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[en] The discrete dipole approximation is an efficient technique for simulating the field radiated by a particle of any shape. In this approach, the object is viewed as a collection of radiating electric dipoles. The field scattered by the particle is obtained by summing the fields radiated by each dipole. When the particle size is much larger than the wavelength, this technique is time consuming. We propose a Fourier based method which permits a significant reduction of the computation time. - Highlights: • We have dramatically accelerated the computation of scattered far-field in DDA. • We use Fast Fourier Transforms to compute far-field in DDA. • Efficient computation of differential cross-section with DDA
[en] For the first time, triazene compound functionalized silica gel was incorporated into carbon paste electrode for the potentiometric detection of silver (I) ion. A novel diazo-thiophenol-functionalized silica gel (DTPSG) was synthesized, and the presence of DTPSG acted as not only a paste binder, but also a reactive material. The electrode with optimum composition, exhibited an excellent Nernstian response to Ag+ ion ranging from 1.0 × 10−6 to 1.0 × 10−1 M with a detection limit of 9.5 × 10−7 M and a slope of 60.4 ± 0.2 mV dec−1 over a wide pH range (4.0–9.0) with a fast response time (50 s) at 25 °C. The electrode also showed a long-time stability, high selectivity and reproducibility. The response mechanism of the proposed electrode was investigated by using AC impedance. Moreover, the electrode was successfully applied for the determination of silver ions in radiology films, and for potentiometric titration of the mixture solution of Cl− and Br− ions. - Highlights: ► Functionalized silica gels have become promising materials. ► This work is the first attempt to apply triazene functionalized silica gel. ► The Functionalized silica gels were used to detect silver. ► The response of the previously reported papers are compared with this work. ► The result indicates the proposed electrode is better than reported Ag+ electrodes.
[en] According to the need of humiture real-time monitoring in warehousing management and Geological nuclear instruments, the design adopts ZigBee wireless communications, uses c8051f320 as the core, combines the digital temperature and humidity sensor SHT10, takes OLED as the display interface and at last it designed one multi-point temperature and humidity measurement system. It has the advantages such as low power consumption, small size and easy to operate ect. It introduced the system constitution, work principle, selection of hardware and design of software. (authors)
[en] Efficient charge transport is a key to the successful design of electrocatalyst. In this work, we report the in-situ growth of ultrathin MOF material (ZIF-67) nanosheets on conductive Ti@TiO2/CdS substrate for high-efficient electrochemical catalysis due to optimized charge transport. The ultrathin ZIF-67 nanosheets were grown on Ti@TiO2/CdS nanowire array substrates resulting unique 3D hierarchical structures, which were investigated as electrocatalyst for the oxygen-evolution reaction (OER) and H2O2 oxidation. The nanowire-supported ZIF-67 nanosheet electrode shows remarkable electrocatalytic activity and excellent stability toward OER and H2O2 oxidation, which can be explained by the rapid electron transport along the 1D Ti@TiO2/CdS nanowire to Ti substrates, large electrochemical active surface area and the rising valence state of Co ions induced by electronegative N atom in imidazole ligands. Compared with other MOFs catalysts, we obtained a very small Tafel slope (42 mV/dec) and a small overpotential (0.41 V) at 10 mA cm−2 for OER. When used for H2O2 detection, the electrode gave a high sensitivity of 1214.3 μAmM−1cm−2, a wide linear range of 5 μM–14 mM and a low detection limit of 1.11 μM. This research suggests that the in-situ grown nanostructure of Ti@TiO2/CdS/ZIF-67 hold great promise for advanced electrocatalytic electrode in water oxidation and H2O2 detection.
[en] Highlights: • Flow-regime characteristics in pool sloshing behavior with solid particles modeled. • A regime map developed based on competitive role between bubble impulsion and bed inertia. • Respectable agreement between experiments and regime-map predictions obtained. • Reasonability of developed map confirmed through parametric analyses. - Abstract: To understand the pool sloshing behavior with unmelted core materials during a core disruptive accident of sodium-cooled fast reactors, in our earlier publication a series of simulated experiments was performed using different solid particles. It was recognized that due to the different interaction mechanisms between solid particles and the gas bubble injected, three kinds of flow regimes, termed respectively as the bubble-impulsion dominant regime, the transitional regime and the bed-inertia dominant regime, could be identified. In this work, a regime map is developed to describe the regime transition by considering the competitive role between the bubble impulsion and bed inertia during the sloshing process. It is found that a respectable agreement between experiments and the regime-map predictions could be achieved given current range of conditions including much difference in particle size, particle bed height, particle density and the gas-injection pressure.
