[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effect...[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.展开更多
Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The ...Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The water vapor sorption and desorption of the formulated microcapsules was then experimentally studied using dynamic vapor sorption(DVS),with the results fitted to three kinds of adsorption kinetics models.In addition,the specific surface area(SSA)was also calculated based on BET theory;and the thermal performance was investigated by laser flash analysis(LFA).Experimental results show a change of 103%in mass of the microcapsule sample under 90%relative humidity(RH)at 30℃after water vapor sorption.The fitting of results indicates that the adsorption process is mainly governed by the intra-particle diffusion mechanism,followed by the pseudo-first-order adsorption process.In comparison with most conventional pavement materials,it is found that the SSA of the formulated microcapsules is much larger while the thermal conductivity is lower.The unique properties of the formulated SiO_(2)-LiBr microcapsules have significant potential to take the edge off the urban heat island effect and reduce rutting when applied to water-retaining pavement materials.展开更多
[Objective] In order to reveal the effects of reducing the amount of novel nano-carbon humic acid water-retaining fertilizer(CSF) on soil microbial community structure and citrus growth. [Method]In this study,conventi...[Objective] In order to reveal the effects of reducing the amount of novel nano-carbon humic acid water-retaining fertilizer(CSF) on soil microbial community structure and citrus growth. [Method]In this study,conventional fertilization was as the control(KC1) in Wanzhou citrus orchard of Three Gorges Reservoir area. CSF reductions by 0%(KC2),10%(KC3),20%(KC4),30%(KC5) and 40%(KC6) were used to analyze the changes of soil bacterial community structure,citrus yield and quality. [Result]The results showed that the observed species,Shannon index,Chao1 index and PDwholetree of KC6 were higher than those of KC1,and were the same as KC2. The abundance of Xanthomonadaceae was the highest in KC5. Compared with KC1,the Xanthomonadaceae in KC3,KC4 and KC6 was significantly decreased,and the levels of Nitrosomonadaceae and Pseudomonasaceae were higher than that of KC1 after the treatment of KC6. Sphingomonas in different reduction treatments was lower than that of KC1,but Burkholderia and Pseudomonas were significantly higher than those of KC1. It was found that the similarity among treatments was small after bacterial community similarity clustering analysis,and citrus yield increased somewhat after CSF fertilization reduction.When CSF fertilization reduced by 30%,citrus yield increased by 4. 50%. When CSF fertilization reduced by 40%,citrus yield decreased by4. 14%. After CSF fertilization,citrus quality did not change significantly in CSF conventional fertilization and reduction of 10% and 40%,while significantly decreased in 20% and 30% of fertilization reduction. [Conclusion] CSF fertilization reduction changed the diversity of soil bacterial community structure and the yield and quality of citrus.展开更多
There are a number of serious problems connected with building and repairing water-reining elements in embankment dams in cold regions. One of them is the difficulty in finding inexpensive clay materials with the nece...There are a number of serious problems connected with building and repairing water-reining elements in embankment dams in cold regions. One of them is the difficulty in finding inexpensive clay materials with the necessary structural properties and using them in the winter. Another is the cracks that appear in the upper part of a dam when the core freezes to the banks, and leakage along the cracks threatens to desWoy the dam. Still another is the process of erosion at the bottom of the core which may occur through fissures in the rock foundation of a dam and in transport constructions. Also, the behaviour of water-retaining elements during eazthquakes is unreliable. All of these problems can be solved by using iceand cryogel-soil composites created by cryotropic gel formation （CGF）. Our laboratory investigations demonstrate that the materials proposed for water-retaining elements have the necessary permeable, plastic, thermophysical, and slrength properties to solve all of these problems. Certain consmactious of water-retaining elements which may prove to be both safe and cost-effective are proposed. However, these iceand cryogel-soil composites need to be field-validated before they are used in dams and transport structures in cold regions.展开更多
