are invariably temperature dependent. 展开更多
关键词 densities VISCOSITIES Batch Reactor DIESEL Fuel Soy-Biodiesel VEGETABLE Oil
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The effect of different initial densities of nematode (Meloidogyne javanica) on the build-up of Pasteuria penetrans population
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作者 DARBAN Daim Ali PATHAN Mumtaz Ali +1 位作者 BHATTI Abdul Ghaffar MAITELO Sultan Ahmed 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第2期113-118,共6页
Pasteuria penetrans will build-up faster where there is a high initial nematode density and can suppress root-knot nematode populations in the roots of tomato plants. The effect of different initial densities of nemat... Pasteuria penetrans will build-up faster where there is a high initial nematode density and can suppress root-knot nematode populations in the roots of tomato plants. The effect of different initial densities of nematode (Meloidogyne javanica)(150, 750, 1500, 3000) and P. penetrans infected females (F1, F3) densities (F0=control and AC=absolute control without nematode or P. penetrans inoculum) on the build-up of Pasteuria population was investigated over four crop cycles. Two major points of interest were highlighted. First, that within a confined soil volume, densities of P. penetrans can increase >100 times within 2 or 3 crop cycles. Second, from a relatively small amount of spore inoculum, infection of the host is very high. There were more infected females in the higher P. penetrans doses. The root growth data confirms the greater number of females in the controls particularly at the higher inoculum densities in the third and fourth crops. P. penetrans generally caused the fresh root weights to be higher than those in the control. P. penetrans has shown greater reduction of egg masses per plant at most densities.The effects of different initial densities of M. javanica and P. penetrans on the development of the pest and parasite populations were monitored. And no attempt was made to return the P. penetrans spores to the pots after each crop so the build-up in actual numbers of infected females and spores under natural conditions may be underestimated. 展开更多
关键词 Pasteuria penetrans Meloidogyne javanica densities Population build-up
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Porosity Evaluation and the Power Spectral Densities Analyses of Carbon-Nickel Composite Films Annealed at Different Temperatures
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作者 V.Dalouji S.M.Elahi +1 位作者 A.Ghaderi S.Solaymani 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第8期96-99,共4页
The densification and the fractal dimensions of carbon-nickel films annealed at different temperatures 300, 500, 800, and 1000℃ with emphasis on porosity evaluation are investigated. For this purpose, the refractive... The densification and the fractal dimensions of carbon-nickel films annealed at different temperatures 300, 500, 800, and 1000℃ with emphasis on porosity evaluation are investigated. For this purpose, the refractive index of films is determined from transmittance spectra. Three different regimes are identified, T 〈 500℃, 500℃ 〈 T 〈 800℃ and T 〉 800℃. The Rutherford baekscattering spectra show that with increasing the annealing temperature, the concentration of nickel atoms into films decreases. It is shown that the effect of annealing temperatures for increasing films densification at T 〈 500℃ and T 〉 800℃ is greater than the effect of nickel concentrations. It is observed that the effect of decreasing nickel atoms into films at 500℃ 〈 T 〈 800℃ strongly causes improving porosity and decreasing densification. The fractal dimensions of carbon-nickel films annealed from 300 to 500℃ are increased, while from 500 to 1000℃ these characteristics are decreased. It can be seen that at 800℃, films have maximum values of porosity and roughness. 展开更多
关键词 of on it Ni Porosity Evaluation and the Power Spectral densities Analyses of Carbon-Nickel Composite Films Annealed at Different Temperatures is that into
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Saturation Ion Current Densities in Inductively Coupled Hydrogen Plasma Produced by Large-Power Radio Frequency Generator
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作者 WANG Songbai LEI Guangjiu +3 位作者 BI Zhenhua H. GHOMI YANG Size LIU Dongping 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第9期907-911,共5页
An experimental investigation of the saturation ion current densities (Jions) in hydrogen inductively coupled plasma (ICP) produced by a large-power (2-32 kW) radio frequency (RF) generator is reported, then s... An experimental investigation of the saturation ion current densities (Jions) in hydrogen inductively coupled plasma (ICP) produced by a large-power (2-32 kW) radio frequency (RF) generator is reported, then some reasonable explanations are given out. With the increase of RF power, the experimental results show three stages: in the first stage (2-14 kW), the electron temperature will rise with the increase of RF power in the ICP, thus, the Jions increases continually as the electron temperature rises in the ICP. In the second stage (14 20 kW), as some H- ions lead to the mutual neutralization (MN), the slope of Jio^s variation firstly decreases then increases. In the third stage (20-32 kW), both the electronic detachment (ED) and the associative detachment (AD) in the ICP result in the destruction of H- ions, therefore, the increased amplitude of the Jions in the third stage is weaker than the one in the first stage. In addition, with the equivalent transformer model, we successfully Explain that the Jions at different radial locations in ICP has the same rule. Finally, it is found that the Jions has nothing to do with the outer/inner puffing gas pressure ratio, which is attributed to the high-speed movement of hydrogen molecules. 展开更多
关键词 saturation ion current densities large-power RF generator outer/innerpuffing gas pressure ratio H- ion transformer model
