Growth indexes of 47 7-year-old progeny forests of Acacia mearnsii in Huangmian forest farm were measured. A. mearnsii plantation was managed for producing both tannin and timber, and considering the tannin yield and ...Growth indexes of 47 7-year-old progeny forests of Acacia mearnsii in Huangmian forest farm were measured. A. mearnsii plantation was managed for producing both tannin and timber, and considering the tannin yield and timber volume growth index, the family types fall into superior family type(the superior type), to-be superior type(the medium type), and preliminarily eliminated type(the elimination type). Eight superior families can be used for production, namely No.169, No.114, No.177, No.32, No.3, No.145, No.158 and No.134.展开更多
In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge m...In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.展开更多
[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese o...[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese on day 28 with the same genetic background and similar initial weight(1 384.83.73±0.76 g) were randomly assigned into 3 groups, with 4 replicates per group and 10 geese per replicate. Geese were fed the diets containing 4.29%, 5.29% and 6.29 % crude fiber, respectively. The experiment lasted 35 d.[Result] Final weight and daily gain of 5.29 %CF group were significantly higher than those of 6.29 % CF group(P<0.05);Feed intake was markedly higher than those of 4.29% and 6.29 % CF groups(P<0.05);Feed gain ratio was significantly lower than that of 6.29 % CF group(P<0.05). Compared with 4.29% and 6.29 % CF groups, serum albumin concentrations of 5.29 % CF group increased significantly(P<0.05), while serum total protein and globin contents were higher(P>0.05), but serum uric acid level was lower(P>0.05).[Conclusion] 5.29 % crude fiber could lead to higher growth performance of Dingan geese.展开更多
The accelerated cosmic expansion could be due to dark energy within general relativity(GR), or modified gravity. Differentiating between them using both the expansion history and growth history has attracted considera...The accelerated cosmic expansion could be due to dark energy within general relativity(GR), or modified gravity. Differentiating between them using both the expansion history and growth history has attracted considerable attention. In the literature, the growth index γ has been found useful to distinguish these two scenarios. This work aims to consider the non-parametric reconstruction of the growth index γ as a function of redshift z from the latest observational data as of July 2018 via Gaussian processes. We found that f(R) theories and dark energy models within GR(especially ΛCDM) are inconsistent with the results in the moderate redshift range far beyond 3σ confidence level. A modified gravity scenario different from f(R) theories is favored. However, these results can also be due to other non-trivial possibilities in which dark energy models within GR(especially ΛCDM) and f(R) theories may still survive. In all cases, our results suggest that new physics is required.展开更多
According to the growth characteristics of natural Korean pine (Pinus Koraiensis) forests, 6 equations such as Chapman-Richards equation, Logistic equation, Power equation, and so on were selected to ftt for the growt...According to the growth characteristics of natural Korean pine (Pinus Koraiensis) forests, 6 equations such as Chapman-Richards equation, Logistic equation, Power equation, and so on were selected to ftt for the growth modeIs for Korean pine forest. The growth models were developed based on 208 random trees and 24o dominant trees. Results show that the Chapman-Richards equation is the best model for estimating tree height by age and DBH, while the Parabola equation is fittest for predicting DBH by age or estimating age from DBH. The site index table of Korean pine forest was compiled by using the proportional method with the Chapman-Richards equation as the guide curve and vaIidated by accuracy test.展开更多
This study reviews productivity growth in the five major transportation industries in the United States (airline, truck, rail, pipeline, and water) and the pooled transportation industry from 2004 to 2011. We measure ...This study reviews productivity growth in the five major transportation industries in the United States (airline, truck, rail, pipeline, and water) and the pooled transportation industry from 2004 to 2011. We measure the average productivity for these eight years by state in each transportation industry and the annual average productivity by transportation industry. The major findings are that the U.S. transportation industry shows strong and positive productivity growth except that in the years of the global financial crisis in 2007, 2008, and 2010, and among the five transportation industries, the rail and water sectors show the highest productivity growth in 2011.展开更多
基金Sponsored by Special Fund for Public Welfare Forestry Scientific Research(201104019)
文摘Growth indexes of 47 7-year-old progeny forests of Acacia mearnsii in Huangmian forest farm were measured. A. mearnsii plantation was managed for producing both tannin and timber, and considering the tannin yield and timber volume growth index, the family types fall into superior family type(the superior type), to-be superior type(the medium type), and preliminarily eliminated type(the elimination type). Eight superior families can be used for production, namely No.169, No.114, No.177, No.32, No.3, No.145, No.158 and No.134.
