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基于Rosin-Rammler的离散元扩大头抗浮锚杆抗拔力学特性影响研究
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作者 杨靖 《工程技术研究》 2024年第5期4-7,共4页
目前,抗浮锚固技术已被广泛应用于工程建设中。然而,学界对扩大头抗浮锚杆与不同级配土体相互作用的力学机制的研究尚不充分。因此,文章针对扩大头抗浮锚杆与土体级配的相互作用展开了研究。首先通过Rosin-Rammler函数构建级配曲线,并... 目前,抗浮锚固技术已被广泛应用于工程建设中。然而,学界对扩大头抗浮锚杆与不同级配土体相互作用的力学机制的研究尚不充分。因此,文章针对扩大头抗浮锚杆与土体级配的相互作用展开了研究。首先通过Rosin-Rammler函数构建级配曲线,并以曲线形状参数m值表征土体颗粒的不均匀性,然后进行拉拔数值模拟。结果表明,在拉拔过程中,m值越大,土体颗粒越不均匀,并且拉拔承载力随着m值的增大而减小。同时,速度传递区域由类锥形转为类矩形分布,接触力链由粗支网状转为细支网状。 展开更多
关键词 抗浮锚杆 rosin-Rammler函数 力学特性 离散元法
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Synthesis and Properties of Rosin-Based Composite Acrylamide Hydrogels
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作者 Shuangsheng Zhang Bin Sun +3 位作者 Siyu Li Xiangyu Lin Muhua Chen Xu Xu 《Journal of Renewable Materials》 SCIE EI 2023年第2期853-865,共13页
Hydrogels have been widely applied in agricultural drought-resistance,pollution regulation,drug delivery and so on.Acrylamide(AM)is usually used as raw material to synthesize acrylamide hydrogels.However,inherently lo... Hydrogels have been widely applied in agricultural drought-resistance,pollution regulation,drug delivery and so on.Acrylamide(AM)is usually used as raw material to synthesize acrylamide hydrogels.However,inherently low mechanical strength greatly limits their applications in some special areas.Therefore,it is necessary to choose suitable functional monomers to optimize acrylamide hydrogels and improve their mechanical performances.In this paper,a novel acrylamide monomer modified by rosin was synthesized,and then polyacrylamide/rosinbased acrylamide(RAM)composite hydrogels were prepared via free radical polymerization using potassium persulfate as initiator,N,N′-methylene-bisacrylamide(MBA)as a crosslinker.The influence of RAM monomer was investigated in detail.The chemical structure,pore structure,swelling properties,thermal performances and mechanical properties of composite hydrogels were characterized by Fourier Transform Infrared spectrometer(FT-IR),thermogravimetric analysis(TG),scanning electron microscope(SEM),and universal testing,respectively.The results showed that the thermal stability and mechanical property of RAM hydrogels were improved significantly.The compressive strength of RAM hydrogels was increased to 3.5 times than that of AM hydrogels,and the tensile strength was 5.1 times compared with AM hydrogels as well.Moreover,RAM hydrogels exhibited a faster initial swelling rate due to the new pore structure formed after introducing the RAM monomer. 展开更多
关键词 HYDROGEL rosin swelling property mechanical property thermal stability
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Characteristics and High-yield Cultivation Techniques of the Main Potato Variety Jinshu 16 in Shanxi Province
