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161.
Ja-Yu Lu Li-Jin Chen Tzeng-Fu Kao Hsu-Hao Chang Hung-Wen Chen An-Shyi Liu Yi-Chun Chen Ruey-Beei Wu Wei-Sheng Liu Jeng-Inn Chyi Chi-Kuang Sun 《Photonics Technology Letters, IEEE》2006,18(21):2254-2256
To accurately detect minute amounts of substances without disturbing the surroundings of target molecules has been a major goal in bioanalytical technology. Here by integrating an optoelectronic terahertz (THz) microsource into a glass-substrated microchip within the near-field distance, we demonstrate a compact, label-free, noninvasive, and sensitive microbiosensing system with low-power consumption. The demonstrated THz microchip allows us to locally specify various illicit drug powders with weights of nanograms, with a promising future for rapid identification of the static status or even the dynamics of various biomolecules 相似文献
162.
163.
164.
Sheu J.K. Lee M.L. Tun C.J. Kao C.J. Yeh L.S. Chang S.J. Chi G.C. 《IEEE journal of selected topics in quantum electronics》2002,8(4):767-772
Si ion implantation into p-type GaN followed by rapid thermal annealing (RTA) in N/sub 2/ has been performed. X-ray diffraction analyses indicate that ion-implanted damage remains even with 1050/spl deg/C, 60 s RTA. By varying implantation and postimplantation annealing conditions, we could convert carrier concentration from p-type 3 /spl times/ 10/sup 17/ cm/sup -3/ into n-type 2 /spl times/ 10/sup 17/ cm/sup -3/ /spl sim/2 /spl times/ 10/sup 19/ cm/sup -3/. It was found that typical activation energies of Si implants in p-GaN are lower than 10 meV. Such activation energies are smaller than those observed from epitaxially grown Si-doped GaN films. A deep donor level with activation energy of 60 meV was also found from some samples. Photoluminescence studies show that the peak appears at 372 nm might be related to implantation-induced defects. It was also found that a green emission band could be observed from Si-implanted GaN. It was shown that such a green emission is related to the yellow band observed from epitaxially grown Si-doped GaN. The transport properties of these Si-implanted samples were also studied. 相似文献
165.
通过对某停建多年建筑物的安全性鉴定,发现已建楼层的部分梁、柱、剪力墙等构件存在结构安全问题,并对该部分构件分别采用几种可行的加固措施进行处理,同时,还对续建楼层的钢筋连接提出了解决的方法。 相似文献
166.
Jonsson U.T. Chung-Yao Kao Megretski A. 《Automatic Control, IEEE Transactions on》2002,47(11):1842-1856
A robustness problem for periodic trajectories is considered. A nonautonomous system with a periodic solution is given. The problem is to decide whether a stable periodic solution remains in a neighborhood of the nominal periodic solution when the dynamics of the system is perturbed. The case with a structured dynamic perturbation is considered. This makes the problem a nontrivial generalization of a classical problem in the theory of dynamical systems. A solution to the robustness problem will be obtained by using a variational system obtained by linearizing the system dynamics along a trajectory, which is uncertain but within the prespecified neighborhood of the nominal trajectory. This gives rise to robustness conditions that can be solved using integral quadratic constraints for linear time periodic systems. 相似文献
167.
Magnetic resonance images are reconstructed from digitized raw data, which are collected in the spatial-frequency domain (also called kappa-space). Occasionally, single or multiple data points in the k-space data are corrupted by spike noise, causing striation artifacts in images. Thresholding methods for detecting corrupted data points can fail because of small alterations, especially for data points in the low spatial frequency area where the k-space variation is large. Restoration of corrupted data points using interpolations of neighboring pixels can give incorrect results. We propose a Fourier transform method for detecting and restoring corrupted data points using a window filter derived from the striation-artifact structure in an image or an intermediate domain. The method provides an analytical solution for the alteration at each corrupted data point. It can effectively restore corrupted kappa-space data, removing striation artifacts in images, provided that the following three conditions are satisfied. First, a region of known signal distribution (for example, air background) is visible in either the image or the intermediate domain so that it can be selected using a window filter. Second, multiple spikes are separated by the full-width at half-maximum of the point spread function for the window filter. Third, the magnitude of a spike is larger than the minimum detectable value determined by the window filter and the standard deviation of kappa-space random noise. 相似文献
168.
H. C. Ku H. M. Luo Y. P. Chi B. N. Lin Y. Y. Hsu T. J. Lee J. B. Shi H.-C. I. Kao 《Journal of Low Temperature Physics》1999,117(3-4):885-889
Magnetic measurement and powder X-ray Rietveld analysis are performed on oxygenated Pr
1.5
Ba
1.5
Cu
3
O
7.2
cuprate. This tetragonal compound with lattice parameters a = 0.38916 nm and c = 1.16177 nm is found to form the TlBa
2
CaCu
2
O
7
1212-type structure when written as Cu[Ba
1.5
Pr
0.5
]PrCu
2
O
7.2. Low temperature magnetic data indicate that anomalous Pr order temperature T
N
(Pr) decreases from 18 K for orthorhombic PrBa
2
Cu
3
O
6.9
to 10.5 K for Pr
1.5
Ba
1.5
Cu
3
O
7.2. The increasing Pr-O bond length with decreasing T
N
indicates that Pr ordering is closely correlated with the wave function overlap between Pr-4f orbital and O-2p
orbital in the CuO
2
bi-layers. 相似文献
169.
170.
Congenital abnormalities in Brazilian children associated with misoprostol misuse in first trimester of pregnancy 总被引:1,自引:0,他引:1
CH Gonzalez MJ Marques-Dias CA Kim SM Sugayama JA Da Paz SM Huson LB Holmes 《Canadian Metallurgical Quarterly》1998,351(9116):1624-1627
BACKGROUND: Misoprostol is commonly used to induce abortion in Brazil, and in other countries in South and Central America where abortions are illegal. However, misoprostol is not very effective in inducing abortions, and exposure to the drug in utero can cause abnormalities in the fetus. We aimed to define the common phenotypical effects of exposure to the drug. METHODS: We studied 42 infants from S?o Paulo, Brazil, who were exposed to misoprostol during the first 3 months of gestation, and then born with congenital abnormalities. We interviewed each of the infants' mothers to find out about misoprostol exposure and dosage. Each infant was physically examined by a geneticist or a neuropaediatrician. FINDINGS: 17 of the infants had equinovarus with cranial-nerve defects. Ten children had equinovarus as part of more extensive arthrogryposis. The most distinctive phenotypes were arthrogryposis confined to the legs (five cases) and terminal transverse-limb defects (nine cases) with or without Mobius sequence. The most common dose of misoprostol taken was 800 microg (range 200-16000 microg). INTERPRETATION: Deformities attributed to vascular disruption were found in these children. We suggest that the uterine contractions induced by misoprostol cause vascular disruption in the fetus, including brain-stem ischaemia. Information on the effects of taking misoprostol during pregnancy should be made more widely available, to dissuade women from misusing the drug. 相似文献