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fMRI Study Revealing Neural Mechanisms of the Functions of SOA in Spatial Orienting
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作者 Yin Tian Qian Zhang De-Zhong Yao 《Journal of Electronic Science and Technology of China》 2009年第3期236-239,共4页
It is well documented that orienting attention plays an important role in visual search. However, it remains unclear how the executive brain regions will act when two different stimulus onset asynchrony (SOA) are us... It is well documented that orienting attention plays an important role in visual search. However, it remains unclear how the executive brain regions will act when two different stimulus onset asynchrony (SOA) are used in visual search. In this work, event-related fMRI was used to investigate neural mechanisms on the functions of SOA in endogenous and exogenous orienting. The results showed that in the endogenous orienting, long SOA versus short SOA resulted in widespread cortical activation mainly including right medial frontal gyrus and bilateral middle frontal gyri. Conversely, in exogenous orienting, long SOA compared to short SOA resulted in only activations in bilateral middle frontal gyri. These findings indicated that these two spatial orienting involved different brain areas and neural mechanisms. 展开更多
关键词 Endogenous orienting event-relatedfMRI exogenous orienting stimulus onset asynehronies(SOA)
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Orienting a new generation of nurses: Expectations of the millennial new graduate
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作者 Elaine M. Riegel 《Open Journal of Nursing》 2013年第7期461-466,共6页
Generational diversity provides a unique quandary for nursing leaders and educators to enlist, orient, and retain nurses. Millennials are the largest cohort since the Baby Boomers and the age group from which the nurs... Generational diversity provides a unique quandary for nursing leaders and educators to enlist, orient, and retain nurses. Millennials are the largest cohort since the Baby Boomers and the age group from which the nursing profession will build its future workforce. This study examined the experiences of the new graduate nurse of the millennial generation as they navigate orientation in an acute care setting. Using a Web-based survey to conduct the study allowed nurses from across the country to participate while providing easy access to the study questions. Analysis of the data through qualitative content analysis demonstrated a dominate theme of seeking structure while expecting an individualized orientation. The survey also revealed the importance of the preceptor and manager in the perceived success of this generation’s transition and a need to assimilate into the professional role of RN. Recognizing that there is a need to promote a more individualized orientation with improved mentoring for novice nurses and their preceptors is evident and challenges nursing leaders and educators to rethink current practices to retain new nurses. Established roles within the hospital and individual nursing units are changing and traditional strategies for recruitment and retention no longer apply. A structured orientation can facilitate the transition from new graduate to professional nurse and assist in the retention of qualified nurses and ultimately safe patient care. 展开更多
关键词 NEW GRADUATE Nurses Millennial Nurses ORIENTATION Generational DIVERSITY
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一种改进Oriented RepPoints的遥感图像有向目标检测
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作者 谢国波 张家源 +1 位作者 林志毅 廖文康 《小型微型计算机系统》 CSCD 北大核心 2024年第11期2725-2731,共7页
为解决Oriented RepPoints算法在遥感图像有向目标检测中因遥感图像背景干扰信息较多和目标尺度大小不一所导致的检测精度不高、易漏检误检等问题,提出一种改进Oriented RepPoints的遥感图像有向目标检测方法MA-RPDet(Mixed Attention R... 为解决Oriented RepPoints算法在遥感图像有向目标检测中因遥感图像背景干扰信息较多和目标尺度大小不一所导致的检测精度不高、易漏检误检等问题,提出一种改进Oriented RepPoints的遥感图像有向目标检测方法MA-RPDet(Mixed Attention RepPoints Detector).首先,采用了PVTv2作为主干网络,该网络利用线性空间缩减自注意力机制提取出更具局部连续性的特征图,并保持与卷积运算类似的线性复杂度.其次,在特征融合阶段设计了串联性混合注意力模块,进一步强化了重要特征,促进了多尺度特征的高效交互.最后,引入平滑GIoU损失函数对模型学习策略进行优化,提高了检测精度.在两个遥感图像目标检测数据集DOTA和HRSC2016上的实验结果表明,所提方法的检测精度mAP分别达到了77.19%和90.3%,均高于其他对比算法,证明了本文方法的有效性. 展开更多
关键词 遥感图像 有向目标检测 Oriented RepPoints 注意力机制 损失函数
