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A review of rock macro-indentation:Theories,experiments,simulations,and applications

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2351-2374页

作者： Weiqiang Xie Xiaoli liu Xiaoping Zhang xinmei Yang Xiaoxiong Zhou State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing100084China Yunlong Lake Laboratory of Deep Underground Science and Engineering Xuzhou221116China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application,such as drilling,tunneling,cutting,and sawing.Over the past decades,extensive research has been conducted to understand the indentation mechanisms and responses through various approaches.This review aims to provide an overview of the current status and recent advancements in theories,experiments,numerical simulations,and applications of macro-indentation in rock engineering.It starts with elaborating on the mechanisms of macro-indentation,followed by a discussion of the merits and limitations of commonly used models.Influence factors and their effects on indentation test results are then summarized.Various numerical simulation methods for rock macro-indentation are highlighted,along with their advantages and disadvantages.Subsequently,the applications of indentation tests and indentation indices in characterizing rock properties are explored.It reveals that compression-tension,compression-shear,and composite models are widely employed in rock macroindentation.While the compression-tension model is straightforward to use,it may overlook the anisotropic properties of rocks.On the other hand,the composite model provides a more comprehensive description of rock indentation but requires complex calculations.Additionally,factors,such as indentation rate,indenter geometry,rock type,specimen size,and confining pressure,can significantly influence the indentation results.Simulation methods for macro-indentation encompass continuous medium,discontinuous medium,and continuous-discontinuous medium methods,with selection based on their differences in principle.Furthermore,rock macro-indentation can be practically applied to mining engineering,tunneling engineering,and petroleum drilling engineering.Indentation indices serve as valuable tools for characterizing rock strength,brittleness,and drillability.This review sheds light on the development of rock macro-indentation and its extensive application in enginee

关键词： Rock macro-indentation Indentation test Indentation indices Mechanism Rock breaking

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Porous high-entropy rare-earth phosphate(REPO_(4),RE=La,Sm,Eu,Ce,Pr and Gd)ceramics with excellent thermal insulation performance via pore structure tailoring

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1651-1658页

作者： Peixiong Zhang Enhui Wang Jingjing liu Tao Yang Hailong Wang xinmei Hou Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China Liaoning Academy of Materials Shenyang 110000China Technical Support Center for Prevention and Control of Disastrous Accidents in Metal Smelting University of Science and Technology BeijingBeijing 100083China School of Materials Science Engineering Zhengzhou UniversityZhengzhou 450001China

Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4)(HE(6RE_(1/6))PO_(4))ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents(0–60vol%)on this ceramic properties was systematically investigated.The results show that the porous HE(6RE_(1/6))PO_(4)ceramics with 60vol%starch exhibit the lowest thermal conductivity of 0.061 W·m^(-1)·K^(-1)at room temperature and good pore structure stability with a linear shrinkage of approximately1.67%.Moreover,the effect of large regular spherical pores(>10μm)on its thermal insulation performance was discussed,and an optimal thermal conductivity prediction model was screened.The superior properties of the prepared porous HE(6RE_(1/6))PO_(4)ceramics allow them to be promising insulation materials in the future.

关键词： porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4) ceramics high-entropy strategy pore-forming agent method thermal insulation material thermal conductivity

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Competitive oxidation behavior of Ni-based superalloy GH4738 at extreme temperature

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 138-145页

作者： Hui Xu Shufeng Yang Enhui Wang Yunsong liu Chunyu Guo xinmei Hou Yanling Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Institute for carbon neutrality University of Science and Technology BeijingBeijing 100083China

A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isothermal experiments. As a result of the competitive diffusion of alloying elements, the oxide scale included an outermost porous oxide layer (OOL), an inner relatively dense oxide layer (IOL), and an internal oxide zone (IOZ), depending on the temperature and time. A high temperature led to the formation of large voids at the IOL/IOZ interface. At 1200℃, the continuity of the Cr-rich oxide layer in the IOL was destroyed, and thus, spallation occurred. Extension of oxidation time contributed to the size of Al-rich oxide particles with the increase in the IOZ. Based on this finding,the oxidation kinetics of GH4738 was discussed, and the corresponding oxidation behavior at 900-1100℃ was predicted.

