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Interactions between soil conservation and dryland farming of heterogeneously eroding areas in Loess Hills,China

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International Soil and Water Conservation Research 2022年第4期10卷 574-585页

作者： Boyang Sui Xiaohu Dang liangxin Fan Bo Guo Wei Bi Guobin Liu college of Geology and Environment Xi'an University of Science and TechnologyXi'an710054China college of Geomatics and Land Information Engineering Henan Polytechnic UniversityJiaozuo454000China college of Geomatics Xi'an University of Science and TechnologyXi'an710054China Institute of Soil and Water Conservation Chinese Academy of Science and Ministry of Water ResourcesYangling712100China

The unidirectional impacts of soil conservation on dryland farming and local livelihood have been well studied.However,there are gaps in literature regarding the interactions among factors,such as labor force and financial capital,in response to soil conservation,as well as the influence of such interactions on the relationships between environmental projects and agricultural development.By combining the Chinese Soil Loss Equation(CSLE)model and statistical analyses,this study investigated the spatiotemporal characteristics of soil erosion while also identifying the controlling factors that affect crop and livestock farming.The aim was to reveal how these factors interacted to influence agriculture in two case study areas between 2000 and 2017.The results showed that soil erosion substantially declined as a consequence of soil conservation,while the output from crop farming increased,indicating that there was a synergy between soil conservation and dryland farming in both the districts,over time;and factors facilitating crop farming,such as labor force,agricultural machinery,and irrigation,appeared to exert an adverse effect on livestock farming in both areas,implying a tradeoff between livestock and crop farming in the context of programs such as the Grain for Green Program(GGP)in the Loess Hills.Such a tradeoff is a result of the competition for cropland and labor that exists due to grazing prohibition and rural-urban migration.Therefore,policy-related resolutions are required to address the land use conflicts and migration-related rural labor losing due to implementation of the GGP in the Loess Hills.

关键词： Heterogeneous erosion environment Soil conservation Dryland farming Tradeoff/synergy of conservation and agriculture Loess hills

Study on positive-negative pressure seed metering device for wide-seedling-strip-seeding

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International Journal of Agricultural and Biological Engineering 2022年第6期15卷 124-133页

作者： Xiaoshun Zhao Wenjie Bai Jincai Li Huali Yu Dawei Zhao Baozhong Yin college of Mechanical and Electrical Engineering Hebei Agricultural UniversityBaoding 071001HebeiChina State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001HebeiChina college of Plant Protection Hebei Agricultural UniversityBaoding 071001HebeiChina

In order to solve the problem of poor uniformity of wheat strip sowing,this paper designs a positive-negative pressure wheat wide-seedling-strip-seeding precision seed metering device,which adopts the roller structure with the principle of combined positive-negative pressure.Through theoretical analysis and relevant data,the structure of the seed metering device and the structure of the positive-negative pressure air chamber were designed.The internal flow field conditions were simulated by Fluent software under different structural parameters.The design of the seed holes was completed by analyzing the pressure cloud diagram and the flow velocity vector diagram,and the optimal combination of parameters was obtained and the influence law of negative pressure on the flow field was obtained.The effect of rotational speed on the flow field was studied by EDEM-Fluent coupling technique.In this paper,a three-factor and three-level response surface test was conducted on a JPS-12 test bench with liangxin-99 wheat as the research object.The experiment was conducted with the rotational speed of seed metering device,the negative pressure of seed suction and the seeding height as factors,and the qualified index,the reseeding index and the miss-seeding index as evaluation indicators.Through the test,the optimal structure and working parameters of the seed metering device were determined as follows:the diameter of the seed hole was 2 mm,and the number of seed holes per row was 28,negative pressure was−3.5 kPa,rotational speed of seed metering device was 19 r/min,and seeding height was 180 mm.Validation test was carried out on the optimized seed metering device:the qualified index was 80.62%,the reseeding index was 9.22%,and the miss-seeding index was 10.16%,which reached the parameter indicator in JB/T 10293-2013 Technical conditions of single seed(precision)seeder and met the agronomic requirements for wheat wide-seedling-strip-seeding.

关键词： wheat precision seed metering device wheat wide-seedling-strip-seeding positive-negative pressure fluent EDEM-Fluent coupling response surface test

High-Resolution Imaging of Latent Fingerprints through Near-Infrared Organoboron AIEgens

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Chinese Journal of Chemistry 2023年第12期41卷 1465-1470页

作者： Lijie Liu Jinjin Wang Xingxiao Wang Haoran Wang Mengzhen Li Tongyuan Wu Guangqin Gao Xin Zheng Guoxing Liu liangxin Fan Wenbo Shen Guangxin Ru Zheng Zhao Ben Zhong Tang college of Science Henan Agricultural University 63 Agricultural Road Zhengzhou Henan 450002 China School of Science and Engineering Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong Kong Shenzhen Guangdong 518172 China

A new class of near-infrared(NIR)fluorescent organoboron AIEgens was successfully developed for latent fingerprints(LFPs)imaging.They exhibit real-time and in situ high-resolution imaging performance at 1-3 levels of LFPs by spraying method.In addition,we systematically elucidate the fingerprint imaging mechanism of these AIEgens.Significantly,the excellent level 3 structural imaging capabilities enable the application of them for analyzing incomplete LFPs and identifying individuals in different scenarios.

关键词： Organoboron AIEgens Aggregation-induced emission Near-infrared emission High-resolution imaging of latent fingerprints

An analysis on pseudo-tea from perspective of Chinese medical literature

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An analysis on pseudo-tea from perspective of Chinese medica...