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基于改进Oriented R-CNN的旋转框麦穗检测与计数模型 被引量:1
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作者 于俊伟 陈威威 +2 位作者 郭园森 母亚双 樊超 《农业工程学报》 EI CAS CSCD 北大核心 2024年第6期248-257,共10页
为对干扰、遮挡等复杂的田野环境中麦穗进行精准定位与计数,该研究提出了一种改进的Oriented R-CNN麦穗旋转框检测与计数方法,首先在主干网络中引入跨阶段局部空间金字塔(spatial pyramid pooling cross stage partial networks,SPPCSPC... 为对干扰、遮挡等复杂的田野环境中麦穗进行精准定位与计数,该研究提出了一种改进的Oriented R-CNN麦穗旋转框检测与计数方法,首先在主干网络中引入跨阶段局部空间金字塔(spatial pyramid pooling cross stage partial networks,SPPCSPC)模块扩大模型感受野,增强网络感知能力;其次,在颈网络中结合路径聚合网络(PANet,path aggregation network)和混合注意力机制(E2CBAM,efficient two convolutional block attention module),丰富特征图包含的特征信息;最后采用柔性非极大值抑制算法(Soft-NMS,soft-non maximum suppression)优化预测框筛选过程。试验结果显示,改进的模型对复杂环境中的麦穗检测效果良好。相较原模型,平均精确度均值mAP提高了2.02个百分点,与主流的旋转目标检测模型Gliding vertex、R3det、Rotated Faster R-CNN、S2anet和Rotated Retinanet相比,mAP分别提高了4.99、2.49、3.94、2.25和4.12个百分点。该研究方法利用旋转框准确定位麦穗位置,使得框内背景区域面积大幅度减少,为实际观察麦穗生长状况和统计数量提供了一种有效的方法。 展开更多
关键词 图像识别 作物 注意力机制 麦穗 Oriented R-CNN
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厄瓜多尔Oriente盆地白垩系Napo组LU亚段沉积模式
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作者 韩立杨 孙雨 +3 位作者 张克鑫 闫百泉 张超前 杨国庆 《海洋地质前沿》 CSCD 北大核心 2024年第5期80-90,共11页
厄瓜多尔Oriente盆地北部白垩系Napo组LU亚段地层油气资源极其丰富,具有较大的油气勘探潜力,由于目前对LU亚段地层沉积模式认识不清晰,极大程度上限制了研究区进一步勘探开发。依据LU亚段岩芯观察、测井、成熟度分析以及镜下薄片等资料... 厄瓜多尔Oriente盆地北部白垩系Napo组LU亚段地层油气资源极其丰富,具有较大的油气勘探潜力,由于目前对LU亚段地层沉积模式认识不清晰,极大程度上限制了研究区进一步勘探开发。依据LU亚段岩芯观察、测井、成熟度分析以及镜下薄片等资料,通过岩芯岩性、结构等岩石学特征,沉积构造、生物遗迹化石、沉积韵律等沉积学特征,以及测井相标志认为,研究区LU亚段地层发育于潮汐作用为主的海陆过渡环境,并在前人研究基础上提出潮控河口湾与陆棚之间存在过渡带沉积,形成了潮控河口湾-过渡带-陆棚沉积体系,识别出潮汐水道、潮汐砂坝、砂坪、海绿石砂席、混合坪、陆棚泥和灰质滩共7种沉积微相,其中,优势储层相带为潮汐水道和潮汐砂坝,砂坪次之。建立研究区潮控河口湾-过渡带-陆棚沉积模式,以期对Oriente盆地白垩系Napo组油气勘探提供有利的科学依据。 展开更多
关键词 沉积模式 沉积微相 潮控河口湾 Oriente盆地
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In Situ Deposition of Drug and Gene Nanoparticles on a Patterned Supramolecular Hydrogel to Construct a Directionally Osteochondral Plug 被引量:1
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作者 Jiawei Kang Yaping Li +7 位作者 Yating Qin Zhongming Huang Yifan Wu Long Sun Cong Wang Wei Wang Gang Feng Yiying Qi 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期341-359,共19页
The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,sp... The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair. 展开更多
关键词 Osteochondral regeneration Oriented hydrogel Kartogenin miRNA-26a
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Hepatolithiasis:Epidemiology,presentation,classification and management of a complex disease 被引量:1
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作者 Rodrigo V.Motta Francesca Saffioti Vasileios K Mavroeidis 《World Journal of Gastroenterology》 SCIE CAS 2024年第13期1836-1850,共15页
The term hepatolithiasis describes the presence of biliary stones within the intrahepatic bile ducts,above the hilar confluence of the hepatic ducts.The disease is more prevalent in Asia,mainly owing to socioeconomic ... The term hepatolithiasis describes the presence of biliary stones within the intrahepatic bile ducts,above the hilar confluence of the hepatic ducts.The disease is more prevalent in Asia,mainly owing to socioeconomic and dietary factors,as well as the prevalence of biliary parasites.In the last century,owing to migration,its global incidence has increased.The main pathophysiological mechanisms involve cholangitis,bile infection and biliary strictures,creating a self-sustaining cycle that perpetuates the disease,frequently characterised by recurrent episodes of bacterial infection referred to as syndrome of“recurrent pyogenic cholangitis”.Furthermore,long-standing hepatolithiasis is a known risk factor for development of intrahepatic cholangiocarcinoma.Various classifications have aimed at providing useful insight of clinically relevant aspects and guidance for treatment.The management of symptomatic patients and those with complications can be complex,and relies upon a multidisciplinary team of hepatologists,endoscopists,interventional radiologists and hepatobiliary surgeons,with the main goal being to offer relief from the clinical presentations and prevent the development of more serious complications.This comprehensive review provides insight on various aspects of hepatolithiasis,with a focus on epidemiology,new evidence on pathophysiology,most important clinical aspects,different classification systems and contemporary management. 展开更多
