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International study of the Complex Stress Reaction Syndrome:Implications for transdiagnostic clinical practice
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作者 Sari Goldstein Ferber Aron Weller +15 位作者 Adele M Hayes Tracy D Vannorsdall Yaroup Ajlouni Mo'nes Qudah Gil Zalsman Gal Shoval Tommaso Benedetto Jannini Racquel Fiedler Lily X Chen Danielle R Shayani Elin Kachuki Dory Dana Stolowicz-Melman Connor Evans Megan Trow Giorgio Di Lorenzo Rodolfo Rossi 《World Journal of Psychiatry》 SCIE 2023年第10期803-815,共13页
BACKGROUND The debate regarding diagnostic classification systems in psychiatry(categorial vs dimensional systems)has essential implications for the diagnosis,prevention and treatment of stress reactions.We previously... BACKGROUND The debate regarding diagnostic classification systems in psychiatry(categorial vs dimensional systems)has essential implications for the diagnosis,prevention and treatment of stress reactions.We previously found a unique pattern of stress reaction in a study executed during the coronavirus disease 2019 pandemic using large representative samples in two countries,and termed it the Complex Stress Reaction Syndrome(CSRS).AIM To investigate CSRS,Type A(psychiatric symptoms,spanning anxiety,depression,stress symptoms,and posttraumatic stress disorder(PTSD)),with or without long-coronavirus disease(COVID)residuals(CSRS,Type B,neuropsychiatric symptoms spanning cognitive deficits and fatigue,excluding systemic symptoms).Our two-tailed hypothesis was that CSRS is a condition related to an unrecognized type of stress reaction in daily life in the general population(Type A)or that it is related to the severe acute respiratory syndrome coronavirus 2 infection and its long-COVID residuals(Type B).METHODS 977 individuals in four continents(North America,Europe,Australia and the Middle East)completed the online study questionnaire in six languages using the Qualtrics platform.The study was managed by six teams in six countries that promoted the study on social media.The questionnaire assessed anxiety,depression,stress symptoms and PTSD(CSRS,Type A),cognitive deficits and fatigue(CSRS,Type B).The data were analyzed using Proportion Analyses,Multivariate Analysis of Co-Variance(MANCOVA),linear regression analyses and validated clinical cutoff points.RESULTS The results of the Proportion Analyses showed that the prevalence of 4 symptoms spanning anxiety,depression,stress symptoms,and PTSD was significantly higher than the most prevalent combinations of fewer symptoms across 4 continents,age groups,and gender.This supports the transdiagnostic argument embedded in the CSRS(Type A).The same pattern of results was found in infected/recovered individuals.The prevalence of the 4 psychiatric symptoms combination was significantly greater than that of 5 and 6 symptoms,when adding cognitive deficits and fatigue,respectively.MANCOVA showed a significant three-way interaction(age×gender×continent).Further analyses showed that the sources of this three-way interaction were threefold relating to two sub-populations at-risk:(1)Individuals that self-identified as non-binary gender scored significantly higher on all 4 psychiatric symptoms of the CSRS,Type A at young age groups(<50 years old)in North America compared to(self-identified)women and men located in the 4 continents studied,and to other ages across the adult life span;and(2)This pattern of results(CSRS,Type A)was found also in women at young ages(<40 years old)in North America who scored higher compared to men and women in other continents and other ages.Linear regression analyses confirmed the MANCOVA results.CONCLUSION These results show a combined mental health risk factor related to stress reactivity,suggesting that the CSRS is sensitive to populations at risk and may be applied to future identification of other vulnerable sub-populations.It also supports the transdiagnostic approach for more accurate prevention and treatment.Time will tell if such transdiagnostic syndromes will be part of the discussions on the next revisions of the traditional classification systems or whether the crisis in psychiatry further evolves. 展开更多
