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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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刚性阻振质量阻隔振动波传递特性数值研究 被引量:5
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作者 钱德进 缪旭弘 +1 位作者 贾地 王雪仁 《中国舰船研究》 2010年第5期22-26,33,共6页
基于阻抗失配原理,从波动角度分析了刚性阻振质量阻隔振动波传递的特性,并利用有限元法数值研究了重量及截面形状参数对刚性阻振质量隔振性能的影响。结果表明:刚性阻振质量能有效隔离中高频振动波的传递,且其重量越大,隔振效果越好,而... 基于阻抗失配原理,从波动角度分析了刚性阻振质量阻隔振动波传递的特性,并利用有限元法数值研究了重量及截面形状参数对刚性阻振质量隔振性能的影响。结果表明:刚性阻振质量能有效隔离中高频振动波的传递,且其重量越大,隔振效果越好,而对低频振动波则几乎不起隔离作用;对于矩形截面的刚性阻振质量,适当增大其截面高度同时减小截面宽度,可有效提高刚性阻振质量的隔振降噪效果,这对刚性阻振质量在船体结构减振降噪中的应用具有一定的参考意义。 展开更多
关键词 刚性阻振质量 阻抗失配 振动波 传递特性 减振降噪
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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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高频热声制冷机中的压电喇叭特性 被引量:1
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作者 张晓青 蒋华 +1 位作者 陈宇 柳玉林 《低温工程》 CAS CSCD 北大核心 2005年第6期33-36,共4页
研究建立了1台5 kHz微型热声制冷实验样机,对压电喇叭谐振系统的阻抗特性,以及频率和电压响应特性进行了实验研究。初步的实验显示,压电喇叭与驱动电源和热声谐振系统之间需要在电学和声学上进行匹配,PZT5的压电陶瓷材料发热较大,且提... 研究建立了1台5 kHz微型热声制冷实验样机,对压电喇叭谐振系统的阻抗特性,以及频率和电压响应特性进行了实验研究。初步的实验显示,压电喇叭与驱动电源和热声谐振系统之间需要在电学和声学上进行匹配,PZT5的压电陶瓷材料发热较大,且提供的声功率较小,这些是影响微型制冷的重要因素。 展开更多
关键词 热声制冷机 高频 压电喇叭 阻抗特性 耦合特性
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市话信道测试研究
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作者 苗长云 梁全市 +1 位作者 薛鹏骞 杨维 《辽宁工程技术大学学报(自然科学版)》 CAS 1993年第3期58-61,共4页
在对市内电话信道阻抗特性、衰耗特性测试的基础上,提出市话线路可采用频分复用的方法传递载波信号,如数字调制信号、语言载波信号等。从而提高市话信道的利用率。该测试结果可为研制市话信道复用的通信设备提供参考.
关键词 电话信道 阻抗特性 衰耗特性 频分复用 测试
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椭圆锥带线的严格解
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作者 阮成礼 《电子科技大学学报》 EI CAS CSCD 北大核心 2001年第1期33-36,共4页
研究了椭圆锥带线的特性阻抗等基本参数。假设中心导体带是无限薄理想导体,传输的是TEM模,通过坐标变换和共形映射,把椭圆锥带线变为有限宽平行板带线。应用椭圆积分变换得到了椭圆锥带线参数的严格解。该方法可用于圆柱、椭圆柱、... 研究了椭圆锥带线的特性阻抗等基本参数。假设中心导体带是无限薄理想导体,传输的是TEM模,通过坐标变换和共形映射,把椭圆锥带线变为有限宽平行板带线。应用椭圆积分变换得到了椭圆锥带线参数的严格解。该方法可用于圆柱、椭圆柱、圆锥和椭圆锥问题的求解。 展开更多
关键词 椭圆锥带线 严格解 共形天线 共形传输线
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变形对梯形单脊波导衰减等传输特性影响 被引量:2
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作者 李向葵 陈小强 陈彩红 《兰州大学学报(自然科学版)》 CAS CSCD 北大核心 2012年第5期124-128,共5页
针对脊波导器件在使用中可能产生的变形,采用Matlab环境下的PDE工具箱进行二次编程,研究了错位变形和受力变形对梯形单脊波导衰减特性、功率容量和阻抗特性的影响,给出了不同变形对特性参数影响的关系曲线图.数值分析结果表明:随着脊波... 针对脊波导器件在使用中可能产生的变形,采用Matlab环境下的PDE工具箱进行二次编程,研究了错位变形和受力变形对梯形单脊波导衰减特性、功率容量和阻抗特性的影响,给出了不同变形对特性参数影响的关系曲线图.数值分析结果表明:随着脊波导变形程度的增大,衰减常数增大,功率容量和阻抗减小,其中下侧受力变形对梯形单脊波导的特性参数影响最大,冈此在脊波导器件的使用过程中应尽量避免下侧受力变形. 展开更多
关键词 有限元法 脊波导 衰减特性 功率容量 阻抗特性
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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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基于新型SCRLH TL结构的超宽带滤波器设计 被引量:1
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作者 王政平 韩振豫 《光学与光电技术》 2012年第3期81-84,共4页
提出了利用去除并联电感实现简化左右手(SCRLH)复合传输线(TL)结构的方法,及利用该方法实现超宽带滤波器的设计。设计了一个中心频率为7.05GHz、相对带宽约为70%、带内群延时小于0.4ns的超宽带滤波器。分别应用HFSS和Designer软件对该... 提出了利用去除并联电感实现简化左右手(SCRLH)复合传输线(TL)结构的方法,及利用该方法实现超宽带滤波器的设计。设计了一个中心频率为7.05GHz、相对带宽约为70%、带内群延时小于0.4ns的超宽带滤波器。分别应用HFSS和Designer软件对该器件进行了微波全波仿真及电路仿真。用不同方法仿真获得的结果吻合良好。由此证明了用去除并联电感的新型SCRLH TL结构实现滤波器的正确性与有效性。 展开更多
关键词 超宽带滤波 简化的左右手复合传输线 色散 阻抗特性 滤波器设计
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