期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Scenario analysis of the environmental impacts of breeding structure change from the perspective of farming and breeding balance in Northeast China 被引量:1
1
作者 Zhe Zhao Sijian Jiang Xuanchang Zhang 《Chinese Journal of Population,Resources and Environment》 2025年第1期132-142,共11页
This study uses prefecture-level city statistical data from China from 2000-2022 to measure the supply and demand of livestock manure nitrogen nutrients and calculates farmland livestock carrying capacity using the ni... This study uses prefecture-level city statistical data from China from 2000-2022 to measure the supply and demand of livestock manure nitrogen nutrients and calculates farmland livestock carrying capacity using the nitrogen nutrient balance method.We investigate nitrogen supply and demand and livestock carrying capacity in northeast China by comparing emissions from 2000-2022 over the past several decades.The poultry and livestock industry in northeast China has changed significantly over the past two decades:pigs are now the most bred animal and poultry production has increased dramatically.Regional livestock nitrogen emissions are influenced primarily by the size of the local livestock industry chain.Due to regional differences,each region has unique breeding structures.We also predict the anticipated situation in 2050 using the business-as usual scenario.High-risk livestock carrying capacity areas will be concentrated in the northeast and southeast regions,with significantly increased risk indices,compared with those of 2022,particularly in Shenyang,Fushun,and Tieling.Therefore,promoting farming and breeding,improving livestock manure utilization,and returning manure to nearby farmlands are crucial for meeting agricultural green development goals. 展开更多
关键词 breeding structure change Farming and breeding balance Agricultural green development Northeast China
在线阅读 下载PDF
An Investigation Report on Production Conditions of Sugarcane in Guangxi in 2016
2
作者 Yuchi DENG Weizan WANG +11 位作者 RonghuaZHANG Shiyun TANG Shanhai LIN Qiang LIANG Weixing DUAN Xiang LI Guoying LU Shijian HAN Youzong HUANG Yebin YANG Yanni HUANG Lunwang WANG 《Asian Agricultural Research》 2017年第6期79-83,共5页
To predict and assess production conditions of sugarcane in Guangxi in 2016,by using methods of field survey and data collection,the seedling situation,breed structure,planting area,planting period,plant diseases and ... To predict and assess production conditions of sugarcane in Guangxi in 2016,by using methods of field survey and data collection,the seedling situation,breed structure,planting area,planting period,plant diseases and insect pests of sugarcane in six major sugarcane producing cities of Guangxi were surveyed. The results show that the overall situation of sugarcane seedlings in Guangxi in 2016 became slightly worse than that in 2015,but there were enough good sugarcane seedlings in 2016. The dead heart rate of sugarcane decreased in most sugarcane regions from 2015 to 2016,that is,the comprehensive control of borers gave initial results; the smut infection rate of sugarcane rose from 2015 to 2016 and tended to increase. The situation of decrease in the planting area of sugarcane in three consecutive years was controlled,and the planting area of sugarcane increased slightly from 2015 to 2016. Due to the construction of ' double high' bases,the breed variety of sugarcane in Guangxi was improved further in 2016. It is necessary to strengthen field management and conduct chemical weeding,prevention and control of borers and aphids in the later period in time. 展开更多
关键词 SUGARCANE Seedling situation breed structure Planting area Plant diseases and insect pests
在线阅读 下载PDF
Colony and population genetic structure of the newly invasive white-footed ant(Technomyrmex difficilis)in the United States
3
作者 Kuan-Ling Kelly Liu Pierre-Andre Eyer +2 位作者 Anjel M.Helms Robert T.Puckett Edward L.Vargo 《Insect Science》 2025年第6期1954-1968,共15页
The invasive white-footed ant Technomyrmex difficilis has emerged as a rising pest in several regions,yet its invasion dynamics remain underexplored.This species outcompetes native ants and causes agricultural losses ... The invasive white-footed ant Technomyrmex difficilis has emerged as a rising pest in several regions,yet its invasion dynamics remain underexplored.This species outcompetes native ants and causes agricultural losses by tending pest insects,including aphids and mealybugs.This study provides the first integrated analysis of the species'behavioral,chemical,and genetic variation across Texas and Florida populations.Observations suggest that the recently discovered Texas population of white-footed ants originated from Florida.Microsatellite and mitochondrial DNA analyses revealed low genetic diversity in both populations,with a shared haplotype consistent with the Texas population originating from Florida.STRUCTURE analysis further supported genetic clustering between the two regions.Despite similar within-colony coefficients of relatedness for workers,the populations differed in reproductive strategy:Florida colonies showed signs of inbreeding and high inter-colony aggression,whereas Texas colonies exhibited potential localized outbreeding,low aggression,and more uniform cuticular hydrocarbon profiles.Aggression was positively correlated with chemical divergence but not with genetic differentiation.This study establishes a foundational understanding and highlights the importance of integrating multiple types of data to understand the invasion biology of Technomyrmex difficilis. 展开更多
关键词 aggression behavior breeding structure CHC COI MICROSATELLITE nestmate recognition
原文传递
Algorithm based on local breeding of growing modes for convection-allowing ensemble forecasting 被引量:4
4
作者 Chaohui CHEN Xiang LI +2 位作者 Hongrang HE Jie XIANG Shenjia MA 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第4期462-472,共11页
We propose a method based on the local breeding of growing modes(LBGM) considering strong local weather characteristics for convection-allowing ensemble forecasting. The impact radius was introduced in the breeding of... We propose a method based on the local breeding of growing modes(LBGM) considering strong local weather characteristics for convection-allowing ensemble forecasting. The impact radius was introduced in the breeding of growing modes to develop the LBGM method. In the local breeding process, the ratio between the root mean square error(RMSE) of local space forecast at each grid point and that of the initial full-field forecast is computed to rescale perturbations. Preliminary evaluations of the method based on a nature run were performed in terms of three aspects: perturbation structure, spread,and the RMSE of the forecast. The experimental results confirm that the local adaptability of perturbation schemes improves after rescaling by the LBGM method. For perturbation physical variables and some near-surface meteorological elements, the LBGM method could increase the spread and reduce the RMSE of forecast,improving the performance of the ensemble forecast system.In addition, different from those existing methods of global orthogonalization approach, this new initial-condition perturbation method takes into full consideration the local characteristics of the convective-scale weather system, thus making convectionallowing ensemble forecast more accurate. 展开更多
关键词 Convection-allowing ensemble forecasting Local breeding of growing modes Perturbation structure Spread Root mean square error of forecast
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部