关键词 TRANSDIAGNOSTIC complex stress Reaction Syndrome stress reactivity Affective disorders Debate in psychiatry
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Stiffness Degradation of Undisturbed Saturated Soft Clay in the Yangtze Estuary Under Complex Stress Conditions 被引量:6
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作者 栾茂田 刘功勋 +1 位作者 王忠涛 郭莹 《China Ocean Engineering》 SCIE EI 2010年第3期523-538,共16页
Stiffness degradation will occur due to the generation of accumulated pore pressure in saturated soft clays under cyclic loading. The soil static-dynamic multi-purpose triaxial and torsional shear apparatus in Dalian ... Stiffness degradation will occur due to the generation of accumulated pore pressure in saturated soft clays under cyclic loading. The soil static-dynamic multi-purpose triaxial and torsional shear apparatus in Dalian University of Technology was employed to perform different types of test on the saturated soft marine clay in the Yangtze Estuary. Undisturbed samples of the clay were subjected to undrained cyclic vertical and torsional coupling shear and cyclic torsional shear after three-directional anisotropic consolidation with different initial consolidation parameters. Investigated were the effects of the initial orientation angle of the major principal stress, initial ratio of deviatoric stress, initial coefficient of intermediate principal stress and continuous rotation of principal stress axes on the stiffness degradation. It is found that the degradation index decreases (or degradation degree increases) significantly with increasing initial orientation angle of the major principal stress and initial ratio of deviatoric stress. Compared with the effects of the initial orientation angle of the major principal stress and initial ratio of deviatoric stress, the effect of initial coefficient of intermediate principal stress is less evident and this trend is more clearly reflected by the results of the cyclic torsional shear tests than those of the cyclic coupling shear tests. At the same cycle number, the degradation index obtained from the cyclic torsional shear test is higher than that from the cyclic coupling shear test. The main reason is that the continuous rotation in principal stress directions during cyclic coupling shear damages the original structure of the soil more than the cyclic torsional shear does.Based on a series of experiments, a mathematical model for stiffness degradation is proposed and the relevant parameters are determined. 展开更多
关键词 undisturbed saturated soft clay complex stress condition stiffness degradation three-directional anisotropic consolidation continuous rotation of principal stress axes cyclic coupling shear test cyclic torsional shear test
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Effect of intermediate principal stress on strength of soft rock under complex stress states 被引量:1
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作者 马宗源 廖红建 党发宁 《Journal of Central South University》 SCIE EI CAS 2014年第4期1583-1593,共11页
A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/s... A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account. 展开更多
关键词 soft rock strength strain-softening complex stress state effect of intermediate principal stress
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Analysis of the stress intensity factor of welded joints under prior corrosion and complex stress fields
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作者 Zhiyu Jie Yadong Li Xing Wei 《Journal of Modern Transportation》 2016年第4期270-276,共7页
