Search

In this study, an axicon metalens comprising a large central disc surrounded by nanoposts for energy harvesting in composite metal-oxide semiconductor sensors was designed, fabricated, and experimentally characterized. The main role of the central disc is focusing light; the nanoposts of various diameters deflect light to form a Bessel-like beam. The spatial distribution of the optical transmission was measured using micro-hyperspectral imaging. The axicon metalens concentrates the light to the sensitive area of the sensor and also harvests light from adjacent pixels. After adding an axicon metalens, the normalized peak transmission is up to 250% at λ = 700 nm as compared to a blank TiO2 film. The experimental results had fair agreement with the finite-difference-time-domain simulation. The ultra-broadband energy-harvesting performance of the sensor suggests that it could be applied in surveillance and Internet of Things applications.

Micro/nano-textured Si wafers manufactured using metal-assisted chemical etching (MACE) have been the focus of several studies, but the mechanism of bubble generation during the MACE process affecting textured surfaces has rarely been reported. This study investigated the bubble effect due to the different placement patterns of the Si wafer (face-up, stirred face-down, and face-down). The results indicated that the placement pattern of the Si wafer notably influences the uniformity of outward appearance. At 2 h of etching, the outward appearance uniformity of face-up etching was more homogeneous than that of stirred face-down and face-down patterns, and the Si nanowires (SiNWs) processed through face-up etching were longer (41 μm) than those subjected to stirred face-down etching (36 μm) and face-down etching (32 μm). Therefore, the placement pattern of Si wafer can affect the uniformity and properties of SiNWs because of bubbles trapped inside cavities or between SiNWs.

Ankyrin repeat domain 49 (ANKRD49) has been found to highly expressed in multiple cancer including lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). However, the function of ANKRD49 in the pathogenesis of NSCLC still remains elusive. Previously, ANKRD49 has been demonstrated to promote the invasion and metastasis of A549 cells, a LUAD cell line, via activating the p38-ATF-2-MMP2/MMP9 pathways. Considering the heterogeneity of tumor cells, the function and mechanism of ANKRD49 in NSCLC need more NSCLC-originated cells to clarify. We found that ANKRD49 promoted the migration and invasion of NCI-H1299 and NCI-H1703 cells via enhancing the levels of MMP-2 and MMP-9. Furthermore, ANKRD49 elevated phosphorylation of JNK and then activated c-Jun and ATF2 which interact in nucleus to promote the binding of ATF2:c-Jun with the promoter MMP-2 or MMP-9.In vivoassay showed that ANKRD49 promoted lung metastasis of injected- NSCLC cells and the high metastatic rate was positively correlated with the high expression of ANKRD49, MMP-2, MMP-9, p-JNK, p-c-Jun and p-ATF2. In conclusion, the present study indicated that ANKRD49 accelerated the invasion and metastasis of NSCLC cells via JNK-mediated transcription activation of c-Jun and ATF2 which regulated the expression of MMP-2/MMP-9.

A novel bacterium, designated TRM 44457T, belonging to the genus Streptomyces , was isolated from soil sampled in cotton fields in Xinjiang, PR China. Comparative 16S rRNA gene sequence analysis indicated that strain TRM 44457T was phylogenetically most closely related to Streptomyces laurentii LMG 19959T (99.38 % sequence similarity); however, strain TRM 44457T had a relatively low DNA–DNA relatedness value with S. laurentii LMG 19959T as determined by calculating the average nucleotide identity value (84.42 %). Strain TRM 44457T possessed ll-diaminopimelic acid as the diagnostic cell-wall diamino acid, MK-9 (H6) and MK-9 (H10) as the major menaquinone. The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphotidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The major fatty acids were anteiso-C15:0, iso-C16:0, anteiso-C17:0, iso-C15:0, C16:0, iso-C17:0, cyclo-C17:0 and anteiso-C17:1ω9c. The genomic DNA G+C content was 72.6 mol%. Based on the evidence from this polyphasic study, strain TRM 44457T represents a novel species of the Streptomyces , for which the name Streptomyces roseicoloratus is proposed. The type strain is TRM 44457T (=KCTC 39904T=CCTCC AA 2016040T).

This study proposes a novel passive auto-focusing algorithm which is applied in the optical microscope. The main core of the proposed auto-focusing algorithm is the weight distribution of Gaussian pyramid and the zero weight values in the designed median mask. It is robust for the noise problem. The optical microscope measurement is one of non-contact optical measurement technology. The captured images will be blurred when the depth of the sample exceeds the depth of field in the microscope. The blurred area in the image easily produces the noise. In order to reduce the problems of the image blurring and the noise, the proposed auto-focusing algorithm is applied in the process of image fusion algorithm. The stack of the images is captured by the microscope system which contains the CCD (i.e. Charge-coupled devices) and the PZT (i.e. piezoelectric transducer). The stack of images contains the clear image on the focal plane and the blurred image out of the depth of field. The process of the image fusion algorithm calculates this stack of the images to obtain the 2D fusion image and the 3D profile, simultaneously. The proposed algorithm is compared to the known four autofocusing algorithms. In the experiment results of the 2D fusion image, the proposed algorithm is as good as the four auto-focusing algorithms. Moreover, in the results of 3D profile, the RMSE error of the proposed algorithm is 287.628, which is lower than the other RMSE errors of the four auto-focusing algorithms.

