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A novel and highly efficient Ag3VO4/C3N4/reduced TiO2 microsphere composite was obtained through a hydrothermal and depositional process. The microstructure, individual components with different proportions, and optical properties of the ternary nanocomposites were intensively studied. The prepared ternary composites exhibited superior photocatalytic performance of degradation of methylene blue compared with single component and S1 (C3N4/reduced TiO2) binary composites, demonstrating that the introduction of Ag3VO4 into g-C3N4/r-TiO2 can effectively improve the photocatalytic activity. Recycling experiments confirmed that the nanocomposites exhibited superior cycle performance. The enhanced capability could be attributed to a synergetic effect including the formation of heterojunction, large surface area, improved light absorption, matched energy band structure, and the improved separation efficiency of photogenerated charges coming from dual Z-scheme structure. Particularly, the introduction of Ag3VO4 makes the dual Z-scheme charge transfer pathway completed with improved separation efficiency and stronger redox ability of photogenerated electrons and holes. The work provides a promising method to develop a new dual Z-scheme photocatalytic system to remove environmental pollutant.
AgNPs@g-C3N4 composite was synthesized from Ag-containing sol and g-C3N4 powder by the ultrasonic-assisted self-assembly method. The composite has hierarchical pore size distributions, which will be beneficial to the ion transport with different size. Ag nanoparticles with the size of 5 nm successfully adhere on the surface of g-C3N4. The AgNPs@g-C3N4 composite has excellent specific capacitance and specific power performance for the supercapacitors as an electrode material. The specific capacitance of composite is 4 times greater than that of g-C3N4. It can be ascribed to the introduction of Ag nanoparticles that the internal resistance of the composite is significantly decreased.
A compact reconfigurable filtering ultra-wideband (UWB) antenna with switchable band-notched functions is proposed. The basic structure of the proposed design is a filtering slot antenna with good band-edge selectivity using stepped impedance resonator feeding line. The reconfigurability is achieved by using two microstrip lines paralleling to the feeding line and two PIN diodes. The reconfigurable structure and bias circuit of the antenna are relatively simple and are not connected to the radiation structure, so they have little negative influence on the radiation characteristics of the antenna. Total four states could be achieved by using two PIN diodes to short the microstrip lines and ground. To verify the performance of the final design, multiple measured and simulated results in frequency and time domain are studied and analyzed. The measured results agreed very well with simulation. Compared with the traditional UWB antenna, the proposed antenna has advantages in size, filtering function in-band and out-of-band, and tunable states for multiple UWB applications.
The aim of this study was to investigate the in vivo degradation mechanism and the mechanical properties of poly(lactide-co-glycolide)/beta-tricalcium phosphate (PLGA/β-TCP) composite anchors. Anchors composed of PLGA and β-TCP were implanted in the dorsal subcutaneous tissue of beagle dogs for 6, 12, 16, and 26 weeks. The degradation of the materials was evaluated by measuring the changes in thermal behavior, crystallinity, and mechanical properties. Scanning electron microscope (SEM) was used to observe the surface and longitudinal section of the material. The evaluation of mechanical strength retention and degradation properties suggest that the addition of β-TCP particles efficiently enhances their mechanical properties and thermal characteristics and delays their degradation rate. By analyzing the results of SEM, X-ray diffraction, and differential scanning calorimetry, we can infer that after 12 weeks, the connection between β-TCP and PLGA becomes less compact, which accelerates the decline of mechanical strength.
In this paper, the design of a graded honeycomb radar absorbing structure (RAS) is presented to realize both a wide bandwidth and absorption over a wide range of angles. For both transverse-electric and transverse-magnetic polarization, a fractional bandwidth of more than 118.6% is achieved for at least a 10 dB reflectivity reduction when the incident angle is <45°, an 8 dB reduction when the incident angle is <55° and a 5 dB reduction when the incident angle is <70°. Meanwhile the 10 dB reduction upper angle limit is approximately 30° for the uniform coating honeycomb RAS in the literature, which loses its absorbing ability when the incident angle is larger than 55°. Furthermore, the total thickness of our design is 10.7 mm, which is only approximately 1.29 times that of the theoretical limitation. The good agreement between the calculated, simulated, and measured results demonstrates the validity of this optimization.