Taking cruciform welded joints under different corrosion degrees, together with 45° inclined angle and full penetration load-carrying fillet, as the research object, the stress intensity factor of a quarter-circu... Taking cruciform welded joints under different corrosion degrees, together with 45° inclined angle and full penetration load-carrying fillet, as the research object, the stress intensity factor of a quarter-circular comer crack of welded joints is calculated based on FRANC3D with ABAQUS. Effects of different corrosion pit sizes, crack aspect ratios, and crack depths on stress intensity factor are analyzed. The results show that pit depth plays a major role in stress intensity factor, while the effect of pit radius is relatively small. The cracking modes of the surface and the deepest point are mode I, and mixed modes I and II, respectively. Effects of pit depths, crack aspect ratios, and crack depths on the stress intensity factor at the surface point are greater than at the deepest point. 展开更多
关键词 stress intensity factor Welded joint Prior corrosion complex stress field. Numerical simulation
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Critical Cyclic Stress Ratio of Undisturbed Saturated Soft Clay in the Yangtze Estuary under Complex Stress Conditions
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作者 刘功勋 栾茂田 +2 位作者 唐小微 王忠涛 郭莹 《Transactions of Tianjin University》 EI CAS 2010年第4期295-303,共9页
There exists a critical cyclic stress ratio when sand or clay is subjected to cyclic loading. It is an index dis-tinguishing stable state or failure state. The soil static and dynamic universal triaxial and torsional ... There exists a critical cyclic stress ratio when sand or clay is subjected to cyclic loading. It is an index dis-tinguishing stable state or failure state. The soil static and dynamic universal triaxial and torsional shear apparatus de-veloped by Dalian University of Technology in China was employed to perform different types of tests on saturated soft marine clay in the Yangtze estuary. Undisturbed samples were subjected to undrained cyclic vertical and torsional coupling shear and cyclic torsional shear after three-directional anisotropic consolidation with different initial consoli-dation parameters. The effects of initial orientation angle of major principal stress, initial ratio of deviatoric stress,initial coefficient of intermediate principal stress and stress mode of cyclic shear on the critical cyclic stress ratio wereinvestigated. It is found that the critical cyclic stress ratio decreases significantly with increasing initial orientation angle of major principal stress and initial ratio of deviatoric stress. Compared with the effects of the initial orientationangle of major principal stress and initial ratio of deviatoric stress, the effect of initial coefficient of intermediate prin-cipal stress is less evident. Under the same consolidation condition, the critical cyclic stress ratio from the cyclic cou-pling shear test is lower than that from the cyclic torsional shear test, indicating that the stress mode of cyclic shear has an obvious effect on the critical cyclic stress ratio. The main reason is that the continuous rotation in principal stressdirections during cyclic coupling shear damages the original structure of soil more than the cyclic torsional shear does. 展开更多
关键词 complex stress condition undisturbed saturated soft clay critical cyclic stress ratio three-directional anisotropic consolidation cyclic coupling shear cyclic torsional shear
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ANALYSIS OF COMPLEX STRESS INTENSITIES FOR CRACKED LAMINATES
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作者 胡互让 吴承平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第2期119-132,共14页
