期刊文献+
共找到1,556篇文章
< 1 2 78 >
每页显示 20 50 100
Attack on Optical Double Random Phase Encryption Based on the Principle of Ptychographical Imaging 被引量:2
1
作者 李拓 史祎诗 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第1期63-66,共4页
The principle of ptychography is applied in known plain text attack on the double random phase encoding (DRPE) system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can... The principle of ptychography is applied in known plain text attack on the double random phase encoding (DRPE) system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can be converted to the model of ptyehographical imaging. Owing to the inherent merits of the ptyehographical imaging, the DRPE system can be breached totally in a fast and nearly perfect way, which is unavailable for currently existing attack methods. Further, since the decryption keys can be seen as an object to be imaged from the perspective of imaging, the ptychographical technique may be a kind of new direction to further analysis of the security of other encryption systems based on double random keys. 展开更多
关键词 of as for it Attack on Optical double random Phase Encryption Based on the Principle of Ptychographical Imaging in IS on
下载PDF
Effect of Jianpi Shengxue Tablet on Iron Metabolism and Nutritional Status in Patients with Renal Anemia:A Prospective,Randomized,Open,Parallel Controlled and Multicenter Clinical Study
2
作者 Juan YANG Meng-yuan LIANG +15 位作者 Yu LI Hao ZHANG Wei LI Jing LV Li-ping DONG Jing-song JIN Cheng YANG Qing-hong ZHANG Li LONG Rong ZOU Yi GAO Dan SONG Chun-qin PAN Ying YAO Xiao-lin ZHAN Xiao-hui WANG 《Current Medical Science》 SCIE CAS 2024年第3期603-610,共8页
Objective This study aimed to analyze the clinical efficacy of the Jianpi Shengxue tablet for treating renal anemia.Methods A total of 200 patients with renal anemia from December 2020 to December 2022 were enrolled a... Objective This study aimed to analyze the clinical efficacy of the Jianpi Shengxue tablet for treating renal anemia.Methods A total of 200 patients with renal anemia from December 2020 to December 2022 were enrolled and randomly divided into two groups.Patients in the control group were treated with polysaccharide-iron complex,and those in the experimental group were administered Jianpi Shengxue tablet.After 8 weeks of continuous treatment,the therapeutic outcomes regarding anemia were compared between the two groups.Results After treatment,the red blood cell(RBC)count,hematocrit(HCT),reticulocyte percentage(RET),ferritin(SF),serum iron(SI),transferrin saturation(TSAT),and serum albumin(ALB)all increased(P<0.01),and the clinical symptom score and total iron binding capacity decreased(P<0.01)in the experimental group.Moreover,the improvements in RBC,HCT,RET,SF,SI,TAST,ALB,and clinical symptoms(fatigue,anorexia,dull skin complexion,numbness of hands and feet)in the experimental group were significantly greater than those in the control group(P<0.05).The total effective rate for treating renal anemia was significantly higher in the experimental group than in the control group(P<0.01).Conclusion The Jianpi Shengxue tablet demonstrates efficacy in treating renal anemia,leading to significant improvements in the laboratory examination results and clinical symptoms of patients with renal anemia. 展开更多
