检索结果-南通市图书馆

Improving maize grain yield by formulating plant growth regulator strategies in North China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第2期20卷 622-632页

作者： GONG Li-sha QU Shu-jie HUANG Guan-min guo yu-ling ZHANG Ming-cai LI Zhao-hu ZHOU yu-yi DUAN Liu-sheng Engineering Research Center of Plant Growth Regulator Ministry of Education/College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193P.R.China Experimental Base Service Center of Agricultural Sciences Jiyang 251400P.R.China

Plant growth regulators(PGRs) are artificially synthesized compounds that have become an important technical guarantee for agricultural production. EDAH(containing 27% ethephon and 3% DA-6) has been proven to inhibit stalk elongation, promote stalk bold and increase mechanical strength and number of vascular bundles. DA-6 could enhance plant photosynthetic capacity and promote cell division and growth. In our study, experiments were performed at summer maize growing season during 2018–2019. The result showed that plant height, ear height and center of gravity height of maize with EDAH+DA-6 treatment were decreased by 10.18, 16.77 and 13.21%, respectively;leaf area and leaf area index also significantly(P<0.001) decreased by 24.11 and 60.15%, respectively;the value of mean tilt angle significantly(P<0.001) increased by 16.72% compared with the control plants, which meant that EDAH+DA-6 could shape more compact plant type. Therefore, lodging rate of maize with EDAH+DA-6 treatment decreased by 6.95% compared with control plants, and the grain yield was increased by 15.51%. In addition, EDAH+DA-6 treatment significantly improved the quality of maize base stalks, such as improving mechanical properties, which increased maize base stalk crushing strength by 22.23%;increased the hemicellulose, cellulose and lignin contents by 6.93, 3.87 and 30.21%, respectively. In conclusion, EDAH+DA-6 treatment could improve summer maize yield by shaping plant morphological characteristics and group photosynthesis.

关键词： plant grown regulators canopy structure lodging resistance photosynthetic

在线全文

学校读者我要写书评

暂无评论

我国高校武术创新环境存在的问题与对策探讨

成都体育学院学报 2008年第12期34卷 86-88页

作者：郭凌宇山西大学体育学院山西太原030006

从我国高校武术创新环境的硬环境和软环境两个方面,对其存在的诸多问题做了较为详尽的分析:科技投入和资源共享环境是阻碍武术科研快速发展的硬环境,学术交流不够、武术创新团队建设不完善以及创新团队成员的素质不高是软环境中存在的... 详细信息

从我国高校武术创新环境的硬环境和软环境两个方面,对其存在的诸多问题做了较为详尽的分析:科技投入和资源共享环境是阻碍武术科研快速发展的硬环境,学术交流不够、武术创新团队建设不完善以及创新团队成员的素质不高是软环境中存在的主要问题。建议借鉴国外先进团队的建设经验组建我国高校武术创新团队,各高校要建立专门的武术科研机构,正确把握高校武术研究方向和内涵,做到教学与科研相结合,积极开展校内外的科研交流活动。

关键词：高校武术创新环境硬环境软环境对策

在线全文

学校读者我要写书评

暂无评论

中国人均预期寿命时空变化及影响因素分析

中国卫生政策研究 2018年第8期11卷 44-49页

作者：郭玉玲南京晓庄学院江苏南京211171

运用变异系数和灰色关联分析法,对中国人均预期寿命时空变化特征及影响因素的强度进行研究。结果表明:(1) 1981—2015年,我国人均预期寿命增长经历了慢—快—慢—快的四个阶段,预期寿命增长指数上升到113,其中男性上升到111,女性上升到1... 详细信息