基金This study was funded by the National Key R&D Program of China(2021YFD1900700)the National Natural Science Foundation of China(51909221)the China Postdoctoral Science Foundation(2020T130541 and 2019M650277).
文摘In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.
基金Special Project for Technical Development of Hainan Scientific Research Institutions(SQ2017JSKF0008)China Agricultural Industry Research System(CARS-43-42)
文摘[Objective] The study was carried out to investigate the effects of dietary crude fiber on growth performance and serum biochemical in-dex of Dingan geese aged from 35 to 70 days.[Method] A total of 120 Dingan geese on day 28 with the same genetic background and similar initial weight(1 384.83.73±0.76 g) were randomly assigned into 3 groups, with 4 replicates per group and 10 geese per replicate. Geese were fed the diets containing 4.29%, 5.29% and 6.29 % crude fiber, respectively. The experiment lasted 35 d.[Result] Final weight and daily gain of 5.29 %CF group were significantly higher than those of 6.29 % CF group(P<0.05);Feed intake was markedly higher than those of 4.29% and 6.29 % CF groups(P<0.05);Feed gain ratio was significantly lower than that of 6.29 % CF group(P<0.05). Compared with 4.29% and 6.29 % CF groups, serum albumin concentrations of 5.29 % CF group increased significantly(P<0.05), while serum total protein and globin contents were higher(P>0.05), but serum uric acid level was lower(P>0.05).[Conclusion] 5.29 % crude fiber could lead to higher growth performance of Dingan geese.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575022,and 11175016)
文摘The accelerated cosmic expansion could be due to dark energy within general relativity(GR), or modified gravity. Differentiating between them using both the expansion history and growth history has attracted considerable attention. In the literature, the growth index γ has been found useful to distinguish these two scenarios. This work aims to consider the non-parametric reconstruction of the growth index γ as a function of redshift z from the latest observational data as of July 2018 via Gaussian processes. We found that f(R) theories and dark energy models within GR(especially ΛCDM) are inconsistent with the results in the moderate redshift range far beyond 3σ confidence level. A modified gravity scenario different from f(R) theories is favored. However, these results can also be due to other non-trivial possibilities in which dark energy models within GR(especially ΛCDM) and f(R) theories may still survive. In all cases, our results suggest that new physics is required.
文摘According to the growth characteristics of natural Korean pine (Pinus Koraiensis) forests, 6 equations such as Chapman-Richards equation, Logistic equation, Power equation, and so on were selected to ftt for the growth modeIs for Korean pine forest. The growth models were developed based on 208 random trees and 24o dominant trees. Results show that the Chapman-Richards equation is the best model for estimating tree height by age and DBH, while the Parabola equation is fittest for predicting DBH by age or estimating age from DBH. The site index table of Korean pine forest was compiled by using the proportional method with the Chapman-Richards equation as the guide curve and vaIidated by accuracy test.
文摘This study reviews productivity growth in the five major transportation industries in the United States (airline, truck, rail, pipeline, and water) and the pooled transportation industry from 2004 to 2011. We measure the average productivity for these eight years by state in each transportation industry and the annual average productivity by transportation industry. The major findings are that the U.S. transportation industry shows strong and positive productivity growth except that in the years of the global financial crisis in 2007, 2008, and 2010, and among the five transportation industries, the rail and water sectors show the highest productivity growth in 2011.