关键词 Jianpi Shengxue tablet renal anemia randomIZED open parallel control multicenter clinical study
下载PDF
Effects of Depth of Needle Insertion with Risperidone Long-Acting Injectable in Persons with Schizophrenia: A Randomized Double-Blind Study
3
作者 Yueren Zhao Tetsuya Tanioka +5 位作者 Yuko Yasuhara Kensaku Takase Soji Tsuboi Kiyoshi Fujita Rozzano C. Locsin Nakao Iwata 《Open Journal of Psychiatry》 2017年第4期374-385,共12页
In some cases, if the insertion depth is shallower than expected, intramuscular (IM) injection of risperidone long-acting injectable (RLAI) may not penetrate the muscle fascia. However, if needle insertion depth is de... In some cases, if the insertion depth is shallower than expected, intramuscular (IM) injection of risperidone long-acting injectable (RLAI) may not penetrate the muscle fascia. However, if needle insertion depth is deeper than anticipated, needle penetration may cause damage to nerves, arteries and veins. Few clinical studies were done to evaluate the depth of needle length insertion reaching the intended gluteal muscle. The aim of this study was to evaluate the suitable depth of injecting RLAI. Twenty-six patients with schizophrenia were treated with RLAI, and randomly divided into two groups: 50 mm needle inserted group (Group-D, deep insertion, n = 13) and 20 mm needle insertion group (Group-S, shallow insertion, n = 13). For Group-S, the needle length was marked with a spacer at exactly 20 mm. Injections were performed by the psychiatrist or nurse, alternating between the two gluteal sites by double-cross method every two weeks. Clinical psychotic symptoms and injection site reactions were recorded throughout the study period. Experienced psychologists who were blinded from the needle-length experimental variable evaluated patients’ psychotic symptoms using the Positive and Negative Syndrome Scale (PANSS) every two weeks. The plasma 9-hydroxyrisperidone (9-OH-RIS) concentrations were measured every two weeks;comparison data were determined on the 8th week and the 14th week. No significant difference was observed in 9-OH-RIS concentrations, psychotic symptoms, injection site skin reactions of subjects in both groups. However, in Group-D, injection site adverse reactions were confirmed in two subjects (15%). In Group-S, injection site reactions were confirmed in six subjects (46%). Although effective 9-OH-RIS concentrations were obtained with the insertion using both depth, it was concluded that the 50 mm insertion length was more suitable for dorsogluteal IM injections in adult patients with schizophrenia as demonstrated by the incidence of local adverse skin reactions. 展开更多
关键词 Inserted DEPTH of Injection Needle LONG-ACTING INJECTABLE PERSONS with SCHIZOPHRENIA randomIZED double-Blind Study 9-Hydroxyrisperidone Pharmacokinetics
下载PDF
Three-dimensional image authentication using binarized images in double random phase integral imaging 被引量:2
4
作者 Weitao Song Qijia Cheng +3 位作者 Yue Liu Yuanjin Zheng Zhiping Lin Yongtian Wang 《Chinese Optics Letters》 SCIE EI CAS CSCD 2019年第5期21-25,共5页
