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排序方式: 共有765条查询结果,搜索用时 10 毫秒
21.
Chakrabarti A Naik V Dechoudhury S Bandyopadhyay A Mondal M Pandey HK Roy TK Sanyal D Bhowmick D 《The Review of scientific instruments》2007,78(4):043303
A 33.7 MHz heavy-ion radio frequency quadrupole (RFQ) linear accelerator has been designed, built, and tested. It is a four-rod-type RFQ designed for acceleration of 1.38 keVu, qA> or =116 ions to about 29 keVu. Transmission efficiencies of about 85% and 80% have been measured for the unanalyzed and analyzed beams, respectively, of oxygen ((16)O(2+), (16)O(3+), (16)O(4+)), nitrogen ((14)N(3+), (14)N(4+)), and argon ((40)Ar(4+)). The system design and measurements along with results of beam acceleration test will be presented. 相似文献
22.
An inertia-adaptive particle swarm system with particle mobility factor for improved global optimization 总被引:2,自引:2,他引:0
Sayan Ghosh Swagatam Das Debarati Kundu Kaushik Suresh B. K. Panigrahi Zhihua Cui 《Neural computing & applications》2012,21(2):237-250
Particle Swarm Optimization (PSO) has recently emerged as a nature-inspired algorithm for real parameter optimization. This
article describes a method for improving the final accuracy and the convergence speed of PSO by firstly adding a new coefficient
(called mobility factor) to the position updating equation and secondly modulating the inertia weight according to the distance
between a particle and the globally best position found so far. The two-fold modification tries to balance between the explorative
and exploitative tendencies of the swarm with an objective of achieving better search performance. We also mathematically
analyze the effect of the modifications on the dynamics of the PSO algorithm. The new algorithm has been shown to be statistically
significantly better than the basic PSO and four of its state-of-the-art variants on a twelve-function test-suite in terms
of speed, accuracy, and robustness. 相似文献
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3D integration of ICs is an emerging technology where multiple silicon dies are stacked vertically. The manufacturing itself
is based on wafer-to-wafer bonding, die-to-wafer bonding or die-to-die bonding. Wafer-to-wafer bonding has the lowest yield
as a good die may be stacked against a bad die, resulting in a wasted good die. Thus the latter two options are preferred
to keep yield high and manufacturing costs low. However, these methods require dies to be tested separately before they are
stacked. A problem with testing dies separately is that the clock network of a prebond die may be incomplete before stacking.
In this paper we present a solution to address this problem. The solution is based on on-die Delay Lock Loop (DLL) implementations
that are only activated during testing prebond unstacked dies to synchronize disconnected clock regions. A problem with using
DLLs in testing is that they cannot be turned on or off within a single cycle. Since scan-based testing requires that test
patterns be scanned in at a slow clock frequency before fast capture clocks are applied, On-Product Clock Generation (OPCG)
must be used. The proposed solution addresses the above problems and allows a prebond with an incomplete clock network to
be tested with low skew. 相似文献
26.
The crystallization kinetics of Sn40Se60 thin films has been successfully investigated using sheet resistance versus temperature measurements. Thermal evaporation was used to deposit the films on ordinary glass substrates. The crystallization temperature for Sn40Se60 thin film was found to be 156.6 ± 0.3 ℃. In the as-deposited state, the sheet resistance was found to be 195 MΩ, this value declined to 1560 Ω/口 upon annealing. The value of activation energy obtained from the Kissinger plot was 0.62 ± 0.07 eV. From the results obtained, Sn40Se60 is a promising alloy for PCM application because of its high electrical contrast, high crystallization temperature, and relatively high activation energy. 相似文献
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Banani Kundu Nicholas E. Kurland Subia Bano Chinmoy Patra Felix B. Engel Vamsi K. Yadavalli Subhas C. Kundu 《Progress in Polymer Science》2014
Biomaterials of either natural or synthetic origin are used to fabricate implantable devices, as carriers for bioactive molecules or as substrates to facilitate tissue regeneration. For the design of medical devices it is fundamental to use materials characterized by non-immunogenicity, biocompatibility, slow and/or controllable biodegradability, non-toxicity, and structural integrity. The success of biomaterial-derived biodevices tends to be based on the biomimetic architecture of the materials. Recently, proteins from natural precursors that are essentially structural and functional polymers, have gained popularity as biomaterials. The silks produced by silkworms or spiders are of particular interest as versatile protein polymers. These form the basis for diverse biomedical applications that exploit their unique biochemical nature, biocompatibility and high mechanical strength. This review discusses and summarizes the latest advances in the engineering of silk-based biomaterials, focusing specifically on the fabrication of diverse bio-mimetic structures such as films, hydrogels, scaffolds, nanofibers and nanoparticles; their functionalization and potential for biomedical applications. 相似文献
30.
The absorber of a collector receives solar energy which is delivered to the transport medium to be carried away as useful energy. During this process, temperature of the absorber plate increases and therefore, thermophysical parameters engaged to determine the thermal performance of an absorber plate varies with temperature of the plate. The present study demonstrates analytically to determine the performance of an absorber plate fin with temperature dependent both thermal conductivity and overall heat loss coefficient. The decomposition method is proposed for the solution methodology. An optimum design analysis has also been carried out. A comparative study has been executed among the present results and that of existed in the published work, and a notable difference in results has been found. Finally, unlike published work, dependency parameters on the performances and optimum design have been highlighted. 相似文献