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充填混凝土徐变特性的试验

长沙矿山研究院季刊 1981年第1期 84-91页

作者：柳自强何荣生长沙矿山研究院锡矿山矿务局工程师

本文论述锡矿山南矿胶结充填混凝土的徐变特性。文中简要介绍了目前沿用的徐变基本理论和本试验工作的研究方法及条件,分别用图解法和拟合法对试验结果进行了整理和分析,阐明了该种混凝土在单轴压缩荷载作用下的徐变特性,得出了其瞬时... 详细信息

本文论述锡矿山南矿胶结充填混凝土的徐变特性。文中简要介绍了目前沿用的徐变基本理论和本试验工作的研究方法及条件,分别用图解法和拟合法对试验结果进行了整理和分析,阐明了该种混凝土在单轴压缩荷载作用下的徐变特性,得出了其瞬时弹性模量及徐变度的经验公式。

关键词：徐变试件持荷混凝土无机非金属材料徐变度龄期生活史弹性模量弹性系数徐变变形

Clinicopathological differences between patients with schistosomal appendicitis and non schistosomal appendicitis:A retrospectively study of past ten years

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World Journal of Clinical Cases 2025年第2期13卷 24-32页

作者： Xiao-Yi Wang Yao Hao zi-jian Wang Xiu-Liang Xu jiang-Hua Yang Department of Infectious Diseases The First Affiliated of Wannan Medical CollegeWuhu 241001Anhui ProvinceChina

BACKGROUND Chronic schistosomiasis causes multiple organ and multiple system diseases,especially the digestive *** eggs are mainly deposited in the stomach,liver and colorectal,but a few eggs are deposited in the appendix and cause *** present,there are few studies on schistosomal *** To explore the differences in epidemiological,clinical and pathological characteristics between schistosomal appendicitis and non-schistosomal appendicitis over the past decade in order to assess the impact of schistosomiasis on *** The differences of general data,clinical data and laboratory examination data of patients with appendicitis from October 2013 to October 2023 were retrospectively *** patients were divided into two groups for *** were 136 patients in schistosomal appendicitis group and 5418 patients in non-schistosomal appendicitis *** Schistosomal appendicitis accounted for 2.45%of all patients with appendicitis,and the annual proportion in the past decade was 2.2%,2.9%,1.8%,1.9%,3.4%,3.1%,1.9%,1.6%,3%,2.6%,*** prevalence of schistosomal appendicitis was middle-aged and elderly males,with an average age of 61.73±15.335 *** main population of non-schistosomal appendicitis was middle-aged men,with an average age of 35.8±24.013 years(Phe distribution of pathological types of appendicitis was different between the two groups(Phe incidence of acute suppurative appendicitis in non-schistosomal appendicitis was higher than that in schistosomal appendicitis[odds ratio(OR)=0.504;95%confidence interval(CI):0.349-0.728;Phe proportion of acute attack of chronic appendicitis in schistosomal appendicitis was higher than that in non-schistosomal appendicitis(OR=2.614;95%CI:1.815-3.763;Phe proportion of schistosomal appendicitis patients complicated with colorectal cancer was higher than that of nonschistosomal appendicitis patients(OR=5.087;95%CI:1.427-

关键词： Schistosomal appendicitis Schistosomiasis Appendix Colorectal cancer Clinicopathological characteristics

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不同溶剂抽提对杉木声学振动性能的影响

林产工业 2017年第3期44卷 21-25页

作者：武亚峰黄文娟赵紫剑何正斌伊松林北京林业大学材料科学与技术学院

为研究不同溶剂抽提对杉木声学振动性能的影响,分别用苯醇、二氯甲烷和冷水对杉木试件进行固体抽提处理并对抽提物化学成分进行检测分析。研究发现:冷水抽提后,杉木的比动弹性模量平均降低了1.25%,对数衰减系数平均提高了4.28%,而二氯... 详细信息

为研究不同溶剂抽提对杉木声学振动性能的影响,分别用苯醇、二氯甲烷和冷水对杉木试件进行固体抽提处理并对抽提物化学成分进行检测分析。研究发现:冷水抽提后,杉木的比动弹性模量平均降低了1.25%,对数衰减系数平均提高了4.28%,而二氯甲烷和苯醇抽提后,杉木的比动弹性模量分别平均提高了2.91%和5.59%,对数衰减系数分别平均降低了13.05%和13.73%。分析抽提物成分发现,萜烯类化合物抑制了杉木声学振动性能的提高,烃类等抽提物的存在则有利于提高杉木的声学振动性能。