A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/...A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/Wo) on the discharge efficiency of MPKW is still not investigated numerically. The present work utilized the numerical modeling to investigate and analyze the effects of the inlet/outlet key width ratios on the hydraulic characteristics and discharge capacity of the MPKW. To validate the numerical model with the experimental data, the results indicate that the average relative error is 2.96%, which confirms that the numerical model is fairly well to predictthe specifications of flow over on the MPKW. Numerical simulation results indicated that the discharge capacity of the MPKW can be improved up to 8.5% by optimizing the Wi/Wo ratio ranging from 1.53 to 1.67 even if the other parameters of the MPKW keep unchanged. A big Wi/Wo ratio generally leads to an increase in discharge capacity at low heads and a little effect on the discharge efficiency at high heads. The discharge efficiency of the inlet and outlet crests increases up to 9.6% for high heads, while discharge efficiency of the lateral crest decreases up to 23.5% compared with the reference model. The findings of the study revealed that the intrinsic influencing mechanism of the Wi/Wo ratio on the discharge performance of MPKWs.展开更多
河道内鱼类上溯路径不唯一,聚集位置更是难以预测,对鱼类上溯行为进行有效引导有助于提升过鱼设施进口的效率。为此,该研究提出了一种导鱼堰的概念和设计方法,结合姚家坪水电站的过鱼设施,利用流场三维数值模拟、鱼类洄游(active fish m...河道内鱼类上溯路径不唯一,聚集位置更是难以预测,对鱼类上溯行为进行有效引导有助于提升过鱼设施进口的效率。为此,该研究提出了一种导鱼堰的概念和设计方法,结合姚家坪水电站的过鱼设施,利用流场三维数值模拟、鱼类洄游(active fish migration,AFM)模型和实鱼试验对导鱼堰的效果进行评估。结果表明:姚家平水利枢纽工程的导鱼堰上下游水面落差为0.36~0.40 m,过堰水流流速可达1.5~2.8 m/s,形成阻鱼的屏障,并在导鱼堰下游侧形成了诱导鱼类向集鱼渠进鱼口游动的唯一低流速上溯通道,鱼类聚集点趋于唯一,验证了导鱼堰方案的合理性。利用鱼类洄游模型对导鱼堰的导鱼效果进行预测,结果表明,下游高水位和低水位2种工况下,90%以上的鱼类游动路径均表现出相似的规律,鱼类沿河道右岸和导鱼堰下游侧的低流速通道上溯,并最终聚集在集鱼渠的进鱼口处。放鱼试验中试验个体全部进入集鱼渠,结果进一步证实导鱼堰可以有效引导鱼类游动路线,并在集鱼渠进鱼口处形成唯一的聚集区。本文提出的导鱼堰丰富了生态水工建筑物的形式,可为过鱼设施进口的水力设计及下游河道的局部整治提供参考。展开更多
基金Supported by Science and Technology Program of the Fourth Division Kekedala City(2023GG11).
文摘[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.
基金financial support of The National Scholarship Foundation of China,China Scholarship Council([2018]3101)。
文摘Novel SiO_(2)-LiBr microcapsules for water-retaining pavement were prepared and firstly characterized by scanning electron microscope(SEM),particle size analysis,and Fourier transform infrared spectroscopy(FT-IR).The water vapor sorption and desorption of the formulated microcapsules was then experimentally studied using dynamic vapor sorption(DVS),with the results fitted to three kinds of adsorption kinetics models.In addition,the specific surface area(SSA)was also calculated based on BET theory;and the thermal performance was investigated by laser flash analysis(LFA).Experimental results show a change of 103%in mass of the microcapsule sample under 90%relative humidity(RH)at 30℃after water vapor sorption.The fitting of results indicates that the adsorption process is mainly governed by the intra-particle diffusion mechanism,followed by the pseudo-first-order adsorption process.In comparison with most conventional pavement materials,it is found that the SSA of the formulated microcapsules is much larger while the thermal conductivity is lower.The unique properties of the formulated SiO_(2)-LiBr microcapsules have significant potential to take the edge off the urban heat island effect and reduce rutting when applied to water-retaining pavement materials.
基金Supported by the National Natural Science Foundation of China(41571303)Science and Technology Development Plan of Tai’an City,Shandong Province(2018HZ0115)
文摘[Objective] In order to reveal the effects of reducing the amount of novel nano-carbon humic acid water-retaining fertilizer(CSF) on soil microbial community structure and citrus growth. [Method]In this study,conventional fertilization was as the control(KC1) in Wanzhou citrus orchard of Three Gorges Reservoir area. CSF reductions by 0%(KC2),10%(KC3),20%(KC4),30%(KC5) and 40%(KC6) were used to analyze the changes of soil bacterial community structure,citrus yield and quality. [Result]The results showed that the observed species,Shannon index,Chao1 index and PDwholetree of KC6 were higher than those of KC1,and were the same as KC2. The abundance of Xanthomonadaceae was the highest in KC5. Compared with KC1,the Xanthomonadaceae in KC3,KC4 and KC6 was significantly decreased,and the levels of Nitrosomonadaceae and Pseudomonasaceae were higher than that of KC1 after the treatment of KC6. Sphingomonas in different reduction treatments was lower than that of KC1,but Burkholderia and Pseudomonas were significantly higher than those of KC1. It was found that the similarity among treatments was small after bacterial community similarity clustering analysis,and citrus yield increased somewhat after CSF fertilization reduction.When CSF fertilization reduced by 30%,citrus yield increased by 4. 50%. When CSF fertilization reduced by 40%,citrus yield decreased by4. 14%. After CSF fertilization,citrus quality did not change significantly in CSF conventional fertilization and reduction of 10% and 40%,while significantly decreased in 20% and 30% of fertilization reduction. [Conclusion] CSF fertilization reduction changed the diversity of soil bacterial community structure and the yield and quality of citrus.
