No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working d...No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.展开更多
重点知识园地重点单词1.mess n.杂乱;不整洁"What a mess!" she said after the party.聚会后她说:"真是一片狼藉!"短语(1)in a mess混乱;凌乱The room was in a mess.这个房间杂乱不堪。(2)make a mess弄脏;搞成...重点知识园地重点单词1.mess n.杂乱;不整洁"What a mess!" she said after the party.聚会后她说:"真是一片狼藉!"短语(1)in a mess混乱;凌乱The room was in a mess.这个房间杂乱不堪。(2)make a mess弄脏;搞成一团糟The kids made a mess in the living room.孩子们把客厅搞得一塌糊涂。展开更多
重点词汇1.fold v.折叠;对折Fold the card.折叠这张卡片。拓展unfold v.展开2.mess n.杂乱;不整洁The room was in a mess.这个房间杂乱不堪。'What a mess.'she said after the party.聚会后她说:'真是一片狼藉.'拓展...重点词汇1.fold v.折叠;对折Fold the card.折叠这张卡片。拓展unfold v.展开2.mess n.杂乱;不整洁The room was in a mess.这个房间杂乱不堪。'What a mess.'she said after the party.聚会后她说:'真是一片狼藉.'拓展in a mess混乱;凌乱make a mess弄脏;搞成一团糟The kids made a mess in the living room.孩子们把客厅搞得一塌糊涂。3.throw v.(threw)扔;掷Throw me the car keys.=Throw the car keys to me.把车钥匙扔给我。She threw her coat on the bed.她把外套扔在了床上。展开更多
重点知识园地重点单词1.cheer v.欢呼;喝彩cheer up (使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌只是为了给自己打气。拓展cheern.欢呼声;喝彩声2.volunteerv.义务做;自愿做n.志愿者volunteer to do ...重点知识园地重点单词1.cheer v.欢呼;喝彩cheer up (使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌只是为了给自己打气。拓展cheern.欢呼声;喝彩声2.volunteerv.义务做;自愿做n.志愿者volunteer to do sth自愿做某事Jack volunteered to carry water.杰克自愿去运水。展开更多
重点词汇1.cheerv.欢呼;喝彩cheer up(使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌是给我自己打气的。拓展cheer n.欢呼声;喝彩声2.volunteer v.义务做;自愿做n.志愿者volunteer to do sth自愿做某事J...重点词汇1.cheerv.欢呼;喝彩cheer up(使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌是给我自己打气的。拓展cheer n.欢呼声;喝彩声2.volunteer v.义务做;自愿做n.志愿者volunteer to do sth自愿做某事Jack volunteered to carry water.杰克自愿去运水。I need one volunteer.我需要一名志愿者。3.notice n.通知;通告;注意v.注意到;展开更多
基金supported by National Key Research and Development Program of China(Grant No.2023YFD1500404)Jilin Science and Technology Development Plan(Grant No.20220508113RC).
文摘No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.
文摘重点知识园地重点单词1.mess n.杂乱;不整洁"What a mess!" she said after the party.聚会后她说:"真是一片狼藉!"短语(1)in a mess混乱;凌乱The room was in a mess.这个房间杂乱不堪。(2)make a mess弄脏;搞成一团糟The kids made a mess in the living room.孩子们把客厅搞得一塌糊涂。
文摘重点词汇1.fold v.折叠;对折Fold the card.折叠这张卡片。拓展unfold v.展开2.mess n.杂乱;不整洁The room was in a mess.这个房间杂乱不堪。'What a mess.'she said after the party.聚会后她说:'真是一片狼藉.'拓展in a mess混乱;凌乱make a mess弄脏;搞成一团糟The kids made a mess in the living room.孩子们把客厅搞得一塌糊涂。3.throw v.(threw)扔;掷Throw me the car keys.=Throw the car keys to me.把车钥匙扔给我。She threw her coat on the bed.她把外套扔在了床上。
文摘重点知识园地重点单词1.cheer v.欢呼;喝彩cheer up (使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌只是为了给自己打气。拓展cheern.欢呼声;喝彩声2.volunteerv.义务做;自愿做n.志愿者volunteer to do sth自愿做某事Jack volunteered to carry water.杰克自愿去运水。
文摘重点词汇1.cheerv.欢呼;喝彩cheer up(使)变得更高兴;振奋起来I wrote that song just to cheer myself up.我写那首歌是给我自己打气的。拓展cheer n.欢呼声;喝彩声2.volunteer v.义务做;自愿做n.志愿者volunteer to do sth自愿做某事Jack volunteered to carry water.杰克自愿去运水。I need one volunteer.我需要一名志愿者。3.notice n.通知;通告;注意v.注意到;