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作者 Yun CHEN Xiaodong BAI +2 位作者 Yao LU Xiangbin FAN Peibing DU 《Plant Diseases and Pests》 CAS 2023年第3期14-15,18,共3页
With NL94014 as the female parent and 9333-11 as the male parent,the potato research laboratory of High Latitude Crops Institute,Shanxi Academy of Agricultural Sciences obtained true seeds through sexual hybridization... With NL94014 as the female parent and 9333-11 as the male parent,the potato research laboratory of High Latitude Crops Institute,Shanxi Academy of Agricultural Sciences obtained true seeds through sexual hybridization,and systematically and directionally bred a new potato variety Jinshu 16 with high yield,good comprehensive resistance and middle and late maturity.This variety has been listed as one of the mainstay varieties in Shanxi Province for many times.In this paper,the characteristics and high-yield cultivation techniques of Jinshu 16 are introduced,in order to guide field production and get better returns. 展开更多
关键词 POTATO Jinshu 16 CHARACTERISTICS high-yield cultivation techniques
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Selection of Greenhouse Zucchini Varieties and High-Quality,High-Yield and High-Efficiency Cultivation Techniques
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作者 Haijuan ZHANG Guanghui FENG +3 位作者 Lifeng YANG Bo GENG Xiangying HOU Dongwen SUN 《Asian Agricultural Research》 2023年第6期38-40,共3页
[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were... [Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated. 展开更多
关键词 ZUCCHINI VARIETY HIGH-QUALITY high-yield and high-efficiency Cultivation techniques
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紫外分光光度法测定歧化松香中去氢枞酸含量的干扰因素研究
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作者 王宏晓 沈娟章 +1 位作者 马艳 谭卫红 《林产化学与工业》 CAS CSCD 北大核心 2024年第3期30-36,共7页
利用液相色谱仪、制备液相色谱仪、气相色谱质谱联用仪,对歧化松香(DR)中去氢枞酸(DA)紫外光谱测定方法的干扰因素进行了详细研究。测定的市售不同省份的5个样品中有2个主要干扰物质,进一步定性,确定干扰物质1为6,8,11,13-枞四烯酸(ATA)... 利用液相色谱仪、制备液相色谱仪、气相色谱质谱联用仪,对歧化松香(DR)中去氢枞酸(DA)紫外光谱测定方法的干扰因素进行了详细研究。测定的市售不同省份的5个样品中有2个主要干扰物质,进一步定性,确定干扰物质1为6,8,11,13-枞四烯酸(ATA),干扰物质2为混合物,主要检出物为去氢枞醛(D)和枞酸(AA)。采用二阶导数光谱法和偏最小二乘(PLS)法对紫外光谱数据进行分析,以消除去氢枞酸紫外分光光度法的干扰,结果表明:PLS法比二阶导数光谱法误差更小,能够同时消除多种干扰因素,使测试结果更加接近真实值。 展开更多
关键词 歧化松香 紫外可见分光光度法 干扰因素 偏最小二乘法
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马来海松基环氧树脂的制备与性能研究
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作者 刘贺晨 葛琦 +4 位作者 吴璇 孙章林 黎馨阳 周松松 刘云鹏 《绝缘材料》 CAS 北大核心 2024年第5期34-41,共8页
在“双碳”发展战略目标的背景下,为探索绿色环保型生物基环氧树脂在电工设备上的应用前景,本文以可再生资源松香为原料,制备了一种生物基树脂——马来海松基环氧树脂(MPAER)。以甲基六氢邻苯二甲酸酐(MHHPA)为固化剂,对MPAER/MHHPA体... 在“双碳”发展战略目标的背景下,为探索绿色环保型生物基环氧树脂在电工设备上的应用前景,本文以可再生资源松香为原料,制备了一种生物基树脂——马来海松基环氧树脂(MPAER)。以甲基六氢邻苯二甲酸酐(MHHPA)为固化剂,对MPAER/MHHPA体系的固化特性、热性能、力学性能和电气性能进行了系统研究,并和商用双酚A二缩水甘油醚(DGEBA)组成的DGEBA/MHHPA体系进行对比。结果表明:MPAER/MHHPA和DGEBA/MHHPA体系的固化反应活性相当,MPAER/MHHPA体系的玻璃化转变温度为112.8℃,其力学性能和电气性能均稍弱于DGEBA/MHHPA体系,其中MPAER/MHHPA体系的电气强度比DGEBA/MHHPA体系低9.4%。但MPAER/MHHPA体系的综合性能仍较好,可以通过对MPAER进行结构优化或者与其他类型的环氧树脂共混来进一步提高其性能。 展开更多
