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Comparison of Group-Buying Online Auction and Posted Pricing Mechanism in an Uncertain Market
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作者 CHEN Jian, LIU Yunhui, SONG Xiping (School of Economics and Management, Tsinghua University Beijing 100084 China Department of System Engineering and Engineering Management, The Chinese University of Hong Kong Shatin NT Hong Kong China) 《Journal of Electronic Science and Technology of China》 2004年第3期1-5,共5页
Demand uncertainty is a key factor for the seller's decision making, especially in the e-business environment, for the website to sell products through the online auction. In this paper, two kinds of demand uncert... Demand uncertainty is a key factor for the seller's decision making, especially in the e-business environment, for the website to sell products through the online auction. In this paper, two kinds of demand uncertainties are considered: the consumer regime uncertainty and the inherent randomness of the market environment. Then, how to use a novel business model and group-buying auction (GBA) is analyzed in such a market environment. Based on the comparison of the GBA and the posted price mechanism, some conditions that favor the GBA are provided. 展开更多
关键词 group-buying auction demand uncertainty posted pricing mechanism
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Effect of mother’s knowledge on posteducation toward rehospitalization of young children with pneumonia
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作者 Casman Casman Nani Nurhaeni Fajar Tri Waluyanti 《Frontiers of Nursing》 2022年第3期269-274,共6页
Objective:The rehospitalization rate of children<5 years old with pneumonia is still high.The risk of hospitalization becomes higher in mothers with low knowledge of their child’s disease.The purpose of this study... Objective:The rehospitalization rate of children<5 years old with pneumonia is still high.The risk of hospitalization becomes higher in mothers with low knowledge of their child’s disease.The purpose of this study was to determine the effect of post-health-education maternal knowledge in cases of rehospitalization and to determine the differences in rehospitalization rate based on the type of health education media.Methods:This study is a quasi-experiment.Health education was given to both groups:one group received education through audiovisual media and the other group through leaflet media.The level of post-health-education knowledge was measured on the third day,then followed up until the 30th day after the patient was discharged from the hospital.Results:Post-health-education knowledge significantly reduced the cases of rehospitalization in both groups.However,the rehospitalization rate in the audiovisual group was lower than in the leaflet group(P=0.047,odds ratio=5.870).Conclusions:Post-health-education knowledge is effective in reducing the risk of rehospitalization,and health education using audiovisual media is more effective,compared to health education using leaflets,in reducing the cases of rehospitalization in children<5 years of age with pneumonia. 展开更多
关键词 CHILDREN mother’s post–health-education knowledge PNEUMONIA REHOSPITALIZATION
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Unraveling the role of ufmylation in the brain
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作者 Rita J.Serrano Robert J.Bryson-Richardson 《Neural Regeneration Research》 2026年第2期667-668,共2页
Ufmylation is an ubiquitin-like post-translational modification characterized by the covalent binding of mature UFM1 to target proteins.Although the consequences of ufmylation on target proteins are not fully understo... Ufmylation is an ubiquitin-like post-translational modification characterized by the covalent binding of mature UFM1 to target proteins.Although the consequences of ufmylation on target proteins are not fully understood,its importance is evident from the disorders resulting from its dysfunction.Numerous case reports have established a link between biallelic loss-of-function and/or hypomorphic variants in ufmylation-related genes and a spectrum of pediatric neurodevelopmental disorders. 展开更多
关键词 target proteins post translational modification pediatric neurodevelopmental disorders covalent binding mature ufm target proteinsalthough biallelic loss function ufmylation hypomorphic variants neurodevelopmental disorders
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气象格点数算一体空间分析库的设计与实现 被引量:2
