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水工隧洞施工对围岩变形影响分析

水利技术监督 2024年第1期 223-225,247页

作者：陆亮王成华山东润泰水利工程有限公司山东泰安271000

围岩的受力及变形特性对引水隧洞施工安全具有重要影响,为保证引水隧洞掘进施工安全,以某引水隧洞施工为例,对围岩变形进行监测,结果表明:引水隧洞围岩变形总体分为急剧变形阶段、快速变形阶段和缓慢变形阶段,采用锚杆、钢筋挂网、喷射... 详细信息

围岩的受力及变形特性对引水隧洞施工安全具有重要影响,为保证引水隧洞掘进施工安全,以某引水隧洞施工为例,对围岩变形进行监测,结果表明:引水隧洞围岩变形总体分为急剧变形阶段、快速变形阶段和缓慢变形阶段,采用锚杆、钢筋挂网、喷射混凝土层等措施控制引水隧洞施工过程中的围岩变形效果较好。建议施工过程中持续对围岩变形进行监测,变形异常的部位及时采取相应加固措施。

关键词： TBM 引水隧洞围岩变形变形监测

“互联网+”背景下大学生在乡村纺织产业振兴中的作用研究

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山东纺织经济 2024年第8期41卷 37-40页

作者：梁璐臧庆玉王军捷山东协和学院山东济南250107

随着信息技术的普及和发展,互联网已成为社会经济发展的重要驱动力之一。在“互联网+”背景下,大学生作为新生代群体,拥有丰富的知识技能和创新意识,被寄予了更多的社会责任和期望。本研究旨在探讨在“互联网+”背景下,大学生在乡村纺... 详细信息

随着信息技术的普及和发展,互联网已成为社会经济发展的重要驱动力之一。在“互联网+”背景下,大学生作为新生代群体,拥有丰富的知识技能和创新意识,被寄予了更多的社会责任和期望。本研究旨在探讨在“互联网+”背景下,大学生在乡村纺织产业振兴中的作用。通过文献综述和实地调研,发现大学生在乡村纺织产业振兴中发挥着重要作用。首先,大学生利用互联网技术推动乡村纺织产业的数字化、智能化发展,提高生产效率和产品质量;其次,大学生作为新鲜血液和创新思维的源泉,参与乡村纺织产业的创新活动,推动产业升级和转型。此外,大学生还通过参与乡村纺织产业扶贫项目和创业创新活动,为乡村经济发展注入新动力。综上所述,大学生在乡村纺织产业振兴中担当重要角色,其积极参与将对乡村经济的可持续发展产生积极影响。

关键词：互联网+ 大学生乡村纺织产业振兴发展

不同品种玉米根-冠生长对土壤紧实胁迫的差异性响应特征

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作物学报 2024年第8期50卷 2053-2066页

作者：梁璐周宝元高卓晗王瑞王新兵赵明李从锋中国农业科学院作物科学研究所/农业农村部作物生理生态重点实验室北京100081 内蒙古农业大学农学院内蒙古呼和浩特010019 河北科技师范学院农学与生物科技学院/河北省作物逆境生物学重点实验室河北秦皇岛066004

黄淮海地区农业集约化和机械化发展导致土壤紧实问题日益加重,限制玉米产量的进一步提升。明确不同品种玉米根系和地上部生长对土壤紧实胁迫的差异性响应特征,可为该区玉米高产栽培提供理论依据。本研究选用3个玉米品种,采用机械碾压的... 详细信息

黄淮海地区农业集约化和机械化发展导致土壤紧实问题日益加重,限制玉米产量的进一步提升。明确不同品种玉米根系和地上部生长对土壤紧实胁迫的差异性响应特征,可为该区玉米高产栽培提供理论依据。本研究选用3个玉米品种,采用机械碾压的方法在同一田块模拟无紧实胁迫(NC:no compaction stress,容重1.0~1.3 g cm^(-3))、中度紧实胁迫(MC:moderate compaction stress,容重1.4~1.5 g cm^(-3))和重度紧实胁迫(HC:heavy compaction stress,容重>1.6 g cm^(-3))3个紧实程度处理,定量解析不同程度土壤紧实胁迫下不同品种玉米根冠生长各指标及产量的变化规律。结果表明,与NC相比,MC和HC处理导致玉米减产3.8%~10.3%和12.5%~33.3%。玉米根冠生长及产量形成对土壤紧实胁迫的响应存在基因型差异。MC处理下,DK517的根长、根干重及根冠比较ZD958和DH605分别提高6.0%和14.0%、15.7%和29.6%、18.8%和24.8%,但最大叶面积指数、植株总干物重和产量无显著差异;HC处理下,DK517的根长和根干重较ZD958和DH605分别提高8.4%和22.5%、29.6%和57.8%,且最大叶面积指数、植株总干物重和根冠比分别提高4.6%和15.5%、3.7%和20.9%、28.0%和32.1%,因此产量分别增加7.5%和27.2%。相关分析表明,土壤容重和贯穿阻力与玉米根冠生长各指标和产量呈显著负相关关系(P<0.01)。综上所述,土壤紧实胁迫会显著抑制玉米根系和地上部生长而造成减产,但不同品种玉米根冠生长对不同程度土壤紧实胁迫的响应存在着差异,重度土壤紧实胁迫下根冠生长均具有优势的品种能够维持较高的产量,研究结果可为玉米品种改良和土壤紧实下耕作措施优化提供理论依据。

