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基于变形的降雨后地震基覆型边坡劣化特性与机制研究

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岩土力学 2024年第6期45卷 1789-1802页

作者：何梓雷蒋关鲁冯海洲陈虹羽郭玉丰何晓龙李杰西南交通大学土木工程学院四川成都610031 西南交通大学高速铁路线路工程教育部重点实验室四川成都610031 中铁十八局集团有限公司天津300222

降雨地震多因素作用下基覆型边坡破坏模式的识别和评估具有重大工程意义。为研究降雨后地震作用下基覆型边坡的失稳演化机制,开展一组大型振动台模型试验,基于边坡土体空间变形特性和坡面位移特性识别和评估边坡的劣化模式,综合土体应力... 详细信息

降雨地震多因素作用下基覆型边坡破坏模式的识别和评估具有重大工程意义。为研究降雨后地震作用下基覆型边坡的失稳演化机制,开展一组大型振动台模型试验,基于边坡土体空间变形特性和坡面位移特性识别和评估边坡的劣化模式,综合土体应力−应变特性、渗流场特性、地震动应力分布及边坡变形特性,对降雨后地震下边坡的变形演化机制进行探讨。结果表明:(1)降雨阶段,边坡坡顶与坡脚饱和度显著升高区强度劣化显著,但整体无明显变形;地震阶段,坡顶首先滑塌失稳,进一步演化为多级滑塌的整体失稳。(2)宏观破坏具有突发特征,边坡内部土体的空间应变分布特性能更好地识别边坡塑性区扩展−贯通−失稳的演化历程。(3)基于位移残余率分析的边坡失稳演化模式与土体空间应变演化特性结果吻合,相较于累积位移量对边坡损伤状态的识别更准确。(4)含水率变化影响土体力学特征,降雨后的渗流场分布影响边坡整体力学特性及地震动应力的传递及空间分布,土体力学特性和动应力空间特征决定边坡的破坏模式。

关键词：基覆型边坡振动台试验降雨变形空间特性劣化机制稳定性评估

地震作用下桩板墙-锚索组合支护基覆型边坡的动力响应特性

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岩土力学 2024年第7期45卷 2011-2023页

作者：何梓雷蒋关鲁冯海洲潘申鑫何晓龙李杰西南交通大学土木工程学院四川成都610031 西南交通大学高速铁路线路工程教育部重点实验室四川成都610031 中铁十八局集团有限公司天津300222

地震作用下,惯性力方向对组合结构、土体、岩体的平衡状态影响显著。为深入理解桩板墙组合支护结构-基覆型边坡相互作用特性,以西南地区一隧道进口端基覆型高陡边坡为原型,开展一组简谐波加载下组合结构加固边坡的大型振动台模型试验,... 详细信息

地震作用下,惯性力方向对组合结构、土体、岩体的平衡状态影响显著。为深入理解桩板墙组合支护结构-基覆型边坡相互作用特性,以西南地区一隧道进口端基覆型高陡边坡为原型,开展一组简谐波加载下组合结构加固边坡的大型振动台模型试验,考虑惯性力方向对桩-土、格构锚索-坡体时程特性展开分析。结果表明:(1)惯性力作用下格构锚索-土体相互作用与桩-土相互作用表现出近似的时程一致性规律,但坡面加固结构惯性力峰值沿高程存在的相位差不可忽视。(2)结构与边坡土体的相互作用大小取决于相对惯性运动,桩-基岩相互作用由悬臂段变形状态决定。(3)惯性力达到临空面峰值,动土压力达到峰值,桩-土位移差达到正向峰值,桩身呈现外倾的主动破坏状态,锚固段前侧受力因外倾而挤压增大,因而悬臂段采用库仑主动土压力进行设计需结合桩土状态进行修正。(4)简谐波作用下,坡体惯性力及变形是组合支挡结构沿高程受力分布特性的关键因素,组合结构设计时需重点关注坡脚应力集中区及坡顶惯性力放大区。本研究可为组合结构抗震加固设计提供理论支撑。

关键词：高陡边坡桩板墙锚索振动台试验相互作用时程特性相位

Outcome of in vitro fertilization in endometriosis-associated infertility： a 5-year database cohort study

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Chinese Medical Journal 2012年第15期125卷 2688-2693页

作者： LIN Xiao-na WEI Min-ling TONG Xiao-mei XU Wei-hai zhou feng HUANG Qiong-xiao WEN Guo-feng ZHANG Song-ying Assisted Reproduction Unit Department of Obstetrics andGynecology Sir Run Run Shaw Hospital Zhejiang UniversitySchool of Medicine Hangzhou Zhejiang 310016 China