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作者 王舒 徐拥军 +6 位作者 何文春 吴焕萍 高峰 刘媛媛 刘北 吕冠儒 倪学磊 《应用气象学报》 北大核心 2025年第1期121-128,共8页
气象格点数据通常以文件形式存储在分布式文件库中,业务系统在使用过程中需要将文件下载到本地,对文件解析后再进行分析计算。这种方式导致数据检索困难、响应时间长、无法满足业务在线计算及交互式应用需求。为此,2022年底国家气象信... 气象格点数据通常以文件形式存储在分布式文件库中,业务系统在使用过程中需要将文件下载到本地,对文件解析后再进行分析计算。这种方式导致数据检索困难、响应时间长、无法满足业务在线计算及交互式应用需求。为此,2022年底国家气象信息中心基于天擎空间分析库研发完成了分布式环境下气象格点数据与计算集成的数算一体数据库——Post Grid,该数据库包含数据层和算子层。数据层将气象格点数据在要素、起报、预报、空间、层次、样本等维度上的拆分后统一规范化存储,提高数据库的数据读取和分析效率。算子层通过数据库中的SQL函数实现,支持在数据库内部对格点数据进行各种操作,且算子支持分布式并行计算。性能测试和业务应用结果表明:Post Grid数据库能将传统的聚合计算服务时效由分钟级提升至毫秒级,极大提高了气象格点数据服务的性能、灵活性和数算一体能力,具有广泛应用价值。 展开更多
关键词 数算一体 气象格点数据 Post Grid 并行计算 分布式
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Mechanism of post cardiac arrest syndrome based on animal models of cardiac arrest
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作者 Halidan ABUDU WANG Yiping +10 位作者 HE Kang LIU Ziquan GUO Liqiong DONG Jinrui Ailijiang KADEER XU Guowu LIU Yanqing MENG Xiangyan CAI Jinxia LI Yongmao FAN Haojun 《中南大学学报(医学版)》 北大核心 2025年第5期731-746,共16页
Cardiac arrest(CA)is a critical condition in the field of cardiovascular medicine.Despite successful resuscitation,patients continue to have a high mortality rate,largely due to post CA syndrome(PCAS).However,the inju... Cardiac arrest(CA)is a critical condition in the field of cardiovascular medicine.Despite successful resuscitation,patients continue to have a high mortality rate,largely due to post CA syndrome(PCAS).However,the injury and pathophysiological mechanisms underlying PCAS remain unclear.Experimental animal models are valuable tools for exploring the etiology,pathogenesis,and potential interventions for CA and PCAS.Current CA animal models include electrical induction of ventricular fibrillation(VF),myocardial infarction,high potassium,asphyxia,and hemorrhagic shock.Although these models do not fully replicate the complexity of clinical CA,the mechanistic insights they provide remain highly relevant,including post-CA brain injury(PCABI),post-CA myocardial dysfunction(PAMD),systemic ischaemia/reperfusion injury(IRI),and the persistent precipitating pathology.Summarizing the methods of establishing CA models,the challenges encountered in the modeling process,and the mechanisms of PCAS can provide a foundation for developing standardized CA modeling protocols. 展开更多
关键词 cardiac arrest animal model post cardiac arrest syndrome PATHOPHYSIOLOGY modeling method
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The desert post office
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作者 胡金莹 《疯狂英语(新读写)》 2025年第12期52-53,78,共3页
Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't... Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't get too many visitors anyway.But after being abandoned for over 35 years,it actually doesn't look half bad. 展开更多
关键词 ABANDONMENT Inner Mongolia Autonomous Region loneliest post office post office wooden post office DESERT sand Tengger Desert
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An Investigation of the Shu Road Transportation Culture
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作者 Ma Qiang 《Contemporary Social Sciences》 2025年第2期25-44,共20页
During its millennium of development,the ancient Shu Road system fostered a unique post station culture.In the Qin and Han dynasties,various postal service facilities,termed you,ting,yi,zhi,and si,emerged along the Ba... During its millennium of development,the ancient Shu Road system fostered a unique post station culture.In the Qin and Han dynasties,various postal service facilities,termed you,ting,yi,zhi,and si,emerged along the Baoxie Road,an important segment of the Shu Road system.In the Tang Dynasty,a dense network of post stations was built along the Shu Road.It was during this period that the post stations gained refined names on a substantial scale.Their names were based on the landscapes,resources,histories,and geographical locations of their sites,all of which displayed the characteristics of local gazetteers.During the Tang and Song dynasties,the post stations became large-scale facilities with well-established functions and beautiful environments.The Shu Road post station culture was carried forward in the Ming and Qing dynasties.However,due to frequent warfare and destruction,the Shu Road post station culture was on a declining trajectory during this period.Additionally,the means of transportation exhibited characteristics that varied with time to adapt to the terrain features of the Shu Road system.During the Qin and Han dynasties,transportation was primarily achieved by courier and horse relays.During the Three Kingdoms period,Zhuge Liang devised wooden oxen and gliding horses to transport military supplies and provisions.In the Tang Dynasty,the administration of horses saw remarkable progress,and horses became the primary means of transportation,supplemented by mail coaches.From the Song to the Ming and Qing dynasties,horses,donkeys,and sedans all served as transportation,reflecting the diversity of transportation means in the later periods of imperial China. 展开更多
