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排序方式: 共有230条查询结果,搜索用时 31 毫秒
1.
Wireless Networks - One of the biggest challenges of distributed software defined networks (SDNs) is to create load balancing on controllers to reduce response time. Although recent studies have... 相似文献
2.
The convective batch drying of Western Hemlock hog fuel-sized particles in fixed beds under various operating conditions quantiatively established the effect of factors which govern the drying process. A correlation was obtained for the Nusselt number during the heat transfer controlled period. Under specific conditions, the existence of a unified characteristic drying rate curve was confirmed. Drying behaviour as described by the receding plane model provided a mathematical expression for such a curve. The existence of an inversion point temperature was experimentally confirmed. 相似文献
3.
In this paper, the problem of motion planning for parallel robots in the presence of static and dynamic obstacles has been investigated. The proposed algorithm can be regarded as a synergy of convex optimization with discrete optimization and receding horizon. This algorithm has several advantages, including absence of trapping in local optimums and a high computational speed. This problem has been fully analyzed for two three-DOF parallel robots, ie 3s-RPR parallel mechanism and the so-called Tripteron, while the shortest path is selected as the objective function. It should be noted that the first case study is a parallel mechanism with complex singularity loci expression from a convex optimization problem standpoint, while the second case is a parallel manipulator for which each limb has two links, an issue which increases the complexity of the optimization problem. Since some of the constraints are non-convex, two approaches are introduced in order to convexify them: (1) A McCormick-based relaxation merged with a branch-and-prune algorithm to prevent it from becoming too loose and (2) a first-order approximation which linearizes the non-convex quadratic constraints. The computational time for the approaches presented in this paper is considerably low, which will pave the way for online applications. 相似文献
4.
Arrays of precisely positioned single crystal silicon nanopillars, nanoneedles, and nanoblades with minimum feature sizes as small as 30 nm are fabricated using entirely scalable top-down fabrication techniques. Using the same scalable technologies, devices consisting of electrically connected silicon nanopillars with multiple addressable electrodes for each nanostructure are realized. The arrays of nanopillars, nanoneedles, and nanoblades are shown to exhibit Raman signal enhancement on 1,2-benzenedithiol monolayers, opening a path to nanodevices that manipulate, position, detect and analyze molecules. 相似文献
5.
Adhesion plays an important role in the final properties of nanocomposites. This study explored the surface interaction of
cellulose nanocrystals (CNCs) and the effect of CNC sources on adhesion between individual CNCs and the Si tip of an AFM cantilever
using a force mapping technique called FMap. The adhesion between CNCs and a Si tip from five different sources has been studied:
cotton, Whatman filter paper, hemp, softwood chemical kraft pulp, and softwood-dissolving pulp (alistaple). Mica was used
as the background substrate to act as an internal standard. This study’s findings suggest that adhesion is not the same for
all CNCs. Transmission electron microscopy and atomic force microscopy were used to determine the size and shape of each CNC.
The experimental quantitative data showed that adhesion between CNCs and the Si tip has a close correlation with the diameter
of the CNCs. X-ray photoelectron spectroscopy confirmed the presence of sulfate groups on the surface of the CNCs and a correlation
between adhesion and surface chemistry of the CNCs was observed. 相似文献
6.
V. Najafi K. Kabiri F. Ziaee H. Omidian M. J. Zohuriaan-Mehr H. Bouhendi H. Farhadnejad 《Journal of Polymer Research》2012,19(6):9866
Alcohol absorbents based on poly(ethylene glycol methyl ether methacrylate) and vinyl phosphonic acid (VPA) were prepared
via solution polymerization using poly(ethylene glycol dimethacrylate) macrocrosslinker. Swelling capacity of these materials
was measured in water, ethanol and methanol. Alcohol absorbency was increased with increase of VPA content that can be attributed
to ability of VPA in formation of H-bonding and disassociation of phosphonic acid group to produce mobile ions. The alcogels
could absorb ethanol and methanol up to 15.1 and 17.8 g/g respectively. Thermo-gravimetric analysis showed that increase in
VPA concentration increased char yield and decreased the initial decomposition temperature (IDT) due to forming anhydride
crosslinks during heating. Based on rheological measurements, the storage modulus was increased with increase in PEGMEMA content.
The prepared alcogels were further characterized using FTIR, NMR and DMTA. 相似文献
7.
8.
Jalalzadeh-Esfahani Mehrnoosh Sedaghat Tahereh Beheshti Azizollah Azadi Roya 《Journal of Porous Materials》2022,29(4):1149-1164
Journal of Porous Materials - Benzimidazole functionalized mesoporous silica nanoparticles immobilized Pd(0)/Pd(II) has been proposed as an efficient catalyst for the one-pot preparation of biaryls... 相似文献
9.
Fatemeh Asghari Roya Salehi Marziyeh Agazadeh Effat Alizadeh Khosro Adibkia Mohammad Samiei 《国际聚合物材料杂志》2016,65(14):720-728
The authors aimed to design nanofibrous (NF) scaffolds that facilitate odontogenic and osteogenic differentiation of human dental pulp-derived mesenchymal stem cells (DPSCs) in vitro. For this purpose, hydroxyapatite (HA)–loaded poly (L-lactic acid)/poly (?-caprolactone) (PLLA:PCL 2;1) blend NFs were prepared using the electrospinning method. Alizarin red activity and cell viability were evaluated by MTT assay, and SEM revealed the proliferation properties of NF scaffolds. QRT-PCR results demonstrated that HA-loaded PLLA/PCL can lead to osteoblast/odontoblast differentiation in DPSCs through the up-regulation of related genes, thus indicating that electrospun biodegradable PCL/PLA/HA has remarkable prospects as scaffolds for bone and tooth tissue engineering. 相似文献
10.
Ahmadi Ameneh Sedaghat Tahereh Azadi Roya 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(10):4126-4140
Journal of Inorganic and Organometallic Polymers and Materials - 3-Chloropropyltrimethoxysilane (CPTMS) was grafted on the surface of silica coated Fe3O4 core (Fe3O4@MCM-41) and then condensed with... 相似文献