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Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang 被引量:2
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作者 殷剑美 韩晓勇 +3 位作者 王立 张培通 郭文琦 李春宏 《Agricultural Science & Technology》 CAS 2014年第3期375-378,共4页
The growth and development of Jingjiang Taro [Colocasia esculenta(L.) Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germinatio... The growth and development of Jingjiang Taro [Colocasia esculenta(L.) Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting (7-8 leaves); the first taro began to expand, from 125 d after sprouting (12 leaves) when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting (15-16 leaves). The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant. 展开更多
关键词 Xiangsha taro in Jingjiang Growth and development Dynamic charac- teristics Cultivation technology
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Effects of Cultivation Methods on Yield Formation and Photosynthetic Characteristics of Zhuliangyou 4024 and H You 159 as Doublecropping Rice 被引量:1
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作者 刘利成 敬礼恒 +3 位作者 李蓉 何川 洪珊 邓化冰 《Agricultural Science & Technology》 CAS 2015年第7期1381-1384,共4页
To explore the high-yield cultivation methods of Zhuliangyou 4024 and H You 159 when planted as double-cropping rice, the effects of two cultivation meth- ods, i.e., seedling broadcasting and transplanting, were studi... To explore the high-yield cultivation methods of Zhuliangyou 4024 and H You 159 when planted as double-cropping rice, the effects of two cultivation meth- ods, i.e., seedling broadcasting and transplanting, were studied on SPAD value, photosynthetic rate, grain yield and yield components. The results showed that the seedling broadcasting cultivation was conducive to Zhuliangyou 4024 and H You 159 to obtain higher yield. The higher chlorophyll content and photosynthetic rate and their slower decrease of flag leaf after full heading of the seedling broadcasting cultivation were thought to be the physiological basis of high yield. 展开更多
关键词 Double-cropping rice Cultivation method YIELD Photosynthetic charac- teristic
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The Impact of Electrode Configuration on Characteristics of Vacuum Discharge Plasma 被引量:5
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作者 刘文正 张德金 孔飞 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第2期122-128,共7页
Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteri... Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteristics of the metal plasma which consists of metal ions coming from cathode and generated by vacuum discharge. In this research, the generation characteristics of the metal plasma generated by vacuum discharge are discussed for four patterns of electrode configurations, i.e. cone-mesh electrode setup, cone-cross line electrode setup, cone-line electrode setup and cone-ring electrode setup. Characteristics of the metal plasma, such as elec- tron density, electron temperature, space potential, ion energy, are measured by the probe method for discussing the impacts of different electrode configurations on the density of generated metal plasma. Moreover, the diffusion velocities of the metal plasma are measured for cathode materials of Pb, Al, and Cu, respectively. The experimental results indicate that the plasma generated by the discharge of cone-ring electrode configuration possesses the maximum density and the metal plasma generated by the Al cathode possesses the fastest diffusion velocity and the highest kinetic energy. 展开更多