关键词 Shu Road post station culture naming of post stations environmental beautification
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Effect of thermal annealing on cold crystallization ability of thermoset polyurethane elastomer synthesized from fully bio-derived polyol
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作者 Jaeheon Lee Jung Hyeun Kim 《Chinese Journal of Structural Chemistry》 2025年第5期28-35,共8页
Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products.However,one of the popular bio-polyols,polytrimethylene ether glycol(PO3G),is reluctant to crystallize and therefore exhibit... Bio-polyol is considered as a core material to synthesize eco-friendly polyurethane products.However,one of the popular bio-polyols,polytrimethylene ether glycol(PO3G),is reluctant to crystallize and therefore exhibits a cold crystallization behavior.This abnormal behavior causes unstable mechanical properties at low-temperature and limits its applications in shape memory devices where crystallization is an essential mechanism.To analyze the unusual phenomenon,we compared different ether polyols focusing on symmetry characteristics and the evenodd effect of carbon backbones.It is found that PO3G has a slow crystallization rate because its ether linkages require specific chain arrangement for attractive interactions.Consequently,a thermal learning mechanism is developed to restore the normal crystallization behavior of elastomers synthesized from the bio-polyol.Repetitive heating and cooling cycles with high-temperature annealing induce urethane exchange reaction and reconstruct the chain orientations for fast crystallization.Results suggest the degree of crystallizations in polyurethane elastomer can be precisely controlled by introducing repetitive thermal treatments to enhance the potential applications of bio-polyols in polymer industries. 展开更多
关键词 Bio-polyol Cold crystallization Post treatment POLYURETHANE ELASTOMER
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Efficacy of elobixibat for elderly patients with chronic constipation in a clinic
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作者 Yuji Sakai Toshio Tsuyuguchi +4 位作者 Junichiro Kumagai Hiroshi Ohyama Takashi Kaiho Masayuki Ohtsuka Naoya Kato 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 2025年第2期41-48,共8页
BACKGROUND Elobixibat reportedly improves bowel movements in patients with chronic constipation.However,its effect on bowel movements in elderly patients with chronic constipation in clinical settings has not been exa... BACKGROUND Elobixibat reportedly improves bowel movements in patients with chronic constipation.However,its effect on bowel movements in elderly patients with chronic constipation in clinical settings has not been examined.AIM To examine bowel movement frequency and stool form before and after elobixibat administration in elderly patients with chronic constipation at our clinic.METHODS A total of 10 mg elobixibat was administered to 35(<65 years old)patients and 45(≥65 years old)patients with chronic constipation.The frequency of bowel movements and stool forms,assessed using the Bristol Stool Form Scale(BSFS),were compared between the two groups 1 week before and after elobixibat administration.RESULTS In patients aged<65 years with chronic constipation,the pre-elobixibat frequency of bowel movements and BSFS scores were 2.167±0.732 and 2.286±0.742,respectively.After elobixibat administration,the frequency of bowel movements and BSFS scores improved to 2.389±0.502 and 3.995±0.566,respectively,showing a significant improvement in bowel movement status.In patients aged≥65 years with chronic constipation,the pre-elobixibat frequency of bowel movements and BSFS scores were 2.003±0.733 and 2.217±0.758,respectively.After elobixibat administration,the frequency of bowel movements and BSFS scores improved to 4.402±1.346 and 3.800±0.704,respectively,indicating an improvement in bowel movement status(P<0.001).No