Background Endometriosis affects natural fertility through various approaches, and in vitro fertilization （IVF） is a good treatment. But the IVF result of endometriosis patients is still under debate. We investigated the effect of endometriosis on IVF by analyzing the data from a single reproductive center. Methods A retrospective, database-searched cohort study was performed. Relevant information was collected from the electronic records of women who underwent IVF/intracytoplasmic sperm injection between January 2006 and December 2010 in the Assisted Reproductive Unit of Sir Run Run Shaw Hospital. Patients with endometriosis were enrolled the study group. The rest of the women formed the control group. The main outcome was the clinical pregnancy rate. Secondary outcomes were oocytes retrieved number, fertilization rate, high-quality embryo rate, number of high-quality embryo for embryo transplantation, and implantation embryo/high-quality embryo ratio （IE/HQE ratio）. Comparisons were performed by the z2-test and independent t-test. Results The endometriosis group （n=177） had a markedly lower oocytes retrieved number, fertilization rate, implantation rate, and clinical pregnancy rate （7.6_＋5.1, 63.6%, 27.7%, and 45.2%, respectively） compared with the non-endometriosis group （n=4267; 11.8＋7.3, 68.4%, 36.2%, and 55.2%, respectively）. Stratified analysis showed that this difference was found in the subgroup younger than 35-years old, while only fertilization rate and implantation rate were different in the elder subgroup. The ratio of high-quality embryos transferred is lower in endometriosis group （53.7% vs. 71.8%, P 〈0.05）, but there is no difference in IE/HQE ratio between two groups. There is no significant difference in fertilization rate, implantation rate, and clinical pregnancy rate between mild and severe endometriosis patients. Conclusions Endometriosis patients suffer a decreasing IVF pregnancy rates mainly caused by reducing oocytes number and fertilization

关键词： fertilization in vitro, endometriosis pregnancy rate cohort study

Rapid recovery of desert shrubs is attributed to imbalance of water supply to demand after disturbance in Northwest China

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Ecological Processes 2024年第02期13卷 118-129页

作者： hai zhou Xiangyan feng Zhibin He Qiyue Yang Heng Ren Wenzhi Zhao Linze Inland River Basin Research Station Chinese Ecosystem Research Network Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences University of Chinese Academy of Sciences

Background Disturbance is a key driver of changes in terrestrial ecosystems, especially in water limited regions. In the desert ecosystem of Northwest China, shrubs are often foraged by camels and this causes the shrubs lost their aboveground tissues. Although the aboveground tissue could recover after the disturbance, the mechanisms of resprouts' recovery after the disturbance are still poorly understood. We investigated the morphological and physiological characteristics and root water uptake sources of resprouts and non-disturbed seedlings of four desert shrub species that were often foraged by *** The results showed that the resprouts grew rapidly after the removal of aboveground tissue. The height and aboveground biomass of resprouts reached the level of 5-year-old seedlings following a growing season. Compared to un-disturbed seedlings, higher leaf water potential, leaf hydraulic conductance and photosynthesis rate were observed in resprouts, indicating that resprouts grew rapidly after disturbance. Furthermore, we found that the root water uptake source did not change after disturbance. This indicated that the roots of resprouts kept intact water uptake capacity after disturbance, which could keep supplying sufficient water to the aboveground tissue. Due to the removal of aboveground tissue of the resprouts, the water demand of aboveground tissue decreased, which induced an imbalance of water supply from roots to demand of aboveground tissues of resprouts. This explained the improved physiological performance and rapid recovery of resprouts after *** The imbalance of water supply to demand contributes to the rapid recovery of desert shrubs after disturbance. The findings provide insight into the eco-physiological mechanism for the maintenance of desert ecosystems that are facing disturbance.

关键词： Disturbance Resprout Physiological performance Shrub Water uptake source

Supermassive black holes triggered by QCD axion bubbles

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Communications in Theoretical Physics 2024年第5期76卷 134-139页

作者： hai-Jun Li Ying-Quan Peng Wei Chao Yu-feng zhou Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/HangzhouChina

Supermassive black holes(SMBHs)are ubiquitous in the center of galaxies,although the origin of their massive seeds is still *** this paper,we investigate the formation of SMBHs from the quantum chromodynamics(QCD)axion *** this case,primordial black holes(PBHs)are considered as the seeds of SMBHs,which are generated from the QCD axion bubbles due to an explicit Peccei–Quinn(PQ)symmetry breaking after *** QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase *** consider a general case in which the axion bubbles are formed with the bubble effective angle θ_(eff)∈(0,π],leading to the minimum PBH mass∼■(10^(4)−10^(7))M⊙for the axion decay constant f_(a)∼■(10^(16))*** PBHs at this mass region may account for the seeds of SMBHs.

