检索结果-南通市图书馆

Stem cell therapies and regenerative medicine in China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2014年第2期57卷 157-161页

作者： HUANG sha FU XiaoBing Wound Healing and Cell Biology Laboratory Institute of Basic Medical Sciences Chinese PLA General Hospital Key Laboratory of Wound Repair and Regenerative Medicine of PLA the First Affiliated Hospital of the PLA General Hospital Hainan Branch of the Chinese PLA General Hospital

Stem cells are the core of tissue repair and regeneration,and a promising cell source for novel *** recent years,research into stem cell therapies has been particularly exciting in *** remarkable advancements in basic stem cell research and clinically effective trials have led to fresh insights into regenerative medicine,such as treatments for sweat gland injury after burns,diabetes,and liver *** hopes have inspired numerous experimental and clinical *** the same time,government investment and policy support of research continues to increase ***,numerous challenges must be overcome before novel stem cell therapies can achieve meaningful clinical outcomes.

关键词： stem cells regenerative medicine tissue engineering clinical trial

Frequency Loss and Recovery in Rolling Bearing Fault Detection

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2019年第2期32卷 145-156页

作者： Aijun Hu Ling Xiang sha Xu Jianfeng Lin Department of Mechanical Engineering North China Electric Power University

Rolling element bearings are key components of mechanical equipment. The bearing fault characteristics are a ected by the interaction in the vibration signals. The low harmonics of the bearing characteristic frequencies cannot be usually observed in the Fourier spectrum. The frequency loss in the bearing vibration signal is presented through two independent experiments in this paper. The existence of frequency loss phenomenon in the low frequencies, side band frequencies and resonant frequencies and revealed. It is demonstrated that the lost frequencies are actually suppressed by the internal action in the bearing fault signal rather than the external interference. The amplitude and distribution of the spectrum are changed due to the interaction of the bearing fault signal. The interaction mechanism of bearing fault signal is revealed through theoretical and practical analysis. Based on mathematical morphology, a new method is provided to recover the lost frequencies. The multi-resonant response signal of the defective bearing are decomposed into low frequency and high frequency response, and the lost frequencies are recovered by the combination morphological filter(CMF). The e ectiveness of the proposed method is validated on simulated and experimental data.

关键词： Rolling element bearing Signal processing Frequency loss Fault detection Morphological filter

Surface metallization of PTFE and PTFE composites by ion implantation for low-background electronic substrates in rare-event detection experiments

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第7期33卷 37-47页

作者： shao-Jun Zhang Yuan-Yuan Liu sha-sha Lv Jian-Ping Cheng Bin Liao Pan Pang Zhi Deng Li He College of Nuclear Science and Technology Beijing Normal UniversityJoint Laboratory of Jinping Ultra-low Radiation Background Measurement of Ministry of Ecology and Environment Beijing Normal UniversityKey Laboratory of Beam Technology of Ministry of EducationBeijing Normal UniversityBeijing100875China Beijing Radiation Center Beijing100875China Department of Engineering Physics Key Laboratory of Particle and Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing100084China Joint Research Center Nuctech Company LimitedBeijing100084China

Polytetrafluoroethylene(PTFE)is a low-background polymer that is applied to several applications in rare-event detection and underground low-background ***-based electronic substrates are important for reducing the detection limit of high-purity germanium detectors and scintillator calorimeters,which are widely applied in dark matter and 0υββdetection *** traditional adhesive bonding method between PTFE and copper is not conducive to working in liquid nitrogen and extremely low-temperature *** avoid adhesive bonding,PTFE must be processed for surface metallization owing to the mismatch between the PTFE and copper conductive ***-background PTFE matrix composites(m-PTFE)were selected to improve the electrical and mechanical properties of PTFE by introducing SiO_(2)/TiO_(2) *** microstructures,surface elements,and electrical properties of PTFE and m-PTFE were characterized and analyzed following ion *** and m-PTFE surfaces were found to be broken,degraded,and cross-linked by ion implantation,resulting in C=C conjugated double bonds,increased surface energy,and increased surface ***,the surface roughness,bond strength,and conjugated double bonds of m-PTFE were significantly more intense than those of ***,the interface bonding theory between PTFE and the metal copper foil was analyzed using the direct metallization ***,the peel strength of the optimized electronic substrates was higher than that of the industrial standard at extremely low temperatures,while maintaining excellent electrical properties.