significant differences were observed in the frequency and improvement status of bowel movements or BSFS scores between patients with chronic constipation aged≥65 years and<65 years.Adverse events due to the administration of elobixibat occurred in 16 cases(20%).No significant differences were found in the incidence of adverse events between patients with chronic constipation aged<65 years(8 cases,22.9%)and those aged≥65 years(8 cases,17.8%).CONCLUSION Elobixibat is effective in improving bowel movement status in patients with chronic constipation.No significant differences were found in the improvement of bowel movement status or the incidence of adverse events between patients with chronic constipation aged<65 years and≥65 years,suggesting that the drug may be safely used in elderly patients. 展开更多
关键词 Bile acid Elderly patients Elobixibat Chronic constipation Post cholecystectomy CONSTIPATION
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Synthesis of New Functionalized Polymers Through the Post-Modification of Polyvinyl Chloride
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作者 Yuchen Li Ruochen Cao +4 位作者 Yuxiang Qin Haoran Zhang Xiaoyan Tang Meng Wang Ding Ma 《Carbon and Hydrogen》 2025年第1期52-57,共6页
Polyvinyl chloride(PVC)is one of the most widely used plastic materials worldwide,particularly in long-life applications such as construction materials.However,recycling options for PVC waste remain limited,as convent... Polyvinyl chloride(PVC)is one of the most widely used plastic materials worldwide,particularly in long-life applications such as construction materials.However,recycling options for PVC waste remain limited,as conventional methods often degrade material quality or generate environmentally hazardous byproducts.In this study,we demonstrate an efficient process to convert PVC into new polymers with variable aromatic groups,using triethylsilane as the reductant in different solvents.This approach enables the production of polymers analogous to functionalized polyethylene(PE),which are typically challenging to obtain through conventional copolymerization or direct post-modification of C-H bonds in PE.The resulting polymers exhibit tunable thermal and mechanical properties depending on the introduced aromatic groups,which not only enhance the sustainable valorization of PVC waste,but also provide an opportunity for the synthesis of new functionalized polymers. 展开更多
关键词 functionalized polymer polyvinyl chloride post‐modification upcycling
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Nomographic predictive models for complications after minimally invasive esophagectomy:Current status and future perspectives
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作者 Kush S Parikh Ashok Kumar 《World Journal of Gastrointestinal Surgery》 2025年第12期65-80,共16页
Perioperative morbidity of esophagectomy significantly affects the surgical outcome,like any major gastrointestinal procedure.Despite introduction of minimally invasive esophagectomy,the morbidity is still close to 30... Perioperative morbidity of esophagectomy significantly affects the surgical outcome,like any major gastrointestinal procedure.Despite introduction of minimally invasive esophagectomy,the morbidity is still close to 30%-40%.The common complications following esophagectomy are pulmonary infections,cardiac events,anastomotic leakage,bleeding,chylous leak,and recurrent laryngeal nerve palsy which in turn lead to longer hospital stay,increased treatment cost and poor quality of life.A nomographic model comprising preoperative(patient,disease and treatment related)and intraoperative factors in combination with Artificial Intelligence may accurately identify the patients at higher risk of morbidity.This will aid in optimizing the modifiable risk factors preoperatively,and closely monitor these patients post operatively for early identification of complications and to initiate early corrective measures to improve the surgical outcome. 展开更多
关键词 Minimally invasive esophagectomy COMPLICATIONS Risk factors NOMOGRAM Post operative outcome Early detection of complications PROGNOSTICATION
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Tailoring microstructure,tensile properties,and creep resistance of additively manufactured Inconel 718 superalloy by post heat treatment
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作者 Sajad GHAEMIFAR Milad ROOSTAEI +2 位作者 Mohammad REZA ZAMANI Stefan WURSTER Hamed MIRZADEH 《Transactions of Nonferrous Metals Society of China》 2025年第6期1890-1906,共17页