关键词： Ni-based superalloy GH4738 extreme temperature competitive oxidation oxidation mechanism oxidation kinetics

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Surface cleaned Cu_(x)Pd_(y)alloy:Synthesis and their superior performances in hydrogen evolution reaction and biosensor

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Nano Research 2023年第5期16卷 7941-7949页

作者： xinmei liu Xue Li Wenlong Yang Gang liu Yu Wang Yuhang Zuo Harbin University of Science and Technology Harbin 150001China Jiangsu Zhongsheng Gaoke Environment Co. Ltd.Wuxi 214244China

High cost and restricted activity of electrocatalysis are the major challenges for hydrogen generation and biosensors.In this work,we provided a one-pot synthesis of Cu_(x)Pd_(y)alloy nanoparticles(NPs)with controllable atomic ratio and“clean surface”.Benefiting from the preferable d-band structure,the Cu_(62)Pd_(38)NPs exhibited a lower overpotentials in the hydrogen evolution reaction(HER)over the full pH range.In the acidic media,Cu_(62)Pd_(38)NPs achieved a low overpotential of 28.12 mV for HER,which was 25.73%of Pd NPs.In the neutral solution,the overpotential by Cu_(62)Pd_(38)NPs is only 41.71%for that by uncleaned CuPd NPs.In alkaline media,the overpotential by Cu_(62)Pd_(38)NPs was declined from 38.01 to 20.20 mV after 720 min yielding hydrogen,which was only 53.14%for the initial overpotential.As applied in biosensor,the synergistic effect of Cu and Pd accelerated the kinetics of electrocatalytic process,resulting in an enhanced performance.The glucose sensor constructed by Cu_(67)Pd_(33)exhibited a wider detection range up to 100.0 mM.And the sensitivity is 379.4μA/(mM·cm^(2)),which is ca.4.63 and 14.09 folds for that by pure Cu NPs and Pd NPs,respectively.An optimal atomic percent would be conducive to optimize electrocatalytic activity of Cu_(x)Pd_(y)alloy.The volcano plots for Cu_(x)Pd_(y)would open up a new avenue for designing electrocatalysis with rationalized cost and optimized performance.

关键词： alloy biosensor hydrogen evolution reaction overpotential detection range

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Lactobacillus rhamnosus MP108 alleviates ulcerative colitis in mice by enhancing the intestinal barrier， inhibiting inflammation， and modulating gut microbiota

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Food Science and Human Wellness 2024年

作者： Huizhen Li Yang Chen Huiting Fang xinmei Guo Xuecong liu Jianxin Zhao Wei Chen Bo Yang State Key Laboratory of Food Science and Resources Jiangnan University School of Food Science and Technology Jiangnan University Jinqiao Biotechnology Co. Ltd. Huai'an Jiangsu China National Engineering Research Center for Functional Food Jiangnan University International Joint Research Center for Probiotics & Gut Health Jiangnan University

Ulcerative colitis (UC) is a long-term inflammatory disorder that has evolved into a worldwide challenge. The development of new therapies against UC is imperative as all current therapies for UC are flawed in some way. Thus， the present study aimed to assess the palliative effects of Lactobacillus rhamnosus MP108 on UC in mice and to explore its potential mechanisms. The results showed that L. rhamnosus MP108 ameliorated the symptoms of UC， including preventing body weight loss， DAI elevation， and colon shortening， and attenuated colonic pathological damage. L. rhamnosus MP108 dramatically increased the number of goblet cells， MUC2 level， and tight junction protein level in the colon and remarkably inhibited epithelial cell apoptosis， thereby strengthening the intestinal barrier. L. rhamnosus MP108 pronouncedly diminished pro-inflammatory cytokine levels and strikingly augmented anti-inflammatory cytokine levels， in turn suppressing inflammation. Furthermore， L. rhamnosus MP108 conspicuously boosted the proportion of short-chain fatty acids (SCFAs) producers in gut microbiota， contributing to increased levels of acetate and butyrate. Therefore， L. rhamnosus MP108 might alleviate UC via improving the intestinal barrier， inhibiting inflammation， and modulating intestinal microbiota.