Classical plate theory has been used to find out interfacial stress intensity factors in composite laminates. By using a well-known relation between the crack-tip energy release rate and the complex stress intensity f... Classical plate theory has been used to find out interfacial stress intensity factors in composite laminates. By using a well-known relation between the crack-tip energy release rate and the complex stress intensity factor. a closed-form solution for complex. Stress intensity in terms of external loading and a mode mix parameter for fairly. general composite laminates is given. Then a procedure for determining this mode mix. parameter is presented. followed by numerical results for some laminates. Small scale contact condition is expressed in terms of external loading In particular, a symmetric property of interfacial toughness curye is proven. Finally. the accuracy of failure load predicled by elininating oscllation index is discussed. and an example is presented to show the validity and limitation of β=0 approximation. 展开更多
关键词 composite materials. laminates complex stress intensity factor.energy release rate. inlerface Crack
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Modeling time-dependent mechanical behavior of hard rock considering excavation-induced damage and complex 3D stress states 被引量:1
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作者 Peiyang Yu Xiuli Ding +3 位作者 Peng-Zhi Pan Shuting Miao Zhaofeng Wang Shuling Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4046-4065,共20页
To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main compon... To investigate the long-term stability of deep rocks,a three-dimensional(3D)time-dependent model that accounts for excavation-induced damage and complex stress state is developed.This model comprises three main components:a 3D viscoplastic isotropic constitutive relation that considers excavation damage and complex stress state,a quantitative relationship between critical irreversible deformation and complex stress state,and evolution characteristics of strength parameters.The proposed model is implemented in a self-developed numerical code,i.e.CASRock.The reliability of the model is validated through experiments.It is indicated that the time-dependent fracturing potential index(xTFPI)at a given time during the attenuation creep stage shows a negative correlation with the extent of excavationinduced damage.The time-dependent fracturing process of rock demonstrates a distinct interval effect of the intermediate principal stress,thereby highlighting the 3D stress-dependent characteristic of the model.Finally,the influence of excavation-induced damage and intermediate principal stress on the time-dependent fracturing characteristics of the surrounding rocks around the tunnel is discussed. 展开更多
关键词 Hard rock Excavation damage complex stress state Three-dimensional(3D)time-dependent model
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On the formation of shear bands in a metallic glass under tailored complex stress fields 被引量:2
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作者 S.H.Chen T.Li +6 位作者 W.J.Chang H.D.Yang J.C.Zhang H.H.Tang S.D.Feng F.F.Wu Y.C Wu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第18期112-117,共6页
The formation of shear bands in metallic glasses(MGs)was examined by tailoring localized complex stress fields(LCSFs).The findings have shown that the LCSFs in MGs can increase the localization of strained atoms and a... The formation of shear bands in metallic glasses(MGs)was examined by tailoring localized complex stress fields(LCSFs).The findings have shown that the LCSFs in MGs can increase the localization of strained atoms and accelerate the release of accumulated deformation energy for initiating a shear band in confined and thin-layered regions.The findings not only add more knowledge to the formation mechanisms of shear bands in MGs,but also provide possible rationale for the discrepancies in the mechanical properties of different-sized MGs.As compared with the bulk samples,the higher strength and larger elastic limits in nanoscaled MGs could be attributed to the elimination of stress-concentrators,which can serve as LCSFs. 展开更多
关键词 Localized complex stress field Shear band Metallic glass Molecular dynamics simulation Size effect
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Stochastic fatigue damage model for concrete under complex stress states
