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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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Analytical investigations of in situ stress inversion from borehole breakout geometries
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作者 Zizhuo Xiang Taehyun Moon +2 位作者 Joung Oh Guangyao Si Ismet Canbulat 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2375-2387,共13页
This study aims to investigate the feasibility of deriving in situ horizontal stresses from the breakout width and depth using the analytical method.Twenty-three breakout data with different borehole sizes were collec... This study aims to investigate the feasibility of deriving in situ horizontal stresses from the breakout width and depth using the analytical method.Twenty-three breakout data with different borehole sizes were collected and three failure criteria were studied.Based on the Kirsch equations,relatively accurate major horizontal stress(sH)estimations from known minor horizontal stress(sh)were achieved with percentage errors ranging from 0.33%to 44.08%using the breakout width.The Mogi-Coulomb failure criterion(average error:13.1%)outperformed modified Wiebols-Cook(average error:19.09%)and modified Lade(average error:18.09%)failure criteria.However,none of the tested constitutive models could yield reasonable sh predictions from known sH using the same approach due to the analytical expression of the redistributed stress and the nature of the constitutive models.In consideration of this issue,the horizontal stress ratio(sH/sh)is suggested as an alternative input,which could estimate both sH and sh with the same level of accuracy.Moreover,the estimation accuracies for both large-scale and laboratory-scale breakouts are comparable,suggesting the applicability of this approach across different breakout sizes.For breakout depth,conformal mapping and complex variable method were used to calculate the stress concentration around the breakout tip,allowing the expression of redistributed stresses using binomials composed of sH and sh.Nevertheless,analysis of the breakout depth stabilisation mechanism indicates that additional parameters are required to utilise normalised breakout depth for stress estimation compared to breakout width.These parameters are challenging to obtain,especially under field conditions,meaning utilising normalised breakout depth analytically in practical applications faces significant challenges and remains infeasible at this stage.Nonetheless,the normalised breakout depth should still be considered a critical input for any empirical and statistical stress estimation method given its significant correlation with horizontal stresses.The outcome of this paper is expected to contribute valuable insights into the breakout stabilisation mechanisms and estimation of in situ stress magnitudes based on borehole breakout geometries. 展开更多
关键词 Borehole failure In situ stress estimation In situ horizontal stress ratio Conformal mapping complex variable method Breakout stabilisation
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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 统一强度理论 中间主应力 软岩石 复杂应力状态 真三轴试验 FLAC3D 固结不排水 数值模拟
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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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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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Local Shear Stresses Elicit Different Mechanical Response and Gene Expression from Complex Stresses
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作者 Fuxiang Wei Cunyu Zhang +1 位作者 Yawen Liao Ning Wang 《医用生物力学》 EI CAS CSCD 北大核心 2019年第A01期147-147,共1页
It is well established that living cells and tissues respond to mechanical forces such as flow-related shear stresses in blood or interstitial space and complex tractional stresses at cell-matrix contacts and cell-cel... It is well established that living cells and tissues respond to mechanical forces such as flow-related shear stresses in blood or interstitial space and complex tractional stresses at cell-matrix contacts and cell-cell contacts.However,how different modes of forces impact mechanical and biological responses is elusive.Here we describe a strategy of using the three-dimensional magnetic twisting cytometry(3D MTC)technology to apply forces in any desired directions to the same living cell.We reveal that for a fixed stress amplitude and frequency,a live cell exhibits mechanical anisotropy and responds to a local shear stress differently from responding to a local complex stress by stretching chromatin and upregulating gene transcription to different levels,extending our previous finding on force-induced direct gene activation.This finding highlights the importance of force modes in impacting cellular mechanical and biological responses in living cells and tissues and may have implications in tissue patterning and embryonic development. 展开更多