关键词 CHOLELITHIASIS Intrahepatic stones Cholangiocarcinoma Biliary parasites Recurrent pyogenic cholangitis Oriental cholangiohepatitis Hepatectomy CHOLANGIOSCOPY Liver transplant PAEDIATRIC
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Accelerated Sequential Deposition Reaction via Crystal Orientation Engineering for Low-Temperature,High-Efficiency Carbon-Electrode CsPbBr_(3) Solar Cells 被引量:1
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作者 Zeyang Zhang Weidong Zhu +10 位作者 Tianjiao Han Tianran Wang Wenming Chai Jiaduo Zhu He Xi Dazheng Chen Gang Lu Peng Dong Jincheng Zhang Chunfu Zhang Yue Hao 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第1期168-175,共8页
Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation en... Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved. 展开更多
关键词 carbon-electrode perovskite solar cells crystal orientation engineering CsPbBr_(3) low temperature two-step sequential deposition
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3D DEM simulation of hard rock fracture in deep tunnel excavation induced by changes in principal stress magnitude and orientation 被引量:1
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作者 Weiqi Wang Xia-Ting Feng +2 位作者 Qihu Wang Rui Kong Chengxiang Yang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期3870-3884,共15页
To achieve the loading of the stress path of hard rock,the spherical discrete element model(DEM)and the new flexible membrane technology were utilized to realize the transient loading of three principal stresses with ... To achieve the loading of the stress path of hard rock,the spherical discrete element model(DEM)and the new flexible membrane technology were utilized to realize the transient loading of three principal stresses with arbitrary magnitudes and orientations.Furthermore,based on the deep tunnel of China Jinping Underground Laboratory II(CJPL-II),the deformation and fracture evolution characteristics of deep hard rock induced by excavation stress path were analyzed,and the mechanisms of transient loading-unloading and stress rotation-induced fractures were revealed from a mesoscopic perspective.The results indicated that the stressestrain curve exhibits different trends and degrees of sudden changes when subjected to transient changes in principal stress,accompanied by sudden changes in strain rate.Stress rotation induces spatially directional deformation,resulting in fractures of different degrees and orientations,and increasing the degree of deformation anisotropy.The correlation between the degree of induced fracture and the unloading magnitude of minimum principal stress,as well as its initial level is significant and positive.The process of mechanical response during transient unloading exhibits clear nonlinearity and directivity.After transient unloading,both the minimum principal stress and minimum principal strain rate decrease sharply and then tend to stabilize.This occurs from the edge to the interior and from the direction of the minimum principal stress to the direction of the maximum principal stress on theε1-ε3 plane.Transient unloading will induce a tensile stress wave.The ability to induce fractures due to changes in principal stress magnitude,orientation and rotation paths gradually increases.The analysis indicates a positive correlation between the abrupt change amplitude of strain rate and the maximum unloading magnitude,which is determined by the magnitude and rotation of principal stress.A high tensile strain rate is more likely to induce fractures under low minimum principal stress. 展开更多
关键词 Deep hard rock tunnel Three-dimensional(3D)discrete element model(DEM) Magnitude and orientation of principal stress Transient unloading Fracture mechanism
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Gender differences associated with orienting attentional networks in healthy subjects 被引量:3
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作者 LIU Gang HU Pan-pan +1 位作者 FAN Jin WANG Kai 《Chinese Medical Journal》 SCIE CAS CSCD 2013年第12期2308-2312,共5页