We proposed a three-dimensional (3D) image authentication method using binarized phase images in double random phase integral imaging (Ini). Two-dimensional (2D) element images obtained from Ini are encoded using a do... We proposed a three-dimensional (3D) image authentication method using binarized phase images in double random phase integral imaging (Ini). Two-dimensional (2D) element images obtained from Ini are encoded using a double random phase encryption (DRPE) algorithm. Only part of the phase information is used in the proposed method rather than using all of the amplitude and phase information, which can make the final data sparse and beneficial to data compression, storage, and transmission. Experimental results verified the method and successfully proved the developed 3D authentication process using a nonlinear cross correlation method. 展开更多
关键词 three-dimensional(3D) Two-dimensional(2D) double random phase encryption(DRPE)
原文传递
Antibiotics for lower respiratory tract infection in children presenting in primary care in England (ARTIC PC): a double-blind, randomised, placebo-controlled trial 被引量:4
5
作者 Paul Little 《四川生理科学杂志》 2021年第8期1411-1411,共1页
Methods:ARTIC PC was a double-blind,randomised,placebo-controlled trial done at 56 general practices in England.Eligible children were those aged 6 months to 12 years presenting in primary care with acute uncomplicate... Methods:ARTIC PC was a double-blind,randomised,placebo-controlled trial done at 56 general practices in England.Eligible children were those aged 6 months to 12 years presenting in primary care with acute uncomplicated LRTI judged to be infective in origin,where pneumonia was not suspected clinically,with symptoms for less than 21 days.Patients were randomly assigned in a 1:1 ratio to receive amoxicillin 50 mg/kg per day or placebo oral suspension,in three divided doses orally for 7 days.Patients and investigators were masked to treatment assignment.The primary outcome was the duration of symptoms rated moderately bad or worse(measured using a validated diary)for up to 28 days or until symptoms resolved.The primary outcome and safety were assessed in the intention-to-treat population.The trial is registered with the ISRCTN Registry(ISRCTN79914298). 展开更多
关键词 doses random double
下载PDF
Thermal stability and data retention of resistive random access memory with HfOx/ZnO double layers
6
作者 赖云锋 陈凡 +3 位作者 曾泽村 林培杰 程树英 俞金玲 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期411-416,共6页
As an industry accepted storage scheme, hafnium oxide(HfO_x) based resistive random access memory(RRAM)should further improve its thermal stability and data retention for practical applications. We therefore fabri... As an industry accepted storage scheme, hafnium oxide(HfO_x) based resistive random access memory(RRAM)should further improve its thermal stability and data retention for practical applications. We therefore fabricated RRAMs with HfO_x/ZnO double-layer as the storage medium to study their thermal stability as well as data retention. The HfO_x/ZnO double-layer is capable of reversible bipolar switching under ultralow switching current(〈 3 