运用变异系数和灰色关联分析法,对中国人均预期寿命时空变化特征及影响因素的强度进行研究。结果表明:(1) 1981—2015年,我国人均预期寿命增长经历了慢—快—慢—快的四个阶段,预期寿命增长指数上升到113,其中男性上升到111,女性上升到115,男女预期寿命差距逐步增大。(2) 1990—2010年,全国31个省份人均预期寿命变异系数从0. 051降低到0. 036,预期寿命水平较低省份的增长速度明显高于较高的省份。(3)我国人均预期寿命的地域分布大体上分为东南部高预期寿命水平区、中北部中预期寿命水平区、西南部低预期寿命水平区。2010年我国人均预期寿命水平绝大多数省份处于第二级(76～80岁)和第三级(71～75岁),相对于1990年提高了两级。到2020年,我国将有北京、天津和上海3市处于第一级寿命水平(81～85岁),其余为第二和第三级预期寿命水平。影响我国省际人均预期寿命时空差异的因素是多方面的,其中最主要的是各地区的经济发展、医疗服务和医疗保障水平。

关键词：人均预期寿命时空变化灰色关联分析中国

Research and application of absorbable screw in orthopedics： a clinical review comparing PDLLA screw with metal screw in patients with simple medial malleolus fracture

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Traumatology 2013年第1期16卷 27-30页

作者： TANG Jin HU Jin-feng guo Wei-chun yu ling ZHAO Sheng-hao Foxconn Clinic Renmin Hospital of Wuhan UniversityWuhan 430060 China

Objective： To observe the therapeutic effect of absorbable screw in medial malleolus fracture and discuss its clinical application in orthopedics. Methods： A total of 129 patients with simple medial malleolus fracture were studied. Among them, 64 patients were treated with poly-D, L-lactic acid （PDLLA） absorbable screws, while the others were treated with metal screws. All the patients were followed up for 12-20 months （averaged 18.4 months） and the therapeutic effect was evaluated according to the American Orthopaedic Foot and Ankle Society clinical rating systems. Results： In absorbable screw group, we obtained excel- lent and good results in 62 cases （96.88%）; in steel screw group, 61 cases （93.85%） achieved excellent and good results. There was no significant difference between the two groups. Conclusion： In the treatment of malleolus fracture, absorbable screw can achieve the same result compared with metal screw fixation. Absorbable screw is preferred due to its advantages of safety, cleanliness and avoiding the removal procedure associated with metallic implants.

关键词： Ankle Bone screws Fractures, bone

在线全文

学校读者我要写书评

暂无评论

应用高温快速熔炼工艺生产耐压锡青铜铸件

铸造技术 2006年第9期27卷 1020-1022页

作者：郭玉玲经纬纺织机械股份有限公司榆次分公司山西榆次030601

几年来,我们在生产中对液压泵的配油盘锡青铜铸件进行了试验. 铸件的材质牌号为日本标准BC7,其化学成分及力学性能要求如表1.铸件为圆盘状(172 mm×15 mm),重3.1 kg.铸件表面全部经机械加工,其中有一个平面需加工出2 mm深的沟槽.铸件承... 详细信息

几年来,我们在生产中对液压泵的配油盘锡青铜铸件进行了试验. 铸件的材质牌号为日本标准BC7,其化学成分及力学性能要求如表1.铸件为圆盘状(172 mm×15 mm),重3.1 kg.铸件表面全部经机械加工,其中有一个平面需加工出2 mm深的沟槽.铸件承受液体工作压力70 MPa,因而对合金的致密性要求比较高.提高配油盘锡青铜铸件的耐液压性能,避免产生渗漏成为生产中的关键.

关键词：锡青铜铸件生产熔炼工艺耐压高温应用机械加工耐液压性能

Conformational Analysis of Erythromycin A Oxime and Its 9-（O-t-Butyldimethylsilyl） Derivatives

在线全文

学校读者我要写书评

暂无评论

Conformational Analysis of Erythromycin A Oxime and Its 9-（...

Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels

中国化学会第四届有机化学学术会议

作者： SUN, Jing-guo FENG, yu-ling (College of Chemistry, Hebei Normal University, Shijiazhuang 050091)

＜正＞Recently, various chemical modifications of natural macrolide antibiotics have been made to develop synthetic novel macrolide antibiotics. The C-9 carbonyl group of erythromycin A has been the focus of considerable chemical modification. 9-Oxime and 9-（O-t-butyldimethylsilyl） erythromycin A derivatives is important intermediates of the second generation of erythromycin. When C-9 carbonyl was converted to 9-oxime, the （9E）-isomer and （9Z）-isomer of erythromycin A oxime were formed in different ratio which have a influence for further chemical modification. We have prepared the title compounds and isolated their Z,E isomers, which identified by MS and H

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 380-390页

作者： Yishuang yu Jingxiao Zhao Xuelin Wang Hui guo Zhenjia Xie Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic *** results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without ***,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to *** improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant ***,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant *** findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels.

关键词： high-strength steel cobalt transformation kinetics crystallography impact toughness

基于ZigBee技术的无线自动滴灌系统设计

在线全文

学校读者我要写书评

暂无评论

节水灌溉 2011年第2期 66-68,72页

作者：郭毓灵宁芊四川大学电子信息学院四川成都610065

ZigBee是近期大量研究与应用的一种短距离无线传输技术,在介绍该技术特点基础上,研究其在农田自动滴灌系统中的应用。采用网状拓扑结构、CC2430和CC2591芯片、水压传感器和电磁阀,设计了一种基于ZigBee技术包含土壤湿度监控的自动滴灌... 详细信息

ZigBee是近期大量研究与应用的一种短距离无线传输技术,在介绍该技术特点基础上,研究其在农田自动滴灌系统中的应用。采用网状拓扑结构、CC2430和CC2591芯片、水压传感器和电磁阀,设计了一种基于ZigBee技术包含土壤湿度监控的自动滴灌系统。该系统监控土壤湿度变化,通过无线传输网络反馈传感信号,结合传感器融合技术对滴灌动作进行精确控制和判断。通过相关实验结果表明,ZigBee技术是实现无线自动滴灌系统的一种理想解决方案。

关键词：自动滴灌 ZigBee 无线传感网络网状拓扑

运用均衡凝固模数法设计液压试验平台铸铁件压边浇冒口系统

在线全文

学校读者我要写书评

暂无评论

铸造技术 2006年第7期27卷 659-661页

作者：连炜白继昌郭玉玲郭秀楼魏兵西安工业大学机电工程学院陕西西安710032 太原铁建晋中鑫合铸造有限公司山西晋中030600 经纬纺织机械股份有限公司榆次分公司山西晋中030600 西安理工大学材料学院陕西西安710048

液压试验平台,材质HT200,铸件重2 800 kg,轮廓尺寸2 400 mm×1 000 mm×275 mm,平板壁厚95 mm,肋条壁厚40 mm,周边框壁厚50 mm,粘土砂,干型。选用直浇道-横浇道-压边冒口系统,运用均衡凝固收缩模数法设计压边冒口体和冒口颈尺寸,运用大... 详细信息

液压试验平台,材质HT200,铸件重2 800 kg,轮廓尺寸2 400 mm×1 000 mm×275 mm,平板壁厚95 mm,肋条壁厚40 mm,周边框壁厚50 mm,粘土砂,干型。选用直浇道-横浇道-压边冒口系统,运用均衡凝固收缩模数法设计压边冒口体和冒口颈尺寸,运用大孔出流理论计算压边冒口金属液充满高度。计算结果:直浇道φ75 mm,横浇道45/65 mm×70 mm,压边冒口体φ104 mm,高度200 mm,冒口颈尺寸104 mm×8 mm,冒口体浇注过程充满高度80 mm,具有挡渣能力。生产结果表明,铸件无缩孔、气孔、夹渣缺陷,铸件工艺出品率95%。实践证明采用均衡凝固收缩模数法设计液压试验平台浇冒口系统是可行的。

关键词：铸铁件均衡凝固浇注与补缩模数法