PCF8583在水文数据采集终端中的应用

本文首先简要地叙述了Philips公司生产的RTC芯片PCF8583的主要特点、内部结构和工作模式,并给出一个典型应用实例--水文数据采集器.该采集器同时采用两片PCF8583,简单、可靠地实现了水位、雨量数据的采集.     

Dielectric properties of spark-plasma-sintered BaTiO3

Spark-plasma-sintering (SPS) has been applied to BaTiO₃ to prepare dense ceramics consisting of submicrometre-sized powder. Relatively dense (typically 97% of the theoretical X-ray density) pellets with an average grain size remaining similar to that of the starting powder, approximately 0.6 m, were obtained by the SPS process. Fixed frequency (1 kHz) measurements show the room temperature permittivity of SPS ceramics to be relatively high, approximately 3500, and at least double the value of conventionally sintered ceramics, approximately 1500. Alternating current (a.c.) impedance spectroscopy measurements show that SPS is an effective process to reduce the influence of intergranular (grain boundary) effects on the permittivity and direct current (d.c.) resistance characteristics of BaTiO₃ ceramics substantially.     

Acoustic emission and precision force-displacement observations of pointed and spherical indentation of silicon and TiN film on silicon

Simultaneous measurements have been recorded of the force, displacement and acoustic emission (AE) during the loading and unloading of a spherical indentor on to a silicon and a physical-vapour deposited 2.7 m thick TiN film on silicon. The AE signals were able to detect the formation of small cracks, such as Hertzian cracks, lateral cracks in silicon and to detect the onset of film cracking during loading and film delamination during unloading in TiN film. The measure data were also compared with SEM cross-section observations of the indented region. Excellent correlation between AE, force-displacement and SEM observation was found.     

A Linear-Time Algorithm for 7-Coloring 1-Plane Graphs

A graph G is 1-planar if it can be embedded in the plane in such a way that each edge crosses at most one other edge. Borodin showed that 1-planar graphs are 6-colorable, but his proof does not lead to a linear-time algorithm. This paper presents a linear-time algorithm for 7-coloring 1-plane graphs (which are 1-planar graphs already embedded in the plane). The main difficulty in the design of our algorithm comes from the fact that the class of 1-planar graphs is not closed under the operation of edge contraction. This difficulty is overcome by a structural lemma that may be useful in other problems on 1-planar graphs. This paper also shows that it is NP-complete to decide whether a given 1-planar graph is 4-colorable. The complexity of the problem of deciding whether a given 1-planar graph is 5-colorable is still unknown.     

Anti-oxidant content of different coloured sweet peppers, white, green, yellow, orange and red (Capsicum annuum L.)

Five different coloured sweet peppers (Capsicum annuum cv. Signal), white, green, yellow, orange and red were analysed for total carotenoids, α‐tocopherol, sugars (glucose, fructose and sucrose), organic acids (citric and ascorbic acids) and anti‐oxidant properties. The mature fruits, ‘Signal Red’, ‘Signal Orange’ and ‘Signal Yellow’ contained higher carotenoids, α‐tocopherol, sugars and organic acids than the immature fruits, ‘Signal Green’ and ‘Signal White’. Among the mature fruits, ‘Signal Red’ was the highest in total carotenoids [9.15 mg (100 g)^?1 of fresh weight] while ‘Signal Orange’ was the highest in α‐tocopherol [5.40 mg (100 g)^?1 of fresh weight]. ‘Signal Red’ and ‘Signal Orange’ contained the most sugars and organic acids. The suppression of 2,2′‐azobis (2,4‐dimethylvaleronitrile) (AMVN)‐induced oxidation of methyl linoleate by the acetone extracts from the coloured sweet peppers resulted as follows: ‘Signal Red’ > ‘Signal Orange’ ≈ ‘Signal Yellow’ > ‘Signal Green’ ≈ ‘Signal White’. The order of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities of the acetone extracts was similar to that of suppression of methyl linoleate oxidation.     

Pursuit‐Escape Particle Swarm Optimization

This paper presents a new Particle Swarm Optimization (PSO) with pursuit and escape behavior. This method takes a cue from the behaviors of schools of sardines and pods of killer whales. When the sardines are attacked by the killer whales, they would behave unusually, that is, the sardines would escape from the killer whales, and on another front, the killer whales would pursue the sardines. By this method, particles are divided into two categories called the pursuit‐particles and the escape‐particles, having interactions with each other. They play the key roles of intensification and diversification, respectively. This allows the particles to avoid local optimal solutions and find a global optimal one, and also achieve an appropriate balance between diversification (global search) and intensification (local search) during the search. Then, the proposed method is validated through numerical simulations using several functions which are well‐known as the optimization benchmark problems by comparing them to powerful methods such as SAPPO, LDIWM, and CFM. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