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组织创造力与创新绩效:长期导向与战略柔性的联合调节作用

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当代经济科学 2024年第1期46卷 131-140页

作者：刘博刘超刘新梅西安交通大学管理学院陕西西安710049 西安邮电大学经济与管理学院陕西西安710121

组织创造力被认为是能快速提升企业创新绩效、获取未来市场竞争优势的重要来源。然而,由于组织惯性阻碍了创造性想法的成功实施,因而如何降低组织惯性给创造性想法的实施带来的不利影响是提升企业创新效率的关键。以318家中国企业为研... 详细信息

组织创造力被认为是能快速提升企业创新绩效、获取未来市场竞争优势的重要来源。然而,由于组织惯性阻碍了创造性想法的成功实施,因而如何降低组织惯性给创造性想法的实施带来的不利影响是提升企业创新效率的关键。以318家中国企业为研究对象,运用层次回归方法,分析并检验长期导向、战略柔性以及两者的交互对组织创造力与创新绩效关系的调节作用,并运用斜率逐对比较法对比在长期导向与战略柔性的不同交互状态下,组织创造力对创新绩效的差异化影响水平。实证结果表明:战略柔性以及长期导向与战略柔性的交互能增强组织创造力与创新绩效之间的关系;当长期导向与战略柔性均强时,组织创造力对创新绩效的影响最强。因此,企业在实施创造性想法的过程中应当采取一定的举措来提升战略柔性,帮助决策者尤其是高层管理者树立长期导向,促进组织创造力向创新绩效的成功转化。

关键词：组织创造力长期导向战略柔性创新绩效组织惯性

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Intrauterine hyperglycemia impairs endometrial receptivity via up-regulating SGK1 in diabetes

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Science China(Life Sciences) 2022年第8期65卷 1578-1589页

作者： Haiyan Xu Jingyi Li Luyang Jin Dan Zhang Bin Chen xinmei liu Xianhua Lin Yiting Huang Zhanghong Ke Juan liu Lin Gao Jianzhong Sheng Hefeng Huang Reproductive Medicine Center Ningbo First HospitalNingbo 315100China Key Laboratory of Reproductive Genetics Ministry of Education(Zhejiang University)Hangzhou 310058China Department of Reproductive Endocrinology Women’s HospitalZhejiang University School of MedicineHangzhou 310006China Department of Pathology&Pathophysiology Zhejiang University School of MedicineHangzhou 310058China Shanghai Key Laboratory of Embryo Original Diseases Shanghai 200030China

Diabetes is a complex metabolic disorder which can adversely affect reproductive function. SGK1 is found to be up-regulated in multiple tissues of diabetic patients. However, the effects of diabetes on endometrial SGK1 expression and endometrial receptivity remain unknown. In this study, we established a streptozotocin-induced diabetic mouse model and observed reduced implantation sites, retarded development of pinopodes, increased SGK1, and aberrant expression of LIF and MUC1 in the endometrial epithelium. We injected the uterine lumen of normal mice with high-glucose solution and cultured endometrial cells in high-glucose medium to mimic intrauterine hyperglycemia. Both studies provided compelling evidence that hyperglycemia could lead to diminished embryo implantation and dysregulated SGK1, LIF and MUC1. Additionally, through over-expression of SGK1 in vivo and in vitro, we found that enhanced SGK1 also decreased LIF expression, increased MUC1 expression, and attenuated embryo implantation rate. We further identified that hyperglycemia-activated SMAD2/3 might be responsible for the enhancement of SGK1 and verified directly the interaction between SMAD3 and corresponding SMAD binding elements within SGK1 promoter. Taken together, our study confirmed the association between diabetes-related hyperglycemia and endometrial receptivity defects. Hyperglycemia-induced SGK1 has a tremendous role in this pathological process, rendering it as an attractive therapeutic target for diabetes-related reproductive disorders.