关键词：玉米根-冠生长土壤紧实胁迫响应特征

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基于ITHBC理论AVF肾病患者围透析期自我管理方案的构建

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临床医学研究与实践 2024年第9期9卷 9-12页

作者：卢亮魏丽丽高欣青岛大学附属医院山东青岛266011 青岛黄海学院山东青岛266005

目的构建科学、可行的自体动静脉内瘘(AVF)肾病患者围透析期自我管理方案。方法通过文献检索,以健康行为改变整合理论(ITHBC)为理论基础初步构建AVF肾病患者围透析期自我管理方案,应用德尔菲法对24名专家进行2轮专家咨询,对各级指标进... 详细信息

目的构建科学、可行的自体动静脉内瘘(AVF)肾病患者围透析期自我管理方案。方法通过文献检索,以健康行为改变整合理论(ITHBC)为理论基础初步构建AVF肾病患者围透析期自我管理方案,应用德尔菲法对24名专家进行2轮专家咨询,对各级指标进行评定与修改。结果2轮专家咨询问卷回收率均为100%(24/24),专家权威系数(Cr)分别为0.895、0.915,专家协调系数Kendall's W分别为0.153、0.221。第2轮专家意见变异系数为0.010~0.099,均小于0.250。2轮德尔菲专家咨询确定3个一级指标、10个二级指标和22个三级指标。结论基于ITHBC理论构建AVF肾病患者围透析期自我管理方案具有较好的科学性与可操作性,能够为AVF肾病患者围透析期间自我管理提供依据和指导。

关键词：自体动静脉内瘘围透析期健康行为改变整合理论

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航空发动机起动系统性能匹配与分析

内燃机与配件 2024年第7期 5-8页

作者：卢明亮徐嘉悦沈阳发动机研究所辽宁沈阳110015

发动机起动系统匹配的好坏直接影响起动功能、性能能否满足指标要求。在起动系统设计阶段,提出一种适用于工程应用的以辅助动力装置和空气涡轮起动机为主的起动系统性能匹配与计算方法,根据得到的匹配功率,结合起动需求进行评估,保证满... 详细信息

发动机起动系统匹配的好坏直接影响起动功能、性能能否满足指标要求。在起动系统设计阶段,提出一种适用于工程应用的以辅助动力装置和空气涡轮起动机为主的起动系统性能匹配与计算方法,根据得到的匹配功率,结合起动需求进行评估,保证满足发动机起动包线范围内的起动要求。最后,以某型发动机起动系统匹配分析为例,验证了计算方法的可行性,研究了匹配过程可能遇到的问题并提出改进措施,能够为起动系统设计提供技术支撑。

关键词：航空发动机起动系统性能匹配起动机功率

Squeal noise in hydraulic poppet valves

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2016年第4期17卷 317-324页

作者： Da-yun YI liang lu Jun ZOU Xin FU The State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou 310027 China

The poppet valve is a fundamental component in fluid power systems. Under particular conditions, annoying ＂squeal＂ noises may be generated in hydraulic poppet valves. In the present study, the frequency spectrum of the squeal noise is obtained by analyzing the sampling data from the accelerometer mounted on the valve body. It is found that the flow velocity, pressure, and structural parameters have crucial effects on the properties of squeal noise, especially frequency. Larger valve chamber volume or lower backpressure leads to lower fundamental frequency of the squeal noise. An explanation for the squeal noise, as a result of Helmholtz resonance, is suggested and proved by experimental results.

关键词： Poppet valve Squeal noise Helmholtz resonance Fluid acoustics Shear layer instability

Lasiodiplodia pseudotheobromae causes stem canker of Chinese hackberry in China

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Journal of Forestry Research 2020年第6期31卷 2571-2580页

作者： lu liang Huan Li Lifeng Zhou Fengmao Chen Co-Innovation Center for Sustainable Forestry in Southern China College of ForestryNanjing Forestry UniversityNanjing 210037JiangsuPeople’s Republic of China

Chinese hackberry(Celtis sinensis Pers.)is an adaptable species widely growing in southern *** symptoms of canker on stems of seedlings were discovered mid-July 2017 in Shuyang,Jiangsu *** diseased portions of the stems were dark brown due to discoloured *** seedlings showed symptoms of wilting,leaf fall,twig dieback,and tissue *** outbreak period was concentrated in July and August,suggesting that the disease spread during summer *** fungal causal agents were isolated from naturally infected canker tissue and discoloured *** isolate from xylem tissue with a high frequency(>50%)was named Ls7 *** tests were carried out on 4-yearold *** symptoms of canker began to develop 20 days after inoculation with Ls7 isolate and by day 35,there were dark,enlarged longitudinal lesions.A phylogenetic tree of the isolate was developed using the internal transcribed spacer,elongation factor-1α(tef1-α),β-tubulin gene(TUB)and RNA polymerase II subunit primer genes(RPB2).Based on morphological features and phylogenetic information,the pathogen was identifi ed as Lasiodiplodia *** is the fi rst report of *** causing canker on Chinese hackberry stems in China.