关键词：抽提杉木振动性能 GC-MS

Observations of counter-propagating Alfvénic and compressive fluctuations in the chromosphere

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Research in Astronomy and Astrophysics 2014年第3期14卷 299-310页

作者： zi-Xu Liu jian-Sen he Li-Mei Yan School of Earth and Space Sciences Peking University

Recent observations have found that chromospheric spicules behave likeAlfvenic fluctuations. Low-frequency Alfven waves are predicted to partially reflectin the transition region that has a gradient in the Alfven speed, thereby producinginward Alfven waves, which may interact nonlinearly with outward Alfven wavesto generate Alfv6nic turbulence. However, the signature of Alfvenic turbulence in thechromosphere has not yet been quantitatively analyzed with observations. here we an-alyze some characteristics related to Alfv6nic turbulence with the observations fromHinode/SOT. We decompose the height-time diagram of the transverse oscillationsto separate the outward and inward propagating Alfvenic-like signals. The counter-propagating waves are found to have similar amplitude, period and phase speed, sug-gesting a state having an approximate balance in bi-directional energy fluxes. Counter-propagation of intensity oscillation with lower propagation speed is also presented,probably indicating the presence of slow mode waves. Moreover, we attempt to esti-mate the Elseisser spectra of the chromospheric turbulence for the first time. The rela-tive fluctuations in the magnetic field may be measured as the local slope of wave-likeshapes in spicules. The resulting low-frequency Elsaisser power spectra look similarto each other without showing a dominant population, which confirms these counter-propagating low-frequency Alfv6nic waves are in a state of balanced flux. These obser-vational results are believed to help us better understand the nature of chromosphericturbulence as well as chromospheric heating.

关键词： Sun: chromosphere turbulence solar wind

基于机器学习筛选猪活体肌内脂肪含量间接选育和构建预测模型的关键性状

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南京农业大学学报 2025年第1期48卷 161-170页

作者：吴建杨文孟孜查成万吴望军南京农业大学动物科技学院江苏南京210095

[目的]本研究旨在探究猪断奶重、屠宰前活体重、背膘厚等性状因素对猪肌内脂肪(intramuscular fat,IMF)含量的影响,确定影响猪IMF含量的关键性状因素。[方法]以805头皮特兰×[杜洛克×(长白×大白)]四元商品猪群为试验对象,记录性别,测... 详细信息

[目的]本研究旨在探究猪断奶重、屠宰前活体重、背膘厚等性状因素对猪肌内脂肪(intramuscular fat,IMF)含量的影响,确定影响猪IMF含量的关键性状因素。[方法]以805头皮特兰×[杜洛克×(长白×大白)]四元商品猪群为试验对象,记录性别,测定初生重、断奶重、屠宰前活体重和IMF含量等14个性状,然后通过相关性分析从14个性状中初步筛选出影响IMF含量的性状因素,再通过随机森林模型评估各性状因素对IMF含量影响的重要性,进一步通过LASSO回归和逐步回归筛选出影响IMF含量的关键性状因素;在此基础上,利用广义线性模型(generalized linear model,GLM)分析关键性状因素不同水平对IMF含量的影响。[结果]相关性分析结果显示,猪IMF含量与断奶重(r=0.13, P0.05)。胸腰椎结合处背膘厚大于26 mm组的平均IMF含量(2.73%)显著高于其他背膘厚组(P0.05)。[结论]本研究通过机器学习确定了性别、断奶重、屠宰前活体重和胸腰椎结合处背膘厚4个与IMF含量显著相关的活体可测定性状,并发现平均IMF含量随着屠宰前活体重和胸腰椎结合处背膘厚的增加呈明显的上升趋势。

关键词：猪肌内脂肪间接选择模型构建机器学习活体可测定性状

Effects of Ag addition on the microstructures and properties of Al–Mg–Si–Cu alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 62-72页

作者： Li-zi he Yi-heng Cao Yi-zhou Zhou jian-zhong Cui Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern University School of Materials Science and Engineering Northeastern University Institute of Metal Research Chinese Academy of Sciences