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作者 WANG YanPeng LI Jie 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2022年第11期2641-2648,共8页
This paper presents a stochastic fatigue damage model for concrete subjected to complex stress states.A constitutive framework considering the tensile and shear damage mechanisms and elastic and plastic energy dissipa... This paper presents a stochastic fatigue damage model for concrete subjected to complex stress states.A constitutive framework considering the tensile and shear damage mechanisms and elastic and plastic energy dissipations is employed.The damage law is established through a multiscale analysis of the damage evolution mechanism.Validation results against test data show that the model can effectively predict the static strength,stress-strain curve,fatigue life,and scattering range of concrete under various multidimensional loading scenarios. 展开更多
关键词 CONCRETE FATIGUE stochastic damageevolution complex stress states multiscale
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Complex posttraumatic stress disorder: The need to consolidate a distinct clinical syndrome or to reevaluate features of psychiatric disorders following interpersona trauma?
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作者 Evangelia Giourou Maria Skokou +3 位作者 Stuart P Andrew Konstantina Alexopoulou Philippos Gourzis Eleni Jelastopulu 《World Journal of Psychiatry》 SCIE 2018年第1期12-19,共8页
Complex posttraumatic stress disorder(Complex PTSD)has been recently proposed as a distinct clinical entity in the WHO International Classification of Diseases,11^(th) version, due to be published, two decades after i... Complex posttraumatic stress disorder(Complex PTSD)has been recently proposed as a distinct clinical entity in the WHO International Classification of Diseases,11^(th) version, due to be published, two decades after its first initiation. It is described as an enhanced version of the current definition of PTSD, with clinical features of PTSD plus three additional clusters of symptoms namely emotional dysregulation, negative self-cognitions and interpersonal hardship, thus resembling the clinical features commonly encountered in borderline personality disorder(BPD). Complex PTSD is related to complex trauma which is defined by its threatening and entrapping context, generally interpersonal in nature. In this manuscript, we review the current findings related to traumatic events predisposing the above-mentioned disorders as well as the biological correlates surrounding them, along with their clinical features. Furthermore, we suggest that besides the present distinct clinical diagnoses(PTSD; Complex PTSD; BPD), there is a cluster of these comorbid disorders, that follow a continuum of trauma and biological severity on a spectrum of common or similar clinical features and should be treated as such. More studies are needed to confirm or reject this hypothesis, particularly in clinical terms and how they correlate to clinical entities' biological background, endorsing a shift from the phenomenologically only classification of psychiatric disorders towards a more biologically validated classification. 展开更多
关键词 complex POSTTRAUMATIC stress DISORDER POSTTRAUMATIC stress DISORDER BORDERLINE personality DISORDER TRAUMA complex TRAUMA
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Effect of Complex Preparation on the Hemorheological Indexes of Heat Stress Piglets
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作者 Peng Xiaoqing Liu Fenghua Yan Peishi 《Animal Husbandry and Feed Science》 CAS 2015年第4期253-256,共4页
