检索结果-南通市图书馆

Effects of Impurity on the Ground—state Transitions of a Quantum Dot in strong Magnetic Field

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2001年第6期35卷 735-739页

作者： k.s.chan E.Y.B.PUN 等 DepartmentofPhysicsandMaterialsscience CityuniversityofHongKongHongKongChina DepartmentofElectronic

The low-lying spectra of parabolic quantum dots with or without an impurity at the center are investigated.While it has been known that the electron-electron interaction leads to ground-state transitions on magic values of angular momentum in a magnetic field. We show, in this paper, that the implantation of an impurity ion at the center can either enhance or suppress such transitions, depending on whether it is an acceptor or a donor ion.

关键词： impurity states quantum dots

Assessment of Deformation of shear Localized Chip in High speed Machining

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 11-12页

作者： T C LEE W s LAU s k chan Industrial system Engineering Department Hong Kong Polytechnic UniversityHong Kong Institute of Vocational EducationGolden Tech Machinery Ltd. Hong Kong China Hong Kong China Hong Kong China

As the cutting speed goes higher, the mechanism of chip deformation will be changed significantly, i.e., continuous chip in low cutting speed will shift to serrated chip with shear localization. For the shear localized chip, the parameters used to assess the chip deformation for continuous chip, such as shorten coefficient ξ, shear angle φ and shear strain ε, can not describe the chip deformation correctly or comprehensively. This paper deals with the assessment of chip deformation of shear localization. There are two deformation regions in shear localized chip, one is the chip segment body with relative smaller plastic deformation, another one is the boundary between segments with shear localization, so called shear band. Considering the two distinct deformation regions, two parameters are used to define their deformation respectively. According to the analysis of chip formation process, the equations have been deduced to calculate the shear strains of shear band ε, shear strain of chip segment ε 1 and shear rate so that the shear localized chip deformation can be assessed correctly and comprehensively. By use of this assessment, the chip deformation in machining selenium treated stainless steel (sTss) and common stainless steel at various cutting conditions is investigated. The experiment results obtained by the machining of stainless steel prove that: (1) the shear strain and strain rate increase with the increasing of cutting speed; (2) the shear strain in shear band can be over 10 when cutting speed exceeding 200 m/min for both types of stainless steel, and it is much higher than the strain of chip segment. The difference will be enlarged as the cutting speed increasing; (3) As the comparison, the shear strain for the sTss is a little lower than that for JIs304; (4) The stain rate is extremely high (= 2.5×10 5 1/s ). In range of cutting speed less than 180 m/min, the strain rate for sTss is lower than that for JIs304. However, when the cutting speed is higher t

关键词： chip deformation shear localization high speed machining

New evidence for the epigenetic regulation of skeletal stem cells

在线全文

学校读者我要写书评

暂无评论

science Bulletin 2024年第13期69卷 2004-2006页

作者： Liming Zhao Jun Xiao Charles k.F.chan Institute for stem Cell Biology and Regenerative Medicine Stanford University School of MedicineStanford CA 94305USA Department of surgery Division of Plastic and Reconstructive SurgeryStanford University School of MedicineStanford CA 94305USA Department of Orthopaedic surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

skeletal stem cells(ssCs)are crucial for skeletal development and regeneration,yet the epigenetic regulation of these cells remains poorly *** studies have delineated the epigenetic landscape across the developmental trajectory of ssCs,highlighting the involvement of Ptip in regulating ssC *** skeletal system undergoes dynamic remodeling throughout *** stem cells(ssCs),residing within the skeleton and lineage-restricted,serve as a cellular reserve to foster development and maintain skeletal *** categorized within the broader mesenchymal stromal/stem cells(MsCs).