关键词 松香基环氧树脂 环保 电工设备 双酚A环氧树脂
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两种添加剂对石蜡-硬脂酸蜡料性能的影响
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作者 尤畅 程姣姣 +3 位作者 史昆 刘田雨 刘泊良 李欣 《材料导报》 EI CAS CSCD 北大核心 2024年第S01期558-563,共6页
为探究改性松香和聚乙烯对中温模料组织性能的影响,本研究以石蜡-硬脂酸二元系模料为基体,在此基础上逐步添加改性松香和聚乙烯,探究二元基体配比、改性松香及聚乙烯含量对模料熔点、抗弯强度、针入度和融合均匀性等物理特性的影响,在... 为探究改性松香和聚乙烯对中温模料组织性能的影响,本研究以石蜡-硬脂酸二元系模料为基体,在此基础上逐步添加改性松香和聚乙烯,探究二元基体配比、改性松香及聚乙烯含量对模料熔点、抗弯强度、针入度和融合均匀性等物理特性的影响,在此基础上研制出一种针入度达1.06 mm、强度达6.02 MPa、熔点在58℃附近的综合性能良好的中温模料,为中温模料改良优化提供理论支持。 展开更多
关键词 熔模铸造 硬脂酸 改性松香 中温蜡料
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Effect of N Fertilization on Yield, N Absorption and Utilization of Two Species of Super High-Yielding Summer Maize 被引量:6
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作者 王宜伦 刘天学 +2 位作者 谭金芳 张许 李潮海 《Agricultural Science & Technology》 CAS 2012年第2期339-342,374,共5页
[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilizati... [Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization. 展开更多
关键词 Super high-yielding Summer maize CULTIVAR N-FERTILIZER YIELD Accumulation of N N efficiency
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运用Rosin-Rammler分布函数研究煤尘粒径分布规律 被引量:46
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作者 郑钢镖 康天合 +1 位作者 柴肇云 尹志宏 《太原理工大学学报》 CAS 北大核心 2006年第3期317-319,共3页
运用Rosin-Rammler分布函数对伯方煤矿3#煤层煤样进行粒径分布情况的分析,得出结论:在双对数lnd-ln{-ln[1-F(d)]}坐标系下,所研究的材料颗粒分布的回归曲线为一条直线,R2=0.9672,线性回归良好。并得到了所研究粒径分布的具体函数表达式... 运用Rosin-Rammler分布函数对伯方煤矿3#煤层煤样进行粒径分布情况的分析,得出结论:在双对数lnd-ln{-ln[1-F(d)]}坐标系下,所研究的材料颗粒分布的回归曲线为一条直线,R2=0.9672,线性回归良好。并得到了所研究粒径分布的具体函数表达式。由此可以对该煤层的冲击产尘的粒径分布有一个总体上的量化认识,为指导实际生产降尘、除尘提供了理论上的依据。 展开更多
关键词 rosin-Rammler函数 粒径分布
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马来海松酸十八酰胺双羧酸钠表面活性剂的制备及其自组装性能研究
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作者 张文静 孙兴燊 +3 位作者 翟兆兰 王丹 商士斌 宋湛谦 《林产化学与工业》 CAS CSCD 北大核心 2024年第4期51-60,共10页
以松香为原料经D-A加成、酰胺化和酸碱中和反应,合成了马来海松酸十八酰胺双羧酸钠(C_(18)MPA2Na),并利用FT-IR、^(1)H NMR、质谱确证了结构。采用表面张力法和尼罗红(NR)荧光探针法研究了C_(18)MPA2Na的表面活性,其临界胶束浓度(cmc)为... 以松香为原料经D-A加成、酰胺化和酸碱中和反应,合成了马来海松酸十八酰胺双羧酸钠(C_(18)MPA2Na),并利用FT-IR、^(1)H NMR、质谱确证了结构。采用表面张力法和尼罗红(NR)荧光探针法研究了C_(18)MPA2Na的表面活性,其临界胶束浓度(cmc)为0.29 mmol/L,达到cmc时的表面张力值(γcmc)为41.11 mN/m,具有良好的表面活性。将C_(18)MPA2Na与十六烷基三甲基溴化铵(CTAB)复配,成功制备了一类黏弹溶液,采用原位冷冻电镜(Cryo-TEM)和流变性能测试研究了复配体系的微观结构和流变行为,结果表明黏弹溶液的聚集体为蠕虫胶束。固定复配体系中CTAB的浓度为80 mmol/L,零剪切黏度(η0)随C_(18)MPA2Na浓度的增加先增加后降低,C_(18)MPA2Na为15 mmol/L时,η0最大值为5.67×10^(4)mPa·s;固定复配体系中C_(18)MPA2Na与CTAB的比例(3∶16),η0随复配体系中C_(18)MPA2Na和CTAB总浓度的增加,表现出先快速升高后趋于平稳的趋势,η0与浓度的幂指数值为11.7;当C_(18)MPA2Na为15 mmol/L,CTAB浓度为80 mmol/L时,随着pH值的降低,η0先增加后降低,且在pH值为7.13时η0值最大,为7.67×10^(4)mPa·s。该研究表明松香的刚性骨架能够促进表面活性剂自组装。 展开更多
关键词 松香 表面活性剂 黏弹溶液 蠕虫状胶束
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含松香的聚氨酯载药微球的制备及性能
