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1.
In this paper, experimental and numerical studies are presented to understand why some trees close to the shoreline survived the 25 October 2010 Mentawai tsunami, while trees further inland before a steep coastal hill were all destroyed. A set of experiments were performed in a wave flume to measure the flow depths and forces acting on tree models, and the experimental results were used to verify our numerical model. Cross-shore distribution of the flow depth and the flow-induced bending moment acting on tree trunks were studied using our numerical model. Our results show that the presence of the steep hill increased both the flow depth and the bending moment acting on trees close to the steep hill, and might be an important mechanism responsible for the destruction of coastal trees.  相似文献   
2.
In this paper, a novel inspection technique for the cascaded fiber fabrication is proposed to improve the coupling performance of such fibers. Instead of using a direct-monitoring method, an indirect technique with the help of the ray tracing and the lens-fiber interference is used. By calculating the optical-path length of the light rays passing through the fiber, the interference fringes and light intensity can be counted. Then, the splicing plane of the cascaded fiber can be determined by observing the difference between the two fiber sections. Simulations and experiments have been performed to find the splicing plane. Finally, the accuracy of fabrication can be improved from 10 to about 1 mum; thus, the coupling loss due to the fabrication process can be reduced.  相似文献   
3.
In this paper, we propose an efficient algorithm, called CMP-Miner, to mine closed patterns in a time-series database where each record in the database, also called a transaction, contains multiple time-series sequences. Our proposed algorithm consists of three phases. First, we transform each time-series sequence in a transaction into a symbolic sequence. Second, we scan the transformed database to find frequent patterns of length one. Third, for each frequent pattern found in the second phase, we recursively enumerate frequent patterns by a frequent pattern tree in a depth-first search manner. During the process of enumeration, we apply several efficient pruning strategies to remove frequent but non-closed patterns. Thus, the CMP-Miner algorithm can efficiently mine the closed patterns from a time-series database. The experimental results show that our proposed algorithm outperforms the modified Apriori and BIDE algorithms.  相似文献   
4.
The effect of palmitoylethanolamide (PEA), an endogenous fatty acid amide displaying neuroprotective actions, on glutamate release from rat cerebrocortical nerve terminals (synaptosomes) was investigated. PEA inhibited the Ca2+-dependent release of glutamate, which was triggered by exposing synaptosomes to the potassium channel blocker 4-aminopyridine. This release inhibition was concentration dependent, associated with a reduction in cytosolic Ca2+ concentration, and not due to a change in synaptosomal membrane potential. The glutamate release-inhibiting effect of PEA was prevented by the Cav2.1 (P/Q-type) channel blocker ω-agatoxin IVA or the protein kinase A inhibitor H89, not affected by the intracellular Ca2+ release inhibitors dantrolene and CGP37157, and partially antagonized by the cannabinoid CB1 receptor antagonist AM281. Based on these results, we suggest that PEA exerts its presynaptic inhibition, likely through a reduction in the Ca2+ influx mediated by Cav2.1 (P/Q-type) channels, thereby inhibiting the release of glutamate from rat cortical nerve terminals. This release inhibition might be linked to the activation of presynaptic cannabinoid CB1 receptors and the suppression of the protein kinase A pathway.  相似文献   
5.
6.
This report describes the synthesis and self-assembly of poly(l-lysine)-block-poly(l-tyrosine) (PLL-b-PLT) block copolypeptides. These block copolypeptides self-assembled to form vesicles or micelles with sizes between 100 and 350 nm as confirmed by light scattering and electron microscopy. The spectral properties and chain conformation of these block copolypeptides were studied by UV/vis, fluorescence, and circular dichroism. UV cross-linked micelles and vesicles can be prepared by dimerization of tyrosine residues, evidenced by the presence of fluorescence emission at 410–430 nm. The block copolypeptides can be functionalized by a variety of cell-targeted ligands as demonstrated by conjugation of a saccharide group, lactobionolactone, onto the copolymers. A preliminary evaluation of the glycopeptides for in vitro drug release was studied. Due to the unique features exhibited by both PLL and PLT segments, it can be expected that these amphiphilic block copolypeptides to be useful as targeted drug carriers, functional nanobioreactors, and biomimetic encapsulants in the biomedical fields.  相似文献   
7.
Optical fiber polishing automation with on-line force sensing   总被引:1,自引:0,他引:1  
This study proposes a bare fiber polishing control strategy and force sensing mechanism to improve the performance of fiber polishing in optical communication. By analyzing the force and problems encountered during polishing, this study successfully measured the force with the required precision. Finally, the experimental results demonstrate a yield improvement from 20% to 80%, for a fiber tip offset within 1.5 μm.  相似文献   
8.
Caramelization, a good source of food color and antioxidant capacity, depends on pH and sugars. However, no thorough study regarding the interactive role of the color and antioxidant capacity in caramel could be found. In this paper, four sugars (including monosaccharide and disaccharide) with different concentrations (1–40%) at different pH (pH 3, 7 and 10) were heated at 90 °C for various durations (0–42 h). Results from 240 samples indicated that caramels from monosaccharide with higher concentration exhibited better antioxidant capacity at more alkaline condition. High sugar concentration (40%) may partially overcome the influence of low pH on monosaccharides or high pH on disaccharide. Browning intensity (A420) was found to be a good index in monitoring the antioxidant capacity of caramel. ΔpH may closely reflect the increase rate of antioxidant capacity, which has not been reported before. Further statistic analysis through principal component analysis (PCA) and structural equation model (SEM) revealed that browning pigment, the interactive result of sugar concentration and pH, instead of colorless intermediate, was the major contributor on classifying the caramels or exhibiting antioxidant capacity. This is the first paper regarding the representative role of A420 in caramel by confirmatory path analysis.  相似文献   
9.
Feasibility of single-wafer rapid-thermal process as an alternative to the conventional batch-type furnace process is evaluated on a 0.15-/spl mu/m 128-Mb mask read only memory (MROM) product. Excellent gate oxide integrity and device characteristics are achieved with a single-wafer rapid-thermal process. Superior yield and product reliability by using single-wafer process tool have also been achieved. Shortened process cycle time and better thermal process uniformity by using single-wafer rapid-thermal processing are demonstrated.  相似文献   
10.
The detection of fraudulent financial statements (FFS) is an important and challenging issue that has served as the impetus for many academic studies over the past three decades. Although nonfinancial ratios are generally acknowledged as the key factor contributing to the FFS of a corporation, they are usually excluded from early detection models. The objective of this study is to increase the accuracy of FFS detection by integrating the rough set theory (RST) and support vector machines (SVM) approaches, while adopting both financial and nonfinancial ratios as predictive variables. The results showed that the proposed hybrid approach (RST+SVM) has the best classification rate as well as the lowest occurrence of Types I and II errors, and that nonfinancial ratios are indeed valuable information in FFS detection.  相似文献   
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