关键词 electrode configuration VACUUM PLASMA probe method generation charac- teristics
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Characteristic Analysis of AC Plasma Arc in Water
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作者 周恩平 杨嘉祥 马凤莲 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第1期111-114,共4页
An experimental system of AC arc discharge in water was designed with pole-pole electrodes and a peak voltage of 1500 V and a test circuit was set up using virtual instrument technology. The mechanism of an AC plasma ... An experimental system of AC arc discharge in water was designed with pole-pole electrodes and a peak voltage of 1500 V and a test circuit was set up using virtual instrument technology. The mechanism of an AC plasma arc generated in water was analyzed. The voltage- current characteristic of the AC plasma are was obtained from the waveform. The temperature characteristic was tested with a spectrum diagnosis system, and the effect of different electrode materials on the striking voltage and peak current was analyzed. The results show that when a power supply of 6 kW is applied on electrodes with a gap of 2 mm in water, the striking voltage is from 900 V to 1300 V, the arc voltage is from 40 V to 100 V, the arc current is from 2 A to 7 A, and the zero rest period is from 1 ms to 2 ms. In addition, the arc voltage and current are different for electrodes in aluminum, copper and stainless steel. The arc voltage is lower and the current is higher for an aluminum electrode than those for copper and stainless steel ones. The highest temperature of the arc is 7643 K. 展开更多
关键词 discharge in water AC plasma arc V-I characteristics temperature charac- teristics electrode material characteristics
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自主致密局部特征尺度分解方法及其应用 被引量:4
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作者 吴占涛 程军圣 +1 位作者 李宝庆 郑近德 《中国机械工程》 EI CAS CSCD 北大核心 2015年第11期1464-1470,共7页
针对局部特征尺度分解(LCD)的模态混叠问题,提出了自主致密局部特征尺度分解(ACLCD)方法。该方法通过确定待分解信号的最小信号极值尺度来度量其信号尺度,采用新增伪极值点均匀化信号尺度,可有效抑制模态混叠的产生;引入了最优致密系数... 针对局部特征尺度分解(LCD)的模态混叠问题,提出了自主致密局部特征尺度分解(ACLCD)方法。该方法通过确定待分解信号的最小信号极值尺度来度量其信号尺度,采用新增伪极值点均匀化信号尺度,可有效抑制模态混叠的产生;引入了最优致密系数的概念,并给出了最优致密系数评价准则。研究了ACLCD方法的原理,通过仿真信号将ACLCD与LCD和EMD进行分析对比,结果表明,ACLCD在提高分量精确性和正交性、抑制模态混叠等方面具有一定的优越性。将ACLCD方法应用于转子碰摩故障的诊断,结果表明该方法有效。 展开更多
关键词 自主致密局部特征尺度分解 局部特征尺度分解 模态混叠 最优致密系数 内禀尺度分量
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Analysis on Characters and Growth Factors of academicians of Agriculture Faculty of Chinese Academy of Engineering 被引量:1
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作者 邓文 单杨 《Agricultural Science & Technology》 CAS 2015年第12期2664-2669,共6页
The research analyzed birthplace, work site and Work unit, discipline, agri- cultural product variety, current age, and selected age, as well as internal and exter- nal factors for growth, which providers references f... The research analyzed birthplace, work site and Work unit, discipline, agri- cultural product variety, current age, and selected age, as well as internal and exter- nal factors for growth, which providers references for exploring development of high- level agricultural S&T talents and formulation of relevant policies. 展开更多
关键词 Chinese Academy of Engineering Faculty of Agriculture Group charac- teristics Growth factors
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一种去除地震背景噪音的新方法 被引量:1
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作者 杨光亮 《大地测量与地球动力学》 CSCD 北大核心 2011年第4期90-93,共4页