In the study, heat stress environment was simulated by artificial climate cabin to establish the heat stress model of piglets. A total of 64 2-month-old Chinese miniature pigs used for test were sdected and randomly d... In the study, heat stress environment was simulated by artificial climate cabin to establish the heat stress model of piglets. A total of 64 2-month-old Chinese miniature pigs used for test were sdected and randomly divided into control group, heat stress group, complex preparation extract I treatment group and complex preparation extract II treatment group. Hematocrit was analyzed by Wintrobe test, meanwhile, the hemorheological indexes such as whole blood viscosity were analyzed by the automated analysis system of hemorrheology. In order to study the dynamic changes of complex preparation on the hemorheologieal indexes of heat stress piglets. The results showed that the piglets whole blood viscosity at high shear rate on the 10~ days in heat stress group was significantly highe~ than that in control group (P 〈 0.05) ; erythrocyte deformation indexes on the 6th and 10th days in heat stress group were significantly lower than that in control group (P 〈 0.05) ; hematocfit on the 1", 3'~, 6~h and 10'h days in heat stress group was significantly higher than that in control group (P 〈 0.05). Hemorhealogieal inde- xes of the piglets in treatment group adding with complex preparation had been significantly restored, the effect on the 10th day after the stress was the most significant (P 〈 0.05). The test results indicated that heat stress showed some significant influences on the health of piglets. Complex preparation could reduce the physiological damage causing by heat stress, and the effect of complex preparation II was better than that of complex preparation I. 展开更多
关键词 complex preparation Heat stress PIGLETS Hemorhealogy
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Complex Post Traumatic Stress Disorder (PTSD) in Defilement: Case Report
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作者 D. A. Kokonya W. M. Kuria +2 位作者 F. A. Ong’echa J. M. Mburu D. M. Ndetei 《Open Journal of Psychiatry》 2014年第3期176-181,共6页
We report a case of the debilitating and lifelong complex post traumatic stress disorder. Data on rape/defilement-related complex post traumatic stress disorder (PTSD) is rare due to low reporting rates and misdiagnos... We report a case of the debilitating and lifelong complex post traumatic stress disorder. Data on rape/defilement-related complex post traumatic stress disorder (PTSD) is rare due to low reporting rates and misdiagnosis in Kenya. Childhood complex PTSD is compounded by its symptomatic overlap with rape trauma syndrome (RTS) and attention deficit hyperactivity disorder (ADHD). This case demonstrated the difficulties involved in making the correct diagnosis while at the same time it brought to the fore clearly the features of complex PTSD as opposed to ordinary PTSD. Strengths in management depended on making appropriate diagnosis based on concerted efforts by clinicians, comprehensive care, team work, sensitivity to age and sex, winning trust of the child and the care taker among others and bearing in mind the in-ward handling of the trauma by the rape/defilement victims. This case shared a lot with other cases of complex PTSD in its presentation, course of illness, diagnosis and response to management protocol instituted yielding positive results. Using the lessons learnt from this case, her response was satisfactory based on her improved social and occupational functioning. The patient continues to respond well to treatment to date, bearing in mind that her presentation and age within a dysfunctional family background did not offer good prognosis, especially if the management and social support system will not be steadfast and innovative. 展开更多
关键词 Defilement complex PTSD ADHD RTS Extreme stress PSYCHIATRIC MORBIDITIES
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复杂应力条件下岩心水力压裂实验装置设计及验证
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作者 李沁 代朝辉 +4 位作者 卢渊 伊向艺 陈文玲 刘旭 吴元琴 《实验技术与管理》 CAS 北大核心 2024年第11期131-136,共6页
非常规油气储层物性特征差、应力条件复杂,水力压裂是提高非常规油气勘探开发效率的关键技术之一。该文研制了轴向应力独立加载的全直径岩心水压致裂超声波检测装置,实验装置包含多套独立加压系统,可以模拟实际地层的复杂应力条件,并根... 非常规油气储层物性特征差、应力条件复杂,水力压裂是提高非常规油气勘探开发效率的关键技术之一。该文研制了轴向应力独立加载的全直径岩心水压致裂超声波检测装置,实验装置包含多套独立加压系统,可以模拟实际地层的复杂应力条件,并根据声发射实时检测岩石破坏特征。基于实验装置开展了30°、45°、60°天然裂缝的岩心在复杂应力条件下的水力压裂实验,实验结果表明:45°天然裂缝的岩心相较于其他角度稳定性最差,压力达到14.1 MPa时产生破裂,声发射特征明显;天然诱导应力干扰下,水力裂缝逼近时扩展路径发生偏移,随着天然裂缝角度增大,偏移更加明显。该实验装置可以为复杂应力的储层增产改造提供理论依据。 展开更多