Background Selective attention is considered one of the main components of cognitive functioning.A number of studies have demonstrated gender differences in cognition.This study aimed to investigate the gender differe... Background Selective attention is considered one of the main components of cognitive functioning.A number of studies have demonstrated gender differences in cognition.This study aimed to investigate the gender differences in selective attention in healthy subjects.Methods The present experiment examined the gender differences associated with the efficiency of three attentional networks:alerting,orienting,and executive control attention in 73 healthy subjects (38 males).All participants performed a modified version of the Attention Network Test (ANT).Results Females had higher orienting scores than males (t=2.172,P 〈0.05).Specifically,females were faster at covert orienting of attention to a spatially cued location.There were no gender differences between males and females in alerting (t=0.813,P 〉0.05) and executive control (t=0.945,P 〉0.05) attention networks.Conclusions There was a significant gender difference between males and females associated with the orienting network.Enhanced orienting attention in females may function to motivate females to direct their attention to a spatially cued location. 展开更多
关键词 GENDER attentional networks alerting network orienting network executive control network
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Attentional orienting and response inhibition: insights from spatial-temporal neuroimaging 被引量:1
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作者 Yin Tian Shanshan Liang Dezhong Yao 《Neuroscience Bulletin》 SCIE CAS CSCD 2014年第1期141-152,共12页
Attentional orienting and response inhibition have largely been studied separately. Each has yielded important findings, but controversy remains concerning whether they share any neurocognitive processes. These confli... Attentional orienting and response inhibition have largely been studied separately. Each has yielded important findings, but controversy remains concerning whether they share any neurocognitive processes. These conflicting findings may originate from two issues: (1) at the cognitive level, attentional orienting and response inhibition are typically studied in isolation; and (2) at the technological level, a single neuroimaging method is typically used to study these processes. This article reviews recent achievements in both spatial and temporal neuroimaging, emphasizing the relationship between attentional orienting and response inhibition. We suggest that coordinated engagement, both top-down and bottom-up, serves as a common neural mechanism underlying these two cognitive processes. In addition, the right ventrolateral prefrontal cortex may play a major role in their harmonious operation. 展开更多
关键词 attentional orienting response inhibition bottom-up driven top-down control event-related potentials functional magnetic resonance imaging
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Three-dimensionally oriented organization of hexagonal MIL-96 microplates toward superior film microstructure
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作者 Sixing Chen Xinmiao Jin +3 位作者 Yuyang Wu Taotao Ji Fei Wang Yi Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第8期69-73,共5页
Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane a... Preferential orientation control of metal—organic framework(MOF)films is advantageous for maximizing pore uniformity and minimizing grain-boundary defects.Nonetheless,the preparation of MOF films with both in-plane and out-of-plane orientations remains a grand challenge.In this study,we reported the preparation of three-dimensionally oriented MIL-96 layers through combining morphology control of MIL-96 seeds with addition of polyvinylpyrrolidone surfactants and arachidonic acids.The three-dimensionally oriented MIL-96 film was readily obtained through in-plane epitaxial growth.It is anticipated that the aforementioned protocol can be effective for obtaining diverse MOF films with a three-dimensionally oriented organization. 展开更多
关键词 Metaleorganic framework FILM Orientation Epitaxial growth Morphological control
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Manipulating Crystal Growth and Secondary Phase PbI_(2)to Enable Efficient and Stable Perovskite Solar Cells with Natural Additives