μA) with a Schottky emission dominant conduction for the high resistance state and a Poole–Frenkel emission governed conduction for the low resistance state. Compared with a drastically increased switching current at 120℃ for the single HfO_x layer RRAM, the HfO_x/ZnO double-layer exhibits excellent thermal stability and maintains neglectful fluctuations in switching current at high temperatures(up to 180℃), which might be attributed to the increased Schottky barrier height to suppress current at high temperatures. Additionally, the HfO_x/ZnO double-layer exhibits 10-year data retention @85℃ that is helpful for the practical applications in RRAMs. 展开更多
关键词 resistive random access memory (RRAM) thermal stability data retention double layer
下载PDF
Averaging in SU(2) open quantum random walk
7
作者 Clement Ampadu 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第3期109-111,共3页
We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with ... We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT. 展开更多
关键词 open quantum random walk central limit theorem average position SU(2) operator
下载PDF
Double Autocorrelation in Two Way Error Component Models
8
作者 J. M. Bosson Brou Eugene Kouassi Kern O. Kymn 《Open Journal of Statistics》 2011年第3期185-198,共14页
In this paper, we extend the works by [1-5] accounting for autocorrelation both in the time specific effect as well as the remainder error term. Several transformations are proposed to circumvent the double autocorrel... In this paper, we extend the works by [1-5] accounting for autocorrelation both in the time specific effect as well as the remainder error term. Several transformations are proposed to circumvent the double autocorrelation problem in some specific cases. Estimation procedures are then derived. 展开更多
关键词 TWO WAY random Effect Model double AUTOCORRELATION GLS FGLS
下载PDF
Modeling and Analysis of a Random Excited Double-Clamped Piezoelectric Energy Harvester
9
作者 Xiaoya Zhou Shiqiao Gao Haipeng Liu 《Journal of Beijing Institute of Technology》 EI CAS 2017年第3期297-303,共7页
A double-clamped piezoelectric energy harvester subjected to random excitation is presented,for which corresponding analytical model is established to predict its output characteristics.With the presented theoretical ... A double-clamped piezoelectric energy harvester subjected to random excitation is presented,for which corresponding analytical model is established to predict its output characteristics.With the presented theoretical natural frequency and equivalent stiffness of vibrator,the closed-form expressions of mean power and voltage acquired from the double-clamped piezoelectric energy harvester under random excitation are derived.Finally theoretical analysis is conducted for the output performance of the doubleclamped energy harvester with the change of spectrum density(SD)of acceleration,load resistance,piezoelectric coefficient and natural frequency value,which is found to closely agree with Monte Carlo simulation and experimental results. 展开更多
关键词 double-clamped energy harvester random excitation output characteristics
下载PDF