关键词 复杂应力 天然裂缝 水力压裂 声发射特征
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Development and applications of the quasi‐dynamic triaxial apparatus for deep rocks
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作者 Jinzhi Luo Yanyan Cai +3 位作者 Jin Yu Jianzhi Zhang Yaoliang Zhu Yao Wei 《Deep Underground Science and Engineering》 2024年第1期70-90,共21页
The mechanical behaviors of deep rocks have always posed a challenge for the implementation and safe operation of major underground engineering projects.To this end,this study modified the existing mainstream rock mec... The mechanical behaviors of deep rocks have always posed a challenge for the implementation and safe operation of major underground engineering projects.To this end,this study modified the existing mainstream rock mechanics instruments equipped with a dynamic disturbance loading system and developed a second‐generation TFD‐2000/D triaxial instrument.The first‐generation device is equipped with an independent disturbance system and an advanced EDC‐580 all‐digital servo controller,which can apply disturbing load independently,implement the function of cyclic disturbance,and combine dynamic and static disturbances.The instrument was found to be reliable for use in analyzing the damage process of rocks in the disturbance test of marbles.The second‐generation instrument tackles three limitations of the first‐generation instrument:(i)it upgrades the strain measurement system and uses extensometers with linear variable differential transformers to accurately measure deformation;(ii)it uses the self‐balanced chamber to replace the Hoek–Franklin triaxial cell and auto‐balancing triaxial pressure chamber;and(iii)the loading rod is independently equipped with an EDC‐580 all‐digital servo controller,which measures precise loads.The experimental findings confirmed that the second‐generation instrument can be used for rock mechanics testing under cyclic disturbance loading,the disturbance–stress relaxation cycle,and the creep–fatigue cycle.In this sense,the second‐generation instrument can be a useful addition to deep rock mechanical instruments and provide a valuable reference. 展开更多
关键词 complex stress conditions deep rock disturbance loading modification of instrument rock mechanics
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盐碱胁迫下2,4-表油菜素内酯和褪黑素对百合幼苗光合生理的影响
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作者 李雪芬 田旭平 李文涛 《北方园艺》 CAS 北大核心 2024年第19期52-61,共10页
以‘西伯利亚’百合种球为试材,采用室内盆栽试验的方法,研究了中度(150 mmol·L^(-1))盐碱胁迫下叶施2,4-表油菜素内酯(EBR)、褪黑素(MT)及其复合处理对百合幼苗生长、光合和叶绿素荧光参数、离子转运及抗氧化系统的影响,以期为二... 以‘西伯利亚’百合种球为试材,采用室内盆栽试验的方法,研究了中度(150 mmol·L^(-1))盐碱胁迫下叶施2,4-表油菜素内酯(EBR)、褪黑素(MT)及其复合处理对百合幼苗生长、光合和叶绿素荧光参数、离子转运及抗氧化系统的影响,以期为二者缓解百合盐碱胁迫提供参考依据。结果表明:盐碱胁迫下百合株高、叶表面积以及生物量显著下降,施用EBR和/或MT可以缓解百合受到的生长抑制。150 mmol·L^(-1)盐碱胁迫下,与喷施清水对照(CK)处理相比,EBR+MT处理的SPAD值增加37.2%,百合地上部和地下部N含量分别增加83.6%和40.7%,叶绿素荧光参数中PSⅡ最大光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)和光化学淬灭系数(qP)分别增加14.6%、42.9%和50.0%,而非光化学淬灭系数(NPQ)下降9.2%,净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)分别增加56.3%、29.7%和42.7%,胞间二氧化碳(Ci)下降19.3%。150 mmol·L^(-1)盐碱胁迫下,百合地上部和地下部Na^(+)含量增加,而K^(+)含量下降,EBR+MT处理后百合地上部和地下部K^(+)/Na^(+)值分别增加110.9%和98.8%;同时,施用EBR和/或MT处理能够促进百合Cu/Zn-SOD、POD以及CAT基因的表达,激活抗氧化酶SOD、POD以及CAT活性。综上所述,施用EBR和/或MT处理均能够不同程度的提高百合SPAD值,减缓盐碱胁迫对PSⅡ光系统的抑制,维持植物体内Na^(+)和K^(+)的平衡,激活SOD、POD和CAT等抗氧化酶基因表达并提高酶活性,促进百合株高和生物量的增加,其中以复合喷施EBR+MT处理下百合幼苗的抗盐碱性效果更好。 展开更多
关键词 2 4-表油菜素内酯 褪黑素 盐碱胁迫 百合 离子平衡
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围缘扁钢加强的开圆孔无限平板应力解析算法
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作者 王小明 王红旭 《船舶力学》 EI CSCD 北大核心 2024年第5期748-759,共12页
为了研究围缘扁钢加强的开圆孔无限平板应力解析计算方法,近似认为围缘扁钢区域的平均应力处于广义平面应力状态。运用复变函数论的方法,将应力函数表示为两个待定的解析函数;列出围缘扁钢的边界条件、围缘扁钢与平板之间的应力连接条... 为了研究围缘扁钢加强的开圆孔无限平板应力解析计算方法,近似认为围缘扁钢区域的平均应力处于广义平面应力状态。运用复变函数论的方法,将应力函数表示为两个待定的解析函数;列出围缘扁钢的边界条件、围缘扁钢与平板之间的应力连接条件和位移连接条件,求出应力函数,根据求出的应力函数便可求出应力。为了描述围缘扁钢减缓孔口应力集中的效果,提出围缘扁钢加强系数的定义。算例计算表明:本文提出的解析算法计算结果与有限元法计算结果吻合良好,围缘扁钢加强的开圆孔无限平板应力普遍小于开圆孔无限平板应力,围缘扁钢加强效果明显;相同体积的加强构件,围缘扁钢的加强效果优于环形加厚板。 展开更多