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作者 Yirong Wang Yaohui Cheng +5 位作者 Chunchun Yin Jinming Zhang Jingxuan You Jizheng Wang Jinfeng Wang Jun Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期432-448,共17页
In perovskite solar cells(PSCs),the inherent defects of perovskite film and the random distribution of excess lead iodide(PbI_(2))prevent the improvement of efficiency and stability.Herein,natural cellulose is used as... In perovskite solar cells(PSCs),the inherent defects of perovskite film and the random distribution of excess lead iodide(PbI_(2))prevent the improvement of efficiency and stability.Herein,natural cellulose is used as the raw material to design a series of cellulose derivatives for perovskite crystallization engineering.The cationic cellulose derivative C-Im-CN with cyano-imidazolium(Im-CN)cation and chloride anion prominently promotes the crystallization process,grain growth,and directional orientation of perovskite.Meanwhile,excess PbI_(2)is transferred to the surface of perovskite grains or formed plate-like crystallites in local domains.These effects result in suppressing defect formation,decreasing grain boundaries,enhancing carrier extraction,inhibiting non-radiative recombination,and dramatically prolonging carrier lifetimes.Thus,the PSCs exhibit a high power conversion efficiency of 24.71%.Moreover,C-Im-CN has multiple interaction sites and polymer skeleton,so the unencapsulated PSCs maintain above 91.3%of their initial efficiencies after 3000 h of continuous operation in a conventional air atmosphere and have good stability under high humidity conditions.The utilization of biopolymers with excellent structure-designability to manage the perovskite opens a state-of-the-art avenue for manufacturing and improving PSCs. 展开更多
关键词 PEROVSKITE Solar cells Defect passivation Biomass additives Crystal orientation
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A new rhombohedral phase and its 48 variants inβtitanium alloy
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作者 Xin-nan WANG Ming HAN +2 位作者 Fu-rong ZHANG Guang-ming ZHAO Zhi-shou ZHU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期2849-2863,共15页
A new rhombohedral phase(termed R′)in a solution-aging-treated titanium alloy(Ti-4.5Al-6.5Mo-2Cr-2Nb-1V-1Sn-1Zr,wt.%)was identified.Its accurate Bravais lattice parameters were determined by a novel unit cell reconst... A new rhombohedral phase(termed R′)in a solution-aging-treated titanium alloy(Ti-4.5Al-6.5Mo-2Cr-2Nb-1V-1Sn-1Zr,wt.%)was identified.Its accurate Bravais lattice parameters were determined by a novel unit cell reconstruction method based on conventional selected-area electron diffraction(SAED)technique.The orientation relationship between R'phase and BCC phase was revealed.The results show that the R′phase is found to have 48crystallographically equivalent variants,resulting in rather complicated SAED patterns with high-order reflections.A series of in-situ SAED patterns were taken along both low-and high-index zone axes,and all weak and strong reflections arising from the 48 variants were properly explained and directly assigned with self-consistent Miller indices,confirming the presence of the rhombohedral phase.Additionally,some criteria were also proposed for evaluating the indexed results,which together with the Bravais lattice reconstruction method shed light on the microstructure characterization of even unknown phases in other alloys. 展开更多
关键词 titanium alloy rhombohedral phase Bravais lattice reconstruction VARIANT orientation relationship
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Effects of orientation on the fatigue crack growth behaviors of the ZK60 magnesium alloy in air and PBS
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作者 Jiaqi Hu Zheng Liu +1 位作者 Zuoliang Ning Hong Gao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期281-294,共14页
Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tes... Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS. 展开更多
关键词 Magnesium alloy ORIENTATION CORROSION Fatigue crack growth
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Effects of pressure relief holes on coal burst:Insights from true-triaxial unloading tests