The Efficacy and Safety of a Patent Pending Combination of Ginger and Goldenrod Extracts on the Management of Cold Symptoms: A Randomized, Double-Blind Controlled Trial
10
作者 Johane Guay Pierre Champagne +1 位作者 Pascal Guibord Joerg Gruenwald 《Food and Nutrition Sciences》 2012年第12期1651-1657,共7页
Objective: In a randomized, double-blind, exploratory, active-controlled trial, the efficacy and safety of a patent-pending combination of Ginger and Goldenrod extracts (BDI-630) in alleviating cold symptoms in commun... Objective: In a randomized, double-blind, exploratory, active-controlled trial, the efficacy and safety of a patent-pending combination of Ginger and Goldenrod extracts (BDI-630) in alleviating cold symptoms in community-dwelling adults was compared to a combination of standardized amounts of Echinacea (EC) components. Methods: 44 healthy adults, experiencing new onset of cold symptoms were randomly assigned to receive either BDI-630 (900 mg) or EC (500 mg) twice daily for 10 days. The severity of cold symptoms and the quality of life was assessed by self-reporting of subjects using the Wisconsin Upper Respiratory Symptom Survey (WURSS-21? 2004). Results: The intent-to-treat population (ITT) consisted of 44 subjects (n = 22 for BDI-630;n = 22 for EC). The modified ITT (mITT) population consisted of 40 subjects, excluding four subjects with major protocol deviations related to inclusion/exclusion criteria and/or use of prohibited drugs from the efficacy analysis (n = 3 for BDI-630 and n = 1 for EC). Results indicated a sig-nificant difference between the two groups: the superiority of BDI-630 over EC was particularly noticeable between Day 1 and Day 7, as demonstrated by a 14-fold difference of the mean percentage of change of total score from baseline in the mITT population. Adverse events (AEs) following the intake of BDI-630 were mostly limited to mild gastrointestinal intolerance in less than 10% of the subjects. Conclusions: BDI-630 was shown to be more effective than EC in alleviating cold symptoms in the adult population, particularly during the first 7 days of treatment. BDI-630 was very well tolerated by all subjects. 展开更多
关键词 randomIZED double-BLIND Active-Controlled Trial Common COLD
下载PDF
Code Reviewer Intelligent Prediction in Open Source Industrial Software Project
11
作者 Zhifang Liao Bolin Zhang +2 位作者 Xuechun Huang Song Yu Yan Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期687-704,共18页
Currently, open-source software is gradually being integrated into industrial software, while industry protocolsin industrial software are also gradually transferred to open-source community development. Industrial pr... Currently, open-source software is gradually being integrated into industrial software, while industry protocolsin industrial software are also gradually transferred to open-source community development. Industrial protocolstandardization organizations are confronted with fragmented and numerous code PR (Pull Request) and informalproposals, and differentworkflowswill lead to increased operating costs. The open-source community maintenanceteam needs software that is more intelligent to guide the identification and classification of these issues. To solvethe above problems, this