[Objective] The aim was to present a proposal about a new image compression technology, in order to make the image be able to be stored in a smaller space and be transmitted with smaller bit rate on the premise of gua...[Objective] The aim was to present a proposal about a new image compression technology, in order to make the image be able to be stored in a smaller space and be transmitted with smaller bit rate on the premise of guaranteeing image quality in the rape crop monitoring system in Qinling Mountains. [Method] In the proposal, the color image was divided into brightness images with three fundamental colors, followed by sub-image division and DCT treatment. Then, coefficients of transform domain were quantized, and encoded and compressed as per Huffman coding. Finally, decompression was conducted through inverse process and decompressed images were matched. [Result] The simulation results show that when compression ratio of the color image of rape crops was 11.972 3∶1, human can not distinguish the differences between the decompressed images and the source images with naked eyes; when ratio was as high as 53.565 6∶1, PSNR was still above 30 dD,encoding efficiency achieved over 0.78 and redundancy was less than 0.22. [Conclusion] The results indicate that the proposed color image compression technology can achieve higher compression ratio on the premise of good image quality. In addition, image encoding quality and decompressed images achieved better results, which fully met requirement of image storage and transmission in monitoring system of rape crop in the Qinling Mountains.展开更多
The experiment was designed to study whether the decrease of Cd in the rhizosphere of Zhongyouza Ⅰ ,one breed of oilseed rapes (Brassica junica) that can hyperaccumulate cadmium from the soil, can improve the living ...The experiment was designed to study whether the decrease of Cd in the rhizosphere of Zhongyouza Ⅰ ,one breed of oilseed rapes (Brassica junica) that can hyperaccumulate cadmium from the soil, can improve the living condition of less Cd-tolerant plant pai-tsai (Brassia chinensis) with their roots permitted to intermingle and develop coincident rhizosphere. The extent of rhizosphere interactions between ZhongyouzaⅠ and pai-tsai was controlled by different root barriers, or without barrier. The results show that in the 10 and 20 mg/kg Cd treated soils, pai-tsai gets higher shoot mass and less Cd accumulation in its shoot than in the barrier treatments or in the mono cultures, when its roots are permitted to intermingle with those of ZhongyouzaⅠ .Meanwhile, soil decontamination rates of ZhongyouzaⅠ are not affected much by co-cropping with pai-tsai, they are 80.0% and 91.8% of that in the mono cultures of ZhongyouzaⅠ, respectively. However, the co-cropping method in meliorating the living condition of pai-tsai is not obvious when Cd concentration in soil reaches 40 mg/kg, and soil decontamination rate decreases to 0.14, which is 58.3% of that in the mono culture. These results indicate that the oilseed rape ZhongyouzaⅠ may alleviate Cd toxicity of surrounding less-tolerant species, and its ability of phytoremediation is not affected much at the same time, especially in the middle polluted soil.展开更多
Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice...Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice grown after oilseed rape had significantly lower Cd and Pb concentrations in both straw and grains.Cd and Pb concentrations in the grains of the rice rotated with oilseed rape decreased by approximately 46-80% and 17-86%,respectively,although the Cd and Pb removal by oilseed rape ranged only from 2.39-3.67 and 0.032-0.13% of the total content in soil.Compost amendment also decreased the bioavailability of Cd and Pb in the soil and reduced Cd and Pb uptake by oilseed rapes and rice.The concentrations of Cd and Pb significantly decreased in the exchangeable and carbonate fractions and Pb concentration decreased in the organic matter and sulfide fractions in the contaminated soil after planting oilseed rapes.展开更多
针对饲料油菜机械化收获中的切碎、抛送等关键环节离散元仿真缺乏准确模型的问题,以抽薹期饲料油菜茎秆为研究对象,利用EDEM仿真软件开展饲料油菜茎秆破碎离散元仿真模型参数标定研究。试验测定了饲料油菜本征参数,应用HertzMindlin基...针对饲料油菜机械化收获中的切碎、抛送等关键环节离散元仿真缺乏准确模型的问题,以抽薹期饲料油菜茎秆为研究对象,利用EDEM仿真软件开展饲料油菜茎秆破碎离散元仿真模型参数标定研究。试验测定了饲料油菜本征参数,应用HertzMindlin基本模型进行饲料油菜茎秆颗粒堆积仿真试验,通过二水平因子试验、最陡爬坡试验和响应曲面试验,确定了饲料油菜茎秆颗粒碰撞恢复系数、静摩擦因数和滚动摩擦因数等基本接触参数。在此基础上,应用HertzMindlin with bonding接触模型进行饲料油菜茎秆弯曲破坏仿真试验,通过响应面分析确定了饲料油菜茎秆颗粒法向接触刚度、切向接触刚度、临界法向应力与临界切向应力等饲料油菜茎秆破碎离散元仿真模型的主要参数。以确定的参数进行堆积角仿真试验,结果表明,仿真结果与实测值相对误差为2.27%;不同直径油菜茎秆破碎仿真试验表明,仿真结果与实测值相对误差不大于4.21%,说明标定方法正确可行,标定参数准确可靠。展开更多
基金Supported by Special Fund for Scientific Research of Shannxi Education Department(No:2010JK463)Shaanxi Natural Science Foundation(2011JE012)~~
文摘[Objective] The aim was to present a proposal about a new image compression technology, in order to make the image be able to be stored in a smaller space and be transmitted with smaller bit rate on the premise of guaranteeing image quality in the rape crop monitoring system in Qinling Mountains. [Method] In the proposal, the color image was divided into brightness images with three fundamental colors, followed by sub-image division and DCT treatment. Then, coefficients of transform domain were quantized, and encoded and compressed as per Huffman coding. Finally, decompression was conducted through inverse process and decompressed images were matched. [Result] The simulation results show that when compression ratio of the color image of rape crops was 11.972 3∶1, human can not distinguish the differences between the decompressed images and the source images with naked eyes; when ratio was as high as 53.565 6∶1, PSNR was still above 30 dD,encoding efficiency achieved over 0.78 and redundancy was less than 0.22. [Conclusion] The results indicate that the proposed color image compression technology can achieve higher compression ratio on the premise of good image quality. In addition, image encoding quality and decompressed images achieved better results, which fully met requirement of image storage and transmission in monitoring system of rape crop in the Qinling Mountains.