关键词： skeletal involvement maintain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

《跨边界资源管理》书评

地理学报 2013年第6期68卷 870-871页

作者： Guo changlei Faith k.s. chan school of Geography University of Leeds

由郭荣星教授撰写的《跨边界资源管理（第二版）》（英文名：Cross—BorderResourceManagement--second Edition”，由荷兰Elsevier出版社于2012年出版；网络版：http：／／***／science／bookseries／14748177／10）是一本系统阐述在跨边界地区或是边界过渡地区对自然与环境资源如何有效管理的学术专著。在跨边界地区，政府行为和管理手段是复杂的，司法权通常受制于两个或以上的独立政权或行政／军事势力影响。

关键词：资源管理跨边界 Edition 书评学术专著有效管理环境资源过渡地区

Exploring the synergy of the eyebrain connection:neuromodulation approaches for neurodegenerative disorders through transcorneal electrical stimulation

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第10期19卷 2097-2098页

作者： Antara Verma stephen k.Agadagba Leanne Lai-Hang chan Department of Electrical Engineering City University of Hong KongKowloonHong Kong Special Administrative RegionChina Centre for Eye and Vision Research Ltd. Hong Kong Special Administrative RegionChina Pennsylvania state University University ParkPAUSA

The connection and interaction between the eye and the brain are crucial to understanding brain disorders(Marchesi et al.,2021).Both the eye and the brain have a limited regenerative capacity as there are few progenitor cells,and nerve cells do not ***,neurodegeneration implicates irreversible damage to the central nervous system,as observed in several neurodegenerative diseases(Marchesi et al.,2021).

关键词： stimulation degenerative

A harmonisation approach to traditional Chinese medicine registration in Asian countries

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medical sciences 2024年第2期11卷 143-147页

作者： Vivian s.W.chan Fung Independent scholar 2 Woodward PlaceSt IvesNSW 2075Australia

The traditional Chinese medicine(TCM)industry is critical to not only for public health but also for economic *** to the European Union(EU)directives,under the EU framework for(traditional)herbal medicinal products,herbal medicines with long history of use can be registered in ***,there is a condition in this directive in which only those that have at least 10e15 years in the EU market are accepted for registration and/or marketing *** author opinion,the condition of 10-15 years of use in EU countries set within the EU regulatory framework is with consideration of the genetic differences which can result in variation in adverse drug responses among different world *** this concept in mind,it is reasonable to project the principal of the EU directive to the Asian countries where TCM is *** like China,singapore,Japan and south korea that have well established drug registration framework are in best position in executing the best practice and facilitate harmonization of registration for TCM within the ***,the registration process itself allows more safety and efficacy data to be collected systemically before and after product registration/marketing *** are valuable information for future drug *** therapeutic value of TCM is limitless,it has been left out in the EU regulatory framework,and the opportunity for it to be expanded and carried forward in modern medicines is shadowed by the limited number of TCM that are qualified to be registered under the EU regulatory *** early establishment of a harmonized risk-based registration process for TCM in Asian countries is *** will strengthen the database to substantiate the history of safe use and further preserving and expanding the therapeutic values of TCM within and beyond the Asian region.

关键词： Traditional Chinese medicines Population genetic Harmonization Registration Asian countries

The protean manifestations of central nervous system IgG4-related hypertrophic pachymeningitis:a report of two cases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Neurosurgical Journal 2021年第4期7卷 306-312页

作者： Peter Y.M.Woo Ben C.F.Ng June H.M.Wong Oliver k.s.Ng Timothy s.k.chan Ngai-Fung kwok kwong-Yau chan Department of Neurosurgery Kwong Wah HospitalHong KongHong KongChina Department of Internal Medicine Caritas Medical CenterHong KongHong KongChina Department of Pathology Kwong Wah Hospital25 Waterloo RoadYaumateiHong KongHong KongChina Department of Neurosurgery Queen Elizabeth HospitalHong KongHong KongChina