结合希尔伯特-黄变换方法,根据信号背景噪音时间延续性假设,提出了一种自适应地震信号去噪算法。利用该算法实现了台站地震监测信号的去噪分析。分析表明:1)该去噪算法能根据背景信号特性有效去除信号的低频干扰;2)该算法可自适应完成... 结合希尔伯特-黄变换方法,根据信号背景噪音时间延续性假设,提出了一种自适应地震信号去噪算法。利用该算法实现了台站地震监测信号的去噪分析。分析表明:1)该去噪算法能根据背景信号特性有效去除信号的低频干扰;2)该算法可自适应完成信号分解去噪,计算效率高,无时间分辨率和频率分辨率问题;3)该算法处理高频干扰存在缺陷,有待进一步完善。 展开更多
关键词 模态分解 固有模态函数 相关分析 特性时间延续 去噪
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基于改进小波分析的电网故障诊断研究 被引量:5
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作者 陈靖秋 向强铭 +1 位作者 刘智俊 王茜 《电测与仪表》 北大核心 2015年第10期119-123,共5页
传统电网故障诊断大多基于开关量进行分析,当获得的开关量信息不完备不可信的时候,诊断容错性较差,甚至会出现错误的诊断结果。电气量中蕴含丰富的暂态信息,能够直观的反映电网特性,利用多分辨分析的小波理论对电力系统故障采集到的电... 传统电网故障诊断大多基于开关量进行分析,当获得的开关量信息不完备不可信的时候,诊断容错性较差,甚至会出现错误的诊断结果。电气量中蕴含丰富的暂态信息,能够直观的反映电网特性,利用多分辨分析的小波理论对电力系统故障采集到的电流波形进行分析,针对故障电流在电网中的分布特性,提出对改进小波分析故障诊断,建立IEEE39节点仿真模型,实例验证,得到各故障候选线路的各小波故障度。 展开更多
关键词 多分辨小波分析 奇异值分解 故障电流分布特性
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MECHANICAL BEHAVIORS OF SATURATED SAND UNDER COMPLICATED LOADING 被引量:2
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作者 ShaoShengjun 《Acta Mechanica Solida Sinica》 SCIE EI 2004年第1期32-44,共13页
The different physical states of saturated sand, including shear elasticity, positive dilatancy, and negative dilatancy (preliminary negative dilatancy, secondary negative dilatancy and reversal negative dilatancy) ar... The different physical states of saturated sand, including shear elasticity, positive dilatancy, and negative dilatancy (preliminary negative dilatancy, secondary negative dilatancy and reversal negative dilatancy) are revealed based on the pore water pressure response of saturated sand in undrained dynamic torsional tests of thin cylinder samples and also checked by the drained cyclic triaxial tests under a given mean effective normal stress. According to the effective stress path of different physical states under the undrained cyclic torsional tests the physical state transformation surface, stress history boundary and yield surface are determined, and the state boundary surface is also determined by the range of effective frictional stress state movement. Based on the moving yield surface without rotation, and the expanding stress history boundary surface relevant to the stress path variations under different physical states in 3D stress space, a physical state model is proposed to provide a new approach to calculating the transient pore water pressure under the undrained condition, and the volume strain of dilatation under drained condition in this paper. 展开更多
关键词 saturated sand cyclic torsional tests cyclic triaxial tests physical states charac- teristic surfaces in 3D stress space physical states model
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一类3×3拟线性双曲方程组的弱间断传播(英文)
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作者 葛菊 《应用数学与计算数学学报》 2017年第3期334-340,共7页
在双曲型偏微分方程组理论中,弱间断传播理论是非常重要的.利用特征分解方法给出了一类3×3拟线性双曲方程组的弱间断传播理论,证明了弱间断是沿特征线传播这一结论.最后,将结果应用到多方气体的Euler方程组中.
关键词 弱间断 双曲偏微分方程 特征分解 可压Euler方程组
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利用Yamaguchi分解保持地物散射特性的极化SAR分类 被引量:1
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作者 付姣 张永红 +1 位作者 刘晓龙 孙广通 《测绘科学》 CSCD 北大核心 2014年第3期81-84,共4页
本文提出一种利用Yamaguchi分解保持地物散射特性的极化SAR数据分类方法。该方法利用Yamaguchi分解获得4种散射机理:表面散射、体散射、偶次散射和螺旋体散射,根据4种散射机理的功率大小判断地物的主散射机理和类别之间的Wishart距离,... 本文提出一种利用Yamaguchi分解保持地物散射特性的极化SAR数据分类方法。该方法利用Yamaguchi分解获得4种散射机理:表面散射、体散射、偶次散射和螺旋体散射,根据4种散射机理的功率大小判断地物的主散射机理和类别之间的Wishart距离,合并到指定个数的初始类别;并结合Wishart距离分类器对初始类进行迭代修正,实现极化SAR图像的非监督分类。最后利用AIRSAR数据与已有分类方法进行对比实验,验证了本方法的优势及适用性。 展开更多
关键词 极化SAR Yamaguchi分解 Wishart迭代 散射特性保持
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