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作者 Fuqiang Ren Murat Karakus +1 位作者 Giang Nguyen Thomas Bruning 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3378-3394,共17页
Drilling pressure relief is one of the methods to reduce the risk of coal bursts in deep mines.However,the effect of the drill hole orientations has not been studied well enough to understand their impact on the burst... Drilling pressure relief is one of the methods to reduce the risk of coal bursts in deep mines.However,the effect of the drill hole orientations has not been studied well enough to understand their impact on the burst failure mechanism.In this study,we investigated two designs of drill hole orientations.The first design includes drill holes located on the upper free face of the rectangular samples and labelled as upper hole(UH)and centre hole(CH)e the long axes of the drill holes are aligned with minor principal stress,s3,direction.The second design includes drill holes at the top(TH)and the side(SH)of the rectangular samples in which the long axes of the drill holes are aligned with the maximum,s1,and intermediate principal stress,s2,directions,respectively.The coal samples with the proposed drill hole orientations were subjected to the true-triaxial unloading coal burst tests.The results show that the drill holes reduce the risk of coal bursts.However,we found that the intensity of coal burst was significantly reduced with the SH-type,followed by the CH-types.We also observed that the coal burst intensity is reduced better for the CH,UH,TH,and SH-type drilling patterns.However,it was found that the orientations of drill holes have little influence on the failure mode(splitting).The acoustic emission(AE)activities for coal with drill holes noticeably decreased,especially for the UH and CH layouts.The drill holes reduced the upper limit of the AE entropy(chaos of microcracks generation).However,regarding reducing the coal burst risk,the TH and SH are less effective than UH and CH. 展开更多
关键词 Coal burst Triaxial unloading Drilling orientation Ejection characteristic Acoustic emission(AE)
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Distributional and behavioral responses of the wintering Oriental Storks to drought in China’s largest freshwater lake
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作者 Fucheng Yang Mingqin Shao Jianying Wang 《Avian Research》 SCIE CSCD 2024年第2期187-195,共9页
Extreme droughts are increasing in frequency and severity globally as a result of climate change.Developing understanding of species’responses to drought is crucial for their conservation,especially in regions experi... Extreme droughts are increasing in frequency and severity globally as a result of climate change.Developing understanding of species’responses to drought is crucial for their conservation,especially in regions experi-encing increased aridity.Although numerous studies have investigated birds’responses to drought,the emphasis has primarily been on landbirds.Drought can significantly alter the wetland environments that waterbirds inhabit,but the response of waterbirds to drought remains understudied.In this study,we surveyed the distri-bution and behavior of Oriental Storks(Ciconia boyciana)in Poyang Lake,which is the largest freshwater lake in China.Results indicate that drought-induced catchment areas at the lowest water level limited the total popu-lation size of Oriental Storks in the sub-lakes.Sub-lakes with large catchment areas at the lowest water level demonstrated a capacity to support a larger population of wintering Oriental Storks.Over time,Oriental Storks exhibited a gradual concentration in Changhu Lake,characterized by larger catchments,after resource depletion in sub-lakes with smaller catchments.Additionally,the duration of Oriental Storks’vigilance and moving be-haviors decreased significantly compared with that observed before the drought.After the drought,Oriental Storks increased their foraging efforts,as evidenced by increased presence in deeper water and reaching their heads and necks into deeper water to forage,higher search rates,but lower foraging rates.In accordance with area-restricted search theory,reductions in habitat quality resulting from drought,including extensive fish die-offs,forced Oriental Storks to increase their foraging efforts.Sustaining a specific water area in sub-lakes during droughts can preserve resource availability,which is crucial for the conservation of Oriental Storks.Imple-menting measures such as water level control and micro-modification of lake bottoms in sub-lakes might mitigate the impact of drought on the piscivorous Oriental Storks. 展开更多