Triticum monococcum ssp. monococcum has useful traits for bread wheat improvement. The synthesis of Triticum turgidum–T. monococcum amphiploids is an essential step for transferring genes from T. monococcum into bread wheat. In this study, 264 wide hybridization combinations were done by crossing 60 T. turgidum lines belonging to five subspecies with 83 T. monococcum accessions. Without embryo rescue and hormone treatment, from the 10,810 florets pollinated, 1983 seeds were obtained, with a mean crossability of 18.34% (range 0–89.29%). Many hybrid seeds (90.73%, 923/1017) could germinate and produce plants. A total of 56 new amphiploids (AABBAmAm) were produced by colchicine treatment of T. turgidum × T. monococcum F1 hybrids. The chromosome constitution of amphiploids was characterized by fluorescence in situ hybridization using oligonucleotides probes with different chromosome and sub-chromosome specificities. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis indicated that the Glu-A1m-b, Glu-A1m-c, Glu-A1m-d and Glu-A1m-h proteins of T. monococcum were expressed in some amphiploids. Despite resistance reduction in several cases, 45 out of 56 amphiploids exhibited resistance to the current predominant Chinese stripe rust races at both the seedling and adult plant stage. These novel amphiploids provide new germplasm for the potential improvement of bread wheat quality and stripe rust resistance.
A compact printed reconfigurable monopole antenna with switchable band-notches is designed and manufactured. The proposed antenna mainly consists of a disc-like radiator with two pairs of T-shaped strips protruded inside a rectangular aperture. Five PIN diode switches are employed to bridge or open the slots, which allow the antenna to be configured into three different structures functioning as an ultra-wideband (UWB) antenna, or an antenna with notched frequencies at WLAN or WiMAX band. Design and optimization of the antenna are done using CST Microwave Studio. After fabrication on an FR4 substrate with dimensions of 35 mm (width) × 41 mm (length) × 1.5 mm (thickness), numerical and experimental results of the proposed reconfigurable antenna are presented and discussed. The experimental results confirm the design as a good candidate for UWB applications.
In the design process, different problem statements result in different problem-solving strategies. A proper problem statement is the key to effective problem-solving. Based on the characteristics of the product design process, we divided design problem statements into open-ended (OE), decision-making (DM), and constrained (CO) statements and attempted to investigate the influences of different problem statements on designers’ cognitive behaviors from three perspectives, namely divergent thinking, convergent thinking, and mental workload. Then we provided quantification description to these influences based on electroencephalography (EEG) technology. We conducted experiments on 19 participants and used the BrainProduct™ actiChamp-32 to record the EEG data. Results are as follows: (1) The higher task-related α power was found in the temporal and occipital regions in the OE task compared with that in the DM and CO tasks. The OE statement also would help designers get novel ideas by strengthening their divergent thinking. (2) In the DM and CO tasks, there was no significant difference in the impact of the brain region on convergent thinking, but activities in the left hemisphere were stronger than that in the right hemisphere. The DM and CO tasks have better performance in convergent thinking than the OE task. (3) In the CO task, the designer's mental workload is the highest and mainly related to the activation of the centroparietal and occipital regions. These findings help designers understand the design problem-solving process from the perspective of cognitive science and monitor their thinking modes in the design process so as to improve their design performance.