关键词： Surface modification Polytetrafluoroethylene Ion implantation Surface metallization Low temperature resistance

Mitochondrial phylogenomics reveal the origin and adaptive evolution of the deep-sea caridean shrimps(Decapoda:Caridea)

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

Journal of Oceanology and Limnology 2021年第5期39卷 1948-1960页

作者： shao’e SUN Zhongli sha Yanrong WANG Deep Sea Research Center Institute of OceanologyChinese Academy ofSciencesQingdao 266071China Laboratory for Marine Biology and Biotechnology Pilot NationalLaboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao266071China University of Chinese Academy of Sciences Beijing 100049China

The deep-sea is considered as the most extensive ecosystem on the *** is meaningful for elucidating the life origins by exploring the origin and adaptive genetic mechanisms of the large deepsea *** shrimps have colonized and successfully adapted to deep-sea *** provide an ideal model to analyze the origin and adaptive evolution of modern deep-sea ***,we conducted the phylogenetic analyses of mitocho ndrial genomes(mitogenomes)from carideans,including 11 newly sequences reported in this investigation to explore the habitat origins,divergence times,and adaptive evolution of deep-sea(seamounts and hydrothermal vents)caridean *** results showed that the species of deep-sea Caridea formed a monophyletic *** analysis supported that the deepsea caridean shrimps may originated from shallow *** hydrothermal vents alvinocaridid shrimps and Lebbeus shinkaiae from Thoridae underwent a second range expansion from seamounts to vent *** of divergence time showed that the caridean shrimps invaded into deep-sea at 147.75 *** divergence of most of the modern seamount and hydrothermal vent species are in the late Cretaceous/early *** may associate with the geological events of the Western Pacific,the climate change,and the global deep-water anoxic/dysoxic events during this ***-two potentially important adaptive residues were detected in the deep-sea shrimp lineage,which were located in atp6,atp8,cox1,cox3,cytb,nad2,nad4 l,and *** investigation adds our understanding of the evolutionary history of deep-sea caridean shrimps,and provides insights into the mitochondrial genetic basis of deep-sea adaptation in this group.

关键词： hydrothermal vents seamounts Caridea mitochondrial genome phylogenetic analysis evolutionary history

BER analysis of STBC hybrid carrier system based on WFRFT with frequency domain equalization

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2018年第8期61卷 147-159页

作者： Zhenduo WANG Lin MEI Xuejun sha Naitong ZHANG Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory

The inherent characteristic of hybrid carrier(HC) scheme based on the weighted-type fractional Fourier transform(WFRFT) is revealed. The proposed linear combination of single carrier(SC) and multicarrier’s(MC) characteristics is helpful to balance the conflicting requirements and achieve the comparative analysis of SC/MC. As an example, analytical SER/BER expressions of HC system with zero forcing(ZF)and minimum mean square error(MMSE) equalization are derived. In addition, the derived BER expressions are extended to multi-input systems. A unified framework of space time block code(STBC) HC scheme is proposed with two WFRFT modules at the transmitter or receiver, where STBC-SC and STBC-MC systems are the special cases of the novel structure.

关键词： single carrier multi-carrier weighted-type fractional Fourier transform hybrid carrier zero forcing minimum mean square error space time block code

A retrospective study of 2228 cases with eyelid tumors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2018年第11期11卷 1835-1841页

作者： sha-sha Yu Yun Zhao Hong Zhao Jin-Yong Lin Xin Tang Clinical College of Ophthalmology Tianjin Medical University Tianjin 300020 China Tianjin Eye Hospital Tianjin 300020 China Tianjin Key Laboratory of Ophthalmology and Visual Science Tianjin 300020 China Tianjin Eye Institute Tianjin 300020 China