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作者 严成飞 张发爱 +1 位作者 邵金涛 余彩莉 《桂林理工大学学报》 CAS 北大核心 2024年第1期155-161,共7页
采用预聚—扩链—中和法合成松香基聚氨酯(RPU),以其为载体,以5-氟尿嘧啶(5-Fu)为模型药物,通过悬浮聚合法制备了负载5-Fu的松香基聚氨酯微球(5-Fu/RPUMs)。采用单因素实验优化了药物负载条件,通过红外光谱、X射线光电子能谱、扫描电子... 采用预聚—扩链—中和法合成松香基聚氨酯(RPU),以其为载体,以5-氟尿嘧啶(5-Fu)为模型药物,通过悬浮聚合法制备了负载5-Fu的松香基聚氨酯微球(5-Fu/RPUMs)。采用单因素实验优化了药物负载条件,通过红外光谱、X射线光电子能谱、扫描电子显微镜、能谱分析等对载药微球进行表征,研究了载药微球的体外释放性能及药物释放动力学模型。结果表明:成功制备了5-Fu/RPUMs微球,平均粒径为35.0μm,表面光滑圆整且有孔。药物最佳负载条件为:ρ_(5-Fu)=120 mg/mL,致孔剂种类为正丁醇/甲苯,此条件下RPU对5-Fu的包封率达63.35%,载药量达7.60%。5-Fu/RPUMs在不同pH下表现出不同的缓释性能,具有pH敏感性;在pH=6.8的PBS缓冲溶液中,264 h后的累积释放率为65.80%,具有长效的缓释作用。 展开更多
关键词 松香 聚氨酯微球 载药 释放
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Effects of Ratio of Row Spacing to Intrarow Spacing on Yield and Top Three Leaves of Super High-yielding Early and Late Rice 被引量:2
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作者 林洪鑫 彭春瑞 +5 位作者 雷享亮 袁展汽 肖运萍 刘仁根 胡启锋 张结刚 《Agricultural Science & Technology》 CAS 2014年第1期52-56,101,共6页
Using a split plot design, super high-yielding early rice &quot;Zhongjiazao 17&quot;and &quot;Ganxin 203&quot; and super high-yielding late rice &quot;Ganxin 688&quot; and &quot;Wufengy-ouT025&quot; were taken... Using a split plot design, super high-yielding early rice &quot;Zhongjiazao 17&quot;and &quot;Ganxin 203&quot; and super high-yielding late rice &quot;Ganxin 688&quot; and &quot;Wufengy-ouT025&quot; were taken as materials with planting density the same at 312 000 hil s/hm2, to explore the effects of RS/IS (Ratio of row spacing to intrarow row spacing) on yield, top three leaves morphological features and its relationship of them in 2011 and 2012. The results showed that, whether early or late rice, biomass, accumula-tion and apparent utilizing rate of nitrogen were lower in RS/IS5.0 (40.0 cm &#215;8.0 cm) treatment, but yield of rice was higher in RS/IS2.0 (25.0 cm &#215;12.8 cm) treatment;grain numbers per spike of rice was more in RS/IS2.8 (30.0 cm&#215;10.7 cm) treatment, and thousand-grain weight of rice was higher in RS/IS1.3 (20.0 cm&#215;16.0 cm) treat-ment. For 4 varieties of early or late rice aforementioned, basal angle, opening an-gle and leaf area of 2nd leaf from top were larger in RS/IS5.0 treatment, and basal angle and opening angle were smal er in RS/IS2.0 treatment and leaf area smal er in RS/IS1.3 treatment. 展开更多
关键词 Super high-yielding early and late rice Ratio of row spacing to intrarowspacing Top three leaves Leaf morphology
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熔融石英陶瓷材料介电性能影响因素分析
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作者 崔唐茵 王鹏 +3 位作者 刘瑞祥 王洪升 曹俊倡 陈东杰 《硅酸盐通报》 CAS 北大核心 2024年第2期666-672,共7页