OBJECTIVE: To assess the treatment outcome of patients who completed their orthodontic treatment by using Andrews' six elements and the American Board of Orthodontic (ABO) objective grading system (OGS); to determine whether Andrews' six elements can be used as a new assessment system for patients who completed their orthodontic treatment. METHODS: A total of 160 patients who completed their orthodontic treatment were included in the study. The participants were randomly selected from patients who completed their orthodontic procedures in Kunming Medical University Affiliated Stomatological Hospital during the period of 2015 to 2019. The retrospective completed cases were examined in accordance with the Andrews' six elements and ABO measuring scales. Scores were assigned to each tooth in each category. All the measurement items in both evaluation criteria, the composite category score, and the total score were calculated. The passing and potential passing rates of the completed cases were compared with two measuring scales via the Chi-square test. RESULTS: The passing rate for the evaluation of cases by using the Andrews' six elements measuring scale was 83.8%, and that for the evaluation of cases by using the ABO measuring scale was 86.3%. The differences in achieving the standard between the cases of Andrews' six elements and ABO-OGS via the Chi-square test were statistically insignificant (P>0.05). The mean Andrews' six elements score for the completed cases: the category of the anteroposterior change in position of the incisors contributed the most, whereas the core discrepancy presented the least percentage in total scores. In ABO-OGS, alignment and marginal ridges contributed the most, whereas interproximal contacts exhibited the least percentage in total scores. CONCLUSION: The performance of Andrews' six elements was comparable with that of ABO-OGS in assessing the treatment outcome of patients who completed their orthodontic treatment. Andrews' six elements can be used as a new system for assessing the treatment outcome of patients who completed their orthodontic treatment. It demonstrated particular advantage in controlling facial profile, and had just completed material of patients who completed their orthodontic treatment it can measure. The Andrews' six elements measuring scale is convenient to disseminate and use.

The resistive switching (RS) characteristics of flexible films deposited on mica substrates have rarely been reported upon, especially flexible HfO2 films. A novel flexible Au/HfO2/Pt/mica resistive random access memory device was prepared by a sol-gel process, and a Au/HfO2/Pt/Ti/SiO2/Si (100) device was also prepared for comparison. The HfO2 thin films were grown into the monoclinic phase by the proper annealing process at 700 &deg, C, demonstrated by grazing-incidence X-ray diffraction patterns. The ratio of high/low resistance (off/on) reached 1000 and 50 for the two devices, respectively, being relatively stable for the former but not for the latter. The great difference in ratios for the two devices may have been caused by different concentrations of the oxygen defect obtained by the X-ray photoelectron spectroscopy spectra indicating composition and chemical state of the HfO2 thin films. The conduction mechanism was dominated by Ohm&rsquo, s law in the low resistance state, while in high resistance state, Ohmic conduction, space charge limited conduction (SCLC), and trap-filled SCLC conducted together.

This paper presents a passive autofocus algorithm applicable to interferometric microscopes. The proposed algorithm uses the number of slope variations in an image mask to locate the focal plane (based on focus-inflection points) and identify the two neighboring planes at which fringes respectively appear and disappear. In experiments involving a Mirau objective lens, the proposed algorithm matched the autofocusing performance of conventional algorithms, and significantly outperformed detection schemes based on zero-order interference fringe in dealing with all kinds of surface blemish, regardless of severity. In experiments, the proposed algorithm also proved highly effective in cases without fringes.

Composite oxide ionic conductors consisting of Zr0.85Y0.15O1.925 (YSZ) and La9.33Si6O26 (LSO) have been synthesized by a modified coprecipitation method. X-ray diffraction, electron microscope, and complex impedance were adopted to investigate the phase component, microstructures, and conductivities, respectively. The results show that the average grain sizes of the composite powders and as-sintered pellets are less than 20 nm and 200 nm, respectively. The conductivity of the composite materials composed of 94 wt% YSZ and 6 wt% LSO is 0.215 S/cm at 700 ℃. The conductivity of the composite is three times higher than that of the polycrystalline YSZ and has two orders in magnitude higher than that of the polycrystalline LSO at 700 ℃. By analyzing the impedance spectra and modulus spectra, the grain-boundary effect on the conductivity improvement is investigated and the conductive mechanisms of the composite materials are discussed.