关键词： diabetes endometrial receptivity hyperglycemia serum/glucocorticoid-regulated kinase

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Prophylactic treatment of Lacticaseibacillus paracasei K56 ameliorates asthma by regulating short-chain fatty acid production and Treg differentiation

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Food Science and Human Wellness 2024年

作者： Jiaqi Cui Yanfei Hong Wei-Hsien liu Wen Zhao xinmei Nan Xuekai Shang Yalan Li Haotian Feng Qiuyue Jiang Weilian Hung Guiying Peng Inner Mongolia Yili Industrial Group Co. Ltd. Department of Immunology and Microbiology School of Life Sciences Beijing University of Chinese Medicine

Many studies have shown that the development of allergic asthma is associated with intestinal microbiota dysbiosis. Based on the gut-lung axis theory， probiotic intervention may be a potential strategy for respiratory diseases. Lacticaseibacillus paracasei K56 was reported to regulate gut microbiota in mice. However， its effect on allergic asthma has not been reported. In this study， we investigated the effect of the K56 on ovalbumin-induced asthma and its possible mechanisms. Our results showed that K56 reduced asthma symptoms and inflammatory cell infiltration in the lung of asthmatic mice. And K56 regulated the differentiation of helper T cells in the lung and intestine. Results from 16S rRNA gene sequencing showed that K56 prophylaxis significantly elevated the richness of Akkermansia and Burkholderia. Meanwhile， K56 abrogated the decrease in the levels of short-chain fatty acids (SCFAs) in the feces. In addition， a rebound in the mRNA expression of the SCFA receptors was observed after K56 prophylaxis. Notably， the regulatory T cell (Treg) frequencies and the FFAR3 levels were positively correlated. These results suggest that K56 could attenuate asthma， possibly by modulating the intestinal microbiota and regulating Treg differentiation through SCFA metabolized. Our study showed that K56 may be used as a probiotic to prevent pulmonary inflammation and dysbiosis of the intestinal microbiota in allergic asthma.

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奥运金牌的心理效应及其影响因素

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上海体育大学学报 2024年第5期48卷 27-40页

作者：刘东锋魏歆媚上海体育大学研究生处上海200438 上海体育大学经济管理学院上海200438

奥运金牌对国民的心理影响以及公众对竞技体育的态度在一定程度上关乎动用公共资金发展竞技体育的合理性与合法性。基于社会认同理论提出假设,以1697名年满16周岁的中国民众为调查对象进行实证检验,探讨国民奥运金牌的心理效应及其影响... 详细信息

奥运金牌对国民的心理影响以及公众对竞技体育的态度在一定程度上关乎动用公共资金发展竞技体育的合理性与合法性。基于社会认同理论提出假设,以1697名年满16周岁的中国民众为调查对象进行实证检验,探讨国民奥运金牌的心理效应及其影响因素。结果显示:国民对增加公共财政投入支持竞技体育发展持肯定态度,从而为举国体制和公共资金投入竞技体育确立了政策合法性与正当性;国家认同和奥运会性质认知对奥运金牌的心理效应产生显著正向影响,证实了以社会认同理论解释认知与心理作用关系的适切性。

关键词：奥运金牌奥运会竞技体育国家认同社会认同理论心理效应

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Preparation of Cu/ZrO2 catalysts for methanol synthesis from CO2/H2

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Frontiers of Chemical Science and Engineering 2012年第1期6卷 47-52页

作者： xinmei liu Shaofen BAI Huidong ZHUAN Zifeng YAN State Key Laboratory for Heavy Oil Processing Key Laboratory of Catalysis(China National Petroleum Corporation)Chiina University of PetroleumQingdao 266555China

为从 CO2/H2 的甲醇合成的 Cu/ZrO2 催化剂被免职一起沉淀(DP ) 和稳固的州的反应(SR ) 分别地准备方法。在铜和氧化锆之间有一个亲密相互作用，它强烈影响减小性质和催化剂的催化性能。越强壮相互作用，越多降低减小温度并且更好催化... 详细信息

为从 CO2/H2 的甲醇合成的 Cu/ZrO2 催化剂被免职一起沉淀(DP ) 和稳固的州的反应(SR ) 分别地准备方法。在铜和氧化锆之间有一个亲密相互作用，它强烈影响减小性质和催化剂的催化性能。越强壮相互作用，越多降低减小温度并且更好催化剂的表演。表面区域，毛孔结构和催化剂的水晶结构被准备方法和合成系统的碱度主要控制。CO2 的变换和甲醇的选择比为 SP 催化剂为 DP 催化剂是更高的。

关键词： Cu/ZrO2 二氧化碳加氢甲醇催化剂合成甲醇制备方法催化性能固态反应共沉淀法

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