paper proposes a PR review prediction model based on multi-dimensional features. Weextract 43 features of PR and divide them into five dimensions: contributor, reviewer, software project, PR, andsocial network of developers. The model integrates the above five-dimensional features, and a prediction model isbuilt based on a Random Forest Classifier to predict the review results of PR. On the other hand, to improve thequality of rejected PRs, we focus on problems raised in the review process and review comments of similar PRs.Wepropose a PR revision recommendation model based on the PR review knowledge graph. Entity information andrelationships between entities are extracted from text and code information of PRs, historical review comments,and related issues. PR revisions will be recommended to code contributors by graph-based similarity calculation.The experimental results illustrate that the above twomodels are effective and robust in PR review result predictionand PR revision recommendation. 展开更多
关键词 open source software pull request random forest knowledge graph
下载PDF
簇状分布的刚性双层植被明渠紊流特性分析
12
作者 吕升奇 陈俊舟 +1 位作者 陈红 陈界仁 《水利水电科技进展》 CSCD 北大核心 2024年第3期8-12,33,共6页
采用RNG k-ε紊流模型,对簇状分布的刚性双层植被明渠水流进行了模拟和分析;根据时间及空间的双平均方法对植被明渠水流的流速及紊动参数进行了统计。结果表明:簇状分布的植被明渠水流可以分为植物区、间隙区及主流区,不同区域时均流速... 采用RNG k-ε紊流模型,对簇状分布的刚性双层植被明渠水流进行了模拟和分析;根据时间及空间的双平均方法对植被明渠水流的流速及紊动参数进行了统计。结果表明:簇状分布的植被明渠水流可以分为植物区、间隙区及主流区,不同区域时均流速的大小和分布各异;双层植被明渠水流中,时均流速垂线分布在近床面、低植物顶部附近及高植物顶部附近均出现拐点,脉动强度和紊动能的最大值出现在高植物顶部附近。 展开更多
关键词 双层植被 簇状分布 植被明渠水流 紊流特性 紊动能
下载PDF
口炎清颗粒(无糖)治疗慢性咽炎的多中心、随机、开放、阳性平行对照临床研究
13
作者 张孝文 马兆鑫 +7 位作者 霍红 江萍 何培杰 谢景华 任理 林娟 刘旻 魏春生 《中华中医药学刊》 CAS 北大核心 2024年第9期1-4,共4页
目的评价口炎清颗粒(无糖)治疗慢性咽炎的有效性和安全性。方法采用多中心、随机、开放、阳性平行对照方法,将纳入的186例慢性咽炎患者按1∶1比例随机分为试验组与对照组,分别给予口炎清颗粒(无糖)、慢严舒柠?清喉利咽颗粒,服用方法为... 目的评价口炎清颗粒(无糖)治疗慢性咽炎的有效性和安全性。方法采用多中心、随机、开放、阳性平行对照方法,将纳入的186例慢性咽炎患者按1∶1比例随机分为试验组与对照组,分别给予口炎清颗粒(无糖)、慢严舒柠?清喉利咽颗粒,服用方法为口炎清颗粒(无糖)一次2袋,2次/d,慢严舒柠?清喉利咽颗粒一次1袋,3次/d,两组疗程均为4周。观察慢性咽炎患者的咽痛、咽痒、咽干等临床症状。结果调整意向治疗患者,试验组92例,对照组88例。主要有效性指标第28天的临床症状与总有效率,试验组为76.7%,对照组为71.8%,两组差异无统计学意义(P>0.05),总有效率试验组非劣效于对照组。次要有效性指标第7天的临床症状与体征总有效率,试验组为32.6%,对照组为19.3%,两组比较差异有统计学意义(P<0.05)。治疗第28天单项临床症状与体征咽痛消失率,试验组为58.0%,对照组为34.0%,两组比较差异有统计学意义(P<0.05)。其他次要有效性评价指标,两组差异均无统计学意义,但试验组的点估计值高于对照组。试验中,不良事件发生率试验组为30.4%,对照组为27.3%。严重不良事件,试验组1例,对照组2例。与试验药物相关的治疗期不良事件试验组和对照组均有2例。两组不良事件发生率比较,差异无统计学意义(P>0.05)。结论口炎清颗粒(无糖)治疗慢性咽炎,可有效改善临床症状,且临床应用安全性较好。 展开更多
关键词 口炎清颗粒(无糖) 慢性咽炎 随机开放试验
下载PDF
基于网格优化双层随机森林的采空区煤氧化升温预测研究
14
作者 张春 隋彦臣 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第5期177-183,共7页
为了对采空区煤氧化升温的温度进行预测,在内蒙古某煤矿16402综放工作面进行长期的采空区气体和温度观测实验,采集到准确的采空区煤氧化升温过程中气体及温度数据,提出1种基于网格优化双层随机森林(WG-DRF)的采空区煤氧化升温预测方法,... 为了对采空区煤氧化升温的温度进行预测,在内蒙古某煤矿16402综放工作面进行长期的采空区气体和温度观测实验,采集到准确的采空区煤氧化升温过程中气体及温度数据,提出1种基于网格优化双层随机森林(WG-DRF)的采空区煤氧化升温预测方法,用该方法构建预测模型并与传统随机森林、BP神经网络和支持向量回归模型的预测结果进行对比。研究结果表明:WG-DRF模型预测的平均绝对误差MAE,均方误差MSE,决定系数R~2分别为1.725,6.158,0.903,优于其他模型。通过更换数据集对WG-DRF方法进行测试,验证双层随机森林模型具有较强的泛化性。研究结果可为采空区煤氧化升温的温度预测提供参考。 展开更多
关键词 采空区 煤氧化升温 温度预测 网格优化双层随机森林
下载PDF
双种群协同演化的改进蜜獾算法
15
作者 柴岩 王如新 任生 《计算机应用研究》 CSCD 北大核心 2024年第3期736-745,771,共11页