Based on the requirement of earthquake resistance and disaster prevention in city’s master planning, taking the city's urban disaster prevention function and safety of residents in the great earthquake, large earthquake, middle seism into account, an idea for planning the layout of seismic disaster-prevention space treating city as an object was brought forward in this thesis. Especially, we mainly studied the restrictive conditions of the urban planning and construction from urban disaster prevention and reasonably planned urban disaster prevention security space structure and layout. Then it would certainly gain the spatial pattern of disaster-prevention and obtain the right resources of earthquake emergency relief, and ensure the safety of cities against earthquake disaster.

In order to improve the accuracy of earthquake damage assessment of reinforced concrete structure, the earthquake damage assessment mutation model and four-dimensional model of seismic damage analysis are established using catastrophe theory. Firstly, internal damage index, number of inelastic cycles, maximum inter-storey drift and energy-concentrated quotient were taken as evaluation factors. Value assignment and standardization of each evaluation index is conducted. The appropriate mutation model is selected to calculate the total mutation value of seismic damage and comparison with the evaluation criteria of seismic damage of reinforced concrete structure, the extent of structural damage is differentiated. Secondly, comprehensive consideration of people's initiative and non-linear characteristics of the system, a four-dimensional seismic damage analysis model is build based on the mutation assessment of earthquake damage. Finally, four different structures are calculated and the results are compared with the ones of variable fuzzy set theory, set-pair theory to verify the reasonableness and effectiveness of the method.

To improve the conductivity of Y2O3-stabilized ZrO2 (YSZ) based oxygen-ion conductor, Zr0.85Y0.15O1.925-La9.33Si6O26 (YSZ-LSO) composite ceramics with the mass fraction of La9.33Si6O26 (LSO) of 15% were prepared by using a modified coprecipitation method. The phases, microstructures and conductivities of the YSZ, LSO and YSZ-LSO were investigated by X-ray diffraction, electron microscopy and complex impedance, respectively. The results show that the as-calcined powder of YSZ-LSO composite has the grain size less than 10 nm, and the as-sintered composite ceramics are composed of YSZ and LSO phases. The conductivity can be enhanced obviously by composite method. At 700 °C, the conductivity of the composite ceramic is 0.125 S/cm, which is one order in magnitude higher than that of the YSZ ceramic and two orders in magnitude higher than that of LSO ceramic. By analyzing the impedance spectra and modulus spectra, the interfacial effect on the conductivity improvement was proposed.

采用改性共沉淀法合成了La 9.33 Si 6 O 26 -10wt% Zr 0.86 Y 0.14 O 1.92 两相共存的氧离子导电复合材料, 利用X射线衍射、扫描电子显微镜、交流阻抗技术分别表征了材料的相组成、微观组织和离子导电性. 结果表明, 复合材料粉体平均晶粒尺寸为35 nm, 烧结块体的平均颗粒尺寸为500 nm; 在300~700℃温度范围内, 复合材料的导电率均高于La 9.33 Si 6 O 26 或Zr 0.86 Y 0.14 O 1.92 单相材料, 且700℃时比La 9.33 Si 6 O 26 高出1个数量级. 结合交流阻抗谱及电模量谱对复合材料的导电机理进行了分析讨论.

Taken examples of recent major disasters，the deficiencies of shelter and evacuation system in planning，construction, etc.. and the inadaptability of protecting security needs of the city under extreme disasters is analyzed. Given this, on the basis of the analysis of the connotation of catastrophic environment and adaptation and the relationship between them, the concept of adaptive planning of urban shelter and evacuation system under the disastrous environment is proposed. Based on dynamic planning idea, the adaptive planning is preliminarily discussed in the three perspectives of disaster prevention functions, fortification level, hierarchical structures and spatial characteristics and some planning strategies and measures coping with catastrophes are given.

The headstock is one of the most important parts of a machining center, however there are a lot of designing variables that may influence the static and dynamic capability of the headstock. How to find these variables and optimize them seems to be very important. In this paper, using the modal frequency as the performance index, Pro/Mechanical was used to analyse the sensitivity of the DVG850 high-speed vertical machining center headstock. The result of the analysis was a set of main design-variables that influence the first-order natural frequency of the headstock. The machine’s typical operating conditions were compared against the results of the sensitivity analysis. This provided a basis for structural design and optimization of the headstock directly and quickly.

For the current B-learning system's deficiencies appeared in the realization of personalized learning, and combined with the basic process and key technology of Web mining, this paper presents a B-learning system model based on user behavior mining. In the learning process, learning behavior of users can be invisibly obtained by using web browser plug-in technology, to get learners' feature information, such as learning target, style, preference. Then, user interest model can be established, and B-learning system personalization can be achieved better.