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1.
The surface chemical states of the perovskite-type compounds, strontium doped lanthanum cobalt oxides (La1?x Sr x CoO3), have been investigated using X-ray photoelectron spectroscopy (XPS). Catalytic oxidations of both methane and CO have also been investigated using flow methods. The chemical composition of the surface of La1?x Sr x CoO3 was very different from that in the bulk, which was measured by X-ray fluorescence spectroscopy (XRFS). The catalytic activity of La1?x Sr x CoO3 increased with an increase in the quantity of cobalt atoms on the surface.  相似文献   
2.
Selective nucleation and deposition of diamonds were achieved on an SiO2-patterned Si substrate. The substrate was pre-treated with an electric field in plasma to introduce diamond nuclei. This treatment did not affect the SiO2 area. Consequently, diamonds grew only on the area where Si was exposed under the conventional conditions of diamond growth. The maximum nucleation density on the area of SiO2was about 5 × 107 cm−2. The ratio of the selectivity was 2 × 102 or higher. This process will be useful and very promising for manufacturing diamond electronic devices.  相似文献   
3.
We have produced diffraction gratings for obtaining high resolution X-ray phase imaging, such as X-ray Talbot interferometer. These diffraction gratings were required to have a fine, high accuracy, high aspect ratio structure. Therefore, we decided to use the X-rays lithography technique that used synchrotron radiation of the directivity for a manufacture process. The accuracy of the completed structure depends largely on the accuracy of the X-ray mask. In our group, a resin material is conventionally used for the membrane of large X-ray masks. However, X-ray masks comprising a resin membrane have the disadvantage that, after several cycles of X-ray exposure, they crease and sag due to X-ray-derived heat. As a substitute for the conventional resin membrane, we experimentally fabricated a new X-ray mask using a carbon wafer membrane. The newly fabricated X-ray mask was subjected to X-ray exposure experiment. We succeeded in making the structure body which was almost shape. And the experimental results verified that the new mask did not deteriorate even when used repeatedly, demonstrating that it was highly durable.  相似文献   
4.
The static and dynamic magnetic properties of W-type hexaferrites are tuned to meet the requirements of wide band frequencies for attenuation of electromagnetic interference and microwave absorptions purposes. For this purpose, the W-type hexaferrite of entirely new composition of BaCoZnFe16−2yAlyCeyO27 (y = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) has been synthesized by the chemical co-precipitation. The material is characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The complex permittivity (?r = ?′ − j?″) and permeability (μr = μ′ − ″) spectra are determined using Vector Network Analyzer (VNA) in a range from 0.5 GHz to 10 GHz. During this study, it is noticeable that the Al3+ and Ce3+ ions have considerable effect on the shape of the nanoparticles. Samples having Al-Ce contents y = 0.2 and y = 0.4 showed large values for magnetization (70.5 emu/g) and remanent magnetization (32.9 emu/g). In addition, more than 99% absorption (>−20 dB) is noted for this sample composition. Based on these results it is concluded that the microwave absorption characteristics of these compounds can be tuned for the required frequency by varying the thickness of the absorber. Due to this reason, potential employment of the synthesized nanoparticles for absorption of electromagnetic radiations at wide frequency band of 0.5-10 GHz has been proposed.  相似文献   
5.
For measuring the velocities in a fluctuating fluid flow, the new Disa 56C00 multichannel constant-temperature anemometer system can be used with the 56N00 signal analysis equipment to provide a digital output of mean, root mean square or correlation values. A simple interface arrangement and appropriate software control for reading data directly into an Apple II computer are described. With these the subsequent calculation of derived parameters, such as displacement and momentum thickness of boundary layers and turbulence intensity, can be quickly and easily completed.  相似文献   
6.
7.
A relationship between real poles and real zeros of SISO (single-input, single-output) sampled data systems is presented, which is independent of the sampling period. The relation is stated in terms of a parity property involving the number of real zeros between any two real poles. This property allows the investigation of conditions for the preservation of stable or unstable zeros under sampling. A sufficient condition for stability of a sampled system with a continuous-time plant having all real zeros, and a sufficient condition for instability of a two-sampled system with an unstable plant is developed  相似文献   
8.
XPS (X-ray photoemission spectroscopy) and IR (infrared) analyses of poly(3-methylthienylene) films, electrochemically or chemically redoped0 with various chemical species at varying doping levels, have been investigated. On the basis of these results, the major chemical species of dopants have been identified. As a results, the dopant content was determined and the poly(3-methylthienylene) films were classified as light or heavy by doping level. The conductivity ranged from about 10?12 to 102 S cm?1 for all the films investigated. The conductivity and the activation energy of conduction for the heavily-doped films vary as a function of the dopant content, independent of the different chemical species of dopants. In particular, a sudden change is observed in the dependence of activation energy on dopant content. This sudden change may be associated with the semi-conductor-metal transition. Furthermore, it is shown that the specific absorption bands in the infrared are induced by the doping, intensified with increasing dopant uptake and accompanied by an increase in conductivity.  相似文献   
9.
We selected eight pharmaceuticals with relatively high potential ecological risk and high consumption—namely, acetaminophen, atenolol, carbamazepine, ibuprofen, ifenprodil, indomethacin, mefenamic acid, and propranolol—and conducted laboratory experiments to examine the persistence and partitioning of these compounds in the aquatic environment. In the results of batch sunlight photolysis experiments, three out of eight pharmaceuticals—propranolol, indomethacin, and ifenprodil—were relatively easily photodegraded (i.e., half-life < 24 h), whereas the other five pharmaceuticals were relatively stable against sunlight. The results of batch biodegradation experiments using river water suggested relatively slow biodegradation (i.e., half-life > 24 h) for all eight pharmaceuticals, but the rate constant was dependent on sampling site and time. Batch sorption experiments were also conducted to determine the sorption coefficients to river sediments and a model soil sample. The determined coefficients (Kd values) were much higher for three amines (atenolol, ifenprodil, and propranolol) than for neutral compounds or carboxylic acids; the Kd values of the amines were comparable to those of a four-ring polycyclic aromatic hydrocarbon (PAH) pyrene. The coefficients were also higher for sediment/soil with higher organic content, and the organic carbon-based sorption coefficient (log Koc) showed a poor linear correlation with the octanol-water distribution coefficient (log Dow) at neutral pH. These results suggest other sorption mechanisms—such as electrochemical affinity, in addition to hydrophobic interaction—play an important role in sorption to sediment/soil at neutral pH.  相似文献   
10.
Analysis of reports about incidental and accidental events in nursing care were made using a reliability engineering method. Unnatural working hours, such as evening duty, night duty falling next to a holiday, two consecutive night-duty shifts, and two consecutive evening-duty shifts were major factors in the occurrence of errors. In a mixed-division ward (a ward containing patients belonging to different divisions), rule-based errors happened more frequently than in a single-division ward. Also, less experienced nursing staffs made errors more frequently than experienced nursing staffs.  相似文献   
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