针对蜜獾算法存在的局部搜索能力不足、易陷入局部最优值等问题,提出一种双种群协同演化的改进蜜獾算法。在初始化阶段采用Cubic混沌映射对种群进行初始化,扩大可行解的搜索范围并提高种群的分布均衡性;引入融合黏菌算法和蜜獾算法的双... 针对蜜獾算法存在的局部搜索能力不足、易陷入局部最优值等问题,提出一种双种群协同演化的改进蜜獾算法。在初始化阶段采用Cubic混沌映射对种群进行初始化,扩大可行解的搜索范围并提高种群的分布均衡性;引入融合黏菌算法和蜜獾算法的双种群优化机制,依托两者的更新优势协同推进个体逼近目标位置,进而提高整个算法的搜索效率和优化性能;采用柯西随机反向扰动策略对蜜獾种群最优位置进行扰动,以提高算法跳出局部最优的能力。通过评估单一策略的改进有效性实验、与七种对比算法的不同高维实验以及Wilcoxon秩和检验,结果表明该算法具有良好的收敛精度和求解速度。最后将改进算法应用于压缩弹簧设计和压力容器设计问题,进一步验证了改进策略的有效性及该算法的工程实用性。 展开更多
关键词 蜜獾算法 Cubic混沌映射 双种群协同优化 柯西随机反向扰动 工程应用
下载PDF
在自由贸易试验区发展跨境科技贸易的实证分析:以海南为例
16
作者 任丽梅 黄意泉 《重庆社会科学》 北大核心 2024年第8期111-123,共13页
发展跨境科技贸易可以最大限度地匹配科技创新资源,带动经济社会真正转到依靠科技创新的发展轨道上来。随着科技水平的快速提升,中国发展跨境科技贸易的基础与条件日趋成熟。而享有零关税、低税率优惠政策以及在人员资金信息数据来往等... 发展跨境科技贸易可以最大限度地匹配科技创新资源,带动经济社会真正转到依靠科技创新的发展轨道上来。随着科技水平的快速提升,中国发展跨境科技贸易的基础与条件日趋成熟。而享有零关税、低税率优惠政策以及在人员资金信息数据来往等方面具有更多优势的自由贸易试验区将是发展跨境科技贸易的前沿。海南自贸港背靠国家科技力量和新型科技创新举国体制的战略与政策支持,较早试行发展跨境科技贸易,为自由贸易试验区乃至全国发展跨境科技贸易提供了宝贵经验。未来,全国的自由贸易试验区都应充分发挥自贸区最高水平开放政策激励的价值和作用,主动布局积极融入并引导国际科技创新大循环,将自身建设成为国家科技创新双循环的重要交汇点。 展开更多
关键词 科技贸易 自由贸易试验区 科技创新双循环 最高水平开放
下载PDF
基于小波压缩深度学习重构的多图像光学加密
17
作者 郭媛 贾德宝 +1 位作者 敬世伟 翟平 《计算机工程与设计》 北大核心 2024年第2期367-375,共9页
为解决多图像加密算法密文体积大、加密效果差、重构效果不理想等问题,提出一种基于小波压缩和深度学习重构的多图像光学加密方法。利用小波压缩提取多图像的低频部分,将重排后的新图放入改进的FDT-DRPE光学加密系统中得到密文;利用矢... 为解决多图像加密算法密文体积大、加密效果差、重构效果不理想等问题,提出一种基于小波压缩和深度学习重构的多图像光学加密方法。利用小波压缩提取多图像的低频部分,将重排后的新图放入改进的FDT-DRPE光学加密系统中得到密文;利用矢量分解和螺旋相位变换克服FDT-DRPE不敏感问题;构造的L_S混沌系统提高密钥敏感性。提出新型深度学习网络模型BHCN,解决传统图像重构精度不高问题。实验结果表明,密文体积可压缩至原图的1/4,重构图像的峰值信噪比为34.57 dB,结构相似性为0.9521,与同类文献相比,速度更快,重构效果更好,安全性更高。 展开更多
关键词 多图像光学加密 深度学习 小波压缩 菲涅尔双随机相位编码 矢量分解 混沌系统 比特分层
下载PDF
小转弯曲线隧道TBM选型与掘进姿态调控方法
18
作者 杜立杰 郝洪达 +5 位作者 杨亚磊 李青蔚 张卫东 刘家驿 冯宏朝 贾连辉 《隧道建设(中英文)》 CSCD 北大核心 2024年第5期1106-1115,共10页
小转弯隧道施工时全断面隧道掘进机(full-section tunnel boring machine,TBM)的选型设计和掘进姿态控制具有特殊性,目前还缺乏通用的理论依据和指导方法。针对此问题,首先,对传统类型TBM小转弯选型进行研究,结合已有项目数据和几何模拟... 小转弯隧道施工时全断面隧道掘进机(full-section tunnel boring machine,TBM)的选型设计和掘进姿态控制具有特殊性,目前还缺乏通用的理论依据和指导方法。针对此问题,首先,对传统类型TBM小转弯选型进行研究,结合已有项目数据和几何模拟,确定传统类型TBM能适应的最小转弯半径。然后,对双盾敞开式TBM的推进系统和导向系统进行针对性设计,通过分析双盾敞开式TBM推进系统结构和实际施工,提出转弯时双盾敞开式TBM推进油缸内外侧行程差值的理论计算方法和施工过程中的姿态调控方法。最后,得出如下结论:1)当隧道转弯半径小于200 m时,敞开式TBM适应难度较大,需要采用双盾敞开式TBM;2)结合抚宁抽水蓄能电站项目实际施工情况,提出的双盾敞开式TBM的理论计算方法和姿态调控方法确保了转弯段隧道的轴线偏差在要求范围内。 展开更多
关键词 全断面隧道掘进机 选型设计 双盾敞开式TBM 小转弯掘进 姿态调控
下载PDF
“双高”院校开放式党建工作格局构建探索
19
作者 方静 《芜湖职业技术学院学报》 2024年第1期16-18,共3页
基层党建工作应打破地域界限和党组织间壁垒,促进各种要素流动,探索党建体制机制创新。“双高”院校始终坚持以服务为宗旨、以就业为导向、以技能为核心的办学指导思想,通过党建引领,构建“开放式党建”格局,促进不同类型党组织资源共... 基层党建工作应打破地域界限和党组织间壁垒,促进各种要素流动,探索党建体制机制创新。“双高”院校始终坚持以服务为宗旨、以就业为导向、以技能为核心的办学指导思想,通过党建引领,构建“开放式党建”格局,促进不同类型党组织资源共享、组织共建、人才共育、品牌共创,驱动学校党建与业务深入融合。 展开更多
关键词 “双高”院校 开放式党建 合作平台 党建体制创新 高质量发展
下载PDF
考虑双重剪切的开放系统梯形渠道Pasternak双参数冻土地基梁模型 被引量:2
20
作者 肖旻 王正中 +3 位作者 吴浪 杨晓松 崔浩 葛建锐 《工程力学》 EI CSCD 北大核心 2024年第4期70-80,共11页
Winkler冻土地基模型无法考虑土弹簧间相互作用,且需要预先假定切向冻结力分布。为克服这些不足之处,在现有模型基础上引入Pasternak剪切层反映冻土-衬砌间法向相互作用,引入切向弹簧组成的接触界面层反映冻土-衬砌间切向相互作用,构建... Winkler冻土地基模型无法考虑土弹簧间相互作用,且需要预先假定切向冻结力分布。为克服这些不足之处,在现有模型基础上引入Pasternak剪切层反映冻土-衬砌间法向相互作用,引入切向弹簧组成的接触界面层反映冻土-衬砌间切向相互作用,构建考虑双重剪切的梯形渠道Pasternak双参数冻土地基模型。以塔里木灌区某渠道为例计算衬砌冻胀变形,并与材料力学法、Winkler模型计算值及观测值进行对比。结果表明:与材料力学法、Winkler模型相比,该文模型计算值更接近观测值。根据该模型估算的衬砌板易开裂范围也与灌区现场调查结果相符,表明模型适用性。通过参数研究分析了界面切向刚度kx对各处切向位移及切向冻结力分布的影响。结果表明:kx越小时,切向位移与切向冻结力趋于线性分布;kx较大时,两者均偏离线性分布且kx越大偏离越明显,线性分布假设不再适用。该模型可较充分地反映冻土与衬砌板间接触界面相互作用的基本特征,从而有效提高模型的计算精度。 展开更多
关键词 冻土工程 渠道 冻胀 Pasternak模型 双重剪切 开放系统
下载PDF
上一页 1 2 78 下一页 到第
使用帮助 返回顶部