关键词 应力集中 开孔加强板 复变函数论方法 应力解析算法 加强系数
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ULK1在炎症性疾病中的研究进展 被引量:1
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作者 刘婉婷 徐畅 +3 位作者 王重阳 宋艺兰 李莉 延光海 《中国免疫学杂志》 CAS CSCD 北大核心 2024年第6期1302-1306,1314,共6页
UNC-51样激酶1(ULK1)是参与调节自噬启动的重要因子,ULK1通过自噬和线粒体氧化应激调节炎症细胞因子,参与了多种疾病的病理过程。ULK1及其复合体受雷帕霉素(mTOR)和AMP活化蛋白激酶(AMPK)调节启动自噬,从而对多种炎症性疾病产生不同影... UNC-51样激酶1(ULK1)是参与调节自噬启动的重要因子,ULK1通过自噬和线粒体氧化应激调节炎症细胞因子,参与了多种疾病的病理过程。ULK1及其复合体受雷帕霉素(mTOR)和AMP活化蛋白激酶(AMPK)调节启动自噬,从而对多种炎症性疾病产生不同影响。而在炎症性疾病中,线粒体氧化应激可使ULK1入核加速细胞凋亡。因此,ULK1在炎症性疾病中发挥不同的重要作用。例如,ULK1在哮喘中启动气道上皮细胞线粒体的自噬,在急性肝衰竭中参与线粒体氧化应激,在动脉粥样硬化中影响相关炎症因子,在糖尿病中调节自噬。本文从ULK1的生物学功能、在炎症性疾病中的影响和靶向药物的研究进展进行综述。 展开更多
关键词 ULK1 复合体 自噬 线粒体氧化应激 炎症
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复合材料复杂环境效应加速试验设计及评估方法
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作者 赵朋飞 李昊 +2 位作者 刘艳 王增凯 张生鹏 《装备环境工程》 CAS 2024年第7期36-44,共9页
目的指导复合材料在复杂湿热环境下环境适应性摸底与评价试验的开展,分析评估复合材料在复杂综合应力下的激活能参数。方法分析装备全寿命周期复杂自然环境剖面及各环境因素影响效应,确定复合材料各工作阶段敏感应力类型及条件,基于应... 目的指导复合材料在复杂湿热环境下环境适应性摸底与评价试验的开展,分析评估复合材料在复杂综合应力下的激活能参数。方法分析装备全寿命周期复杂自然环境剖面及各环境因素影响效应,确定复合材料各工作阶段敏感应力类型及条件,基于应力加速模型及累积损伤等原理,制定复合材料复杂环境效应综合加速试验剖面。构建复合材料复杂环境条件下的动力学模型,并提出相应参数估计方法。开展复合材料加速试验,并基于实测数据开展复合材料性能退化建模与评估。结果分析了复合材料全寿命周期环境影响因素及环境效应,明确了各工作阶段敏感应力主要有温度、湿度、太阳辐照、温度交变、振动以及冲击等。依据实际环境数据,设计并开展了3组不同湿热条件(80℃/75%RH、80℃/85%RH、80℃/95%RH)的综合试验,收集得到复合材料拉伸强度、拉剪强度、径向弯曲强度以及纬向弯曲强度等4种性能指标的试验数据。试验数据表明,拉剪强度(最大相对退化速率为0.1773/循环)、径向弯曲强度(最大相对退化速率为0.1292/循环)以及纬向弯曲强度(最大相对退化速率为0.2610/循环)等性能参数可用于产品退化建模与评估。通过参数估计,进一步确定了退化速率与湿热应力的关系,并针对当前试验提供了改进依据。结论复杂环境效应综合加速试验对装备复合材料产品经历复杂环境条件的模拟效果和加速效果较好,试验可实施性较强。提出的改进广义Eyring模型可涵盖温度应力与湿热应力的加速效应,并综合考虑多种应力的相互作用,通过少量组合试验便可量化评估激活能等参数。所建模型指出当前基于激活能参考值(Ea=0.7eV)试验方案可由不同温度应力的综合试验数据进一步修正与优化,且所提试验与分析方法主要针对大部分树脂基复合材料产品,并可依据需要推广至电子产品、机电产品等试验对象。 展开更多
关键词 复合材料 复杂环境效应 试验设计 加速试验 湿热应力 性能退化
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复杂应力环境下胶结充填采矿法进路开采顺序优化
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作者 李彦龙 余龙哲 +2 位作者 陈仲杰 郁标 王文杰 《矿冶工程》 CAS 北大核心 2024年第4期144-149,共6页
针对复杂应力环境下胶结充填采矿法进路开采顺序合理性问题,以金川二矿区为例,借助数值仿真软件构建三维数值模型,对不同进路开采顺序下应力场、位移场及塑性破坏区进行分析;在此基础上,采用组合赋权与模糊综合评价相结合的方法对进路... 针对复杂应力环境下胶结充填采矿法进路开采顺序合理性问题,以金川二矿区为例,借助数值仿真软件构建三维数值模型,对不同进路开采顺序下应力场、位移场及塑性破坏区进行分析;在此基础上,采用组合赋权与模糊综合评价相结合的方法对进路开采顺序优化,并开展现场工业试验。结果表明:不同走向进路开采顺序和进路开采空间顺序均对开采区域最大主应力、最大拉应力、垂直位移、塑性破坏区以及临近下一采场最大主应力、垂直位移有一定程度影响;采用下盘至上盘、先开采垂直矿体走向进路的开采顺序时,采场整体开采安全性高,且现场试验效果良好。研究结果可为复杂应力环境下胶结充填采矿法进路开采顺序设计与优化提供理论依据。 展开更多
关键词 复杂应力环境 胶结充填采矿法 下向分层水平进路采矿法 进路开采顺序 采场应力 数值分析
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Simulation of temperature and stress in 6061 aluminum alloy during online quenching process 被引量:6
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作者 王孟君 杨刚 +1 位作者 黄长清 陈彬 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2168-2173,共6页
The cooling curves of 6061 aluminum alloy were acquired through water quenching experiment. The heat transfer coefficient was accurately calculated based on the cooling curves and the law of cooling. The online quench... The cooling curves of 6061 aluminum alloy were acquired through water quenching experiment. The heat transfer coefficient was accurately calculated based on the cooling curves and the law of cooling. The online quenching process of complex cross-section profile was dynamically simulated by the ABAQUS software. The results suggest that the heat transfer coefficient changes during online quenching process. Different parts of the profile have different cooling velocity, and it was verified by water quenching experiment. The maximum residual stress of the profile was predicted using FEM simulation based on ABAQUS software The relations between the temperature and stress were presented by analyzing the data of key points. 展开更多
关键词 6061 aluminum alloy QUENCHING complex cross-section profile residual stress ABAQUS
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