采用凝胶注模成型工艺制备熔融石英陶瓷,通过XRD、SEM和电性能网络分析仪对陶瓷样品的晶体结构、微观形貌、介电性能进行分析,研究了熔融石英陶瓷介电性能的影响因素,为筛选制备石英陶瓷材料最优工艺方案提供依据。研究结果表明:材料制... 采用凝胶注模成型工艺制备熔融石英陶瓷,通过XRD、SEM和电性能网络分析仪对陶瓷样品的晶体结构、微观形貌、介电性能进行分析,研究了熔融石英陶瓷介电性能的影响因素,为筛选制备石英陶瓷材料最优工艺方案提供依据。研究结果表明:材料制备工艺一定时,制备不同厚度的石英陶瓷板,平铺烧结,同一块方板沿垂直方向自上而下,密度逐渐下降,密度与介电常数呈正相关,密度每上升0.01 g/cm^(3),介电常数对应上升0.01~0.02,密度对损耗角正切数值影响不大;同一块板同样厚度位置,边角与中间位置的密度几乎没有变化;同一块板,同样厚度方向,介电常数变化不大;石英陶瓷板中引入松香导致试样更致密,密度升高,介电常数随之增大;相同密度的试样,采用不同的介电测试方式计算所得的介电常数有约0.03的偏差。 展开更多
关键词 熔融石英陶瓷 凝胶注模成型 坯板厚度 坯板密度 松香 介电性能
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用双 Rosin-Rammler 函数求颗粒尺寸分布 被引量:5
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作者 刘铁英 范利民 郑刚 《上海理工大学学报》 CAS 1998年第2期135-138,共4页
用双Rosin-Rammler分布函数不但可以求解具有双峰形式的颗粒尺寸分布,而且也可以求解具有单峰形式的实际颗粒系.模拟计算和实测表明,即便是求解单峰分布的颗粒尺寸,用双Rosin-Rammler分布函数也明显比常... 用双Rosin-Rammler分布函数不但可以求解具有双峰形式的颗粒尺寸分布,而且也可以求解具有单峰形式的实际颗粒系.模拟计算和实测表明,即便是求解单峰分布的颗粒尺寸,用双Rosin-Rammler分布函数也明显比常用的单Rosin-Rammler函数具有更高的反演算精度. 展开更多
关键词 颗粒尺寸 双R-R分布 算法 光散射测粒
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Brønsted-Lewis双酸性低共熔溶剂催化松香聚合反应
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作者 于亚莉 于凤丽 《青岛科技大学学报(自然科学版)》 CAS 2024年第1期42-48,共7页
合成了一系列Brønsted-Lewis双酸性低共熔溶剂(DESs),并将其用于催化松香聚合反应。筛选出催化活性最高的催化剂ZnCl_(2)/2CH_(3)COOH,同时考察了不同DES物质的量比的组成,DES催化剂的用量、反应温度和反应时间对松香聚合反应的影... 合成了一系列Brønsted-Lewis双酸性低共熔溶剂(DESs),并将其用于催化松香聚合反应。筛选出催化活性最高的催化剂ZnCl_(2)/2CH_(3)COOH,同时考察了不同DES物质的量比的组成,DES催化剂的用量、反应温度和反应时间对松香聚合反应的影响。最佳反应条件:松香15 g,甲苯5.6 mL,正辛烷12.4 mL,低共熔溶剂5 g,反应温度110℃,反应时间10 h。在最佳反应条件下,聚合松香的软化点为139.4℃。EDS与反应物分离后可以重复使用,经过5次循环使用后催化剂活性未见明显的下降。 展开更多
关键词 低共熔溶剂 松香 聚合松香 LEWIS酸 Brønsted酸
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聚合松香辅助制备聚丙烯熔喷纤维膜及耐久超疏水改性
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作者 王文刚 钱裕洁 +3 位作者 皮秋月 王艳红 侯秀良 徐荷澜 《化工进展》 EI CAS CSCD 北大核心 2024年第9期5123-5132,共10页
超疏水材料因其卓越的防腐蚀、防覆冰和自清洁等性能,在日用纺织、生物医学和建筑涂料等领域具有巨大的发展前景。为了满足实际应用的需求,开发低成本的超疏水表面结构显得尤为重要。本文采用聚合松香(PR)作为辅助材料与聚丙烯(PP)进行... 超疏水材料因其卓越的防腐蚀、防覆冰和自清洁等性能,在日用纺织、生物医学和建筑涂料等领域具有巨大的发展前景。为了满足实际应用的需求,开发低成本的超疏水表面结构显得尤为重要。本文采用聚合松香(PR)作为辅助材料与聚丙烯(PP)进行熔喷纺丝,然后去除PR组分,得到多孔纤维膜,并进行十八烷基三氯硅烷改性,获得具有耐久性的超疏水材料。结果表明,PR的辅助加入可以诱导纤维变细、增加纤维膜的孔隙率,制备出的7PP/3PR纤维膜比10PP/0PR纤维膜的接触角提高了20°左右,疏水物质溶液的均匀分散增加了纤维膜的耐磨损和自清洁性能。7PP/3PR纤维膜的超疏水材料性能最佳,接触角为159.8°,历经5次摩擦循环后的接触角仍有152.6°,保留率在95.27%,而10PP/0PR纤维膜的超疏水材料的接触角保留率仅在87.46%。 展开更多
关键词 聚丙烯 聚合松香 纤维膜 超疏水
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Structure Parameters and Physiological Indices Research of High-quality and High-yield Apple Orchards 被引量:1
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作者 薛晓敏 王翠玲 +2 位作者 王金政 孟海凤 聂佩显 《Agricultural Science & Technology》 CAS 2014年第11期1953-1956,1959,共5页