The effects of post heat treatment on the microstructure,aging kinetics,and room/elevated temperature mechanical properties of additively manufactured Inconel 718 superalloy were investigated.Scanning electron microsc... The effects of post heat treatment on the microstructure,aging kinetics,and room/elevated temperature mechanical properties of additively manufactured Inconel 718 superalloy were investigated.Scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),and X-ray diffraction(XRD),as well as hardness,tensile,and creep testing were used for characterization.At temperatures higher than 1100°C,homogenization treatment resulted in the appearance of equiaxed grains by recrystallization and diminishing the dislocation density.The precipitation activation energy for the homogenized and aged condition was obtained as 203.2 kJ/mol,which was higher than the value of~160 kJ/mol for the as-built IN718 superalloy.Therefore,direct aging resulted in a faster aging response,which led to a significant improvement in tensile properties,as rationalized by the strengthening mechanisms.Direct aging treatment resulted in a higher elevated-temperature ultimate tensile strength(UTS)as well as the optimum creep life and the lowest minimum creep rate in comparison with other heat treatment routes,which were attributed to the presence of fine and uniformly dispersed strengthening precipitates in conjunction with the high dislocation density. 展开更多
关键词 Inconel 718 superalloy additive manufacturing post heat treatment mechanical properties creep resistance
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UG后置处理链接技术在ZXC车削中心上的应用
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作者 潘腾 袁小兵 +1 位作者 郭辉 许锋国 《机械工程师》 2025年第10期153-156,共4页
阐述了Link Post技术原理及特点,以ZXC车铣复合后置处理构建为案例,详细介绍了借助Post Builder构建车削、铣削后置处理的过程,及在车削后置处理中链接铣削后置处理的方法、使用前在UG软件CAM模块中的设置等操作。对其后处理的NC代码通... 阐述了Link Post技术原理及特点,以ZXC车铣复合后置处理构建为案例,详细介绍了借助Post Builder构建车削、铣削后置处理的过程,及在车削后置处理中链接铣削后置处理的方法、使用前在UG软件CAM模块中的设置等操作。对其后处理的NC代码通过VERICUT仿真、工艺件加工验证,Link Post技术可用于复杂后置处理的开发。文中采用Link Post技术快速搭建后置处理构建方法和思路,为独立完成复杂机床后置处理的工程人员提供参考。 展开更多
关键词 后置处理 Link Post技术 链接 动力头 车铣中心 数控仿真
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Post-cardiac arrest imaging:Unraveling etiology and predicting neurological outcome
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作者 George Latsios Elias Sanidas +6 位作者 Maria Velliou Marina Kalogridaki Pavlos Bounas Andreas Synetos Constantina Aggeli Konstantinos Toutouzas Costas Tsioufis 《World Journal of Radiology》 2025年第9期73-82,共10页
Cardiac arrest is associated with high rates of mortality and significant long-term neurological disability in survivors.Timely and accurate assessment following successful resuscitation is critical for optimizing out... Cardiac arrest is associated with high rates of mortality and significant long-term neurological disability in survivors.Timely and accurate assessment following successful resuscitation is critical for optimizing outcomes.Imaging plays a central role in this evaluation process,providing crucial insights into the etiology of arrest,the extent of cerebral and cardiac injury,and guiding both acute management and long-term prognostication.A structured,multimodal imaging approach utilizing tools such as computed tomography,magnetic resonance imaging,echocardiography,and angiography is increasingly recognized as es-sential in the post-cardiac arrest setting.This review aims to consolidate current evidence related to the use of various imaging modalities across neurological,cardiac and systemic contexts.Particular emphasis is placed on the prognostic value and optimal timing of neuroimaging,the detection of potentially reversible causes of arrest,such as coronary occlusion or pulmonary embolism,and the emerging role of whole-body imaging in evaluating patients with non-traumatic out-of-hospital cardiac arrest. 展开更多
关键词 Post cardiac arrest setting Return of spontaneous circulation IMAGING Computed tomography Magnetic resonance imaging Coronary angiography ECHOCARDIOGRAPHY
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Acceptance and commitment therapy for enhancing mental health in military personnel:A comprehensive review and meta-analysis
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作者 Jun-Qiao Wang Xin-Zhe Wang Wen-Xiao Wang 《World Journal of Psychiatry》 2025年第3期319-336,共18页
