检索结果-南通市图书馆

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.J.Hall O.Hetherington T.w.Buggey T.arnold M.w.J.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their *** order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance *** CCDs have been characterised,the two flight devices and the flight spa *** has been carried out at the Open University in a bespo ke cleanroom measure ment *** results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe *** at the nominal ope rating tempe rature(-120℃) it is within the procure ment ***,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science *** se rial charge transfer inefficiency degrades with temperature in full frame *** any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE

The CCD instrument background of the SMILE SXI

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.w.J.Hubbard O.Hetherington D.J.Hall T.w.Buggey S.Parsons T.arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

An investigation into the potential of Gabor wavelet features for scene classification in wild blueberry fields

在线全文

学校读者我要写书评

暂无评论

Artificial Intelligence in Agriculture 2021年第1期5卷 72-81页

作者： Gashaw Ayalew Qamar Uz Zaman arnold w.Schumann David C.Percival Young Ki Chang Independent Researcher ThoroldON L2V 1Z8Canada Engineering Department Dalhousie University Faculty of AgricultureTruroNS B2N 5E3Canada Citrus Research and Education Centre University of FloridaLake AlfredFL33850USA Plant Animal and Environmental Sciences DepartmentDalhousie University Faculty of AgricultureTruroNS B2N 5E3Canada

A Gabor wavelets based technique was investigated as a potential tool for scene classification(into one of bare patch,plant,or weed)for its ultimate utility in site-specific application of agrochemicals inwild blueberry *** were gathered from five sites located in central Nova Scotia,*** wavelet features extracted from these images were used to classify scenes according to visually determined classes using step-wise linear discriminant *** individual fields,classification accuracy attained ranged between 87.9%and 98.3%;selected Gabor features ranged between 27 and 72;contextual accuracy for herbicide ranged between 67.5%and 96.7%,and contextual accuracy for fertilizer ranged between 63.6%and 97.1%.The pooled scenes yielded a classification accuracy of 81.4%,and contextual accuracy figures of 61.1%and 73.1%for herbicide and fertilizer,respectively,with selected Gabor features of *** based on LDA coefficients from the pooled scenes could help avoid the need to re-calibrate for each field,whereas those based on individual field LDA coefficients could improve accuracy,hence enable saving on expensive agrochemicals.

关键词： wavelet transforms wild blueberry Computer vision Machine learning Discriminant analysis Precision agriculture

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

干旱土:它们是否最后的边疆

干旱区研究 1993年第4期10卷 3-5页

作者： Richard w. arnold 夏荣基美国农业部土壤保持局

人类的侵入人类察看和访问了地球上暴露在大气中所有的环境,他亦探测了海洋表面以下的和拜访了外层空间,纪录了许多不同种类的环境,并在卫星图片上得到鉴别。通过千百人的活动,勘察了所有的沙漠环境,并选择了一部分作为弥补生存条件的不... 详细信息

人类的侵入人类察看和访问了地球上暴露在大气中所有的环境,他亦探测了海洋表面以下的和拜访了外层空间,纪录了许多不同种类的环境,并在卫星图片上得到鉴别。通过千百人的活动,勘察了所有的沙漠环境,并选择了一部分作为弥补生存条件的不足,通常用作放牧。他们避开了极端干旱和极端寒冷的荒漠地区。

关键词：土壤干旱土研究

在线全文

学校读者我要写书评

暂无评论

冠状病毒与鼻咽癌

中华耳鼻咽喉头颈外科杂志 1983年第1期18卷 23-25+62+70页

作者：汪吉宝魏能润 arnold w Schmidt w A K 武汉医学院第一附属医院耳鼻咽喉科德意志联邦共和国Dusseldorf大学

前言近10余年来,肿瘤的病毒病因学说受到了很多人的重视,许多分子生物学和免疫学的研究提示,EB病毒与鼻咽癌之间存在着甚为密切的关系。1979年arnold对鼻咽癌活检组织进行电子显微镜检查后提出,鼻咽癌肿瘤细胞中存在着类似冠状病毒的微... 详细信息

前言近10余年来,肿瘤的病毒病因学说受到了很多人的重视,许多分子生物学和免疫学的研究提示,EB病毒与鼻咽癌之间存在着甚为密切的关系。1979年arnold对鼻咽癌活检组织进行电子显微镜检查后提出,鼻咽癌肿瘤细胞中存在着类似冠状病毒的微粒。作者检查了3例鼻咽癌活检组织的超微结构,进行了一系列与冠状病毒相关的免疫血清学试验,报告如下。

关键词：肿瘤

Predictors of the placebo response in a nutraceutical randomized controlled trial for depression

