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A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

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A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy. In ME it is hard to distinguish between expenditure on research and development and the costs incurred for the current output. The reason is that in a process with a high share of made-to-measure products, some research and a lot of development may be undertaken in connection with special orders. That is especially the case for small and medium-sized firms. Thus it is true that the available figures for research and development in ME do not reflect all the efforts taken by firms to find new technical solutions and to optimize products as well as clients’ processes. However, all of.... Giống những tài liệu khác được bạn đọc giới thiệu hoặc do sưu tầm lại và giới thiệu lại cho các bạn với mục đích học tập , chúng tôi không thu tiền từ thành viên ,nếu phát hiện nội dung phi phạm bản quyền hoặc vi phạm pháp luật xin thông báo cho chúng tôi,Ngoài thư viện tài liệu này, bạn có thể tải bài giảng miễn phí phục vụ nghiên cứu Một ít tài liệu download mất font không xem được, nguyên nhân máy tính bạn không hỗ trợ font củ, bạn tải các font .vntime củ về cài sẽ xem được.

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Tài Liệu Miễn Phí xin chia sẽ tới cộng đồng tài liệu A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy.Để chia sẽ thêm cho các Thầy cô, các bạn sinh viên, học viên nguồn tài liệu tham khảo phục vụ cho công tác giảng dạy, học tập và nghiên cứu khoa học, trân trọng kính mời bạn đọc đang tìm cùng tham khảo ,Thư viện A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy thuộc danh mục ,Kỹ Thuật - Công Nghệ,Cơ khí - Chế tạo máy được chia sẽ bởi bạn cokhichetaomay tới mọi người nhằm mục tiêu nâng cao kiến thức , thư viện này được chia sẽ vào chủ đề Kỹ Thuật - Công Nghệ,Cơ khí - Chế tạo máy , có tổng cộng 140 page , thuộc file .PDF, cùng chuyên mục còn có protected against, automated, event-driven backups, Reliable, automated recovery, computer systems ,bạn có thể download miễn phí , hãy chia sẽ cho mọi người cùng nghiên cứu . Để download file về, các bạn click chuột nút download bên dưới
In ME it is hard to distinguish between expenditure on research and development and the , nói thêm là costs incurred for the current output, tiếp theo là The reason is that in a process with a high share of , tiếp theo là made-to-measure products, some research and a lot of development may be undertaken in , ngoài ra connection with special orders, bên cạnh đó That is especially the case for small and medium-sized , nói thêm firms, cho biết thêm Thus it is true that the available figures for research and development in ME do not ,còn cho biết thêm reflect all the efforts taken by firms to find new technical solutions and to optimize , kế tiếp là products as well as clients’ processes, ngoài ra However, all of, tiếp theo là MECHANICAL AND ELECTRICAL PROPERTIES OF GRAPHENE SHEETS A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Joseph Scott Bunch May 2008 © 2008 Joseph Scott Bunch MECHANICAL AND ELECTRICAL PROPERTIES OF GRAPHENE SHEETS Joseph Scott Bunch, Ph, bên cạnh đó D, thêm nữa Cornell University 2008 This thesis examines the electrical and mechanical properties of graphene sheets,còn cho biết thêm We perform low temperature electrical transport measurements on gated, quasi-2D graphite quantum dots, bên cạnh đó In devices with low contact
MECHANICAL AND ELECTRICAL PROPERTIES OF GRAPHENE SHEETS A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Joseph Scott Bunch May 2008 © 2008 Joseph Scott Bunch MECHANICAL AND ELECTRICAL PROPERTIES OF GRAPHENE SHEETS Joseph Scott Bunch, Ph. D. Cornell University 2008 This thesis examines the electrical and mechanical properties of graphene sheets. We perform low temperature electrical transport measurements on gated, quasi-2D graphite quantum dots. In devices with low contact resistances, we use longitudinal and Hall resistances to extract a carrier density of 2-6 x 1011 holes per sheet and a mobility of 200-1900 cm2/V-s. In devices with high resistance contacts, we observe Coulomb blockade phenomena and infer the charging energies and capacitive couplings. These experiments demonstrate that electrons in mesoscopic graphite pieces are delocalized over nearly the whole graphite piece down to low temperatures. We also fabricate nanoelectromechanical systems (NEMS) from ultra thin graphite and graphene by mechanically exfoliating thin sheets over trenches in SiO2. Vibrations with fundamental resonant frequencies in the MHz range are actuated either optically or electrically and detected optically by interferometry. We demonstrate room temperature charge sensitivities down to 2x10-3 e/Hz½. The thinnest resonator consists of a single suspended layer of atoms and represents the ultimate limit of a two dimensional NEMS. In addition to work on doubly clamped beams and cantilevers, we also investigate the properties of resonating drumheads, which consist of graphene sealed microchambers containing a small volume of trapped gas. These experiments allow us to probe the membrane properties of single atomic layers of graphene. We show that these membranes are impermeable and can support pressure differences larger than one atmosphere. We use such pressure differences to tune the mechanical resonance frequency by ~100 MHz. This allows us to measure the mass and elastic constants of graphene membranes. We demonstrate that atomic layers of graphene have stiffness similar to bulk graphite (E ~ 1 TPa). These results show that single atomic sheets can be integrated with microfabricated structures to create a new class of atomic scale membrane-based devices. BIOGRAPHICAL SKETCH Joseph Scott Bunch was born on November 8, 1978 in Miami, Florida. He attended elementary, middle, and high school in Miami. After high school, he remained in Miami and enrolled at Florida International University (FIU) where he received his B.S. degree in physics in 2000. While at FIU, he was introduced to nanoscience research through an undergraduate research opportunity studying electrodeposition of metallic nanowires in Professor Nongjian Tao’s lab. He also spent one summer in a research program at the University of Tennessee, Knoxville working with a scanning tunneling microscope in Professor Ward Plummer’s lab. After graduation from FIU, Scott was awarded a graduate fellowship from Lucent Technologies, Bell Laboratories to continue his education. He spent the summer of 2000 at Bell Laboratories in Murray Hill, N.J. working with Nikolai Zhitenev on the electrodeposition of scanning single electron transistor tips. In August 2000, he enrolled in the physics department at Cornell University where he joined Paul McEuen’s group and continued nanoscience research. His research focused primarily on the electrical and mechanical properties of graphene. After finishing his Ph.D. in May 2008, Scott will do postdoctoral research on mass sensing with nanoelectromechanical systems in Professor Harold Craighead and Professor Jeevak Parpia’s lab at Cornell University before heading off to Colorado in August 2008 to become an Assistant Professor of Mechanical Engineering at the University of Colorado at Boulder. iii ... - tailieumienphi.vn 803760

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