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Non-Markovian dynamics of two non-coupled qubits interacting with two separate reservoirs with different spectral densities
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作者 王小云 丁邦福 赵鹤平 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第4期128-132,共5页
The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two differen... The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two different types of spectral densities, which are a Lorentzian distribution and an Ohmic spectral density with a Lorentzian–Drude cutoff function. For two qubits initially prepared in the initial Bell state, quantum discord can keep longer time and reach larger values in nonMarkovian reservoirs for the first spectral distribution or by reducing the cutoff frequency for the second case. For the initial Bell-like state, the dynamic behaviors of quantum discord and entanglement are compared. The results show that a long time of quantum correlation can be obtained by adjusting some parameters in experiment and further confirm that the discord can capture quantum correlation in addition to entanglement. 展开更多
关键词 Lorentzian and Ohmic spectral densities the time convolution-less projection operator method non-Markovian and Markovian regime quantum discord and entanglement
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Seasonal Differences in Live Foraminiferal Densities: Case Studies from Tropical and Temperate Intertidal Environments
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作者 Ashleigh Costelloe Brent Wilson 《Journal of Environmental Science and Engineering(B)》 2015年第11期591-606,共16页
Statistically significant differences (when p 〈 0.05 using the permutation t-test) among Live Foraminiferal Densities (LFDs) recovered in August, November, March and May were detected at tropical Caroni swamp, Cl... Statistically significant differences (when p 〈 0.05 using the permutation t-test) among Live Foraminiferal Densities (LFDs) recovered in August, November, March and May were detected at tropical Caroni swamp, Claxton bay (Trinidad), temperate Cowpen marsh and Brancaster marsh (U.K.). The monthly mean LFDs of the foraminiferal metacommunities (all stations), assemblages (groups of stations defined by cluster analysis), and the agglutinated and calcareous specimens within each were compared separately. The LFDs of the Caroni swamp metacommunity did not fluctuate significantly among months, but significantly higher abundances of agglutinated specimens occurred in the upper assemblage in March; and calcareous specimens in the lower assemblage in November. At Claxton bay, monthly LFDs of the metacommunities and assemblages did not vary significantly, but calcareous and agglutinated species within each favoured dry (March and May) and wet (August and November) months respectively At the temperate marshes, significantly higher LFDs of the metacommunities and assemblages were recorded in warmer months. August blooms of the Cowpen marsh metacommunity was attributed to agglutinated specimens in the upper assemblage, and calcareous specimens in the lower assemblage. May blooms of the Brancaster marsh upper assemblage were attributed to calcareous specimens, but there were no seasonal blooms of the lower assemblage. 展开更多
关键词 FORAMINIFERA MARSH SWAMP INTERTIDAL SEASONAL trends densities.
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Simple Method Obtaining Analytical Expressions of Particle and Kinetic—Energy Densities for One—Dimensional Confined Fermi Gases
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作者 YANGXiao-Xue WUYing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第3期293-296,共4页
We develop a simple approach to obtain explicitly exact analytical expressions of particle and kinetic-energy densities for noninteracting Fermi gases in one-dimensional harmonic confinement, and in one-dimensional bo... We develop a simple approach to obtain explicitly exact analytical expressions of particle and kinetic-energy densities for noninteracting Fermi gases in one-dimensional harmonic confinement, and in one-dimensional boxconfinement as well. 展开更多
关键词 confined Fermi gases particle and kinetic-energy densities
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Breeding Status, Nesting Densities & Diet Trends of Two Endangered California Least Tern Colonies
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作者 David L. Riensche Meredith L. Elliott Susan H. Euing 《Journal of Environmental Science and Engineering(B)》 2012年第10期1135-1145,共11页
The California least tern (Sternula antillarum browni) is an endangered species. The two largest colonies of this bird species in the San Francisco Bay, California, USA, are located 23 km apart at Alameda Point and ... The California least tern (Sternula antillarum browni) is an endangered species. The two largest colonies of this bird species in the San Francisco Bay, California, USA, are located 23 km apart at Alameda Point and Hayward Regional Shoreline. The Alameda Point colony, on the former Naval Air Station, Alameda, has grown at an average rate of 9.2% per year since its discovery in 1976 and has a nesting density ranging from 1-153 nests per ha. Long-term breeding success at Alameda has averaged 0.86 fledglings per breeding pair. Least tems began appearing in 2003, at an island in Hayward enhanced with substrate mediums and social attraction devices. Successful breeding attempts have been observed at the Hayward colony since 2006. The Hayward colony has grown at an average rate of 51.5% per year, has a nesting density ranging from 33-333 nests per ha and long-term breeding success average of 0.87 fledglings per breeding pair. Dropped fish have been collected from both colonies, and silversides (family Atherinopsidae) are the dominant prey. Alameda terns forage on a greater variety of species than the Hayward terns. The regression results indicate the importance of Northern anchovy (Engraulis mordax) to the breeding success of the Alameda colony. 展开更多
关键词 California least tern endangered species breeding status nesting densities diet trends.