BACKGROUND Military personnel frequently face unique psychological challenges due to highstress environments,which increase the risk of mental health issues like anxiety and depression.Acceptance and commitment therap... BACKGROUND Military personnel frequently face unique psychological challenges due to highstress environments,which increase the risk of mental health issues like anxiety and depression.Acceptance and commitment therapy(ACT)has shown potential in addressing these issues by enhancing psychological flexibility and resilience.AIM To systematically evaluate the effectiveness of ACT in improving the mental health of military personnel.Through a scoping review and meta-analysis,we quantitatively assess the impact of ACT on psychological outcomes,guiding future research and clinical practice.METHODS Relevant literature was searched systematically from database inception to June 30,2023,across multiple databases,including PubMed,Web of Science,Cochrane Library,and Embase.The Joanna Briggs Institute's(JBI)scoping review guidelines were used as the methodological framework.Meta-analysis was performed using a random-effects model,and publication bias was assessed through Egger's regression test and Begg's funnel plot.RESULTS Twenty-six studies were included,highlighting the application of ACT in addressing PTSD,chronic pain,anxiety,and depression among military personnel.The meta-analysis of eight studies demonstrated a significant positive effect of ACT on mental health,with a pooled mean difference of-4.99(95%CI:-6.53 to-3.45).Despite high heterogeneity(I^(2)=63%),sensitivity analyses confirmed the robustness of the findings.CONCLUSION This study underscores the potential of ACT as an effective intervention for improving the mental health of military personnel.Future research should focus on large-scale,multi-center RCTs to further validate these findings,particularly within diverse military populations. 展开更多
关键词 Acceptance and commitment therapy Military health META-ANALYSIS Psychological therapy Post traumatic stress disorder management
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Navigating Complexity:Building the Next Chapter of China-EU Relations
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作者 CHINA TODAY 《China Today》 2025年第9期16-19,共4页
FIVE decades ago,the establishment of China-EU diplomatic ties signaled a significant shift in the post-war world order.This year,as leaders gathered in Beijing for the 25th China-EU Summit commemorating this mileston... FIVE decades ago,the establishment of China-EU diplomatic ties signaled a significant shift in the post-war world order.This year,as leaders gathered in Beijing for the 25th China-EU Summit commemorating this milestone,they faced a turbulent global landscape marked by geopolitical friction,economic uncertainty,and contested rules. 展开更多
关键词 contested rules economic uncertainty post war world order China EU relations geopolitical friction diplomatic ties
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Seismic design of variable cross-section damped steel support frame for post equipment
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作者 Yang Zhenyu Ma Yuhong +2 位作者 Zhao Guifeng Feng Zhiwei Fu Mingyang 《Earthquake Engineering and Engineering Vibration》 2025年第1期155-167,共13页
High-voltage electrical post equipment is generally installed on steel supports,which amplifies the seismic inputs and degrades the seismic performance of equipment.This study proposed a variable cross-section damped ... High-voltage electrical post equipment is generally installed on steel supports,which amplifies the seismic inputs and degrades the seismic performance of equipment.This study proposed a variable cross-section damped steel support frame(VCDFS)with viscous dampers to reduce seismic responses of both tall and low-rise electrical equipment.The VCDFS contains a trapezoidal damper layer to generate rocking motions,enabling the diagonal viscous dampers to dissipate seismic inputs.A theoretical model of post equipment with VCDFS is established,and an optimal design procedure is proposed.The analysis shows that the remaining static stiffness ratio λ_(k) is the key parameter that determines the effectiveness of the VCDFS.The VCDFS reduces the average displacement and stress response of a post insulator by 39.4%and 44.6%,respectively,together with a significant decrease in the dynamic amplification factor.Therefore,it is recommended to use the VCDFS instead of the conventional latticed-steel frame in earthquake zones. 展开更多
关键词 electrical post equipment steel support frame passive control seismic performance upgrading