关键词： Botryosphaeriaceae Plant pathogen Tree disease

Magnetic Resonance Imaging and Biomechanical Analysis of Adipose-derived Stromal Vascular Fraction Applied on Rotator Cuff Repair in Rabbits

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Chinese Medical Journal 2018年第1期131卷 69-74页

作者： liang-Yu lu Chun-Yan Kuang Feng Yin Department of Joint and Sports Medicine East Hospital Tongji University School of Medicine Shanghai 200120 China Department of Rehabilitation East Hospital Tongji University School of Medicine Shanghai 200120 China

Background： Adipose-derived stromal vascular fraction （ADSVF） can be applied to repair tendon and ligament tears. ADSVF treatment has a better therapeutic potential than adipose stem cells alone in promoting the healing of connective tissue injury in rabbit models. Magnetic resonance imaging （MRI） and biomechanical testing were used in this study to evaluate the efficiency of SVF in the healing of tendon-bone interface of a rotator cuff injury after reattachment. Methods： A total of 36 rabbits were studied between March and June 2016, 18 rabbits received the SVF-fibrin glue （SVF-FG） treatment and the other 18 formed the control group. ADSVF was isolated from each rabbit. A bilateral amputation of the supraspinatus tendon and parallel reconstruction was also performed on all the 36 rabbits. Then, a mixture of SVF and FG was injected into the tendon-bone interface of the SVF-FG group, whereas the control group only received FG. Tile animals were randomly sacrificed at 4, 8, and 12 weeks after surgery （n = 6 per group）, respectively. The shoulders were prepared for MRI scanning and analysis of biomechanical properties. Analyses of variance were pertbrmed using SPSS 13.0. Results： MRI scanning showed that the signal-to-noise quotient of the SVF-FG group was not significantly higher than that of the control group at either 4 （20.1 ± 3.6 vs. 18.2 ± 3.4, F = 1.570, P = 0.232） or 8 weeks （20.7 ±3.3 vs. 18.0 ± 3.0, F = 2.162, P = 0.117） posttreatment, and only became significant after 12 weeks （27.5± 4.6 vs. 22.1 ± 1.9, F 4.968, P = 0.009）. Biomechanical properties such as the maximum load, maximum strength, and the stiffness for the SVF-FG group were significantly greater than that for the control group at 8 weeks＇ posttreatment （maximum load： 166.89 ± 11.62 N vs. 99.40 ± 5.70 N, P 〈 0.001： maximum strength： 8.22 ± 1.90 N/ram vs. 5.82 ±0.68 N/ram, P 〈 0.010： and the stiffness： 34.85±3.00 Pa vs. 24.57±5.72 Pa, P 〈 0.010）. Conclusion： Local application of ADSVF might lead to

关键词： Biomechanical Magnetic Resonance hnaging: Rotator Cuff Healing

Adaptive Change Detection for Long-Term Machinery Monitoring Using Incremental Sliding-Window

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Chinese Journal of Mechanical Engineering 2017年第6期30卷 1338-1346页

作者： Teng Wang Guo-liang lu Jie Liu Peng Yan Key Laboratory of High-Efficiency and Clean Mechanical Manufacture of MOE School of Mechanical EngineeringShandong University Department of Mechanical and Aerospace Engineering Carleton University

Detection of structural changes from an opera- tional process is a major goal in machine condition moni- toring. Existing methods for this purpose are mainly based on retrospective analysis, resulting in a large detection delay that limits their usages in real applications. This paper presents a new adaptive real-time change detection algorithm, an extension of the recent research by combin- ing with an incremental sliding-window strategy, to handle the multi-change detection in long-term monitoring of machine operations. In particular, in the framework, Hil- bert space embedding of distribution is used to map the original data into the Re-producing Kernel Hilbert Space （RK_HS） for change detection; then, a new adaptive threshold strategy can be developed when making change decision, in which a global factor （used to control the coarse-to-fine level of detection） is introduced to replace the fixed value of threshold. Through experiments on a range of real testing data which was collected from an experimental rotating machinery system, the excellent detection performances of the algorithm for engineering applications were demonstrated. Compared with state-of- the-art methods, the proposed algorithm can be more suitable for long-term machinery condition monitoring without any manual re-calibration, thus is promising in modern industries.

关键词： Machine monitoring Change detection Long-term monitoring Adaptive threshold