One of the key concerns in estuarine and coastal environments is eutrophication, which is known to be closely connected to nutrient enrichment. To control and improve surface water quality, nutrient criteria are recom...One of the key concerns in estuarine and coastal environments is eutrophication, which is known to be closely connected to nutrient enrichment. To control and improve surface water quality, nutrient criteria are recommended in order to provide reference conditions for the environment. However, the current datasets of nutrient criteria in China are either designed for surface water or sea water, and as such these are not suitable for assessing estuarine water quality, especially given the unique ecosystem and dynamic properties of estuaries. To address this issue in current estuarine water management, nutrient criteria have been developed for a local estuary in the southeast of China. Segmentation of the Jiulong River Estuary, China was firstly analysed through field investigations carried out during 2013–2014, which resulted in the delineation of three segments characterized by their distinct properties in relation to salinity, hydrology, ecosystems, etc. Historical records from 1997 to 2014 were then analysed using statistical modelling to develop candidate nutrient criteria for the estuary.This stage of the analysis was undertaken in combination with the study of nutrient status records from the 1980s,which were used to establish a baseline reference condition. The recommended criteria values of dissolved inorganic nitrogen(DIN) in Segments Ⅰ, Ⅱ and Ⅲ of the Jiulong River Estuary are 64, 21 and 14 μmol/L,respectively, and the corresponding values for soluble reactive phosphorus(SRP) are 0.89, 0.76 and 0.89 μmol/L,respectively. It should be emphasised that these values are site-dependent, and that different results may be achieved at other locations depending on the physical and biogeochemical characteristics of an estuary, or even a single site within a catchment. It is hoped that by demonstrating a possible methodological approach and methods of nutrient criteria derivation in the Jiulong River Estuary, the current study will offer researchers some fundamental basis from which to begin to develop more complete nutrient criteria indices for the study of nutrient conditions in other estuaries throughout China.展开更多
[Objective]The paper was to study the control effect of pheromone insect-attracting board on tea green leafhopper(Empoasca vitis Gothe)in fields. [Method]Pheromone insect-attracting board and ordinary insect-attract...[Objective]The paper was to study the control effect of pheromone insect-attracting board on tea green leafhopper(Empoasca vitis Gothe)in fields. [Method]Pheromone insect-attracting board and ordinary insect-attracting board were used to trap tea green leafhopper in fields,and control efficacies were studied.[Result]The daily trapping effect of pheromone insect-attracting board on tea green leafhopper was 19.0 insect/grid,while that of ordinary insect-attracting board was 13.8 insect/grid.The highest control effect of pheromone insect-attracting board and ordinary insect-attracting board were 71.6% and 63. 6%,respectively.The distribution of tea green leafhopper in two types of boards showed the following regularities:more in upper edge and less in lower edge of boards,more on both sides and less in the middle of boards.The mean values of control effects of two insect-attracting boards were significantly different(t =5.66展开更多
In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that ...In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that the existence of defocus aberration,tilt aberration and astigmatic aberration in the unstable resonator can cause the center of the far-field spot of the output annular beam to drift,the number of peripheral diffraction rings to increase,the beam quality to deteriorate,and the degree of effect is different.展开更多
In order to meet the reflectivity measurement requirements of any incident angle at different points of the large size special high mirror,a rotating cavity ring-down spectroscopy high reflectivity measurement system ...In order to meet the reflectivity measurement requirements of any incident angle at different points of the large size special high mirror,a rotating cavity ring-down spectroscopy high reflectivity measurement system was built,in which the rotation function of the resonant cavity was set,and the lifting and parallel travelling mechanism of the measured mirror was added.Furthermore,the uncertainty of the measurement results was analyzed and calculated.The results showed that the reflectivity of a high reflective mirror measured by the system was 99.9795%,the measurement accuracy reached the order of 10-6,and the combined standard uncertainty of reflectivity measurement was 0.0028%.Collectively,these results provide a detection guarantee for the maintenance of the large size special high mirror,and provide ideas and methods for the uncertainty analysis of measurement results of similar equipment parameters.展开更多