关键词 LOCAL SHEAR stresses Elicit DIFFERENT Mechanical Response GENE EXPRESSION complex stresses
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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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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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Effects of complex salvia miltiorrhiza on blood coagulation, inflammation, oxidative stress and endothelial index in patients with acute pancreatitis
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作者 Ye Zhang Chun-Tao Li Lei Lu 《Journal of Hainan Medical University》 2018年第21期23-27,共5页
Objective: To investigate the effects of complex salvia miltiorrhiza on blood coagulation, inflammation, oxidative stress and endothelial index in patients with acute pancreatitis. Methods: A total of 122 patients wit... Objective: To investigate the effects of complex salvia miltiorrhiza on blood coagulation, inflammation, oxidative stress and endothelial index in patients with acute pancreatitis. Methods: A total of 122 patients with acute pancreatitis admitted to digestive system department in our hospital from April 2016 to November 2017 were randomly divided into control group (n=61) and observation group (n=61), the control group was treated with ulinastatin and the observation group was treated with complex salvia miltiorrhiza injection on the basis of the control group. The levels of coagulation, inflammation, oxidative stress and endothelial markers were compared between the two groups. Results: After treatment, the levels of APTT and PT in the two groups were significantly higher than those before treatment, while the levels of DD were significantly lower than those before treatment, and the levels of APTT and PT [(38.19±7.05) s,(17.60±3.68) s] in the observation group were significantly higher than those in the control group, while the levels of DD [(0.51±0.10) mg/L] in the observation group were significantly lower than those in the control group;the levels of CRP, PCT and TNF-α in the two groups were significantly lower than those before treatment, and the levels of CRP, PCT and TNF-α [(29.10±4.76) mg/L, (0.59±0.17) μg/L, (57.28±10.61) ng/L] in the observation group were significantly lower than those in the control group;the levels of SOD in the two groups were significantly higher than those before treatment, but MDA was significantly lower than that before treatment, and the level of SOD [(179.10±4.76) U/mL] in the observation group was significantly higher than that in the control group after treatment, while the level of MDA [(1.97±0.55) mmol/mL] in the observation group was significantly lower than that in the control group after treatment;the levels of NO in the two groups were significantly higher than those before treatment, while the levels of ET and vWF were significantly lower than those before treatment, and the levels of NO [(10.56±1.17) U/mL] in the observation group were significantly higher than those in the control group after treatment, while the levels of ET and vWF [(105.83±5.20) pg/mL, (102.47±16.91)%] in the observation group were significantly lower than those in the control group after treatment. Conclusions:Complex salvia miltiorrhiza injection can improve the blood coagulation function, alleviate inflammation, enhance antioxidant function and vascular endothelial function in patients with acute pancreatitis, which has clinical value of promotion. 展开更多
关键词 complex SALVIA miltiorrhiza Acute PANCREATITIS Blood COAGULATION INFLAMMATION Oxidative stress ENDOTHELIAL
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Complex post-traumatic stress disorder
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作者 Andreas Maercker 《四川生理科学杂志》 2022年第6期1030-1030,共1页
Complex post-traumatic stress disorder(complex PTSD)is a severe mental disorder that emerges in response to traumatic life events.Complex PTSD is characterised by three core post-traumatic symptom clusters,along with ... Complex post-traumatic stress disorder(complex PTSD)is a severe mental disorder that emerges in response to traumatic life events.Complex PTSD is characterised by three core post-traumatic symptom clusters,along with chronic and pervasive disturbances in emotion regulation,identity,and relationships. 展开更多
关键词 TRAUMATIC complex stress
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An Automatic Classification Grading of Spinach Seedlings Water Stress Based on N-MobileNetXt