AIM： To describe the histopathologic and clinical features of eyelid tumor cases from Tianjin Eye Hospital during 2002 to 2015. METHODS： In this retrospective study, a total of 2228 cases of eyelid tumors with pathologic diagnoses were enrolled. The eyelid tumors were classified into three groups according to tumor origin： epidermal, adnexal and miscellaneous, including melanocytic, neural and vascular lesions. Inflammatory tumor-like lesions were excluded. The clinical characteristics of the eyelid tumors were analyzed, including age, gender and lesion location. RESULTS： Most eyelid tumors were epidermal in origin（1080, 48.5%）, followed by miscellaneous（885, 39.7%） and adnexal tumors（263, 11.8%）. Among all the tumors, 292（13.1%） were malignant lesions, 1910（85.7%） benign and 26（1.1%） premalignant lesions. Most malignant tumors originated from epidermal cells（60.0%）, followed by adnexal cells（34.6%）. The most common malignant tumors were basal cell carcinomas（56.5%） followed by sebaceous carcinoma（34.6%）, squamous cell carcinomas（3.8%） and lymphoma/plasmocytoma（1.7%）. The benign and premalignant eyelid lesions mostly originated from epidermal cells（46.4%） followed by miscellaneous cell sources（45.2%）, including melanocytic nevus（33.8%）, seborrheic keratosis（13.7%）, squamous cell papilloma（13.0%） and epidermal cysts（11.5%）. CONCLUSION： Eyelid tumors are mostly epithelial in origin. Benign tumors are significantly more common than malignant tumors with an obvious female predominance, and the most frequent malignant tumor are basal cell carcinoma, sebaceous carcinoma and squamous cell carcinomas. The tumor clinical features varied among the different subtypes.

关键词： eyelid tumors benign tumors malignant tumor basal cell carcinoma sebaceous carcinoma squamous cell carcinoma melanocytic nevus

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

Road to Rio+20

Chinese Journal of Population,Resources and Environment 2011年第4期9卷 3-8页

作者： sha Zukang Secretary-General for Economic and Social Affairs Secretary-General of the 2012 UN Conference on Sustainable Development

1 Introduction It is a privilege for me, as Secretary-General of the Rio+20 Conference, to be here with all of you. On behalf of the United Nations, let me express my sincere gratitude to the Global Mayor's Forum for this important contribution to the preparations for the United Nations Conference on Sustainable Development (Rio+20).

关键词：摘要编辑部编辑工作读者

Low complexity bit loading algorithm for OFDM system

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2006年第1期17卷 71-74页

作者： Yang Yu sha Xuejun Zhang Zhonghua National Key Laboratory of Tunable Laser Technology Harbin Inst. of Technology Harbin 150001 P. R. China Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

A new approach to loading for orthogonal frequency division multiplexing （OFDM） system is proposed, this bit-loading algorithm assigns bits to different subchannels in order to minimize the transmit energy. In the algorithm, first most bit are allocated to each subchannels according to channel condition, shannon formula and QoS require of the user, then the residual bit are allocated to the subchannels bit by bit. In this way the algorithm is efficient while calculation is less complex. This is the first time to load bits with the scale following shannon formula and the algorithm is of O （4 N） complexity.

关键词： OFDM bit loading shannon formula QoS

Texture Evolutions in Fe-6.5%Si Produced by Rapid Solidification and Chemical Vapor Deposition

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2002年第6期18卷 516-518页

作者： Liang ZUO Guangyong HU Yuhui sha Claude ESLING School of Materials Science and Metallurgy Northeastern UniversityShenyang 110004China Laboratoire d'Etude des Textures et Application aux Materiaux CNRS UMR 7078Universite de Metz 57045 Metz Cedex 1France

Fe-Si ribbons and thin sheets with 6.5%Si content were prepared by means of the single roller rapid solidification and chemical vapor deposition (CVD), respectively. The initial textures of rapidly solidified Fe-6.5%Si ribbons were characteristic of the {100} fiber-type, which became weakened during primary recrystallization in various atmospheres. At the stage of secondary recrystallization, the {100} texture formed in Ar and the {110} texture in hydrogen, while there occurred a texture transformation from the {100} type to the {110} type in vacuum with the increase of annealing temperature. For Fe-6.5%Si sheets prepared by Si deposition in cold-rolled Fe-3%Si matrix sheets, their textures were dominated by the η-fiber (//RD) with the maximum density at the {120} orientations. After homogenization annealing, the η-fiber could evolve into the {130} type or become more concentrated on the {120} orientations, depending on the cold rolling modes of Fe-3%Si matrix sheets.

关键词： Fe-6.5%Si alloy Texture Rapid solidification Chemical vapor deposition