文摘One of the key concerns in estuarine and coastal environments is eutrophication, which is known to be closely connected to nutrient enrichment. To control and improve surface water quality, nutrient criteria are recommended in order to provide reference conditions for the environment. However, the current datasets of nutrient criteria in China are either designed for surface water or sea water, and as such these are not suitable for assessing estuarine water quality, especially given the unique ecosystem and dynamic properties of estuaries. To address this issue in current estuarine water management, nutrient criteria have been developed for a local estuary in the southeast of China. Segmentation of the Jiulong River Estuary, China was firstly analysed through field investigations carried out during 2013–2014, which resulted in the delineation of three segments characterized by their distinct properties in relation to salinity, hydrology, ecosystems, etc. Historical records from 1997 to 2014 were then analysed using statistical modelling to develop candidate nutrient criteria for the estuary.This stage of the analysis was undertaken in combination with the study of nutrient status records from the 1980s,which were used to establish a baseline reference condition. The recommended criteria values of dissolved inorganic nitrogen(DIN) in Segments Ⅰ, Ⅱ and Ⅲ of the Jiulong River Estuary are 64, 21 and 14 μmol/L,respectively, and the corresponding values for soluble reactive phosphorus(SRP) are 0.89, 0.76 and 0.89 μmol/L,respectively. It should be emphasised that these values are site-dependent, and that different results may be achieved at other locations depending on the physical and biogeochemical characteristics of an estuary, or even a single site within a catchment. It is hoped that by demonstrating a possible methodological approach and methods of nutrient criteria derivation in the Jiulong River Estuary, the current study will offer researchers some fundamental basis from which to begin to develop more complete nutrient criteria indices for the study of nutrient conditions in other estuaries throughout China.
基金Supported by Science and Technology Promotion Project of Ningbo Forestry Bureau "Application Research and Extension of Insect Pheromone in Tea Garden"(2010L05)
文摘[Objective]The paper was to study the control effect of pheromone insect-attracting board on tea green leafhopper(Empoasca vitis Gothe)in fields. [Method]Pheromone insect-attracting board and ordinary insect-attracting board were used to trap tea green leafhopper in fields,and control efficacies were studied.[Result]The daily trapping effect of pheromone insect-attracting board on tea green leafhopper was 19.0 insect/grid,while that of ordinary insect-attracting board was 13.8 insect/grid.The highest control effect of pheromone insect-attracting board and ordinary insect-attracting board were 71.6% and 63. 6%,respectively.The distribution of tea green leafhopper in two types of boards showed the following regularities:more in upper edge and less in lower edge of boards,more on both sides and less in the middle of boards.The mean values of control effects of two insect-attracting boards were significantly different(t =5.66
基金supported by the Hunan Department of Education Funded Research Project(No.23A0581)the Hunan Provincial Social Science Achievement Committee Project(No.XSP24YBZ198)the Teaching Reform Project of Hunan University of Science and Engineering(No.[2022]45-XKYJ2022014)。
文摘In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that the existence of defocus aberration,tilt aberration and astigmatic aberration in the unstable resonator can cause the center of the far-field spot of the output annular beam to drift,the number of peripheral diffraction rings to increase,the beam quality to deteriorate,and the degree of effect is different.
基金supported by the 2021 Annual Instructional Science and Technology Program of Yongzhou(No.2021-YZKJZD-009)the Outstanding Youth Foundation of Hunan Province(No.2020JJ2015)the Science Research Project of Hunan Institute of Science and Technology(No.21xky040).
文摘In order to meet the reflectivity measurement requirements of any incident angle at different points of the large size special high mirror,a rotating cavity ring-down spectroscopy high reflectivity measurement system was built,in which the rotation function of the resonant cavity was set,and the lifting and parallel travelling mechanism of the measured mirror was added.Furthermore,the uncertainty of the measurement results was analyzed and calculated.The results showed that the reflectivity of a high reflective mirror measured by the system was 99.9795%,the measurement accuracy reached the order of 10-6,and the combined standard uncertainty of reflectivity measurement was 0.0028%.Collectively,these results provide a detection guarantee for the maintenance of the large size special high mirror,and provide ideas and methods for the uncertainty analysis of measurement results of similar equipment parameters.