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界面力限控制技术试验研究 被引量:1
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作者 孙佳川 庞家志 +3 位作者 李航 吴俊娴 马璐军 孙勇 《环境技术》 2021年第6期136-142,共7页
研究界面力限控制方法的关键技术和力限控制对振动试验响应限制的优越性。开展力限试验,用力传感器对界面力进行测量和限制,研究力限试验中的关键技术。并通过力限控制与加速度控制的对比试验,研究两种控制方法对振动试验响应限制的优... 研究界面力限控制方法的关键技术和力限控制对振动试验响应限制的优越性。开展力限试验,用力传感器对界面力进行测量和限制,研究力限试验中的关键技术。并通过力限控制与加速度控制的对比试验,研究两种控制方法对振动试验响应限制的优劣。在试验中以加速度信号作为限制时,被试品一阶固有频率处的放大现象被轻度抑制;而以力信号作为限制时,被试品一阶固有频率处的放大现象被抑制较为明显,甚至出现下凹。在振动试验中被试品的一阶频率附近,力限控制的控制效果要优于加速度控制,可以更有效减轻被试品的过试验问题。 展开更多
关键词 界面力 力限控制 力传感器 振动试验 过试验
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Impact of Long-Term Fertilization on Cropland Soil Fauna Community at Loess Soil, Shannxi, China 被引量:1
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作者 LIN Ying-hua YANG Xue-yun +3 位作者 ZHANG Fu-dao GU Qiao-zhen SUN Ben-hua ma lu-jun 《Agricultural Sciences in China》 CAS CSCD 2005年第12期924-930,共7页
The relationship between long-term fertilization and cropland network for soil fertility and fertilizers in Loess soil of Shannxi soil fauna was studied at the station's experiment research Provincefrom Jul. 2001 to ... The relationship between long-term fertilization and cropland network for soil fertility and fertilizers in Loess soil of Shannxi soil fauna was studied at the station's experiment research Provincefrom Jul. 2001 to Oct. 2002. Six types of long-term fertilizer were carried out for this study including non-fertilizer (CK), abandonment (ABAND), nitrogenous and phosphors and potassium fertilizers combined (NPK), straw and NPK (SNPK), organic material and NPK (MNPK) and 1.5 times MNPK (1.5MNPK). 72 soil samples were collected and 5 495 species of cropland soil fauna obtained by handsorting and Cobb methods at 4 times, belonging to 6 Phyla, 11 Classes, 22 Orders, 2 Superfamilies, 61 Families and 35 Genera. The result showed that different fertilizer had significantly impacted on the cropland soil fauna (F = 2.24, P〈0.007). The number of the cropland soil fauna was related to the soil physicochemical properties caused by long-term fertilization. The result by principal component analysis, focusing on the number of 15 key soil fauna species group's diversity, evenness of community and the total soil fauna individuals indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different from that of the cropland soil fauna, in which, SNPK and NPK had the positive effect on cropland soil fauna, and MNPK and 1.5 MNPK had the negative affect, others could not be explained. By principal component I, the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significant, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the minimum one was - 1.0904, that means the 6 types of fertilization did not affect evenly the cropland soil fauna. 展开更多
关键词 Cropland soil fauna Community diversity Long term fertilization Principal component analysis Loss soi of Shannxi
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振动试验扩展台的设计与动力学分析 被引量:1
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作者 王毅 庞家志 +2 位作者 杨仕超 马璐军 欧阳宏宇 《装备环境工程》 CAS 2020年第8期104-109,共6页
目的验证碗型工装和板型工装结构在动力学试验方面的优劣。方法由于导弹舱段进行振动、冲击、加速度等动力学试验时,不能直接安装在台面结构上,需要设计和优化工装进行固定安装。针对某弹体舱段试验用的工装进行结构设计,并通过有限元... 目的验证碗型工装和板型工装结构在动力学试验方面的优劣。方法由于导弹舱段进行振动、冲击、加速度等动力学试验时,不能直接安装在台面结构上,需要设计和优化工装进行固定安装。针对某弹体舱段试验用的工装进行结构设计,并通过有限元仿真分析得出前六阶模态的频率和振型方式,判别碗型和板型两种结构设计方式的优劣。同时,对设计工装的结构进行优化,得出加强筋对模态参数的影响。结果质量相同的碗型工装的各阶频率均高于板型工装,加强筋的优化方式对于碗型工装结构的前三阶模态频率提升25%左右。结论碗型的工装结构形式能够有效地传递力学信号,保证信号传递的均匀性,加强筋结构可以有效地增强工装结构的动力学性能。 展开更多
关键词 板型工装 碗型工装 模态分析 动力学试验 优化设计
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