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作者 Yanlei Xu Xue Cong +2 位作者 Yuting Zhai Zhiyuan Gao Helong Yu 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期3019-3037,共19页
To solve inefficient water stress classification of spinach seedlings under complex background,this study proposed an automatic classification method for the water stress level of spinach seedlings based on the N-Mobi... To solve inefficient water stress classification of spinach seedlings under complex background,this study proposed an automatic classification method for the water stress level of spinach seedlings based on the N-MobileNetXt(NCAM+MobileNetXt)network.Firstly,this study recon-structed the Sandglass Block to effectively increase the model accuracy;secondly,this study introduced the group convolution module and a two-dimensional adaptive average pool,which can significantly compress the model parameters and enhance the model robustness separately;finally,this study innovatively proposed the Normalization-based Channel Attention Module(NCAM)to enhance the image features obviously.The experimental results showed that the classification accuracy of N-MobileNetXt model for spinach seedlings under the natural environment reached 90.35%,and the number of parameters was decreased by 66%compared with the original MobileNetXt model.The N-MobileNetXt model was superior to other net-work models such as ShuffleNet and GhostNet in terms of parameters and accuracy of identification.It can provide a theoretical basis and technical support for automatic irrigation. 展开更多
关键词 Deep learning water stress grade classification image processing complex background
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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 应力条件 临界循环 长江口 土应力 饱和
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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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矿物掺合料对复合胶凝材料浆体静态屈服应力的影响
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作者 阎培渝 刘宇 《硅酸盐通报》 CAS 北大核心 2024年第3期922-928,共7页
复合胶凝材料浆体的静态屈服应力可用于表征浆体内部微观结构建立的特性,且对新拌水泥基材料的施工与3D打印过程有很大影响。本文研究了矿物掺合料的种类和掺量对复合胶凝材料浆体静态屈服应力变化规律的影响。研究发现,矿物掺合料的细... 复合胶凝材料浆体的静态屈服应力可用于表征浆体内部微观结构建立的特性,且对新拌水泥基材料的施工与3D打印过程有很大影响。本文研究了矿物掺合料的种类和掺量对复合胶凝材料浆体静态屈服应力变化规律的影响。研究发现,矿物掺合料的细度增大使颗粒表面的水膜层厚度减小,导致浆体的静态屈服应力增大。复合胶凝材料浆体的静态屈服应力在加水搅拌后的一段时间内缓慢增加,浆体结构建立速率较小。在加水搅拌后大约1.5 h,复合胶凝材料浆体的静态屈服应力迅速增大,表明浆体内部结构的连接程度已接近不可破坏的程度,浆体开始凝结,向固体状态转变。 展开更多
关键词 静态屈服应力 浆体结构建立 复合胶凝材料 矿物掺合料 细度 掺量 水膜层厚度
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高地应力缓斜半煤岩巷道断面形状优化研究
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作者 王志强 尹安然 +2 位作者 李敬凯 柴虎虎 王燕飞 《煤炭工程》 北大核心 2024年第1期105-112,共8页
为了优化高地应力缓斜半煤岩巷道的断面形状,以东欢坨矿3018工作面运道为工程背景展开研究。通过复变函数理论推导得出了倾斜煤层中不同断面形状的应力解析解,然后运用FLAC3D数值模拟求解了不同断面形状巷道的应力集中和塑性区情况,并... 为了优化高地应力缓斜半煤岩巷道的断面形状,以东欢坨矿3018工作面运道为工程背景展开研究。通过复变函数理论推导得出了倾斜煤层中不同断面形状的应力解析解,然后运用FLAC3D数值模拟求解了不同断面形状巷道的应力集中和塑性区情况,并以此为基础确定了巷道最优断面形状,最后结合现场工业性试验对研究结果的可靠性进行了验证。研究结果表明:高地应力作用下缓斜半煤岩巷道破坏呈现非对称形式;不管断面形状如何,巷道均在左、右两底角处呈现高应力集中,且应力集中程度矩形>梯形>直墙拱形;直墙拱形巷道稳定性最佳,梯形巷道次之,矩形稳定性最差,确定直墙拱形为最终巷道断面形状;现场巷道表面位移量监测结果表明,直墙拱形巷道更能满足现场安全生产要求。 展开更多
关键词 高地应力 缓斜半煤岩巷道 巷道断面形状 复变函数
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ULK1在炎症性疾病中的研究进展
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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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喷丸强化对预变形CP800复相钢疲劳性能的影响
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作者 崔浩诚 王荃 +3 位作者 陈卓 周俊 戚天武 汪宏斌 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期278-288,共11页
喷丸强化可以提高CP800复相钢的抗疲劳性能.采用低(0.15 mmA)、中(0.3 mmA)、高(0.5 mmA)3种喷丸强度对5%预拉伸变形后的CP800复相钢进行表面喷丸处理,研究了喷丸后材料的表面形貌和表面残余应力,并通过拉压疲劳试验分析了疲劳断口.研... 喷丸强化可以提高CP800复相钢的抗疲劳性能.采用低(0.15 mmA)、中(0.3 mmA)、高(0.5 mmA)3种喷丸强度对5%预拉伸变形后的CP800复相钢进行表面喷丸处理,研究了喷丸后材料的表面形貌和表面残余应力,并通过拉压疲劳试验分析了疲劳断口.研究发现:2 mm板厚的CP800复相钢更适合采用低喷丸强度,疲劳寿命约为未喷丸试样的3倍;疲劳寿命的提升归因于表层发生塑性变形、位错密度提高,且残余压应力可抑制裂纹萌生;喷丸后材料表面粗糙度增大;喷丸强度过高易造成表面缺陷增多,尤其在高喷丸强度下,试样表面会出现分层损伤现象,对疲劳性能有不利影响. 展开更多
关键词 喷丸强化 CP800复相钢 抗疲劳性能 残余压应力
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基于复变函数理论的无中导连拱隧道应力与位移解析解
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作者 毕钛俊 邓琴 +2 位作者 汤华 姜成业 秦雨樵 《岩土力学》 EI CAS CSCD 北大核心 2024年第3期777-787,共11页
无中导连拱隧道由于后行洞衬砌搭接于先行洞衬砌拱腰之上,围岩与衬砌受力情况复杂,开展相应的围岩与衬砌应力和位移分析具有重要的工程意义。基于复变函数理论和Schwarz交替法,提出了深埋条件下考虑衬砌的无中导连拱隧道围岩与衬砌应力... 无中导连拱隧道由于后行洞衬砌搭接于先行洞衬砌拱腰之上,围岩与衬砌受力情况复杂,开展相应的围岩与衬砌应力和位移分析具有重要的工程意义。基于复变函数理论和Schwarz交替法,提出了深埋条件下考虑衬砌的无中导连拱隧道围岩与衬砌应力和变形的计算方法。针对无中导连拱隧道两洞具有共用边界的特点,在利用柯西积分法进行求解时,将单洞衬砌与围岩接触的边界积分条件转化为仅存在单洞时的完整边界积分与共用边界积分之差,对于Schwarz交替法中求解“附加面力”的过程亦进行类似处理。给出共用边界应力与位移的计算方法。通过算例,将上述解析结果和数值仿真结果进行对比,证明了方法的可行性和准确性。 展开更多
关键词 无中导连拱隧道 复变函数 SCHWARZ交替法 应力场 位移场
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