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对专用液压驱动链锯马达的柱塞、缸体、配流盘进行设计计算,得到了采伐联合作业机专用液压驱动链锯马达的设计参数。 相似文献
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以典型斜盘式轴向柱塞泵为载体,分析了其工作原理,利用AMESim搭建其虚拟样机软件的液压模型,并对其进行参数设置。利用所建模型,分别对泵在配流盘开设三角槽、偏转安装以及三角槽与偏转安装相结合三种情况进行仿真。通过对比柱塞腔油压及输出压力曲线,得出以下结论:在配流盘上开设三角槽和配流盘偏转安装对泵的柱塞腔油压及泵的输出压力冲击均有很好的减弱作用;同时采用开设三角槽与偏转安装这两种方式时,压力冲击减弱更加明显。该仿真结果可为轴向柱塞泵的减振减噪提供有益的参考。 相似文献
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ZHAI Hongbo LI Jiyue NIE Lishui College of Resources Environment Beijing Forestry University P. R. China College of Soil Water Conservation Beijing Forestry University P. R. China 《中国林业科技(英文版)》2004,3(1):53-58
INTRODUCTIONShinozakifirstproposedthepipemodeltheoryin1964(Shinozaki,1964a,1964b).Inthistheory,thewholexylemsoftheplantisassumedasauniformpipe.Hebelievedthatperunitareaofleavesdependedonperunitofareaofthepipetogrowth.Thistheoryisagreedbyresearcherswhofoundthatthesectionareaofthexylemisdirectproportiontotheareaoftheleavesintheendofthexylem.Laterthistheorywasfoundverypracticalinestimatingtheleavesarea,understandingthegrowthandthedistributionofmaterialandenergyintrees(Shinozakig,Yoda,Hozum… 相似文献
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In order to isolate and clone water-stress-responsive genes, total RNA was extracted from water-stressed plantlets regenerated in vitro of Populus hopeiensis using a QIAGEN RNeasy Plant Mini Kit. CDNA, synthesized by LD-PCR with the SMART cDNA Library Construction Kit, was n vitro packaged into a phage λTriplEx2 vector. The resulting primary library and amplified library have a titer of 1.68×10i6 and 1.69×109 pfu·mL–1 respectively. The combination ratio reached 98.8% and the average size of inserts was about 800 bp. In addition, the percentage of inserted fragments (> 400 bp) was approximately 90%. The results indicate that a cDNA library has been successfully constructed. 相似文献
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以设计为依据,结合工程实际情况,通过碎石桩在粉砂地基中的试桩实验,提出如何控制碎石桩施工时的水压、电流、留振时间等施工要点,以便更好的提高碎石桩的使用效果。 相似文献
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阐述了存在多层地下水的场地 ,其沉降计算不同于传统静止水压力计算 ,各层地下水之间渗流 ,造成的孔隙水压力分布场 ,对沉降计算的影响不可忽视 相似文献
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经济的发展和生育政策的放开,为儿童家具发展带来了新机遇。概述了儿童家具的基本分类及其情感化设计特点。为更好地了解用户需求,采用层次分析法(AHP)对情感化设计的儿童家具的功能性、易用性、审美性、安全性进行分析,构建了相应要素的判断矩阵,并分别计算每个的子准则层权重。结果显示,家具结构的稳定性、造型、储存和可持续性是设计中的主要影响要素。同时,从情感化设计的三个方面分别分析了儿童生长阶段对家具的需求和痛点,并提出相应的解决方案。最后,以层次分析法得出的数据和情感化分析为依据,设计了一款儿童情感化家具——床头柜加以验证,为儿童家具的设计提供思路与参考。 相似文献
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Fan Yi-juan Liu Qing Wei Kai-fa Li Bing-bing Ren Hui-bo Gao Zhi-hui Jia Wen-suo College of Agronomy Biotechnology State Key Laboratory of Plant Physiology Biochemistry China Agricultural University Beijing P. R. China 《中国林学(英文版)》2006,8(4):1-5
Signal communication between root and shoot plays a crucial role in plant resistance to water stress. While many studies on root to shoot signals have been carried out in many plant species, no information is available for the model plant, Arabidopsis, whose adoption has great significance for further probing the molecular aspects of long distance stress signals. Here, we introduced the establishment of techniques for investigations of root to shoot signals in Arabidopsis. Stomatal movements in relation to root signals were probed by using these techniques. The results show that Arabidopsis is a suitable plant species for partial roots drying (PRD) experiments. In the PRD system, while no significant differences were found in leaf water potential between well-watered and stressed plants, water stress led to a decrease in leaf conductance, which suggests a regulation of stomatal movements by root to shoot signals. While water stress caused a significant increase in the concentration of sap abscisic acid (ABA) of xylem, no increase in xylem sap pH was observed. Moreover, the increase in the ABA content of xylem coincided with the decrease in leaf conductance, which suggests a possible role of ABA in the regulation of stomatal movements. Infrared temperature images showed that leaf temperatures of PRD plant were higher compared with those of well-watered plants, which further indicates that stomatal movements can be modulated by root signals. The confirmation of root to shoot signaling in Arabidopsis has established a basis for further investigation into the molecular mechanisms of the root to shoot signaling under water stress. 相似文献
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为提升房车家具生产制造的效率和成功率,并为房车家具CMF设计数据库提供新的设计思路和方法,本文以CMF设计理论为基础,进行设计要素的分析与解读,协助设计师能更好的从色彩、材料和工艺的角度确定设计方向。通过对数据库建立关键技术,着重进行房车家具CMF设计数据库架构和应用策略的分析。得出CMF设计要素对产品感知质量、产品美学和情感属性、用户需求和感知的影响,构建了包含CMF语义库、主题风格、业务数据和索引数据的房车家具数据库。数据库包括四个层次模型,为房车家具设计提供了精准可靠、清晰客观的数据支持,大大缩短了目标家具的设计周期,提高了用户的满足率和企业实际生产效率,从科学性和可行性方向为数据库研究和应用提供了策略。 相似文献
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现行的挡土墙设计方法中存在许多不完善之处,针对挡土墙设计中的几个主要环节进行理论分析,指出其不合理之处,并提出修正公式、措施及方向,可供设计参考。 相似文献
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勘察设计质量成本是将勘察设计成果质量保持在规定的水平以上所需的费用,通过分析质量成本项目的构成,确定质量成本项目,收集质量成本数据,统计、核算质量成本,可以有效地进行质量成本管理,保证勘察设计成果质量,增强竞争能力,提高经济效益。 相似文献