In order to research environment parameters and physiological indices of high-quality and high-yield apple trees, two orchards with young and mature apples trees were investigated to explore structural parameter of ap... In order to research environment parameters and physiological indices of high-quality and high-yield apple trees, two orchards with young and mature apples trees were investigated to explore structural parameter of apple tree and community, and some physiological indices in fields and by room measurements. The results showed that tree height of high-quality orchard was in the range of 260 to 290 cm, branch angle in 70°-75°, and orchard coverage rate in 75%-94%, and the connec-tion rates between rows and trees were lower. Furthermore, the total branches of mature orchard reached 1.04 ×106 per hm2, while the young orchard was 8.79 ×105 per hm2; the leaves were thick and chlorophyl content was high, with SPAD value at 58.22. Additional y, the photosynthesis of the orchard was strong, and net photo-synthetic rate was 17.48-21.8 μmolCO2/(m2·s). The proportions of lateral shoot of bearing part were 81% and 75% respectively. 展开更多
关键词 High-quality and high-yield Apple orchard Structure parameters Physio-logical index
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聚合松香增容聚乳酸/聚(己二酸丁二醇酯-对苯二甲酸丁二醇酯)共聚物共混纤维的结构与性能
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作者 钱裕洁 王文刚 +4 位作者 皮秋月 王艳红 侯秀良 徐荷澜 刘鹏 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第7期52-62,共11页
以聚合松香(PR)为相容剂,采用熔融共混法制备了不同比例的聚乳酸/聚(己二酸丁二醇酯-对苯二甲酸丁二醇酯)(PLA/PBAT)共混纤维。采用拉伸试验、微观结构、热分析和流变测试分析评估了熔体和纤维的物化性能。PR的引入使得PBAT和PLA的玻璃... 以聚合松香(PR)为相容剂,采用熔融共混法制备了不同比例的聚乳酸/聚(己二酸丁二醇酯-对苯二甲酸丁二醇酯)(PLA/PBAT)共混纤维。采用拉伸试验、微观结构、热分析和流变测试分析评估了熔体和纤维的物化性能。PR的引入使得PBAT和PLA的玻璃化转变温度及熔融温度降低,促进了PBAT相的均匀分散,分散相尺寸明显减小,增强了PBAT的非均相成核效应,提高了PLA的结晶温度,并在30%PR时观测到了直径小于2μm的微纤结构。随着PBAT含量的增加,共混纤维的断裂伸长率与断裂强度均得到显著提升,断裂伸长率最多提高了近600%,同时断裂强度不仅得到了保留,还提升了200%左右。 展开更多
关键词 聚乳酸 聚(己二酸丁二醇酯-对苯二甲酸丁二醇酯) 聚合松香 增容 共混纤维
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Artificial selection of the Green Revolution gene Semidwarf 1 is implicated in upland rice breeding
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作者 Shuliang Jiao Qinyan Li +6 位作者 Fan Zhang Yonghong Tao Yingzhen Yu Fan Yao Qingmao Li Fengyi Hu Liyu Huang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期769-780,共12页
Semidwarf breeding has boosted crop production and is a well-known outcome from the first Green Revolution. The Green Revolution gene Semidwarf 1(SD1), which modulates gibberellic acid(GA) biosynthesis, plays a princi... Semidwarf breeding has boosted crop production and is a well-known outcome from the first Green Revolution. The Green Revolution gene Semidwarf 1(SD1), which modulates gibberellic acid(GA) biosynthesis, plays a principal role in determining rice plant height. Mutations in SD1 reduce rice plant height and promote lodging resistance and fertilizer tolerance to increase grain production. The plant height mediated by SD1 also favors grain yield under certain conditions. However, it is not yet known whether the function of SD1 in upland rice promotes adaptation and grain production. In this study, the plant height and grain yield of irrigated and upland rice were