关键词： supermassive black holes primordial black holes quantum chromodynamics axion

Microalbuminuria associated with systolic blood pressure and arterial compliance in Chinese metabolic syndrome patients

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Chinese Medical Journal 2007年第16期120卷 1395-1399页

作者： LI Xin-li XU Qiong LU Xin-zheng ZHANG hai-feng zhou Yan-li CAO Ke-jiang HUANG Jun Department of Cardiology First Aftiliated Hospital of Nanjing Medical University Nanjing 210029 China

Background There is significant evidence showing that microalbuminuria and arterial compliance are sensitive markers for early cardiovascular diseases. However, whether microalbuminuria is associated with reduced arterial compliance in Chinese metabolic syndrome （MS） patients remains unknown. Methods According to the definition of MS proposed by ATPⅢ in 2001, USA, subjects （n=362） were divided into three groups according to the number of risk factors： group 1 （control）, group 2 （medium, 〈 3 risk factors） and group 3 （MS, ≥ 3 risk factors）. Both large artery compliance （C1） and small artery compliance （C2） were measured with the CVProfilor DO-2020 Cardiovascular Profiling System, and microalbuminuria was evaluated with the ratio of albumin to urine creatinine. Results （1） As C1 and C2 levels elasticity decreased, albumin creatinine ratio （ACR） and the prevalence of microalbuminuria increased within those groups with MS risk factors. C1 and C2 were negatively correlated with the ranking of MS risk factors, ACR was positively correlated with the ranking of MS risk factors （all P〈0.05）. （2） Subjects were also categorized into a microalbuminuria group and a normal group, C1 and C2 in the microalbuminuria group were lower than in the normal group. （3） Multivariate regression analysis showed that increased systolic blood pressure （SBP） and reduced arterial compliance were the main risk factors for microalbuminuria in the MS group. Conclusions The risk of developing microalbuminuria was higher in the subjects with multiple metabolic abnormalities. Increased systolic blood pressure and reduced arterial compliance may be the main predictors for microalbuminuria in MS.

关键词： metabolic syndrome microalbuminuria arterial elasticity

A hybrid technique： intra-arterial catheter-directed thrombolysis following the recanalization of superior mesenteric artery in acute mesenteric ischemia

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Chinese Medical Journal 2013年第7期126卷 1381-1383页

作者： ZHU Jie-chang DAI Xiang-chen FAN hai-lun feng zhou ZHANG Yi-wei LUO Yu-dong Department of General Surgery General Hospital of Tianjin Medical University Tianjin 300052 China

Acute mesenteric ischemia is a deadly process withoverall mortality rate of 40%. Acute thrombosis of an atherosclerotic lesion with previous partial occlusion isone of the common causes. Peri-operative mortality ofsu... 详细信息

关键词： superior mesenteric artery mesenteric ischemia thrombosis embolectomy angioplasty intra-arterial catheter-directed thrombolysis

Derivation of Expanded Isospectral-Nonisospectral Integrable Hierarchies via the Column-vector Loop Algebra

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 778-800页

作者： hai-feng WANG Yu-feng ZHANG School of Science Jimei UniversityXiamen 361021China School of Mathematics China University of Mining and TechnologyXuzhou 221116China

A scheme for generating nonisospectral integrable hierarchies is *** on the method,we deduce a nonisospectral hierarchy of soliton equations by considering a linear spectral *** follows that the corresponding expanded isospectral and nonisospectral integrable hierarchies are deduced based on a 6 dimensional complex linear space ■.By reducing these integrable hierarchies,we obtain the expanded isospectral and nonisospectral derivative nonlinear Schr?dinger *** using the trace identity,the biHamiltonian structure of these two hierarchies are also ***,some symmetries and conserved quantities of the resulting hierarchy are discussed.

关键词： expanded isospectral-nonisospectral integrable hierarchies column-vector loop algebra bi-Hamiltonian structure symmetry

Catalyst-free and Reprocessable Aromatic Polydithiourethanes

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Chinese Journal of Polymer Science 2024年第10期42卷 1435-1441页

作者： Bo Yang hai-Jun feng Tian-Tian Ni Xiao-Rui zhou Tao Xie Ning Zheng State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering Zhejiang University Department of Colorectal Surgery and Oncology Key Laboratory of Cancer Prevention and Intervention Ministry of Education The Second Affiliated HospitalZhejiang University School of Medicine

The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks, thereby meeting the sustainable requirements for polymer recycling. However, the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing conditions. In this work, we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst, enabling the efficient reprocessing of the corresponding *** a consequence, the mechanical properties of the polydithiourethane can be largely preserved after reprocessing. The discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.

关键词： Dynamic covalent bond Polydithiourethane Reprocessing