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Psychoactive Substances:Transforming the Paradigm for Treating Mental Health Disorders in the Post‑Pandemic Era
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作者 Haojiang Zhai Yibo Wang Xiaohui Wang 《Neuroscience Bulletin》 2025年第3期536-538,共3页
Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,wit... Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,with~1 in 8 people,equivalent to 970 million individuals suffering from a mental disorder in 2019(https://vizhub.healthdata.org/gbd-results).Anxiety and depressive disorders are predominant,contributing significantly to the burden of mental health issues,according to the World Health Organization.The COVID-19 pandemic has further exacerbated this situation.It led to a notable upsurge in anxiety and major depressive disorders in 2020.Estimates indicate a 26%rise in anxiety and a 28%increase in depression within that year(https://www.who.int/publications/i/item/WHO-2019-nCoVSci_Brief-Mental_health-2022.1)[1]. 展开更多
关键词 psychoactive substances depressive disorders post pandemic era mental health disorders mental disorder global health challenge mental health problems ANXIETY
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Effect of Post Weld Heat Treatment on Residual Stress and Mechanical Properties of 106 mm Thick TC4 Titanium Alloy Electron Beam Welded Joints
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作者 Yunlu Jiang Lihui Wu +5 位作者 Dingrui Ni Hongbo Zhao Xu Han Peng Xue Bolv Xiao Zongyi Ma 《Acta Metallurgica Sinica(English Letters)》 2025年第7期1083-1094,共12页
This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-... This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-hole drilling(DHD)methods,and investigated the microstructure and mechanical properties.During the PWHT at 600℃,a phase transformation(β→α)occurred in the EBW joint and affected the residual stress distribution and mechanical properties.The surface residual stress was mainly compressive stress,while the internal residual stress was mainly tensile stress in the welded joint.For the as-welded joint,the absolute value of surface residual stress was higher than the absolute value of internal residual stress.After PWHT,the residual stress in the treated joint was substantially reduced compared to the as-welded joint,particularly the surface stress,which relieved from−425 to−90 MPa.However,the residual stress relief effect had minimal positive impact on the internal region at 600℃.PWHT resulted in a shift of the joint fracture location from the fusion zone(FZ)to the base metal(BM),and therefore exerted no noticeable effect on the joint strength,but increased the joint elongation significantly.This study provides valuable insights into the regulation of residual stress distribution of ultra-thick titanium alloy plates. 展开更多
关键词 Titanium alloy Electron beam welding Residual stress Post weld heat treatment Mechanical property
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Strength Optimization of Diffusion-Bonded Ti_(2)AlNb Alloy by Post-Heat Treatment
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作者 Haijian Liu Tianle Li +3 位作者 Xifeng Li Huiping Wu Zhiqiang Wang Jun Chen 《Acta Metallurgica Sinica(English Letters)》 2025年第4期614-626,共13页
Diffusion-bonded Ti_(2)AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize ... Diffusion-bonded Ti_(2)AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize the microstructure, contributing to strength improvement and appropriate ductility sacrifice. An available method by the introduction of fine size (both 20-100 nm) and a high fraction (59.7% and 13.7%) of O and α_(2) phases using both solution at 1000℃ for 1 h and aging at 750℃ for 5 h can result in excellent tensile strength (992 MPa and 858 MPa) at room temperature and 650℃, respectively, which increases 5.3% and 44.5% than that of as-received sample. The aging treatment can contribute to lamellar O and α2 grains precipitated from the B_(2) parent, which results in limited dislocation slip systems and slip spaces to resist plastic deformation. Moreover, the crack propagation and fracture surfaces are also comparatively analyzed to reveal the fracture behaviors in the samples with high and low strength. This study can provide a new method for the mechanical property optimization of the welded Ti_(2)AlNb alloys. 展开更多
关键词 Ti_(2)AlNb alloy Diffusion bonding Post heat treatment Phase transformation Mechanical properties
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