Effects of Ag addition on the microsmactures, aging characteristics, tensile properties, electrochemical properties, and intergranu- lar corrosion （IGC） properties of Al 1.1Mg-0.8Si-0.9Cu-0.35Mn4）.02Ti alloy were investigated using scanning electronic microscopy and transmission electronic microscopy. The aging process of Al-Mg-Si-Cu alloys was accelerated by the addition of Ag. The strength of peak-aged Al-Mg-Si-Cu alloys was enhanced by Ag addition because of the high density of β＂- and L-phase age-hardening precipitates. The corrosion performance of the Al-Mg-Sii-Cu alloy is closely related to the aging conditions and is independent of the Ag content. The IGC susceptibility is serious in the peak-aged alloy because of the continuous distribution of Cu-rich Q-phase precipitates along grain boun- daries. Ag addition reduces the size of the grain-boundary-precipitate Q phase and the width of the precipitate-free zone and thus results in decreased IGC susceptibility of Al-Mg-Si Cu alloys.

关键词： Al-Mg-Si-Cu alloys silver addition aging tensile properties corrosion properties microstructures

Three-dimensional numerical simulation and earth pressure analysis on double-row piles with consideration of spatial effects

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第10期12卷 758-770页

作者： zi-han WANG jian ZHOU Department of Geotechnical Engineering Tongji University Shanghai 200092 China

As a new kind of technology in retaining structures, the characteristics of double-row piles are significantly affected by spatial effects. In this paper, double-row piles as a retaining structure are simulated numerically in three-dimension by finite element software PLAXIS 3D FOUNDATION. The behavior differences of piles in different positions around the foundation pit are analyzed. By changing the parameters, including the length-width ratio, the excavation depth, the distance between rows and the diameter of piles, the variations of the lateral deformation, the bending moment and the earth pressure around the piles are determined. The reasonable values of parameters and some suggestions with consideration of earth pressure are proposed for the design of double-row piles as a retaining structure. The results show that the lateral deformation and bending moment are the largest in the middle of long side of the foundation pit, which is identified as the most unfavorable position. It is indicated that the earth pressure between rows above pit bottom is close to active earth pressure, while the earth pressure between rows under pit bottom is close to static earth pressure. It is suggested that 1/2-2/3 of pile length, 0.6-1.2 m, 3d-6d, and 2d-2.5d be chosen as embedded depth of piles, diameter of piles, distance between rows, and distance between piles, respectively, where d is the pile diameter.

关键词： Double-row piles Retaining structure Spatial effect Finite element Earth pressure

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

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Petroleum Science 2024年第4期21卷 2625-2637页

作者： Zhi-Qiang he he-Ping Xie Ling Chen jian-Ping Yang Bo Yu zi-Jie Wei Ming-Zhong Gao State Key Laboratory of Intelligent Construction and healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065SichuanChina Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen518060GuangdongChina School of Mechanical Engineering Sichuan UniversityChengdu610065SichuanChina College of Polymer Science and Engineering Sichuan UniversityChengdu610065SichuanChina

Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource *** development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are ***,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation *** materials properties under coupled hightemperature and high-pressure(HTHP)conditions were *** results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the *** temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal *** temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the *** materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring ***,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 *** further improve the materials properties,the interface layer and EP matrix should be *** results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resourc

关键词： Deep oil and gas reservoir rock In situ temperature-preserved coring(ITPCoring) Hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials) High-temperature and high-pressure(HTHP) Physical and mechanical properties

New multi-camera calibration algorithm based on 1D objects

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第6期9卷 799-806页

作者： zi-jian ZHAO Yun-cai LIU Institute of linage Processing and Pattern Recognition Shanghai Jiao Tong University Shanghai 200240 China

A new calibration algorithm for multi-camera systems using 1D calibration objects is proposed. The algorithm inte- grates the rank-4 factorization with Zhang (2004)'s method. The intrinsic parameters as well as the extrinsic parameters are re- covered by capturing with cameras the 1D object's rotations around a fixed point. The algorithm is based on factorization of the scaled measurement matrix, the projective depth of which is estimated in an analytical equation instead of a recursive form. For more than three points on a 1D object, the approach of our algorithm is to extend the scaled measurement matrix. The obtained parameters are finally refined through the maximum likelihood inference. Simulations and experiments with real images verify that the proposed technique achieves a good trade-off between the intrinsic and extrinsic camera parameters.

关键词： Multi-camera calibration Homography Factorization Scaled measurement matrix Projective depth