Background:IgG4-related hypertrophic pachymeningitis is a relative newly recognized and rare manifestation of IgG4-related disease,an immune-mediated fibroinflammatory tumefactive *** than 80 patients have been reported in the literature,and it can mimic common neurosurgical *** describe the clinical presentation of two patients that were initially considered to have a subdural collection,tuberculous meningitis,and a cervical spinal meningioma,but were eventually diagnosed with this *** presentation:Two ethnic Chinese men,86 and 62 years old,experienced a 4-week history of *** patients had a history of autoimmune disease,namely glomerulonephritis and Grave’s disease,*** resonance brain imaging revealed diffuse dural thickening with the latter patient exhibiting homogeneous and intense gadolinium-contrast *** the 86-year-old patient also had progressive bilateral visual loss,giant cell arteritis was suspected and a 2-week course of glucocorticoid therapy was prescribed,but his symptoms failed to *** 62-year-old patient also had accompanying low-grade fever and was treated empirically as having tuberculous meningitis although there were no confirmatory microbiological *** patient further developed right hemiparesis,and additional imaging revealed a C4/5 intradural-extramedullary contrast-enhancing lesion resembling a meningioma causing cord *** patients underwent neurosurgical intervention with the former undergoing a dural biopsy and the latter having the cervical lesion *** final diagnosis was IgG4-related hypertrophic pachymeningitis with the hallmark histological features of lymphoplasmacytic infiltration of IgG4+plasma cells,storiform fibrosis,and obliterative *** addition,their serum IgG4 levels were elevated(i.e.,>135 mg/dL).Both patients received at least 6 months of glucocorticoid therapy while the latter also had *** symptom

关键词： Hypertrophic pachymeningitis IgG4-related disease IgG4-related sclerosing disease Central nervous system

Understanding the corrosion and bio-corrosion behaviour of Magnesium composites – a critical review

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3期12卷 890-939页

作者： Prithivirajan sekar s.k.Panigrahi Department of Mechanical Engineering Indian Institute of Technology MadrasChennai600036India Applied Magnesium Research Center Center of Excellence in Materials and Manufacturing for Futuristic MobilityIndian Institute of Technology MadrasChennai600036India

Realising the potential of Magnesium(Mg),several globally leading ventures have invested in the Mg industry,but their relatively poor corrosion resistance is a never ending saga till *** corrosion and bio-corrosion behaviour of Mg has gained research attention and still remains a hot topic in the application of automobile,aerospace and biomedical *** intrinsic high electrochemical nature of Mg limits their utilization in diverse *** scenario has prompted the development of Mg composites with an aim to achieve superior corrosion and bio-corrosion *** present review enlightens the influence of grain size(Gs),secondary phase,texture,type of matrix and reinforcement on the corrosion and bio-corrosion behaviour of Mg ***,the corrosion and bio-corrosion behaviour of Mg composites manufactured by primary and secondary processing routes are ***,the comprehensive corrosion and bio-corrosion mechanisms of these Mg composites are ***,the individual role of Gs,texture and corrosive medium on corrosion and bio-corrosion behaviour of Mg composites are clarified and *** challenges encountered,unanswered issues in this field are explained in detail and accordingly the scope for future research is *** review is presented from basic concrete background to advanced corrosion mechanisms with an aim of creating interest among the readers like students,researchers and industry experts from various research ***,the corrosion and bio-corrosion behaviour of Mg composites are critically reviewed for the first time to:(i)contribute to the body of knowledge,(ii)foster research and development,(iii)make breakthrough,and(iv)create life changing innovations in the field of Mg composite corrosion.

关键词： Corrosion Bio corrosion Magnesium alloys Magnesium composites Magnesium implants.

A new route to weak force sensing beyond sQL:squeezed magnons in cavity magnomechanics

在线全文

学校读者我要写书评

暂无评论

science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 166-167页

作者： s.k.Özdemir Department of Engineering science and Mechanics and Materials Research Institute(MRI)The Pennsylvania State UniversityUniversity ParkPA 16802USA

Quantum mechanics imposes limits on measurement accuracy through quantum noise which typically has two components:First is the shot noise originating from vacuum fluctuations and referred to as the imprecision *** is ... 详细信息

关键词： quantum typically vacuum