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第1期22卷 46-53页

作者： Rosemary arnold Jenifer Murphy-Smith Chee H.Ng David Mischoulon Gerard J.Byrne Chad A.Bousman Con Stough Michael Berk Jerome Sarris Professorial Unit the Melbourne ClinicDepartment of PsychiatryUniversity of MelbourneRichmond 3121Australia Depression Clinical and Research Program Department of PsychiatryMassachusetts General HospitalHarvard Medical SchoolBostonMA 02115USA Faculty of Medicine Discipline of PsychiatryCentre for Clinical ResearchRoyal Brisbane&Women’s HospitalHerstonthe University of QueenslandBrisbane 4006Australia Departments of Medical Genetics PsychiatryPhysiology&Pharmacology and Community Health SciencesUniversity of CalgaryCalgaryAB T2N 1N4Canada Department of Psychiatry the University of MelbourneMelbourne 3052Australia Centre for Human Psychopharmacology Swinburne UniversityMelbourne 3122Australia The Institute for Mental and Physical Health and Clinical Translation School of MedicineBarwon HealthDeakin UniversityGeelong 3220Australia The Centre of Excellence in Youth Mental Health the University of MelbourneParkville 3052Australia Florey Institute of Neuroscience and Mental Health the University of MelbourneParkville 3052Australia NICM Health Research Institute Western Sydney UniversityWestmeadNSW 2145Australia

Objective The placebo response in depression studies is the change in symptoms amongst those who receive an inactive *** well-designed randomized controlled trials(RCTs)of depression have a high proportion of placebo responders,with little understanding as to *** present study assesses characteristics associated with the placebo response in a nutraceutical trial with a large proportion of placebo *** This is a secondary analysis of a nutraceutical depression RCT which identified no overall treatment benefit relative to placebo(n=69 in placebo group).we investigated participant characteristics such as socio-demographics,clinical features,and recruitment methods,and their association with the placebo *** genetic polymorphisms were also *** response was measured based on change in Montgomery-Asberg Depression Rating Scale *** association of these hypothesis-driven variables of interest and the placebo response was examined using linear mixed effects *** Greater levels of education,particularly pursuing post-high school education,better self-reported general health,marriage/de facto,greater improvement in the first trial week,and more failed antidepressant therapies in the current depressive episode were associated with greater placebo *** increased placebo response was not found in those recruited via social media nor in those with concomitant antidepressant *** nucleotide polymorphisms from the tryptophan hydroxylase 1(TPH1)gene(A779C and A218C)were weakly associated with greater placebo response,although the evidence was attenuated after accounting for multiple *** This is,to our knowledge,the first study within nutraceutical research for depression to assess the association between participant characteristics and variation in the placebo *** variables appeared to predict the placebo *** findings may encourage future trial design

关键词： Randomized controlled trial Placebo Depression Nutraceutical Psychiatry

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Global warming Some Perspectives

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(B) 2012年第4期1卷 499-509页

作者： Anatoly D. Erlykin arnold w. wolfendale Edward Hanna P.N. Lebedev Physical Institute Moscow 119991 Russia Department of Physics University of Durham Durham DH1 3LE UK Department of Geography University of Sheffield Sheffield Sl O 2TN UK

Here the authors critically review the IPCC"s claim that global warming is "very likely" caused by human activity: such a description underestimates the likelihood of the warming being due to this mechanism. Next examined are known alternative "natural" mechanisms which could give rise to the warming if, despite many claims, the man-made explanation was false because of compensation effects (greenhouse gases versus aerosol effects). Also, a number of difficulties, as yet unresolved, in the human-induced warming explanation are considered.

关键词：全球变暖气候变暖人类活动温室气体补偿效果气溶胶机制自然

晚白垩世真兽类Zalamdalestes揭示哺乳动物独特的枢椎及其复杂的进化过程

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2024年第11期69卷 1767-1775页

作者： Patrick arnold Katarzyna Janiszewska 李茜 Jingmai K.O'Connor Lucja Fostowicz-Frelik Institute of Biochemistry and Biology University of PotsdamPotsdam D-14476Germany Environmental Paleobiology Department Institute of PaleobiologyPolish Academy of SciencesWarsaw 00-818Poland Key Laboratory of Evolutionary Systematics of Vertebrates Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China The Field Museum of Natural History Chicago IL 60605USA Department of Organismal Biology and Anatomy The University of ChicagoChicago IL 60637USA Evolutionary Paleobiology Department Institute of PaleobiologyPolish Academy of SciencesWarsaw 00-818Poland

The typical mammalian neck consisting of seven cervical vertebrae(C1–C7)was established by the Late Permian in the cynodont forerunners of modern *** structure is precisely adapted to facilitate movements of the head during feeding,locomotion,predator evasion,and social ***,the clade including crown placentals,has a fossil record extending back more than 125 million years revealing significant morphological diversification in the *** very little is known concerning the early evolution of eutherian cervical morphology and its functional adaptations.A specimen of Zalambdalestes lechei from the Late Cretaceous of Mongolia boasts exceptional preservation of an almost complete series of cervical vertebrae(C2–C7)revealing a highly modified axis(C2).The significance of this cervical morphology is explored utilizing an integrated approach combining comparative anatomical examination across mammals,muscle reconstruction,geometric morphometrics and virtual range of motion *** compared the shape of the axis in Zalambdalestes to a dataset of 88 mammalian species(monotremes,marsupials,and placentals)using three-dimensional landmark *** results indicate that the unique axis morphology of Zalambdalestes has no close analog among living *** range of motion analysis of the neck strongly implies Zalambdalestes was capable of exerting very forceful head movements and had a high degree of ventral flexion for an animal its *** findings reveal unexpected complexity in the early evolution of the eutherian cervical morphology and suggest a feeding behavior similar to insectivores specialized in vermivory and defensive behaviors in Zalambdalestes akin to modern spiniferous mammals.

关键词： Atlas Axis Vertebral column Stem placental Morphology paleoecology