STEAM DRYING OF SINTERED SPHERES OF GLASS BEADS

Superheated steam drying of sintered spheres of glass beads with different diameters is investigated to reveal the effects of the gravitational force on drying rates. In a previous study, the drying rate curves of small samples with coarse glass beads in which the frictional resistance to flow of water and the effect of the gravitational force are negligible, were predicted by an evaporation zone model.In the present investigation, the drying rate curves of sintered spheres of glass beads with diameters ranging from 1.53×10^-2m to 4.99×lO^-2m are experimentally and theoretically obtained, and also the capillary pressure curves are measured by use of Haines' apparatus. The drying rate curves of large samples in which the effect of the gravitational force can not be negligible, are compared with those for small samples and the difference among these curves is discussed in terms of the moisture distributions which are estimated from the evaporation zone model with the observed capillary pressure curves.     

Emission rate of carbon dioxide while sleeping

Humans emit carbon dioxide (CO₂) as a product of their metabolism. Its concentration in buildings is used as a marker of ventilation rate (VR) and degree of mixing of supply air, and indoor air quality (IAQ). The CO₂ emission rate (CER) may be used to estimate the ventilation rate. Many studies have measured CERs from subjects who were awake but little data are available from sleeping subjects and the present publication was intended to reduce this gap in knowledge. Seven females (29 ± 5 years old; BMI: 22.2 ± 0.8 kg/m²) and four males (27 ± 1 years old; BMI: 20.5 ± 1.5 kg/m²) slept for four consecutive nights in a specially constructed capsule at two temperatures (24 and 28°C) and two VRs that maintained CO₂ levels at ca. 800 ppm and 1700 ppm simulating sleeping conditions reported in the literature. The order of exposure was balanced, and the first night was for adaptation. Their physiological responses, including heart rate, pNN_50, core body temperature, and skin temperature, were measured as well as sleep quality, and subjective responses were collected each evening and morning. Measured steady-state CO₂ concentrations during sleep were used to estimate CERs with a mass-balance equation. The average CER was 11.0 ± 1.4 L/h per person and was 8% higher for males than for females (P < 0.05). Increasing the temperature or decreasing IAQ by decreasing VR had no effects on measured CERs and caused no observable differences in physiological responses. We also calculated CERs for sleeping subjects using the published data on sleep energy expenditure (SEE) and Respiratory Quotient (RQ), and our measured CERs confirmed both these calculations and the CERs predicted using the equations provided by ASHRAE Standard 62.1, ASHRAE Handbook, and ASTM D6245-18. The present results provide a valuable and helpful reference for the design and control of bedroom ventilation but require confirmation and extension to other age groups and populations.     

Analysis of the Circulating Tumor Cell Capture Ability of a Slit Filter-Based Method in Comparison to a Selection-Free Method in Multiple Cancer Types

Circulating tumor cells (CTCs) are a promising biomarker for cancer liquid biopsy. To evaluate the CTC capture bias and detection capability of the slit filter-based CTC isolation platform (CTC-FIND), we prospectively compared it head to head to a selection-free platform (AccuCyte^®-CyteFinder^® system). We used the two methods to determine the CTC counts, CTC positive rates, CTC size distributions, and CTC phenotypes in 36 patients with metastatic cancer. Between the two methods, the median CTC counts were not significantly different and the total counts were correlated (r = 0.63, p < 0.0001). The CTC positive rate by CTC-FIND was significantly higher than that by AccuCyte^®-CyteFinder^® system (91.7% vs. 66.7%, p < 0.05). The median diameter of CTCs collected by CTC-FIND was significantly larger (13.0 μm, range 5.2–52.0 vs. 10.4 μm, range 5.2–44.2, p < 0.0001). The distributions of CTC phenotypes (CK+EpCAM+, CK+EpCAM− or CK−EpCAM+) detected by both methods were similar. These results suggested that CTC-FIND can detect more CTC-positive cases but with a bias toward large size of CTCs.     

Experimental Investigation on Noise Suppression in Supersonic Jets from Convergent-Divergent Nozzles with Baffles

The acoustic properties of supersonic jet noise from a convergent-divergent nozzle with a baffle have been studied experimentally over the range of nozzle pressure ratios from 2.0 to 8.0. Acoustic measurements were conducted in a carefully designed anechoic room providing a free-field environment. A new approach for screech noise suppression by a cross-wire is proposed. Schlieren photographs were taken to visualize the shock wave patterns in the supersonic jet with and without the cross-wire. The effects of the baffle and the cross-wire on acoustic properties are discussed. It is shown that the baffle has little effect on the screech frequency for the underexpanded supersonic jet without the cross-wire. Also, the cross-wire introduced in supersonic jets is found to lead to a significant reduction in overall sound pressure level.