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Charge Exchange Effect on Space-Charge-Limited Current Densities in Ion Diode
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作者 石磊 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第2期1239-1242,共4页
The article theoretically studied the charge-exchange effects on space charge limitedelectron and ion current densities of non-relativistic one-dimensional slab ion diode, and comparedwith those of without charge exch... The article theoretically studied the charge-exchange effects on space charge limitedelectron and ion current densities of non-relativistic one-dimensional slab ion diode, and comparedwith those of without charge exchange. 展开更多
关键词 Charge Exchange Effect on Space-Charge-Limited Current densities in Ion Diode THAN
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Solar Radiation Interception, Dry Matter Production and Yield among Different Plant Densities of <i>Arachis spp</i>. in Ibadan, Nigeria
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作者 Kolapo O. Oluwasemire George O. Odugbenro 《Agricultural Sciences》 2014年第10期864-874,共11页
The production of grain legumes is becoming a popular practice in the humid south western Nigeria. Apart from the decreasing trends observed in rainfall amount and duration as a result of climate change, solar radiati... The production of grain legumes is becoming a popular practice in the humid south western Nigeria. Apart from the decreasing trends observed in rainfall amount and duration as a result of climate change, solar radiation interception also constitutes a limitation to crop production because of persistent cloud cover. A trial was conducted at the University of Ibadan experimental site to determine the effect of different plant densities of Arachis spp. on solar radiation interception, dry matter production and yield in Ibadan, Nigeria with the aim of ascertaining the best practice for groundnut production in the zone. The treatments were three plant spacings (60 cm×20 cm,75 cm×20 cmand75 cm×40 cm), and three Arachis varieties (Samnut 10, Samnut 21 and Pintoi) arranged in a split plot, randomized complete block design with Arachis varieties as the main plot while plant densities formed the subplot and replicated three times. Growth parameters (number of leaves, dry leaf weight and dry stem weight) were measured at two weeks interval while yield parameters (number of pods, dry pod weight, dry seed weight and total dry matter) were determined at harvest. Intercepted radiation by plants (PAR) was also taken along with the growth parameters. The highest light interception from 42 - 105 days after planting (DAP) among the Arachis spp. was recorded by Samnut 10, while at 42 - 87 DAP, plant density of75 cm×20 cmhad the highest light interception. Dry matter production increased with light interception and was highest at 105 DAP when light interception was between 55% and 60% for all Arachis varieties and all plant densities. In terms of pod weight and grain yield, Samnut 10 performed better than Samnut 21 and also recorded the highest Radiation Use Efficiency (RUE) for pod, seed and total dry matter. However, Arachis pintoi, a sterile and forage plant with slower growth rate served as a cover crop capable of replenishing soil nutrients and physical properties. 展开更多
关键词 RADIATION Use Efficiency ARACHIS spp. PLANT densities Solar RADIATION INTERCEPTION
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Effects on the Behavior and Neuroimmunity of Pulsed Microwaves with Different Peak Densities
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作者 YANG Zhen Zhong WU Da Wei +2 位作者 MA Hong Bo FEI Jin Xue ZHAO Ya Li 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第12期893-897,共5页
Pulsed microwaves are widely used inradar,navigation, and communication. The average power density is low at narrow pulse widths or large pulse intervals,but pulsed microwaves at certain peak densities exert numerous ... Pulsed microwaves are widely used inradar,navigation, and communication. The average power density is low at narrow pulse widths or large pulse intervals,but pulsed microwaves at certain peak densities exert numerous biological effects, including 展开更多
关键词 Effects on the Behavior and Neuroimmunity of Pulsed Microwaves with Different Peak densities
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Bayesian Analysis of Simple Random Densities
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作者 Paulo C.Marques F. Carlos A.de B.Pereira 《Open Journal of Statistics》 2014年第5期377-390,共14页
A tractable nonparametric prior over densities is introduced which is closed under sampling and exhibits proper posterior asymptotics.
关键词 Bayesian Nonparametrics Bayesian Density Estimation Random densities Random Partitions Stochastic Simulations SMOOTHING
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