[en] Purpose: To discuss CT findings of 6 cases of urachal anomalies in order to enhance the knowledge of this diseases and choosing suitable examination method. Methods: All 6 cases of urachal anomalies were studied with CT scans (plain, enhanced) and proved by surgery and pathology. Results: Among of 6 cases of urachal anomalies, urachal fistula associated with infection 1 case, transitional cell carcinoma 1 case, urachal cyst 2 cases, urahal cyst associated with infection and adenocarcinoma 1 cases each. CT scans showed cystic mass of middle line in inferior abdominal wall, peripheral enhancement or nodular enhancement with intravenous injection of contrast medium. the authors considered that irregular cystic wall and nodular protrusion were signs of malignant change. Conclusion: CT scan can demonstrate the location, shape, extent and density of lesions as well as its relation with adjacent structures, thereby providing useful information to guide therapy. The authors were of the opinion that CT scan is a valuable method for diagnosing this disease
[en] The reason of cracking of 304L stainless steel covered on the refueling pool was found out through analyses of macrostructure, microstructure, chemical composition, mechanical properties, morphology of fracture and chemical composition of corrosion products. The results show that it was typical stress corrosion cracking of 304L stainless steel induced by Cl-. The main source of Cl- is the Cl emulsion copolymerization used in the course of the execution of concrete. It was suggested that clear the concrete with Cl emulsion copolymerization thoroughly during subsequent maintenance of the stainless steel panel with cracks, reinforce the water quality control and concrete addition management during other similar concrete executions. (authors)
[en] Objective: To analyze the imaging features of Peutz-Jeghers syndrome and assess the values of imaging diagnosis. Methods: 4 cases of Peutz-Jeghers syndrome were collected. All cases were conformed by clinic and surgery. Abdominal plain film and pneumobarium double contrast examination of GI were performed in 4 cases. Spiral CT plain scan were performed in 3 cases. The imaging features of 4 cases of Peutz-Jeghers syndrome were analyzed retrospectively. Results: 4 cases have gastrointestinal polyps and descendible, freckling of the lips, buccal mucosa. Abdominal plain film suggested gastrointestinal polyps in 1 case. Pneumobarium double contrast examination and CT revealed gastrointestinal polyps in 4. Pneumobadum double contrast examination and CT scan revealed intussuception in 3 cases. Conclusion: Three characters were found in Peutz-Jeghers syndrome, including an autosomally dominant disorder, gastrointestinal polyps and descendible, freckling of the lips, buccal mucosa. Pneumobarium double contrast examination and CT scan can reveal the characteristic features of gastrointestinal polyps and intussuception of the small bowel. (authors)
[en] The second law of thermodynamics has been proven by many facts in classical world. Is there any new property of it in quantum world? In this paper, we calculate the change of entropy in T.D. Kieu's model for quantum heat engine (QHE) and prove the broad validity of the second law of thermodynamics. It is shown that the entropy of the quantum heat engine neither decreases in a whole cycle, nor decreases in either stage of the cycle. The second law of thermodynamics still holds in this QHE model. Moreover, although the modified quantum heat engine is capable of extracting more work, its efficiency does not improve at all. It is neither beyond the efficiency of T.D. Kieu's initial model, nor greater than the reversible Carnot efficiency.
[en] Objective: To study the manifestations and its pathologic basis of pancreatic tubeiculosis and peripancreatic tuberculous lymphadenopathy. And evaluate the diagnostic values of CT and MRI. Methods: Two cases of pancreatic tuberculosis and eleven cases of peripancreatic tuberculous lymphadenopathy were collected. All cases were conformed by pathology or clinic. Plain scan and enhanced scan with spiral CT were performed in all cases. Plain scan and enhanced scan with MRI were performed in two cases. The CT and MRI features of 13 cases were analyzed retrospectively. Results: Pancreatic tuberculosis showed that the lesion was located mainly at the head of the pancreas and displayed on CT as a low-density mass with marginal or honeycomb enhancement. Peripancreatic tuberculous lymphadenopathy was seen in 11 cases, of which ring-like enhancement was seen in seven cases, calcifications in two cases and mixed in two cases. Splenic involvement was found in five cases. Conclusion: Pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy have the main features of low-density mass With marginal or honeycomb enhancement and ting-like enhancement in petipancreatic lymphadenopathy. CT and MRI are feasible methods in diagnosis of pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy. (authors)