关键词 Climate change Extreme drought Foraging behavior Oriental stork Poyang lake
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Transfer film effects induced by 3D-printed polyether-ether-ketone with excellent tribological properties for joint prosthesis
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作者 Yang Li Jibao Zheng +1 位作者 Changning Sun Dichen Li 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第1期43-56,共14页
Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint prostheses.In this study,we created a polyether-ether-ketone(PEEK)joint prosthesis ... Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint prostheses.In this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf serum.An ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology,which is significantly impacted by the printing orientation of PEEK.When the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady stress.This transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,respectively.Furthermore,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications. 展开更多
关键词 3D printing orientation Transfer film Tribological properties Polyether-ether-ketone Knee prosthesis
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Effects of mesoclimate and microclimate variations mediated by high altitude and row orientation on sucrose metabolism and anthocyanin synthesis in grape berries
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作者 Haining Yin Zhaoxiang Wang +3 位作者 Lin Wang Jianhong Cao Jiakui Wang Zhumei Xi 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期713-731,共19页
Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with ... Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards. 展开更多
关键词 Vitis vinifera L. Orientated rows Berry composition SUGAR PHENOLIC Light quality Solar radiation
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Alleviating the anisotropic microstructural change and boosting the lithium ions diffusion by grain orientation regulation for Ni-rich cathode materials
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作者 Xinyou He Shilin Su +3 位作者 Bao Zhang Zhiming Xiao Zibo Zhang Xing Ou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期213-222,I0005,共11页
Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in t... Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in the properties of Ni-rich cathodes.The disordered particle arrangement is harmful to the cyclic performance and structural stability,yet the fundamental understanding of disordered structure on the structural degradation behavior is unclarified.Herein,we have designed three kinds of LiNi_(0.83)Co_(0.06)Mn_(0.11)O_(2) cathode materials with different primary particle orientations by regulating the precursor coprecipitation process.Combining finite element simulation and in-situ characterization,the Li^(+)transport and structure evolution behaviors of different materials are unraveled.Specifically,the smooth Li^(+)diffusion minimizes the reaction heterogeneity,homogenizes the phase transition within grains,and mitigates the anisotropic microstructural change,thereby modulating the crack evolution behavior.Meanwhile,the optimized structure evolution ensures radial tight junctions of the primary particles,enabling enhanced Li^(+)diffusion during dynamic processes.Closed-loop bidirectional enhancement mechanism becomes critical for grain orientation regulation to stabilize the cyclic performance.This precursor engineering with particle orientation regulation provides the useful guidance for the structural design and feature enhancement of Ni-rich layered cathodes. 展开更多
关键词 Ni-rich cathode Grain orientation regulation Anisotropic microstructural change Precursor engineering Li~+-ions diffusion
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