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61.
J.Z. Wu S.H. Yoo T. Aytug A. Gapud B.W. Kang S. Wu W. Zhou 《Journal of Superconductivity》1998,11(1):169-171
The effect of Na- and Li-doping in Hg-based cuprates has been studied. It has been found that superconductivity can be achieved in samples containing small amount of Na or Li. While little change is found in the crystalline structure, the formed superconducting phase have the onset Tc typically above 140 K and zero-resistance Tc up to 136K. More interestingly, the processing temperature for the doped Hg-1223 can be reduced significantly to near 700 °C which is promising for thin films growth on many technologically compatible substrates. 相似文献
62.
The importance of the misframe times for DS1 frame synchronization has often been addressed in designing and using network elements and mediation units. By extending the work of J. H. Eu and W. W. Rollins (1991), Markov chain first passage time analysis is used to derive higher moments of the misframe times in both random and burst error environments. This methodology is of great value in evaluating frame synchronization techniques for digital transmission systems. By experimenting with several out-of-frame detection schemes and reasonable values for bit error ratio (BER), it is shown that misframe times are always approximately exponentially distributed for all schemes 相似文献
63.
Beckwith-Wiedemann syndrome (BWS) comprises of a number of childhood abnormalities, often associated with one or more tumors. Thirty-eight patients were investigated to determine clinical and/or biological signs associated with a tumor presence. Our patients exhibited a higher incidence of tumor development (21%) than that previously reported, underlying the care with which such patients should be followed, when particular clinical features are observed: visceromegaly affecting three organs (liver, kidney, spleen), and also family history with sign of BWS such as macroglossia, omphalocele, hemihypertrophy, embryonic tumor), high body weight at birth (> or = +2 standard deviations and diastasis recti. 相似文献
64.
Zeolite beta with a low SiO2/Al2O3 ratio was synthesized by a novel two-step process.The synthesized sample was characterized with XRD,SEM,FTIR,and N2 adsorption-desorption and solid-state MAS NMR.The results showed that aluminium species were inserted into the framework of zeolite beta.The BET surface area,volume,and particle size of the zeolite beta sample decreased with decreasing SiO2/Al2O3 ratio.Our process was proved an efficient route to synthesize zeolite beta with a low SiO2/Al2O3 ratio. 相似文献
65.
Because of concerns among veterans over Agent Orange exposure, the Department of Veterans Affairs (VA) has conducted a series of studies of specific cancers among Vietnam veterans. Lung cancer is the topic of investigation in this report. The VA's Patient Treatment File (PTF) was used to identify 329 Vietnam era veterans with a diagnosis of lung cancer made between 1983 and 1990. The PTF is a computerized hospitalized database of inpatient records, including patients' demographic data, and diagnoses. A record is created for each patient discharged from any one of the VA's Medical Centers. Variables abstracted from the military record include education, race, branch of service, Military Occupational Specialty Code, rank, and units served within Vietnam. Two hundred sixty-nine controls were randomly selected from the PTF file of men hospitalized for a reason other than cancer. A second control group numbering 111 patients with colon cancer was also selected from the PTF file. Data were also gathered on exposure to Agent Orange through the location of each individual ground troop veteran's unit in relation to an area sprayed and the time elapsed since that area was sprayed. The crude odds ratio between service in Vietnam and lung cancer was of borderline significance (odds ratio = 1.39 with 95% confidence interval = 1.01-1.92). The relationship disappeared when the confounder year of birth was considered. We conclude from these data that there is no evidence of increased risk in lung cancer associated with service in Vietnam at this time. 相似文献
66.
We used the fluorescent labelled dopamine D1-receptor antagonist Bodipy-SCH 23390 for the cellular localization of D1-ligand binding sites in the retinae of different vertebrates (teleosts, Xenopus, turtle, rat and rabbit). Competition experiments with unfixed cryosections of fish retina were performed to characterize the binding conditions of Bodipy-labelled SCH 23390. Tissue bound [3H]SCH 23390 was displaceable with increased amounts of bodipy-SCH 23390. The pharmacological specificity of the D1 fluorescent antagonist was determined by competition experiments with an excess of unlabelled SCH 23390. This treatment significantly reduced the level of fluorescence of the retina confirming the specificity of the binding. We observed a homogeneously distributed fluorescence signal in both plexiform layers in unfixed cryosections of fish, frog, turtle, rat and rabbit. Similar staining intensities of both plexiform layers were found in frog, turtle, rat and rabbit retina. In teleosts, the label of the outer plexiform layer was markedly more intense. Non-specific label was associated with photoreceptor outer and inner segments. The specific labelling of both plexiform layers indicates a mismatch of dopamine releasing and D1-binding sites, and suggests a possible extrasynaptic localization of the D1-receptor. The physiological significance of the observed distribution of D1-ligand binding sites is discussed with respect to the role of dopamine in controlling adaptational processes in the retina. 相似文献
67.
Mei Xuan Xu Wen Guang Liu Yun Lin Guan Zuo Peng Bi Kang De Yao 《Polymer International》1995,38(2):205-209
The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties. 相似文献
68.
Kyeong-Sik Shin Kyeong-Kap Paek Jung-Ho Park Tae-Song Kim Byeong-Kwon Ju Ji Yoon Kang 《Electron Device Letters, IEEE》2007,28(7):581-583
In this letter, we examined whether the parasitic bipolar junction transistors (BJTs) in the MOSFET fabricated by the standard CMOS process can play a role as a fluorescence detector. To suppress the action of two vertical parasitic BJTs, the gate and n-well were tied in the parasitic BJTs, and the body node was connected to the drain. The proposed device was compared with the inherent and the parasitic diodes in the MOSFET. It had 100 times higher photocurrents than the diodes in the MOSFET. In addition, it was applied for the detection of the fluorescent signal, and could detect near 10 nM of Alexa 546. Therefore, CMOS-process-compatible parasitic BJTs can be used as a photodetector in an integrated fluorescence detector. 相似文献
69.
Sae-Kyoung Kang Tae-Woo Lee D.V. Plant Hyo-Hoon Park 《Photonics Technology Letters, IEEE》2006,18(1):70-72
A novel bidirectional complementary metal-oxide-semiconductor (CMOS) transceiver for chip-to-chip optical interconnects operating at 2.5 Gb/s is proposed, which shares the common block of a receiver and a transmitter on a single chip. The share of the common block of two circuits makes it possible to save 55% or 20% of power dissipation, depending on the operating mode. The chip in 0.18-/spl mu/m CMOS technology occupies an area of 0.82/spl times/0.82 mm/sup 2/, 70% of the total area of a typical unshared transceiver chip. The transmitting and receiving modes of operation show -3-dB bandwidths of 2.2 and 2.4 GHz and electrical isolations of -28 and -40 dB, respectively. 相似文献
70.