comparatively analyzed under paddy and dryland conditions. In response to dryland environments, rice requires a reduction in plant height to cope with water deficits. Upland rice accessions had greater plant heights than their irrigated counterparts under both paddy and dryland conditions, and appropriately reducing plant height could improve adaptability to dryland environments and maintain high grain yield formation. Moreover, upland rice cultivars with thicker stem diameters had stronger lodging resistance, which addresses the lodging problem. Knockout of SD1 in the upland rice cultivar IRAT104 reduced the plant height and grain yield, demonstrating that the adjustment of plant height mediated by SD1 could increase grain production in dryland fields. In addition, an SD1 genetic diversity analysis verified that haplotype variation causes phenotypic variation in plant height. During the breeding history of rice, SD1 allelic mutations were selected from landraces to improve the grain yield of irrigated rice cultivars, and this selection was accompanied by a reduction in plant height. Thus, five known mutant alleles were analyzed to verify that functional SD1 is required for upland rice production. All these results suggest that SD1 might have undergone artificial positive selection in upland rice, which provides further insights concerning greater plant height in upland rice breeding. 展开更多
关键词 Green Revolution Semidwarf 1 high-yield breeding upland rice plant height
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Simplified High-yielding Cultivation Technology of Rice
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作者 王云华 周红萍 +3 位作者 潘涛芬 梅贵华 闻高能 黄吉美 《Agricultural Science & Technology》 CAS 2016年第9期2048-2050,共3页
[Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rot... [Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rotary tillage and deep ploughing, mechanical transplanting and hand transplanting, controlled-release fertilizer and quantitative fertilization in order to investigate effects of different treatment groups on rice characteristics, economic characteristics, as well as labor saving, yield increasing and profit improving. [Result] Rice increased by 596.4-809.55 kg/hm2, labor saving reached 120-135 per hm2, and profit improved in the range from 5 521.39 to 8 727.48 yuan/hm2 in the treatment groups by combinations of shallow rotary tillage, mechanical transplanting, and controlled-release fertilizer, of shallow rotary tillage, mechanical transplanting, and quantitative fertilization, and of deep ploughing, mechanical transplanting, and controlled release fertilizer. [Conclusion] The three models are of promising prospects in production. 展开更多
关键词 RICE Simplified cultivation high-yielding cultivation Technology model
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