Previous studies have yielded conflicting results on the associations of maternal Fe intake with birth outcomes. This study aimed to investigate the associations between maternal Fe intake (total Fe from diet and supplements, dietary total Fe, haeme Fe, non-haeme Fe and Fe supplements use) and adverse birth outcomes in Shaanxi Province of Northwest China. In all, 7375 women were recruited using a stratified multistage random sampling method at 0–12 months (median 3; 10th–90th percentile 0–7) after delivery. Diets were collected by a validated FFQ and maternal characteristics were obtained via a standard questionnaire. The highest tertile of haeme Fe intake compared with the lowest tertile was negatively associated with low birth weight (LBW) (OR 0·68; 95 % CI 0·49, 0·94), small for gestational age (SGA) (OR 0·76; 95 % CI 0·62, 0·94) and birth defects (OR 0·55; 95 % CI 0·32, 0·89). Maternal haeme Fe intake was associated with a lower risk of intra-uterine growth retardation (IUGR) (medium tertile v. lowest tertile: OR 0·78; 95 % CI 0·61, 0·95; highest tertile v. lowest tertile: OR 0·76; 95 % CI 0·59, 0·93; Ptrend=0·045). The OR of LBW associated with Fe supplements use were as follows: during pregnancy: 0·72 (95 % CI 0·50, 0·95); in the second trimester: 0·67 (95 % CI 0·42, 0·98); in the third trimester: 0·47 (95 % CI 0·24, 0·93). We observed no associations of total Fe, dietary total Fe or non-haeme Fe intake with birth outcomes. The results suggest that maternal haeme Fe intake is associated with a reduced risk of LBW, SGA, IUGR and birth defects, and Fe supplements use during pregnancy reduces LBW risk.
Recently, countries at high latitudes have updated their vitamin D recommendations to ensure adequate intake for the musculoskeletal health of their respective populations. In 2010, the dietary guidelines for vitamin D for Canadians and Americans aged 1–70 years increased from 5 μg/d to 15 μg/d, whereas in 2016 for citizens of the UK aged ≥4 years 10 μg/d is recommended. The vitamin D status of Canadian children following the revised dietary guidelines is unknown. Therefore, this study aimed to assess the prevalence and determinants of vitamin D deficiency and sufficiency among Canadian children. For this study, we assumed serum 25-hydroxy vitamin D (25(OH)D) concentrations <30 nmol/l as ‘deficient’ and ≥50nmol/l as ‘sufficient’. Data from children aged 3–18 years (n 2270) who participated in the 2012/2013 Canadian Health Measures Survey were analysed. Of all children, 5·6 % were vitamin D deficient and 71 % were vitamin D sufficient. Children who consumed vitamin D-fortified milk daily (77 %) were more likely to be sufficient than those who consumed it less frequently (OR 2·7; 95 % CI 1·4, 5·0). The 9 % of children who reported taking vitamin D-containing supplements in the previous month had higher 25(OH)D concentrations (OR 6·9 nmol/l; 95 % CI 1·1, 12·7 nmol/l) relative to those who did not. Children who were older, obese, of non-white ethnicity and from low-income households were less likely to be vitamin D sufficient. To improve vitamin D status, consumption of vitamin D-rich foods should be promoted, and fortification of more food items or formal recommendations for vitamin D supplementation should be considered.
The present study aims to evaluate the antiparasitic activity of active components from Cynanchum paniculatum against Ichthyophthirius multifiliis. The antiparasitic activities of two bioassay-guided fractionationated compounds from C. paniculatum identified as Cynatratoside-A and Cynanversicoside C, by comparing spectral data (NMR and ESI-MS) with literature values, were evaluated by in vitro assay. These showed that both could kill theronts of I. multifiliis at a concentration of 10·0 mg L−1, with the median effective concentration (EC50) values of 4·6 mg L−1 and 5·2 mg L−1 for Cynatratoside-A and Cynanversicoside C, respectively. Encysted tomonts were killed at concentrations of 8·0 mg L−1 with both compounds. In vivo experiments demonstrated that fish treated with both compounds at 15·0 mg L−1 carried significantly fewer parasites than controls (P < 0·05). There were no mortalities among treated fish group compared with 75% mortality of untreated fish. Cynatratoside-A and Cynanversicoside C are therefore potential candidate drugs for use against I. multifiliis.
The lithium ion battery is the most promising battery candidate to power battery electric vehicles. For these vehicles to be competitive with those powered by conventional internal combustion engines, significant improvements in battery performance are needed, especially in the energy density and power delivery capabilities. Promising substitutes for graphite as the anode material include silicon, tin, germanium, and various metal oxides that have much higher theoretical storage capacities and operated at slightly higher and safer potentials. In this critical review, metal oxides-based materials for lithium ion battery anodes are reviewed in detail together with the progress which is made in my lab on that topic. Their advantages, disadvantages, and performance in lithium ion batteries are discussed through extensive analysis of the literature, and new trends in materials development are also reviewed. Two important future research directions are proposed and performed in my lab, based on results published in the literature: the development of composite and nanostructured metal oxides to overcome the major challenge posed by the high capacity of metal oxide anodes.