基金Project(04JJ3013) supported by the Natural Science Foundation of Hunan Province, ChinaProject(2001AA644020) supported by the National High-Tech Research and Development Program of China
文摘The experiment was designed to study whether the decrease of Cd in the rhizosphere of Zhongyouza Ⅰ ,one breed of oilseed rapes (Brassica junica) that can hyperaccumulate cadmium from the soil, can improve the living condition of less Cd-tolerant plant pai-tsai (Brassia chinensis) with their roots permitted to intermingle and develop coincident rhizosphere. The extent of rhizosphere interactions between ZhongyouzaⅠ and pai-tsai was controlled by different root barriers, or without barrier. The results show that in the 10 and 20 mg/kg Cd treated soils, pai-tsai gets higher shoot mass and less Cd accumulation in its shoot than in the barrier treatments or in the mono cultures, when its roots are permitted to intermingle with those of ZhongyouzaⅠ .Meanwhile, soil decontamination rates of ZhongyouzaⅠ are not affected much by co-cropping with pai-tsai, they are 80.0% and 91.8% of that in the mono cultures of ZhongyouzaⅠ, respectively. However, the co-cropping method in meliorating the living condition of pai-tsai is not obvious when Cd concentration in soil reaches 40 mg/kg, and soil decontamination rate decreases to 0.14, which is 58.3% of that in the mono culture. These results indicate that the oilseed rape ZhongyouzaⅠ may alleviate Cd toxicity of surrounding less-tolerant species, and its ability of phytoremediation is not affected much at the same time, especially in the middle polluted soil.
基金supported by the National Natural Science Foundation of China (40971261)the Special Fund for Argo-Scientific Reserch in the Public Interest,China (200903015).
文摘Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice grown after oilseed rape had significantly lower Cd and Pb concentrations in both straw and grains.Cd and Pb concentrations in the grains of the rice rotated with oilseed rape decreased by approximately 46-80% and 17-86%,respectively,although the Cd and Pb removal by oilseed rape ranged only from 2.39-3.67 and 0.032-0.13% of the total content in soil.Compost amendment also decreased the bioavailability of Cd and Pb in the soil and reduced Cd and Pb uptake by oilseed rapes and rice.The concentrations of Cd and Pb significantly decreased in the exchangeable and carbonate fractions and Pb concentration decreased in the organic matter and sulfide fractions in the contaminated soil after planting oilseed rapes.
文摘针对饲料油菜机械化收获中的切碎、抛送等关键环节离散元仿真缺乏准确模型的问题,以抽薹期饲料油菜茎秆为研究对象,利用EDEM仿真软件开展饲料油菜茎秆破碎离散元仿真模型参数标定研究。试验测定了饲料油菜本征参数,应用HertzMindlin基本模型进行饲料油菜茎秆颗粒堆积仿真试验,通过二水平因子试验、最陡爬坡试验和响应曲面试验,确定了饲料油菜茎秆颗粒碰撞恢复系数、静摩擦因数和滚动摩擦因数等基本接触参数。在此基础上,应用HertzMindlin with bonding接触模型进行饲料油菜茎秆弯曲破坏仿真试验,通过响应面分析确定了饲料油菜茎秆颗粒法向接触刚度、切向接触刚度、临界法向应力与临界切向应力等饲料油菜茎秆破碎离散元仿真模型的主要参数。以确定的参数进行堆积角仿真试验,结果表明,仿真结果与实测值相对误差为2.27%;不同直径油菜茎秆破碎仿真试验表明,仿真结果与实测值相对误差不大于4.21%,说明标定方法正确可行,标定参数准确可靠。