文摘There are a number of serious problems connected with building and repairing water-reining elements in embankment dams in cold regions. One of them is the difficulty in finding inexpensive clay materials with the necessary structural properties and using them in the winter. Another is the cracks that appear in the upper part of a dam when the core freezes to the banks, and leakage along the cracks threatens to desWoy the dam. Still another is the process of erosion at the bottom of the core which may occur through fissures in the rock foundation of a dam and in transport constructions. Also, the behaviour of water-retaining elements during eazthquakes is unreliable. All of these problems can be solved by using iceand cryogel-soil composites created by cryotropic gel formation （CGF）. Our laboratory investigations demonstrate that the materials proposed for water-retaining elements have the necessary permeable, plastic, thermophysical, and slrength properties to solve all of these problems. Certain consmactious of water-retaining elements which may prove to be both safe and cost-effective are proposed. However, these iceand cryogel-soil composites need to be field-validated before they are used in dams and transport structures in cold regions.
文摘A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/Wo) on the discharge efficiency of MPKW is still not investigated numerically. The present work utilized the numerical modeling to investigate and analyze the effects of the inlet/outlet key width ratios on the hydraulic characteristics and discharge capacity of the MPKW. To validate the numerical model with the experimental data, the results indicate that the average relative error is 2.96%, which confirms that the numerical model is fairly well to predictthe specifications of flow over on the MPKW. Numerical simulation results indicated that the discharge capacity of the MPKW can be improved up to 8.5% by optimizing the Wi/Wo ratio ranging from 1.53 to 1.67 even if the other parameters of the MPKW keep unchanged. A big Wi/Wo ratio generally leads to an increase in discharge capacity at low heads and a little effect on the discharge efficiency at high heads. The discharge efficiency of the inlet and outlet crests increases up to 9.6% for high heads, while discharge efficiency of the lateral crest decreases up to 23.5% compared with the reference model. The findings of the study revealed that the intrinsic influencing mechanism of the Wi/Wo ratio on the discharge performance of MPKWs.
文摘河道内鱼类上溯路径不唯一,聚集位置更是难以预测,对鱼类上溯行为进行有效引导有助于提升过鱼设施进口的效率。为此,该研究提出了一种导鱼堰的概念和设计方法,结合姚家坪水电站的过鱼设施,利用流场三维数值模拟、鱼类洄游(active fish migration,AFM)模型和实鱼试验对导鱼堰的效果进行评估。结果表明:姚家平水利枢纽工程的导鱼堰上下游水面落差为0.36~0.40 m,过堰水流流速可达1.5~2.8 m/s,形成阻鱼的屏障,并在导鱼堰下游侧形成了诱导鱼类向集鱼渠进鱼口游动的唯一低流速上溯通道,鱼类聚集点趋于唯一,验证了导鱼堰方案的合理性。利用鱼类洄游模型对导鱼堰的导鱼效果进行预测,结果表明,下游高水位和低水位2种工况下,90%以上的鱼类游动路径均表现出相似的规律,鱼类沿河道右岸和导鱼堰下游侧的低流速通道上溯,并最终聚集在集鱼渠的进鱼口处。放鱼试验中试验个体全部进入集鱼渠,结果进一步证实导鱼堰可以有效引导鱼类游动路线,并在集鱼渠进鱼口处形成唯一的聚集区。本文提出的导鱼堰丰富了生态水工建筑物的形式,可为过鱼设施进口的水力设计及下游河道的局部整治提供参考。
基金教育部考试中心-英国文化教育协会2020年英语测评科研课题“An Empirical Study into the Validity ofa CSE-based Placement test in China’s Transnational Higher Education”(考协[2020]263号)。