To describe nutrient intakes, characterize dietary patterns and analyse their associations with sociodemographic characteristics among pregnant women in Shaanxi, China.
Population-based cross-sectional survey.
Twenty counties and ten districts in Shaanxi Province of Northwest China, 2013.
Women (n 7462) were recruited using a stratified multistage random sampling method to report diets during pregnancy, at 0–12 months (median 3 months; 10th–90th percentile, 0–7 months) after delivery.
Pregnant women had higher intakes of fat, niacin and vitamin E than the nutrient reference values, while most micronutrients such as vitamin A, folate, Ca and Zn were reportedly low. Women in the highest education, occupation and household income groups had higher nutrient intakes than those in the lowest groups. Nutrient intake differences also existed by geographic area, residence and maternal age at delivery. Three dietary patterns were identified: balanced pattern, vegetarian pattern and snacks pattern. Participants with high balanced pattern scores tended to be better educated, wealthier, 25–29 years old at delivery, working outside and living in urban areas and central Shaanxi. Women with high scores on the vegetarian pattern and snacks pattern tended to be in low balanced pattern score groups, and had lower nutrient intakes than those in the high balanced pattern score groups.
The study suggested that pregnant women in Shaanxi, China had low intakes of most nutrients such as vitamin A, folate and Ca. Dietary patterns and most nutrient intakes varied by sociodemographic characteristics. Targeted programmes are needed to improve dietary intakes and dietary patterns among sociodemographically disadvantaged groups.
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
Animal bones and tortoise shells were used for divination by the Chinese royal family during the Shang Dynasty (∼16th–11th century BC), and the divination results were recorded as inscriptions on oracle bones and shells, which are very valuable cultural remains and record many important events in the Shang Dynasty period. Thus, radiocarbon dating of oracle bones was used to build a precise chronology of the late Shang Dynasty. Due to their original burial conditions and the fact that in subsequent decades the pieces were traded or archived in museums, oracle bones are expected to be contaminated with exogenous materials from the environment and the conservation process. During dating, we found that some samples were contaminated by conservation chemical reagents. The contaminated samples were purified by removing exogenous chemicals with a series of organic solvents, in a method modified from Bruhn et al. (2001). Both whole bone and gelatin samples were processed with this purification method, resulting in satisfactory improvements in dating results.
A meter-wave sky survey of the region north of declination +30°, excluding only four fields straddling the Galactic plane (each 8° × 8° in angular size), has been conducted with the Miyun Synthesis Radio Telescope operating at 232 MHz. The reduced Miyun General Catalogue contains 34,426 radio sources in total. To distinguish which sources were not observed by other sky surveys, we first identify sources in the MGC with those in the 6C (151 MHz) catalogue, using a matching radius of 100 arcseconds. The remaining MGC objects were then matched with the B2/B3 (408 MHz), 4C (178 MHz), Texas (365 MHz, 1400 MHz) and 87GB (4.85 GHz) catalogues. 6850 MGC sources were found to lack any radio counterpart in these reference catalogues. It means 19.9% of sources listed in the MGC are probably new.
In current transparent Si based photovoltaic (PV) module fabrication, green or infrared laser is the most common used band frequency to wipe off the silicon and back contact layer in perpendicular direction of cells. However, this method would result in more power loss than calculation value due to the side effects during the process such as constructional damage of module and shunt effect. A new method is presented here which focus on wiping off more silicon layer by employing green pulsed laser(532 nm wavelength) along the parallel direction of Pattern2, and it shows higher efficiency and more attractive appearance.
Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at the Institute of Modern Physics of Chinese Academy of Science. The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring. The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6 GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 and G4beamline codes are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles can be neglected. To test this proton radiography system, the proton images for an aluminum plate sample with two rectangular orifices and a step brass plate sample are respectively simulated using Geant4 code. The results show that the best spatial resolution is about 36 μm, and the differences of the thickness are not >10%.